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Biomedical subjects

M M Costa

Publications and source records attributed to M M Costa.

32 records · Page 2Linked to original sources

Oxygen consumption and ventilation during constant-load exercise in runners and cyclists.

The effect of using specialized or no specialized muscle groups on ventilatory threshold (VT) and on maintenance of steady-state oxygen consumption during long term exercise on treadmill and on cycle ergometer was studied in ten endurance runners and nine cyclists. Initially, maximum oxygen consumption (VO2max) and VT were determined. Oxygen consumption (VO2) ventilation (VE) respiratory rate (f), and blood lactate (in the beginning and at the end of exercise) were measured during exercise at constant relative loads of 60, 70, and 80% of VO2max. In the runners, both VO2max and VT (expressed as % VO2max and VO2 l/min) were greater on treadmill than on cycle ergometer and in the cyclists, VO2max was higher on cycle ergometer than on treadmill, but no differences in VT were detected between the two tests. The VO2, VE, and f drifts correlated with blood lactate level as well as with the calculated VT. The results suggest that the effect of using specialized or no specialized muscle groups on the maintenance of VO2 steadiness is achieved through training-induced changes on the level of blood lactate and, in VT.

Adult↗

Hormone receptor analysis in endometrial cytologic samples collected with the Gynoscann device.

Eighteen patients underwent endometrial cytologic sampling using the Gynoscann instrument immediately before curettage. The material obtained was used for cytologic diagnosis and for measurements of estrogen receptors (ERs) and progesterone receptors (PRs). The material collected with the Gynoscann device provided conclusive cytologic diagnoses in 88% of the cases, as compared with the histologic classification of samples collected by curettage. The DNA content in the samples obtained by the Gynoscann device varied from 5 micrograms to 218 micrograms; this amount was sufficient for the analysis of both ER and PR. Thus, assays for steroid receptors may be performed on endometrial cytologic samples obtained by the Gynoscann; this method may be especially useful for cases in which it is difficult to take a surgical biopsy.

Adult↗

Endometrial carcinoma diagnosed by the Gynoscann method.

A simple method for screening of the endometrium is a desirable complement to the gynecological examination. Between February and June, 1984, 94 patients underwent cytological sampling by the Gynoscann method immediately before dilatation and curettage at the Department of Gynecological Oncology, Radiumhemmet, and at the Department of Obstetrics and Gynecology, Karolinska Hospital, Stockholm. Ninety-six per cent of the cytological samples were adequate for cytological diagnosis and the same proportion of the curettage specimens for histology. The correlation between cytology and histology was correct in 84% of the cases. Among the 26 cases of endometrial carcinoma, 21 (80%) were correctly diagnosed by cytology. There were no false-positive diagnoses for carcinoma. Atypical hyperplastic endometrium was found in 2 cases by curettage and was correctly correlated with cytology in one case. The sensitivity for endometrial carcinoma was 81% and the specificity 100%. Our conclusion is that the Gynoscann method is safe, easy to use and has proved reliable for the diagnosis of endometrial carcinoma. Further evaluation with larger series giving the cytopathologists increased experience is needed before optimal sensitivity can be achieved.

Adenocarcinoma↗

Long and short-term effect of prednisolone in hospitalized infants with acute bronchiolitis.

OBJECTIVE: To assess long and short-term effect of prednisolone in hospitalized infants with bronchiolitis. METHODOLOGY: A randomized and controlled trial was carried out at the Federal University of Rio Grande, Rio Grande-RS, Brazil. Twenty-eight patients were randomly allocated prednisolone (1 mg/kg/day for 5 days) plus standard care, and 24 patients allocated standard care alone. The primary endpoint was the prevalence of post-bronchiolitis wheezing at 1, 3, 6 and 12 months after hospital discharge. The secondary endpoints were: length of hospital stay, duration of oxygen therapy and time to clinical improvement during the hospitalization. RESULTS: There were no significant differences between the prednisolone and control group in the prevalence of post-bronchioltis wheezing at 1 month (73.1 vs 83.3%, P = 0.5), 3 months (73.1 vs 79.2%, P = 0.7), 6 months (65.4 vs 66.7%, P = 0.9) and 12 months (50.0 vs 58.3%, P = 0.5) after hospital discharge. No reduction was observed in the prednisolone group, compared with the control group, in terms of length of hospital stay (6.0 vs 5.0 days, P = 0.7), duration of oxygen therapy (24.0 vs 24.0 h, P = 0.4) and time to clinical resolution (4.0 vs 4.0 days, P = 0.8). CONCLUSIONS: Prednisolone has no significant effect on reducing the prevalence of post-bronchiolitis wheezing and on improving the acute course of illness in hospitalized infants with bronchiolitis.

Acute Disease↗

[Qualitative and quantitative evaluation of gastric emptying using a videofluoroscopic method].

We studied the gastric emptying of 21 healthy volunteers using a standard contrasted diet composed of a lipid, carbohydrate, protein and barium sulfate solution homogenate. We did six one-minute videofluoroscopic recordings in a 12-minute interval for the first hour, and in a 30 minute interval until the complete emptying. We selected eight exams for the emptying quantification. We could observe and estimate subjectively the functional behavior and the gastric emptying. Digital representative images of each emptying time point we were able to quantify those observations and describe them as a mathematical function. We developed a macro procedure using the Media Cybernetics ImagePro-Plus software for this quantification. We conclude that: 1--The videofluoroscopic method provides better resolution than the other methods in the analysis of the gastric motility and emptying. 2--It is possible to computationally quantify the morphological differences observed with the sequential registration radiological methods, specially the videofluoroscopic method that generates 30 frames per second. 3--Our results generate a gastric emptying index, based on the area of a gastric projection in radiological images obtained in a standing position over a one-hour period (T1/2). 4--The quantitative analysis should not exclude the qualitative analysis.

Adult↗

[Trends in hospital admissions for pediatric asthma in childrenduring a period of eighteen years]

OBJECTIVE: To study trends in hospital admissions for acute pediatric asthma in the Hospital da Santa Casa do Rio Grande during the period of 1979 to 1996. METHODS: This is a study of a series of cases. We reviewed all the discharge records of pediatric patients with diagnosis of acute asthma, pneumonia, and bronchiolitis within the period mentioned above. The main variable in this study was the percentage of admissions for acute asthma in relation to the total amount of hospital admissions. The percentages of admissions for bronchiolitis and pneumonia in relation to the total amount of hospital admissions were also calculated as reference values. RESULTS: There were 3,493 admissions for acute asthma in 3,122 patients during the studied period, with an average of 194 admissions per year. The percentage of admissions for acute asthma to total hospital admissions increased from 5,5% to 14,7% between 1983/84 and 1991/92. Half of this increase occurred during the period 1987-1992 in which hospitalizations for bronchiolitis and pneumonia were stable. This percentage decreased from 14,7% to 10,6% in the period of 1991/92 - 1995/96. CONCLUSIONS: There was a significant increase in hospital admissions for acute pediatric asthma in the Hospital da Santa Casa do Rio Grande during the period of 1983 - 1992. From then on, hospital admissions for asthma showed downward trends.

Journal Article↗

[Videofluoroscopic evaluation of the functional significance of the epiglottis in adults].

Our intention was to define the functional role of the epiglottis. Accordingly, we analysed its movements and correlation in 53 videofluroscopic exams: 26 were good health volunteers, 25 were patients with dysphagia and two were persons with pharyngeal diverticula. The exams register the rest phase, chewing, and the swallowing movements during the intake of the saliva, water, barium solution and different volumes of mass made with crumbled bread mixed with barium powder. We can see three sequential stages in epiglottic movement during swallowing. The first stage involves an upward epiglottic shift determined by hioepiglottic ligament, associated with a simultaneous bending caused by the tongue backward projection. The second stage is a posterior rotation of the epiglottis, limited by the adjustment of the epiglottic tubercle to the vestibular fold, determined by laryngeal upward shift against hyoid bone. The third stage in which occurs an eversion of the free extremity of the epiglottis beyond the horizontal plane can be absent in slow pressure swallowing. All stages of the epiglottic dynamics are passive. We have shown that the epiglottis has a protective action on the repiratory airways not limited to swallowing. It participates, during swallowing and regurgitation (vomica), through the passive adjustment of the intralaryngeal posterior surface of the epiglottis (epiglottic tubercle) to the vestibular folds. Both before and after swallowing, when frequently there are escapes of residues and small volumes out of the oral cavity, the epiglottis protects the repiratory airways, through its participation in the formation of the valleculae and as an insertion point for the aryepiglottic folds. In association with epiglottis participation there is a stretching of the aryepiglottic folds that allow a definition of the lateral channels. The upward and forward movements of the larynx associated with the opening of the pharyngoesophageal transition, that occurs synchronously with the ejection of the swallowed bolus, has been shown to be an important factor in the protective laringeal mechanism. The increase in the laryngeal resistance, in which the epiglottis takes part, is only efficient when there is wide and synchronous opening of the pharyngoesophageal transition. In this context the epiglottis is a secondary element in the protection of the respiratory airways.

Adolescent↗

[Structural changes in pulmonary vessels and coronary arteries in hypoplastic left heart syndrome].

In order to correlate gross morphological features with pulmonary and coronary vasculature changes in hypoplastic left heart syndrome (HLHS) 15 heart-lung necropsy specimens from neonates were analysed. Histology of left atrium wall, lung vessels with pulmonary arteriolar disease morphometric grading, study of intra and extra pulmonary wall veins and coronary arteries were recorded. Classic HLHS was observed in 11, and DORV with mitral atresia in 4, the foramen ovale (FO) being the only left atrium outflow tract in all. All specimens had increased % of thickness and muscular extension of arterioles and increased wall thickness of pulmonary veins, but severer arteriolar and venous changes with left atrium fibrosis were noticed in 8 specimens with either closed FO (3 cases) or mean FO diameter (d) of 5 mm when compared with specimens with mean FOd of 9 mm. Coronary arteries histology disclosed in 4 of 8 specimens with opened but hypoplastic mitral valve, intima proliferative changes with lumen narrowing, not observed in 7 specimens with mitral valve atresia. We concluded that in HLHS closed or restrictive FO and permeable mitral valve may predispose neonates to respiratory complications, right ventricle abnormal function and arrhythmias, specially after cardiac surgery.

Aorta↗

[Meconium proteins in small-for-gestational-age infants].

Considering that a greater concentration of proteins in the meconium of children with pancreatic achylia has been reported, the possibility was set forth that a similar finding was present in infants with intrauterine malnutrition; this probability was established on the basis that a dysfunction of the exocrine pancreas is present in postnatal malnutrition. The study comprised 37 samples of meconium from full-term infants; 27 of them from adequate weight newborns and the remaining 10, from low weight infants for their gestational age. The results showed a significant difference when the concentration of albumin and of alpha-1-antitrypsin registered for both groups was compared. In infants classed as malnourished because of their lower weight expected for their gestational age, both the albumin as the alpha-1-antitrypsin were found raised.

Albumins↗

[Swallowing defects determined by tracheostomy].

We have studied the interference on swallowing of the skin-tracheal fixation determined by tracheostomy. We have analyzed this interference by videofluoroscopy. One hundred and twelve patients with complain of dysphagia have been studied by videofluoroscopy at the Hospital Universitário "Clementino Fraga Filho", Rio de Janeiro, RJ. Four have undertaken tracheostomy. One (female, 52 years) had already a metal cannula in the trachea, three others (two females and one male/40 to 66 years) exhibited a longitudinal anterior depressed scar, for more than five years. Two patients had also a neurological disease. In the videofluoroscopic observation it was used liquid medium (barium solution) and also solid and soft contrast media made of barium powder mixed with a bread dough. We have found a correlation between skin-tracheal fixation and swallowing defects. The skin-tracheal fixation interference occurs basically by opposition to the hyo-larynx free displacement. This limited displacement determines a small amplification of the laryngo-pharyngeal space, a restrictive opening of the pharingo-esophageal segment and also determines that the laringeous aditus remains near the pharingo-esophageal limit. We have observed swallowing defects in all the four tracheostomized patients. The observed defects relative to tracheostomy was the penetration of contrast medium in the airway. This penetration was cleared by forced expiration. In three patients the swallowing defects was clearly linked to tracheostomy. We can admit that the skin-tracheal fixation, without any other pathology, can determine dysphagia. In association with other diseases this fixation can increase the disturbance: On the other hand it can run unnoticed due to more evident pathology. The consequence of skin-tracheal fixation is better determined by videofluroscopy.

Adult↗

[Swallowing apnea in adults].

We have studied the swallowing apnea in 66 persons. Five were laryngectomized. We analysed 1916 breathing/swallowing correlation charts, 109 in laryngectomized and 1807 in not laryngectomized persons. The correlation charts were done using a piezoelectric and thermistor register coupled to a manometric system developed by Synetics Medical interfaced to a microcomputer running software Polygram upper 4.21. Our observation allows us to conclude that: 1. the swallowing apnea has not the same reflex path of the breathing interruption that occurs when a foreign body stimulates the laryngeal receptors; 2. the swallowing apnea installation is not dependent on the laryngeal structures; 3. the swallowing apnea and rima glottidis closure, that occur in the same moment, are correlated phenomena, but are a distinct part of the airway protective mechanisms; and 4. even though the swallowing apnea can occur in every moment of the breathing cycle, it occurs more frequently at the end of expiratory and beginning of the inspiratory phase of breathing cycle; it is usually continued by a complementary expiration. We believe that the less lung volume is the basic condition to the establishment of the more frequent kind of swallowing apnea reflex.

Adult↗