Serum lipoprotein(a) dynamics before/after menopause and long-term effects of hormone replacement therapy on lipoprotein(a) levels in middle-aged and older Japanese women.

AIM: To assess lipoprotein(a) Lp(a) dynamics before and after menopause and to examine long-term changes during hormone replacement therapy (HRT) in middle-aged and older Japanese women. METHODS: (1) Serum total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and Lp(a) concentrations of 526 patients were compared. The patients were divided into 3 groups on the basis of menopausal status (premenopause, perimenopause, postmenopause). (2) Serum markers of lipid metabolism were measured at baseline and at 6-month intervals in 161 postmenopausal women who continuously received HRT with conjugated equine estrogen (CEE) and medroxyprogesterone acetate (MPA) for 4 years. (3) Changes in serum concentrations of markers were compared among 120 women with hypercholesterolemia who were randomly assigned to receive HRT (CEE plus MPA, or transdermal estradiol plus MPA) or pravastatin. RESULTS: (1) Lp(a) concentrations were significantly higher in the postmenopausal women than in the premenopausal or perimenopausal women. (2) The mean Lp(a) concentration after 6 months of HRT decreased by about 19%, and similar levels were maintained for 4 years (3). The mean Lp(a) concentration after 6 months of HRT decreased by 19.9% in the CEE plus MPA group, but did not change significantly in the transdermal estradiol plus MPA group or the pravastatin group. CONCLUSION: Our results suggest that HRT with CEE plus MPA is useful for the management of elevated serum Lp(a) concentrations in middle-aged and older women. However, follow-up studies are needed to determine whether this finding is related to the future prevention of coronary heart disease events.

Solid-phase synthesis of deoxyribonucleotides having a cap structure analog.

In this study, the solid-phase synthesis of oligodeoxyribonucleotides having a guanosine pyrophosphate cap structure (Gpp-) was achieved by using a new guanosine monophosphate unit having the DMTr group capable of estimation of coupling efficiency of the pyrophosphate bond formation. Since 7-methylguanosine base was unstable under basic conditions, Gpp-capped DNA oligomers were synthesized by using a new linker having a silanediyl bond, which allowed to release the DNA chain from the solid support by treatment with fluoride anion under neutral conditions.

Solid phase synthesis of U1 RNA oligomers containing a TMG cap structure.

We report the solid-phase synthesis of a 5'-terminal part of U1 RNA. In this approach, a new method for pyro- and tri-phosphate bond formation on solid supports was studied. Since 2,2,7-trimethyl guanosine (TMG) in the cap structure was unstable under basic conditions, a RNA oligomer was synthesized by using a linker having the P-N bond, which can be cleaved from the solid support by treatment with 80% acetic acid.