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Biomedical subjects

S O'Brien

Publications and source records attributed to S O'Brien.

At least 361 records · Page 20Linked to original sources
PubMed1986

Parathyroid hormone and neonatal calcium homeostasis: evidence for secondary hyperparathyroidism in the Asian neonate.

Calcium, 25-hydroxyvitamin D (25 OHD), and parathyroid hormone (PTH) concentrations were measured in 11 Asian and ten Caucasian pregnant women at parturition and in their respective newborns following a full term normal delivery. Maternal calcium and 25 OHD concentrations were significantly lower while PTH concentrations were significantly greater in Asians than those in Caucasians. There was a significant inverse relationship between calcium and PTH and the relationship between 25 OHD and PTH concentrations. Neonatal calcium and 25 OHD concentrations were also significantly lower and PTH concentrations significantly higher in Asians than those in Caucasians. There was a highly significant inverse correlation between neonatal calcium and PTH concentrations. Three of the 11 Asian babies had supranormal concentrations of PTH in their cord blood. We conclude that PTH participates in neonatal calcium homeostasis and Asian newborns have frequent secondary hyperparathyroidism.

Adult↗
PubMed1986

Analysis of environmental determinants of aggression and disruption in mentally retarded children.

This study evaluated methods for empirically identifying environmental determinants of aggressive and disruptive behavior in three developmentally delayed children. A variety of sessions conducted on an inpatient treatment unit were designed to stimulate contingencies maintaining aggression and disruption in the subjects' natural environments. The basic analog conditions included: instructional demands, contingent social disapproval, and structured play. In addition, variations of the three basic conditions were developed based on informal observation and parental reports of naturally occurring contingencies. Results showed considerable variability both between and within subjects. However, for each subject a specific analog condition was shown to produce relatively higher rates of aberrant behavior. Subsequently, behavioral treatments based on assessment results were successfully implemented with two of the subjects. Results are discussed in terms of the importance and practical limitations of conducting systematic assessment of aberrant repertoires in developmentally delayed clients.

Adolescent↗
PubMed1986

Cloning, characterization, expression, and chromosomal localization of a human ferritin heavy-chain gene.

A genomic phage clone containing a full-length copy of a functional human gene for ferritin heavy chain has been isolated. The gene consists of four exons spanning approximately 3 kilobases and has been localized to chromosome 11. The functionality of the gene was demonstrated by the fact that both transient transfectants and stable transformants of murine fibroblasts actively transcribe human ferritin heavy-chain mRNA.

Amino Acid Sequence↗
PubMed1986

Primary encopresis: evaluation and treatment.

Cathartic and behavioral treatment procedures for eliminating diurnal and nocturnal primary encopresis were investigated using a multiple-baseline design across four children. The dependent and independent variables measured were appropriate bowel movements, soiling accidents, independent toiletings, and cathartic use. Over 177 reliability observations (home visits) were conducted. For two of the children, treatment with cathartics and child-time remedied their soiling accidents and increased their independent toiletings in 8 to 11 weeks. While the cathartics and child-time increased the rate of appropriate bowel movements, they did not eliminate the soiling accidents with the other two children. Independent toiletings for these two children were achieved after 32 to 39 weeks of treatment when punishment procedures (positive practice, time-out, and hourly toilet sits) were incorporated and the suppositories were faded systematically.

Behavior Therapy↗
PubMed1986

Effectiveness of brief time-out with and without contingent delay: a comparative analysis.

We evaluated a commonly used component of brief time-out, in which release from time-out is delayed contingent on the occurrence of disruption. Data were collected for one normal and two mentally retarded children on time-out-producing behaviors (aggression and disruption) as well as delay-producing behaviors during time-out (loud vocalizations, out-of-chair, aggression, and disruption). The results of a combination ABAC reversal and multiple-baseline design indicated that, under the conditions used in this investigation, both delay and no delay variations were effective in reducing the frequency of the target behaviors. Implications for the use of time-out to reduce aberrant behaviors are discussed.

Adolescent↗
PubMed1985

Organization and chromosomal specificity of autosomal homologs of human Y chromosome repeated DNA.

The human Y chromosome contains a group of repeated DNA elements, identified as 3.4-kilobase pair (kb) fragments in Hae III digests of male genomic DNA, which contain both Y-specific and non-Y-specific sequences. We have used these 3.4-kb Hae III Y fragments to explore the organizational properties and chromosomal distribution of the autosomal homologs of the non-Y-specific (NYS) 3.4-kb Hae III Y elements. Three distinct organizations, termed domains, have been identified and shown to have major concentrations on separate chromosomes. We have established that domain K is located on chromosome 15 and domain D on chromosome 16 and suggested that domain R is on chromosome 1. Our findings suggest that each domain is composed of a tandemly arrayed cluster of a regularly repeating unit containing two sets of repeated sequences: one that is homologous to the NYS 3.4-kb Hae III Y sequences and one that does not cross-react with the 3.4-kb Hae III Y repeats. Thus, these autosomal repeated DNA domains, like their Y chromosome counterparts, consist of a complex mixture of repeated DNA elements interspersed among each other in ways that lead to defined periodicities. Although each of the three identified autosomal domains cross-reacts with 3.4-kb Hae III Y fragments purified from genomic DNA, the length periodicities and sequence content of the autosomal domains are chromosome specific. The organizational properties and chromosomal distribution of these NYS 3.4-kb Hae III homologs seem inconsistent with stochastic mechanisms of sequence diffusion between chromosomes.

Animals↗
PubMed1985

Social validation of heterosexual social behavior in community settings: a comparison of mentally retarded and non-mentally retarded adults.

Adaptive heterosexual social interaction in community settings is an age-appropriate social skill. Subjective evaluation methodology was used as a social validation procedure to establish the appropriateness and optimal rate of occurrence of heterosexual social behaviors in bar and restaurant settings. Professionals working with mentally retarded persons and college students completed rating scales for hypothetical mentally retarded as well as non-mentally retarded subjects, respectively. The results show congruity between the behavioral expectations for mentally retarded and non-mentally retarded people in community settings. The findings suggest appropriate behaviors for training mentally retarded clients who lack adequate heterosexual community social skills.

Adolescent↗
PubMed1984

ERV3, a full-length human endogenous provirus: chromosomal localization and evolutionary relationships.

A full-length human endogenous provirus termed ERV3 was isolated from a human fetal recombinant DNA library by low stringency hybridization with two probes: baboon endogenous virus LTR; and a pol-env subclone from the endogenous chimpanzee provirus, CH2. DNA sequencing within the clone and comparisons with other retroviruses revealed that ERV3 contains gag and pol gene sequences that are significantly related to those of mammalian type C retroviruses and previously described human endogenous proviruses. The ERV3 genome was determined to reside at a single locus on human chromosome 7 using a panel of rodent X human somatic cell hybrids.

Amino Acid Sequence↗
PubMed1983

In-home parent training, treatment of migraine headaches, and marital counseling as an ecobehavioral approach to prevent child abuse.

A low-income family received in-home treatment after the mother expressed a desire to kill her daughter. The ecobehavioral approach focused on stress reduction of the frequency and duration of the mother's migraine headaches, on parent-child training, and on behavioral marital counselling. Follow-up data 1 yr after the beginning of services indicated maintenance of improvements in all areas. This was sufficient to terminate services. Also, the mother reported that she no longer had any negative feelings about her child, and the home environment lacked the stressors originally seen when the counselors began treatment. Finally, a consumer satisfaction questionnaire indicated a high level of satisfaction by the couple about the services offered by Project 12-Ways, an ecobehavioral approach to the treatment and prevention of child abuse and neglect.

Adult↗
PubMed1982

Dispermic origin and clinical outcome of three complete hydatidiform moles with 46,XY karyotype.

Three new cases of complete, classic hydatidiform mole with a 46,XY karyotype are described. They originated by dispermy as demonstrated by chromosome and enzyme analyses. Levels of human chorionic gonadotropin decreased to normal spontaneously within a short time, indicating a benign course in these three cases. Of a total of 18 cases reported to data, postoperative clinical information was available for 10 patients. Two of these 10 patients had a malignant course with lung metastases. It is of theoretical and clinical importance to establish the magnitude of the risk of malignancy for hydatidiform mole with a 46,XY karyotype.

Adult↗
PubMed1982

Urine and tissue oxalate and hippurate levels in ethylene glycol intoxication in the dog.

Oxalate, hippurate and ethylene glycol were measured in dogs given 5 ml/kg ethylene glycol orally. Eight hours after administration, oxalate levels were 7.2-9.1 ppm in renal tissue and 10-100 ppm in urine. Hippurate was 40-90 ppm in urine. Ethylene glycol was 10-100 ppm in renal tissue and 5,300-27,000 ppm in urine. The above substances were measured in urine and renal tissue from normal dogs, dogs in non-toxic renal failure and clinical cases of ethylene glycol intoxication. Urine was analyzed for ethylene glycol by gas chromatography using direct injection. Ethyl ether extraction provided good recovery of ethylene glycol from tissues and blood. Results were confirmed by gas chromatography/mass spectrometry (GC/MS). Oxalic acid (CA oxalate) was extracted with acidic methanol, methylated and analyzed by GC. Results were confirmed by GC/MS. Hippuric acid (calcium hippurate) was extracted with acidic methanol and chromatographed by thin layer chromatography (TLC). Ultraviolet spectrometry and mass spectroscopy were used to confirm the results. High performance liquid chromatography (HPLC) and TLC with densitometry were used to quantitate hippuric acid.

Animals↗
PubMed1981

[Hyperlipoproteinaemia during additional methenolone administration in the treatment of metastasizing carcinoma of the breast].

The effect of additive administration of methenolone oenanthate (Primobolan) on lipid metabolism was studied in 28 menopausal women with metastasizing carcinoma of the breast. In ten women hyperlipoproteinaemia type IIa was demonstrated in the course of treatment, while in two there was hyperlipoproteinaemia type IIb. One of the latter patients had a myocardial infarction in the course of treatment. There was no relationship between the level of hypercholesterolaemia and the methenolone dosage. Nor was it possible to classify the type of cholesterolaemia as a bile stasis syndrome. The hyperlipoproteinaemia regressed in every case once methenolone treatment was discontinued.

Bone Neoplasms↗
PubMed1981

Movement of antibody-coated latex beads attached to the spirochete Leptospira interrogans.

Antibody-coated latex beads (Ab-beads) were attached to Leptospira interrogans serovars illini 3055 and icterohaemorrhagiae SC1157. The movement of the Ab-beads relative to the motion of the cells was observed by direct darkfield microscopy or was recorded on videotape. When the Ab-beads were attached to the front end of motile cells, the Ab-beads were displaced towards the back end of the cells. When the cells reversed direction, the Ab-beads also reversed direction. A number of hypotheses were proposed and tested to account for this Ab-bead displacement. The one best supported by the evidence states that the Ab-beads are attached to antigens of the outer membrane sheath. These antigens are dragged laterally through the sheath due to the forward motion of the cells and the retarding forces of the medium acting on the beads. The results obtained provide information on the nature of the outer membrane sheath of L. interrogans, the basis for certain movements of spirochetes, and insight on how spirochetes attach to eukaryotic cells and tissues. In addition, the results indicate that antigens can move laterally through membranes as rapidly as 11 micrometers/sec.

Antibodies↗