Biomedical subjects
Publications and source records attributed to R A Gordon.
The coordination numbers and the interatomic distances for 50, 75 and 80 at.% Ni-Mn alloys in ordered and disordered states are presented. A new method for determining the first and second nearest neighbor coordination numbers in a binary alloy is applied. It is shown that magnetic properties of these alloys depend on short range order in atomic arrangement.
Lack of high-quality, affordable, and accessible child care is an often-cited impediment to a manageable balance between work and family. Researchers, however, have been restricted by a scarcity of data on the availability of child care across all U.S. communities. In this paper we describe and evaluate several indicators of child care availability that have been released by the U.S. Census Bureau over the last 15 years. Using community- and individual-level analyses, we find that these data sources are useful for indicating child care availability within communities, even though they were collected for other purposes. Furthermore, our results generally suggest that the data on child care availability are equally valid across communities of different urbanicity and average income levels, although it appears that larger geographic areas more accurately capture the child care market of centers than that of family day care providers. Our analyses indicate that center child care is least available in nonmetropolitan, poor communities, and that family day care is most available in nonmetropolitan, mixed-income communities. We discuss the benefits and limitations of the data sources, and point to directions for future data developments and research.
In a representative sample of boys who were in the 7th grade of an urban public school system at the start of a 6-year longitudinal study, more African American boys (23.8%) than non-Hispanic White boys (3.9%) had entered an antisocial gang by age 19. There were too few White gang members to study, but among African American boys, first gang entry was predicted prospectively by both baseline conduct disorder (CD) behaviors and increasing levels of CD behaviors prior to gang entry. This suggests that gang entry may be a further developmental step for some boys who are already on a trajectory of worsening antisocial behavior. Having friends prior to gang entry who engaged in aggressive delinquency increased the risk of gang entry further, but only during early adolescence. Family income and parental supervision also independently predicted gang entry, but the direction of their influences depended on the youth's age.
Research productivity in the areas of child abuse and domestic violence was reviewed for the years 1990-1996 by examining articles published in Child Abuse and Neglect, the Journal of Family Violence, and the Journal of Interpersonal Violence. To examine productivity across institutions, quantification of productivity was based on ordinal position of authorship as previously used. Productivity across these three journals was also summed based on the 1987 composite productivity index formula of Howard, et al., and the data were compared with a productivity assessment based on a search process in the PsycLIT database. Rank-order correlations between the raw productivity total, the composite measure, and productivity based on first-authored publications in PsycLIT were all significant. The findings suggest that the composite measure represents a good estimate of productivity across the three journals and that publication in these three journals provides a good representation of research in the general areas of child abuse and domestic and interpersonal violence. The findings, along with implications regarding the relative utility of such information for selection of graduate programs that have a strong research focus on child abuse or domestic violence, are discussed.
OBJECTIVE: To report a case of a 3-year-old child with an extraordinarily massive lead concentration, 26.4 micromol/L (550 microg/dL), following environmental exposure to lead paint in the home. LITERATURE REVIEW: The relevant literature concerning the treatment of lead encephalopathy was reviewed during the treatment of this child and preparation of the manuscript. To our knowledge, the landmark article written by Julian Chisolm in 1968 is the only recent article that reported similarly high levels of lead concentration. This case, however, is the first in which 3 chelating agents were used for the treatment of lead encephalopathy. We also reviewed the literature on the use of whole bowel irrigation in heavy metal intoxications. CONCLUSIONS: In this case, aggressive gut decontamination with whole bowel irrigation and triple chelation therapy with British anti-Lewisite, EDTA, and oral succimer was well tolerated and seemed effective for rapidly deleading the child. The extent to which her lead concentration increased while being treated with oral succimer alone necessitated further chelation with EDTA. Further evaluation is necessary to determine if triple chelation therapy is an appropriate method for severe lead intoxication, and if the use of whole bowel irrigation should be considered in heavy metal intoxication.
PURPOSE: The purpose of the study was to examine spherical equivalent refractive errors, especially myopia, at six ages between 3 months and 5 1/2 years post-term in preterm children with birth weights of less than 1251 g. DESIGN: A cohort study. PARTICIPANTS: There were a total of 827 participants in the multicenter study of cryotherapy for retinopathy of prematurity (ROP). Approximately one third of the eyes did not develop ROP, whereas two thirds developed mild-to-severe ROP. None of the eyes underwent cryotherapy. INTERVENTION: Refractive error was measured at 3 months, 1 year, and 5 1/2 years term due date at the five long-term follow-up centers. In most eyes, refractive error also was measured at 2, 3 1/2, and 4 1/2 years. MAIN OUTCOME MEASURE: Myopia was defined as 0.25 diopter (D) or greater with high myopia as 5 D or greater. RESULTS: The proportion of eyes with myopia in this preterm population was increased compared to published data on full-term children and was related to severity of both acute-phase and cicatricial-phase ROP. The percentage of eyes with myopia varied little across ages, ranging from 21.2% at 1 year to 15.7% at 4 1/2 years. The percentage of eyes with high myopia doubled from 1.8% to 3.9% between 3 months and 1 year and remained stable thereafter. The distribution of refractive errors in eyes with mild acute-phase ROP was similar to that of eyes with no ROP. In contrast, eyes with moderate or severe acute-phase ROP showed an increased prevalence of high myopia. The distribution of refractive errors changed between 3 months and 1 year with little change after 1 year. This pattern of refractive development differs from that of full-term infants. Birth weight, severity of ROP, and degree of myopia at 3 months predicted the presence of myopia and high myopia at 5 1/2 years of age. CONCLUSIONS: The distribution of refractive errors in preterm infants from age 3 months to 5 1/2 years varies with severity of acute-phase ROP and cicatricial disease. Changes in refractive error distribution occur primarily between 3 months and 1 year and involve a decrease in the proportion of eyes with hyperopia and an increase in the proportion with high degrees of myopia.
The need of a sample of U.S. students to cognitively structure reality as measured by the Personal Need for Structure (PNS) Scale was examined as a predictor of attitudes toward homosexuality measured by the Attitudes Toward Lesbians and Gay Men (ATLG) Scale. Significant relationships between the two constructs and strong gender differences on the ATLG were found.
BACKGROUND: Previous animal and human studies have indicated that prenatal exposure to nicotine is associated with adverse reproductive outcomes, including altered neural structure and functioning, cognitive deficits, and behavior problems in the offspring. Our study extends previous research on humans by controlling a broad range of correlates of maternal smoking during pregnancy to determine if smoking is associated with behavior problems in the offspring severe enough to qualify for DSM-III-R diagnosis. METHODS: Subjects were 177 clinic-referred boys, ages 7 to 12 years at the time of the first assessment, who underwent longitudinal assessment for 6 years using annual structured diagnostic interviews. Correlates of maternal smoking during pregnancy and previously identified demographic, parental, perinatal, and family risk factors for the disruptive behavior disorders were controlled in logistic regression analyses. RESULTS: Mothers who smoked more than half a pack of cigarettes daily during pregnancy were significantly more likely to have a child with conduct disorder (odds ratio, 4.4; P = .001) than mothers who did not smoke during pregnancy. This association was statistically significant when controlling for socioeconomic status, maternal age, parental antisocial personality, substance abuse during pregnancy, and maladaptive parenting. CONCLUSIONS: Maternal smoking during pregnancy appears to be a robust independent risk factor for conduct disorder in male offspring. Maternal smoking during pregnancy may have direct adverse effects on the developing fetus or be a marker for a heretofore unmeasured characteristic of mothers that is of etiologic significance conduct disorder.
Advantage has been taken of the extensive and reversible incorporation of long-chain fatty acids by erythrocyte ghosts to characterize the interaction of tritium-labeled palmitic acid with human serum albumin (pH 7.4, 37 degrees C). A stoichiometric binding constant for 1:1 complex formation (K1) of 4.6 (+/-0.3) x 10(8) M-1 was obtained from experiments in which erythrocyte ghosts were the source of fatty acid. An essentially identical estimate of 4.1 (+/-0.7) x 10(8) M-1 was obtained from a second series of experiments in which the [3H]palmitate was included with the albumin in the aqueous phase. The magnitude of the present K1 estimate, which is three- to fivefold larger than most recently reported values, reflects binding measurements restricted to a very limited range of unbound palmitate concentration (-0.2 nM) to ensure that the ligand is essentially monomeric. This use of erythrocyte ghosts to quantify the palmitate-albumin interaction has reinforced the basic tenets of a published procedure [I. N. Bojesen, and E. Bojesen (1992) J. Lipid Res. 33, 1327-1334], the major virtue of which is its ability to provide a direct measure of the equilibrium concentration of unbound fatty acid in albumin-palmitate mixtures.
OBJECTIVE: To determine whether the extent of retinal vessel development present on early screening examinations for retinopathy of prematurity has prognostic value? DESIGN: The prospectively collected data from the Multicenter Trial of Cryotherapy for Retinopathy of Prematurity were used to compare the development of acute retinopathy of prematurity and long-term structural and visual outcomes for eyes with differing extents of retinal vessel development. PATIENT: Study patients had eyes with the following vessel development. In zone I eyes, vessels extended from the disc less than twice the distance from the disc to the macula. In zone II eyes, vessels extended beyond zone I but not to the nasal ora serrata. Transitional eyes had vessels partly in zone I and partly in zone II. RESULTS: The chance of developing threshold retinopathy of prematurity was inversely related to the early degree of vessel development: 54% for zone I eyes, 25% for transitional eyes, and 8% for zone II eyes. The presence of prominent iris vessels at 34 to 35 weeks of postmenstrual age was associated with increased risk for all three groups; zone I eyes almost always needed treatment (94%). The chance of having an unfavorable anatomic alteration of the posterior fundus, or poor vision at the ages of 1 year and 3 1/2 years, was also inversely related to the degree of early vessel development. Vessel development was an independently important factor even when birth weight, gestational age, and race were considered. CONCLUSIONS: The degree of early retinal vessel development is a significant predictor of outcome from retinopathy of prematurity. Iris vessel dilatation is an important indication for greater vigilance in following these infants.
To determine if the sex differences in clearance of long chain fatty acids by the liver observed in the rat are relevant to humans, the authors isolated hepatocytes from human adult males and females (five per group) and measured the initial (unidirectional) clearance of [3H]-palmitate from buffer containing albumin. The clearance was significantly higher (about twofold) in hepatocytes from females because of a higher permeability of the plasma membrane to the fatty acid. The livers had been perfused with University of Wisconsin (UW) solution and stored for 12-16 h before isolation of the cells. The magnitudes of the clearances in humans were similar to those in the rat when the livers were stored similarly, but lower than in cells isolated from fresh rat liver. When hepatocytes isolated from fresh rat liver were stored in UW solution, clearance of [3H]-palmitate was unaffected. Thus, hepatocytes prepared from intact liver stored for several hours in UW solution do not have as good preservation of function as hepatocytes isolated from fresh liver and then stored in UW solution.
The human serum albumin (HSA)-dependent unbound clearance (Clu) of [3H]palmitic acid (PA) by hepatocyte suspensions isolated from immature and mature male and female and pregnant female rats was studied. The Clu values obtained experimentally were compared with the predictions of a noncompartmental diffusion-reaction (Bass-Pond) theory for the cellular uptake of protein-bound ligands. In all groups, as the concentration of HSA (Ca) was increased, there was a striking increase in Clu. These enhancement factors were predicted by the theory. Adult females had higher Clu values at high Ca values than males or immature females. Furthermore, at high Ca values, Clu in pregnant animals was twice as high as in the nonpregnant animals and four times as high as in the aged-matched males. The absolute values of Clu obtained experimentally in both pregnant and nonpregnant females exceeded the maximal predictions of the theory, using reasonable values of all of the parameters. Thus, according to current data on the physicochemical characteristics of the uptake system, the study demonstrates that some specialized process exists to facilitate hepatocellular uptake of fatty acid from albumin, and that it is potentiated by the female sex hormones.
The Immaturity (IMM) Scale was developed as a supplementary scale for the Minnesota Multiphasic Personality Inventory-Adolescent (MMPI-A). This study describes the development of the IMM Scale and presents some concurrent validity data derived from the MMPI-A normative sample of 1,620 adolescents and a clinical sample of 122 adolescent inpatients. The IMM Scale was examined in relation to Biographical and Life Events data to identify external correlates for the MMPI-A normative sample. In the clinical sample, external correlates were derived from diagnostic and rating form data provided by the adolescents' treatment staff and by their parents. Current findings were discussed in terms of the relationship of correlate patterns to descriptions of the preconformist and conformist stages of Loevinger's (1976) concept of ego development, and future research directions were suggested.
This study examined the influences of age and ethnicity on perceived item subtlety in Minnesota Multiphasic Personality Inventory (MMPI) Scales F and 9. One hundred twenty-one male adolescents (67 White, 54 Black) rated the items composing these scales in terms of their relationship to a psychological problem. The mean item ratings and subsequent subtle-obvious classifications were then compared to established ratings obtained from adults (Christian, Burkhart, & Gynther, 1978; Wiener, 1948). Results indicated significant differences in both item ratings and classifications between adolescents and adults on Scales F and 9. Significant differences between Black and White adolescents were found on Scale F but not on Scale 9, even when differences in verbal-comprehension abilities between groups were considered. These results suggest that it may be inappropriate to use current subtle-obvious keys with adolescents and minorities.
Explore the source record for details and available documents.
Albumin-dependent uptake of unbound [3H]palmitic acid by hepatocytes isolated from female rat livers was studied and the experimental results compared with the predictions of a noncompartmental diffusion-reaction theory for the cellular uptake of protein-bound ligands. The outright theoretical predictions involve values for the parameters of the system, some newly measured (hepatocyte radii and the rate constant for the dissociation of palmitate-albumin complex) and some taken from the literature (diffusion coefficients and the equilibrium association constant for the palmitate-albumin complex). The measured unbound clearance of [3H]palmitic acid, defined as the initial uptake velocity divided by the unbound [3H]palmitic acid concentration in the medium, was enhanced 6.6-fold as the concentration of human serum albumin was increased from approximately 5 to 480 microM. This enhancement factor was predicted by the theory, according to which the enhancement reflects codiffusion of bound ligand across the unstirred layer adjacent to the cell membrane and, therefore, an increased delivery of unbound ligand to the cell surface. In contrast, the absolute magnitude of the unbound clearance was consistent with the theory only for the lowest published value for the equilibrium association constant, 15 microM-1. For higher published values (62 and 94 microM-1), the magnitude of the unbound clearance observed experimentally was severalfold higher than that predicted by the theory. If in fact the association constant exceeds 30 microM-1, the data would imply that an albumin-dependent facilitation mechanism exists which enhances the availability of palmitate to the cell over and above the enhancement predicted by the diffusion-reaction theory.
Empirical research focused on the stressful aspects of residency training has largely ignored the interactions between residents' psychosocial and demographic characteristics, stressful experiences, emotional responsivity, and coping styles. This article presents the results of a questionnaire, completed by 165 residents, that consisted of the Profile of Mood States, the Hassles Scale, the Ways of Coping Questionnaire, and a series of questions regarding demographic data, social support system features, and residency stress factors. The residents reported that time demands and indebtedness were the major sources of stress in their residency programs. Social support variables were significantly related to the degrees to which the residents successfully coped with daily stress factors. While the women residents reported higher stress levels than did the men, they did not report higher levels of emotional distress. Finally, the lengths of time residents had spent in training were significantly related to the levels of their mood disturbances and daily hassles.
Exner (1983, 1986) developed and recently revised (1990b) a Rorschach Depression Index based on scores from variables in the Comprehensive System. This study evaluated both the original and the revised DEPIs for child and adolescent outpatient (n = 67) and inpatient (n = 99) samples in order to assess the diagnostic utility of these indices. There were no significant relationships between the original form and the revised form of the DEPI and clinical elevations on the Depression scale of the Personality Inventory for Children in the outpatient sample or treatment team diagnostic judgments in the inpatient sample. These findings sound a strong cautionary note for using only Rorschach Depression indices to diagnose depression in children and adolescents.