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Biomedical subjects

J Gonzalez

Publications and source records attributed to J Gonzalez.

At least 163 records · Page 9Linked to original sources
PubMed1991

Hepatic disposition of organic anions in rats infested with Fasciola hepatica.

This study was undertaken to investigate the effects of subclinical fascioliasis at various stages of its development (3, 6, and 11 weeks after infestation with an oral dose of 20 metacercariae of Fasciola hepatica) on the hepatobiliary transport of organic anions in rats. Basal bile acid secretion was not significantly modified in infested rats as compared to the controls but there was a significantly increased bile flow in the 11-week group. In all infested rats, maximal biliary excretion and cumulative excretion of bromosulphthalein was significantly reduced, although there was a tendence to recovery in the 11-week infested group. Decreased biliary secretion was accompanied by increased plasma and liver concentrations of bromosulphthalein. Glutathione S-transferase activity was significantly reduced by Weeks 3 and 6 postinfestation. Liver glutathione concentration was significantly reduced in all infested rats. Maximal excretion of dibromosulphthalein, a compound not biotransformed in the liver, fell by Week 6 postinfestation and recovered a normal value thereafter. These results indicate that effects of experimentally induced fascioliasis on hepatic disposition of organic anions depend upon the stage of its development and that are a consequence of both metabolism and transport related factors.

Animals↗
PubMed1991

Hepatic transport of bilirubin in rats with streptozotocin-induced diabetes.

This study was undertaken to evaluate the effects of streptozotocin-induced diabetes on the hepatic transport of bilirubin in male Wistar rats. Rats were pretreated with streptozotocin (60 mg/kg i.p.) to induce uncontrolled diabetes. Six days later endogenous biliary excretion and plasma bilirubin concentration were significantly enhanced compared to control animals (+36% and +46%, respectively), while the blood levels of free hemoglobin remained unchanged. Following a bilirubin load, the maximal biliary excretion of the pigment (Tm) in diabetic animals was significantly enhanced compared to control animals (+49%). Liver and plasma bilirubin concentrations at the end of bilirubin administration were significantly reduced (-28% and -30%, respectively). Bilirubin UDP-glucuronosyltransferase activity and UDP-glucose concentration in liver were significantly enhanced (+31% and +81%, respectively), as was the biliary excretion of unconjugated bilirubin (+37%) and bilirubin mono- (+38%) and diconjugates (+53%). When streptozotocin-diabetic rats were treated with insulin, the parameters of bilirubin transport and metabolism were significantly reduced compared to diabetic animals receiving no hormone replacement. In summary, our data indicate that in short-term streptozotocin-diabetic rats there is increased bilirubin production as well as enhanced hepatic conjugation and subsequent biliary excretion of the pigment. These effects appear to be a direct consequence of diabetes.

Animals↗
PubMed1991

Lymphoma of the gastric stump: report of a case.

We report a case of primary lymphoma on a previously resected stomach in a 62-year-old man. The patient was treated 22 years earlier with a partial gastrectomy and Billroth II reconstruction for a benign gastric ulcer. The rarity of this entity and its possible relationship with pseudolymphoma or lymphoid nodular hyperplasia is discussed, and the literature is reviewed.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Impairment of maximal bilirubin secretion by cyclosporin A in the rat.

The effect of cyclosporin A on the maximal secretion of bilirubin was investigated in male Wistar rats. Following a saturating load of the pigment, intravenous administration of cyclosporin A as a single bolus (20 mg/kg) significantly reduced bile flow and bile acid secretion. The bilirubin secretory transport maximum was alos significantly reduced. The decreased excretion of the bile pigment corresponded both to bilirubin mono- and di-conjugates, the excretion of unconjugated bilirubin being slightly and non-significantly reduced. Plasma and liver bilirubin concentrations were significantly increased, while liver UDP-glucuronosyltransferase activity did not significantly differ between control and cyclosporin A-treated rats. Our data indicate that, although in cyclosporin A-treated rats there are no changes in the activities of others markers of hepatocellular dysfunction, the overall plasma to bile transfer of bilirubin is altered. The reduced hepatobiliary transport of the pigment is mainly caused by an impairment of its intracellular/canalicular transport.

Animals↗
PubMed1990

Changes in the biliary excretion of organic anions following exhaustive exercise in rats.

The effect of exhaustive exercise on the hepatobiliary transport of organic anions was investigated in rats. Animals were run on a rodent treadmill at 24 m/min up a 12% grade (152 +/- 15 min). Exercise resulted in significant hypoglycaemia (-46%) and increased plasma levels of lactate (+12%), together with a marked reduction of glycogen concentration in the liver (-72%). When bromosulphthalein was administered i.v., its maximal biliary excretion (Tm) was significantly reduced (-30%), and plasma and liver concentrations of the dye were increased (+31% and +56%, respectively). The decrease corresponded both to the excretion of the conjugated and unconjugated dye (-30% and -33%, respectively). Cytosolic glutathione S-transferase activity in the liver was not affected by exercise, but there was a significant reduction in the hepatic concentration of glutathione (-50%). The Tm of dibromosulphthalein was also significantly reduced (-36%) and its plasma and liver concentrations increased (+67% and +33%, respectively) in exercised rats. The results suggest that, in addition to the direct effect of liver glutathione depletion, other factors must be involved in the impairment of the biliary excretion of organic anions caused by exercise.

Animals↗
PubMed1990

Effects of ursodeoxycholate on maximal biliary secretion of bilirubin in the rat.

The effect of sodium ursodeoxycholate (0.5 and 1.0 mumol/min/100 g) on the maximal biliary secretion (Tm) of bilirubin and on the concentration of bilirubin in liver and plasma at the end of a bilirubin load was studied in Wistar rats. Administration of ursodeoxycholate at 0.5 mumol/min/100 g caused a 0.8-fold increase in bile flow and a significant increase in the bilirubin Tm (+24%). This was associated with a significant reduction of liver and plasma bilirubin concentrations (-16% and -17%, respectively). Bilirubin UDP-glucuronosyltransferase activity was not significantly enhanced. There was a significant increase in the biliary excretion of bilirubin conjugates (+30%) and in the diconjugates/monoconjugates ratio in bile (+31%). When ursodeoxycholate was given at 1.0 mumol/min/100 g, it produced a 1.7-fold increase in bile flow, but the bilirubin Tm was significantly reduced (-21%). Liver bilirubin concentrations were decreased (-20%) and there was a significant enhancement in total pigment concentration in plasma (+19%). Both the excretion of unconjugated bilirubin and that of bilirubin conjugates were significantly reduced (-60% and -18%, respectively). There was a significant decrease in the bilirubin-UDP glucuronosyltransferase activity and the diconjugates/monoconjugates ratio in bile (-27% and -27%, respectively). These results indicate that ursodeoxycholate is able to increase maximal bilirubin secretion only when administered at low doses and that infusion at higher rates can significantly interfere with different steps in the hepatobiliary transport of the pigment.

Animals↗
PubMed1990

Microdochectomy for discharge from a single lactiferous duct.

Microdochectomy for persistent discharge from a single lactiferous duct was performed in 162 women. Invasive or in situ ductal carcinoma was diagnosed in 16 patients (10 per cent), none of whom had a palpable lump. The discharge was blood-stained in 14 of these women and in two it was clear. Mammography was performed in 15 of these 16 patients and was abnormal in only five. Three patients had atypical ductal hyperplasia, one of whom subsequently developed an invasive ductal carcinoma. Microdochectomy for persistent discharge from a single lactiferous duct is curative and gives a diagnosis of the cause. It remains the treatment of choice whether the discharge is blood-stained or clear.

Adolescent↗
PubMed1990

A patient with hyperkalemia and metabolic acidosis.

Uptake of potassium by extrarenal tissues, primarily muscle and liver, represents a major defense mechanism in the maintenance of normokalemia following an acute elevation in the serum potassium concentration. Insulin, epinephrine, and aldosterone all play major roles in maintaining the normal distribution of potassium between the intracellular and extracellular environment. In addition to hormonal regulation, changes in blood pH and tonicity also exert a strong influence on extrarenal potassium metabolism. Last, the serum potassium concentration per se directly influences its own cellular uptake and this transport mechanism appears to be inhibited by uremia.

Acidosis↗
PubMed1990

An unusual case of intraparotid foreign body.

Foreign bodies in salivary glands are an unusual event; foreign bodies simulating parotid tumors are an exceptional finding. A posttraumatic case of intraparotid foreign body and a brief literature review are presented.

Adult↗
PubMed1990

Spontaneous bacterial peritonitis due to Salmonella enteritidis in cirrhotic ascites.

Spontaneous bacterial peritonitis due to Salmonella is uncommon. We report three patients with ascites infected by Salmonella. All three patients had advanced chronic liver disease, typically cirrhosis with portal hypertension. Salmonella enteritidis grew in the ascite fluid culture of the three patients. There was no clinical or microbiological evidence of Salmonella infection other than in the ascitic fluid. One patient died before antibiotic treatment was started, but the other two were treated with different combinations of antimicrobial drugs. One of them died on the fourteenth day of hospitalization, and the other survived.

Ascites↗
PubMed1990

Effect of norepinephrine on diaphragm contractility and blood flow.

Recent studies have shown that diaphragm fatigue can be reversed by mechanical augmentation of phrenic arterial flow. The purpose of the present experiment was to determine whether it was possible to pharmacologically augment diaphragm blood flow and reverse fatigue by the administration of norepinephrine. Four groups of studies were performed, all employing our previously described in situ isometric canine diaphragm strip preparation (Supinski et al., J. Appl. Physiol. 60: 1789-1796, 1986). Group I studies examined the effects of norepinephrine on the contractility of the nonfatigued diaphragm in normotensive dogs, group II studies examined the effects of this drug on the contractility of the fatigued diaphragm in normotensive animals, and group III studies examined the effect of this drug on the contractility of the fatigued diaphragm in hypotensive animals. Group IV studies examined the effect of norepinephrine in normotensive animals in which the phrenic artery was cannulated and pump perfused at constant flow. Fatigue was induced in group II, III, and IV studies by rhythmically stimulating the diaphragm via intramuscular electrodes. Norepinephrine had no effect on the contractility of the nonfatigued diaphragm (group I). In normotensive (group II) and hypotensive animals (group III), norepinephrine elicited dramatic increases in arterial blood pressure and phrenic arterial flow and produced a significant upshift in the force-frequency curve of the fatigued diaphragm. However, when phrenic flow was held constant (group IV experiments), norepinephrine failed to augment the contractility of the fatigued diaphragm. These results indicate that 1) norepinephrine can increase phrenic blood flow and augment the contractility of the fatigued diaphragm in both normotensive and hypotensive conditions and 2) this effect of norepinephrine to partially reverse fatigue is secondary to its action to augment diaphragmatic blood flow.

Animals↗
PubMed1990

Central pontine myelinolysis following correction of hyponatremia: MRI diagnosis.

A 37-year-old woman with hepatic failure developed a locked-in syndrome after correction of a severe symptomatic hyponatremia. Magnetic resonance imaging showed a lesion involving the basis pontis and extending into the midbrain, consistent with central pontine myelinolysis. In this patient the rate of correction of hyponatremia was within the range considered sure by several authors, but factors such as hepatic encephalopathy, a single generalized seizure and correction of hyponatremia in 42 h with a change in serum sodium concentration of 34 mmol/l were present, and they could have been etiologically relevant. This case, like other recent reports, suggests new views about the pathogenesis of cerebral demyelinating lesions in patients with hyponatremia.

Adult↗
PubMed1989

Evaluation of culture techniques for identification of catheter-related infection in hemodialysis patients.

A prospective study was conducted over eight months to evaluate the usefulness of two culture techniques using different catheter parts for detection of bacterial colonization or catheter-related bacteremia in patients with jugular or subclavian hemodialysis catheters. A combination of semiquantitative culture of the external surface and quantitative culture of the intraluminal surface of the intradermal catheter segment provided the best means of detecting catheter colonization. For detection of catheter-related bacteremia, this combination had 100% sensitivity and a positive predictive value similar to the actual rate of catheter-related bacteremia.

Bacteria↗
PubMed1989

Biocarbon ureterostomy device for urinary diversion. Multicenter clinical trial.

The bioCarbon ureterostomy device is a stomal prosthesis for upper tract urinary diversion that has had preliminary successes in animal and human trials in Europe and Peru. Implantation of a pure carbon stomal prosthesis offers the potential advantages of high biocompatibility, lack of encrustation, and elimination of stomal stenosis which is frequently associated with cutaneous ureterostomy. Nine bioCarbon ureterostomy devices were implanted from August, 1984 through July, 1985. Although successful implantation was achieved in 2 patients, the complication rate was high. The bioCarbon ureterostomy device has potential as an alternative form of urinary diversion. However, significant problems need to be remedied before it can be recommended for routine clinical application.

Aged↗