Biomedical subjects

D S Scherr

Publications and source records attributed to D S Scherr.

4 recordsLinked to original sources

PubMed2006

Diagnosis of renal tumors on needle biopsy specimens by histological and molecular analysis.

PURPOSE: We diagnosed the subtypes of renal cell carcinoma on needle core biopsies using a combination of histopathology and a molecular diagnostic algorithm. MATERIALS AND METHODS: Core biopsies were taken of renal tumors following nephrectomy. RNA was extracted and quantitative real-time polymerase chain reaction was performed for 4 gene products to differentiate among renal cell carcinoma subtypes. Histopathological diagnosis was achieved on a second core before and after obtaining the molecular diagnostic algorithm results. RESULTS: Based on the nephrectomy diagnosis 6 of 77 renal masses were nonneoplastic and 71 were tumors, including 65 renal cell carcinoma/oncocytomas. The overall diagnostic accuracy using histology and our molecular diagnostic algorithm combined was 90.0% (70 of 77). Side by side comparison of histology vs molecular diagnostic algorithm was feasible for 60 classifiable renal cell carcinoma/oncocytomas (31 clear cell, 14 papillary renal cell carcinoma, 6 chromophobe renal cell carcinoma, 2 mucinous tubular and spindle cell carcinoma, and 7 oncocytoma). In this group histology correctly predicted the final histological subtype in 83.3% (50 of 60) of cores. Addition of the molecular diagnostic algorithm to histology improved the subtyping accuracy to 95% (57 of 60), whereas the molecular diagnostic algorithm alone was accurate in 50 of 60 cases (83.3%). Dividing these 60 specimens into clear cell and nonclear cell neoplasms, the addition of the molecular diagnostic algorithm improved the sensitivity for the diagnosis of clear cell carcinoma from 87.1% (27 of 31) to 100% and the negative predictive value from 87.5% to 100%. CONCLUSIONS: Core biopsies of renal tumors provide adequate material for diagnosing and subtyping renal cell carcinoma. The addition of our molecular diagnostic algorithm to histology improved the diagnostic accuracy of core biopsies of renal masses.

Adult↗

PubMed1999

BCL-2 and p53 expression in clinically localized prostate cancer predicts response to external beam radiotherapy.

PURPOSE: Clinicians have long been hampered by the inability to distinguish patients with localized prostate cancer who will and will not respond to radiotherapy. In a significant proportion of patients therapy fails as determined by increasing posttreatment serum prostate specific antigen (PSA). We evaluated the expression of 2 key regulators of apoptosis, bcl-2 and p53, relative to treatment outcomes in patients who received external beam radiotherapy for clinically organ confined carcinoma of the prostate. MATERIALS AND METHODS: Immunohistochemical staining for bcl-2 and p53 on pretreatment needle biopsies was performed in 54 patients who were treated with radiotherapy for localized prostate cancer. Expression was scored using strict criteria. Nadir PSA less than 1 ng./ml. after therapy was considered a successful treatment response. RESULTS: There was a predominance of stage T1c cancer (74%) with a mean Gleason score of 6.9 and an average pretreatment PSA of 25.3 ng./ml. Overall 54% of the patients did not have a nadir PSA of less than 1 ng./ml. Of the bcl-2 positive cases therapy ultimately failed in 85%. Similarly 88% of the patients with p53 positive biopsies had treatment failure and in all with bcl-2 as well as p53 expression radiotherapy failed. Expression of bcl-2 and p53 was an independent prognostic variable for treatment failure with odds ratios (95% confidence interval) of 7.3 and 10.8, respectively. CONCLUSIONS: Expression of bcl-2 and p53 was associated with treatment failure after external beam radiation therapy. These findings suggest that bcl-2 and p53 expression in pretreatment biopsies may be helpful for predicting response to definitive radiotherapy.

Adenocarcinoma↗

PubMed1998

Laser tissue welding.

Laser tissue welding is a technologic innovation that is beginning to move from the theoretical laboratory environment to the reality of clinical application. This article reviews the concepts, potential advantages, and techniques involved in laser tissue welding as they apply to urology.

Humans↗

PubMed1998

Laser tissue welding: a urological surgeon's perspective.

Laser tissue welding has proven its efficacy in the laboratory setting when compared with more traditional modalities of tissue reapproximation. In the clinical environment, several areas including urethral reconstructive surgery have shown great promise. Several technological advancements including solder development, chromophore enhancement and temperature control have improved upon the welding process and have added more precision and reproducibility to the technique. The current potential applications for laser welding in urology are numerous. On a molecular level, growth factor supplementation has certain potential in improving upon weld site healing and wound strength. Laparoscopic surgery with its need for less cumbersome modes of tissue closure is a field that will greatly benefit from the technology of laser tissue welding. Surgical specialties outside of urology are also participating in developing the field of laser welding. In particular, cardiothoracic surgery, otolaryngology, plastic surgery, neurosurgery among others, have utilized the concept of laser tissue welding. There are many ares that have potential use for laser welding that have yet to be explored. Further investigation will likely reveal more applications for this valuable technology.

Forecasting↗