226 research outputs found

    Quercetin elevates p27Kip1 and arrests both primary and HPV16 E6/E7 transformed human keratinocytes in G1

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    Our previous work with primary bovine fibroblasts demonstrated that quercetin, a potent mutagen found in high levels in bracken fern (Pteridium aquilinum), arrested cells in G1 and G2/M, in correlation with p53 activation. The expression of bovine papillomavirus type 4 (BPV-4) E7 overcame this arrest and lead to the development of tumorigenic cells lines (Beniston et al., 2001). Given the possible link between papillomavirus infection, bracken fern in the diet and cancer of the upper gastrointestinal (GI) tract in humans, we investigated whether a similar situation would occur in human cells transformed by human papillomavirus type 16 (HPV-16) oncoproteins. Quercetin arrested primary human foreskin keratinocytes in G1. Arrest was linked to an elevation of the cyclin-dependent kinase inhibitor (cdki) p27Kip1. Expression of the HPV16 E6 and E7 oncoproteins in transformed cells failed to abrogate cell cycle arrest. G1 arrest in the transformed cells was also linked to an increase of p27Kip1 with a concomitant reduction of cyclin E-associated kinase activity. This elevation of p27Kip1 was due not only to increased protein half-life, but also to increased mRNA transcription

    Clinical and Genetic Tumor Characteristics of Responding and Non-Responding Patients to PD-1 Inhibition in Hepatocellular Carcinoma.

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    Immune checkpoint inhibitors (ICIs) belong to the therapeutic armamentarium in advanced hepatocellular carcinoma (HCC). However, only a minority of patients benefit from immunotherapy. Therefore, we aimed to identify indicators of therapy response. This multicenter analysis included 99 HCC patients. Progression-free (PFS) and overall survival (OS) were studied by Kaplan-Meier analyses for clinical parameters using weighted log-rank testing. Next-generation sequencing (NGS) was performed in a subset of 15 patients. The objective response (OR) rate was 19% median OS (mOS)16.7 months. Forty-one percent reached a PFS > 6 months; these patients had a significantly longer mOS (32.0 vs. 8.5 months). Child-Pugh (CP) A and B patients showed a mOS of 22.1 and 12.1 months, respectively. Ten of thirty CP-B patients reached PFS > 6 months, including 3 patients with an OR. Tumor mutational burden (TMB) could not predict responders. Of note, antibiotic treatment within 30 days around ICI initiation was associated with significantly shorter mOS (8.5 vs. 17.4 months). Taken together, this study shows favorable outcomes for OS with low AFP, OR, and PFS > 6 months. No specific genetic pattern, including TMB, could identify responders. Antibiotics around treatment initiation were associated with worse outcome, suggesting an influence of the host microbiome on therapy success

    Three different ways of training ultrasound student-tutors yield significant gains in tutee’s scanning-skills

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    Aim: Many medical universities rely these days on trained student tutors to enable faculty-wide undergraduate ultrasound training. However, there is neither consensus on an optimal method nor any developed and agreed standard in the training of these student tutors. Usually internships and courses are employed which have both a specific set of advantages and disadvantages. We conducted a prospective quasi-randomized study of assess the effects of three types of tutor training on the resulting improvement in scanning skills of their tutees.Methods: Three batches of student tutors were trained by a course only (C-group), by an internship only (I-group) or by a course and an internship (CI-group). The respective gains in ultrasound scanning skills of the tutees were measured prospectively. A total 75 of the 124 5th year medical students (60.5%) who attended the mandatory ultrasound course completed both pre- and post-exams on a voluntary basis. Within a limit of eight minutes and three images, they were asked to depict and label a maximum of 14 anatomical structures. Two blinded raters independently awarded two points for each label with an identifiable structure and one point for each label with a possibly identifiable structure.Results: In all three groups, the tutees improved significantly by more than doubling their pre-score results and comparably (Gains: C-group 9.19±5.73 points, p<.0001, I-group 9.77±4.81 points, p<.0001, CI-group 8.97±5.49 points, p<.0001).Conclusion: Student tutors, who were trained with a course or an internship or a course and an internship could teach scanning skills to 5th year medical students very effectively and with similar success.Ziel: Viele medizinische Universitäten bieten heutzutage mit der Hilfe von ausgebildeten studentischen Tutoren eine fakultätsweite Ultraschall-Grundausbildung an. Es gibt jedoch weder einen Konsens über eine optimale Methode noch einen verbindlichen Standard für die Ausbildung dieser studentischen Tutoren. In der Regel werden zur Ausbildung Praktika und Kurse eingesetzt, die sowohl spezifische Vor- als auch Nachteile aufweisen.Wir führten eine prospektive, quasi-randomisierte Studie durch, um die Auswirkungen von drei Arten von Tutorentraining auf die daraus resultierende Verbesserung der Scanfähigkeiten ihrer Tutees zu bewerten.Methoden: Drei Gruppen studentischer Tutoren wurden nur durch einen Kurs (K-Gruppe), nur durch eine Famulatur (F-Gruppe) oder durch einen Kurs und eine Famulatur (KF-Gruppe) geschult. Die jeweiligen Zuwächse an Scanfähigkeiten der Tutees wurden prospektiv gemessen. 75 der 124 Medizinstudenten im fünften Studienjahr (60,5%), die den curricularen Ultraschallkurs besuchten, haben sowohl den Vor- als auch den Nachtest auf freiwilliger Basis absolviert. Innerhalb von acht Minuten sollten maximal 14 anatomische Strukturen in drei Bildern dargestellt und beschriftet werden. Zwei verblindete Bewerter vergaben unabhängig voneinander zwei Punkte für jede sicher identifizierbare Struktur und einen Punkt für jede möglicherweise identifizierbare Struktur.Ergebnisse: In allen drei Gruppen verbesserten sich die Tutees signifikant, indem sie ihre Ergebnisse von vor dem Unterricht mehr als verdoppelten (Zuwachs: K-Gruppe 9,19±5,73 Punkte, p<0,0001; F-Gruppe 9,77±4,81 Punkte, p<0,0001; KF-Gruppe 8,97±5,49 Punkte, p<0,0001).Fazit: Studentische Tutoren, die mit einem Kurs oder einer Famulatur oder einem Kurs und einer Famulatur geschult wurden, konnten Medizinstudenten im 5. Jahr sehr effektiv und mit vergleichbarem Erfolg Scanfähigkeiten vermitteln

    Non-Newtonian characteristics of peristaltic flow of blood in micro-vessels

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    Of concern in the paper is a generalized theoretical study of the non-Newtonian characteristics of peristaltic flow of blood through micro-vessels, e.g. arterioles. The vessel is considered to be of variable cross-section and blood to be a Herschel-Bulkley type of fluid. The progressive wave front of the peristaltic flow is supposed sinusoidal/straight section dominated (SSD) (expansion/contraction type); Reynolds number is considered to be small with reference to blood flow in the micro-circulatory system. The equations that govern the non-Newtonian peristaltic flow of blood are considered to be non-linear. The objective of the study has been to examine the effect of amplitude ratio, mean pressure gradient, yield stress and the power law index on the velocity distribution, wall shear stress, streamline pattern and trapping. It is observed that the numerical estimates for the aforesaid quantities in the case of peristaltic transport of the blood in a channel are much different from those for flow in an axisymmetric vessel of circular cross-section. The study further shows that peristaltic pumping, flow velocity and wall shear stress are significantly altered due to the non-uniformity of the cross-sectional radius of blood vessels of the micro-circulatory system. Moreover, the magnitude of the amplitude ratio and the value of the fluid index are important parameters that affect the flow behaviour. Novel features of SSD wave propagation that affect the flow behaviour of blood have also been discussed.Comment: Accepted for publication in Communications in Nonlinear Science and Numerical Simulation, Elsevier. arXiv admin note: text overlap with arXiv:1006.017

    Successful direct acting antiviral (DAA) treatment of HCV/HIV-coinfected patients before and after liver transplantation

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    Objectives The aim of this multicenter retrospective study was to investigate safety and efficacy of direct acting antiviral (DAA) treatment in the rare subgroup of patients with HCV/HIV-coinfection and advanced liver cirrhosis on the liver transplant waiting list or after liver transplantation, respectively. Methods When contacting 54 German liver centers (including all 23 German liver transplant centers), 12 HCV/HIV-coinfected patients on antiretroviral combination therapy were reported having received additional DAA therapy while being on the waiting list for liver transplantation (patient characteristics: Child-Pugh A (n = 6), B (n = 5), C (n = 1);MELD range 7-21;HCC (n = 2);HCV genotype la (n = 8), 1 b (n = 2), 4 (n = 2)). Furthermore, 2 HCV/HIV-coinfected patients were denoted having received DAA therapy after liver transplantation (characteristics: HCV genotype 1a (n = 1), 4 (n = 1)). Results Applied DAA regimens were SOF/DAC (n = 7), SOF/LDV/RBV (n = 3), SOF/RBV (n = 3), PTV/r/OBV/DSV (n = 1), or PTV/r/OBV/DSV/RBV (n = 1), respectively. All patients achieved SVR 12, in the end. In one patient, HCV relapse occurred after 24 weeks of SOF/DAC therapy;subsequent treatment with 12 weeks PTV/r/OBV/DSV achieved SVR 12. One patient underwent liver transplantation while on DAA treatment. Analysis of liver function revealed either stable parameters or even significant improvement during DAA therapy and in followup. MELD scores were found to improve in 9/13 therapies in patients on the waiting list for liver transplantation;in only 2 patients a moderate increase of MELD scores persisted at the end of follow-up. Conclusion DAA treatment was safe and highly effective in this nation-wide cohort of patients with HCV/HIV-coinfection awaiting liver transplantation or being transplanted

    Intestinal B-cells license metabolic T-cell activation in NASH microbiota/antigen-independently and contribute to fibrosis by IgA-FcR signalling

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    BACKGROUND & AIMS The progression of nonalcoholic steatohepatitis (NASH) to fibrosis and hepatocellular carcinoma (HCC) is aggravated by auto-aggressive T cells. The gut-liver axis contributes to NASH, but the mechanisms involved and the consequences for NASH-induced fibrosis and liver cancer remain unknown. We investigated the role of gastrointestinal B cells in the development of NASH, fibrosis and NASH-induced HCC. METHODS C57BL/6J wild-type (WT), B cell-deficient and different immunoglobulin-deficient or transgenic mice were fed distinct NASH diets (for example, choline-deficient high-fat diet, CD-HFD) or chow diet for 6 or 12 months, whereafter NASH, fibrosis, and NASH-induced HCC were assessed and analysed. Specific pathogen-free/germ-free WT and μMT mice (containing B cells only in the gastrointestinal tract) were fed a CD-HFD, and treated with an anti-CD20 antibody, whereafter NASH and fibrosis were assessed. Tissue biopsy samples from patients with NAFL, NASH and cirrhosis were analysed to correlate the secretion of immunoglobulins to clinicopathological features. Flow cytometry, immunohistochemistry and scRNA-Seq analysis were performed in liver and gastrointestinal tissue for immune cells in mice and humans. RESULTS Activated intestinal B cells were increased in mouse and human NASH samples and licensed metabolic T-cell activation to induce NASH independently of antigen-specificity and gut microbiota. Genetic or therapeutic depletion of systemic or gastrointestinal B cells prevented or reverted NASH and liver fibrosis. IgA secretion was necessary for fibrosis induction by activating CD11b+CCR2+F4/80+CD11c-FCGR1+ hepatic myeloid cells through an IgA-FcR signalling axis. Similarly, patients with NASH had increased numbers of activated intestinal B-cells and showed a positive correlation between IgA levels and activated FcRγ+ hepatic myeloid cells as well extent of liver fibrosis. CONCLUSIONS Intestinal B cells and the IgA-FcR signalling axis represent potential therapeutic targets for treating NASH. IMPACT AND IMPLICATIONS Nonalcoholic steatohepatitis (NASH) is a chronic inflammatory condition on the rise and can lead to hepatocellular carcinoma (HCC), the 3rd most common cause of cancer-related death worldwide. Currently, there is no effective treatment for this progressive disease that correlates with a marked risk of HCC mortality and carries a substantial healthcare burden. To date, among all the solid tumours, especially in HCC, the incidence and mortality rates are almost the same, making it crucial to find curative treatments for chronic diseases, such as NASH, which highly predispose to tumorigenesis. We have previously shown that NASH is an auto-aggressive condition aggravated, amongst others, by T cells. Therefore, we hypothesized that B cells might have a role in disease induction and progression. Our present work highlights that B cells have a dual role in NASH pathogenesis, being implicated in the activation of auto-aggressive T cells and the development of fibrosis via activation of monocyte-derived macrophages by secreted immunoglobulins (e.g., IgA). Furthermore, we could show that the absence of B cells prevented HCC development. B-cell intrinsic signalling pathways, secreted immunoglobulins, and interactions of B cells with other immune cells are potential targets in combinatorial NASH therapies against inflammation and fibrosis

    NASH limits anti-tumour surveillance in immunotherapy-treated HCC.

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    Hepatocellular carcinoma (HCC) can have viral or non-viral causes1-5. Non-alcoholic steatohepatitis (NASH) is an important driver of HCC. Immunotherapy has been approved for treating HCC, but biomarker-based stratification of patients for optimal response to therapy is an unmet need6,7. Here we report the progressive accumulation of exhausted, unconventionally activated CD8+PD1+ T cells in NASH-affected livers. In preclinical models of NASH-induced HCC, therapeutic immunotherapy targeted at programmed death-1 (PD1) expanded activated CD8+PD1+ T cells within tumours but did not lead to tumour regression, which indicates that tumour immune surveillance was impaired. When given prophylactically, anti-PD1 treatment led to an increase in the incidence of NASH-HCC and in the number and size of tumour nodules, which correlated with increased hepatic CD8+PD1+CXCR6+, TOX+, and TNF+ T cells. The increase in HCC triggered by anti-PD1 treatment was prevented by depletion of CD8+ T cells or TNF neutralization, suggesting that CD8+ T cells help to induce NASH-HCC, rather than invigorating or executing immune surveillance. We found similar phenotypic and functional profiles in hepatic CD8+PD1+ T cells from humans with NAFLD or NASH. A meta-analysis of three randomized phase III clinical trials that tested inhibitors of PDL1 (programmed death-ligand 1) or PD1 in more than 1,600 patients with advanced HCC revealed that immune therapy did not improve survival in patients with non-viral HCC. In two additional cohorts, patients with NASH-driven HCC who received anti-PD1 or anti-PDL1 treatment showed reduced overall survival compared to patients with other aetiologies. Collectively, these data show that non-viral HCC, and particularly NASH-HCC, might be less responsive to immunotherapy, probably owing to NASH-related aberrant T cell activation causing tissue damage that leads to impaired immune surveillance. Our data provide a rationale for stratification of patients with HCC according to underlying aetiology in studies of immunotherapy as a primary or adjuvant treatment
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