Effect of high-dose isoflavones on cognition, quality of life, androgens, and lipoprotein in post-menopausal women

CONTEXT

Recent interventional studies indicate that post-menopausal hormone replacement therapy is associated with an increased risk of cardiovascular mortality and breast cancer. Isoflavones, a class of plant estrogens, have structural similarities to estradiol. Hence, isoflavones may exert beneficial estrogenic health effects in postmenopausal women with fewer adverse effects.

OBJECTIVE

To evaluate the effect of high-dose isoflavones on self-reported quality of life (QOL), cognition, lipoproteins and androgen status in post-menopausal women.

DESIGN AND SUBJECTS

Double-blind, randomized, placebo-controlled, 12-week trial of 93 healthy, ambulatory, post-menopausal women (mean age 56 yr). The study was conducted at a tertiary care center in the United States.

INTERVENTION

Participants were randomly assigned to receive 20 g of soy protein containing 160 mg of total isoflavones vs taste-matched placebo (20 g whole milk protein). Both soy and the placebo were provided in the form of a powder to be mixed with beverages.

MAIN OUTCOME MEASURES

QOL was judged by the Menopause-specific Quality of Life (MENQOL) questionnaire while cognitive function was assessed with standard instruments. Total, free, and bioavailable testosterone, gonadotropins, SHBG, and fasting lipids were measured.

RESULTS

Eighty-four women (90%) completed the study (active=38, placebo=46). There was a significant improvement in all 4 QOL subscales (vasomotor, psychosexual, physical, and sexual) among the women taking isoflavones, while no changes were seen in the placebo group. No significant changes in cognition, serum androgens or plasma lipids were seen within any of the groups. However, at the end of the study, a group-by-time interaction was observed such that total testosterone and HDL levels were significantly lower in the isoflavones compared to placebo groups.

CONCLUSION

High-dose isoflavones is associated with improved QOL among women who have become menopausal recently. Hence, the timing of isoflavone supplementation with regards to the onset of menopause appears to be important. The use of isoflavones, as an alternative to estrogen therapy, may be potentially useful and seemingly safe in this group of women who are looking for relief from menopausal symptoms.

RWJ-54428 (MC-02,479), a new cephalosporin with high affinity for penicillin-binding proteins, including PBP 2a, and stability to staphylococcal beta-lactamases

RWJ-54428 (MC-02,479) is a new cephalosporin active against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA). The potency of this new cephalosporin against MRSA is related to a high affinity for penicillin-binding protein 2a (PBP 2a), as assessed in a competition assay using biotinylated ampicillin as the reporter molecule. RWJ-54428 had high activity against MRSA strains COL and 67-0 (MIC of 1 micro g/ml) and also showed affinity for PBP 2a, with a 50% inhibitory concentration (IC(50)) of 0.7 micro g/ml. RWJ-54428 also displayed excellent affinity for PBP 5 from Enterococcus hirae R40, with an IC(50) of 0.8 micro g/ml and a MIC of 0.5 micro g/ml. The affinity of RWJ-54428 for PBPs of beta-lactam-susceptible S. aureus (MSSA), enterococci (E. hirae), and Streptococcus pneumoniae showed that the good affinity of RWJ-54428 for MRSA PBP 2a and E. hirae PBP 5 does not compromise its binding to susceptible PBPs. RWJ-54428 showed stability to hydrolysis by purified type A beta-lactamase isolated from S. aureus PC1. In addition, RWJ-54428 displayed low MICs against strains of S. aureus bearing the four classes of staphylococcal beta-lactamases, including beta-lactamase hyperproducers. The frequency of isolation of resistant mutants to RWJ-54428 from MRSA strains was very low. In summary, RWJ-54428 has high affinity to multiple PBPs and is stable to beta-lactamase, properties that may explain our inability to find resistance by standard methods. These data are consistent with its excellent activity against beta-lactam-resistant gram-positive bacteria.

Enhanced tumor killing by Apo2L/TRAIL and CPT-11 co-treatment is associated with p21 cleavage and differential regulation of Apo2L/TRAIL ligand and its receptors

Apo2L/TRAIL exhibits enhanced apoptotic activity in tumor xenograft models when used in combination with the topoisomerase 1 inhibitor CPT-11. To investigate the cellular mechanisms involved in this increased tumor-killing activity, a series of in vitro experiments were conducted using the human colon carcinoma cell line (HCT116). Apo2L/TRAIL induced a transient upregulation of DR5 mRNA, while CPT-11 increased both death and decoy receptor expression. Upregulation of decoy receptors by CPT-11 was partially inhibited by co-administration of Apo2L/TRAIL. CPT-11 treatment resulted in accumulation of cells at G(2)M-phase and correlated with a substantial increase in the protein levels of the cyclin-dependent kinase inhibitor p21. However, cells co-treated with CPT-11 and Apo2L/TRAIL, or pretreated with CPT-11 for up to 24 h followed by 2 h Apo2L/TRAIL, resulted in a caspase-dependent degradation of p21, reversal of G(2)-M phase arrest with a concomitant increase in apoptosis. The sequential treatment produced the greatest induction of DR5 and DR4, caspase-3-like cleavage/activation and p21 degradation, as well as increased apoptosis. These data indicate that the up-regulation of Apo2L/TRAIL ligand and its death receptors as well as cleavage of p21 protein in the Apo2L/TRAIL plus CPT-11 treatment contributes to the positive cooperation between these agents in enhancing tumor cell apoptosis.