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Biomedical subjects

B Hopkins

Publications and source records attributed to B Hopkins.

At least 73 records · Page 4Linked to original sources
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↗
PubMed1987

Identity of cells containing apolipoprotein B messenger RNA, in 6- to 12-week postfertilization human embryos.

Apolipoprotein B (Apo B) mRNA has been localized by in situ hybridization to various cell types in the liver, gut and yolk sack of the 6- to 12-week postfertilization human conceptus. In the fetal liver it is probable that the immature hepatocytes contain Apo B mRNA. In the yolk sack, the Apo B cDNA probe hybridizes mainly to the large endodermal cells and in the fetal gut the epithelium seems responsible for the majority of Apo B mRNA production. The fetal brain did not show any detectable hybridization to the Apo B probe. Unlike the situation seen in the adult, immunoprecipitation experiments demonstrated that only the B100 form of the protein was synthesized and secreted by the liver, gut and yolk sack at this early stage of human development.

Apolipoproteins B↗
PubMed1987

Postural and motor asymmetries in newlyborns.

Twelve full-term newlyborns were examined during wakefulness for head turning and maintenance of head position within the first hour after birth. Ten showed a rightward bias on both these measures. This is the youngest age since birth at which such lateralized functions have been reported. In all infants head position was strongly related to the hand which contacted the mouth but not with contacts to other parts of the face. The reason for this difference is discussed and it is suggested that head position and hand-mouth contacting may form a lateralized synergism which biases the development of handedness.

Dominance, Cerebral↗
PubMed1986

Developmental transformations of spontaneous movements in early infancy.

One component of the major transformation of neural functions at the end of the second postnatal month is concerned with a change in the appearance of general movements. These endogenously generated complex movements lose their writhing character and are replaced by a transient form, termed 'fidgety' movements. There are individual differences in the age of onset and duration as revealed by longitudinal observations. It is speculated that 'fidgety' movements may be related to a postnatal calibration of the proprioceptive system.

Aging↗
PubMed1986

Organ distribution of apolipoprotein gene transcripts in 6-12 week postfertilization human embryos.

In the liver and the yolk sack of 6-12 week postfertilization human embryos, we have detected RNA transcripts from the following apolipoprotein genes: AI, AII, B, CII, CIII and E. The mRNA from the apolipoprotein CIII gene was relatively more abundant in the total RNA from the yolk sack than in that from the liver. The gut and adrenals contained transcripts of all these apolipoprotein genes apart from apolipoprotein AII. The kidneys and heart contained some apolipoprotein transcripts. In conjunction with previous studies, these results suggest that in the human embryo apolipoprotein genes are transcribed in a much larger range of organs than is the case in the adult. Many of these organs lack endoderm tissues.

Apolipoprotein A-I↗
PubMed1985

Staring in infancy.

Staring in the infant is a condition of complete immobility typically accompanied by a lack of active posture. In 14 healthy infants seen in their homes from 3 to 18 weeks, it occurred for periods of 11-84 s in 2 situations: with infant alone lying supine and in face-to-face interaction with the mother. No clear heart rate and respiration patterns were noted during staring. Appearing when the infant is alone, questions a previous assumption that this condition serves to protect the immature infant from overstimulation. This neglected but well-defined condition needs to be considered in the context of the behavioural state concept.

Child Behavior↗
PubMed1985

Synthesis of apolipoproteins, alphafoetoprotein, albumin, and transferrin by the human foetal yolk sack and other foetal organs.

Fragments of human foetal organs and blood at 5-11 weeks of postfertilization development were cultured in radioactive protein precursors. The secreted products were characterized by immunoprecipitation, and by measuring the mobility of the immunoprecipitates on polyacrylamide gels. It was found that secondary human yolk sacks secreted apolipoproteins A1 and B. The work of previous authors on the synthesis of other serum products by this organ and by the foetal liver and by the foetal intestines was confirmed. Within the yolk sack, the endoderm, the blood cells, and the outside epithelium reacted with antibodies against apolipoprotein A1 and transferrin. By metabolic labelling of umbilical cord blood, it was found that blood did not secrete apolipoproteins A1 and B. Blood cells could therefore not be a source of these secreted products.

Albumins↗
PubMed1984

Cloned human teratoma cells differentiate into neuron-like cells and other cell types in retinoic acid.

Single cell clones were isolated from the human teratoma line, Tera-2. The cells of three of these clones were studied. The progressively growing cells were shown to be tumorigenic, and they were characterized by the lack of expression of beta 2-microglobulin and HLA-A,B,C determinants on the cell surface. The majority of the cells expressed Thy-1 antigen and a 90 X 10(3) molecular weight protein recognized by the monoclonal antibody F10.44.2; between a third and half of the cells expressed the sugar specificities detected by the anti-SSEA-1 monoclonal antibody. In response to 5 X 10(-5) M-retinoic acid applied to cells in monolayer culture, the cells differentiated into a population of flat static cells arrested in the G1 phase of the cell cycle. A substantial proportion of these differentiated cells expressed beta 2-microglobulin and 43 X 10(3) molecular weight HLA-A,B,C polypeptides, Thy-1, SSEA-1 sugar determinants, and the 90 X 10(3) Mr protein recognized by F10.44.2. The apparent molecular weight of fibronectin secreted by the cells decreased by about 5 X 10(3) Mr to 235 X 10(3) Mr after differentiation. The progressively growing cells lacked reactivity with reagents that mark cells in the nervous system. Following aggregation and retinoic acid treatment, neuron-like cells were formed. These cells reacted with reagents that also react with human neurons in culture: they reacted with tetanus toxin, the anti-neurofilament antibodies BF10 and RT97, the anti-ganglioside, GQ1c antibody F12 A2B5, and anti-Thy-1. The progressively growing cells of these Tera-2 clones are therefore capable of forming at least two types of cell: the flat cells in monolayer cultures and the neuron-like cells. None of the cell populations reacted with the monoclonal antibody against SSEA-3 and these cloned cells are therefore distinct from previous isolates from Tera-2.

Animals↗