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Biomedical subjects

M Pereira

Publications and source records attributed to M Pereira.

At least 91 records · Page 5Linked to original sources
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↗
PubMed1986

Polymyalgia rheumatica and temporal arteritis: managing older patients.

PMR and GCA are diagnosed relatively frequently in the white geriatric population. Patients may suffer from both conditions or from either alone. PMR is considered a diagnosis of exclusion, with the most characteristic symptoms being profound morning stiffness affecting the hip and shoulder girdles. The diagnosis of PMR can be buttressed by the findings of an elevated ESR, anemia, and mildly elevated liver enzymes. PMR can be controlled with less than or equal to 20 mg/d of prednisone, whereas higher doses of glucocorticoids are required for GCA. Classic GCA is characterized by headache, visual changes, and constitutional symptoms. GCA can be confirmed by a biopsy revealing a histologic picture of granulomatous inflammation centered around the elastin of the involved vessel. Judicious efforts to taper steroids are indicated in both syndromes, but many patients require therapy for at least 2 years.

Aged↗
PubMed1985

Nodular duodenitis in chronic maintenance hemodialysis patients.

A retrospective study of 138 cases of chronic hemodialysis between 1977 and 1982 were reviewed for endoscopic, radiographic, and histologic characteristics of duodenitis. Forty patients underwent upper gastrointestinal barium x-rays; 13 were found to have multiple duodenal bulb nodules and three of these patients had very prominent duodenal bulb folds. There were 42 patients on whom upper panendoscopy was performed, and multiple duodenal nodules were seen in 15 patients and thickened folds in three patients. There were five patients in whom nodules were seen only on endoscopy. The size of the nodules varied between 3 and 8 mm in diameter and mucosal folds between 4 and 8 mm. Duodenal mucosal hyperplasia with chronic inflammatory cell infiltrate was found on biopsy of the nodules in 12 cases, while three cases with nodules revealed blunted villous structure with chronic inflammatory cells.

Adult↗
PubMed1985

[Diagnosis of internal jugular vein thrombosis by x-ray computed tomography].

We made the diagnosis of internal jugular vein thrombosis by computed tomography in 3 cases. The CT diagnostic signs are the following: widening of the vein caliber, absence of opacification or nonhomogeneous aspect of the opacification of the lumen, and parietal contrast fixation. Classical and more recent etiology refers to cervico-facial infections and injuries, central venous catheterizations and local surgery, compression by a cervical mass, and use of oral contraceptives. The advantage of CT consists in its noninvasive contribution to defining a diagnosis that pathology, which is nonspecific (painful cervical tumefaction), often cannot reach.

Adult↗
PubMed1985

Bancroftian filariasis and malaria in island and hinterland populations in Sabah, Malaysia.

An epidemiological survey of filariasis and malaria in Banggi Island and Upper Kinabatangan, Sabah, revealed microfilarial rates of 7.2% and 8.6% respectively and malaria prevalence of 9.7% and 16.9% respectively. Wuchereria bancrofti was a rural nocturnally periodic type with a periodicity index of 137.2 and average peak hour at 01.32 hrs; 9.2% of microfilaremic carriers as compared to 2.4% amicrofilaremic subjects had clinical filariasis. The Plasmodium falciparum: P. vivax: P. malariae ratios were 1:1:0.17 and 1.4:1:0.12 for Banggi and Upper Kinabatangan respectively. Anopheles flavirostris was incriminated as a new malaria vector in Banggi where the well-known primary malaria vector is An. balabacensis. The latter was also found for the first time to be a vector of rural W. bancrofti in Upper Kinabatangan. Experimental feeding also showed that L3 larvae of W. bancrofti were recovered at low rates from An. balabacensis. Aedes togoi appeared to be a suitable laboratory vector for W. bancrofti.

Adolescent↗
PubMed1984

Intragastric bacterial activity and nitrosation before, during, and after treatment with omeprazole.

Ten healthy volunteers were studied before, during, and after treatment with omeprazole 30 mg daily for two weeks. On the 14th night mean nocturnal (2100-0700) intragastric acidity was significantly decreased by 75% (p less than 0.001). At 0700, 22 hours after the last dose of omeprazole, there were significant increases in the bacterial count and the nitrite and N-nitrosamine concentrations in the gastric juice (p less than 0.001). Three days later these changes had resolved. Short term treatment of healthy volunteers with omeprazole is associated with a short lived increase in the gastric bacterial flora, with endogenous production of N-nitroso compounds.

Adult↗
PubMed1984

[Not Available].

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Biochemistry↗
PubMed1984

[Not Available].

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Biochemistry↗
PubMed1984

ABO and Lewis typing of semen, saliva and other body fluids.

It is well known that ABH group specific substances are usually present in high concentrations in body fluids of secretors. In normal circumstances these substances can withstand drying and retain their antigenic activity over a prolonged period. This enables the forensic serologist to assist in the investigation of various crimes by grouping stains of body fluids such as semen and saliva. It is possible, for instance, to group saliva and lip mucosa stains on cigarette ends, gags, masks, postage stamps and envelope flaps etc. but it is the grouping of seminal stains in the investigation of sexual crimes which predominates. The results of such tests can be extremely valuable in either including or excluding suspects.

ABO Blood-Group System↗
PubMed1983

An atypical subcutaneous infection associated with acquired immune deficiency syndrome.

Cases of acquired immune deficiency syndrome (AIDS) continue to be reported at an alarming rate. As the numbers of cases increase, so too does the list of unusual manifestations associated with this syndrome. We report here a patient with AIDS who, during his clinical course, had a previously undescribed, histologically atypical, subcutaneous infection develop. Light microscopic, electron microscopic, and microbiologic data are presented. The cause and pathogenesis of this lesion are discussed.

Acquired Immunodeficiency Syndrome↗