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Dive into the research topics where Robert E. Weiss is active.

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Featured researches published by Robert E. Weiss.


The Journal of Urology | 2000

URETEROENTERIC ANASTOMOSIS IN CONTINENT URINARY DIVERSION: LONG-TERM RESULTS AND COMPLICATIONS OF DIRECT VERSUS NONREFLUXING TECHNIQUES

Allan J. Pantuck; Ken‐ryu Han; Michael Perrotti; Robert E. Weiss; Kenneth B. Cummings

PURPOSE Controversy exists over the importance of antireflux mechanisms in large volume, low pressure intestinal bladder substitutions. Despite the theoretical benefits of reflux prevention, antirefluxing ureteral reimplantations may have a greater risk of anastomotic stricture. We hypothesize that this inherent stricture rate may outweigh the potential benefits associated with reflux prevention. To assess this question critically we compare our results to those of direct and nonrefluxing techniques of ureterointestinal anastomosis during continent diversion. MATERIALS AND METHODS Between 1990 and 1998, 58 patients underwent continent urinary diversion using an Indiana pouch or ileal orthotopic neobladder following cystectomy for muscle invasive bladder cancer. A total of 56 renal units were implanted using an end-to-side Nesbit direct anastomosis and 60 were implanted in a nonrefluxing manner. Clinical end points included anastomotic stricture formation, hydronephrosis, pyelonephritis, upper tract stone formation and renal deterioration, and were assessed with a mean followup of 41 months. RESULTS Of 60 nonrefluxing ureteroenteric anastomoses 8 (13%) resulted in nonneoplastic stricture formation compared to 1 of 56 (1.7%) direct anastomoses, which was statistically significant (Fishers exact test p <0.05). Strictures occurred up to 6 years following the original surgery. There was no significant difference between the 2 groups in regard to hydronephrosis, pyelonephritis, upper tract stone formation or azotemia. CONCLUSIONS Nonrefluxing methods of ureterointestinal reimplantation resulted in a statistically significant higher rate of anastomotic stricture than the end-to-side direct anastomosis. This finding appears to outweigh any theoretical benefits of preventing pyelonephritis, stones or azotemia. For patients undergoing large volume, low pressure continent diversion the refluxing ureterointestinal anastomosis may be the technique of choice since it preserves renal function as well as the nonrefluxing method, is technically easier to perform and poses less risk of stricture. Delayed stricture formation years after surgery underscores the necessity for long-term radiological followup in patients following continent diversion.


The Journal of Urology | 1999

Female urethral adenocarcinoma : Immunohistochemical evidence of more than 1 tissue of origin

David P Murphy; Allan J. Pantuck; Peter S. Amenta; Kiron M. Das; Kenneth B. Cummings; Gary L. Keeney; Robert E. Weiss

PURPOSE Urethral adenocarcinoma is a rare malignancy whose origin remains controversial. The monoclonal antibody mAbDas1 (formerly 7E12H12) was developed against a unique colonic epithelial epitope and is reactive in areas of intestinal metaplasia. Recently the antibody was shown to react in cystitis glandularis as well as adenocarcinoma of the bladder, suggesting that cystitis glandularis may be the precursor of bladder adenocarcinoma. We examined urethral adenocarcinomas and benign urethral specimens using mAbDas1 to determine whether it could provide insight into their histogenesis. MATERIALS AND METHODS Archival tissue from 12 cases of primary female urethral adenocarcinoma and urethral specimens of inflamed urethral mucosa, urethritis glandularis and transitional cell carcinoma was studied. Immunohistochemical analysis of formalin fixed, paraffin embedded archival tissue was done using the monoclonal antibody mAbDas1. Tumors were also evaluated with a prostate specific antigen (PSA) polyclonal antibody as previous studies have noted PSA reactivity in these tumors. RESULTS Of the 12 cases 9 were columnar/mucinous adenocarcinoma, 2 clear cell adenocarcinoma and 1 a cribriform pattern resembling adenocarcinoma of the prostate. All columnar/mucinous adenocarcinomas reacted positively (6 strongly and 3 focally) with the mAbDas1 antibody but did not react with the PSA antibody. The tumor with a cribriform pattern reacted strongly with PSA but did not react with mAbDas1. The 2 clear cell adenocarcinomas did not react with either antibody. The benign urethral specimens demonstrated strong reactivity to the mAbDas1 antibody in areas of urethritis glandularis but normal and inflamed urethral mucosa and transitional cell carcinoma did not react. CONCLUSIONS Primary adenocarcinoma of the female urethra arises from more than 1 tissue of origin. Columnar/mucinous adenocarcinomas of the female urethra and urethritis glandularis demonstrate consistent reactivity with the mAbDas1 antibody, suggesting that these tumors arise from glandular metaplasia analogous to the potential histogenesis previously demonstrated in the bladder. PSA reactivity occurred in 1 tumor with a cribriform pattern and likely represents origin from Skenes glands. Clear cell adenocarcinomas did not react with either antibody, suggesting a third possible pathway in the development of this rare subset of adenocarcinomas.


The Journal of Urology | 1997

ADENOCARCINOMA OF THE URACHUS AND BLADDER EXPRESSES A UNIQUE COLONIC EPITHELIAL EPITOPE: AN IMMUNOHISTOCHEMICAL STUDY

Allan J. Pantuck; Edita Bancila; Kiron M. Das; Peter S. Amenta; Kenneth B. Cummings; Michael Marks; Robert E. Weiss

PURPOSE Primary adenocarcinoma of the bladder is a rare neoplasm whose histogenesis is poorly understood. Current data support the concept that adenocarcinoma of the bladder and urachus evolves from zones of intestinal metaplasia that become dysplastic and invasive. To address this hypothesis further we determined the immunoreactivity of benign and malignant epithelial tissue from the bladder and urachus with a monoclonal antibody that is reactive with colonic epithelium to evaluate the presence of a common reactive epitope. MATERIALS AND METHODS The monoclonal antibody 7E12H12 (IgM isotype), developed against a colonic epithelial protein, was used in an immunoperoxidase assay to survey formalin fixed, paraffin embedded archival tissue specimens. A total of 26 specimens obtained by endoscopic biopsy or extirpative surgery, including benign and malignant bladder and urachal epithelial abnormalities, was chosen for retrospective evaluation. RESULTS All adenocarcinoma reacted positively regardless of the histological variant, differentiation, or bladder or urachal origin. In contrast, transitional cell and squamous cell carcinomas were nonreactive. Also, the pattern of reactivity in tissues that contained benign epithelial proliferations suggested a stepwise transition with no reactivity in normal urothelium or Brunns epithelial nests, rare staining of cystitis cystica, and uniformly positive reactivity in cystitis glandularis and frank colonic intestinal metaplasia of the bladder and urachus. CONCLUSIONS The shared, aberrant phenotypic expression of a unique colonic epitope in benign epithelial metaplasia, and adenocarcinoma of the bladder and urachus suggests a common underlying pathway toward adenocarcinoma in cystic and urachal adenocarcinoma. The implications for diagnostic pathology are discussed.


Urology | 2000

Lymphatic mapping and intraoperative lymphoscintigraphy for identifying the sentinel node in penile tumors.

Ken‐ryu Han; Brian N Brogle; James Goydos; Michael Perrotti; Kenneth B. Cummings; Robert E. Weiss

Lymph node mapping has become an integral part of the management of melanoma and breast cancer with regard to both staging and treatment. We report our technique for lymphatic mapping and intraoperative lymphoscintigraphy applied to a patient with penile melanoma. This technique may improve the sensitivity of identifying the sentinel lymph node in patients with malignant penile lesions.


Urology | 1999

Behçet's syndrome with left ventricular aneurysm and ruptured renal artery pseudoaneurysm.

Ken-ryu Han; Randall Siegel; Allan J. Pantuck; Mukaram A Gazi; Derrick K Burno; Robert E. Weiss

A 21-year-old man with Behçets syndrome presented with both a left ventricular aneurysm and a left renal artery pseudoaneurysm. After successful embolization of the ruptured pseudoaneurysm, the patient underwent successful repair of the left ventricular aneurysm. Although multiple aneurysms have been reported previously, we believe this to be the first reported case of both a ventricular aneurysm and a renal artery pseudoaneurysm afflicting a patient with Behçets syndrome.


The Journal of Urology | 1998

CORRELATION OF MECHANICAL IMAGING AND HISTOPATHOLOGY OF RADICAL PROSTATECTOMY SPECIMENS: A PILOT STUDY FOR DETECTING PROSTATE CANCER

Peter Niemczyk; Kenneth B. Cummings; Armen Sarvazyan; Edita Bancila; W. Steven Ward; Robert E. Weiss

PURPOSE A new modality termed mechanical imaging has recently been developed. We determined whether mechanical imaging could be used to detect prostate cancer in radical prostatectomy specimens. MATERIALS AND METHODS Stress patterns on the surface of excised prostates were evaluated using the data obtained from a planar piezoelectric resistive force sensor array. Seven radical prostatectomy and 2 cystoprostatectomy specimens were manually palpated and evaluated by the mechanical imager. The prostates were histopathologically analyzed for the presence of cancer. The results of the manual palpation, mechanical imaging and pathological analysis were correlated. RESULTS Mechanical imaging correlated closely with nodules palpated in all specimens and in 1 it revealed a suspicious area undetected by palpation, which on subsequent histological analysis demonstrated carcinoma. CONCLUSIONS Mechanical imaging can detect areas of heterogeneity in prostate tissue which correlate with cancer. Our findings provide the basis for the development of a transrectal mechanical imaging probe for prostate cancer detection.


Urology | 2012

Association between pioglitazone and urothelial bladder cancer.

Yanina Barbalat; Viktor Y. Dombrovskiy; Robert E. Weiss

The U.S. Food and Drug Administration and the European Medicines Agency have recently informed the public of a potential impact of pioglitazone (Actos) use on bladder cancer incidence. These recommendations are based on 2 recent large published cohort studies indicating a possible association between pioglitazone use and bladder cancer development. Currently, there is no urology literature on this subject. We present the current literature reporting the association between pioglitazone and bladder cancer.


Urology | 1998

Adenocarcinoma Arising within a Testicular Metastasis

David P Murphy; Edita Bancila; Rocco G. Ciocca; Kenneth B. Cummings; Robert E. Weiss

Teratoma with malignant transformation is defined as the emergence of a non-germ cell tumor from a teratoma. Although extremely rare in extraovarian sites, cases have been reported that involve primary extragonadal germ cell tumors with transformation to variants of sarcoma. We report a 54-year-old man who was found to have adenocarcinoma arising within a mature teratomatous retroperitoneal metastasis 15 years after treatment of a nonseminomatous testicular germ cell tumor. The tumor was successfully excised and he remains without evidence of disease.


The Journal of Urology | 1997

Seizures After Ureteral Stone Manipulation With Lidocaine

Allan J. Pantuck; Joel W. Goldsmith; John B. Kuriyan; Robert E. Weiss

A 40-year-old 62 kg. woman with no medical history, no known drug allergies and no prior exposure to lidocaine presented with acute onset of colicky left flank pain. Excretory urography showed a 3 mm. stone at the left ureteropelvic junction with moderate hydronephrosis. After failing to pass the stone and remaining symptomatic, she was hospitalized for extracorporeal shock wave lithotripsy with the stone now in the lower ureter. After induction of intravenous sedation, an 8F open ended catheter was passed over a 0.38 guide wire following several unsuccessful attempts due to resistance met in the distal ureter. Then, 20 ml. 2% lidocaine hydrochloride jelly (400 mg.) diluted to half strength with saline were injected with manipulation of the stone to the sacroiliac joint. Because of inability to pass a 10F catheter an 8F manipulator catheter was passed and 20 ml. 2% lidocaine were injected with manipulation of the stone to the L5 vertebrae. Within several minutes of the second injection the patient experienced 3 to 4 episodes of generalized tonic-clonic seizures each lasting 30 to 40 seconds, which stopped after treatment with thiopental. The procedure was terminated after placement of a DoubleJ* stent. Evaluation by a neurologist, including computerized tomography of the head, was negative. She underwent ureteroscopic stone extraction 5 days later without complication, and remained stone-free and without neurological sequela 1 year later. DISCUSSION


The Journal of Urology | 2016

Comparison of Urinary Tract Infection Rates Associated with Transurethral Catheterization, Suprapubic Tube and Clean Intermittent Catheterization in the Postoperative Setting: A Network Meta-Analysis

Christopher Han; Sinae Kim; Kushan Radadia; Philip Zhao; Sammy E. Elsamra; Ephrem O. Olweny; Robert E. Weiss

Purpose: We performed a network meta‐analysis of available randomized, controlled trials to elucidate the risks of urinary tract infection associated with transurethral catheterization, suprapubic tubes and intermittent catheterization in the postoperative setting. Materials and Methods: PubMed®, EMBASE® and Google Scholar™ searches were performed for eligible randomized, controlled trials from January 1980 to July 2015 that included patients who underwent transurethral catheterization, suprapubic tube placement or intermittent catheterization at the time of surgery and catheterization lasting up to postoperative day 30. The primary outcome of comparison was the urinary tract infection rate via a network meta‐analysis with random effects model using the netmeta package in R 3.2 (www.r‐project.org/). Results: Included in analysis were 14 randomized, controlled trials in a total of 1,391 patients. Intermittent catheterization and suprapubic tubes showed no evidence of decreased urinary tract infection rates compared to transurethral catheterization. Suprapubic tubes and intermittent catheterization had comparable urinary tract infection rates (OR 0.903, 95% CI 0.479–2.555). On subgroup analysis of 10 randomized, controlled trials with available mean catheterization duration data in a total of 928 patients intermittent catheterization and suprapubic tube were associated with significantly decreased risk of urinary tract infection compared to transurethral catheterization when catheterization duration was greater than 5 days (OR 0.173, 95% CI 0.073–0.412 and OR 0.142, 95% CI 0.073–0.276, respectively). Conclusions: Transurethral catheterization is not associated with an increased urinary tract infection risk compared to suprapubic tubes and intermittent catheterization if catheterization duration is 5 days or less. However, a suprapubic tube or intermittent catheterization is associated with a lower rate of urinary tract infection if longer term catheterization is expected in the postoperative period.

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