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Background: Even in the presence of oxygen, malignant cells often highly depend on glycolysis for energy generation, a phenomenon known as the Warburg effect. One strategy targeting this metabolic phenotype is glucose restriction by administration of a high-fat, low-carbohydrate (ketogenic) diet. Under these conditions, ketone bodies are generated serving as an important energy source at least for non-transformed cells. Methods: To investigate whether a ketogenic diet might selectively impair energy metabolism in tumor cells, we characterized in vitro effects of the principle ketone body 3-hydroxybutyrate in rat hippocampal neurons and five glioma cell lines. In vivo, a non-calorie-restricted ketogenic diet was examined in an orthotopic xenograft glioma mouse model. Results: The ketone body metabolizing enzymes 3-hydroxybutyrate dehydrogenase 1 and 2 (BDH1 and 2), 3-oxoacid-CoA transferase 1 (OXCT1) and acetyl-CoA acetyltransferase 1 (ACAT1) were expressed at the mRNA and protein level in all glioma cell lines. However, no activation of the hypoxia-inducible factor-1alpha (HIF-1alpha) pathway was observed in glioma cells, consistent with the absence of substantial 3-hydroxybutyrate metabolism and subsequent accumulation of succinate. Further, 3-hydroxybutyrate rescued hippocampal neurons from glucose withdrawal-induced cell death but did not protect glioma cell lines. In hypoxia, mRNA expression of OXCT1, ACAT1, BDH1 and 2 was downregulated. In vivo, the ketogenic diet led to a robust increase of blood 3-hydroxybutyrate, but did not alter blood glucose levels or improve survival. Conclusion: In summary, glioma cells are incapable of compensating for glucose restriction by metabolizing ketone bodies in vitro, suggesting a potential disadvantage of tumor cells compared to normal cells under a carbohydrate-restricted ketogenic diet. Further investigations are necessary to identify co-treatment modalities, e.g. glycolysis inhibitors or antiangiogenic agents that efficiently target non-oxidative pathways.
Seroconversion rates following influenza vaccination in patients with hematologic malignancies after hematopoietic stem cell transplantation (HSCT) are known to be lower compared to healthy adults. The aim of our diagnostic study was to determine the rate of seroconversion after 1 or 2 doses of a novel split virion, inactivated, AS03-adjuvanted pandemic H1N1 influenza vaccine (A/California/7/2009) in HSCT recipients (ClinicalTrials.gov Identifier: NCT01017172). Blood samples were taken before and 21 days after a first dose and 21 days after a second dose of the vaccine. Antibody (AB) titers were determined by hemagglutination inhibition assay. Seroconversion was defined by either an AB titer of ≤1:10 before and ≥1:40 after or ≥1:10 before and ≥4-fold increase in AB titer 21 days after vaccination. Seventeen patients (14 allogeneic, 3 autologous HSCT) received 1 dose and 11 of these patients 2 doses of the vaccine. The rate of seroconversion was 41.2% (95% confidence interval [CI] 18.4-67.1) after the first and 81.8% (95% CI 48.2-97.7) after the second dose. Patients who failed to seroconvert after 1 dose of the vaccine were more likely to receive any immunosuppressive agent (P = .003), but time elapsed after or type of HSCT, age, sex, or chronic graft-versus-host disease was not different when compared to patients with seroconversion. In patients with hematologic malignancies after HSCT the rate of seroconversion after a first dose of an adjuvanted H1N1 influenza A vaccine was poor, but increased after a second dose.
Background: Although being considered as a rarely observed HIV-1 protease mutation in clinical isolates, the L76V-prevalence increased 1998-2008 in some European countries most likely due to the approval of Lopinavir, Amprenavir and Darunavir which can select L76V. Beside an enhancement of resistance, L76V is also discussed to confer hypersusceptibility to the drugs Atazanavir and Saquinavir which might enable new treatment strategies by trying to take advantage of particular mutations. Results: Based on a cohort of 47 L76V-positive patients, we examined if there might exist a clinical advantage for L76V-positive patients concerning long-term success of PI-containing regimens in patients with limited therapy options. Genotypic- and phenotypic HIV-resistance tests from 47 mostly multi-resistant, L76V-positive patients throughout Germany were accomplished retrospectively 1999-2009. Five genotype-based drug-susceptibility predictions received from online interpretation-tools for Atazanavir, Saquinavir, Amprenavir and Lopinavir, were compared to phenotype-based predictions that were determined by using a recombinant virus assay along with a Virtual Phenotype™(Virco). The clinical outcome of the L76V-adapted follow-up therapy was determined by monitoring viral load for 96 weeks. Conclusions: In this analysis, the mostly used interpretation systems overestimated the L76V-mutation concerning Atazanavir- and SQV resistance. In fact, a clear benefit in drug susceptibility for these drugs was observed in phenotype analysis after establishment of L76V. More importantly, long-term therapy success was significantly higher in patients receiving Atazanavir and/or Saquinavir plus one L76V-selecting drug compared to patients without L76V-selecting agents (p = 0.002). In case of L76V-occurrence ATV and/or SQV may represent encouraging options for patients in deep salvage situations.
High attrition rates of novel anti-cancer drugs highlight the need for improved models to predict toxicity. Although polo-like kinase 1 (Plk1) inhibitors are attractive candidates for drug development, the role of Plk1 in primary cells remains widely unexplored. Therefore, we evaluated the utility of an RNA interference-based model to assess responses to an inducible knockdown (iKD) of Plk1 in adult mice. Here we show that Plk1 silencing can be achieved in several organs, although adverse events are rare. We compared responses in Plk1-iKD mice with those in primary cells kept under controlled culture conditions. In contrast to the addiction of many cancer cell lines to the non-oncogene Plk1, the primary cells' proliferation, spindle assembly and apoptosis exhibit only a low dependency on Plk1. Responses to Plk1-depletion, both in cultured primary cells and in our iKD-mouse model, correspond well and thus provide the basis for using validated iKD mice in predicting responses to therapeutic interventions.
Although essential for T cell function, the identity of the T cell receptor (TCR) “inside-out” pathway for the activation of lymphocyte function-associated antigen 1 (LFA-1) is unclear. SKAP1 (SKAP-55) is the upstream regulator needed for TCR-induced RapL-Rap1 complex formation and LFA-1 activation. In this paper, we show that SKAP1 is needed for RapL binding to membranes in a manner dependent on the PH domain of SKAP1 and the PI3K pathway. A SKAP1 PH domain-inactivating mutation (i.e. R131M) markedly impaired RapL translocation to membranes for Rap1 and LFA-1 binding and the up-regulation of LFA-1-intercellular adhesion molecule 1 (ICAM-1) binding. Further, N-terminal myr-tagged SKAP1 for membrane binding facilitated constitutive RapL membrane and Rap1 binding and effectively substituted for PI3K and TCR ligation in the activation of LFA-1 in T cells.
Event-related potential (ERP) data in monolingual German speakers have shown that sentential metric expectancy violations elicit a biphasic ERP pattern consisting of an anterior negativity and a posterior positivity (P600). This pattern is comparable to that elicited by syntactic violations. However, proficient French late learners of German do not detect violations of metric expectancy in German. They also show qualitatively and quantitatively different ERP responses to metric and syntactic violations. We followed up the questions whether (1) latter evidence results from a potential pitch cue insensitivity in speech segmentation in French speakers, or (2) if the result is founded in rhythmic language differences. Therefore, we tested Spanish late learners of German, as Spanish, contrary to French, uses pitch as a segmentation cue even though the basic segmentation unit is the same in French and Spanish (i.e., the syllable). We report ERP responses showing that Spanish L2 learners are sensitive to syntactic as well as metric violations in German sentences independent of attention to task in a P600 response. Overall, the behavioral performance resembles that of German native speakers. The current data suggest that Spanish L2 learners are able to extract metric units (trochee) in their L2 (German) even though their basic segmentation unit in Spanish is the syllable. In addition Spanish in contrast to French L2 learners of German are sensitive to syntactic violations indicating a tight link between syntactic and metric competence. This finding emphasizes the relevant role of metric cues not only in L2 prosodic but also in syntactic processing.
Zum virologischen Nachweis einer akuten Influenza und zur Überprüfung des Immunstatus steht eine Vielzahl von Untersuchungsmethoden zur Verfügung. Bei Verdacht auf eine Influenzavirusinfektion liefert der Rachenabstrich das geeignete Untersuchungsmaterial. Das tiefe Nasopharynxaspirat ist etwas sensitiver, Sputum etwas weniger ergiebig. Die RT-PCR ermöglicht in 1–2 h nach Materialeingang ein sensitives und spezifisches Ergebnis. Typen, Subtypen und Driftvarianten lassen sich durch geeignete Primersonden, die kommerziell zur Verfügung stehen, einwandfrei identifizieren. Demgegenüber ist die Zellkultur-gestützte Virusisolierung zeitaufwendiger und stärker abhängig von einer sachgerechten Materialgewinnung und –überbringung (Kühlkette). PCR und Virusanzüchtung ermöglichen die geno- bzw. phänotypische Testung auf Therapieresistenzen. Der Antigentest ist eine einfache (bed-side) Schnellmethode. Seine Spezifität ist gut, die Sensitivität limitiert; daher kann der Antigentest nicht zur individuellen Ausschlussdiagnose eingesetzt werden. Influenzavirusspezifische Antikörper erscheinen im Blut erst in der zweiten Krankheitswoche. Die Serodiagnostik erfolgt typenspezifisch mit Komplementbindungsreaktion (KBR), IFT und ELISA über eine signifikante Titerbewegung oder den Nachweis von IgA-Antikörpern. IgG-spezifische IFT und ELISA Methoden geben Auskunft über die Influenzavirus-typspezifische Durchseuchung. Die klinisch relevantere subtypen- und variantenspezifische Influenzavirusimmunität wird mit dem HHT oder NT gemessen.
Die Labordiagnose einer Infektionskrankheit beruht auf dem Nachweis des Infektionserregers oder der spezifischen Immunreaktion unter Berücksichtigung der klinischen Plausibilität. Biologische Testverfahren wie der Zellkulturversuch erbringen nur näherungsweise ein quantitatives Ergebnis und sind mit einer relativ großen Streuung behaftet. Das gilt auch für Antikörperassays, soweit sie über ein biologisches Testsignal abgelesen werden (CPE, Agglutination, Komplementverbrauch). Moderne serologische und molekularbiologische Untersuchungsmethoden der Virologie werden i. d. R. über ein physikochemisches Testssignal abgelesen und quantitativ ausgewertet. Dadurch gelingt die nationale und internationale Standardisierung, die sich in Ringversuchen gut überprüfen lässt. Aus biologischen Gründen ist meist eine log. Ergebnisberechnung angezeigt, was für „ signifikante “ Unterschiede in Verlaufsuntersuchungen zu berücksichtigen ist: Da sowohl Infektion als auch Immunreaktion dynamische Prozesse darstellen, können Normalwerte in der virologischen Labordiagnostik nur restriktiv definiert werden. Ihre Ergebnisse sind mehr oder minder individuell interpretationsbedürftig.
Background: Patients with cancer have an increased risk of VTE. We compared VTE rates and bleeding complications in 1) cancer patients receiving LMWH or UFH and 2) patients with or without cancer.
Patients with cancer have an increased risk of VTE. We compared VTE rates and bleeding complications in 1) cancer patients receiving LMWH or UFH and 2) patients with or without cancer.
Methods: Acutely-ill, non-surgical patients ≥70 years with (n = 274) or without cancer (n = 2,965) received certoparin 3,000 UaXa o.d. or UFH 5,000 IU t.i.d. for 8-20 days.
Results: 1) Thromboembolic events in cancer patients (proximal DVT, symptomatic non-fatal PE and VTE-related death) occurred at 4.50% with certoparin and 6.03% with UFH (OR 0.73; 95% CI 0.23-2.39). Major bleeding was comparable and minor bleedings (0.75 vs. 5.67%) were nominally less frequent. 7.5% of certoparin and 12.8% of UFH treated patients experienced serious adverse events. 2) Thromboembolic event rates were comparable in patients with or without cancer (5.29 vs. 4.13%) as were bleeding complications. All cause death was increased in cancer (OR 2.68; 95%CI 1.22-5.86). 10.2% of patients with and 5.81% of those without cancer experienced serious adverse events (OR 1.85; 95% CI 1.21-2.81).
Conclusions: Certoparin 3,000 UaXa o.d. and 5,000 IU UFH t.i.d. were equally effective and safe with respect to bleeding complications in patients with cancer. There were no statistically significant differences in the risk of thromboembolic events in patients with or without cancer receiving adequate anticoagulation.
Trial Registration: clinicaltrials.gov, NCT00451412
We searched for a drug capable of sensitization of sarcoma cells to doxorubicin (DOX). We report that the dual PI3K/mTOR inhibitor PI103 enhances the efficacy of DOX in several sarcoma cell lines and interacts with DOX in the induction of apoptosis. PI103 decreased the expression of MDR1 and MRP1, which resulted in DOX accumulation. However, the enhancement of DOX-induced apoptosis was unrelated to DOX accumulation. Neither did it involve inhibition of mTOR. Instead, the combination treatment of DOX plus PI103 activated Bax, the mitochondrial apoptosis pathway, and caspase 3. Caspase 3 activation was also observed in xenografts of sarcoma cells in nude mice upon combination of DOX with the specific PI3K inhibitor GDC-0941. Although the increase in apoptosis did not further impact on tumor growth when compared to the efficient growth inhibition by GDC-0941 alone, these findings suggest that inhibition of PI3K may improve DOX-induced proapoptotic effects in sarcoma. Taken together with similar recent studies of neuroblastoma- and glioblastoma-derived cells, PI3K inhibition seems to be a more general option to sensitize tumor cells to anthracyclines.