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Biomedical subjects

G F Steinhardt

Publications and source records attributed to G F Steinhardt.

At least 37 records · Page 2Linked to original sources
PubMed1991

Urinary PGE2 in rats with chronic partial unilateral ureteral obstruction.

Urinary prostaglandin E2 (PGE2) was measured in Munich-Wistar rats with surgically created chronic partial unilateral ureteral obstruction (UUO). Mean values of bladder urine PGE2 were higher in sham than in UUO (24.5 +/- 14.4 vs 12.9 +/- 8.2 ng/mg creatinine, respectively, P less than 0.05). Following diuresis, both ureters were cannulated and urine was collected. PGE2 excretion was increased in sham (66.5 +/- 34.4 and 70.1 +/- 44.5 ng/mg creatinine, left and right, respectively). But in UUO, the obstructed kidney excreted less PGE2 than the contralateral kidney (32.1 +/- 6.0 vs 62.3 +/- 40.4 ng/mg creatinine, obstructed vs contralateral, respectively, P = 0.08). PGE2 synthesis was then determined in separated renal medullary and cortical slices. Renal medullary slices from kidneys with severe obstruction synthesized less PGE2 than the contralateral unobstructed side (3.30 +/- 1.22 vs 10.52 +/- 3.23 ng/mg wet wt-30 min, respectively, P less than 0.05) and failed to respond to arachidonic acid stimulation with any significant increase in PGE2 synthesis (3.30 +/- 1.22 vs 4.47 +/- 1.04 ng/mg wet wt-30 min, baseline vs stimulated). In contrast, contralateral unobstructed kidney slices responded with a significant increase in PGE2 synthesis (10.52 +/- 3.23 vs 21.10 +/- 2.50 ng/mg wet wt-30 min, baseline vs stimulated, P less than 0.05). We conclude that chronic partial UUO in the Munich-Wistar rats resulted in significantly less PGE2 elaboration.

Animals↗
PubMed1990

Medicolegal aspects of testicular torsion.

Testicular torsion is a surgical emergency which requires prompt exploration, detorsion, and bilateral orchiopexy. The authors present information helping to explain why testicular torsion often leads to lawsuits for physicians.

Adolescent↗
PubMed1988

Malignancy associated with ureterosigmoidostomy: detection by mucosa ornithine decarboxylase.

Urinary diversion into the gastrointestinal tract (ureterosigmoidostomy) is associated with stepwise malignant degeneration of colonic mucosa. Early detection of such malignancy can be difficult. Ornithine decarboxylase (ODC) is an enzyme that initiates polyamine synthesis that is elevated in malignant colonic mucosa, but its level in premalignant mucosa after ureterosigmoidostomy is unknown. Ten Wistar rats underwent urinary diversion (bladder trigone to sigmoid colon), and were maintained on a regular diet with antibiotics for 6 months, then killed. All animals developed metaplastic changes histologically at the anastomosis. Mean ODC levels of colonic mucosa at the anastomosis v normal colon 8 cm proximal were 515 +/- 177 pmole v 24.5 +/- 4.4 (P less than .01). These data show that premalignant changes in colonic mucosa after ureterosigmoidostomy can be detected by elevated colonic biopsy ODC levels. Periodic sigmoidoscopy with colon mucosa biopsy for histology and ODC levels in children with ureterosigmoidostomy is recommended.

Adenocarcinoma↗
PubMed1988

Induced renal dysplasia in the young pouch opossum.

Using the North American opossum, Didelphis virginiana, we have developed a new model for studying the effects of early fetal urinary obstruction on subsequent renal development. We have successfully induced renal dysplasia in the marsupial that has a typically mammalian kidney.

Animals↗
PubMed1988

Defective antiadherence activity of bladder extracts from patients with recurrent urinary tract infection.

A substantial body of animal work indicates that the initial first line defense against invading microorganisms in the urinary tract is the antiadherence activity of the surface mucin layer. Previous work has demonstrated that bacterial adherence to anion exchange resin can be used as a model for adherence to the mucin deficient rabbit bladder. This anion exchange resin adherence model can also be used as a rapid screen for potential antiadherence agents. In vitro saline extracts of bladder mucosa from various mammalian species including man have been shown to inhibit bacterial adherence to both anion exchange resin and the mucin deficient rabbit bladder. The present report investigates the ability of in vivo saline bladder washes from several groups of patients to inhibit bacterial adherence to anion exchange resin. This has an advantage over other methods of quantitation or visualization of mucin since it is the ability of the bladder extract to prevent bacterial adherence, and not merely the quantity of mucin, that determines the effectiveness of the mucin lining in preventing bacterial attachment. Bladder washes from patients with recurrent urinary tract infection were significantly less potent at inhibiting bacterial adherence than extracts from other groups of patients. This decreased functional antiadherence activity of bladder extracts may help explain the frequency of urinary tract infection in this group of patients.

Adult↗
PubMed1988

Prostatic suppuration and destruction in patients with myelodysplasia: a newly recognized entity.

Prostatic abscess is an unusual occurrence in the era of modern antibiotics. In 5 patients with myelodysplasia extravasation of contrast material to the boundaries of the prostate was noted on voiding cystourethrography. All patients were adolescents who, with varying degrees of compliance, had managed the neurogenic bladder with intermittent catheterization since childhood. All patients had chronic urinary tract infections. In 2 patients subjected to transurethral resection the prostatic parenchyma was completely replaced by the suppurative process. Neither patient demonstrated much clinical improvement after resection. The possible etiological factors and various therapeutic options are discussed for the previously unreported condition of chronic prostatic abscess in myelomeningocele patients.

Abscess↗
PubMed1988

The effect of intravesical pressure on glomerular filtration rate in patients with myelomeningocele.

Numerous investigators have demonstrated the development of hydronephrosis and renal deterioration in patients with myelomeningocele who have high pressure bladders. By drawing blood at sequential intervals during 99mtechnetium-diethylenetriaminepentaacetic acid renal scanning we are able to generate nuclide clearance curves that correlate well with glomerular filtration rate. Renal scanning is done most frequently with the bladder catheterized and left to gravity drainage. By filling the bladder under manometric control to a pressure of 35 to 40 cm. water we have followed routine scanning with continued blood sampling to generate nuclide clearance at low and high bladder pressures. In 5 myelomeningocele patients so studied we found consistent and significant decreases in glomerular filtration rate at high bladder pressures.

Adolescent↗
PubMed1988

Glomerulosclerosis in obstructive uropathy.

Obstructive uropathy is said to result in populations of remnant nephrons subject to hyperfiltration. We studied all obstructed renal tissue removed at our pediatric institution during a 10-year period for focal segmental glomerulosclerosis, which is the histological hallmark of hyperfiltration. Over-all, the histological specimens from 20 patients with ureteropelvic junction obstruction, 14 who underwent heminephrectomy for duplication anomalies and 5 with posterior urethral valves who underwent native nephrectomy were studied. Focal segmental glomerulosclerosis was one of the most common histological findings in these obstructed kidneys but it almost always was found in association with intense interstitial and periglomerular inflammation. We conclude that although focal segmental glomerulosclerosis is common in obstructive uropathological conditions it results from the inflammatory response within the renal parenchyma and not from the hyperfiltration of remnant nephron populations.

Child↗
PubMed1986

Gonadoblastoma presenting as isosexual precocious puberty in a genetic female.

A 6 1/2-year-old female with pseudoprecocious puberty was found to have a gonadoblastoma. Her karyotype was 46, XX; serum estradiol level was markedly elevated; and androgens were within the range of normal. The importance of the Y chromosome and dysgenetic gonad in the predisposition to development of a gonadoblastoma is reviewed. A further categorization of gonadoblastomas based on the presence or absence of the Y chromosome is suggested.

Child↗
PubMed1985

Male urethral diverticulum: the double density sign.

An anatomic defect of the urethra is occasionally the cause of voiding dysfunction in the young male patient. A urethral diverticulum can often be overlooked if retrograde urethrography is not performed properly. Two cases are presented along with a discussion of the technique for dynamic retrograde urethrography. The description of a new radiologic sign indicative of a posterior bulbar urethral diverticulum, is presented.

Adult↗
PubMed1985

Tunica vaginalis free graft for the correction of chordee.

Tunica vaginalis free grafts were used to correct severe chordee not amenable to other surgical maneuvers in 11 boys. Postoperatively, the penis was straight in 10 patients and had some degree of downward angulation in 1 boy. The tunica vaginalis free graft seems to be a useful technique for the correction of severe chordee.

Child, Preschool↗
PubMed1985

Noncompliant bladder resulting from posterior urethral valves.

We report on 4 boys with abnormally functioning, poorly compliant bladders and residual urine associated with posterior urethral valves. All 4 boys have been managed with clean intermittent self-catheterization and have shown stabilization or improvement in renal function, and improvement in upper tract drainage and urinary continence. The pathophysiological findings of this type of bladder dysfunction are discussed.

Child↗
PubMed1985

Orchiopexy: planned 2-stage technique.

Planned unilateral 2-stage orchiopexy was undertaken in 14 of 919 primary inguinal explorations for an undescended or nonpalpable testis. In 9 of the 14 cases a silicone sheath was placed around the spermatic cord to protect the cord structures from injury at the time of the second stage. An adequate-sized scrotal testis resulted in 83 per cent of these planned 2-stage orchiopexies. Our impression is that the silicone sheath greatly facilitates the second stage.

Child↗
PubMed1985

Simple renal cysts in infants.

Two cases of renal cysts in infants less than one year of age are presented. In both instances percutaneous puncture of the cyst aided in establishing the diagnosis without the need for an operative procedure.

Contrast Media↗