Enzymes involved in arachidonic acid release in adrenal and Leydig cells.

Stimulation of receptors and subsequent signal transduction results in the activation of arachidonic acid (AA) release. Once AA is released from phospholipids or others esters, it may be metabolized via the cycloxygenase or the lipoxygenase pathways. How the cells drive AA to these pathways is not elucidated yet. It is reasonable to speculate that each pathway will have different sources of free AA triggered by different signal transduction pathways. Several reports have shown that AA and its lipoxygenase-catalyzed metabolites play essential roles in the regulation of steroidogenesis by influencing cholesterol transport from the outer to the inner mitochondrial membrane, the rate-limiting step in steroid hormone biosynthesis. Signals that stimulate steroidogenesis also cause the release of AA from phospholipids or other esters by mechanisms that are not fully understood. This review focuses on the enzymes of AA release that impact on steroidogenesis.

[Treatment results with external radiotherapy in prostate cancer]. / Resultados del tratamiento con radioterapia externa en el cáncer de próstata.

OBJECTIVE: External irradiation is an accepted curative treatment modality for patients with localized prostatic tumor. The 15-year results in patients treated by radical irradiation alone are presented. The determinant prognostic factors for local tumor control and disease free survival are analyzed. METHODS: 135 patients with a histologically confirmed localized carcinoma of the prostate were treated at our department from May 1972 to January 1998. Fifty patients received Co-60 therapy; the linear accelerator and high energy photons were utilized in the remaining 80 patients. By tumor stage, 53 patients were B1, 49 B2 and 33 C. The mean follow-up was 61 months (range 1-180). Most patients were exposed to localized fields of irradiation; dose ranged from 50-74 Gy, fractionated at a dose of 180-200 cGy/day. RESULTS: Overall local tumor control was 77% at 5 years and 73% at 15 years, with a disease free survival of 63% and 45% at 5 and 15 years, respectively. Local tumor control at 13 years was 71% for stage B1, 82% for B2 and 70% for C. The disease free survival at 13 years for stages B1, B2 and C were 46%, 49% and 36%, respectively. The BD and MD tumors had a 15-year disease free survival of 48% vs 32% for the PD tumors (p = 0.005). Patients with PSA < or = 20 ng/ml before treatment showed a disease free survival of 87% vs 48% for those with PSA > 20 ng/ml ((p = 0.011). Multivariate analysis showed dose to be a determinant prognostic factor for local tumor control (0.0432); dose and histological grade were determinants for disease free survival (p = 0.029 and 0.033). CONCLUSIONS: This retrospective study found dose to be a determinant prognostic factor for local tumor control and both dose and histological grade were determinants for disease free survival. Radiotherapy is a therapeutic option for these patients. The results can be enhanced if the dose delivered to the prostate can be increased while maintaining the complication rate within the same ranges.

[Combination of interstitial implants of Au-198 seeds and external irradiation in the treatment of prostatic carcinoma. Preliminary communication]. / Combinación de implante intersticial de granos de Au-198 e irradiación externa en el tratamiento del carcinoma de próstata. Comunicación preliminar.

The usefulness of external and interstitial radiotherapy in the treatment of prostatic carcinoma is well-documented. We report on our experience in 23 cases using interstitial Au-198 seed implants in combination with external radiation. The diagnostic protocol and therapeutic approach are described. Local control was achieved in 73% and the disease-free survival at 36 months was 49%. The mean follow-up was 44 months. The problems resulting from TUR and the different factors that might be responsible for the failure of local treatment are discussed.

[Radiotherapy as the definitive treatment of patients with carcinoma of the bladder]. / Radioterapia como tratamiento definitivo en pacientes con carcinoma de vejiga.

Sixty-one patients, who refused surgery or whose overall medical status advised against radical cystectomy, were submitted to radical radiotherapy at the Oncology Radiotherapy Service of the General Hospital of Asturias. Irradiation was performed in a cobalt therapy unit. Radiation dose ranged from 50-70 Gy, with a daily dose of 190-200 cGy. Local control was achieved in 71% for stage A, 68% for B1. 17% for B2, and 0% for stage C. Disease-free survival was 63% for stage A, 48% for B1, 14% for B2, 0% for C, and 17% for D1. Overall disease-free survival was 20%, and the morbidity and mortality rates were 11.4% and 3.2%, respectively. In view of the poor results achieved in our setting, we have considered using combined external and interstitial radiation for tumors localized in the muscle layer, and adjuvant chemotherapy for stage C tumors (or those infiltrating perivesical fat).