Papers by George Steinhardt
The Journal of urology, 1988
A substantial body of animal work indicates that the initial first line defense against invading ... more 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 no...
The Journal of …, 2010
Included in the study were 128 girls and 75 boys 1 to younger than 2 years with grade IIIIV refl... more Included in the study were 128 girls and 75 boys 1 to younger than 2 years with grade IIIIV reflux. Voiding cystourethrography and dimercapto-succinic acid scintigraphy were done before randomization and after 2 years. Febrile urinary tract infections were recorded during ...
J Urol, 1999
KEY WORDS: kidney; nephrolithotomy, percutaneous; hydrothorax
Urology, Mar 31, 1996
Objectives: To develop a method for assessing absolute renal function (as well as morphology) in ... more Objectives: To develop a method for assessing absolute renal function (as well as morphology) in children, using gamma camera imaging of intravenously injected technetium-99m (99mTc) dimercaptosuccinic acid (DMSA).
The Journal of Urology, Jan 10, 2010
We established the baseline occurrence of epididymal cysts, and the correlation between epididyma... more We established the baseline occurrence of epididymal cysts, and the correlation between epididymal cysts and testicular size.
Biomedical Environmental Mass Spectrometry, Aug 1, 1987
Analysis of reports in the world's literature suggests that average sperm densities for groups of... more Analysis of reports in the world's literature suggests that average sperm densities for groups of unselected males were relatively constant at about 108 million cells per ml prior to 1950. Subsequent to that time mean sperm densities appear to have declined. Regression analysis indicates the existence of significant negative correlations between mean sperm densities and production of synthetic organic chemicals among other parameters. Phthalate esters are one class of large volume organic chemicals that are known to disturb testicular function in laboratory animals. These compounds are also the most abundant man-made chemicals in the environment. Plots of the concentration of dibutylphthalate in the cellular fraction of ejaculates against either the sperm density or the total number of sperm for the same ejaculates gave two clusters of points. These clusters suggest the existence of two or more populations uis a uis phthalate metabolism; both of which show a negative correlation between phthalate concentration and sperm production. tane. Evaporation under a stream Of dry nitrogen reduced the volume to 2o F1. The was then examined by GC/mass spectrometry.
J Matern Fetal Neonatal Med, 1992
ABSTRACT This retrospective study examines the postnatal management of 87 babies who were diagnos... more ABSTRACT This retrospective study examines the postnatal management of 87 babies who were diagnosed with prenatal ultrasonography as having some type of urologic abnormality. All of these infants were referred to our pediatric facilty for postnatal urologic care. Of the babies 66 were male and 21 were female. The types of abnormalities seen fall into several diagnostic categories. Urinary obstructions, either at the level of the kidney (UPJ obstruction) or at the ureterovesical junction (UVJ) were the most common diagnosis with 51% of all of the babies falling into either one of these groups. Vesicoureteral reflux was found to be the cause of the prenatal dilation in 18 patients (20.6%) of the total group. Duplication anomalies were present in 7 (8%) of the patients. Posterior urethral valves were found in 7 boys and the triad syndrome (prune belly) in another 4. Multicystic dysplastic kidneys (MCDk) were confirmed to be present by postnatal testing in 6 patients. Considering all of the patients, urologic operations were performed in 36 babies (41%); of these only 6 were performed in the neonatal period, mostly in the patients were valves. Though abnormalities of the urinary system are well visualized prenatally, it is clear that most babies so imaged do not require surgical intervention either in the immediate postnatal period or during infancy. The renal outcome for all of these babies is really quite good; 95.5% of the patients had normal renal function (creatinine <0.7 mg/dl) at long-term follow-up.
The Journal of Urology, Apr 1, 2012
J Appl Stat, 2011
We proposed two simple moment-based procedures, one with (GCCC1) and one without (GCCC2) normalit... more We proposed two simple moment-based procedures, one with (GCCC1) and one without (GCCC2) normality assumptions, to generalize the inference of concordance correlation coefficient for the evaluation of agreement among multiple observers for measurements on a continuous scale. A modified Fisher's Z-transformation was adapted to further improve the inference. We compared the proposed methods with U-statistic-based inference approach. Simulation analysis showed
American journal of men's health, Jan 26, 2016
Scrotal sonography is commonly used for evaluation of the infertile male. While epididymal cysts ... more Scrotal sonography is commonly used for evaluation of the infertile male. While epididymal cysts are frequently observed during sonographic assessment, their presence has uncertain import. This study is a retrospective case-control sonographic and chart review comparison of infertile men and fertile volunteers to clarify the possible association of epididymal cysts and infertility. The study included 91 consecutively recruited patients from January 2012 to December 2014. The infertile group consisted patients with male factor infertility who underwent scrotal sonography (n = 67). The fertile group consisted of men requesting vasectomy who were recruited for study involvement and consented to undergo scrotal sonography (n = 24). The main outcome measure was infertility. The existence of epididymal cysts on scrotal sonography was the main risk factor. Predictably, the only sonographic findings associated with infertility were small testes (right: t(df = 89) = -2.52; left: t(df = 89) =...
Yearbook of Urology, 2006
ABSTRACT We applied a recently developed multivariable renal size nomogram to sonographic measure... more ABSTRACT We applied a recently developed multivariable renal size nomogram to sonographic measurements of kidneys with known scarring to assess systematically their sizes and growth patterns compared to normal kidneys. We retrospectively reviewed renal sonograms of 138 kidneys (55 right and 83 left) with known scarring. The sizes of these scarred kidneys were compared to the 95% prediction limits calculated according to the multivariable renal size nomogram, adjusting for patient age, gender, race, weight and height. The growth of scarred kidneys was evaluated by fitting individual linear regression lines using serial sonographic measurements and comparing the results with normal predicted values. The sizes of 89.1% of the right and 81.9% of the left scarred kidneys were within the 95% normal prediction limits. Only 17 of 138 of the scarred renal units showed smaller kidney sizes compared to the normal prediction limits. Serial sonographic measurements revealed that compared to normal predicted values, 24 of 60 left and 16 of 38 right scarred kidneys grew within +/- 1.0% annually of the boundaries of normal predicted values. Additionally, 8 left and 7 right scarred kidneys indicated a growth rate of more than 1% annually higher than the normal predicted values. Multivariable analyses of renal sonographic measurements provided a dynamic picture of kidney well-being in children with renal scarring. We found that the majority of scarred kidneys were within the normal predicted limits, and a large proportion of these kidneys grew equally well compared to those with normal anatomy.
Urology, May 1, 2006
To examine the variables relative to the response of oxybutynin treatment in children with daytim... more To examine the variables relative to the response of oxybutynin treatment in children with daytime urinary incontinence. The records of patients seen for voiding problems between 1999 and 2003 were reviewed. Patients taking oxybutynin for 3 months or longer were included in the study. Patients with structural or neurologic bladder abnormalities and those taking oxybutynin at the initial visit were excluded. Age, sex, uroflowmetry findings, postvoid residual urine volume, duration and severity of symptoms before oxybutynin, urinary tract infection history, constipation, and the duration, dosage, and adverse effects of oxybutynin treatment were evaluated. Data were analyzed using Fisher's exact test for categorical variables, the two-sample t test or Wilcoxon rank-sum test for continuous and ordinal variables, and the linear mixed model analysis for uroflow data. Eighty-one patients met the inclusion criteria. After an average follow-up of 1.2 years, 31 (38.3%) were dry, 25 (30.9%) had experienced significant improvement, 19 (23.5%) had experienced slight improvement, and 6 (7.4%) were unchanged. No significant differences were detected between those who became dry and those with little to no improvement with respect to age, sex, duration of symptoms, follow-up, uroflow pattern, postvoid residual urine volume, or bladder capacity. Those children presenting with decreased frequency of wetting episodes were significantly more likely to obtain daytime continence. The most common side effects were constipation (18.5%), dry mouth (17.3%), and flushing (13.6%). Children with daytime incontinence presenting with the lowest frequency of wetting were most likely to achieve continence. The frequency of wetting should be considered a significant prognostic variable when assessing the results of therapeutic intervention trials.
Some patients with hydrocephalus cannot be adequately treated with either ventriculo-peritoneal o... more Some patients with hydrocephalus cannot be adequately treated with either ventriculo-peritoneal or ventriculo-atrial shunts. Ventriculo-ureteral (VU) shunts are seldom considered in this group of patients because of the belief that nephrectomy is an essential part of the procedure. We report a case in which a VU shunt was performed with direct ureteral re-implantation and we suggest that a VU shunt is a reasonable alternative for the treatment of a patient with difficult-to-manage hydrocephalus.
Microsc Res Technique, 1997
We have used our opossum model of fetal nephrotoxicity to investigate uranyl nitrate-induced morp... more We have used our opossum model of fetal nephrotoxicity to investigate uranyl nitrate-induced morphologic changes in the developing kidney. The present study establishes a renal dose response curve for the uranyl nitrate (UN). We find that pups treated with nonlethal doses of UN do not demonstrate growth retardation compared to saline-treated controls. The kidneys of UN-treated pups are heavier than the control animals, an effect less apparent the longer the pups are followed. A low dose of 60 mg/kg of UN administered to small pups causes slight histologic derangement but nevertheless more change than the same dose administered to larger more mature pups. Using a dose of 100 mg/kg of UN that effectively causes nonfatal renal disruption, we examined the kidneys from 4 to 42 days following injection. We find that tubular dilation and epithelial necrosis starts soon after treatment (day 4) and reaches its maximum during the second and third week (11 and 22 days). Architectural restoration appears complete by the end of the third week. By electron microscopy, UN induces sequential structural damage with loss of proximal tubule brush border, epithelial necrosis with intact basement membranes and regeneration at 4, 11, and 22 days. Residual tubular mitochondrial damage is present at 42 days in spite of histologically normal tubules. No apparent lesions are seen in glomeruli. Fibroblastic interstitial proliferation in UN-treated kidneys at 11 days is not followed by appreciable fibrosis when assessed at 22 and 42 days. As the structural changes caused by 100 mg/ml UN administration in fetal opossum kidneys are reversible, this is a useful model to study the molecular mediators responsible for this form of renal damage and repair.
The Journal of Urology, Aug 1, 1997
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The Journal of Urology
Acute urinary retention in female patients often is attributed to psychogenic disturbances. Howev... more Acute urinary retention in female patients often is attributed to psychogenic disturbances. However, it is apparent that this problem may be the harbinger of significant organic illness. Our experience with 27 patients reveals that careful evaluation and appropriate treatment prevent further urological complications and aid in the diagnosis of underlying pathological conditions.
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Papers by George Steinhardt