Expression of the integrin subunits alpha 5, alpha 6 and beta 1 in the testes of the common marmoset

Integrin subunits alpha 5, alpha 6 and beta 1 were localized in the testis of pre-pubertal or adult non-human primates (Callithrix jacchus) by immunofluorescence staining and in situ hybridization. In animals of all ages subunits alpha 5 and beta 1 were localized in cells of the lamina propria of the seminiferous epithelium. In prepubertal animals, the integrin subunits alpha 5, alpha 6, as well as beta 1, were distributed all over the plasma membrane of Sertoli cells. In adult animals the integrin subunits were confined to those plasma membrane regions of Sertoli cells which are assigned to the basal compartment, including the basement membrane of the seminiferous tubules. Protein expression of integrin subunits alpha 6 and beta 1 was most pronounced in tubular stages in which elongated spermatids were not yet present in the adluminal compartment of the epithelium, suggesting that these integrin subunits are particularly essential at certain developmental stages of spermatogenesis. Non-radioactive in situ hybridization revealed that the mRNA for integrin subunits alpha 5, alpha 6 and beta 1 was expressed by Sertoli cells. In situ hybridization, together with immunofluorescence data, shows that these integrin subunits were exclusively synthesized in Sertoli cells. As to functional aspects, it is concluded that during primate spermatogenesis. Sertoli cell integrins may be involved in both cell matrix as well as cell-cell interactions, particularly during early spermatogenesis.     

Proposal of a new electromechanical total artificial heart: the TAH Serpentina

A new type of energy converter for an electro-mechanical total artificial heart (TAH) based on the principle of a unidirectional moving motor is described. Named the TAH Serpentina, the concept consists of 2 major parts, a pendulum shaped movable element fixed on one side using a joint bearing and a special shaped drum cam. Pusher plates are mounted flexibly to the crossbar of the pendulum. A motor drives the special shaped drum cam linked to the pendulum through a ball bearing. The circular motion of the unidirectional moving brushless DC motor is transferred into the linear motion of the pendulum to drive the pusher plates. Using a crossbar with a variable length, the stroke of the pendulum and therefore the displaced blood volume is alterable. To achieve a variable length, an electric driven screw thread or a hydraulic system is possible. Comparable to the natural heart, cardiac output would be determined by frequency and stroke volume.     

Termination of extracorporeal membrane oxygenation for cardiac support

The determination of when to stop extracorporeal membrane oxygenation (ECMO) rests upon demonstration of the return of adequate cardiac function to support vital organs and permit subsequent recovery. In general, patients with myocardial stun will recover function within several days. Factors that limit recovery include elevated end diastolic pressures leading to marginal myocardial perfusion, ongoing organ damage, massive anasarca, or progressive deterioration in lung function. Following a trial of slow weaning of ECMO support to condition the heart to take over the entire system flow requirements, decannulation can be accomplished in a standard fashion. When weaning is not successful and additional time does not lead to adequate recovery of cardiac function, physicians and nurses must be prepare to realistically advise families regarding such options as cardiac transplantation or withdrawal of support. It is critically important to provide an open and nonjudgmental environment for families to make these difficult decisions. The greatest difficulties involve ethical and emotional decisions that need to be made in a timely fashion to prevent undo burden on the patient when further ECMO support is futile.     

Structure-activity relationships of quaternary protoberberine alkaloids having an antimalarial activity

Seventeen quaternary protoberberine alkaloids related to berberine 1 were tested for antimalarial activity in vitro against Plasmodium falciparum and structure-activity relationships are proposed. The activity of the protoberberine alkaloids was influenced by the type of the oxygen substituents on rings A, C and D and the position of the oxygen functions on ring D. The position of the oxygen functions on ring D and the type of the oxygen substituents at the C-13 position (ring C) strongly influenced the activity. Shifting the oxygen functions at C-9 and C-10 to C-10 and C-11 on ring D resulted in a significant increase in the activity. Compounds bearing a methylenedioxy function at C-2 and C-3 (ring A) or C-9 and C-10 (ring D) showed higher activity than those which have methoxy groups at the same positions. Introduction of a methoxy group into the C-1 position (ring A) decreased the activity. Replacement of a hydroxy group at C-2 or C-3 (ring A) by a methoxy group led to a reduction in the activity. Displacement of a hydroxy function at C-13 (ring C) by the oxygen substituents such as OMe, OEt, OCOOEt, and OCON(Me)₂ reduced the activity. In the same replacement at C-9 (ring D), the activity depended upon the type of the oxygen function. Six protoberberines displayed more potent activity than berberine 1. The activity decreased in the order: 10, 11, 17 and 18 > 7 and 8 > 1.     

Rapid repeat pregnancy and experiences of interpersonal violence among low-income adolescents

CONTEXT: Rapid repeat pregnancy (RRP) among adolescents, usually defined as pregnancy onset within 12-24 months of the previous pregnancy outcome, has frequently been the target of public health interventions, due to the exacerbation of negative consequences associated with recurrent adolescent pregnancy (and more specifically with childbearing). OBJECTIVE: To examine what, if any, relationship exists between RRP and the experience of interpersonal violence and abuse among low-income adolescents at one semi-urban health center. DESIGN: Case-control study using retrospective chart review. PARTICIPANTS AND SETTING: 100 women aged 13-21 who received prenatal care at one independent nonprofit health center that serves adolescents and their children from June 1994 through June 1996. MAIN OUTCOME MEASURES: Number and timing of pregnancies, occurrence of physical or sexual abuse; other psychosocial risk factors were evaluated. RESULTS: In this population, the experience of any form of physical or sexual violence during the study interval was associated with RRP within 12 months (p = 0.01, OR = 3.46) and 18 months (p = 0.013, OR = 4.29). Other previously reported predictors of RRP, including family stress, financial stress, and other environmental stressors did not reach statistical significance at either 12 months or 18 months in this sample. Of additional note, young women who experienced any form of abuse during the 12-month study interval were substantially more likely to miscarry than were their nonabused peers, and spontaneous abortion was also very strongly associated with RRP (p < 0.00001; OR = 22.6). CONCLUSIONS: The experience of interpersonal violence is correlated with rapid repeat pregnancy among low-income adolescents. This study strongly suggests a need for both extensive screening for partner and family violence among pregnant and postpartum adolescents, and follow-up safety planning support in combination with family planning interventions.     

内燃机车乘务员和轮轴工外周血淋巴细胞微核观察

本文作者对５１名内燃机车乘务员和车辆维修车间的３０名轮轴工外周血淋巴细胞微核进行了分析。结果表明,机车乘务员和轮轴工微核阳性检出率、微核细胞率和微核率均明显高于对照组（Ｐ＜０．０１）,而且随着作业工龄的延长,微核细胞率和微核率有接近显著（０．０５＜Ｐ＜０．０１）或显著（Ｐ＜０．０５）意义的增高。对两类作业工作人员微核增高的原因进行了讨论     

3种细胞因子在体外对阿糖胞苷细胞毒性的影响

采用对碘硝基四唑（ＩＮＴ）比色法,观察了１７例急性髓性白血病（ＡＭＬ）患者和８例正常人的骨髓,在体外对阿糖胞苷的敏感性,同时分别观察了粒细胞集落刺激因子（Ｇ－ＣＳＦ）,粒－巨噬细胞集落刺激因子（ＧＭ－ＣＳＦ）,白细胞介素－３（ＩＬ－３）３种细胞因子对其敏感性影响。结果显示ＡＭＬ细胞与正常细胞对Ａｒａ－Ｃ敏感性存在显著差异;Ｇ－ＣＳＦ,ＧＭ－ＣＳＦ,ＩＬ－３此３种因子均能增加Ａｒａ－Ｃ对ＡＭＬ细胞的     

三种镍化合物诱发转化细胞恶性度的鉴别与分析

目的 :利用已建立的三种镍化合物体外转化细胞进行裸鼠体内成瘤实验研究 ,比较它们恶性度的差异。方法 :三种镍化合物转化细胞接种BALB/C裸鼠 ,进行肿瘤细胞和转化细胞的透射电镜及扫描电镜观察。结果 :硫化镍 ,氯化镍 ,硫酸镍分别诱发的转化细胞都能在BALB/C裸鼠皮下形成肿瘤 ,病理组织学检查确定为纤维肉瘤。经扫描电镜与透射电镜观察瘤细胞形态与转化细胞有一定差别。结论 :本文进一步说明了三种镍化合物所诱发的细胞转化为恶性转化 ,且都具有体内致瘤性。     

铁路危险品货运站空气污染物的致遗传毒性作用研究

采用ＳＯＳ／ｕｍｕ 试验和ＳＯＳ 原位试验,对铁路危险品货运站（ 以下简称危货站） 空气污染物的致遗传毒性进行了研究。结果表明：在不加Ｓ９ 活化系统的条件下,危货站空气污染颗粒提取物具有致遗传毒性作用,可使ＴＡ１５３５／ＰＳＫ１００２ 菌株产生β半乳糖苷酶的量增加,并存在剂量—反应关系;加入Ｓ９ 活化系统后,则ＳＯＳ／ｕｍｕ 试验阴性。同时,应用ＳＯＳ 原位法,对危货站空气污染的综合致遗传毒性进行了现场监测。结果显示,随采样体积的增加,β半乳糖苷酶的量也增加,采样体积与酶诱导率之间,存在剂量—反应关系。     

地砷病患者部分生化指标的测定

对病区地砷病、非地砷病患者及对照组居民体内的部分生化指标进行了检测。结果表明,地砷病患者血清中的ＧＰＴ活性、ＵＮ和ＳＡ含量明显高于对照组,ＬＤＨ及ＧＳＨＰｘ活性明显降低;病区非地砷病患者ＬＤＨ活性、ＳＡ含量明显升高,ＧＳＨＰｘ活性明显降低,其它各组及各指标与对照组相比无显著差异。相关分析显示,病区病人组及非病人组血中ＳＡ含量与各自尿砷水平呈正相关（ｒ＝０５０,ｒ＝０４６）,ＧＳＨＰｘ与尿砷呈负相关（ｒ＝－０５１,ｒ＝－０４８）。提示,ＳＡ和ＧＳＨＰｘ可作为砷中毒的早期诊断指标。砷可能对接砷居民肝功、肾功产生一定影响。