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Biomedical subjects

F Requena

Publications and source records attributed to F Requena.

18 recordsLinked to original sources
PubMed1987

[Biochemical complications of experimental vesico-sigmoidostomy].

Three experimental models of vesico-sigmoidostomy are studied (model-1, end to side V-S plus urethral ligation, model-2, end to end V-S, in "Y of Rous" plus urethral ligation and model-3, vesico-sigmoidoplasty), with aim of reproducing chemical imbalance observed in human subjects with ureterosigmoidostomy. Authors have evaluated clinical biochemical (serum acido-base balance, Cl, Na+, K+, BUN, creatinine, ammonia and albumin), and histologic variables in the first, third and fifth month after operation in 225 rats. Animal of model-1 presented more frequently than model-2 and model-3, alterations (hyperchloraemic acidosis, uraemia, hyperammonemia and hypoalbumin) as well as affectation of upper urinary system for acute or chronic pyelonephritis.

Animals↗
PubMed1985

Portoenterostomy diversion. Experimental study in antireflux technique.

Ascending cholangitis was induced in dogs by performing a biliodigestive Roux-Y anastomosis. Then two valvular antireflux mechanisms were performed on separate groups of these dogs with the aim of preventing the onset of ascending cholangitis. One was performed by a laterolateral plicature at the intestinal anastomosis and the other by invagination of the mucosa in the nonworking loop that had been anastomosed to the bile duct. All the dogs underwent analytic tests over a period of 3 months and histopathologic tests at the end of the study period. Results showed cholangitis and pericholangitis in the liver biopsy specimens of the group with no antireflux valve, to a lesser degree in the group with laterolateral plicature, and almost none in the animals with the invaginated valve.

Animals↗
PubMed1980

Possible mechanism of stimulation of gastrin secretion by exogenous serotonin in rats.

The effect of 6-hydroxydopamine, propranolol, phentolamine, alpha-methyl-tyrosine and alpha-methyl-tyrosine plus propranolol on serotonin-stimulated gastrin secretion in rats has been examined. Gastrin secretion in response to administration of serotonin alone (10 mg/kg i.p.) was significantly reduced in rats pretreated with 6-hydroxydopamine or with propranolol. These results suggest that the effect of exogenous serotonin on gastrin secretion can be described as sympathomimetic and indirect. The serotonin-stimulated gastrin secretion was significantly enhanced by previous administration of phentolamine. Pretreatment with alpha-methyl-tyrosine also elevated serotonin-stimulated gastrin secretion, indicating that in the presence of diminished concentrations of the catecholamines, the influence of exogenous serotonin on secretion by G cells is increased. This enhancement in the serum gastrin levels was also reduced to a significant extent by simultaneous administration of propranolol, which suggested the activation of G-cell beta-adrenergic receptors after serotonin administration.

Animals↗
PubMed1979

Effect of exogenous serotonin on intragastric pH and its influence on serum gastrin levels in rats.

The effect of various doses of serotonin on the serum gastrin levels and intragastric pH in rats, was studied. After serotonin administration of 10 mg/kg i.p., a significant increase in serum gastrin levels was noted, as well as a strong increase in the intragastric pH. It was also observed that a lower dose, 5 mg/kg i.p., significantly increased serum gastrin levels, while intragastric pH was not affected, remaining at baseline values throughout the study. These results suggest that the increase observed in serum gastrin levels after administration of exogenous serotonin is not mediated by increase in intragastric pH.

Animals↗
PubMedDate not supplied

Transperitoneal absorption of intralipid in rats: total serum fatty acids and triglyceride after absorption.

Intralipid 20% was injected percutaneously into the peritoneum of 58 female rats. The rats were divided into seven groups (with an additional control group of 35 rats). To measure transperitoneal absorption, we determined the serum fatty acid and triglyceride concentrations at 3-hr intervals for 24 hr, and found a considerable increase in all of the levels measured, with a maximum at about 6 hr. The serum triglyceride levels never rose above a mean value of 200 mg/100 ml. A second and smaller rise was seen after 15 hr, declining again to the initial values. The relative proportions of the different fatty acids changed, but not drastically.

Absorption↗
PubMedDate not supplied

Functional anatomy of the medial collateral ligament of the ankle joint.

The calcaneotibial and posterior talotibial ligaments slacken and the naviculotibial ligament tightens as the ankle plantarflexes; the reverse occurs in ankle extension. The naviculotibial ligament increases its length and the posterior talotibial ligament relaxes in abduction. The cutting of the posterior talotibial ligament repercutes on other parts of the medial collateral ligament. The cutting of other parts of the medial collateral ligament produces very little change on the posterior talotibial ligament. When the whole medial collateral ligament is severed, there is a lateral displacement of the talus. This may be important in the diagnosis and surgical treatment of a torn medial collateral ligament.

Ankle Joint↗