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M C Vieira

Publications and source records attributed to M C Vieira.

14 recordsLinked to original sources
PubMed2001

Anatomic study of the tricuspid valve in children.

We performed an anatomic study of the right atrioventricular valve in children under one year of age using a conservative method of dissection of the heart valve. The main aspects studied were the number of cusps and their morphometric characteristics, such as the width of the base and the depth of the cusps. Other parameters studied were the number of papillary muscles, number of tendinous cords, and diameter of the fibrous ring and the last one were divided in three regions, anterior, posterior and septal for localization of cusps. Our results showed that the number of cusps varied from two to four. Three cusps was the commonest finding and the fourth cusp, if present, was classified as anterolateral in location. The anterior and septal cusps had bases bigger than those of the posterior and anterolateral cusps; the septal cusp was deeper than the others; and the number of tendinous cords was greater for the anterior and septal cusps than for the posterior and anterolateral cusps. In addition, the posterior region showed great variability: in 35.7% it was occupied by undeveloped valve tissue and the posterior valve in these cases was located anteriorly.

Cadaver↗
PubMed1999

Thermal inactivation of Alicyclobacillus acidoterrestris spores under different temperature, soluble solids and pH conditions for the design of fruit processes.

Alicyclobacillus acidoterrestris, a thermoacidophilic, non-pathogenic and spore-forming bacterium has been detected in several spoiled commercial pasteurised fruit juices. A. acidoterrestris spores, besides being resistant to the pasteurisation treatment conditions normally applied to acidic fruit products, can germinate and grow causing spoilage. Therefore, this microorganism was suggested as the target to be used in the design of adequate pasteurisation processes. The objectives of this work were to investigate the influence of temperature (T: 85-97 degrees C), total soluble solids (SS: 5-60 degrees Brix or % by weight) and pH (2.5-6.0) on D-values (decimal reduction time) of Alicyclobacillus acidoterrestris (type strain, NCIMB 13137) spores, and to fit a model using response surface methodology. A central composite face-centred experimental design was used, and the response, D-value determined in malt extract broth, ranged between 0.498+/-0.045 and 94.9+/-6.7 min. Within the factor ranges studied, temperature was the parameter that most affected the D-value. Following this was the SS and, lastly, the pH value. A linear decrease in D-value was observed with decreasing SS and pH, and a non-linear decrease in D-value was noticed with increasing temperature. A second order polynomial was successfully fitted to the data (R2 = 0.98). In general, D-values measured in real fruit systems, such as orange, apple and grape juices, blackcurrant concentrates, cupuaçu (exotic fruit) extract and orange juice drink, were higher than those predicted by the malt extract broth model. This result emphasises the importance of experimental validation of any model-derived process.

Bacillaceae↗
PubMed1998

[Angiography of the coronary venous system. Use in clinical electrophysiology].

PURPOSE: To study the angiographic anatomy of human coronary veins and the possibility of epicardial venous mapping through microelectrode catheters. METHODS: We evaluated 30 patients with sustained ventricular tachycardia using a catheter which provided occlusion of the coronary sinus ostium during venous angiography. They were 25 males, 5 females, ages ranging from 24 to 76 years (mean = 52.7). The veins were studied according to their number, caliber and distribution in the anterior and posterior wall of the left ventricle. RESULTS: Coronary sinus was catheterized in all patients. No discomfort or complication were observed. The number of veins from posterior wall of the left ventricle was 3.1 and anterior wall, 1.9, p < 0.05. The caliber of the coronary veins were: anterior interventricular vein (distal segment = 1.19 +/- 0.22 mm, middle segment = 1.65 +/- 0.35 mm), posterior interventricular vein (distal segment = 1.83 +/- 0.47 mm, middle segment = 2.00 +/- 0.52 mm), left posterior vein (distal segment = 1.45 +/- 0.25 mm, middle segment = 2.49 +/- 0.92 mm); p < 0.05. CONCLUSION: The balloon occlusion technique for coronary venous angiography is feasible and safe. The number and the caliber (distal and middle) of the veins from the posterior wall of the left ventricle were significantly greater than those from the anterior wall. Anatomic conditions for venous epicardial mapping are more adequate in the posterior wall of the left ventricle.

Adult↗
PubMed1995

Linear growth after colectomy for ulcerative colitis in childhood.

Eighteen children and adolescents, of a total of 90 treated in our unit between 1982 and 1992, underwent colectomy for ulceractive colitis. Six (6.7%) of the 90 patients had short stature, i.e., a height below the 3rd centile, and 8 of the 18 who had surgery had a subnormal height velocity, i.e., below the 25th centile for age at the time of surgery. Surgery was performed for resistance to medical therapy (n = 13) or toxic megacolon (n = 5). Surgery was followed by catch-up growth, i.e., increasing height velocity, in eight subjects and cessation of the trend of diminishing height velocity, but without catch-up growth, in five. In 11 of the subjects who were prepubertal, the median height velocity increased from 3.85 cm/year preoperatively to 7.35 cm/year postoperatively (p < 0.01). One year after surgery, 14 of the 18 patients were either asymptomatic or substantially improved. Surgery therefore led to improved linear growth and a prolonged symptom-free period in most of the children and adolescents with ulcerative colitis undergoing this treatment.

Adolescent↗
PubMed1991

The recurrent laryngeal nerve in relation to the inferior constrictor muscle of the pharynx.

The point of penetration of the recurrent laryngeal nerve into the larynx is recognized as the most frequent site of injury to the nerve during surgical procedures of the thyroid gland. The anatomical relationships of 25 right and left recurrent laryngeal nerves in 25 anatomical blocks from formalin-fixed human corpses have been studied. In 34 cases (68%), the recurrent laryngeal nerve penetrated into the larynx below the lower fibers of the inferior constrictor muscle of the pharynx (type 1 of penetration). In the remaining 16 cases (32%), the nerve crossed through those muscle fibers to penetrate into the larynx (type 2 of penetration). The thyroid gland was found to involve the recurrent laryngeal nerve at the penetration point into the larynx in 19 of 50 cases (38%).

Humans↗
PubMed1990

Anatomical study of the human tricuspid valve.

An anatomical study of the tricuspid valve was carried out in 50 human hearts of both female and male individuals using a method of dissection which preserves the integrity of the valve. Morphometric criteria such as area of cusp, width of cusp base, relation between commissure depth and cusp depth and morphological criteria such as the presence of atrioventricular cusp node, number of tendinous cords, perimeter of fibrous ring, and properties of papillary m. were adopted for characterization of a cusp. In 64% of cases, commissural cusps were present independent of the number of tricuspid cusps. The tricuspid valve was not consistently tricuspid, but was observed to present 2, 4, 5 or 6 cusps in 72% of cases.

Female↗
PubMed1990

[Regional irrigation of the pericardium in children].

PURPOSE: To investigate the irrigation of both fibrous pericardium and the parietal layer of serosal pericardium in children. PATIENTS AND METHODS: The cadavers of 10 children of both sexes, under the age of one. In this study we adopted the regional divisions described by DI Dio, which considers a plane between the two phrenic nerves that divides the areas of pericardium into ventral and dorsal regions. We also refer to these regions as antephrenic and retrophrenic respectively. In addition, we consider the inferior pericardium to be that portion of pericardial sac related to the diaphragm. RESULTS: The pericardium ventralis was more frequently irrigated by branches of the following arteries: thoracicae internae dextra and sinistra, pericardiacophrenica dextra in 9 cases; pericardiacophrenica sinistra in 8 cases; and less frequently, by branches of the arteriae phrenicae inferiores dextra and sinistra, epigastrica superior sinistra, thimica, rami thimici of the a. thoracica interna dextra, and rami thimicus and esophagealis of the a. subclavia dextra. The pericardium dorsalis was more frequently supplied b the following arterial branches: bronchiales in 9 cases; esophagealis of the aorta in 8 cases; and in a frequency inferior than 4 cases, we observed the following arteries: thyroidea inferior sinistra, intercostalis suprema, pericardiacophrenicae dextra and sinistra, subclavia sinistra, coronariae dextra and sinistra, phrenicae superior and inferior sinistra, thoracica interna dextra, intercostales posteriores primae dextra and sinistra, truncus costocervalis and rami esophageales of the a. gastrica sinistra. The pericardium inferior was irrigated by branches of the arteriae phrenicae inferiores dextra in 10 cases and sinistra in 9 cases. CONCLUSION: Analysis of the results demonstrated that similar behavior in the pericardium regional irrigation offers a standard for intervention in the pericardium.

Coronary Circulation↗
PubMed1990

Morphological study of one septal trabecula carnea of the left ventricle.

This work was carried out in 50 hearts of human adult cadavers of both sexes, whose obit causes were not related to diseases which could have been directly involved with the heart. The septal trabecula carnea was identified in 45 hearts (90%), with origin in the superior portion of the interventricular septum and the other extremity was sited in 33 cases (61.1%) in the base of the anterior papillary muscle. It was unique in 37 hearts (82.2%) and dissociated in 8 hearts (17.8%). The more frequent length and width was 40 mm and 3 mm, respectively.

Female↗
PubMedDate not supplied

Kinetic parameters estimation for ascorbic acid degradation in fruit nectar using the Partial Equivalent Isothermal Exposures (PEIE) method under non-isothermal continuous heating conditions.

With the purpose of testing the Paired Equivalent Isothermal Exposures (PEIE) method to determine reaction kinetic parameters under non-isothermal conditions, continuous pasteurizations were carried out with a tropical fruit nectar [25% cupuaçu (Theobroma grandiflorum) pulp and 15% sugar] to estimate the ascorbic acid thermal degradation kinetic parameters. Fifteen continuous thermal exposures were studied, with seven being cycled. The experimental ascorbic acid thermal degradation kinetic parameters were estimated by the PEIE method (E(a) = 73 +/- 9 kJ/mol, k(8)(0)( degrees )(C) = 0.017 +/- 0.001 min(-)(1)). These values compared very well to the previously determined values for the same product under isothermal conditions (E(a) = 73 +/- 7 kJ/mol, k(8)(0)( degrees )(C) = 0.020 +/- 0.001 min(-)(1)). The predicted extents of reaction presented a good fit to the experimental data, although the cycled thermal treatments presented some deviation. In addition to being easier and faster than the Isothermal method, the PEIE method can be a more reliable method to estimate first-order reaction kinetic parameters when continuous heating is considered.

Ascorbic Acid↗
PubMedDate not supplied

Adsorption of protein from several commercial lipase preparations onto a hollow-fiber membrane module.

Ten commercially available crude preparations of lipase from various microbial sources were adsorbed from aqueous buffers at several initial concentrations onto a bundle of hydrophobic hollow fibers made of poly(propylene) at pH 7.0 and 40 degrees C. The kinetics of adsorption were evaluated from measurements at various times of the protein content of the supernatant solution (using BSA as equivalent) in a well-mixed reservoir placed in series with the hollow fiber module. Preliminary tracer experiments have indicated that the module and the tank can be simulated as a system consisting of a plug flow reactor in series with a continuous stirred tank reactor. A mechanistic model based on the hydrodynamic assumptions associated with this system coupled with the postulation of two reversible first-order steps for the adsorption of protein was successfully fitted to the experimental data via nonlinear regression analysis. The statistical significance of the model was checked using tests for lack of fit. This work is useful in predicting the time period required to immobilize a (crude) lipase by adsorption onto a hydrophobic hollow fiber module, a configuration which has proved successful in the recent past for the performance of lipase-catalyzed reactions.

Adsorption↗