Biomedical subjects

J T Bihun

Publications and source records attributed to J T Bihun.

4 recordsLinked to original sources

PubMed2000

Perception of induced bronchoconstriction in a community sample of adolescents.

BACKGROUND: Poor perception of asthma symptoms has been cited as a risk factor for asthma death, yet there is no consensus as to the best way to characterize perception, and little is known about perception in normative samples. Hypoperceivers are of clinical interest because of risks of undertreatment; hyperperceivers are at risk for adverse iatrogenic effects caused by overtreatment. OBJECTIVE: This study investigates perception of methacholine-induced bronchoconstriction in 175 adolescents. METHODS: Breathlessness was rated after each inhalation by using the Borg scale. Perception groups were calculated on the basis of change from placebo Borg to high Borg scores (perception score at the highest methacholine dose). Subjects were called hypoperceivers if their Borg change score was greater than 1 SD below the mean for their FEV(1) group, hyperperceivers if their Borg change score was greater than 1 SD above the mean for their FEV(1) group, and accurate perceivers otherwise. RESULTS: For subjects with an FEV(1) drop of less than 10%, accurate perceivers had a change in Borg score of 1.4 or less, and hyperperceivers had a change of greater than 1.4. For a drop in FEV(1) between 10% and 19%, hypoperceivers had a change in Borg score of less than 0.2, accurate perceivers had a change between 0.2 and 2.1, and hyperperceivers had a change of greater than 2.1. For those with an FEV(1) drop of 20% or greater, hypoperceivers had a Borg change of less than 0.2, accurate perceivers had a change between 0.2 and 2.6, and hyperperceivers had a change of greater than 2.6. No differences in age, sex, placebo Borg ratings, baseline pulmonary functions, PC(20) values, or psychologic variables were found among perception groups. CONCLUSION: This study provides reference Borg values during methacholine challenge for 175 community adolescents.

Adolescent↗

PubMed1999

Effects of prenatal alcohol and cocaine exposure on infant cortisol levels.

Elevated corticosterone levels to stress have been found in adult rats exposed prenatally to alcohol, but little is known about the effects of prenatal alcohol exposure on the cortisol response in humans. To date, one study has found that crack/cocaine was related to depressed newborn cortisol levels following a heel prick. In the present study saliva samples were obtained before and after a blood draw from 83 inner-city African American 13-month-old infants exposed prenatally to alcohol, cocaine, and other illicit drugs. Post-blood draw cortisol levels did not differ from basal levels in many of the infants, confirming recent studies indicating adaptation of the adrenocortical response to this type of stress at this age. Maternal depression and emergence of teeth were positively related to cortisol levels. Alcohol exposure was related to elevated basal levels, cocaine to lower basal levels. As predicted from animal findings, heavy alcohol exposure was related to elevated poststress cortisol levels.

Black People↗

PubMed1997

Conceptualizing genetic influences on early behavioral development.

The overarching goal of human behavioral genetics is to understand genetic influences on behavior while also considering the complementary influence of the environment. This paper highlights the explicit goals of behavioral genetics, including some that are particularly relevant to the study of human development, and some common misunderstandings concerning the field. Examples are given to illustrate specifically the degree of genetic influence in behaviors representing physical, cognitive and emotional development during infancy using the methodology of twin, adoption and parent-offspring designs. The effect sizes in the prediction of complex behaviors are typically modest, and thus there is ample room for multiple predictors from different domains. Moreover, there is a fundamental recognition that distal and proximal causes can be different in kind, and that factors that play a role in the origins of behavioral dispositions are different from those that elicit or maintain actual behavior.

Child Development↗

PubMed1992

Visual expectation and dimensions of infant information processing.

Visual expectation was assessed in 103 black 6.5-month-olds using Haith, Hazan, and Goodman's paradigm and related to performance on standard developmental assessments and tests of information processing skill. As expected, percent anticipations was higher and RT lower than in 3.0-month-olds previously tested. Split-half and left-right correlations for the RT measures were moderate and similar to those previously reported, as was split-half reliability for percent anticipations. The 2 RT measures were related to fixation duration on both visual recognition memory (VRM) and cross-modal transfer, suggesting moderate cross-task and cross-age consistency in processing speed. Percent anticipations and baseline RT each contributed independently to the prediction of VRM novelty preference. Data from a factor analysis suggested 3 dimensions of cognitive function: processing speed, developmental level, and memory/attention. These findings suggest that the visual expectation paradigm provides a reliable new approach for assessing cognitive processing efficiency and attention during infancy.

Black or African American↗