Transmitter-induced calcium responses differ in astrocytes acutely isolated from rat brain and in culture

Glial fibrillary acid protein (GFAP)-positive astrocytes isolated from the cerebral cortices of 3-10-day-old rats frequently showed increased intracellular Ca2+ concentration responses to L-glutamate and glutamate analogues. However, few of the acutely isolated cells responded to ATP, and no such cells responded to serotonin [5-hydroxytryptamine (5-HT)]. The same cell that failed to respond to ATP or 5-HT often responded to glutamate. Culturing acutely isolated cells in media containing horse serum decreased Ca2+ responses to glutamate but increased the responses to ATP and induced responses to 5-HT. In primary cultures prepared from the cerebral cortices of 1-day-old rats and cultured in horse serum, fewer of the cells responded to glutamate, but almost all cells responded to ATP and 5-HT. The lack of or limited response to, 5-HT or ATP in the acutely isolated cells seems unlikely to be due to selective damage to the respective receptors because acutely isolated GFAP-negative cells showed responses to ATP, several different proteases and mechanical dissociation yielded cells that also responded to glutamate but not to ATP, and exposure of primary cultures to papain did not abolish Ca2+ responses to several transmitters. The responses of the acutely isolated cells to glutamate but limited or lack of responses to ATP and 5-HT also correspond to what has been seen so far for astrocytes in situ. Thus, the present studies provide direct evidence that some of the receptors seen in primary astrocyte cultures may reflect a response to culture conditions and that, in the context of the relevant information so far available, acutely isolated astrocytes seem to reflect better the in vivo state.     

Sensitivity of Streptococcus agalactiae and Staphylococcus aureus to antibiotics in the Slovak Socialist Republic in the year 1974

In 1974, the State veterinary institutes in the Slovak Socialist Republic studied the sensitivity of 4420 strains of Streptococcus agalactiae and 1056 strains of Staphylococcus aureus to eight antibiotics. The strains were isolated from milk samples obtained from dairy cows suffering from mastitis. 100 per cent of the strains of Streptococcus agalactiae was sensitive to ampicillin, 99.23% to erythromycin, 98.70% to oxytetracycline, 93.02% to bacitracin, 90.77% to chloramphenicol, 41.97% to penicillin, 12.39% to neomycin, 9.73% to streptomycin. As to the strains of Staphylococcus aureus, 98.68 were sensitive to chloramphenicol, 98.50% to ampicillin, 97.92% to erythromycin, 94.98% to oxytetracycline, 93.85% to neomycin, 92.67% to bacitracin 87.50% to streptomycin, and 46.24% to penicillin. The results are discussed in relation to the use of antibiotics in the treatment of mastitis in dairy cows.     

Health care reform in Chile

This is a document presented to the Chilean Academy of Medicine by the Health Minister, the economist Carlos Massad, First of all, he refers to the general context of the reform, that he considers a process and not a breakpoint. Afterwards, he enumerates the change task: a) to generate awareness of the change and to convert health in a State issue; b) to adequate programs to population's new health profile; c) to install new management instruments in the health system; d) to decentralize decisions and to promote the participation of beneficiaries; e) to establish incentives and to flexibilize the Health System and f) to introduce correctives to private health insurance. He believes that Chile must drift to a economical protection system for universal and solidary health events. The additional assurances that people wants to buy, must be delimited.     

Twin Block appliance. Part II

The main purpose of the Twin Block is to advance the mandible and to correct moderate to severe overjets. When the first molars are encouraged to erupt, the Twin Block also results in a partial correction of the overbite. The Rick-A-Nator or Rick-A-Nator 2 Appliances are utilized to hold the mandible in a forward position and also to help erupt the bicuspids to complete the orthopedic correction of the overbite. It is vital that the total treatment time for the active phase with the Twin Block and the support phase with the Rick-A-Nator be a minimum of 15 to 18 months to allow for permanent muscular, skeletal and dental changes to be accomplished.     

A factor analysis of experimental social desirability and response set scales.

Intercorrelations between 19 response set scales, based upon the scores of 110 students, were factor analyzed and the factors rotated orthogonally. Edwards' SD scale and 6 experimental social desirability scales had their highest loadings on the 1st factor. 3 scales containing neutral items in which the probability of a True response to the items varied between scales were found to have their highest loadings on 3 different factors. Scales designed to measure the tendency to give deviant True responses to items with socially undesirable scale values, to items with socially desirable scale values, and to items with neural scale values were found to have their highest loadings on 3 different factors. The tendency to give deviant True responses to items with socially undesirable scale values was found to be related to the tendency to give deviant False responses to items with socially desirable scale values. The tendency to mark items as doubtful and the tendency to answer items marked doubtful as True were identified as 2 factors unrelated to social desirability tendencies. (31 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Readmissions to drug abuse treatment and HIV risk behavior

The objectives of the study were (a) to investigate the characteristics of drug abuse treatment clients who return to treatment and (b) among those with readmissions, to describe changes over time in risk behavior for human immunodeficiency virus (HIV) infection and to identify factors associated with behavior change. Data were derived from a multisite HIV surveillance program in a single community; the program used a unique identifier to link HIV test results and behavioral information from multiple contacts. During a 30-month period, 1994 clients were admitted to three satellite facilities of a single treatment agency: detoxification, long-term residential, and outpatient. Of these clients, 574 (29%) had one or more readmissions to the same or a different facility during the 24 months following the index admission. Drug injectors, those tested for HIV, and those living in the community were more likely to be readmitted to treatment. There was little overall change in HIV risk behavior between the index admission and the readmission furthest in time from the index admission. Clients whose index visit was at the residential facility were more likely to reduce their injection risk behavior than those admitted to the other facilities. Clients readmitted to either the residential or the outpatient facility were more likely to have reduced their injection risk behavior than those readmitted to detoxification. Treatment facility was not associated with sexual risk behavior change. Men were more likely than women to reduce their high-risk sexual behaviors. The results underscore the need for treatment programs to make HIV testing readily available to their clients and to make special efforts to assist female clients to reduce their HIV risk.     

干熄焦运行中的干扰分析与应对措施

介绍干熄焦提升机自动控制系统由提升和走行两大系统组成,调速系统采用变频调速,通过PLC控制系统实现监控,所有监测数据均在控制室监测、记录并进行管理。文章对干熄焦控制系统在运行中出现的故障进行分析,针对干扰类型,提出了针对性的抗干扰措施,确保系统运行稳定性。     

Extrachromosomal resistance in gram-negative organisms: the evolution of beta-lactamase

beta-Lactamases are the major defense used by bacteria to overcome the effects of penicillins, cephalosporins and related beta-lactam antibiotics. In the antibiotic era, the enzymes have evolved to become more prevalent, to appear in new hosts, to be expressed at higher levels, to be acquired by plasmids and to change catalytic properties to increase affinity for what were meant to be nonhydrolysable substrates or to reduce affinity for beta-lactamase inhibitors.     

论农村学生自主学习的培养

教师应转变观念,创设和谐的自主学习氛围,最大限度地激发学生的学习动机,培养他们的学习兴趣,使其掌握正确的学习方法,形成良好的、积极自主的学习习惯,成为学习的主人。     

固定式精炼炉的改进

江西铜业集团公司贵溪冶炼厂(简称贵冶)固定式精炼炉,因其在设计上存在缺陷及生产工艺的改变,不能满足生产的需要。在生产实践中积累经验后,将其进行技术改造。将改造前后的不同状况列出进行比较,从而阐述改造后取得的效果,最后列举出贵冶固定式精炼炉目前还存在的不合理因素,并设计出解决的方案,做到工作持续推进。