RESUMO

PURPOSE: To assess the effects of the elevation of the left-ventricular end-diastolic pressure (LVEDP) on the value of the 1st temporal derivative of the ventricular pressure (dP/dt). METHODS: Nineteen anesthetized dogs were studied. The dogs were mechanically ventilated and underwent thoracotomy with parasympathetic nervous system block. The LVEDP was controlled with the use of a perfusion circuit connected to the left atrium and adjusted to the height of a reservoir. The elevation of the LVEDP was achieved by a sudden increase in the height of a reservoir filled with blood. Continuous recordings of the electrocardiogram, the aortic and ventricular pressures and the dP/dt were performed. RESULTS: Elevation of the LVEDP did not result in any variation of the heart rate (167 +/- 16.0 bpm, before the procedure; 167 +/- 15.5 bpm, after the procedure). All the other variables assessed, including systolic blood pressure (128 +/- 18.3 mmHg and 150 +/- 21.5 mmHg), diastolic blood pressure (98 +/- 16.9 mmHg and 115 +/- 19.8 mmHg), LVEDP (5.5 +/- 2.49 and 9.3 +/- 3.60 mmHg), and dP/dt (4,855 +/- 1,082 mmHg/s and 5,149 +/- 1,242 mmHg/s) showed significant increases following the expansion of the ventricular cavity. Although the elevation of the dP/dt was statistically significant, 6 dogs curiously showed a decrease in the values of dP/dt. CONCLUSION: Sudden elevation of the LVEDP resulted in increased values of dP/dt; however, in some dogs, this response was not uniform.

Assuntos

Pressão Sanguínea/fisiologia , Função Ventricular Esquerda/fisiologia , Pressão Ventricular/fisiologia , Animais , Diástole/fisiologia , Cães , Frequência Cardíaca/fisiologia

RESUMO

OBJECTIVE - Angiotensin-converting enzyme inhibitors (ACEIs) have gained importance in preventing or attenuating the process of ventricular remodeling after myocardial infarction. The significance of infarct size in regard to the response to ACEIs, however, is controversial. This study aimed to analyze the effects of lisinopril on mortality rate, cardiac function, degree of cardiac hypertrophy and fibrosis in rats with different infarct sizes. METHODS - Lisinopril (20 mg/kg/day) dissolved in drinking water was administered to rats immediately after coronary artery occlusion. After being sacrificed, the infarcted animals were divided into two groups: one group of animals with small infarcts (< 40% of the left ventricle) and another group of animals with large infarcts (> 40% of the left ventricle). RESULTS - The mortality rate was 31.7% in treated rats and 47% in the untreated rats. There was no statistical difference between the groups with small and large infarcts in regard to myocardial concentration of hydroxyproline. In small infarcts, the treatment attenuated the heart dysfunction characterized by lower levels of blood pressure and lower values of the first derivative of pressure and of the negative derivative of pressure. The degree of hypertrophy was also attenuated in small infarcts. In regard to large infarcts, no differences between the groups were observed. CONCLUSION - Treatment with the ACEIs had no effect on mortality rate and on the amount of fibrosis. The protective effect of lisinopril on heart function and on the degree of hypertrophy could only be detected in small infarcts

Assuntos

Inibidores da Enzima Conversora de Angiotensina/farmacologia , Lisinopril/farmacologia , Infarto do Miocárdio/fisiopatologia , Remodelação Ventricular/efeitos dos fármacos , Animais , Cardiomegalia/tratamento farmacológico , Fibrose , Hidroxiprolina/análise , Masculino , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/patologia , Ratos , Ratos Wistar

RESUMO

Two experiments were carried out to evaluate a larval development assay for the detection of anthelmintic resistance in O. circumcincta. In Experiment I, the dose responses to levamisole (LEV), thiabendazole (TBZ) and ivermectin (IVM) of 8 isolates of O. circumcincta were measured 34 days after infection (DAI). Four of these isolates were shown to be resistant to 1 or more anthelmintics. With 2 exceptions, all isolates considered to be resistant had higher LD50 values than the susceptible isolates for that anthelmintic. One exception was isolate RM8, which was considered to be resistant to all 3 anthelmintics based on faecal egg count reduction tests in goats, but the LD50 value for LEV did not differ from that for the susceptible isolates. The other exception was an isolate considered to be susceptible to TBZ which had a relatively high LD50 value. In an unrelated trial that was prompted by this finding, this isolate was confirmed to be benzimidazole-resistant. Isolate RM8 and an isolate susceptible to all 3 anthelmintics (SK2) were used in the second experiment, which was conducted to monitor changes in the LD50 values of LEV, TBZ and IVM over time following a single infection of 35,000 infective larvae in young sheep. Faecal samples were collected weekly from 24 to 115 DAI. With all 3 anthelmintics, the LD50 values increased with time to a peak around 50-60 DAI, and then declined to levels similar to those observed soon after patency. This trend was consistent for both isolates. The highest mean LD50 values for isolates SK2 for IVM and TBZ and RM8 for IVM and RM8, respectively, were 1.7 and 1.8 times, and 2.2 and 2.9 times higher than the initial mean LD50 values. There was a clear distinction in LD50 values between isolates at each sampling day for both IVM and TBZ. However, as a consequence of the changes in LD50 values with time, the peak LD50 values of IVM for isolate SK2 were higher than the minimum LD50 values of isolate RM8. As there was no apparent difference in LEV efficacy between these 2 isolates, the data were pooled. The highest mean LD50 value was 2.3 times higher than the initial LD50 value.

Assuntos

Anti-Helmínticos/farmacologia , Ostertagia/efeitos dos fármacos , Animais , Anti-Helmínticos/administração & dosagem , Relação Dose-Resposta a Droga , Resistência a Medicamentos , Estudos de Avaliação como Assunto , Feminino , Ivermectina/administração & dosagem , Ivermectina/farmacologia , Levamisol/administração & dosagem , Levamisol/farmacologia , Ostertagia/crescimento & desenvolvimento , Ostertagia/isolamento & purificação , Ostertagíase/tratamento farmacológico , Ostertagíase/parasitologia , Ostertagíase/veterinária , Contagem de Ovos de Parasitas , Parasitologia/métodos , Ovinos , Doenças dos Ovinos/tratamento farmacológico , Doenças dos Ovinos/parasitologia , Tiabendazol/administração & dosagem , Tiabendazol/farmacologia , Fatores de Tempo

RESUMO

PURPOSE: To analyse the influence of mannitol added to Krebs-Henseleit (KH) solution on the myocardium edema and myocardial function. METHODS: Isolated rat heart under isovolumetric contractions studied according to Langendorff's technique were perfused with KH solution at constant flow during 90 min. The coronary perfusion pressure, diastolic and systolic pressures were recorded at every 15 min. At the end of the experiment, myocardium water content was measured in hearts perfused with KH solution (group I, n = 9) and in hearts perfused with KH solution plus 8mM mannitol (group II, n = 8). These results were compared to non-perfused control heart (n = 9). RESULTS: Myocardial water content was statistically higher in group I (80.8 +/- 1.3%) compared to group II (78.1 +/- 0.7%) and control group (75.5 +/- 0.5%). Systolic arterial pressure was statistically higher in group I (86.2 +/- 11.5mmHg) compared to group II (72.7 +/- 21.1mmHg). There was no difference in the diastolic pressure between the two groups. Coronary perfusion pressure (Pp) increased progressively during the experiment in both groups. However, Pp was lower in group II than in group I. CONCLUSION: Mannitol added to KH solution significantly attenuates the myocardium edema in the isolated perfused rat heart.

Assuntos

Soluções Cardioplégicas/efeitos adversos , Diuréticos Osmóticos/farmacologia , Edema Cardíaco/fisiopatologia , Manitol/farmacologia , Contração Miocárdica/efeitos dos fármacos , Animais , Pressão Sanguínea , Água Corporal/efeitos dos fármacos , Glucose/administração & dosagem , Técnicas In Vitro , Masculino , Análise Multivariada , Ratos , Ratos Wistar , Trometamina/administração & dosagem

RESUMO

PURPOSE: To analyze the influence of the myocardial engorgement due to coronary perfusion on the left ventricular diastolic pressure/volume (P/V) relations. METHODS: The study was undertaken in the isovolumic blood-perfused dog heart preparation (n = 7). The P/V relations were determined promoting ventricular volumes variations by steps of 2ml, in two conditions: during coronary perfusion pressure of 100mmHg and after occlusion of the perfusion line. RESULTS: It was verified that the P/V relations obtained without myocardial perfusion shifted to the down right in respect to the perfused heart. A exponential fitting of the P/V relations allows to conclude that there was no difference among the slopes of the curves obtained with and without perfusion. CONCLUSION: Our results indicated that coronary perfusion restrain the capacity of the left ventricle to receive blood, but there is no influence on the passive elastic stiffness of the chamber. This effect was taught to be consequence of the myocardial erectile property.

Assuntos

Perfusão , Volume Sistólico/fisiologia , Função Ventricular Esquerda/fisiologia , Pressão Ventricular/fisiologia , Animais , Cães , Fatores de Tempo

RESUMO

Several components of the erythrocyte-dependent glutathione redox system (reduced glutathione, GSH; oxidized glutathione, GSSG; glutathione peroxidase, GSH-Px; glutathione reductase, GSH-Red) were determined in patients with types I and II diabetes mellitus (DM). All groups studied were male subjects: G1, 20 young healthy individuals (aged 23.7 +/- 4.2 years); G2, 15 young insulin-treated type I DM patients; G3, 20 older insulin-treated type II DM patients; G4, 21 older oral hypoglycemic agent-treated type II DM patients; G5, 28 aged healthy individuals (aged 68.9 +/- 11.5 years). There were no differences between G1 and G2, G3 or G4 regarding erythrocyte GSH, GSSG, and GSH-Red (without FAD) levels. GSH-Px activity was significantly lower in G2 when compared to G1 (15.2 +/- 4.9 vs 20.6 +/- 6.6 IU/g Hb). The GSH-Red and GSH-Px activities and GSH levels were significantly higher in G3 (4.6 +/- 1.7 IU/g Hb, 20.2 +/- 8.7 IU/g Hb and 3.5 +/- 1.3 microM/g Hb) and G4 (5.0 +/- 2.2 IU/g Hb, 16.9 +/- 6.1 IU/g Hb and 5.0 +/- 2.3 microM/g Hb) when compared to G5 (3.4 +/- 0.9 IU/g Hb, 12.0 +/- 3.6 IU/g Hb and 2.3 +/- 0.9 microM/g Hb). The findings suggest that treatment of DM can stimulate the redox activity of red blood cells in aged subjects.

Assuntos

Diabetes Mellitus Tipo 1/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Eritrócitos/metabolismo , Glutationa/metabolismo , Adulto , Humanos , Masculino , Oxirredução

RESUMO

Several components of the erythrocyte-dependent glutathione redox system (reduced glutathione, GSH; oxidized glutathione, GSSG; glutathione peroxidase, GSH-Px; glutathione reductase, GSH-Red) were determined in patients with types I and II diabetes mellitus (DM). All groups studied were male subjects: G1, 200 young healthy individuals (aged 23.7 ñ 4.2 years); G2, 15 young insulin-treated type I DM patients; G3, 20 older older insulin-treated type II DM patiens; G4, 21 older oral hypoglycemic agent-treated type II DM patients; G5, 28 aged healthy individuals (aged 68.9 ñ 11.5 years). There were no differences between G1 and G3 or G4 regarding erythrocyte GSH, GSSG, and GSH-Red (without FAD) levels. GSH-Px activity was significantly lower in G2 when compared to G1 (15.2 ñ 4.9 vs 20.6 ñ 6.6 IU/g Hb). The GSH-Red and GSH-Px activities and GSH levels were significantly higher in G3 (4.6 ñ 1.7 IU/g Hb, 20.2 ñ 8.7 IU/g Hb and 3.5 ñ 1.3 uM/g Hb) and G4 (5.0 ñ 2.2 IU/g Hb, 16.9 ñ 6.1 IU/g Hb and 5.0 ñ 2.3 uM/g Hb) when compared to G5 (3.4 ñ 0.9 IU/g Hb, 12.0 ñ 3.6 IU/g Hb and 2.3 ñ 0.9 uM/g Hb). The findings suggest that treatment of DM can stimulate the redox activity of red blood cells in aged subjects

Assuntos

Diabetes Mellitus/terapia , Eritrócitos , Glutationa Peroxidase , Glutationa Redutase , Glutationa/efeitos adversos , Hemoglobinas Glicadas , Oxirredução

RESUMO

Hypo- and hyperzincemia has been reported to cause alterations in the adrenal secretion. To determine the acute effect of zinc on cortisol levels, we studied 27 normal individuals of both sexes aged 20-27 y after a 12-h fast. The tests were initiated at 7:00 AM when an antecubital vein was punctured and a device for infusion was installed and maintained with physiological saline. Zinc was administered orally at 8:00 AM. Subjects were divided into an experimental group of 13 individuals who received doses of 25, 37.5, and 50 mg of zinc and a control group of 14 individual who received 20 mL of physiological saline. Serial blood samples were collected over a period of 240 min after basal samples (-30 and 0 min). We detected an acute inhibitory effect of zinc on cortisol secretion during 240 min of the study period in the experimental group.

Assuntos

Córtex Suprarrenal/metabolismo , Hidrocortisona/metabolismo , Zinco/farmacologia , Córtex Suprarrenal/efeitos dos fármacos , Adulto , Brasil , Humanos , Consentimento Livre e Esclarecido , Periodicidade , Estudantes de Medicina , Zinco/sangue

RESUMO

The response of plasma prolactin (PRL) to oral administration of increasing doses of zinc (25.0, 37.5 and 50.0 mg) was studied in 17 normal adult men and women. Blood samples were collected at 10 and 30-min intervals over a period of 120 min after two basal times (-30 and 0 min). PRL concentrations significantly fell below basal levels in all subjects in response to the increase in plasma zinc levels, as compared to the controls. These results suggest that acute hyperzincemia can inhibit basal PRL secretion in normal individuals.

Assuntos

Prolactina/metabolismo , Zinco/farmacologia , Adulto , Feminino , Humanos , Masculino , Radioimunoensaio , Zinco/sangue

RESUMO

PIP: The authors examined the prevalence of vaginal discharge in a sample of sexually active women who spanned 3 different socioeconomic groups. They observed a prevalence of 0.0% in the high socioeconomic group, 21% in the middle group, and 45% in the low income group (rural area). They also studied the conditioning factors for these different prevalences and found that there were no significant differences for age, parity, abortions, or oral contraceptive use. They found significant differences with IUD use and uterine prolapse in 1 of the areas, but these results do not explain the other differences. They feel that further clinical and epidemiologic studies are necessary. It seems that significant differences were associated with genital hygiene which is dependent on socioeconomic level. (author's)^ieng

Assuntos

Genitália Feminina , Fatores Socioeconômicos , Vagina , Aborto Induzido , Fatores Etários , Biologia , Comportamento Contraceptivo , Economia , Genitália , Paridade , Fisiologia , Sistema Urogenital