Identification and Characterization of the First Cholesterol-Dependent Cytolysins from Gram-Negative Bacteria

The cholesterol-dependent cytolysins (CDCs) are pore-forming toxins that have been exclusively associated with a wide variety of bacterial pathogens and opportunistic pathogens from the Firmicutes and Actinobacteria, which exhibit a Gram-positive type of cell structure. We have characterized the first CDCs from Gram-negative bacterial species, which include Desulfobulbus propionicus type species Widdel 1981 (DSM 2032) (desulfolysin [DLY]) and Enterobacter lignolyticus (formerly Enterobacter cloacae) SCF1 (enterolysin [ELY]). The DLY and ELY primary structures show that they maintain the signature motifs of the CDCs but lack an obvious secretion signal. Recombinant, purified DLY (rDLY) and ELY (rELY) exhibited cholesterol-dependent binding and cytolytic activity and formed the typical large CDC membrane oligomeric pore complex. Unlike the CDCs from Gram-positive species, which are human- and animal-opportunistic pathogens, neither D. propionicus nor E. lignolyticus is known to be a pathogen or commensal of humans or animals: the habitats of both organisms appear to be restricted to anaerobic soils and/or sediments. These studies reveal for the first time that the genes for functional CDCs are present in bacterial species that exhibit a Gram-negative cell structure. These are also the first bacterial species containing a CDC gene that are not known to inhabit or cause disease in humans or animals, which suggests a role of these CDCs in the defense against eukaryote bacterial predators.     

The Role of Adult Perceptions and Supervision Behavior in Preventing Child Injury

Supervision is an important factor in reducing injury risk. There are multiple factors that can affect the appropriate level of supervision including risk perception, anticipation of injury, and distracted behaviors. This study examined the perceived risks of child injury among parents and child caregivers and their supervision behavior among adults in an urban playground. Participant data from 25 individuals were collected through observations and anonymous self-reported surveys. More than half of the participants indicated practice of appropriate supervisory behavior, including attentiveness to their child’s behavior and proximity to their child during play. Caregivers were more likely to report more careful levels of supervision. One-fourth of participants reported a change in the supervisory behavior during periods of distraction, specifically with phone use. Of the variables tested, there was a significant association between the variable ‘talking to other adults’ during supervision and ‘prior injury’ (P value?=?0.04, 95% CI 0.03–0.91). Parents were more likely to report that they would leave their child unattended if they believed that the playground was a safe environment for play. There was a difference between self-reported behaviors and actual observed behavior, which is likely due to varying perspectives regarding child safety and injury prevention. In regards to injury risk, findings highlight the important role of appropriate supervisory behaviors and risk perceptions in preventing child injuries.     

孙丽平教授治疗小儿唇风经验

孙丽平教授认为,小儿唇风的发生不外乎内、外二因,心脾积热是导致唇风发生的关键因素.治疗小儿唇风,重在清心泻脾,扶正祛邪.内治法采用泻黄散合导赤散加减为主方,外治法配合本院自制黄连膏,在临床应用中取得满意疗效.     

Effects of bilateral lesion of the locus coeruleus and of neonatal administration of 6-hydroxydopamine on the concentration of individual proteins in rat brain

The role that norepinephrine plays in regulating the concentration of different proteins in the parietal cortex, hippocampus and cerebellum was assessed by investigating the effects of either a bilateral lesion of the locus coeruleus or neonatal administration of 6-hydroxydopamine. Two weeks after lesioning the locus coeruleus, the concentration of two different proteins was elevated in the hippocampus; a third protein was reduced in concentration in this brain area as a result of the lesion. Three proteins were affected in concentration in the cerebellum after the locus coeruleus lesion--two were elevated in concentration and one was reduced in concentration. No proteins were altered in concentration in the parietal cortex as a result of the lesion. Seventy days after neonatal treatment with 6-hydroxydopamine, a total of 6 proteins were found to be changed. Four of these (one in the hippocampus and 3 in the parietal cortex) were reduced in concentration while two proteins (both in the cerebellum) were elevated in concentration after neonatal treatment with the catecholamine neurotoxin. There was little overlap between those proteins affected in concentration by the bilateral lesion of the locus coeruleus and those changed by neonatal treatment with 6-hydroxydopamine. These results suggest that the concentration of a number of different proteins may, under normal physiological conditions, be regulated in vivo by norepinephrine in the brain.     

Effects of pycnogenol on the microsomal metabolism of the tobacco-specific nitrosamine NNK as a function of age.

NNK is a potent environmental carcinogen to which smokers and non-smokers are exposed. The response to NNK can be altered by various factors including nutrition. In this study, we examined the effects of pycnogenol on the in vitro metabolism of the tobacco-specific nitrosamine NNK by liver and lung microsomes from 6- and 20-month-old male F344 rats. The major NNK metabolic pathway in liver microsomes was carbonyl reduction, while alpha-hydroxylation was the major pathway in lung microsomes irrespective of age. Pycnogenol (40 and 120 microg/ml) exhibited a statistically significant inhibition of carbonyl reduction and alpha-hydroxylation pathways in liver microsomes from both age groups and in addition to these pathways, pycnogenol inhibited the N-oxidation pathway in lung microsomes. The liver and lung microsomes from 20-month-old rats were less active than from 6-month-old rats although the difference was not statistically significant.     

21羟化酶缺乏致女性假两性畸形的治疗效果

目的 探讨21-羟化酶缺乏（21-hydroxylase deficiency，21-OHD）致女性假两性畸形的临床诊断及治疗方法。方法 21-羟化酶缺乏症患者24例，女，平均年龄5岁8个月。临床表现为男性化征象，阴蒂肥大、外生殖器模糊不清、身材粗壮、声音低沉等，经醋酸氢化可的松替代治疗3～6个月后，采用保留阴蒂头阴蒂缩短整形术13例，阴蒂阴道成形术11例。结果 随诊2个月～7年，24例均完整保留了阴蒂头组织，22例外阴基本达到正常女性外观，2例阴道开口位置较高者尚待再行阴道成形术。8例进入青春期患者有正常女性性征出现。结论 21-羟化酶缺乏导致的女性假两性畸形应首先行内分泌治疗，外阴显著异常者需结合外阴矫形术，以达到满意效果。     

运用健康信念模式分析影响蒙、汉族婴幼儿母乳喂养的因素

目的比较蒙、汉族婴幼儿母乳喂养状况,探讨健康信念模式在分析母乳喂养影响因素中的作用,为提高母乳喂养率提供建议。方法依据健康信念模式自行设计问卷,采用分层随机整群抽样方法,对117名蒙族婴幼儿母亲和218名汉族婴幼儿母亲进行入户访谈式问卷调查,资料收集时间为2004年4月。结果蒙、汉族婴幼儿4个月母乳喂养率分别为79.5%和73.4%,平均开奶时间为54.5小时,平均断母乳时间为15.4个月,蒙、汉族差异无显著性。蒙族母亲较汉族母亲感知到的母乳喂养益处更多,而障碍更少,二者的差异有显著性。运用健康信念模式分析显示,母乳喂养障碍和母亲年龄是影响母乳喂养的主要因素,R2=0.462,母乳喂养障碍越少,母亲越年轻,越有利于母乳喂养。结论母乳喂养障碍为影响母乳喂养的主要可变因素,蒙、汉族婴幼儿母乳喂养水平相当;健康信念模式可以在一定程度上解释和预测母乳喂养行为。     

紫外分光光度法测定萘普生钠含量

本实验发现普生钠水溶液在波长266nm处有特征吸收峰,浓度在10μg/ml～50μg/ml符合Beer定律,γ=0.9996(P<0.01).本法回收率为100.21%(CV=0.11%).实验结果表明本法与美国药典法测定结果相似.     

高效液相色谱法测定莫达非尼及其胶囊剂含量

目的:测定莫达非尼原料药及其胶囊剂的含量。方法:采用高效液相色谱法。色谱柱为Phenomenex ODS(150mm×4.6mm,5μm),柱温30℃,流动相为甲醇-50mmoL·L~(-1)甲酸(50:50,pH=2.5),流速1.0mL·min~(-1),UV检测波长225nm。结果:莫达非尼浓度在1.0～20μg·mL~(-1)范围标准曲线线性良好,最低检测浓度0.5μg·L~(-1),日内RSD为1.8％(n=5),日间RSD为2.0％(n=5),加样回收率98.0％～99.6％(n=3)。结论:本法简便快速,准确可靠,可用于莫达非尼及其胶囊剂含量测定等相关研究。