Genes associados à virulência e multirresistência de antimicrobianos em linhagens Trueperella Pyogenes isoladas de mastite e outras afecções em animais domésticos

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

Endogenous testosterone increases leukocyte-endothelial cell interaction in spontaneously hypertensive rats

Aims: Inflammation may have an important role in the beginning and in the progress of cardiovascular diseases. Testosterone exerts important effects on vascular function, which is altered in arterial hypertension. Thus, the aim of this study was to evaluate the influence of endogenous testosterone on leukocyte behavior in post-capillary venules of the mesenteric bed of spontaneously hypertensive rats (SHR). Main methods: 18 week-old intact SHR, castrated SHR and normotensive rats (intact Wistar) were used. Blood pressure was measured by tail plethysmography and serum testosterone levels by ELISA. Leukocyte rolling, adhesion and migration were evaluated in vivo in situ by intravital microscopy. Key findings: Castration significantly reduced blood pressure and reversed the increased leukocyte rolling and adhesion observed in SHRs. Leukocyte counts and other hemodynamic parameters did not differ among groups. SHRs displayed increased protein expression of P-selectin and ICAM-1 in mesenteric venules when compared to intact Wistar. Castration of SHRs restored the protein expression of the cell adhesion molecules. Significance: The findings of the present study demonstrate the critical role of endogenous testosterone mediating the effects of hypertension increasing leukocyte-endothelial cell interaction. Increased expression of cell adhesion molecules contribute to the effects of endogenous testosterone promoting increased leukocyte rolling and adhesion in SHRs. (c) 2012 Elsevier Inc. All rights reserved.

Improvement of metabolic parameters and vascular function by metformin in obese non-diabetic rats

Aims: Metformin is an insulin sensitizing agent with beneficial effects in diabetic patients on glycemic levels and in the cardiovascular system. We examined whether the metabolic changes and the vascular dysfunction in monosodium glutamate-induced obese non-diabetic (MSG) rats might be improved by metformin. Main methods: 16 week-old MSG rats were treated with metformin for 15 days and compared with age-matched untreated MSG and non-obese non-diabetic rats (control). Blood pressure, insulin sensitivity, vascular reactivity and prostanoid release in the perfused mesenteric arteriolar bed as well as nitric oxide production and reactive oxygen species generation in isolated mesenteric arteries were analyzed. Key findings: 18-week-old MSG rats displayed higher Lee index, fat accumulation, dyslipidemia, insulin resistance and hyperinsulinemia. Metformin treatment improved these alterations. The norepinephrine-induced response, increased in the mesenteric arteriolar bed from MSG rats, was corrected by metformin. Indomethacin corrected the enhanced contractile response in MSG rats but did not affect metformin effects. The sensitivity to acetylcholine, reduced in MSG rats, was also corrected by metformin. Indomethacin corrected the reduced sensitivity to acetylcholine in MSG rats but did not affect metformin effects. The sensitivity to sodium nitroprusside was increased in preparations from metformin-treated rats. Metformin treatment restored both the reduced PGI2/TXA2 ratio and the increased reactive oxygen species generation in preparations from MSG rats. Significance: Metformin improved the vascular function in MSG rats through reduction in reactive oxygen species generation, modulation of membrane hyperpolarization. correction of the unbalanced prostanoids release and increase in the sensitivity of the smooth muscle to nitric oxide. (c) 2011 Elsevier Inc. All rights reserved.

Time course of the hemodynamic responses to aortic depressor nerve stimulation in conscious spontaneously hypertensive rats

The time to reach the maximum response of arterial pressure, heart rate and vascular resistance (hindquarter and mesenteric) was measured in conscious male spontaneously hypertensive (SHR) and normotensive control rats (NCR; Wistar; 18-22 weeks) subjected to electrical stimulation of the aortic depressor nerve (ADN) under thiopental anesthesia. The parameters of stimulation were 1 mA intensity and 2 ms pulse length applied for 5 s, using frequencies of 10, 30, and 90 Hz. The time to reach the hemodynamic responses at different frequencies of ADN stimulation was similar for SHR (N = 15) and NCR (N = 14); hypotension = NCR (4194 +/- 336 to 3695 +/- 463 ms) vs SHR ( 3475 +/- 354 to 4494 +/- 300 ms); bradycardia = NCR (1618 +/- 152 to 1358 +/- 185 ms) vs SHR (1911 +/- 323 to 1852 +/- 431 ms), and the fall in hindquarter vascular resistance = NCR (6054 +/- 486 to 6550 +/- 847 ms) vs SHR (4849 +/- 918 to 4926 +/- 646 ms); mesenteric = NCR (5574 +/- 790 to 5752 +/- 539 ms) vs SHR (5638 +/- 648 to 6777 +/- 624 ms). In addition, ADN stimulation produced baroreflex responses characterized by a faster cardiac effect followed by a vascular effect, which together contributed to the decrease in arterial pressure. Therefore, the results indicate that there is no alteration in the conduction of the electrical impulse after the site of baroreceptor mechanical transduction in the baroreflex pathway (central and/or efferent) in conscious SHR compared to NCR.

Toll-like receptor 4 contributes to blood pressure regulation and vascular contraction in spontaneously hypertensive rats

Activation of TLRs (Toll-like receptors) induces gene expression of proteins involved in the immune system response. TLR4 has been implicated in the development and progression of CVDs (cardiovascular diseases). Innate and adaptive immunity contribute to hypertension-associated end-organ damage, although the mechanism by which this occurs remains unclear. In the present study, we hypothesize that inhibition of TLR4 decreases BP (blood pressure) and improves vascular contractility in resistance arteries from SHR (spontaneously hypertensive rats). TLR4 protein expression in mesenteric resistance arteries was higher in 15-week-old SHR than in age-matched Wistar controls or in 5-week-old SHR. To decrease the activation of TLR4, 15-week-old SHR and Wistar rats were treated with anti-TLR4 (anti-TLR4 antibody) or non-specific IgG control antibody for 15 days (1 mu g per day, intraperitoneal). Treatment with anti-TLR4 decreased MAP (mean arterial pressure) as well as TLR4 protein expression in mesenteric resistance arteries and IL-6 (interleukin 6) serum levels from SHR when compared with SHR treated with IgG. No changes in these parameters were found in treated Wistar control rats. Mesenteric resistance arteries from anti-TLR4-treated SHR exhibited decreased maximal contractile response to NA (noradrenaline) compared with IgG-treated SHR. Inhibition of COX (cyclo-oxygenase)-1 and COX-2, enzymes related to inflammatory pathways, decreased NA responses only in mesenteric resistance arteries of SHR treated with IgG. COX-2 expression and TXA(2) (thromboxane A(2)) release were decreased in SHR treated with anti-TLR4 compared with IgG-treated SHR. Our results suggest that TLR4 activation contributes to increased BP, low-grade inflammation and plays a role in the augmented vascular contractility displayed by SHR.

Molecular confirmation of ovine herpesvirus 2-induced malignant catarrhal fever lesions in cattle from Rio Grande do Norte, Brazil

Molecular findings that confirmed the participation of ovine herpesvirus 2 (OVH-2) in the lesions that were consistent with those observed in malignant catarrhal fever of cattle are described. Three mixed-breed cattle from Rio Grande do Norte state demonstrated clinical manifestations that included mucopurulent nasal discharge, corneal opacity and motor incoordination. Routine necropsy examination demonstrated ulcerations and hemorrhage of the oral cavity, corneal opacity, and lymph node enlargement. Significant histopathological findings included widespread necrotizing vasculitis, non-suppurative meningoencephalitis, lymphocytic interstitial nephritis and hepatitis, and thrombosis. PCR assay performed on DNA extracted from kidney and mesenteric lymph node of one animal amplified a product of 423 base pairs corresponding to a target sequence within the ovine herpesvirus 2 (OVH-2) tegument protein gene. Direct sequencing of the PCR products, from extracted DNA of the kidney and mesenteric lymph node of one cow, amplified the partial nucleotide sequences (423 base pairs) of OVH-2 tegument protein gene. Blast analysis confirmed that these sequences have 98-100% identity with similar OVH-2 sequences deposited in GenBank. Phylogenetic analyses, based on the deduced amino acid sequences, demonstrated that the strain of OVH-2 circulating in ruminants from the Brazilian states of Rio Grande do Norte and Minas Gerais are similar to that identified in other geographical locations. These findings confirmed the active participation of OVH-2 in the classical manifestations of sheep associated malignant catarrhal fever.

Heterogeneous time-dependent response of adipose tissue during the development of cancer cachexia

Cancer cachexia induces loss of fat mass that accounts for a large part of the dramatic weight loss observed both in humans and in animal models; however, the literature does not provide consistent information regarding the set point of weight loss and how the different visceral adipose tissue depots contribute to this symptom. To evaluate that, 8-week-old male Wistar rats were subcutaneously inoculated with 1 ml (2 x 10(7)) of tumour cells (Walker 256). Samples of different visceral white adipose tissue (WAT) depots were collected at days 0, 4, 7 and 14 and stored at -80 degrees C (seven to ten animals/each day per group). Mesenteric and retroperitoneal depot mass was decreased to the greatest extent on day 14 compared with day 0. Gene and protein expression of PPAR gamma(2) (PPARG) fell significantly following tumour implantation in all three adipose tissue depots while C/EBP alpha (CEBPA) and SREBP-1c (SREBF1) expression decreased over time only in epididymal and retroperitoneal depots. Decreased adipogenic gene expression and morphological disruption of visceral WAT are further supported by the dramatic reduction in mRNA and protein levels of perilipin. Classical markers of inflammation and macrophage infiltration (f4/80, CD68 and MIF-1 alpha) in WAT were significantly increased in the later stage of cachexia (although showing a incremental pattern along the course of cachexia) and presented a depot-specific regulation. These results indicate that impairment in the lipid-storing function of adipose tissue occurs at different times and that the mesenteric adipose tissue is more resistant to the 'fat-reducing effect' than the other visceral depots during cancer cachexia progression. Journal of Endocrinology (2012) 215, 363-373

Disseminated histoplasmosis in a juvenile lupus erythematosus patient

Introduction: Histoplasmosis is an infection caused by dimorphic fungus, Histoplasma capsulatum, and it has not been reported in juvenile systemic lupus erythematosus (JSLE) patients, particularly progressive disseminated histoplasmosis (PDH) subtype. Case report: We reported herein a 14-year old girl who was diagnosed with JSLE. Six months later, she had abdominal distension and received prednisone, hydroxychloroquine and azathioprine. Computer tomography evidenced hepatosplenomegaly and multiple mesenteric, mediastinal and retroperitoneal enlarged lymph nodes, forming large conglomerates at the mesentery, suggestive of lymphoproliferative disorder. After 10 days, she had acute surgical abdominal, and underwent a laparotomy and intestinal perforation and conglomerates of lymph nodes were observed. The jejunum biopsy showed perforated acute enteritis with hemorrhage and necrosis, and Grocott staining identified Histoplasma sp. and the culture showed a heavy growth of Histoplasma capsulatum. At that moment liposomal amphotericin B (1.0 mg/Kg/day) was introduced. Despite this treatment she died due to septic shock eight days later. Diffuse Histoplasma capsulatum was evidenced at autopsy. Conclusion: We reported a severe opportunistic infection in JSLE patient with adenopathy and multiple intestinal perforations. This study reinforces the importance of early diagnosis and antifungal therapy, especially in patients with these uncommon clinical manifestations.

Exercise Training Decreases Adipose Tissue Inflammation in Cachectic Rats

Bearing in mind that cancer cachexia is associated with chronic systemic inflammation and that endurance training has been adopted as a nonpharmacological anti-inflammatory strategy, we examined the effect of 8 weeks of moderate intensity exercise upon the balance of anti-and pro-inflammatory cytokines in 2 different depots of white adipose tissue in cachectic tumour-bearing (Walker-256 carcinosarcoma) rats. Animals were assigned to a sedentary control (SC), sedentary tumour-bearing (ST), sedentary pair-fed (SPF) or exercise control (EC), exercise tumour-bearing (ET), and exercise pair-fed (EPF) group. Trained rats ran on a treadmill (60% VO(2)max) 60 min/day, 5 days/week, for 8 weeks. The retroperitoneal (RPAT) and mesenteric (MEAT) adipose pads were excised and the mRNA (RT-PCR) and protein (ELISA) expression of IL-1 beta, IL-6, TNF-alpha, and IL-10 were evaluated. The number of infiltrating monocytes in the adipose tissue was increased in cachectic rats. TNF-alpha mRNA in MEAT was increased in the cachectic animals (p < 0.05) in relation to SC. RPAT protein expression of all studied cytokines was increased in cachectic animals in relation to SC and SPF (p < 0.05). In this pad, IL-10/TNF-alpha ratio was reduced in the cachectic animals in comparison with SC (p < 0.05) indicating inflammation. Exercise training improved IL-10/TNF-alpha ratio and induced a reduction of the infiltrating monocytes both in MEAT and RPAT (p < 0.05), when compared with ST. We conclude that cachexia is associated with inflammation of white adipose tissue and that exercise training prevents this effect in the MEAT, and partially in RPAT.

Actions of translocator protein ligands on neutrophil adhesion and motility induced by G-protein coupled receptor signaling

The 18 kDa translocator protein (TSPO) also known as the peripheral benzodiazepine receptor (PBR), mediates the transportation of cholesterol and anions from the outer to the inner mitochondrial membrane in different cells types. Although recent evidences indicate a potential role for TSPO in the development of inflammatory processes, the mechanisms involved have not been elucidated. The present study investigated the ability of the specific TSPO ligands, the isoquinoline carboxamide PK11195 and benzodiazepine Ro5-4864, on neutrophil recruitment promoted by the N-formylmethionyl-leucyl-phenylalanine peptide (fMLP), an agonist of G-protein coupled receptor (GPCR). Pre-treatment with Ro5-4864 abrograted fMLP-induced leukocyte-endothelial interactions in mesenteric postcapillary venules in vivo. Moreover, in vitro Ro5-4864 treatment prevented fMLP-induced: (i) L-selectin shedding and overexpression of PECAM-1 on the neutrophil cell surface; (ii) neutrophil chemotaxis and (iii) enhancement of intracellular calcium cations (iCa(+2)). Intriguingly, the two latter effects were augmented by cell treatment with PK11195. An allosteric agonist/antagonist relation may be suggested, as the effects of Ro5-4864 on fMLP-stimulated neutrophils were reverted by simultaneous treatment with PK11195. Taken together, these data highlight TSPO as a modulator of pathways of neutrophil adhesion and locomotion induced by GPCR, connecting TSPO actions and the onset of an innate inflammatory response. (C) 2011 Elsevier Inc. All rights reserved.

Strength training improves plasma parameters, body composition and liver morphology in ovariectomized rats

Objective. - The aim of this study was to identify the effects of strength training on plasma parameters, body composition and the liver of ovariectomized rats. Methods. - Wistar sedentary (SHAM), ovariectomized (OVX), and ovariectomized trained rats (strength training [OVX-EXE]) of 85% of one maximal repetition (1 RM), three times per week, for 10 weeks, were used on this study. We monitored the body weight and visceral (uterine, mesenteric and retroperitoneal) and subcutaneous adiposity, total cholesterol, triglycerides, HDL, blood glucose and liver morphology to identify the presence of macrovesicular steotosis (haematoxylin and eosin staining). Results. - We observed that strength training changed body weight (SHAM 293.0 +/- 14.5 g; OVX 342.6 +/- 10.8 g; OVX-EXE 317.7 +/- 11.9 g, P < 0.05), visceral and subcutaneous adiposity, glucose (SHAM 111.2 +/- 10.0 mg/dL; OVX 147.4 +/- 18.8 mg/dL; OVX-EXE 118.5 +/- 2.2 mg/dL, P < 0.05), increased HDL (SHAM 82.7 +/- 1.4 mg/dL; OVX 64.6 +/- 2.8 mg/dL; OVX-EXE 91.4 +/- 2.6 mg/dL, P < 0.05) and reduced macrovesicular steatosis in liver tissue. Conclusions. - Considering the data obtained in this research, we emphasise the use of strength exercise training as a therapeutic means to combat or control the metabolic disturbances associated with menopause, including adiposity, and adverse changes in blood glucose, blood HDL and macrovesicular steatosis. (C) 2011 Elsevier Masson SAS. All rights reserved.

Enhanced phagocytosis of Corynebacterium pseudotuberculosis by monocyte-macrophage cells from goats naturally infected with caprine arthritis encephalitis virus

Sanches B.G.S., Souza F.N., Azedo M.R., Batista C.F., Bertagnon H.G., Blagitz M.G. & Della Libera A.M.M.P. 2012. [Enhanced phagocytosis of Corynebacterium pseudotuberculosis by monocyte-macrophage cells from goats naturally infected with caprine arthritis encephalitis virus.] Fagocitose intensificada de Corynebacterium pseudotuberculosis por celulas da serie monocito-macrofago de caprinos naturalmente infectados pelo virus da artrite encefalite. Pesquisa Veterinaria Brasileira 32(12):1225-1229. Departamento de Clinica Medica, Faculdade de Medicina Veterinaria e Zootecnia, Universidade de Sao Paulo, Avenida Prof. Dr. Orlando Marques de Paiva 87, Cidade Universitaria, Sao Paulo, SP 05508-270, Brazil. E-mail: camilafb@usp.br Caprine arthritis encephalitis (CAE) and caseous lymphadenitis (CL) have high incidence and transmissibility in small ruminants. Since both virus have tropism for macrophages and monocytes and affect the innate immune response, it is believed that CAE can predispose the animal to infection by Corynebacteruim pseudotuberculosis, the etiological agent of CL. To confirm this hypothesis, we evaluated phagocytosis from the monocyte-macrophage cells from 30 Saanen goats. Goats were uniformly divided in two groups according to results of agar gel immunodiffusion test for CAE virus (CAEV). Peripheral blood mononuclear cells were isolated by density gradient centrifugation and the monocyte-macrophage cells were isolated from the mononuclear cells by their adhesion properties in plaques. Afterwards, phagocytosis of C. psudotuberculosis was performed for two hours at 37 degrees C, 5% of CO2, and assessed by microscopic visualization. There was no difference in the percentage of monocyte-macrophage cells that phagocytozed C. bovis between groups (P = 0.41). However, when phagocytosis rates were classified according to the number of C. pseudotuberculosis phagocyted, the percentage of monocyte-macrophage cells that internalized more than 12 bacteria were higher in serologically CAEV positive animals compared to the serologically negative ones (P < 0.001). Furthermore, a positive and significant correlation (r = 0.488; P = 0.006) between the percentage of monocyte-macrophage cells that internalized more than 12 bacteria and the percentage of monocyte that were carrying out phagocytosis was also encountered in serologically CAEV positive goats, however the same were not observed in serologically negative ones. These results demonstrated an alteration in the intensity of C. pseudotuberculosis phagocytosis by monocytes-macrophages from goats infected by CAEV. Thus, these results indicated that goats infected with CAEV may be more susceptible to CL.

Intestinal Lymph-Borne Factors Induce Lung Release of Inflammatory Mediators and Expression of Adhesion Molecules After an Intestinal Ischemic Insult

Background. Intestinal ischemia and reperfusion (I/R) is a documented cause of acute lung injury (ALI) and systemic inflammation. We previously reported that obstruction of thoracic lymphatic flow during intestinal I/R blunts pulmonary neutrophil recruitment and microvascular injury and decreases the systemic levels of tumor necrosis factor. Here, we consider the existence of a gut-lung axis promoting the induction of systemic inflammation, whereby drained intestinal lymph stimulates lung expression of adhesion molecules and matrix components and generation of inflammatory mediators. Material and Methods. Upon administration of anesthesia, male Wistar rats were subjected to occlusion of the superior mesenteric artery for 45 min, followed by 2 h of intestinal reperfusion (I/R); groups of rats were subjected to I/R with or without thoracic lymphatic duct ligation immediately before the procedure. The non-manipulated rats were used to investigate basal parameters. Results. Obstruction of thoracic lymphatic flow before intestinal I/R decreased the ability of cultured lung tissue explants to release IL-1 beta, IL-10, and VEGF. In contrast, lymphatic obstruction normalized the elevated lung expression of PECAM-1 caused by intestinal I/R. On the other hand, lung E-selectin expression was significantly reduced, whereas fibronectin expression and collagen synthesis were not affected. Lymph levels of LTB4 and TXB2 were found to be significantly increased. Conclusions. These data suggest that lymph factors drained from the intestine during ischemic trauma stimulate the lung to generate inflammatory mediators and alter the expression of adhesion molecules. Disturbances in lung homeostasis mediated by lymph might contribute to the spread of inflammatory processes, thereby accounting for the systemic inflammation induced by intestinal I/R. (C) 2012 Elsevier Inc. All rights reserved.

Alterations in vasoconstrictor responses to the endothelium-derived contracting factor uridine adenosine tetraphosphate are region specific in DOCA-salt hypertensive rats

Uridine adenosine tetraphosphate (Up(4)A) has been recently identified as a novel and potent endothelium-derived contracting factor and contains both purine and pyrimidine moieties, which activate purinergic P2X and P2Y receptors. The present study was designed to compare contractile responses to Up(4)A and other nucleotides such as ATP (P2X/P2Y agonist), UTP (P2Y(2)/P2Y(4) agonist), UDP (P2Y(6) agonist), and alpha,beta-methylene ATP (P2X(1) agonist) in different vascular regions [thoracic aorta, basilar, small mesenteric, and femoral arteries] from deoxycorticosterone acetate-salt (DOCA-salt) and control rats. In DOCA-salt rats [vs. control uninephrectomized (Uni) rats]: (1) in thoracic aorta, Up(4)A-, ATP-, and UP-induced contractions were unchanged; (2) in basilar artery, Up(4)A-, ATP-, UTP- and UDP-induced contractions were increased, and expression for P2X(1), but not P2Y(2) or P2Y(6) was decreased; (3) in small mesenteric artery, Up(4)A-induced contraction was decreased and UDP-induced contraction was increased; expression of P2Y(2) and P2X(1) was decreased whereas P2Y(6) expression was increased; (4) in femoral artery, Up(4)A-. UTP-, and UDP-induced contractions were increased, but expression of P2Y(2), P2Y(6) and P2X(1) was unchanged. The alpha,beta-methylene ATP-induced contraction was bell-shaped and the maximal contraction was reached at a lower concentration in basilar and mesenteric arteries from Uni rats, compared to arteries from DOCA-salt rats. These results suggest that Up(4)A-induced contraction is heterogenously affected among various vascular beds in arterial hypertension. P2Y receptor activation may contribute to enhancement of Up(4)A-induced contraction in basilar and femoral arteries. These changes in vascular reactivity to Up(4)A may be adaptive to the vascular alterations produced by hypertension. (C) 2011 Elsevier Ltd. All rights reserved.

SCG postnatal remodelling - hypertrophy and neuron number stability - in Spix's Yellow-toothed Cavies (Galea spixii)

Whilst a fall in neuron numbers seems a common pattern during postnatal development, several authors have nonetheless reported an increase in neuron number, which may be associated with any one of a number of possible processes encapsulating either neurogenesis or late maturation and incomplete differentiation. Recent publications have thus added further fuel to the notion that a postnatal neurogenesis may indeed exist in sympathetic ganglia. In the light of these uncertainties surrounding the effects exerted by postnatal development on the number of superior cervical ganglion (SCG) neurons, we have used state-of-the-art design-based stereology to investigate the quantitative structure of SCG at four distinct timepoints after birth, viz., 1-3 days, 1 month, 12 months and 36 months. The main effects exerted by ageing on the SCG structure were: (i) a 77% increase in ganglion volume; (ii) stability in the total number of the whole population of SCG nerve cells (no change - either increase or decrease) during post-natal development; (iii) a higher proportion of uninucleate neurons to binucleate neurons only in newborn animals; (iv) a 130% increase in the volume of uninucleate cell bodies; and (v) the presence of BrdU positive neurons in animals at all ages. At the time of writing our results support the idea that neurogenesis takes place in the SCG of preas, albeit it warrants confirmation by further markers. We also hypothesise that a portfolio of other mechanisms: cell repair, maturation, differentiation and death may be equally intertwined and implicated in the numerical stability of SCG neurons during postnatal development. (C) 2011 ISDN. Published by Elsevier Ltd. All rights reserved.