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Biomedical subjects

B Hopkins

Publications and source records attributed to B Hopkins.

At least 19 recordsLinked to original sources
PubMed1994

Prematurity, posture and the development of looking behaviour during early communication.

This study concerns the developing relationship between motor control and looking behaviour in full term (N = 15) and pre-term (N = 29) infants during face-to-face interaction with the mother at 6, 12 and 18 weeks of corrected age. Infants with inborn errors or major medical complications were excluded. In the pre-term infants the development of head and arm postures during interaction differed from the full term pattern, especially in infants born before 32 weeks and/or small-for-gestational age. The full term infants were more advanced than other infants in the ability to grasp an object. These findings were related to group differences in looking behaviour, suggesting that differences in the development of looking behaviour may be (partly) accounted for by differences in the development of motor control.

Communication↗
PubMed1992

A method to assess the development of muscle power in preterms after term age.

The purpose of this paper is to report a detailed description of an instrument for evaluating the development of active and passive muscle power in preterms beyond term age. The instrument is constructed on a basis of age-specific items that assess these two components of muscle power and on the assumption that a persistent discrepancy between them serves to detect those preterms at most risk for disturbances in motor development. The application of the instrument is illustrated by reporting the individual trajectories of five case studies without any serious medical complications. It is concluded that if a marked discrepancy between active and passive power persists beyond the corrected age of 3 months, then this may be a sign of underlying pathology which will eventuate in abnormal postural outcomes and thereby disturbances in the control and coordination of movement. Having now provided a detailed description of how this instrument should be applied in postterm follow-up of preterm infants, we are currently examining its sensitivity and specificity on a much larger sample of similar subjects.

Age Factors↗
PubMed1992

Development of the relationship between active and passive muscle power in preterms after term age.

Fifty-eight infants were assessed with an instrument which is designed to evaluate the development of the relationship between active and passive muscle power. The purpose of this longitudinal assessment was to investigate whether preterms show a different development course than fullterms in the relationship between these two components of muscle power. Thirty-seven low-risk preterms and twenty-one healthy fullterms were followed from term until 24 weeks corrected age. It is concluded that preterms differ markedly from fullterms in the developing interrelationship between active and passive muscle power. The value of the instrument for detecting signs of early pathology is discussed.

Age Factors↗
PubMed1992

Training supervisors in a collaborative team approach to promote peer interaction of children with disabilities in integrated preschools.

Three supervisors of integrated preschools were trained in a collaborative team approach to encourage resource and classroom teachers to develop strategies that promote peer interaction of all children, including children with disabilities. The focus of classroom teachers' behaviors and the interactive play of children with disabilities were measured daily in both a training (indoor play period) and a generalization (outdoor play period) setting. In a multiple baseline design, supervisors were individually trained in a collaborative team approach using a manual, modeling, and role playing; then they implemented the approach with classroom and resource teachers. We found that after supervisor training, classroom teachers increased their behaviors directed towards children with disabilities and decreased their behaviors directed towards nondisabled children. Moreover, we found a doubling of the interactive play of children with disabilities and, for two of the three classes, an increase in the interactive play of comparison children, randomly selected by the classroom teachers. Changes in both teachers' and children's behaviors were also found in the generalization setting. The implications of the results for interventions in community settings are discussed.

Child Behavior Disorders↗
PubMed1991

Isolation and characterisation of the human lung NK-1 receptor cDNA.

Functional cDNA clones for human NK-1 receptor were isolated from human lung RNA using the polymerase chain reaction (PCR). We have screened a human cosmid library and isolated a clone which appeared to contain the entire NK-1 receptor gene. From the published rat NK-1 receptor cDNA sequence we designed primers within the protein coding sequence, but outwards towards both the 5' and 3' ends of the putative human protein sequence. By this method we derived DNA sequence from the 3' end of the human gene. In order to determine the 5' end of the gene we used a PCR based method called Rapid Amplification of cDNA Ends (RACE). From the derived human sequences amplimers were designed upstream of the ATG initiation codon and downstream of the stop codon. The entire cDNA was obtained by RNA-PCR from human lung RNA. The sequence obtained was 407 amino acids in length, encoding an open-reading frame that was highly homologous to the rat NK-1 receptor cDNA (89%). The entire human cDNA was then cloned into a mammalian expression vector and mRNA was synthesized by in vitro transcription. Applications of tachykinins caused membrane current responses in Xenopus oocytes injected with the in vitro synthesized mRNA. The most potent of the three tachykinin peptides tested was Substance P. The human NK-1 receptor gene has been mapped to chromosome 2 using the polymerase chain reaction to specifically amplify the human sequence in hamster/human hybrid DNA and also in mouse/human monochromosome hybrids.

Aged↗
PubMed1991

Isolation and characterisation of the human lung NK-2 receptor gene using rapid amplification of cDNA ends.

Functional cDNA clones for human NK-2 receptor were isolated from human lung RNA using a polymerase chain reaction (PCR) based method (RACE-PCR). In this method the cDNA was isolated as 5' end and 3'-end fragments; the entire cDNA was obtained by RNA-PCR. The sequence derived was 398 amino acids in length encoding an open-reading frame that was highly homologous to both the bovine and rat NK-2 receptor. The entire human cDNA sequence was cloned into a mammalian expression vector and mRNA was synthesised by in vitro transcription. Applications of tachykinins caused membrane current responses in Xenopus oocytes injected with the in vitro synthesised mRNA. The most potent of the three tachykinin peptides tested was neurokinin A. We have screened a human cosmid library and isolated a clone which contains the entire NK-2 receptor gene. The gene contains five exons and we have determined the complete sequence of the exons and the intron-exon junctions.

Aged↗
PubMed1991

Human NK-2 receptor gene maps to chromosome region 10q11-21.

The human NK-2 receptor gene has been mapped to chromosome 10 using the polymerase chain reaction to amplify specifically the human NK-2 receptor sequence in hamster/human hybrid DNA and also in mouse/human monochromosome hybrids. The assignment to chromosome 10 was confirmed by in situ hybridisation to human metaphase chromosomes, giving a regional localisation of 10q11-21.

Base Sequence↗
PubMed1991

Use of DNA fingerprinting in paternity analysis of closely-related Exmoor ponies.

DNA fingerprinting techniques were used to try to resolve the parentage of an Exmoor pony foal. Three young Exmoor ponies, one female and two males, shared a paddock and the female subsequently became pregnant. The two possible sires were three-quarter siblings and were also half-siblings to the dam. Southern hybridisation of Exmoor pony DNA with human mini-satellite probes resolved the disputed parentage in spite of the fact that there was a 70 per cent band share between the individuals involved. Colt M6 was 2.06 times more likely to be the father than an uncle, and Colt M3 was 477 times more likely to be an uncle than the father.

Animals↗
PubMed1991

Severity of growth retardation and physical condition at birth in small for gestational age infants.

Ponderal index divides small for gestational age (SGA) infants into two categories, based upon proportional and disproportional growth retardation. The latter group supposedly suffered from unfavorable intrauterine conditions. The aim of the study was investigation of the value of the ponderal index in the discrimination of underlying fetal disorders and its dependency upon the severity of the intrauterine growth retardation (IUGR). In a cohort of 142 SGA infants we found 12 newborns with congenital anomalies; most of the newborns were disproportionally small. Fourteen newborns expired in the Neonatal Intensive-Care Unit for various reasons, in general not directly related with the IUGR. All of them were disproportionally small. The newborns were divided into two groups according to the severity of IUGR. Proportionality was independent of this severity, indicating that most SGA fetuses remain disproportionally small during long-standing IUGR. It is likely, however, that the proportionally small ones adjust better to the poor intrauterine conditions, since they all survived.

Apgar Score↗
PubMed1990

Development of head position preference during early infancy: a longitudinal study in the daily life situation.

We studied developmental changes in supine head position preference in a group of 14 healthy full-term infants from age 3 to 18 weeks. The infants assumed an initial head-right position until 12 weeks. For the maintenance of a head position, a loglinear analysis revealed a developmental trend from an initial head orientation to the right to one with the head in the midline at around 12 weeks. The maintenance of a midline head position was preceded by a marked improvement in postural stabilization, defined as the ability to hold the head upright when seated in an infant chair. The relationship between head position preference and behavioral state changed with age: At 3 weeks all infants maintained the same position regardless of state, but by 18 weeks this situation held for only 64% of those who cried. The implications of these findings for the development of handedness are discussed.

Follow-Up Studies↗
PubMed1990

Information statistics as applied to social interaction between mother and infant: synergic covariability vs. partial cross-covariability.

Behaviour can, in general, not be quantified on an equal-interval scale; therefore, the description of sequential aspects of the behaviour of two interacting individuals can not be formulated on the basis of the usual cross-correlation techniques. If the information content of behaviour, however, is defined analogously to the entropy in a message, this allows a quantification of the contribution of either participant to the interaction process, and the identification of a non-additive (synergic) component in addition to the auto- and cross-covariability terms. Such a framework, based on the concept of transinformation or mutual information, was developed and realised in a suite of three FORTRAN programs. These were then applied in a longitudinal study on the development of early mother-infant interaction. The synergic term appears to increase with age in the first five months of life. This application illustrates the usefulness of information statistics for quantifying the ways in which participants contribute to a process of interaction.

Data Interpretation, Statistical↗
PubMed1989

Maternal expectations of their infants' development: some cultural differences.

A total of 124 mothers from three cultural groups living in the same British city were asked to give the ages at which they expected their one-month-old infants to achieve three motor milestones. Jamaican mothers expected their infants to sit and walk much earlier than their English and Indian counterparts. The Indian mothers gave later estimates for crawling than those of the other two groups. The actual ages at which the abilities were attained closely reflected the cultural differences in expectations between the Jamaican and English mothers. Jamaican mothers were particularly accurate in predicting sitting age. These results are discussed in relation to cultural theories of child development, together with their implications for child health in multicultural societies.

Child Development↗
PubMed1988

Quieting during early infancy: evidence for a developmental change?

The ability to terminate crying (quieting) without intervention was studied from 0 to 18 weeks. Two groups were involved: 11 newborns during the first hour after birth and a longitudinal group of 14 infants seen every 3 weeks from 3 to 18 weeks. Most newborns who cried showed quieting with and without hand-mouth contacting. In the longitudinal group quieting with hand-mouth contacting appeared for the first time at 9 weeks (quieting without hand-mouth contacting being present from 3 weeks). Quieting with hand-mouth contacting was frequently accompanied by hand chewing/sucking. Explanations for the disappearance in quieting with hand-mouth contacting and its reappearance at 9 weeks concern changes in movement and posture. Explanations based on notions of intentionality in quieting were not supported by the data.

Behavior↗
PubMed1988

Insulin-like growth factors and the multiplication of Tera-2, a human teratoma-derived cell line.

A human teratoma cell line (Tera-2) was grown in serum-free medium, and the population multiplication was stimulated by the addition of somatomedins/insulin-like growth factors (IGFs). Both IGF-I and IGF-II gave maximal stimulation when added daily at 10 ng ml-1. The IGFs did not substantially change the labelling index of the cells, and the IGFs appeared to exert their effect on population multiplication by increasing cell survival. Membranes isolated from Tera-2 cells displayed both type 1 and type 2 IGF receptors.

Cell Division↗
PubMed1988

Maternal handling and motor development: an intracultural study.

Citing a distinction between informal and formal routines used by mothers in handling their infants, we examined formal handling routines, in which the caregiver acts in a pedagogical manner; these routines are widespread in many non-Western countries. We hypothesised that formal handling serves to facilitate gross motor development during early infancy. To examine this hypothesis, the effects of a Jamaican formal handling routine on a broad range of developmental outcomes was examined. Results showed that the effects were specific to early gross motor development and in particular to postural control along the vertical axis of the body. Information is also provided on other aspects of Jamaican child care. It seems that the handling routine forms part of a folk (developmental) medicine system and may serve not only to promote child health but also as a sort of developmental neurological examination.

Adolescent↗
PubMed1987

The development of the crying state during early infancy.

The development of the crying state was studied in 14 infants from 3 to 18 weeks in two situations: the infant alone and in interaction with the mother. A major transformation occurred in the crying state after 3 months, with the appearance of what is termed interrupted fussing, which consists of rapid alternations between fuss sounds and cooing vocalizations. This change was only found in the alone situation. The functional implications of this finding are discussed within the contexts of motor development and the behavioral state concept.

Child Development↗
PubMed1987

Expression of growth regulatory genes in primary human testicular neoplasms.

Seven testicular tumours of different histological type--two seminomas, two teratomas/teratocarcinomas/embryonal carcinomas, one mixed seminoma/teratoma, one Leydig cell tumour and one testicular lymphoma--were examined for the expression of four potentially growth regulatory genes by Northern blotting. Seven out of seven testicular tumours contained transcripts that hybridized with a human insulin cDNA-probe whereas only four out of seven tumours contained IGF II transcripts. One tumour contained high levels of LDL-receptor transcript whereas all seven tumours contained significant quantities of HMG-CoA-reductase mRNA.

DNA↗