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Biomedical subjects

W A Marshall

Publications and source records attributed to W A Marshall.

At least 19 recordsLinked to original sources
PubMed1997

Seasonality in antarctic airborne fungal spores.

Airborne fungal spores were monitored over periods of up to 131/2 months at three sites on Signy Island in the maritime Antarctic. Fungal spore concentrations in the air were much lower than in other parts of the world. Concentrations were very low during the austral winter but increased during the austral summer. Chlamydospores were the most abundant fungal spore type found. Spores of Cladosporium spp. were the second most frequently trapped form. All spore types samples were most abundant in the summer months, except for chlamydospores, which were most numerous during the winter. The concentration of Cladosporium spores in the air at Signy Island was compared with the concentrations of this spore type found in the air in other parts of the world. It was evident that Cladosporium loses its dominance as the most abundant component of the air spora with increasingly high latitude. The peak concentration of fungal spores occurred at two sites following the start of the thaw; at the third site, the peak occurred with the arrival of spores by long-distance transport from more northerly regions.

Journal Article↗
PubMed1989

Estimation of chronological age from different body segments in boys and girls aged 4-19 years, using anthropometric and photogrammetric techniques.

Data obtained from measuring different body segments (stature, sitting height, upper limb, upper arm, forearm, leg, hand and foot length), were used to construct equations for estimating the chronological age of children with unknown date of birth. About 18,510 sets of measurements were taken on boys and 11,568 sets on girls. All were healthy British children aged 4-19 years and participating in three longitudinal studies at the Department of Growth and Development, Institute of Child Health, University of London. Both anthropometric and photogrammetric techniques of measurement were used to construct 35 anthropometric and 49 photogrammetric equations using the multiple linear regression model. These equations give the most likely estimated value for age together with its error. The accuracy of the equations and its applicability both on live children and on postmortem material is discussed.

Adolescent↗
PubMed1986

A longitudinal study of carpal bone development in Perthes' disease: its significance for both radiologic standstill and bilateral disease.

This paper reports a longitudinal study of carpal bone development in 125 children (98 boys, 27 girls) attending a clinic for Perthes' disease. The age at appearance of ossification in each carpal bone was estimated by studying consecutive radiographs obtained at six-months intervals. The results were compared with the findings for normal children published by Stuart et al. Three radiologic groups of carpal bone maturation are defined: not delayed (capitate and hamate); markedly delayed (triquetral and lunate); and slightly delayed (scaphoid, trapezium, and trapezoid). Overall, the bone age delay is severely abnormal at three to five years of chronologic age and indicates the time in development when general abnormalities occur. The mean age at diagnosis (and standard deviation) for 34 boys with skeletal standstill was 4.49 +/- 1.07 years, compared with 7.28 +/- 2.40 years for 51 boys without such standstill; the mean age at appearance of carpal bones was not significantly different between these two groups, suggesting an equally profound delay of carpal maturation in the group of later-diagnosed boys. Boys with bilateral hip disease show a significant delay in age at ossification of the trapezoid compared with boys who have unilateral disease. The immaturity of bone age may be present during a latent period and be of etiologic significance in the onset of the hip disease, but at present the evidence links it only with bilateral disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Carpal Bones↗
PubMed1982

Early postnatal weight gain: comparisons between Asian and Caucasian infants.

Little is known about the early weight gain of British born Asian babies. This study sets out to compare weight gain of 34 healthy Asian term babies with 34 white Caucasian babies over the first two months of life. The Asian infants were lighter at birth but their rate of weight gain did not differ significantly from their white Caucasian counterparts. These findings offer indirect support for the hypothesis that the smaller size at birth of Asian babies is not due to intrauterine growth retardation. Had this occurred a greater weight gain indicating 'catch-up growth would have been expected.

Africa, Eastern↗
PubMed1977

Home haemodialysis in children. Report of the London Children's Home Dialysis Group.

In January, 1973, a study was established to evaluate, prospectively and independently, the growth and psychosocial adaptation of children in end-stage renal failure treated by home haemodialysis at Guy's Hospital and the Royal Free Hospital. By January, 1975, 26 children had entered the study, but 2 died before they were established on home haemodialysis. In this paper a specified 1-yr period starting 6 mo after the onset of haemodialysis was selected for analysis. School attendance, diet, plasma-biochemistry, bone disease, growth, and emotional symptoms were investigated in each child. Rehabilitation was satisfactory, and average school attendance was 65%. Growth in all the prepubertal children was poor, whereas in most pubertal children it was adequate. At the end of the year, only 5 children were emotionally disturbed, but half the families had stress symptoms. The children at Guy's Hospital were dialysed more intensively than those at the Royal Free Hospital, and they had significantly lower mean plasma urea and creatinine concentrations and a greater energy and protein intake. On the other hand, the children at the Royal Free Hospital had a better school attendance. We conclude that home haemodialysis is an acceptable treatment for children in end-stage renal failure.

Adaptation, Psychological↗
PubMed1976

Variation in upper arm length and forarm length in normal British girls: photogrammetric standards.

A photographic measuring technique has been used to study the lengths of the upper arm and forearm in normal British girls. The data are presented graphically, and show: 1. Ellipses which include 97 per cent of normal subjects when upper arm length is plotted against forearm length. 2. Variation of upper arm length and forearm length according to age. 3. Variation of upper arm length in relation to forearm length, irrespective of age. 4. Variation of upper arm length and forearm length in relation to sitting height, irrespective of age. The charts collectively provide a means of defining the exact nature of abnormalities of growth in the arms or of differences between populations. They provide a new aid to the classification of disorders involving abnormal growth of the arms.

Adolescent↗
PubMed1976

Skeletal maturity and the prediction of age at menarche.

The regression of age at menarche on the difference between bone age and chronological age was estimated using hand/wrist radiographs taken between the ages of 10 and 15 years of 352 British girls whose ages at menarche were known. The regression was used to determine, in the case of girls who had not yet menstruated at a given chronological age and bone age, (a) the most probable age at menarche, and (b) the age by which 95 per cent would have experienced menarche. The results were compared with predictions made on the basis of chronological age alone. The range of error of predictions based on chronological age only decreases as age increases. This is true also when bone age is taken into account but, at all ages, the error of prediction using bone age as well as chronological age was less than that of prediction based on chronological age alone.

Adolescent↗
PubMed1976

Steroids after birth-puberty.

The production of gonadal steroids in the perinatal period may have an important influence on the later development of the hypothalamo-pituitary-gonadal axis. In the prepubertal period there is an increased output of gonadal steroids and of androgens from the adrenal cortex, with a further increase as the secondary sex characters develop. The precise role of individual steroids in the maturation of the reproductive system and of the neuroendocrine regulating mechanisms will probably remain unclear unless conclusions are based on longitudinal studies in which hormone production is related precisely to different parameters of sexual development and somatic growth.

Adolescent↗
PubMed1975

The relationship of variations in children's growth rates to seasonal climatic variations.

The growth rates in stature of 300 children in the Orkney Islands, measured at monthly intervals over 2 years, were negatively correlated with various measures of light and temperature. All correlations were small but statistically significant, the highest being with the mean of the maximal daily temperatures (-0.32) for the boys and with hours of bright sunshine (-0.29) for the girls. The children's mean growth rates reached maxima at midwinter and minima at midsummer but the maximum in the winter 1971-72 was much lower than those at the beginning of 1971 and at the end of 1972. The climatic variables were not appreciably different in the two years. Only about 35 per cent of children showed cycles of growth rates which could be regarded as seasonal in that they rose to peak values at approximately the same time in the two successive years. The difference between the maximal and minimal rates exhibited by Orkney children (5.26+/-0.12 cm/yr for boys; 5.46+/-0.14 cm/yr for girls) was almost identical to that in London children. The synchronization of the maximal growth rates was no more precise in Orkney than in London. It is concluded that seasonal variations in light and temperature exert at most only a small effect on growth rate and perhaps none at all. The influence of other factors, as yet unidentified, is greater.

Child↗
PubMed1975

Prediction of adult height from height, bone age, and occurrence of menarche, at ages 4 to 16 with allowance for midparent height.

Multiple regression equations for predicting the adult height of boys and girls from height and bone age at ages 4 and upwards are presented. There is a separate equation for each half year of chronological age; and for pre- and postmenarcheal girls at ages 11 to 14. These are based on longitudinal data from 116 boys and 95 girls of the Harpenden Growth Study and the London group of the International Children's Centre longitudinal study. The bone age used is the revised version of the Tanner-Whitehouse standards, omitting the score for carpal bones (RUS age, TW 2 system). Boys aged 4 to 12 are predicted in 95% of instances to within plus or minus 7 cm of true height, and at ages 13 and 14 to within plus or minus 6 cm. Girls ages 4 to 11 are predicted to within plus or minus 6 cm; premenarcheal girls aged 12 and 13 to within plus or minus 5 and plus or minus 4 cm, respectively; and postmenarcheal girls aged 12 and 13 to within plus or minus 4 and plus or minus 3 cm, respectively. Prediction can be somewhat imporved by allowing for midparent height. One-third of the amount that midparent height differs from mean midparent height is added or subtracted. An alternative system of equations which are based on initial classification by bone age rather than chronological age is given. These have about the same accuracy as the equations based on initial classification by chronological age, but allowance for bone age retardation is less. It is not clear which system is preferable. The equations probably apply to girls complaining of tall stature and boys or girls complaining of shortness and needing reassurance as to normality. In clearly pathological children, such as those with endocrinopathies, they do not apply.

Adolescent↗