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Biomedical subjects

C García

Publications and source records attributed to C García.

At least 217 records · Page 12Linked to original sources
PubMed1990

Trifluoperazine reproduces in rat islets the effects of calcium omission on insulin secretion and de novo lipid synthesis, without affecting 45Ca2(+)-uptake.

Calmodulin is thought to mediate at least some of the effects produced by the elevation of cytosolic calcium in response to a B-cell secretagogue. Trifluoperazine, an inhibitor of calcium-calmodulin interaction, has been used to test, comparatively with calcium-omission, whether the changes of lipid metabolism accompanying the stimulation of insulin release by glucose and palmitate are dependent on activation by the calcium binding protein. Low doses of trifluoperazine (1 and 5 mumol/l) reproduced quantitatively and qualitatively the effects of calcium omission on both insulin secretion and de novo lipid synthesis, without altering islet 45Ca2(+)-uptake. The apparent dependence on calcium-calmodulin of the "de novo" synthesis of neutral lipids, but not of acidic phospholipids, might reflect a possible regulation of islet phosphatidate phosphohydrolase by calcium.

Animals↗
PubMed1990

[Carcinoma of the gastric stump after resection of benign disease (32 cases)].

Gastric stump carcinomas have a poor prognosis; the etiology, diagnosis and treatment are not well-defined. The authors analyze their experience with 32 patients with carcinoma of the gastric stump after gastric resection for peptic ulcer; the age of the patients was 44-72 years. The period of latency, since the previous resection, was 28 years. At the time of diagnosis, all patients were symptomatic. The radiological study was positive in 69% of cases and endoscopic exploration and biopsy in 100%. 47% of patients could be resected but the surgery was considered radical only in 4. The tumors were always adenocarcinomas; the muscular layer was infiltrated in 86% of cases and to adjacent organs in 52%. 76% of cases presented lymph node metastases and 31% distant metastases. There were 8 postoperative deaths (28%). The five years survival was 4.2%. The poor prognosis of this lesion emphasizes the importance of early diagnosis and treatment as well as that of periodic follow-up of gastrectomized patients older than 50.

Adult↗
PubMed1990

In vivo estrogenic and antiestrogenic activity of phenolphthalein and derivative compounds.

The estrogenic activity of phenolphthalein and other related triphenylmethane dyes was evaluated in vivo in the immature rat uterus. Phenolphthalein behaved as a partial agonist of estradiol in stimulating the growth of rat uterus. Other specific estrogenic effects of the dye included an increase of the uterine DNA content, histological changes and induction of estrogen-modulated secretory proteins. The progressive introduction of side chains in the triphenylmethane skeleton concomitantly decreased the estrogenic activity. Triphenylmethanes competed with [3H]estradiol for the binding to the estrogen receptor in vitro, the relative binding affinity being correlated with the estrogenic potency observed in vivo. Phenolphthalein also showed antiestrogenic activity that could be overcome by increasing the dose of estradiol.

Animals↗
PubMed1989

Effect of recombinant human growth hormone therapy on bone and clinical parameters in girls with Turner's syndrome. The Spanish Collaborative Group.

Forty-eight girls with Turner's syndrome were assigned to one of three treatments; recombinant human growth hormone (rhGH) alone, rhGH plus oxandrolone, and rhGH plus ethinyloestradiol. Treatment with rhGH alone or in combination with oxandrolone induced catch-up growth. Older girls treated with rhGH plus ethinyloestradiol showed less marked improvement. The gain in height was associated with a gain in bone diameter and cortical thickness (reflecting increased bone mass). There was a rapid loss of subcutaneous fat. These effects of growth hormone are similar to those observed in patients with growth hormone deficiency.

Adolescent↗
PubMed1989

Effects of neonatal androgenization on growth and carcass composition in female mice.

Sixty female mice were injected neonatally with testosterone propionate. This led to an increase in body weight at 56 days (P less than 0.01) and a reduction in carcass fat (P less than 0.005). Food conversion ratio from 28 to 49 days was lower in the treated group than in the controls (P less than 0.01). The data indicate that treated females can reach values similar to those of males. Histological studies revealed a lack of luteal tissue in treated females at 56 days. This effect might be due to a modification in the nervous control of ovarian activity. Growth hormone secretion was higher in treated females than in controls (P less than 0.05). These results suggest that androgenization of females to achieve the performance characteristics of intact males could have important implications in meat production.

Animals↗
PubMed1989

[Long-term course in asymptomatic carriers of HBsAg in an area of low prevalence of hepatocarcinoma].

Data provided by 51 voluntary blood donors identified as asymptomatic HBsAg carriers five to ten years (mean = 7.5 years) before their inclusion in the study are analysed towards their long-term evolution. HBsAg clearance was estimated 2.5% yearly and 83.9% of those remaining positive showed the classical non-replicative serological pattern; another 12.9% were negative for both HBeAg-Anti HBe (seroconversion window?), one of them presenting raised ASAT-ALAT levels and enhanced histological activity (lobular chronic hepatitis). Neither alpha-fetoprotein seric levels (RIA) nor liver ultrasonography demonstrated hepatocellular carcinoma suspicion signs in 35 HBsAg positive cases to this methods; ASAT-ALAT levels raised over two fold the normal superior limit in only 11.4%, and neither aggressive chronic liver disease nor hepatocyte dysplasia was showed in 17 biopsied cases (70.6% normal; 23.6% chronic reactive or chronic persistent hepatitis; 5.8% chronic lobular hepatitis). One out of five patients biopsied with a seven years interval showed histologic worsening.

Blood Donors↗
PubMed1989

[Type I pseudohypoparathyroidism. Study and prolonged follow-up of a case].

The prolonged evolution of a case of pseudohypoparathyroidism with hereditary osteodystrophy (AHO) and osteitis fibrosa is presented. The diagnosis was confirmed by the existence of a peculiar phenotype, hypocalcaemia, hyperphosphatemia, increased PTH values, and a lack of tubular response after PTH and radiological signs of hyperparathyroidism. The clinical and biochemical evolution, under 1.25 (OH)2D3 therapy with special emphasis on the growth and development were shown. The bibliography was also reviewed.

Child↗
PubMed1988

Palmitate dependence of insulin secretion, "de novo" phospholipid synthesis and 45Ca2+-turnover in glucose stimulated rat islets.

Palmitate ability to modify D-[U-14C]glucose incorporation into different lipids ("de novo" synthesis), as well as sugar-stimulation of insulin release and 45Ca2+-fluxes, was investigated in islets of fed and 48-h starved rats. The fatty-acid induced dose-dependent, correlative increments of insulin secretion, 45Ca2+-influx and the "de novo" synthesis of each phospholipid fraction analysed at 20 mmol/l (but not 3 mmol/l) glucose. Omission of calcium reduced drastically (p less than 0.001) insulin release and the "de novo" synthesis of neutral glycerolipids, leaving unaltered that of acidic phospholipids (phosphatidate and phosphoinositides). The increased synthesis of the latter is therefore not the consequence of stimulated secretion. It could initiate or contribute to maintain an increased turnover of islet phosphoinositides, thus generating some mediators of the calcium signalling system (inositol phosphates). Starvation led to a drastic reduction (p less than 0.001) of both insulin secretion, "de novo" synthesis of each lipid fraction, and 45Ca2+-influx in response to glucose and palmitate. The presence of a fatty-acid oxidation inhibitor (2-bromostearate or 2-tetradecylglycidate) prevented the effect of starvation on 45Ca2+-influx, as it has been shown to do on insulin secretion and palmitate incorporation into islet lipids. It is finally suggested that palmitate might amplify the insulin secretory response of islets to glucose, through the stimulation of the "de novo" synthesis of phosphoinositides and the subsequent generation of inositol phosphates, which would contribute to accelerated calcium turnover.

Animals↗