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Biomedical subjects

R Gonzalez

Publications and source records attributed to R Gonzalez.

At least 325 records · Page 18Linked to original sources
PubMed1985

[Technical approach to excision of renal cancers with venous thrombus extending to the right auricle. Apropos of 4 cases].

The authors report four cases of renal neoplasm with associated thrombosis of the vena cava, extending to the right auricle. Three cases involved the right kidney. Three patients underwent operation with cardio-pulmonary bypass; two operations were successful and one had a fatal outcome. Although the technique of this operation has been considerably simplified, this operation is not performed routinely.

Adult↗
PubMed1984

Undiversion in children with renal failure.

Four children with moderate and 9 with severe chronic renal failure and cutaneous ureterostomies or vesicostomies underwent undiversion to facilitate the eradication of urinary tract infection, reestablish bladder function, and to avoid ablating posterior urethral valves in a dry urethra. This allowed for proper preparation for renal transplantation. In addition, for the less severe cases for whom renal transplantation was more remote, the psychosocial benefits of undiversion were equally important. There were three complications that were easily managed. In four cases of moderate chronic renal failure and in seven cases of severe renal failure not requiring hemodialysis, there was no deterioration of renal function following undiversion. Two patients were on hemodialysis prior to undiversion. The urinary tract became sterile in 12 patients. These preliminary results suggest that chronic renal failure is not a contraindication for urinary undiversion and that this procedure may facilitate future management of the patient, including renal transplantation.

Child, Preschool↗
PubMed1984

Malignant urachal lesions.

Urachal cancers are uncommon malignancies with a location that often permits considerable local extension before they are discovered. The most common histological type is adenocarcinoma, which may produce mucus that is a valuable aid in diagnosis. The presence of stippled calcification in a midline abdominal wall mass is almost pathognomonic for urachal carcinoma. More commonly, however, the symptoms are less specific, such as hematuria and an abdominal mass. Many lesions are visible endoscopically and, thus, the diagnosis can be made preoperatively from a biopsy. Most treatment failures occur because the tumor is not controlled locally by the initial operation and, therefore, we recommend en bloc cystectomy with umbilectomy and pelvic lymphadenectomy unless the tumor is known to be a sarcoma or early stage (I) carcinoma. If these patients are undertreated and there is a local recurrence then the patient usually is not salvageable. Because of the difficulty in identifying the origin of a bladder adenocarcinoma, any tumor on the dome or anterior wall should be approached initially as if it were a urachal tumor.

Adult↗
PubMed1984

Hyperammonemia in a boy with obstructive ureterocele and proteus infection.

We report on a boy with ureteroceles that obstructed the bladder outlet and ureters, who presented with sepsis and hyperammonemia despite normal liver function. The hyperammonemia was most likely caused by excessive absorption of ammonia produced by Proteus mirabilis in the obstructed urinary tract.

Ammonia↗
PubMed1984

Treatment of urinary incontinence with an artificial sphincter: further experience with the AS791/792 device.

Artificial sphincter models AS791 and AS792 were used to treat 36 male and 7 female patients with urinary incontinence. Satisfactory results were obtained in 72 per cent of the patients. Of 100 surgical procedures performed to achieve these results 61 were planned procedures (initial implantation and delayed activation) and 39 were revisions required to improve continence, change mechanically failing devices or remove eroded sphincters. From our study 3 major problems with the artificial sphincter are apparent: 1) stress incontinence, which was present in 55 per cent of the patients with bulbous urethral sphincter compared to 21 per cent with sphincters located at the bladder neck, 2) erosions, which appear to be related to balloon pressure used and location of the artificial sphincter (there seems to be a higher incidence of erosions when the bulbous urethral site is used with balloon pressure greater than 80 cm. water) and 3) mechanical failures of the device, which accounted for 41 per cent of the unplanned operations in our series. These 3 major problems are reviewed, the possible etiology of persistent stress incontinence is discussed and possible ways to avoid these complications are suggested.

Adolescent↗
PubMed1984

Differentiation of upper and lower urinary tract infections: how and when?

The principal purpose of differentiating upper and lower urinary tract infections is to prevent renal damage by determining which patients require long-term antibiotic treatment and follow-up. This article takes a critical look at the method now in use for differentiation of these infections. Special attention is given to the problems of locating a urinary tract infection in a child, both because this is exceptionally difficult in this population and because kidney infections in children carry a high risk of permanent damage including renal failure and hypertension.

Adult↗
PubMed1984

[Bilateral diaphragmatic hernia].

A case of a newborn with bilateral Bochdalek's diaphragmatic hernia is reported. Because of respiratory distress the patient had to be operated on urgently; the left diaphragmatic hernia was repaired. On the 12th day of life, relaparatomy was performed and the right diaphragma was operated because of a suspected ileus. The clinical course was good and at the age of 11 weeks the patient was discharged. This malformation is extremely rare. Extensively studied cases of bilateral diaphragmatic hernia are not often found in literature.

Hernia, Diaphragmatic↗
PubMed1984

Extracellular matrix (ECM) proteoglycans produced by cultured bovine corneal endothelial cells.

The nature of the proteoglycan(s) (PG) found in the extracellular matrix (ECM) layer produced by cultured bovine corneal endothelial (BCE) cells is analyzed. The PG(s) account for approximately 5 to 6% of the dry weight of the ECM, regardless of the amount of extracellular soluble PG available in the medium. A 4 M guanidinium chloride (GuCl) extract of ECM was separated on a dissociative cesium chloride (CsCl) gradient (1.25 g/cm3 starting density). Results showed one main peak of PG substance(s) comprising 91% of the total labelled substance and uronic acid, banding at a specific buoyant density of 1.29 g/cm3. The molecular weight of this major PG(s) as estimated by gel filtration on Sepharose CL-4B ranged from 0.5 to 0.7 X 10(6). Further chemical analysis of the main PG(s) band revealed a protein moiety accounting for 45% of the weight and carbohydrates-glycosaminoglycans (GAG) accounting for the remaining 55%. Analysis of the GAG chains (over the entire gradient) showed a composition, based on the susceptibility of the PG substance(s) to degrading enzymes, of 50% heparan sulfate, 43.5% dermatan sulfate, and 6.5% chondroitin 4- and 6-sulfate chains. BCE cell cultures grown in the presence of beta-D-xyloside produced an ECM lacking more than 90% of the GAG content found in the control ECM. The medium-soluble GAG chains, produced in vast excess in cultures grown in the presence of beta-D-xyloside, are composed mainly of chondroitin 4- and 6-sulfates.

Animals↗
PubMed1983

Are factors originating from serum, plasma, or cultured cells involved in the growth-promoting effect of the extracellular matrix produced by cultured bovine corneal endothelial cells?

The possibilities that the growth-promoting effect of the extracellular matrix (ECM) produced by cultured bovine corneal endothelial (BCE) cells could be due to: (1) adsorbed cellular factors released during the cell lysis process leading to the denudation of the ECM; (2) adsorbed serum or plasma factors: or (3) adsorbed exogenous growth factors have been examined. Exposure of confluent BCE cultures to 2 M urea in medium supplemented with 0.5% calf serum denudes the ECM without cell lysis. The ECM prepared by this procedure supports cell growth just as well as ECM prepared by denudation involving cell lysis. Thus, it is unlikely that the growth-promoting properties of ECM are due to adsorbed cellular factors. When the ECM produced by BCE cells grown in defined medium supplemented with high-density lipoprotein, transferrin, and insulin was compared to the ECMs produced by cells grown in the presence of serum- or plasma-supplemented medium, all were found to be equally potent in stimulating cell growth. It is therefore unlikely that the growth-promoting ability of the ECM is due to adsorbed plasma or serum components. When fibroblast growth factor (FGF)-coated and ECM-coated plastic dishes were submitted to a heat treatment (70 degrees C, 30 min) which results in the inactivation of FGF, the growth-supporting ability of FGF-coated dishes was lost, while the comparable ability of ECM-coated dishes was not affected significantly. This observation tends to demonstrate that the active factor present in the ECM is not FGF. Nor is it platelet-derived growth factor (PDGF), since treatment known to destroy the activity of PDGF, such as exposure to dithiothreitol (0.1 M, 30 min, 22 degrees C) or to beta-mercaptoethanol (10%) in the presence or absence of 6 M urea for 30 min at 22 degrees C, does not affect the growth-promoting activity of ECM. It is therefore unlikely that the growth-promoting effect of ECM is due to cellular growth-promoting agents or to plasma or serum factors adsorbed onto the ECM.

Adsorption↗
PubMed1983

Carcinoma at the site of ureterosigmoidostomy.

A 31-year-old woman who had undergone bilateral ureterosigmoidostomy at age five had a moderately differentiated adenocarcinoma at the anastomotic site that was not detected by preoperative studies or intraoperative palpation. The authors review other reports of anastomotic carcinomas occurring after ureterosigmoidostomy for benign disease and recommend a diagnostic protocol. Whenever the urine is diverted away from the sigmoidostomy (rediversion), the anastomotic site should be resected. Ureterosigmoidostomy should be undertaken only with the understanding that meticulous long-term follow-up is mandatory.

Adenocarcinoma↗
PubMed1983

Closed chest permanent atrioventricular block in dogs.

Ten mongrel dogs underwent transcutaneous His bundle ablation by means of pulsed synchronized electrical shocks delivered between an electrode catheter adjacent to the His bundle and a metal plate behind the dog's back. Detailed histologic studies were performed 3 months after induction of stable complete atrioventricular (AV) block in nine dogs. The ventricular response ranged from 35 to 51 beats/min (bpm). Graded increases in overdrive ventricular pacing resulted in graded increases in pacemaker suppression up to a paced cycle length of 450 msec. All dogs showed extensive damage to the approaches to the AV node, the AV node, and the penetrating portion of the common bundle. This technique resulted in complete AV block with typical features of an infranodal pacemaker and correlated with the histologic findings of severe damage to the AV junction. The minimal myocardial damage suggests that this technique may be applicable for control of drug refractory supraventricular arrhythmias in humans.

Animals↗
PubMed1983

Patency of the cervical canal in cross-bred female Zebu x Brown Swiss selected for non-surgical recovery or transfer of embryos.

A test to evaluate the degree of patency of the cervical canal was carried out on 260 Zebu x Brown Swiss cows and heifers that were assigned for non-surgical recovery or transfer of embryos. A total of 204 females (78.5%) were found to have a patent cervix (P <0.05), compared with 56 (21.5%) which had a blockage or obstruction when an attempt was made to pass a catheter through the cervical canal or the "cervical knot" of the purebred and cross-bred Zebu cows. A smaller percentage (12.89%) of non-patent cervices (P <0.05) were detected in multiparas, compared with 25 and 27.5% in primiparas and nullipara, respectively. The test for cervical patency is carried out on Bos indicus cattle to screen the animals before non-surgical embryo transfer manipulations and to attain better results in the application of non-surgical recovery and transfer of embryos.

Journal Article↗
PubMed1983

Comparison of Doppler examination and retrograde spermatic venography in the diagnosis of varicocele.

The accuracy of the Doppler stethoscope is compared with that of retrograde spermatic venography in the diagnosis of varicocele in 39 subfertile men. In the 38 cases in which left-sided venography was successful, there was a good correlation between the radiographic and Doppler results in 33 cases (87%). The five failures were all false-negative results in patients without clinically diagnosed varicoceles. In the 33 cases in which right-sided venography was successful, there was a good correlation between the radiographic and Doppler results in 17 patients (52%). This low sensitivity on the right side appears to be a minor drawback, because right-sided reflux almost always occurs in conjunction with left-sided reflux, and therefore varicocele would be diagnosed in these patients despite the false-negative Doppler finding. Unlike venography, the Doppler study is noninvasive, inexpensive, and easy to perform. We conclude that it should be part of all studies of varicocele and infertility and that it may prove sufficiently accurate for use in controlled studies of the effectiveness of varicocelectomy and the role of subclinical varicocele in the pathogenesis of infertility.

Humans↗
PubMed1983

Endoscopic re-establishment of urethral continuity after traumatic disruption of the membranous urethra.

We report 3 cases of complete traumatic disruption of the membranous urethra treated by transurethral section of the scar tissue with transvesical endoscopic guidance and digital rectal control. Postoperatively, the patients required an average of 3 subsequent urethrotomies. They remain well, continent and free of voiding symptoms for 28, 11 and 14 months after re-establishment of urethral continuity. We suggest that this treatment be considered as an alternative to conventional surgical repair, particularly in elderly and other high risk patients.

Adult↗