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Biomedical subjects

K A Matthews

Publications and source records attributed to K A Matthews.

At least 109 records · Page 6Linked to original sources
PubMed1990

Functional implications of the unusual spatial distribution of a minor alpha-tubulin isotype in Drosophila: a common thread among chordotonal ligaments, developing muscle, and testis cyst cells.

Three of the four alpha-tubulin genes in Drosophila melanogaster are temporally regulated. mRNA from one of these genes, alpha 85E-tubulin, first appears in 6- to 8-hr embryos and persists, with marked fluctuations, through the end of pupal development. In adults, alpha 85E mRNA has been unequivocally identified only in testes. In the present study, isotype-specific antibodies have been used to localize alpha 85E tubulin protein in whole tissues. The results demonstrate a spatially restricted expression pattern of the alpha 85E gene that includes tissues of both ectodermal and mesodermal origins. Specifically, embryonic accumulation of alpha 85E tubulin is limited to support cells of chordotonal organs and the developing musculature of the viscera and body wall. In late third instar larvae, chordotonal organs and a subset of larval nerves, but not muscle, stain with anti-alpha 85E. The timing of protein accumulation during pupal development suggests that alpha 85E tubulin is involved in the construction of the adult as well as the larval musculature. In testis, only the somatically derived cyst cells that surround developing spermatid bundles accumulate alpha 85E-tubulin. The cell types that express alpha 85E share a requirement for extensive cell shape changes during development, suggesting that this minor alpha-tubulin may have distinct functional properties.

Animals↗
PubMed1990

T-lymphocyte reactivity during the menstrual cycle in women.

Reactivity of blood lymphocytes to nonspecific mitogenic stimulation with phytohemagglutinin (PHA) was measured in nine healthy, regularly cycling women at three phases of their menstrual cycles corresponding to peak levels of estradiol (midfollicular phase), peak levels of progesterone (midluteal phase), and the lowest levels of both hormones (menstrual phase). Sampling points were verified by radioimmunoassay of estrogen, progesterone, luteinizing hormone, and follicle-stimulating hormone. There were significant increases in reactivity associated with an increasing concentration of PHA and with autologous plasma vs AB plasma. However, no differences were found in reactivity to PHA over the three menstrual cycle phases and correlational analyses indicated no relationship between counts and any of the hormones measured.

Adolescent↗
PubMed1990

Physical activity and cardiovascular risk: a cross-sectional study of middle-aged premenopausal women.

The relationship between self-reported physical activity and cardiovascular risk factors was evaluated in a population-based sample. The sample included 541 premenopausal women recruited for a study of the natural history of risk factor change associated with change in sex hormone status. Physical activity was assessed using the Paffenbarger Activity Questionnaire. Women were classified according to quartile of weekly energy expenditure into groups of 0-500, 501-999, 1,000-1,999, and 2,000 kcal or greater. Results showed that the more active the women, the lower their blood pressure and heart rate. More active women had lower cholesterol and triglycerides, and higher high-density lipoprotein (HDL) cholesterol. Tricep and suprailiac skinfolds, fasting insulin, and insulin/glucose levels were also lower among the more active women. When the analysis was repeated controlling for the effect of education and body mass index, the statistical test for linear trend remained significant except for the trend for heart rate, total cholesterol, and triglycerides. Women reporting activity of 1,000 kcal/week had higher high-density lipoprotein cholesterol and lower diastolic blood pressure, body mass index, skinfolds, fasting insulin, and fasting insulin/glucose ratios compared with women reporting lower levels of activity. Only those women who reported 2,000 kcal/week had significantly lower total cholesterol, triglycerides, and low-density lipoprotein cholesterol, and higher HDL2 cholesterol; women reporting less activity did not differ with regard to these lipids and lipoproteins. The study suggests that physical activity is associated with improved cardiovascular risk profiles among middle-aged women and that the beneficial effects of activity are seen at different levels for specific risk factors.

Adult↗
PubMed1990

Influences of natural menopause on psychological characteristics and symptoms of middle-aged healthy women.

We investigated the psychological and symptom consequences of the natural menopause in a longitudinal study of 541 initially premenopausal healthy women. All women were given an extensive evaluation at baseline. After 3 years of follow-up, 69 women ceased cycling for 12 months; another 32 women had ceased cycling and had taken hormone replacement therapy for a total of 12 months. These women were reevaluated in a clinic examination identical with the baseline examination, as were 101 age-matched premenopausal control women. Comparison among groups at the baseline and follow-up examination showed that natural menopause led to few changes in psychological characteristics, with only a decline in introspectiveness and an increase in reports of hot flashes being apparent. We conclude that natural menopause did not have negative mental health consequences for the majority of middle-aged healthy women.

Adaptation, Psychological↗
PubMed1990

Cigarette smoking and oral contraceptive use influence women's lipid, lipoprotein, and cardiovascular responses during stress.

Investigated the effects of behavioral stress and smoking cigarettes on the lipid, lipoprotein, neuroendocrine, and cardiovascular responses of female smokers who either used or did not use oral contraceptives (OC). Thirty-five healthy female smokers (20 of whom used OC) relaxed, smoked, or sham smoked and then prepared, delivered, and reviewed a speech presented in front of a video camera. Results show that behavioral stress increased total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, triglyceride, and free fatty acid levels, with significant increases in cholesterol, LDL-C, and free fatty acids apparent only among women who smoked during the session. In addition, OC users exhibited larger increases in triglyceride and blood pressure responses during stress than did nonusers whether or not they smoked during the protocol. Possible physiological mechanisms for each of the effects, as well as implications of the findings for understanding epidemiological associations among OC use, smoking, and coronary heart disease in women are discussed.

Adolescent↗
PubMed1990

Hormone replacement therapy and lipoprotein changes during early menopause.

The relationship of postmenopausal hormone replacement therapy to lipoproteins was assessed in a cohort of 211 healthy premenopausal women followed during the menopausal transition. Both estrogen and estrogen-progestogen users had minimal increases in low-density lipoprotein (LDL) cholesterol levels, whereas non-users had significant increases in LDL cholesterol over time. Estrogen users had a nonsignificant increase in high-density lipoprotein (HDL) cholesterol, estrogen-progestogen users maintained premenopausal HDL cholesterol levels, and non-users had decreases in HDL cholesterol. Both estrogen and estrogen-progestogen users had increases in apolipoprotein AI, apolipoprotein AII, and triglycerides relative to the changes observed among the menopausal non-users. In summary, estrogen, whether administered with or without medroxyprogesterone acetate, could provide cardiovascular benefits to postmenopausal women by protecting against the atherogenic changes in LDL and HDL cholesterol observed among the non-users. With the exception of the hormone-related increases in triglycerides, the results are consistent with a beneficial effect of hormone replacement therapy on coronary heart disease risk.

Adult↗
PubMed1990

Influences of the normal menstrual cycle on physiologic functioning during behavioral stress.

The purpose of this study was to evaluate the influence of the normal menstrual cycle on lipoprotein, cardiovascular, and neuroendocrine stress responses. Fifteen normally-cycling, healthy women participated in a series of behavioral tasks during the menstrual, follicular, and luteal phases of their menstrual cycle. These women had established menstrual cycle regularity for the three months prior to enrollment in this study, were free from menstrual cycle disturbances, biochemically confirmed that they ovulated, and displayed appropriate patterns of reproductive hormone fluctuations during the study period. Heart rate, blood pressure, low density lipoprotein-cholesterol, and total cholesterol all demonstrated significant elevations from baseline levels during tasks. No differences in the magnitude of stress responses during the three menstrual cycle phases were noted for any physiological variable. We conclude that the hormonal fluctuations that occur in healthy, normally-cycling women during the menstrual cycle do not influence the stress responses that were investigated here. Significant influences of menstrual cycle phase previously reported in the literature, albeit not in a consistent direction, may have been due to the recruitment of women with menstrual cycle irregularities, and to the failure to adequately verify menstrual cycle phase.

Adult↗
PubMed1990

Changes in and stability of cardiovascular responses to behavioral stress: results from a four-year longitudinal study of children.

This study examined the changes in and stability of cardiovascular responses to behavioral stress among 132 children in a 4-year longitudinal study. Children's heart rate and blood pressure were measured at rest and while performing 3 tasks: serial subtraction, mirror image tracing, and isometric exercise. This procedure was followed at study entry when children were in grades 2-12 (ages 6-18 years) and at follow-up when children were in grades 6 through post-high school (ages 11-21 years). Results showed that blood pressure and heart rate responses during the tasks were reliable across time for all measures except heart rate responses during isometric exercise. Systolic blood pressure responses to all tasks increased with age for boys, but not for girls. These results support the notion that cardiovascular responses to behavioral stress are a stable individual difference variable.

Adolescent↗
PubMed1990

Noise-induced hearing loss: a possible marker for high blood pressure in older noise-exposed populations.

The present study assessed the relationships among occupational noise exposure, noise-induced hearing loss, and high blood pressure. The study population consisted of 245 retired metal assembly workers from Pittsburgh aged 56 to 68 with chronic noise exposure of 30 or more years at greater than or equal to 89 dBA. Results of the audiometric testing indicated 52% of the younger workers (ages 56 to 63) have severe noise-induced hearing loss (greater than or equal to 65 dBA loss at 3, 4, or 6 kHz) and 67% of older workers (ages 64 to 68). Body mass index and alcohol intake were significantly related to systolic and diastolic blood pressure. Among older men, there was a marginally significant increased prevalence of high blood pressure (greater than or equal to 90 mm diastolic or taking blood pressure medicine) among those with severe noise-induced hearing loss (P = .05). Moreover, another measure of hearing loss at high frequencies, speech discrimination score in noise (measured in the better ear), referred to as the W-22 MAX score, was also found to be related to the prevalence of high blood pressure in the older (64 to 68) age group (P less than .05). Multiple regression analysis revealed W-22 MAX and severe noise-induced hearing loss were independent predictors of hypertension in the older, but not in the younger group of retired workers.

Age Factors↗
PubMed1989

Menopause and risk factors for coronary heart disease.

Postmenopausal women are believed to have a higher risk of coronary artery disease than premenopausal women. In this study, we prospectively determined changes in coronary risk factors that were attributable to natural menopause in 541 healthy, initially premenopausal women 42 to 50 years of age. After approximately 2 1/2 years, 69 women had spontaneously stopped menstruating for at least 12 months, and 32 women had stopped natural menstruation and received hormone-replacement therapy for a period of at least 12 months. An equal number of age-matched premenopausal women in the study group served as controls. In women who had a natural menopause and did not receive hormone-replacement therapy, serum levels of high-density lipoprotein (HDL) cholesterol declined as compared with those of premenopausal controls (-0.09 vs. 0.00 mmol per liter; P = 0.01), and levels of low-density lipoprotein (LDL) cholesterol increased (+0.31 vs. +0.14 mmol per liter; P = 0.04). In menopausal women who received hormone-replacement therapy, HDL and LDL cholesterol levels did not change, but the levels of triglycerides (+0.42 vs. -0.04 mmol per liter; P less than 0.001), apolipoprotein A-I (+0.18 vs. +0.03 g per liter; P less than 0.01), and apolipoprotein A-II (+0.05 vs. -0.03 g per liter; P less than 0.05) increased as compared with premenopausal controls. Natural menopause did not affect blood pressure, plasma glucose or insulin levels, body weight, the total number of kilojoules consumed in the diet, or the total number of kilojoules expended in physical activity. These results suggest that a natural menopause has an unfavorable effect on lipid metabolism, which may contribute to an increase in the risk of coronary disease. Hormone-replacement therapy may prevent some of these changes.

Apolipoproteins A↗
PubMed1989

Developmental distribution of RNA and protein products of the Drosophila alpha-tubulin gene family.

The developmental pattern of gene expression of the Drosophila melanogaster alpha-tubulin family has been examined in detail at both the mRNA and protein levels. Northern data from 16 stages of development have been quantified to produce estimates of pool sizes of each of the alpha-tubulin transcripts through development. The in situ pattern of alpha 67C RNA localization in developing oocytes and early embryos has also been determined. At the protein level, two of the three previously unidentified products of alpha-tubulin genes (alpha 67C and alpha 85E) have been identified. Evidence that protein from the fourth gene comigrates with the ubiquitously expressed alpha 84B is presented. In addition to the primary translational products of the alpha-tubulin genes, an elaborate series of post-translationally modified alpha-tubulins has been resolved. The developmental profiles of both synthesis and accumulation of these alpha-tubulin proteins are described.

Animals↗
PubMed1989

Characteristics of women with hysterectomy.

Socio-demographic and health information, including history of hysterectomy/oophorectomy, was obtained in a telephone survey of 2137 women aged 40-52. Subjects were randomly selected from a list of all women with a driver's license in Pittsburgh, Pennsylvania. Results showed that 27.3% of women surveyed reported having had a hysterectomy. Women who had undergone hysterectomy were more often black, less educated, older and heavier; and reported less frequent alcohol consumption, younger age at birth of first child and earlier menarche than women who did not report hysterectomy. Forty-seven percent of blacks reported hysterectomy compared with 24% of whites (P less than 0.01) and blacks were significantly younger at surgery than whites (mean age 38.5 vs. 39.6 yr, P less than 0.05). Results of multivariate analyses showed age, black race, less than a college education, menarche before age 12 and having no children to be associated with an increased risk of hysterectomy (P less than 0.01). Additional multivariate analyses conducted separately for blacks and whites showed that, for whites but not blacks, the higher a woman's educational attainment the less likely she was to report having had a hysterectomy (P less than 0.01). Black women with no children more often reported hysterectomy than those with children (P less than 0.01), but this relationship was not found among whites. These findings show the distribution of hysterectomy in the population to vary by race, education and parity.

Adult↗
PubMed1989

Relations between anger expression and cardiovascular reactivity: reconciling inconsistent findings through a matching hypothesis.

Previous psychophysiological research has demonstrated that both anger expression and anger suppression are related to cardiovascular responses, but in an inconsistent fashion. The present study tested the following hypotheses: (a) that the influence of anger expression style on psychophysiological responses would be limited to Ss exposed to an anger instigation, and (b) that the specific pattern of psychophysiological responses would vary as a function of whether Ss were induced to use their preferred vs. nonpreferred mode of anger expression style in response to the instigation. Seventy-eight male college undergraduates were randomly assigned to work on a task with either an annoying or a pleasant confederate and subsequently to write either a negative or a positive evaluation of the confederate. Blood pressure was measured intermittently and heart rate continuously throughout task performance and a subsequent 15-min rest period. Ss' preferred method of anger expression had been previously assessed by a self-report questionnaire. Systolic blood pressure results generally were consistent with the hypotheses. Implications of the findings for the etiology of cardiovascular diseases are discussed.

Adolescent↗
PubMed1989

Dispositional optimism and recovery from coronary artery bypass surgery: the beneficial effects on physical and psychological well-being.

The effect of dispositional optimism on recovery from coronary artery bypass surgery was examined in a group of 51 middle-aged men. Patients provided information at three points in time--(a) on the day before surgery, (b) 6-8 days postoperatively, and (c) 6 months postoperatively. Information was obtained relating to the patient's rate of physical recovery, mood, and postsurgical quality of life. Information was also gathered regarding the manner in which the patients attempted to cope with the stress of the surgery and its aftermath. As expected, dispositional optimism proved to be an important predictor of coping efforts and of surgical outcomes. More specifically, dispositional optimism (as assessed prior to surgery) correlated positively with manifestations of problem-focused coping and negatively with the use of denial. Dispositional optimism was also associated with a faster rate of physical recovery during the period of hospitalization and with a faster rate of return to normal life activities subsequent to discharge. Finally, there was a strong positive association between level of optimism and postsurgical quality of life at 6 months.

Adaptation, Psychological↗
PubMed1989

Familial environment associated with type A behaviors and psychophysiological responses to stress in children.

This study tested two major hypotheses regarding the characteristics of family environments associated with children's Type A behaviors, anger frequency and expression, hostile outlook, hostility displayed during an interview, and cardiovascular responses to laboratory stressors. Two measures of family environment, Positive Affiliation and Authoritarianism, were derived by a factor analysis of the Family Environment Scale completed by parents. The sample consisted of 66 girls and 48 boys enrolled in Grades 2 through 12 from 114 families residing in a predominantly White, upper-middle-class suburb of Pittsburgh. Analyses largely supported the first hypothesis--that a less supportive and positively involved family climate would be associated with attributes of potential coronary heart disease (CHD) risk in children. Families scoring low on Positive Affiliation had children who were assessed as more angry and hostile on the basis of questionnaires and interview. Boys from these families had a more pronounced heart rate response to all laboratory stressors. The second hypothesis--that authoritarianism, in the absence of positive involvement and supportiveness in the family, would be associated with attributes of potential CHD risk in children--received support in regard to boys' heart rate responses to the serial-subtraction and mirror-image-tracing tasks. High Authoritarianism scores in combination with low Positive Affiliation scores in families predicted a heightened heart rate response in boys. Sex differences in the pattern of associations among family and child characteristics were also found. Results suggest that factors in the family environment may be important influences in children's development of characteristics that may, in adulthood, place them at risk for CHD.

Adolescent↗
PubMed1989

Educational attainment and behavioral and biologic risk factors for coronary heart disease in middle-aged women.

Epidemiologic investigations have shown that low socioeconomic status is related to ischemic coronary heart disease mortality in men and women as well as to major risk factors for coronary heart disease, predominantly in men. The present study investigated the associations between educational attainment and biologic and behavioral risk factors for coronary heart disease in a community sample of 2,138 middle-aged women residing in Allegheny County, Pennsylvania. The women were contacted between 1983 and 1985 to determine eligibility for a study of risk factor changes during the perimenopausal period. Eligibility criteria included age 42 to 50 years, premenopausal status, diastolic blood pressure less than 100 mmHg, and nonuse of medications known to influence risk factors. Among the 541 eligible participants, the less education the women reported, the more atherogenic was their risk factor profile, including higher systolic blood pressure, low density lipoprotein (LDL) cholesterol, apolipoprotein B, triglycerides, fasting and two-hour glucose values, two-hour insulin values, body mass indices, and lower high density lipoprotein (HDL) cholesterol and HDL/LDL ratio; the more often they reported being cigarette smokers, taking little physical exercise, and consuming alcohol less than one day a week; the more often they reported on standardized psychologic tests being Type B, angry, pessimistic, depressed, and dissatisfied with paid work, and having little social support and self-esteem (all p values less than 0.01). Similar associations were obtained between educational attainment and risk factors reported by the 1,588 nonparticipants during the telephone screening interview. These results suggest many biologic and behavioral factors by which women with little education are at elevated risk for coronary heart disease. To the extent that advanced education protects women against coronary heart disease, a potentially important public health intervention for women is education.

Adult↗
PubMed1989

Premenopausal and postmenopausal women differ in their cardiovascular and neuroendocrine responses to behavioral stressors.

Middle-aged (45-51 years) women performed four tasks while their heart rate, blood pressure, and plasma catecholamines were measured. The tasks were serial subtraction, mirror image tracing, speech, and postural tilt. The speech task was considered to be particularly relevant to women because of its emphasis on social skills. Fifteen premenopausal women reported menstruating regularly and were tested in the early follicular phase. Sixteen postmenopausal women reported not menstruating for at least 12 months and their hormonal status was verified by serum levels of follicle-stimulating hormone. Results showed that postmenopausal women exhibited greater increases from baseline in heart rate during all tasks, relative to premenopausal women, with a particularly pronounced increase during the speech task. Postmenopausal women exhibited greater increases from baseline in systolic blood pressure and epinephrine, relative to premenopausal women, during the speech task only. Explanations for the stressor-specific effect of menopausal status were discussed. The results suggest that reproductive hormones may interact with stressor characteristics to determine middle-aged women's physiological responses to stress.

Arousal↗