Biomedical subjects
Publications and source records attributed to M L Vieira.
The first human isolate of Borrelia lusitaniae recovered from a Portuguese patient with suspected Lyme borreliosis is described. This isolate, from a chronic skin lesion, is also the first human isolate of Borrelia in Portugal. Different phenotypic and molecular methods are used to characterize it.
BACKGROUND: Age, diabetes and concomitant cardiovascular disease, recorded at the initiation of dialysis, allows the identification of patients with a high probability of early mortality. When all of these factors are taken into account the mortality rate of dialysis patients is still 3.5 times higher than for the general population. Information on the factors that increase the mortality of patients lacking the major cardiovascular risk factors is important because these are likely to be correctable, especially if detected early. METHODS: We investigated prospectively the relevance of blood pressure and other variables recorded at the initiation of dialysis treatment on the survival of a group of 103 relatively young adult haemodialysis patients (mean age 44.3 years +/-13 SD), with a low prevalence of comorbidity and a median follow-up period of 79 months. Data were analysed by the Cox proportional regression model and survival curves were constructed by the Kaplan-Meier method. RESULTS: Forty-four patients died, 20 (46%) of whom as a result of cardiovascular causes. Multivariate analysis showed that mortality was associated with age (P=0.0001), serum creatinine (P=0.005, negative association), left ventricular (LV) mass (P=0.003) and hypertension (P=0.03). Mortality was increased by 7% for each additional year of age, by 0.7% for each 1 g increase in LV mass, and was reduced by 23% for each additional mg/dl of serum creatinine. Hypertensive patients had a higher probability (x2.2) of dying compared with normotensive patients. CONCLUSIONS: In addition to age and conditions of occult malnutrition, hypertension and LV hypertrophy, when present at the initiation of dialysis, play a major role in the mortality of low risk, relatively young dialysis patients. These potentially correctable factors should be actively sought and treated during the early stage of renal insufficiency to improve prognosis.
PURPOSE: To determine the indication for and incidence and evolution of temporary and permanent pacemaker implantation in cardiac transplant recipients. METHODS: A retrospective review of 114 patients who underwent orthotopic heart transplantation InCor (Heart Institute USP BR) between March 1985 and May 1993. We studied the incidence of and indication for temporary pacing, the relationship between pacing and rejection, the need for permanent pacing and the clinical follow-up. RESULTS: Fourteen of 114 (12%) heart transplant recipients required temporary pacing and 4 of 114 (3.5%) patients required permanent pacing. The indication for temporary pacing was sinus node dysfunction in 11 patients (78.5%) and atrioventricular (AV) block in 3 patients (21.4%). The indication for permanent pacemaker implantation was sinus node dysfunction in 3 patients (75%) and atrioventricular (AV) block in 1 patient (25%). We observed rejection in 3 patients (21.4%) who required temporary pacing and in 2 patients (50%) who required permanent pacing. The previous use of amiodarone was observed in 10 patients (71.4%) with temporary pacing. Seven of the 14 patients (50%) died during follow-up. CONCLUSION: Sinus node dysfunction was the principal indication for temporary and permanent pacemaker implantation in cardiac transplant recipients. The need for pacing was related to worse prognosis after cardiac transplantation.
Granuloma gravidarum is a benign lesion of the oral mucosa which occurs during pregnancy. This case report presents the clinical and histological evaluation and treatment of a granuloma gravidarum in a patient in the 9th month of pregnancy.
Complex arrhythmia is frequent in hemodialysis patients but it is not clear if this is a consequence of dialysis or uremia or is secondary to the hemodynamic and cardiovascular alterations often associated with chronic renal failure. The incidence of complex ventricular arrhythmia (frequent multiform premature beats, couplets, and runs) in 31 subjects who had their uremic status recently corrected by renal transplant (Group 1) and in 23 predialysis (Group 2) and 73 hemodialysis (Group 3) chronic renal failure patients were studied with 24-h Holter monitoring. Patients were not receiving antiarrhythmic drugs or digitalis and significant coronary artery disease was excluded by clinical and noninvasive methods. Complex arrhythmia was two times more frequent in dialysis patients but the difference did not reach statistical significance (Group 1: 16%; Group 2: 17%; Group 3: 34%; chi2 4.9, P = .086). The stepwise model of logistic regression analysis identified systolic blood pressure (odds ratio 1.015, 95% confidence interval [CI] 1.001-1.027, P = .03) and left ventricular systolic dysfunction (odds ratio 7.04, 95% CI 1.3-36.7, P = .02) as the only factors that independently influenced the probability of complex arrhythmia. Age, gender, race, diabetes, smoking status, body mass index, diastolic blood pressure, serum creatinine, hematocrit, left ventricular mass index, and use of diuretics, beta-blockers, angiotensin converting enzyme (ACE) inhibitors, sympatolytics, and calcium channel blockers did not influence the occurrence of complex arrhythmia. The data indicate that blood pressure and myocardial dysfunction are more important determinants of complex arrhythmia than dialysis or uremia in chronic renal disease patients.
In hemodialysis patients, large arteriovenous (AV) fistulas for vascular access may cause ventricular hypertrophy and high-output cardiac failure. The long-term cardiac consequences of functional AV fistulas in renal transplant patients are unclear. A precise knowledge of these consequences is important to decide if and when such fistulas should be closed in successfully transplanted patients. In this retrospective study including 61 stable renal transplant patients with adequate renal function (serum creatinine <2.0 mg/100 ml), echocardiography was performed in 39 patients with a functional AV fistula (group 1) and in 22 whose fistulas had been closed, for esthetic reasons, within 2 months postoperatively (group 2). The volume flow of the fistulas, measured in 22 randomly selected individuals of group 1, was 900 +/- 350 ml/min (range 500-1,600). Patients of group 1 were older (40 +/- 12 vs. 33 +/- 12 years, p < 0.05), had longer duration of the fistula (62 +/- 31 vs. 36 +/- 30 months, p < 0.05), higher body mass index (24 +/- 4 vs. 22 +/- 3 kg/m2, p < 0.05), systolic (154 +/- 24 vs. 138 +/- 18 mm Hg, p < 0.05) and diastolic (96 +/- 12 vs. 89 +/- 11 mm Hg, p < 0.05) blood pressure and increased left ventricular (LV) end-diastolic dimension (53 +/- 5 vs. 49 +/- 5 mm, p < 0.01). LV mass, cardiac index, ejection fraction and the proportion of patients with LV hypertrophy were comparable in the two groups. LV end-diastolic dimension was positively and independently influenced only by the presence of the AV fistula (p < 0.01) after adjusting for age, duration of the fistula, body mass index, systolic and diastolic blood pressure and the nature of the antihypertensive drugs used. In conclusion, the persistence of large, high-flow AV fistulas for prolonged periods of time had little impact on cardiac morphology and function of stable renal transplant patients with adequate renal function. The data do not support routine closure of these fistulas in all renal transplant patients.
BACKGROUND: Heart transplantation is a new therapeutic procedure to treat heart failure resulting from Chagas' disease. Experimental studies have demonstrated neoplastic effects of benznidazole, which is used for treatment of Trypanosoma cruzi infection. We compared the incidence and characteristics of neoplasia after heart transplantation for treatment of chronic Chagas' disease with those of other diseases. METHODS: Sixteen patients with Chagas' disease and 75 patients with other diseases underwent heart transplantation. Benznidazole was administered to 14 patients with Chagas's disease either for prophylaxis (4 patients) or for treatment of Chagas' disease reactivation (10 patients). RESULTS: The survival rate of patients in the nonchagasic group was 90% at 1 year and 82.4% at 2 years, and the survival rate in the chagasic group was 63% at 1 year and 57% at 2 years. Six of 16 patients (37.5%) with Chagas' disease had malignant tumors after a mean follow-up time of 25.3+/-2.1 months in contrast to 2 of 75 patients (2.7%) in the nonchagasic group after 34.6+/-3.6 months of follow-up. In the chagasic group, lymphoproliferative disorder was diagnosed in three patients, Kaposi's sarcoma in two, and squamous cell carcinoma in one patient. Reactivation of T. cruzi infection was diagnosed in all patients who had lymphoproliferative disorder. One patient without Chagas' disease had lymphoproliferative disorder in the lung, and another had malignant schwannoma affecting the skin. CONCLUSIONS: We found a higher incidence of malignant neoplasia after heart transplantation for treatment of chronic Chagas' disease. It is likely that the neoplasia is the result of chronic infection with an immunomodulator protozoan, immunosuppression, reactivation of the T. cruzi infection, or the toxicity of therapeutic intervention with benznidazole.
A case of a young patient, heavy drinker, who suffered an acute myocardial infarction (AMI), and whose cinecoronariography, early post unsuccessful intravenous thrombolysis, showed the presence of thrombi in multiple arteries is reported. A second cinecoronariography performed on the 7th day post AMI revealed normal coronary arteries. There were no plasmatic lipid or coagulation abnormalities, nor other risk factors for coronary artery disease. We speculate about the role of the heavy alcohol ingestion in this particular case.
A 30 years old, male, patient with rare multiple aneurysms of sinus of Valsalva associated to mitral and aortic regurgitation and total occlusion of circumflex artery had the clinical diagnosis made accidentally. The multiple aneurysms were detected by transesophageal echodopplercardiography and hemodynamic study. The diagnosis were confirmed at surgery and the patient underwent correction of the aneurysms through the use of pericardial patches and mitral and aortic valve replacement.
We describe the hemodynamic and neurohormonal data during ventricular assistance device system support as a bridge to heart transplantation of one patient, 30 years old, with heart failure due to Chagas' heart disease in functional class IV. We determined the pressures in mmHg of right atrium (RA), pulmonary artery pressure (PAP), pulmonary wedge pressure (WEDGE), arterial blood pressure (AP), and the cardiac output (CO) in l/min. In addition, the blood levels of norepinephrine (Ne), renin (Re), epinephrine (Ep), lactate and the mixed venous oxygen pressure (pVO2) were determined. The CO increased from 2.14 to 3.9-4.2 l/min, the AD decreased from 26mmHg to 8mmHg, the MPAP reduced from 38mmHg to 14-24mmHg, the WEDGE reduced from 25 to 4mmHg and the AP become normal. The Ne reduced from 1927pg/ml to 983pg/ml, the lactate reduced from 99mg/dl to 22mg/dl and the pVO2 increased from 28mmHg to 43mmHg. The EP remained between 81pg/ml and 129pg/ml, the renin activity remained between 113ng/ml/hr and 136ng/ml/hr. Thus, during the ventricular assistance device system support there was a improvement in hemodynamic and neurohormonal conditions. The patient underwent successful heart transplantation.
HLA association with myasthenia gravis (MG) has been studied in a series of 114 patients using class I and class II genotyping after PCR amplification. Positive association was found with DR3, particularly in women (RR = 2.6) and in early MG onset (RR = 3.4). DRB1, DRB3, DQB1, DQA1 and B (B8 and B18) genotyping revealed that the association was predominantly with the B8 DRB1*03 DRB3*0101 DQB1*0201 DQA1*0501 ancestral haplotype. This haplotype frequency was also increased in patients with thymic hyperplasia (RR = 3.5) and was greatly reduced in patients with thymoma (RR = 0.35). Sixteen out of 48 patients carrying this 8.1 ancestral haplotype showed absence of B8 (n = 4) or of DR3 (n = 12). HLA class II genotyping further revealed the existence of two other significant associations. MG was positively associated with the DQB1*0604 allele (RR = 3.4), particularly in patients with thymoma (RR = 5.7). Furthermore, the disease was negatively associated with DR1 in females (RR = 0.32). These data suggest that MG is placed under the control of at least three distinct genes: (1) a class II predisposing gene in the 8.1 ancestral haplotype; (2) a thymoma-associated class II allele on the DQB1*0604 haplotype; and (3) a protective allele DR1.
Play fighting of homosexual and heterosexual dyads in golden hamsters was studied. The behaviors of male-male (MM), female-female (FF), and female-male (FM) dyads were recorded from the 25th to the 31st day of age. Play fighting activity of heterosexual dyads was depressed since MF and FM dyads exhibited a significantly high physical contact time and engaged in less play fighting, with a significantly lower time spent on such activity. Alternation ratio in the pinning posture was very high and subjects did not differ in the mean number of active (top) and passive pinning (under) in each dyad, showing an inexistence of sex dominance. In most cases, differences in the performances of MM and FF dyads were not significant. We have concluded that play fighting in golden hamsters may be predominantly modulated by environmental stimuli (sex of the partner) rather than by endogenous stimuli (androgen level).
The effects of bilateral optic enucleation on play fighting in golden hamster infants were studied. The behaviors of blind-blind (BB), blind-intact (BI) and intact-intact (II) dyads were recorded from the 30th to the 36th day of age. It has been noted that the differences in physical contact, play fighting and grooming time, as well as in the percentage of time spent in play fighting, the amount of locomotion and other activities of BB, BI and II were small and statistically insignificant. The mean number of active and passive pinning in all groups was equivalent and the alternation of active and passive pinning, or vice versa, was around 50%, showing that posture during play fighting is not an indicator of dominance. It has been concluded that vision is not important for either the initiation or the modulation of play fighting in golden hamsters.
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1. Hemoglobin from terrestrial and an aquatic amphibia Bufo paracnemis and Pipa pipae respectively both living in the same region (Belém, Pará) were compared. 2. The number of hemolysate components were determined by starch-gel electrophoresis and CMC-chromatography. P. pipae hemoglobin presented 4 components and B. paracnemis 2, all of anodic mobility. 3. Functional properties of the hemoglobins (oxygen affinity. Bohr effect, carbon monoxide equilibrium) were determined and compared. 4. The differences found in the functional properties were correlated with the different habitat: aquatic or terrestrial for the amphibia. 5. The study of the oxygen functional properties of the hemoglobin showed in the stripped proteins of P. pipae in the presence of ATP, an oxygen affinity (P50 = 7.24 mmHg) that of B. paracnemis at the same pH (P50 = 15.84 mmHg). At high pH the P50 values are different being 15.84 mmHg for the terrestrial frog and 5 mmHg for P. pipae haemoglobin both at pH 8. In addition Bohr effect was noted only in P. pipae hemolysate in the presence of ATP. 6. The CO-equilibrium affinity constant in the presence of ATP are similar in both frogs, of about, log C50 = -6.9. The ratio Pco/Po2 for B. paracnemis hemoglobin was about 300 whereas for that of P. pipae was about 100 only. 7. The kinetic study of reactive sulfhydryl groups in both frog hemoglobin with 4-PDS (specific SH group reagent was used and shown high pseudo-first order constant for B. paracnemis hemoglobin) (k' = 0.46/min) either in presence or not of ATP, compared for that of P. pipae where values were K' = 0.003/min in the stripped protein and k' = 0.014/min in the presence of ATP. 8. Denaturation kinetic studies of the hemoglobin with sodium benzoate was performed and the results were compared with that of Rana catesbeiana, i.e. the pseudo-first order of the hemoglobin denaturation reaction are low for the aquatic P. pipae adult although for the B. paracnemis high molecular resistant was also noted. For P. pipae hemoglobin, nevertheless with ATP such resistance becomes higher. This does not occur with B. paracnemis hemoglobins.
The authors investigated the relation between parasites and host-cells in active and regressed lesions of a patient with diffuse cutaneous leishmaniasis, evaluating the frequency of different cell types, and the location and integrity of amastigotes. No correlation was found between parasite integrity and size of parasitophorous vacuoles. They observed ultrastructural findings characterizing a cell mediated immune response: macrophages lysis, parasitic destruction inside macrophages, close contact between parasitized macrophages and lymphocytes and between parasites and lymphocytes, lymphocytic infiltration and fibrosis. They suggest that in DCL there is a limited cellular immune response, although insufficient to control infection.
Mutation events are responsible for the generation of genetic variability in the populations enabling the occurrence of natural selection which favors the better-adapted types. The exploitation of this variability, though carried out empirically, dates from ten thousand years ago with the domestication of the first cultivated crops. With the advent of genetics, rational selection procedures were adopted with a view of the genetic breeding of plants, animals and microorganisms which might be of interest to men. Recently, new DNA manipulation techniques came up enabling the transference of genes between organisms, cutting across barriers which hindered crossing between the vegetable, animal, protist and fungus kingdoms. The generation of genetically modified organisms, or transgenics, has aroused a heated and controversial debate in various sectors of our society. Yet we must be cautious before generalizing the use of transgenics since each one should be analyzed at a time for its particular advantages and drawbacks, and for its contribution to the improvement of life quality. This paper also considers recent methods of mutation and in vitro genic recombination.
The authors present a clinical case of a patient with a bronchiolo alveolar lung carcinoma with an unusual form of presentation: secretory pattern with large amounts of bronchial secretion--1000 cc per day--. At the same time, a theoretical approach of lung adenocarcinoma is made, in particular the bronchiolo alveolar carcinoma, in which it concerns clinical, radiological, diagnosis, prognosis and therapeutical aspects.