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Biomedical subjects

C Hayward

Publications and source records attributed to C Hayward.

137 records · Page 8Linked to original sources
PubMed1980

Effect of gamma radiation on the molecular weight and the anticoagulant activity of heparin.

4 g% aqueous solutions of heparin were irradiated with the gamma radiation doses of 4.6 x 10(5) or 9.2 x 10(5) rads. The irradiated and also the non-irradiated heparin samples were fractionated using a Sephadex G-200 column. With radiation, the peak of the molecular weight distribution curves shifted toward the lower molecular weight. Also, the number average molecular weight decreased by 8.2 and 11.5% with the doses of 4.6 x 10(5) and 9.2 x 10(5) rads, respectively. The anticoagulant activity depended on the molecular weight of the heparin fractions. For the heparin fractions with molecular weights below 7,900, the anticoagulant activity decreased with radiation. Thus, for a heparin fraction with a molecular weight of 6,200, the anticoagulant activity decreased from 211 to 198 IU/mg after 4 h of irradiation.

Blood Coagulation↗
PubMedDate not supplied

Amniotic fluid microvillar enzyme activities in the early detection of fetal abnormalities.

Measurement of the microvillar enzymes, gamma-glutamyltranspeptidase (GGTP), aminopeptidase M (APM) and alkaline phosphatase (ALP), in amniotic fluid supernatant has been proposed as a method for the early prenatal diagnosis of cystic fibrosis. The activities of these enzymes in a series of other fetal abnormalities have now been examined. GGTP activities were below the 5th percentile in 28 out of 54 cases of trisomy 21 and 9 of 14 cases of trisomy 18, while APM values were below this cut-off in 26 of 54 cases of trisomy 21 and 8 of 14 cases of trisomy 18. Abnormal ALP isoenzyme ratios were found in 6 of 54 cases of trisomy 21 and 4 of 14 cases of trisomy 18. If prenatal cytogenetic studies are routinely carried out on amniotic fluid cells, the occasional confounding effect of abnormal microvillar enzymes associated with fetal trisomies rather than with cystic fibrosis should be avoided.

Alkaline Phosphatase↗
PubMedDate not supplied

Predicting onset of drinking in a community sample of adolescents: the role of expectancy and temperament.

We report results of a prospective examination of the influence of outcome expectancy variables and inherited temperaments on the onset of drinking over a 12-month period in a sample of 1,164 high school students. While univariate prospective analysis indicated that drinkers and nondrinkers were different both on measures of outcome expectancy and temperament, multivariate analysis supported, most strongly, a social learning account of the processes influencing the onset and maintenance of drinking behavior in this sample. The multivariate analysis revealed that only expectancies for enhanced social behavior were consistently associated with the onset of drinking from baseline to 12-month follow-up (p < .001). Among all nondrinkers at baseline, those entertaining higher expectancies about the positive effects of alcohol on social interaction were more likely to begin drinking between baseline and follow-up. At present, few, if any, alcohol abuse prevention studies with adolescents have explicitly attempted to alter alcohol expectancies or to establish a link between expectancy and behavior change. Our results suggest that it may be useful to do so.

Adolescent↗
PubMedDate not supplied

Severity of child maltreatment, pain complaints and medical utilization among women.

High medical utilization in adults has been linked to both reported history of childhood abuse and mental health problems. However, few studies have explored relationships between abuse severity and psychological distress to identify subgroups with unique utilization patterns and medical complaints. This study compared two groups of psychologically distressed, high utilizers. One group (DS) was comprised of those with psychological distress, who reported a history of child sexual abuse (CSA); the other group (DSP) consisted of those with psychological distress, who reported CSA plus a history of childhood physical abuse. The groups were compared on severity of sexual and nonsexual child maltreatment, medical complaints and medical utilization. From a convenience sample of 206 females age 20-63, recruited while waiting for a physician appointment in a primary care clinic, we compared 25 DSPs to 33 DSs. Compared with DSs, DSPs reported significantly more severe: (1) sexual abuse including completed intercourse; (2) emotional abuse; (3) emotional neglect; and (4) psychological distress. DSPs also showed a nonsignificant trend towards more severe physical neglect. In addition to being significantly higher on emergency room visits, DSPs were marginally higher than DSs on nonpsychiatric outpatient visits. DSPs had significantly more frequent chronic and acute pain complaints at emergency room (ER) visits. Headaches were the most frequently coded diagnosis at ER visits in this sample. DSPs accounted for 89% of these ER visits attributable to headaches. The interaction of psychological distress and reported severity of child maltreatment reveals subgroups with unique utilization patterns and medical complaints. Physicians should screen patients for child maltreatment severity and psychological distress and should be involved in mental health referral where necessary.

Adult↗
PubMedDate not supplied

Assessment and phenomenology of nonclinical panic attacks in adolescent girls.

Recent reviews of studies concerning panic attacks in adolescents have emphasized research limitations, noting problems of validity, reliability, and lack of normative data. To address some of these limitations we evaluated two methods of panic ascertainment (questionnaire versus interview), reliability of interview-determined panic, and clinical correlates of panic symptoms in a large sample (N = 1013) of early adolescent girls. The 5.4% of the sample who, when interviewed, reported ever experiencing a panic attack scored significantly higher on measures of depression, anxiety sensitivity, and alcohol use, but were not more avoidant than others. Using the interview as the standard, the questionnaire had a specificity of 81% and a sensitivity of 72%. Adolescents do experience panic attacks-whether identified by questionnaire or interview-although for many the attacks may not be salient. Longitudinal studies are required to determine those qualities of nonclinical panic (severity, context, interpretation/attribution), which render some episodes as clinically meaningful.

Adolescent↗
PubMedDate not supplied

Tissue localization and chromosomal assignment of a serum protein that tracks the cystic fibrosis gene.

The basic gene defect in the autosomal recessive disorder cystic fibrosis has not been identified, and no firm linkage of the disorder to any other marker has been reported. However, a serum protein abnormality present in unaffected heterozygotes as well as in affected homozygotes has been described, and immunological quantitation of this protein, termed cystic fibrosis antigen, allows the three genotypes to be distinguished. We show here that an immunologically indistinguishable protein is present at high concentrations in granulocytes from normal and cystic fibrosis individuals as well as in myeloid leukaemia cells. Somatic cell hybrids between the mouse myeloid stem-cell line WEHI-TG and myeloid leukaemia cells express cystic fibrosis antigen only when human chromosome I is present.

Blood Proteins↗
PubMedDate not supplied

Influence of antenatal ultrasound on the management of fetal exomphalos.

OBJECTIVE: To determine the influence of antenatal ultrasound on the management of exomphalos. METHODS: Retrospective case note review of 23 fetuses and infants referred to our institution with either a pre- or postnatal diagnosis of exomphalos over a 7-year period. RESULTS: There were 21 cases of exomphalos of which 18 were correctly diagnosed on antenatal ultrasound by 18 weeks' gestation. There were 2 false-positives and 3 false-negatives, including 1 case of amniotic band syndrome with an abdominal wall defect and 1 morphologically normal fetus. Associated anomalies were correctly identified in 12 but incorrectly reported in 8. Maternal serum alpha-fetoprotein levels were abnormal in 61% of cases of abdominal wall defects in this series. Amniocentesis was performed in 12 and cordocentesis in 1. There were 13 terminations, including 2 trisomy 18s and 1 trisomy 13. Two fetal deaths followed amniocentesis. Of the 10 live births, 9 had their exomphalos repaired with a 1-year survival rate of 89%. Prenatal diagnosis did not appear to influence outcome. CONCLUSIONS: Antenatal ultrasound diagnosed 86% of cases of exomphalos and correctly reported 67% of associated anomalies. Amniocentesis may have led to the death of 1 morphologically normal fetus.

Abortion, Eugenic↗