613 resultados para Mesenteric cist


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1. We have investigated the cardiovascular pharmacology of the crude venom extract (CVE) from the potentially lethal, very small carybdeid jellyfish Carukia barnesi, in rat, guinea-pig and human isolated tissues and anaesthetized piglets. 2. In rat and guinea-pig isolated right atria, CVE (0.1-10 mu g/mL) caused tachycardia in the presence of atropine (I mu mol/L), a response almost completely abolished by pretreatment with tetrodotoxin (TTX; 0.1 mu mol/L). In paced left atria from guinea-pig or rat, CVE (0.1-3 mu g/mL) caused a positive inotropic response in the presence of atropine (1 mu mol/L). 3. In rat mesenteric small arteries, CVE (0.1-30 mu g/mL) caused concentration-dependent contractions that were unaffected by 0.1 mu mol/L TTX, 0.3 mu mol/L prazosin or 0.1 mu mol/L co-conotoxin GVIA. 4. Neither the rat right atria tachycardic response nor the contraction of rat mesenteric arteries to CVE were affected by the presence of box jellyfish (Chironex fleckeri) antivenom (92.6 units/mL). 5. In human isolated driven right atrial trabeculae muscle strips, CVE (10 mu g/mL) tended to cause an initial fall, followed by a more sustained increase, in contractile force. In the presence of atropine (I mu mol/L), CVE only caused a positive inotropic response. In separate experiments in the, presence of propranolol (0.2 mu mol/L), the negative inotropic effect of CVE was enhanced, whereas the positive inotropic response was markedly decreased. 6. In anaesthetized piglets, CVE (67 mu g/kg, i.v.) caused sustained tachycardia and systemic and pulmonary hypertension. Venous blood samples demonstrated a marked elevation in circulating levels of noradrenaline and adrenaline. 7. We conclude that C. barnesi venom may contain a neural sodium channel activator (blocked by TTX) that, in isolated atrial tissue (and in vivo), causes the release of transmitter (and circulating) catecholamines. The venom may also contain a 'direct' vasoconstrictor component. These observations explain, at least in part, the clinical features of the potentially deadly Irukandji syndrome.

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There is a growing body of experimental evidence suggesting that the gastrointestinal tract (GIT) may be penetrated by sub-micron sized polymeric particles which have the capacity to deliver therapeutic compounds. We investigated this, initially with Fluoresbrite™ carboxylate latex microspheres (0.87 m diameter) which were administered orally to rats. Microsphere numbers within blood samples were then quantified using fluorescence microscopy or FACS technology. These studies were prone to quantitative error, but indicated that increased microsphere translocation occurred if particles were administered in conjunction with large volumes of hypotonic liquid, and that uptake was very rapid. Test particles were detected in blood, only a few minutes after dosing. To improve quantification, GPC technology was adopted. 0.22 m latex particles were found to accumulate in greatest numbers within the Mononuclear phagocyte system tissues after gavage. Again translocation was rapid. The ability of test particles to leave the intestinal lumen and access systemic compartments was found to be highly dependent on their size and hydrophobicity, determined by hydrophobic interaction chromatography. Considerably lower numbers of 0.97 m diameter latex microspheres were detectable within extra-intestinal tissue locations after gavage. Histological studies showed that Fluoresbrite™ microspheres accumulate within the liver, spleen, Mesenteric lymph node and vasculature of rats after oral administration. Fluorescent particles were observed in both the Peyer's patches (PPs), and non lymphoid regions of rat intestinal mucosa after gavage, conductive to the acceptance that more than one mechanism of particle absorption may operate.

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Contractile response of rat aorta, mesenteric artery and femoral artery to noradrenaline and potassium chloride were studied under standard and hypoxic conditions and the effect of hypoxia was dependent upon both the vessel and the stimulant. Hypoxia had less effect upon contractions to potassium chloride than those to noradrenaline. The effects of hypoxia on potassium chloride induced responses in different vessels were relatively similar although responses to noradrenaline were vessel dependent. Noradrenaline induced contractions of the femoral artery were most affected by hypoxia whilst those of the mesenteric artery were least affected. Hypoxia changed the well maintained response of the femoral artery to noradrenaline to a transient form; this effect of hypoxia was not evident in the aorta or the mesenteric artery. The aorta and mesenteric artery contracted in calcium free EGTA PSS suggesting that these vessels displayed a release component. Hypoxia reduced the magnitude of this component. The effects of verapamil on noradrenaline and potassium chloride induced responses were investigated and were found to be different to those of hypoxia. Verapamil exerted a greater effect on contractions to potassium chloride than on those to noradrenaline. The effects of hypoxia on 45calcium flux were also vessel dependent. In the mesenteric and femoral arteries hypoxia increased basal 45calcium accumulation. However, the magnitude of noradrenaline stimulated 45calcium accumulation was reduced in the femoral artery and aorta but was unchanged in the mesenteric artery. The effects of hypoxia on 45calcium accumulation were similar to verapamil only in the aorta. The results provide evidence that the effects of hypoxia may arise from alterations in calcium mobilisation processes and that differences between vessels in these processes accounts for the heterogeneity between vessels in their response to hypoxia.

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Plasmid DNA pRc/CMV HBS encoding the S (small) region of hepatitis B surface antigen (HBsAg) was incorporated by the dehydration-rehydration method into Lipodine™ liposomes composed of 16 μmoles phosphatidylcholine (PC) or distearoyl phosphatidylcholine (DSPC), 8 μmoles of (dioleoyl phosphatidylethanolamine (DOPE) or cholesterol and 4 μmoles of the cationic lipid 1,2-dioleoyl-3-(trimethylammonium propane (DOTAP) (molar ratios 1:0.5:0.25). Incorporation efficiency was high (89-93% of the amount of DNA used) in all four formulations tested and incorporated DNA was shown to be resistant to displacement in the presence of the competing anionic sodium dodecyl sulphate molecules. This is consistent with the notion that most of the DNA is incorporated within the multilamellar vesicles structure rather than being vesicle surface-complexed. Stability studies performed in simulated intestinal media also demonstrated that dehydration-rehydration vesicles (DRV) incorporating DNA (DRV(DNA)) were able to retain significantly more of their DNA content compared to DNA complexed with preformed small unilamellar vesicles (SUV-DNA) of the same composition. Moreover, after 4h incubation in the media, DNA loss for DSPC DRV(DNA) was only minimal, suggesting this to be the most stable formulation. Oral (intragastric) liposome-mediated DNA immunisation studies employing a variety of DRV(DNA) formulations as well as naked DNA revealed that secreted IgA responses against the encoded HBsAg were (as early as three weeks after the first dose) substantially higher after dosing with 100 μg liposome-entrapped DNA compared to naked DNA. Throughout the fourteen week investigation, IgA responses in mice were consistently higher with the DSPC DRV(DNA) liposomes compared to naked DNA and correlated well with their improved DNA retention when exposed to model intestinal fluids. To investigate gene expression after oral (intragastric) administration, mice were given 100 μg of naked or DSPC DRV liposome-entrapped plasmid DNA expressing the enhanced green fluorescent protein (pCMV.EGFP). Expression of the gene, in terms of fluorescence intensity in the draining mesenteric lymph nodes, was much greater in mice dosed with liposomal DNA than in animals dosed with the naked DNA. These results suggest that DSPC DRV liposomes containing DNA (Lipodine™) may be a useful system for the oral delivery of DNA vaccines.

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Environmental perturbations during early mammalian development can affect aspects of offspring growth and cardiovascular health. We have demonstrated previously that maternal gestational dietary protein restriction in mice significantly elevated adult offspring systolic blood pressure. Therefore, the present study investigates the key mechanisms of blood pressure regulation in these mice. Following mating, female MF-1 mice were assigned to either a normal-protein diet (NPD; 18% casein) or an isocaloric low-protein diet throughout gestation (LPD; 9% casein), or fed the LPD exclusively during the pre-implantation period (3.5d) before returning to the NPD for the remainder of gestation (Emb-LPD). All offspring received standard chow. At 22 weeks, isolated mesenteric arteries from LPD and Emb-LPD males displayed significantly attenuated vasodilatation to isoprenaline (P=0.04 and P=0.025, respectively), when compared with NPD arteries. At 28 weeks, stereological analysis of glomerular number in female left kidneys revealed no significant difference between the groups. Real-time RT-PCR analysis of type 1a angiotensin II receptor, Na /K ATPase transporter subunits and glucocorticoid receptor expression in male and female left kidneys revealed no significant differences between the groups. LPD females displayed elevated serum angiotensin-converting enzyme (ACE) activity (P=0.044), whilst Emb-LPD males had elevated lung ACE activity (P=0.001), when compared with NPD offspring. These data demonstrate that elevated offspring systolic blood pressure following maternal gestational protein undernutrition is associated with impaired arterial vasodilatation in male offspring, elevated serum and lung ACE activity in female and male offspring, respectively, but kidney glomerular number in females and kidney gene expression in male and female offspring appear unaffected. © 2010 The Authors.

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To investigate the role of β-(1-3)-D-glucan on 99mTc labelled Escherichia coli translocation and cytokines secretion in rats submitted to small bowel ischemia/reperfusion injury. Methods: Five groups (n=10 each) of Wistar rats were subjected to control(C), sham(S), group IR subjected to 45 min of bowel ischemia/60 min of reperfusion(I/R), and group I/R+glucan subjected to 45 min of bowel ischemia/60 min of reperfusion(I/R) and injected with 2mg/Kg intramuscular. Translocation of labelled bacteria to mesenteric lymph nodes, liver, spleen, lung and serum was determined using radioactivity/count and colony forming units/g(CFU/g). Serum TNFα, IL-1β, IL-6, IL-10 were measured by ELISA. Results: CFU/g and radioactivity/count were higher in I/R than in I/R+glucan rats. In C, S and S+glucan groups, bacteria and radioactivity/count were rarely detected. The I/R+glucan rats had enhancement of IL-10 and suppressed production of serum TNFα, IL-1β and, IL-6, compared to I/R untreated animals. Conclusion: The β-(1-3)-D-glucan modulated the production of pro-inflammatory and anti-inflammatory cytokines during bowel ischemia/reperfusion, and attenuated translocation of labelled bacteria

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Ischemia and reperfusion of the small intestine disrupts gut barrier, causes bacterial translocation and activates inflammatory responses. An experimental study was planned to evaluate if 99mTc labelled Escherichia coli translocates to mesenteric lymph nodes, liver, spleen, lung and serum of rats submitted to mesenteric ischemia/reperfusion. Additionally, it was observed if the time of reperfusion influences the level of translocation. METHODS: Forty male Wistar rats underwent 45 minutes of gut ischemia by occlusion of the superior mesenteric artery. The translocation of labelled bacteria to different organs and portal serum was determined in rats reperfused for 30 minutes, 24 hours, sham(S) and controls(C), using radioactivity count and colony forming units/g (CFU). RESULTS: All the organs from rats observed for 24 hours after reperfusion had higher levels of radioactivity and positive cultures (CFU) than did the organs of rats reperfused for 30 minutes, C and S, except in the spleen (p<0,01). CONCLUSION: The results of this study indicated that intestinal ischemia/reperfusion led to bacterial translocation, mostly after 24 hours of reperfusion

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To investigate whether the alterations of the diverted colon segment mucosa, evidenced in fecal colitis, would be able to alter Bacterial Translocation (BT). Methods: Sixty-two Wistar male rats ranging from 220 to 320 grams of weight, were divided in two groups: A (Colostomy) and B (Control), with 31 animals each one. In group A, all animals underwent end colostomy, one stoma, in ascending colon; and in the 70th POD was injected in five rats, by rectal route – diverted segment - 2ml of a 0.9% saline solution in animals (A1 subgroup); in eight it was inoculated, by rectal route, 2ml of a solution containing Escherichia coli ATCC 25922 (American Type Culture Collection), in a concentration of 108 Colony Forming Unit for milliliters (CFU/ml) - A2 Subgroup; in ten animals the same solution of E. coli was inoculated, in a concentration of 1011 CFU/ml (A3 Subgroup); and in eight it was collected part of the mucus found in the diverted distal colonic segment for neutral sugars and total proteins dosage (A4 subgroup). The animals from the group B underwent the same procedures of group A, but with differences in the colostomy confection. In rats from subgroups A1, A2, A3, B1, B2, and B3 2ml of blood were aspirated from the heart, and fragments from mesenteric lymphatic nodule, liver, spleen, lung and kidney taken for microbiological analysis, after their death. This analysis consisted of evidencing the presence of E. coli ATCC 25922 CFU. Mann-Whitney and ANOVA Tests were applied as analytic techniques for association of variables. Results: The occurrence of BT was evidenced only in those animals in which inoculated concentration of E. coli ATCC 25922, reached levels of 1011CFU/ml, i.e. in Subgroups A3 and B3, although, being significantly greater (80%) in those animals without colostomy (subgroup B3) when compared to the ones with colostomy (20%) from the subgroup A3 (P <0.05). Lung, liver and mesenteric lymphatic nodules were the tissues with larger percentile of bacterial recovery, so much in subgroup A3, as in B3. Blood culture was considered positive in 60% of the animals from subgroup B3 and in 10% of those from subgroup A3 (p <0.05). There was greater concentration of neutral sugars, in subgroup A4 - mean 27.3mg/ml -, than in subgroup B4 - mean 8.4mg/ml - (P <0.05). Conclusion: The modifications in the architecture of intestinal mucosa in colitis following fecal diversion can cause alterations in the intestinal barrier, but it does not necessarily lead to an increased frequency of BT

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To investigate the role of β-(1-3)-D-glucan on 99mTc labelled Escherichia coli translocation and cytokines secretion in rats submitted to small bowel ischemia/reperfusion injury. Methods: Five groups (n=10 each) of Wistar rats were subjected to control(C), sham(S), group IR subjected to 45 min of bowel ischemia/60 min of reperfusion(I/R), and group I/R+glucan subjected to 45 min of bowel ischemia/60 min of reperfusion(I/R) and injected with 2mg/Kg intramuscular. Translocation of labelled bacteria to mesenteric lymph nodes, liver, spleen, lung and serum was determined using radioactivity/count and colony forming units/g(CFU/g). Serum TNFα, IL-1β, IL-6, IL-10 were measured by ELISA. Results: CFU/g and radioactivity/count were higher in I/R than in I/R+glucan rats. In C, S and S+glucan groups, bacteria and radioactivity/count were rarely detected. The I/R+glucan rats had enhancement of IL-10 and suppressed production of serum TNFα, IL-1β and, IL-6, compared to I/R untreated animals. Conclusion: The β-(1-3)-D-glucan modulated the production of pro-inflammatory and anti-inflammatory cytokines during bowel ischemia/reperfusion, and attenuated translocation of labelled bacteria

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Altered tissue fatty acid (FA) composition may affect mechanisms involved in the control of energy homeostasis, including central insulin actions. In rats fed either standard chow or a lard-enriched chow (high in saturated/low in polyunsaturated FA, HS-LP) for eight weeks, we examined the FA composition of blood, hypothalamus, liver, and retroperitoneal, epididymal and mesenteric adipose tissues. Insulin-induced hypophagia and hypothalamic signaling were evaluated after intracerebroventricular insulin injection. HS-LP feeding increased saturated FA content in adipose tissues and serum while it decreased polyunsaturated FA content of adipose tissues, serum, and liver. Hypothalamic C20:5n-3 and C20:3n-6 contents increased while monounsaturated FA content decreased. HS-LP rats showed hyperglycemia, impaired insulin-induced hypophagia and hypothalamic insulin signaling. The results showed that, upon HS-LP feeding, peripheral tissues underwent potentially deleterious alterations in their FA composition, whist the hypothalamus was relatively preserved. However, hypothalamic insulin signaling and hypophagia were drastically impaired. These findings suggest that impairment of hypothalamic insulin actions by HS-LP feeding was not related to tissue FA composition.

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Introduction: There are few studies on body composition and the effects of diet on weight postpartum women. The aim was to evaluate the body composition and bone parameters in lactating rats treated with diet containing flaxseed flour during postweaning period. Methods: After weaning, the lactating rat were divided in control (n = 6) and experimental (F, n = 6) group, treated with 25% flaxseed flour diet. After 30 days, body composition by dual-energy X-ray absorptiometry, serum analysis, organs and intra-abdominal fat mass, femur and lumbar vertebra parameters were determined. Results: The groups showed similar food intake, body mass and bone parameters. While F group showed the following: lower body (-5%), gonadal (-17%), mesenteric (-23%) and intra-abdominal (-6%) fat mass. Increase of HDL-cholesterol (+10%) and lower glucose (-15%), triglycerides (P < 0.05, -37%) and cholesterol (P < 0.05, -21%). Conclusions: The findings highlight the effects of flaxseed for control of adiposity and to maintain a healthy biochemical profile during the postnatal period.

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To investigate the role of β-(1-3)-D-glucan on 99mTc labelled Escherichia coli translocation and cytokines secretion in rats submitted to small bowel ischemia/reperfusion injury. Methods: Five groups (n=10 each) of Wistar rats were subjected to control(C), sham(S), group IR subjected to 45 min of bowel ischemia/60 min of reperfusion(I/R), and group I/R+glucan subjected to 45 min of bowel ischemia/60 min of reperfusion(I/R) and injected with 2mg/Kg intramuscular. Translocation of labelled bacteria to mesenteric lymph nodes, liver, spleen, lung and serum was determined using radioactivity/count and colony forming units/g(CFU/g). Serum TNFα, IL-1β, IL-6, IL-10 were measured by ELISA. Results: CFU/g and radioactivity/count were higher in I/R than in I/R+glucan rats. In C, S and S+glucan groups, bacteria and radioactivity/count were rarely detected. The I/R+glucan rats had enhancement of IL-10 and suppressed production of serum TNFα, IL-1β and, IL-6, compared to I/R untreated animals. Conclusion: The β-(1-3)-D-glucan modulated the production of pro-inflammatory and anti-inflammatory cytokines during bowel ischemia/reperfusion, and attenuated translocation of labelled bacteria