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Biomedical subjects

J S Marks

Publications and source records attributed to J S Marks.

At least 37 records · Page 2Linked to original sources
PubMed1998

Increased cesarean section rates and emerging patterns of health insurance in Shanghai, China.

OBJECTIVES: This study examined the trend in cesarean section deliveries and the factors associated with it in the Minhang District of Shanghai, China. METHODS: A representative sample of the members of 2716 households in the district were interviewed in the fall of 1993. This study analyzed the data from 1959 married women of reproductive age with at least one live birth. RESULTS: During the past 3 decades, the proportion of infants born by cesarean section increased from 4.7% to 22.5%. Logistic regression analysis revealed that the highest cesarean section rate, which occurred in the most recent period of 1988 through 1993, was associated with form of medical payment, self-reported complications during pregnancy, higher birthweight, and maternal age. Government insurance pays all costs of cesarean sections and accounted for the highest proportion of the cesarean section rate. CONCLUSIONS: The high rates of cesarean sections in China are surprising given the lack of the factors that usually lead to cesarean sections. The increasing cesarean section rates may be an early indication that emerging forms of health insurance and fee-for-service payments to physicians will lead to an excessive emphasis on costly, high-technology medical care in China.

Adolescent↗
PubMed1997

Design, synthesis, and cocrystal structure of a nonpeptide Src SH2 domain ligand.

The specific association of an SH2 domain with a phosphotyrosine (pTyr)-containing sequence of another protein precipitates a cascade of intracellular molecular interactions (signals) which effect a wide range of intracellular processes. The nonreceptor tyrosine kinase Src, which has been associated with breast cancer and osteoporosis, contains an SH2 domain. Inhibition of Src SH2-phosphoprotein interactions by small molecules will aid biological proof-of-concept studies which may lead to the development of novel therapeutic agents. Structure-based design efforts have focused on reducing the size and charge of Src SH2 ligands while increasing their ability to penetrate cells and reach the intracellular Src SH2 domain target. In this report we describe the synthesis, binding affinity, and Src SH2 cocrystal structure of a small, novel, nonpeptide, urea-containing SH2 domain ligand.

Binding Sites↗
PubMed1997

Distribution of beta-amyloid in the canine brain.

The distribution of amyloid-beta protein (A beta) in the canine brain was demonstrated by immunochemistry on serially sectioned tissues from 10 aged mixed breed dogs. Summation of quantitative data and relegation to anatomical sites for the 10 dogs showed A beta to be widely distributed in the cortex and hippocampus while completely absent in the brain stem and cerebellum. The highest density of A beta was in the dentate gyrus of the hippocampus. Cortical areas exhibiting the greatest A beta deposition were the posterior and medial suprasylvius gyrus and the proreus gyrus of the frontal lobe. Unlike humans the canine entorhinal cortex, amygdala, basal ganglia and olfactory bulbs were rarely affected. This suggested that the highly developed olfactory pathways of the canine are generally spared from A beta deposition.

Aging↗
PubMed1997

The risk of breast cancer following spontaneous or induced abortion.

To evaluate the relationship between breast cancer risk and spontaneous and induced abortion, we conducted a detailed descriptive review of 32 epidemiologic studies that provided data by type of abortion and by various measures of exposure to abortion-number of abortions, timing of abortion in relation to first full-term pregnancy, length of gestation, and age at first abortion. Breast cancer risk did not appear to be associated with an increasing number of spontaneous or induced abortions. Our review also suggested that breast cancer risk probably was not related to the other measures of exposure to abortion, and probably did not differ by age or a family history of breast cancer. Finally, the data appeared to suggest a slightly increased risk among nulliparous women, but this tendency was based primarily on studies with a small number of nulliparous women who had had spontaneous or induced abortions. Definitive conclusions about an association between breast cancer risk and spontaneous or induced abortion are not possible at present because of inconsistent findings across studies. Future investigations should consider prospective designs, separate analyses of spontaneous and induced abortions, appropriate referent groups, and adequate adjustment for confounding and effect modification. Future investigations also should attempt to determine whether any increased risks reflect the transient increase in breast cancer risk hypothesized for full-term pregnancy or a causal relationship specific to spontaneous or induced abortion.

Abortion, Induced↗
PubMed1996

Prevalence of violence against pregnant women.

OBJECTIVES: To summarize the methods and findings of studies examining the prevalence of violence against pregnant women and to synthesize these findings by comparing study characteristics for studies with similar and dissimilar results. DATA SOURCES: MEDLINE, POPLINE, Psychological Abstracts, and Sociological Abstracts databases were searched for all articles pertaining to violence during pregnancy for the period 1963 through August 1995. STUDY SELECTION: Thirteen studies were selected on the basis of specific criteria: a sample with initially unknown violence status; a clear statement of research question(s), with focus on measuring the prevalence of violence; descriptions of the sample, data source, and data collection methods; and data from the United States or another developed country. DATA EXTRACTION: Relevant data were extracted to compare studies by study description, methods, and results. DATA SYNTHESIS: Evidence from the studies we reviewed indicates that the prevalence of violence during pregnancy ranges from 0.9% to 20.1%. Measures of violence, populations sampled, and study methods varied considerably across studies, and these factors may affect prevalence estimates. Studies that asked about violence more than once during detailed in-person interviews or asked later in pregnancy (during the third trimester) reported higher prevalence rates (7.4%-20.1%). The lowest estimate was reported by women who attended a private clinic and responded to a self-administered questionnaire provided to them by a person who was not a health care provider. CONCLUSIONS: Violence may be a more common problem for pregnant women than some conditions for which they are routinely screened and evaluated. Future research that more accurately measures physical violence during pregnancy would contribute to more effective design and implementation of prevention and intervention strategies.

Battered Women↗
PubMed1996

Pregnancy, abortion, and birth rates among US adolescents--1980, 1985, and 1990.

OBJECTIVE: To analyze pregnancy, abortion, and birth rates among US adolescent girls in 1980, 1985, and 1990. DESIGN: Retrospective analysis of trends in data on pregnancies, abortions, and births. POPULATION: US adolescent girls aged 13 to 19 years. MAIN OUTCOME MEASURES: Pregnancy, abortion, and birth rates (with and without adjustment for sexual experience) among teenaged girls aged 15 to 19 years and girls under 15 years. RESULTS: Although pregnancy rates among all teenaged girls 15 to 19 years old remained fairly stable from 1980 to 1985, they increased by 9% during the last half of the decade, totaling 95.9 pregnancies per 1000 teenaged girls 15 to 19 years old by 1990. Because rates of sexual experience increased even faster, pregnancy rates among sexually experienced teens aged 15 to 19 actually declined between 1980 and 1990 by approximately 8%. Abortion rates among these teens remained stable during the 1980s, with 35.8 and 36.0 abortions per 1000 in 1980 and 1990, respectively. As with overall pregnancy rates, abortion rates among these sexually experienced teenaged girls declined during the 1980s. Between 1980 and 1985, birth rates among teenaged girls aged 15 to 19 years declined by 4%, but they increased by 18% during the latter half of the decade, totaling 59.9 births per 1000 in 1990. Among these sexually experienced teenagers, birth rates also declined between 1980 and 1985 and then increased over the next 5 years. In 1990, pregnancies and abortions among girls younger than 15 years accounted for only 3% of all adolescent pregnancies and abortions. However, the number of births among these younger adolescents increased by 15% over the decade. In that age group, trends in pregnancy, abortion and birth rates over the decade were similar to those for older teens. However, during the late 1980s, the abortion rate declined and the pregnancy rate remained stable, resulting in a 26% increase in the birth rate. CONCLUSIONS: Despite efforts to reduce adolescent pregnancy in the United States, pregnancy and birth rates for that group continue to be the highest among developed countries. Considering that 95% of adolescent pregnancies are unintended, increased efforts to prevent these pregnancies are warranted.

Abortion, Induced↗
PubMed1996

Trends in the percentage of women who received no prenatal care in the United States, 1980-1992: contributions of the demographic and risk effects.

OBJECTIVE: To determine if the increase in the percentage of women who received no prenatal care in the United States relative to 1980 (from 1.3% in 1980 to 2.2% in 1989 and 1.7% in 1992) was due to increasing risks of no care in subgroups of women or increasing percentages of births to women at high demographic risk of no care. METHODS: We analyzed U.S. birth certificates for the period 1980-1992. The annual adjusted odds of no prenatal care relative to 1980 were computed by logistic regression models that included year, maternal characteristics, and interactions of these characteristics with year. We also examined changes in the annual distributions of births by maternal characteristics. RESULTS: The risk of no prenatal care in most subgroups increased during the early 1980s, peaked in the late 1980s, and declined thereafter. For example, among black women, the adjusted risk of no care more than doubled from 1980 to 1989. Throughout the 1980s and into the 1990s, the percentage of births to women at high demographic risk of no care increased. This increase in the percentage of births to women at high demographic risk shows no sign of abating. CONCLUSIONS: During the 1980s, increasing risks in subgroups of women drove the increase in the crude rate of no prenatal care. Despite decreases in the risks of no care in the early 1990s, increasing percentages of births to women with high demographic risk for no care prevented a decrease in the crude rate to the 1980 level.

Black or African American↗
PubMed1996

Hydrophobic D-amino acids in the design of peptide ligands for the pp60src SH2 domain.

Src homology-2 (SH2) domains, containing approximately 100 amino acid residues, are noncatalytic motifs involved with intracellular signal transduction. These domains can be found on nonreceptor kinases, phosphatases, and in regulatory adapter proteins among others. SH2 domains bind proteins containing phosphotyrosine (pTyr) residues in a sequence specific manner. Our efforts have focused on designing peptide mimetic ligands for the SH2 domain of the nonreceptor tyrosine kinase pp60src. We employed the cocrystal structure of the 11mer Glu-Pro-Gln-pTyr-Glu-Glu-Ile-Pro-IIe-Tyr-Leu IC50 = 800 nM as a starting point for our design efforts. These efforts have resulted in the discovery of tripeptide ligands containing D-amino acids that are only 2-fold less potent than the 11mer.

Amino Acid Sequence↗
PubMed1995

PD 90780, a non peptide inhibitor of nerve growth factor's binding to the P75 NGF receptor.

Nerve growth factor is a peptide that supports the survival and differentiation of discrete neuronal populations in the peripheral and central nervous systems. NGF binds to both trkA, a tyrosine kinase receptor, and to the p75 nerve growth factor receptor, a protein lacking a consensus signalling sequence. We have identified a substituted pyrazoloquinazolinone, PD 90780, which inhibits binding of nerve growth factor to the p75 receptor. This inhibition of binding occurs due to PD 90780 binding to nerve growth factor, not to the p75 receptor. This compound may be useful in identifying the region(s) of nerve growth factor involved in binding to the p75 receptor and in clarifying the role of p75 receptor in the actions of the neurotrophins.

Animals↗
PubMed1995

The relationship between pregnancy intendedness and physical violence in mothers of newborns. The PRAMS Working Group.

OBJECTIVE: To determine if pregnancy intendedness is associated with physical violence, and to identify factors that modify this association. METHODS: Three to 6 months after delivery, we mailed a questionnaire to a population-based sample of 12,612 mothers of infants born during 1990 and 1991 in four states. We used multiple logistic regression to compute odds ratios. RESULTS: The state-specific prevalences (+/- standard error) of physical violence ranged from 3.8 +/- 0.5 to 6.9 +/- 0.8%; the prevalences of unwanted or mistimed pregnancies ranged from 36.9-46.3%. In each state, higher rates of physical violence were reported by women who had fewer than 12 years of education, lived in crowded conditions, participated in the Special Supplemental Food Program for Women, Infants, and Children, received no or delayed prenatal care, or were of races other than white, under 20 years old, or not married. Regardless of other attributes, women with unwanted or mistimed pregnancies reported higher rates of physical violence than women with intended pregnancies and accounted for 70% of women who reported physical violence. Overall, women with unwanted pregnancies had 4.1 (95% confidence interval 2.7-6.2) times the odds of experiencing physical violence than did women with intended pregnancies. This association was weaker for women with few social advantages than for those with more advantages. CONCLUSION: Physical violence toward women during the periconceptional and antenatal periods occurs in all sociodemographic groups. Women with unwanted or mistimed pregnancies are at an increased risk for violence by their partners compared with women with intended pregnancies.

Confidence Intervals↗
PubMed1995

Vitamin D intoxication causes hypercalcaemia by increased bone resorption which responds to pamidronate.

OBJECTIVE: Vitamin D intoxication is a relatively rare but treatable cause of hypercalcaemia. In the past this has been undertaken using corticosteroids. Previous observations have suggested that there is increased bone resorption in hypervitaminosis D. If this were to be the case, specific inhibitors of bone resorption might provide more effective treatment. We have therefore studied the mechanisms of hypercalcaemia and response to therapy in a group of patients with vitamin D intoxication. DESIGN: Vitamin D metabolites were measured in six patients with vitamin D intoxication; in five of these the components of hypercalcaemia were calculated. These measurements were repeated following treatment with corticosteroids (two patients) or the bisphosphonate, pamidronate (three patients). RESULTS: In each case the serum 25-hydroxyvitamin D was grossly elevated and there was a more modest elevation in serum 1,25-dihydroxyvitamin D. The components of hypercalcaemia suggest that there was a significant degree of bone resorption in all six patients and that this is the major determinant of hypercalcaemia. Pamidronate treatment resulted in a brisk reduction in plasma calcium concentration. Following corticosteroids the return of calcium to normal was more delayed. CONCLUSION: The hypercalcaemia of vitamin D intoxication is mediated by increased bone resorption and bisphosphonates have a role in its management.

Adrenal Cortex Hormones↗
PubMed1994

Trends in oral contraceptive use and cigarette smoking. Behavioral Risk Factor Surveillance System, 1982 and 1988.

OBJECTIVE: To investigate trends in oral contraceptive (OC) use and smoking among women of reproductive age and to determine factors related to smoking among OC users. DESIGN, SETTING, AND PARTICIPANTS: Telephone interviews of women aged 18 through 45 years in 16 states and the District of Columbia who participated in the Behavioral Risk Factor Surveillance System in 1982 (N = 3553) and in 1988 (N = 7384). RESULTS: Between 1982 and 1988, the prevalence of smoking decreased from 31% to 24% among OC users and from 32% to 28% among non-OC users. In both 1982 and 1988, more than half of the OC users who smoked were heavy smokers (smoked 15 or more cigarettes per day). Nearly one fourth of 35- to 45-year-old women who used OCs were smokers. After we standardized for age, race, and education, the decline in the prevalence of smoking among OC users did not differ substantially from the decline in smoking among non-OC users. CONCLUSIONS: Despite the possible synergistic effects of smoking and OC use on the risk of cardiovascular disease, we found no accelerated decline in the prevalence of smoking among OC users. As of 1988, nearly one fourth of all OC users were smokers. These data emphasize the need to reduce the prevalence of smoking among women who use OCs before they reach the age at which their risk for cardiovascular disease increases substantially.

Adolescent↗
PubMed1993

Cost-benefit analysis of preconception care for women with established diabetes mellitus.

OBJECTIVE: To determine whether the additional costs of preconception care are balanced by the savings from averted complications. Several studies have demonstrated the efficacy of preconception care in reducing congenital anomalies in infants born of mothers with pre-existing diabetes mellitus. RESEARCH DESIGN AND METHODS: This study used literature review, consensus development among an expert panel of physicians, and surveys of medical care personnel to obtain information about the costs and consequences of preconception plus prenatal care compared with prenatal care only for women with established diabetes. Preconception care involves close interaction between the patient and an interdisciplinary health-care team as well as intensified evaluation, follow-up, testing, and monitoring. The outcome measures assessed in this study are the medical costs of preconception care versus prenatal care only and the benefit-cost ratio. RESULTS: The costs of preconception plus prenatal care are $17,519/delivery, whereas the costs of prenatal care only are $13,843/delivery. Taking into account maternal and neonatal adverse outcomes, the net savings of preconception care are $1720/enrollee over prenatal care only and the benefit-cost ratio is 1.86. The preconception care program remained cost saving across a wide range of assumptions regarding incidence of adverse outcomes and program cost components. CONCLUSIONS: Despite significantly higher per delivery costs for participants in a hypothetical preconception care program, intensive medical care before conception resulted in cost savings compared with prenatal care only. Third-party payers can expect to realize cost savings by reimbursing preconception care in this high-risk population.

Blood Glucose↗
PubMed1992

Financial implications of implementing standards of care for diabetes and pregnancy.

This article examines the financial implications of implementing standards of care for pregnancy among women with diabetes, including both the costs of enhanced treatment and the savings of avoided adverse outcomes. Numerous studies have demonstrated the harmful effects of poor blood glucose control for both mother and fetus. Standards set forth by the American Diabetes Association aim to reduce maternal complications and fetal adverse outcomes, such as congenital malformations. Because the precise configuration of resources required to meet these standards was not outlined in the American Diabetes Association statement, a panel of physicians (all specialists in pregnancy care for women with diabetes) was convened to develop a model program. Implementing such a program during the preconception and prenatal periods will represent an intensification of resource use in the outpatient setting. However, through these preventive measures, medical care costs for maternal and fetal complications can be avoided.

Female↗
PubMed1990

Excess deaths from nine chronic diseases in the United States, 1986.

To assess excess mortality from chronic disease in the United States, state age-adjusted combined mortality rates for nine chronic diseases in 1986 were compared with three "minimum" rates--two calculated from rates actually achieved in states and a third estimated as the mortality remaining after elimination of one risk factor for each disease. Hawaii had the lowest mortality rate of combined diseases (305/100,000); state excesses ranged from 0% to 37%. The sum of lowest disease-specific rates in any state was 284 per 100,000, indicating excesses of between 7% and 41%. A minimum mortality rate of 224 per 100,000 was estimated to result from elimination of one risk factor for each of the nine diseases, indicating state excesses from 26% to 54%, or 524,000 US deaths. Reduction of US mortality from the nine diseases to the risk factor--eliminated rate is estimated to be associated with an increased life expectancy at birth of 4 years.

Chronic Disease↗
PubMed1990

The effect of known risk factors on the excess mortality of black adults in the United States.

We compared the mortality rate ratios, before and after adjustment for different risk factors, of black vs white adults in the National Health and Nutrition Examination Survey I Epidemiologic Follow-up Study. For persons 35 to 54 years old, the rate ratio of mortality for blacks vs whites decreased from 2.3 (unadjusted) to 1.9 when adjusted simultaneously for six well-established risk factors (smoking, systolic blood pressure, cholesterol level, body-mass index, alcohol intake, and diabetes) and decreased from 1.9 to 1.4 when adjusted for the six risk factors plus family income. Thus, approximately 31% of the excess mortality can be accounted for by six well-established risk factors and a further 38% by family income. This leaves 31% unexplained. Broader social and health system changes and research targeted at the causes of the mortality gap, coupled with increased efforts aimed at modifiable risk factors, may all be needed for egalitarian goals in health to be realized.

Adult↗