Search PubMed⌕ Search

Biomedical subjects

A Scott

Publications and source records attributed to A Scott.

At least 253 records · Page 14Linked to original sources
PubMed1986

Proportionality of small-for-gestational age babies at birth: perinatal associations and postnatal sequelae.

Head and chest circumference and crown-rump length measurements were obtained for 413 small-for-gestational age (SGA) infants at birth; and head-chest, head-crown-rump and chest-crown rump ratios derived. There was an inverse correlation between head-chest ratios and gestational age, and boys had higher ratios than girls. First-born infants, and those whose mothers had pre-eclampsia had higher ratios than the rest, and higher ratios were associated with instrumental delivery. Higher ratios were also found for girls (but not boys) born to women of above average weight, and those who suffered birth asphyxia or other problems in the neonatal period. When adjustment was made for confounding between variables gestational age and sex were the only factors making a significant contribution to the variance in head-chest ratios at birth. SGA babies with relatively high head-chest ratios at birth grew faster than those with lower ratios during the first 6 mth of life. Girls with above-average ratios were heavier and had larger heads at the age of 7 yr, but no differences were found for either sex in any aspect of developmental ability at 7 yr associated with head-chest ratios at birth.

Anthropometry↗
PubMed1986

Growth and proportionality in early childhood. III. Differences between babies of low birthweight in well-nourished and malnourished populations.

The growth patterns from birth to 7 yr of four groups of children are compared. They comprise: small-for-gestational age children in a highly favoured community born to (A) short mothers, (B) mothers of average height for their population; Guatemalan children living in a community where mild to moderate protein-calorie malnutrition was endemic. Data on a sample of children whose birthweights covered the normal range for gestational age were used as reference standards. At all ages and for almost all measures they were significantly larger than children in the other three groups. No differences were found between the boys in groups A and B; but girls in group A were lighter and shorter from 18 mth onwards. The Guatemalans were shorter and had smaller heads than group A from 12 mth onwards; and the boys were also lighter. No differences were found between the Guatemalans and group A for chest circumference in either sex from 2 yr onwards. Deficits in size at 4 yr of the Guatemalans compared with the Reference Sample ranged from 8.8% for stature, 6.8% head circumference, 5.9% weight, down to 3.9% for chest circumference. The differences between the four groups may broadly be taken to represent those due to low birthweight for gestational age, lower genetic potential, postnatal malnutrition, and their cumulative effects. Our findings offer a new perspective on their varying contributions to growth in size and shape during early childhood.

Body Height↗
PubMed1986

Quantitative structural studies on placentas from pregnancies complicated by diabetes mellitus.

Fourteen placentas from pregnancies complicated by insulin-dependent diabetes mellitus have been examined by quantitative morphometry. The results have been compared with those from 22 placentas of comparable gestation from uncomplicated pregnancies. The volume of parenchymatous tissue in the placentas from diabetic mothers was significantly increased while the volume of nonparenchyma was decreased. The villous surface area was increased in placentas from the diabetic group, the mean value being 17.3 m2 compared with the 11.4 m2 of the normal group. This increase was larger than would be expected when the increase in fetal weight of some babies born to diabetic mothers is taken into account.

Adult↗
PubMed1986

Factors affecting development: similarities and differences among children who were small, average, and large for gestational age at birth.

The development of 118 small-for-gestational age (SGA), 137 average-for-gestational age (AGA), and 118 large-for-gestational age (LGA) children was assessed at 7 years. The contributions of different factors to the variance in developmental scores were investigated by multiple regression analyses. All three groups showed the powerful influence of social class on intellectual ability at this age; and in the SGA and AGA groups the gross and fine-motor skills of girls were superior to boys. Smoking had a small effect in the AGA group, and in the two extreme groups first-born children did slightly better than later-born. Hypertension was associated with reduced scores in the SGA group, and LGA children who had spontaneous vaginal deliveries had higher scores than those delivered instrumentally or by caesarean section. There was a significant positive correlation between gestational age and developmental scores in the AGA group; but in the SGA group the relationship was in the reverse direction. Social class and sex affect the development of most children aged 7 years. Other factors seem to manifest an effect only under specified conditions.

Child↗
PubMed1985

Neoplastic transformation of mast cells by Abelson-MuLV: abrogation of IL-3 dependence by a nonautocrine mechanism.

Normal mast cells can be propagated in culture when medium is supplemented with interleukin-3 (IL-3). We demonstrate that Abelson-MuLV (Ab-MuLV) infection of mast cells eliminates dependence on IL-3 for growth. By contrast, Harvey, BALB, and Moloney MSV, which also productively infect mast cells, are unable to relieve IL-3 dependence. Ab-MuLV-induced IL-3-independent lines express the v-abl-specific transforming protein and have phenotypic characteristics of mast cells. These cells also possess high cloning efficiencies in soft agarose and are tumorigenic in nude mice. In addition, Ab-MuLV induces transplantable mastocytomas in pristane-primed adult mice resistant to lymphoid transformation, defining a new hematopoietic target for malignant transformation by this virus. None of the Ab-MuLV-derived transformants express or secrete detectable levels of IL-3 nor is their growth inhibited by anti-IL-3 serum. These results argue that Ab-MuLV abrogation of the IL-3 requirement is not due to an autocrine mechanism.

Abelson murine leukemia virus↗
PubMed1985

A pilot study on the use of botulinum toxin in spasmodic torticollis.

Dystonic torticollis has been treated with local injections of botulinum toxin in a single blind study of 12 patients. A significant decrease of abnormal movements was recorded, and pain improved. Further studies are desirable to define the optimum dosage and site for injections, and the long term effects of repeated injections.

Adult↗
PubMed1985

Risk factors associated with small-for-dates and large-for-dates infants.

Relative risks were calculated to assess the potency of different factors associated with the two extremes of the birthweight distribution. Maternal height affected the chances of having a small-for-dates (SFD) or large-for-dates (LFD) baby to an equal and opposite extent; but the risks associated with maternal weight were greater for LFD than SFD infants. Smoking increased the SFD risk by 3.5 times, whereas the LFD risk was only reduced by a half. Pre-eclampsia was associated with a very high SFD risk (14.6); in the LFD group it was insignificantly raised. The LFD relative risk steadily rose with increasing parity, but in the SFD group it fluctuated around unity. Among multiparae the risks of an SFD or LFD infant when previous siblings had been of relatively low or high birthweight for gestational age, respectively, were much increased. Estimates of attributable risk showed that if pathological factors such as smoking, hypertensive disorders and congenital abnormalities could be completely eliminated the number of SFD babies in this population would be reduced by about 60%; conversely the number of LFD babies would be increased by about 30%.

Birth Weight↗
PubMed1985

Quantitative structural studies on human placentas associated with pre-eclampsia, essential hypertension and intrauterine growth retardation.

Placentas from pregnancies complicated by pre-eclampsia, essential hypertension, hypertension complicated by pre-eclampsia and from normotensive pregnancies resulting in the birth of a singleton small-for-dates (SFD) infant have been studied by quantitative morphometry. The findings have been compared with those from placentas of uncomplicated pregnancies. The placentas from pregnancies complicated by pre-eclampsia and those resulting in a SFD baby had a significantly lower total volume, volume of parenchyma and villous surface area when compared with normal pregnancies of comparable gestation. They also had an increase in areas of multiple infarction and in the volume proportions occupied by fetal capillaries. The placentas from women with essential hypertension uncomplicated by pre-eclampsia were as large as those from normal pregnancies and the villous surface areas were as high. Villous surface area measurements in the different groups were related to gestation and to fetal weight.

Adult↗
PubMed1985

Children of deviant birthweight: the influence of genetic and other factors on size at seven years.

138 small-for-gestational age (SGA), 138 average-for-gestational age (AGA) and 136 large-for-gestational age (LGA) children who had been followed up from birth were measured at the age of seven years. Parental measurements were also obtained. Significant differences for weight, height and head circumference of the children and their parents were found between the three groups. There were highly significant parent-child correlations for most somatic measures in all groups. Within each group the parental contribution to the variance in children's somatic measures was large; so also was the effect of sex on head circumference. Other biological and pathological factors made only a small contribution in any group.

Adult↗
PubMed1985

Head circumference charts updated.

Head circumference measurements from birth to 7 years, obtained from longitudinal data on children born between 1970 and 1977, are set against those from studies made in the United Kingdom earlier this century. A positive secular trend is shown. The children's heads were significantly larger than those born in the same locality 25 years earlier. Growth charts should be updated, as necessary, with each succeeding generation.

Aging↗
PubMed1985

Nuclear bodies in the caecum of the rabbit.

The structure and cytochemistry of nuclear bodies in the caecum of the rabbit are described and a developmental pathway from morphologically simple to complex forms is proposed. Simple nuclear bodies are proteinaceous in nature while complex bodies possess a proteinaceous capsule with some associated ribonucleoprotein. The interna of complex bodies possess various individual components consisting either of deoxyribonucleoprotein, ribonucleoprotein, or unassociated proteins. The significance of these nuclear bodies in caecal biology is discussed.

Animals↗
PubMed1984

Associations between size and development at four years among children who were small-for-dates and large-for-dates at birth.

Associations were sought between somatic measures and developmental status at 4 years among groups of children who had been small-for-dates (SFD), average-for-dates (AFD) and large-for-dates (LFD) at birth. When the three groups were combined, and adjustment made for sex, social class and series, a significant correlation was found between head circumference and total scores. Within the SFD and AFD groups no correlations were found between any somatic measures and aspects of development; and the only significant finding in the LFD group was a negative correlation between weight-for-height and total developmental scores. The somatic measures were then divided into three subgroups comprising children who had small, average, and large values for that measure, and developmental scores for each subgroup were computed. Within all three birthweight groups significant differences were found for head circumference: those with relatively small heads having lower scores than the rest.

Birth Weight↗
PubMed1984

Children of deviant birthweight at the age of seven years: health, handicap, size and developmental status.

138 small-for-dates (SFD), 138 average-for-dates (AFD) and 136 large-for-dates (LFD) children who had been followed up from birth were examined at the age of 7 years. Nine children had major congenital abnormalities (SFD 5, AFD 2, LFD 2). In addition gross and/or fine motor incoordination was noted in 25 children (SFD 9, AFD 10, LFD 6). There were no differences between the groups in the incidence of chronic or specific ill-health, hearing, sight and speech defects. Highly significant differences were found between the groups for weight, height, head circumference and triceps skinfold thickness; and significant differences were also found between the total developmental scores in the three groups. In every case SFD children had the lowest and LFD children the highest mean values. Within each group analyses were made of 22 parental, pregnancy, perinatal and postnatal factors which might affect growth or development. The net effects of those factors for which significant differences had been found were then assessed, adjustment being made for confounding between variables. In all three groups the children's genetic potential for size was strongly evident by this age, and boys had larger heads than girls. All three groups showed the powerful influence of social class on intellectual ability; and sex on gross and fine-motor function. The other main contributor to developmental differences in the AFD group was gestational age. In the SFD group maternal hypertension was associated with slightly decreased intellectual ability, and in all areas first-born SFD children performed better than subsequent born. Among LFD children instrumental delivery had an adverse effect on all areas of ability, and first-born children had higher intellectual scores. When all the children were considered together and birthweight included as an additional variable the differences in developmental scores between the groups were much reduced. In the SFD and LFD groups some significant correlations were found between size and developmental scores; but none were found among AFD children.

Anthropometry↗
PubMed1984

Cooling dissociates glucose-induced insulin release from electrical activity and cation fluxes in rodent pancreatic islets.

Insulin release and beta-cell membrane potentials in response to glucose at 37 and 27 degrees C have been measured simultaneously in single, micro-dissected, perifused islets of Langerhans from normal mice. Insulin release and 45Ca outflow in response to glucose at 37 and 27 degrees C have been measured simultaneously from perfused islets isolated by collagenase digestion from normal rats. The effect of cooling on beta-cell membrane potassium permeability was assessed by changes in measured membrane potential and input resistance (in the mouse) and by changes in 86Rb outflow (in the rat). Resting and active beta-cell membrane parameters (i.e. membrane potential, spike frequency, input resistance, 45Ca outflow and 86Rb outflow), in both mouse and rat islets, were affected only slightly by cooling to 27 degrees C, with temperature coefficients of 2 or lower. At 27 degrees C glucose-stimulated insulin release was inhibited completely in mouse islets and almost completely in rat islets. The temperature coefficients in both preparations were greater than 5. It is concluded that beta-cell electrical activity and changes in membrane permeability induced by glucose are not consequences of insulin release.

Animals↗
PubMed1984

A monoclonal antibody-based immunoradiometric assay for h-LH.

An immunoradiometric assay (IRMA) for h-LH based upon an 125I-labelled mouse monoclonal antibody (MAb) to h-LH with an effective equilibrium constant of 5.8 X 10(9) l/mol is described. A total incubation time of 3 h at room temperature was required, separation by means of the sucrose layering procedure took a further 1 h and counting times were 1 min/tube. Using the first IRP for h-LH (prep. 68/40) as standard, the detection limit was 0.1 U/l serum and the within-assay CV for duplicate determinations was less than 10% over the range 1-280 U/l and less than 3% at 10-100 U/l. The epitope, with which the MAb reacted, shared structures, on the alpha- and beta-subunits of LH since the assay responded to the intact hormone, but not to either of the subunits. Specificity was greater than 100 000:1 for h-LH vs. h-FSH and greater than 10 000:1 for h-LH vs. h-TSH. h-CG and h-LH were approximately equipotent. The results on 604 unselected samples were generally very similar to those found by RIA except at levels below 2 U/l for which the IRMA regularly gave lower results suggesting relative freedom from non-specific serum effects. The new assay, based upon potentially limitless supplies of a very stable reagent offers advantages of speed, sensitivity, range, and precision over conventional RIA. The specificity appears to be excellent. Although there are marginally more steps the total staff involvement is less than with conventional methods employing centrifugation.

Animals↗