PubMed Health⌕ Search

Biomedical subjects

B D Miller

Publications and source records attributed to B D Miller.

At least 19 recordsLinked to original sources
PubMed2001

Female-selective abortion in Asia: patterns, policies, and debates.

Since the early 1980s, the use of sex-selective abortion increased in many Asian contexts. Estimates indicate that several million female fetuses were aborted in the last two decades of the twentieth century. This article takes a currently unusual approach for a cultural anthropologist in pursuing cross-national comparisons of trends in sex-selective abortion. The risks involved in such an approach are taken in the hope that it will yield insights not gained through localized analysis. After reviewing the available evidence on female-selective abortion, I discuss features of Asian culture that support strong son preference. Next I review the related issues of increased technological availability for prenatal sex selection and national policies about sex selection. Last, I consider several positions on female-selective abortion and how cultural anthropology may contribute to understanding the global context and consequences of prenatal gender discrimination.

Abortion, Eugenic↗
PubMed2000

Ovarian tumors in rats induced by chronic 2,3,7,8-tetrachlorodibenzo-p-dioxin treatment.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a multispecies reproductive toxicant, and it has been recently classified by IARC as a known human carcinogen. Here, we report that TCDD promotes the development of ovarian tumors in an initiation-promotion model in female Sprague Dawley rats. Rats were initiated with diethylnitrosamine (DEN) or vehicle at 70 days of age. Starting 2 or 18 weeks after initiation, rats were exposed biweekly to TCDD at a daily average dose of 125 ng/kg/day for 14, 30, or 60 weeks continuously or for 30 weeks plus withdrawal periods of 16 or 30 weeks. Fifteen of 76 (20%) rats initiated with DEN and promoted with TCDD for various lengths of time developed ovarian sex cord-stromal tumors of Sertoli cell type, whereas no ovarian tumors developed in 86 rats used as vehicle controls or that received DEN alone or TCDD alone. The highest tumor incidence occurred in 6 of 14 rats (43%) after 60 weeks of continuous TCDD after DEN initiation. One of six rats developed a tumor by 30 weeks of exposure. Because most effects of TCDD can be attributed to its activation of the aryl hydrocarbon receptor (AhR), the presence and localization of AhR was determined in the rat ovary and in the ovarian tumors by reverse transcription-PCR, immunohistochemistry, and in situ hybridization. AhR was localized to oocytes, granulosa and thecal cells of growing follicles, surface epithelial cells, and epithelial cells lining single tubules in ovaries from adult control Sprague Dawley rats. Neoplastic cells in the ovarian tumors were also positive for both AhR message and protein. These results indicate that the ability of TCDD to cause ovarian tumors is dependent on initiation, length of promotion, and age of the animal when exposed and evaluated. The tumor type induced by TCDD in this experimental system is the same histological subtype as that reported from an early study of youngsters exposed during an industrial accident in Seveso, Italy.

Animals↗
PubMed2000

Evolving the biobehavioral family model: the fit of attachment.

The 1993 Biobehavioral Family model (BBFM) posits that family relational patterns and biobehavioral reactivity interact so as to influence the physical and psychological health of the children. The revised 1999 BBFM incorporates parent-child attachment as a pivotal construct. The current study tests the 1999 BBFM by predicting, in asthmatic children, that child perception of parental relationship quality, triangulation of child in marital conflict, and parent-child security of relatedness will be associated with hopelessness and vagal activation (one mechanism of airway compromise in asthma). In this study, 22 children with asthma (11 males/11 females, aged 8 to 16), watched, alone, an emotionally challenging movie, then engaged in family discussion tasks (problem solving, loss, conflict, cohesion) and completed the Children's Perception of Interparental Scale, the Relatedness Questionnaire, The Multidimensional Scale of Anxiety in Children, and the Hopelessness Scale for Children. Heart rate variability, measured at baseline and throughout the movie and family tasks, was used to compute respiratory sinus arrhythmia (RSA)--an inferential measure of vagal activation. The child's perception of parental conflict showed trends of association with triangulation and insecure father-child relatedness. Triangulation and hopelessness also were associated with insecure father-child relatedness, all of which were associated with vagal activation. Insecure mother-child relatedness was correlated only with hopelessness. Anxiety was not related to any variables. These findings lend support to the 1999 BBFM, and suggest a key role for parent-child attachment.

Adolescent↗
PubMed1998

Use of solid phase extraction disks for the GC-MS analysis of acidic and neutral herbicides in drinking water.

An analytical procedure was developed in which thirteen herbicides (10 acidic and 3 neutral compounds) may be extracted from drinking water samples using solid phase extraction disks and subsequently analyzed by gas chromatography-mass spectrometry. Using 8 replicate samples consisting of reagent water fortified with nanogram quantities of each herbicide, the average percent recoveries and method detection limits were determined for each analyte. The method was found to be suitable for the determination of individual herbicides in drinking water at concentrations of approximately 10 ng/L.

Gas Chromatography-Mass Spectrometry↗
PubMed1998

Differences in kinetics of induction and reversibility of TCDD-induced changes in cell proliferation and CYP1A1 expression in female Sprague-Dawley rat liver.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a potent tumor promoter in two-stage initiation-promotion models and induces cell proliferation and development of enzyme-altered hepatic foci. It is believed that increased cell proliferation is a necessary step in carcinogenesis. Therefore, the analysis of the effect of TCDD on cell proliferation in rat liver may aid in the understanding of the mechanism of hepatocarcinogenesis induced by TCDD. The aim of this study was to investigate the time course and reversibility of cell proliferation in non-initiated and diethylnitrosamine-initiated female rats exposed biweekly to a daily averaged dose of 125 ng TCDD/kg/day for up to 60 weeks. In addition we evaluated the suitability of different dose metrics for the evaluation of TCDD-induced changes in cell proliferation and CYP1A1 enzyme induction. Cell proliferation was measured as the incorporation of 5-bromo-2'-deoxyuridine (BrdU) into hepatocytes undergoing replicative DNA synthesis. Mean BrdU labeling indices in TCDD-treated animals were not increased over controls after 14 weeks exposure, but were increased 8- and 2-fold after 30 and 60 weeks' treatment respectively, despite similar liver levels of TCDD at all these times (23-30 p.p.b.). In comparison, CYP1A1 activity, as measured by ethoxyresorufin deethylase activity, was significantly induced at all times points analyzed. Sixteen weeks following cessation of TCDD treatment, labeling indices were still significantly elevated over controls, but after 30 weeks of withdrawal, labeling indices were no different from controls, indicating that TCDD-induced changes in cell proliferation were reversible. Dosimetric analysis indicated that rat liver tissue burden was suitable for prediction of CYP1A1 expression but not cell proliferation and that the area under the curve was unsuitable for prediction of both TCDD-induced changes in CYP1A1 expression and cell proliferation.

Animals↗
PubMed1997

Social class, gender and intrahousehold food allocations to children in South Asia.

In the 1980s research on gender-biased food distribution to children within the household in South Asia yielded important findings. Many studies report evidence of substantial discrimination against daughters, but others do not. This paper reviews research of the 1980s with attention to social differentiation in gender bias. My hypothesis is that different results concerning gender bias in intrahousehold allocations are expectable, given variations in gender hierarchy throughout South Asia. Results of the review indicate that seemingly "contradictory" results are often accurate reflections of social status differences within South Asia that create varying female health and nutritional outcomes.

Child↗
PubMed1997

Influence of specific emotional states on autonomic reactivity and pulmonary function in asthmatic children.

OBJECTIVE: Research relating depression/hopelessness to cholinergic activation suggests the hypothesis that sad emotional states evoke patterns of autonomic reactivity that predispose to cholinergically mediated airway constriction in asthma. A corollary hypothesis is that positive (e.g., happy) emotional states evoke opposing effects. The purpose of the current study is to assess whether specific emotional states (sadness and happiness) can be reliably induced, physiologically differentiated, and related to asthma-relevant physiologic (autonomic) reactivity and pulmonary function in asthmatic children. METHOD: Twenty-four children, aged 8 to 17 years, with moderate to severe asthma, viewed the movie E.T., The Extra-Terrestrial while having their heart and respiration rate and oxygen saturation continuously recorded. Specific scenes were identified and preselected to evoke sadness, happiness, and a mixture of happiness and sadness. Self-report of emotion and indices of physiologic response were analyzed for these targeted scenes. RESULTS: Sadness was associated with greater heart rate variability and instability of oxygen saturation compared with happiness, with mixed results for mixed happiness and sadness. CONCLUSION: Results support sadness as evoking patterns of autonomic influence consistent with cholinergically mediated airway constriction. Happiness appears to effect autonomic patterns that would tend to relieve airway constriction.

Adolescent↗
PubMed1996

Predominance of dense low-density lipoprotein particles predicts angiographic benefit of therapy in the Stanford Coronary Risk Intervention Project.

BACKGROUND: LDL particles differ in size and density. Individuals with LDL profiles that peak in relatively small, dense particles have been reported to be at increased risk of coronary artery disease. We hypothesized that response to coronary disease therapy in such individuals might differ from response in individuals whose profiles peak in larger, more buoyant LDL. We examined this hypothesis in the Stanford Coronary Risk Intervention Project, an angiographic trial that compared multifactorial risk-reduction intervention with the usual care of physicians. METHODS AND RESULTS: For 213 men, a bimodal frequency distribution of peak LDL density (g/mL) determined by analytical ultracentrifugation was used to classify baseline LDL profiles as "buoyant mode" (density < or = 1.0378) or "dense mode" (density > 1.0378). Coronary disease progression after 4 years was assessed by rates of change (mm/y, negative when arteries narrow) of minimum artery diameter. Rates for buoyant-mode subjects were -0.038 +/- 0.007 (mean +/- SEM) in usual care (n = 65) and -0.039 +/- 0.010 in intervention (n = 56; P = .6). Rates for dense-mode subjects were -0.054 +/- 0.012 in usual care (n = 51) and -0.008 +/- 0.009 in intervention (n = 41, P = .007). Lipid changes did not account for this difference in angiographic response. CONCLUSIONS: Different types of LDL profile may predict different-responses to specific therapies, perhaps because metabolic processes determine both LDL profiles and responses to therapies.

Aged↗
PubMed1996

Increased oxidative DNA damage in livers of 2,3,7,8-tetrachlorodibenzo-p-dioxin treated intact but not ovariectomized rats.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a more potent hepatocarcinogen in female than in male or ovariectomized rats. A possible mechanism for this increased sensitivity is through enhanced metabolic activation of estrogens by TCDD-induced enzymes leading to oxidative damage in the cell. As a marker for oxidative DNA damage, 8-oxo-deoxyguanosine (8-oxo-dG) was quantitated in livers of intact and ovariectomized Sprague-Dawley rats chronically treated with TCDD (125 ng/kg per day) with and without diethylnitrosamine as initiator. Elevated levels of 8-oxo-dG were detected in a significantly greater number of the intact compared to ovariectomized TCDD-treated rats. Expression of CYP1B1 mRNA, a newly identified cytochrome P450 with proposed estrogen hydroxylase activity, was highly induced by TCDD. The results are consistent with the hypothesis that increased metabolism of endogenous estrogens to catechols by TCDD-induced enzymes may lead to increased oxidative DNA damage and hence contribute to TCDD-mediated hepatocarcinogenicity in female rats.

Animals↗
PubMed1995

Toward a more comprehensive medical anthropology: the case of adolescent psychopathology.

This article argues for a more comprehensive analytical approach in medical anthropology than is currently followed, one that combines attention to structural factors (political, economic, medical/psychiatric), experiential/symbolic expressions and meanings, and biological/bodily features of disorders. We show how subject matter that may be defined as "adolescent psychopathology" would be better understood by a comprehensive approach than by partial views. Three areas within adolescent psychopathology are chosen as illustrative: anorexia nervosa, dissociation, and social aggression. Each of these, like adolescence itself, is powerfully shaped by historical and contemporary cultural influences, and each implicates important theories in medical anthropology.

Adolescent↗
PubMed1991

Childhood asthma in interaction with family, school, and peer systems: a developmental model for primary care.

The developmental/biopsychosocial approach to primary care of childhood asthma offered in the above model emphasizes four interlocking features: 1. Consideration of the biologic, psychologic, and social aspects of asthma which interact with one another and influence disease management and psychosocial functioning and development of the asthmatic child 2. The importance of balance between disease management and quality of life and developmental needs of the patients and their families 3. Appreciation and facilitation of a developmentally synchronized shift toward self care of the asthma and its social and emotional aspects; 4. Central role played by the primary care provider (or health care team) in integrating developmental/biopsychosocial aspects of comprehensive treatment for childhood asthma.

Adaptation, Psychological↗
PubMed1989

Circumstances surrounding the deaths of children due to asthma. A case-control study.

Features of the courses in 12 children who died of an acute attack of asthma were compared with those in 12 children of comparable age and sex who had a life-threatening attack of asthma but survived. Information obtained by structured interviews with the families and physicians and from the medical records was used to characterize (1) the patient, family, severity, and treatment of asthma primarily in the 6 months before the attack and (2) medical circumstances and patient characteristics present on the day of and/or during the acute episode. Patients in the study (mean age, 14.1 years) and controls (mean age, 13.8 years) were in early to late adolescence, had similar long-term medication use histories and an overall rating of the severity of asthma. For the analysis of the information concerning the 6 months before the attacks, the study patients had a greater frequency of respiratory failure requiring intubation, a decrease in steroid use in the month before the attack, history of family disturbance, abnormal reaction to separation or loss, and expressed hopelessness and despair. For the period more immediately surrounding the acute attack, study patients more often had attacks starting during sleep, but less frequently experienced vomiting during the course of the attacks. Treatment of the attack by the parents was poor (primarily because of delays) in 7 of the 12 children who died, but was also a factor in 6 of the 12 controls. Our data suggest that certain characteristics of asthmatic children may place them at greater risk for death due to their asthma. In addition, we postulate that there may be inherent differences in the mechanisms of the acute attacks between the children who died and those who survived.

Adolescent↗
PubMed1988

Excitatory amino acid receptors intrinsic to synaptic transmission in nucleus tractus solitarii.

Excitatory amino acid (EAA) receptors are present in the nucleus tractus solitarii (NTS), and there is growing evidence that L-glutamate (L-Glu) may activate neurons in this region to precipitate changes in autonomic discharge. To evaluate the potential role of EAA agonists in synaptic transmission in NTS, we studied the responses of single units in an in vitro brain slice preparation of NTS to electrical stimulation of one or both solitary tracts (TS) before, during and after superfusion with selected EAA antagonists. Dose-response studies demonstrated that the synaptic input to NTS units was substantially blocked by 2-amino-5-phosphonovaleric acid (APV) at perfusion concentrations of 1 mM, by kynurenic acid (KYN) at 10 mM, and glutamate diethylester (GDEE) at 10 mM. Using these concentrations, we examined the responses of single NTS neurons to afferent input from ipsilateral and contralateral TS stimulation before, during and after perfusion with each antagonist. KYN inhibited afferent input from one TS but not the other in 7 of 13 cells tested, inhibited both inputs in 4, and caused differential augmentation of input in two. APV caused differential inhibition of the two inputs in 4 of 9 cells tested, differential excitation in 1 and inhibition of both inputs in one. GDEE caused differential inhibition in 4 of 9 cells tested, differential excitation in 3 and inhibition of both inputs in one. When inputs from a single TS were examined, those blocked by APV were always blocked by KYN (5 of 16 inputs tested); there was overlap between the blocking effects of KYN and GDEE (4 of 12 inputs tested) and occasionally of APV and GDEE (one of 12 inputs tested). We also observed differential blocking effects of these agents on single inputs to the same neuron. Evoked responses were reduced or enhanced by only one of the two agents for 5 of 16 inputs tested with KYN and APV, 4 of 12 tested with KYN and GDEE, and 7 of 12 tested with APV and GDEE. The average reduction in synaptically evoked responses caused by blocking doses of antagonist was 85 +/- 6% for KYN, 63 +/- 28% for APV and 68 +/- 10% for GDEE. These data indicate that all 3 major EAA antagonists can selectively inhibit electrically evoked afferent input to NTS neurons and suggest a role for specific EAA receptors in mediating input to these neurons over different afferent pathways.

2-Amino-5-phosphonovalerate↗
PubMed1988

Neglect contributing to tertiary hospitalization in childhood asthma.

Clinical experience demonstrates that many chronically ill children have an unstable course of illness ending in tertiary care, not because of extraordinary disease, but because they come from dysfunctional and neglectful households. Families frequently cannot or will not adapt to the demands of their chronically ill child. This study substantiates the extent to which neglect and family dysfunction have contributed to the need for hospitalization of asthmatic children at National Jewish. Neglect accelerates the cycle of morbidity and stress associated with illness. Using a measure of global functioning, we demonstrate a psychologic morbidity associated with medical neglect. We discuss children at imminent risk in their home environment and the process of seeking alternative placements. We acknowledge gaps in delivery of health care to this difficult, treatment-resistant population and encourage development of day treatment and home outreach programs.

Asthma↗