Protective effect of indoleamines on in vitro ascorbate-Fe2+ dependent lipid peroxidation of rod outer segment membranes of bovine retina

Rod outer segment membranes (ROS) are highly vulnerable to autooxidation because of their high content of long chain polyunsaturated fatty acids (PUFAs). Melatonin and N-acetylserotonin are indoleamines synthesized in the pineal gland, retina and other tissues. These compounds are free radical scavengers and indirect antioxidants because of their stimulatory effect on antioxidative enzymes. We compared the in vitro protective effect of melatonin and N-acetylserotonin on the ascorbate-Fe2+ induced lipid peroxidation of PUFAs located in ROS membranes. This process was measured by chemiluminescence and fatty acid composition of total lipids of ROS. We assayed increasing concentrations of melatonin (0-10 mm) and N-acetylserotonin (0-2 mm). In both cases the total cpm originated from light emission (chemiluminescence) was found to be lower in those membranes incubated in the presence of either melatonin or N-acetylserotonin; this decreased proportional to the concentration of the indole. Thus, 10 mm melatonin and 2 mm N-acetylserotonin produced a reduction of 51 +/- 6 and 100% in the total chemiluminescene (lipid peroxidation), respectively. We also noticed a PUFAs protection: the docosahexaenoic acid content decreased considerably when the membranes were submitted to oxidative damage. This reduction was from 37.6 +/- 2.1% in the native membranes to 6.2 +/- 0.8% in those which were peroxidized. These changes were less pronounced in treated ROS membranes; as an example in the presence of 10 mm melatonin or 2 mm N-acetylserotonin we observed a content preservation of 22:6 n-3 (23.6 +/- 1.2 and 39.1 +/- 1.2% respectively). The concentration of each compound required to inhibit 50% of the lipid peroxidation (IC50) was 9.82 mm for melatonin and 0.43 mm for N-acetylserotonin, respectively. N-acetylserotonin shows a protective effect about 20 times higher than that of melatonin.     

AII amacrine cells express the MT1 melatonin receptor in human and macaque retina

AII amacrine cells are critical interneurons in the rod pathway of mammalian retina, active primarily in dim lighting conditions. Melatonin, a neuromodulator produced at night in the retina, is believed to induce retinal adaptation to dim lighting conditions in most vertebrate species examined to date, including humans. We hypothesized that melatonin may influence retinal light adaptation by acting on AII cells directly and thus investigated whether melatonin receptors were expressed in AII neurons. Postmortem nonpathological eyes from four human donors as well as two eyes from two Macaque Fasicularis monkeys were analyzed. Double immunocytochemistry was performed using an anti-MT(1) antibody and an antibody to calretinin, an AII marker. Analysis utilized confocal microscopy. A polyclonal anti-calretinin antibody labelled amacrine cells exhibiting the distinct AII morphology, in both human and macaque retina. MT(1) immunoreactivity in macaque retina was similar to human staining, in that horizontal, amacrine and ganglion cell bodies were stained, as were inner segments of photoreceptors. In human retina 86% of calretinin positive cells expressed the MT(1) receptor peripherally, whereas centrally, 78% colocalization was observed. In the macaque retina, 100% of AII amacrine cells expressed MT(1) immunoreactivity both centrally and peripherally. That virtually all AII neurons express the MT(1) receptor in both human and macaque retina, may provide the first evidence demonstrating a role for melatonin in AII regulation, furthering the hypothesis of melatonin function in retinal light adaptation.     

《金匮要略》“身痛如被杖”相关问题探讨

[目的] 分析《金匮要略·阴阳毒》“身痛如被杖”的含义，以更好地理解仲景所述之意。[方法] 通过采用传世文献与出土文物考证相结合的研究方式，结合文字学、历史学角度探讨，并附医案一则。[结果] “身痛如被杖”是时人描述切身体会的生动表达。“杖”可理解“凡可持之物皆曰杖”，“被杖”分皮肤肿起，出现瘀伤；出现损伤；殴打致死这三种情况。痛感可能是外伤(皮肤肌肉)之痛，也可能是内伤(脏腑受伤)之痛。升麻鳖甲汤总以解毒散邪活血为主，气血兼顾。[结论] 在仲景所属时代，“身痛如被杖”有一定的区分度，表现在施杖方式及痛感等的区分。通过文献与文物考证相结合的方式探讨“身痛如被杖”，更能直观体会当时社会背景下仲景所要表达的含义，提供一个学习《金匮要略》的新方式。     

替硝唑棒剂的制备及临床疗效

目的 :研究替硝唑棒剂的制备及质量控制方法 ,并观察其临床疗效。方法 :采用紫外分光光度法测定替硝唑的含量 ,并对45例牙周病患者进行临床疗效观察。结果 :替硝唑的平均回收率为99 06 % ,RSD=1 03 % ;对牙周病显效率为93 33 %。结论 :替硝唑棒剂的制备工艺合理 ,性质稳定 ,质控方法可行 ;疗效可靠 ,有推广应用价值     

Antibiotic-resistant organisms in the neonatal intensive care unit

Neonates, particularly those born prematurely, are at an increased risk of bacterial infection. Empiric treatment with antimicrobials occurs frequently in the neonatal intensive care unit (NICU). Repeated and/or prolonged courses of antibiotic exposure have resulted in an increase in the prevalence of hospital-acquired, antibiotic-resistant organisms such as methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, and multidrug-resistant Gram-negative rods. As bacterial strains become increasingly resistant to standard antimicrobial therapy, measures to control and prevent this problem are essential. Current efforts have focused on monitoring and restricting the use of antimicrobials, proper hand hygiene, evaluation of potential reservoirs of bacterial acquisition and transmission, cohorting and isolation of colonized infants, decolonization strategies, and fostering of effective inter- and intrahospital communication.     

NEB‐related core‐rod myopathy with distinct clinical and pathological features

Introduction: Mutations in the gene encoding nebulin (NEB) are known to cause several types of congenital myopathy including recessive nemaline myopathy and distal nebulin myopathy. Core‐rod myopathy has recently been reported to be another type of NEB‐related myopathy, and is pathologically characterized by the coexistence of cores and nemaline rods within muscle fibers. Methods: We describe 2 patients with core‐rod myopathy who were analyzed genetically by whole exome sequencing and evaluated clinically and pathologically. Findings were compared with those of patients with the disease of other genetic causes. Results: Three NEB mutations were identified, 2 of which were novel. Mild clinical features, unusual patterns of muscle involvement, and atypical pathological findings were observed. Conclusions: We propose that the clinical and pathological spectrum of core‐rod myopathy should be widened. A significant amount of residual nebulin expression is believed to contribute to the much milder phenotype exhibited by the patients we describe here. Muscle Nerve 53: 479–484, 2016     

髓心减压钽棒假体植入治疗股骨头坏死的临床疗效

目的探讨钽棒假体植入治疗股骨头缺血性坏死的临床疗效。方法选择42例（47髋）缺血性股骨头坏死患者,随机分为治疗组24例（26髋）及对照组18例（21髋）,治疗组采用髓心减压钽棒植入治疗,对照组采用髓心减压加自体腓骨移植术治疗。比较两组患者术中情况、术后恢复时间及术后髋关节功能。结果治疗组手术时间及术中出血量少于对照组（P〈0.01）,治疗组患者住院时间短于对照组（P〈0.05）,两组患者术后Harris评分差异无统计学意义（P〉0.05）。结论髓心减压钽棒植入术手术创伤相对较小,有利于患者术后恢复,治疗股骨头坏死具有较好疗效。     

经伤椎椎弓根椎体内植骨结合短节段钉棒系统内固定治疗胸腰椎爆裂性骨折的临床研究

目的探讨经伤椎椎弓根椎体内植骨结合短节段钉棒系统内固定治疗胸腰椎爆裂性骨折的临床疗效。方法选取本院2009年10月～2011年4月收治的胸腰椎爆裂性骨折患者34例,采用经伤椎椎弓根椎体内植骨结合短节段钉棒系统内固定治疗．比较患者治疗前后的临床指标并进行Frankel分级评定。结果患者手术时间为（127．6±14．8）min,术中出血量为（457．9±103．4）mL,术后24h伤口引流量为（264．3±47．2）mL,骨折愈合时间为（15．0~3．6）周。随访1年后,发生感染2例,断钉1例,脊柱曲度异常改变1例,并发症发生率为11．8％。患者术后伤椎前缘高度和伤椎后缘高度均明显大于术前,患者术后Cobb角和椎管容积减少比均明显小于术前,患者术后Frankel分级评定情况明显好于术前,差异均有统计学意义（P〈0．05）。结论经伤椎椎弓根椎体内植骨结合短节段钉棒系统内固定治疗胸腰椎爆裂性骨折可以有效增强患者伤椎前中柱的稳定性和抗压能力．手术创伤小且安全性高．术后并发症发生率较低,值得临床推广使用。     

Rod and cone input to horizontal cells in the rabbit retina

In the rabbit retina, there are two types of horizontal cell (HC). The A-type HC is axonless and extensively coupled. The B-type HC is axon bearing; the somatic dendrites are radially symmetric and form a second coupled network, while the axon branches expansively to form a complex terminal structure. The B-type axon terminals (ATs) are independently coupled to form a third network in the outer plexiform layer. We have modified our dye-injection methods to obtain detailed fills of the three different horizontal cell networks for analysis via confocal microscopy. We have confirmed that A-type HCs and the somatic dendrites of B-type HCs receive input exclusively from cones, whereas the B-type ATs receive input only from rods. A single B-type AT may receive input from as many as 1,000 rods, but, surprisingly, our data reveal only one end terminal per rod spherule. The somatic dendrites of A- and B-type HCs form clusters at each cone pedicle coincident with GluR2/3 and GluR4 glutamate receptor subunits. The B-type ATs have GluR2/3- or GluR4-labeled glutamate receptors in two locations: small puncta on the end terminals within the rod spherule invagination and large clusters on the terminal stalks, approximately 1.5 microm from the rod synaptic ribbon. We conclude that AMPA receptors of the same or similar composition mediate photoreceptor input to all types of HCs.     

Differential loss and preservation of glutamate receptor function in bipolar cells in the rd10 mouse model of retinitis pigmentosa

Photoreceptor degenerations can trigger morphological alterations in second-order neurons, however, the functional implications of such changes are not well known. We conducted a longitudinal study, using whole-cell patch-clamp, immunohistochemistry and electron microscopy to correlate physiological with anatomical changes in bipolar cells of the rd10 mouse – a model of autosomal recessive retinitis pigmentosa. Rod bipolar cells (RBCs) showed progressive changes in mGluR6-induced currents with advancing rod photoreceptor degeneration. Significant changes in response amplitude and kinetics were observed as early as postnatal day (P)20, and by P45 the response amplitudes were reduced by 91%, and then remained relatively stable until 6 months. These functional changes correlated with the loss of rod photoreceptors and mGluR6 receptor expression. Moreover, we showed that RBCs make transient ectopic connections with cones during progression of the disease. At P45, ON-cone bipolar cells (ON-CBCs) retain mGluR6 responses for longer periods than the RBCs, but by about 6 months these cells also strongly downregulate mGluR6 expression. We propose that the relative longevity of mGluR6 responses in CBCs is due to the slower loss of the cones. In contrast, ionotropic glutamate receptor expression and function in OFF-CBCs remains normal at 6 months despite the loss of synaptic input from cones. Thus, glutamate receptor expression is differentially regulated in bipolar cells, with the metabotropic receptors being absolutely dependent on synaptic input. These findings define the temporal window over which bipolar cells may be receptive to photoreceptor repair or replacement.