Tamoxifen reduces plasma homocysteine levels in healthy women

Treatment with tamoxifen is associated with reduced incidence of myocardial infarction. As plasma homocysteine is an independent risk factor for cardiovascular disease, we studied the effects of tamoxifen on plasma homocysteine in 66 healthy women participating in the Italian prevention trial of breast cancer who were randomized in a double-blind manner to tamoxifen 20 mg day(-1) or placebo for 5 years. They were aged between 35 and 70 years, had undergone previous hysterectomy for non-malignant conditions and had no contraindications to the use of tamoxifen. Plasma levels of total homocysteine (tHcy) were measured at randomization and after 2 and 6 months. The mean +/- s.d. plasma levels of tHcy were 7.59 +/- 1.71 micromol l(-1), 7.25 +/- 1.61 and 7.09 +/- 1.33 in the tamoxifen group and 8.07 +/- 2.06, 7.93 +/- 1.77 and 8.12 +/- 2.04 in the placebo group at 0, 2 and 6 months (P = 0.008 for the between-group difference over time). The higher the baseline tHcy level, the greater was the lowering effect of tamoxifen. No statistically significant effect of age, body mass index or smoking habit on baseline tHcy levels and its variation over time was found. In conclusion, tamoxifen (20 mg day(-1) for 6 months) decreased plasma tHcy levels in healthy women. This effect may contribute to its protective effect on myocardial infarction.     

Does dong quai have estrogenic effects in postmenopausal women? A double-blind, placebo-controlled trial

The simulated extended pedigree data of the Genetic Analysis Workshop 10 were used to examine the relationship between several quantitative traits (Q1-Q5), an environmental factor, age and sex and to identify genes contributing to the quantitative traits. A forward selection procedure was used to identify regression models for each trait. Residuals from these regression models were used as quantitative traits in linkage analysis. Two-point sib-pair analysis was performed on Replicate 1 of the data set using SIBPAL. Sixteen regions on 8 chromosomes yielded two-point p-values < 0.005 in Replicate 1. Two strategies for utilizing a second data set were evaluated. In a two-stage approach, only those regions with p-value < 0.005 in Replicate 1 were followed up in the second data set. Nine of these regions had p-values < 0.05 in Replicate 2; four were associated with major genes included in the generating model and the remaining five regions were false positives. An alternative strategy was to perform a repeat genome wide screen in the second data set. This strategy resulted in the identification of 20 regions with p-values < 0.05 in both replicates; five of which included major genes included in the generating model. Although the false positive rate increased when a complete genome screen was performed on both data sets, the two-stage screen, with a more stringent initial criterion for identifying suggestive linkages, had a higher rate of false negatives. For some studies, conducting two complete genome screens in a split-sample design may be worthwhile.     

Effects of raloxifene on serum lipids and coagulation factors in healthy postmenopausal women

CONTEXT: Raloxifene is a selective estrogen receptor modulator that has estrogen-agonistic effects on bone and estrogen-antagonistic effects on breast and uterus. OBJECTIVE: To identify the effects of raloxifene on markers of cardiovascular risk in postmenopausal women, and to compare them with those induced by hormone replacement therapy (HRT). DESIGN: Double-blind, randomized, parallel trial. SETTING: Eight sites in the United States. PARTICIPANTS: 390 healthy postmenopausal women recruited by advertisement. INTERVENTION: Participants were randomized to receive 1 of 4 treatments: raloxifene, 60 mg/d; raloxifene, 120 mg/d; HRT (conjugated equine estrogen, 0.625 mg/d, and medroxyprogesterone acetate, 2.5 mg/d); or placebo. MAIN OUTCOME MEASURES: Change and percent change from baseline of lipid levels and coagulation parameters after 3 months and 6 months of treatment. RESULTS: At the last visit completed, compared with placebo, both dosages of raloxifene significantly lowered low-density lipoprotein cholesterol (LDL-C) by 12% (P < .001), similar to the 14% reduction with HRT (P < .001). Both dosages of raloxifene significantly lowered lipoprotein(a) by 7% to 8% (P < .001), less than the 19% decrease with HRT (P<.001). Raloxifene increased high-density lipoprotein-2 cholesterol (HDL2-C) by 15% to 17% (P < .05), less than the 33% increase with HRT (P < .001). Raloxifene did not significantly change high-density lipoprotein cholesterol (HDL-C), triglycerides, or plasminogen activator inhibitor-1 (PAI-1); whereas HRT increased HDL-C by 11% and triglycerides by 20%, and decreased PAI-1 by 29% (for all, P < .001). Raloxifene significantly lowered fibrinogen by 12% to 14% (P < .001), unlike HRT, which had no effect. Neither treatment changed fibrinopeptide A or prothrombin fragment 1 and 2. CONCLUSIONS: Raloxifene favorably alters biochemical markers of cardiovascular risk by decreasing LDL-C, fibrinogen, and lipoprotein(a), and by increasing HDL2-C without raising triglycerides. In contrast to HRT, raloxifene had no effect on HDL-C and PAI-1, and a lesser effect on HDL2-C and lipoprotein(a). Further clinical trials are necessary to determine whether these favorable biochemical effects are associated with protection against cardiovascular disease.     

Acute hemodynamic effects of estrogen administration in postmenopausal women

The hemodynamic effects of estrogens in replacement doses have not been fully clarified; therefore, we studied the acute hemodynamic changes after 0.625 and 1.25 mg of conjugated estrogens, administered intravenously, using a thermodilution catheter, in postmenopausal women without structural heart disease. Pulmonary and systemic pressures and resistances and stroke volume did not change compared with baseline, but heart rate and cardiac output decreased significantly, which may be associated with estrogen's previously described calcium-blocking effect or with a more recently contemplated beta-blocking action.     

Acute coronary vascular and myocardial perfusion effects of conjugated equine estrogen in the anesthetized dog

OBJECTIVE: To describe the laser scanning cytometry (LSC) processing and analysis developed for the quantitative analysis of estrogen receptor (ER) content in routine paraffin sections of breast carcinomas. STUDY DESIGN: Histologic sections of archival, paraffin-embedded tissues from 30 breast carcinomas were labeled for ER with fluoresceinated monoclonal antibody. ER expression was quantified by LSC and expressed as percent positive tumor cells and as histogram distributions of receptor expression per cell. Duplicate sections of the same tumors were stained for ER by a conventional immunoperoxidase reaction and percent positive tumor cells counted visually. RESULTS: Percent ER-positive tumor cells by LSC of immunofluorescence-stained sections correlated well with conventional (visual) counts of immunoperoxidase-stained duplicate sections when the latter were categorized as low, intermediate or high percent of positive cells. In addition, the marked variation in relative number of ER binding sites per cell could be quantified by LSC and displayed in histogram distribution. CONCLUSION: LSC measurements are fast and objective and can be carried out on sections of paraffin-embedded tissue after routine processing in the pathology laboratory. In addition, LSC data provide the relative number of ER binding sites per unit of DNA; that may reveal clinically significant skewed distributions or subpopulations of tumor cells.     

Vascular effects of estrogen and cholesterol-lowering therapies in hypercholesterolemic postmenopausal women

BACKGROUND: Lipoproteins affect endothelium-dependent vasomotor responsiveness. Because lipoprotein effects of estrogen and cholesterol-lowering therapies differ, we studied the vascular responses to these therapies in hypercholesterolemic postmenopausal women. METHODS AND RESULTS: We randomly assigned 28 women to conjugated equine estrogen (CE) 0.625 mg, simvastatin 10 mg, and their combination daily for 6 weeks. Compared with respective baseline values, simvastatin alone and combined with CE reduced LDL cholesterol to a greater extent than CE alone (both P<0.05). CE alone and combined with simvastatin raised HDL cholesterol and lowered lipoprotein(a) to a greater extent than simvastatin alone (all P<0.05). Flow-mediated dilation of the brachial artery (by ultrasonography) improved (all P<0.001 versus baseline values) on CE (4.0+/-2.6% to 10.2+/-3.9%), simvastatin (4.3+/-2.4% to 10.0+/-3.9%), and CE combined with simvastatin (4.6+/-2.0% to 9.8+/-2.6%), but similarly among therapies (P=0.507 by ANOVA). None of the therapies improved the dilator response to nitroglycerin (all P>/=0.184). Only therapies including CE lowered levels of plasminogen activator inhibitor type 1 and the cell adhesion molecule E-selectin (all P<0. 05 versus simvastatin). CONCLUSIONS: Although estrogen and statin therapies have differing effects on lipoprotein levels, specific improvement in endothelium-dependent vasodilator responsiveness is similar. However, only therapies including estrogen improved markers of fibrinolysis and vascular inflammation. Thus, estrogen therapy appears to have unique properties that may benefit the vasculature of hypercholesterolemic postmenopausal women, even if they are already on cholesterol-lowering therapy.     

Moderate folate depletion increases plasma homocysteine and decreases lymphocyte DNA methylation in postmenopausal women

To determine the human folate requirement on the basis of changes in biochemical pathways, we studied the effect of controlled folate intakes on plasma homocysteine and lymphocyte DNA methylation and deoxynucleotide content in healthy postmenopausal women. Eight women (49-63 y of age) were housed in a metabolic unit and fed a low folate diet containing 56 microg/d of folate for 91 d. Folate intake was varied by supplementing 55-460 microg/d of folic acid (pteroylglutamic acid) to the diet to provide total folate intake periods of 5 wk at 56 microg/d, 4 wk at 111 microg/d and 3 wk at 286-516 microg/d. A subclinical folate deficiency with decreased plasma folate was created during the first two periods. This resulted in significantly elevated plasma homocysteine and urinary malondialdehyde, and lymphocyte DNA hypomethylation. The folate depletion also resulted in an increased ratio of dUTP/dTTP in mitogen-stimulated lymphocyte DNA and decreased lymphocyte NAD, changes suggesting misincorporation of uracil into DNA and increased DNA repair activity. The DNA hypomethylation was reversed with 286-516 microg/d of folate repletion, whereas the elevated homocysteine decreased with 516 but not 286 microg/d of folate. The results indicate that marginal folate deficiency may alter DNA composition and that the current RDA of 180 microg/d may not be sufficient to maintain low plasma homocysteine concentrations of some postmenopausal women.     

Randomized, double-blind, placebo-controlled study of carvedilol on the prevention of nitrate tolerance in patients with chronic heart failure

OBJECTIVES: This study was designed to evaluate the effect of carvedilol on nitrate tolerance in patients with chronic heart failure. BACKGROUND: The attenuation of cyclic guanosine 5'-monophosphate (cGMP) production due to inactivation of guanylate cyclase by increased superoxide has been reported as a mechanism of nitrate tolerance. Carvedilol has been known to combine alpha/beta-blockade with antioxidant properties. METHODS: To evaluate the effect of carvedilol on nitrate tolerance, 40 patients with chronic heart failure were randomized to four groups that received either carvedilol (2.5 mg once a day [carvedilol group, n=10]), metoprolol (30 mg once a day [metoprolol group, n=10]), doxazosin (0.5 mg once a day [doxazosin group, n=10]) or placebo (placebo group, n=10). Vasodilatory response to nitroglycerin (NTG) was assessed with forearm plethysmography by measuring the change in forearm blood flow (FBF) before and 5 min after sublingual administration of 0.3 mg NTG, and at the same time blood samples were taken from veins on the opposite side to measure platelet cGMP. Plethysmography and blood sampling were obtained serially at baseline (day 0); 3 days after carvedilol, metoprolol, doxazosin or placebo administration (day 3); and 3 days after application of a 10-mg/24-h NTG tape concomitantly with carvedilol, metoprolol, doxazosin or placebo (day 6). RESULTS: There was no significant difference in the response of FBF (%FBF) and cGMP (%cGMP) to sublingual NTG on day 0 and day 3 among the four groups. On day 6, %FBF and %cGMP were significantly lower in the metoprolol, doxazosin and placebo groups than on day 0 and day 3, but these parameters in the carvedilol group were maintained. CONCLUSIONS: These results indicated that carvedilol may prevent nitrate tolerance in patients with chronic heart failure during continuous therapy with NTG.     

Randomized, double-blind, placebo-controlled study of ascorbate on the preventive effect of nitrate tolerance in patients with congestive heart failure

Mitogen-activated protein kinase (MAPK) is a serine-threonine kinase that is activated by various extracellular stimuli. Extracellular signal-regulated kinases (ERK1 and ERK2), an MAPK subfamily, are activated by many oncogenes, such as ras and raf, and they induce cell proliferation. myc is also an oncogene and one of the targets of ERKs. Mutations of ras and overexpression of myc were found in various human cancers, and ERKs were also reported to play a role in carcinogenesis. In this study, we examined 39 biopsy specimens of oral squamous cell carcinoma (OSCC) and 5 of normal gingival mucosa for the expression of ERK protein and the proliferation marker, MIB-1 (Ki-67 antibody). Thirteen OSCC specimens and five normal gingival biopsies were also examined for the expression of ERKs mRNA by in situ hybridization. Double staining for ERKs and MIB-1 was also performed. Histologically, 18 patients (46%) were diagnosed with well-differentiated SCC, 17 (44%) with moderately differentiated SCC, and 4 (10%) with poorly differentiated SCC. The histologic grade correlated with the MIB-1 index. The localization of ERK1 was similar to that of ERK2. Positive signals for ERK proteins were localized in superficial keratinocytes in normal gingival mucosa, whereas these mRNAs were weakly positive in the basal and spinous layer. Basal and suprabasal cells were positive for MIB-1. In well-differentiated and moderately differentiated OSCC, positive signals for ERK mRNA and proteins were found at higher levels than in normal gingival mucosa in keratotic cells around cancer pearls. Some cells showed positive signals for ERKs and MIB-1. Furthermore, most cancer cells in poorly differentiated SCC were positive for both ERK and MIB-1. The histologic grade was statistically related to the percentage of cells positive for both ERK and MIB-1. This suggested that ERKs might be related to proliferation in OSCC.     

Genotype distribution of estrogen receptor polymorphisms in men and postmenopausal women from healthy and coronary populations and its relation to serum lipid levels

The cardiovascular protective effects of estrogen are known to be mediated by its beneficial effects on lipid metabolism and its direct actions on the vessel wall. The latter can be mediated by a specific receptor for estrogen present on smooth muscle cells and endothelial cells. The gene for the receptor (the classic estrogen receptor [ER]) has three known polymorphisms, Pvu II, Xba I, and B-variant polymorphisms, which are reportedly associated with receptor expression and altered receptor function and with some disorders including breast cancer, hypertension, and spontaneous abortion. However, the significance of genetic variations of the ER in vascular diseases has not been reported. We have examined the association between coronary artery disease (CAD) and the three polymorphisms in ER. Genotypes (P1/P2, X1/X2, and B-wild type/B-variant type) were determined in 87 men and postmenopausal women with myocardial infarction or angina pectoris whose lesions were confirmed by coronary angiography, as well as from 94 control individuals from the general population with no coronary heart disease and normal resting ECG. For B-variant polymorphism, all individuals examined had B-wild type, which contrasts with the reported allele frequency for B-variant type (0.1) in the white population. Genotype distributions and allele frequencies of Pvu II or Xba I polymorphisms were not significantly different between control subjects and patients (P > .05 for Pvu II or Xba I genotypes; P > .05 for Pvu II or Xba I allele frequencies). When the allele frequencies were analyzed separately by sex, there was still no statistically significant difference for both polymorphisms (P > .05 for men; P > .05 for women). No association was found between the polymorphisms and the angiographic severity of CAD. Total cholesterol, triglyceride, or HDL-cholesterol levels were not significantly different among ER genotypes. These findings suggest that the three polymorphisms in ER are not associated with the prevalence and severity of CAD and that the polymorphisms are unrelated to the serum lipid levels in control subjects and patients.     

Effect of homocysteine and cholesterol in raising plasma homocysteine, cholesterol and triglyceride levels

A high plasma homocysteine level is a newly regarded risk factor for coronary artery disease. We report a synergistic effect of homocysteine plus cholesterol feeding on further raising total plasma homocysteine, cholesterol and triglycerides levels than each agent alone, which further enhances the risk of coronary artery disease.     

Plasma fibrinogen levels in healthy postmenopausal women: physical activity and hormone replacement status

BACKGROUND: Fibrinogen is a major component of the coagulation system and a powerful independent risk factor for cardiovascular disease in postmenopausal women. Regular physical activity has been recommended as an effective clinical approach to lowering plasma fibrinogen levels; currently, however, there are little or no data to support a relationship between habitual exercise status and plasma fibrinogen levels in healthy postmenopausal women who either use or do not use hormone replacement therapy (HRT). METHODS: Plasma fibrinogen levels were measured in 20 physically active (56 +/- 1 yr) and 31 sedentary (58 +/- 1 yr) healthy postmenopausal women. Nine (45%) physically active and 15 (48%) sedentary women had been using HRT for > 1 year; the others were nonusers of HRT. RESULTS: Plasma fibrinogen levels were approximately 15% lower (p = .001) in the physically active women (2.48 +/- .08 g/L) than the sedentary controls (2.92 +/- .06 g/L) and approximately 7% lower (p = .04) in the users (2.65 +/- .08 g/L) versus nonusers (2.84 +/- .08 g/L) of HRT. Moreover, the lower (0.4 g/L) plasma fibrinogen levels associated with regular physical activity were evident in both the users (2.39 +/- .11 vs 2.80 +/- .08 g/L, p = .001) and nonusers (2.56 +/- .11 vs 3.03 +/- .08 g/L, p = .006) of HRT. Stepwise multiple regression analysis revealed that percent body fat was the primary determinant of plasma fibrinogen levels, accounting for 30% of the variability. CONCLUSIONS: Regular physical activity is associated with lower plasma fibrinogen levels in postmenopausal women; the lower plasma fibrinogen levels associated with regular physical activity are evident in both users and nonusers of HRT; and plasma fibrinogen levels are positively related to percent body fat in postmenopausal women differing in physical activity and HRT status. Lower plasma fibrinogen levels in physically active postmenopausal women may contribute to their lower risk of cardiovascular disease.     

Randomized, double-blind, placebo-controlled study of the preventive effect of supplemental oral vitamin C on attenuation of development of nitrate tolerance

Although resection for pancreatic cancer is occasionally curative, its major value lies in restoring patients to a more normal life. The objective of this study was to evaluate the functional quality of life (QoL) of patients undergoing various treatments for pancreatic cancer using a nationwide, multi-institutional, non-referral patient population. From 822 pancreatic cancer patients treated from 1989 to 1995, and listed in the Department of Defense (DoD) hospital central computerized tumor registry, we selected 781 with evaluable survival information. Local tumor registrars had contacted patients at least yearly and prospectively compiled a QoL index using a self-reported Karnofsky performance status (KPS); values were obtained for patients alive in March of 1995 and/or 1996. Survival duration and KPS scores were then compared by stage and treatment using analysis of variance (F-test). Resection significantly increased KPS and mean survival time with stage I-II cancers and improved mean survival time, but not KPS, in patients with node positive (stage III) disease. The projected five-year survival rate after resection in stages I-II was 24% but zero for stage III. Patients receiving combined chemo- and radiation therapies, whether given as adjuvant or primary treatment, had significantly longer mean survival duration. However, KPS scores were not higher in treated patients. These data indicate that patients live longer and better lives after resection of localized pancreatic cancers, but QoL measurements do not support resection for pancreatic cancer involving lymph nodes. Unresected patients selected for combined chemo- and radiation therapy live longer, but not better, lives.     

Clinical effects of buspirone in social phobia: a double-blind placebo-controlled study

BACKGROUND: The results of open pilot studies suggest that the serotonin-1A (5-HT1A) receptor agonist buspirone might be effective in social phobia. METHOD: In the present study, the efficacy of buspirone was investigated in patients with social phobia using a 12-week double-blind placebo-controlled design. Thirty social phobic patients (DSM-IV) were treated with either buspirone 30 mg daily or placebo. Efficacy of treatment was measured using the Social Phobia Scale (subscores anxiety and avoidance) and the Hamilton Rating Scale for Anxiety. RESULTS: Taking a reduction of 50% or more on the Social Phobia Scale as a criterion for clinically relevant improvement, only 1 patient on buspirone and 1 on placebo were classified as responder to treatment. A subjective and clinically relevant improvement was reported by 4 patients (27%) on buspirone and 2 patients (13%) on placebo. There were no statistically significant differences between buspirone and placebo on any of the outcome measures. Generally speaking, buspirone was well tolerated. CONCLUSION: The results of the study do not support the results of open studies, in which a reduction of social anxiety and social avoidance was reported in patients with social phobia treated with buspirone.     

Effects of folic acid and combinations of folic acid and vitamin B-12 on plasma homocysteine concentrations in healthy, young women

BACKGROUND: Elevated plasma homocysteine concentrations are considered to be a risk factor for vascular disease and fetal malformations such as neural tube defects. Recent studies have shown that plasma homocysteine can be lowered by folic acid in amounts corresponding to 1-2 times the recommended dietary allowance. Preliminary evidence indicates that vitamin B-12 may be beneficial when included in supplements or in a food-fortification regimen together with folic acid. OBJECTIVE: We aimed to compare the homocysteine-lowering potential of a folic acid supplement with that of 2 supplements containing different doses of vitamin B-12 in addition to folic acid. DESIGN: Female volunteers of childbearing age (n = 150) received a placebo for 4 wk followed by a 4-wk treatment with either 400 microg folic acid, 400 microg folic acid + 6 microg vitamin B-12, or 400 microg folic acid + 400 microg vitamin B-12. RESULTS: Significant reductions (P < 0.001) in plasma homocysteine were observed in all groups receiving vitamin treatment. The effect observed with the combination of folic acid + 400 microg vitamin B-12 (total homocysteine, -18%) was significantly larger than that with a supplement containing folic acid alone (total homocysteine, -11%) (P < 0.05). Folic acid in combination with a low vitamin B-12 dose (6 microg) affected homocysteine as well (-15%). CONCLUSIONS: These results suggest that the addition of vitamin B-12 to folic acid supplements or enriched foods maximizes the reduction of homocysteine and may thus increase the benefits of the proposed measures in the prevention of vascular disease and neural tube defects.     

Magnesium in the prophylaxis of migraine--a double-blind placebo-controlled study

The migraine prophylactic effect of 10 mmol magnesium twice-daily has been evaluated in a multicentre, prospective, randomized, double-blind, placebo-controlled study. Patients with two to six migraine attacks per month without aura, and history of migraine of at least 2 years, were included. A 4-week baseline period without medication was followed by 12 weeks of treatment with magnesium or placebo. The primary efficacy end-point was a reduction of at least 50% in intensity or duration of migraine attacks in hours at the end of the 12 weeks of treatment compared to baseline. With a calculated total sample size of 150 patients, an interim analysis was planned after completing treatment of at least 60 patients, which in fact was performed with 69 patients (64F, 5M), aged 18-64 years. Of these, 35 had received magnesium and 34 placebo. The number of responders was 10 in each group (28.6% under magnesium and 29.4% under placebo). As determined in the study protocol, this was a major reason to discontinue the trial. With regard to the number of migraine days or migraine attacks there was no benefit with magnesium compared to placebo. There were no centre-specific differences, and the final assessments of treatment efficacy by the doctor and patient were largely equivocal. With respect to tolerability and safety, 45.7% of patients in the magnesium group reported primarily mild adverse events like soft stool and diarrhoea in contrast to 23.5% in the placebo group.