Participation of alpha-1 and alpha-2 adrenoceptors of the lateral hypothalamic area in water intake, and renal sodium, potassium and urinary Volume excretion induced by central administration of angiotensin II

The circumventricular structures and the lateral hypothalamus (LH) have been shown to be important for the central action of angiotensin II (ANGII) on water and electrolyte regulation. Several anatomical findings have demonstrated neural connection between circumventricular structures and the LH, the present experiments were conducted to investigate the role of the alpha-adrenergic antagonists and agonistic injected into the LH on the water intake, sodium and potassium excretion elicited by injections of ANGII into the lateral ventricle (LV), the water intake was measured every 30 min over a period of 120 min. The sodium, potassium and urinary volume were measured over a period of 120 min in water-loaded rats. The injection of ANGII into the LV increased the water intake, which was reduced by previous injection of clonidine (an alpha-2-adrenergic agonist) into the LH. The injection of yohimbine (an alpha-2-adrenergic antagonist) and prazosin (an alpha-l-adrenergic antagonist) into the LH, which was done before injecting ANGII into the LV, also reduced the water intake induced by ANGII. The injection of ANGII into the LV reduced the sodium, potassium and urinary volume. Previous treatment with clonidine attenuated the action of ANGII in reducing the sodium, potassium and urinary volume, whereas previous treatment with yohimbine attenuated the effects of ANGII but with less intensity than that caused by clonidine. Previous treatment with prazosin increased the inhibitory effects of ANGII in those parameters. The injection of yohimbine and prazosin, which was done before the injection of clonidine, attenuated the effect of clonidine on the ANGII mechanism. The results of this study led us to postulate that when alpha-2-adrenergic receptors are blocked, the clonidine may act on the imidazoline receptors to produce its effects on the ANGII mechanism. We may also conclude that the LH is involved with circumventricular structures, which present excitatory and inhibitory mechanisms. Such mechanisms are responsible for regulating the renal excretion of sodium, potassium and water, (C) 2000 Elsevier B.V.

Short-term induction of thrombocytopenia delays periodontal healing in rats with periodontal disease: participation of endostatin and vascular endothelial growth factor

Background and Objective:Platelets contain factors, including VEGF and endostatin, that can modulate the healing process. We evaluated the effects of severe thrombocytopenia on periodontal healing in rats and determined the contribution of VEGF and endostatin to the healing process.Material and Methods:Rats were distributed into three test groups and two control groups. Cotton ligatures were placed at the gingival margin level of the lower first molar in the test groups. Sham-operated rats and rats in one of the periodontitis groups were killed 15 days later. Rats in the remaining two periodontitis groups had the ligatures removed in order to study the spontaneous recovery from the periodontal disease 15 days later, and these rats were treated with rabbit antiplatelet serum, in order to induce thrombocytopenia, or normal rabbit serum. An additional group without ligatures received antiplatet serum in the same period.Results:After ligature removal, rats treated with normal rabbit serum showed reduced myeloperoxidase activity, decreased alveolar bone loss and increased numbers of blood vessels. Thrombocytopenia caused a delay in alveolar bone regeneration, a decrease in the number of vessels and a modest decrease in myeloperoxidase activity. In the rats with periodontitis, serum endostatin concentrations were slightly decreased and serum VEGF remained unchanged compared with sham-operated animals. After ligature removal, a significant VEGF increase and endostatin decrease were observed in the rats treated with normal rabbit serum. Thrombocytopenia led to a dramatic fall in both VEGF and endostatin concentrations.Conclusion:Thrombocytopenia leads to a delay of periodontal healing in the situation of experimental periodontitis, which might be mediated in part by a decrease in the serum concentration of VEGF and endostatin derived from the platelets. However, other factors derived from the platelets may also have contributed to a delay of periodontal healing in the rats with thrombocytopenia.

PARTICIPATION OF OPIOID RECEPTORS IN THE MODULATION OF THE ANALGESIC RESPONSE BY ADRENAL AND GONADAL GLANDS

The involvement of opioid receptors in the analgesic response was evaluated by the tail-immersion test in simultaneously adrenalectomized and ovariectomized female Wistar rats (210-250 g). The reaction time (mean +/- SEM) for tail withdrawal from hot water decreased significantly 2 weeks after surgery (3.52 +/- 0.20 s) when compared to intact animals (6.09 +/- 0.23 s). Hormonal replacement with dexamethasone (50-mu-g/day) did not affect reaction time (3.38 +/- 0.19 s). However, this response was restored by combined adrenal and gonadal steroid substitution (estradiol 5-mu-g/day and progesterone 1.5-mu-g 6 h before the tests) therapy (5.11 +/- 0.45 s in animals treated with dexamethasone plus estradiol and 5.04 +/- 0.43 s in animals treated with dexamethasone plus estradiol plus progesterone). Naloxone (2 mg/kg) decreased the reaction time of animals treated with adrenal and gonadal steroids (5.11 +/- 0.45 vs 4.15 +/- 0.44 s and 5.04 +/- 0.43 vs 3.87 +/- 0.28 s, respectively, before and after naloxone) but failed to decrease it in rats treated with dexamethasone only (3.88 +/- 0.18 vs 4.34 +/- 0.25 s, before and after naloxone). These observations indicate that gonadal steroids are the most important steroid factors involved in the reaction time to tail immersion in hot water and confirm other reports that the opioid pathways modulating the neuronal circuitry require the presence of these hormones.

PARTICIPATION OF MACROPHAGES IN CHLORAMPHENICOL-POTENTIATED CARRAGEENAN-INDUCED PERITONITIS IN RATS

1. We investigated the possible potentiating effect of chloramphenicol succinate (30 mg/kg, every 12 h for 4 days, ip) on the response of polymorphonuclear neutrophils to carrageenin (150 mug, ip) or dextran (100 mug, ip) in the peritoneal cavity of male Wistar rats (180-230 g; N = 12 in each group).2. Chloramphenicol potentiated the cell migration induced by carrageenin (35%) but not that induced by dextran. Previous macrophage depletion in the peritoneal cavity by washing with sterile saline abolished the cell response, whereas a previous thioglycollate-induced increase in macrophage numbers enhanced the potentiating effect (60%).3. These results suggest that the potentiating effect on polymorphonuclear neutrophil migration induced by chloramphenicol may be related to chemotactic factors released by macrophages.

Participation of the deltoid (anterior portion) and pectoralis major (clavicular portion) muscles in different modalities of supine and frontal elevation exercises with different grips

The muscles deltoid-anterior portion (DA) and pectoralis major-clavicular portion (PMC) were analysed to establish the muscular behavior and intensity patterns, as well to evaluate the connected participation of these muscles during supine and frontal elevation exercises. Twenty-four male volunteers were examined using a 2-channel TECA TE4 electromyograph and Hewlett Packard surface electrodes. Our results showed low levels of activity to PMC in frontal elevation exercises, whereas to DA the levels were very high. In the supine exercise, the action potential levels developed by the PMC were always lower than those presented by DA, however, with action simultaneity. Some suggestions to the use of the tested exercises are presented.

Participation of genes involved in the process of anaerobic respiration of infection in chickens by salmonella typhimurium

Intestinal pathogens are exposed to various stress conditions during their infectious cycle. Anaerobiosis, one of such hostile condition, is offered by the host within gut and intestinal lumen, where survival, multiplication and entry into intestinal epithelial cells are priority for the invasion of the pathogen. The fumarate reductase (frdABCD), dimethyl sulfoxide (DMSO)-trimethylamine N-oxide (TMAO) reductase (dmsABC), and nitrate reductase (narGHIJ) operons in Salmonella Typhimurium (STM) encode enzymes involved in anaerobic respiration to the electron acceptors fumarate, DMSO, TMAO, and nitrate, respectively. They are regulated in response to nitrate and oxygen availability and changes in cell growth rate. Vitamin B12 (cobalamin) is synthesized by Salmonella Typhimurium only under anaerobic growth conditions used as a cofactor in four known reactions. The deletion of cobS and cbiA genes prevent any form of cobalamin production. In the present study we evaluate the infection of birds by mutants of STM, with the anaerobic respiratory system committed by mutations in the genes: narG, napA, cobS, cbiA, frdA, dmsA, and torC. Virulence was assessed by oral inoculation of groups of one-day-old broilers with 0.1 mL of culture contained 10 8 colony forming units (CFU)/mL or diluted at 10 -3 and 10 -2 of strains mutants of Salmonella Typhimurium. Clinical signs and mortality were recorded over a period of 21 days. In general, the symptoms of chickens infected with the mutant strains were similar to those presenting by control birds. Except for STMNalr cbiA, all showed reduced capacity to cause mortality in comparison with the original strain. The mortality of group of chickens infected with STMNal r △narG, STMNal r △frdA, STMNal r △dmsA and STMNal r △cobS△cbiA showed significant decrease in mortality compared to control group (p<0.05).

Acute aerocystitis in Piaractus mesopotamicus: Participation of eicosanoids and pro-inflammatory cytokines

A total of 360 pacus (Piaractus mesopotamicus) were used to study vascular permeability (VP) and inflammatory cell component (CC) in induced aerocystitis in P. mesopotamicus through inoculation of inactivated Aeromonas hydrophila, and the effect of steroidal and nonsteroidal anti-inflammatory drugs. It was observed that after inoculation of A. hydrophila, the maximum VP occurred 180 min post-stimulus (MPS). Pretreatment with anti-inflammatory drugs inhibited VP, and the inhibitory effect of dexamethasone was seen earlier than the effects caused by meloxicam and indomethacin. Inoculation of the bacterium caused a gradual increase in the accumulation of cells, which reached a maximum 24 h post-stimulus (HPS). Pretreatment with dexamethasone, indomethacin and meloxicam reduced the accumulation of lymphocytes, thrombocytes, granulocytes and macrophages. There was no significant difference between the different doses of the drugs tested. The results suggest that eicosanoids and pro-inflammatory cytokines participate in chemical mediation in acute inflammation in pacus. © 2013 Elsevier Ltd.

Participation of the dorsal periaqueductal grey matter in the hypoxic ventilatory response in unanaesthetized rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Participation of α2 -adrenoceptors in sodium appetite inhibition during sickness behaviour following administration of lipopolysaccharide

Sickness behaviour, a syndrome characterized by a general reduction in animal activity, is part of the active-phase response to fight infection. Lipopolysaccharide (LPS), an effective endotoxin to model sickness behaviour, reduces thirst and sodium excretion, and increases neurohypophysial secretion. Here we review the effects of LPS on thirst and sodium appetite. Altered renal function and hydromineral fluid intake in response to LPS occur in the context of behavioural reorganization, which manifests itself as part of the syndrome. Recent data show that, in addition to its classical effect on thirst, non-septic doses of LPS injected intraperitoneally produce a preferential inhibition of intracellular thirst versus extracellular thirst. Moreover, LPS also reduced hypertonic NaCl intake in sodium-depleted rats that entered a sodium appetite test. Antagonism of α2 -adrenoceptors abolished the effect of LPS on sodium appetite. LPS and cytokine transduction potentially recruit brain noradrenaline and α2 -adrenoceptors to control sodium appetite and sickness behaviour.

Participation of dectin-1 receptor on NETs release against Paracoccidioides brasiliensis: role on extracellular killing

Paracoccidioides brasiliensis is a dimorphic fungus from the Paracoccidioides genus, which is the causative agent of paracoccidioidomycosis, a chronic, subacute or acute mycosis, with visceral and cutaneous involvement. This disease that is acquired through inhalation primarily attacks the lungs but, can spread to other organs. Phagocytic cells as neutrophils play an important role during innate immune response against this fungus, but studies on antifungal activities of these cells are scarce. In addition to their ability to eliminate pathogens by phagocytosis and antimicrobial secretions, neutrophils can trap and kill microorganisms by release of extracellular structures composed by DNA and antimicrobial proteins, called neutrophil extracellular traps (NETs). Here, we provide evidence that P. brasiliensis virulent strain (P. brasiliensis 18) induces NETs release. These structures were well evidenced by scanning electron microscopy, and specific NETs compounds such as histone, elastase and DNA were shown by confocal microscopy. In addition, we have shown that dectin-1 receptor is the main PRR to which fungus binds to induce NETS release. Fungi were ensnared by NETs, denoting the role of these structures in confining the fungus, avoiding dissemination. NETs were also shown to be involved in fungus killing, since fungicidal activity detected before and mainly after neutrophils activation with TNF-α, IFN-γ and GM-CSF was significantly inhibited by cocultures treatment with DNAse.

Do Fundef ao Fundeb: avaliando o passado para pensar o futuro: um estudo de caso no município de Pirapozinho-SP

Este artigo, que envolve a combinação de procedimentos quantitativos e qualitativos, traz resultados de pesquisa que analisou o impacto do Fundef na estruturação da rede municipal de ensino de Pirapozinho-SP, e mostra como estes resultados trazem subsídios para um funcionamento mais adequado da atual política de financiamento da educação. Constatou-se que, mesmo sem aumentar os recursos financeiros do ensino fundamental, o Fundef racionalizou e tornou mais eficiente a sua aplicação, diminuindo desvios e desperdícios, e que a instituição dos Conselhos de Acompanhamento e Controle Social possibilitou maior participação popular na fiscalização do executivo aumentando a transparência dos gastos com educação, que a constituição do Fundef abriu a possibilidade de implantação do Fundeb atualmente em vigor e que a melhoria no funcionamento deste está relacionada ao aumento da participação da sociedade nas decisões da política educacional e ao investimento na qualificação desta participação.