Implicações da agregação espacial de parasitas para a dinâmica populacional na interação hospedeiro-parasita

Some aspects of the widely observed over-dispersed pattern of the distribution of parasites within the host population are examined. It has been established in the parasitological literature that most hosts usually harbour few parasites, while only few hosts harbour a large proportion of the parasite population. Factors that may influence the pattern of distribution of parasites, the relation between the level of parasite aggregation and the prevalence of infection, and changes in this level of aggregation as a function of host age are analysed. Factors which determine the diversity of species in parasite communities are presented, and aspects of exploitative and interference competition among parasites and their relations with biological control procedures are also considered. Attention is also focused on the regulatory and destabilizing processes influencing the dynamic behaviour of host-parasite population interactions.

Ocorrência e determinação do perfil de sensibilidade às drogas das cepas de Staphylococcus aureus isoladas de fossas nasais e orofaringe dos servidores hospitalares

Staphylococcus aureus is a very important hospital and community pathogen. This species is related to supurative disease, systemic and widespread metastatic lesions. The ability of S. aureus to develop resistance to antibiotics, more recently to methicillin, associates this bacteria with epidemic outbreaks of severe nosocomial infection. The source of staphylococcal infection is a patient with a staphylococcal lesion or a career member of the hospital staff. We aimed to detect the frequency of S. aureus isolated from anterior nares and oral cavities among the hospital staff in Bauru - SP, and to determine the antibiotic susceptibility of the isolates. Within 213 of the staff members analyzed. S. aureus was found in 94 (44.13%) of careers, with 47 (50%) of nasal carriers, 23 (24.4%) of oral carriers and 24 (25.5%) of both carriers. The biochemical characteristics analyzed for the species identification were similar to S. aureus ATCC 29213. All strains identified as S. aureus showed varied sensibility to the antimicrobial agents tested. No vancomicin resistant strains and only 8 (8.5%) strains with oxacilin resistance were found.

Efeito de drogas utilizadas no tratamento de hipertensão arterial sistêmica sobre a pressão intra-ocular: Estudo experimental no cão

Purpose: To study the effects of two drugs (captopril and propranolol) used in the treatment of systemic hypertension, on the intraocular pressure (IOP) of anesthetized dogs. Methods: 24 dogs, divided into 3 groups of 8 each. In the first group, 1.5 mg/kg IV of captopril (an angiotensin converting enzyme inhibitor) was administered. In the second group, 1.5 mg/kg IV of propranolol (a beta-blocker) was administered. The third group was the control. IOP and blood pressure (BP) were measured by manometry. The perfusion pressure was calculated by the difference between BP and IOP (BP-IOP). The parameters were studied at 6 moments (0, 10, 30, 60, 90 and 120 minutes). Results: There was significant reduction of IOP (p<0.05) with captopril and propranolol, without difference between the drugs. With captopril the BP and PP decreased markedly at 10 and 30 minutes. With propranolol there was no reduction of BP or PP. Conclusions: Captopril and propranolol reduced IOP. However, the marked reduction of BP, and consequently of PP caused by captopril may be undesirable for irrigation of the optic nerve.

Consumo de drogas psicoactivas por adolescentes escolares de Assis, SP

To quantify psychoactive drug use and investigate use-related variables among students of Assis, Brazil, a questionnaire was administered to collect sociodemographic data and identify the pattern of non-medical use of psychoactive drugs in 20% of public and private school students. The largest consumption indexes for lifetime use were seen for alcohol (68.9%) and tobacco (22.7%). Drugs most often used were: solvents (10.0%); marijuana (6.6%); benzodiazepines (3.8%); amphetamines (2.6%); cocaine (1.6%); and anticholinergics (1.0%).

Interação das enterotoxinas estafilocócicas com o sistema imune do hospedeiro

Staphylococcal enterotoxins are among the most common etiologic agents that cause food poisoning and, possibly, nonmenstrual toxic shock syndrome. These enterotoxins are also called superantigens because they are potent T cell and macrophages activators. The superantigens bind directly to the major histocompatibility complex class II molecules on antigen-presenting cells and stimulate T cells expressing specific Vβ elements in the cell receptors. Excessive production of cytokines by these cells and macrophages are responsible for the pathogenesis of food poisoning. These cytokine include tumor necrosis factor (TNF)-α, interferon (IFN)-γ and interleukin (IL)-1, proinflamatory mediators with potent immunoenhancing effects; the nitric oxide (NO). It still has both effects citotoxic and regulatory roles in immune function.

Estudos sobre liberação controlada e vetorização de drogas através de lipossomas

The text highlights the state of research related with the application of liposomes in the control of drug delivery and drug target to infectious diseases. Liposomes have several pharmaceutical applications and this manuscript is primarily focused on the potential of this colloidal system as an antibiotic carrier system and of administration through several accesses via to organism. Numerous case studies in which liposomes have successfully been used to improve pharmacological drug effect are presented. Mechanisms involved in drug delivery, application possibilities, research and development and efforts to reach these objectives are discussed. © Copyright Moreira Jr. Editora. Todos os direitos reservados.

Interação de Paracoccidioides brasiliensis com células endoteliais

Paracoccidioidomycosis has a variety of clinical manifestations and Paracoccidioides brasiliensis, the causative agent, may infect many tissues, most importantly the lungs. Migration of pathogenic yeasts to the endothelial cell layer is considered a prerequisite for multiple organ invasion and dissemination of the fungus. In this study of the adhesion of P. brasiliensis to endothelial cells in vitro, we investigated whether this adhesion could represent a mechanism of dissemination. To this end, as well as using conventional optical microscopy, an alternative in vivo technique was developed, to detect the presence of fungal cells in umbilical cords embedded in paraffin wax. An experiment on the migration of P. brasiliensis through an endothelial cell monolayer was carried out, and the migration of yeast cells was greater, and took less time, in control wells with no cells. The fungus crossed the monolayer, but, compared to control wells, the migration-rate was about 30% lower. This shows that the monolayer only partially blocked migration of the fungus. In these experiments, we had great difficulty finding P. brasiliensis adhered to the cell monolayer, when it was examined at different times, suggesting that migration of the fungus across the endothelial layer is very fast, and cannot normally be observed in cell culture in vitro. Thus, P. brasiliensis can cross the endothelium rapidly and probably invades deeper tissue.

A Qualidade da Interação Positiva e da Consistência Parental na sua Relação com Problemas de Comportamentos de Pré-Escolares

Studies have shown a relationship to exist between behavior problems in children and quality of parental practices such as communication, expressivity, consistency, and monitoring. This study aimed at describing relationships that parents have with their preschool children, and also at relating parenting skills to child behavior. We compared fathers' and mothers' social educational skills in two groups of children, with or without behavior problems at school. Research was conducted in a town in the State of Sao Paulo, BR. Participants were biological mothers and fathers of 48 preschoolers; twenty-five children presented behavior problems at school, and 24 had high social skills. Parents were individually interviewed at home. Results showed that fathers and mothers of socially skilled children were more consistent in their practices. They were more able to identify and describe their children's socially skilled behaviors. They also reported they gave more positive feedbak for their children's good behavior.

Interação entre grau de perda auditiva e o incômodo com zumbidos em trabalhadores com história de exposição ao ruído

Hearing loss and tinnitus impact the lives of workers in every instance of their lives. Aim: this paper aims to investigate the existence of a dose-response relationship between hearing loss and tinnitus by determining whether higher levels of hearing loss can be associated with increased tinnitus-related discomfort. Materials and method: this cross-sectional case study assessed 284 workers exposed to occupational noise through pure tone audiometry. Test results were categorized as defined by Merluzzi. Individuals complaining of tinnitus answered the adapted and validated Brazilian Portuguese version of the Tinnitus Handicap Inventory. A generalized linear model was adjusted for binomial data to test the interaction between these factors. Results: over 60% of the ears analyzed had hearing loss, while more than 46% of them had tinnitus. Tinnitus prevalence and risk rates increased as pure tone audiometry results got worse. The association between both, considering all hearing loss degrees, was statistically significant. Conclusion: the results point to a statistical association between hearing loss and tinnitus; the greater the hearing loss, the greater the discomfort introduced by tinnitus. 2009 © Revista Brasileira de Otorrinolaringologia.

La grieta de las drogas: desintegración social y políticas públicas en América Latina

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La economía política de las drogas en la década de los noventa: una nota de síntesis

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Las drogas ilegales en los países andinos: resultados de estudios recientes patrocinados por el PNUD

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Drogas en Colombia: los efectos de una economía gangsteril

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