Comparison of the antioxidant effects of equine estrogens, red wine components, vitamin E, and probucol on low-density lipoprotein oxidation in postmenopausal women.

OBJECTIVE: Oxidized low-density lipoprotein (LDL) seems to play an important role in the etiology of atherosclerosis. To further study this, we performed two studies: (1) we determined the ability of 10 estrogen components of the drug, conjugated equine estrogen (CEE), trans-resveratrol (t-resveratrol) and quercetin (red wine components), trolox (vitamin E analog), and probucol (a serum cholesterol-lowering drug) to delay or prevent the oxidation of plasma LDL isolated from untreated postmenopausal women, and (2) we assessed the effect of long-term (>1 year) estrogen replacement therapy and hormone replacement therapy on LDL oxidation by ex vivo methods. DESIGN: For the in vivo study, three groups of postmenopausal women were selected based on whether they were on long-term CEE therapy (group A: 0.625 mg CEE; n = 21), on combination CEE plus progestogen therapy (group B: 0.625 mg CEE + 5.0 mg medroxyprogesterone acetate, 10 days; n = 20), or not on any hormone therapy (group C; n = 37). For the in vitro study, only LDL samples obtained from group C were used. The kinetics of LDL oxidation were measured by continuously monitoring the formation of conjugated dienes followed by determination of the lag time. RESULTS: All compounds tested protected the LDL from oxidative damage. The relative antioxidant potency of estrogen components was generally greater than that of the other compounds. The minimum dose (nmoles) required to double the lag time from the control lag time of 57 +/- 2 min was 0.47 for 17beta-dihydroequilenin, 17alpha-dihydroequilenin, Delta 8 -estrone; 0.6 to 0.7 for Delta 8 -17beta-estradiol, equilenin, and quercetin; 0.9 for 17beta-dihydroequilin and 17alpha-dihydroequilin; 1.3 for equilin, estrone, 17beta-estradiol, 17alpha-estradiol; 1.4 for trolox; 1.9 for probucol; and 3.0 for t-resveratrol. The data from the in vivo study indicate that after long-term estrogen replacement therapy (group A) and hormone replacement therapy (group B), the LDL was significantly ( p < 0.01) protected (higher lag time) against oxidation compared with the control (group C). There was no difference between groups A and B. CONCLUSIONS: The oxidation of LDL isolated from postmenopausal women is inhibited differentially by various estrogens and other antioxidants. The unique ring B unsaturated estrogen components of CEE were the most potent, and t-resveratrol, the red wine component, was the least potent. Long-term CEE or CEE + medroxyprogesterone acetate administration to postmenopausal women protects the LDL against oxidation to the same extent. These combined data support the hypothesis that some of the cardioprotective benefits associated with CEE therapy and perhaps red wine consumption may be due to the ability of their components to protect LDL against oxidative modifications.

Effect of tamoxifen treatment on the endometrial expression of human insulin-like growth factors and their receptor mRNAs.

The effect of tamoxifen (Tam) treatment on the endometrial expression of IGF-I and II/IGF-IR and IIR mRNAs was assessed by measuring the levels of expression of these mRNAs in the endometrial samples of Tam-treated postmenopausal breast cancer patients by RT-PCR assays. The levels of these mRNAs were compared with those in normal endometrium and in Type I and Type II endometrial carcinomas (EC). The promoter-specific transcript profiles of IGF-I and II were also elucidated. The levels of IGF/IGF-R mRNAs in the endometrium from Tam-treated patients were found to be comparable with the high levels of these mRNAs observed in the proliferative and early secretory phase endometrium and in the samples of Type I EC. These results indicate that Tam acts as an estrogen agonist in inducing the endometrial expression of these genes. Tam stimulated transcription from the multiple promoters of IGF-I and II, with the exception of IGF-II P2 promoter, in which case the transcription across exon 4 appeared to be inhibited. The profiles of IGF-I and II transcripts of endometrium from Tam-treated patients were similar to Type I EC but differed considerably from those of Type II EC. These results suggest that the Tam-associated ECs are likely to be similar to type I EC and will therefore have a more favorable prognosis.

Loss of IGF-II imprinting in endometrial tumors: overexpression in carcinosarcoma.

The genomic imprinting of the maternal allele defines the monoallelic expression of the IGF-II gene in most human tissues. The loss of imprinting (LOI) leading to biallelic overexpression of IGF-II has been reported in several human malignancies, including uterine leiomyosarcoma. To ascertain if LOI occurs in endometrial malignancies, the allelic expression of the IGF-II gene was examined in samples of normal human endometrium (n=22) and endometrial tumors (n=12) by assessing the ApaI polymorphism in cDNA segments amplified by RT-PCR. The biallelic overexpression of IGF-II mRNA, involving activation of all four (P1-P4) promoters, was detected in one normal endometrium and in one endometrial carcinosarcoma. Low level biallelic expression of IGF-II was also detected in two samples of hormone-unresponsive/Type II endometrial carcinomas. The level of IGF-I mRNA in these four samples was low. The IGF-IR mRNA was overexpressed in all endometrial cancers including the carcinosarcoma sample, but not in normal endometrium. These data suggest that LOI associated with overexpression of IGF-II and concomitant overexpression of IGF-IR may play a role in the rare carcinosarcoma of the endometrium.

Discordant expression of insulin-like growth factors and their receptor messenger ribonucleic acids in endometrial carcinomas relative to normal endometrium.

The inappropriate expressions of insulin-like growth factors (IGF-I and II) and IGF-I receptor (IGF-IR) are implicated in the malignant growth of many cancers. To determine changes, if any, in the levels of expression of IGFs and IGF receptor genes in neoplastic endometrium, relative to normal endometrium, the mRNA levels of IGF-I and II and of IGF-IR and IIR were measured in samples of endometrial carcinomas (EC) and normal endometrium, through all phases of the menstrual cycle, by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) assays. In normal endometrium, the mRNA levels of IGF-I were elevated in the proliferative and early secretory phases. The IGF-II mRNAs were relatively high in the proliferative phase, but unaltered through early and late secretory phases. Significantly elevated levels of IGF-II transcripts were observed during the menstrual phase, suggesting a possible role of IGF-II in endometrial regeneration. A positive correlation between the levels of IGF-I and IGF-IR mRNAs, apparent in the samples of normal endometrium, was not observed in endometrial carcinomas. The IGF-IR and IIR mRNA levels were elevated in endometrial carcinoma samples. On the other hand, the IGF-I and II mRNA levels were conspicuously low in many carcinoma samples, which were not associated with hyperplasia (type II EC), but relatively elevated in two other carcinoma samples, associated with adenomatous hyperplasia (type I EC). These results albeit with few samples suggest the possibility that the overexpressed receptor, IGF-IR, could be activated differently in two types of endometrial carcinomas, namely ligand-dependently in type I ECs and ligand-independently in type II ECs.

Biologic effects of delta-8-estrone sulfate in postmenopausal women.

OBJECTIVE: To determine in postmenopausal women the biological effects of delta-8-estrone sulfate, a novel estrogen component of Premarin (Wyeth-Ayerst, Philadelphia, PA). METHODS: An open-label, nonrandomized study of six healthy postmenopausal women was conducted. Each subject took 0.125 mg of delta-8-estrone sulfate daily for 8 weeks. Blood samples were collected at day 0 (baseline) and once a week for 8 weeks. Urine was collected on day 0 and at weeks 2, 3, 5, 6, 7, and 8. Serum gonadotropins (follicle-stimulating hormone/luteinizing hormone), plasma binding proteins (corticosteroid-binding globulin/sex hormone-binding globulin), a marker for bone turnover (urinary n-telopeptide), and markers for cardiovascular effects (cholesterol, low-density lipoprotein, high-density lipoprotein(c), low-density lipoprotein oxidation, and rate of diene formation) were measured. RESULTS: Follicle-stimulating hormone levels decreased from 84.0 +/- 8.5 to 67.0 +/- 8.5 mlU/mL (P = .02), whereas luteinizing hormone levels did not change. Corticosteroid-binding globulin levels increased from 3.30 +/- 0.16 to 4.10 +/- 0.16 mg/dL (P = .02), and no change in sex hormone-binding globulin was noted. The n-telopeptide levels decreased an average of 31% from 40.7 +/- 4.9 to 28 +/- 7.0 nmol/L bone collagen equivalents/mmol/L creatinine (P = .03). Plasma diene concentration and diene production rate decreased by 34% and 40%, respectively; these changes were not significantly different from baseline values. In contrast, a significant (P = .03) 68% increase in the lag time for low-density lipoprotein(c) oxidation (38.5 +/- 5.5 minutes versus 64.8 +/- 8.5 minutes) was observed. No significant change occurred in total cholesterol, high-density lipoprotein(c), and low-density lipoprotein(c). CONCLUSION: Small doses (0.125 mg) of delta-8-estrone sulfate have profound estrogenic effects in postmenopausal women. The changes observed in n-telopeptide levels and the lag-time delay in oxidation of low-density lipoprotein(c) indicate that this estrogen contributes toward the overall beneficial effects on bone and cardiovascular system associated with Premarin therapy.

Pharmacokinetics and pharmacodynamics of a novel estrogen delta8-estrone in postmenopausal women and men.

Recently a tenth equine estrogen, identified as the sulfate ester of delta8-estrone has been reported to be present in Premarin (a conjugated equine estrogen preparation), and because of its unique ring B unsaturated structure (conjugated double bond in the B ring), we have, in the present study, determined its pharmacokinetics in postmenopausal women and men, its interaction with uterine estrogen receptors and its uterotropic activity. After the administration of [14C]delta8-estrone, blood was drawn at various time intervals, and the plasma fractionated into the unconjugated sulfate and glucuronide fractions. The disappearance of radioactivity as delta8-estrone from plasma can be described as a function of two exponentials. The half-lives of the first and second components were 5+/-0.2 and 40.4 min, respectively. The mean metabolic clearance rate calculated (MCR), was 1711+/-252 l/d m2. From the unconjugated fraction, delta8-17beta-estradiol was also isolated and identified. From the sulfate conjugated fraction, delta8-estrone sulfate and delta8-17beta-estradiol sulfate were isolated in almost equal amounts. No other metabolites of delta8-estrone was detectable in the plasma. Both delta8-estrone and delta8-17beta-estradiol bind with human endometrial and rat uterine estrogen receptors with high affinity. The binding affinities of delta8-17beta-estradiol for human endometrial and rat uterine cytoplasmic receptors were 4 and 25 times higher than those of the parent estrogen delta8-estrone, respectively. Administration of delta8-estrone and delta8-17beta-estradiol (2 microg/100 g body weight) to immature rats significantly (P< 0.05) increased the uterine weight compared to the controls. These data demonstrate that delta8-estrone has estrogenic activity, and that it is further metabolized in man to a single more potent estrogen, delta8-17beta-estradiol. The extent of this activation by 17beta-reduction appears to be greater than that observed with other estrogens. Both estrogens circulate as sulfate conjugates and are very slowly eliminated from the circulation. These data further suggest that delta8-estrone and its major metabolite delta8-17beta-estradiol can contribute to the overall in vivo biological effects of Premarin.

Occupational medicine in Canada in 1996.

Occupational medicine in Canada presents many paradoxes and anomalies. This paper outlines the history, status, and current direction of occupational medicine in the country, with an emphasis on the unusual features of the Canadian experience.

Endometrial transcripts of human insulin-like growth factors arise by differential promoter usage.

By the application of RT-PCR, we have demonstrated that in the human endometrium mRNAs for insulin-like growth factors, IGF-I and II, and their receptors are expressed not only in the intact endometrium, but also in the freshly isolated stromal and epithelial cells. The expression of multiple transcript forms of the IGF-I and II at various phases of the menstrual cycle, occurs by differential use of all four IGF-I transcriptional start sites, and two of the four known promoter sites of the IGF-II gene. The complete spectrum of transcripts is displayed by the proliferative phase and the menstrual phase endometrium. During the secretory phase, the exon 1 upstream start site of the IGF-I gene and the P2 promoter of the IGF-II gene are not used. Irrespective of the phase of the menstrual cycle, the stromal cells always display the same transcriptional patterns of both growth factor genes as those of the intact endometrium. In contrast, the epithelial cells do not express IGF-I transcript originating from the exon 2 upstream initiation site. These results indicate that the expressions of the IGF-I and II genes in the intact endometrium and stromal and epithelial cells are modulated at the transcriptional level during the menstrual cycle by differential usage of promoters and start sites.

Metabolism of [3H] 17 beta-dihydroequilin and [3H] 17 beta-dihydroequilin sulfate in normal postmenopausal women.

The metabolism of 17 beta-dihydroequilin and 17 beta-dihydroequilin sulfate was investigated after intravenous administration of [3H] 17 beta-dihydroequilin and [3H] 17 beta-dihydroequilin sulfate to postmenopausal women. Urine was collected for 3 days and 46.2 +/- 10.5% and 54.5 +/- 8.7% of the injected dose of [3H] 17 beta-dihydroequilin and [17 beta-3H]dihydroequilin sulfate was excreted in the urine respectively. The estrogens present in urine were extracted and fractionated into unconjugated, sulfate, and glucuronide conjugated forms. With both precursors, the major amount (63-64%) of metabolites were excreted in the urine conjugated with glucuronic acid. From the unconjugated, sulfate, and glucuronide fraction, 17 beta-dihydroequilenin, 17 beta-dihydroequilin, equilenin, and equilin were isolated. The conversions with both precursors were similar and 17 beta-dihydroequilenin was the major metabolite isolated from all three fractions; however, the highest levels of all four metabolites were present in the glucuronide fraction. Along with these identifiable metabolites, a large amount (51-81%) of radioactivity was present in the form of metabolites which are more polar than any of the known ring-B unsaturated estrogens. These appear to be polyhydroxy 17 beta-reduced ring-B unsaturated estrogens which remain to be identified. The in-vivo formation of equilenin and 17 beta-dihydroequilenin indicates the presence of the enzyme 6.8(9) steroid dehydrogenase in humans.

Pharmacokinetics of 17 beta-dihydroequilin sulfate and 17 beta-dihydroequilin in normal postmenopausal women.

The MCRs of 17 beta-dihydroequilin sulfate and 17 beta-dihydroequilin were determined in normal postmenopausal women by single iv injection of either 17 beta-[3H]dihydroequilin sulfate ([3H]17 beta-EqS) or 17 beta-[3H]dihydroequilin ([3H]17 beta-Eq). After the administration of [3H]17 beta-EqS, blood was drawn at various time intervals, and the plasma obtained was fractionated into the unconjugated, sulfate, and glucuronide fractions. The bulk of radioactivity was present in the sulfate fraction, and from this [3H]17 beta-EqS, [3H]equilin sulfate, [3H]equilenin sulfate, and 17 beta-[3H]dihydroequilenin sulfate were isolated and purified, and their concentrations were measured. The disappearance of [3H]17 beta-EqS from plasma can be described as a function of two exponentials. The half-life of the initial fast component was 5 +/- 0.2 min; this component represents the distribution and transfer from a space, with a mean volume (V1) of 6 +/- 0.5 L. The value for the rate constant (k) of total removal from this space was 300 +/- 20 U/day, of which 35 +/- 2% was irreversible. The mean half-life of the slower component of 17 beta-EqS was 147 +/- 15 min, and the mean MCR was 376 +/- 93 L/day.m2. Similarly, after the administration of [3H]17 beta-Eq, the disappearance of radioactivity as 17 beta-Eq from plasma also had two components. The half-lives of the fast and slow component were 5.5 +/- 0.8 and 45 +/- 2.0 min, respectively. The MCR of 17 beta-Eq was 1252 +/- 103 L/day.m2. From both series of experiments, unconjugated and sulfate-conjugated equilin, equilenin, and 17 beta-dihydroequilenin were isolated and purified, and their concentrations were measured. No 17 alpha-reduced metabolites were detected. These results indicate that 17 beta-EqS is cleared twice as fast as equilin sulfate (MCR, 176 L/day.m2), whereas the more potent estrogen 17 beta-Eq is cleared 2 times slower than equilin. The slower elimination and greater estrogenic activity of 17 beta-Eq support the hypothesis that the major in vivo activity of equilin sulfate present in conjugated equine estrogen preparations is expressed via its metabolites 17 beta-EqS and 17 beta-Eq.

Metabolic clearance rate of equilin sulfate and its conversion to plasma equilin, conjugated and unconjugated equilenin, 17 beta-dihydroequilin, and 17 beta-dihydroequilenin in normal postmenopausal women and men under steady state conditions.

The constant infusion of [3H]equilin sulfate ([3H]EqS) was used to estimate the MCR of equilin sulfate (EqS) and to measure the conversion of this estrogen to equilin (Eq), equilenin (Eqn), equilenin sulfate (EqnS), 17 beta-dihydroequilin (17 beta-Eq), 17 beta-dihydroequilin sulfate (17 beta-EqS), 17 beta-dihydroequilenin (17 beta-Eqn), and 17 beta-dihydroequilenin sulfate (17 beta-EqnS) in normal postmenopausal women and men. Infusion of [3H]EqS was started in five postmenopausal women and two men 30 min after a priming dose and continued at a constant rate of 12-15 microCi/h for 3 h. Blood samples were taken 15 min before the end of infusion, at the end of the infusion, and 15 min after the end of infusion. Unconjugated and sulfate-conjugated Eq, Eqn, 17 beta-Eq, and 17 beta-Eqn were isolated from plasma. The mean MCR of EqS was calculated to be 280 +/- 24 L/day or 170 +/- 18 L/day.m2. The mean conversion ratios for precursor EqS to product 17 beta-EqS, EqnS, 17 beta-EqnS, 17 beta-Eq, Eq, Eqn, and 17 beta-Eqn were 0.300, 0.190, 0.100, 0.020, 0.016, 0.008, and 0.004 respectively. In both the sulfate-conjugated and unconjugated forms, 17 beta-Eq was the most abundant metabolite formed. 17 beta-Eq estrogen is a potent uterotropic agent and has a much higher affinity for estrogen receptors than Eq. Its formation may be of importance in the overall biological activity of EqS present in conjugated equine estrogen preparations.

Physical abuse in pregnancy.

OBJECTIVES: To determine the prevalence of physical abuse during late pregnancy and to investigate how abused and nonabused pregnant women differ in demographic characteristics, health habits, psychologic distress and attitudes about fetal health. DESIGN: Survey of women attending for prenatal health care or admitted to hospital for delivery. The information was obtained on one occasion from self-report questionnaires, completed with the option of anonymity. SETTINGS: Community-based prenatal clinic, private obstetricians' offices in a large city, private family physicians' offices in a large city, family physicians' offices in a small town, and a university teaching hospital. PATIENTS: English-speaking women at 20 weeks' or more gestation attending or admitted consecutively. INTERVENTIONS: Three self-report questionnaires: the General Health Questionnaire (GHQ), the Fetal Health Locus of Control (FHLC) and the study questionnaire. RESULTS: Thirteen women (2.4%) refused to participate in the survey. Of the 548 women who completed the questionnaires 36 (6.6%) reported physical abuse during the current pregnancy and 60 (10.9%) before it. There were no significant differences in rates of abuse between settings. Of the women abused during the pregnancy 23 (63.9%) reported increased abuse during the pregnancy, and 28 (77.8%) remained with the abuser. Twenty-four pregnant women (66.7%) received medical treatment for abuse, but only 1 (2.8%) told her prenatal care provider of the abuse. Factor analysis revealed three factors associated with physical abuse in pregnancy: "social instability" (comprising low age, unmarried status, lower level of education, unemployment and unplanned pregnancy), "unhealthy lifestyle" (comprising poor diet, alcohol use, illicit drug use and emotional problems) and "physical health problems" (comprising health problems and prescription drug use). The GHQ scores showed that the abused women were significantly more emotionally distressed than the nonabused women (p < 0.001). The FHLC scores showed that the abused women believed they had little "internal control" over the health of their fetuses and that "chance" played the most important role in the outcome of their pregnancy (p < 0.001). CONCLUSIONS: Abused pregnant patients are a frequently undetected high-risk group. Prenatal care should include a routine screening question about domestic violence, and identified patients should be appropriately counselled and referred.

Mortality of 11,500 nickel workers--extended follow up and relationship to environmental conditions.

An extended follow-up from 1977-84 was achieved in a cohort of 11,567 nickel workers engaged in mining, milling and smelting originally studied from 1950-76. Exposure data were incorporated into the analysis. One nasal cancer occurred. The lung cancer Standardized Mortality Ratio beyond 15 years from first exposure was significantly high overall (128) and in miners (153). However, detailed analyses by era of first mining and duration of mining, as well as cumulative exposure to different nickel species, did not appear consistent with an occupational etiology since significant trends were not observed. At the levels of exposure incurred, large increases in lung and nasal cancer, observed in nickel refineries elsewhere, did not occur.

Maternal weight loss associated with hyperemesis gravidarum: a predictor of fetal outcome.

Over a 5-year period in our center 64 patients were hospitalized with a diagnosis of hyperemesis gravidarum. Patients were classified into two groups to determine whether weight loss was an objective predictor of pregnancy outcome. Patients whose weight loss was greater than 5% of their prepregnancy weight were classified as group A (n = 30). Patients with nausea and vomiting of pregnancy but with maintenance of at least 95% of prepregnancy body weight were in group B (n = 34). Infants in group A were significantly smaller with respect to average birth weight expressed as a percentile for gestational age: 38.11 percentile, versus 72.00 percentile for group B (p less than 0.025). Macrosomia (greater than or equal to 4000 gm) was significantly associated with group B (18% versus group A, 0%; p less than 0.025). Growth retardation (less than or equal to 10th percentile weight at birth) was significantly associated with group A (30% versus group B, 6%; p less than 0.01). Three integumentary system abnormalities (3 of 30 cases) occurred in group A compared with none in group B. Although hyperemesis gravidarum has been viewed as a positive predictor, those patients who also demonstrate weight loss and electrolyte disturbance may be a distinct entity and at greater risk for growth retardation and fetal anomalies.

Physicochemical characteristics and biological effects of nickel oxides.

Ten nickel oxides and nickel-copper oxides, which all contained NiO (bunsenite) as the predominant crystalline phase, were assayed as follows: in vitro dissolution tests in water and body fluids; in vitro phagocytosis tests in Chinese hamster ovary and C3H-10T1/2 cells; morphological transformation and cytotoxicity tests in cultured Syrian hamster embryo (SHE) cells; erythropoiesis stimulation assay by intrarenal administration to Fischer-344 rats; and scoring the renal histopathologic responses in rats killed 3 months post-injection. The test compounds differed substantially in their biological effects when tested in the various experimental systems. Based upon highly significant concordance of ranked results in the assays (P less than 0.001), six colligative biological attributes of the compounds were identified: (i) dissolution half-times in rat serum and renal cytosol; (ii) phagocytosis by C3H-10T1/2 cells; (iii) morphological transformation of SHE cells; (iv) erythropoiesis stimulation in rats; (v) induction of tubular hyperplasia in rat kidneys; and (vi) induction of arteriosclerosis in rat kidneys. Strong rank correlation (P less than 0.01) between results of the cell transformation and erythropoiesis stimulation assays is especially notable, since the compounds were tested by blind protocols in independent laboratories. The presence of high surface area and demonstrable Ni(III) were two physicochemical characteristics that were associated with the greatest biological effects of nickel oxides.

The role of oestrogen replacement in the climacteric syndrome.

Using a double-blind placebo-controlled cross-over design, the effect of equine conjugated oestrogens tablets (Premarin) was studied in 20 women with the climacteric syndrome followed during 15 months. Sixteen women were equally improved on placebo and oestrogen. Only 2 patients had an improved sense of well-being on oestrogen and not on placebo. The psychological diagnosis was unrelated to the subjective response to oestrogen or placebo. Performance in psychological tests administered before and during treatment periods was not changed by oestrogen or placebo.

Abdominal pregnancy complicated by genital and renal tuberculosts and hemolytic anemia.

After a 10-year period of primary infertility, a patient presented with abdominal pregnancy. Known to have had previously treated genital tuberculosis, on admission she was found to have renal tuberculosis and autoimmune hemolytic anemia. After fetal death, laparotomy was performed and the fetus was removed. The patient's anemia responded well to steroid therapy and she was discharged on antituberculous triple therapy. The literature on hemolytic anemia in pregnancy and in association with tuberculosis, as well as on ectopic gestations, was reviewed.