Biochemical analysis of human milk treated with sodium dodecyl sulfate, an alkyl sulfate microbicide that inactivates human immunodeficiency virus type 1.

Reduction of transmission of human immunodeficiency virus type 1 (HIV-1) through human milk is needed. Alkyl sulfates such as sodium dodecyl sulfate (SDS) are microbicidal against HIV-1 at low concentrations, have little to no toxicity, and are inexpensive. The authors have reported that treatment of HIV-1-infected human milk with < or = 1% (10 mg/mL) SDS for 10 minutes inactivates cell-free and cell-associated virus. The SDS can be removed with a commercially available resin after treatment without recovery of viral infectivity. In this article, the authors report results of selective biochemical analyses (ie, protein, immunoglobulins, lipids, cells, and electrolytes) of human milk subjected to SDS treatment and removal. The SDS treatment or removal had no significant effects on the milk components studied. Therefore, the use of alkyl sulfate microbicides to treat milk from HIV-1-positive women may be a simple, practical, and nutritionally sound way to prevent or reduce transmission of HIV-1 while still feeding with mother's own milk.     

Candida albicans growth studies: a hypothesis for the pathogenesis of Candida infections in burns.

The proteolytic environment in which Candida albicans exists strongly affects its virulence. To determine whether virulence might be related to C. albicans growth in different proteolytic environments, we measured renal fungal load in burned mice and found significantly greater Candida census in kidneys from mice that were challenged with a high proteinase-generating parent C. albicans (MY 1044) versus those that were challenged with its low proteinase-generating mutant (MY 1049). In vitro, MY 1044 cells grew faster than MY 1049 cells in media that contained sera from burned mice as the only nitrogen source. Augmentation of media with proteinase or a mixture of amino acids increased growth of MY 1049 cells, whereas augmentation with proteinase inhibitor decreased MY 1044 growth. In conclusion, in vitro growth of both the mutant and its parent strain was affected by the proteolytic environment in which they existed; thus, virulence differences for MY 1044 and MY 1049 could be due in part to growth differences between these two strains in different proteolytic environments. These results were combined with existing observations, and we proposed a theory for the pathogenesis of C. albicans in burns.     

Prevalence of juvenile periodontitis in a circumpubertal population

A cross-sectional radiographic screening was performed on bite-wing pairs (BW) from 1872 10-12 year old schoolchildren in the Greater Worcester, Massachusetts area to assess the prevalence of juvenile periodontitis (JP). The 3-stage screening process entailed: (1) visual identification of possible cases based upon a visual assessment of BW for interproximal crestal bone levels greater than or equal to 2 mm from the cemento-enamel junction (CEJ) on greater than or equal to 1 permanent first molar; (2) identification of probable cases based upon BW from possible cases measured with a transparent ruler calibrated in millimeters; (3) finally, clinical confirmation of JP in consenting probable cases. A total of 1038 subjects were eligible to be included in the study (greater than or equal to 3 mesial sites readable). Of the 1038 eligible subjects, 117 possible and 103 probable cases were identified in stage 1 and stage 2, respectively. A total of 99 probable cases could be contacted and 43 were examined clinically. Two cases of JP were confirmed clinically in stage 3, yielding a prevalence rate of 4.6/1000. Specifically, this report defines a rate of JP in 10-12 year-old schoolchildren for the first time. In addition, these results indicate that BW can be used to identify children with JP from large data sets. However, further studies including complete clinical and radiographic examinations are necessary to determine whether this method is adequate for large epidemiologic studies.     

Foreign metallic pellet in the heart

Foreign bodies in the heart are a rare but serious form of cardiac injury. The objects usually are sharp pointed. Such as acupuncture needles,sewing needles, coat hangers, fragments of Kirschner wires, pins, etc. 1 We report a patient with a metallic pellet lodged in the heart, which was accurately diagnosed and successfully removed.     

Immunoassays for quantifying choriogonadotropin compared for assay performance and clinical application.

We examined calibration and accuracy, precision, sensitivity, specificity, and "hook" effects for recently revised automated choriogonadotropin (hCG) immunoassay systems (Baxter-Dade Stratus II, Abbott IMx intact hCG and total beta hCG) and compared them with a widely used immunoradiometric assay (Hybritech). We estimated hCG in pregnant women, women with trophoblastic disease, nonpregnant young and menopausal women, normal men, and men with testicular tumors. We found clinically unimportant differences in calibration (all calibrated to the 3rd International Standard). Detection of hCG by all four assays was limited by their responses in serum from nonpregnant women and men. Precision within-run was best for the automated instruments, but all four assays had similar between-run precision. The Hybritech, Stratus, and IMx intact assays are specific for intact hCG. The IMx total beta assay quantifies both free beta subunit and beta subunit present in intact hCG. There is a clinically important hook effect in the Hybritech assay but not the Stratus or IMx assays (to 1.2 x 10(6) int. units/L). Results for pregnant women were similar by all four assays. We measured "hCG" to 8 int. units/L in menopausal women, which weakly correlated with concentrations of lutropin and follitropin and was, in part, explained by crossreactivity. There was no sample-probe carryover in either instrument. We found the IMx diluting module as well as results at the extremes of the IMx calibration curves (less than 10, 800-1200 int. units/L) unreliable but encountered no such problems with the Stratus system. Both automated systems involve batch analyzers with limited throughput but provide hCG concentration estimates much more quickly than the Hybritech assay can.     

树突状细胞在胆囊癌组织内浸润的研究

目的通过对胆囊癌组织中树突状细胞浸润情况的研究,阐述树突状细胞与肿瘤免疫之间的关系。方法采用免疫组化SP法。结果树突状细胞在胆囊癌组织的浸润程度与年龄、性别和病理组织学类型无关,与病理分化程度呈负相关关系(P<005)。结论树突状细胞在胆囊癌组织的浸润程度与病理分化程度、Nevin分期、肝浸润及淋巴结转移存在密切的关系。树突状细胞的定量检测可作为估计胆囊癌预后的标志。     

三氧化二砷诱导肺癌细胞凋亡及对细胞周期的影响

目的 :探讨三氧化二砷 (As2 O3 )对人肺癌细胞株 (Spc- A1)诱导凋亡的机制 ,为抗肿瘤药物的筛选和用药方式提供理论依据。方法 :体外培养 Spc- A1细胞株与不同浓度的 As2 O3 进行作用 ,应用 MTT比色法、流式细胞仪技术、电子显微镜技术观察细胞增殖率、细胞周期率、细胞凋亡率及亚细胞水平变化。结果 :As2 O3 能够抑制 Spc- A1细胞的增殖 ,且呈时间剂量依赖性 ,Spc- A1细胞凋亡率与药物浓度和时间呈依赖关系。电镜观察细胞线粒体肿胀、空泡 ,染色质浓缩、核碎裂。结论 :As2 O3 可诱导 Spc- A1细胞凋亡 ,细胞周期延长 ,线粒体变性。     

大鼠原生殖细胞的形态学及分化特性

目的 研究大鼠胚胎原生殖细胞（Primordial germ cells, PGCs）的形态及其分化特性。方法 取受精后10.5 d的大鼠胚胎作HE染色,取受精后11.0~12.5 d的大鼠胚胎生殖嵴进行PGCs原代培养,光、电镜观察PGCs及其分化细胞的微细结构,碱性磷酸酶 (ALP) 染色检测细胞的分化程度。结果 大鼠PGCs位于卵黄囊内胚层深部的间充质内,体积大,呈椭圆形或不规则形;核大,染色质细密,含1~2个核仁。体外培养可见PGCs大而圆,散在分布,或聚集成团,胞质中含有椭圆形的线粒体和丰富的核糖体,ALP反应呈阳性;培养4~5 d,PGCs形态不规则,有伪足,ALP反应减弱,进一步分化可形成神经元样细胞、表皮细胞、心肌细胞、分泌细胞以及类似血管、心脏的管腔样结构等。由PGCs分化来的细胞ALP反应均呈阴性。结论 大鼠生殖嵴来源的PGCs是一种具有发育全能的、可分化形成3个胚层衍生物的胚胎多能干细胞。