Partial urethral obstruction of rabbit urinary bladder: stereological evidence that the increase in muscle content is mostly driven by changes in number, rather than size, of smooth muscle cells

The effects of partial urethral obstruction on the detrusor muscle of rabbit urinary bladder were investigated using stereological sampling and estimation tools. Twelve female Norfolk rabbits (2.5-3.0 kg body weight) were divided into four groups: 3, 7 and 12 weeks after surgical intervention to produce a standard partial obstruction and unobstructed controls. Following removal, bladder axes (craniocaudal, dorsoventral and laterolateral) and organ weights were recorded. Bladders were prepared for light microscopy by multistage random sampling procedures. Stereological methods were used to estimate the volume of muscle and the packing density and total number of myocyte nuclei in each bladder. We also estimated mean myocyte volume and the mean cross-sectional area and length of myocytes. Group comparisons were made by one-way analysis of variance. Changes in bladder axes were mainly laterolateral and craniocaudal. Mean bladder weight increased roughly six-fold by 3 weeks and 17-fold by 12 weeks and was accompanied, on average, by 12- and 33-fold increases in total muscle volume. These variables did not differ at 3 and 7 weeks post-obstruction. Increases in muscle content were not accompanied by changes in packing densities but were associated with increases in the total numbers of myocyte nuclei (13-fold by 3 weeks, 28-fold by 12 weeks). Mean myocyte volume did not vary significantly between groups but cells in obstructed groups were shorter and wider. These findings support the notion that partial outflow obstruction leads to an increase in the number, but not mean volume, of myocytes. If due solely to myocyte mitosis, the total of 43 x 10(8) cells found at 12 weeks could be generated by the original complement of 15 x 10(7) cells if an average of only 2.1 x 10(6) new cells was produced every hour. In reality, even this modest proliferation rate is unlikely to be achieved because myocyte proliferation rates are very low and it is possible that new myocytes can arise by differentiation of mesenchymal or other precursor cells.     

A new DNA binding protein highly conserved in diverse crenarchaeal viruses

Sulfolobus turreted icosahedral virus (STIV) infects Sulfolobus species found in the hot springs of Yellowstone National Park. Its 37 open reading frames (ORFs) generally lack sequence similarity to other genes. One exception, however, is ORF B116. While its function is unknown, orthologs are found in three additional crenarchaeal viral families. Due to the central importance of this protein family to crenarchaeal viruses, we have undertaken structural and biochemical studies of B116. The structure reveals a previously unobserved fold consisting of a five-stranded beta-sheet flanked on one side by three alpha helices. Two subunits come together to form a homodimer with a 10-stranded mixed beta-sheet, where the topology of the central strands resembles an unclosed beta-barrel. Highly conserved loops rise above the surface of the saddle-shaped protein and suggest an interaction with the major groove of DNA. The predicted B116-DNA interaction is confirmed by electrophoretic mobility shift assays.     

Dissociation of dorsal root ganglion neurons induces hyperexcitability that is maintained by increased responsiveness to cAMP and cGMP

Injury or inflammation affecting sensory neurons in dorsal root ganglia (DRG) causes hyperexcitability of DRG neurons that can lead to spontaneous firing and neuropathic pain. Recent results indicate that after chronic compression of DRG (CCD treatment), both hyperexcitability of neurons in intact DRG and behaviorally expressed hyperalgesia are maintained by concurrent activity in cAMP-protein kinase A (PKA) and cGMP-protein kinase G (PKG) signaling pathways. We report here that when tested under identical conditions, dissociation produces a pattern of hyperexcitability in small DRG neurons similar to that produced by CCD treatment, manifest as decreased action potential (AP) current threshold, increased AP duration, increased repetitive firing to depolarizing pulses, increased spontaneous firing and resting depolarization. A novel feature of this hyperexcitability is its early expression-as soon as testing can be conducted after dissociation (approximately 2 h). Both forms of injury increase the electrophysiological responsiveness of the neurons to activation of cAMP-PKA and cGMP-PKG pathways as indicated by enhancement of hyperexcitability by agonists of these pathways in dissociated or CCD-treated neurons but not in control neurons. Although inflammatory signals are known to activate cAMP-PKA pathways, dissociation-induced hyperexcitability is unlikely to be triggered by signals released from inflammatory cells recruited to the DRG because of insufficient time for recruitment during the dissociation procedure. Inhibition by specific antagonists indicates that continuing activation of cAMP-PKA and cGMP-PKG pathways is required to maintain hyperexcitability after dissociation. The reduction of hyperexcitability by blockers of adenylyl cyclase and soluble guanylyl cyclase after dissociation suggests a continuing release of autocrine and/or paracrine factors from dissociated neurons and/or satellite cells, which activate both cyclases and help to maintain acute, injury-induced hyperexcitability of DRG neurons.     

《预包装食品标签通则》(GB7718-2011)跟踪评价及对策建议

本研究对全国8个省市执行《预包装食品标签通则》(GB7718-2011)执行情况进行了跟踪评价情况分析。分析结果显示:生产企业的预包装食品名称标示符合GB7718标准要求的显著高于商场超市和农贸市场。商场超市预包装食品配料表标示以及配料表中添加剂的标示形式符合标准要求的显著高于农贸市场和生产企业。商场超市和生产企业的预包装食品标准代号标示符合标准要求的显著高于农贸市场。被调查的监管部门和食品生产经营单位GB7718标准知晓率为94.92%,社会公众调查该标准知晓率为78.35%。调查的各级监管部门和食品生产经营单位中有70.85%组织宣贯培训过该标准。各级监管部门和食品生产经营单位中有30.49%认为食品添加剂标示形式太复杂为主要难度内容,有16.59%认为配料表标示内容等要求太严。大部分监管部门和食品生产经营单位没有反馈过对GB7718标准的意见或建议。建议管理部门要重视标准工作,提升食品安全保障能力;要广泛吸纳意见,进一步完善标准的科学性和操作性;强化标准的宣传培训,提高标准的应用能力;进一步完善标准的跟踪评价机制;加强部门协作互享信息,提高标准执行力。     

吗替麦考酚酯联合泼尼松治疗进展性IgA肾病的效果

目的 探讨吗替麦考酚酯（MMF）联合泼尼松治疗进展性免疫球蛋白A(Ig A)肾病的效果。方法 选取2020年1月至2022年6月于新余市人民医院治疗的50例进展性Ig A肾病患者作为研究对象,按随机数字表法将其分为他克莫司（FK506）组与MMF组,每组各25例。FK506组采用FK506+泼尼松治疗,MMF组采用MMF+泼尼松治疗。比较两组患者的临床疗效、实验室指标及不良反应。结果 MMF组患者总有效率高于FK506组,差异有统计学意义（P<0.05）。治疗后,两组患者的24 h尿蛋白定量均低于本组治疗前,白蛋白（ALB）均高于本组治疗前,且MMF组患者24 h尿蛋白定量低于FK506组,差异有统计学意义（P<0.05）;治疗后,两组患者的ALB、血肌酐（SCr）、尿酸（UA）、葡萄糖（Glu）、天冬氨酸转氨酶（AST）、丙氨酸转氨酶（ALT）、总胆红素（TBil）比较,差异无统计学意义（P>0.05）。两组患者的不良反应总发生率比较,差异无统计学意义（P>0.05）。结论 进展性Ig A肾病患者采用MMF联合泼尼松治疗有利于降低24 h尿蛋白定量,提高ALB...     

二度房室传导阻滞并3相不完全性右束支传导阻滞及4相完全性右束支传导阻滞1例

1病例报告 患者,女性,56岁.因胸闷,心悸2天来院就诊.体检:BP:130/90mmHg,心界不大,心率68次/分,律不齐,未闻及病理性杂音.