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.     

Illusion d’incompétence, attitudes dysfonctionnelles et distorsions cognitives chez des élèves du primaire.

The first objective of this study is to determine whether the illusion of incompetence schema is related to the presence of other dysfunctional schemas, such as dysfunctional attitudes related to success, to dependence on others and to self-control. The second objective is to examine whether these schemas are related to the occurrence of cognitive errors. Some 577 students of primary school grades five and six took part in the study. It appears the illusion of incompetence is linked more to dysfunctional attitudes related to success and less to those related to self-control. The canonical correlations for examining the second objective point to two dynamics: the illusion of incompetence combined with higher levels of dysfunctional attitudes related to success is linked to the occurrence of three types of cognitive errors examined; the illusion of incompetence coupled with lower levels of dysfunctional attitudes related to success and to dependence is related more to negative treatment of positive information and less to the anticipation of catastrophe. The discussion makes a link to the results obtained with the Beck model, which holds that the presence of dysfunctional schemas contributes to the occurrence of cognitive errors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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.     

Legal rights of the physician as the defendant

Until recently, physicians were confronted with a certain risk of prosecution typical of the medical profession such as personal injury or sometimes manslaughter. Now, physicians are compelled to face accusations apparently outside of this profession such as fraud, embezzlement, or cheating. When physicians get contact with the executive power (i.e. on the occasion of a search), it should be questioned whether one is seen as an accused or as witness. Both positions contain different rights and duties. The witness always has to testify. He can refuse to testify due to personal and professional reasons. Additionally, he may refuse to answer questions that would expose himself or a relative to the risk of charges. According to the German constitution, the witness may request the support of a lawyer. The main duty of the accused is to endure the proceedings against him. There is no option to appeal against the opening of criminal proceedings. The most important rights of the accused are the right to refuse the testimony and the right to be heard at court. The right of hearing includes the right to decide about the time and kind of a possible attendance during the proceedings. This right should be used in any case. Every unconsidered or uncertain statement may be of severe disadvantage. It is regularly indicated to ask a lawyer for legal support which is also the right of the accused. During testimony, the physician faces the problem whether he is allowed to reveal facts that are subject of medical discretion. He has the right to do so if he is unable to refute the accusation otherwise leading to legal sanctions or to a charge. The specific rights and options of an attorney include the scrutiny of the procedures of the executive power and the active participation to find the true facts of the case. It is the attorney but not the accused who has the right to examine the records. Both have the right to influence the criminal proceedings by contribution of evidence.     

A novel electrostatic approach to enzyme mechanisms: carbonic anhydrase as an example

A novel electrostatic approach to the manner in which enzymes catalyze reactions is developed. In this development, the author's interpretations of, and additions to, the late K. Fajans' theory of electronic structure (referred to as the Quanticule theory of chemical binding) are presented. This theory is based upon electron densities, in analogy to density functional theory. It is used to derive formulations of molecular structure, (Fajans' formulations) which show the charges of the atomic components. These charges are shown to be reduced by polarization to what are commonly referred to as partial charges. These formulations relate to the exchange of charged atomic components during reactions. The relevance of the formulations to the catalytic activity of enzymes is illustrated with carbonic anhydrase. When viewed in terms of Fajans' formulations, the active site is seen to consist of an array of charged atoms. The positive and negative charges tend to alternate. When closely positioned, these charges provide a basis for drawing atomic components of the molecules, which are exchanged in a given reaction, into the new positions. The charges are shown to be related to the binding of substrates to the enzyme and the positioning of them so that they can interact, to the reaction itself, to an essential proton transfer, and to the dissociation of the product from the enzyme. This more extensive scope of electrostatic interactions provides a more simple view of the manner in which the catalysis is accomplished. Such catalysis is consistent with a number of other proposals about enzyme mechanisms, and appears to be applicable to a large majority of enzyme-catalyzed reactions.     

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。     

Linkage disequilibrium mapping of complex disease: fantasy or reality?

In the past year, data about the level and nature of linkage disequilibrium between alleles of tightly linked SNPs have started to become available. Furthermore, increasing evidence of allelic heterogeneity at the loci predisposing to complex disease has been observed, which has lead to initial attempts to develop methods of linkage disequilibrium detection allowing for this difficulty. It has also become more obvious that we will need to think carefully about the types of populations we need to analyze in an attempt to identify these elusive genes, and it is becoming clear that we need to carefully re-evaluate the prognosis of the current paradigm with regard to its robustness to the types of problems that are likely to exist.     

Ethics in sports medicine--health and/or performance?

Ethics in the field of sports medicine embraces a number of issues of general human interest. While it is important to determine the salubrious potential of exercise and sports, it is open to question whether it is reasonable to invest massive research resources in attempts to induce high-performance elite athletes to perform yet better, or to remedy sports injuries to enable athletes to continue exposing themselves to the risk of further injuries. When such questions arise as the extent to which physicians should attempt to modify unhealthy lifestyle factors, for example the use of doping, or whether it is right that athletes should take precedence in waiting lists for health care, it is important to be aware of the singular practical potential of sports medicine.     

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.     

Transition from paediatric to adult-orientated care for adolescents with cystic fibrosis

Adolescence is a time of major physical and psychological change. Young teenagers need to become comfortable with their developing sexuality, to begin moving towards independence with a greater reliance on peer group acceptance, to face the future and to make important decisions about their education, career and goals. Difficulties inherent in all of these steps to adult life are magnified by chronic ill health. It is harder for adolescent patients to break family ties, harder to feel accepted by their peer group, harder to plan realistically for the future. It must be the overriding aim of the professional health carers to encourage these patients to confront the problems of adolescence and to help them maintain their physical and emotional stability throughout this challenging period. Parents also must be supported, and encouraged gradually to devolve to their child responsibilities for decision making and for taking prescribed medication. A planned and sensitive transition from a paediatric to an adult health-care system will aid a successful evolution to an independent adult life. The paediatric hospital environment is not best equipped to deal with the problems of adolescence. Just as parents must allow their child to move on, so the paediatric caring team must loosen its ties with the patient and allow transfer to the adult team. There are several ways of effecting this transfer of care. None of them is proven to be better than any other, but the transfer should always be planned, smooth, efficient and expected by the patient. Ideally, all patients should have the opportunity to transfer to a properly equipped and properly staffed adult cystic fibrosis centre where they can continue to receive the highest standards of care from an experienced multidisciplinary team.     

A clinicopathological study of the effects of topical retinyl propionate cream in skin photoageing

To study the influence exerted by cutaneous ligands in nickel reactions we have evaluated the patch tests responses to 4 aqueous nickel salts (sulfate, chloride, nitrate, acetate) able to form different complexes with different geometry. Two groups of respectively 71 subjects who previously reacted only to nickel sulfate 5% petrolatum (pet) and of 30 subjects who previously reacted to nickel sulfate 5% pet and to at least 1 other transition metal, were simultaneously repatch-tested to 200 microg of Ni++ contained in nickel sulfate in pet and to 47 microg of Ni++ contained in 4 different aqueous nickel salts. Another 2 groups of 25 subjects with the same characteristics were simultaneously repatch tested to 200 microg of Ni++ in pet and to 12 microg of aq Ni++ as in the first 2 groups. Visual score, total score, and mean value of the reactions were utilized in evaluating the degree of the responses. On testing to 200 microg of Ni++ in pet all the subjects were able to give positive responses. Whilst a higher percentage of the responses of 2+ degrees was found in subjects reacting to nickel sulfate 5% pet alone, a higher percentage of responses of 3+ degrees was observed in subjects reacting to more transition metals. On testing to 47 and 12 microg of aqueous Ni++ a large variability of responses to the single salts was observed in all the subjects. However, in subjects reacting to more metals there were either a greater number of multiple responses to 3 or 4 salts or responses stronger than those found in subjects reacting to nickel sulfate alone. Although patch testing cannot give us complete information about the degree of previous exposure, the results arising from the tests seem to demonstrate that the subjects allergic to nickel and other transition metals are more reactive than the subjects allergic only to nickel to the application of the same amounts of Ni++ contained in different salts. When considering the QSAR model, the difference in the sensitizing potential of the metal at the same penetration properties can depend on the possibility of combining with specific ligands. Therefore, it is likely that in subjects reacting to more metals there is a more uniform availability of cutaneous ligands which conditions the formation of complexes more immunogenic. The arising inflammatory reaction in these cases leads to a stronger but less specific response.     

The reduced responsiveness of neurones in nucleus reticularis gigantocellularis following their excitation by peripheral nerve stimulation

1. Post-stimulus histograms of neuronal activity, constructed from extracellular recordings in decerebrate, decerebellate cats, have been used to investigate the responsiveness of neurons in nucleus reticularis gigantocellularis following their excitation by a peripheral nerve stimulus. 2. The response to a testing stimulus applied to a peripheral nerve was depressed following the response to a conditioning stimulus applied to the same or a different peripheral nerve. This reduction in responsiveness was maximal within 50 msec of the peak of the response to the conditioning stimulus. Response latencies to the testing stimulus were increased during the period of reduced responsiveness. 3. Responsiveness to a peripheral nerve stimulus was also reduced following a spontaneous or an antidromically evoked spike, but this effect was weaker and much shorter-lasting than that following a nerve-evoked spike. Thus, the reduced responsiveness cannot be solely due to phenomena which are an inevitable consequence of an action potential in the neurone. 4. In spontaneously firing neurones, the duration of the reduced responsiveness to a testing stimulus generally outlasted the depression of spontaneous activity which often followed an excitation evoked by a peripheral nerve conditioning stimulus. 5. The reduction in responsiveness to a testing stimulus applied to the same nerve as the conditioning stimulus was greater and longer-lasting than that to a testing stimulus applied to a different nerve. 6. When stimuli were applied to one nerve at a relatively high rate, the neurone became much less responsive to that input, but simultaneously became more responsive to low rate stimulation of other nerves. 7. It is concluded that the greater part of the reduced responsiveness is due to events occurring on the input pathway to a reticular neurone, or possibly in the region of the afferent endings on its dendrites. These processes may allow selective changes in responsiveness to different inputs, and enable the units to act as novelty detectors.     

Multicenter trial of Enterococcus antibiotic susceptibility

Antibiotic susceptibility of 446 Enterococcus isolates from 9 medical centres of Moscow and St. Petersburg was tested. Among the isolates 386 belonged to E.faecalis, 48 to E.faecium and 12 to the other species. All the isolates were susceptible to vancomycin. As for E.faecalis 84 and 85 per cent of the isolates were susceptible to ampicillin and ampicillin/sulbactam respectively (no production of beta-lactamases), the frequency of high resistance to aminoglycosides amounted to 44 per cent with respect to streptomycin and to 25 per cent with respect to gentamicin, 75 per cent of the isolates was susceptible to ciprofloxacin. As for E.faecium and the rare species of Enterococcus more than 70 per cent of the isolates was resistant to ampicillin and ampicillin/sulbactam, the frequency of high resistance to aminoglycosides exceeded 60 per cent, 17 and 25 per cent of the isolates were susceptible to ciprofloxacin.     

Screening for deficits in DNA repair by the response of irradiated human lymphocytes to phytohemagglutinin

An assay has been developed to measure the ability of human lymphocytes to repair damage to DNA. In this assay, purified human lymphocytes are exposed to graded doses of radiation and then stimulated with phytohemagglutinin to undergo DNA replication. The rate of incorporation of thymidine in irradiated lymphocytes during the second and subsequent rounds of DNA replication is taken to be indicative of the ability of the cells to repair damage to DNA. In lymphocytes from normal individuals, X-irradiation with doses of 100 to 800 rads was found to inhibit phytohemagglutinin-stimulated thymidine incorporation proportionally to the dose of radiation without curtailing the induction of DNA polymerase. The response to phytohemagglutinin of lymphocytes from a patient with xeroderma pigmentosum after exposure to graded doses of X-irradiation was found to be similar to that of the normal controls, whereas the response after ultraviolet irradiation was markedly impaired. In contrast, lymphocytes from patients with ataxia telangiectasia were hypersensitive to X-irradiation. The data on these clinical syndromes support the idea that this assay measures DNA repair and indicates the feasibility of using this method for screening individuals for genetic deficits in DNA repair.     

Neonatal murine B lymphocytes respond to polysaccharide antigens in the presence of IL-1 and IL-6

Unlike adults, neonates are unable to respond to polysaccharide Ags, making them especially vulnerable to pathogenic encapsulated bacteria. Since the Ab response to polysaccharides in adult mice requires certain cytokines, it was hypothesized that neonatal murine B cells may be competent to respond to such Ags, but may fail to do so due to a deficiency of cytokines. Neonatal splenocyte cultures, which were otherwise unresponsive to trinitrophenyl (TNP)-Ficoll, a haptenated polysaccharide Ag, mounted an adult-like Ab response when supplemented with IL-1. However, IL-1 failed to induce such a response to TNP-Ficoll when purified B cells were used instead. Although IL-6 alone did not induce a response in whole spleen cells or purified B cells from neonates, it synergized with IL-1 in inducing purified neonatal B cells to respond to TNP-Ficoll. The avidity of the cytokine-induced neonatal anti-TNP Abs was comparable to that of Abs made by adult splenocyte cultures. One effect of IL-1 may be at the level of clonal expansion, since it induced neonatal B cells to proliferate in response to anti-IgM, which was further enhanced by IL-6. The spontaneous secretion of IL-1 by neonatal splenocytes was below the detection limit, while adult splenocytes secreted 30.8 +/- 5.2 U/ml, which is of the same order of magnitude as what was required to stimulate neonatal B cells to respond to TNP-Ficoll. Thus, the neonatal unresponsiveness to polysaccharide Ags could be due to the inability of a non-B cell population resident in the neonatal spleen to secrete sufficient quantities of IL-1.     

La relation père-enfant, la nature et l’organisation des relations d’attachement.

Faithfully following the tradition of Bowlby’s theoretical framework, until recently research in developmental psychology has more often confirmed the importance of attachment to mother than to father in their children’s development. Based on this statement, Paquette (2004) proposed a different theoretical model to account for the father’s specific role in children’s development. The purpose of this review of the literature is to examine results of studies including measures of attachment to mother and to father and to answer the questions raised by different theoretical models accounting for the organization of children’s attachment relationships, that is to say hierarchy in children’s attachment to mother and to father, correspondence between the quality of these two relationships and their influence on children’s development. Whether the attachment theoretical framework seems to partially account for the specificity and the complementarity of parental roles, results of the studies reviewed in this article underline the necessity to operationalize the activation dimension of attachment relationships (Paquette, 2004) in order to better understand how children’s attachment relationships to parents do develop and how they do organize themselves to influence children’s development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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.     

Identification of a carbohydrate recognition domain in filamentous hemagglutinin from Bordetella pertussis

The adherence of Bordetella pertussis to ciliated cells and macrophages is critical to colonization and infection of the respiratory tract. Adherence to both types of cells involves the recognition of eukaryotic carbohydrates by the bacterial adhesin filamentous hemagglutinin (Fha). The carbohydrate recognition domain (CRD) of Fha is considered an important antigen for subcomponent vaccines to maximize the generation of antiadherence antibodies capable of protecting against colonization. For identification of the CRD of Fha, a bank of eight monoclonal antibodies (MAbs) that mapped to four contiguous regions were tested for their ability to block Fha binding to lactosylceramide or to block bacterial binding to ciliated cells. Only MAb 12.5A9, which maps to amino acid residues 1141 to 1279, blocked both Fha binding to lactosylceramide and bacterial binding to ciliated cells. An 18-kDa polypeptide corresponding to this region was expressed in Escherichia coli. Cell lysates containing this protein bound to lactosylceramide in a manner identical to that of native Fha. Mutant strains of B. pertussis that contained an in-frame deletion of the coding sequence for this region produced a truncated Fha that showed negligible cross-reactivity with MAb 12.5A9. In an adherence assay, these mutant strains failed to bind efficiently to either ciliated cells or macrophages. The numbers of adherent bacteria for these strains were reduced to the number obtained with a nonadherent strain. We conclude that the region defined by residues 1141 to 1279 of Fha constitutes a CRD critical for bacterial adherence and represents a potential candidate for a subcomponent vaccine.     

rOmpA is a critical protein for the adhesion of Rickettsia rickettsii to host cells

rOmpA and rOmpB are immunodominant, surface-exposed proteins of Rickettsia rickettsii. Prior evidence suggests that adhesion of R. rickettsii to the host cell is mediated by a rickettsial protein. Five monoclonal antibodies to rOmpA, five to rOmpB, and one to the rickettsial lipopolysaccharide (LPS) were tested for inhibition of rickettsial attachment. All the monoclonal antibodies to rOmpA inhibited adhesion of rickettsiae to the L-929 cells with some inhibition rates as high as 90%. In contrast, monoclonal antibodies to rOmpB and LPS did not block attachment. When Fab fragments of monoclonal antibodies against rOmpA and rOmpB were used, similar results were observed as for the intact monoclonals, non-adhesion and adhesion, respectively. Purified rOmpA showed a competitive inhibitive effect on the attachment of R. rickettsii to host cells. Trypsin completely digested rOmpA but not rOmpB from the surface of intact R. rickettsii, resulting in loss of the ability of the rickettsiae to attach to the host cell. rOmpA appears to play an important role in the initial adhesion of R. rickettsii to the host cell.     

45t AOD配气模型

针对传统AOD配气方式的缺点,研究了基于魏季和等的脱碳精炼数学模型的配气模型,使AOD脱碳配气可根据钢水碳含量的变化自动调整氧氩比、根据钢水温度变化自动调整供氧强度,以及根据炉役中炉容比的变化自动调整最大供氧强度。该模型应用于AOD不锈钢冶炼系统中,既提高了氧气利用率,又缩短了冶炼时间,而且吨钢氧耗和还原硅消耗也略有改善,取得了较好的效果,为AOD不锈钢冶炼智能化打下了良好的基础。