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Biomedical subjects

A A Lopes

Publications and source records attributed to A A Lopes.

At least 73 records · Page 4Linked to original sources

Platelet regeneration time: a statistical approach.

The determination of platelet regeneration half-time (PRT t1/2) by measuring malondialdehyde after intake of acetylsalicylic acid is a simple nonisotopic method for the estimation of platelet survival. There is no available information concerning the populational distribution of PRT t1/2. Consequently, there is controversy about the utilization of parametric or nonparametric statistical tests in studies of PRT. In the present study, we demonstrate the closeness of the fit of log PRT t1/2 to the normal (Gaussian) distribution.

Aspirin↗

Correction of pulmonary atresia with ventricular septal defect in the absence of the pulmonary trunk and the central pulmonary arteries (so-called truncus type IV).

A child with pulmonary atresia and ventricular septal defect and no extraparenchymal pulmonary arteries had all the bronchopulmonary arterial segments connected to naturally occurring systemic-pulmonary collaterals. A three-staged surgical correction was performed. At the first and second stages, the arteries of each hilus were interconnected with synthetic arteries. At the third stage, the ventricular septal defect was closed, and continuity between the right ventricle and the bilateral pulmonary circulation was established with a valved conduit giving rise to a side arm. Postoperative evolution was good, with acceptable postrepair per right ventricular--left ventricular pressure ratio.

Collateral Circulation↗

Analysis of barbiturates in blood by high-performance liquid chromatography.

A high-performance liquid chromatographic (HPLC) assay for the identification and quantification of barbiturates in blood at therapeutic levels had been developed. An ODS-silica column is used with an eluent of 40% methanol at pH 8.5. The barbiturates are detected at 240 nm. The sample preparation procedure involves extraction of unfractionated blood (100 microliter) with hexane-diethyl ether (50 : 50, v/v) ang is very rapid. Talbutal is used as an internal standard. The method has been applied to the determination of five barbiturates (amylobarbitone, butobarbitone, cyclobarbitone, pentobarbitone and quinalbarbitone) in blood after therapeutic doses of the drugs. An application of the HPLC assay to forensic casework is demonstrated.

Barbiturates↗

Amoxicillin-clavulanic acid in treatment of urinary tract infection due to gram-negative bacteria resistant to penicillin.

Twenty-two adult patients with urinary tract infections caused by penicillin-resistant bacteria completed treatment with amoxicillin alone or amoxicillin plus clavulanic acid in a randomized double-blind clinical trial. Of the 13 patients treated with amoxicillin plus clavulanic acid, the absence of bacteriuria within 7 days of therapy was observed in 85%, as compared with only 25% of the 8 patients receiving amoxicillin only. There were no significant side effects nor any clinical, biochemical, or hematological abnormalities related to either treatment. It was concluded that the combination of clavulanic acid and amoxicillin could be useful in the treatment of uncomplicated urinary tract infection caused by penicillin-resistant bacteria.

Amoxicillin↗

Massive ocular hemorrhage resulting in blindness in a patient with the sickle cell trait who developed leptospirosis. Case report.

This case report describes the findings of a 18 year-old black male from Bahia, a Northeastern state in Brazil, with the sickle cell trait, who developed bilateral hyphema and vitreous hemorrhage with blindness in the course of leptospirosis. The patient started to complain of blurred vision four days after the start of fever and muscular pain and approximately twelve hours after the introduction of penicillin. The severity of the leptospirosis in conjunction with sickle cell trait was considered to be the most likely explanation for this ocular complication.

Adolescent↗

The association between serum potassium at hospital admission and the case-fatality rate of leptospirosis in men.

Severe leptospirosis affects predominantly males and presents a high susceptibility to hypokalemic acute renal failure. As hypokalemia and hyperkalemia induce severe complications, it is important to evaluate if the initial serum potassium is an independent risk factor for death in leptospirosis. The medical records of 1016 patients hospitalized with the diagnosis of leptospirosis were reviewed. The analysis was restricted to 442, according to the following criteria: male, 18 years or older, information about death or hospital discharge and recorded values of serum potassium, serum creatinine and duration of symptoms at admission. Potassium values lower than 3.5 mEq/L (hypoK), 3.5-5 mEq/L (normoK) and above 5 mEq/L (hyperK) were detected in 180, 245 and 17 patients, respectively. The death rate increased with serum potassium: 11.1% in the hypoK, 14.7% in the normoK and 47.1% in the hyperK group (p = 0.002). In a logistic regression model (normoK as referent), including age, creatinine and duration of symptoms, hypoK was not associated with increased death rate (odds ratio (OR) = 0.80; p > 0.1). On the other hand, hyperK showed a significant association with increased risk of death (OR = 3.95, p = 0.021). In conclusion, in this sample of men with leptospirosis initial serum potassium was positively and independently correlated with the risk of in-hospital death.

Adolescent↗

Facial nerve palsy associated with leptospirosis.

This case report describes the findings of a 27-year-old black male from Bahia, Brazil, who developed facial palsy during the convalescence phase of leptospirosis. The patient recovered without neurological sequel. This work calls attention to a possible association between leptospirosis and facial palsy.

Adult↗

[Severe forms of leptospirosis: clinical, demographic and environmental aspects].

Characteristics of 1,016 patients hospitalized with leptospirosis in the Hospital Couto Maia, Salvador, BA, Brazil, between 1993 and 1997 are described. Higher pluviometric precipitation was related to an increase in the number of hospitalizations during the following month. Males corresponded to 81.1% (824/1,016) of these; mean age was 35.7+/-15.4 years. Almost 94% (778/829) of the 829 patients with information about race were black or mulatto (mixed race). For ages 18 years or above, almost 93% had not completed high school level. The mean incubation period was estimated as 6.3+/-3.9 days. Average duration of symptoms was 6.1+/-2.4 days. Hemorrhagic events corresponded to 14.3% (145/1,016). The case-fatality rate among 1,009 patients that were not transferred was 14.2% (143/1,009). Renal failure was the attributable cause of death in 76.2% (109/143). The data indicate that leptospirosis is closely related to lower socioeconomic levels, and that higher pluviometric precipitation antecedes the outbreaks.

Adult↗

[Increase in the frequency of norfloxacin and ciprofloxacin resistance of bacteria isolated from urine culture].

OBJECTIVE: To assess time trends in the frequency of norfloxacin and ciprofloxacin resistance of bacteria isolated from urine culture. METHODS: Results of all urine cultures with a bacterial growth of at least 10(5) colony-forming units per milliliter, performed at the Renal Service of the Federal University of Bahia, Brazil, from 1983 to 1994 were analyzed. The bacteria considered for this analysis were those most often isolated: Escherichia coli (n = 668), Klebsiella spp. (n = 286), Staphylococcus spp. (n = 186), Proteus spp. (n = 135) and Enterobacter spp. (n = 129). RESULTS: The frequencies of norfloxacin resistance for the periods 1983-1986, 1987-1990 and 1991-1994 were 3.2%, 5.9% and 9.1%, respectively (p-value < 0.05). The most pronounced increases in the frequencies of norfloxacin-resistance were observed for Klebsiella spp. and Enterobacter spp. The frequency of ciprofloxacin resistance was 7.4% in the period 1985-1989 and 16.5% in the period 1990-1994 (p-value < 0.05). This time trend in ciprofloxacin resistance was more striking for Enterobacter spp. and Staphylococcus spp. CONCLUSION: The results show a gradual increase in the frequency of norfloxacin and ciprofloxacin resistance of the bacteria most commonly isolated from urine cultures. The influence of previous treatment with quinolones and characteristics of the infecting bacteria on these findings are important questions to to be addressed in future investigations.

Anti-Infective Agents↗

[Racial differences between patients with focal segmental glomerulosclerosis and membranoproliferative glomerulonephritis from the State of Bahia].

OBJECTIVE: To assess the association between race and type of glomerulonephritis, taking into account age, gender and the presence of hepatosplenic schistosomiasis mansoni. METHODS: Patients from the Renal Service of the Federal University of Bahia, Brazil, 80 with focal segmental glomerulosclerosis (FSG) and 50 with membranoproliferative glomerulonephritis (MPGN) were compared regarding the distribution of the racial types (black, mulatto, white). Patients with systemic lupus erythematosus or any kind of autoimmune disease were not included in the present analysis. Adjusted comparisons were performed using the Mantel-Haenszel method and a multivariate logistic regression model. RESULTS: Race was significantly associated with histologic type; the odds of being classified as black or mulatto were approximately 2.4 times higher (odds ratio = 2.43; IC 95% = 1.09-5.45) in patients with FSG than in those with MPGN. The association between race and histologic type was not influenced by the potential effects of age, gender and hepatosplenic schistosomiasis. In the multivariate logistic regression model, race was significantly associated (p = 0.037) with type of glomerulonephritis (odds ratio = 2.54; IC 95% = 1.06-6.06). CONCLUSION: A higher frequency of negroes and mulattoes in the FSG group (compared with MPGN) in this sample from the State of Bahia is consistent with findings of previous studies from the United States. The data support the possibility of a greater susceptibility to FSG among negroes and mulattoes, independently of age, gender and schistosomiasis. The identification of the mechanisms that determine this racial difference represents an important question for future investigations.

Adolescent↗

[Association between race and incidence of end-stage renal disease secondary to glomerulonephritis: influence of the histologic type and presence of arterial hypertension].

OBJECTIVE: To assess, retrospectively, the association between race and incidence of end-stage renal disease (ESRD) in patients with glomerulonephritis in a University Hospital of Bahia, Brazil. METHODS: The sample was comprised of 79 patients with focal segmental glomerulosclerosis (FSG), 50 with membranoproliferative glomerulonephritis (MPGN) and 49 with other types of glomerulonephritis (OTGN), followed-up between 1970 and 1996 for at least 6 months. It was not included patients with acute glomerulonephritis, minimal change disease, crescentic glomerulonephritis, connective tissue diseases or patients with serum creatinine level greater than or equal to 4.0 mg/dl. The patients were classified according to race as caucasian (white), mulatto or negro. For patients older than 18 yr, not taking antihypertensives drugs, hypertension was defined as a mean of three blood pressure measurements greater than or equal to 140 mmHg for systolic or 90 mmHg for diastolic; for ages </= 18 years. The definition was based on criteria recommended by the Task Force on Blood Pressure in Children. RESULTS: In the normotensive group, the incidence of ESRD was 72% lower in mulattos and negroes (relative risk (RR)=0.28; 95% confidence interval (CI)=0.11-0.67). In the group with hypertension, the direction of association between race and ESRD was opposite to that observed in the normotensive group (RR=1.49; 95% CI= 0.68-4.34). The modification in the RR depending on the presence or the absence of hypertension was statistically significant (p=0.01). In the normotensive group the RR shifted toward the null hypothesis after the inclusion of histologic type in the Cox model. CONCLUSIONS: Among normotensive patients with glomerulonephritis the incidence of ESRD was greater in caucasians (whites) than in negroes or mulattoes. By contrast among hypertensive patients there was a trend for a higher risk of ESRD in negroes. The study suggests that hypertension and the histologic type of glomerulonephritis influence the association between race and ESRD.

Adult↗

[Evidence-based medicine: the art of applying scientific knowledge in clinical practice].

This article was written with the objective of describing the concept of Evidence Based Medicine (EBM) and the competences required for its practice. EBM should be viewed as an integration of clinical experience with the ability to analyze and rationally apply the scientific information while taking care of patients. The application of methods and strategies to enhance the scientific background of the physician while taking into account the humanitarian values of the medical profession should contribute to improve the quality of the medical care that is offered in Brazil. The Medical Schools and Associations may play important roles in the promotion of EBM.

Clinical Competence↗