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Biomedical subjects

R Gonzalez

Publications and source records attributed to R Gonzalez.

At least 271 records · Page 15Linked to original sources
PubMed1988

Luteinizing hormone, testosterone and cortisol responses in rams upon presentation of estrous females in the nonbreeding season.

The physiological responses of luteinizing hormone, testosterone and cortisol in sexually experienced Ile de France rams to the introduction of estrous females were studied during the nonbreeding season. Blood sampling were collected from males for 7 h at 20-min intervals, starting 3 h before stimulation by estrous females. The differences in hormonal secretions were tested by comparisons between pretreatment and treatment Periods in 45 stimulated rams. Comparisons were conducted between rams that had increased LH pulse frequency and those that did not, between rams that ejaculated and those that did not, and between rams that were in direct physical contact and those that were kept at a distance of 30 cm from estrous females. Twenty-five rams (55% of the total) showed significant increases in LH pulse frequency (range, 0.80 to 4.00 peaks/ram/6 h, P<0.05), in basal and mean LH levels (1.5- and 2.5-fold, respectively), and in mean testosterone levels (3.5-fold). More frequent LH pulses had been found during the pretreatment period in 20 rams without increased LH pulse frequency. Eight ejaculating rams showed higher cortisol and mean, basal, and peak LH amplitude levels. Deprivation of physical contact with estrous females was associated with an absence of endocrine response. These results suggest that olfactory and/or tactile cues may be involved in the female effect on hormone levels.

Journal Article↗
PubMed1988

Endoscopic treatment of posterior urethral obliteration: long-term followup and comparison with transpubic urethroplasty.

We compare our results with the endoscopic management of posterior urethral obliteration in 8 patients to our previous experience with transpubic urethroplasty in 6 patients. Although most patients who underwent an endoscopic procedure required 2 or 3 followup internal urethrotomies within the first 2 to 10 months after treatment, 6 have remained free of stricture for more than 2 years after this initial period of aggressive endoscopic management. This finding suggests that total obliteration of the posterior urethra can be managed effectively by endoscopic techniques. Comparison of endoscopic treatment with transpubic urethroplasty revealed a decrease in operative time, blood loss and hospital stay with endoscopic management. We recommend that transpubic urethroplasty be reserved for patients in whom urethral continuity cannot be re-established with relatively safe and simple endourological techniques.

Adult↗
PubMed1988

The outcome of renal transplantation in children with posterior urethral valves.

The effect of vesical dysfunction on the survival and function of renal transplants was evaluated by a retrospective study in which 18 children with posterior urethral valves and 18 children with vesicoureteral reflux were randomly matched with 36 children used as controls. There was no statistically significant difference in patient survival among the 3 groups. Five years after transplantation 50 per cent of the grafts in children with posterior urethral valves were functioning, while 73 and 75 per cent, respectively, of the grafts were functioning in children with vesicoureteral reflux and in the control group. Renal function during the 5 years was significantly better in children in the control group and in those with vesicoureteral reflux than in children with posterior urethral valves. We believe that the presence of an abnormal bladder may alter graft survival and adversely affect the function of the transplanted kidney.

Adolescent↗
PubMed1988

Usefulness of sotalol for drug-refractory malignant ventricular arrhythmias.

Fifty patients with recurrent sustained symptomatic ventricular tachycardia (43 patients) or ventricular fibrillation (7 patients) resistant to a mean of 2.8 + 1.4 antiarrhythmic drugs were treated with sotalol, a beta-adrenergic receptor antagonist, and 45 underwent invasive electrophysiologic testing before and after sotalol therapy. The arrhythmia became noninducible in 10, was slower and hemodynamically well tolerated in 12 and was poorly tolerated in 23. Four patients were empirically treated with long-term administration of oral sotalol as were 21 patients who either had noninducible arrhythmia (10 patients) or had hemodynamically stable ventricular tachycardia (11 patients). In these 25 patients treated with long-term administration of sotalol, there was no recurrence of ventricular tachycardia in the group with noninducible arrhythmia, whereas 37% of patients with inducible ventricular tachycardia had new ventricular tachycardia or sudden death. Programmed ventricular stimulation with up to three extrastimuli proved to be an excellent predictor of drug efficacy and a good predictor of inefficacy. A positive prior response to amiodarone was not a reliable indicator of a positive response to sotalol. Side effects included those attributed to both beta-adrenergic blockade as well as proarrhythmic effects. The latter were observed in two of four patients with a QT interval greater than 600 ms. Sotalol was found to be effective therapy for a subset of patients with ventricular tachycardia unresponsive to type IA drugs.

Adult↗
PubMed1988

Effect of a low-protein diet on urinary albumin excretion in uremic patients.

Fifteen patients with advanced renal failure (creatinine clearance less than 25 ml/mn) and with severe albuminuria (greater than 1.5 g/24 h) were put on a low-protein (0.3 g/kg body weight), low-phosphorus (5-7 mg/kg body weight) diet supplemented with essential amino acids and ketoanalogues. During the 6-month follow-up, urinary albumin excretion and fractional renal albumin clearance were reduced significantly while serum albumin concentration increased; no nutritional change occurred during the study.

Adult↗
PubMed1988

Management of ureteropelvic junction obstruction in infants and neonates.

From June 1980 to October 1985 we performed 22 ureteropyeloplasties on 20 infants and neonates with ureteropelvic junction obstruction. All patients were males less than 2 years old; 12 were less than 1-month-old. The diagnosis was suspected on the basis of maternal ultrasonography in 10 patients (50%), a palpable abdominal mass was the presenting symptom in 7 (35%), and obstruction was detected during evaluation of congenital heart disease in 3 (15%). This change in mode of presentation is expected to become even more pronounced as the use of fetal ultrasonography increases. All patients in whom the diagnosis was suspected antenatally underwent ultrasonography after birth to confirm the presence of hydronephrosis. All 22 obstructed kidneys were repaired by a dismembered technique under optical magnification. There were no operative mortalities. Of 21 postoperative intravenous pyelograms available, 3 demonstrated marked improvement, 17 showed improvement with residual hydronephrosis, and 1 showed deterioration. The methods used to diagnose, treat and evaluate ureteropelvic junction obstruction in 20 infants and neonates are presented. Given the existing clinical and experimental data we advocate early postnatal surgical correction of ureteropelvic junction obstruction to achieve a maximum recovery of renal function.

Female↗
PubMed1988

Temporal variation in LH and testosterone responses of rams after the introduction of oestrous females during the breeding season.

The response of sexually experienced Ile-de-France rams to the presentation of oestrous females in October at sunrise (Subgroup S) or at 11:00 h (Subgroup N) was studied and compared with unstimulated controls (Subgroup C). Animals (12 per group) were bled for 7 h at 20-min intervals, starting 3 h before stimulation by oestrous females (3 per group). Eight rams from Subgroup S showed an increase of LH pulse frequency and only 3 in Subgroup N (P less than 0.03). In Subgroup S the introduction of females led to 2- and 3-fold increases in LH pulse frequency during the stimulation period compared with values in Subgroup C or before the stimulation period (3, 1.6 and 1 peaks/rams/6 h respectively; P less than 0.05). The presence of females also led to an increase in mean testosterone concentrations, and small increases in basal and mean LH values. No differences were found in LH peak amplitudes. In Subgroup N only inconsistent evidence of increases in mean LH and testosterone values was found. No differences between Subgroups S and N in behavioural patterns during stimulation were detected. We conclude that the presence of females affects LH pulse frequency at sunrise but not at noon during the breeding season and this effect is at least partly independent of sexual behaviour. These results suggest a possible circadian variation in CNS sensitivity involving the hypothalamic regulation of LH secretion in response to the presence of oestrous females.

Animals↗
PubMed1988

Specificity of natural serum antibodies present in phylogenetically distinct fish species.

The following fish orders, at different stages of phylogenetic development, were tested for serum antibody activity against actin, myosin, tubulin, thyroglobulin, haemocyanin, single-stranded DNA and trinitrophenyl (TNP): Elasmobranches (sharks), Chondrosteans (sturgeons), and Teleosts (bony fish). Significant antibody activity was found against all these self and non-self antigens but, in particular, high titres of natural anti-TNP antibodies were noted. Anti-TNP antibodies were then isolated by affinity chromatography from pooled sera of several representative fish species, and studied by a non-competitive and a competitive enzyme immunoassay. When the isolated antibodies were tested by the non-competitive assay, Teleost (tench) anti-TNP antibodies bound almost exclusively to TNP, whereas Chondrostean and Elasmobranche antibodies bound mainly to TNP but also to one or more other antigens. When the isolated antibodies were examined by the competitive assay, they could be separated into three groups: (i) anti-TNP antibodies whose binding could be inhibited by TNP only (Teleosts); (ii) anti-TNP antibodies mainly inhibited by TNP but also significantly inhibited by two or three other antigens (Chondrosteans); and (iii) anti-TNP antibodies binding to different antigens but only slightly inhibited by them (Elasmobranches). These antibodies were found by immunocytochemical staining to bind to normal cell constituents, and especially to cytoskeletal proteins. The results strongly suggest that natural antibodies against the seven antigens examined are present in normal fish serum, and that their specificities differ with the stage of phylogenetic development.

Animals↗
PubMed1987

Normal pregnancy in a patient with a postpartum factor VIII inhibitor.

A patient who had developed a VIII:C IgG-Kappa antibody after her first delivery became pregnant for a second time. At that time the titer of the inhibitor had increased fourfold, remaining at high levels throughout the rest of the pregnancy. The neonate exhibited an inhibitor with characteristics identical to that of the mother which could not be detected 3 months after birth. No hemorrhagic complications in either of the subjects were observed.

Adult↗
PubMed1987

Natural History Study of Congenital Heart Defects.

A strategy designed to locate and recruit individuals who were part of a study in the 1960s of congenital aortic stenosis, pulmonary stenosis, and ventricular septal defect for purposes of a follow-up examination is presented. These individuals are now adults living throughout the United States and some foreign countries. The present study, referred to as NHS-2, is designed to bring the survivors back to one of six clinical centers for medical evaluation to study the long-term results of medical and surgical treatment of such patients.

Adult↗
PubMed1987

Evaluation of Gen-Probe DNA hybridization systems for the identification of Mycobacterium tuberculosis and Mycobacterium avium-intracellulare.

The Gen-Probe DNA hybridization system, rapid diagnostic assays for the identification of Mycobacterium tuberculosis (MTB) complex and Mycobacterium avium-intracellulare (MAIC) complex, were evaluated. Designed to identify a primary mycobacterial isolate, the former correctly identified 91 of 92 MTB and all 27 non-MTB isolates and controls when compared with conventional identification methods for a sensitivity of 98.91% and specificity of 100%. The latter correctly identified 63 of 64 MAIC isolates and controls and 31 of 32 non-MAIC isolates and controls when compared with conventional identification methods for a sensitivity of 98.43% and a specificity of 96.87%. The one false positive noted with the MAIC probe was an MTB misidentified as an MAIC. The two false negatives noted above were subsequently shown to be contaminated. The tests are fast and easy to perform and interpret.

DNA, Bacterial↗
PubMed1987

Congenital ureteral valves in children: case report and review of the literature.

Congenital ureteral valves are a rare cause of ureteral obstruction. While only 17 pediatric cases have been reported in the literature, this condition should be considered in the differential diagnosis of the child with upper urinary tract obstruction. The pediatric cases are reviewed, and we present an additional case in which unilateral hydronephrosis caused by a ureteral valve was first detected by ultrasound in utero.

Female↗
PubMed1987

Enterocystoplasty in the management and reconstruction of the pediatric neurogenic bladder.

Eighteen children and young adults with neurogenic bladder underwent enterocystoplasty as part of urinary undiversion or for treatment of incontinence associated with reduced bladder compliance or detrusor sphincter dyssynergia. In 12, tubular sigmoid enterocystoplasty with transureteroureterostomy was performed with the smaller diameter ureter implanted into the bowel tenia. In two patients the ileocecal segment was used to augment the bladder, and the ureters were anastomosed to the ileum. In four patients the cecum or a patch of sigmoid colon was used to augment the bladder. Young-Dees bladder neck reconstruction was performed on eight patients at the time of surgery; one later required bladder neck reconstruction, and two later required an artificial sphincter. After a mean follow-up of 20 months, 16 of the 17 available for follow-up are continent with clean intermittent catheterization every 3 to 4 hours. Nine patients require anticholinergic or smooth muscle relaxing medication to increase functional bladder capacity. Most of the patients need chronic antimicrobial treatment to control bacteriuria.

Adolescent↗
PubMed1987

Localization of bacteriuria in patients with enterocystoplasty and nonrefluxing conduits.

Urine cultures were obtained by percutaneous aspiration of renal pelvic urine in an attempt to localize the source of chronic asymptomatic bacteriuria in 10 patients with intestinal segments incorporated into the urinary tract. One child with a nonrefluxing colonic conduit and 6 of 8 patients with nonrefluxing enterocystoplasties had upper tract bacteriuria. One patient with a ureterosigmoidostomy and a history of pyelonephritis had negative cultures while on prophylactic antibacterials. The significance of upper tract bacteriuria in these patients is unknown but lifelong followup of renal function is necessary.

Bacteriuria↗
PubMed1987

Comparison of artificial sphincter implantation and bladder neck reconstruction in patients with neurogenic urinary incontinence.

The results of artificial urinary sphincter implantation and Young-Dees-Leadbetter bladder neck reconstruction were compared in 27 patients with neurogenic urinary incontinence. Although an equal degree of continence was achieved with both procedures the reoperation rate was significantly higher in patients who underwent artificial sphincter implantation. The advantages and disadvantages of each procedure are discussed.

Adolescent↗
PubMed1987

Posterior lumbotomy in pediatric pyeloplasty.

Between 1981 and 1985 we performed 32 ureteropyeloplasties on 29 infants and children with ureteropelvic junction obstruction. The posterior lumbotomy incision was used in 14 cases and proved to offer distinct advantages when compared to the anterior and flank incisions. The surgical technique is described in detail and the advantages are discussed.

Child↗