Role of androgens and glucocorticoids in the regulation of diazepam-binding inhibitor mRNA levels in male mouse hypothalamus.

In peripheral organs, gonadal and adrenal steroids regulate diazepam-binding inhibitor (DBI) mRNA expression. In order to further investigate the involvement of peripheral steroid hormones in the modulation of brain DBI mRNA expression, we studied by semiquantitative in situ hybridization the effect of adrenalectomy (ADX) and castration (CX) and short-term replacement therapy on DBI mRNA levels in the male mouse hypothalamus. Cells expressing DBI mRNA were mostly observed in the arcuate nucleus, the median eminence and the ependyma bordering the third ventricle. In the median eminence and the ependyma bordering the third ventricule, the DBI gene expression was decreased in ADX rats and a single injection of corticosterone to ADX rats induced a significant increase in DBI gene expression at 3 and 12 h time intervals without completely restoring the basal DBI mRNA expression observed in intact mice. In the arcuate nucleus, ADX and corticosterone administration did not modify DBI mRNA expression. CX down-regulated DBI gene expression in the ependyma bordering the third ventricle. The administration of dihydrotestosterone (3-24 h) completely reversed the inhibitory effect of CX. In the median eminence and arcuate nucleus, neither CX or dihydrotestosterone administration modified DBI mRNA levels. These results suggest that the effects of glucocorticoids on the hypothalamo-pituitary-adrenocortical axis and androgens on the hypothalamo-pituitary-gonadal axis are mediated by DBI.

Heated intra-operative intraperitoneal oxaliplatin after complete resection of peritoneal carcinomatosis: pharmacokinetics and tissue distribution.

PURPOSE: This article reports the pharmacokinetics (PK) of heated intra-operative intraperitoneal oxaliplatin and its tolerance profile. Oxaliplatin has demonstrated significant activity in advanced colorectal cancer, and this is the first publication concerning its intraperitoneal administration. METHODS: Twenty consecutive patients with peritoneal carcinomatosis (PC) of either gastrointestinal or uniquely peritoneal origin underwent complete cytoreductive surgery followed by intra-operative intraperitoneal chemo-hyperthermia (IPCH) with increasing doses of oxaliplatin. We performed IPCH using an open procedure (skin pulled upwards), at an intraperitoneal temperature of 42-44 degrees C, with 2 l/m2 of 5% dextrose instillate in a closed circuit. The flow-rate was 2 l/min for 30 min. Patients received intravenous leucovorin (20 mg/m2) and 5-fluorouracil (400 mg/m2) just before the IPCH to maximize the effect of oxaliplatin. We treated at least three patients at each of the six intraperitoneal oxaliplatin dose levels (from 260 to 460 mg/m2) before progressing to the next. We analysed intraperitoneal, plasma and tissue samples with atomic absorption spectrophotometry. RESULTS: The mean duration of the entire procedure was 8.4 +/- 2.7 h. Half the oxaliplatin dose was absorbed in 30 min at all dose levels. Area under the curve (AUC) and maximal plasma concentration (Cmax) increased with dose. At the highest dose level (460 mg/m2), peritoneal oxaliplatin concentration was 25-fold that in plasma. AUCs following intraperitoneal administration were consistently inferior to historical control AUCs after intravenous oxaliplatin (130 mg/m2). Intratumoral oxaliplatin penetration was high, similar to absorption at the peritoneal surface and 17.8-fold higher than that in non-bathed tissues. Increasing instillate volume to 2.5 l/m2 instead of 2 l/m2 dramatically decreased oxaliplatin concentration and absorption. There were no deaths, nor severe haematological, renal or neurological toxicity, but we observed two fistulas and three deep abscesses. CONCLUSIONS: Heated intraperitoneal chemotherapy gives high peritoneal and tumour oxaliplatin concentrations with limited systemic absorption. We recommend an oxaliplatin dose of 460 mg/m2 in 2 l/m2 of 5% dextrose for intraperitoneal chemo-hyperthermia, at a temperature of 42-44 degrees C over 30 min. We may be able to improve these results by increasing the intraperitoneal perfusion duration or by modifying the instillate composition.

Intraperitoneal chemohyperthermia: rationale, technique, indications, and results.

Intraperitoneal chemohyperthermia (IPCH) is a loco-regional treatment for intraperitoneal malignancies. This ultra-radical treatment combines complete cytoreduction of macroscopic peritoneal disease preceding perioperative intraperitoneal perfusion of a chemotherapeutic drug heated to 42 degrees to 44 degrees to treat microscopic residual disease. At present time, this approach is mainly indicated for isolated limited peritoneal carcinomatosis (PC) of colorectal origin and for treatment of low-grade pseudomyxoma peritonei. In selected patients, IPCH may lead to 27% five-year overall survival in cases of PC, and as high as 86% five-year survival in cases of pseudomyxoma peritonei. In the near future, this approach will become the standard treatment for selected cases of PC.