160 resultados para Liu, Yung-yung.
em Université de Lausanne, Switzerland
Resumo:
BACKGROUND: Little is known about the early phases of bipolar disorders (BPAD) and most of current knowledge derives from putative "high-risk" studies conducted in populations of bipolar off-spring; such information may therefore be relevant only to a sub-group of at-risk subjects. METHODS: Retrospective assessment of the phase preceding the emergence of mania and of premorbid characteristics of patients treated for a first episode of psychotic mania. The collected data was used mainly to generate hypotheses. RESULTS: Before onset of a first episode of psychotic mania, patients go through a phase of change from previous mental state where they present mood symptoms, sleep disruption and general functional decline. These clinical manifestations are however likely to have low specificity. However, their occurrence in patients presenting certain risk factors or markers of vulnerability that were identified at a relatively high prevalence in our sample, may be an indicator of impending first episode mania. LIMITATIONS: This is a retrospective study, in a small sample of patients presenting with psychotic mania. Criteria identified need therefore to be validated in larger prospective studies. CONCLUSIONS: Early identification of patients at risk to develop a first episode of psychotic mania is unlikely to be possible on the basis of symptoms alone. However, the occurrence of certain clinical characteristics in patients who have risk factors or markers of vulnerability to BPAD could be a sign of impending first episode mania.
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INTRODUCTION: We have developed ultra-high risk criteria for bipolar affective disorder (bipolar at-risk - BAR) which include general criteria such as being in the peak age range of the onset of the disorder and a combination of specific criteria including sub-threshold mania, depressive symptoms, cyclothymic features and genetic risk. In the current study, the predictive validity of these criteria were tested in help-seeking adolescents and young adults. METHOD: This medical file-audit study was conducted at ORYGEN Youth Health (OYH), a public mental health program for young people aged between 15 and 24years and living in metropolitan Melbourne, Australia. BAR criteria were applied to the intake assessments of all non-psychotic patients who were being treated in OYH on 31 January, 2008. All entries were then checked for conversion criteria. Hypomania/mania related additions or alterations to existing treatments or initiation of new treatment by the treating psychiatrist served as conversion criteria to mania. RESULTS: The BAR criteria were applied to 173 intake assessments. Of these, 22 patients (12.7%) met BAR criteria. The follow-up period of the sample was 265.5days on average (SD 214.7). There were significantly more cases in the BAR group (22.7%, n=5) than in the non-BAR group (0.7%, n=1) who met conversion criteria (p<.001). CONCLUSIONS: These findings support the notion that people who develop a first episode of mania can be identified during the prodromal phase. The proposed criteria need further evaluation in prospective clinical trials.
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BACKGROUND: Anti-CD154 (MR1) monoclonal antibody (mAb) and rapamycin (RAPA) treatment both improve survival of rat-to-mouse islet xenograft. The present study investigated the effect of combined RAPA/MR1 treatment on rat-to-mouse islet xenograft survival and analyzed the role of CD4(+)CD25(+)Foxp3(+) T regulatory cells (Treg) in the induction and maintenance of the ensuing tolerance. METHODOLOGY/PRINCIPAL FINDINGS: C57BL/6 mice were treated with MR1/RAPA and received additional monoclonal anti-IL2 mAb or anti CD25 mAb either early (0-28 d) or late (100-128 d) post-transplantation. Treg were characterised in the blood, spleen, draining lymph nodes and within the graft of tolerant and rejecting mice by flow cytometry and immunohistochemistry. Fourteen days of RAPA/MR1 combination therapy allowed indefinite islet graft survival in >80% of the mice. Additional administration of anti-IL-2 mAb or depleting anti-CD25 mAb at the time of transplantation resulted in rejection (100% and 89% respectively), whereas administration at 100 days post transplantation lead to lower rejection rates (25% and 40% respectively). Tolerant mice showed an increase of Treg within the graft and in draining lymph nodes early post transplantation, whereas 100 days post transplantation no significant increase of Treg was observed. Rejecting mice showed a transient increase of Treg in the xenograft and secondary lymphoid organs, which disappeared within 7 days after rejection. CONCLUSIONS/SIGNIFICANCES: These results suggest a critical role for Treg in the induction phase of tolerance early after islet xenotransplantation. These encouraging data support the need of developing further Treg therapy for overcoming the species barrier in xenotransplantation.
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OBJECTIVE Streptozotocin (STZ) is the most widely used diabetogenic agent in animal models of islet transplantation. However, the immunomodifying effects of STZ and the ensuing hyperglycemia on lymphocyte subsets, particularly on T regulatory cells (Tregs), remain poorly understood. RESEARCH DESIGN AND METHODS This study evaluated how STZ-induced diabetes affects adaptive immunity and the consequences thereof on allograft rejection in murine models of islet and skin transplantation. The respective toxicity of STZ and hyperglycemia on lymphocyte subsets was tested in vitro. The effect of hyperglycemia was assessed independently of STZ in vivo by the removal of transplanted syngeneic islets, using an insulin pump, and with rat insulin promoter diphtheria toxin receptor transgenic mice. RESULTS Early lymphopenia in both blood and spleen was demonstrated after STZ administration. Direct toxicity of STZ on lymphocytes, particularly on CD8(+) cells and B cells, was shown in vitro. Hyperglycemia also correlated with blood and spleen lymphopenia in vivo but was not lymphotoxic in vitro. Independently of hyperglycemia, STZ led to a relative increase of Tregs in vivo, with the latter retaining their suppressive capacity in vitro. The higher frequency of Tregs was associated with Treg proliferation in the blood, but not in the spleen, and higher blood levels of transforming growth factor-β. Finally, STZ administration delayed islet and skin allograft rejection compared with naive mice. CONCLUSIONS These data highlight the direct and indirect immunosuppressive effects of STZ and acute hyperglycemia, respectively. Thus, these results have important implications for the future development of tolerance-based protocols and their translation from the laboratory to the clinic.
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OBJECTIVE: Intervention during the pre-psychotic period of illness holds the potential of delaying or even preventing the onset of a full-threshold disorder, or at least of reducing the impact of such a disorder if it does develop. The first step in realizing this aim was achieved more than 10 years ago with the development and validation of criteria for the identification of young people at ultra-high risk (UHR) of psychosis. Results of three clinical trials have been published that provide mixed support for the effectiveness of psychological and pharmacological interventions in preventing the onset of psychotic disorder. METHOD: The present paper describes a fourth study that has now been undertaken in which young people who met UHR criteria were randomized to one of three treatment groups: cognitive therapy plus risperidone (CogTher + Risp: n = 43); cognitive therapy plus placebo (CogTher + Placebo: n = 44); and supportive counselling + placebo (Supp + Placebo; n = 28). A fourth group of young people who did not agree to randomization were also followed up (monitoring: n = 78). Baseline characteristics of participants are provided. RESULTS AND CONCLUSION: The present study improves on the previous studies because treatment was provided for 12 months and the independent contributions of psychological and pharmacological treatments in preventing transition to psychosis in the UHR cohort and on levels of psychopathology and functioning can be directly compared. Issues associated with recruitment and randomization are discussed.
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Bipolar affective disorder (BD) is a severe, recurrent and disabling disorder with devastating consequences for individuals, families and society. Although these hazards and costs provide a compelling rationale for development of early detection and early intervention strategies in BD, the development of at-risk criteria for first episode mania is still in an early stage of development. In this paper we review the literature with respect to the clinical, neuroantomical and neuropsychological data, which support this goal. We also describe our recently developed bipolar at-risk criteria (BAR). This criteria comprises the peak age range of the first onset of bipolar disorder, genetic risk, presenting with sub-threshold mania, cyclothymic features or depressive symptoms. An initial pilot evaluation of the BAR criteria in 22 subjects indicated conversion rates to proxies of first-episode mania of 23% within 265 days on average, and high specificity and sensitivity of the criteria. If prospective studies confirm the validity of the BAR criteria, then the criteria would have the potential to open up new avenues of research for indicated prevention in BD and might therefore offer opportunities to ameliorate the severity of, or even prevent BD.
Resumo:
Objectives: Streptozotocin (STZ) induced diabetes is currently the most commonly used animalmodel for islet transplantation.However, STZtreatment and the ensuing hyperglycemia were both shown to affect the immune response, including an apparent induction of lymphopenia. The aim of this study was to evaluate the respective effect of STZ and hyperglycemia on the immune system in STZ induced diabetic C57BL/6 mice. Methods: Phenotypes and levels of T and B cells were analyzed by flow cytometry in blood and spleen over time. The effect of hyperglycemia was further characterized by insulin replacement, islet transplantation and by using Rip (rat insulin promoter) DTR (dipheteria tocin receptor) transgenic mice. Results: STZ but not hyperglycemia was toxic for splenocytes in vitro, whereas hyperglycemia correlated with diabetes associated blood and spleen lymphopenia in vivo. Moreover, independently of hyperglycemia, STZ lead to a relative increase of T regulatory cells which retained their suppressive capacity in vitro. Conclusion: These data suggest thatSTZand the ensuing acute hyperglycemia have major direct and indirect effects on immune homeostasis. Thus, high caution needs to be exercised in the interpretation of the results of tolerance induction and/or immunosuppressive protocols in STZ-induced diabetes and islet transplantation models.
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In the present study, we evaluated stimulation of the angiotensin type 2 receptor (AT2R) by the selective non-peptide agonist Compound 21 (C21) as a novel therapeutic concept for the treatment of multiple sclerosis using the model of experimental autoimmune encephalomyelitis (EAE) in mice. C57BL-6 mice were immunized with myelin-oligodendrocyte peptide and treated for 4 weeks with C21 (0.3 mg/kg/day i.p.). Potential effects on myelination, microglia and T-cell composition were estimated by immunostaining and FACS analyses of lumbar spinal cords. The in vivo study was complemented by experiments in aggregating brain cell cultures and microglia in vitro. In the EAE model, treatment with C21 ameliorated microglia activation and decreased the number of total T-cells and CD4+ T-cells in the spinal cord. Fluorescent myelin staining of spinal cords further revealed a significant reduction in EAE-induced demyelinated areas in lumbar spinal cord tissue after AT2R stimulation. C21-treated mice had a significantly better neurological score than vehicle-treated controls. In aggregating brain cell cultures challenged with lipopolysaccharide (LPS) plus interferon-γ (IFNγ), AT2R stimulation prevented demyelination, accelerated re-myelination and reduced the number of microglia. Cytokine synthesis and nitric oxide production by microglia in vitro were significantly reduced after C21 treatment. These results suggest that AT2R stimulation protects the myelin sheaths in autoimmune central nervous system inflammation by inhibiting the T-cell response and microglia activation. Our findings identify the AT2R as a potential new pharmacological target for demyelinating diseases such as multiple sclerosis.
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Background: Leptin is produced primarily by adipocytes. Although originally associated with the central regulation of satiety and energy metabolism, increasing evidence indicates that leptin may be an important factor for congestive heart faire (CHF). In the study, we aimed to test the hypothesis that leptin may influence CHF pathophysiology via a pathway of increasing body mass index (BMI). Methods: We studied 2,389 elderly participants aged 70 and older (M; 1161, F: 1228) without CHF and with serum leptin measures at the Health Aging, and Body Composition study. We analyzed the association between serum leptin level and risk of incident CHF using Cox hazard proportional regression models. Elevated leptin level was defined as more than the highest quartile (Q4) of leptin distribution in the total sample for each gender. Adjusted-covariates included demographic, behavior, lipid and inflammation variables (partially-adjusted models), and further included BMI (fully-adjusted models). Results: In a mean 9-year follow-up, 316 participants (13.2%) developed CHF. The partially-adjusted models indicated that men and women with elevated serum leptin levels (>=9.89 ng/ml in men and >=25 ng/ml in women) had significantly higher risks of developing CHF than those with leptin level of less than Q4. The adjusted hazard ratios (95%CI) for incident CHF was 1.49 (1.04 -2.13) in men and 1.71 (1.12 -2.58) in women. However, these associations became non-significant after adjustment for including BMI for each gender. The fully-adjusted hazard ratios (95%CI) were 1.43 (0.94 -2.18) in men and 1.24 (0.77-1.99) in women. Conclusion: Subjects with elevated leptin levels have a higher risk of CHF. The study supports the hypothesis that the influence of leptin level on risk of CHF may be through a pathway related to increasing BMI.
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Clinical responses to anticancer therapies are often restricted to a subset of patients. In some cases, mutated cancer genes are potent biomarkers for responses to targeted agents. Here, to uncover new biomarkers of sensitivity and resistance to cancer therapeutics, we screened a panel of several hundred cancer cell lines--which represent much of the tissue-type and genetic diversity of human cancers--with 130 drugs under clinical and preclinical investigation. In aggregate, we found that mutated cancer genes were associated with cellular response to most currently available cancer drugs. Classic oncogene addiction paradigms were modified by additional tissue-specific or expression biomarkers, and some frequently mutated genes were associated with sensitivity to a broad range of therapeutic agents. Unexpected relationships were revealed, including the marked sensitivity of Ewing's sarcoma cells harbouring the EWS (also known as EWSR1)-FLI1 gene translocation to poly(ADP-ribose) polymerase (PARP) inhibitors. By linking drug activity to the functional complexity of cancer genomes, systematic pharmacogenomic profiling in cancer cell lines provides a powerful biomarker discovery platform to guide rational cancer therapeutic strategies.
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Introduction. Selective embolization of the left-gastric artery (LGA) reduces levels of ghrelin and achieves significant short-term weight loss. However, embolization of the LGA would prevent the performance of bariatric procedures because the high-risk leakage area (gastroesophageal junction [GEJ]) would be devascularized. Aim. To assess an alternative vascular approach to the modulation of ghrelin levels and generate a blood flow manipulation, consequently increasing the vascular supply to the GEJ. Materials and methods. A total of 6 pigs underwent a laparoscopic clipping of the left gastroepiploic artery. Preoperative and postoperative CT angiographies were performed. Ghrelin levels were assessed perioperatively and then once per week for 3 weeks. Reactive oxygen species (ROS; expressed as ROS/mg of dry weight [DW]), mitochondria respiratory rate, and capillary lactates were assessed before and 1 hour after clipping (T0 and T1) and after 3 weeks of survival (T2), on seromuscular biopsies. A celiac trunk angiography was performed at 3 weeks. Results. Mean (±standard deviation) ghrelin levels were significantly reduced 1 hour after clipping (1902 ± 307.8 pg/mL vs 1084 ± 680.0; P = .04) and at 3 weeks (954.5 ± 473.2 pg/mL; P = .01). Mean ROS levels were statistically significantly decreased at the cardia at T2 when compared with T0 (0.018 ± 0.006 mg/DW vs 0.02957 ± 0.0096 mg/DW; P = .01) and T1 (0.0376 ± 0.008mg/DW; P = .007). Capillary lactates were significantly decreased after 3 weeks, and the mitochondria respiratory rate remained constant over time at the cardia and pylorus, showing significant regional differences. Conclusions. Manipulation of the gastric flow targeting the gastroepiploic arcade induces ghrelin reduction. An endovascular approach is currently under evaluation.
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BACKGROUND: The FTO gene harbors the strongest known susceptibility locus for obesity. While many individual studies have suggested that physical activity (PA) may attenuate the effect of FTO on obesity risk, other studies have not been able to confirm this interaction. To confirm or refute unambiguously whether PA attenuates the association of FTO with obesity risk, we meta-analyzed data from 45 studies of adults (n = 218,166) and nine studies of children and adolescents (n = 19,268). METHODS AND FINDINGS: All studies identified to have data on the FTO rs9939609 variant (or any proxy [r(2)>0.8]) and PA were invited to participate, regardless of ethnicity or age of the participants. PA was standardized by categorizing it into a dichotomous variable (physically inactive versus active) in each study. Overall, 25% of adults and 13% of children were categorized as inactive. Interaction analyses were performed within each study by including the FTO×PA interaction term in an additive model, adjusting for age and sex. Subsequently, random effects meta-analysis was used to pool the interaction terms. In adults, the minor (A-) allele of rs9939609 increased the odds of obesity by 1.23-fold/allele (95% CI 1.20-1.26), but PA attenuated this effect (p(interaction) = 0.001). More specifically, the minor allele of rs9939609 increased the odds of obesity less in the physically active group (odds ratio = 1.22/allele, 95% CI 1.19-1.25) than in the inactive group (odds ratio = 1.30/allele, 95% CI 1.24-1.36). No such interaction was found in children and adolescents. CONCLUSIONS: The association of the FTO risk allele with the odds of obesity is attenuated by 27% in physically active adults, highlighting the importance of PA in particular in those genetically predisposed to obesity.