Biomedical subjects
Publications and source records attributed to A Cruz.
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PURPOSE: To evaluate the cardiac involvement in Human Immunodeficiency Virus (HIV) infection. DESIGN: Prospective and normal individuals group controlled study. SETTING: The departments of cardiology and infectious diseases of an university hospital. PATIENTS: 137 consecutive HIV infected patients at all stages of the infection and 40 normal noninfected controls. MEASUREMENTS AND MAIN RESULTS: Clinical and echocardiographic evaluation was performed. Cardiac symptoms were observed in 10 (7.3%) patients, manifested as congestive heart failure. The global HIV infected population had increased left ventricular (LV) dimensions and wall thickness and decreased LV fractional shortening and ejection fraction when compared with the control population. Seven (5.1%) patients had dilated cardiomyopathy, 9 (6.5%) had global LV hypokinesis with or without LV dilatation and 17 (12.4%) had segmental LV wall motion abnormalities. Right ventricular dilatation was present in 23 (16.8%). Mitral or tricuspid regurgitation of a moderate or severe degree was found in 3 (2.2%) patients. No valvular vegetations were found. Fifty nine (43.1%) patients presented a pericardial effusion. An echocardiogram with at least one abnormality was observed in 104 (75.9%) and a severely abnormal echocardiogram in 34 (24.8%). The presence of cardiac symptoms and of abnormal and severely abnormal echocardiograms was more frequent in patients with the acquired immunodeficiency syndrome than in asymptomatic HIV infected patients. When comparing HIV-1 with HIV-2 populations the first showed increased LV systolic and diastolic diameters and LV mass index. There was no statistically significant difference between all risk behavior groups regarding the frequency of cardiac symptoms or the echocardiographic abnormalities found. HIV infected patients with CD4+ lymphocytes counts < or = 100/mm3 had more frequent abnormal and severely abnormal echocardiograms than those with CD4+ lymphocytes counts > 100/mm3. CONCLUSIONS: Although cardiac symptoms were rare in our population, subclinical cardiac involvement detected by echocardiography was frequent and could involve any cardiac layer. It was not influenced by the patients' risk behavior. The left ventricular trophic response observed in HIV-2 infection seemed less intense than that in HIV-1 infection. Cardiac involvement was more frequent in the more advanced stages of the infection and in patients with lower CD4+ lymphocyte counts.
The aim of this study is to compare the performance of Transesophageal Echocardiography (TEE) and the Transthoracic approach (TTE) in the diagnosis of Infectious Endocarditis (IE). Between October/90, the data we started transesophageal ultrasound, till April/92, we performed 33 TTE in inpatients with clinical suspicion of IE. Twenty pts (61%) had one or two prosthesis. All the pts had a previous TTE. The diagnosis of IE determined by non-echocardiographic data was established on 18 pts. The other 15 pts, without clinical criteria of IE, were used as the control group. The Echocardiographic criteria for the diagnosis of IE were for both diagnostic tools the presence of masses suggesting vegetation of abscess. The diagnosis was correctly made by TTE in 8 of the 18 pts (S-44%) and by TEE in 16 of the 18 pts (S-89%) with clinical criteria for IE. Of the 15 patients without clinical criteria for IE 14 were correctly identified by TTE (Sp-93%) and 13 by TEE (Sp-89%). With a similar VPP (89%) for both tools has TEE a significative higher value for NPV than TTE (87% vs 58%). This study suggests that TEE, at a same level of specificity as TTE, is highly more sensitive in the diagnosis of IE (S-89 14 for TEE and S-44 23 for TTE) a figure that recommends that all patients with clinical suspicion of IE and a negative TTE should perform a TEE.
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The solubility of hydrophobic pulmonary surfactant proteins in different organic solvents and organic solvent/water combinations has been analyzed. Three organic solvents have been selected: methanol (MetOH), acetonitrile (ACN) and trifluoroethanol (TFE). Porcine SP-B showed very similar calculated secondary structure when dissolved in methanol, 60% ACN or 70% TFE and reconstituted in lysophosphatidylcholine (LPC) micelles or dipalmitoylphosphatidylcholine (DPPC) vesicles, as deduced from circular dichroism studies. SP-B was calculated to possess around 45% of alpha-helix in all these systems. The fluorescence emission spectrum of SP-B has been also characterized in aqueous solvents and lipids. It always showed a splitting of the tryptophan contribution into two components with different emission maxima. SP-C had a very different structure in 80% ACN or 70% TFE. While alpha-helix was the main secondary structure of SP-C in ACN/water mixtures--around 50%--, it had almost exclusively beta-structure when dissolved in 70% TFE. The CD spectrum of SP-C in TFE showed dependence on the protein concentration, suggesting that protein-protein interactions could be important in this beta-conformation. SP-C reconstituted in LPC micelles or DPPC vesicles had a CD spectrum qualitatively similar to that one in aqueous ACN, with a dominant alpha-helical structure. The alpha-helical content of SP-C in micelles of LPC and vesicles of DPPC, 60 and 70%, respectively, was calculated to be higher than the alpha-helical content of the protein dissolved in any aqueous organic solvent.
Serum lipoprotein(a) [Lp(a)], blood lipids, serum insulin and anthropometric parameters were determined in randomized samples of 38-year-old men living in six European cities: Ede (The Netherlands), Deinze (Belgium), Warsaw (Poland), Lumiar (Portugal), Verona and Naples (respectively in northern and in southern Italy). In total, 406 healthy men were studied. Serum Lp(a), blood lipids and serum insulin were measured in one laboratory. All the anthropometric and metabolic variables considered were statistically different among the participating sites, with the exception of Lp(a) serum levels. In spite of the lack of overall significant inter-center differences (Kruskal-Wallis test), the subjects from the two Italian cities had significantly lower Lp(a) serum levels than the subjects from Belgium and Portugal (Mann-Whitney U test, p < 0.01). In all cities the distribution of serum Lp(a) levels were highly skewed; the percentage of subjects with serum Lp(a) levels higher than 30 mg/dl (i.e., the commonly accepted risk level of cardiovascular disease) was 6% in both Verona and Naples (Italy), 12% in The Netherlands, 16% in Poland, 18% in Belgium and 19% in Portugal (for the last two cities, respectively, p < 0.02 and p < 0.01 vs Italian cities, chi-square test). Neither anthropometric (body mass index, waist/hip circumference ratio) nor metabolic (serum lipids and insulin) parameters showed any significant relationship with serum Lp(a) levels in any of the sites (Spearman's rank correlation). These data support the possibility of a difference in serum Lp(a) levels among different European countries.
A reverse-phase HPLC method for the determination of colchicine in biological fluids is proposed. Blood, liver and kidney colchicine concentrations were determined in rats at different times following intraperitoneal (i.p.) injection of 10 mg/kg of the drug. Colchicine was extracted from the samples studied using dichloromethane at pH 8. The dry extract was redissolved in the mobile phase and analyzed with simultaneous detection at 254 and 350 nm.
There is limited information on the accuracy of bioelectrical impedance analysis (BIA) for estimating body composition in children. The purpose of this study was to evaluate BIA measurements for estimating fat mass and fat-free mass in 94 Chinese boys and girls aged 11-17 years. Percent fat (%fatskf) and fat-free mass (FFMskf) were predicted by regression of skinfolds in an equation which is founded on a multicomponent model of body composition in children. Multiple-regression analyses were applied to the data to determine if height2 divided by resistance (resistance index) (RI) could accurately predict FFMskf and %fat. Correlations (R) and predictive accuracy (standard error of the estimate, S.E.E.) for FFMskf for RI alone were 0.94 and 2.7 kg; for RI and body mass this improved to 0.96 and 2.2 kg, and for estimation of %fatskf from RI and body mass these values were 0.78 and 4.7%, respectively. A previously published prediction equation, developed on Caucasian children and which also used RI and body mass, was also cross-validated with the Chinese sample in this study. There was no difference between the predicted values from this equation and FFM and %fat predicted by the skinfold technique. The correlation coefficient for FFM was 0.96 and the S.E.E. was similar to that originally reported for the Caucasian sample. We conclude that BIA is a reliable and acceptably accurate method of estimating anthropometrically determined body composition in Chinese youth.
Due to the short period of the time elapsed since its existence has been described, and the difficulty for its diagnosis, contagiousness of hepatitis C virus in hemodialysis, together with the need of specific measures to avoid its transmission in units where this therapy is performed--similar to the ones adopted with hepatitis B--are still under discussion. A group of thirty patients, dialyzed in the same unit and by the same staff personnel has been studied. All staff members and 29 of the patients were anti-HCV negative. Only one patient was anti-HCV positive, showing at the same time a persistent raise of transaminases and having received previously 12 blood transfusions. On a monthly basis serology for HCV, transaminases GT and alkaline phosphatase were evaluated. Follow-up period has oscillated between 6 and 22 months, mean 14.07 +/- 6.23 months. 53.3% of patients were over a year follow-up, and 43% were over 6 months. A patient died, two were transplanted and a fourth one was lost to follow-up after more than one year. All the transfusions performed in this period (done to six patients) have been checked negative for antibodies anti-HCV. Only an episode of raise in transaminases has been detected during this study, with no serological-conversion to any of the studied virus and with a probable drug-related origin. All negative anti-HCV patients have stayed in the same status. We concluded that HCV shows low contagiousness in hemodialysis. Regular cleaning measures within the Unit seems to be enough to prevent the disease.(ABSTRACT TRUNCATED AT 250 WORDS)
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It has been proposed that subcutaneous fat patterning assessed by skinfolds is measuring different aspects of fat distribution compared to circumferences and circumference ratios. In this study in 510 men born in 1950 selected from six European towns we compared the associations between five skinfolds, eight circumferences and several skinfold and circumference ratios and metabolic risk factors after adjustment for body mass index (BMI). All skinfolds were independently of BMI positively related to diastolic blood pressure. Waist circumferences at most levels were independently of BMI positively related to blood pressure and triglycerides and negatively to HDL-cholesterol. Circumferences at the levels of chest, hips, thigh and arm were not related to any of the risk factors studied. Waist/thigh ratios were generally more strongly and more consistently related to risk factors than waist/hip ratios. The partial correlations of anthropometric variables with risk factors were relatively weak and never exceeded r = 0.20. The results give an indication, however, that subcutaneous fat patterning is related to different risk factors compared to waist/hip ratios. Moreover, waist/thigh and waist circumference alone (measured either as the minimal circumference or midway between the lower rib margin and the iliac crest) were stronger correlates of cardiovascular risk factors compared to waist/hip ratio.
We have used double gene targeting to create homozygous gene replacements in the protozoan parasite Leishmania major, an asexual diploid. This method uses two independent selectable markers in successive rounds of gene targeting to replace both alleles of an endogenous gene. We developed an improved hygromycin B-resistance cassette encoding hygromycin phosphotransferase (HYG) for use as a selectable marker for Leishmania. HYG-containing vectors functioned equivalently to those containing the neomycin phosphotransferase (NEO) cassette previously used for extrachromosomal transformation or gene targeting. Drug resistances conferred by the NEO and HYG markers were independent, allowing simultaneous selection for both markers. A HYG targeting vector was utilized to replace the single dihydrofolate reductase-thymidylate synthase (DHFR-TS) gene remaining in a line heterozygous for a NEO replacement at the dhfr-ts locus (+/neo), with a targeting efficiency comparable to that seen with wild-type recipients. The resultant dhfr-ts- line (hyg/neo) was auxotrophic for thymidine. The double targeted replacement method will enable functional genetic testing in a variety of asexual diploids, including cultured mammalian cells and fungi such as Candida albicans. Additionally, it may be possible to use Leishmania bearing conditionally auxotrophic gene replacements as safe, improved live vaccines for leishmaniasis.
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The authors studied 512 European men all born in 1950 from six different towns in the period October 1988 to May 1989. Anthropometric measurements were taken, including weight, height, and circumferences (waist, hip, thigh). Educational level, activity scores and information on smoking habits were obtained from a questionnaire. Higher educational level was associated with lower body mass index, waist/hip ratio, and waist/thigh ratio. The sports activity score was negatively related to waist/hip ratio (beta +/- standard error of the mean (SEM): -0.009 +/- 0.003) and waist/thigh ratio (-0.041 +/- 0.007), and this could be attributed to a negative relation with waist circumference and a positive relation to thigh circumference. Smoking habits were not related to body mass index but heavy smokers had larger waist circumferences (difference +/- SEM: 1.4 +/- 0.5 cm) as well as higher waist/hip ratios (difference +/- SEM: 0.014 +/- 0.005) and waist/thigh ratios (0.043 +/- 0.013) compared with men who never smoked. These associations between activity scores and smoking habits and fat distribution remained after adjustment for each other and for body mass index and educational level. The authors conclude that physical activity and smoking are independently related to indicators of fat distribution and may be potential confounders in the relations between fat distribution, risk factors, and disease.
During surveillance for endemic visceral leishmaniasis on an island off the Pacific coast of Honduras, an unusual form of cutaneous leishmaniasis was encountered. By clinical and laboratory criteria, 17 cases were identified over 5 months; children aged 4 to 15 years were primarily affected. Lesions were generally few in number, small, always papular, and non-ulcerative, even when present for several years. Patients with skin lesions seemed otherwise healthy and were well nourished. Montenegro skin tests with Leishmania mexicana and L major antigens were positive in 10 of 17 patients tested, and lesions from 9 patients were positive by culture. Since the summer of 1988, cases of atypical cutaneous leishmaniasis continue to occur on the island (8) as well as on the mainland of southern Honduras (23). A total of 9 parasite isolates from skin lesions, 4 from bone marrow of patients with kala-azar, and 2 from sandflies were identified as L donovani chagasi and were indistinguishable from one another by isoenzyme analysis.
A study on 512 38-year-old European men selected from 6 different towns was conducted. There were significant differences between the centers in averages of anthropometric variables (except for thigh circumference), serum lipids (except for LDL-cholesterol), and blood pressure. In the pooled material, body mass index (BMI) as well as waist circumference, waist/hip ratio and waist/thigh ratio and subscapular skinfold were positively correlated to serum triglycerides, total cholesterol, LDL-cholesterol, and blood pressure and negatively with HDL-cholesterol. After adjustment for BMI, waist, waist/hip, and waist/thigh were all still significantly correlated with serum triglycerides (P less than 0.001). In addition, waist/hip and waist/thigh ratio showed significant partial correlations with total cholesterol (r = 0.16, P less than 0.001, r = 0.10, P less than 0.05 respectively), and diastolic blood pressure (r = 0.10, P less than 0.05, r = 0.09, P less than 0.05 respectively). In addition, waist/hip was, independently of BMI, correlated to LDL-cholesterol (r = 0.12, P less than 0.01), and waist/thigh ratio with HDL-cholesterol (r = -0.12, P less than 0.01). The partial association between waist/thigh with HDL cholesterol became insignificant after adjustment for smoking habits and physical activity. Adjustment for differences in anthropometric measurements did not explain the differences in serum lipids and blood pressure between the centers. The authors conclude that indicators of body fat distribution are associated with unfavorable risk profiles for cardiovascular disease in European men covering a large geographical and cultural variety and a wide range of body measurements and cardiovascular risk factors.