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Biomedical subjects

W S McDougal

Publications and source records attributed to W S McDougal.

At least 19 recordsLinked to original sources
PubMed2004

Effect of keratinocyte growth factor and activin on cell growth in the human prostatic cancer cell line LNCaP.

Keratinocyte growth factor (KGF) has paracrine properties in the human prostate which stimulate epithelial cell growth. Activins have profound effects on cell growth and function in the human prostate, and are expressed in LNCaP, DU 145 and PC3 cells. LNCaP cells were characterized by immuncytochemistry, an immunoassay and polymerase chain reaction. A 3[H]thymidine assay was used with 0.01-10 nM dihydrotestosterone, 10 micro M flutamide, 1-100 ng/ml KGF and 3 nM activin. LNCaP cells expressed Ki67, PSA, cytokeratins (8, 18, 19, 14, 15) androgenreceptor but no KGF protein. LNCaP cells showed telomerase activity. Furthermore, ARmRNA (365 bp), but no KGF or KGFRmRNA were expressed. KGF ELISA detected no intracellular or secreted KGF. DHT (1, 10 and 100 nM) and KGF (10 and 100 ng/ml) significantly stimulated LNCaP cell proliferation. However, flutamide and 3 nM activin A significantly decreased cell proliferation in the presence and absence of KGF. The results of our experiments support the hypothesis that cell growth and proliferative characteristics of LNCaP cells are modulated by KGF and activin A.

Activins↗
PubMed2004

Studies on the differentiation pathway and growth characteristics of epithelial culture cells of the human prostate.

We established explant primary cultures in order to study the growth and hormone responsiveness, and the differentiation process of prostatic epithelial cells. Cell outgrowth was achieved from explant tissue by using a new DU145-cell-conditioned medium and special plastic coverslips. To define the present model, proliferation assays were tested by [3H]thymidine assay and planimetric analysis. Cells were analyzed using immunocytochemistry, light, phase contrast and electron microscopy, polymerase chain reaction, telomerase ELISA and immunoassay (PSA). Morphology and electron microscopy revealed typical epithelial differentiation. Immunocytochemistry showed the content of basal and secretory epithelial cells, endocrine paracrine cells and a high level of proliferation. With increasing culture time, mature epithelial differentiation (PSA) increases and the initial increase of alpha-smooth muscle actin (alpha-SMA) decreases again. After further passaging, alpha-SMA expression is no longer detected and PSA expression decreases. Furthermore, epithelial cells showed both androgen responsiveness and androgen receptor expression. These findings show the presence of epithelial cells in a process of differentiation with endocrine paracrine cells and a high level of proliferation. This model may maintain the cellular and functional properties more closely related to the human prostate and may provide a valuable tool for studying stem cells and differentiation characteristics.

Cell Culture Techniques↗
PubMed2001

Regulation of keratinocyte growth factor receptor and androgen receptor in epithelial cells of the human prostate.

PURPOSE: Stromal-epithelial interactions of growth factors and the androgen receptor may have implications for the pathophysiology of benign and neoplastic transformation of the human adult prostate. We investigated a possible interaction of keratinocyte growth factor with its receptor as well as with the androgen receptor signaling pathway in human prostatic epithelial cells. MATERIALS AND METHODS: Human prostatic epithelial cells were obtained from explant primary culture, established in DU145 cell conditioned medium and maintained in keratinocyte serum-free medium with supplements. Epithelial cells were characterized by light and electron microscopy, and immunocytochemical study using epithelial and mesenchymal markers. Androgen receptor, keratinocyte growth factor receptor and keratinocyte growth factor messenger RNA expression was measured by polymerase chain reaction (PCR). The response to 0.01 to 10 nM. dihydrotestosterone, 10 microM. flutamide and 1 to 1,000 ng./ml. keratinocyte growth factor was tested by [3H] thymidine assay. The difference in keratinocyte growth factor receptor and androgen receptor gene expression after treatment with and without keratinocyte growth factor and flutamide were determined by quantitative multiplex PCR and quantitated using densitometry analysis. RESULTS: Immunocytochemical and electron microscopy characterization revealed typical epithelial differentiation. PCR showed keratinocyte growth factor receptor and androgen receptor expression in epithelial cultured cells but no keratinocyte growth factor expression. Epithelial cells showed a significant time and dose dependent stimulation of cell proliferation with keratinocyte growth factor and dihydrotestosterone (p <0.05). When combined with the anti-androgen flutamide the effect of 100 ng./ml. keratinocyte growth factor was significantly decreased (p <0.05). At 100 ng./ml. keratinocyte growth factor quantitative multiplex PCR revealed stimulated keratinocyte growth factor receptor and androgen receptor messenger RNA expression. CONCLUSIONS: These results show that keratinocyte growth factor up-regulates the keratinocyte growth factor and androgen receptors in the absence of androgen. Thus, the androgen signaling pathway may be activated by growth factors such as keratinocyte growth factor in an androgen deficient environment.

Androgen Antagonists↗
PubMed2000

Family history and the risk of prostate cancer.

OBJECTIVES: Several studies have identified prostate cancer family history as a risk factor for prostate cancer incidence, typically associated with a twofold to fourfold increase in risk. A family history of breast cancer has also been implicated. We investigated the associations between prostate cancer incidence and family histories of prostate and breast cancer, controlling for possible confounding due to environmental factors. METHODS: Data from the random sample-based Massachusetts Male Aging Study cohort (1987 to 1997) were used. Incidence rates were calculated as the number of cases per person-year of follow-up. Covariates were adjusted for using Poisson regression. RESULTS: Among 1149 men with an average of 8.7 person-years of follow-up, 57 were diagnosed with prostate cancer, 110 men reported a prostate cancer family history, and 157 reported a breast cancer family history. The age-adjusted relative risk (RR) of prostate cancer incidence associated with prostate cancer family history was 3.29 (95% confidence interval [CI] 1.82 to 5.94). No evidence of heterogeneity was found across age levels (P = 0.83). Additional adjusting for environmental factors such as smoking, alcohol use, body mass index, physical activity, education, sexually transmitted disease history, diet, and hormone levels yielded a slightly higher RR (3.78, 95% CI 1.96 to 7.28). No association with a family history of breast cancer was evident (RR = 1.18, 95% CI 0.51 to 2.43). CONCLUSIONS: We found an association between prostate cancer incidence and a family history of prostate cancer, independent of environmental factors. No association with a family history of breast cancer was evident.

Aged↗
PubMed2000

Laser-induced hyperthermia in rat prostate cancer: role of site of tumor implantation.

OBJECTIVES: To investigate the importance of the site of tumor implantation on the treatment response to laser-induced hyperthermia (LIH) of rat prostate cancer (PCa), because interventional manipulations of PCa have been reported to increase metastatic dissemination. METHODS: Seven to nine days after either subcutaneous or orthotopic implantation of MatLyLu cells, LIH (46.5 degrees C) was induced using pulsed irradiations of a neodymium:yttrium-aluminum-garnet laser. Both local control and distant metastases were evaluated. Plasma metalloproteinase 9 (MMP-9) was tested as a possible marker of PCa progression and LIH response. RESULTS: Twelve days after LIH treatment of subcutaneous tumors, the volumes were reduced by 64% after 8 minutes of irradiation, 73% after 10 minutes, 81% after 15 minutes, and 91.1% after 20 minutes. In the orthotopic model, the corresponding tumor reductions were 44% after 10 minutes, 61% after 20 minutes, and 65% after 30 minutes. Lung metastases were observed in only 1 animal with subcutaneous tumors. In contrast, 86% of the orthotopic tumor-bearing animals treated for 30 minutes had lung metastases compared with 23% of the untreated tumor-bearing rats. MMP-9 expression was detected in both orthotopic and subcutaneous tumor tissue and in the plasma of tumor-bearing rats. The prostate tissue of healthy rats and subcutaneous tumor-bearing rats was devoid of MMP-9. The plasma levels of MMP-9 showed a trend toward direct correlation with local tumor control but no correlation with the incidence of metastasis. CONCLUSIONS: These data emphasize the importance of the site of tumor implantation for evaluation of the efficacy of therapeutic interventions and may warrant further studies before widespread clinical application of LIH as monotherapy.

Animals↗
PubMed2000

Utility of nuclear matrix protein (NMP22) in the detection of recurrent bladder cancer.

This article examines the Nuclear Matrix Protein (NMP22) urine test for recurrent bladder cancer detection. Studies with NMP22 are compared to cytology for sensitivity and specificity. False positives and false negatives do occur, and consequences of these are discussed. Speculations are made regarding possible future uses of this test.

Biomarkers, Tumor↗
PubMed2000

Radio-frequency ablation of renal cell carcinoma: early clinical experience.

PURPOSE: To report the authors' early experience with radio-frequency (RF) ablation of renal cell carcinoma. MATERIALS AND METHODS: Twenty-four percutaneous RF ablation treatments for nine tumors were performed in eight patients with renal cell carcinoma. Indications included coexistent morbidity, previous surgery, or solitary kidney in patients with a life expectancy shorter than 10 years. Smaller (</=3-cm) peripheral lesions (n = 3) were treated with single electrodes. All but one of the larger (>3 cm) and/or central lesions (n = 6) were treated with cluster or multiple electrodes. Patients returned for a second treatment when follow-up imaging depicted tumor enhancement. Follow-up imaging was performed at 1 and 3 months and then at 6-month intervals, with a mean follow-up of 10.3 months. Seven patients were alive at least 6 months after their initial treatment. RESULTS: All five exophytic tumors were free of enhancement. One of three central tumors was free of enhancement. One tumor had both central and exophytic components and was free of enhancement. Three tumors were 3 cm or smaller and free of enhancement. Of the six tumors larger than 3 cm, four were free of enhancement. CONCLUSION: Percutaneous RF ablation is a promising treatment for select patients with renal cell carcinoma. The ultimate role of this modality will continue to evolve and warrants further study.

Aged↗
PubMed1999

Immunolocalization of the keratinocyte growth factor in benign and neoplastic human prostate and its relation to androgen receptor.

BACKGROUND: Growth and development of the prostate are androgen-dependent. Keratinocyte growth factor (KGF), widely expressed by mesenchymal cells, is thought to act like an andromedin between stroma and epithelium of the prostate. Since KGF has recently emerged as an autocrine mediator in prostate cancer, we investigated the role KGF plays in the human prostate and its relationship to androgen receptor (AR). METHODS: Normal (n = 13), benign hyperplastic (n = 5), and neoplastic (n = 14) human prostate tissues as well as cultured epithelial and stromal cells were analyzed using polymerase chain reaction (PCR), Western blot analysis, and immunohistochemistry. RESULTS: Reverse transcriptase polymerase chain reaction and Western blotting showed KGF expression in stromal cultured cells of the normal prostate but not in epithelial cells. Using immunohistochemistry, KGF was found to be localized in fibroblasts and smooth muscle cells, independent of prostate disease. There was KGF expression in epithelial cells of BPH and prostate cancer. Human androgen receptor was uniformly expressed in the same secretory glandular cells that were positive for KGF in BPH and prostate cancer. CONCLUSIONS: Our results provide evidence that KGF is a stromal-derived mediator, recently shown to act in a paracrine manner in normal prostate but now detected in epithelial cells in prostate cancer and BPH. These findings support the hypothesis that KGF might act as an autocrine factor in prostate cancer and BPH.

Antibody Specificity↗
PubMed1999

Ammonium transport in the intestine chronically exposed to urine: is it reduced over time?

OBJECTIVES: To determine whether chronic exposure of urine to intestinal segments alters ammonium transport and thereby would be expected to reduce the metabolic acidosis of intestinal diversion. METHODS: Ileal patch cystoplasty specimens and control-matched ileum segments were harvested from mongrel dogs after 6 months. Acridine orange fluorescence quenching was used to determine the Km, Vmax, and Hill coefficient of ileal patch cystoplasty membrane vesicles and of control-matched ileum membrane vesicles. Enzyme activities for glucose uptake and sodium transport were also determined. RESULTS: A shift of the Km and Vmax for ammonium occurred with chronic exposure of the intestine to urine. However, some specific enzyme activities remained unchanged, particularly those of intracellular and basolateral membrane locations. CONCLUSIONS: Chronic exposure of the intestine to urine alters transport at the brush border by reducing the number of ports available for ammonium transport. It is less detrimental to intracellular and basolateral membrane enzyme activities.

Animals↗
PubMed1999

Obstructive uropathy.

There have been a significant number of advances in the understanding of the pathophysiology of obstructive uropathy. Of particular interest are the molecular biologic advances with respect to apoptosis, TGF-beta and the definition of the expression of certain genes. Research in the developing kidney in the fetus as it is affected by obstructive uropathy has had no significant advances in the past year.

Animals↗
PubMed1999

Characterization of a stromal cell model of the human benign and malignant prostate from explant culture.

PURPOSE: There is a lack of suitable in vitro models for the human prostate. To study stromal-epithelial interactions, we established stromal cells in cultures from benign and malignant prostate tissue that resemble more closely the in vivo conditions of the human prostate. MATERIALS AND METHODS: Stromal cells were obtained from explant primary culture, established in DU145 cell conditioned medium and maintained in RPMI-fetal bovine serum (FBS) supplemented with insulin, transferrin and selenium (ITS). Proliferation studies to compare different media were performed using a 3[H]thymidine assay. Stromal cells were characterized by immunocytochemistry using epithelial and mesenchymal markers. Morphology was evaluated by electron microscopy, light and phase-contrast microscopy. Androgen receptor (AR) mRNA expression was measured by polymerase-chain-reaction (PCR). The response to different concentrations of dihydrotestosterone (DHT) and the antihormones flutamide and hydroxyflutamide was tested by 3[H] thymidine assay. RESULTS: Microscopic evaluation revealed typical stromal morphology with elongated cell shapes, cilia, collagen and microfilaments. Immunocytochemical characterization revealed typical fibroblastic and smooth muscle differentiation. ITS supplemented in RPMI-FBS showed the best growth stimulation compared with other serum-free media (p <0.05) and became our basal medium. The presence of DU145 cell conditioned medium in this basal medium showed a significant increase in cell proliferation in stromal cells. Stromal cells maintained AR mRNA expression and significant DHT dose dependent growth stimulation in up to 10 passages. Both the antiandrogens flutamide and hydroxyflutamide counteracted the DHT effect (p <0.05). CONCLUSIONS: This stromal cell model maintains many cellular and functional properties of the human prostate, which may enable us to study growth factor modulation, drug and hormone metabolism in stromal-epithelial interaction with emphasis on the pathogenesis of BPH and prostate cancer.

Cell Division↗
PubMed1998

Androgen responsiveness of stromal cells of the human prostate: regulation of cell proliferation and keratinocyte growth factor by androgen.

PURPOSE: Growth and development of the prostate are androgen dependent and mainly influenced by stromal-epithelial interaction. It is believed that indirect androgenic activation of paracrine factors like keratinocyte growth factor (KGF) in the prostatic stroma influences the growth of epithelial cells. In this study we investigated the role androgen plays in stromal cell growth and stimulation of KGF in the human prostate. MATERIALS AND METHODS: Stromal cells were derived from explant primary culture of human normal or benign prostatic tissue. The effect of different dihydrotestosterone (DHT) concentrations on cell proliferation was measured using 3[H]thymidine incorporation assay. The effect of DHT on levels of KGF protein was determined by Western blotting. The effect of DHT on levels of KGF gene expression was measured by various cycles of polymerase-chain-reaction (PCR) and multiplex PCR. RESULTS: Characterization of stromal cells showed epithelial cells less than 9.5% in all passages. DHT stimulated human prostate stromal cells in a dose dependent fashion over a concentration range of 0.001-10 nM. Immunocytochemical evaluation of KGF after DHT exposure showed a higher staining intensity. Relative quantitation of Western blotting showed a 1.93-fold increase in KGF protein in the androgen treated stromal cells. At 1 nM DHT conventional and multiplex PCR revealed a significant stimulation of the KGF mRNA expression. CONCLUSIONS: These data show for the first time that androgen stimulates cell proliferation as well as KGF protein and gene expression in human prostate stromal cells. This supports the hypothesis that androgen-induced stromal-derived KGF stimulates prostate epithelial cell growth.

Aged↗
PubMed1998

Postgraduate education: does it improve the knowledge base of practitioners with time?

PURPOSE: We evaluate the effect of the provision of postgraduate educational material on improving practitioner knowledge base during a 3-year period. MATERIALS AND METHODS: A total of 210 urologists were provided 67 monographs in a 2-year period. They were given a pretest before and posttest 1 year after receipt of all monographs. RESULTS: There was significant improvement in posttest scores for the group as a whole. Improvement correlated with years post-training and number of monographs read. Multivariate analysis revealed the number of monographs read was the only independent predictor of outcome. CONCLUSIONS: Although the improvement in test scores was significant and did correlate with the postgraduate educational material read, it was modest. This finding raises significant concerns about the usefulness of this format for graduate medical education.

Clinical Competence↗
PubMed1998

Evaluation of NMP22 in the detection of transitional cell carcinoma of the bladder.

PURPOSE: Urinary nuclear matrix protein (NMP22) was evaluated for detection of new and recurrent bladder tumors in patients with a history of transitional cell carcinoma. Our objective was to determine sensitivity and specificity of this marker for tumors of various stages and grades, as well as its use as an adjunct to or substitute for urinary cytology. MATERIALS AND METHODS: A total of 231 patients with a history of transitional cell carcinoma provided 288 voided urine samples before cystoscopic examination at 1 of 3 institutions (53 patients were reevaluated at least once). Urine samples were assayed for NMP22 using the NMP22 Test Kit. Select patients underwent biopsy with appropriate additional therapy. Voided urinary cytology was obtained in 200 cases. End points for determination of the absence and presence of tumor were negative cystoscopy and positive biopsy, respectively. A receiver operating characteristics curve was constructed to determine the optimal NMP22 threshold for detection of transitional cell carcinoma. For positive biopsies NMP22 values were also correlated with tumor stage and grade. Comparison to cytology was limited to patients with complete data. RESULTS: There were 208 negative cystoscopies (158 with cytology) and 66 positive cystoscopies with biopsy (42 with cytology). Of the cases 14 were eliminated from statistical analysis due to incomplete data. Receiver operating characteristics curve interpretation determined that 6.4 units per ml. was an optimal reference value for detection of transitional cell carcinoma in this patient group. Sensitivity and specificity for all pathological groupings was 68 and 80%, respectively. When compared to cytology the sensitivities of NMP22 and cytology were 67 versus 31 or 40% (depending on the definition of positive cytology). CONCLUSIONS: NMP22 values represented significant improvement over urinary cytology for detection of transitional cell carcinoma. The sensitivity of NMP22 for detection of transitional cell carcinoma in bladder cancer patients was as much as twice that of cytology when a reference value of 6.4 units per ml. was used. NMP22 analysis was less costly than cytology and operator independent. While NMP22 has previously been shown to be a strong predictor of recurrence after tumor resection, it is an effective and sensitive screening test for detecting tumors in patients with transitional cell carcinoma.

Aged↗
PubMed1997

The use of in bowel urology. Metabolic and nutritional complications.

Metabolic and nutritional complications of urinary diversion through bowel or stomach segments are common, but fortunately, not often severe. When metabolic abnormalities are problematic, deterioration or baseline insufficiency in renal function is the most likely cause. Deterioration is most commonly associated with obstruction or infection. The urologist should be acutely aware of the potential for metabolic derangements when the prediversion creatinine is greater than 2.0 mg/dL. In this situation, the urologist should employ the basic principles in this article when planning the procedure in order to minimize metabolic complications and morbidities. In the setting of significant renal insufficiency, a short colon or ileal conduit would likely be superior to an ileal or colonic neobladder, or a diversion, incorporating a large gastric segment. Furthermore, in the absence of symptomatic metabolic abnormalities, we advocate treatment of minor laboratory abnormalities, particularly acidosis, to reduce the incidence of metabolic bone disease. Nutritional and gastrointestinal complications are treated on an "as needed" basis, with the exception of metabolic bone disease, which we would hope to prevent with alkalinization and Vitamin C supplementation. Some of the nutritional and gastrointestinal complications are best avoided by leaving the ileocecal valve intact, or by minimizing the use of certain segments. Some evidence exists that over time, histologic changes in the epithelium of diversion segments may impair absorption and contribute to greater resistance against metabolic derangements. Whether the changes truly reduce the incidence of metabolic abnormalities remains to be studied. The ideal, complication-free, diversion with universal application does not exist; however, the urologist must strive to select an option that will provide a functional result for the patient with minimal associated morbidity.

Humans↗