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Biomedical subjects

I Silva

Publications and source records attributed to I Silva.

50 records · Page 3Linked to original sources
PubMed1990

Chronic intrathecal baclofen administration in severe spasticity.

On the basis of previous experimental and clinical studies, 14 patients with severe spasticity due to central or spinal cord damage, resistant to all conservative treatments, were selected after a percutaneous trial period for chronic intrathecal baclofen infusion by programmable pumps. The agent was delivered at C4 in quadriplegic patients or in cases with central spasticity and in the neighbouring areas on the affected segments in paraplegic patients. The daily baclofen dose varied from 25 to 260 micrograms and was infused in a bolus, continuously infused or both combined according to the results during the trial period. After a mean follow-up period of 11 months, constant decrease of rigidity, absence of spasms, improvement of bladder function, cramping pain remission, and moderate improvement in walking capacity and transfer activities were usually observed. Neither complications nor side effects were noted.

Adolescent↗
PubMed1990

Role of vasoactive substances in the segmentary vasomotor response following spinal cord stimulation. An experimental study.

It is presumed today that spinal cord stimulation induces local delivery of vasoactive substances, such as prostacyclins, histamine, substance P, and vasoactive neuropeptides, in the perivascular environment and the vascular wall to mediate the segmental vasodilator response. To investigate this mechanism, 9 dogs were subjected to low thoracic spinal cord stimulation. Venous and arterial blood samples from the paraesthesic area in the lower limbs were obtained before and 120 min after stimulation to measure changes in the plasma concentration of vasoactive intestinal peptide, substance P, and histamine. The results were compared with those obtained from vessels of the upper limbs. Blood flow changes following stimulation were recorded by electromagnetic flowmeters. Local arterial vasoactive intestinal peptide showed a mean increase of 33% after 60 min of stimulation. Changes concerning substance P were inconclusive. Local arterial and venous histamine concentrations increased 26 and 29%, respectively, after 60 min of stimulation.

Animals↗
PubMed1988

Presynaptic modulation of the release of GABA by GABAA receptors in pars compacta and by GABAB receptors in pars reticulata of the rat substantia nigra.

The effect of GABA agonists and antagonists on K+-stimulated [3H]GABA release was studied to assess how presynaptic GABA receptors modulate GABA release. The release was affected in a quite different manner in the pars compacta and in the pars reticulata. Muscimol markedly inhibited the release from the pars compacta but had no effect on the release from the pars reticulata. Baclofen inhibited the release from the pars reticulata without affecting the release from the pars compacta. Bicuculline itself facilitated the release from the pars compacta but inhibited the release from the pars reticulata. Picrotoxin facilitated the release from the pars compacta and had no effect in the pars reticulata. The results suggest that the release of GABA from GABAergic terminals in the substantia nigra of the rat brain is modulated by GABAA autoreceptors in the pars compacta and by GABAB receptors in the pars reticulata.

Animals↗
PubMed1988

[Incontinentia pigmenti in 2 newborn infants].

Incontinentia pigmenti (IP) is a genodermatosis, which is of X-linked dominant transmission, uncommonly diagnosed in newborn babies. The skin lesions usually develop in 4 stages: inflammatory, hypertrophic, pigmentary and regressive. The authors report 2 cases of IP in female newborn babies who were previously treated for pyodermatitis.

Female↗
PubMed1988

Tears of the meniscus as revealed by magnetic resonance imaging.

Forty-four patients who were examined by magnetic resonance imaging and arthroscopy to detect tears of the meniscus of the knee were studied. Twenty-eight patients (Group I) had had no previous operations on the knee. Sixteen patients (Group II) had had a previous operation on the knee that had been performed after a meniscal injury. In Group I, the percentage of correct diagnoses by magnetic resonance imaging was 45 per cent. If the false-negative results are excluded, the rate of accuracy was 65 per cent. Similarly poor results were found in Group II: a rate of accuracy of 49 per cent and, if we eliminate the false-negative results, the rate of accuracy was only 55 per cent.

Adolescent↗
PubMed1985

Antigenic population changes of Leptospira biflexa strains grown under the selective pressure of factorial antibodies.

Serovars jequitaia and tororò of Leptospira biflexa were cultured in the presence of homologous factor serum containing factorial antibodies (FcAbs) to their major antigens. After 39 serial passages they were then re-tested to determine whether their major antigens had remained unchanged. It was found that each parent strain had been replaced by an antigenic variant. The disappearance of each parent strain and its replacement by an antigenic variant was attributed to the selective conditions imposed by FcAbs. The antigenic variants behaved like true mutants. They lacked the major serovar antigens of the parent strains and had acquired some major antigens similar to those of two different serovars, one of which belonged to the same serogroup as the parent strain and the other to a different serogroup. A comparison of the major antigens of the parent strains with those of their antigenic variants indicated that factorial antibodies may be used selectively to obtain antigenic variants with a predefined pattern of major antigens.

Agglutination Tests↗
PubMed1983

[Effect of lactation on the weight and body composition of wet nurses].

In order to assess the impact of lactation on the nutritional status and body composition of mothers, 134 women were followed up during a period of six months (95 were exclusively breast-feeding and 39 were bottle-feeding their babies). Their weight was measured at monthly intervals, and mid-arm circumference, skinfold thickness and food intake were determined at two and six months, respectively, as well as food intake by the 24-hour recall method. Both groups evidenced similar non significant and slight changes in weight and body composition. Only 10% of mothers showed weight losses above 4 kg; weight loss was significantly higher in overweight and obese women as compared to underweight and normal mothers. Both arm circumference and total fat (sum of skinfolds thickness) followed the same trend. Dietary intake revealed to be deficient in calories, protein, calcium, iron and vitamin A when compared to the FAO/WHO standards. Given the excellent growth curves of the children as well as the minimal changes observed in maternal nutrition and body composition, it may be assumed that the current recommended dietary allowances (FAO/WHO) are overestimated for a population of the type studied.

Body Composition↗
PubMed1978

Gas-liquid-chromatography of trimethylsilyl derivatives from whole cell methanolysates of Leptospira : preliminary evaluation of its applicability to the taxonomy of the genus.

Gas-liquid-chromatography of trimethylsilyl derivatives from whole cell methanolysates was investigated as a supplmentary means for taxonomical classification within the genus Leptospira. Reproducibility of this technique was assessed through the peak height variations occurring in chromatograms of strain Patoc 1, serotype patoc, when samples either from the same or different batches of culture were used. From each chromatogram seven peaks were selected. Their heights were measured and calculated as percent values of the seven peaks total height. The values of relative standard deviation reported show that the reproducibility of this technique lies within the usual limits of biological methods. Four out of seven different serotypes analyzed gave elution patterns dissimilar enough to allow a clear distinction among them by the simple visual examination. Differentiation of the other three had to be done comparing the relative heights of the seven selected peaks. One not yet classified new strain was submitted to this technique; results seemed to confirm available serological information about it. Data reported encourage further research in order to evaluate the potential of GLC as an useful aid in the taxonomy of genus Leptospira.

Chromatography, Gas↗
PubMed1974

Electron microscope identification of mesosomes in some water strains of Leptospira by reduction of tetrazolium chloride to formazans.

Rounded granules protruding from the external surface of some water Leptospira strains and considered as mesosomes were studied by electron microscope and by means of the intravital reduction of tetrazolium chloride. Satisfactory results were obtained with two of the strains studied. It appears that neither the culture medium nor the age of the culture have any influence on the unusual position of the mesosomes.

Formazans↗
PubMedDate not supplied

Evaluation of residual instability after arthroscopic meniscectomy in anterior cruciate deficient knees.

Forty-five patients who underwent a partial meniscectomy in an anterior cruciate deficient knee were followed from 2 to 9 years. The average age at the time of the meniscectomy was 28.6 years. The majority of the patients were injured in recreational athletics. The subjects were evaluated preoperatively by a questionnaire and clinical examination, both of which were repeated at followup. The efficacy of the postsurgical rehabilitation was monitored with measurement of quadriceps and hamstring strength on the Cybex Dynamometer. All of the patients had a KT-1000 knee ligament arthrometer test at followup that was compared with the clinical examination. Sixty-five percent of the subjects (13 of 20) with a Lachman and pivot shift of +1 returned to their previous activity level without limitation. Of the patients with a KT-1000 compliance index of 1 mm, 70% (11 of 17) returned to the same athletic level. However, only 20% (2 of 11) of the patients with a clinical instability greater than +1 or a compliance index of 2 mm were able to perform without limitation. The location of the meniscal tear did not correlate with the functional outcome. Six patients required ACL reconstruction.

Adult↗