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Biomedical subjects

A Teixeira

Publications and source records attributed to A Teixeira.

At least 55 records · Page 3Linked to original sources
PubMed1992

Purification and characterization of a new 120 kDa alkaline proteinase of Trypanosoma cruzi.

A new alkaline proteinase activity was identified in cell-free extracts of Trypanosoma cruzi epimastigotes on the basis of its ability to hydrolyze the fluorogenic substrate N-Z-Gly-Gly-Arg-AMC. The optimal activity was at pH 8.0. After a three step-chromatography procedure using two anionic columns (DEAE-Sepharose and Mono Q) and a chromatofocusing column (Mono P), the proteolytic activity was associated with a single 120 kDa protein and was called Tc 120 proteinase. The molecular mass of the proteinase was confirmed by direct visualization of the proteolytic activity using a fluorometric assay on SDS-PAGE. The Tc 120 proteinase which also cleaves N-Z-Arg-AMC, N-Z-Phe-Arg-AMC and N-glutaryl-Gly-Arg-AMC substrates, is a cysteine-type proteinase with an unusual low sensitivity to E-64.

Amino Acid Sequence↗
PubMed1992

[Exercise performance after long-term administration of enalapril or metoprolol. A randomized double-blind study of hypertensive leisure-time sportsmen].

A randomized double-blind trial was conducted in 36 leisure-time sportsmen (mean age 40.1 +/- 5.4 years) with mild or moderate essential hypertension (WHO groups I or II) to find out whether an 8-week antihypertensive treatment with daily 10-20 mg enalapril or 100-200 mg metoprolol changed their exercise performance. This was measured by bicycle spiroergometry together with determination of lactate levels, before and at the end of the treatment period. Maximal oxygen uptake rose by 1.86 ml/kg.min during enalapril administration and by 1.06 ml/kg.min at the individual anaerobic threshold. But under metoprolol these parameters fell by 6.57 ml/kg.min and 4.61 ml/kg.min, respectively. After treatment with these two drugs 3 and 15 patients, respectively, had the sensation of greater exercise performance at identical exercise levels. The differences in exercise between the two drugs using the stated three primary criteria were statistically significant. The Watt-time product decreased in only one of the patients of the enalapril group, but in 17 of the metoprolol group. Only metoprolol significantly reduced exercise heart rate. Both drugs caused a similar fall in systolic blood pressure during exercise.

Adult↗
PubMed1992

Specific removal of transthyretin from plasma of patients with familial amyloidotic polyneuropathy: optimization of an immunoadsorption procedure.

Familial amyloidotic polyneuropathy is characterized by the presence in patients plasma of a genetic variant of transthyretin. No specific treatment has been found and extracorporeal immunoadsorption on immobilized anti-transthyretin antibodies appears as a potentially attractive procedure. Parameters involved in specific immunoadsorption of transthyretin were studied and optimized. Several monoclonal anti-TTR antibodies were compared as affinity ligands and one of them was found to be suitable for such purposes. Optimum quantities of antibodies to be immobilized on the gel were determined. Three desorption agents were tested for regenerating immunoadsorbents and best results were obtained with basic variation of pH, allowing total desorption of TTR and possibility of multiple use without loss of adsorption capacity. Simulation of an immunoadsorption procedure in well-defined conditions showed efficiency and specificity of adsorption to remove TTR and the system thus should be subjected to clinical trials.

Amyloidosis↗
PubMed1992

[Stapling in surgery of cancer of the rectum. Experience with 100 cases].

The authors relate their experience with 100 cases of anterior resections operated using stapling techniques, 43 with double stapling. Fifty three were males and forty seven females, the youngest being 35 year's old and the oldest 87. The tumour was located at the upper third in 54 cases, at the middle third in 41 and at the lower third in five cases. One hundred anterior resections were executed, fifty of the low type. As to the Dukes classification, 15 were A type, 45 type B, 35 type C and 5 type D. There were no operative mortality until the 30th post operative day. As early post-operative complications there were one case of hemorrhage, two pneumopathies, one urinary retention, one cardio-respiratory insufficiency three cases of fistulae and 6 wound infections. In the last 65 cases only one wound infection and two pneumopathies were found. As late complications there were three anastomotic stenosis (all of them satisfactorily solved with dilatation) and six cases with small degree incontinence for gas and faeces recovering spontaneously. The recurrence rate was 14%; in three it has been possible to proceed with its excision by means of abdominoperineal amputation. They conclude stating that mechanical suturing specially is a good alternative to manual suturing in patients with low rectal tumours.

Adult↗
PubMed1991

Separation and simultaneous high-performance liquid chromatographic determination of benzocaine and benzyl benzoate in a pharmaceutical preparation.

A simple reversed-phase high-performance liquid chromatographic method suitable for the simultaneous determination of benzocaine and benzyl benzoate in dermatological preparations is described. An internal standard method was employed, using C18 "bonded phase" silica column and a mobile phase consisting of acetonitrile - water (40:60, v/v), with absorption of the column effluent monitored at 254 nm. No sources of interference were observed. The simultaneous determination of both compounds by the method described is rapid and accurate.

Benzoates↗
PubMed1976

Evidences for duodenopancreatic reflexes and an anti-CCK factor with lidocaine infused intravenously and sprayed topically on pancreatic papilla in nonalcoholic and alcohol-fed dogs.

In 14 duodenal Thomas fistula dogs, four of them alcohol-fed for two years, lidocaine, applied topically to the duodenal pancreatic papilla, inhibited secretin-induced pancreatic secretion probably by interrupting duodenopancreatic reflexes that contribute to the "pancreon's" cholinergic tone. Opposite effects were observed with lidocaine administered against a CCK plus secretin background stimulation of the pancreas. The significant rising of volume and protein output above plateau levels were enhanced by chronic alcohol feeding. Lidocaine infused intravenously did not change secretin-induced pancreatic secretion but raised CCK and secretin evoked plateau secretion levels. Chronic alcoholism enhanced these latter effects. Atropine perfusion superimposed on CCK and secretin stimulation did not prevent but raised the intravenous lidocaine-induced pancreatic secretion changes. It is postulated that the modifications elicited by lidocaine sprayed topically and infused intravenously on CCK plus secretin evoked pancreatic secretion plateau levels are due to depression of an anti-CCK factor secreted by the small intestine mucosa.

Administration, Topical↗
PubMed1972

The stereospecificity of nicotinamide-adenine dinucleotide-dependent oxidoreductases from plants.

1. The stereospecificity of 20 enzymes from plants is reported. 2. The stereospecificity of all known forms of malate dehydrogenase in plants and animals has been shown to be A-specific. 3. The generalization that ;the stereospecificity of a particular reaction is independent of the source of the enzyme' is confirmed for a total of 12 plant enzymes. 4. A new generalization is proposed: ;When a metabolic sequence involves consecutive nicotinamide-adenine dinucleotide-dependent reactions, the dehydrogenases have the same stereospecificity.'

Alcohol Oxidoreductases↗
PubMedDate not supplied

[Cobb's collar. Unusual cause of hematuria].

The Cobb's collar is a congenital narrowing of the bulbar urethra with variable clinical presentation and obstruction grade. Herein we report a clinical case of a 13-year-old boy presenting terminal macroscopic haematuria and post-mictional urethral bleeding. At cystoscopy a membrane on the bulbar urethra distal to the external sphincter and prominent vessels in the prostatic urethra were found. Transurethral endoscopic incision was carried out with no complications or recurrence at 9-month follow-up. The authors briefly review the embryopathogenesis, clinical features and treatment of this uncommon anomaly.

Adolescent↗
PubMedDate not supplied

Molecular analysis of CDKN2 (p16) in gliomas associated with clinical data.

We analyzed alterations in CDKN2 in gliomas from an ethically mixed population and correlated the results with patients clinical data. We screened for methylation at CDKN2 and for microsatellite instability (MSI) and loss of heterozygosity (LOH) in the region 9p21-22 using 4 markers. We found: 3/30 (10%) cases with CDKN2-methylated gliomas; an average of 4% of MSI; and 24.5% of LOH in the region 9p21-22. Methylation of CDKN2 was only detected in patients showing high-grade gliomas with short survival. MSI and LOH in the region 9p21-22 were detected in patients showing high-grade gliomas with short survival and in one patient with a recurrent low-grade astrocytoma grade II who died from the disease after 3 years, indicating that such alterations represent poor prognosis.

Adolescent↗
PubMedDate not supplied

Conversion factors in laparoscopic cholecystectomy for acute cholecystitis.

BACKGROUND/AIMS: Although laparoscopic cholecystectomy already occupies an important role in acute cholecystitis, a high rate of conversion continues to be referred to in the series published. One of the objectives of this study is to assess the preoperative factors that might lead to conversion. METHODOLOGY: 100 laparoscopic cholecystectomies for acute cholecystitis were studied of which 24 were converted. Several parameters are taken into consideration: age, sex, ASA, echographic data, bacteriological examination of the bile, time elapsing between diagnosis and surgery, morbidity and mortality. RESULTS: The analysis made in relation to the preoperative, predetermining factors with regards to the converted cases provided the following elements in unvaried analysis: Preoperative existence of: "plastron" gallbladder (P < 0.002), temperature above 38 degrees C (P < 0.04), leucocytosis (P < 0.02)), time elapsing between diagnosis and surgery (P < 0.005), presence in the echography of pericholecystic liquid (P < 0.0005) and edema (P < 0.001); Klebsiella in the gallbladder bile (P < 0.005). Age (P = 0.136), sex (P = 0.992), associated diseases (P = 0.961), and gallbladder pathology (P = 0.282) did not present statistical differences that would prevent valid conclusions. In multi-varied analysis it was only possible to consider as independent factors the leucocytosis and the time between diagnosis and surgery. CONCLUSIONS: Laparoscopic cholecystectomy is a safe and efficient technique in the treatment of acute cholecystitis, which should constitute the first choice of treatment for this disease. However, it should be carried out within the first 4 days following surgical diagnosis.

Acute Disease↗
PubMedDate not supplied

[Malignant histiocytosis].

The authors report a case of malignant histiocytosis, with sub acute evolution and fatal outcome in a 36 year old male, presenting with fever, hemoptysis, splenomegaly, parietal mass, anemia and bilateral pulmonary nodules. Despite one transbronchial pulmonary biopsy non diagnostic, both myelogram and histology of parietal tumor aroused the suspicion of malignant histiocytosis, later confirmed through a bronchoalveolar lavage. We didn't find any other case yet published in portuguese literature.

Adult↗