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Biomedical subjects

J Stevenson

Publications and source records attributed to J Stevenson.

At least 181 records · Page 10Linked to original sources
PubMed1988

Research note: recurrent headaches and stomachaches in preschool children.

Data are presented on headaches and stomachaches in a sample of 189 3-year-old children obtained as part of community based study. These data provide a partial replication of an earlier study on a separate sample of children [Zuckerman, B., Stevenson, J. and Bailey, V. (1987). Stomachaches and headaches in a community sample of preschool children. Pediatrics, 79, 677-682]. The results supported the previous findings of a link between family factors and recurrent stomachache, and a less strong association with headaches. The conclusions reinforce the notion that these two somatic symptoms should be considered separately in preschool children.

Child Development↗
PubMed1987

Plasma-free homovanillic acid: within- and across-day stability in children and adults with Tourette's syndrome.

Within- and across-day stability of plasma-free homovanillic acid (pHVA) was assessed in children and adults with Tourette's syndrome. A diurnal fall in pHVA was observed in 13 of 15 subjects. There was a small but significant (p less than .0001) decrease (8%) in mean morning pHVA levels obtained just 20 minutes apart (8:30 A.M. and 8:50 A.M.). A substantial and significant (p less than .001) mean decrease in pHVA (25%) was observed when samples obtained between 8:00 and 8:30 A.M. were compared with samples obtained at 12:00 noon. Changes in pHVA levels observed during the afternoon (between 12:00 noon and 4:00 P.M.) were small, nondirectional, and nonsignificant. Repeated measurement of morning pHVA in the same individual after 24 or more hours revealed marked increases or decreases in many individuals, suggesting that morning pHVA is not a stable measure. The results of this and previous studies suggest that pHVA obtained at 12:00 noon or later in the day may be a more reliable measure of centrally produced HVA. Further studies are needed regarding the stability of pHVA over time.

Adolescent↗
PubMed1987

Replacement of transferrin in serum-free cultures of mitogen-stimulated mouse lymphocytes by a lipophilic iron chelator.

Proliferation of mouse lymph node lymphocytes in response to concanavalin A in serum-free medium is normally dependent upon the presence of transferrin. In the absence of transferrin, little proliferation occurred, but the response was restored by addition of the iron complex of pyridoxal isonicotinoyl hydrazone (FePIH), a lipophilic iron chelator. Since cellular acquisition of PIH-bound iron is known not to involve the transferrin receptor, these results indicate that transferrin promotes lymphocyte proliferation solely because of its iron-donating properties, and does not provide any additional signalling event for proliferation.

Animals↗
PubMed1987

Temperament and psychiatric disorder: the genetic contribution to behaviour in childhood.

The studies stemming from the New York longitudinal study of temperament in childhood are summarised and conceptual difficulties and problems arising from them are described. An alternative model of temperament provided by Buss and Plomin is also considered. Finally, a new typology of temperament is proposed. It is based on the suggestion that ordinary, non-pathological behaviours, in extreme form, can be viewed as manifestations of emotional disorder, hyperactivity and antisocial disorder. Empirical evidence derived both from twin studies and from epidemiological investigations is put forward to support this view.

Child↗
PubMed1987

A twin study of genetic influences on reading and spelling ability and disability.

The reading skills of 285 pairs of 13-year-old twins drawn from the general population were studied. The twins were independently tested using standardized measures of intelligence, reading and spelling ability. The genetic contribution to reading ability was assessed by examination of correlations in monozygotic (MZ) and same-sex dizygotic (DZ) twins, and by analysing differences between MZ and DZ twins in concordance of reading disability rates. The results suggested that, at this age, genetic factors play only a moderate role in general reading backwardness or specific reading retardation. However, when spelling ability was investigated, a heritability of 0.53 was obtained, increasing to 0.75 when intelligence was controlled. Strong genetic influences on spelling were also found when concordance rates for spelling disability were compared for MZ and DZ pairs.

Adolescent↗
PubMed1987

Stomachaches and headaches in a community sample of preschool children.

The epidemiology of recurrent stomachache and headache was studied in a community sample of 308 preschool children, most of whom were white. When the children were 3 years old, interviews with their mothers indicated that 3% had recurrent headaches and 9% had recurrent stomachaches. Children with recurrent stomachaches were more likely than those without recurrent stomachaches to have mothers who were emotionally depressed (P less than .01), had marital problems (P less than .05), and perceived their own health as poor (P less than .05). When maternal poor health was controlled, depression was still associated with their children having stomachaches (P less than .05). Prospectively collected data demonstrate that children with recurrent stomachaches did not have bowel difficulties when they were infants. Other psychosocial stresses and demographic factors were not associated with stomachaches. The only variable associated with recurrent headache was maternal depression. Children with recurrent headaches or stomachaches were more likely to have behavior problems, as measured by the Behavior Screening Questionnaire, than were children without these symptoms. The analysis presents new data on these common symptoms of childhood.

Abdomen↗
PubMed1987

Sleep problems in early childhood: continuities, predictive factors, and behavioral correlates.

A longitudinal study, based on interviews with 308 middle-class, preponderantly white mothers, provided an opportunity to evaluate the continuity, predictive factors, and behavioral correlates of sleep problems in young children. When their children were 8 months old, 10% of the mothers reported that their babies woke three or more times per night, 8% reported that the babies took an hour or more to settle after waking, 5% complained that their own sleep was severely disrupted by the child, and 18% reported at least one of these problems. At 3 years of age, 29% of the children had difficulty getting to bed and/or falling asleep or staying asleep. Of children with a sleep problem at 8 months of age, 41% still had a problem at 3 years of age, whereas only 26% of children without a problem at 8 months of age had a problem at 3 years of age (P less than .001). Among children with sleep problems at 8 months of age, mothers' depressed feelings were the only measured demographic or psychosocial factor associated with persistent sleep problems (P = .02). A separate analysis indicated that these depressed feelings did not appear to be a consequence of the child's sleep problem. Future studies should evaluate how maternal depression interacts with other factors to result in persistent sleep problems. Children with persistent sleep problems were more likely to have behavior problems, especially tantrums (P less than .02) and behavior management problems (P less than .01), than were children without persistent sleep problems (P less than .02).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

The effect of iron and agar on production of hydrogen peroxide by stimulated and activated mouse peritoneal macrophages.

The effect of iron on H2O2 production by mouse peritoneal macrophages exposed to opsonised zymosan has been investigated. Macrophages elicited with thioglycollate broth produced less H2O2 than macrophages activated by Corynebacterium parvum, and levels were not affected by prior incubation of the cells with 0.1 mM iron nitrilotriacetate. However, preincubation with the iron chelator desferrioxamine (1 mM) reduced H2O2 production by both types of macrophages. Incubation of macrophages with agar, a component of thioglycollate broth, also reduced H2O2 production, particularly by C. parvum-activated macrophages. The results indicate that although iron appears to be necessary for H2O2 production by macrophages, the low level of production by thioglycollate-elicited macrophages is not due to an inadequate level of metabolically utilisable iron, but may be a result of prior ingestion of agar present in the broth.

Agar↗
PubMed1986

Growth hormone-binding proteins in high-speed cytosols of multiple tissues of the rabbit.

Soluble, specific binding protein(s) for growth hormone (GH) have been identified and partially characterized in high-speed cytosolic preparations from a number of rabbit tissues. The binding of 125I-labelled human GH to proteins in liver, heart, adipose tissue, skeletal muscle and kidney cytosols was dependent on time and cytosolic protein concentration. By Scatchard analysis, the binding affinities (KA: (2-7) X 10(9) M-1) were somewhat higher than those generally reported for membrane GH receptors. The binding proteins had a greater specificity for somatotrophic hormones than lactogenic hormones, although the kidney appeared to have, in addition, a lactogen-binding protein. By gel filtration, the Mr of the cytosolic GH-binding protein was approximately 100 000 in all tissues. None of the binding proteins was detectable by the poly(ethylene glycol) precipitation method used widely for soluble hormone receptors. The cytosolic GH-binding proteins also cross-reacted with a monoclonal antibody to the rabbit liver membrane GH receptor. These results indicate the ubiquitous presence of apparently naturally soluble GH-binding proteins in the cytosolic fractions of several tissues in the rabbit. Of great interest is their presence in muscle, where GH receptors or binding proteins have not previously been detected, despite muscle being recognized as a classical GH target tissue.

Adipose Tissue↗
PubMed1986

Calcitonin gene-related peptide: a potent dilator of human epicardial coronary arteries.

To investigate the action of calcitonin gene-related peptide (CGRP) on human epicardial coronary arteries, six patients received intracoronary CGRP at doses of 50,100, and 200 ng/min. The effect of CGRP was measured angiographically with a computerized analysis system. A dose-dependent increase in coronary arterial diameter was observed. At the highest dose there were 34%, 7%, 38%, and 40% mean increases in the diameters of the circumflex, proximal, mid, and distal left anterior descending arteries, respectively. No further increase in diameter was found after a subsequent dose of 1 mg intracoronary isosorbide dinitrate. Prior infusion of CGRP did not prevent coronary arterial spasm induced by ergonovine in two patients with variant angina, but a subsequent bolus of CGRP partially relieved the spasm. We propose that CGRP has a role in the regulation of coronary vascular smooth muscle tone.

Angina Pectoris↗
PubMed1986

Identification and characterization of specific binding proteins for growth hormone in normal human sera.

The well-recognized "big" forms (45,000-100,000 mol wt) of immunoreactive human growth hormone (hGH) in human serum have been reported to be random aggregates or formal polymers. However, we have now investigated the possibility that they are protein-bound forms. After incubation of monomeric 125I-hGH with normal serum, gel chromatography indicated a peak of bound 125I-hGH (at approximately 120,000 mol wt), which was completely displaced by excess unlabeled hGH. When serum alone was chromatographed two peaks of specific binding were subsequently detected, the major peak, eluting between 74,000 and 85,000 mol wt corresponded to the 125I-hGH-binding protein complex observed at approximately 120,000 mol wt. Using a mini-gel filtration system for separating bound from free hormone, binding of 125I-hGH by normal human serum was dependent on time (equilibrium was reached in 2 h at 21 degrees C), temperature (21 degrees C greater than 37 degrees C), Ca2+ and serum concentrations. Binding was reversible and highly specific for hGH, not being displayed by GH or prolactins from several species. Scatchard analysis revealed linear plots with an affinity (KA) of 0.32 +/- 0.06 X 10(9) M-1 (n = 7). Human serum with low endogenous hGH levels, when added to rabbit liver membranes, decreased the binding of 125I-hGH in this tissue in a dose-dependent manner. These data indicate that human sera contain a specific, high affinity binding protein for hGH and that this may account, at least in part, for the known size heterogeneity of GH in serum. Its effect on GH binding to target tissues may indicate a role for the binding protein in the regulation of GH action.

Animals↗
PubMed1986

Characterization of a soluble prolactin-binding activity in rat liver cytosol.

Soluble binding activity for lactogenic hormones has been detected in high-speed cytosolic preparations from the livers of 21-day-old male and female rats. No lactogenic hormone binding was detected in cytosols from rat heart, kidney, skeletal muscle or adipose tissue. Liver cytosol binding of 125I-labelled human growth hormone or ovine prolactin was dependent on time, temperature, and protein and calcium concentrations. Binding was specific for lactogenic hormones and not somatotrophic hormones. Scatchard analysis revealed linear plots with an affinity of 2.9-4.6 litres/nmol. By gel filtration the molecular weight of the lactogen-binding activity was greater than 450,000. The cytosolic binding activity may be an internalized form of the membrane-bound lactogen receptor, which has similar binding characteristics, or alternatively it may be a distinct binding species, with a defined role in mediating intracellular effects of prolactin in the liver.

Animals↗
PubMed1985

Behaviour problems and language abilities at three years and behavioural deviance at eight years.

A representative sample of 535 children were followed up from their third to their eighth birthday using measures of language ability and behaviour. At age 8 yr it was found that there were significantly more boys with behavioural deviance than girls, and that children from manual social class backgrounds also showed more behavioural deviance. The only difference between the immigrant and non-immigrant children was a less frequent occurrence of neurotic deviance in the immigrant group. It was found that behaviour problems at age 3 yr were strongly related to behavioural deviance at school at age 8 yr, particularly for boys. This medium-term stability in behaviour problems had not been found in previous studies looking at younger children. A low score on a measure of language structure at age 3 yr was found to be related to a high rate of neurotic deviance at age 8 yr even when behaviour at age 3 yr was controlled. The implications of these findings for the early identification and intervention with children at risk for later behaviour deviance are discussed.

Antisocial Personality Disorder↗