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J M Bailey

Publications and source records attributed to J M Bailey.

At least 37 records · Page 2Linked to original sources
PubMed1999

Human frontal cortex: an MRI-based parcellation method.

The frontal lobe is not a single anatomical and functional brain region. Several lines of research have demonstrated that particular subregions within the frontal lobe are associated with specific motor and cognitive functions in the human being. Our main purpose is to develop a magnetic resonance image (MRI)-based parcellation method of the frontal lobe that permits us to explore plausible abnormalities in functionally relevant frontal subregions in brain illnesses. We describe a procedure using MRI for subdividing the entire frontal cortex into 11 subregions: supplementary motor area (SMA), rostral anterior cingulate gyrus (r-ACiG), caudal anterior cingulate gyrus (c-ACiG), superior cingulate gyrus (SCiG), medial frontal cortex (MFC), straight gyrus (SG), orbitofrontal cortex (OFC), precentral gyrus (PCG), superior frontal gyrus (SFG), inferior frontal gyrus (IFG), and middle frontal gyrus (MFG). Our method posits to conserve the topographic uniqueness of individual brains and is based on our ability to visualize both the three-dimensional (3D) rendered brain and the three orthogonal planes simultaneously. The reliability study for gray matter volume and surface area of each subregion was performed on a set of 10 MR scans by two raters. The intraclass R coefficients for gray matter volume of each subregion ranged between 0.86 and 0.99. We describe here a reproducible and reliable topography-based parcellation method of the frontal lobe that will allow us to use new approaches to understand the role of particular frontal cortical subregions in schizophrenia and other brain illnesses.

Brain Diseases↗
PubMed1999

How accurate is the family history method for assessing siblings' sexual orientation?

Previous studies investigating the familial nature of sexual orientation have often relied on the reports of siblings. They have generally obtained extremely high accuracy rates for proband rating of the sexual orientation of siblings. However, participants in these studies have probably been unusually open about their sexual orientation, and thus it is uncertain if more representative participants would have as accurate knowledge about their families. An unselected sample of twins from the Australian Twin Registry rated their own, their cotwins', and their siblings' sexual orientations. We examined accuracy of heterosexual and homosexual probands' assessments of their twins' sexual orientations, as well as cotwins' agreement about other siblings' orientations. Concordance between twins' ratings of their cotwins' orientations with the cotwins' self-rated orientations was considerably lower than that found in previous studies, as was the level of agreement between members of a twin pair in the assessment of other siblings' sexual orientations. Marital history as a proxy variable for determining the sexual orientation of older subjects did not support its use with women, though its use for older men received some weak support.

Adult↗
PubMed1999

A family history study of male sexual orientation using three independent samples.

Available evidence suggests that male homosexuality is both familial and somewhat heritable and that some cases may be caused by an X-linked gene. However, most studies have recruited subjects in a relatively unsystematic manner, typically via advertisements, and hence suffer from the potential methodological flaw of ascertainment bias due to volunteer self-selection. In the present study we assessed the familiality of male homosexuality using two carefully ascertained samples and attempted to replicate findings consistent with X-linkage in three samples. The percentage of siblings of the probands rated as either homosexual or bisexual, with a high degree of certainty, ranged from 7 to 10% for brothers and 3 to 4% for sisters. These estimates are higher than recent comparable population-based estimates of homosexuality, supporting the importance of familial factors for male homosexuality. Estimates of lambda s for male homosexuality ranged from 3.0 to 4.0. None of the samples showed a significantly greater proportion of maternal than paternal homosexual uncles or homosexual male maternal first cousins. Although our results differed significantly with those of some prior studies, they do not exclude the possibility of moderate X-linkage for male sexual orientation.

Adolescent↗
PubMed1999

The pharmacokinetics of milrinone in pediatric patients after cardiac surgery.

BACKGROUND: Milrinone has been shown to increase cardiac output in children after cardiac surgery, but pharmacokinetic analysis has not been used to identify effective dose regimens. The purpose of this study was to characterize the pharmacokinetics of milrinone in infants and children and to apply the results to the issue of dosing. METHODS: Twenty children were studied after they underwent repair of congenital cardiac defects. Control hemodynamic measurement was made after the children were separated from cardiopulmonary bypass, and each patient was given a loading dose of 50 microg/kg progressively in 5 min. Hemodynamic measurements were recorded again at the end of the loading dose and when a blood sample was taken to determine milrinone plasma concentrations. Further blood samples were taken during the next 16 h for milrinone plasma concentration analysis. The pharmacokinetics of milrinone were analyzed using the population pharmacokinetic program NONMEM. RESULTS: The loading dose of milrinone resulted in a mean decrease in mean blood pressure of 12% and a mean increase in cardiac index of 18% at a mean peak plasma concentration of 235 ng/ml. The pharmacokinetics of milrinone were best described by a three-compartment model. In the optimal model, all volumes and distribution clearances were proportional to weight, and weight-normalized elimination clearance was proportional to age; ie., Cl1 = 2.5 x weight x (1 + 0.058 x age) where Cl1 is expressed as ml/min, and the units of weight and age are kg and months, respectively. CONCLUSIONS: A loading dose of 50 microg/kg effectively increases cardiac index in children after cardiac surgery. Simulations indicate that the peak plasma concentration can be maintained by following the loading dose of 50 microg/kg with an infusion of approximately 3 microg x kg(-1) x min(-1) for 30 min and then a maintenance infusion, which may require adjustment for age.

Body Weight↗
PubMed1998

Hematologic and economic impact of aprotinin in reoperative pediatric cardiac operations.

BACKGROUND: Aprotinin consistently reduces blood loss and transfusion requirements in adults during and after cardiac surgical procedures, but its effectiveness in children is debated. We evaluated the hemostatic and economic effects of aprotinin in children undergoing reoperative cardiac procedures with cardiopulmonary bypass. METHODS: Control, low-dose aprotinin, and high-dose aprotinin groups were established with 15 children per group. Platelet counts, fibrinogen levels, and thromboelastographic values at baseline and after protamine sulfate administration, number of blood product transfusions, and 6-hour and 24-hour chest tube drainage were used to evaluate the effects of aprotinin on postbypass coagulopathies. Time needed for skin closure after protamine administration and lengths of stay in the intensive care unit and the hospital were recorded prospectively to determine the economic impact of aprotinin. RESULTS: Coagulation tests performed after protamine administration rarely demonstrated fibrinolysis but did show significant decreases in platelet and fibrinogen levels and function. The thromboelastographic variables indicated a preservation of platelet function by aprotinin. Decreased blood product transfusions, shortened skin closure times, and shortened durations of intensive care unit and hospital stays were found in the aprotinin groups, most significantly in the high-dose group with a subsequent average reduction of nearly $3,000 in patient charges. CONCLUSIONS: In children undergoing reoperative cardiac surgical procedures, aprotinin is effective in attenuating postbypass coagulopathies, decreasing blood product exposure, improving clinical outcome, and reducing patient charges.

Adolescent↗
PubMed1998

Sex differences in perceived controllability of mate value: an evolutionary perspective.

Men and women value different characteristics in potential partners. It was hypothesized that women feel they have less control over traits relevant to their desirability than men feel they have over traits related to male desirability. In Study 1, undergraduates (N = 150) completed questionnaires measuring (a) the importance they attributed to 64 characteristics when choosing a mate and (b) their perceived control over these traits. Men selected partners on the basis of traits that are relatively uncontrollable (e.g., youth, attractiveness), whereas women selected partners on the basis of traits that are more controllable (e.g., status, industriousness; d = 1.75). In Study 2, these findings were replicated in an older, representative community sample (N = 301; d = 1.03). Greater uncontrollability of traits relevant to female mate value may place women at elevated risk for negative affect, depression, low self-esteem, and body dissatisfaction.

Adult↗
PubMed1998

A bolus dose of 1.5 mg/kg amrinone effectively improves low cardiac output state following separation from cardiopulmonary bypass in cardiac surgical patients.

BACKGROUND: The aim of this study was to evaluate the efficacy of 1.5 mg/kg bolus of amrinone on low cardiac output (CO) state following emergence from cardiopulmonary bypass (CPB) in cardiac surgical patients. METHODS: Immediately after emergency from CPB, 14 patients with a cardiac index (CI) less than 2.2 l.min-1.m-2 despite administration of inotropes and nitroglycerin, received 1.5 mg/kg amrinone over 3 min without changing catecholamine infusion rates (amrinone group). Hemodynamics and left ventricular short axis views with transesophageal echocardiography were recorded at baseline, 3, 4, and 10 min following amrinone administration. Left ventricular filling volumes were maintained constant by volume reinfusion from the CPB reservoir. We matched the data of the amrinone group with the other 14 patients who did not receive amrinone (non-amrinone group) to evaluate the efficacy of amrinone in low CO state. RESULTS: At baseline, CI (1.8 +/- 0.1 l.min-1.m-2) in the amrinone group was significantly lower than CI (3.0 +/- 0.2) in the non-amrinone group. Following amrinone administration, CI and velocity of circumferential fibershortening corrected for heart rate (Vcfc) significantly increased, and systemic vascular resistance index and pulmonary vascular resistance index significantly decreased from the baseline within 10 min without changes in heart rate, mean arterial blood pressure, or pulmonary artery occlusion pressure, and became equivalent with those of the non-amrinone group. CONCLUSIONS: A 1.5 mg/kg amrinone loading dose to patients in a low CO state, despite catecholamine therapy immediately after emergence from CPB, effectively improves ventricular function when loading conditions are maintained constant.

Adult↗
PubMed1998

Human sexual orientation has a heritable component.

We present an overview of behavioral genetics research on homosexual and heterosexual orientation. Family, twin, and adoptee studies indicate that homosexuality and thus heterosexuality run in families. Sibling, twin, and adoptee concordance rates are compatible with the hypothesis that genes account for at least half of the variance in sexual orientation. We note observations of homosexual behavior in animal species, but the analogy to human sexual orientation is unclear. We discuss the reproductive disadvantage of a homosexual orientation and present possible mechanisms that could maintain a balanced polymorphism in human populations.

Animals↗
PubMed1997

Sexual orientation and professional dance.

The stereotypical professional male dancer is a gay man. However, little if any systematic research has investigated the validity of this stereotype, much less the reasons why male sexual orientation would be associated with interest in dance. We interviewed 136 professional dancers about the prevalence of homosexuality among dancers, the dancers' own sexual development, and relationships between dancers of different sexual orientations. Dancers estimated that over half of male dancers are gay, but that only a small minority of female dancers are lesbian. Gay men recalled more intense early interest in dance compared to heterosexual men and women, and were more feminine as boys than were heterosexual men. Gay men's homosexual feelings typically preceded their dance experience, and only one gay man felt that his dance experiences may have influenced his sexual orientation. Heterosexual men voiced some mild complaints about gay male dancers, but these were balanced by positive sentiments.

Adolescent↗
PubMed1997

Butch, femme, or straight acting? Partner preferences of gay men and lesbians.

On average, gay men are somewhat feminine and lesbians somewhat masculine, but there is variation within each group. The authors examined the consequences of this variation for gay men's and lesbians' desirability as romantic partners. In 2 studies the authors analyzed personal advertisements. Homosexual people were more likely than heterosexual people to mention traits related to sex typicality and more likely to request sex-typical than sex-atypical partners. In 2 studies the authors assessed partner preferences directly. On average, gay men preferred men who described themselves as masculine rather than feminine, but this preference was weaker among men who rated themselves as relatively feminine. Lesbians preferred women who described themselves as feminine looking but did not discriminate against women calling themselves masculine acting. The authors discuss implications of the results for theories of sexual orientation and the adjustment of sex-atypical homosexual people.

Adult↗