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Biomedical subjects

M Pereira

Publications and source records attributed to M Pereira.

At least 19 recordsLinked to original sources
PubMed1995

Characterization of Paracoccidioides brasiliensis isolates by random amplified polymorphic DNA analysis.

We initially used 25 different random primers in order to test their ability to generate random amplified polymorphic DNA fragments from the dimorphic human pathogenic fungus Paracoccidioides brasiliensis. From the tested primers we chose five to distinguish between seven isolates of this microorganism. The DNA amplification patterns allowed clear differentiation of the seven isolates into two distinct groups with only 35% genomic identity. One of these groups contained two subgroups with 81% genetic similarity. The random amplified polymorphic DNA analysis method proved to be a good tool for analyzing and comparing different genomes of P. brasiliensis isolates.

Base Sequence↗
PubMed1995

[Effectiveness of ciprofibrate. Open study in a Portuguese population].

STUDY OBJECTIVE: To determine the efficacy of ciprofibrate in portuguese patients with hypercholesterolaemia, hypertriglyceridaemia and mixed hyperlipidaemia. DESIGN: Open-label study with 6-month therapy. SETTING: Out-patient clinics of two Central Hospitals. PARTICIPANTS: Sequential sample of 40 patients 20 from each hospital. 37 patients (92.5%) completed the study; 14 had dyslipidaemia type IIa, 12 type IIb and 11 type IV. METHODS: After at least one month of diet or washout period, all participants were given 100 mg/day of ciprofibrate, taken after the evening meal. Analysis and clinical examinations were performed at weeks (-4), (0), (+8), (+16) and (+24). Total (TC) and HDL (HDL-C) cholesterol, triglycerides (TG), apoproteins A-I, B100, and (a), and fibrinogen were determined. LDL-cholesterol (LDL-C) was calculated by means of the Friedewald formula, whenever TG < or = 400 mg/dl. MAIN RESULTS: With ciprofibrate, in the whole population, TC, TG, LDL-C, apoB100, and TC/HDL-C ratio diminished, respectively 16.6%, 46.2%, 20.7%, 12.6% and 24.6%. HDL-C and apoA-I increased 10.4% and 4.2%. LDL-C was reduced by 29.5% (p = 0.0001) in type IIa patients, and increased 23% (not statistically significant) in type IV patients. The reduction of TG attained 57.4% in type IIb patients. One type IIb patient received 200 mg/day of the drug from week (+16) on. BMI, waist/hip ratio, hypertension, alcohol consumption and sex didn't affect ciprofibrate activity. CONCLUSIONS: These results confirm the high efficacy of ciprofibrate in patients with hypercholesterolaemia, hypertriglyceridaemia and mixed hyperlipidaemia. In type IIa dyslipidaemia, the reduction of LDL-C was roughly equivalent to that of the less potent statins. In type IV dyslipidaemia LDL-C may increase moderately. The influence on apoprotein (a) and fibrinogen was positive but modest.

Adolescent↗
PubMed1995

[Safety of ciprofibrate. Open study in a Portuguese population].

STUDY OBJECTIVE: To determine the safety of ciprofibrate in portuguese patients with dyslipidaemia. DESIGN: Open-label study with 6-month therapy. PARTICIPANTS: Sequential sample of 40 patients, 20 from each hospital, 37 patients (92.5%) completed the study. METHODS: After at least one month of diet or washout period, all participants were given 100 mg/day of ciprofibrate, taken after the evening meal. Analysis and clinical examinations were performed at weeks (-4), (0), (+8), (+16) and (+24). Glycemia, uric acid, creatine kinase, creatinine and transaminases were determined. MAIN RESULTS: Thirty-seven patients ended the study (92.5%), three abandoned because of gastrointestinal adverse effects, six other patients also complaint of gastrointestinal side effects. The creatinine and creatine kinase levels increased 9.7% and 19.2%, although kept in the normal range. There were no statistically significant changes in glycemia, uric acid and transaminases levels. CONCLUSIONS: These results confirm the high safety of ciprofibrate in patients with dislipidaemia. The short term of this study does not allows taking conclusions about long term use of this drug.

Adolescent↗
PubMed1994

[Representational analysis: a means to evaluate teacher training in health education].

Research and evaluation of social representations as determinants of behaviour are fundamental components for health education and promotion programmes. The research presented in this article was funded as part of the "Europe against Cancer" programme, and follows the evolution over a five year period, of representations and behaviours of 1500 children from cities in France, Belgium, Spain, Greece, and Portugal. In each city, three different groups were followed and evaluated: Children in the first groups participated in a year-long tobacco prevention programme conducted by specially trained teachers; those in the second groups only participated in sporadic activities designed around World Tobacco Day; those in the third group did not participate in any particular tobacco prevention activities. The evaluation concentrated on analysing the changes in participants' social representations regarding tobacco and smoking related behaviour throughout the five year period. A variety of comparative analysis techniques were used to prepare, evaluate, and modify the content of the teacher training programmes in order to succeed in fulfilling one of the primary objectives of the programme--that of assisting teachers to develop educational attitudes for tobacco prevention in primary schools. The authors esteem that the type of training offered to the teachers had a marked influence on the length and type of programmes they offered to their students.

Child↗
PubMed1994

[Homocysteinemia as a risk factor in early cerebrovascular disease].

PURPOSE: To determine whether hyperhomocysteinemia represents a risk factor of early thrombotic cerebrovascular disease. METHOD: In a group of patients under 55 years of age (n = 33, 19 males) which had suffered a stroke from 3 months to 1 year before the study, defined by clinical criteria and presence of cerebral infarction confirmed by tomography, without history or predisposition to embolic disease. The patients were matched with a group of normal controls of checkup program, in terms of age, and sex. Patients and controls with a history of alcoholism, clinical or laboratory signs of renal or hepatic insufficiency or with a history of recent ingestion of Group B vitamins were excluded since these conditions would influence homocysteinemia levels. We measured the plasmatic basal homocysteinemia of patients and controls (HC) and 6 hours later a methionine overload of 0.1 g/Kg body weight (LOAD HC). RESULTS: Patients; Controls; Signific.; Age 46.0 +/- 7.7; 45.9 +/- 7.8; NS; Basal HC. 10.1 +/- 3.4; 8.5 +/- 1.7; p < 0.05; Load HC 28.0 +/- 7.6; 22.7 +/- 5.5; p < 0.01. CONCLUSION: In this study hyperhomocysteinemia appears as a risk factor for thrombotic cerebrovascular disease before the age of 55;-The measurement of homocysteinemia after the methionine loading test was more discriminative than the basal measurement;-A larger number of patients and controls will be necessary to establish the relative importance of homocysteinemia among other vascular risk factors in cerebrovascular disease.

Adult↗
PubMed1992

Acanthamoebae bind to glycolipids of rabbit corneal epithelium.

By use of a thin-layer chromatogram (TLC) overlay procedure, 35S-labeled acanthamoebae were shown to bind to seven glycolipids of rabbit corneal epithelium. Corneal epithelial cells were grown in culture and were subjected to Folch extraction to isolate a chloroform-rich lower phase containing neutral glycosphingolipids (NGSL) and an aqueous upper phase containing gangliosides, i.e., sialic acid-containing glycolipids. Thin-layer chromatography of the upper phase revealed the presence of 10 ganglioside components. Acanthamoebae were shown to bind to four of these components, referred to as 2, 3, 6, and 7. On TLC plates, ganglioside components 2 and 3 migrated slightly ahead of the glycolipid standard GD1a, component 7 comigrated with standard GM3, and component 6 migrated a little more slowly than GM3. Likewise, of the 10 NGSL known to be present in the lower phase, acanthamoebae bound to components 1, 5, and 6. NGSL components 1, 5, and 6 migrated on TLC plates with relative mobilities similar to those of standards asialo GM1, asialo GM2, and ceramidetrihexoside, respectively. We propose that one or more of the Acanthamoeba-reactive glycolipids of corneal epithelium identified in this study may play a role in the pathogenesis of Acanthamoeba keratitis by mediating the adherence of the parasites to the cornea.

Acanthamoeba↗
PubMed1992

Factors influencing medical interns trained at U.W.I. to work subsequently in a rural area in Jamaica.

Recognising the present paucity of doctors trained at the University of the West Indies who are working in rural government health facilities in Jamaica, and its impact on the health services, this study was done to determine the factors influencing the decision of UWI-trained interns to work in these facilities post-internship. A questionnaire was administered to 57 UWI-trained medical graduates presently doing their internship in Jamaica. The results showed that there was no significant difference in the choice of placement with respect to sex, or residential background of the intern, though the latter seemed to indicate a trend. Of those who thought they would work in a rural government health facility, two-thirds would do so immediately post-internship but 50% did not plan to work there for more than five years. Opportunities for postgraduate training and lack of equipment were the most important deterrents to working in a rural government health facility.

Choice Behavior↗
PubMed1992

[Echocardiographic assessment of interventricular septal defect corrected during the first year of life].

OBJECTIVE: To evaluate the medium term results of surgical closure of ventricular septal defect (VSD) performed during the first year of life, using echocardiography (echo). MATERIAL AND METHODS: We studied prospectively 29 patients aged from 17 to 68 months (mean = 37) who underwent surgical closure of perimembranous VSD during the first year of life. The postoperative follow-up time ranged from 6 to 60 months (mean = 26). Fifteen age-matched normal children were used as a control group in evaluating the left ventricular (LV) systolic function. The echo study included: 1) the assessment of LV systolic function using the shortening fraction, ejection fraction, pre-ejection to ejection time ratio (PET/ET), aortic flow acceleration time, acceleration to ejection time ratio, mean aortic flow acceleration; 2) detection and quantification of residual VSD as well as tricuspid and or aortic regurgitation; 3) determination of right ventricular systolic pressure (RVSP). The RVSP was evaluated from the maximum flow velocity from a residual VSD or tricuspid regurgitation, using the simplified Bernoulli equation. RESULTS: The LV systolic function parameters from patients versus (vs) normals showed a significantly different shortening fraction (34 +/- 5 vs 39 +/- 4; p = 0.005) and PET/ET ratio (0.34 +/- 0.04 vs 0.31 +/- 0.03; p = 0.02). None of the other studied parameters was significantly different from normal. Five (17%) patients had a small residual VSD. Two (7%) patients had mild aortic regurgitation. Tricuspid regurgitation was detected in 23 (79%) patients being trivial in 20 and mild to moderate in 3. The RVSP was quantified in 22 (76%) patients, ranging from 30 to 45 mmHg (mean +/- SD = 36 +/- 4). None of the remaining 7 patients showed changes in the end-systolic interventricular septal configuration. CONCLUSIONS: Our study shows that surgical closure of perimembranous VSD performed during the first year of life was possible without significant mobility. Furthermore, the echo allowed a complete and noninvasive cardiac evaluation of the anatomic, functional and hemodynamic status of this group of patients, thus limiting the need for postoperative control cardiac catheterization.

Echocardiography↗
PubMed1991

The prevalence of Toxocara canis ova in soil samples from parks and gardens in the London area.

Toxocara canis is an ascarid parasite of the dog. Human infection is acquired when ova of T. canis are ingested. Parks and play areas contaminated with dog faeces are recognised as potential sources of infection. Five hundred and twenty one soil samples were examined from fifteen parks and gardens in the greater London area to establish the prevalence of soil contamination in those facilities. Samples were examined using a magnesium sulphate floatation method. T. canis ova were found in 6.3% of the samples. Positive samples were commonly found in lawns, playing fields and children's play areas. The authors believe that this may constitute a significant health risk, particularly to children.

Animals↗
PubMed1990

Cardiac arrhythmias in critically ill patients: epidemiologic study.

The general prevalence of cardiac arrhythmias in 2,820 consecutive patients was 78%, ranging from 44% in multiple trauma patients to 90% in primary cardiovascular patients. Patients without recorded arrhythmias (22%, n = 621) were used as control subjects. No clinical group was free from cardiac arrhythmias. Atrial tachyarrhythmias had the highest prevalence in the population as a whole (28%) and in all clinical groups except multiple trauma. Atrial fibrillation was the most common atrial arrhythmia (52%); ventricular arrhythmias followed. Patients with atrial tachyarrhythmias, nodal rhythm ventricular bradyarrhythmias, and ventricular rapid rhythms had significantly (p less than .01) increased mortality rates (40%, 44%, 77%, and 51%, respectively) when compared with patients without arrhythmias (35%). The relative risk of dying (RRD) of these clinical groups was increased by 1.16, 1.27, 2.20, and 1.47, respectively. Patients with cardiorespiratory precipitating disease and any arrhythmia except atrial bradyarrhythmia had a mortality rate between 32% and 74%, significantly (p less than .05) different from that of patients within the same clinical groups without arrhythmias. The RRD was increased by 1.67 to 3.40. Septic patients with atrial tachyarrhythmia or nodal rhythm and neurologic patients with nodal or ventricular arrhythmias also had significantly (p less than .01 and .05, respectively) increased mortality and were at higher RRD (1.53 to 2.81). Our data suggest that severe illness may be present in some clinical groups of critically ill patients with cardiac arrhythmias.

Adult↗
PubMed1990

Serodiagnosis of leprosy in patients' contacts by enzyme-linked immunosorbent assay.

Serum samples from 3336 contacts of leprosy patients were tested for antiphenolic glycolipid I antibodies by enzyme-linked immunosorbent assay with the albumin coupled synthetic disaccharide antigen. The overall positivity rate was 9.3%. No significant differences were seen between a group of household contacts of lepromatous patients and those of the other types of the disease. The proportion of ELISA positives was slightly higher in the relatives as compared to workplace contacts and neighbours but significantly different only between the two former (p less than 0.05). Among those contacts with absorbance values higher than 0.100, 5 new leprosy patients were diagnosed, 2 of them with positive skin smears. A sixth contact was detected with a very high absorbance value in whom no single skin lesion was found but whose lepromin reaction was 0 mm and the skin smear showed a bacteriological index of 3+.

Antibodies, Bacterial↗
PubMed1989

[Internal urethrotomy under direct vision. Review of 183 operations].

The authors report on their experience with the Sachse urethrotomy procedure performed in 125 patients from 1981-1987, with a minimum follow-up of 12 months and a maximum of 6 years. The etiology was iatrogenic in 46%, trauma in 25%, and inflammatory in 33%. Stricture was frequently localized in the bulbous urethra (63%). Local anesthesia was the most widely used particularly during the latter stage of this period. The authors prefer to use Sylastic-type catheters left indwelling for a short period of time. Their recurrence rate was 15%. Although most of the patients (67%) required one procedure, urethrotomy had to be repeated up to three times (3%) in several patients. Good results were achieved in 57%, fair in 32%, and poor in 11%.

Follow-Up Studies↗
PubMed1988

"Subversive" substrates for the enzyme trypanothione disulfide reductase: alternative approach to chemotherapy of Chagas disease.

The trypanosomatid flavoprotein disulfide reductase, trypanothione reductase, is shown to catalyze one-electron reduction of suitably substituted naphthoquinone and nitrofuran derivatives. A number of such compounds have been chemically synthesized, and a structure-activity relationship has been established; the enzyme is most active with compounds that contain basic functional groups in side-chain residues. The reduced products are readily reoxidized by molecular oxygen and thus undergo classical enzyme-catalyzed redox cycling. In addition to their ability to act as substrates for trypanothione reductase, the compounds are also shown to effectively inhibit enzymatic reduction of the enzyme's physiological substrate, trypanothione disulfide. Under aerobic conditions, trypanothione reductase is not inactivated by these redox-cycling substrates, whereas under anaerobic conditions the nitrofuran compounds cause irreversible inactivation of the enzyme. When tested for biological activity against Trypanosoma cruzi trypomastigotes, many of the test compounds were trypanocidal, and this activity correlated with their relative ability to act as substrates for trypanothione reductase. The activity of the enzyme with these redox-cycling derivatives constitutes a subversion of its normal antioxidant role within the cell. For this reason these compounds may be termed "subversive" substrates for trypanothione reductase.

Aerobiosis↗