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M C Martins

Publications and source records attributed to M C Martins.

At least 19 recordsLinked to original sources
PubMed1997

Immunohistochemical expression of S-100 beta in choroidal melanomas.

OBJECTIVE: To investigate the expressivity of S-100 beta antibodies in choroidal melanomas and to compare it with that of S-100 protein and HMB-45. DESIGN: Twenty-seven choroidal melanoma specimens obtained from the McGill University Ophthalmic Pathology Registry were classified as spindle cell, epithelioid cell or mixed-cell type. Immunohistochemistry was performed using the standard peroxidase-antiperoxidase technique with monoclonal HMB-45, polyclonal S-100, polyclonal S-100 beta and monoclonal S-100 alpha beta antibodies in formalin-fixed, paraffin-embedded sections. OUTCOME MEASURE: Intensity of immunoreaction. The result was considered positive when at least five focal areas of stained cells were observed within the tumour. RESULTS: All 27 tumours were positive for HMB-45, 19 (70%) for S-100, 23 (85%) for S-100 beta, and 21 (78%) for S-100 alpha beta. No correlation was found between the intensity of the immunoreaction and cell classification. CONCLUSIONS: HMB-45 is the most reliable marker for choroidal melanomas. S-100 beta is a more sensitive marker than S-100 for choroidal melanomas regardless of cell type. Contrary to previous reports, S-100 beta should not be considered a useful immunomarker to differentiate between primary choroidal melanoma and cutaneous melanoma metastatic to the choroid.

Antibodies, Monoclonal↗
PubMed1996

Indapamide (Natrilix): the agent of choice in the treatment of recurrent renal calculi associated with idiopathic hypercalciuria.

OBJECTIVE: To compare the hypocalciuric and potential side-effects of hydrochlorothiazide (HCT) to indapamide (IND; a thiazide-like drug) in patients with idiopathic hypercalciuria. PATIENTS, SUBJECTS AND METHODS: Twelve patients with recurrent renal calculi and renal hypercalciuria were studied using a randomized double-blind cross-over protocol. In addition, because the side-effects of HCT are attenuated using small doses, the hypocalciuric effect of 12.5, 25 and 50 mg daily was assessed in six normal subjects. RESULTS: There was a significant reduction in urinary calcium excretion using both agents, with a mean (SD) of 6.06 (2.68) and 3.37 (2.00) mmol/24 h using IND, and 5.58 (1.98) and 3.93 (2.35) mmol/24 h using HCT, before and after treatment (P < 0.05). The treatment was not sufficiently prolonged to assess adequately all the side-effects of either agent but both produced a similar decrease in serum potassium, whilst HCT significantly increased the mean (SD) serum urate levels, from 0.34 (0.09) to 0.43 (0.08) mmol/L (P < 0.01). There was also a significant decrease in mean (SD) urinary citrate excretion in those receiving HCT, from 1.41 (1.05) to 1.00 (0.71) mmol/24 h (P < 0.001), but not in those receiving IND, from 1.19 (0.71) to 1.18 (0.79) mmol/24 h. Although there was a hypocalciuric effect with doses of 12.5 and 25 mg HCT, it was sub-therapeutic when compared with the dose of 50 mg. CONCLUSION: At a daily dose of 2.5 mg, IND is at least as effective as 50 mg HCT in controlling hypercalciuria. Because of its safety profile and lack of effects on urinary citrate excretion, this agent should be the preferred therapy for patients with idiopathic hypercalciuria and recurrent renal calculi.

Calcium↗
PubMed1996

Mechanisms of interferon-induced inhibition of Toxoplasma gondii replication in human retinal pigment epithelial cells.

Inflammation associated with retinochoroiditis is a major complication of ocular toxoplasmosis in infants and immunocompetent individuals. Moreover, Toxoplasma gondii-induced retinal disease causes serious complications in patients with AIDS and transplant patients. The retinal pigment epithelial (RPE) cell is an important regulatory cell within the retina and is one of the cells infected with T. gondii in in vivo. We have developed a human RPE (HRPE) cell in vitro model system to evaluate T. gondii replication and the regulation of this replication by cytokines. T. gondii replication was quantitated by counting the foci of infection (plaque formation) and the numbers of tachyzoites released into the supernatant fluids. Pretreatment of cultures with recombinant human tumor necrosis factor alpha, alpha interferon (IFN-alpha), IFN-beta, or IFN-gamma for 24 h prior to inoculation inhibited T. gondii replication in a dose-dependent manner. Of these cytokines, IFN-gamma was the most potent, and T. gondii replication was completely inhibited at a concentration of 100 U/ml. The anti-toxoplasmotic activity of IFN-gamma was significantly blocked by monoclonal antibody to IFN-gamma. Treatment of the cultures with IFN-gamma from day 1 or 2 postinoculation with T. gondii also offered protection against the parasite. The anti-toxoplasmotic activity of tumor necrosis factor alpha or IFN-alpha, -beta, or -gamma in these cultures was found to be independent of the nitric oxide (NO) pathway, since NO production was not found in HRPE cells treated with these cytokines. However, addition of tryptophan to IFN-gamma-treated cells significantly reversed the inhibitory effects of IFN-gamma, suggesting that IFN-gamma acts by depleting cellular tryptophan. This effect was further confirmed by reverse transcription-PCR and Northern (RNA) blot analysis, which indicated induction of indoleamine 2,3-dioxygenase (IDO), an enzyme that converts tryptophan to kynurenine. These results indicated that interferons inhibited T. gondii replication in HRPE by NO-independent but IDO-dependent mechanisms. This in vitro model of T. gondii replication in HRPE may be useful in evaluating the effects of cytokines and drugs on T. gondii replication within the retina.

Animals↗
PubMed1996

[Nutritional status of pre-school children of the semi-arid region of Bahia (Brazil): II--Vitamin A deficiency].

A survey of 754 preschool children was undertaken in the urban areas of seven small towns of the semi-arid region of Bahia, Northeastern Brazil, to determine the prevalence of vitamin A deficiency, as well as its association with variables such as a age, family income, mother's schooling and dietary adequacy in vitamin A. Protein energy malnutrition and anemia were also studied and are reported separately. The clinical ophthalmological examination did not reveal any signs or symptoms of xerophthalmia amongst these children. In 563 children serum retinol was determined and the average value found was 20.3 micrograms/dl (SD = 10.8 micrograms/dl); the prevalence of deficient serum retinol (below 10.0 micrograms/dl) was of 15.3%. In all 7 localities studied, the prevalence of deficient retinol levels was above 5.0%, the criterion recommended by WHO for considering it a Public Health Problem. The distribution of serum retinol was similar between the sexes, but there was an age trend: the prevalence of deficient and low levels decreased with age. There was no association between deficient serum retinol and family income per capita or mother's education. Results from the 24 h food consumption survey revealed that only 8% of children had an adequate intake of vitamin A through the diet; 66% received less than 1/2 and 35% less than 1/4 of the recommended daily intake of vitamin A. Vitamin A deficiency should be considered a Public Health Problem in the region due to the high prevalence of deficient levels of serum retinol as well as the large dietary inadequacy.

Age Factors↗
PubMed1996

Propranolol stimulates testicular interstitial fluid formation and testosterone secretion in rats.

We investigated the effect of intratesticularly injected propranolol on testicular interstitial fluid (TIF) formation and on testosterone levels in the TIF of intact adult male Wistar rats (4-9 rats per group). dl-propranolol at doses of 0.6, 1.2, or 6.0 mg/kg was injected into the left (L) testis whereas the right (R) testis (control testis) received vehicle. dl-propranolol (6.0 mg/kg) caused a significant increase in both TIF volume (329%) and TIF levels of testosterone (257%) in the L testis but not in the R (control) testis 3 h post-injection. In rats treated simultaneously with human chorionic gonadotropin (hCG, 5 IU/rat, sc) the same dose or propranolol (6.0 mg/kg) significantly increased the stimulatory effect of hCG on testosterone secretion by 1.8-fold, but hCG did not modify the stimulatory effect of propranolol on TIF volume. These results demonstrate a direct stimulatory effect of propranolol on TIF volume and testosterone secretion, both under basal and hCG-stimulated conditions.

Animals↗
PubMed1995

Beta-thalassaemia unlinked to the beta-globin gene interacts with sickle-cell trait in a Portuguese family.

An autosomally transmitted hypochromic microcytic mild anaemia with elevated haemoglobin (Hb) A2 and globin chain imbalance has been observed in a three-generation family of Portuguese origin. Extensive DNA analysis of the beta-globin gene cluster, including the complete sequencing of the beta-globin gene and flanking regions, failed to reveal any genetic alteration. The co-segregation of sickle-cell trait in this family enabled us to postulate a defective erythroid trans-acting factor was playing a role in the down-regulation of both beta A- and beta S-globin genes. Among the transcription factors that could possibly have caused the reported phenotype, NF-E2 is unlikely to be implicated, whereas Nrf1 and Nrf2 cannot be ruled out. Thus, this family carries a novel beta-thalassaemia autosomal determinant unlinked to the beta-globin gene. This observation reinforces the notion of the haemoglobinopathies as single gene disorders under polygenic regulation.

Adult↗
PubMed1995

High frequency of strains multiply resistant to ampicillin, trimethoprim-sulfamethoxazole, streptomycin, chloramphenicol, and tetracycline isolated from patients with shigellosis in northeastern Brazil during the period 1988 to 1993.

The occurrence and antimicrobial resistance pattern of Shigella isolates obtained from persons in community and hospital-based studies of diarrhea and matched controls in northeastern Brazil were studied. The isolation rate of Shigella spp. from patients with diarrhea during 1988 to 1993 varied from 4.5% (26 of 575) for the urban community of Gonçalves Dias to 6.7% (12 of 179) and 5.9% (7 of 119) for Hospital Infantil and Hospital Universitário, respectively. Of the 55 Shigella isolates (45 from patients with diarrhea, 8 from controls, and 2 undetermined) 73% (40 of 55) were Shigella flexneri, 16% (9 of 55) were S. sonnei, 7% (4 of 55) were S. boydii, and 4% (2 of 55) were S. dysenteriae. Of 39 S. flexneri strains, over half were resistant to ampicillin, trimethoprim-sulfamethoxazole, or both. Over 64% were resistant to streptomycin, chloramphenicol, and tetracycline. Overall, 82% of all S. flexneri isolates were resistant to four or more antimicrobial agents tested. As elsewhere, in the northeast of Brazil, ampicillin and trimethoprim-sulfamethoxazole are no longer reliable for treatment of S. flexneri infection. Most Shigella strains were resistant to four or more antimicrobial agents. Nalidixic acid was still useful for treatment of infections due to S. flexneri.

Adolescent↗
PubMed1995

Molecular basis of alpha-thalassemia in Portugal.

We have estimated the incidence and molecular basis of alpha-thalassemia in a Portuguese population, mostly from the Greater Lisbon area. In a group of 100 consecutive cord blood samples, the gene frequency of the rightward deletion (-alpha 3.7) was 0.035, and the leftward deletion (-alpha 4.2) was 0.015. In this group, we have also found four heterozygotes for the triple alpha-globin gene rearrangement (alpha alpha alpha anti 3.7. gene frequency 0.020). We have characterized the subtypes of -alpha 3.7 and alpha alpha alpha anti 3.7 rearrangements. On the whole, these results give an incidence of 10% for deletional alpha-thalassemia carriers in the studied Portuguese population. In a group of 342 subjects presenting beta-thalassemia, or Hb S trait, beta-thalassemia major sickle cell disease or low red blood cell indices, the -alpha 3.7, -alpha 4.2, -SEA, -MED, (alpha alpha)MM, and alpha alpha alpha anti 3.7 haplotypes were found in different combinations. Only one nondeletional alpha-thalassemia determinant (a 5 nucleotide deletion in the alpha 2-globin gene in the second intervening sequence donor site) was detected, which might suggest a low incidence of these defects in the Portuguese population.

Adult↗
PubMed1995

[Lipids in children and young people. A public health problem].

Cardiovascular diseases represent an important Public Health problem among us. It is known that the atherosclerotic process on which they are based is mostly dependent on hyperlipidemia, mainly of those characterized by hypercholesterolemia and starts early in childhood. In this paper some lipid parameters were evaluated in children and youngsters and the prevalence of those at risk was compared with the one found in a population sample of adult people, collected at random, using the same determinations and laboratory methods. The authors conclude that preventive measures should be implemented as early as possible in childhood as there are many children and youngsters with hypercholesterolemia and the latter may become lower; some ideas and recommendations for those measures are pointed out.

Adolescent↗
PubMed1995

Clearance of a chylomicron-like emulsion from plasma is delayed in patients with coronary artery disease.

To determine whether the metabolism of chylomicrons and their remnants is related to atherogenesis, a triglyceride-rich emulsion known to mimic chylomicron behavior in plasma and labeled with 1-14C-cholesteryl oleate was injected intravenously into 11 normolipidemic patients (triglycerides: 133 +/- 60 mg/dl; total cholesterol: 207 +/- 20 mg/dl; LDL: 143 +/- 20 mg/dl; VLDL: 27 +/- 13 mg/dl; and HDL cholesterol: 41 +/- 11 mg/dl; apo AI: 1.27 +/- 0.54 g/l and apo B: 1.42 +/- 0.31 g/l) with atherosclerotic coronary artery disease and into 11 control subjects (triglycerides: 109 +/- 32 mg/dl; total cholesterol: 190 +/- 38 mg/dl; LDL: 125 +/- 29 mg/dl; VLDL: 22 +/- 6 mg/ dl; and HDL cholesterol: 44 +/- 9 mg/dl; apo AI: 1.09 +/- 0.28 g/l and apo B: 1.09 +/- 0.28 g/l) without the disease. The emulsion (69% triolein, 23% lecithin, 6% cholesteryl oleate and 2% cholesterol) was injected intravenously at approximately 9:00 a.m., after a 12-h fast. The clearance of the emulsion label from plasma, expressed as fractional clearance rate (FCR), was lower in coronary artery disease compared to controls (0.019 +/- 0.005/min vs 0.036 +/- 0.018/min, respectively, P < 0.05). These results indicate that the rate of removal of chylomicron remnants is slower in patients with coronary artery disease.

Adult↗
PubMed1995

Quality assurance programmes in Portugal in the fields of clinical chemistry and haematology.

Quality assurance programmes in Portugal in the fields of clinical chemistry and haematology are running on under the organization of the correspondent laboratories of the National Institute of Health. They are carried out with voluntary participation for public and private clinical laboratories with confidentiality of results. The design comprehends two parts, each one supplementing the other: internal quality control, external quality assessment being the motivation for quality assurance usually done through courses and laboratory activities organized even before the laboratories enter the external scheme. In clinical chemistry: with six trials a year and 23 parameters to be analysed, the target values are assigned by reference laboratories. The survey reports involve a personal message and an Youden plot being the assessment of performance done either by a deviation index (DI) or, on enzymes, by a consensus value established among the participants. Yearly an individual message is produced to report the evolution of laboratory results. The state of the art shows a good performance of reference laboratories. The participant laboratories still evidence some difficulties on enzymes, bilirubin, creatinine, urates and urea determinations. In haematology the target value is the consensus median value of participant laboratories using the same kind of equipment, semi and totally automated. As survey reports two kinds of computer forms are produced: an individual message where each laboratory results are compared with the others through a DI, an yearly message with the DI evolution. Up to this date ten surveys a year are carried on for general haematology.(ABSTRACT TRUNCATED AT 250 WORDS)

Chemistry, Clinical↗
PubMed1995

[Vitamin A deficiency in children of rural areas of the semi-arid region in Bahia].

The distribution and magnitude of vitamin A deficiency and dietary consumption of 161 children at 6 to 72 months of age in rural zones in Cansancao-Bahia-Brazil were evaluated. The serum retinol levels were measured by the spectrophotometric method (Bassey-Lowry modified by Araujo and Flores). The serum retinol average was found to be distributed homogeneously throughout the different age groups. Inadequate serum retinol levels (<20,0 mu g/dl) were detected in 44.7% of the children, which characterized the deficiency as constituting a public health problem. The serum retinol levels showed no statistically significant association as between the sex and age of the children; however the children of less than 24 months showed a higher prevalence of inadequate serum retinol levels. The main available source of vitamin A for these children was represented by carotenoids, especially beta-carotene. Foods regarded as being rich in vitamin A were consumed by all age groups. The greatest diversification of consumption of foodstuffs with moderate and low vitamin A content was observed in the group of children of from 24 to 72 months of age, through this was no guarantee of adequate serum retinol levels in this group however.

Analysis of Variance↗
PubMed1994

Asymptomatic environmental enteropathy among slum-dwelling infants.

OBJECTIVE: We documented asymptomatic environmental enteropathy, which may occur in low socioeconomic populations, and which is manifested by bacterial proliferation in the upper portions of the small bowel and by alterations in the digestive-absorptive capacity. DESIGN: Forty asymptomatic infants (< 1 year) of the Cidade Leonor slum in São Paulo, Brazil, were investigated for digestive-absorptive function, bacterial proliferation in the small bowel lumen, and jejunal morphology. They were compared with a control group of 8 well-nourished children from economically sound families. RESULTS: Mean value of the D-xylose absorption test in the slum infants 21.0 +/- 10.0 mg%) was significantly lower than in controls (46.0 +/- 13.8 mg%) (p < 0.001). Colonic bacterial proliferation in the small bowel was identified in 25 (62.5%) of slum-dwelling infants. Grade II villous atrophy with inflammatory infiltration in the lamina propria was the most frequent alteration found. CONCLUSION: These data show that alterations in the microecology, function and morphology of the small intestine can occur even in the absence of diarrhea. Therefore, the absence of symptoms does not necessarily imply a healthy well-being among children living in a slum.

Bacteria↗
PubMed1994

Frequency of Candida sp infection in tuberculous patients with acquired immunodeficiency syndrome: morphological and immunocytochemical study in sputum.

Sputum samples from AIDS patients with and without pulmonary tuberculosis were analyzed morphologically and immunocytochemically to determine the frequency of occurrence of Candida sp. Mycobacterial infection was detected by bacterioscopy and/or culture and cytological evaluation was performed using Papanicolaou and Toluidine Blue staining. Immunoreaction for Candida sp was performed using polyclonal antibody in selected cases with fungal structures in smears stained by the Papanicolaou or Toluidine Blue method. An increased frequency of Candida sp (2.5 times) was observed in the tuberculous group compared to the group of AIDS patients without tuberculosis. The Toluidine Blue stain showed good results for the detection of Candida sp in sputum. Due to the increased risk of this opportunistic infection among more severely immunocompromised patients. Toluidine Blue staining of sputum samples submitted to analysis seems to be a reliable screening method.

AIDS-Related Opportunistic Infections↗
PubMed1994

[The Program of External Quality Evaluation in Clinical Chemistry. An overview and evaluation after 11 years of functioning].

After an eleven-year period, the goals and way of functioning are remembered the External Quality Assessment Scheme in Clinical Chemistry, under the responsibility of the National Institute of Health. The authors try to evaluate the quality of results obtained at the time by the 160 participant laboratories, belonging to the public and private sectors as well as to the Portuguese reference laboratories which have to assign the expected values on the control sera to be analysed. As regards the 22 biochemical blood parameters, we came to the conclusion that there is a high performance level in what concerns the reference laboratories and a quality level of participant laboratories in accordance with their considered peer foreign laboratories.

Chemistry, Clinical↗
PubMed1993

Isolation of Mycobacterium avium complex from bone marrow aspirates of AIDS patients in Brazil.

Mycobacterium avium complex (MAC) infection has not been reported as a major opportunistic infection among patients with AIDS in Latin America or Africa. In this study, 125 AIDS patients who had persistent fever, anemia, and leukopenia were examined among 2628 AIDS patients admitted to Instituto de Infectologia Emilio Ribas between May 1990 and April 1992. From the bone marrow aspirates of the 125 patients, MAC was isolated from 23 (18.4%) and Mycobacterium tuberculosis was isolated from 9 (7.2%). Between 1985 and 1990, only 11 MAC isolations among 60,000 cultures obtained from human immunodeficiency virus-seronegative patients were documented in São Paulo. Hence, the minimal estimated rate of MAC infection in AIDS patients in this city was 23/2628, or 0.88%. These findings suggest that MAC infection is an important opportunistic infection, especially among a subset of patients with AIDS in Brazil who have clinical characteristics and risk activities similar to those associated with MAC infections in North America and Europe.

AIDS-Related Opportunistic Infections↗
PubMed1993

Hereditary anaemias in Portugal: epidemiology, public health significance, and control.

A countrywide prospective study aimed at establishing the prevalence of the haemoglobinopathy genes in the Portuguese population was carried out by screening 15,208 randomly selected blood samples from young males. This male based survey provided the opportunity of assessing simultaneously the prevalence of the red cell enzyme glucose-6-phosphate dehydrogenase (G6PD) deficiency, thus giving a picture of these important hereditary anaemias in Portugal. The results showed a low average frequency of beta thalassaemia (0.45%) and haemoglobin S (0.32%) carriers as well as G6PD deficiency (0.51%). However, these disorders are unevenly distributed throughout the country with a higher prevalence in some areas, mainly in the south. The relationship of this pattern of haemoglobinopathies to the known haplotypes linked to beta thalassaemia and sickle cell disease, relevant historical events, and local selective pressure was investigated. Hb D and Hb J are the commonest other structural variants. The implemented programme for control of these hereditary anaemias is described.

Erythrocyte Indices↗