Medizin - Open Access LMU - Teil 19/22

Die Universitätsbibliothek (UB) verfügt über ein umfangreiches Archiv an elektronischen Medien, das von Volltextsammlungen über Zeitungsarchive, Wörterbücher und Enzyklopädien bis hin zu ausführlichen Bibliographien und mehr als 1000 Datenbanken reicht. Auf iTunes U stellt die UB unter anderem eine Auswahl an elektronischen Publikationen der Wissenschaftlerinnen und Wissenschaftler an der LMU bereit. (Dies ist der 19. von 22 Teilen der Sammlung 'Medizin - Open Access LMU'.)

  • NFAT5 Contributes to Osmolality-InducedMCP-1 Expression in Mesothelial Cells
    Increased expression of the C-C chemokine monocyte chemoattractant protein-1 (MCP-1) in mesothelial cells in response to high glucose concentrations and/or high osmolality plays a crucial role in the development of peritoneal fibrosis during continuous ambulatory peritoneal dialysis (CAPD). Recent studies suggest that in kidney cells osmolality-induced MCP-1 upregulation is mediated by the osmosensitive transcription factor, nuclear factor of activated T cells 5 (NFAT5). The present study addressed the question of whether activation of NFAT5 by hyperosmolality, as present in PD fluids, contributes to MCP-1 expression in the mesothelial cell line Met5A. Hyperosmolality, induced by addition of glucose, NaCl, or mannitol to the growth medium, increased NFAT5 activity and stimulated MCP-1 expression in Met5A cells. siRNA-mediated knockdown of NFAT5 attenuated osmolality-induced MCP-1 upregulation substantially. Hyperosmolality also induced activation of nuclear factor-kappa B (NF-kappa B). Accordingly, pharmacological inhibition of NF-kappa B significantly decreased osmolality-induced MCP-1 expression. Taken together, these results indicate that high osmolalities activate the transcription factor NFAT5 in mesothelial cells. NFAT5 in turn upregulates MCP-1, likely in combination with NF-kappa B, and thus may participate in the development of peritoneal fibrosis during CAPD.
    1 January 2012, 11:00 am
  • IGFBP3 impedes aggressive growth of pediatric liver cancer and is epigenetically silenced in vascular invasive and metastatic tumors
    Background: Hepatoblastoma (HB) is an embryonal liver neoplasm of early childhood with a poor prognosis for patients with distant metastases and vascular invasion. We and others have previously shown that the overexpression of insulin-like growth factor 2 (IGF2), loss of imprinting at the IGF2/H19 locus, and amplification of pleomorphic adenoma gene 1 (PLAG1) are common features in HB, suggesting a critical role of the IGF axis in hepatoblastomagenesis. In this study, we investigated the role of the insulin-like growth factor binding protein 3 (IGFBP3), a known competitor of the IGF axis, in pediatric liver cancers. Results: The IGFBP3 gene was highly expressed in normal pediatric livers but was heavily downregulated in four HB cell lines and the majority of HB primary tumors (26/36). Detailed methylation analysis of CpG sites in the IGFBP3 promoter region by bisulfite sequencing revealed a high degree of DNA methylation, which is causatively associated with the suppression of IGFBP3 in HB cell lines. Consequently, the treatment of HB cell lines with 5-aza-2'-deoxycytidine resulted in DNA demethylation and reactivation of the epigenetically silenced IGFBP3 expression. Interestingly, IGFBP3 promoter methylation predominantly occurred in metastatic HB with vascular invasion. Restoring IGFBP3 expression in HB cells resulted in reduced colony formation, migration, and invasion. Conclusion: This study provides the first direct evidence that the reactivation of IGFBP3 decreases aggressive properties of pediatric liver cancer cells and that IGFBP3 promoter methylation might be used as an indicator for vessel-invasive tumor growth in HB patients.
    1 January 2012, 11:00 am
  • Prothrombotic effects of tumor necrosis factor alpha in vivo are amplified by the absence of TNF-alpha receptor subtype 1 and require TNF-alpha receptor subtype 2
    Introduction: Elevated serum levels of the proinflammatory cytokine tumor necrosis factor alpha (TNF alpha) correlate with an increased risk for atherothrombotic events and TNF alpha is known to induce prothrombotic molecules in endothelial cells. Based on the preexisting evidence for the impact of TNF alpha in the pathogenesis of autoimmune disorders and their known association with an acquired hypercoagulability, we investigated the effects of TNF alpha and the role of the TNF receptor subtypes TNFR1 and TNFR2 for arteriolar thrombosis in vivo. Methods: Arteriolar thrombosis and platelet-rolling in vivo were investigated in wildtype, TNFR1-/-, TNFR2-/- and TNFR1-/R2-/-C57BL/6 mice using intravital microscopy in the dorsal skinfold chamber microcirculation model. In vitro, expression of prothrombotic molecules was assessed in human endothelial cells by real-time PCR and flow cytometry. Results: In wildtype mice, stimulation with TNF alpha significantly accelerated thrombotic vessel occlusion in vivo upon ferric chloride injury. Arteriolar thrombosis was much more pronounced in TNFR1-/- animals, where TNF alpha additionally led to increased platelet-endothelium-interaction. TNF alpha dependent prothrombotic effects were not observed in TNFR2-/- and TNFR1-/R2- mice. In vitro, stimulation of human platelet rich plasma with TNF alpha did not influence aggregation properties. In human endothelial cells, TNF alpha induced superoxide production, p-selectin, tissue factor and PAI-1, and suppressed thrombomodulin, resulting in an accelerated endothelial dependent blood clotting in vitro. Additionally, TNF alpha caused the release of soluble mediators by endothelial cells which induced prothrombotic and suppressed anticoagulant genes comparable to direct TNF alpha effects. Conclusions: TNF alpha accelerates thrombus formation in an in vivo model of arteriolar thrombosis. Its prothrombotic effects in vivo require TNFR2 and are partly compensated by TNFR1. In vitro studies indicate endothelial mechanisms to be responsible for prothrombotic TNF alpha effects. Our results support a more selective therapeutic approach in anticytokine therapy favouring TNFR2 specific antagonists.
    1 January 2012, 11:00 am
  • Open-label trial with artemether-lumefantrine against uncomplicated Plasmodium falciparum malaria three years after its broad introduction in Jimma Zone, Ethiopia
    Background: In Jimma Zone, Ethiopia, the first-line treatment of uncomplicated falciparum malaria has been changed from sulphadoxine-pyrimethamine (SP) to artemether-lumefantrine (AL) in 2006. The objective of this study was to assess the effectiveness of AL in Jimma Zone two to three years after its broad introduction. Methods: An open-label, single-arm, 42-day study of AL against falciparum malaria was conducted in four areas with moderate transmission in Jimma Zone between November 2008 and January 2009 and between August and December 2009. Patients (one-81 years) with uncomplicated Plasmodium falciparum mono-infection were consecutively enrolled. Follow-up visits were at day 2, 3, 7, 28 and 42 or any other day if symptoms reoccurred. Primary and secondary endpoints were PCR-corrected and uncorrected cure rates (molecular differentiation between recrudescence and re-infection) on days 28 and 42. Other secondary endpoints were gametocytaemia at day 7 and day 28, parasitaemia at day 2 and 3, and re-infection rates at day 28 and day 42. Results: Of 348 enrolled patients, 313 and 301 completed follow-up at day 28 and at day 42, respectively. No early treatment failure occurred. For per protocol analysis, PCR-uncorrected cure rates at day 28 and 42 were 99.1% (95% CI 98.0-100.0) and 91.1% (95% CI 87.9-94.3), respectively. PCR-corrected cure rates at day 28 and 42 were 99.4% (95% CI 98.5-100.0) and 94.7% (95% CI 92.2-97.2), respectively. PCR-corrected cure rate at day 42 for children <= 5 years was 90.6% (95% CI 82.4-98.7) only. Adverse events were in general mild to moderate. Incidence of new infections was 3.4% during 42 days, no new infections with Plasmodium vivax were observed. Microscopically detected gametocytaemia was reduced by 80% between day 0 and day 7. Conclusion: In general, AL was effective and well tolerated in Jimma Zone, Ethiopia. However, the PCR-corrected recrudescence rate per-protocol at day 42 for children <= 5 years was 9.4%. Therefore, further development should be monitored on a regular basis as recommended by WHO.
    1 January 2012, 11:00 am
  • The German fibromyalgia consumer reports - a cross-sectional survey
    Background: Consumer surveys provide information on effectiveness and side effects of medical interventions in routine clinical care. A report of fibromyalgia syndrome (FMS) consumers has not been carried out in Europe. Methods: The study was carried out from November 2010 to April 2011. Participants diagnosed with FMS rated the effectiveness and side effects of pharmacological and non-pharmacological FMS interventions on a 0 to 10 scale, with 10 being most efficacious (harmful). The questionnaire was distributed by the German League for people with Arthritis and Rheumatism and the German Fibromyalgia Association to their members and to all consecutive FMS patients of nine clinical centers of different levels of care. Results: 1661 questionnaires (95% women, mean age 54 years, mean duration since FMS diagnosis 6.8 years) were analysed. The most frequently used therapies were self-management strategies, prescription pain medication and aerobic exercise. The highest average effectiveness was attributed to whole body and local warmth therapies, thermal bathes, FMS education and resting. The highest average side effects were attributed to strong opioids, local cold therapy, gamma-amino-butyric acid analogues (pregabalin and gabapentin), tramadol and opioid transdermal systems. Conclusion: The German fibromyalgia consumer reports highlight the importance of non-pharmcological therapies in the long-term management of FMS, and challenges the strong recommendations for drug therapies given by FMS-guidelines.
    1 January 2012, 11:00 am
  • Age and gender as determinants of the bone quality of the greater tuberosity: A HR-pQCT cadaver study
    Background: Age-dependent trabecular changes of the humeral head might weaken the fixation of suture anchors used for rotator cuff (RC) repair. This might lead to suture anchor loosening and thus compromise the integrity of the repair. The aim of this study was to analyze whether the trabecular microstructure within the RC footprint is influenced by age, gender or handedness. Methods: Axial HR-pQCT scans (Scanco Medical) of 64 freshly frozen cadaveric human humeral head specimens (age 72.3 +/- 17.4 years) were analyzed to determine the bone volume-to-total volume ratio (BV/TV), trabecular thickness (Trab Th), trabecular number (Trab N) and connectivity density (Conn Dens). Within the RC footprint, 2 volumes of interest (VOI), posteromedial (PM) and anterolateral (AL) and one control VOI in the subarticular bone (SC) were set. Results: The highest BV/TV was found in SC: 0.22 +/- 0.06% vs. PM: 0.04 +/- 0.05% vs. AL: 0.02 +/- 0.04%; p < 0.05. Trab Th accounted for 0.26 +/- 0.05 mu m in SC, 0.23 +/- 0.09 mu m in AL and 0.21 +/- 0.05 mu m in PM. In parallel, Trab N and Conn Dens were found to be the highest in SC. Gender analysis yielded higher values for BV/TV, Trab Th, Trab N and Conn Dens for PM in males compared to females (p < 0.05). There were no significant findings when comparing both sides. We furthermore found a strong inverse correlation between age and BV/TV, which was more pronounced in the female specimens (r = -0.72, p < 0.00001). Conclusions: The presented microarchitectural data allow for future subtle biomechanical testing comprising knowledge on age-and sex-related changes of the tuberosities of the humeral head. Furthermore, the insights on the trabecular structure of the humeral head of the elderly may lead to the development of new fixation materials in bone with inferior bone quality.
    1 January 2012, 11:00 am
  • Plasticity of HIV-specific CD8 T cell responses in untreated HIV-1 infection- a step towards a therapeutic vaccine against drug resistance mutations
    1 January 2012, 11:00 am
  • The Incidence and Clinical Relevance of Graft Hypertrophy After Matrix-Based Autologous Chondrocyte Implantation
    Background: Graft hypertrophy is the most common complication of periosteal autologous chondrocyte implantation (p-ACI). Purpose: The aim of this prospective study was to analyze the development, the incidence rate, and the persistence of graft hypertrophy after matrix-based autologous chondrocyte implantation (mb-ACI) in the knee joint within a 2-year postoperative course. Study Design: Case series; Level of evidence, 4. Methods: Between 2004 and 2007, a total of 41 patients with 44 isolated cartilage defects of the knee were treated with the mb-ACI technique. The mean age of the patients was 35.8 years (standard deviation [SD], 11.3 years), and the mean body mass index was 25.9 (SD, 4.2; range, 19-35.3). The cartilage defects were arthroscopically classified as Outerbridge grades III and IV. The mean area of the cartilage defect measured 6.14 cm2 (SD, 2.3 cm2). Postoperative clinical and magnetic resonance imaging (MRI) examinations were conducted at 3, 6, 12, and 24 months to analyze the incidence and course of the graft. Results: Graft hypertrophy developed in 25% of the patients treated with mb-ACI within a postoperative course of 1 year; 16% of the patients developed hypertrophy grade 2, and 9% developed hypertrophy grade 1. Graft hypertrophy occurred primarily in the first 12 months and regressed in most cases within 2 years. The International Knee Documentation Committee (IKDC) and visual analog scale (VAS) scores improved during the postoperative follow-up time of 2 years. There was no difference between the clinical results regarding the IKDC and VAS pain scores and the presence of graft hypertrophy. Conclusion: The mb-ACI technique does not lead to graft hypertrophy requiring treatment as opposed to classic p-ACI. The frequency of occurrence of graft hypertrophy after p-ACI and mb-ACI is comparable. Graft hypertrophy can be considered as a temporary excessive growth of regenerative cartilage tissue rather than a true graft hypertrophy. It is therefore usually not a persistent or systematic complication in the treatment of circumscribed cartilage defects with mb-ACI.
    1 January 2012, 11:00 am
  • Factors Associated With Health-Related Quality of Life After Stroke: A 1-Year Prospective Cohort Study
    Background: In line with patient-centered health care, it is necessary to understand patients’ perceptions of health. How stroke survivors perceive their health at different time points after stroke and which factors are associated with these feelings provide important information about relevant rehabilitation targets. Objective. This study aimed to identify the independent factors of health-related quality of life (HRQoL) from a biopsychosocial perspective using the methods of multivariate regression at 3 different time points poststroke. Methods. Included in the study were 99 patients from stroke units with diagnosed first-ever stroke. At admission and at 6 weeks, 3 months, and 1 year poststroke, HRQoL was assessed using the EuroQoL-5D Visual Analogue Scale (EQ-5D VAS). Consequences in Body Functions and Activities and Participation, and Environmental Factors were documented using 155 categories of the International Classification of Functioning, Disability and Health (ICF) Core Set for Stroke. Results. For a period of 1 year, problems with recreation and leisure, personality functions, energy and drive functions, and gait pattern functions were repeatedly associated with worse HRQoL. Whereas Body Functions and Activities and Participation explained more than three-fourths of the variances of HRQoL at 6 weeks and 3 months (R2 = 0.80-0.93), the variation at 1 year was best explained by either Body Functions or Environmental Factors (R2 = 0.51). Conclusions. The results indicate the importance of Body Functions and Activities and Participation (mainly personality functions and recreation and leisure) on HRQoL within 3 months poststroke, but increased impact of Environmental Factors on HRQoL at 1 year.
    1 January 2012, 11:00 am
  • Whey- vs Casein-Based Enteral Formula and Gastrointestinal Function in Children With Cerebral Palsy.
    Objectives: Children with severe cerebral palsy (CP) commonly have gastrointestinal (GI) dysfunction. Whey-based enteral formulas have been postulated to reduce gastroesophageal reflux (GOR) and accelerate gastric emptying (GE). The authors investigated whether whey-based (vs casein-based) enteral formulas reduce GOR and accelerate GE in children who have severe CP with a gastrostomy and fundoplication. Methods: Thirteen children received a casein-based formula for 1 week and either a 50% whey whole protein (50% WWP) or a 100% whey partially hydrolyzed protein (100% WPHP) formula for 1 week. Reflux episodes, gastric half-emptying time (GE t1/2), and reported pain and GI symptoms were measured. Results: Whey formulas emptied significantly faster than casein (median [interquartile range (IQR)] GE t1/2, 33.9 [25.3-166.2] min vs 56.6 [46-191] min; P = .033). Reflux parameters were unchanged. GI symptoms were lower in children who received 50% WWP (visual analog symptom score, median [IQR], 0[0-11.8]) vs 100% WPHP (13.0 [2.5-24.8]) (P = .035). Conclusion: This pilot study shows that in children who have severe CP with a gastrostomy and fundoplication, GE of the whey-based enteral formula is significantly faster than casein. The acceleration in GE does not alter GOR frequency, and there appears to be no effect of whey vs casein in reducing acid, nonacid, and total reflux episodes. The results indicate that enteral formula selection may be particularly important for children with severe CP and delayed GE. (JPEN J Parenter Enteral Nutr. 2012;36:118S-123S)
    1 January 2012, 11:00 am
  • Sports Activity After Short-Stem Hip Arthroplasty
    Background: No data are available about the sports activity of patients with bone-conserving short-stem hip implants. Hypothesis: Patients can return to a good level of sports activity after implantation of a short-stem hip implant. Study Design: Case series; Level of evidence, 4. Methods: The sports activity level of 68 patients (76 hips) after short-stem hip arthroplasty was assessed for a minimum of 2 years after implantation. In addition to the clinical examination, a detailed evaluation of the patients’ sports pattern was obtained. Furthermore, the results were analyzed with regard to gender (female and male) and age (<=55 and >55 years). Results: After a mean of 2.7 years, patients showed a Harris Hip Score (HHS) of 93.6, a Western Ontario and McMaster Universities Arthritis Index (WOMAC) score of 9.5, and a University of California, Los Angeles (UCLA) activity score of 7.6, with each individual participating on average in 3.5 different disciplines after surgery compared with 3.9 before surgery. High-impact activities decreased significantly postoperatively, whereas low-impact activities increased significantly. The duration of the sports activities remained stable, while the frequency actually increased. In contrast, men participated preoperatively in more sports than women (4.3 men vs 3.3 women). However, because of a pronounced decrease in high-impact activities by men, both genders participated in an equal number of sports postoperatively (3.5 men vs 3.5 women). Finally, 45% (n = 31) reported at least one activity that they missed. Most of them were disciplines with an intermediate- or high-impact level. Conclusion: Patients with a short-stem hip implant can return to a good level of activity postoperatively. Participation in sports almost reached similar levels as preoperatively but with a shift from high- to low-impact activities. This seems desirable from a surgeon’s point of view but should also be communicated to the patient before hip replacement
    1 January 2012, 11:00 am
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