Publications by authors named "David Buethe"

Introduction: Up to 50% of patients will have disease reclassification while on active surveillance (AS) for their prostate cancer. Determining which patients will have reclassification that will impact their survival is difficult. We investigated clinicopathologic factors associated with disease reclassification and differences in both overall and metastasis free survival between those treated and those remaining on AS.

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Perivascular epithelioid cell-containing tumors (PEComas) represent a rare family of neoplasms. Their dichotomous phenotypic features, including both myogenic and mylanocytic features, can make a definitive diagnosis difficult. Such tumors have been associated with the overexpression of transcription factor E3 (TFE3).

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Purpose: We report a multicenter international cohort representing what is to our knowledge the largest surgical experience with managing isolated retroperitoneal nodal recurrence of renal cell carcinoma, a unique subset of locoregional disease, yet to be described in detail.

Materials And Methods: Patients with isolated nodal recurrence of pTanyN+M0 disease after nephrectomy were identified by retrospective chart review at 3 independent institutions. Progression-free survival was estimated by the Kaplan-Meier method and used to compare survival outcomes between primary T(1-2)N(any)M0 and T3N(any)M0 tumors as well as clear cell and nonclear cell histology renal cell carcinoma.

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Background: Nephron-sparing treatments remain underutilized for the management of small renal masses despite a rise in incidentally detected renal cell carcinoma and a downward stage migration.

Methods: Historical publications representative of currently accepted paradigms were reviewed, and the results of a contemporary scientific literature search conducted in PubMed focusing on studies involving humans, published in English, and inclusive of clinical trials, meta-analyses, randomized controlled trials, and practice guidelines are included. Results from contemporary retrospective trials augment the data when level I or II evidence is absent.

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In the era of widespread prostate-specific antigen screening, low-risk and very-low-risk prostate cancers are commonly identified, many of which will be of clinical insignificance. This has led to overtreatment and undue exposure to treatment-related morbidity in men harboring indolent tumors. Over the past 10 years, active surveillance (AS) has been evolving as a management strategy for these cancers.

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Primary large cell neuroendocrine carcinomas (NECs) of the bladder are rarely encountered, and only a few reports have been documented. Frequently, they are found to be admixed with other histologies. In this report, we describe such a tumor found in a 65-year-old man who underwent radical cystectomy, after initial transurethral resection discovered a small cell NEC pathology.

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Multiple Endocrine Neoplasia type 2A (MEN-2a) is a rare disease associated with tumors of endocrine organs. Presentation most commonly is with medullary thyroid cancer and infrequently with other complaints. Pituitary adenoma has been seen coincidentally with this disease very rarely.

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A 7-year-old male with bilateral palpable testicular masses was found to have metastatic stage IV Wilms' tumors associated with both left renal and lung lesions. The patient was treated successfully with testicular-sparing bilateral partial orchiectomies, radical nephrectomy, chemotherapy, and radiation, with 8 years free of recurrence. This is the only reported case of bilateral testicular tumors from metastatic Wilms' tumor that were present at the initial presentation.

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Penile cancer is an uncommon disease in the industrialized world that most frequently presents at low stage and is cured with treatment of local and regional surgery. In cases of advanced cancer, the use of more aggressive surgical techniques and the addition of adjuvant therapy may be warranted. So far, few agents have been found that improve survival with metastatic disease and thus aggressive primary treatment is required.

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We report on the evaluation and management of a 47-year-old white male found to have primary carcinoid tumor of the ileal segment of his diverting ileovesicostomy thirty-five months after initial creation. Subsequent to presentation with intermittent gross hematuria, CT urogram highlights an 8 mm enhancing lesion near the enterovesical junction of urinary diversion. Office cystoscopy confirms presence of a lesion that was later endoscopically resected and found to be a well-differentiated carcinoid tumor.

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Purpose: Chondroitin sulfate (Stellar Pharmaceuticals, London, Ontario, Canada), which is less expensive and more inert than heparinoids, hyaluronan or pentosan polysulfate, has been introduced to restore the barrier function lost due to epithelial dysfunction in interstitial cystitis cases. To our knowledge chondroitin sulfate binding to damaged bladder as a function of the urinary pH range, its efficacy in restoring the bladder permeability barrier and the capacity of the damaged bladder to bind chondroitin sulfate have not been determined previously.

Materials And Methods: Chondroitin sulfate binding to bladder urothelium was investigated quantitatively using chondroitin sulfate highly labeled with Texas Red(R) and quantitative fluorescence microscopy in a mouse model of urothelial acid damage.

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A statistically robust and biologically-based approach for analysis of microarray data is described that integrates independent biological knowledge and data with a global F-test for finding genes of interest that minimizes the need for replicates when used for hypothesis generation. First, each microarray is normalized to its noise level around zero. The microarray dataset is then globally adjusted by robust linear regression.

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Compacting plasmid DNA (pDNA) into a small size is a fundamental necessity for the efficient in vivo transfer of nucleic acids to somatic cells. An approach for accomplishing this is to condense pDNA using cationic detergents with sulfhydryl groups, near their critical micelle concentration. In this study, a model surfactant was used to study how the rate of disulfide bond formation relates to environmental factors.

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