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OBJECTIVE: To investigate the effect of sildenafil citrate on the prevention and progression of experimental periodontitis (EP) in rats. MATERIALS AND METHODS: Thirty-six male Wistar rats were randomly assigned into two groups: Group 1 (preventive) and Group 2 (progression). In Group 1, the animals received daily doses of sildenafil (10 mg/kg) or vehicle for 30 days, and EP was induced on the 15th day. In Group 2, the EP was induced on the first day, and the animals received daily doses of sildenafil (10 mg/kg) or vehicle from the 15th day. For EP, ligatures were placed around the right first mandibular molars. Microtomographic, histomorphometric and histological analyses were carried out to evaluate the alveolar bone loss and inflammatory degree. For statistical analyses, t test and the Mann-Whitney test were used, considering a level of significance of 95%. RESULTS: In Group 2, the animals treated with sildenafil showed a significantly lower bone resorption (p = .05). Similarly, the subgroup treated with sildenafil displayed a significantly lesser degree of inflammation (p = .01). No significant differences were observed between the subgroups of the Group 1. CONCLUSIONS: Sildenafil decreased the inflammatory process, as well as the alveolar bone loss when used to modulate the progression of experimental periodontitis.

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This study compared the ability of CRF and UCN1 to induce a thermoregulatory response when centrally injected into rats. The effects of antipyretic drugs and CRF receptor antagonists (CRF1 and CRF2) on the temperature (T) changes induced by these peptides were also investigated. Rectal (rT) and tail skin (T(sk)) temperatures were measured with a thermistor probe while body (bT) temperature was measured with a battery-operated biotelemetry transmitter in male Wistar rats (200 g) every 30 min over a period of 6h, after intracerebroventricular (i.c.v.) injection of 1 nmol of either CRF or UCN1. Rats were pre-treated with indomethacin (2 mg kg⁻¹, i.p.) or celecoxib (5 mg kg⁻¹, p.o.), dexamethasone (0.5 mg kg⁻¹, s.c.), astressin (a CRF1/CRF2 antagonist, 7 nmol, i.c.v.) or antalarmin (a CRF1 antagonist, 20 mg kg⁻¹, i.p.). The increase in body temperature induced by CRF was accompanied by a reduction in T(sk) while the response induced by UCN1 was accompanied by an elevation in T(sk). Indomethacin or celecoxib did not change the increases in rT caused by either CRF or UCN1. Although dexamethasone attenuated the increase in rectal temperature in response to CRF, dexamethasone did not modify the response induced by UCN1. Astressin blocked the UCN1-induced hyperthermia and reduced CRF-induced fever. Antalarmin did not modify the hyperthermia in response to UCN1, but reduced the fever evoked by CRF. This study demonstrated that CRF by acting on the CRF1 receptor induces a prostaglandin-independent fever which seems to depend, at least in part, on the synthesis of other mediators while UCN1 acts on the CRF2 receptor, promoting a hyperthermic response which seems to be independent on synthesis/release of any mediator.

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Two fish species, Astronotus ocellatus (Cichlidae) and Macropodus opercularis (Anabatidae) were tested for predacious behavior toward immature mosquitoes (Aedes fluviatilis, Diptera:Culicidae) and schistosomiasis snail hosts (Biomphalaria glabrata, Mollusca:Planorbidae), in the presence or absence of non-living food and in laboratory conditions. A. ocellatus, a species indigenous to Brazil, was a very efficient predator of both organisms (alpha = 0.05); M. opercularis, an exotic species, preyed well on immature mosquitoes, but small snails and snail egg-masses were ingested only irregularly. Both fish species seemed to prefer live to non-living food.

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A review is presented of 20 patients consecutively operated on for acute valvular endocarditis. The diagnosis was established from at least two of the criteria: (a) typical clinical features, (b) two blood cultures positive for the same causal microorganism, and (c) echocardiographic evidence of vegetations. In all cases there was histologic evidence of active infection in the surgical specimen. Only three of the 20 patients had no previous cardiac disease. The most common causal agent was Staphylococcus aureus. The indications for surgery were refractory cardiac failure or infection (18 and 2 cases, respectively). Aortic valve replacement was performed in 16 of the 20 cases, suggesting that aortic valvulopathy aggravates the course of infective endocarditis and increases the risk of heart failure. The overall mortality rate was 30%. All surviving patients were infection-free at postoperative bacteriologic follow-up. Surgery is considered to be the management of choice in active valvular, therapy-resistant bacterial endocarditis with or without cardiac failure.

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O potencial de predacao de Helobdella triserialis lineata sobre desovas e exemplares de Biomphalaria straminea e Biomphalaria tenagophila foi estudado em laboratorio visando, por um lado, verificar a influencia desta predacao sobre criacoes destes moluscos em laboratorio e, por outro, avaliar a possivel utilizacao deste hirudineo no controle de populacoes de planorbineos hospedeiros intermediarios da esquistossomose mansoni em condicoes naturais. Nas condicoes experimentais exemplares recem-eclodidos,jovens e adultos de B.straminea e B. tenagophila, foram predados por H: t. lienata que nao predou as desovas dos planorbineos. Observou-se uma ligeira aceleracao no crescimento e uma discreta reducao na oviposicao dos planorbineos mantidos juntos com os hirudineos

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