989 resultados para Prospective organ dose estimation
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OBJECTIVE - To evaluate the cardiac abnormalities and their evolution during the course of the acquired immunodeficiency syndrome, as well as to correlate clinical and pathological data. METHODS - Twenty-one patients, admitted to the hospital with the diagnosis of acquired immunodeficiency syndrome, were prospectively studied and followed until their death. Age ranged from 19 to 42 years (17 males). ECG and echocardiogram were also obtained every six months. After death, macro- and microscopic examinations were also performed. RESULTS - The most frequent causes of referral to the hospital were: diarrhea or repeated pneumonias, tuberculosis, toxoplasmosis or Kaposi sarcoma. The most frequent findings were acute or chronic pericarditis (42%) and dilated cardiomyopathy (19%). Four patients died of cardiac problems: infective endocarditis, pericarditis with pericardial effusion, bacterial myocarditis and infection by Toxoplasma gondii. CONCLUSION - Severe cardiac abnormalities were the cause of death in some patients. In the majority of the patients, a good correlation existed between clinical and anatomical-pathological data. Cardiac evaluation was important to detect early manifestations and treat them accordingly, even in asymptomatic patients.
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OBJETIVO: Avaliar a eficácia terapêutica do verapamil COER-24 180/240 mg, em dose única, ao deitar, como monoterapia para a hipertensão arterial leve a moderada. MÉTODOS: Estudo multicêntrico, aberto, não comparativo com 81 pacientes de ambos os sexos, com idade >20 anos e hipertensão arterial essencial leve e moderada. Medimos a pressão arterial no consultório e com a monitorização ambulatorial (MAPA) durante 24h antes e ao final de 8 semanas do uso da medicação. RESULTADOS: Verificou-se diminuição (p<0,0001) das pressões sistólicas e diastólicas medidas no consultório às semanas 3 e 8. A MAPA demonstrou que tanto a pressão sistólica, diastólica, média e freqüência cardíaca, quando as cargas pressóricas médias de 24h apresentaram reduções após 8 semanas de tratamento, além da redução do duplo-produto, especialmente pela manhã. A tolerabilidade foi boa, 68% dos pacientes não apresentaram eventos adversos. CONCLUSÃO: A monoterapia com o verapamil COER-24 180/240mg em dose única é eficaz para o controle da pressão arterial em hipertensos leves e moderados, com redução tanto na pressão casual quanto na MAPA/24h, além de apresentar boa tolerabilidade.
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OBJETIVE: The evaluation, by exercise stress testing, of the cardiorespiratory effects of pyridostigmine (PYR), a reversible acetylcholinesterase inhibitor. METHODS: A double-blind, randomized, cross-over, placebo-controlled comparison of hemodynamic and ventilation variables of 10 healthy subjects who underwent three exercise stress tests (the first for adaptation and determination of tolerance to exercise, the other two after administration of placebo or 45mg of PYR). RESULTS: Heart rate at rest was: 68±3 vs 68±3bpm before and after placebo, respectively (P=0.38); 70±2 vs 59±2bpm, before and after pyridostigmine, respectively (P<0.01). During exercise, relative to placebo: a significantly lower heart rate after PYR at, respectively, 20% (P=0.02), 40% (P=0.03), 80% (P=0.05) and 100% (P=0.02) of peak effort was observed. No significant differences were observed in arterial blood pressure, oxygen consumption at submaximal and maximal effort, exercise duration, respiratory ratio, CO2 production, ventilation threshold, minute ventilation, and oxygen pulse. CONCLUSION: Pyridostigmine, at a dose of 45mg, decreases heart rate at rest and during exercise, with minimal side effects and without interfering with exercise tolerance and ventilation variables.
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OBJECTIVE: To determine the characteristics associated with the dropout of patients followed up in a Brazilian out patient clinic specializing in hypertension. METHODS: Planned prospective cohort study of patients who were prescribed an antihypertensive treatment after an extensive initial evaluation. The following parameters were analyzed: sex, age, educational level, duration of disease, pressure level used for classifying the patient, previous treatment, physical activity, smoking, alcohol consumption, familial history of hypertension, and lesion in a target organ. RESULTS: We studied 945 hypertensive patients, 533 (56%) of whom dropped out of the follow-up. The mean age was 52.3±12.9 years. The highest probabilities of dropout of the follow-up were associated with current smoking, relative risk of 1.46 (1.04-2.06); educational level equal to or below 5 years of schooling, relative risk of 1.52 (1.11-2.08); and hypertension duration below 5 years, relative risk of 1.78 (1.28-2.48). Age increase was associated with a higher probability of follow-up with a relative risk of 0.98 (0.97-0.99). CONCLUSION: We identified a group at risk for dropping out the follow-up, which comprised patients with a lower educational level, a recent diagnosis of hypertension, and who were smokers. We think that measures assuring adherence to treatment should be directed to this group of patients.
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Dissertação de mestrado em Estatística
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OBJECTIVE - A prospective, nonrandomized clinical study to assess splanchnic perfusion based on intramucosal pH in the postoperative period of cardiac surgery and to check the evolution of patients during hospitalization. METHODS - We studied 10 children, during the immediate postoperative period after elective cardiac surgery. Sequential intramucosal pH measurements were taken, without dobutamine (T0) and with 5mcg/kg/min (T1) and 10 (T2) mcg/kg/min. In the pediatric intensive care unit, intramucosal pH measurements were made on admission and 4, 8, 12, and 24 hours thereafter. RESULTS - The patients had an increase in intramucosal pH values with dobutamine 10mcg/kg/min [7.19± 0.09 (T0), 7.16±0.13(T1), and 7.32±0.16(T2)], (p=0.103). During the hospitalization period, the intramucosal pH values were the following: 7.20±0.13 (upon admission), 7.27±0.16 (after 4 hours), 7.26±0.07 (after 8 hours), 7.32±0.12 (after 12 hours), and 7.38±0.08 (after 24 hours), (p=0.045). No deaths occurred, and none of the patients developed multiple organ and systems dysfunction. CONCLUSION - An increase in and normalization of intramucosal pH was observed after dobutamine use. Measurement of intramucosal pH is a type of monitoring that is easy to perform and free of complications in children during the postoperative period of cardiac surgery.
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OBJECTIVE: To study the effect of propafenone on the contractile function of latissimus dorsi muscle isolated from rats in an organ chamber. METHODS: We studied 20 latissimus dorsi muscles of Wistar rats and divided them into 2 groups: group I (n=10), or control group - we studied the feasibility of muscle contractility; group II (n=10), in which the contralateral muscles were grouped - we analyzed the effect of propafenone on muscle contractility. After building a muscle ring, 8 periods of sequential 2-minute baths were performed, with intervals of preprogrammed electrical stimulation using a pacemaker of 50 stimuli/min. In group II, propafenone, at the concentration of 9.8 µg/mL, was added to the bath in period 2 and withdrawn in period 4. RESULTS: In group I, no significant depression in muscle contraction occurred up to period 5 (p>0.05). In group II, a significant depression occurred in all periods, except between the last 2 periods (p<0.05). Comparing groups I and II only in period 1, which was a standard period for both groups, we found no significant difference (p>0.05). CONCLUSION: Propafenone had a depressing effect on the contractile function of latissimus dorsi muscle isolated from rats and studied in an organ chamber.
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OBJECTIVE: To compare the accuracy of 4 different indices of cardiac risk currently used for predicting perioperative cardiac complications. METHODS: We studied 119 patients at a university-affiliated hospital whose cardiac assessment had been required for noncardiac surgery. Predictive factors of high risk for perioperative cardiac complications were assessed through clinical history and physical examination, and the patients were followed up after surgery until the 4th postoperative day to assess the occurrence of cardiac events. All patients were classified according to 4 indices of cardiac risk: the Goldman risk-factor index, Detsky modified risk index, Larsen index, and the American Society of Anesthesiologists' physical status classification and their compared accuracies, examining the areas under their respective receiver operating characteristic (ROC) curves. RESULTS: Cardiac complications occurred in 16% of the patients. The areas under the ROC curves were equal for the Goldman risk-factor index, the Larsen index, and the American Society of Anesthesiologists' physical status classification: 0.48 (SEM ± 0.03). For the Detsky index, the value found was 0.38 (SEM ± 0.03). This difference in the values was not statistically significant. CONCLUSION: The cardiac risk indices currently used did not show a better accuracy than that obtained randomly. None of the indices proved to be significantly better than the others. Studies to improve our ability to predict such complications are still required.
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OBJECTIVE: To assess pregnancy outcome in women with peripartum cardiomyopathy and to compare it with idiopathic cardiomyopathy. METHODS: Twenty-six pregnant women, aged 28.4±6.1 years, with dilated cardiomyopathy were followed. Eighteen patients had peripartum cardiomyopathy [11 with persistent left ventricular systolic dysfunction (EF=45.2±2) and 7 with recovered ventricular function (EF=62.3±3.6)]. The 8 remaining patients had idiopathic cardiomyopathy (EF= 43.5±4.1). During the prenatal period, limited physical activity and a low-sodium diet were recommended, and hospitalization was recommended when complications occurred. RESULTS: Of the 26 patients, 11 (42.3%) had a normal delivery; 9(35.5%) had cardiac complications, 6 (22.2%) had obstetric complications. Two patients (7.7%) died. Two preterm pregnancies occurred, with 26 health newborns (2 sets of twins). Two miscarriages took place. The cardiac complication rate during pregnancy was lower (p<0.009) in the peripartum cardiomyopathy group without ventricular dysfunction and greater (p=0.01) in the idiopathic group when compared with the peripartum group with ventricular dysfunction. Changes in left ventricular ejection fraction were not observed (p<0.05) in the postpartum period, when compared with that during pregnancy in the 3 groups. CONCLUSION: Pregnancy in patients with dilated cardiomyopathy is associated with maternal morbidity. Left ventricular function is a prognostic factor and must be the most parameter when counseling patients with peripartum cardiomyopathy about a new pregnancy.
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OBJECTIVE: Detect of cardiac alterations in children with AIDS and compare their evolution with the administration of only one anti-retroviral and the recent cases who received drugs in combination. METHODS: We prospectively studied 47 children in 3 groups: group 1, 20 cases treated only with zidovudine; group 2, 10 patients treated initially with zidovudine and later with a combination of drugs and in group 3, 17 patients, who receiced two or three since the beginning. In all patients it was done chest X-ray, EKG and echocardiography every 6 months and after death complete pathological study. RESULTS: Among the 45 patients cases 26 (57%) were index cases. Malnutrition, diarrhea tachycardia, signs of congestive heart failure, pericardial effusion, abnormal ventricular repolarization and arrhythmias were more frequent in group 1. Echocardiographic abnormalities were present in 10 (50%) children of group 1. They were less frequent in the others two groups. In regard to the outcome in group 1, two patients had worsening of sings of cardiomyopaty and 4 died. Cardiac dysfunction in all cases of group 2 and 3 improved with the medication. CONCLUSION:- The children who received combination and their cardiac alterations had more favorable outcome than those who received only one drug.
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OBJECTIVE: To determine whether arginine vasopressin releases endothelium-derived nitric oxide (EDNO) from the epicardial coronary artery. METHODS: We studied segments of canine left circumflex coronary arteries suspended in organ chambers to measure isometric force. The coronary artery segments were contracted with prostaglandin F2alpha (2 x 10-6M) and exposed to a unique, strong arginine vasopressin concentration (10-6M) or titrated concentrations (10-9 a 10-5 M). RESULTS: The unique dose of arginine vasopressin concentration (10-6M) induced transient, but significant (p<0.05), relaxation in arterial segments with endothelium, and an increase, not significant, in tension in arteries without endothelium. Endothelium-dependent relaxation to arginine vasopressin was inhibited by Ng-monomethyl-L-arginine (L-NMMA, 10-5M) or N G-nitro-L-arginine (L-NOARG) (10-4M), 2 inhibitors of nitric oxide synthesis from L-arginine. Exogenous L-arginine (10-4M), but not D-arginine (10-4M), reversed the inhibitory effect of L-NMMA on vasopressin-mediated vasorelaxation. Endothelium dependent relaxation to vasopressin was also reversibly inhibited by the vasopressin V1-receptor blocker d(CH2)5Try(Me) arginine vasopressin (10-6M) (n=6, P<0.05). CONCLUSION: Vasopressin acts through V1 endothelial receptors to stimulate nitric oxide release from L-arginine.
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OBJECTIVE: To characterize the cardiac electrophysiologic effects of cocaine. METHODS: In 8 dogs (9-13 kg), electrophysiologic parameters and programmed stimulation were undertaken using transvenous catheters at baseline, and after cocaine intravenous infusion (12 mg/kg bolus followed by 0.22 mg/kg/min for 25 minutes). RESULTS: Cocaine plasma levels (n=5) rose to 6.73± 0.56 mg/mL. Cocaine did not affect sinus cycle length and arterial pressure. Cocaine prolonged P wave duration (54±6 vs 73±4 ms, P<0.001), PR interval (115±17 vs 164±15 ms, P<0.001), QRS duration (62±10 vs 88±14 ms, P<0.001), and QTc interval (344±28 vs 403±62 ms, P=0.03) but not JT interval (193±35 vs 226±53 ms, NS). Cocaine prolonged PA (9±6 vs 23±8 ms, P<0.001), AH (73±16 vs 92±15 ms; P=0.03), and HV (35±5 vs 45±3ms; P<0.001) intervals and Wenckebach point (247±26 vs 280±28 ms, P=0.04). An increase occurred in atrial (138±8 vs 184± 20 ms; P<0.001) and ventricular (160±15 vs 187±25 ms; P=0.03) refractoriness at a cycle length of 300 ms. Atrial arrhythmias were not induced in any dog. Ventricular fibrillation (VF) was induced in 2/8 dogs at baseline and 4/8 dogs after cocaine. CONCLUSION: High doses of cocaine exert significant class I effects and seem to enhance inducibility of VF but not of atrial arrhythmias.
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OBJETIVO: Avaliar estratégia de titulação para prescrever uma dose de propranolol que seria eficiente em reduzir isquemia do miocárdio em idosos. MÉTODOS: Foram estudados 14 homens idosos (73,6 ± 5,3 anos), portadores de doença coronariana estável, documentada pela cinecoronariografia, com resposta isquêmica ao teste ergométrico e função ventricular esquerda preservada. O propranolol foi titulado a fim de atingir redução de 15% na freqüência cardíaca, ao final da carga de 50 W (correspondente às atividades diárias normais de idosos), em testes ergométricos semanais e feito estudo cintilográfico sincronizado das câmaras cardíacas, em repouso e durante exercício, antes e após seu uso. RESULTADOS: As reduções da freqüência cardíaca na carga de 50 W e em repouso foram semelhantes (21% vs 20%; p=0,5100). O propranolol melhorou a duração do exercício (12,2 ± 2,0 min vs 13,1 ± 1,8 min; p=0,0313) e aboliu as alterações do segmento ST induzidas pelo exercício em 8 (57%) pacientes. Em repouso, a fração de ejeção não foi modificada pelo betabloqueador. Durante o exercício máximo, o propranolol reduziu o índice de volume sistólico final e aumentou a fração de ejeção. CONCLUSÃO: A estratégia de empregar betabloqueadores para reduzir a freqüência cardíaca em 15% na carga de 50 W é segura e benéfica nos idosos com isquemia miocárdica e função ventricular preservada. A dose utilizada reduziu a isquemia miocárdica e melhorou a tolerância ao exercício, sem prejudicar o desempenho ventricular durante exercício máximo.
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The relationship between estimated and real motor competences was analyzed for several tasks. Participants were 303 children (160 boys and 143 girls), which had between 6 and 10 years of age (M=8.63, SD=1.16). None of the children presented developmental difficulties or learning disabilities, and all attended age-appropriate classes. Children were divided into three groups according to their age: group 1 (N= 102; age range: 6.48-8.01 years); group 2 (N= 101; age range: 8.02-9.22 years); and group 3 (N=100; age range: 9.24-10.93 years). Children were asked to predict their maximum distance for a locomotor, a manipulative, and a balance task, prior to performing those tasks. Children’s estimations were compared with their real performance to determine their accuracy. Children had, in general, a tendency to overestimate their performance (standing long jump: 56.11%, kicking: 63.37%, throwing: 73.60%, and Walking Backwards (WB) on a balance beam: 45.21%), and older children tended to be more accurate, except for the manipulative tasks. Furthermore, the relationship between estimation and real performance in children with different levels of motor coordination (Köperkoordinationstest für Kinder, KTK) was analyzed. The 75 children with the highest score comprised the Highest Motor Coordination (HMC) group, and the 78 children with the lowest score were placed in the Lowest Motor Coordination (LMC) group. There was a tendency for LMC and HMC children to overestimate their skills at all tasks, except for the HMC group at the WB task. Children with the HMC level tended to be more accurate when predicting their motor performance; however, differences in absolute percent error were only significant for the throwing and WB tasks. In conclusion, children display a tendency to overestimate their performance independently of their motor coordination level and task. This fact may be determinant to the development of their motor competences, since they are more likely to engage and persist in motor tasks, but it might also increase the occurrence of unintended injuries.
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OBJETIVOS: Avaliar se a administração de amiodarona, em doses altas e curso rápido, reduz a incidência de fibrilação ou flutter atrial, após cirurgia de revascularização miocárdica e se reduz, também, o tempo de internação hospitalar. MÉTODOS: A amostra se constituiu de 93 pacientes randomizados, em estudo duplo-cego, para receberem amiodarona (46 pacientes) ou placebo (47 pacientes). A terapia consistia na aplicação de 600mg de amiodarona, três vezes ao dia, iniciada no mínimo 30 horas e no máximo 56 horas antes da cirurgia. RESULTADOS: Fibrilação ou flutter atrial no pós-operatório ocorreu em 8 dos 46 pacientes no grupo amiodarona (17,4%) e em 19 dos 47 pacientes no grupo placebo (40,4%) (p=0,027). A dose média de amiodarona foi de 2,8g. Os pacientes do grupo amiodarona ficaram hospitalizados por 8,9±3,1 dias, enquanto a internação dos pacientes do grupo placebo foi de 11,4± 8,7 dias (p=0,07). O tempo de internação foi significativamente prolongado nos pacientes que desenvolveram fibrilação ou flutter atrial após a cirurgia, independente do grupo randomizado. CONCLUSÃO: Esta nova alternativa de administração de amiodarona em alta dose e por um curto período, antes da cirurgia de revascularização miocárdica, reduz a incidência de fibrilação ou flutter atrial no pós-operatório desta cirurgia.