Correlação de diferentes períodos de jejum com níveis séricos de cortisol, glicemia plasmática, estado clínico e equilíbrio ácido-base em case submetidos à anestesia geral inalatória

This study correlated the solid preoperative fasting periods with plasma glycemia, serum cortisol, condition clinic and acid-base balance in dogs submitted to inhalation of general anaesthesia. Eight adults, animals were distributed into three groups in accordance with solid preoperative fasting: group 1 (12 hours), group 2 (18 hours) and group 3 (24 hours). Gastric emptying was observed and following this animals were submitted to the same anesthetic procedure. Heart and respiratory rate, rectal temperature, capillary refill time, percent hydration and noninvasive arterial pressure determined before and after Acepromazine and every 10 minutes during anaesthesia, included ETCO 2; values blood gas (pH, PaCO 2, PaO 2, HCO 3, TCO 2, SaO 2, BE), glycemic and serum cortisol were analyzed before MPA and each 30 minutes during anaesthesia. In recovery anaesthetic, glycemia and serum cortisol were repeated. During anaesthesia there were little cardiovascular and respiratory alteration not having interference of the preoperative fasting periods. Animals with 12 hours of the preoperative fasting showed a higher rise in glycemia levels than others groups in recovery anaesthetic. Serum cortisol wasn't influenced by fasting. Solid preoperative fasting independent of the duration describe a discreet respiratory alkalosis. All animals showed good clinical condition in all three groups. Solid preoperative fasting of the 18 hours is recommended to ensure a complete absence of the solid food contents in stomach.

Contribuição ao entendimento da patogenia da sepse

The most frequent cause of vasodilatory shockis outcome from sepsis, a systemic inflammatory response to infection, characterized by hypotension, hyporeactivity to the catecholamines and disseminated intravascular coagulation. The commonest cause of sepsis has reported to be infection with Gram-negative bacteria, typically E. coli, resulting in the release of lipopolysaccharide (endotoxin) from the bacterial outer membrane during autolysis or death of these microorganisms, with the involvement of many mediators, including nitric oxide. Later it was found that plasma levels of vasopressin in sepsis patients were abnormally low and observed that some patients with advanced septic shock were extremely sensitive to the activity actions of exogenous vasopressin.

Efeito hipotensor do extrato aquoso de alpiste (Phalaris canariensis L.) em ratos

The plant species Phalaris canariensis, known as canary grass, is widely used in folk medicine as diuretic, as well as in culinary and animal feed. In this study, the effect of P. canariensis aqueous extract (AE) on water flow (V) and sodium renal excretion (Qe (Na+)) was evaluated in anesthetized Wistar rats. Arterial pressure alterations (AP) were also assessed. Two groups were studied: Control group (CON) - oral administration of 1.0 mL distilled water, and Experimental group (EA) - oral administration of 1.0 mL P. canariensis aqueous extract 40%. Rats were anesthetized and subjected to cannulation of trachea (for better pulmonary ventilation), left carotid artery (for arterial pressure measurement) and urinary bladder (for urine collection). Control animals did not present significant alterations (p>0.05) in all analyzed parameters after water administration. EA group had a significant arterial pressure reduction at 60 minutes (31.4%) and 90 minutes (49.1%) after the extract administration (p<0.05). Renal parameters did not have any significant alteration (p>0.05). In this study, P. canariensis aqueous extract had a hypotensive effect in anesthetized Wistar rats, without renal alterations.

Effects of pentoxifylline and n-acetylcysteine on injuries caused by ischemia and reperfusion of splanchnic organs in rats

Aim. Occlusion and reperfusion of splanchnic arteries cause local and systemic changes due to the release of cytotoxic substances and the interaction between neutrophils and endothelial cells. This study evaluated the role of pentoxifylline (PTX) and n-acetylcysteine (NAC) in the reduction of ischemia, reperfusion shock and associated intestinal injury. Methods. Sixty rats were divided into 6 groups of 10 animals. Rats in three groups underwent mesenteric ischemia for 30 minutes followed by 120 minutes of reperfusion, and were treated with saline (SAL-5 mL/kg/ h), pentoxifylline (PTX-50 mg/kg) or n-acetylcysteine (NAC-430 mg/kg/h). The other 3 groups underwent sham ischemia and reperfusion (I/R) and received the same treatments. Hemodynamic, biochemical and histological parameters were evaluated. Results. No significant hemodynamic or intestinal histological changes were seen in any sham group. No histological changes were found in the lung or liver of animals in the different groups. There was a progressive decrease in mean arterial blood pressure, from mean of 111.53 mmHg (30 minutes of ischemia) to 44.30±19.91 mmHg in SAL-I/R. 34.52±17.22 mmHg in PTX-I/R and 33.81±8.39 mmHg in NAC-I/R (P<0.05). In all I/R groups, there was a progressive decrease in: aortic blood flow, from median baseline of 19.00 mL/min to 2.50±5.25 mL/min in SAL-I/ R; 2.95±6.40 mL/min in PTX-I/R and 3.35±3.40 mL/min in NAC-I/R (P<0.05); in the heart rate, from mean baseline of 311.74 bpm to 233.33±83.88 bpm in SAL-I/R, 243.20±73.25 bpm in PTX-I/R and 244.92±76.05 bpm in NAC-I/R (P<0.05); and esophageal temperature, from mean baseline of 33.68°C to 30.53±2.05°C in SAL-I/R, 30.69±2.21°C in PTX-I/R and 31.43±1.03°C in NAC-I/R (P<0.05). In the other hand, there was an attenuation of mucosal damage in the small intestine of the animals receiving PTX, and only in the ileum of the animals receiving NAC. No changes were found in ileum or plasma malondialdehyde levels in any group. Conclusion. PTX was more efficient in reducing histological lesions than NAC, but neither treatment prevented hemodynamic changes during splanchnic organs I/R.

Efeitos sedativo e cardiorrespiratório da administração da metadona, isoladamente ou em associação à acepromazina ou xilazina, em gatos

Six cats weighting 3.3±0.3 kg were randomly allocated to 6 treatments, with at least one-week intervals. The cats received intramuscular administration of physiological saline (control), methadone (0.3 mg/ kg), acepromazine (0,1 mg/kg), xylazine (1.0 mg/kg), acepromazine (0.05 mg/kg) plus methadone (0.3 mg/kg) or xylazine (0.5 mg/kg) plus methadone (0.3 mg/kg). Heart rate (HR), respiratory rate (RR), indirect systolic arterial pressure (SAP), rectal temperature, sedation score and pedal withdrawal reflex were evaluated before (baseline) and at selected intervals after treatment administration for 90 minutes. Respiratory rate, HR and rectal temperature decreased in cats given xylazine or xylazine plus methadone. In 1 out of 6 cats given xylazine and 2 out of 6 cats given xylazine/methadone, pedal withdrawal reflex was absent. In cats given 0.1 mg/kg of acepromazine, SAP decreased compared to baseline. Sedation scores were greater in cats given xylazine or xylazine plus methadone. Methadone alone or in combination with acepromazine did not produce a satisfactory degree of sedation and resulted in signs of excitement in some of the cats. Methadone alone or combination with acepromazine was not considered an effective protocol when moderate to deep sedation is required in cats. Methadone in combination with xylazine produces moderate to deep sedation, being this effect comparable to that achieved with a higher dose of xylazine alone.

Contribuição do uso de medicamentos para a admissão hospitalar

According to the Word Health Organization, adverse drug reactions (ADR) are any harmful and non intentional answer which occurred in doses normally used in human beings. The ADR can be responsible for 2.4% to 11.5% of hospital admissions. Therefore, this study aimed at knowing the admitted patient's demographic profile due to possible ADR, identifying the most frequent drugs and complaints, and evaluating the incidence of hospital admission related to drug use. Patients who were 18 years old or more and were admitted during a period of one month to a medical clinical of a general hospital were interviewed for one month about drug use before being admitted, as well as regarding to the complaint which led them to hospital. These information were analyzed according to official data, like MICROMEDEX® and WHO criteria as well. It was observed that the admission due to drug use occurred in most part of the cases in elderly [47.5% (66/139)] and women [62% (87/139)]. The most frequent drugs used were: omeprazole (16), analgesics (31), antihypertensive (31), simvastatin (7) and formoterol fumarate (6), and the symptoms were normally associated to the digestive (20.5%), circulatory (20.2%), respiratory (18.2%) and central nervous systems (13.9%). It was estimated that 15.5% (139/897) of the hospital admission occurred possibly due to the drug use. The data found by present study suggests some strategies in order to prevent ADR in the context of primary health care services, such as monitoring drug therapy, manly for patients with chronic diseases, elderly and polimedicated people; and pharmaceutical care including dispensation and purchasing of the drugs, a lot of them dispensed over the counter (OTC).

Effect of 6-months of physical exercise on the nitrate/nitrite levels in hypertensive postmenopausal women

Background: Evidences have showed that the incidence of arterial hypertension is greater in postmenopausal women as compared to premenopausal. Physical inactivity has been implicated as a major contributor to weight gain and abdominal obesity in postmenopausal women and the incidence of cardiovascular disease increases dramatically after menopause. Additionally, more women than men die each year of coronary heart disease and are twice as likely as men to die within the first year after a heart attack. A healthy lifestyle has been strongly associated with the regular physical activity and evidences have shown that physically active subjects have more longevity with reduction of morbidity and mortality. Nitric oxide (NO) produced by endothelial cells has been implicated in this beneficial effect with improvement of vascular relaxing and reduction in blood pressure in both laboratory animals and human. Although the effect of exercise training in the human cardiovascular system has been largely studied, the majority of these studies were predominantly conducted in men or young volunteers. Therefore, the aim of this work was to investigate the effects of 6 months of dynamic exercise training (ET) on blood pressure and plasma nitrate/nitrite concentration (NOx-) in hypertensive postmenopausal women. Methods: Eleven volunteers were submitted to the ET consisting in 3 days a week, each session of 60 minutes during 6 months at moderate intensity (50% of heart rate reserve). Anthropometric parameters, blood pressure, NOx- concentration were measured at initial time and after ET. Results: A significant reduction in both systolic and diastolic blood pressure values was seen after ET which was accompanied by markedly increase of NOx- levels (basal: 10 ± 0.9; ET: 16 ± 2 μM). Total cholesterol was significantly reduced (basal: 220 ± 38 and ET: 178 ± 22 mg/dl), whereas triglycerides levels were not modified after ET (basal: 141 ± 89 and ET: 147 ± 8 mg/dl). Conclusion: Our study shows that changing in lifestyle promotes reducftion of arterial pressure which was accompanied by increase in nitrite/nitrate concentration. Therefore, 6-months of exercise training are an important approach in management arterial hypertension and play a protective effect in postmenopausal women. © 2009 Zaros et al; licensee BioMed Central Ltd.

Cardiac baroreflex is already blunted in eight weeks old spontaneously hypertensive rats

Background. The literature did not evidence yet with which age spontaneously hypertensive rats (SHR) start to present baroreflex reduction. We endeavored to evaluate the baroreflex function in eight-week-old SHR. Methods. Male Wistar Kyoto (WKY) normotensive rats and SHR aged eight weeks were studied. Baroreflex was calculated as the variation of heart rate (HR) divided by the mean arterial pressure (MAP) variation (HR/MAP) tested with a depressor dose of sodium nitroprusside (SNP, 50 g/kg) and with a pressor dose of phenylephrine (PHE, 8 g/kg) in the right femoral venous approach through an inserted cannula in the animals. Significant differences for p < 0.05. Results. Baseline MAP (p < 0.0001) and HR (p = 0.0028) was higher in SHR. Bradycardic peak was attenuated in SHR (p < 0.0001), baroreflex gain tested with PHE was also reduced in the SHR group (p = 0.0012). PHE-induced increase in MAP was increased in WKY compared to SHR (p = 0.039). Bradycardic reflex responses to intravenous PHE was decreased in SHR (p < 0.0001). Conclusion. Eight weeks old SHR already presents impairment of the parasympathetic component of baroreflex. © 2010 Cisternas et al; licensee BioMed Central Ltd.

Paraventricular nucleus of the hypothalamus glutamate neurotransmission modulates autonomic, neuroendocrine and behavioral responses to acute restraint stress in rats

In the present study, the involvement of paraventricular nucleus of the hypothalamus (PVN) glutamate receptors in the modulation of autonomic (arterial blood pressure, heart rate and tail skin temperature) and neuroendocrine (plasma corticosterone) responses and behavioral consequences evoked by the acute restraint stress in rats was investigated. The bilateral microinjection of the selective non-NMDA glutamate receptor antagonist NBQX (2 nmol/ 100 nL) into the PVN reduced the arterial pressure increase as well as the fall in the tail cutaneous temperature induced by the restraint stress, without affecting the stress-induced tachycardiac response. On the other hand, the pretreatment of the PVN with the selective NMDA glutamate receptor antagonist LY235959 (2 nmol/100 nL) was able to increase the stress-evoked pressor and tachycardiac response, without affecting the fall in the cutaneous tail temperature. The treatment of the PVN with LY235959 also reduced the increase in plasma corticosterone levels during stress and inhibited the anxiogenic-like effect observed in the elevated plus-maze 24 h after the restraint session. The present results show that NMDA and non-NMDA receptors in the PVN differently modulate responses associated to stress. The PVN glutamate neurotransmission, via non-NMDA receptors, has a facilitatory influence on stress-evoked autonomic responses. On the other hand, the present data point to an inhibitory role of PVN NMDA receptors on the cardiovascular responses to stress. Moreover, our findings also indicate an involvement of PVN NMDA glutamate receptors in the mediation of the plasma corticosterone response as well as in the delayed emotional consequences induced by the restraint stress. © 2012 Elsevier B.V. and ECNP.

Activation of central aα-adrenoceptors mediates salivary gland vasoconstriction

Objective: Peripheral treatment with the cholinergic agonist pilocarpine increases salivary gland blood flow and induces intense salivation that is reduced by the central injection of moxonidine (aα-adrenoceptors/ imidazoline agonist). In the present study, we investigated the effects of the intracerebroventricular (i.c.v.) injection of pilocarpine alone or combined with moxonidine also injected i.c.v. On submandibular/sublingual gland (SSG) vascular resistance. In addition, the effects of these treatments on arterial pressure, heart rate and on mesenteric and hindlimb vascular resistance were also tested. Design: Male Holtzman rats with stainless steel cannula implanted into lateral ventricle and anaesthetized with urethane + α-chloralose were used. Results: Pilocarpine (500 nmol/1 μl) injected i.c.v. Reduced SSG vascular resistance and increased arterial pressure, heart rate and mesenteric vascular resistance. Contrary to pilocarpine alone, the combination of moxonidine (20 nmol/1 μl) and pilocarpine injected i.c.v. Increased SSG vascular resistance, an effect abolished by the pre-treatment with the α2-adrenoceptor antagonist yohimbine (320 nmol/2 μl). The increase in arterial pressure, heart rate and mesenteric resistance was not modified by the combination of moxonidine and pilocarpine i.c.v. Conclusion: These results suggest that the activation of central α2- adrenoceptors may oppose to the effects of central cholinergic receptor activation in the SSG vascular resistance. © 2012 Elsevier Ltd. All rights reserved.

Effects of Jugular Vein Occlusion on Cardiovascular Parameters in Horses During Exercise on a Treadmill

The purpose of the present investigation was to examine the effects of unilateral and bilateral jugular vein occlusion by temporary surgical ligature on the heart rate and arterial and venous blood pressure in sedentary horses during progressive treadmill exercise. Six horses performed three exercise tests (ET). ET1, considered the control, was performed in horses without jugular occlusions. ET2 and ET3 were performed with unilateral and bilateral occlusion by temporary surgical ligature of the jugular veins, respectively. Heart rate, arterial pressure, and pressure of the occluded jugular vein were evaluated. Clinically, the horses presented apathy, head edema, congested mucous membranes, increased capillary refill time, and dysphagia. These signs were observed with the unilateral jugular vein occlusion and became more evident with the bilateral occlusion. Comparing ETs, no differences were observed in heart rate. However, jugular occlusions promoted a decrease in the mean arterial pressure and a severe increase in jugular pressure. Head edema caused by the jugular vein occlusion in the horses could interfere with the autonomic cardiovascular regulation of arterial blood pressure during exercise, likely leading to an impairment of tissue perfusion. Jugular occlusion, even unilateral, also causes severe head venous congestion, leading to venous hypertension that was aggravated by exercise, which could risk development of cerebral edema and neurological damage. The present results obtained from sedentary horses are preliminary data that lead us to suggest that sport horses presenting jugular occlusive thrombophlebitis, even unilateral, may be prevented from performing athletic activities. © 2013 Elsevier Inc. All rights reserved.

Sidestream cigarette smoke and cardiac autonomic regulation

Background: The literature has already demonstrated that cigarette influences the cardiovascular system. In this study, we performed a literature review in order to investigate the relationship between sidestream cigarette smoke (SSCS) and cardiac autonomic regulation. Methods. Searches were performed on Medline, SciELO, Lilacs and Cochrane databases using the crossing between the key-words: cigarette smoking, autonomic nervous system, air pollution and heart rate variability. Results: The selected studies indicated that SSCS exposure affects the sympathetic and parasympathetic responses to changes in arterial blood pressure. Moreover, heart rate responses to environmental tobacco smoke are increased in smokers compared to non-smokers. The mechanism involved on this process suggest increased oxidative stress in brainstem areas that regulate the cardiovascular system. Conclusion: Further studies are necessary to add new elements in the literature to improve new therapies to treat cardiovascular disorders in subjects exposed to sidestream cigarette smoke. © 2013 Valenti et al; licensee BioMed Central Ltd.

Doppler echocardiography in athletes from different sports

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Risk of metabolic syndrome in postmenopausal breast cancer survivors

The aim of this study was to assess the risk of metabolic syndrome (MetS) in postmenopausal breast cancer survivors as compared with postmenopausal women without breast cancer. METHODS: In this cross-sectional study, 104 postmenopausal breast cancer survivors were compared with 208 postmenopausal women (controls) attending a university hospital. Eligibility criteria included the following: amenorrhea longer than 12 months and aged 45 years or older, treated for breast cancer, and metastasis-free for at least 5 years. The control group consisted of women with amenorrhea longer than 12 months and aged 45 years or older and without breast cancer, matched by age and menopause status (in a proportion of 1:2 as sample calculation). Clinical and anthropometric data were collected. Biochemical parameters, including total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, glucose, and C-reactive protein, were measured. Women showing three or more diagnostic criteria were diagnosed as having MetS: waist circumference of 88 cm or larger, blood pressure of 130/85 mm Hg or higher, triglycerides level of 150 mg/dL or higher, high-density lipoprotein cholesterol level lower than 50 mg/dL, and glucose level of 100 mg/dL or higher. For statistical analysis, Student's t test, χ2 test, and logistic regression (odds ratio [OR]) were used. RESULTS: The mean (SD) age of breast cancer survivors was 60.6 (8.6) years, with a mean (SD) follow-up of 9.4 (4.4) years. A higher percentage of breast cancer survivors (46.2%) were obese as compared with controls (32.7%; P < 0.05), and a smaller percentage showed optimal values for low-density lipoprotein cholesterol, glucose, and C-reactive protein versus controls (P < 0.05). MetS was diagnosed in 50% of breast cancer survivors and in 37.5% of control group women (P < 0.05). Among the MetS diagnostic criteria, the most prevalent was abdominal obesity (waist circumference >88 cm), affecting 62.5% and 67.8% of the participants, respectively. In the control group, breast cancer survivors had a higher risk for MetS (OR, 1.66; 95% CI, 1.04-2.68), dysglycemia (OR, 1.05; 95% CI, 1.09-3.03), and hypertension (OR, 1.71; 95% CI, 1.02-2.89). CONCLUSIONS: Postmenopausal breast cancer survivors present a higher risk of developing MetS as compared with women without breast cancer. © 2012 by The North American Menopause Society.