Relationship between height, collagen metabolism, hair zinc and excessive fluoride intake]

After eliminating confounding factors, the study was made on the relationship between height, collagen metabolism, hair zinc and excessive fluoride intake. 140 schoolchildren aged 12-13 years born and reared in endemic fluorosis areas were surveyed. The results were as follows: 1. The average height of children with dental fluorosis III degree (DF III degree) was appreciably smaller than that of children without dental fluorosis. Among children with excessive fluoride intake, a negative correlation between the height and fluoride level in staple foods was seen. 2. The more the fluoride ingested, the higher the urinary THP excreted, showing that fluoride intoxication interfered with the collagen metabolism. 3. Among children with excessive fluoride intake, the height showed negative correlation with urinary THP/Cr, suggesting that the effect of fluoride on collagen metabolism indicated the mechanism of height retardation. 4. As compared to control group with the excessive fluoride intake but without dental fluorosis group, there was a significant reduction in hair zinc in group with DF III degree, suggesting that the zinc in the body decreased because of zinc metabolism disturbance by excessive fluoride intake. But among cases with excessive fluoride intake, no appreciable correlation between hair zinc and height was found. Therefore, it could not be confirmed that the effect of fluoride on zinc metabolism affected the height development.     

Identification of widespread Helicobacter hepaticus infection in feces in commercial mouse colonies by culture and PCR assay.

The identification of a new murine pathogen, Helicobacter hepaticus, and its association with chronic active hepatitis and liver tumors prompted an evaluation of the prevalence of H. hepaticus in commercially available mice. Of the 28 different strains or stocks, totaling 160 mice from four major commercial vendors, cultured for H. hepaticus, 100% of mice from two outbred strains from one vendor were infected with H. hepaticus, whereas 9 of 13 inbred mouse strains from another vendor were infected. This high prevalence of H. hepaticus established a need for a rapid and reproducible, noninvasive assay for the screening of colony-maintained mice being used for biomedical research. The culturing of fecal material by using 0.45-microns-pore- size filtration for H. hepaticus consistently yielded reproducible results but required extended periods of time. (1 to 3 weeks) to obtain a definitive answer. Although it is rapid, the use of a direct PCR-based detection assay with fecal specimens is restricted by inhibitory agents. to circumvent these inhibitory agents and to augment our H. hepaticus culture technique, we have developed a novel PCR system in which the bacteria are isolated from fecal material in the presence of polyvinylpyropyrollidone and lysed by treatment with Chelex 100. The PCR is performed with Tth polymerase supplemented with a polymerase enhancer. By this PCR method, 24 H. hepaticus culture-positive and 30 H. hepaticus culture-negative fecal samples were correctly identified. Moreover, two samples which were PCR positive and culture negative initially were positive by both methods upon retesting of fresh material. Southern blot hybridizations and sequencing of PCR products showed them to be H. hepaticus specific. A comparison of results obtained under identical conditions indicated a 100-fold increase in sensitivity with Tth polymerase over Taq polymerase. This PCR method can be used as a noninvasive means of rapidly screening large numbers of colony mice for H. hepaticus.     

Omega-3 fatty acids in major depressive disorder. A preliminary double-blind, placebo-controlled trial.

Patients with depression have been extensively reported to be associated with the abnormality of omega-3 polyunsaturated fatty acids (PUFAs), including significantly low eicosapentaenoic acid and docosahexaenoic acid in cell tissue contents (red blood cell membrane, plasma, etc.) and dietary intake. However, more evidence is needed to support its relation. In this study, we conducted an 8-week, double-blind, placebo-controlled trial, comparing omega-3 PUFAs (6.6 g/day) [corrected] with placebo, on the top of the usual treatment, in 28 patients with major depressive disorder. Patients in the omega-3 PUFA group had a significantly decreased score on the 21-item Hamilton Rating Scale for Depression than those in the placebo group (P < 0.001). From the preliminary findings in this study, omega-3 PUFAs could improve the short-term course of illness and were well tolerated in patients with major depressive disorder.     

新形势下中学与大学学生党建衔接工作的思考

在青年学生中吸收优秀分子已成为高校党组织发展工作的重要组成部分,最近几年来,高中党建工作也不断发展。了解青年学生党建现状,更好地利用中学党建工作成果,提出了做好衔接工作的现实意义及对策措施。     

上海市外来人员肺结核病分布与临床特征

目的：了解上海市外来人口中肺结核病人的分布和临床特征。方法：对1996年1～12月全市外来人口活动性肺结核病报告登记资料进行分析。结果：外来人员肺结核病人总数达2279人，青壮年占总病例65％以上；男性病例为主；主要来源于江苏、浙江、安徽、四川、江西等省；登记病人来沪暂居地主要集中在市区及城乡地区，外来人口结核病管理重点在市区及城乡地区。病人分型以Ⅲ型为主。查痰率仅60．1％，但排菌率高达40％。外来人。的病例发现工作及治疗管理难度较大，目前登记病例规则化疗仅占10．4％。结论：有必要通过有关部门的共同协作，拟定切实可行的外来人口结核病管理办法。     

酸性染料比色法测定甲氧异腈冻干品含量

本文采用酸性洒料比色法测定甲氧异腈冻干品的含量。结果表明，使用溴甲酚紫１．５ｍｌ，ＰＨ值为６．０的磷酸盐缓冲液５ｍｌ，氯仿５ｍｌ提取，经振摇２ｍｉｎ，静置１５ｍｉｎ为较理想比色条件，显色液稳定，甲氧异腈浓度在４－２０μｇ／ｍｌ范围内与吸收度呈良好线性关系。     

上尿路结石致肾积水患者锂清除率的测定

采用原子吸收光谱法对４０例上尿路结石致肾积水患者进行了锂清除率测定。结果显示：梗阻所致肾积水患者的ＣＬｉ明显低于正常人（Ｐ〈０．００１），ＣＣｒ、ＣＮａ、Ｃｋ与正常对照组相比差异无显著意义（Ｐ〉０．０５）；并发现ＣＬｉ与肾积水程度呈负相关。认为可将ＣＬｉ作为发现梗阻性肾病早期肾功能损害的可靠指标，评价肾功能损害的程度和预后。     

Interaction of 2-halogenated dATP analogs (F, Cl, and Br) with human DNA polymerases, DNA primase, and ribonucleotide reductase

Recently, 2-halogenated deoxyadenosine analogs (F, Cl, and Br) have been shown to have antitumor activity. These analogs are phosphorylated by cells and are believed to exert their cytotoxic action at the nucleoside triphosphate level. In this work the interaction of these nucleoside triphosphate analogs with potential targets, such as DNA polymerase alpha, beta, and gamma, DNA primase, and ribonucleotide reductase was examined in detail. All of these compounds competitively inhibited the incorporation of dAMP into DNA by DNA polymerase alpha, beta, or gamma. F-dATP was able to completely substitute for dATP using DNA polymerase alpha and gamma, but not with DNA polymerase beta. Cl-dATP and Br-dATP substituted poorly for dATP using DNA polymerase alpha and beta. Extension of a 32P-labeled primer by DNA polymerase alpha, beta, or gamma on a single-stranded M13 template showed that these compounds were incorporated into the 3' end of the growing DNA chain and that elongation beyond the incorporated analogs was significantly retarded for Cl-dATP and Br-dATP using either DNA polymerase alpha or beta. DNA primase using poly(dC) as template was inhibited by these compounds at a concentration 4 to 5 times greater than that required for 2-F-araATP. The 2-halogenated dATP analogs were potent inhibitors of ADP reduction by ribonucleotide reductase. In conclusion, the cytotoxic action of 2-Cl-deoxyadenosine and 2-Br-deoxyadenosine may partially be mediated through the mechanism of "self-potentiation," by depression of the deoxynucleoside triphosphate pools due to inhibition of ribonucleotide reductase, which would facilitate their incorporation into DNA and result in the inhibition of DNA synthesis.