Zinc, calcium, and magnesium metabolism: effects on plasmacytomas in Balb/c mice

The effects of different amounts of dietary zinc on the Zn absorption rate and on Zn, calcium and magnesium concentrations in tissues of MOPC 104E tumor-bearing Balb/c mice were determined. The Zn absorption rate was inversely related to the amounts of Zn in their diets and was lower than that of nontumor-bearing control mice fed a laboratory mice chow. Zn concentrations of tumor-bearing mice were also low compared with control mice but tumor Zn concentrations, regardless of the concentrations of Zn in the diets, were higher than those of normal tissues of the host other than the pancreas. Ca concentrations in tumor and tissues of tumor-bearing mice were higher than in control animals but Mg concentrations in tissues of tumor-bearing mice appeared to be similar to those of control mice. Results suggest that tumor-bearing mice have a lower intestinal Zn absorption capacity and a higher Zn uptake rate causing other tissues to become hypozincemic and hypercalcemic.     

Detection of cell apoptosis by MTT assay.]

OBJECTIVE: To study the feasibility of using MTT assay to detect cell apoptosis. METHODS: K562 cells were grown in RPMI 1640 medium supplemented with 10% calf serum and 4 micromol/L arsenic trioxide. Apoptosis was induced in the cultured cells by As2O3, and the cells were detected with optical microscope, DNA gel electrophoresis and MTT staining respectively. RESULT: MTT staining could also accurately detect cell apoptosis, by which the apoptotic cells were easily distinguished from normal cells and dead cells. CONCLUSION: MTT staining is simple, convenient and practical for detecting cell apoptosis.     

Isolation of a rat S100 alpha cDNA and distribution of its mRNA in rat tissues.

In order to clarify the reported discrepancies in S100 alpha protein and mRNA distribution in rat tissues, a rat S100 alpha cDNA has been isolated and this species homologous probe along with a rat S100 beta cDNA probe has been used to examine S100 mRNA expression in rat tissues. Although the rat S100 alpha cDNA was missing approximately 30 nucleotides of coding sequence, only 4 conservative changes in amino acid sequence were observed when the deduced amino acid sequence was compared to the bovine S100 alpha amino acid sequence. Thus, S100 alpha proteins, like S100 beta proteins, are highly conserved among species. All nineteen of the tissues examined (including cerebrum and cerebellum) contained S100 alpha mRNA. In addition, S100 beta mRNA was detected in thirteen of the nineteen tissues examined. These results are in agreement with previous protein distribution studies and further demonstrate that S100 proteins are not brain-specific and are expressed in a large number of tissues. Although S100 alpha and S100 beta mRNAs were detected in rat tissues which had previously been reported to contain S100 alpha and S100 beta protein, a direct correlation between the protein and mRNA levels were not observed, suggesting that different mechanisms regulate S100 expression in various tissues. S100 alpha exhibited a single similar size mRNA species (0.5 Kb) in all tissues examined, as did S100 beta (1.5 Kb), suggesting that the individual S100 proteins are expressed as single mRNA and protein products in rat tissues.     

骨肉瘤与活化B淋巴细胞融合疫苗的抗肿瘤效应

目的　建立骨肉瘤与活化 B淋巴细胞融合的肿瘤疫苗 ,探讨其生物学与抗肿瘤特性 .方法　以 50 0 g· L-1 聚乙二醇为融合剂 ,将 C3 h小鼠来源的 HGRPT基因缺陷型 LM9骨肉瘤细胞与脂多糖活化的小鼠 B淋巴细胞进行融合 .经HAT选择性培养基筛选后 ,再观察该融合瘤株的体内外生长特性 ,对小鼠的致瘤性以及抗肿瘤活性 .结果　该融合瘤株体外生长缓慢 ,对 C3 h小鼠无致瘤性 ,杂交瘤细胞细胞表达B7(70 .6% ) H- 2 Kb (53.4% ) ,融合疫苗保护的小鼠可获 1 0 0 %无瘤生存 (8/ 8)而 LM9和射线照射后的 L M9对照组小鼠全部死亡 (0 / 8) ,皮下接种融合疫苗治疗的荷瘤小鼠可获得80 %无瘤生存 .结论　活化 B淋巴细胞融合骨肉瘤细胞可能改变其生物学特性 ,对小鼠有较好的预防和治疗作用 ,说明了细胞融合方法构建的肿瘤疫苗具有潜在的应用价值     

单能量X线测定骨密度的初步分析

目的：了解温州地区人群不同年龄组骨质疏松患病率及同年龄组男女骨质疏松患病的差异，强调早期预防治疗老年人及绝经期妇女骨质疏松的重要性，方法：应用单能量X线（SXA）骨密度仪测量246例正常人的右跟骨骨密度，结果：男性大于60岁组较小于60岁组骨密度（BMD）降低明显（P＜0．05）；女性50岁以上组与小于50岁组相比，BMD下降差异有极显性（P＜0．01）；各年龄组男女相比，男性BMD明显高于女性（P＜0．05）。结论：女性骨质疏松症的发病大多以绝经后为主，雌激素在维持骨量方面具有重要的作用。SXA检测的跟骨含95％小梁骨，能较好地确定骨质疏松的风险水平，且其具有价廉、简便，快捷，较准确等特点，故不失为一种较好的临床筛查手段。     

Good titles makes good articles: designing of English titles for medical papers.]

Based on the experience of the author and an intensive study of the titles of English medical papers written by authors in English-speaking countries, the characteristics and styles of the titles were expounded with well-selected examples. The paper also introduces some practical skills to write good English titles and enumerates some frequently used structures and expressions, which might be helpful for potential Chinese contributors to medical journals.     

肿瘤坏死因子与甲状腺细胞凋亡及相关蛋白的检测和表达的意义

目的　探讨肿瘤坏死因子 a(TNF a)诱导Graves病甲状腺细胞凋亡与相关蛋白表达在Graves病 (GD)发病关系中的意义。方法　采用免疫组织化学S P方法检测 5 0例Graves病患者TNF a,并检测对照组对Fas表达的影响。采用原代细胞培养方法进行细胞培养 ,细胞培养液中的sFas含量采用ELISA法检测。Fas/sFasmRNA检测采用半定量RT PCR法。结果　含有TNF aGD组细胞凋亡率为 92 6 % ,显著高于对照组的凋亡率 (36 0 % ) (P <0 0 1)。其含有TNF aGD组甲状腺细胞sFas、Fas/sFasmRNA含量与对照组比较差异有显著意义 (P <0 0 1)。结论　TNF a诱导Graves病甲状腺细胞凋亡及凋亡相关蛋白sFas、Fas/sFasmRNA有一定水平的表达 ,这些改变可能是TNF a破坏甲状腺细胞的重要机制之一。     

贫困家庭子女心理健康状况与对策研究

目的 了解贫困家庭子女心理健康状况。方法 利用中国人心理健康量表对2013名学生进行测量、统计和对比分析。结果 贫困家庭子女的总体平均分、各因子平均分以及中度症状的比例均高于非贫困家庭子女。结论 家庭经济状况是影响子女心理健康的一个重要因素，贫困家庭子女更需要心理卫生服务。     

Inhibition of the expression of lysyl oxidase and its substrates in cadmium-resistant rat fetal lung fibroblasts.

Copper (Cu)-dependent lysyl oxidase (LO) catalyzes crosslinking of collagen and elastin stabilizing the extracellular matrix (ECM). Chronic inhalation of cadmium (Cd), a toxic metal, induces emphysema. To probe mechanisms of Cd injury to the lung, we developed Cd-resistant (CdR) cells from rat fetal lung fibroblasts (RFL6) by chronic exposure to CdCl(2) from 1 to 40 microM and further examined their expressions of LO, LO substrates, and Cu-scavenging thiols. Levels of cellular thiols, metallothionein, and glutathione in CdR cells were elevated to 13.0- and 3.2-fold of parental controls, respectively, whereas LO mRNA and protein levels were markedly reduced in these cells, with catalytic activity declining to only 16% of the parental control. A conspicuous 52 kDa species rather then the normal 50 kDa proenzyme appeared in the CdR cell extract but not in the conditioned medium, which was codistributed with the endoplasmic reticulum marker [DiOC5(3)] within the cell, implying the Cd-induced 52 kDa species as a product of an abnormal LO-processing defect in secretion. Addition of Cu into CdR cell cultures enhanced the expression of LO mRNA, protein and catalytic activities reflecting limitation of Cu bioavailability for LO in these cells. With inhibition of LO, CdR cells also displayed downregulation of collagen and elastin, substrates of LO. Restoration of collagen synthesis by exposure of CdR cells to purified LO or Cu suggests that inhibition of LO and limitation of Cu cofactor by Cd, as key phenotype changes, accelerated collagen and elastin damage, a critical event pertinent to emphysema pathogenesis.