Search PubMed⌕ Search

Biomedical subjects

R Gonzalez

Publications and source records attributed to R Gonzalez.

At least 307 records · Page 17Linked to original sources
PubMed1986

The metabolic disposition of acifran, a new antihyperlipidemic agent, in rats and dogs.

The metabolic disposition of the antihyperlipidemic agent acifran (AY-25, 712) was determined in rats and dogs. The synthesis of 14C-labelled acifran is described. Serum levels of 14C and acifran were measured in rats and dogs after p.o. and i.v. administration of 14C-acifran at a dose of 10 mg/kg. Over 80% of the 14C in serum was due to acifran. The drug was rapidly absorbed and the pharmacokinetics, unaffected by increasing the dose or by daily multiple doses, were characterized by a two-compartment open model. Food reduced the bioavailability of acifran by 27% in the dog. About 65% of the dose was absorbed in rats, and at least 88% in dogs. The elimination t 1/2 of acifran from serum was 1.5 h in the rat and 3 h in the dog. Acifran was partially bound to serum proteins, man greater than rat greater than dog; the drug was found to displace protein-bound warfarin in rat and dog, but not in human serum. Radioactivity did not tend to accumulate in tissues, except for the kidney, where the 14C concentration was five times higher than in the serum; elimination of 14C from all the tissues was similar to that from serum. Most of the absorbed dose was excreted in the urine. Acifran did not undergo enterohepatic circulation in the rat. Virtually all the urinary 14C in both species was due to the unchanged compound. In conclusion, the disposition of acifran was similar in rats and dogs. The drug was rapidly absorbed and eliminated, and underwent no detectable biotransformation. There was no tissue retention and excretion was mainly in the urine.

Animals↗
PubMed1986

New congenital deficiency of high molecular weight kininogen and prekallikrein (Fitzgerald trait). Study of response to DDAVP and venous occlusion.

The prolonged partial thromboplastin time observed in the plasma of a 36 year old asymptomatic man was related to the reduced prekallikrein activities (coagulant; antigenic; and amidolytic) and the absence of coagulant and immunologic activities of high molecular weight kininogen (HMWKg). The patient's plasma also exhibited impaired surface-mediated fibrinolysis and impaired generation of kallikrein. The coagulation defect was identified as the "Fitzgerald trait". The levels of CH50, C2, C4 and C-1 inactivator were normal. Venous occlusion in the patient gave rise to a normal release of extrinsic plasminogen activator from the vascular endothelium. The administration of DDAVP led to a FVIII/VWF response which was similar to that obtained in healthy subjects. No alteration could be observed in the contact phase proteins after DDAVP administration.

Adult↗
PubMed1986

[Tuberculosis of the knee joint in a BCG-vaccinated child].

The case of a 17-month-old boy with tuberculosis of the knee is presented. Problems in diagnosis and treatment of this uncommon joint disease are pointed out. This complication is becoming nearly unknown, so that nowadays the diagnosis and therapy are almost regularly delayed. In every case of disease of the knee all diagnostic methods have to be used to recognize it. In this case, 5 months of therapy elsewhere passed before the diagnosis was made at a surgical exploration with biopsy of the joint. After drainage, inmobilisation and chemotherapy the healing was uneventful. The patient has no complaints and has full range movement of the knee 1/2 year after the end of therapy.

BCG Vaccine↗
PubMed1985

Protein C deficiency--response to danazol and DDAVP.

We studied a Spanish family in which one of the female members presented recurrent thrombophlebitis in both legs after three different deliveries. Biological and antigenic activity of protein C was decreased (35% and 42% respectively). Reduced protein C levels were also observed in 6 other family members. Administration of danazol (600 mg/day) in two patients with protein C deficiency elevated this protein and discontinuation of the drug resulted in a reduction of protein C to pretreatment values. The proposita showed a normal fibrinolytic activity and infusion of DDAVP produced a similar response of FVIII/VWF and plasminogen activator to those observed in healthy subjects.

Antithrombin III↗
PubMed1985

Endoscopic treatment of complete urethral obstruction using thin trocar.

We used an endoscopic thin trocar to reestablish the continuity of the completely obliterated urethra in 2 patients. In 1 man the obstruction resulted from a pelvic fracture and in 1 woman from early removal of the urethral catheter after a bladder neck reconstruction. We found this technique safe and effective, and we consider it to represent an improvement over previously described methods of endoscopic treatment of the obliterated urethra.

Adult↗
PubMed1985

Uncoupling of the calcium pump of the sarcoplasmic reticulum by kerosene.

The effect of kerosene on the calcium pump of sarcoplasmic reticulum vesicles was investigated. Kerosene induces an increase in the rates of ATP hydrolysis without a change in calcium influx, so there is an overall decrease in the efficiency of the pump. These effects are dose-dependent. Our findings imply that kerosene induces an effect on the membrane of vesicles, reducing or inhibiting net calcium accumulation. It is concluded that kerosene induces an 'uncoupling' of the calcium pump through an alteration in the permeability of the membrane.

Animals↗
PubMed1985

Preoperative prediction of continence after enterocystoplasty or undiversion in children with neurogenic bladder.

Fifteen children and young adults with neurogenic bladder undergoing enterocystoplasty were evaluated preoperatively to determine subsequent urinary continence and to establish the need for bladder neck reconstruction. The proximal sphincter mechanism was studied with an erect cystogram under fluoroscopic monitoring and the distal sphincter mechanism was studied with direct electromyography. In 8 patients the distal and proximal sphincters were incompetent, and all underwent a Young-Dees bladder neck reconstruction. In 7 patients 1 or both sphincters were competent and none underwent bladder neck reconstruction during enterocystoplasty. Of the 14 patients followed 13 are continent on intermittent catheterization.

Adolescent↗
PubMed1985

The diagnosis of upper urinary tract obstruction in children: comparison of diuresis renography and pressure flow studies.

We report the use of diuresis renography and pressure flow studies to diagnose urinary tract obstruction in 41 collecting systems of 33 children. If differential pressures between the renal pelvis and the bladder in excess of 22 cm. water at a flow rate of 10 ml. per minute is accepted as evidence of obstruction and below 15 cm. water is accepted as normal the interpretation of the renogram showing O'Reilly's pattern IIIa as evidence of stasis without obstruction was correct in 74 per cent of the cases. Likewise, the interpretation of O'Reilly's renogram pattern IIIb as showing partial obstruction was correct in only 40 per cent of the cases. Thus, we urge caution in the use of the diuresis renogram to diagnose or to rule out upper urinary tract obstruction.

Adolescent↗
PubMed1985

Effect of tolrestat on red blood cell sorbitol levels in patients with diabetes.

The effect of the aldose reductase inhibitor, tolrestat, on red blood cell (RBC) sorbitol levels was studied in 23 patients with diabetes after oral dosing with tolrestat, 25 or 100 mg b.i.d. The mean (+/- SE) RBC sorbitol levels (measured 12 hours after the preceding dose) after 3, 7, and 13 days of dosing decreased after both dose levels. After 25 mg tolrestat the RBC sorbitol levels fell from 25.1 +/- 4.0 to 20.0 +/- 5.7 nmol/gm hemoglobin (21%) and after 100 mg tolrestat the level fell from 26.7 +/- 3.7 to 11.4 +/- 1.7 nmol/gm hemoglobin (57%; P less than 0.001). This latter RBC sorbitol concentration is similar to levels in individuals without diabetes. At both dosage levels the maximum decrease in RBC sorbitol levels occurred after only 3 days of dosing. Tolrestat had no effect on plasma glucose or hemoglobin A1 concentrations. The overall mean plasma unbound drug concentration measured 12 hours after 100 mg tolrestat (11.7 +/- 3.0 ng/ml; 3.3 X 10(-8) mol/L) was similar to the median inhibitory level (3 X 10(-8) mol/L) of tolrestat for sorbitol accumulation in human RBCs incubated in a high-glucose medium. Our results demonstrate the systemic bioavailability of tolrestat and its aldose reductase inhibitory activity in erythrocytes of patients with diabetes.

Administration, Oral↗
PubMed1985

Pulmonary arteriovenous fistula in childhood.

We report two cases of children with pulmonary arteriovenous fistula treated at the University Clinic of Mainz. This angiodysplasia is relatively more diffuse and the clinical signs are more marked in childhood. The non-invasive techniques should be preferred for diagnosis. Complications occur frequently even in asymptomatic children so it is recommended to operate them. The local excision without extirpation of lung tissue should be preferred to segmentectomy or lobectomy for peripheral lesions. Therapeutic embolisation should be tried in inoperable cases.

Arteriovenous Malformations↗
PubMed1985

Prevention of cataract development in severely galactosemic rats by the aldose reductase inhibitor, tolrestat.

With a fixed time period of galactose feeding, the rate of appearance of lenticular opacities depended on the severity of galactosemia, while with a fixed amount of galactose fed, the rate was time dependent. The capacity of tolrestat, a structurally novel inhibitor of aldose reductase (AR), to control cataract development was assessed in rats fed 30-50% galactose with the diet for 7 to 277 days. In rats fed 30% galactose for 31 days, the controlling effect of tolrestat was dose dependent, and no cataracts were detected at a dose of 35 mg/kg/day. In rats given tolrestat with the diet for 14 days, then rendered severely galactosemic with a diet containing 50% galactose, and subjected to continued treatment with tolrestat at a dose of 43 mg/kg/day, no changes were detected by slit-lamp microscopy after 207 days. The preventive effect was also dose dependent. In view of the established similarity in the pathogenesis of galactosemic and diabetic cataracts, the results obtained with tolrestat support its potential for controlling cataract development in diabetics.

Animals↗