Yet Another Doctor Blog On The Internet

[Bromocriptine-associated postpartum psychotic exacerbation].


Data from 257 patients treated with Flutamide or Cyproterone acetate within the EORTC GU Group protocol 30892 have been used and analysis by Cox models.

On average, 2.6 venous blood samples per patient were analyzed with a mean Met-Hb concentration of 1.9% of total Hb. Mean concentrations of > or = 3% were detected in only six patients (13%). The data from 12 patients evaluated before and after initiating flutamide therapy were without significantly different changes. During the study period, no clinical signs of methemoglobinemia were reported or observed.

Flutamide, a widely used nonsteroidal anti-androgen, but not its bioisostere bicalutamide, has been associated with idiosyncratic drug-induced liver injury. Although the susceptibility factors are unknown, mitochondrial injury has emerged as a putative hazard of flutamide. To explore the role of mitochondrial sensitization in flutamide hepatotoxicity, we determined the effects of superimposed drug stress in a murine model of underlying mitochondrial abnormalities. Male wild-type or heterozygous Sod2(+/-) mice were injected intraperitoneously with flutamide (0, 30 or 100 mg/kg/day) for 28 days. A kinetic pilot study revealed that flutamide (100 mg/kg/day) caused approximately 10-fold greater exposure than the reported therapeutic mean plasma levels. Mutant (5/10), but not wild-type, mice in the high-dose group exhibited small foci of hepatocellular necrosis and an increased number of apoptotic hepatocytes. Hepatic GSSG/GSH, protein carbonyl levels, and serum lactate levels were significantly increased, suggesting oxidant stress and mitochondrial dysfunction. Measurement of mitochondrial superoxide in cultured hepatocytes demonstrated that mitochondria were a significant source of flutamide-enhanced oxidant stress. Indeed, mitochondria isolated from flutamide-treated Sod2(+/-) mice exhibited decreased aconitase activity as compared to vehicle controls. A transcriptomics analysis using MitoChips revealed that flutamide-treated Sod2(+/-) mice exhibited a selective decrease in the expression of all complexes I and III subunits encoded by mitochondrial DNA. In contrast, Sod2(+/-) mice receiving bicalutamide (50 mg/kg/day) did not reveal any hepatic changes. These results are compatible with our concept that flutamide targets hepatic mitochondria and exerts oxidant stress that can lead to overt hepatic injury in the presence of an underlying mitochondrial abnormality.

135 patients with stage T1-3N0M0 prostatic carcinoma were submitted to prolonged PSA-monitored neoadjuvant endocrine treatment (PPNET). The rate of pT0 reports was three times higher (15%) than after the standard 3-month therapy (5%). The present work was done to elucidate the initial characteristics of these tumors, to see if additional workup of these prostatectomy specimens is able to detect tumor vestiges and, if so, to describe their morphology.

Eligibility criteria included progressive prostate adenocarcinoma despite combined androgen blockade. Eligible patients received prior initial treatment with an antiandrogen plus orchiectomy or luteinizing hormone-releasing hormone (LHRH) agonist. Patients were stratified according to type of antiandrogen, type of progression (prostate-specific antigen [PSA] or radiographic), presence or absence of metastatic disease, and prior LHRH agonist versus surgical castration.

We have examined the human androgen receptor (hAR) for its ability to activate AR-dependent transcription of a transgene in a ligand-independent manner. The transcriptional activity was determined by analysis of chloramphenicol acetyltransferase (CAT) activity in T47D cells cotransfected with a plasmid expressing the hAR and a natural AR-regulated promoter (the MVDP androgen-dependent enhancer) ligated to the reporter CAT gene. In this study, the effects of the protein kinase C (PKC) activator 12-O-tetradecanoyphorbol-13 acetate (TPA) on AR activity were tested. We demonstrated that in the absence of androgen, TPA enhanced AR-mediated transactivation by 10-12-fold. This effect was specific of the PKC pathway since stimulation to the PKA pathway did not activate the unliganded AR. This ligand-independent pathway can function through another androgen-regulated promoter as shown by the use of the mouse mammary tumor virus MMTV-CAT reporter. The human glucocorticoid receptor (hGR) and the rabbit progesterone receptor (rPR) could not be activated by TPA, indicating that the effects are not universal for steroid receptors. A reporter plasmid containing the MVDP androgen response element (ARE) in front of the thymidine kinase promoter ligated to the CAT gene was activated by DHT but not by TPA, indicating that the context of the natural promoter is critical for ligand-independent activation of the AR. Exogenous c-jun enhanced transcriptional activation by the AR in a ligand-dependent manner, but had no effect in the absence of DHT. Base pair substitutions in both AR-binding (5'-TGTTCT-3' to 5'-TTTTTT-3') and NF1-binding (5'-GTGGCTG-3' to 5'-GTTTTTG-3') sites resulted in a loss of TPA responsiveness. Our results suggest that ligand-independent activation of the AR by TPA results from interaction of unliganded AR with other proteins in the transcription machinery.