Wie sekundäre Pflanzeninhaltsstoffe uns vor Krankheiten schützen : von molekularen Wirkmechanismen zu neuen Medikamenten
Jürgen M. Stein
- Wirkungen von Heilpflanzen, Gewürzen, Tees und Lebensmitteln werden in der Naturheilkunde seit der Antike genutzt. Pharmakologisch wirksam sind in der Regel nur die sekundären Pflanzeninhaltsstoffe. Diese in den oft aus vielen Bestandteilen zusammengesetzten Naturstoffen aufzuspüren und ihren molekularbiologischen Wirkungsmechanismus im Körper aufzuklären, ist das Ziel eines Forschungsnetzwerks am Frankfurter ZAFES (Zentrum für Arzneimittelforschung, -Entwicklung und -Sicherheit). So konnten Pharmazeuten und Kliniker gemeinsam herausfinden, wie ein Bestandteil des Rotweins, das Resveratrol, vor Darmkrebs schützt. Die Inhaltsstoffe von Salbei und Rosmarin bieten vielversprechende Ausgangspunkte für neue Medikamente gegen Altersdiabetes. Weihrauch, Myrte und Johanniskraut enthalten Wirkstoffe, die Schlüsselenzyme für Entzündungsreaktionen – etwa bei rheumatischen Beschwerden – hemmen.
Targeting cyclin B1 inhibits proliferation and sensitizes breast cancer cells to taxol
- Background Cyclin B1, the regulatory subunit of cyclin-dependent kinase 1 (Cdk1), is essential for the transition from G2 phase to mitosis. Cyclin B1 is very often found to be overexpressed in primary breast and cervical cancer cells as well as in cancer cell lines. Its expression is correlated with the malignancy of gynecological cancers. Methods In order to explore cyclin B1 as a potential target for gynecological cancer therapy, we studied the effect of small interfering RNA (siRNA) on different gynecological cancer cell lines by monitoring their proliferation rate, cell cycle profile, protein expression and activity, apoptosis induction and colony formation. Tumor formation in vivo was examined using mouse xenograft models. Results Downregulation of cyclin B1 inhibited proliferation of several breast and cervical cancer cell lines including MCF-7, BT-474, SK-BR-3, MDA-MB-231 and HeLa. After combining cyclin B1 siRNA with taxol, we observed an increased apoptotic rate accompanied by an enhanced antiproliferative effect in breast cancer cells. Furthermore, control HeLa cells were progressively growing, whereas the tumor growth of HeLa cells pre-treated with cyclin B1 siRNA was strongly inhibited in nude mice, indicating that cyclin B1 is indispensable for tumor growth in vivo. Conclusion Our data support the notion of cyclin B1 being essential for survival and proliferation of gynecological cancer cells. Concordantly, knockdown of cyclin B1 inhibits proliferation in vitro as well as in vivo. Moreover, targeting cyclin B1 sensitizes breast cancer cells to taxol, suggesting that specific cyclin B1 targeting is an attractive strategy for the combination with conventionally used agents in gynecological cancer therapy.
"Die Menschheit der Gegenwart ist eine vorzugsweise nervöse geworden" : Heinrich Hoffmann und das Frankfurter "Irrenschloss"
Permanent biventricular ICD-implantation in a heart failure second re-do-CABG patient : a case report
- Biventricular pacing has been suggested in end-stage heart failure. We present a 59-year-old patient undergoing second re-do CABG (coronary artery bypass graft) and carotid artery endarterectomy. Ejection fraction was 15%, QRS-width 175 ms. Following the carotid and CABG procedure, an implanted single-chamber ICD (implantable cardioverter defibrillator) was upgraded to permanent biventricular DDD pacing by implantation of one epicardial left ventricular and one epicardial atrial electrode. At follow-up two months postoperatively ejection fraction had significantly improved to 45%, the patient underwent stress test with adequate load and reported a good quality of life.
HCV-related burden of disease in Europe : a systematic assessment of incidence, prevalence, morbidity, and mortality
- Background Hepatitis C virus (HCV) is a leading cause of chronic liver disease, end-stage cirrhosis, and liver cancer, but little is known about the burden of disease caused by the virus. We summarised burden of disease data presently available for Europe, compared the data to current expert estimates, and identified areas in which better data are needed. Methods Literature and international health databases were systematically searched for HCV-specific burden of disease data, including incidence, prevalence, mortality, disability-adjusted life-years (DALYs), and liver transplantation. Data were collected for the WHO European region with emphasis on 22 countries. If HCV-specific data were unavailable, these were calculated via HCV-attributable fractions. Results HCV-specific burden of disease data for Europe are scarce. Incidence data provided by national surveillance are not fully comparable and need to be standardised. HCV prevalence data are often inconclusive. According to available data, an estimated 7.3–8.8 million people (1.1–1.3%) are infected in our 22 focus countries. HCV-specific mortality, DALY, and transplantation data are unavailable. Estimations via HCV-attributable fractions indicate that HCV caused more than 86000 deaths and 1.2 million DALYs in the WHO European region in 2002. Most of the DALYs (95%) were accumulated by patients in preventable disease stages. About one-quarter of the liver transplants performed in 25 European countries in 2004 were attributable to HCV. Conclusion Our results indicate that hepatitis C is a major health problem and highlight the importance of timely antiviral treatment. However, data on the burden of disease of hepatitis C in Europe are scarce, outdated or inconclusive, which indicates that hepatitis C is still a neglected disease in many countries. What is needed are public awareness, co-ordinated action plans, and better data. European physicians should be aware that many infections are still undetected, provide timely testing and antiviral treatment, and avoid iatrogenic transmission.
Quality management: reduction of waiting time and efficiency enhancement in an ENT-university outpatients' department
Heike Anette Kahla-Witzsch
- Background Public health systems are confronted with constantly rising costs. Furthermore, diagnostic as well as treatment services become more and more specialized. These are the reasons for an interdisciplinary project on the one hand aiming at simplification of planning and scheduling patient appointments, on the other hand at fulfilling all requirements of efficiency and treatment quality. Methods As to understanding procedure and problem solving activities, the responsible project group strictly proceeded with four methodical steps: actual state analysis, analysis of causes, correcting measures, and examination of effectiveness. Various methods of quality management, as for instance opinion polls, data collections, and several procedures of problem identification as well as of solution proposals were applied. All activities were realized according to the requirements of the clinic's ISO 9001:2000 certified quality management system. The development of this project is described step by step from planning phase to inauguration into the daily routine of the clinic and subsequent control of effectiveness. Results Five significant problem fields could be identified. After an analysis of causes the major remedial measures were: installation of a patient telephone hotline, standardization of appointment arrangements for all patients, modification of the appointments book considering the reason for coming in planning defined working periods for certain symptoms and treatments, improvement of telephonic counselling, and transition to flexible time planning by daily updates of the appointments book. After implementation of these changes into the clinic's routine success could be demonstrated by significantly reduced waiting times and resulting increased patient satisfaction. Conclusion Systematic scrutiny of the existing organizational structures of the outpatients' department of our clinic by means of actual state analysis and analysis of causes revealed the necessity of improvement. According to rules of quality management correcting measures and subsequent examination of effectiveness were performed. These changes resulted in higher satisfaction of patients, referring colleagues and clinic staff the like. Additionally the clinic is able to cope with an increasing demand for appointments in outpatients' departments, and the clinic's human resources are employed more effectively.
Job stress and job satisfaction of physicians, radiographers, nurses and physicists working in radiotherapy : a multicenter analysis by the DEGRO Quality of Life Work Group
Hans Joachim Wypior
- Background Ongoing changes in cancer care cause an increase in the complexity of cases which is characterized by modern treatment techniques and a higher demand for patient information about the underlying disease and therapeutic options. At the same time, the restructuring of health services and reduced funding have led to the downsizing of hospital care services. These trends strongly influence the workplace environment and are a potential source of stress and burnout among professionals working in radiotherapy. Methods and patients A postal survey was sent to members of the workgroup "Quality of Life" which is part of DEGRO (German Society for Radiooncology). Thus far, 11 departments have answered the survey. 406 (76.1%) out of 534 cancer care workers (23% physicians, 35% radiographers, 31% nurses, 11% physicists) from 8 university hospitals and 3 general hospitals completed the FBAS form (Stress Questionnaire of Physicians and Nurses; 42 items, 7 scales), and a self-designed questionnaire regarding work situation and one question on global job satisfaction. Furthermore, the participants could make voluntary suggestions about how to improve their situation. Results Nurses and physicians showed the highest level of job stress (total score 2.2 and 2.1). The greatest source of job stress (physicians, nurses and radiographers) stemmed from structural conditions (e.g. underpayment, ringing of the telephone) a "stress by compassion" (e.g. "long suffering of patients", "patients will be kept alive using all available resources against the conviction of staff"). In multivariate analyses professional group (p < 0.001), working night shifts (p = 0.001), age group (p = 0.012) and free time compensation (p = 0.024) gained significance for total FBAS score. Global job satisfaction was 4.1 on a 9-point scale (from 1 – very satisfied to 9 – not satisfied). Comparing the total stress scores of the hospitals and job groups we found significant differences in nurses (p = 0.005) and physicists (p = 0.042) and a borderline significance in physicians (p = 0.052). In multivariate analyses "professional group" (p = 0.006) and "vocational experience" (p = 0.036) were associated with job satisfaction (cancer care workers with < 2 years of vocational experience having a higher global job satisfaction). The total FBAS score correlated with job satisfaction (Spearman-Rho = 0.40; p < 0.001). Conclusion Current workplace environments have a negative impact on stress levels and the satisfaction of radiotherapy staff. Identification and removal of the above-mentioned critical points requires various changes which should lead to the reduction of stress.
Mitochondrial TERT enhances mitochondria functions in vivo by protecting mitochondrial DNA integrity from oxidative damage : meeting abstract
- Mitochondria are essential for respiration and oxidative phosphorylation. Mitochondrial dysfunction due to aging processes is involved in pathologies and pathogenesis of a series of cardiovascular disorders. New results accumulate showing that the enzyme telomerase with its catalytic subunit telomerase reverse transcriptase (TERT) has a beneficial effect on heart functions. The benefit of short-term running of mice for heart function is dependent on TERT expression. TERT can translocate into the mitochondria and mitochondrial TERT (mtTERT) is protective against stress induced stimuli and binds to mitochondrial DNA (mtDNA). Because mtDNA is highly susceptible to damage produced by reactive oxygen species (ROS) which are generated in close proximity to the respiratory chain, the aim of this study was to determine the functions of mtTERT in vivo and in vitro. Therefore, mitochondria from hearts of adult, 2nd generation TERT-deficient mice (TERT -/-) and wt littermates were isolated and state 3 respiration was measured. Strikingly mitochondria from TERT -/- revealed a significantly lower state 3 respiration (TERTwt: 987 +/- 72 pmol/s*mg vs. TERT-/-: 774 +/- 38 pmol/s*mg, p < 0.05, n = 5). These results demonstrated that TERT -/- mice have a so far undiscovered heart phenotype. In contrast mitochondria isolated from liver tissues did not show any differences. To get further insights in the molecular mechanisms, we reduced endogenous TERT levels by shRNA and measured mitochondrial reactive oxygen species (mtROS). mtROS were increased after ablation of TERT (scrambled: 4.98 +/- 1.1% gated vs. shTERT: 2.03 +/- 0.7% gated, p < 0.05, n = 4). We next determined mtDNA deletions, which are caused by mtROS. Semiquantitative realtime PCR of mtDNA deletions revealed that mtTERT protects mtDNA from oxidative damage. To analyze whether mitochondrial integrity is required to protect from apoptosis, vectors with mitochondrially targeted TERT (mitoTERT) and wildtype TERT (wtTERT) were transfected and apoptosis was measured. mitoTERT showed the most prominent protective effect on H2O2 induced apoptosis. In conclusion, mtTERT has a protective role in mitochondria by importantly contributing to mtDNA integrity and thereby enhancing respiration capacity of the heart.
T-cell metagene predicts a favorable prognosis in estrogen receptor-negative and HER2-positive breast cancers
- Introduction Lymphocyte infiltration (LI) is often seen in breast cancer but its importance remains controversial. A positive correlation of human epidermal growth factor receptor 2 (HER2) amplification and LI has been described, which was associated with a more favorable outcome. However, specific lymphocytes might also promote tumor progression by shifting the cytokine milieu in the tumor. Methods Affymetrix HG-U133A microarray data of 1,781 primary breast cancer samples from 12 datasets were included. The correlation of immune system-related metagenes with different immune cells, clinical parameters, and survival was analyzed. Results A large cluster of nearly 600 genes with functions in immune cells was consistently obtained in all datasets. Seven robust metagenes from this cluster can act as surrogate markers for the amount of different immune cell types in the breast cancer sample. An IgG metagene as a marker for B cells had no significant prognostic value. In contrast, a strong positive prognostic value for the T-cell surrogate marker (lymphocyte-specific kinase (LCK) metagene) was observed among all estrogen receptor (ER)-negative tumors and those ER-positive tumors with a HER2 overexpression. Moreover ER-negative tumors with high expression of both IgG and LCK metagenes seem to respond better to neoadjuvant chemotherapy. Conclusions Precise definitions of the specific subtypes of immune cells in the tumor can be accomplished from microarray data. These surrogate markers define subgroups of tumors with different prognosis. Importantly, all known prognostic gene signatures uniformly assign poor prognosis to all ER-negative tumors. In contrast, the LCK metagene actually separates the ER-negative group into better or worse prognosis.
The effect of the dual Src/Abl kinase inhibitor AZD0530 on Philadelphia positive leukaemia cell lines
Patricia Mambou Gwanmesia
Oliver Gerhard Ottmann
- Background Imatinib mesylate, a selective inhibitor of Abl tyrosine kinase, is efficacious in treating chronic myeloid leukaemia (CML) and Ph+ acute lymphoblastic leukaemia (ALL). However, most advanced-phase CML and Ph+ ALL patients relapse on Imatinib therapy. Several mechanisms of refractoriness have been reported, including the activation of the Src-family kinases (SFK). Here, we investigated the biological effect of the new specific dual Src/Abl kinase inhibitor AZD0530 on Ph+ leukaemic cells. Methods Cell lines used included BV173 (CML in myeloid blast crisis), SEM t(4;11), Ba/F3 (IL-3 dependent murine pro B), p185Bcr-Abl infected Ba/F3 cells, p185Bcr-Abl mutant infected Ba/F3 cells, SupB15 (Ph+ ALL) and Imatinib resistant SupB15 (RTSupB15) (Ph+ ALL) cells. Cells were exposed to AZD0530 and Imatinib. Cell proliferation, apoptosis, survival and signalling pathways were assessed by dye exclusion, flow cytometry and Western blotting respectively. Results AZD0530 specifically inhibited the growth of, and induced apoptosis in CML and Ph+ ALL cells in a dose dependent manner, but showed only marginal effects on Ph- ALL cells. Resistance to Imatinib due to the mutation Y253F in p185Bcr-Abl was overcome by AZD0530. Combination of AZD0530 and Imatinib showed an additive inhibitory effect on the proliferation of CML BV173 cells but not on Ph+ ALL SupB15 cells. An ongoing transphosphorylation was demonstrated between SFKs and Bcr-Abl. AZD0530 significantly down-regulated the activation of survival signalling pathways in Ph+ cells, resistant or sensitive to Imatinib, with the exception of the RTSupB15. Conclusion Our results indicate that AZD0530 targets both Src and Bcr-Abl kinase activity and reduces the leukaemic maintenance by Bcr-Abl.