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Biomedical subjects

I Kaplan

Publications and source records attributed to I Kaplan.

At least 37 records · Page 2Linked to original sources
PubMed1998

Biochemical outcome after radical prostatectomy, external beam radiation therapy, or interstitial radiation therapy for clinically localized prostate cancer.

CONTEXT: Interstitial radiation (implant) therapy is used to treat clinically localized adenocarcinoma of the prostate, but how it compares with other treatments is not known. OBJECTIVE: To estimate control of prostate-specific antigen (PSA) after radical prostatectomy (RP), external beam radiation (RT), or implant with or without neoadjuvant androgen deprivation therapy in patients with clinically localized prostate cancer. DESIGN: Retrospective cohort study of outcome data compared using Cox regression multivariable analyses. SETTING AND PATIENTS: A total of 1872 men treated between January 1989 and October 1997 with an RP (n = 888) or implant with or without neoadjuvant androgen deprivation therapy (n = 218) at the Hospital of the University of Pennsylvania, Philadelphia, or RT (n = 766) at the Joint Center for Radiation Therapy, Boston, Mass, were enrolled. MAIN OUTCOME MEASURE: Actuarial freedom from PSA failure (defined as PSA outcome). RESULTS: The relative risk (RR) of PSA failure in low-risk patients (stage T1c, T2a and PSA level < or =10 ng/mL and Gleason score < or =6) treated using RT, implant plus androgen deprivation therapy, or implant therapy was 1.1 (95% confidence interval [CI], 0.5-2.7), 0.5 (95% CI, 0.1-1.9), and 1.1 (95% CI, 0.3-3.6), respectively, compared with those patients treated with RP. The RRs of PSA failure in the intermediate-risk patients (stage T2b or Gleason score of 7 or PSA level >10 and < or =20 ng/mL) and high-risk patients (stage T2c or PSA level >20 ng/mL or Gleason score > or =8) treated with implant compared with RP were 3.1 (95% CI, 1.5-6.1) and 3.0 (95% CI, 1.8-5.0), respectively. The addition of androgen deprivation to implant therapy did not improve PSA outcome in high-risk patients but resulted in a PSA outcome that was not statistically different compared with the results obtained using RP or RT in intermediate-risk patients. These results were unchanged when patients were stratified using the traditional rankings of biopsy Gleason scores of 2 through 4 vs 5 through 6 vs 7 vs 8 through 10. CONCLUSIONS: Low-risk patients had estimates of 5-year PSA outcome after treatment with RP, RT, or implant with or without neoadjuvant androgen deprivation that were not statistically different, whereas intermediate- and high-risk patients treated with RP or RT did better then those treated by implant. Prospective randomized trials are needed to verify these findings.

Adenocarcinoma↗
PubMed1998

Radiation-associated morbidity in patients undergoing small-field external beam irradiation for prostate cancer.

PURPOSE: To quantify complication rates after small-field external beam irradiation for adenocarcinoma of the prostate in a uniformly treated patient population with long follow-up using a simple tool designed to identify subtle treatment-related side effects; and to identify clinical and technical variables associated with increased morbidity after irradiation. METHODS AND MATERIALS: A total of 441 patients with nonmetastatic adenocarcinoma of the prostate treated at the Joint Center for Radiation Therapy between 1985 and 1989 were eligible for analysis. Gastrointestinal, genitourinary, and sexual function were assessed retrospectively using a patient self-scoring, five-grade toxicity scale. Seven clinical and 15 technical variables were recorded for each patient. The association between the clinical and technical variables and rectal, bladder, and sexual side effects was examined. The 375 patients who received small-field (<12.5 x 12.5-cm) external beam irradiation via a four-field box on a 6-MV (n = 74, or 20% of patients), 8-MV (n = 140, or 37%), or 15-MV (n = 161, or 43%) linear accelerator form the basis for the study. Ninety-one percent of patients received treatment with 1.8-2.0 Gy fractions to a delivered dose of at least 66 Gy. Follow-up was complete through 62 months in living patients, with five (1%) of the entire group lost to follow-up. RESULTS: A total of 137 of 354 evaluable patients (39%) reported rectal complications after treatment; however, 20 patients(6%) had heme-positive stools as their only symptom and 66 (19%) had mild symptoms not requiring treatment. Only 14% of the entire group required intervention. Of 356 patients, 117 (33%) evaluable for bladder complications developed genitourinary changes: In 14 patients (4%) asymptomatic hematuria occurred, 71 (20%) had mild symptoms not requiring treatment, and 32 (9%) required treatment. Of the 171 patients who were potent prior to radiation, 106 (62%) reported impotence after treatment. No statistically significant association was identified between any clinical or technical variables (including machine energy) assessed and complications. CONCLUSIONS: In this retrospective review, treatment-related bowel and bladder side effects were not identified in the majority of patients despite the use of a grading system designed to identify subtle changes. Impotence, however, was common. Although pretreatment clinical characteristics varied among patients, they could not be used to predict the subsequent development of complications. The only treatment-related characteristic that varied in this study was machine energy, which did not correlate with complications.

Adenocarcinoma↗
PubMed1998

Calculated prostate carcinoma volume: The optimal predictor of 3-year prostate specific antigen (PSA) failure free survival after surgery or radiation therapy of patients with pretreatment PSA levels of 4-20 nanograms per milliliter.

BACKGROUND: In this study, the authors evaluated whether a clinically relevant stratification of prostate specific antigen (PSA) failure free survival (bNED) after definitive local therapy could be made for patients with prostate carcinoma clinically classified as T1 or T2 and pretreatment PSA levels of 4-20 ng/mL. METHODS: Multivariate Cox regression analysis and Kaplan-Meier analysis were performed for clinically localized prostate carcinoma patients who presented with PSA levels of 4-20 ng/mL. Three hundred forty-eight of the patients were managed definitively with conventional external beam radiation therapy (median dose, 67 gray), whereas 547 of the patients were managed definitively with a radical retropubic prostatectomy. The outcome tested was time to posttreatment PSA failure. The clinical predictors evaluated included the standard paradigm (PSA, biopsy Gleason score, and clinical stage); type of local therapy; and a newly defined factor, the calculated prostate cancer volume (cV[Ca]). RESULTS: Time to posttreatment PSA failure was equivalent (P = 0.52) independent of the type of local therapy. The cV(Ca) (P < 0.0001), pretreatment PSA (P = 0.003), and clinical classification of T2c (P = 0.04) remained significant predictors of time to posttreatment PSA failure in multivariate analysis. CONCLUSIONS: The staging system described herein, which is based on cV(Ca) and PSA, may optimize patient selection for definitive local therapy and entry onto randomized clinical trials examining the use of adjuvant hormonal or chemotherapy in patients with clinically localized disease who present with PSA levels of 4-20 ng/mL. Validation of this staging system by other investigators is currently underway.

Antineoplastic Agents, Hormonal↗
PubMed1998

Reconstruction of soft tissue and bone defects in lower extremity with free flaps.

This article reports our experiences treating soft tissue and bone defects in the lower extremity with free flaps. One of the most common causes for lower extremity wounds are high-energy injuries. These kinds of injuries contain soft tissue and bone defects beyond neurovascular complications. The rate of infection and nonunion is very high in these injuries. Between 1988 and 1996, we applied 33 flaps to 28 patients. The numbers and kinds of the free flaps are as follows: 12 latissimus dorsi, nine radial forearm, seven lateral arm, three vascularised fibula grafts with skin, one gracilis, and one medial plantar flap. Three free flaps were lost (12%). The success rate is 88%. The advantage of free flaps is that they allow the reconstruction of the large defects in one-session operations. Thus, they decrease the rate of infection and increase that of nonunion. The patient returns to his active life at an earlier stage.

Adolescent↗
PubMed1998

Beta-2-microglobulin-associated nodular amyloidosis of the tongue.

The tongue is an uncommon site for the deposition of beta-2-microglobulin amyloid. A case is presented of nodular amyloidosis of the tongue in a patient having prolonged hemodialysis. The lesions were small, firm, yellowish nodules on the lateral aspect of the tongue and were shown to be deposits of beta-2-microglobulin amyloid. The pathogenesis and differential diagnosis are discussed.

Amyloidosis↗
PubMed1998

An immunohistochemical study of p53 and PCNA in inflammatory papillary hyperplasia of the palate: a dilemma of interpretation.

OBJECTIVE: Inflammatory papillary hyperplasia of the palate (IPHP) or the granular type of denture stomatitis, is a non-neoplastic lesion characterized histologically by a significant epithelial hyperplasia and inflammatory infiltrate usually caused by trauma and Candida infection. p53 and proliferative cell nuclear antigen (PCNA) are cell-cycle regulators, that when overexpressed, are considered by many investigators as markers of malignant transformation. The objective of this study was to investigate the immunodetection of p53 and PCNA in IPHP, and to correlate these results with the degree of epithelial hyperplasia and inflammatory infiltrate. MATERIALS AND METHODS: In 12 cases diagnosed clinically as IPHP, Candida was cultured from the denture base and the palatal mucosa. Lesions were biopsied and stained with H&E for histomorphometric analysis of the epithelial width and inflammatory infiltrate. PAS and Gram stains were used for screening of Candida. Sections were immunostained with DO-7 for p53 and PC-10 for PCNA. Fifteen palatal biopsies obtained from autopsies of edentulous subjects with normal palatal mucosa served as controls. RESULTS: All cultures of swabs from both the palatal mucosa and denture base were positive for Candida. Candidal hyphae could not be identified in PAS stained sections. Small foci of Gram-positive organisms were found in two cases of IPHP. Epithelial width and inflammation were significantly higher in IPHP than in controls (P < 0.001). A three-fold increase in positively stained cells for p53 and a two-fold increase in positively stained cells for PCNA were seen in IPHP compared with controls (P < 0.001). CONCLUSIONS: Although a significant increase in the immunodetection of p53 and PCNA may indicate a malignant potential, IPHP has never been reported to undergo malignant transformation nor is it associated with cytologic signs of dysplasia. The increase in the epithelial width and inflammation degree is probably associated with the colonization of the denture bases with Candida organisms. The increased detection of p53 and PCNA can be a secondary effect of cytokines originating from both the inflammatory cells and the keratinocytes. Thus, immunodetection of p53 and PCNA by current immunohistochemical methods on archival tissues is neither specific nor sensitive enough to be used as indicators for malignant potential in the absence of cytological dysplastic changes or genetic proof of mutated cell cycle genes.

Aged↗
PubMed1998

Patient-reported symptoms after primary therapy for early prostate cancer: results of a prospective cohort study.

PURPOSE: To assess complications of therapy for early (nonmetastatic) prostate cancer. PATIENTS AND METHODS: A prospective study of a cohort of 279 men who sought treatment advice and completed required pretreatment forms. The measures were self-reported patient symptoms and other measures of quality of life before therapy and at 3 and 12 months afterward. RESULTS: Bowel and bladder symptoms were uncommon pretreatment. Patients frequently reported irritative bowel and bladder symptoms at 3 months after radiotherapy, although these subsided somewhat at 12 months. Substantial ("a lot") urinary incontinence and wearing of absorptive pads were reported by 11% and 35% at 12 months after surgery and varied little by age. Incontinence occurred after radiotherapy infrequently, and only in men more than 65 years old. Inadequate erections, present in one third of men pretreatment, were nearly universal at 3 months after surgery, although some improvement, primarily in men under 65 years of age, was evident at 12 months. Sexual dysfunction after radiotherapy increased less but continually through 12 months, suggesting that observed treatment-related differences would decline with further follow-up. CONCLUSION: External-beam radiotherapy of early prostate cancer is followed by bowel and bladder irritability, by increasingly severe sexual dysfunction and, in men aged more than 65 years, occasional urinary incontinence. Greater sexual dysfunction and urinary incontinence occur in the year following radical prostatectomy. These postsurgical complication rates from patient questionnaires are greater than have been reported in other treatment series and confirm the results of two retrospective studies of patient-reported complications.

Adult↗
PubMed1998

Calculated prostate cancer volume greater than 4.0 cm3 identifies patients with localized prostate cancer who have a poor prognosis following radical prostatectomy or external-beam radiation therapy.

PURPOSE: Patients with palpable extraprostatic disease (T3) have a poor prostate-specific antigen (PSA) failure-free (bNED) survival rate after radical prostatectomy (RP) or external-beam radiation therapy (RT). This study was performed to validate or refute the prognostic value of the previously defined calculated prostate cancer volume (cV(Ca)). PATIENTS AND METHODS: For patients with clinically localized disease (T1c,2), a Cox regression multivariable analysis was used to assess the ability of the cV(Ca) value to predict time to posttherapy PSA failure following RP or RT. RESULTS: The cV(Ca) value was a significant predictor (P < or = .0005) of time to posttherapy PSA failure in both an RP and RT data set independent of the one used to derive the cV(Ca)-based clinical staging system. In both RP- and RT-managed patients, estimates of 3-year bNED survival were not statistically different for patients with either T1c,2 disease and a cV(Ca) greater than 4.0 cm3 (RP, 27%; RT, 18%) or T3 disease (RP, 37%; RT, 34%). Despite pathologic T2 disease, the 3-year estimate of bNED survival was at most 51% in RP-managed patients with T1c,2 disease and cV(Ca) greater than 4.0 cm3. CONCLUSION: A cV(Ca) greater than 4.0 cm3 identified patients with T1c.2 disease whose bNED survival was poor after RT or RP despite pathologic T2 disease that suggests the presence of occult micrometastatic disease in many of these patients. Prospective randomized trials to evaluate the impact on survival of adjuvant systemic therapy in these high-risk patients are justified.

Disease-Free Survival↗
PubMed1997

Equivalent 5-year bNED in select prostate cancer patients managed with surgery or radiation therapy despite exclusion of the seminal vesicles from the CTV.

PURPOSE: Prostate Specific Antigen (PSA) failure free survival was determined for select prostate cancer patients managed definitively with external beam radiation therapy to the prostate only or radical retropubic prostatectomy. METHODS AND MATERIALS: A logistic regression multivariable analysis evaluating the variables of PSA, biopsy Gleason score, and clinical stage was used to evaluate the endpoint of pathologic seminal vesicle invasion (SVI) in 749 consecutive prostate cancer patients managed with a radical retropubic prostatectomy. In a subgroup of 332 surgically and 197 radiation managed patients who did not have the clinical predictors of SVI, PSA failure free survival (bNED) was determined. Comparisons were made using the log rank test between surgically and radiation managed patients in this subgroup. In this subgroup, radiation managed patients were treated to a median dose of 66 Gy (66-70 Gy) to the prostate only. RESULTS: The pretreatment PSA (> 10 ng/ml), biopsy Gleason score (> or = 7), and clinical stage (T2b, 2c, or 3) were found to be significant independent predictors (p < 0.001) of SVI. Only 2% of patients without any of these factors had SVI and 17% had extracapsular extension (15% microscopic; 2% macroscopic). In this subgroup the 5-year bNED rates were equivalent [84 vs. 89% (p = 0.67)] for surgically and radiation managed patients, respectively. CONCLUSIONS: Conventional dose external beam radiation therapy directed at the prostate alone resulted in 5-year bNED rates equivalent to surgery on retrospective comparison in patients with clinical stage T1,2a, PSA < or = 10 ng/ml, and biopsy Gleason < or = 6 prostate cancer.

Biopsy↗
PubMed1997

Equivalent biochemical failure-free survival after external beam radiation therapy or radical prostatectomy in patients with a pretreatment prostate specific antigen of > 4-20 ng/ml.

PURPOSE: Biochemical failure-free survival stratified by the pretreatment prostate-specific antigen (PSA) and biopsy Gleason score (bGl) is determined for prostate cancer patients managed definitively with external beam radiation therapy or radical retropubic prostatectomy. METHODS AND MATERIALS: A Cox regression multivariable analysis evaluating the variables of PSA, bGl, and clinical stage was used to evaluate the end point of time to PSA failure in 867 and 757 consecutive prostate cancer patients managed definitively with external beam radiation therapy or radical retropubic prostatectomy, respectively. PSA failure-free survival was determined using Kaplan-Meier analysis. Comparisons were made using the log rank test. RESULTS: The pretreatment PSA, bGl, and clinical stage (T3,4 vs. T1,T2) were found to be independent predictors of time to post-treatment PSA failure for both surgically and radiation managed patients using Cox regression multivariable analysis. Patients with a pretreatment PSA of > 4 ng/ml and < or = 20 ng/ml could be classified into risk groups for time to post-therapy PSA failure: low = PSA > 4-10 ng/ml and bGl < or = 4; intermediate = PSA > 4-10 and bGl 5-7; or PSA > 10-20 ng/ml and bGl < or = 7; high = PSA > 4-20 ng/ml and bGl > or = 8. Two-year PSA failure-free survival for surgically managed and radiation-managed patients, respectively, were 98% vs. 92% (p = 0.45), 77% vs. 81% (p = 0.86), and 51% vs. 53% (p = 0.48) for patients at low, intermediate, and high risk for post-therapy PSA failure. CONCLUSIONS: There was no statistical difference in the 2-year PSA failure-free survival for potentially curable patients managed definitively with surgery or radiation therapy when a retrospective comparison stratifying for the pretreatment PSA and bGl was performed.

Disease-Free Survival↗
PubMed1997

The human thymic microenvironment during organ culture.

Cultured human thymic tissue has been transplanted into many patients with T cell dysfunction; however, little is known about the effect of in vitro culture on thymic tissue. Human postnatal thymic organ cultures were established in vitro to study the growth potential of the thymic epithelium and the expression of intracellular and surface antigens with time in culture. Marked depletion of bone marrow-derived cells was observed within 3 weeks of initiation of organ cultures although some viable CD3+ cells could still be detected. Thymic epithelial cells in in vitro explants continued to express MHC class I and class II antigens as well as cytokeratins. Thymic epithelial cells within cultured thymic organ slices maintained their postnatal growth potential, in that cytokeratin-positive epithelial monolayers could be established in vitro from these thymic slices up to 12 weeks after initiation of organ culture. Thus, thymic explants remained viable in culture and could potentially be used to reconstitute immunity in T cell deficient patients.

Antibodies, Monoclonal↗
PubMed1997

General Health Questionnaire (GHQ12 & GHQ28): psychometric properties and factor structure of the scales in a Turkish primary care sample.

The General Health Questionnaire is a widely used screening instrument. It detects a wide range of psychological disorders, mainly the anxiety/depression spectrum, and has been shown to be a valid and reliable instrument across cultures. This study reports the psychometric properties of the 12- and 28-item versions of the questionnaire among Turkish primary care attenders, focusing mainly on the factor structures. Both questionnaires were found to be reliable and they had factor structures consistent with the original studies.

Adolescent↗
PubMed1997

Finasteride and flutamide as potency-sparing androgen-ablative therapy for advanced adenocarcinoma of the prostate.

OBJECTIVES: Androgen ablation with luteinizing hormone-releasing hormone (LHRH) agonists, orchiectomy, or oral estrogens has significant untoward sexual side effects. We evaluated a combination of finasteride and flutamide as potency-sparing androgen ablative therapy (AAT) for advanced adenocarcinoma of the prostate. In addition, we evaluated whether finasteride provided additional intraprostatic androgen blockade to flutamide. METHODS: Twenty men with advanced prostate cancer were given flutamide, 250 mg orally three times daily. Serum prostate-specific antigen (PSA) values were measured weekly. At a nadir PSA value, finasteride, 5 mg orally every day, was added. PSA values were then measured weekly until a second nadir PSA value was achieved. Sexual function was evaluated at baseline, at the second nadir PSA value, and every 3 months thereafter. Testosterone, dihydrotestosterone (DHT), and dehydroepiandrostenedione (DHEA) levels were measured at baseline and at the first and second nadir PSA values. RESULTS: The median follow-up period was 16.9 months. Therapy failed in 1 patient with Stage D2 disease at 12 months, but an additional response to subsequent LHRH agonist therapy was observed. One patient developed National Cancer Institute grade 3 diarrhea and was withdrawn from the study. Seven of 20 men developed mild gynecomastia, and 3 of 20 developed mild transient liver function test elevations. Mean PSA levels were 94.6 +/- 38.2 ng/mL at baseline and 7.8 +/- 2.7 and 4.7 +/- 2.2 ng/mL at the first and second PSA nadir values, respectively (P = 0.034). Mean percent decline in PSA value from baseline was 87.0 +/- 3.1% with flutamide alone and 94.0 +/- 1.9% with both flutamide and finasteride (P = 0.001). Eleven of 20 men were potent at baseline. At the second nadir PSA value, 9 (82%) of 11 were potent, whereas 2 (18%) of 11 were impotent. With longer follow-up (median 16.4 months), 6 (55%) of 11 men were potent, 2 (18%) of 11 were partially potent, and 3 (27%) of 11 were impotent. With flutamide alone, testosterone rose a mean of 77 +/- 14.7% of baseline (P = 0.0001), DHEA fell a mean of 32.4 +/- 4.6% (P = 0.0001), and DHT was unchanged. With the addition of finasteride, testosterone rose another 14 +/- 6% (P = 0.06, not significant), DHEA was unchanged, and DHT fell a mean of 34.8 +/- 4.7% (P = 0.0009). CONCLUSIONS: Finasteride and flutamide were safe and well tolerated as AAT for advanced prostate cancer. Finasteride provided additional intraprostatic androgen blockade to flutamide, as measured by additional PSA suppression. Sexual potency was preserved initially in most patients, although there was a reduction in potency and libido in some patients on longer follow-up. Further evaluation of this therapy is needed.

Adenocarcinoma↗
PubMed1997

Experimental tongue cancer in desalivated rats.

A group of 39 rats underwent excision of the submandibular and sublingual glands and ligation of the parotid ducts through the midventral incision of the neck, while the control group (41 rats) underwent a sham operation. All rats were administered 4NQO in a final concentration of 0.001% in drinking water. At 7, 14, 22 and 28 weeks after administering 4NQO, both groups of rats were killed and their tongues dissected, inspected and then fixed in 10% buffered formalin for histopathological examination. Clinical examination during the first 14 weeks revealed that rats in both groups looked healthy and no differences in body weight were noticed. Afterwards, the average weight gain of the desalivated rats was lower than in the control group (P < 0.01). The number of macroscopic oral lesions increased with time in both groups. However, in the desalivated rats, the first identifiable lesions were seen as early as week 7, whereas in the control group macroscopic lesions were seen only after 22 weeks. Histological examination revealed more affected rats in the desalivated group in the first 14 weeks after administering the carcinogen; lesions showed more severe pathological changes including two cases with evidence of squamous cell carcinoma. The differences between the desalivated groups and control decreased after 22 weeks with almost no differences at the end of the experiment.

4-Nitroquinoline-1-oxide↗
PubMed1997

Support of a cucumber mosaic virus satellite RNA maps to a single amino acid proximal to the helicase domain of the helper virus.

Cucumber mosaic virus (CMV) is a tripartite RNA virus that can support the replication of satellite RNAs, small molecular parasites of the virus. Satellite RNAs can have a dramatic effect on the helper virus and the host plant in a manner specific to the helper, satellite, and host. Previously, we showed that the Sny-CMV strain is not able to support the replication of the WL1 satellite RNA in zucchini squash and that this phenotype maps to RNA 1. In the present study, we use recombinant cDNA clones of Fny- and Sny-CMV RNA 1 and a site-directed mutant of Fny-CMV RNA 1 to demonstrate that the inability to support WL1 satellite RNA maps to a single amino acid at residue 978 in the 1a protein, proximal to the helicase domain VI. Support of satellite RNA in whole plants and in protoplasts of zucchini squash is analyzed.

Amino Acid Sequence↗
PubMed1997

Complications after treatment with external-beam irradiation in early-stage prostate cancer patients: a prospective multiinstitutional outcomes study.

PURPOSE: To use data from a prospective quality-of-life study to assess differences in disease-specific and general health-related quality-of-life changes after treatment with different external-beam irradiation techniques for prostate cancer. PATIENTS AND METHODS: Patients were divided into three groups based on their pretreatment field size and planning technique: whole pelvis, small field, or conformal. Measures of bowel, urinary, and sexual function and of global health-related quality-of-life parameters (from the Health Survey Short Form [SF-36] and the Profile of Mood States [POMS]) were obtained from self-report questionnaires completed before initiation of therapy and at 3 and 12 months after therapy. RESULTS: Irritative gastrointestinal and genitourinary side effects were frequent 3 months after treatment, but were substantially improved at 12 months. Sexual dysfunction increased steadily over the study period. The POMS and the SF-36 did not demonstrate significant changes over time. Despite small patient numbers, we found trends in favor of conformal therapy across several symptom measures, including sexual function. In the fatigue, energy, and vigor subscales, patients who received whole-pelvis treatment fared significantly worse than those in the other two groups. CONCLUSION: Prospective, detailed data from a feasibility study allowed us to assess the effect of technique on quality of life following external-beam irradiation. Although limited by the small planned sample size, these results suggest that smaller radiation fields limit treatment-related complications, including, unexpectedly, sexual dysfunction. However, confirmation in a larger study is necessary.

Affect↗
PubMed1997

Mitogen-activated protein kinase phosphatase 1 is overexpressed in prostate cancers and is inversely related to apoptosis.

Several oncogenes involved in prostate carcinogenesis activate mitogen-activated protein (MAP) kinases, which can relay both proliferative (via extracellular regulated kinases (ERK)) and apoptotic signals (via jun N-terminal protein kinases (JNK)) to the nucleus. Mitogen-activated protein kinase phosphatase 1 (MKP-1) is induced by several oncogenes in the ras-dependent pathway and can inactivate both MAP kinase pathways. The role of MKP-1 in proliferation and apoptosis is, however, still controversial. A series of 51 prostate cancers, including a subset (n = 13) that had been previously treated by androgen ablation, was used to examine whether MKP-1 mRNA and protein expression correlated with that of ERK-1, JNK-1, bcl-2, which confers resistance to apoptosis, and apoptotic index measured by in situ end-labeling of fragmented DNA. In a subset of tumors, MKP-1 expression was assessed by semiquantitative RT-PCR and was compared with both ERK-1 and JNK-1 enzymatic activity. In cases not treated by androgen ablation, MKP-1 was overexpressed in the preinvasive stage of prostate cancer, but its expression decreased with higher histologic grade and advanced disease stage. There was coexpression of MKP-1, ERK-1, and JNK-1 proteins. In addition, MKP-1 expression was inversely correlated to JNK-1 but not to ERK-1 enzymatic activity. Finally, MKP-1 and bcl-2 were inversely related to apoptotic indices. In cases treated by total androgen ablation, MKP-1 and bcl-2 were both down-regulated, whereas JNK-1 was up-regulated. Subpopulations of cells that did not undergo apoptosis maintained expression of both MKP-1 and bcl-2. These results suggest that MKP-1 overexpression is associated with the early phases of neoplastic transformation in prostate tissue. The enzymatic data on MKP-1 kinase substrates and the inverse correlation between MKP-1 and parameters of programmed cell death support the hypothesis that MKP-1 inhibits apoptosis in human prostate tumors, perhaps through the JNK pathway.

Apoptosis↗