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Limited association between a catechol-O-methyltransferase (COMT) polymorphism and breast cancer risk in Japan.

BACKGROUND: Catechol-O-methyltransferase (COMT) inactivates the estradiol metabolites, 2-hydroxy estradiol and 4-hydroxy estradiol. To date, three studies in Caucasians and one study in Chinese have been conducted to determine the association with breast cancer risk of a functional polymorphism (G-to-A, Val158Met) of this enzyme, but the results were inconsistent. In order to examine the impact of this polymorphism on breast cancer risk in Japan, a case-control study was conducted, at Aichi Cancer Center Hospital. METHODS: The cases were 150 patients with histologically confirmed breast cancer who had been diagnosed within 4 years before enrollment at this hospital. The controls were 165 non-cancer patients, mainly from the gastroenterology and breast surgery clinics at the hospital. COMT-H (Val) is the wild-type allele, with high enzyme activity, while the COMT-L (Met) allele has low activity. Genotyping was conducted by a polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method. RESULTS: The allele frequency of COMT-L was 36.0% for cases and 33.0% for controls. Age-adjusted odds ratios relative to the COMT-HH genotype were 1.46 (95% confidence interval [CI], 0.90-2.36) for COMT-HL, and 0.99 (95% CI, 0.49-2.02) for the COMT-LL genotype. Significant odds ratios were not observed for any subgroup stratified by menopausal status, age at menarche, age at birth of first child, body mass index, and breast cancer history of mother and/or sister(s). CONCLUSION: The present study suggested that any association of the COMT polymorphism with breast cancer risk is limited in Japanese.

Adult↗

Neurobehavioural consequences of prenatal low level exposures to lead.

A cohort of 318 children born in three Sydney hospitals between April 1982 and March 1983 were recruited into a five year prospective study designed to investigate the relationship between low level lead exposures and neurobehavioural development. Blood samples were obtained at the time of birth, then at 6 month intervals to 4 years and then at 5 years; neurobehavioural and physical measures were taken at 6 months, 12 months and hence annually to 5 years. This paper presents some of the findings from the first three years of the study and addresses the issue of the relationship between fetal exposures to lead and child development to three years. Maternal and cord blood lead levels were in range 0-29 microgram/dl with the majority less that 15 micrograms/dl. The geometric means were, respectively, 9.1 micrograms/dl and 8.1 micrograms/dl. The analyses presented do not support the hypothesis of a relationship between maternal and cord blood lead levels in this range and developmental deficits in young children to the age of three years.

Adult↗

Cesarean delivery and postpartum mortality among primiparas in Washington State, 1987-1996(1).

OBJECTIVE: To examine the association between delivery method and mortality within 6 months of delivery among primiparas. METHODS: We conducted a population-based, retrospective cohort analysis using statewide, maternally linked birth certificate, hospital discharge, and death certificate data. The present cohort was all primiparas who gave birth to live-born infants in civilian hospitals in Washington State from January 1, 1987 through December 31, 1996 (n = 265,471). Odd ratios (OR) and 95% confidence intervals (CI) were calculated for overall mortality, pregnancy-related mortality, and pregnancy-unrelated mortality associated with delivery method. RESULTS: Thirty-two women (12.1 per 100,000 singleton live births) died within 6 months of delivery of their first child. Eleven of 32 deaths were pregnancy related (4.1 per 100,000 singleton live births, 95% CI 1.6, 6.5), and 21 of the 32 deaths were not pregnancy related (7.9 per 100,000 singleton live births, 95% CI 4.5, 11.3). The pregnancy-related mortality rate was higher among women delivered by cesarean (10.3/100,000) than among women delivered vaginally (2.4/100,000). In logistic regression analyses, women who had cesarean delivery were not at significantly higher risk of death overall after adjustment for maternal age (OR 1.7, 95% CI 0.3, 3.6), pregnancy-related death after adjustment for maternal age and severe preeclampsia (OR 2.2, 95% CI 0.6, 7.9), or pregnancy-unrelated death after adjustment for maternal age and marital status (OR 0.9, 95% CI 0.3, 2.7), relative to women who had vaginal delivery. CONCLUSION: Cesarean delivery might be a marker for serious preexisting morbidities associated with increased mortality risk rather than a risk factor for death in and of itself. Data from additional sources such as medical records and autopsy reports are necessary to disentangle preexisting mortality risk from risk associated solely with delivery method.

Adolescent↗

Maturation of the mitogen responsiveness, and IL2 and IL6 production by neonatal swine leukocytes.

The maturation of the immune system of neonatal piglets was studied by following changes in the phenotypic composition and function of blood-borne leukocytes. The proportion of mature T and B lymphocytes decreased in the first week of birth and the circulating cells had poorly developed capacities to respond to mitogens and to secrete interleukins. From the end of the first week, however, there was a steady increase in the proportion of mature T cells (CD4+ and CD8+) and B cells in blood until 6-7 weeks after birth, when the study was ended. By 3-4 weeks, the relative proportions of different lymphocyte subsets resembled an adult-type composition. As they increased in prevalence, lymphocytes also developed capacities to proliferate and secrete interleukins. Proliferative responses to T-cell and B-cell mitogens reached adult levels within 2 weeks and 4-5 weeks, respectively. Blood leukocytes produced large quantities of IL6 by 1-2 weeks after birth and IL2 by 2-3 weeks. In contrast to lymphocyte patterns, the myeloid and granulocyte lineages were dominant at birth but then declined steadily. Unlike lymphocytes, the monocytes, macrophages and granulocytes appeared to be fully functional from the time of birth and exhibited a strong oxidative burst after appropriate stimulations. The magnitude of this response remained constant over the first 6-7 weeks. These results indicate that the first 3-4 weeks of post-natal life are a particularly susceptible interval for newborn piglets because constitutive and functional components necessary for specific cellular immune responses remain immature. This deficit may be offset by non-specific cellular mechanisms and maternally derived antibodies.

Animals↗

Effect of birth litter size, birth parity number, growth rate, backfat thickness and age at first mating of gilts on their reproductive performance as sows.

The present study was performed to evaluate retrospectively the influence of birth litter size, birth parity number, performance test parameters (growth rate from birth to 100kg body weight and backfat thickness at 100kg body weight) and age at first mating (AFM) of gilts on their reproductive performance as sows. Traits analysed included remating rate in gilts (RRG), litter size, weaning-to-first-service interval (WSI), remating rate in sows and farrowing rate (FR). Data were collected from 11 Swedish Landrace (L) and 8 Swedish Yorkshire (Y) nucleus herds and included 20712 farrowing records from sow parities 1-5. Sows that farrowed for the first time during 1993-1997, having complete records of performance test and AFM, were followed up to investigate their subsequent reproductive performance until their last farrowing in 1999. Analysis of variance and multiple regression were applied to continuous data. Logistic regression was applied to categorical data. The analyses were based on the same animals and the records were split into six groups of females, i.e. gilts, primiparous sows, and sows in parities 2-5, respectively. Each additional piglet in the litter in which the gilt was born was associated with an increase of her own litter size of between 0.07 and 0.1 piglets per litter (P<0.001). Gilts born from sow parity 1 had a longer WSI as primiparous sows compared with gilts born from sow parity 4 (0.3 days; P<0.05) or parity 5 (0.4 days; P<0.01). Gilts with a higher growth rate of up to 100kg body weight had a larger litter size (all parities 1-5; P<0.05), shorter WSI (all parities 1-5; P<0.05) and higher FR (parities 2 and 5; P<0.05) than gilts with a lower growth rate. Gilts with a high backfat thickness at 100kg body weight had a shorter WSI as primiparous sows (P<0.001) compared with low backfat gilts, and 0.1 piglets per litter more as second parity sows (P<0.01). A 10 day increase in AFM resulted in an increase in litter size of about 0.1 piglet for primiparous sows (P<0.001) and a decrease (P<0.05) for sow parities 4 and 5.

Adipose Tissue↗

Risk factors for breast cancer in women under 40 years.

The relation between hormonal and lifestyle factors and breast cancer risk in women younger than 40 years was investigated using data from two case-control studies conducted in Italy between 1983 and 1994. Cases were 579 women with histologically confirmed, incident breast cancer and controls were 668 women admitted to hospital for acute, non-neoplastic, non-hormone-related diseases. Breast cancer risk was inversely related to age at menarche with a multivariate odds ratio (OR) of 0.53 (95% confidence interval, CI, 0.31-0.89) for women reporting menarche at the age of > or = 15 years compared with < 12 years. Breast cancer risk was significantly higher in parae than in nulliparae (OR 1.58), and was directly associated with age at first birth (OR 5.31 among women aged > or = 30 years at first birth compared with those aged < 20), and inversely with time since last birth (OR 3.80 for < 3 years compared with > or = 12). Compared with women reporting no abortion, the OR were 1.10 for any spontaneous, 0.87 for any induced and 0.90 for > or = 2 abortions. With reference to oral contraceptive use, the OR was 1.05 for ever users compared with never users, and no material association was evident with duration, time since first and last use. The OR was 1.79 for more than 13 years of education compared with < 9, 1.85 for a family history of breast cancer and 1.85 for a history of benign breast disease. Breast cancer risk was inversely related to body mass index with an OR of 0.51 (95% CI 0.26-0.97) for > or = 30 kg/m2 compared to < 20. Total energy and alcohol intake were directly related to the risk (OR 1.38 and 1.27 for the highest tertiles of intake compared with the lowest), although the estimates were not significant, whilst raw vegetable and beta-carotene consumption were inversely related to breast cancer risk (OR 0.57 and 0.67 for the highest tertile of intake compared with the lowest). Thus, most risk factors in this large dataset of women aged less than 40 years were similar to those described in breast cancer epidemiology at any age. Of interest are the inverse associations with body mass index, age at menarche and time since last birth, the direct ones with age at first and last birth, and the higher risk of parous women compared with nulliparae.

Abortion, Induced↗

Early serial EEG in hypoxic ischaemic encephalopathy.

OBJECTIVES: To perform early serial EEGs in infants with hypoxic ischaemic encephalopathy (HIE) and compare the findings with neurodevelopmental outcome. METHODS: Nine full-term neonates with HIE had simultaneous video-EEG polygraphic studies within 8 h of birth. The EEG was repeated at 12-24 h intervals. All surviving infants had a neurodevelopmental assessment at 1 year. RESULTS: Two infants had a normal or mildly abnormal EEG within 8 h of birth and neurodevelopmental outcome was normal. Seven infants had severely depressed background activity in the first 8 h of life. In 3 infants the EEG activity recovered within 12-24 h showing continuous activity with no or only minor abnormalities. All these infants had a normal outcome. The remaining 4 infants, who also had an initially inactive recording, subsequently developed severe background abnormalities. At follow-up, two infants had died and the remainder developed major neurological sequelae. CONCLUSIONS: Early EEG is an excellent prognostic indicator for a favourable outcome if normal within the first 8 h of life and for a poor outcome if the background activity continues to be inactive or grossly abnormal beyond 8-12 h of life. However, an inactive or very depressed EEG within the first 8 h of life can be associated with good outcome if the EEG activity recovers within 12 h.

Aging↗

Phenotypic study on total and partial lifetime traits for dairy ewes.

A data file on 36,396 lactations was used to determine the strength of the phenotypic relationship between productive, reproductive and lifespan traits for 7935 Spanish Churra ewes. These ewes first lambed between 1989 and 1997 and belonged to 23 flocks. The study took into account four lifespan traits (lifetime, productive life, useful life and lifetime score), three productive traits (total milk yield produced during lifetime, lambs weaned during ewe lifetime and total revenues from sold milk and weaned lambs during lifetime) and two reproductive traits (age at first lambing and mean interval between successive lambings). Moreover, milk yield and revenues from sold milk and weaned lambs were calculated per day of lifetime, productive life and useful life. Partial lifespan traits were considered for the first three parities. The model included flock, birth year within flock and season of birth of the ewe as fixed effects. The first two effects contributed significantly to variation in all traits, while season significantly affected lifespan traits, productive traits and age at first lambing. Milk production level was added to the model for lifespan traits only. It significantly contributed to explaining the variation in all lifespan traits with high percentage of variance explained averaging 14.91%. Lifetime averaged 2324 d. Productive life accounted for 57% of lifetime while useful life represented 50% of productive life. Age at first lambing averaged 622 d and average days dry during lifetime was 560. During lifetime, ewes gave an average of 4.6 parities, 6.5 weaned lambs and 636 l of milk. Average revenue from milk and lambs during lifetime was 673 euros. Milk/day of lifetime, productive life and useful life averaged 0.26, 0.51 and 0.93 l, respectively. The corresponding per-day revenues from sold milk and weaned lambs were, 0.27 euros, 0.55 euros and 1.01 euros, respectively. Lifespan and productive traits had strong relationships (rp among these traits ranged between 0.75 and 0.95). Two-parity and three-parity per-day milk yield had moderately high correlation (0.70-0.83) with total lifetime per-day milk yield traits. Therefore, good use of these traits would be helpful in determining best individuals early in life.

Analysis of Variance↗

Association of maternal caffeine consumption with decrements in fetal growth.

Whether caffeine consumption during pregnancy represents a fetal hazard remains uncertain. The authors report on a large prospective study designed to examine this question. In 1996-2000, 2,291 mothers with singleton livebirths in Connecticut and Massachusetts were evaluated after their first prenatal visit and were questioned about caffeine consumption and important confounding factors. Urine samples were provided to analyze urinary caffeine, cotinine, and creatinine levels. Mothers were followed throughout pregnancy to monitor changes in consumption. Pregnancy outcomes were obtained from medical records. Self-reports of caffeine consumption in the first and third trimesters were not associated with intrauterine growth retardation, low birth weight, or preterm delivery. For every 1 mg/g creatinine increase in urinary caffeine, risk of intrauterine growth retardation was essentially unchanged (odds ratio (OR) = 0.96, 95% confidence interval (CI): 0.85, 1.08). In contrast, a 0.005 mg/g creatinine increase in urinary cotinine significantly increased risk (OR = 1.003, 95% CI: 1.001, 1.005). Mean birth weight was reduced by reported caffeine consumption (-28 g per 100 mg of caffeine consumed daily, 95% CI: -0.10, -0.46, p = 0.001) but not mean gestational age. Decaffeinated coffee did not increase risk for any perinatal outcome. This small decrease in birth weight, observed for maternal caffeine consumption, is unlikely to be clinically important except for women consuming >/=600 mg of caffeine daily (approximately six 10-ounce (1 ounce = 28.3 g) cups of coffee).

Adult↗

The effects of neonatal orchidectomy on the developmental pattern of gonadotropin secretion in the male rhesus monkey (Macaca mulatta).

Plasma concentrations of LH and FSH in immature male rhesus monkeys were determined at weekly intervals from birth until 300 days of age, and the effect of bilateral orchidectomy at 1 week of age on the neonatal pattern of gonadotropin secretion was studied. Plasma FSH and LH concentrations in intact animals were elevated during the first few months of neonatal life but then declined to undetectable values characteristic of the prepubertal state in this species. Neonatal castration, but not sham castration, resulted in a progressive and dramatic rise in circulating gonadotropin concentrations, which plateaued approximately 3 weeks later at values an order of magnitude greater than those observed in intact animals. The hypersecretion of LH and FSH after removal of the gonads was not sustained, however, and by 32 weeks of age plasma gonadotropin concentrations in the agonadal animals were indistinguishable from those in age-matched intact controls. These findings suggest that, in the rhesus monkey, the testes do not play a major role in determining the pattern of gonadotropin secretion throughout neonatal and prepubertal development. They further suggest that a profound inhibitory influence of nongonadal origin impinges upon the neuroendocrine control system governing gonadotropin secretion in the neonate, thereby initiating the diminished secretion of LH and FSH which is characteristic of the prepubertal stage of development in primates.

Aging↗

Ontogeny of gonadotropin receptors in the fetal and neonatal rat testis.

To evaluate the extent to which LH receptors may participate in the regulation of testosterone production by the fetal and neonatal rat testis, the gonadal content of LH receptors was determined and correlated with the gonadal content of testosterone and other steroids at daily intervals throughout the period of sexual differentiation and early neonatal life. Also, to determine if FSH has a potential role during fetal life, FSH receptors were measured from 14.5 until 21.5 days of gestation, just before birth. LH receptors were first detected in the fetal rat testis at 15.5 days of gestation, at a concentration of 0.072 +/- 0.016 fmol/gonad. This is the time at which previous studies have shown a biological response to LH stimulation with increases in cAMP and testosterone production. LH receptor content remained constant from 15.5-17.5 days of gestation and then increased sharply at 18.5 days of gestation to 0.706 +/- 0.046 fmol/gonad, coincident with a surge in the testosterone content of the fetal testis. LH receptor content continued to rise until birth, reaching a maximum level of 2.00 +/- 0.24 fmol/gonad at 21.5 days of gestation, and did not significantly differ from this value through 5 days after birth, whereas intratesticular testosterone content decreased after birth. FSH receptors could be measured from 17.5 days of gestation, but remained very low through 19.5 days of fetal life. At 20.5 days, FSH receptor levels began to rise sharply and continued to increase through 21.5 days of gestation, just before birth. These data show that LH receptors are measurable at the time when the fetal testis becomes responsive to LH stimulation. It is possible that the increase in LH receptors may act as a mechanism for amplification of the stimulatory effect of low circulating LH levels on the fetal testis being concomitant with the intratesticular testosterone increase at the same stage. The decrease in testosterone production after birth cannot be attributed to a decrease in LH receptors in the neonatal gonad. Since 5 alpha-reduced androgens increase after birth, other possibilities, such as alternative steroid pathways, are a more likely explanation for the decrease in testosterone content. The presence of FSH receptors in the fetal testis imply that this hormone may have a function in the developing gonad, particularly in the last 2 days of fetal life.

Aging↗

Plasma adiponectin concentrations and risk of incident breast cancer.

INTRODUCTION: Previous retrospective case-control studies suggest that adiponectin, an obesity-related hormone, is inversely associated with breast cancer risk, particularly in postmenopausal women; however, no prospective studies exist. Therefore, we conducted a prospective case-control study nested within the Nurses' Health Study (NHS) and NHSII cohorts examining the association between plasma adiponectin concentrations and breast cancer risk. MATERIALS AND METHODS: Blood samples were collected from 1989 through 1990 (NHS) and 1996 through 1999 (NHSII); adiponectin was measured by RIA. The analysis included 1477 breast cancer cases diagnosed after blood collection and before June 2000 (NHS) or June 2003 (NHSII) who had one or two controls (n=2196) matched on age, menopausal status, postmenopausal hormone (PMH) use, fasting, and time of day and month of blood collection. We adjusted for body mass index at age 18, weight change from age 18 to blood draw, family history of breast cancer, history of benign breast disease, duration of PMH use, ages at menarche and first birth, and parity. RESULTS: Although we observed no association between adiponectin and breast cancer risk overall, there was a nearly significant interaction by menopausal status (P=0.08), with a relative risk, top vs. bottom quartile of 0.73 (95% confidence interval, 0.55-0.98; P trend=0.08) among postmenopausal women and 1.30 (95% confidence interval, 0.80-2.10; P trend=0.09) for premenopausal women. Among postmenopausal women, adiponectin appeared more strongly inversely associated in women who never used PMH (P heterogeneity=0.05) and women with low circulating estradiol levels (P heterogeneity=0.05). DISCUSSION: Our results suggest that adiponectin may be inversely associated with postmenopausal breast cancer risk, particularly in a low-estrogen environment.

Adiponectin↗

Endotoxin exposure and eczema in the first year of life.

OBJECTIVE: Exposure to endotoxin in early life has been proposed as a factor that may protect against the development of allergic diseases such as eczema. The objective of this study was to examine the relation between endotoxin exposure in early life and eczema in the first year of life in children with parental history of asthma or allergies. METHODS: This study used a prospective birth cohort study of 498 children who had a history of allergy or asthma in at least 1 parent and lived in metropolitan Boston. A subset of 401 living rooms had house dust samples adequate for analysis of endotoxin. RESULTS: In multivariate analyses adjusting for gender, income, and season of birth, endotoxin levels in the living room at 2 to 3 months of age was inversely associated with physician- or nurse-diagnosed eczema in the first year of life (odds ratio [OR] for each quartile increment: 0.76; 95% confidence interval [CI]: 0.61-0.96). Exposure to a dog in the home at age 2 to 3 months was also inversely associated with eczema in the first year of life, but the CI widened when endotoxin was included in the multivariate model (OR: 0.54; 95% CI: 0.27-1.09). Other variables associated with eczema in the first year of life included paternal history of eczema (OR: 1.91; 95% CI: 1.03-3.55) and maternal specific immunoglobulin E positivity to > or =1 allergen (OR: 1.61; 95% CI: 1.01-2.56). CONCLUSIONS: Among children with parental history of asthma or allergies, exposure to high levels of endotoxin in early life may be protective against eczema in the first year of life. In these children, paternal history of eczema and maternal sensitization to at least 1 allergen are associated with an increased risk of eczema in the first year of life.

Analysis of Variance↗

Patterns of cognitive development in very low birth weight children during the first six years of life.

BACKGROUND: Cognitive development in very low birth weight (VLBW, < or = 1500 g) infants typically has been reported based on mean endpoints in cross-sectional studies. These overall group means mask individual patterns of cognitive development. Given the heterogeneity of VLBW infants, it is important to identify individual patterns of development and the factors associated with the different patterns. OBJECTIVE: We sought to determine individual patterns of cognitive development over the first 6 years in VLBW children and to examine the relative influence of selected biomedical and sociodemographic factors on these patterns. METHOD: VLBW infants (N = 203) were followed from birth to six years. Cognitive scores were obtained at four yearly intervals, and biomedical and social data were obtained beginning with the neonatal period. Cluster analysis was used to identify individual patterns of cognitive development. RESULTS: Five developmental patterns were identified: average-stable (13% of the sample); average-declined to low average (24% of the sample); average-declined to below average (43% of the sample); very low-increased to low average (8% of the sample); and very low-stable (12% of the sample). The patterns could be differentiated by several biomedical factors, including birth weight, gestational age, neonatal health, and 1-year assessments of neurological status and head circumference, as well as by level of maternal education. In particular, abnormal neurological status at 1 year was associated with a pattern of very low stable scores, and a suspicious status was associated with a pattern of improving cognitive development. Maternal education was influential among children born at the upper end of the VLBW range, who had a more favorable set of biomedical factors. CONCLUSIONS: Biomedical factors are of major importance for the cognitive development of VLBW infants, and their influence increases as birth weight declines. Differences in neurological integrity at 1 year were an important indicator of different patterns of cognitive development, especially for infants at the lower end of the VLBW range.

Child Development↗

Determinants of growth retardation in Southern Brazil.

A cross-sectional population-based study of determinants of growth retardation in under-five children (3,389) in the city of Porto Alegre, Rio Grande do Sul, Brazil estimated odds ratios (OR) for stunting, defined as height-for-age < -2 zeta-scores of the NCHS standards. Hierarchical modeling based on a framework of the process of stunting was used. Stunting prevalence was 6.8%; the main determinants were per capita family income < 0.8 times the minimum wage (OR: 3.95; 95%CI: 2.10-7.42), maternal illiteracy (OR: 17.17; 95%CI: 4.43-66.54), living in a wooden or mixed-construction house (OR: 2.33; 95%CI: 1.35-4.01), inadequate housing (OR: 2.75; 95%CI: 1.70-4.43), maternal age at the child's birth < 20 years (OR: 1.73; 95%CI: 1.11-2.70), being an adopted child (OR: 3.28; 95%CI: 1.52-7.07), third-born child or greater (OR: 2.04; 95%CI: 1.15-3.62), birth interval < 24 months since previous child (OR: 1.69; 95%CI: 1.13-2.53), subsequent sibling (OR: 1.91; 95%CI: 1.16-3.13), multiple birth (OR: 2.40; 95%CI: 1.04-5.50), low birth weight (OR: 3.79; 95%CI: 2.38-6.02), and hospitalization in the first year of life (OR: 1,65; 95%CI: 1.01-2.68). The findings can be used by primary healthcare services to design specific interventions to prevent stunting.

Brazil↗

Consumption of oily fish and childhood asthma risk.

OBJECTIVE: To investigate the association between diet and airway disease in children in the light of epidemiological studies suggesting that consumption of fish more than once a week reduces the risk of developing airway hyperresponsiveness (AHR). DESIGN: Diet was assessed by a detailed food frequency questionnaire and airway disease by respiratory symptoms or airway responsiveness to exercise. METHODS: A questionnaire, containing questions about the frequency of eating more than 200 foods, was sent to the parents of 574 children in whom we had measured recent wheeze (by questionnaire), AHR (by exercise) and atopy (by skin prick tests) six months before this study. We defined current asthma as the presence of both recent wheeze and AHR. RESULTS: Response rate to the questionnaire was 81.5% (n=468.) After adjusting for confounders such as sex, ethnicity, country of birth, atopy, respiratory infection in the first two years of life and a parental history of asthma or smoking, children who ate fresh, oily fish (>2% fat) had a significantly reduced risk of current asthma (odds ratio, 0.26; 95% confidence interval, 0.09-0.72; P<0.01). No other food groups or nutrients were significantly associated with either an increased or reduced risk of current asthma. CONCLUSION: These data suggest that consumption of oily fish may protect against asthma in childhood.

Asthma↗

Mean arterial pressure, pregnancy-induced hypertension, and preeclampsia: evaluation as independent risk factors and as surrogates for high maternal serum alpha-fetoprotein in estimating breast cancer risk.

Data from a nested case-control study were analyzed to examine high mean arterial pressure (MAP), hypertension of pregnancy, and preeclampsia as independent predictors and as surrogate markers for elevated alpha-fetoprotein (AFP) levels in evaluating breast cancer risk. Cases (n = 205) were identified by the California Cancer Registry from a cohort of pregnant women who were part of the Kaiser Health Plan and took part in the Child Health and Development Studies initiated by the University of California, Berkeley, from June 1959 to September 1966. Controls (n = 337) were selected by randomized recruitment from the same cohort probability matched to cases by distribution of birth dates of cases. High MAP was associated with breast cancer risk and is different across quartile of age at first full-term pregnancy as is high AFP. Odds ratios (OR) across quartiles for MAP were 0.24 [95% confidence interval (CI), 0.08-0.71], 0.84 (95% CI, 0.39-1.66), 1.00 (referent), and 2.50 (95% CI, 1.21-5.13), and for AFP were 0.34 (95% CI, 0.13-0.93), 0.77 (95% CI, 0.36-1.67), 1.00 (referent), and 2.38 (95% CI, 1.13-5.00). Neither diagnosed preeclampsia nor hypertension of pregnancy showed any association with breast cancer risk. When both high AFP and high MAP were entered into the same analysis, neither changed the OR for the other more than 8%. Additionally, AFP level was not a linear function of MAP. Although the pattern of ORs across quartiles of age at first full-term pregnancy was similar for the two variables, it cannot be concluded that high MAP is an adequate surrogate for high levels of maternal serum AFP, but rather represents some related process that is in and of itself a risk factor for breast cancer.

Adolescent↗

Immigration, below-replacement fertility, and long-term national population trends.

The long-term demographic effects of immigration on a population experiencing below-replacement fertility are studied by assuming that the size and age composition of the immigrant population do not change over time. The size of the first-generation immigrant population becomes stationary within a time period not greater than the human life span. Thereafter, the number dying equals the number entering over any given time interval. The stationarity of the native population, among which deaths exceed births, is maintained by the compensating number of births to the immigrant population. The limiting age distribution of the country's population, although stationary, may not decline monotonically with age and may look like a camel's back, with one or two humps.

Demography↗