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Biomedical subjects

M da Silva

Publications and source records attributed to M da Silva.

At least 19 recordsLinked to original sources
PubMed2001

Determinants of physical performance in ambulatory patients on hemodialysis.

BACKGROUND: Physical performance measures, particularly gait speed, have been useful as predictors of loss of independence, institutionalization, and mortality in older nonuremic individuals. Gait speed has not been evaluated as a predictor of these important outcomes in patients on hemodialysis, nor have the determinants of gait speed in the dialysis population been studied. METHODS: We performed a cross-sectional analysis to determine whether demographic, clinical, or nutritional status variables were related to physical performance in a group of 46 hemodialysis patients treated at three University of California San Francisco-affiliated dialysis units. Three physical performance measures were examined, including gait speed, time to climb stairs, and time to rise from a chair five times in succession. Forward stepwise linear-regression analysis was performed with each physical performance measure as the dependent variable and the following candidate predictor variables: age, gender, body mass index, dialysis vintage, Kt/V, albumin, blood urea nitrogen, creatinine, hematocrit, lean body mass, phase angle, ferritin, and the following comorbidities: hypertension, diabetes mellitus, coronary artery disease, peripheral vascular disease, and cerebrovascular disease. RESULTS: Subjects included 31 men and 15 women aged 22 to 87 years (mean +/- SD, 52 +/- 17). The mean gait speed for the group was 113.1 +/- 34.5 cm/s (low compared with norms established for persons of similar age). Results of multivariable regression showed that age, albumin, and Kt/V were important determinants of gait speed in this population. Overall, the model explained 52% of the variability in gait speed (r = 0.72, P < 0.0001). Qualitatively similar results were obtained using stair-climbing time or chair-rising time as the dependent variables, except that comorbidity was more important than age for stair climbing. The addition of physical activity level to the models did not eliminate the associations of albumin or Kt/V with physical performance. CONCLUSIONS: Physical performance is significantly impaired in ambulatory hemodialysis patients and is related to age, serum albumin, and dialysis dose. Prospective studies are needed to determine whether modification of dialysis dose or nutritional interventions can improve physical performance in patients on hemodialysis.

Adult↗
PubMed2000

Permanent pacing in patients with congenital atrio-ventricular block--experience of 33 cases.

OBJECTIVES: The authors review permanent pacing in patients with congenital atrioventricular block (CAVB) and present their experience in permanent pacing in this pathology. STUDY POPULATION AND METHODS: In a population of 4,355 patients submitted to implantation of permanent pacing between January 1980 and January 1998, 33 (0.75%) had CAVB. The mean age of the patient population with CAVB was 16.7 years (aged from eleven days to 35 years); 33% were below 10 years of age; 16 patients were male. The majority of the patients had symptoms of brain hypoperfusion; two patients had concomitant malignant ventricular tachyarrythmias (one of these with Torsade de Pointes due to congenital long QT syndrome). Transvenous (endocardial) pacing was used in 32 patients (two with previous epicardial pacing and exit block) and epicardial pacing in one. The mode of stimulation used was VVI in three patients, DDD in eight patients, VVIR in 14 patients, DDDR in four patients and VDD in four. Smaller pulse generators were used in children of lower weight. In recent years single lead VDD systems have been preferred whenever technically possible. Vascular access was the left cephalic vein in 17 patients; the left subclavian vein in 14 patients and the right jugular vein in one patient. During a mean follow-up of 6.9 years, two patients with ventricular stimulation systems developed "Pacemaker Syndrome" and required a change of mode of stimulation. Lead fracture and posterior cutaneous necroses were observed in two other patients, who were accordingly submitted to surgical revision. It was deemed necessary, one year later, to increase the lead loop in a child with a permanent pacemaker implanted at eleven days of age. No other complications occurred with the other patients; replacement of the pulse generators was performed in an elective manner. CONCLUSIONS: CAVB is a rare indication for the implantation of a permanent pacemaker. In children, in the majority of cases, endocardial stimulation is possible in spite of the obvious technical difficulties due to low weight. Sequential, more physiological, stimulation systems should be preferred. However, VVIR stimulation systems of smaller dimensions can be the first choice of mode of stimulation in smaller children, mainly due to anatomical and technical limitations.

Adolescent↗
PubMed1998

Systematics and environmental application of the genus Trichoderma.

Trichoderma, an anamorphic Hypocreaceae (class Ascomycetes), is common in the environment, especially in soils. Species of this genus have been used in the production of cellulolytic and hemicellulolytic enzymes, biological control of plant disease, biodegradation of chlorophenolic compounds, and soil bioremediation. They are also the cause of disease in commercially produced mushrooms. The species Trichoderma has not been clearly defined yet, despite being a very common fungus with an expanding number of applications. Therefore, we highlight the importance of the use of molecular techninques along with conventional methodologies based on morphological characters in order to achieve a "natural" taxonomic system for this group of fungi, as well as for any other complex group of fungi.

Biodegradation, Environmental↗
PubMed1997

Vestibular abnormalities in charge association.

We report the vestibular abnormalities in 5 patients with the CHARGE association (Coloboma, Heart disease, Atresia of choanae, Retarded growth and development and/or central nervous system anomalies, Genital hypoplasia, and Ear anomalies). All patients had absent vestibular function as indicated by absent vestibulo-ocular reflexes and severe imbalance on simultaneous deprivation of proprioception and vision, as well as delayed motor development. All 6 semicircular canals were aplastic in each of the patients. While cochlear function was severely reduced in 6 of the 10 ears, it was absent only in 3 ears and was actually intact below 3 kHz in 1 ear. All 10 bony cochleas were present on computed tomography, and although 7 appeared abnormal, 3 appeared normal. This study confirms that absence of the bony semicircular canals in the presence of a bony cochlea is a characteristic finding in CHARGE association. It also demonstrates that these disproportionate structural abnormalities are reflected in the functional abnormalities: absent vestibular function with preservation of some cochlear function.

Adolescent↗
PubMed1990

Detection of HIV-related protein in testes and prostates of patients with AIDS.

The testes and prostates of 14 patients with acquired immune deficiency syndrome (AIDS) for whom autopsies were performed were examined for the presence of human immunodeficiency virus (HIV) and the pathologic alterations seen in AIDS. Histologically, the testes contained peritubular fibrosis and variable spermatogenic arrest, which were inconsistent with the young age of these patients. There were also numerous foci of germ cell degeneration and occasional germ cell loss. The Leydig cells were atrophic and decreased in number. The prostates contained increased numbers of concretions. Sections of testis and prostate were stained with an anti-HIV P17 monoclonal antibody with the use of the avidin-biotin technique. Small scattered foci of positive staining were identified in 8 of 14 testes (57%). They were located over one or several degenerating germ cells and the surrounding Sertoli cells. In addition, in 9 of 14 prostates (64%) there were a few minute foci of positive staining in several adjacent glandular epithelial cells. In one case the testis was positive and the prostate was negative, whereas in two cases the testes were negative and the prostate positive. In contrast, 22 testes and 22 prostates of control non-AIDS patients, read double-blind, were negative. The positive controls were HIV-infected tissue culture HUT 78 lymphoma cells in which there were many scattered positive cells. The results indicate the presence of focal HIV-associated protein in the testes and prostates of patients with AIDS, particularly within the foci of germ cell degeneration. The present observations are in accordance with previous research demonstrating the presence of HIV in the seminal fluid of patients with AIDS and appears to indicate the presence of an infection of the male genital tract by the HIV virus.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Familial combined hyperlipidemia and otosclerosis--the occurrence in a large kindred.

The occurrence of otosclerosis and hyperlipidemia in four generations of a single family is described. The lipid abnormality fulfilled the characteristics of combined familial hyperlipidemia. Whereas a genetic linkage between combined hyperlipidemia and otosclerosis is feasible, our study indicates that both conditions are inherited through autosomal but unlinked genes.

Adolescent↗
PubMed1984

Transstomal endoscopic monitoring of patients managed by tracheal silicone T-tubes.

Transstomal preoperative endoscopic examination (using rigid Hopkins type telescopes) of patients considered for surgical repair or stenting of laryngotracheal stenosis is described. This technique is further employed in patients managed with silicone T-tubes to monitor the airway during the stenting period and to determine the timing for removal of the tubes. Immediate post-removal endoscopic follow-up is most valuable in determining the patency and stability of the newly reconstructed airway.

Endoscopy↗
PubMed1982

Nasal septal abscess of dental origin.

A nasal septal abscess can be a serious complication of trauma or surgery. Dental infections that lead to this condition are rarely mentioned in the dental literature, and no report was found in the English otorhinolaryngological literature. As septal suppuration causes destruction of the cartilaginous septum, saddle-nose formation, and severe intracranial complications, immediate treatment is necessary. Two patients had septal abscesses as a complication of dental infection. Development of the condition, possible complications, and treatment are discussed.

Abscess↗
PubMedDate not supplied

Genetic an antigenic analysis of adenovirus type 3 strains showing intermediate behavior in standard seroneutralization test.

During an epidemiological survey of acute respiratory infection in Rio de Janeiro, among 208 adenovirus isolates, we found two strains that we were not able, by a standard neutralization procedure, to distinguish between type 3 or 7. However, DNA restriction pattern for the two strains with different enzymes were analyzed and showed a typical Ad3h profile. Using a cross-neutralization test in which both Ad3p and Ad7p antisera were used in different concentration against 100 TCID50 of each adenovirus standard and both isolates, we were able to confirm that the two isolates belong to serotype 3. An hemagglutination inhibition test also corroborated the identification of both strains as adenovirus type 3. Comparing Ad3h and Ad3p genome, we observed 16 different restriction enzyme sites, three of which were located in genomic regions encoding polypeptides involved in neutralization sites.

Adenoviruses, Human↗
PubMedDate not supplied

[Analysis of the use of fluoridated dentifrices in Curitiba].

The use of fluoride dentifrices in Curitiba (Brazil) was studied. The scholarity and socio-economical levels of the population were related to the use of fluoride dentifrices. The sample was composed of 155 persons, men and women. The results showed that 96.8% used dentifrices, but only 36.2% used fluoride dentifrices. The use of fluoride dentifrices was more significant among the higher socioeconomical and school levels.

Brazil↗