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Biomedical subjects

M C Silva

Publications and source records attributed to M C Silva.

At least 19 recordsLinked to original sources

Testing of nursing theory: critique and philosophical expansion.

The authors first critique Silva's 1986 article in Advances in Nursing Science entitled "Research Testing Nursing Theory: State of the Art." They specifically focus on her evaluation criteria for the empirical testing of nursing theory and then develop evaluation criteria for three alternative approaches to theory testing in nursing. In addition, they describe how philosophy in general, and epistemology in particular, affect testing of nursing theory. Finally, they raise philosophical issues and state conclusions related to the testing of nursing theory within the discipline and practice of nursing.

Cognition

Anorectal electromanometry in the diagnosis of neuronal intestinal dysplasia in childhood.

The diagnosis of neuronal intestinal dysplasia (NID) is currently established by histochemical procedures. From October 1, 1981, until July 31, 1990, we submitted a total number of 737 patients under 15 years of age with several distinct colonic and anorectal disorders, to clinical, radiological, electromanometrical, histochemical and histological evaluation. 573 had a clinical diagnosis of chronic constipation, and in 38 of these NID could be demonstrated by histochemical examination. Motivated by our own findings with the anorectal electromanometry in these patients we performed a double-blind prospective study to find out if there are any particular and pathognomonic manometric parameters of NID in childhood. 80% of our patients with NID diagnosed prospectively since April 1st, 1986, had a relaxation of the internal anal sphincter which was not proportional to the volume of rectal distention. Anorectal hyperexcitability was also present in these patients, whereas a statistically highly significant (p less than 0.01) increase of the amplitude of anorectal fluctuations (7.27 +/- 1.12 mmHg) as compared to the values measured in our own patients with functional chronic constipation (2.87 +/- 0.33 mmHg) could be demonstrated. Considering only those patients who simultaneously presented all of the above mentioned electromanometric criteria (e.g. non-proportional relaxation of the internal anal sphincter, anorectal hyperexcitability, increased amplitude of anorectal fluctuations) without an increase of the anorectal pressure profile, we could demonstrate that the correlation between the electromanometric diagnosis of NID and the final histochemical diagnosis was 100%. Nevertheless, under these conditions, 30% (9 out of 30) of patients with NID were not recognized electromanometrically because they had been excluded as false negative cases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

[Autoimmune phenomena in the elderly].

We analyzed sera from 102 subjects older than 65 years of age with no clinical evidence of autoimmune disorders, inflammatory diseases or pharmacological interventions. Positive titers for antinuclear antibodies were found in 18.6%, anti-smooth muscle fibre in 16.6%, and rheumatoid factor in 11.8%. These values were significantly higher than those of a control group of healthy younger adults (p < 0.0001). Anti mitochondrial antibodies were present in 1% (NS). Thus, a greater proportion of autoimmune phenomena is demonstrated in the elderly.

Age Factors

Null allele in a human polymorphism restricted to the placenta: call for a search.

The identification of a null allele in a human genetic system restricted to the placenta is a great challenge for two reasons: the impossibility of carrying out family studies and the unviability of sample recollections because the placenta itself is a disposable universe. Thus, in addition to reporting the finding of a null phenotype of placental alkaline phosphatase in a dark mulatto newborn from a black mixed population of Bahia, Brazil, here we present other evidence for the presence of the ALPP*Q0 allele with considerably high frequency in this population.

Alkaline Phosphatase

Radioimmunoassay of carboxyl and amino terminal fragments of parathyroid hormone for the evaluation of secondary hyperparathyroidism in chronic renal failure.

1. Some parameters of calcium and phosphorus metabolism and the radioimmunoassay of plasma concentrations of both the carboxyl (COOH) (residues 53-84) and amino (NH2) terminal (residues 1-34) fragments of parathyroid hormone (PTH) were measured to evaluate secondary hyperparathyroidism in 68 patients with chronic renal failure (CRF), 34 of whom were on hemodialysis therapy. 2. The upper limits of the normal values for serum PTH-NH2 and PTH-COOH concentrations were 28 and 146 pmol/l, respectively. Patients with mild CRF (plasma creatinine (CRp) 1.2-2 mg/dl) had normal mean serum total calcium, low mean serum phosphorus, undetectable plasma levels of PTH-NH2 (less than 10 pmol/l), slightly elevated mean plasma PTH-COOH concentration and normal fractional excretion of phosphorus (FEP). Patients with moderate CRF (CRp 2.1-4 mg/dl) had normal mean serum concentrations of both total calcium and phosphorus, and elevated mean levels of both plasma PTH-COOH and PTH-NH2 associated with increased FEP. Patients with end-stage CRF (CRp greater than 4 mg/dl) and those on hemodialysis had elevated mean serum phosphorus levels and decreased mean serum total calcium concentrations compared with those with mild and moderate CRF, and more pronounced increases in both mean plasma PTH-COOH and PTH-NH2. 3. The logarithm of plasma PTH-NH2, but not PTH-COOH, concentration correlated positively with FEP and serum phosphorus concentration and negatively with total serum calcium concentration, while the logarithms of both PTH-NH2 and PTH-COOH levels correlated positively with CRp.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

Augmented antibody response to live attenuated measles vaccine in children with Plasmodium falciparum parasitaemia.

The impact of malarial infection on the humoral immunological response to measles virus antigen was studied in 184 children aged 8-19 months in Guinea-Bissau. Pre- and post-immunization measles serology was performed using dried blood on absorbent paper and the ELISA technique. Blood smears obtained at the time of vaccination and 2 and 4 weeks afterwards were examined for malaria parasites. Pre-vaccination antibodies to measles were found in 44 out of 184 children (24%). Plasmodium falciparum was identified in 62 of the 132 initially non-immune children who completed the study. The rate of seroconversion was 127 out of 132 (96%). Post-immunization measles antibody titres were significantly higher in the vaccinees with P. falciparum than in those without malaria parasites in the blood.

Antibodies, Viral