Potential of intestinal electrical stimulation for obesity: a preliminary canine study

Objective: The aims of this study were to investigate the therapeutic potential of intestinal electrical stimulation (IES) for obesity. Experiments were performed to investigate the effects of IES on food intake, gastric tone, gastric accommodation, and its possible pathway. Research Methods and Procedures: Ten normal dogs and six dogs with truncal vagotomy were used in this study. Each dog was equipped with a gastric cannula for the measurement of gastric tone and accommodation by barostat and one pair of duodenal serosal electrodes for IES. The experiment on food intake was composed of both control session without IES and IES session after a 28‐hour fast. The experiment on gastric tone and accommodation was performed in the fasting and fed states and composed of three sessions: control, IES, and IES with N^G‐nitro‐l ‐arginine. Results: IES significantly reduced food intake in the normal dogs (459.0 vs. 312.6 grams, p < 0.001). The food intake was negatively correlated with the fasting gastric volume during IES. IES significantly decreased fasting gastric tone in the normal dogs reflected as a decrease in gastric volume (89.1 vs. 261.3 mL, p < 0.01), which was abolished by vagotomy and N^G‐nitro‐l ‐arginine. Discussion: IES reduces food intake and inhibits gastric tone in the fasting state. The inhibitory effect of IES on gastric tone is mediated by both vagal and nitrergic pathway.     

Coxsackievirus entry across epithelial tight junctions requires occludin and the small GTPases Rab34 and Rab5

The major group B coxsackievirus (CVB) receptor is a component of the epithelial tight junction (TJ), a protein complex that regulates the selective passage of ions and molecules across the epithelium. CVB enters polarized epithelial cells from the TJ, causing a transient disruption of TJ integrity. Here we show that CVB does not induce major reorganization of the TJ, but stimulates the specific internalization of occludin-a TJ integral membrane component-within macropinosomes. Although occludin does not interact directly with virus, depletion of occludin prevents CVB entry into the cytoplasm and inhibits infection. Both occludin internalization and CVB entry require caveolin but not dynamin; both are blocked by inhibitors of macropinocytosis and require the activity of Rab34, Ras, and Rab5, GTPases known to regulate macropinocytosis. Thus, CVB entry depends on occludin and occurs by a process that combines aspects of caveolar endocytosis with features characteristic of macropinocytosis.     

The cyclic AMP cascade is altered in the fragile X nervous system

Fragile X syndrome (FX), the most common heritable cause of mental retardation and autism, is a developmental disorder characterized by physical, cognitive, and behavioral deficits. FX results from a trinucleotide expansion mutation in the fmr1 gene that reduces levels of fragile X mental retardation protein (FMRP). Although research efforts have focused on FMRP's impact on mGluR signaling, how the loss of FMRP leads to the individual symptoms of FX is not known. Previous studies on human FX blood cells revealed alterations in the cyclic adenosine 3', 5'-monophosphate (cAMP) cascade. We tested the hypothesis that cAMP signaling is altered in the FX nervous system using three different model systems. Induced levels of cAMP in platelets and in brains of fmr1 knockout mice are substantially reduced. Cyclic AMP induction is also significantly reduced in human FX neural cells. Furthermore, cAMP production is decreased in the heads of FX Drosophila and this defect can be rescued by reintroduction of the dfmr gene. Our results indicate that a robust defect in cAMP production in FX is conserved across species and suggest that cAMP metabolism may serve as a useful biomarker in the human disease population. Reduced cAMP induction has implications for the underlying causes of FX and autism spectrum disorders. Pharmacological agents known to modulate the cAMP cascade may be therapeutic in FX patients and can be tested in these models, thus supplementing current efforts centered on mGluR signaling.     

BMI and retinal vascular caliber in children

Objective: In adult populations, changes in retinal vascular caliber have been linked with obesity and metabolic syndrome. We examined the association of BMI and weight with retinal vascular caliber in children. Research Methods and Procedures: This was a school‐based, cross‐sectional study of 768 children, 7 to 9 years old, randomly sampled from the Singapore Cohort Study of the Risk Factors for Myopia. Participants had digital retinal photographs. Retinal vascular caliber was measured using a computer‐based program and combined to provide average calibers of arterioles and venules in that eye. Weight and height were measured using standardized protocol. These data were used to calculate BMI. Results: In this population, the mean retinal arteriolar and venular calibers were 156.40 μm [95% confidence interval (CI), 155.44 to 157.36] and 225.43 μm (95% CI, 224.10 to 226.74) respectively. After controlling for age, gender, race, parental monthly income, axial length, birth weight, and birth length, each 3.1 kg/m² (standard deviation) increase in BMI was associated with a 2.55‐μm (95% CI, 1.21 to 3.89; p < 0.001) larger retinal venular caliber. In multivariable analysis, greater weight was also significantly associated with larger retinal venular caliber. BMI and weight were not associated with retinal arteriolar caliber. Height was not significantly associated with retinal arteriolar or venular caliber. Discussion: Greater BMI and weight are associated with larger retinal venular caliber in healthy children.     

Identification of the gene imds-60 in mouse epididymis

Sperm maturation, including the acquisition of motility and the full ability to fertilize oocyte, occurs during its transit through the dynamic environment of the epididymis. However, the roles of many genes involved in the process of sperm maturation still remain to be found. Based on an expressed sequence tag named imds-60, which was first found in uterus but is highly expressed in epididymis, the full-length cDNA sequence of imds-60 with a complete open reading frame was obtained in mouse epididymis by GenBank searching, polymerase chain reaction-based procedures, and 5＇- and 3＇-rapid amplification of cDNA ends. This protein was predicted to have an N-terminal signal peptide and a C-terminal DNase I-like domain with nine transmembrane motifs in the middle part of the protein. Northern blot analysis showed that the mRNA of imds-60 was highly expressed in epididymis but at a rather lower level in uterus, seminal vesicle gland, and stomach. Further study revealed that the mRNA of imds-60 is only expressed in corpus and cauda regions of epididymis, not in caput. It is regulated partially by androgen and peaked in male mice aged from 3 weeks to adult. The imds-60 protein might play an important role in cell communication during sperm maturation.     

肾上腺素对THP-1巨噬细胞TGF-β1、SR-A1和CD36表达的影响

目的:探讨肾上腺素对THP-1巨噬细胞TGF-β1、SR-A1和CD36表达的影响。方法:不同浓度肾上腺素处理THP-1巨噬细胞24h,运用逆转录多聚酶链反应检测其TGF-β1、SR-A1和CD36的mRNA表达,酶联免疫吸附试验检测TGF-β1蛋白的表达,Westem-blotting检测SR-A1蛋白的表达。结果:100nmol/L及1μmol/L的肾上腺素作用THP-1巨噬细胞,引起TGF-β1 mR- NA和蛋白表达下调(p<0.05),SR-A1 mRNA和蛋白表达上调(P<0.05),1pmol/L～1μmol/L的肾上腺素处理后,各组CD36 mRNA水平无显著性变化(p>0.05)。结论:应激浓度的肾上腺素可能通过影响TGF-β1和SR-A1的表达而参与和/或促进AS的发生发展。     

CDC6靶向RNA干扰质粒载体的构建及生物活性鉴定

目的:构建小鼠CDC6基因的RNAi真核表达载体PGCsilencer TM u6/Neo/GFP/RNAi,观察其转染小鼠肝细胞前后CDC6的表达变化。方法:根据GenBank中CDC6的序列,设计特异性siRNA序列,将模板序列克隆至PGCsilencer U6/Neo/GFP质粒中,通过测序鉴定后,用脂质体将重组子转染至正常小鼠肝细胞中,用RT-PCR检测CDC6的mRNA的表达及用Western blot方法检测CDC6蛋白水平的表达,并比较转染前后其表达水平的变化。结果:经测序,模板序列与设计序列完全正确,经过RT-PCR及Western blot方法检测,转染干扰质粒后,小鼠肝细胞中CDC6表达在mRNA及蛋白水平都有明显的下降。结论:成功构建了CDC6基因的RNAi真核表达载体并转染至小鼠肝细胞中,为下一步探讨CDC6在肝再生的作用奠定了基础。     

基于电子病历的急性ST段抬高型心肌梗死临床路径与决策辅助系统

目的:研究在结构化电子病历上实现计算机化的急性ST段抬高型心肌梗死临床路径,进一步评价该方法的试用结果,为辅助临床医生治疗决策、规范治疗行为,并借此提高医疗质量,合理控制医疗费用提供有效的手段。方法:选取最新的、具有权威性的关于急性ST段抬高型心肌梗死诊治指南作为制定治疗决策方案及编写临床路径的依据;通过程序设计将临床路径编写入医学知识库系统,并将医学知识库系统与结构化电子病历进行无缝连接;将20例无严重并发症的急性ST段抬高型心肌梗死病人均分为两组,其中观察组推行计算机化临床路径,在患者住院天数、住院费用、患者及家属满意度以及医生对该系统的评价方面与对照组进行比较。结果:观察组患者平均住院天数及平均住院费用明显低于对照组(p＜0．000);患者及家属满意度普遍提高(p＜0．05);该系统得到所有被调查医生的认可。结论:运用计算机化临床路径管理无严重并发症的急性ST段抬高型心肌梗死患者能在维持甚至提高医疗质量的前提下,减少患者平均住院天数、平均住院费用,提高患者及家属对医疗行为的满意度,增强医生对治疗指南的顺从性。     

环孢素A对人早孕期滋养细胞MMP-9与MMP-2表达的调控作用

本研究的目的是探讨环孢素A对人早孕期滋养细胞侵袭能力及基质金属蛋白酶9与2 (matrix metalloproteinase 9 and 2,简称MMP-9与MMP-2)表达的调节作用,为治疗反复自然流产等妊娠疾患提供新的线索。侵袭试验观察CsA对人早孕期滋养细胞侵袭能力的调节作用;RT-PCR与明胶酶谱分析CsA对滋养细胞MMP-9与MMP-2 mRNA及蛋白水平表达的影响;In-cell West- ern检测CsA作用后滋养细胞ERK1/2磷酸化水平。结果发现,1．0μmol/L CsA明显增强滋养细胞侵袭能力,MEK激酶抑制剂U0126可抑制CsA对滋养细胞的促侵袭作用;1．0μmol/L CsA可诱导MMP- 9与MMP-2基因的转录与蛋白分泌;该诱导效应同样可被U0126所阻滞;1．0μmol/L CsA以时间依赖方式促进ERK1/2的磷酸化。结果表明,CsA可激活ERK1/2,通过MAPK/ERK1/2途径促进滋养细胞MMP-9与MMP-2基因的转录与蛋白分泌,从而增强滋养细胞的侵袭能力,对滋养细胞生物学功能具有良性调节作用。