Perturbations of enzymic uracil excision due to guanine modifications in DNA.

Phage PBS2 DNA, which contains uracil in place of thymine, was used as substrate for purified Bacillus subtilis uracil:DNA glycosylase. Incubation of this DNA with the ultimate carcinogen N-acetoxy-N-2-acetylaminofluorene resulted in the production of N-(deoxyguanosin-8-yl)acetylaminofluorene. A decreased Vmax resulted from the reaction of the glycosylase with this arylamidated substrate. Addition of a 2-fold excess of control PBS2 DNA following initiation of the reaction with the modified substrate showed delayed dissociation of the enzyme from the arylamidated DNA. This shows that the presence of a carcinogen-modified DNA base can reduce the capacity for uracil excision. Therefore, interference with enzymic release of uracil from DNA may be an indirect mechanism of mutagenesis by carcinogen:DNA adducts.

The placental transfer of propylthiouracil, methimazole and carbimazole.

The placental transfer of 35S-labelled methimazole (MMI), carbimazole and propylthiouracil (PTU) has been examined in the rat in late pregnancy and in patients undergoing therapeutic abortion. Although rapid equilibrium of fetal and maternal serum radioactivity (FS:MS ratio 1:1) occurred after iv administration of 35S-carbimazole or 35S-MMI in rats, a persistent fetal to maternal ratio of less than one was observed after 35S-PTU administration. Results from human studies after a single oral dose indicate that, as in the rat, the placenta appeared to be more permeable to 35S-MMI than to 35S-PTU as shown by the marked difference in fetal serum:maternal serum ratios and amounts accumulated in the fetus. Localization of radioactivity in the human fetal thyroid was also observed after administration of 35S-labelled MMI, carbimazole or PTU.

The effect of estradiol and a combined estradiol/progestagen preparation on insulin sensitivity in healthy postmenopausal women.

Abnormalities of carbohydrate metabolism and insulin sensitivity have been reported in estrogen deficiency. Estrogen replacement appears to result in an improvement in these parameters, although progestagens may antagonize these effects. We have examined the effects of transdermal estradiol and oral norethisterone on insulin sensitivity using the hyperinsulinemic euglycemic clamp method by performing a randomized, double blind, placebo-controlled study in 22 healthy women after a surgically induced menopause. After baseline measurements, subjects were randomized to receive either transdermal 17beta-estradiol (50 microg) or matching placebo patches for 6 weeks. The subjects were then further randomized to receive either estradiol in combination with oral norethisterone (1 mg) or a matching oral placebo preparation, crossing over after 6 weeks, with assessment of insulin sensitivity at the end of each treatment. No significant increase in insulin sensitivity was observed after 6 weeks of transdermal 17beta-estradiol treatment (95% confidence interval, -0.54, 1.86; P = 0.27). Addition of norethisterone for a further 6 weeks had no detectable effect on insulin sensitivity (95% confidence interval, -1.65, 1.10; P = 0.65). The results of this study using transdermal estradiol do not support previous reports that unopposed estrogens exert potentially beneficial effects on insulin sensitivity and suggest that the addition of an oral progestagen confers no clinically important risk or benefit. It is therefore unlikely that effects on insulin sensitivity contribute appreciably to the cardioprotective benefits attributed to hormone replacement therapy.

Effects of postmenopausal hormone replacement therapy on lipoproteins including lipoprotein(a) and LDL subfractions.

The purpose of this study was to examine the effects on lipoprotein risk markers for CHD of oestradiol given alone and in combination with the androgenic progestogen, norethisterone. Eighty postmenopausal women were randomly allocated to receive oestradiol (2 mg/day) alone or with continuous norethisterone (1 mg/day). Serum lipoprotein levels, including lipoprotein(a), were monitored during 12 months on treatment in all the women, and in a sub-set of 32 patients cholesterol was measured in the two major density subfractions of LDL. Oestradiol caused a transient rise in triglycerides, a small decrease in LDL cholesterol (significant only at 3 and 6 months, P < 0.05) and a consistent significant increase in HDL cholesterol (16%, P < 0.01). There was a downward trend in lipoprotein(a) levels which did not achieve statistical significance. The combined preparation caused significant, sustained decreases in triglycerides (31%, P < 0.01), total cholesterol (15%, P < 0.001), VLDL (42%, P < 0.01), LDL (9%, P < 0.05) and HDL (11%, P < 0.001). Lipoprotein(a) was also reduced (39%, P < 0.05). In the sub-set of patients in which LDL subfractions were measured, the reduction in LDL induced by oestradiol monotherapy was significant only at the 3-month visit (6%, P < 0.05). This was due to a decrease in the 'light' (1.025 < d < 1.044 g/ml) subfraction (10%, P < 0.05) and resulted in an apparent shift in subfraction distribution towards the 'heavy' (1.044 < d < 1.060 g/ml) subfraction, although there was no absolute increase in the latter. None of these changes was statistically significant at 12 months. Oestradiol/norethisterone caused sustained decreases in both 'light' (15%, P < 0.05) and 'heavy' (29%, P < 0.05) subfractions, with no significant change in the relative amounts. The changes in 'light' and 'heavy' LDL in this group were highly correlated with changes in triglyceride levels (r = -0.57, P < 0.05 and r = 0.82, P < 0.01 respectively). Therefore, at the end of 1 year's treatment with unopposed oestradiol the only statistically significant change was an increase in HDL cholesterol. Addition of norethisterone to the preparation reversed this potentially beneficial change, but favourably influenced triglycerides, VLDL, LDL subfraction profile and lipoprotein(a), which may counteract the adverse effect on HDL.

Effects of tibolone on serum lipoprotein and apolipoprotein levels compared with a cyclical estrogen/progestogen regimen.

OBJECTIVE: The purpose of the study was to examine the effects of tibolone, a synthetic steroid that alleviates climacteric symptoms and prevents bone loss without inducing monthly bleeds, on lipoprotein cardiovascular risk markers and to compare the effects with those of a standard combined estrogen/progestogen preparation. DESIGN: Ninety-seven postmenopausal women were randomly allocated to receive either tibolone 2.5 mg/day or conjugated equine estrogens 0.625 mg/day with norgestrel 0.15 mg/day for 12 of each 28 days. Fasting serum levels of lipids, lipoproteins, and apolipoproteins (Apo) were monitored during 18 months of treatment. Women on the cyclical preparation had levels determined during both estrogen-only and combined phases. RESULTS: Tibolone caused reductions in triglycerides (33%, p < 0.001), very low density lipoprotein (VLDL) cholesterol (43%, p < 0.001), and high density lipoprotein (HDL) cholesterol (18%, p < 0.001). The HDL2/HDL3 ratio fell by 22% (p < 0.001). Levels of Apo AI and AII were reduced by 18 and 8%, respectively (p < 0.001). The combined preparation caused reductions in VLDL cholesterol (23%, p < 0.001) and low density lipoprotein cholesterol (15%, p < 0.001). There were small reductions in HDL3 cholesterol and in Apo AII and Apo B. All parameters, except for Apo AII and Apo B and lipoprotein (a) [Lp (a)], showed cyclical changes. Lp (a) levels were reduced significantly by both treatments. CONCLUSIONS: The cyclical preparation had potentially beneficial effects on LP risk markers. The reduction in HDL induced by tibolone constitutes a potentially adverse change, which may be offset by the substantial falls in triglycerides, VLDL cholesterol, and Lp (a).

Modifications of circular DNA by photoalkylation.

The effects of photoalkylation on superhelical PM2 DNA were examined. The chief product was 8-(2-hydroxy-2-propyl)guanine, formed exclusively in sequences of alternating purines and pyrimidines. Other purine damages included 8-(2-hydroxy-2-propyl)adenine and smaller quantities of two uncharacterized adenine products. DNA strand breaks were formed with increasing irradiation. A small quantity of thymine-containing photodimers was formed. Photoalkylation of poly(dG-dC):poly(dG-dC) reduced the concentration of salt required to effect inversion of the circular dichroic spectrum. This suggests that photoalkylation induces the transition of poly(dG-dC):poly(dG-dC) from the right-handed B form of DNA to the left-handed Z form.

The minimum effective dose of estrogen for prevention of postmenopausal bone loss.

In a controlled single blind study to determine the minimal effective dose of estrogen for protection against bone loss, conjugated equine estrogens in doses of 0.625 and 1.25 mg per day were equally effective in reducing bone loss in postmenopausal and oophorectomized women when bone mass was estimated by single-photon absorptiometry or radiogrammetry . Daily dose levels of less than 0.625 mg were essentially ineffective. Fifty percent response level was calculated to be 0.45 mg per day. Concomitant biochemical effects, reduction in urine calcium and hydroxyproline, were compatible with the observed effects on bone mineral.

Prevention of bone mineral loss in postmenopausal women by norethisterone.

The effect of norethisterone on bone mineral metabolism was examined in 43 postmenopausal women. A significant decline in serum calcium, phosphate, and alkaline phosphatase in urinary calcium/creatinine ratio and in tubular maximum reabsorption of phosphate was demonstrated. There was no alteration in urinary hydroxyproline/creatinine ratio. The bone mineral content measured over two years by single photon absorptiometry was compared in 20 patients receiving norethisterone and a matched control group receiving placebo. There was significant protection against bone loss in the norethisterone group.

Long-term hormone implant therapy--hormonal and clinical effects.

Long-term effects of hormone implants (estradiol or estradiol plus testosterone) were examined in 75 menopausal women. Both therapies relieved vasomotor symptoms with a return of significant flushing after six months, thus reimplantation was performed every six months. Estradiol levels had not returned to baseline by six months, and significant accumulation of estradiol occurred by three years. The patients given testosterone experienced a similar accumulation of testosterone. There was no significant change in mean weight, blood pressure, or liver function tests during three years. Both therapies reversed the bone biochemical changes of menopause, and in both groups there was no significant loss in bone density. Supplementation of estradiol with testosterone in implant therapy was not observed to provide additional benefit in terms of the parameters studied.

Family history of problem drinking among young male social drinkers: reliability of the Family Tree Questionnaire.

The test-retest reliability of the Family Tree Questionnaire to detect drinking problems of family members was examined in a sample of 60 male volunteer university undergraduates. The Questionnaire was completed twice. The first occasion employed a group administration procedure, and an average of 4 months later it was readministered on an individual basis. Thus the length of time and the different administration procedures provided an extreme test of the reliability of the Questionnaire. Test-retest scores of the number of problem drinkers reported by a subject were significantly correlated for first degree and for second degree relatives. The reliability of the classification of an individual family member was also satisfactory. The Family Tree Questionnaire thus appears to be a potentially useful, reliable tool for assessing the incidence of problem drinkers within families of young male social drinkers.

Changes in the bone and liver isoenzymes of alkaline phosphatase in postmenopausal women being treated with norethisterone.

The effects of norethisterone therapy on alkaline phosphatase isoenzyme activities were studied in a group of postmenopausal women. There was a significant fall in total alkaline phosphatase activity after 8 wk which was still in evidence after 24 wk. Both bone and liver alkaline phosphatase isoenzyme activities were decreased during the first 16 wk on treatment, but after 24 wk only the bone phosphatase activity was significantly lower than the pretreatment level. The other biochemical indices of bone metabolism and liver function were also measured during the study. The results indicate that bone specific alkaline phosphatase activity is a more sensitive index of bone activity than total alkaline phosphatase and that monitoring of total activity may in some instances be misleading.

Lipoprotein and apoprotein levels in postmenopausal women during treatment with norethisterone.

Lipoprotein and apolipoprotein levels were monitored in 21 postmenopausal women during 6 months' treatment with norethisterone. There was no significant change in low density lipoprotein (LDL) cholesterol but apoprotein B levels rose significantly (p less than 0.001) thus increasing the apoprotein:cholesterol ratio in LDL. High density lipoprotein (HDL) cholesterol levels decreased significantly (p less than 0.001) in the first two months and did not change significantly thereafter. The HDL2 subfraction was reduced to a greater extent than the HDL3 subfraction. Apoprotein AI and AII levels were both reduced as was the apoprotein AI:AII ratio. The ratios of apoproteins AI and AII to HDL cholesterol were increased. We conclude that norethisterone has an adverse effect on the important risk factors for cardiovascular disease.

A long-term study of the effects of norethisterone on lipoprotein metabolism in menopausal women.

Long-term effects of the androgenic progestogen norethisterone on lipoprotein metabolism were studied by measuring lipoprotein concentrations in 21 women during one year on treatment for the relief of climacteric symptoms. There were significant reductions in total serum triglyceride (p less than 0.01), very low density lipoprotein (VLDL) cholesterol (p less than 0.01) and high density lipoprotein (HDL) cholesterol (p less than 0.001) after two months on treatment, all of which were still in evidence after one year. Low density lipoprotein (LDL) cholesterol levels climbed gradually becoming significantly higher than baseline after one year on treatment (p less than 0.01). Comparison of cholesterol concentrations in HDL subfractions in the one year treated subjects with those in a control group of untreated subjects suggests that the fall in HDL cholesterol is due to reductions in both the HDL2 and HDL3 fractions. We conclude that norethisterone adversely affects the important lipoprotein risk factors for coronary heart disease.

Evaluation of a psychological treatment programme for climacteric women.

A psychological assessment and treatment programme designed for a group of climacteric women with severe and varied psychological complaints and symptoms is described and evaluated. All the women were currently experiencing stressful psychosocial difficulties within their life situation. The treatment programme comprised an educational, a counseling and a behavioural component. By the end of the sixth session of therapy, most women showed a significant improvement in their main complaint, accompanied by improvements in general symptoms and personal adjustment. Two-thirds considered that they had benefited substantially from treatment. The outcome of the treatment was considered to be encouraging in what might otherwise be considered a potentially unresponsive group of women.

Failure of response of menopausal vasomotor symptoms to clonidine.

A double-blind crossover trial of clonidine failed to show any effect of the drug on menopausal vasomotor symptoms. A significant placebo effect was observed, the effect being greater in those with long-standing symptoms and a high neurotic index.

Short-term changes in lipoproteins and apoproteins during cyclical oestrogen-progestogen replacement therapy.

Lipoproteins and apoproteins were measured weekly in a group of 18 post-menopausal women treated with a cyclical hormone replacement regimen comprising 28 days on conjugated equine oestrogens (0.625 mg/day) with the addition of norgestrel (0.15 mg/day) for the last 12 days of the cycle. There were no significant changes in total triglyceride, very low-density-lipoprotein (VLDL) cholesterol or high-density-lipoprotein (HDL) cholesterol levels. Low-density lipoprotein (LDL) and total cholesterol levels fell, the differences being significant after two weeks. The LDL/HDL cholesterol ratio also fell significantly over 1 week of treatment. There were no significant changes in either HDL2 or HDL3 cholesterol. The HDL2/HDL3 cholesterol ratio did, however, alter significantly, increasing during the oestrogen-only phase. Apart from this ratio, none of the parameters measured showed any significant differences as between the oestrogen-only phases and the oestrogen/norgestrel phases. There were no significant changes from baseline values in the levels of apoproteins AI, AII or B. The apoprotein AI/AII ratio was significantly increased, the levels being higher during the oestrogen phase of the cycle. There was no significant change in the apoprotein B/AI ratio. The apoprotein B/LDL cholesterol ratio showed a statistically significant increase after 4 weeks. There was no evidence of any cyclical changes. We conclude that the results of this study are generally favourable with regard to coronary heart disease risk but that the change in the apoprotein B/LDL ratio merits further investigation.

A comparison of the effects of lipoproteins of two progestogens used during cyclical hormone replacement therapy.

Lipoprotein levels were measured in 11 women who had been treated with 0.625 mg/day conjugated equine oestrogens with the addition of 0.15 mg/day DL-norgestrel for the last 12 days of each 28 day cycle for 48 wk. Treatment was then changed to an identical oestrogen regimen with dydrogesterone, 10 mg/day, as progestogen and monitoring continued for a further 24 wk. The oestrogen plus norgestrel regimen caused a significant reduction in low density lipoprotein (LDL) cholesterol levels. During the 24 wk after the change of therapy, levels of high density lipoprotein (HDL) increased significantly due to an increase in the HDL2 fraction and there was an upward trend in LDL cholesterol which did not attain statistical significance. We conclude that, when used in combination with conjugated equine oestrogens, changing from norgestrel, 0.15 mg/day, to dydrogesterone, 10 mg/day, does not lead to any significant improvement in lipoprotein profile.

Organon OD 14 (tibolone) and menopausal dynamic hormone profiles.

Hormonal profiles were studied in 15 post-menopausal women, 7 of whom had been treated with Organon OD 14 (Tibolone) and 8 with placebo tablets for 3 yr. In the Tibolone-treated group, the sex hormone binding globulin (SHBG) levels were significantly lower, while the estimated free testosterone levels, the testosterone/SHBG ratio and the thyroid-stimulating hormone (TSH) response to thyrotrophin-releasing hormone (TRH) were significantly higher than in the placebo group. Prolactin and triiodothyronine (T3) concentrations were lower in the actively treated group, although the differences were not statistically significant. No significant differences were observed with respect to thyroxine (T4), TSH, basal cortisol or cortisol response to synacthen.

Investigation of the bleeding patterns of postmenopausal women treated with Estrapak-50.

Diary cards of patients in two similar trials of Estrapak-50 hormone replacement therapy were analysed with regard to the characteristics of progestogen-associated bleeding (PAB) and breakthrough bleeding (BTB). Forty out of 52 patients in Study A and 74 out of 92 patients in Study B had diaries suitable for analysis. One patient in Study A and two patients in Study B who withdrew from treatment did so because of unacceptable bleeding problems. Similar results were obtained from both trials. After 6 months of treatment approximately 90% of patients in study A and approximately 70% of patients in study B had PAB on or before day 11. Twenty-seven percent and 49% in studies A and B, respectively, bled prior to day 8, which in the majority of instances affected one treatment cycle. Duration of PAB varied from 1 to 14 days (median 7 days) and the pattern of bleeding in the second cycle was predictive of bleeding in subsequent cycles. Although over 1/3 of women reported some heavy bleeding days, this usually only affected one treatment cycle, and the majority of bleeding was only spotting or light flow. BTB patterns did not raise suspicions of endometrial pathology. Bleeding patterns were both acceptable to patients and, in as much as the current literature indicates that bleeding patterns can be interpreted, were consistent with adequate progestogenic protection of the endometrium.

Effects of conjugated equine oestrogens with and without the addition of cyclical norgestrel on serum and urine electrolytes, and the biochemical indices of bone metabolism and liver function.

Serum and urine electrolytes, and biochemical indices of bone metabolism and liver function were measured in 51 post-menopausal women treated with two hormone replacement therapy regimens for 24 wk. Twenty-six of the women were treated continuously with conjugated equine oestrogens (0.625 mg/day) and the remainder were treated as above with the addition of norgestrel (0.15 mg/day) during the last 12 days of each 28-day cycle. Both treatment regimens affected electrolytes in a similar manner. The most consistent effect was a reduction in serum sodium levels and a reduction in urinary sodium/creatinine ratios. The combined regimen appeared to have a greater effect on sodium reabsorption. Both regimens decreased all the biochemical indices of bone metabolism measured, viz serum calcium (corrected for albumin), phosphate and alkaline phosphatase and urinary calcium/creatinine and hydroxyproline/creatinine ratios. The preparations used decreased the parameters by similar amounts over the 24 wk indicating that both were equally effective in reducing bone turnover. The data suggested, however, that the combined regimen had a more profound effect on bone metabolism during the early phase of treatment. The two treatment regimens had broadly the same effects on the biochemical indices of liver function, reducing albumin levels and all the liver enzymes. Judging by these indices neither regimen had a deleterious effect on liver function. We conclude that the two hormone replacement regimens have similar effects on the biochemical indices measured, but there are subtle differences between the two treatments which merit further research.