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Im Altenheim gehören Psychopharmaka ganz selbstverständlich zum Pflegealltag. Damit daraus keine gefährliche Routine entsteht, hat ein Team aus Gerontopsychiatern, Medizinethikern und Juristen der Johann Wolfgang Goethe-Universität ein Frankfurter Pflegeheim auf dessen Wunsch hin unter die Lupe genommen. Ihr Maßnahmenkatalog gibt allen beteiligten Personen und Institutionen und sogar der Politik Hinweise, wie mehr Achtsamkeit im Umgang mit diesen Medikamenten erreicht werden kann. Es geht nämlich keineswegs darum, Psychopharmaka generell zu verteufeln. In manchen Fällen bemängeln die Fachleute, dass notwendige Antidementiva oder Antidepressiva nicht verschrieben wurden, in anderen wurden dagegen Doppelmedikation und oft zu lange Therapiedauer gerügt. Die Wissenschaftler entwickeln über 70 Handlungsempfehlungen, mit denen die Versorgung optimiert und somit die Lebensqualität der Bewohner erhöht werden kann.
Anderer Fehler sind gute Lehrer « – so lautet ein nur wenig bekanntes altes deutsches Sprichwort. Für medizinische Fehler galt das die längste Zeit nicht: entweder totgeschwiegen oder als »Kunstfehler « in das Licht der Öffentlichkeit gezerrt, entzogen sich ärztliche Fehler einer systematischen Analyse. Damit hat die Medizin lange eine wichtige Chance vertan. Am Institut für Allgemeinmedizin der Universität Frankfurt beschäftigt sich seit einigen Jahren ein Team unter Leitung von Prof. Dr. Ferdinand Gerlach intensiv mit der Fehlerforschung. ...
Mitte März 2003 löste die WHO einen weltweiten Alarm aus, nachdem sich eine neuartige, schwere und unter bestimmten Umständen hochansteckende Atemwegserkrankung scheinbar unaufhaltsam über weite Teile der Welt auszubreiten schien. Am 15. März desselben Jahres landeten die ersten Patienten mit Verdacht auf Schweres Akutes Respiratorisches Syndrom (SARS) in Frankfurt und wurden auf die Isolierstation des Universitätsklinikums aufgenommen. Auslöser war ein zuvor nicht bekanntes Coronavirus, das heute als SARS-CoV bezeichnet wird. Derzeit laufen Untersuchungen zur Biologie und Epidemiologie des neuen Erregers, zu antiviralen Hemmstoffen sowie zu Desinfektions- und Inaktivierungsmöglichkeiten und neuen Therapieoptionen. Daneben wird analysiert, wie sich das öffentliche Gesundheitswesen auf eine mögliche Wiederkehr vorbereiten muss. SARS ist ein Beispiel dafür, wie schnell sich eine Infektionskrankheit in der modernen Welt international ausbreiten kann und wie wichtig in einem solchen Falle eine gut koordinierte internationale Kooperation ist. Frankfurter Forscher berichten.
Background: West Nile virus (WNV) infection can cause severe meningitis and encephalitis in humans. Apoptosis was recently shown to contribute to the pathogenesis of WNV encephalitis. Here, we used WNV-infected glioma cells to study WNV-replication and WNV-induced apoptosis in human brain-derived cells. Results: T98G cells are highly permissive for lytic WNV-infection as demonstrated by the production of infectious virus titre and the development of a characteristic cytopathic effect. WNV replication decreased cell viability and induced apoptosis as indicated by the activation of the effector caspase-3, the initiator caspases-8 and -9, poly(ADP-ribose)polymerase (PARP) cleavage and the release of cytochrome c from the mitochondria. Truncation of BID indicated cross-talk between the extrinsic and intrinsic apoptotic pathways. Inhibition of the caspases-8 or -9 inhibited PARP cleavage, demonstrating that both caspases are involved in WNV-induced apoptosis. Pancaspase inhibition prevented WNV-induced apoptosis without affecting virus replication. Conclusions: We found that WNV infection induces cell death in the brain-derived tumour cell line T98G by apoptosis under involvement of constituents of the extrinsic as well as the intrinsic apoptotic pathways. Our results illuminate the molecular mechanism of WNV-induced neural cell death.
Why is it hard to divide attention between dissimilar activities, such as reading and listening to a conversation? We used functional magnetic resonance imaging (fMRI) to study interference between simple auditory and visual decisions, independently of motor competition. Overlapping activity for auditory and visual tasks performed in isolation was found in lateral prefrontal regions, middle temporal cortex and parietal cortex. When the visual stimulus occurred during the processing of the tone, its activation in prefrontal and middle temporal cortex was suppressed. Additionally, reduced activity was seen in modality-specific visual cortex. These results paralleled impaired awareness of the visual event. Even without competing motor responses, a simple auditory decision interferes with visual processing on different neural levels, including prefrontal cortex, middle temporal cortex and visual regions.
Im Jahre 2002 wurde von der Food and Drug Administration (FDA) ein vermehrtes Auftreten von Meningitiden bei Cochlea-Implant (CI) -Trägern verzeichnet. Dies wurde durch eine retrospektive Studie des Centers for Disease Control (CDC) bestätigt: Unter 4264 Kindern musste ein mehr als 30fach erhöhtes Erkrankungsrisiko für Meningitis nach CI-Versorgung verzeichnet werden. Als häufigster Krankheitserreger ließ sich Streptococcus pneumoniae isolieren, dessen Pathogenität u.a. von speziellen Wirtsfaktoren - z.B. schlechte Abwehrlage, Z.n. Meningitis - abhängig ist. Zur Evaluierung bestehender Impfempfehlungen hinsichtlich Pneumokokkeninfektionen wurden in der Klinik für Pädaudiologie in Zusammenarbeit mit der Kinderimmunologie 174 CI-Träger untersucht hinsichtlich ihres Immunstatus und ihrer Ansprechbarkeit auf die Impfstoffe: Pneumokokken-Polysaccharid-Vakzine (PPV23) und Pneumokokken-Konjugat-Vakzine (PCV7). Es wurde eine Einteilung bezüglich Patientenalter sowie der Genese der Schwerhörigkeit vorgenommen. Es zeigte sich u.a. im Alter von 2 - 5 Jahren eine signifikant immunogenere Wirkung des PCV7 sowie eine schlechtere Immunsituation bei postmeningeal Ertaubten. Daher empfiehlt es sich, alle CI-Träger bis zum 5.Lebensjahr sowie Patienten mit zusätzlichen Risiken über das 5. Lebensjahr hinaus nach einem kombinierten Pneumokokken-Impf-Schema: PCV7 und PPV23 zu immunisieren.
Kurzfassung Vortrag: Fächerübergreifende Lehre und verpflichtende Fortbildung (CME) für Ärzte erfordern innovative Lernmethoden. Eine Lösung wird teilweise in der Nutzung elektronischer Medien gesehen. Unklar ist jedoch, wie konkret eine Umsetzung in der Aus-, Fort- und Weiterbildung im Fach Allgemeinmedizin bisher erfolgte, welche Chancen und Möglichkeiten es gibt und wie die weitere Entwicklung aussehen kann. Um einen Überblick über die aktuellen E-Learning-Aktivitäten zu erhalten, formierte sich eine universitäts- und bundesländerübergreifende Initiative. In drei Phasen soll die Grundlage für die Entwicklung einer Strategie für die effektive Nutzung elektronischer Lehr- und Lernmedien für das Fach Allgemeinmedizin geschaffen werden: Phase 1 - Nationales Expertentreffen (Juli 2005 in Frankfurt): Diskussion von Erfahrungen, Problemen und Möglichkeiten des Einsatzes elektronischer Medien in der Allgemeinmedizin. Phase 2 - Gründung eines Netzwerks: Zusammenarbeit, Koordination und gegenseitige Unterstützung bei der Entwicklung von E-Learning-Modulen. Phase 3 - Evaluation von E-Learning in der Allgemeinmedizin: systematische qualitative und quantitative Untersuchungen. Im Rahmen eines Workshops sollen die Erfahrungen aus dem Expertentreffen mit Lehrenden und Fortbildenden aus anderen Fachbereichen diskutiert werden. Kooperationen über die Allgemeinmedizin hinaus können weitere Synergien schaffen. Der Workshop dient dem Austausch über Chancen und Limitationen entsprechender Angebote.
Im Jahr 2003 begann die HNO-Universitätsklinik Frankfurt / Main mit der Einführung eines Qualitätsmanagement-Systems, die im August 2005 zur erfolgreichen Zertifizierung nach der vom Klinikumsvorstand geforderten DIN EN ISO 9001:2000 führte. Ziele unseres Qualitätsmanagements waren die Optimierung der internen Betriebsabläufe und die Standardisierung von Arbeitsvorgängen unter Einbeziehung von logistischen Schnittstellen mit externen Strukturen unter Berücksichtigung der besonderen Anforderungen einer Universitätsklinik. Neben einer grundsätzlichen Prüfung und Optimierung sämtlicher Organisationsabläufe wurden für die Kernprozesse unserer Klinik Zielvorgaben festgelegt. Diese Ziele betrafen die Qualität der Arbeitsabläufe für alle Bereiche der HNO-ärztlichen ambulanten und stationären Versorgung ebenso, wie Aufgaben in Forschung und Lehre, die durch ein Ausbildungscurriculum für Mitarbeiter und Sudenten abgebildet wurde. Es wurden aber auch Serviceaspekte, wie Terminvergabe und Befundübermittlung, sowie ökonomische und wirtschaftliche Aspekte unserer Arbeit optimiert. Durch Umstrukturierung und Neuorganisation konnte die Effizienz der Arbeitsabläufe deutlich gesteigert werden, wovon vor allem Patienten und Mitarbeiter erheblich profitieren. Die Einführung eines Qualitätsmanagementsystems in der Frankfurter HNO-Universitätsklinik war zunächst mit einem entsprechenden Arbeitsaufwand verbunden und erforderte ein Umdenken in den einzelnen Funktionsbereichen. Insgesamt überwiegt der positive Einfluss auf die Struktur und Arbeitsabläufe, sodass die Umsetzung eines Qualitätsmanagementsystems in der Universitätsklinik empfehlenswert ist.
k-MED entwickelte sich von einem fachbezogenen Projekt im Jahr 1999 zu einem e-Learning-Dienstleister mit umfangreichen Lehr-Lernangeboten sowie einer technischen und organisatorischen Infrastruktur für Autoren und Nutzer. Es bietet heute – Mitte 2006 – 5000 Studierenden, v.a. der Humanmedizin, ca. 170 Lernkurse aus 16 medizinischen Fächern. Das Projekt umfasst erfahrenes Fachpersonal und nutzt eine eigene Online-Autorenumgebung sowie eine internetbasierte Lernplattform, deren Funktionalitäten in Abstimmung mit evaluierten Lehr- und Lern-Szenarien ständig weiter entwickelt werden. Die wichtigste Aufgabe ist die Vollversorgung von Bildungseinrichtungen, darunter vor allem medizinische Fakultäten, mit Lehr-Lern- und Kommunikationsinstrumenten. Aktuelle Informationen sind zu finden unter http://www.k-med.org.
Die Vermittlung der Zusammenhänge zwischen psychologischen Funktionen und körperlichen Veränderungen sowie deren Relevanz für die Entstehung und Aufrechterhaltung von Krankheiten stellt ein zentrales Ziel der Ausbildung in Medizinischer Psychologie dar. Zur Veranschaulichung dieser Zusammenhänge führten wir ein Psychophysiologie-Praktikum im ersten vorklinischen Semester ein. Die Studierenden führten in Vierergruppen mit Hilfe ausführlicher schriftlicher Instruktionen jeweils ca. 30 Minuten andauernde praktische Übungen durch, die die folgenden Themen behandelten: (1) Stress (abhängige Variable: Herzrate), (2) "Lügendetektor" (abhängige Variable: Hautleitwertsreaktionen), (3) Biofeedback (abhängige Variable: Hauttemperatur) und (4) Elektroenzephalogramm (abhängige Variable: Amplituden der vier klassischen Frequenzbänder). Die praktischen Übungen wurden durch theoretische Gruppenarbeiten und einen Termin zur Zusammenfassung der Ergebnisse der Übungen ergänzt. Die studentische Evaluation des Praktikums war durchweg positiv. So wurde das Praktikum als Bereicherung des Kurses angesehen, und der selbstbeurteilte Kenntnisstand auf dem Gebiet der Psychophysiologie zeigte eine signifikante Verbesserung. Diese Ergebnisse sowie unsere Eindrücke während des Praktikums bekräftigten unseren Entschluss, ein Psychophysiologie-Praktikum als Teil des Kurses der Medizinischen Psychologie und Medizinischen Soziologie fest zu etablieren.
Following publication of the data presented by von Minckwitz and colleagues it has been brought to our attention that some patients should be scored differently. Stable disease was seen in three of the eighteen patients instead of two of the eighteen patients: one patient with transitional cell carcinoma treated at 4 µg/kg scFv(FRP5)-ETA per day, and two breast cancer patients treated at 4 and 12.5 µg/kg scFv(FRP5)-ETA per day. Disease progression occured in 9 of the eighteen patients evaluated (see corrected Table 2 overleaf). This does not affect the conclusions of our study. In addition we would like to correct the following errors: patient IDs for patients U01 and U02 in the original Table 2 were interchanged. In addition, patient N03 had a grade 3 elevation of gamma-glutamyl transferase, and not grade 2 (see corrected Table 2 overleaf).
Aims: To analyze the relationship between exposure to chlorinated and aromatic organic solvents and malignant lymphoma in a multi-centre, population-based case-control study.
Methods: Male and female patients with malignant lymphoma (n=710) between 18 and 80 years of age were prospectively recruited in six study regions in Germany (Ludwigshafen /Upper Palatinate, Heidelberg/ Rhine-Neckar-County, Wurzburg/ Lower Frankonia, Hamburg, Bielefeld/ Gutersloh, and Munich). For each newly recruited lymphoma case, a gender, region and age-matched (+/- 1 year of birth) population control was drawn from the population registers. In a structured personal interview, we elicited a complete occupational history, including every occupational period that lasted at least one year. On the basis of job task-specific supplementary questionnaires, a trained occupational physician assessed the exposure to chlorinated hydrocarbons (trichloroethylene, tetrachloroethylene, dichloromethane, carbon tetrachloride) and aromatic hydrocarbons (benzene, toluene, xylene, styrene). Odds ratios (OR) and 95% confidence intervals (CI) were calculated using conditional logistic regression analysis, adjusted for smoking (in pack years) and alcohol consumption. To increase the statistical power, patients with specific lymphoma subentities were additionally compared with the entire control group using unconditional logistic regression analysis.
Results: We observed a statistically significant association between high exposure to chlorinated hydrocarbons and malignant lymphoma (Odds ratio = 2.1; 95% confidence interval 1.1-4.3). In the analysis of lymphoma subentities, a pronounced risk elevation was found for follicular lymphoma and marginal zone lymphoma. When specific substances were considered, the association between trichloroethylene and malignant lymphoma was of borderline statistical significance. Aromatic hydrocarbons were not significantly associated with the lymphoma diagnosis.
Conclusions: In accordance with the literature, this data point to a potential etiologic role of chlorinated hydrocarbons (particularly trichloroethylene) and malignant lymphoma. Chlorinated hydrocarbons might affect specific lymphoma subentities differentially. Our study does not support a strong association between aromatic hydrocarbons (benzene, toluene, xylene, or styrene) and the diagnosis of a malignant lymphoma.
Poster presentation: Light is the main phase-adjusting stimulus of the circadian clock located in the suprachiasmatic nucleus (SCN). A candidate pathway transmitting photic information at the postsynaptic site in the SCN is the extracellular signal-regulated kinase (ERK 1/2) which has been previously shown to be an essential element in the photoentrainment of the circadian rhythm. An upstream activator of the ERK signalling route is the small intracellular GTPase Ras. Here we observed that endogenous Ras activity in the SCN was subjected to rhythmic changes, reaching maximum levels at the late subjective day and minimum levels at the late subjective night (CT22). In order to investigate if Ras would modulate the circadian cycle, we used transgenic mice expressing constitutively activated Val-12 Ha-Ras selectively in neurons (synRas mice). In these mice Ras activity was also cycling during the circadian rhythm yet, Ras activities were up-regulated at each time point measured. We investigated if this change in Ras activity translates into a behavioral phenotype by monitoring free-running activity rhythms under conditions of constant darkness. SynRas mice exhibited circadian rhythms in locomotor activities similar to WT mice. However, when challenged by applying a 15 minutes light pulse at CT22 to promote phase advance shifts, synRas mice were completely non-responsive. As a first step towards the possible intracellular mechanism of this behavioral change we analyzed ERK1/2 activities in more details: We found a 1,7-fold increase of circadian peak levels of ERK 1/2 activities at CT10 and CT14 in synRas mice, while at minimum levels (CT18, CT22) no differences were found between ERK1/2 activities of WT and synRas mice. In WT animals the 15 minutes light pulse at CT22 resulted in rapid up regulations of Ras, ERK1/2 and CREB activities as described previously by others. However, in correlation with the lack of a behavioral response, ERK1/2 but not Ras and CREB activities remained unchanged in synRas mice, suggesting that Ras-dependent and Ras-independent pathways may co-exist to regulate ERK1/2 and behavioral phase shifts in response to the acute light treatment. Next we investigated the length "tau" of the locomotor activity rhythm during constant darkness and found a slight shortening by about 10 minutes in synRas mice as compared to the WT littermates. Recently, "tau" has been discussed to be modulated by the interaction between glycogen synthase 3beta (GSK3beta) and a clock gene product (Per 2) that is involved in the determination of circadian phase durations. We describe here a down-regulation of GSK3beta phosphorylation in synRas mice as a possible mechanism of "tau" shortening. Taken together, cycling of Ras activity at elevated levels in the SCN during the circadian rhythm results in a distinct pattern of behavioral phenotype changes correlating with de-regulated ERK1/2 or GSK3beta activities.
Poster presentation: Hyperphosphorylation of tau is a characteristic of Alzheimer's disease (AD). Our group has established a model for tau hyperphosphorylation by mutating 10 residues from Ser/Thr to Glu to simulate the negative charge of phosphorylated residues ("pseudohyperphosphorylated (PHP)-tau"). In order to analyze temporal and spatial effects of hyperphosphorylation of tau in a systemic context, we have established transgenic mouse lines that express human wild-type (wt)- or PHP-tau under the control of the CamKIIalpha-promoter that leads to a forebrain specific moderate expression in neurons, i.e. the region where also tau-pathology in AD is abundant. For the evaluation of tau-induced changes in the transgenic mice, we quantified spine densities in the neocortex and hippocampus of transgenic mice. The spine densitiy was significantly increased in PHP-tau compared to wt-tau expressing mice. It is known that AD is associated with aberrant pre- and postsynaptic sprouting. Axonal sprouting is also observed in transgenic mice expressing mutated amyloid precursor protein (APP), which suggests that Abeta plays a significant role in this process. We deduce from our results, that (pseudo)-hyperphosphorylation of tau is sufficient to induce aberrant sprouting in the absence of Abeta. Analyses whether this sprouting is induced by pre- or postsynaptic changes and if functionally active synapses are formed are in progress. It will be interesting to determine if stabilization of these newly formed synapses slows or – in contrary – accelerates the progression of the disease. Sprouting as observed in our PHP-tau expressing mice is part of neuronal differentiation. One family of enzymes that is involved in cell differentiation are mitogen-acitvated protein kinases (MAPK). Western blot analysis was performed with brain lysates from transgenic mice to check whether PHP-tau induced sprouting is associated with MAPK activation. In fact, we also observed an increased activation of the MAPK ERK1/2 evident by phosphorylation of the residues Thr202 and Tyr204. ERK1/2 is also known to phosphorylate tau at sites characteristic for AD. Our results suggest the presence of a vicious circle by which (pseudo)-hyperphosphorylated tau activates ERK1/2 which in turn phosphorylates tau.
Poster presentation: Here we investigated the role of the amyloid precursor protein (APP) in regulation of Ca2+ store depletion-induced neural cell death. Ca2+ store depletion from the endoplasmic reticulum (ER) was induced by the SERCA (Sarco/Endoplasmic Reticulum Calcium ATPase) inhibitor thapsigargin which led to a rapid induction of the unfolded protein response (UPR) and a delayed activation of executioner caspases in the cultures. Overexpression of APP potently enhanced cytosolic Ca2+ levels and cell death after ER Ca2+ store depletion in comparison to vector-transfected controls. GeneChipR and RT-PCR analysis revealed that the expression of classical UPR chaperone genes was not altered by overexpression of APP.Interestingly, the induction of the ER stress-responsive pro-apoptotic transcription factor CHOP was significantly upregulated in APP-overexpressing cells in comparison to vectortransfected controls. Chelation of intracellular Ca2+ with BAPTA-AM revealed that enhanced CHOP expression after store depletion occured in a Ca2+-dependent manner in APPoverexpressing cells. Prevention of CHOP induction by BAPTA-AM and by RNA interference was also able to abrogate the potentiating effect of APP on thapsigargin-induced apoptosis. Application of the store-operated channel (SOC)-inhibitors SK F96365 and 2-APB downmodulated APP-triggered potentiation of cytosolic Ca2+ levels and apoptosis after treatment with thapsigargin. Our data demonstrate that APP-mediated regulation of ER Ca2+ homeostasis significantly modulates Ca2+ store depletion-induced cell death in a SOC- and CHOP-dependent manner, but independent of the UPR.
Poster presentation: The transcription factor NF-kappaB plays a pivotal role in the development and maintenance of the central nervous system and its constitutive activation in neurons has been previously reported. NF-kappaB is post-translationally activated upon phosphorylation of the IkappaBalpha inhibitory protein by the activated IkappaB kinase (IKKalpha/beta) and the subsequent degradation of IkappaBalpha by the proteasome. Recently, we had demonstrated an unexpected accumulation of three components of the NF-kappaB cascade in the axon initial segment (AIS): Activated IKK, phosphorylated IkappaBalpha and phosphorylated-p65(Ser536). These are all associated with detergent-insoluble cytoskeletal components of the AIS. We observed further compartimentalization as pIKKalpha/beta primarily associated with the membrane cytoskeleton, whereas pIkappaBalpha was sequestered to fasciculated microtubules. Colchicine-induced depolymerization of microtubules was associated with reduced sequestration of pIkappaBalpha in the AIS, which could be blocked by use of proteasome inhibitors like Mg-132 or Lactacystin. Concurrently, enhanced nuclear immunoreactivity for the NF-kappaB subunit p65 was noted. Using NF-kappaB-dependent reporter gene assays, a significant increase in NF-kappaB activity was observed after depolymerization of microtubules and this was inhibited by the microtubule-stabilizing drug paclitaxel. The use of transiently transfected, photoactivatable-GFP p65 fusion proteins will allow us to specifically analyse the compartimentalized signal transduction pathways in unique spatial and temporal resolution. Taken together, these observations provide strong evidence for compartmentalized activation of NF-kappaB in the AIS and modulation of neuronal NF-kappaB activity by microtubule dynamics.
Poster presentation: The mammalian pineal organ is a peripheral oscillator, depending on afferent information from the so-called master clock in the suprachiasmatic nuclei of the hypothalamus. One of the best studied outputs of the pineal gland is the small and hydrophobic molecule melatonin. In all vertebrates, melatonin is synthesized rhythmically with high levels at night, signalling the body the duration of the dark period. Changes or disruptions of melatonin rhythms in humans are related to a number of pathophysiological disorders, like Alzheimer's disease, seasonal affective disorder or the Smith-Magenis-Syndrome. To use melatonin in preventive or curative interferences with the human circadian system, a complete understanding of the generation of the rhythmic melatonin signal in the human pineal gland is essential. Melatonin biosynthesis is best studied in the rodent pineal gland, where the activity of the penultimate and rate-limiting enzyme, the arylalkylamine N-acetyltransferase (AA-NAT), is regulated on the transcriptional level, whereas the regulatory role of the ultimate enzymatic step, achieved by the hydroxyindole O-methyltransferase (HIOMT), is still under debate. In rodents, Aa-nat mRNA is about 100-fold elevated during the night in response to adrenergic stimulation of the cAMP-signalling pathway, with AA-NAT protein levels closely following this dynamics. In contrast, in all ungulates studied so far (cow, sheep), a post-transcriptional regulation of the AA-NAT is central to determine rhythmic melatonin synthesis. AA-NAT mRNA levels are constantly elevated, and lead to a constitutive up-regulation of AA-NAT protein, which is, however, rapidly degraded via proteasomal proteolysis during the day. AA-NAT proteolysis is only terminated upon the nocturnal increase in cAMP levels. Similar to ungulates, a post-transcriptional control of this enzyme seems evident in the pineal gland of the primate Macaca mulatta. Studies on the molecular basis of melatonin synthesis in the human being are sparse and almost exclusively based on phenomenological data, derived from non-invasive investigations. Yet the molecular mechanisms underlying the generation of the hormonal message of darkness can currently only be deciphered using autoptic material. We therefore analyzed in human post-mortem pineal tissue Aa-nat and Hiomt mRNA levels, AA-NAT and HIOMT enzyme activity, and melatonin levels for the first time simultaneously within tissue samples of the same specimen. Here presented data show the feasibility of this approach. Our results depict a clear diurnal rhythm in AA-NAT activity and melatonin content, despite constant values for Aa-nat and Hiomt mRNA, and for HIOMT activity. Notably, the here elevated AA-NAT activity during the dusk period does not correspond to a simultaneous elevation in melatonin content. It is currently unclear whether this finding may suggest a more important role of the ultimate enzyme in melatonin synthesis, the HIOMT, for rate-limiting the melatonin rhythm, as reported recently for the rodent pineal gland. Thus, our data support for the first time experimentally that post-transcriptional mechanisms are responsible for the generation of rhythmic melatonin synthesis in the human pineal gland.
Poster presentation: The transcription factor NF-kappaB plays a central role in the development and maintenance of the central nervous system and its constitutive activation in neurons has been repeatedly reported. Previous work from our laboratories (poster presentation: Compartimentalized NF-kappaB activity in the axon initial segment) had revealed an intriguing clustering of activated IKKalpha/beta and other downstream elements of an activated NF-kappaB cascade (phospho-IkappaBalpha, phospho-p65(Ser536)) in the axon initial segment (AIS). Accumulation of certain voltage-gated sodium channels (Na(v)1.2), M-type potassium channels (KCNQ2) as well as cytoskeletal anchoring proteins (AnkyrinG) characterise the AIS. However, it is not yet clear how AIS-localized IKK gets activated and whether this can be connected to the constitutive activation of NF-kappaB. Long-term blockade of sodium channels with tetrodotoxin, potassium-channels with linopirdine or NMDA-receptors with MK-801 did not elicit any change upon the constitutive activation of the pathway. Strikingly, the occurrence of phosphorylated IkappaBalpha was even unaltered by 24 h of incubation with protein synthesis inhibitors. Others have reported that impairment of NF-kappaB inhibits neuritogenesis. In this line we observed that the early initiation of IkappaBalpha phosphorylation was susceptible to inhibition of IKK in DIV1–2 neurons. We therefore aim to identify the interaction partners of the activated IKK complex in the AIS. Proteomic methods such as co-immunoprecipitation analyses and mass-spectrometry will help us to identify the key players in the initiation of constitutive IKK phosphorylation and activation in neurons.
Background The Deltaretrovirus genus comprises viruses that infect humans (HTLV), various simian species (STLV) and cattle (BLV). HTLV-I is the main causative agent in adult T-cell leukemia in endemic areas and some of the simian T-cell lymphotropic viruses have been implicated in the induction of malignant lymphomas in their hosts. BLV causes enzootic bovine leukosis in infected cattle or sheep. During the past few years several new Deltaretrovirus isolates have been described in various primate species. Two new HTLV-like viruses in humans have recently been identified and provisionally termed HTLV-III and HTLV-IV. In order to identify a broad spectrum of Deltaretroviruses by a single PCR approach we have established a novel consensus PCR based on nucleotide sequence data obtained from 42 complete virus isolates (HTLV-I/-II, STLV-I/-II/-III, BLV). The primer sequences were based on highly interspecies-conserved virus genome regions. We used this PCR to detect Deltaretroviruses in samples from adult patients with a variety of rare T-cell neoplasms in Germany. Results: The sensitivity of the consensus PCR was at least between 10-2 and 10-3 with 100% specificity as demonstrated by serial dilutions of cell lines infected with either HTLV-I, HTLV-II or BLV. Fifty acute T-cell lymphoblastic leukemia (T-ALL) samples and 33 samples from patients with various rare mature T-cell neoplasms (T-PLL, Sezary syndrome and other T-NHL) were subsequently investigated. There were no cases with HTLV-I, HTLV-II or any other Deltaretroviruses. Conclusions: The results rule out a significant involvement of HTLV-I or HTLV-II in these disease entities and show that other related Deltaretroviruses are not likely to be involved. The newly established Deltaretrovirus PCR may be a useful tool for identifying new Deltaretroviruses.
Background A procedure for including activity against enveloped viruses in the post-contamination treatment of hands has been recommended, but so far no European standard is available to implement it. In 2004, the German Robert Koch-Institute (RKI) and the German Association for the Control of Virus Disease (DVV) suggested that vaccinia virus and bovine viral diarrhea virus (BVDV) should be used as test viruses in a quantitative suspension test to determine the activity of a disinfectant against all enveloped viruses. Methods We have studied the activities of three commonly-used alcohol-based hand rubs (hand rub A, based on 45% propan-2-ol, 30% propan-1-ol and 0.2% mecetronium etilsulfate; hand rub B, based on 80% ethanol; hand rub C, based on 95% ethanol) against vaccinia virus and BVDV, and in addition against four other clinically relevant enveloped viruses: herpes simplex virus (HSV) types 1 and 2, and human and avian influenza A virus. The hand rubs were challenged with different organic loads at exposure time of 15, 30 and 60 s. According to the guidelines of both BGA/RKI and DVV, and EN 14476:2005, the reduction of infectivity of each test virus was measured on appropriate cell lines using a quantitative suspension test. Results All three alcohol-based hand rubs reduced the infectivity of vaccinia virus and BVDV by >= 4 log10-steps within 15 s, irrespective of the type of organic load. Similar reductions of infectivity were seen against the other four enveloped viruses within 15 s in the presence of different types of organic load. Conclusions Commonly used alcohol-based hand rubs with a total alcohol concentration >= 75% can be assumed to be active against clinically relevant enveloped viruses if they effectively reduce the infectivities of vaccinia virus and BVDV in a quantitative suspension test.
Background Drug resistance to chemotherapy is often associated with increased malignancy in neuroblastoma (NB). One explanation for the link between resistance and malignancy might be that resistance facilitates cancer progression and invasion. To investigate this hypothesis, adhesion, transendothelial penetration and NCAM (CD56) adhesion receptor expression of drug-resistant versus drug-sensitive NB tumor cells were evaluated. Methods Acquired drug resistance was mimicked by exposing parental UKF-NB-2, UKF-NB-3 or IMR-32 tumor cells to increasing concentrations of vincristine- (VCR) or doxorubicin (DOX) to establish the resistant tumor cell sublines UKF-NB-2VCR, UKF-NB-2DOX, UKF-NB-3VCR, UKF-NB-3DOX, IMR-32VCR and IMR-32DOX. Additionally, the malignant behaviour of UKF-NB-4, which already possessed the intrinsic multidrug resistance (MDR) phenotype, was analyzed. UKF-NB-4 exposed to VCR or DOX were designated UKF-NB-4VCR or UKF-NB-4DOX. Combined phase contrast - reflection interference contrast microscopy was used to separately evaluate NB cell adhesion and penetration. NCAM was analyzed by flow cytometry, western blot and RT-PCR. Results VCR and DOX resistant tumor sublines showed enhanced adhesion and penetration capacity, compared to their drug naive controls. Strongest effects were seen with UKF-NB-2VCR, UKF-NB-3VCR and IMR-32DOX. DOX or VCR treatment also evoked increased invasive behaviour of UKF-NB-4. The process of accelerated tumor invasion was accompanied by decreased NCAM surface and protein expression, and down-regulation of NCAM coding mRNA. Transfection of UKF-NB-4VCR cells with NCAM cDNA led to a significant receptor up-regulation, paralleled by diminished adhesion to an endothelial cell monolayer. Conclusions It is concluded that NB cells resistant to anticancer drugs acquire increased invasive capacity relative to non-resistant parental cells, and that enhanced invasion is caused by strong down-regulation of NCAM adhesion receptors.
Background Anti-angiogenic treatment is believed to have at least cystostatic effects in highly vascularized tumours like pancreatic cancer. In this study, the treatment effects of the angiogenesis inhibitor Cilengitide and gemcitabine were compared with gemcitabine alone in patients with advanced unresectable pancreatic cancer. Methods A multi-national, open-label, controlled, randomized, parallel-group, phase II pilot study was conducted in 20 centers in 7 countries. Cilengitide was administered at 600 mg/m2 twice weekly for 4 weeks per cycle and gemcitabine at 1000 mg/m2 for 3 weeks followed by a week of rest per cycle. The planned treatment period was 6 four-week cycles. The primary endpoint of the study was overall survival and the secondary endpoints were progression-free survival (PFS), response rate, quality of life (QoL), effects on biological markers of disease (CA 19.9) and angiogenesis (vascular endothelial growth factor and basic fibroblast growth factor), and safety. An ancillary study investigated the pharmacokinetics of both drugs in a subset of patients. Results Eighty-nine patients were randomized. The median overall survival was 6.7 months for Cilengitide and gemcitabine and 7.7 months for gemcitabine alone. The median PFS times were 3.6 months and 3.8 months, respectively. The overall response rates were 17% and 14%, and the tumor growth control rates were 54% and 56%, respectively. Changes in the levels of CA 19.9 went in line with the clinical course of the disease, but no apparent relationships were seen with the biological markers of angiogenesis. QoL and safety evaluations were comparable between treatment groups. Pharmacokinetic studies showed no influence of gemcitabine on the pharmacokinetic parameters of Cilengitide and vice versa. Conclusion There were no clinically important differences observed regarding efficacy, safety and QoL between the groups. The observations lay in the range of other clinical studies in this setting. The combination regimen was well tolerated with no adverse effects on the safety, tolerability and pharmacokinetics of either agent.
Neben dem alltagsbegrifflichen Verständnis der "Unternehmer", das deren Lagerbildung und Interessenhomogenität unterstellt, lassen sich bei genauerem Hinsehen immer schon interne Differenzierungen erkennen, erfassbar v.a. mit der Kategorie der "Kapitalfraktionen". Öffentliche politische Interventionen des "Unternehmerlagers" erscheinen wiederum auf den ersten Blick homogen. Rolf Schmucker zeigt empirisch, dass auch dieser Blick trügt.
Klassenmedizin
(2003)
Im März 2000 hat der Europäische Rat von Lissabon das strategische Ziel der EU formuliert, "die Union zum wettbewerbsfähigsten und dynamischsten wissensbasierten Wirtschaftsraum der Welt zu machen – ... der fähig ist, ein dauerhaftes Wirtschaftswachstum mit mehr und besseren Arbeitsplätzen und einem größeren sozialen Zusammenhalt zu schaffen". Die Umsetzung soll u. a. durch die "Offene Methode der Koordinierung" (OMK) vorangetrieben werden. Damit wird eine Leitungs- und Koordinierungsfunktion des Rates auch auf solchen Politikfeldern angestrebt, die nach dem Vertragsrecht in die alleinige Gestaltungskompetenz der Mitgliedstaaten fallen. Die OMK lässt sich als eine Art Benchmarking-Verfahren ohne unmittelbar verpflichtende Konsequenzen für die Mitgliedstaaten beschreiben. Ein ähnliches Vorgehen wird seit 1997 in der Beschäftigungspolitik praktiziert. Mit der Lissabon-Strategie wird die OMK sukzessive auf weitere sozialpolitische Bereiche ausgedehnt. Im Bereich der Alterssicherung kommt sie ebenso zum Einsatz wie bei der Bekämpfung von Armut und sozialer Ausgrenzung. Künftig wird auch die Gesundheitspolitik der Mitgliedsländer auf dem Prüfstand der OMK stehen.
Kurzfassung eines Vortrags gehalten auf der GMA-Tagung vom 04.11.-06.11.2005 in Münster. Aufgrund wenig überzeugender Leistungen seiner Studierenden im vorklinischen Studienabschnitt hat der Fachbereich Medizin der Goethe-Universität zum Wintersemester 2001/02 eine völlig neue Studienordnung eingeführt, deren wesentliche Ziele das erfolgreiche Erlernen natur-, geistes- und sozialwissenschaftlicher Komponenten der normalen Biologie des Menschen mit optimaler Vorbereitung auf den klinischen Studienabschnitt binnen zweier Studienjahre und die Kompatibilität mit der ÄAppO und der ZÄAppO (jeweils alte und neue Version bzw. Vorentwurf) sind. Grundprinzipien des Curriculums sind: 1. Logisch aufeinander abgestimmte Themenblöcke, 2. Integration von makroskopischer und mikroskopischer Anatomie, 3. Interdisziplinärität der Themenblöcke, 4. Immanente Wiederholung von Lehrinhalten durch enge Verzahnung von Plenar- und Kleingruppenveranstaltungen, 5. Aufteilung der Studienanfänger in gemischte Gruppen nach den Kriterien Geschlecht, Herkunft und Studienfach, 6. Erlernen des Umgangs mit Patienten schon vom ersten Semester an durch "Anatomie am Lebenden"-Kurse und durch den Kurs Einführung in die klinische Medizin. Wichtigste Ergebnisse: Steigerung der Referenzgruppe beim Physikum von ca. 25% auf >60%, relativ guter Prüfungserfolg, hervorragende Sozialisation durch die frühe randomisierte Zuordnung in Kleingruppen und der sehr glatte Übergang in den klinischen Abschnitt des Medizin- bzw. Zahnmedizinstudiums.
Gute naturwissenschaftliche Vorkenntnisse sind insbesondere für den vorklinischen Studienabschnitt wichtig. Wegen der heterogenen Auswahl von Leistungskursen und Abituranforderungen kann jedoch nicht unbedingt von einem einheitlichen Wissensstand ausgegangen werden. Daher wurde versucht, mit einem Testbogen aus insgesamt 40 Aufgaben zur Biologie, Chemie, Mathematik und Physik den Wissensstand der Studienanfänger in Humanmedizin in Deutschland zu quantifizieren. Der Fragebogen enthielt neben Faktenaufgaben auch Anwendungen vor allem mathematischer und chemischer Prinzipien. Alle Fragen mussten durch Freitextantworten oder Skizzen beantwortet werden. Teilgenommen haben insgesamt 2 935 Studienanfänger des Wintersemesters 2004/2005 von 14 deutschen Universitäten (etwa 40% des Jahrganges). Im Mittel wurden 14,34 der 40 Aufgaben richtig beantwortet; etwas bessere Kenntnisse wurden in den 15 Biologiefragen (6,89) und den 8 Mathematikfragen erreicht (3,23), während vor allem in Chemie (2,18 von 10 Fragen) und Physik (1,55 von 8 Fragen) große Wissenslücken bestehen. Die Ergebnisse bestätigen, dass die naturwissenschaftlichen Vorkenntnisse der Studienanfänger schlecht sind; sie erfordern einen größeren Zeitaufwand für die Vermittlung des Abiturwissens im ersten vorklinischen Semester. Sinnvoll erscheint alternativ die verpflichtende Teilnahme an Zusatzkursen in diesen Fächern vor Aufnahme des eigentlichen Fachstudiums.
Mit der Neuregelung der Studienplatzverteilung von 2005 haben die Universitäten in Deutschland die Möglichkeit, bis zu 60% der Studienplätze nach universitätseigenen Kriterien zu vergeben. Implizit wird vom Gesetzgeber und der öffentlichen Meinung gefordert, nicht-leistungsbezogene Kriterien und Persönlichkeitsmerkmale verstärkt zur Bewerberauswahl einzusetzen (Motivation, Identifikation, Vermeidung von Fehlvorstellungen). Da in Anbetracht der Bewerberzahlen mündliche Auswahlgespräche als ungeeignet erscheinen, wurde vom Fachbereich Medizin der Johann Wolfgang Goethe Universität ein Fragebogen entworfen, um nichtschulische Leistungen zu erfassen. Dieser Fragebogen wurde am Beginn des Wintersemesters 2005/2006 von allen Studienanfängern der JWG-Universität Frankfurt und der Medizinischen Universität Innsbruck ausgefüllt. Entgegen der initialen Erwartungen der Verfasser gaben nur etwa 15% Prozent Medizin-spezifische berufliche Vorerfahrungen an (Rettungsdienst, Ausbildung als Krankenschwester/pfleger oder ähnliches); dagegen wurden von etwa 60% angegeben, mindestens ein Musikinstrument zu spielen oder länger sportlich aktiv gewesen zu sein. Die Zusammenstellung der Selbstangaben zeigt, dass Medizin-relevante Vorkenntnisse nur bei einem kleinen Anteil der Studienbewerber in größerem Umfang vorhanden sind. Aufgrund der großen Streuung in der Art und Dauer der angegebenen Vorleistungen sollte die Erhebung von Parametern zur Beurteilung von soft skills, z.B. durch Online-Fragebogen, als (Vor)Selektionsinstrument nur sehr vorsichtig eingesetzt werden.
Maßgeblich unter dem wachsenden externen Druck hat die didaktische Qualifizierung in den medizinischen Fakultäten an Bedeutung gewonnen. Im Rahmen der Professionalisierung der medizinischen Aus-, Fort- und Weiterbildung ist eine pädagogisch-didaktische Ausbildung der Lehrenden unumgänglich. Um Orientierung und Argumentationshilfe zu geben, werden in einer dreiteiligen Artikelfolge Stellenwert der Medizindidaktik, Anforderungsprofil der Angebote und Konzepte zur Implementierung und zur Erfolgsmessung für den deutschsprachigen Raum beleuchtet. In Teil II beleuchten wir den Ausbildungsbedarf und erstellen ein Anforderungsprofil für ein strukturiertes systematisches Qualifizierungsangebot. Der Hauptbedarf besteht in der Qualifizierung der Lehrenden, die den täglichen Unterricht durchführen. Insbesondere sie brauchen das Handwerkszeug, das ihnen erlaubt, ihre verschiedenen Lehraufgaben effizienter zu bewältigen. Seitens der Fakultät und der Studierenden bestehen Ansprüche an qualifizierte Lehrende; ebenso bestehen Forderungen seitens der Lehrenden an adäquat qualifizierende Kurse. Zur Umsetzung dieser berechtigten Ansprüche sind modular aufgebaute Programme nötig, die eine zumindest national qualitativ und quantitativ vergleichbare Ausbildung gewährleisten. Anforderungen an derartige Kurse sind bereits definiert und lokal zum Beispiel in Baden-Württemberg und zum Teil auch in Nordrhein-Westfalen umgesetzt. Es gilt nun, diese auf breiter Basis in die Praxis umzusetzen.
Alle Leistungsnachweise des klinischen Studienabschnittes nach neuer Ärztlicher Approbationsordnung müssen benotet werden; hierzu sind in der Regel schriftliche Prüfungen notwendig. Bisher erprobte Methoden beinhalten die Prüfung passiven Wissens (Einfachauswahlfragen, multiple choice-Fragen, progress test-Fragen) und aktiven Wissens (short essay questions, long essay questions). Vor- und Nachteile dieser Verfahren werden diskutiert, sowie die zur Erstellung, Durchführung und Auswertung schriftlicher Prüfungen notwendigen Ressourcen.
Maßgeblich unter dem wachsenden externen Druck hat die didaktische Qualifizierung in den medizinischen Fakultäten an Bedeutung gewonnen. Im Rahmen der Professionalisierung der medizinischen Aus-, Fort- und Weiterbildung ist eine pädagogisch-didaktische Ausbildung der Lehrenden unumgänglich. Um Orientierung und Argumentationshilfe zu geben, werden in einer dreiteiligen Artikelfolge Stellenwert der Medizindidaktik, Anforderungsprofil der Angebote und Konzepte zur Implementierung und zur Erfolgsmessung für den deutschsprachigen Raum beleuchtet. In Teil I geben wir eine Bestandsaufnahme zur Medizindidaktik. Aktuell gibt es bundesweit ein breit gefächertes Qualifizierungsangebot. Es reicht von einfachen unstrukturierten Kurzfortbildungen wie zum Beispiel Vorträgen und Seminaren, die inhaltlich, formal und qualitativ eine große Beliebigkeit zeigen, bis hin zu umfassenden mehrjährigen (Aufbau-)Studiengängen mit "Master-Degree". Im internationalen Vergleich fehlt in Deutschland ein allgemein verbindliches "Basis-Programm", das die täglich Lehrenden systematisch auf ihre Ausbildungsaufgaben vorbereitet. Dies ist bisher nur lokal umgesetzt wie zum Beispiel in Baden-Württemberg mit dem ministeriell zertifizierten Programm der Medizindidaktischen Qualifikation I und II. Vergleichbares ist in Nordrhein-Westfalen und Bayern im Aufbau.
Enzymatic and antisense effects of a specific anti-Ki-ras ribozyme in vitro and in cell culture
(1999)
Due to their mode of action, ribozymes show antisense effects in addition to their specific cleavage activity. In the present study we investigated whether a hammerhead ribozyme is capable of cleaving mutated Ki-ras mRNA in a pancreatic carcinoma cell line and whether antisense effects contribute to the activity of the ribozyme. A 2[prime]-O-allyl modified hammerhead ribozyme was designed to cleave specifically the mutated form of the Ki-ras mRNA (GUU motif in codon 12). The activity was monitored by RT-PCR on Ki-ras RNA expression by determination of the relative amount of wild type to mutant Ki-ras mRNA, by 5-bromo-2[prime]-deoxy-uridine incorporation on cell proliferation and by colony formation in soft agar on malignancy in the human pancreatic adenocarcinoma cell line CFPAC-1, which is heterozygous for the Ki-ras mutation. A catalytically inactive ribozyme was used as control to differentiate between antisense and cleavage activity and a ribozyme with random guide sequences as negative control. The catalytically active anti-Ki-ras ribozyme was at least 2-fold more potent in decreasing cellular Ki-ras mRNA levels, inhibiting cell proliferation and colony formation in soft agar than the catalytically inactive ribozyme. The catalytically active anti-Ki-ras ribozyme, but not the catalytically inactive or random ribozyme, increased the ratio of wild type to mutated Ki-ras mRNA in CFPAC-1 cells. In conclusion, both cleavage activity and antisense effects contribute to the activity of the catalytically active anti-Ki-ras hammerhead ribozyme. Specific ribozymes might be useful in the treatment of pancreatic carcinomas containing an oncogenic GTT mutation in codon 12 of the Ki-ras gene.
Mismatch repair is a highly conserved system that ensures replication fidelity by repairing mispairs after DNA synthesis. In humans, the two protein heterodimers hMutSα (hMSH2‐hMSH6) and hMutLα (hMLH1‐hPMS2) constitute the centre of the repair reaction. After recognising a DNA replication error, hMutSα recruits hMutLα, which then is thought to transduce the repair signal to the excision machinery. We have expressed an ATPase mutant of hMutLα as well as its individual subunits hMLH1 and hPMS2 and fragments of hMLH1, followed by examination of their interaction properties with hMutSα using a novel interaction assay. We show that, although the interaction requires ATP, hMutLα does not need to hydrolyse this nucleotide to join hMutSα on DNA, suggesting that ATP hydrolysis by hMutLα happens downstream of complex formation. The analysis of the individual subunits of hMutLα demonstrated that the hMutSα–hMutLα interaction is predominantly conferred by hMLH1. Further experiments revealed that only the N‐terminus of hMLH1 confers this interaction. In contrast, only the C‐terminus stabilised and co‐immunoprecipitated hPMS2 when both proteins were co‐expressed in 293T cells, indicating that dimerisation and stabilisation are mediated by the C‐terminal part of hMLH1. We also examined another human homologue of bacterial MutL, hMutLβ (hMLH1–hPMS1). We show that hMutLβ interacts as efficiently with hMutSα as hMutLα, and that it predominantly binds to hMutSα via hMLH1 as well.
RNA interference (RNAi) has emerged as a powerful tool to induce loss-of-function phenotypes by post-transcriptional silencing of gene expression. In this study we wondered whether inducible RNAi-cassettes integrated into cellular DNA possess the power to trigger neoplastic growth. For this purpose inducible RNAi vectors containing tetracycline (Tet)-responsive derivatives of the H1 promoter for the conditional expression of short hairpin RNA (shRNA) were used to target human polo-like kinase 1 (Plk1), which is overexpressed in a broad spectrum of human tumors. In the absence of doxycycline (Dox) HeLa clones expressing TetR, that carry the RNAi-cassette stably integrated, exhibited no significant alteration in Plk1 expression levels. In contrast, exposure to Dox led to marked downregulation of Plk1 mRNA to 3% and Plk1 protein to 14% in cell culture compared to mismatch shRNA/Plk1-expressing cells. As a result of Plk1 depletion cell proliferation decreased to 17%. Furthermore, for harnessing RNAi for silencing disease-related genes in vivo we transplanted inducible RNAi-HeLa cells onto nude mice. After administration of Dox knockdown of Plk1 expression was observed correlating to a significant inhibition of tumor growth. Taken together, our data revealed that genomically integrated RNAi-elements are suitable to hamper tumor growth by conditional expression of shRNA.
Natural objects provide partially redundant information to the brain through different sensory modalities. For example, voices and faces both give information about the speech content, age, and gender of a person. Thanks to this redundancy, multimodal recognition is fast, robust, and automatic. In unimodal perception, however, only part of the information about an object is available. Here, we addressed whether, even under conditions of unimodal sensory input, crossmodal neural circuits that have been shaped by previous associative learning become activated and underpin a performance benefit. We measured brain activity with functional magnetic resonance imaging before, while, and after participants learned to associate either sensory redundant stimuli, i.e. voices and faces, or arbitrary multimodal combinations, i.e. voices and written names, ring tones, and cell phones or brand names of these cell phones. After learning, participants were better at recognizing unimodal auditory voices that had been paired with faces than those paired with written names, and association of voices with faces resulted in an increased functional coupling between voice and face areas. No such effects were observed for ring tones that had been paired with cell phones or names. These findings demonstrate that brief exposure to ecologically valid and sensory redundant stimulus pairs, such as voices and faces, induces specific multisensory associations. Consistent with predictive coding theories, associative representations become thereafter available for unimodal perception and facilitate object recognition. These data suggest that for natural objects effective predictive signals can be generated across sensory systems and proceed by optimization of functional connectivity between specialized cortical sensory modules.
Background The proto-oncogene pituitary tumor-transforming gene (PTTG) has been shown to be abundantly overexpressed in a large variety of neoplasms likely promoting neo-vascularization and tumor invasiveness. In this study, we investigated a potential role for PTTG mRNA expression as a marker to evaluate the future clinical outcome of patients diagnosed with primary cancer of the head and neck. Methods Tumor samples derived from primary tumors of 89 patients suffering from a squamous cell carcinoma were analyzed for PTTG mRNA-expression and compared to corresponding unaffected tissue. Expression levels were correlated to standard clinico-pathological parameters based on a five year observation period. Results In almost all 89 tumor samples PTTG was found to be overexpressed (median fold increase: 2.1) when compared to the unaffected tissue specimens derived from the same patient. The nodal stage correlated with PTTG transcript levels with significant differences between pN0 (median expression: 1.32) and pN+ (median expression: 2.12; P = 0.016). In patients who developed a tumor recurrence we detected a significantly higher PTTG expression in primary tumors (median expression: 2.63) when compared to patients who did not develop a tumor recurrence (median expression: 1.29; P = 0.009). Since the median expression of PTTG in patients with tumor stage T1/2N0M0 that received surgery alone without tumor recurrence was 0.94 versus 3.82 in patients suffering from a tumor recurrence (P = 0.006), PTTG expression might provide a feasible mean of predicting tumor recurrence. Conclusion Elevated PTTG transcript levels might be used as a prognostic biomarker for future clinical outcome (i.e. recurrence) in primary squamous cell carcinomas of the head and neck, especially in early stages of tumor development.
Multiple choice (MC)-Klausuren sind im deutschen Medizinstudium trotz weitgehend fehlender Daten zur Validität dieser Prüfungsform zur Regelprüfung geworden. Darüber hinaus ist unklar, in welchem Ausmaß die Studierenden - auch solche mit guten Prüfungsergebnissen - den geprüften Lernstoff tatsächlich beherrschen. Am Fachbereich Medizin der Johann-Wolfgang-Goethe-Universität Frankfurt wurde am Ende des SS 2003 im Fach Mikrobiologie für die Studierenden des 2. klinischen Semesters eine MC-basierte Abschlussprüfung geschrieben. Die Studierenden des 1. klinischen Semesters hatten - bedingt durch Umstellungen des Curriculums - eine identische Ausbildung. Diese wurde durch eine inhaltlich weitgehend identische, im Format aber andere Klausur abgeschlossen, in der sowohl offene Fragen enthalten waren als auch Fragen, bei denen die Studierenden jede Aussage einzeln auf Korrektheit bewerten mussten. Der Vergleich der Ergebnisse für inhaltlich gleiche Fragen zeigt, dass die Studierenden im MC-Format eine hohe Quote richtiger Antworten erzielen, diese jedoch durch ein geändertes Fragenformat stark reduziert wird. So erreichten nur 20 - 30% der Studierenden ein vollständig richtiges Ergebnis, wenn jede Aussage einzeln bewertet werden musste, während die inhaltlich gleiche Frage im MC-Format 80 - 90% richtige Ergebnisse erzielte. In freien Fragen konnten nur 30 - 40% der Studierenden die richtige Antwort aktiv niederschreiben, während 90 -99% der Studierenden die richtige Lösung passiv erkannten. Wir interpretieren diese Ergebnisse dahin, dass der Entscheidungszwang in MC-basierten Fragen einen starken Einfluss auf die Quote richtiger Antworten hat, und die Prüfungsergebnisse damit wesentlich durch das Format beeinflusst werden, das Wissen dagegen nicht beherrscht wird. Die Ergebnisse dieser Studie legen nahe, Sorgfalt bei der Auswahl des Prüfungsverfahrens walten zu lassen und der Steuerung des studentischen Lernverhaltens durch das Prüfungsformat wesentlich mehr Aufmerksamkeit zu widmen als bisher.
Wenn auch heute, nachdem Staat und Kommunen die Führung übernommen haben, der konfessionellen Wohlfahrtspflege nicht mehr die Bedeutung zukommt, wie in früheren Zeiten, so weist sie doch auch gegenwärtig noch höchst beachtenswerte Leistungen auf; sie ergänzt die öffentliche Wohlfahrtspflege in einem Maße, daß sie in dem weitverzweigten Betriebe unserer öffentlichen Einrichtungen gar nicht wegzudenken ist. Das gilt sowohl von der christlichen, wie der jüdischen Charitas. Aber während die Leistungen der ersteren vor allen Augen offen daliegen, blüht die jüdische Wohlfahrtspflege vielfach im Verborgenen. Sie ist außerdem so weit verzweigt und so reich gegliedert, daß sie kaum von wenigen, und auch von den Fachmännern nicht übersehen werden kann; dies um so mehr, als auch die Literatur die Materie bisher sehr stiefmütterlich behandelt hat und, von dem Aufsatze Breslauers: "Die jüdische Wohltätigkeit und Wohlfahrtspflege in Deutschland" (Archiv für Volkswohlfahrt 1908 S. 97) abgesehen, keine zusammenfassende Bearbeitung dieses Gegenstandes vorhanden ist. ES dürfte daher nicht überflüssig sein, einmal im Zusammenhang darzustellen, wie sich die jüdische WohIfahrtspflege historisch entwickelt hat, welchen Umfang sie in der Gegenwart angenommen hat, ihre charakteristischen Merkmale herauszuschälen und darzulegen, welche Bedeutung ihr im Rahmen der allgemeinen Wohlfahrtspflege zukommt. Dies soll Aufgabe dieser Untersuchung sein, bei der in erster Linie die Verhältnisse in Deutschland berücksichtigt werden sollen.
Background: PPARs exhibit anti-inflammatory capacities and are potential modulators of the inflammatory response. We hypothesized that their expression and/or function may be altered in cystic fibrosis (CF), a disorder characterized by an excessive host inflammatory response.
Methods: PPARα, β and γ mRNA levels were measured in peripheral blood cells of CF patients and healthy subjects via RT-PCR. PPARα protein expression and subcellular localization was determined via western blot and immunofluorescence, respectively. The activity of PPARα was analyzed by gel shift assay.
Results: In lymphocytes, the expression of PPARα mRNA, but not of PPARβ, was reduced (-37%; p < 0.002) in CF patients compared with healthy persons and was therefore further analyzed. A similar reduction of PPARα was observed at protein level (-26%; p < 0.05). The transcription factor was mainly expressed in the cytosol of lymphocytes, with low expression in the nucleus. Moreover, DNA binding activity of the transcription factor was 36% less in lymphocytes of patients (p < 0.01). For PPARα and PPARβ mRNA expression in monocytes and neutrophils, no significant differences were observed between CF patients and healthy persons. In all cells, PPARγ mRNA levels were below the detection limit.
Conclusion: Lymphocytes are important regulators of the inflammatory response by releasing cytokines and antibodies. The diminished lymphocytic expression and activity of PPARα may therefore contribute to the inflammatory processes that are observed in CF.
Background While there is enough convincing evidence in childhood acute lymphoblastic leukemia (ALL), the data on the pre-natal origin in childhood acute myeloid leukemia (AML) are less comprehensive. Our study aimed to screen Guthrie cards (neonatal blood spots) of non-infant childhood AML and ALL patients for the presence of their respective leukemic markers. Methods We analysed Guthrie cards of 12 ALL patients aged 2–6 years using immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangements (n = 15) and/or intronic breakpoints of TEL/AML1 fusion gene (n = 3). In AML patients (n = 13, age 1–14 years) PML/RARalpha (n = 4), CBFbeta/MYH11 (n = 3), AML1/ETO (n = 2), MLL/AF6 (n = 1), MLL/AF9 (n = 1) and MLL/AF10 (n = 1) fusion genes and/or internal tandem duplication of FLT3 gene (FLT3/ITD) (n = 2) were used as clonotypic markers. Assay sensitivity determined using serial dilutions of patient DNA into the DNA of a healthy donor allowed us to detect the pre-leukemic clone in Guthrie card providing 1–3 positive cells were present in the neonatal blood spot. Results In 3 patients with ALL (25%) we reproducibly detected their leukemic markers (Ig/TCR n = 2; TEL/AML1 n = 1) in the Guthrie card. We did not find patient-specific molecular markers in any patient with AML. Conclusion In the largest cohort examined so far we used identical approach for the backtracking of non-infant childhood ALL and AML. Our data suggest that either the prenatal origin of AML is less frequent or the load of pre-leukemic cells is significantly lower at birth in AML compared to ALL cases.
Background: Experimental animal data show that protection against severe acute respiratory syndrome coronavirus (SARS-CoV) infection with human monoclonal antibodies (mAbs) is feasible. For an effective immune prophylaxis in humans, broad coverage of different strains of SARS-CoV and control of potential neutralization escape variants will be required. Combinations of virus-neutralizing, noncompeting mAbs may have these properties. Methods and Findings: Human mAb CR3014 has been shown to completely prevent lung pathology and abolish pharyngeal shedding of SARS-CoV in infected ferrets. We generated in vitro SARS-CoV variants escaping neutralization by CR3014, which all had a single P462L mutation in the glycoprotein spike (S) of the escape virus. In vitro experiments confirmed that binding of CR3014 to a recombinant S fragment (amino acid residues 318–510) harboring this mutation was abolished. We therefore screened an antibody-phage library derived from blood of a convalescent SARS patient for antibodies complementary to CR3014. A novel mAb, CR3022, was identified that neutralized CR3014 escape viruses, did not compete with CR3014 for binding to recombinant S1 fragments, and bound to S1 fragments derived from the civet cat SARS-CoV-like strain SZ3. No escape variants could be generated with CR3022. The mixture of both mAbs showed neutralization of SARS-CoV in a synergistic fashion by recognizing different epitopes on the receptor-binding domain. Dose reduction indices of 4.5 and 20.5 were observed for CR3014 and CR3022, respectively, at 100% neutralization. Because enhancement of SARS-CoV infection by subneutralizing antibody concentrations is of concern, we show here that anti-SARS-CoV antibodies do not convert the abortive infection of primary human macrophages by SARS-CoV into a productive one. Conclusions: The combination of two noncompeting human mAbs CR3014 and CR3022 potentially controls immune escape and extends the breadth of protection. At the same time, synergy between CR3014 and CR3022 may allow for a lower total antibody dose to be administered for passive immune prophylaxis of SARS-CoV infection.
Antileukoproteinase (ALP) is a physiological inhibitor of granulocytic serine proteases that has been shown to have anti-inflammatory properties in addition to its antiproteolytic activity. On the basis of its potential to block anti-collagen type II (CII) antibody-induced arthritis (CAIA) and to suppress the conformational activation of β2-integrins in leukocytes, the present study was undertaken to investigate its interference with leukocyte adherence to cytokine-activated endothelium. The potential of recombinant ALP to block the interactions of leukocytes with the endothelial lining was concomitantly investigated in vitro and in vivo. Thus, intravital fluorescence microscopic imaging of leukocyte rolling and firm adhesion to postcapillary venules were performed in the knee joints of DBA1/J mice after intravenous injection of anti-CII mAbs. An IL-1β-activated endothelial layer formed by a murine glomerular cell line (glEND.2) was used to assay the interaction with human leukocytes in vitro. Electromobility shift and luciferase reporter gene assays permitted the analysis of cytokine-induced activation of the NF-κB pathway. Fluorescence-activated cell sorting was applied to determine endothelial E-selectin expression. Leukocyte rolling and firm adhesion to the synovial endothelium in an early response to the anti-CII antibody transfer were significantly decreased in ALP-pretreated mice. Concomitantly, ALP suppressed the IL-1β-induced NF-κB activation and the upregulation of E-selectin expression in glEND.2 cells in vitro. These findings support the notion that the newly uncovered properties of ALP to interfere with cytokine signalling and upregulation of adhesion molecules in endothelial cells are likely to contribute to the therapeutic potential of ALP in immune-complex-induced tissue injury.
The illusion of apparent motion can be induced when visual stimuli are successively presented at different locations. It has been shown in previous studies that motion-sensitive regions in extrastriate cortex are relevant for the processing of apparent motion, but it is unclear whether primary visual cortex (V1) is also involved in the representation of the illusory motion path. We investigated, in human subjects, apparent-motion-related activity in patches of V1 representing locations along the path of illusory stimulus motion using functional magnetic resonance imaging. Here we show that apparent motion caused a blood-oxygenation-level-dependent response along the V1 representations of the apparent-motion path, including regions that were not directly activated by the apparent-motion-inducing stimuli. This response was unaltered when participants had to perform an attention-demanding task that diverted their attention away from the stimulus. With a bistable motion quartet, we confirmed that the activity was related to the conscious perception of movement. Our data suggest that V1 is part of the network that represents the illusory path of apparent motion. The activation in V1 can be explained either by lateral interactions within V1 or by feedback mechanisms from higher visual areas, especially the motion-sensitive human MT/V5 complex.
Gene trapping is a method of generating murine embryonic stem (ES) cell lines containing insertional mutations in known and novel genes. A number of international groups have used this approach to create sizeable public cell line repositories available to the scientific community for the generation of mutant mouse strains. The major gene trapping groups worldwide have recently joined together to centralize access to all publicly available gene trap lines by developing a user-oriented Website for the International Gene Trap Consortium (IGTC). This collaboration provides an impressive public informatics resource comprising ~45 000 well-characterized ES cell lines which currently represent ~40% of known mouse genes, all freely available for the creation of knockout mice on a non-collaborative basis. To standardize annotation and provide high confidence data for gene trap lines, a rigorous identification and annotation pipeline has been developed combining genomic localization and transcript alignment of gene trap sequence tags to identify trapped loci. This information is stored in a new bioinformatics database accessible through the IGTC Website interface. The IGTC Website (www.genetrap.org) allows users to browse and search the database for trapped genes, BLAST sequences against gene trap sequence tags, and view trapped genes within biological pathways. In addition, IGTC data have been integrated into major genome browsers and bioinformatics sites to provide users with outside portals for viewing this data. The development of the IGTC Website marks a major advance by providing the research community with the data and tools necessary to effectively use public gene trap resources for the large-scale characterization of mammalian gene function.
Kongressbericht: Auf der Tagung der Deutschen Gesellschaft für Allgemeinmedizin und Familienmedizin e.V. (DEGAM) 2004 entstand die Idee, E-Learning-Aktivitäten in der Allgemeinmedizin sichtbar zu machen und zu bündeln. Ein Kongress sollte die allgemeinmedizinischen Vertreter aus Lehre und Forschung sowie Industrievertreter zusammenbringen, um das Spektrum der Möglichkeiten und laufende Projekte kennen zu lernen. Mit motivierten Referenten, über 60 aktiven Teilnehmern und einem positiven Feedback, kann der Kongress in Frankfurt am 8. und 9. Juli 2005 als erster dieser Art in Deutschland als erfolgreich bezeichnet werden.
Background: Depression is a disorder with high prevalence in primary health care and a significant burden of illness. The delivery of health care for depression, as well as other chronic illnesses, has been criticized for several reasons and new strategies to address the needs of these illnesses have been advocated. Case management is a patient-centered approach which has shown efficacy in the treatment of depression in highly organized Health Maintenance Organization (HMO) settings and which might also be effective in other, less structured settings. Methods/Design: PRoMPT (PRimary care Monitoring for depressive Patients Trial) is a cluster randomised controlled trial with General Practice (GP) as the unit of randomisation. The aim of the study is to evaluate a GP applied case-management for patients with major depressive disorder. 70 GPs were randomised either to intervention group or to control group with the control group delivering usual care. Each GP will include 10 patients suffering from major depressive disorder according to the DSM-IV criteria. The intervention group will receive treatment based on standardized guidelines and monthly telephone monitoring from a trained practice nurse. The nurse investigates the patient's status concerning the MDD criteria, his adherence to GPs prescriptions, possible side effects of medication, and treatment goal attainment. The control group receives usual care – including recommended guidelines. Main outcome measure is the cumulative score of the section depressive disorders (PHQ-9) from the German version of the Prime MD Patient Health Questionnaire (PHQ-D). Secondary outcome measures are the Beck-Depression-Inventory, self-reported adherence (adapted from Moriskey) and the SF-36. In addition, data are collected about patients' satisfaction (EUROPEP-tool), medication, health care utilization, comorbidity, suicide attempts and days out of work. The study comprises three assessment times: baseline (T0) , follow-up after 6 months (T1) and follow-up after 12 months (T2). Discussion: Depression is now recognized as a disorder with a high prevalence in primary care but with insufficient treatment response. Case management seems to be a promising intervention which has the potential to bridge the gap of the usually time-limited and fragmented provision of care. Case management has been proven to be effective in several studies but its application in the private general medical practice setting remains unclear.
Background: Diabetes model projects in different regions of Germany including interventions such as quality circles, patient education and documentation of medical findings have shown improvements of HbA1c levels, blood pressure and occurrence of hypoglycaemia in before-after studies (without control group). In 2002 the German Ministry of Health defined legal regulations for the introduction of nationwide disease management programs (DMP) to improve the quality of care in chronically ill patients. In April 2003 the first DMP for patients with type 2 diabetes was accredited. The evaluation of the DMP is essential and has been made obligatory in Germany by the Fifth Book of Social Code. The aim of the study is to assess the effectiveness of DMP by example of type 2 diabetes in the primary care setting of two German federal states (Rheinland-Pfalz and Sachsen-Anhalt). Methods/Design: The study is three-armed: a prospective cluster-randomized comparison of two interventions (DMP 1 and DMP 2) against routine care without DMP as control group. In the DMP group 1 the patients are treated according to the current situation within the German-Diabetes-DMP. The DMP group 2 represents diabetic care within ideally implemented DMP providing additional interventions (e.g. quality circles, outreach visits). According to a sample size calculation a sample size of 200 GPs (each GP including 20 patients) will be required for the comparison of DMP 1 and DMP 2 considering possible drop-outs. For the comparison with routine care 4000 patients identified by diabetic tracer medication and age (> 50 years) will be analyzed. Discussion: This study will evaluate the effectiveness of the German Diabetes-DMP compared to a Diabetes-DMP providing additional interventions and routine care in the primary care setting of two different German federal states.
Das Projekt LaMedica (http://www.lamedica.de) hat zum Ziel, eine multimediale Lehr- und Lernplattform zu entwickeln, Inhalte für die Medizin zu erstellen und diese in die Lehre zu implementieren. Es wurde eine on-line Autorenumgebung geschaffen, die sehr unterschiedliche didaktische Ansätze unterstützt: systematische und vernetzte Wissensvermittlung, fallbasiertes Lernen, Erstellung von Vorlesungen und Lernerfolgskontrolle. Die Lehrinhalte können zielgruppenspezifisch aufbereitet und dargestellt werden und richten sich insbesondere an Studenten, Ärzte in der Weiterbildung und Fachärzte. Eine on-line Medien-Datenbank unterstützt die Wiederverwendung und den Austausch von Inhalten auf der Basis eines Content-Management-Systems durch Verwendung des Learning Objects Metadata Standards (LOM). Die Förderung erfolgt durch das BMBF (FKZ NM054A).
Celiac disease
(2006)
Celiac disease is a chronic intestinal disease caused by intolerance to gluten. It is characterized by immune-mediated enteropathy, associated with maldigestion and malabsorption of most nutrients and vitamins. In predisposed individuals, the ingestion of gluten-containing food such as wheat and rye induces a flat jejunal mucosa with infiltration of lymphocytes. The main symptoms are: stomach pain, gas, and bloating, diarrhea, weight loss, anemia, edema, bone or joint pain. Prevalence for clinically overt celiac disease varies from 1:270 in Finland to 1:5000 in North America. Since celiac disease can be asymptomatic, most subjects are not diagnosed or they can present with atypical symptoms. Furthermore, severe inflammation of the small bowel can be present without any gastrointestinal symptoms. The diagnosis should be made early since celiac disease causes growth retardation in untreated children and atypical symptoms like infertility or neurological symptoms. Diagnosis requires endoscopy with jejunal biopsy. In addition, tissue-transglutaminase antibodies are important to confirm the diagnosis since there are other diseases which can mimic celiac disease. The exact cause of celiac disease is unknown but is thought to be primarily immune mediated (tissue-transglutaminase autoantigen); often the disease is inherited. Management consists in life long withdrawal of dietary gluten, which leads to significant clinical and histological improvement. However, complete normalization of histology can take years.
Background: Osteoarthritis (OA) has a high prevalence in primary care. Conservative, guideline orientated approaches aiming at improving pain treatment and increasing physical activity, have been proven to be effective in several contexts outside the primary care setting, as for instance the Arthritis Self management Programs (ASMPs). But it remains unclear if these comprehensive evidence based approaches can improve patients' quality of life if they are provided in a primary care setting. Methods/Design: PraxArt is a cluster randomised controlled trial with GPs as the unit of randomisation. The aim of the study is to evaluate the impact of a comprehensive evidence based medical education of GPs on individual care and patients' quality of life. 75 GPs were randomised either to intervention group I or II or to a control group. Each GP will include 15 patients suffering from osteoarthritis according to the criteria of ACR. In intervention group I GPs will receive medical education and patient education leaflets including a physical exercise program. In intervention group II the same is provided, but in addition a practice nurse will be trained to monitor via monthly telephone calls adherence to GPs prescriptions and advices and ask about increasing pain and possible side effects of medication. In the control group no intervention will be applied at all. Main outcome measurement for patients' QoL is the GERMAN-AIMS2-SF questionnaire. In addition data about patients' satisfaction (using a modified EUROPEP-tool), medication, health care utilization, comorbidity, physical activity and depression (using PHQ-9) will be retrieved. Measurements (pre data collection) will take place in months I-III, starting in June 2005. Post data collection will be performed after 6 months. Discussion: Despite the high prevalence and increasing incidence, comprehensive and evidence based treatment approaches for OA in a primary care setting are neither established nor evaluated in Germany. If the evaluation of the presented approach reveals a clear benefit it is planned to provide this GP-centred interventions on a much larger scale.
The large conductance voltage- and Ca2+-activated potassium (BK) channel has been suggested to play an important role in the signal transduction process of cochlear inner hair cells. BK channels have been shown to be composed of the pore-forming alpha-subunit coexpressed with the auxiliary beta-1-subunit. Analyzing the hearing function and cochlear phenotype of BK channel alpha-(BKalpha–/–) and beta-1-subunit (BKbeta-1–/–) knockout mice, we demonstrate normal hearing function and cochlear structure of BKbeta-1–/– mice. During the first 4 postnatal weeks also, BKalpha–/– mice most surprisingly did not show any obvious hearing deficits. High-frequency hearing loss developed in BKalpha–/– mice only from ca. 8 weeks postnatally onward and was accompanied by a lack of distortion product otoacoustic emissions, suggesting outer hair cell (OHC) dysfunction. Hearing loss was linked to a loss of the KCNQ4 potassium channel in membranes of OHCs in the basal and midbasal cochlear turn, preceding hair cell degeneration and leading to a similar phenotype as elicited by pharmacologic blockade of KCNQ4 channels. Although the actual link between BK gene deletion, loss of KCNQ4 in OHCs, and OHC degeneration requires further investigation, data already suggest human BK-coding slo1 gene mutation as a susceptibility factor for progressive deafness, similar to KCNQ4 potassium channel mutations. © 2004, The National Academy of Sciences. Freely available online through the PNAS open access option.
Background: The existence of a constitutively expressed machinery for death in individual cells has led to the notion that survival factors repress this machinery and, if such factors are unavailable, cells die by default. In many cells, however, mRNA and protein synthesis inhibitors induce apoptosis, suggesting that in some cases transcriptional activity might actually impede cell death. To identify transcriptional mechanisms that interfere with cell death and survival, we combined gene trap mutagenesis with site-specific recombination (Cre/loxP system) to isolate genes from cells undergoing apoptosis by growth factor deprivation.
Results: From an integration library consisting of approximately 2 × 106 unique proviral integrations obtained by infecting the interleukin-3 (IL-3)-dependent hematopoietic cell line - FLOXIL3 - with U3Cre gene trap virus, we have isolated 125 individual clones that converted to factor independence upon IL-3 withdrawal. Of 102 cellular sequences adjacent to U3Cre integration sites, 17% belonged to known genes, 11% matched single expressed sequence tags (ESTs) or full cDNAs with unknown function and 72% had no match within the public databases. Most of the known genes recovered in this analysis encoded proteins with survival functions.
Conclusions: We have shown that hematopoietic cells undergoing apoptosis after withdrawal of IL-3 activate survival genes that impede cell death. This results in reduced apoptosis and improved survival of cells treated with a transient apoptotic stimulus. Thus, apoptosis in hematopoietic cells is the end result of a conflict between death and survival signals, rather than a simple death by default.
An excess of the proinflammatory substance IL-18 is present in joints of patients with rheumatoid arthritis (RA), and expression of IL-18 receptor (IL-18R) regulates IL-18 bioactivity in various cell types. We examined the expression of IL-18R alpha-chain and beta-chain and the biologic effects of IL-18 in fibroblast-like synoviocytes (FLS) after long-term culture. The presence of both IL-18R chains was a prerequisite for IL-18 signal transduction in FLS. However, all FLS cultures studied were either resistant or barely responsive to IL-18 stimulation as regards cell proliferation, expression of adhesion molecules ICAM-1 and vascular cell adhesion molecule (VCAM)-1, and the release of interstitial collagenase and stromelysin, IL-6 and IL-8, prostaglandin E2, or nitric oxide. We conclude that the presence of macrophages or IL-18R+ T cells that can respond directly to IL-18 is essential for the proinflammatory effects of IL-18 in synovitis in RA. Open Access: Published: 14 November 2001 © 2002 Möller et al., licensee BioMed Central Ltd (Print ISSN 1465-9905; Online ISSN 1465-9913)
Background: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is performed mainly in patients with high-risk or advanced hematologic malignancies and congenital or acquired aplastic anemias. In the context of the significant risk of graft failure after allo-HSCT from alternative donors and the risk of relapse in recipients transplanted for malignancy, the precise monitoring of posttransplant hematopoietic chimerism is of utmost interest. Useful molecular methods for chimerism quantification after allogeneic transplantation, aimed at distinguishing precisely between donor's and recipient's cells, are PCR-based analyses of polymorphic DNA markers. Such analyses can be performed regardless of donor's and recipient's sex. Additionally, in patients after sex-mismatched allo-HSCT, fluorescent in situ hybridization (FISH) can be applied. Methods: We compared different techniques for analysis of posttransplant chimerism, namely FISH and PCR-based molecular methods with automated detection of fluorescent products in an ALFExpress DNA Sequencer (Pharmacia) or ABI 310 Genetic Analyzer (PE). We used Spearman correlation test. Results: We have found high correlation between results obtained from the PCR/ALF Express and PCR/ABI 310 Genetic Analyzer. Lower, but still positive correlations were found between results of FISH technique and results obtained using automated DNA sizing technology. Conclusions: All the methods applied enable a rapid and accurate detection of post-HSCT chimerism.
Background: To investigate the occupational risk of tuberculosis (TB) infection in a low-incidence setting, data from a prospective study of patients with culture-confirmed TB conducted in Hamburg, Germany, from 1997 to 2002 were evaluated. Methods: M. tuberculosis isolates were genotyped by IS6110 RFLP analysis. Results of contact tracing and additional patient interviews were used for further epidemiological analyses. Results: Out of 848 cases included in the cluster analysis, 286 (33.7%) were classified into 76 clusters comprising 2 to 39 patients. In total, two patients in the non-cluster and eight patients in the cluster group were health-care workers. Logistic regression analysis confirmed work in the health-care sector as the strongest predictor for clustering (OR 17.9). However, only two of the eight transmission links among the eight clusters involving health-care workers had been detected previously. Overall, conventional contact tracing performed before genotyping had identified only 26 (25.2%) of the 103 contact persons with the disease among the clustered cases whose transmission links were epidemiologically verified. Conclusion: Recent transmission was found to be strongly associated with health-care work in a setting with low incidence of TB. Conventional contact tracing alone was shown to be insufficient to discover recent transmission chains. The data presented also indicate the need for establishing improved TB control strategies in health-care settings.
Introduction: ScFv(FRP5)-ETA is a recombinant antibody toxin with binding specificity for ErbB2 (HER2). It consists of an N-terminal single-chain antibody fragment (scFv), genetically linked to truncated Pseudomonas exotoxin A (ETA). Potent antitumoral activity of scFv(FRP5)-ETA against ErbB2-overexpressing tumor cells was previously demonstrated in vitro and in animal models. Here we report the first systemic application of scFv(FRP5)-ETA in human cancer patients.
Methods: We have performed a phase I dose-finding study, with the objective to assess the maximum tolerated dose and the dose-limiting toxicity of intravenously injected scFv(FRP5)-ETA. Eighteen patients suffering from ErbB2-expressing metastatic breast cancers, prostate cancers, head and neck cancer, non small cell lung cancer, or transitional cell carcinoma were treated. Dose levels of 2, 4, 10, 12.5, and 20 μg/kg scFv(FRP5)-ETA were administered as five daily infusions each for two consecutive weeks.
Results: No hematologic, renal, and/or cardiovascular toxicities were noted in any of the patients treated. However, transient elevation of liver enzymes was observed, and considered dose limiting, in one of six patients at the maximum tolerated dose of 12.5 μg/kg, and in two of three patients at 20 μg/kg. Fifteen minutes after injection, peak concentrations of more than 100 ng/ml scFv(FRP5)-ETA were obtained at a dose of 10 μg/kg, indicating that predicted therapeutic levels of the recombinant protein can be applied without inducing toxic side effects. Induction of antibodies against scFv(FRP5)-ETA was observed 8 days after initiation of therapy in 13 patients investigated, but only in five of these patients could neutralizing activity be detected. Two patients showed stable disease and in three patients clinical signs of activity in terms of signs and symptoms were observed (all treated at doses ≥ 10 μg/kg). Disease progression occurred in 11 of the patients.
Conclusion: Our results demonstrate that systemic therapy with scFv(FRP5)-ETA can be safely administered up to a maximum tolerated dose of 12.5 μg/kg in patients with ErbB2-expressing tumors, justifying further clinical development.
Dendritic cells (DC) are known to present exogenous protein Ag effectively to T cells. In this study we sought to identify the proteases that DC employ during antigen processing. The murine epidermal-derived DC line Xs52, when pulsed with PPD, optimally activated the PPD-reactive Th1 clone LNC.2F1 as well as the Th2 clone LNC.4k1, and this activation was completely blocked by chloroquine pretreatment. These results validate the capacity of XS52 DC to digest PPD into immunogenic peptides inducing antigen specific T cell immune responses. XS52 DC, as well as splenic DC and DCs derived from bone marrow degraded standard substrates for cathepsins B, C, D/E, H, J, and L, tryptase, and chymases, indicating that DC express a variety of protease activities. Treatment of XS52 DC with pepstatin A, an inhibitor of aspartic acid proteases, completely abrogated their capacity to present native PPD, but not trypsin-digested PPD fragments to Th1 and Th2 cell clones. Pepstatin A also inhibited cathepsin D/E activity selectively among the XS52 DC-associated protease activities. On the other hand, inhibitors of serine proteases (dichloroisocoumarin, DCI) or of cystein proteases (E-64) did not impair XS52 DC presentation of PPD, nor did they inhibit cathepsin D/E activity. Finally, all tested DC populations (XS52 DC, splenic DC, and bone marrow-derived DC) constitutively expressed cathepsin D mRNA. These results suggest that DC primarily employ cathepsin D (and perhaps E) to digest PPD into antigenic peptides.
Background: The neurophysiological and neuroanatomical foundations of persistent developmental stuttering (PDS) are still a matter of dispute. A main argument is that stutterers show atypical anatomical asymmetries of speech-relevant brain areas, which possibly affect speech fluency. The major aim of this study was to determine whether adults with PDS have anomalous anatomy in cortical speech-language areas. Methods: Adults with PDS (n = 10) and controls (n = 10) matched for age, sex, hand preference, and education were studied using high-resolution MRI scans. Using a new variant of the voxel-based morphometry technique (augmented VBM) the brains of stutterers and non-stutterers were compared with respect to white matter (WM) and grey matter (GM) differences. Results: We found increased WM volumes in a right-hemispheric network comprising the superior temporal gyrus (including the planum temporale), the inferior frontal gyrus (including the pars triangularis), the precentral gyrus in the vicinity of the face and mouth representation, and the anterior middle frontal gyrus. In addition, we detected a leftward WM asymmetry in the auditory cortex in non-stutterers, while stutterers showed symmetric WM volumes. Conclusions: These results provide strong evidence that adults with PDS have anomalous anatomy not only in perisylvian speech and language areas but also in prefrontal and sensorimotor areas. Whether this atypical asymmetry of WM is the cause or the consequence of stuttering is still an unanswered question. This article is available from: http://www.biomedcentral.com/1471-2377/4/23 © 2004 Jäncke et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
First paragraph (this article has no abstract) Persistent stimulation of nociceptors results in sensitization of nociceptive sensory neurons, which is associated with hyperalgesia and allodynia. The release of NO and subsequent synthesis of cGMP in the spinal cord are involved in this process. cGMP-dependent protein kinase I (PKG-I) has been suggested to act as a downstream target of cGMP, but its exact role in nociception hadn't been characterized yet. To further evaluate the NO/cGMP/PKG-I pathway in nociception we assessed the effects of PKG-I inhibiton and activaton in the rat formalin assay and analyzed the nociceptive behavior of PKG-I-/- mice. Open access article.
Background: Tumor development remains one of the major obstacles following organ transplantation. Immunosuppressive drugs such as cyclosporine and tacrolimus directly contribute to enhanced malignancy, whereas the influence of the novel compound mycophenolate mofetil (MMF) on tumor cell dissemination has not been explored. We therefore investigated the adhesion capacity of colon, pancreas, prostate and kidney carcinoma cell lines to endothelium, as well as their beta1 integrin expression profile before and after MMF treatment. Methods: Tumor cell adhesion to endothelial cell monolayers was evaluated in the presence of 0.1 and 1 μM MMF and compared to unstimulated controls. beta1 integrin analysis included alpha1beta1 (CD49a), alpha2beta1 (CD49b), alpha3beta1 (CD49c), alpha4beta1 (CD49d), alpha5beta1 (CD49e), and alpha6beta1 (CD49f) receptors, and was carried out by reverse transcriptase-polymerase chain reaction, confocal microscopy and flow cytometry. Results: Adhesion of the colon carcinoma cell line HT-29 was strongly reduced in the presence of 0.1 μM MMF. This effect was accompanied by down-regulation of alpha3beta1 and alpha6beta1 surface expression and of alpha3beta1 and alpha6beta1 coding mRNA. Adhesion of the prostate tumor cell line DU-145 was blocked dose-dependently by MMF. In contrast to MMF's effects on HT-29 cells, MMF dose-dependently up-regulated alpha1beta1, alpha2beta1, alpha3beta1, and alpha5beta1 on DU-145 tumor cell membranes. Conclusion: We conclude that MMF possesses distinct anti-tumoral properties, particularly in colon and prostate carcinoma cells. Adhesion blockage of HT-29 cells was due to the loss of alpha3beta1 and alpha6beta1 surface expression, which might contribute to a reduced invasive behaviour of this tumor entity. The enhancement of integrin beta1 subtypes observed in DU-145 cells possibly causes re-differentiation towards a low-invasive phenotype.
Introduction: This open label, multicentre study was conducted to assess the times to offset of the pharmacodynamic effects and the safety of remifentanil in patients with varying degrees of renal impairment requiring intensive care.
Methods: A total of 40 patients, who were aged 18 years or older and had normal/mildly impaired renal function (estimated creatinine clearance ≥ 50 ml/min; n = 10) or moderate/severe renal impairment (estimated creatinine clearance <50 ml/min; n = 30), were entered into the study. Remifentanil was infused for up to 72 hours (initial rate 6–9 μg/kg per hour), with propofol administered if required, to achieve a target Sedation–Agitation Scale score of 2–4, with no or mild pain.
Results: There was no evidence of increased offset time with increased duration of exposure to remifentanil in either group. The time to offset of the effects of remifentanil (at 8, 24, 48 and 72 hours during scheduled down-titrations of the infusion) were more variable and were statistically significantly longer in the moderate/severe group than in the normal/mild group at 24 hours and 72 hours. These observed differences were not clinically significant (the difference in mean offset at 72 hours was only 16.5 min). Propofol consumption was lower with the remifentanil based technique than with hypnotic based sedative techniques. There were no statistically significant differences between the renal function groups in the incidence of adverse events, and no deaths were attributable to remifentanil use.
Conclusion: Remifentanil was well tolerated, and the offset of pharmacodynamic effects was not prolonged either as a result of renal dysfunction or prolonged infusion up to 72 hours.
Western cultures have witnessed a tremendous cultural and social transformation of sexuality in the years since the sexual revolution. Apart from a few public debates and scandals, the process has moved along gradually and quietly. Yet its real and symbolic effects are probably much more consequential than those generated by the sexual revolution of the sixties. Sigusch refers to the broad-based recoding and reassessment of the sexual sphere during the eighties and nineties as the "neosexual revolution". The neosexual revolution is dismantling the old patterns of sexuality and reassembling them anew. In the process, dimensions, intimate relationships, preferences and sexual fragments emerge, many of which had submerged, were unnamed or simply did not exist before. In general, sexuality has lost much of its symbolic meaning as a cultural phenomenon. Sexuality is no longer the great metaphor for pleasure and happiness, nor is it so greatly overestimated as it was during the sexual revolution. It is now widely taken for granted, much like egotism or motility. Whereas sex was once mystified in a positive sense - as ecstasy and transgression, it has now taken on a negative mystification characterized by abuse, violence and deadly infection. While the old sexuality was based primarily upon sexual instinct, orgasm and the heterosexual couple, neosexualities revolve predominantly around gender difference, thrills, self-gratification and prosthetic substitution. From the vast number of interrelated processes from which neosexualities emerge, three empirically observable phenomena have been selected for discussion here: the dissociation of the sexual sphere, the dispersion of sexual fragments and the diversification of intimate relationships. The outcome of the neosexual revolution may be described as "lean sexuality" and "self-sex".
E-Learning soll im Rahmen der allgemeinmedizinischen Ausbildung von Medizinstudierenden erprobt werden. Ein zielgruppenspezifisches, multimodulares Online-Angebot begleitet Medizinstudenten des 10. Semesters während ihres dezentralen Praktikums in hausärztlichen Praxen. Folgende Lehrziele werden angestrebt: (1) Einführung in das E-Learning, (2) Klinische Allgemeinmedizin - Online-Modul, (3) Chronic Care Online-Modul, (4) Online-Bewerbung. Die systematische Evaluation zeigt, dass E-Learning die Kommunikation der Studierenden untereinander und mit der universitären Lehreinheit während des Praktikum fördert. Auf der Grundlage der in diesem Pilotversuch gewonnenen Erfahrungen erscheint die Kombination mit Präsenzunterricht (Blended Learning) eine vielversprechende Option für die allgemeinmedizinische Ausbildung zu sein.