Co-operative mineralization and protein self-assembly in amelogenesis: silica mineralization and assembly of recombinant amelogenins in vitro

An amorphous silica mineralization technique was used to produce inorganic/protein composites to elucidate the structure and mechanism of formation of amelogenin assemblies, which may play an important role in regulating enamel structure during the initial stages of amelogenesis. Full-length recombinant amelogenins from mouse (rM179) and pig (rP172) were investigated along with key degradation products (rM166 and native P148) lacking the hydrophilic C terminus found in parent molecules. The resulting products were examined using transmission electron microscopy and/or small-angle X-ray scattering. Using protein concentrations of 0.1–3 mg ml⁻¹, large monodisperse spheres of remarkably similar mean diameters were observed using rM179 (124 ± 4 nm) and rP172 (126 ± 7 nm). These spheres also exhibited 'internal structure', comprising nearly spherical monodisperse particles of ≈ 20 nm in diameter. In the presence of rM166, P148, and bovine serum albumin (control), large unstructured and randomly shaped particles (250–1000 nm) were observed. Without added protein, large dense spherical particles of silica (mean ≈ 500 nm) lacking internal structure were produced. These findings demonstrate that full-length amelogenins have the ability to form higher-order structures, whereas amelogenins that lack the hydrophilic C terminus do not. The results also suggest that full-length amelogenin can guide the formation of organized mineralized structures through co-operative interactions between assembling protein and forming mineral.     

精神病人与正常人戒烟前后焦虑抑郁症状的对照研究

目的　了解精神病人和正常人戒烟前后精神状况的变化及差异性 ,探讨戒烟措施。方法　对 71例精神病人和 5 0例正常人戒烟前及戒烟后 1周分别应用汉密顿焦虑量表 (HAMA)、汉密顿抑郁量表 (HAMD)、焦虑自评量表 (SAS)、抑郁自评量表 (SDS)、简明精神病量表 (BPRS )进行测评。结果　精神病人强制性戒烟前HAMA、HAMD、SAS、SDS、BPRS分值分别为 (8.2 1± 6 .4 1)、(7.6 4± 5 .71)、(36 .81± 7.14 )、(33.71± 7.1)、(2 9.4 5± 8.4 7) ;戒烟后HAMA、HAMD、SAS、SDS、BPRS分值分别为 (16 .4 5± 6 .34)、(19.73± 8.71)、(5 8.1± 12 .12 )、(5 6 .31± 11.4 )、(37.32± 7.95 ) ;戒烟前后 5种量表分值变化与正常人戒烟前后分值变化比较有极显著性差异(P <0 .0 1)。结论　对精神病人强制性戒烟可引起明显的情绪反应 ,应适宜控制病人吸烟 ,建立一个合理的管理制度     

Renal vascular resistance in normal children – a color Doppler study

To investigate the relationship between age and renal vascular resistance and to establish nomative data of the systolic/diastolic ratio (S/D ratio), pulsatility index (PI), and resistant index (RI) of the renal artery in the normal pediatric population, we studied 252 normal children aged newborn to 13 years (a total of 449 kidneys) with a color Doppler unit. After the normality of the kidney was established, color flow mapping was performed to localize the segmental portion of the renal artery. Flow velocity waveforms were then obtained by pulsed Doppler, and S/D ratio, PI, and RI were calculated. Multiple regression analysis confirmed the age dependence of the S/D ratio, PI, and RI of the renal artery in normal children. Renal vascular resistance continuously declines after birth and stabilizes at the age of 102 – 130 months. Normative data for S/D ratio, PI, and RI of the renal artery in normal children were established for each age group. Since renal vascular resistance decreases with age and stabilizes at 8 – 10 years, we suggest using different normal ranges for each age group when studying renal vascular resistance in pediatric patients. Received October 5, 1995; received in revised form and accepted April 24, 1996     

继发性唇裂鼻畸形硅胶植入整复术

本文介绍一种使继发性唇裂鼻畸形获得较好外形的新手术方法。术式包括切除偏曲的鼻中隔软骨,并将一片硅胶植入于中央作为鼻小柱支柱,从而矫正歪斜的鼻小柱和抬高鼻尖,使两侧鼻孔形态对称一致,用本法为11例单侧唇裂畸形较重者进行了整复,随访4个月至4年半。绝大多数(10/11)取得满意效果,未见有严重感染和变形等并发症。     

50例正常生育力男子精液和血液激素的一年动态观察

作者对南京市50名正常男子,每月1次、连续12个月测定了精液常规、某些精液生化和血清激素水平。结果表明:精子密度每次之间波动范围较大,冬季数值比夏季显著为高(P<0.01)。其它指标包括正常形态精子、活动精子、前向运动级别、精液果糖、硷性磷酸酶、酸性磷酸酶及血清,FSH LH T 则变动不显著。精液常规中除精子密度和各参数关系不明显外,所有其它参数之间呈正相关;但精液常规、精液生化和血清激素三者互不相关。从本组研究结果,作者提出了南京市正常男子这些指标的参考正常值。     

Case-control study of silicosis, silica exposure, and lung cancer in white South African gold miners

A case-control study was undertaken to assess the association between lung cancer and silicosis or silica dust exposure in white South African gold miners. Cases and controls were identified from deaths reported to the Gold Miners Provident Fund for the period January, 1979-October, 1983. Two controls were matched to each case by year of birth (+/- 2 years) and by smoking (+/- 5 cigarettes or equivalents per day) assessed 10 years (+/- 2 years) prior to death. One hundred thirty-three matched triplets were identified. The results showed no overall association between lung cancer and radiological silicosis (OR = 1.08, p = 0.92). Autopsy data indicated no overall associations between lung cancer and silicosis of the lung parenchyma (OR = 1.49, p = 0.11), the pleura (OR = 0.72, p = 0.30), or the hilar glands (OR = 0.85, p = 0.72). A trend toward increased severity of silicosis of the parenchyma was evident; however, this was not statistically significant (p = 0.08). Odds ratios for lung cancer and silicosis were higher at lower levels of cumulative silica dust exposure (ORs = 2.43, 1.72, 1.35 and 0.62 for lung cancer and autopsy silicosis of the parenchyma for the lowest, second, third, and highest quartiles of dust exposure, respectively; all p greater than 0.05). Cases did not differ from controls for total silica dust exposure, length of exposure, weighted average intensity of exposure, or number of shifts at high dust (all p greater than 0.20). The data do not support the hypothesis of a carcinogenic role for silica dust and no statistically significant associations were found between lung cancer and silicosis.(ABSTRACT TRUNCATED AT 250 WORDS)     

人皮质骨矿化基质中骨盐框架结构

目的：研究人皮质骨矿化基质中骨盐的框架结构及框架中骨微间隙。方法：应用透射电镜、场发射扫描电镜观察、电脑图像分析及能谱分析，分析无骨病成人长骨、扁骨２００例骨盐分布特征。结果：骨盐框架结构由微柱、微梁、微小梁、弓状梁、致密点、隔板和骨微间隙构成。骨微间隙由洞、内衬和壁组成，洞平均直径为８４．４±７５．６ｎｍ，与骨小管相比有显著差异（Ｐ值＜０．００１），平均密度为１１～１７个／μｍ２，与骨小管之比超过１０：１。骨盐分针形结晶和微颗粒结晶。结论：骨盐框架结构及骨微间隙是骨盐在人皮质骨矿化基质中的存在形式，可能与骨盐吸收、沉着有关。     

Does the shunt opening pressure influence the effect of shunt surgery in normal pressure hydrocephalus?

Summary Thirteen patients with normal pressure hydrocephalus were operated upon with an externally manoeuvrable shunt system (Sophy SU8) in order to investigate its influence on clinical outcome, intracranial pressure and cranial CT parameters. The opening pressure was set at high at surgery and lowered stepwise at intervals of three months to medium and low. The clinical condition, intracranial pressure and cranial CT parameters were examined at the end of the 3 months interval on each pressure level.The patients improved within the first 3 months inspite of an unchanged mean intracranial pressure and remained in a stable clinical condition during the rest of the study period. The intracranial pressure was significantly reduced at 9 months. The ventricular index, Evans index, temporal horn and third ventricle width were reduced 3 months post-operatively and did not change significantly during the rest of the study. The pre-operative third ventricle width was correlated to high psychometric test results after shunt surgery. Reduction in ventricular index, Evans index and third ventricle width after surgery correlated to improvement in psychometric scoring.The clinical improvement after shunt surgery for normal pressure hydrocephalus is seen within 3 months and is independent of the adjusted valve pressure.     

师范大学学生艾滋病知识现况调查及健康教育近期效果评价

目的 了解师范大学学生艾滋病相关知识及行为现状，为高校制定艾滋病健康教育规划提供参考。方法 抽取天津师范大学2000年入学新生，通过集体讲座，使用统一的调查问卷在教育前后分别调查学生艾滋病相关知识及态度，并利用EPIinf0软件进行分析。结果 天津师范大学一年级学生健康教育后对艾滋病性质、主要传播途径等的正确回答率都有所提高，能够正确对待艾滋病病毒感染者，教育前后学生对性行为的态度无明显改变。学生希望获得艾滋病知识的前4位方式均为电视、报刊书籍、卫生课和医生。结论 从国情和现实需要出发，在大学生中开展适时、适度、适量的性健康教育和健康行为教育，对预防性病艾滋病有着积极的意义。     

硕士生睡眠质量状况及其与心理健康的相关研究

目的了解硕士生睡眠质量状况及其与心理健康的关系;为提高硕士生的睡眠质量和心理健康水平提供参考。方法采用匹兹堡睡眠质量指数(PSQI)和症状自评量表(SCL-90)对高校298名硕士生进行睡眠质量和心理健康调查。结果①以PSQI总分≥8作为判断睡眠质量问题的标准,27.4%的硕士生存在睡眠质量问题,睡眠质量不佳主要体现在日间功能障碍(58.4%)、入睡时间(38.6%)、睡眠质量(31%)和睡眠障碍(19.3%)。②一、二年级与三年级在入睡时间上存在显著差异(P<0.05)。公费和自费硕士生在PSQI总分和睡眠效率上存在显著性差异。文科和理科硕士生在催眠药物和日间功能障碍上存在显著性差异。年龄≥30岁和年龄<30岁的硕士生在睡眠效率上存在显著性差异。③硕士生PSQI总分及大多数成份与SCL-90各因子呈显著正相关(P<0.05)。④不同睡眠质量硕士生的心理健康状况分析显示,睡眠质量好、一般和差的硕士生在SCL-90均分及各因子得分上存在显著性差异。结论研究生睡眠质量不尽人意;睡眠质量与心理健康高度相关。各个部门及研究生自身应该引起高度重视,保证良好睡眠,促进身心健康。