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Biomedical subjects

R B White

Publications and source records attributed to R B White.

At least 19 recordsLinked to original sources
PubMed1992

Adrenal-kidney and gonadal steroidogenesis during sexual differentiation of a reptile with temperature-dependent sex determination.

Adrenal-kidney and gonadal steroidogenesis were studied during early development in the red-eared slider turtle, Trachemys scripta, which exhibits temperature-dependent sex determination. In vitro steroid secretion by adrenal-kidney-gonad complexes (AKGs) incubated for 6 hr was determined by radioimmunoassay (RIA). AKGs from presumptive males and females secreted progesterone at developmental stages before (stage 15), during (stages 17 and 19), and after (stage 21) the temperature-sensitive period for sex determination, and progesterone secretion increased significantly throughout the period from stage 15 to 21. Presumptive male AKGs secreted significantly more progesterone than female AKGs at stage 19. Corticosterone secretion by AKGs was observed at stage 17 in males only, but in both sexes at stages 19 and 21. Testosterone, estradiol, androstenedione, and dehydroepiandrosterone secretion by AKGs was detected only at stage 21. Of the steroids measured, progesterone and corticosterone were consistently secreted at the highest levels. Although some sex differences were observed, no obvious patterns of sexually dimorphic steroid secretion from AKGs were apparent. Gonads from stage 21, stage 24, and 10-day-old hatchlings from both presumptive sexes incubated with [7-3H]pregnenolone showed only weak precursor conversion, primarily to polar metabolites, in incubations as long as 24 hr. None of the steroids assessed by RIA of AKG incubates could be identified by TLC or HPLC analysis of the stage 21 and stage 24 gonadal incubates. However, progesterone was tentatively identified in incubates of 10-day post-hatch female gonads. For stage 21 females, AKGs were separated into gonadal and adrenal-kidney tissue (AK) components and incubated in vitro for 1, 3, and 18 hr.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Glands↗
PubMed1992

Current parental stress in maltreating and nonmaltreating families of children with multiple disabilities.

Questionnaires were mailed to families of children with multiple disabilities to investigate whether differences in parental perception of stress and burden of care could be identified in those families who had previously been reported and substantiated as abusive or neglectful as compared to those families who had not been so reported. Two hundred and fifty-seven parents completed Friedrich's revised version of Holroyd's Questionnaire on Resources and Stress (QRS-F), an instrument designed to measure stress and burden of care in families of children with disabilities. Twenty-five (9.7%) had previously substantiated maltreatment reports. Results suggest that a history of maltreatment is not related to the family's currently perceived stress levels as measured by the Friedrich scale. Implications of the results are discussed.

Adolescent↗
PubMed1992

Stimulation of in vitro steroidogenesis by pituitary hormones in a turtle (Trachemys scripta) within the temperature-sensitive period for sex determination.

To investigate the possible involvement of pituitary hormones in the regulation of steroidogenesis during reptilian sexual differentiation, we tested the ability of gonadotropin (ovine FSH), adrenocorticotropin (porcine ACTH), and growth hormone (bovine GH) to stimulate in vitro steroidogenesis in embryonic adrenal-kidney-gonad complexes (AKGs) of a turtle, Trachemys scripta, during and after the temperature-sensitive period for sex determination (TSP). Radioimmunoassays were used to measure progesterone, testosterone, estradiol, and corticosterone in incubation media; additionally, immunoreactive ACTH was measured in plasma. Presumptive male and female AKGs were stimulated by both FSH and ACTH at each stage investigated. Secretion of progesterone and corticosterone was usually far greater than that of testosterone or estradiol in both basal and hormone-stimulated incubations. In general, AKGs from presumptive males secreted more progesterone and corticosterone than AKGs from presumptive females. Progesterone and estradiol secretions were stimulated by both FSH and ACTH, but testosterone secretion was stimulated only by ACTH. Corticosterone secretion was strongly stimulated by ACTH. GH failed to significantly stimulate steroid secretion. Plasma ACTH levels were significantly higher in males than in females, and both sexes had significantly higher plasma levels of ACTH after the TSP compared to during the TSP. Our data demonstrate that during the temperature-sensitive period AKGs are responsive to both gonadotropin and ACTH, and that there are significant sex differences in steroidogenesis, sensitivity to gonadotropin and ACTH, and plasma ACTH levels.

Adrenocorticotropic Hormone↗
PubMed1991

Targeted enzyme therapy of experimental glomerulonephritis in rats.

We sought to determine whether systemic administration of proteases ameliorates membranous nephritis induced in rats by immunization and challenge with cationic bovine gamma globulin, and whether targeting of protease to glomerular capillaries increases efficacy. Proteases substituted with biotin were targeted via the cationic protein avidin A, which by virtue of its charge has affinity for the glomerular basement membrane. Despite identical pretreatment proteinuria, rats given untargeted protease (biotin-conjugated without avidin, or unconjugated plus avidin) had significantly less proteinuria than saline-treated controls and nephrotic rats given avidin plus biotin-conjugated (targeted) protease had even less proteinuria and reduced glomerular rat IgG and C3. Among more severely nephrotic rats, targeted protease was again more effective than untargeted protease at reducing proteinuria, and also decreased the size of electron-dense glomerular deposits, hypercholesterolemia, and creatininemia. Inactivated targeted proteases had no effect on proteinuria, hypercholesterolemia, or azotemia. Finally, active targeted protease did not affect proteinuria in the nonimmune mediated nephrosis induced by puromycin aminonucleoside. We conclude that systemic protease can specifically diminish glomerular immune deposits, proteinuria, hyperlipidemia, and creatininemia associated with experimental immune complex glomerulonephritis but not toxic nephrosis, and that targeted protease is more effective than untargeted protease.

Albuminuria↗
PubMed1990

Reported maltreatment in children with multiple disabilities.

This study examined a population of children with multiple disabilities to investigate whether functional, developmental, or perinatal factors could differentiate children reported and substantiated as maltreated from those not so reported. Data were collected from medical records of a cohort of 500 children evaluated between 1973 and 1984 at the Kennedy Institute in Baltimore, Maryland. Maltreatment reporting was documented through the State of Maryland Abuse Registry and the counties of residence of all study children. Results indicated that the profiles of demographic and family characteristics associated with child maltreatment reporting in this population are consistent with the literature, but child functional and developmental characteristics were not confirmed as risk factors for substantiated maltreatment reports. Indeed, contrary to investigator expectations, the more severely disabled children, in terms of functioning, appeared at less risk of maltreatment than did disabled children functioning at more age-appropriate levels.

Activities of Daily Living↗
PubMed1985

Maternal perinatal risk factors and child abuse.

A retrospective matched pair study was designed to compare maternal perinatal factors such as abnormal pregnancy history and labor and delivery experience in families who subsequently were reported as physically abusive to one or more of their children as compared to non-abusive families. The study population consisted of the mothers of 532 children reported to the Baltimore (Maryland) Department of Social Services as physically abused during the years 1975-77. The comparison group was handmatched to the study group from State of Maryland birth certificates on the basis of the abused child's birth year and sex, maternal race, education and hospital of delivery. The study population was 67% black with a mean maternal education of 10.5 completed years. The abused children were 59% male with 48% less than 2 years of age. Results indicated that selected medical definitions of abnormal pregnancy, labor and delivery did not identify families at differential risk of maltreatment. However, mothers in maltreating families were younger, had shorter birth intervals, less prenatal care and were significantly more likely to have had a stillbirth or reported abortion or a prior child death. Study limitations are addressed as are suggestions for future research.

Adolescent↗
PubMed1985

Selected perinatal factors and child abuse.

A matched pair case-control study was conducted to compare birth weights, gestations, and length of hospital stay (LOS) of 532 children subsequently reported as physically abused with comparable data from a group of control children matched on age, sex, race, and maternal education. Our results indicated a moderate association between both low birthweight and very short gestation with physical abuse. Results for LOS were inconclusive.

Adolescent↗
PubMed1979

Relationship of scores on the Escapism Scale of the MMPI to escape from minimum security federal custody.

Investigated the ability of the Escapism (Ec) scale of the MMPI to differentiate between escape and non-escape minimum security federal prisoners. At the .05 level there was no difference between the scores of the two groups on the Ec scale or on comparisons of other correctional data, age, and ethnic composition. It appears that the Ec scale alone or in combination with other data will be a poor predictor of escape. Also, the rate of escape was so low as to make accurate prediction from any criteria extremely unlikely.

Adult↗
PubMed1978

Interdisciplinary training for child welfare and health.

Recognition of the symbiotic relationship of the child welfare and child health disciplines led to a project that developed and tested health concepts and methods curricula for child welfare administrators and research staff.

Child↗
PubMed1976

Variations of Bender-Gestalt constriction and depression in adult psychiatric patients.

The present study explored variations of Bender-Gestalt constriction and their relation to depression. 20 Ss showing constriction of drawings on the upper half-page and 20 Ss showing constriction of drawings on the left half-page were compared with regard to MMPI Depression scores. No significant difference was found between these groups. However, when the constricted groups were combined and then compared with 40 Ss who did not show constriction of Bender drawings, the constricted group had significantly higher (p less than .05) MMPI Depression scores. Thus, variations in Bender constriction are not differently related to depression, but presence of constriction is an indicator. However, its rate of occurrence is so infrequent, appearing in only 5% of the records examined, that its clinical usefulness in the detection of depression is quite limited.

Adolescent↗