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Sprecher DL, Kobayashi J, Rymaszewski M, Goldberg IJ, Harris BV, Bellet PS, Ameis D, Yunker RL, Black DM, Stein EA. Trp64----nonsense mutation in the lipoprotein lipase gene. J Lipid Res 1992; 33:859-66. [PMID: 1512512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
A lipoprotein lipase (LpL) gene defect has been identified, a G----A transition at nucleotide position 446 of exon 3, resulting in a premature termination codon (Trp----stop) at amino acid residue 64. This defect was identified in a Type I hyperlipoproteinemic subject with an amino acid residue 194 defect in the other allele. Plasma lipoprotein values as well as LpL mass and activity in postheparin plasma were determined in the subjects with the residue 64 defect and in other LpL-deficient heterozygotes. LpL mass levels in both the Type I and the other subject with a 64 LpL defect were markedly reduced. This may be explained by rapid degradation of LpL protein or decreased secretion from the 64 defective allele. Alternatively, the marked reduction or absence of mass associated with the 64 defect may be due to synthesis of a severely truncated protein which escapes immunologic detection.
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Wetterau JR, Combs KA, Albers HW, Lamkin G, Stein EA, Barnhart RL, Chi EM, Jackson RL, Harmony JA. Effects of probucol on plasma lipids, lipoproteins and parameters of high density lipoprotein metabolism. Horm Metab Res 1992; 24:289-96. [PMID: 1634195 DOI: 10.1055/s-2007-1003315] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Eight patients with primary hypercholesterolemia were treated with probucol for 17 weeks. Plasma total cholesterol, low density lipoprotein (LDL)-cholesterol, and high density lipoprotein (HDL)-cholesterol decreased by 16.6, 15.0 and 25.7%, respectively, in response to probucol treatment. Plasma levels of apolipoprotein B and apolipoprotein A-I also decreased, while apolipoprotein A-II concentrations were unchanged. The decrease in HDL-cholesterol levels was associated with a reduction in HDL particle size. No changes in the plasma lecithin:cholesterol acyltransferase activity or mass occurred in response to probucol treatment. In contrast, a significant 25% increase in plasma cholesteryl ester and triglyceride transfer activity occurred following probucol treatment. There was a positive correlation (R = 0.94) between cholesterol ester and triglyceride transfer. We propose that the increase in lipid transfer activity may in part explain the changes in HDL concentration and size, as well as the previously reported effect probucol has on reducing atherosclerosis in animal models.
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Eichner JE, Ferrell RE, Kamboh MI, Kuller LH, Becker DJ, Drash AL, Stein EA, Orchard TJ. The impact of the apolipoprotein E polymorphism on the lipoprotein profile in insulin-dependent diabetes: the Pittsburgh Epidemiology of Diabetes Complications Study IX. Metabolism 1992; 41:347-51. [PMID: 1556940 DOI: 10.1016/0026-0495(92)90066-j] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The apolipoprotein (apo) E polymorphism has been related to differences in lipoprotein metabolism and lipid/lipoprotein concentrations in a number of studies. Whether these associations are seen in insulin-dependent diabetes mellitus (IDDM), which itself affects many of the same aspects of lipoprotein metabolism as does the apo E polymorphism, is unknown. The present study is an investigation into the influence of apo E phenotype on lipoprotein concentrations in a large group of IDDM patients (n = 433) participating in the Pittsburgh Epidemiology of Diabetes Complications (EDC) Study. The frequency of the three apo E alleles 2, 3, and 4 did not differ in this population from that reported in general white populations. Although the diabetic subjects show the same trends as seen in the general population, ie, apo E-2 is associated with lower and apo E-4 with higher low-density lipoprotein cholesterol (LDLc) compared with apo E3 (P less than .03), they also show relationships with glycemic control that influence the relative levels of lipid measures with respect to apo E phenotype. Results also raise the possibility that lipoprotein composition varies according to apo E phenotype in IDDM.
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Czech DA, Stein EA. Effect of drinking on angiotensin-II-induced shifts in regional cerebral blood flow in the rat. Brain Res Bull 1992; 28:529-35. [PMID: 1617435 DOI: 10.1016/0361-9230(92)90099-j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A map of brain regions affected by central administration of the octapeptide angiotensin II (AII) and that would further reflect the consequences of AII's well-known dipsogenic action was developed. Regional cerebral blood flow (rCBF) as an indicator of neuronal activity was measured in conscious rats shortly after an ICV bolus injection of 100 ng AII or saline vehicle (VEH). AII-treated animals were further subdivided into two groups that were either permitted to drink [AII (W+)] or whose water was removed when drinking was attempted [AII (W-)]. When compared to VEH condition, blood flow increased significantly within 1 min after AII treatment in 33 of 53 regions sampled in those rats not given an opportunity to drink. In 11 of these 33 regions, ingestion of a small amount of water was associated with a reversal of AII-induced elevation in blood flow [i.e., AII (W+) less than AII (W-)]; these regions included the organum vasculosum lamina terminalis, rostral lateral hypothalamus, supraoptic nuclei, rostral zona incerta, and median eminence. A group of similarly treated rats exhibited a significant elevation of mean arterial blood pressure following AII treatment without significant shifts in arterial blood gases, pH, or bicarbonate. These data are consistent with prominent involvement of the anteroventral third ventricular region of the rat brain. The results further indicate that rCBF may be a sensitive measure for the identification of central sites of action of AII as a dipsogenic agent and may reveal distinctions between regions associated primarily with initiation of drinking and those reflecting the results of subsequent behavioral events.
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Abstract
The widespread, heterogeneous distribution of opiate receptors and their endogenous ligands in the nervous system are reflective of the variety of central and systemic effects seen after opiate administration. Most neurons respond to either systemic or local opiate application with a decrease in firing rate, although increased neuronal activity has also been reported in such regions as the caudate, amygdala, ventral tegmentum, and substantia nigra. While regional metabolic studies have consistently reported neuronal suppression, some portion of this might be secondary to systemic hypercapnia. Using a brief blood flow marker, we recently reported a heterogenous increase in activity in more than half of the brain regions examined. To extend that study, we report herein the results of a dose-response and antagonist challenge experiment. Rats received an acute injection of one of the following: heroin (0.1, 0.3 or 1.0 mg/kg), naloxone (1.0 mg/kg), a cocktail of heroin (0.3 mg/kg) plus naloxone or saline. One min after drug administration, 160 muCi/kg [1-14C] octanoate, a marker for cerebral blood flow, was delivered IV. Rats were sacrificed two min later, brains removed and prepared for autoradiography. Of the fifty-eight areas analyzed, heroin caused an increase in blood flow in the caudate, claustrocortex, laterodorsal thalamus and dentate gyrus. Decreases were found for the bed nucleus of the stria terminalis, preoptic area, basolateral nucleus of the amygdala, dorsomedial and paraventricular hypothalamus, entorhinal and cingulate cortices and dorsal raphe. Naloxone resulted in significant increases in the olfactory tubercle and paraventricular nucleus while decreases were seen in the cingulate and basolateral amygdala.
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Hawkins M, Stein EA. Effects of continuous naloxone administration on ventral tegmental self-stimulation. Brain Res 1991; 560:315-20. [PMID: 1662111 DOI: 10.1016/0006-8993(91)91250-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Continuous subcutaneous administration of naloxone (3 mg/kg/h), shifted ventral tegmental self-stimulation rate-frequency curves to the right, without suppressing behavioral performance. In addition this chronic blockade of opioid receptors altered mu binding parameters in the hippocampus and olfactory tubercle of naloxone-treated animals. These findings speak to the role opioid peptides paly in the mediation of brain stimulation reward.
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Sprecher DL, Knauer SL, Black DM, Kaplan LA, Akeson AA, Dusing M, Lattier D, Stein EA, Rymaszewski M, Wiginton DA. Chylomicron-retinyl palmitate clearance in type I hyperlipidemic families. J Clin Invest 1991; 88:985-94. [PMID: 1885783 PMCID: PMC295501 DOI: 10.1172/jci115402] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Our primary aim was to determine the extent to which intraplasmic retinyl palmitate (RP) transfers to other lipoprotein particles when chylomicron remnants are not produced and/or the plasma RP residence time is increased. The study was conducted on three familial type I hyperlipoproteinemic patients, four lipoprotein lipase (LpL)-deficient heterozygotes, and three controls on a metabolic research unit. To each subject, a fat load was administered containing 16% of total daily calories in type I patients, 40% in heterozygotes and controls, plus 60,000 U/m2 vitamin A. Triglyceride (TG) and RP levels were evaluated in chylomicron and nonchylomicron fractions. Delay in the clearance of chylomicron fraction RP and the marked deficiency in nonchylomicron-RP (presumed lack of remnant production) in all three type I patients suggests that RP does not demonstrate significant intraplasmic transfer from chylomicrons to existent apolipoprotein B100 particles. In contrast to noncoincident TG and RP peaking in the normal subject, heterozygotes were found to demonstrate coincident plasma TG and RP curves, which is consistent with a common catabolic pathway for both TG and RP and inconsistent with intraplasmic RP transfer. This corroborates reports on compromised chylomicron clearance in heterozygotes. We conclude that RP is an appropriate representative marker for intestinally derived particles in LpL-deficient or partially deficient individuals.
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Meilahn EN, Kuller LH, Matthews KA, Wing RR, Caggiula AW, Stein EA. Potential for increasing high-density lipoprotein cholesterol, subfractions HDL2-C and HDL3-C, and apoprotein AI among middle-age women. Prev Med 1991; 20:462-73. [PMID: 1908079 DOI: 10.1016/0091-7435(91)90044-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Studies have shown high-density lipoprotein cholesterol (HDL-C) to be a strong predictor of cardiovascular disease (CVD) risk. METHODS Determinants of HDL-C and apoprotein AI concentrations were evaluated cross-sectionally in 1987 among 429 women, ages 45-54, from a population-based study of CVD risk factors through menopause (the Healthy Women Study, University of Pittsburgh). RESULTS Subjects were healthy and not taking hormone replacement therapy. Results showed levels of HDL-C (mg/dl) to range from 23 to 117, HDL2-C from 0 to 53, HDL3-C from 16 to 66, and apoprotein AI from 87 to 204. Multivariate analyses which included age, cigarettes/day, alcohol intake (g/day), physical activity (Paffenbarger questionnaire), body mass index (BMI), and waist/hip ratio (WHR) showed that women who smoked greater than or equal to 20 cigarettes a day, reported little or no alcohol intake, expended less than 500 kcal/week, and were in the highest quintile of BMI and WHR had, on average, 33 mg/dl lower HDL-C than slender, nonsmoking women who drank moderately and exercised. HDL2-C showed a similar pattern, whereas the HDL3-C concentration had only a modest association with these factors. HDL-C was somewhat lower among women who had stopped menstruating than among premenopausal women. The apoprotein AI level was associated with alcohol intake (positively) and BMI (negatively). CONCLUSION Theoretically, by raising their HDL-C by 10 mg/dl, women could reduce their CVD risk by as much as one-third (based on results from the Framingham Heart Study). As CVD is the leading cause of death among postmenopausal women, the potential impact of such a reduction in risk would be large.
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Maser RE, Wolfson SK, Ellis D, Stein EA, Drash AL, Becker DJ, Dorman JS, Orchard TJ. Cardiovascular disease and arterial calcification in insulin-dependent diabetes mellitus: interrelations and risk factor profiles. Pittsburgh Epidemiology of Diabetes Complications Study-V. ARTERIOSCLEROSIS AND THROMBOSIS : A JOURNAL OF VASCULAR BIOLOGY 1991; 11:958-65. [PMID: 2065046 DOI: 10.1161/01.atv.11.4.958] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Cardiovascular disease is a frequent complication of insulin-dependent diabetes mellitus (IDDM), but the prevalence, interrelations, and risk factors of its principal components (coronary, cerebrovascular, and lower-extremity arterial disease) and of medial arterial wall calcification are not well understood. To address these issues, data from the Epidemiology of Diabetes Complications Study (n = 657) baseline examination were examined. The term coronary heart disease (CHD) was applied to those with myocardial infarction or angina, whereas lower-extremity arterial disease (LEAD) was applied to those who had undergone amputation of a lower limb or who had an ankle to arm blood pressure ratio less than 0.8 at rest or after exercise. Calcification of the lower-extremity arteries was considered to be present if ankle pressure was more than 100 mm Hg higher than brachial pressure. Although the prevalence of CHD was low, LEAD was significantly more common in women than in men (p less than 0.01), whereas calcification was more frequent in men than in women (p less than 0.01). Ten percent of those with LEAD also had CHD, and 8% with LEAD had calcification. Modeling of potential risk factors (e.g., diabetes duration and glycosylated hemoglobin) revealed that duration, female gender, fibrinogen, low density lipoprotein cholesterol, high density lipoprotein cholesterol, and high density lipoprotein cholesterol to apolipoprotein A-I ratio were independent predictors of LEAD, whereas for CHD only, diabetes duration and hypertension contributed to CHD. Calcification revealed a mixed pattern, with duration, hypertension, and triglyceride to apolipoprotein A-I ratio being the statistically significant associated factors. The results suggest that although LEAD, CHD, and calcification often coexist, their risk factor profiles differ.
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Lohse P, Mann WA, Stein EA, Brewer HB. Apolipoprotein E-4Philadelphia (Glu13----Lys,Arg145----Cys). Homozygosity for two rare point mutations in the apolipoprotein E gene combined with severe type III hyperlipoproteinemia. J Biol Chem 1991; 266:10479-84. [PMID: 1674745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The molecular defect in a 24-year-old white female with severe type III hyperlipoproteinemia has been elucidated. The patient's apolipoprotein (apo) E migrated in the apoE-4 position on isoelectric focusing gels. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis the apoE-4 variant had a smaller apparent molecular weight than apoE-4(Cys112----Arg). Sequence analysis of DNA amplified with the polymerase chain reaction revealed two nucleotide substitutions in the proband's apoE gene. A C to T mutation converted arginine (CGT) at position 145 of the mature protein to cysteine (TGT) thus creating the apoE-2 variant. A second G to A substitution at amino acid 13 led to the exchange of lysine (AAG) for glutamic acid (GAG), thereby adding 2 positive charge units to the protein and producing the apoE-5 variant. Computer analysis of the apoE-4Philadelphia gene revealed that the G to A mutation in exon 3 resulted in the loss of an AvaI restriction enzyme site. The second mutation, a C to T substitution in the fourth exon of the apoE gene, eliminated a cleavage site for the enzyme BbvI. Using these restriction fragment length polymorphisms as well as DNA sequence analysis we have demonstrated that the patient is homozygous for both point mutations in the apoE gene.
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Stein EA, Carr KD, Simon EJ. Brain stimulation-induced feeding alters regional opioid receptor binding in the rat: an in vivo autoradiographic study. Brain Res 1990; 533:213-22. [PMID: 1963108 DOI: 10.1016/0006-8993(90)91342-e] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Although opioid antagonists block feeding behavior in a variety of animal models, the number and identity of CNS regions in which the inferred endogenous opioid activity mediates feeding have yet to be established. Furthermore, it is not yet clear whether the opioid activity that sustains feeding is a concomitant of the appetitive motivational state or the consummatory response. In an effort to address these issues, an in vivo autoradiographic method was used to visualize CNS regional changes in opioid release during appetitively motivating electrical stimulation in the lateral hypothalamus (ESLH) and during consummatory behavior elicited by such stimulation. Regional decreases in [3H]diprenorphine [(3H]Dpr) binding, suggesting increased release of an endogenous opioid peptide, were observed in the medial prefrontal cortex, medial septum, gustatory cortex, zona incerta, mediodorsal thalamus, and hippocampus of rats receiving ESLH. Decreased binding in the latter 4 structures did not appear when animals were allowed to eat during ESLH, suggesting that the inferred opioid release is associated with appetitive behaviors elicited by ESLH which are suppressed when food is available and consummatory behavior predominates. When animals were allowed to eat during ESLH, [3H]Dpr binding in anterior cingulate cortex decreased substantially, suggesting that feeding behavior specifically triggers opioid release in this region. ESLH and feeding were found to increase [3H]Dpr binding in a number of CNS regions. Alternative explanations for increased binding, including inhibition of tonic opioid release, changes in cerebral blood flow, and opioid receptor up-regulation are discussed.
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Satterfield S, Greco PJ, Goldhaber SZ, Stampfer MJ, Swartz SL, Stein EA, Kaplan L, Hennekens CH. Biochemical markers of compliance in the Physicians' Health Study. Am J Prev Med 1990; 6:290-4. [PMID: 2268456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The Physicians' Health Study is a randomized, double-blind, placebo-controlled trial using a 2 x 2 factorial design to test the effects of low-dose aspirin on risk of cardiovascular disease and beta-carotene supplementation on the incidence of cancer. To evaluate self-reported compliance with assigned treatment, we measured serum thromboxane B2, which is decreased after aspirin use, and plasma beta-carotene in samples of study participants drawn from three geographic locations in three different time periods. Thromboxane B2 levels were markedly lower in those assigned to aspirin (median = 63.5 pg/mL) than in those given aspirin placebo (median = 3,600 pg/mL, P less than .0001). Similarly, those assigned to beta-carotene had significantly higher levels (median = 1,176 ng/mL) than those given placebo (median = 306 ng/mL, P less than .0001). In addition, there was a highly significant positive correlation between levels of these biochemical markers and the self-reports of compliance (r = 0.65 for thromboxane B2 and r = 0.69 for beta-carotene, P less than .0001). These findings support the validity of the self-reported compliance in the Physicians' Health Study.
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Gormley GJ, Stoner E, Rittmaster RS, Gregg H, Thompson DL, Lasseter KC, Vlasses PH, Stein EA. Effects of finasteride (MK-906), a 5 alpha-reductase inhibitor, on circulating androgens in male volunteers. J Clin Endocrinol Metab 1990; 70:1136-41. [PMID: 2156887 DOI: 10.1210/jcem-70-4-1136] [Citation(s) in RCA: 97] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Finasteride, a 5 alpha-reductase inhibitor, was administered to normal male volunteers in a blinded placebo-controlled study at daily oral doses of 25, 50, and 100 mg for 11 days (part 1) and daily oral doses of 0.04, 0.12, 0.2, and 1.0 mg for 14 days (part 2). Results from part 1 showed a significant reduction in dihydrotestosterone (DHT) at all doses and a significant increase in both testosterone (T) and delta 4-androstenedione at the 50- and 100-mg doses. No change was seen in LH, FSH, cortisol, or estradiol levels. Serum lipids, including total cholesterol, low density lipoprotein, high density lipoprotein, and triglycerides were not affected by treatment. Results from part 2 again showed significant reduction in DHT at all doses. DHT levels returned to pretreatment values within 14 days of discontinuing treatment. Significant increases in T were observed only in the 1.0 mg group and only during the first 8 days of treatment. The T/DHT ratio increased with all doses and returned to baseline when drug was discontinued. The DHT metabolites and androstanediol glucuronide and androsterone glucuronide were significantly reduced at all doses. There were no significant adverse experiences reported during part 1 or 2. In conclusion, finasteride is well tolerated by normal volunteers and results in significant suppression of serum DHT at all doses tested.
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Stryker WS, Stampfer MJ, Stein EA, Kaplan L, Louis TA, Sober A, Willett WC. Diet, plasma levels of beta-carotene and alpha-tocopherol, and risk of malignant melanoma. Am J Epidemiol 1990; 131:597-611. [PMID: 2316493 DOI: 10.1093/oxfordjournals.aje.a115544] [Citation(s) in RCA: 102] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Dietary intake and the plasma levels of retinol, alpha-tocopherol, lycopene, alpha-carotene, and beta-carotene for 204 cases with malignant melanoma were compared with those of 248 controls. Cases and controls were patients 18 years of age or older making their first visit to a dermatology subspecialty clinic for pigmented lesions from July 1, 1982 to September 1, 1985. Intakes of nutrients were estimated using a semiquantitative food frequency questionnaire. No significant associations with malignant melanoma were observed for higher plasma levels of lycopene, retinol, or alpha-carotene in logistic regression analyses after controlling for age, sex, plasma lipids, and known constitutional risk factors (hair color and ability to tan). In similar models, the odds ratio comparing the highest with the lowest quintile was 0.9 (95% confidence interval (CI) 0.5-1.5) for plasma beta-carotene, 0.7 (95% CI 0.5-1.3) for plasma alpha-tocopherol, 0.7 (95% CI 0.4-1.2) for carotene intake, and 0.7 (95% CI 0.4-1.3) for total vitamin E intake. A trend toward reduced risk of melanoma was observed for increasing intake of iron (not including supplements); this was related to the more frequent consumption of baked goods, such as cake, among controls. Alcohol consumption was positively associated with risk of melanoma (chi for trend = 2.1, p = 0.03); the odds ratio for consumption of over 10 g/day compared with persons with no alcohol intake was 1.8 (95% CI 1.0-3.3).
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Kaplan LA, Miller JA, Stein EA, Stampfer MJ. Simultaneous, high-performance liquid chromatographic analysis of retinol, tocopherols, lycopene, and alpha- and beta-carotene in serum and plasma. Methods Enzymol 1990; 189:155-67. [PMID: 2292931 DOI: 10.1016/0076-6879(90)89286-q] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Abstract
The benefit of lowering elevated plasma low-density lipoprotein cholesterol levels and preventing coronary artery disease is now well documented. The guidelines formulated by the Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults provide a rational approach to lipid level management. Once an elevation in low-density lipoprotein cholesterol level has been confirmed in an accurate and precise laboratory, the initial step in therapy remains regulation of diet. Pharmacologic intervention is recommended only if patients do not achieve desirable low-density lipoprotein cholesterol levels after an adequate period receiving regulated diet. The guidelines provide a mix of specific low-density lipoprotein level cutoff points and additional cardiovascular risk factors on which to base decisions in regard to drug therapy. The initial approach should be monotherapy with either a bile acid binding resin or nicotinic acid, with selection based on a variety of factors, including patient age, sex, and the severity and exact type of lipid disorder. Should difficulties or inadequate control occur with either of these agents, the hydroxy-methylglutaryl-coenzyme A reductase inhibitors should be utilized, since their ability to reduce low-density lipoprotein cholesterol levels is significantly greater than that of the other available agents. If inadequate control is obtained with monotherapy, combination therapy is recommended. Optimal combinations of drugs and dosages have yet to be fully assessed and will ultimately depend on patient acceptance, efficacy, side effects, and cost effectiveness. Severely affected subjects may require triple-drug therapy. Other agents, such as fibric acid derivatives and probucol, have only a limited role when elevated low-density lipoprotein cholesterol level is the only abnormality. In patients with combined hyperlipidemias, especially when the very low-density lipoprotein level is significantly increased, the fibrates may even be used for initial therapy.
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Stein EA, Trachte GJ. Thromboxane mimetics enhance adrenergic neurotransmission in the rabbit-isolated portal vein. J Cardiovasc Pharmacol 1989; 14:469-74. [PMID: 2476628 DOI: 10.1097/00005344-198909000-00017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The thromboxane/prostaglandin H mimetics, U46619 and carbocyclic thromboxane A2 (cTA2) were examined for influences on adrenergic neural responses. Force generation in response to low-frequency electrical stimulation was enhanced 21 +/- 5% by U46619 and 20 +/- 4% by cTA2. These effects were antagonized by the thromboxane/prostaglandin H receptor antagonist, SQ29548. Norepinephrine-induced contractions were not significantly potentiated by the presence of U46619 or cTA2. Norepinephrine release from electrically stimulated portal veins was augmented by U46619 as compared to control preparations (p less than 0.05). These results are consistent with the hypothesis that thromboxane/prostaglandin H receptors mediate a potentiation of adrenergic neural responses by augmenting the release of neurotransmitters from adrenergic nerves and are inconsistent with a postjunctional potentiative site of action. The constrictor effect of U46619 on portal vein smooth muscle was less potent than the potentiative effect on neural responses suggesting that the latter would be a more likely physiological action of thromboxanes or prostaglandin endoperoxides in this vascular bed.
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Trachte GJ, Stein EA. Thromboxane receptor agonists enhance adrenergic neurotransmission in rabbit isolated mesenteric arteries. J Pharmacol Exp Ther 1989; 249:216-20. [PMID: 2540313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Two thromboxane receptor agonists, carbocyclic thromboxane A2 (CTA) and 9,11-dideoxy-11,9-epoxymethano prostaglandin F2 alpha (U46619), were examined for their influence on basal force and electrically induced force of isolated superior mesenteric arterial rings from rabbits. Both CTA and U46619 contracted the arterial rings and augmented contractile responses to electrical stimulation (4-20 Hz). The CTA and U46619 also augmented contractile responses to norepinephrine (P less than .05) and enhanced norepinephrine release in response to a 16 Hz electrical stimulation (P less than .05). The increases in basal force, neurogenic responses and norepinephrine release were prevented by the thromboxane receptor antagonist, (1S-[1-alpha,2-beta(5Z),3-beta, 4-alpha])-7-[3- [(2- [(phenylamino)carbonyl]hydrazino]methyl]-7- oxabicyclo[2.2.1]hept-2-yl]-5-heptenoic acid. The U46619 was more potent than CTA and had a more consistent effect on norepinephrine release. These results are consistent with the hypothesis that thromboxane receptor agonists augment adrenergic neurogenic responses via thromboxane receptors. The mechanism of the enhanced neurogenic responses involved both pre- and postjunctional effects of the thromboxane receptor agonists.
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Stein EA, Steiner PM. Triglyceride measurement and its relationship to heart disease. Clin Lab Med 1989; 9:169-85. [PMID: 2647372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Elevated triglycerides are clinically important owing to their direct relationship to pancreatitis, and their association with glucose intolerance, and renal and hepatic disease. Their direct role in atherosclerosis is still controversial and their inter-relationships with other lipoproteins make clarity of this issue difficult. Triglyceride measurements, as part of lipid evaluation for atherosclerotic risk, are important as they provide the only convenient and cost-effective method for routinely estimating LDL cholesterol. Their inverse relationship to HDL makes triglyceride measurements a cost-effective screening procedure. Unlike cholesterol measurements, triglycerides should always be assessed in the fasting state. Analytical methods are predominantly based on enzymatic reagent systems that reliably measure the glycerol component after fatty acid hydrolysis. Standardization (that is, accuracy) is still a major problem, while precision appears satisfactory in most clinical laboratories.
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Stein EA. Treatment of familial hypercholesterolemia with drugs in children. ARTERIOSCLEROSIS (DALLAS, TEX.) 1989; 9:I145-51. [PMID: 2912428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We assessed plasma lipid levels in children and adolescents who were on various drug regimens and who were attending a specialized lipid treatment center. All subjects had familial hypercholesterolemia (FH), and the study group included 30 subjects with heterozygous (He) and three with homozygous (Ho) FH. In the 30 He FH subjects treated with 5 to 30 g/day of a bile-acid-binding resin, plasma lipid levels were still substantially above optimal (less than or equal to 50th percentile for age and sex), although statistically significant (p less than 0.001) reductions in total and low density lipoprotein (LDL) cholesterol of 15% and 21% compared with baseline were achieved. In eight subjects who received resin plus niacin, additional reductions in total and LDL cholesterol of 15% and 17%, respectively, were achieved. Even though the combination therapy produced reductions in total, LDL, and LDL/high density lipoprotein cholesterol of 29%, 37%, and 47%, respectively, compared with baseline, resulting absolute levels were still well above optimal. Six subjects with severe He FH received a 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitor (lovastatin, 80 mg/day or simvastatin, 40 mg/day), and substantial total and LDL cholesterol reductions on the order of 35% and 41%, respectively, were found compared with diet alone. The decreases were substantially greater than those achieved with either resin or resin plus niacin. In a number of these subjects, absolute lipid levels were approaching optimal levels. In the three Ho FH subjects, the response to HMG CoA reductase inhibitors was variable but generally poor.(ABSTRACT TRUNCATED AT 250 WORDS)
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Wones RG, Kerman KM, Hissa DC, Meloy N, Stein EA. Comparisons of referral criteria for public screening of blood cholesterol levels. Public Health Rep 1989; 104:425-32. [PMID: 2508171 PMCID: PMC1579962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Total and high-density lipoprotein (HDL) cholesterol levels of 2,387 adults were screened at a worksite and a bloodbank. Hypothetical referral decisions were made according to three sets of guidelines: the 1984 National Institutes of Health Consensus Conference guidelines (NIHCC), a single referral cutpoint of 5.2 millimoles per liter (mmol per L), and the current National Cholesterol Education Program (NCEP) guidelines for screening in physicians' office. Under the NIHCC guidelines, 31 percent of the participants would have been referred to their physicians, 32 percent under the NCEP guidelines, and 56 percent would have been referred had the 5.2 mmol per L cutpoint been used. Twenty-four percent of the participants would have been referred under both the NIHCC and NCEP guidelines; 7 percent would have been referred under the NIHCC guidelines, but not the NCEP's. Eight percent would have been referred under the NCEP guidelines, but not the NIHCC's. Those who would have been referred were older, and more likely to be male and to have low levels of HDL cholesterol than the 7 percent who would have been referred under NIHCC guidelines only. All of the 8 percent had coronary heart disease, or two or more other coronary risk factors, whereas none of the 7 percent did. If low HDL had been used as a risk factor under NCEP guidelines, the number of persons referred would have increased slightly (to 34 percent) and low HDL levels would have become one of the most prevalent risk factors. The researchers concluded that public cholesterol screening programs should use the NCEP guidelines (with or without HDL), rather than the NIHCC guidelines, or a single 5.2 mmol per L cutpoint.
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Stein EA, Brady KD. Ophthalmologic and electro-oculographic findings in Gardner's syndrome. Am J Ophthalmol 1988; 106:326-31. [PMID: 3421294 DOI: 10.1016/0002-9394(88)90369-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We examined six patients with Gardner's syndrome, eight first-degree relatives, and 31 age- and sex-matched controls to document the presence, distribution, and morphologic features of congenital hypertrophy of the retinal pigment epithelium. Patients with Gardner's syndrome had multiple, bilateral lesions, with 288 of 346 foci (83%) located posterior to the equator. Linear-shaped congenital hypertrophy of the retinal pigment epithelium, a distinctive finding in these patients, accounted for 44 of 140 large lesions (31%). Despite multifocal fundus involvement, results of electro-oculography were normal in all eyes tested.
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Meilahn EN, Kuller LH, Stein EA, Caggiula AW, Matthews KA. Characteristics associated with apoprotein and lipoprotein lipid levels in middle-aged women. ARTERIOSCLEROSIS (DALLAS, TEX.) 1988; 8:515-20. [PMID: 3142451 DOI: 10.1161/01.atv.8.5.515] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Recent evidence indicates that measurement of apoproteins may enhance evaluation of coronary heart disease risk. The purpose of the present study was to identify factors associated with interindividual variation in apoproteins (apo) A-I, A-II, and B and lipoprotein lipid levels in 541 healthy premenopausal women, a random sample ages 42 to 50 taken from driver's license lists. The results of multivariate analyses that included alcohol intake, obesity, smoking, exercise, and age as predictor variables showed alcohol consumption to be strongly, positively related to apo A-I and A-II and smoking and obesity to have modest lowering effects on apo A-I. Concentration of the high density lipoprotein subfraction, HDL2c, however, was highly negatively related to body mass index, with alcohol intake and smoking each contributing about 5% to the variation. HDL3c had a similar relationship to obesity, alcohol, and smoking, but the magnitude of effect was much smaller than that for HDL2c. Thus, the concentration of cholesterol relative to protein found in HDL, particularly HDL2, was lower in overweight women and higher in women who reported alcohol intake. About 10% of variation in low density lipoprotein cholesterol (LDLc) was explained jointly by smoking, obesity, and alcohol intake compared with 15% of variation in apo B associated primarily with obesity (8%) and, to a lesser extent, with age and smoking. Physical activity was not independently associated with any of the lipoprotein lipid or apoprotein measures. In sum, results show that obese women exhibited reduced HDLc per mole of protein and that alcohol intake was linked to increased HDL particle number.(ABSTRACT TRUNCATED AT 250 WORDS)
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