139 research outputs found
Intermolecular cycloaddition of ethyl glyoxylate O-tert- butyldimethylsilyloxime with alkenes
金沢大学大学院自然科学研究科生理活性物質科学金沢大学薬学部Ethyl glyoxylate O-tert-butyldimethylsilyloxime, on treatment with various alkenes in the presence of BF3·OEt2, generated a C-ethoxycarbonyl N-boranonitrone intermediate, which underwent intermolecular cycloaddition to afford 3-(ethoxycarbonyl)isoxazolidines in moderate to high yields. © Georg Thieme Verlag Stuttgart
Inhibition of Hsp90 Leads to Cell Cycle Arrest and Apoptosis in Human Malignant Pleural Mesothelioma
IntroductionHeat shock protein 90 (Hsp90) is an abundant molecular chaperone that mediates the maturation and stability of a variety of proteins associated with the promotion of cell growth and survival. Inhibition of Hsp90 function leads to proteasomal degradation of its mis-folded client proteins. Recently, Hsp90 has emerged as being of prime importance to the growth and survival of cancer cells and its inhibitors have already been used in phase I and II clinical trials.MethodsWe investigated how 17-allylamino-17-demethoxygeldanamycin (17-AAG), a small molecule inhibitor of Hsp90, is implicated in human malignant pleural mesothelioma (MM).ResultsWe found that 17-AAG led to significant G1 or G2/M cell cycle arrest, inhibition of cell proliferation, and decrease of AKT, AKT1, and survivin expression in all human malignant pleural mesothelioma cell lines examined. We also observed significant apoptosis induction in all MM cell lines treated with 17-AAG. Furthermore, 17-AAG induced apoptosis in freshly cultured primary MM cells and caused signaling changes identical to those in 17-AAG treated MM cell lines.ConclusionThese results suggest that Hsp90 is strongly associated with the growth and survival of MM and that inhibition of Hsp90 may have therapeutic potential in the treatment of MM
Cyclin D1 activation through ATF-2 in Reg-induced pancreatic β-cell regeneration
AbstractRegenerating gene product (Reg) is induced in pancreatic β-cells and acts as an autocrine/paracrine growth factor for regeneration via a cell surface Reg receptor. However, the manner by which Reg induces β-cell regeneration was unknown. In the present study, we found that Reg increased phospho-ATF-2, which binds to −57 to −52 of the cyclin D1 gene to activate the promoter. The Reg/ATF-2-induced cyclin D1 promoter activation was attenuated by PI(3)K inhibitors such as LY294002 and wortmannin. In Reg knockout mouse islets, the levels of phospho-ATF-2, cyclin D1, and phospho-Rb were greatly decreased. These results indicate that the Reg–Reg receptor system stimulates the PI(3)K/ATF-2/cyclin D1 signaling pathway to induce β-cell regeneration
5-Aminosalicylic acid aggravates colitis mimicking exacerbation of ulcerative colitis
Ulcerative colitis (UC) is one of the major clinical phenotypes of inflammatory bowel diseases. Although 5-aminosalicylic acid (5-ASA) is widely used for UC and its efficacy and safety have been demonstrated, a few patients paradoxically develop a severe exacerbation of colitis by 5-ASA administration. It is crucial to know clinical features including endoscopic findings in this condition for making a correct diagnosis and a prompt decision to withdraw the medication. Here, we report case series with UC exacerbated by 5-ASA. Medical records of 8 UC patients experiencing an exacerbation of colitis after induction of 5-ASA that was improved by the withdrawal of 5-ASA but also re-aggravated by dose increase or re-administration of 5-ASA were reviewed. The patients were newly diagnosed with UC, started 5-ASA and developed an exacerbation in approximately 2 to 3 weeks. They did not appear to have systemic allergic reactions. Seven of the 8 patients had a high fever. Three of 5 patients who undertook total colonoscopy showed right-side-dominant colitis. These findings suggest clinical characteristics in this condition. Further assessment of clinical and endoscopic features in more cases is necessary for establishing diagnostic criteria and understanding underlying mechanisms in those cases where 5-ASA aggravates the colitis
Novel, Objective, Multivariate Biomarkers Composed of Plasma Amino Acid Profiles for the Diagnosis and Assessment of Inflammatory Bowel Disease
BACKGROUND: Inflammatory bowel disease (IBD) is a chronic intestinal disorder that is associated with a limited number of clinical biomarkers. In order to facilitate the diagnosis of IBD and assess its disease activity, we investigated the potential of novel multivariate indexes using statistical modeling of plasma amino acid concentrations (aminogram). METHODOLOGY AND PRINCIPAL FINDINGS: We measured fasting plasma aminograms in 387 IBD patients (Crohn's disease (CD), n = 165; ulcerative colitis (UC), n = 222) and 210 healthy controls. Based on Fisher linear classifiers, multivariate indexes were developed from the aminogram in discovery samples (CD, n = 102; UC, n = 102; age and sex-matched healthy controls, n = 102) and internally validated. The indexes were used to discriminate between CD or UC patients and healthy controls, as well as between patients with active disease and those in remission. We assessed index performances using the area under the curve of the receiver operating characteristic (ROC AUC). We observed significant alterations to the plasma aminogram, including histidine and tryptophan. The multivariate indexes established from plasma aminograms were able to distinguish CD or UC patients from healthy controls with ROC AUCs of 0.940 (95% confidence interval (CI): 0.898-0.983) and 0.894 (95%CI: 0.853-0.935), respectively in validation samples (CD, n = 63; UC, n = 120; healthy controls, n = 108). In addition, other indexes appeared to be a measure of disease activity. These indexes distinguished active CD or UC patients from each remission patients with ROC AUCs of 0.894 (95%CI: 0.853-0.935) and 0.849 (95%CI: 0.770-0.928), and correlated with clinical disease activity indexes for CD (r(s) = 0.592, 95%CI: 0.385-0.742, p<0.001) or UC (r(s) = 0.598, 95%CI: 0.452-0.713, p<0.001), respectively. CONCLUSIONS AND SIGNIFICANCE: In this study, we demonstrated that established multivariate indexes composed of plasma amino acid profiles can serve as novel, non-invasive, objective biomarkers for the diagnosis and monitoring of IBD, providing us with new insights into the pathophysiology of the disease
Impaired Prefrontal Hemodynamic Maturation in Autism and Unaffected Siblings
BACKGROUND: Dysfunctions of the prefrontal cortex have been previously reported in individuals with autism spectrum disorders (ASD). Previous studies reported that first-degree relatives of individuals with ASD show atypical brain activity during tasks associated with social function. However, developmental changes in prefrontal dysfunction in ASD and genetic influences on the phenomena remain unclear. In the present study, we investigated the change in hemoglobin concentration in the prefrontal cortex as measured with near-infrared spectroscopy, in children and adults with ASD during the letter fluency test. Moreover, to clarify the genetic influences on developmental changes in the prefrontal dysfunction in ASD, unaffected siblings of the ASD participants were also assessed. METHODOLOGY/PRINCIPAL FINDINGS: Study participants included 27 individuals with high-functioning ASD, age- and IQ-matched 24 healthy non-affected siblings, and 27 unrelated healthy controls aged 5 to 39 years. The relative concentration of hemoglobin ([Hb]) in the prefrontal cortex was measured during the letter fluency task. For children, neither the [oxy-Hb] change during the task nor task performances differed significantly among three groups. For adults, the [oxy-Hb] increases during the task were significantly smaller in the bilateral prefrontal cortex in ASD than those in control subjects, although task performances were similar. In the adult siblings the [oxy-Hb] change was intermediate between those in controls and ASDs. CONCLUSION/SIGNIFICANCE: Although indirectly due to a cross-sectional design, the results of this study indicate altered age-related change of prefrontal activity during executive processing in ASD. This is a first near-infrared spectroscopy study that implies alteration in the age-related changes of prefrontal activity in ASD and genetic influences on the phenomena
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