Serenoa repens extract for benign prostate hyperplasia: a randomized controlled trial.

OBJECTIVE: To compare the effect of a Serenoa repens extract with placebo for symptoms of benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: In a double-blind placebo-controlled randomized trial between January 1999 and March 2000, 100 men with symptoms of BPH, aged < 80 years, with a maximum urinary flow rate of 5-15 mL/s for a voiding volume of 150 mL, were randomly and equally allocated to 320 mg S. repens extract or placebo (paraffin oil). The main outcome measures were the International Prostate Symptom Score (IPSS), peak urinary flow rate, and the Rosen International Index of Erectile Function (IIEF) questionnaire. RESULTS: There was no significant difference between the treatments over the 12 weeks of the study in the IPSS, peak urinary flow rate or for the IIEF questionnaire. CONCLUSIONS: During the trial all participants had some improvement in their symptoms of BPH but there was no significant beneficial effect of this S. repens extract over placebo in this 12-week trial.

DNA repair enzyme uracil DNA glycosylase is specifically incorporated into human immunodeficiency virus type 1 viral particles through a Vpr-independent mechanism.

The Vpr protein, encoded by the human immunodeficiency virus type 1 (HIV-1) genome, is one of the nonstructural proteins packaged in large amounts into viral particles. We have previously reported that Vpr associates with the DNA repair enzyme uracil DNA glycosylase (UDG). In this study, we extended these observations by investigating whether UDG is incorporated into virions and whether this incorporation requires the presence of Vpr. Our results, with highly purified viruses, show that UDG is efficiently incorporated either into wild-type virions or into Vpr-deficient HIV-1 virions, indicating that Vpr is not involved in UDG packaging. Using an in vitro protein-protein binding assay, we reveal a direct interaction between the precursor form of UDG and the viral integrase (IN). Finally, we demonstrate that IN-defective viruses fail to incorporate UDG, indicating that IN is required for packaging of UDG into virions.

Effects of exogenous wild-type p53 on a human lung carcinoma cell line with endogenous wild-type p53.

Several studies have shown that expression of exogenous wild-type p53 is detrimental to the growth of cell lines with absent or mutant p53. In this study, wild-type p53 cDNA expression plasmids were transfected into A549 lung carcinoma cells which had previously been shown by sequencing to contain wild-type p53. When a constitutively expressed wild-type p53 plasmid containing the neomycin resistance gene was transfected into these cells, no G418-resistant colonies contained the exogenous p53 cDNA even though the neomycin resistance gene was integrated. When cells were transfected with a dexamethasone-inducible wild-type p53 cDNA expression plasmid, induction of p53 expression resulted in a decreased growth rate and a decreased proportion of S-phase cells. Continuous treatment with dexamethasone resulted in continued p53 expression for 16 days, but beyond that time expression ceased and could not be reinduced. These data indicated that although the A549 cell line could proliferate in the presence of endogenous wild-type p53 there was a strong selection pressure against continued expression of additional exogenous wild-type p53.

Purification and properties of a novel insulin-like growth factor-II binding protein from transformed human fibroblasts.

We have purified an insulin-like growth factor (IGF) binding protein from culture medium conditioned by the SV40-transformed human fibroblast line AG 2804. This protein (TFBP), of apparent Mr = 34,000 on gel electrophoresis, binds IGF-II with an affinity constant of 3 x 10(11) liters/mol, 100-fold higher than its affinity for IGF-I. Amino-terminal sequencing indicated no structural relationship to any previously characterized IGF binding protein or receptor. Like a protein in cerebrospinal fluid with selective affinity for IGF-II, TFBP does not bind IGF-I lacking the amino-terminal tripeptide. In contrast with binding proteins produced by normal human fibroblasts, TFBP does not cross-react in radioimmunoassays for the plasma protein IGFBP-3 or the amniotic fluid protein IGFBP-1; however, after affinity labeling with IGF-II, it is immunoprecipitable by an anti-IGFBP-3 antiserum. The cerebrospinal fluid binding protein is not precipitable by this antiserum and appears smaller than TFBP. TFBP reacts with wheat germ agglutinin, but not with concanavalin A, or with the acid-labile subunit of the high molecular weight serum IGF binding protein complex. Furthermore, since RNA from transformed fibroblasts does not hybridize with an IGFBP-3 cDNA probe, TFBP is not derived from the IGFBP-3 gene. We conclude that, although TFBP appears to share an epitope with IGFBP-3, it is distinctly different from any previously described IGF binding protein.