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Biomedical subjects

D Hull

Publications and source records attributed to D Hull.

At least 127 records · Page 7Linked to original sources
PubMed1982

Energy intake and weight gain of very low birthweight babies fed raw expressed breast milk.

The energy intake and weight gain of low birthweight infants (under 1500 g) fed expressed breast milk were measured. Between the second and fourth weeks of life the mean energy intake was 577 kJ (138 kcals)/kg/day and the mean weekly increase in weight 119 g/week. Feeding energy-rich hind milk to two babies increased their energy intake but had little effect on their rate of weight gain. There appeared to be no correlation between energy intake and weight gain, probably owing to variation in the absorption of nutrients from expressed breast milk. This study forms a basis for a comparison of weight gain in babies fed alternative regimens of artificial milks.

Aging↗
PubMed1982

A study of the interface between a fibrous polyurethane arterial prosthesis and natural tissue.

Fibrous polyurethane samples were implanted in subcutaneous tissue, muscle, and as an arterial prosthesis for periods up to six months. The interface between the polymer and living tissue was studied using optical, scanning, and transmission electron microscopy. A good correlation was found between the micromorphology of the polymer-tissue interface observed in three experimental methods used. Ingrowth of tissue occurs by cell penetration into the fibrous network of the polymer implant and eventual encapsulation by connective tissue. Full details of the distribution of collagen and the cell components around the individual polymer fibers and the structure of the connective tissue are given.

Animals↗
PubMed1982

Behavioral thermoregulation in newborn rabbits.

Newborn rabbits show behavioral and physiological thermoregulatory responses within the first hours of life. Although the mother prepares a nest for her young, she does not stay with them. The hairless immature young survive by huddling together in the nest. In this study, ambient temperature had a powerful influence on the behavior of newborn rabbits, and, providing they were warm, they did not huddle. The rabbits were studied over the first 10 days of life during which time their fur grows rapidly and their body weight nearly trebles. As each day passed, their preferred environmental temperature fell. In these observations smell and contact with littermates did not appear to have a major effect.

Animals↗
PubMed1982

Onset of thermogenesis in response to cold in newborn mice.

The onset of thermogenesis in response to cold exposure in individual mice was studied using a sensitive close circuit system for measuring their rate of oxygen consumption. On the day of birth, exposure to a cool environment did not stimulate an increase in oxygen consumption, but 48 h later the majority of mice respond by doubling their metabolic rate in response to a fall from 36 to 31 degrees C in ambient temperature. When 5 mice huddled together an ambient temperature drop from 36 to 23 degrees C was required to provoke the same response. Brown adipose tissue is present at birth but the cells are relatively small and contain little fat. By the second day they are three times larger and contain far more fat. The onset of thermogenesis appears to await the development of brown adipose tissue.

Adipose Tissue, Brown↗
PubMed1982

The constituents of neonatal milk.

The electrolyte, lactose, total protein and lipid composition of neonatal milk has been examined. Electrolyte values were similar to those found in maternal milk; the sodium concentration of milk from one infant with adrenal insufficiency and two infants with cystic fibrosis were normal. Inflammation of the breast was associated with high sodium and low potassium values. The concentrations of lactose and total protein were similar to maternal milk. Neonatal milk contained significant amounts of fat with a full range of fatty acids. Total fat concentrations was less but the relative amount of shorter chain fatty acids was greater than in maternal milk. Milk from malnourished newborns contained less fat than the secretion of healthy infants. Total milk fat level appeared to increase with postnatal age. It is concluded that the neonatal breast produces a complex secretion, that neonatal milk is indeed a 'true milk'. The study of neonatal milk sheds light on the physiology of lactation and on metabolic processes in the newborn.

Electrolytes↗
PubMed1982

Prosthetic hip range of motion and impingement. The effects of head and neck geometry.

Two major design parameters to total hip arthroplasty which can be selected to optimize for anatomical variation are head diameter and neck length. By using a cadaveric pelvis mounted in a three-dimensional protractor, it was shown that increased head-neck diameter ratio results in increased range of motion, with decreased prosthetic impingement, and that increased neck-length results in increased range of motion, with increased prosthetic impingement. Head diameter has no range of motion effect in arcs characterized exclusively by bony impingement, and neck length has no range of motion effect in arcs characterized exclusively by prosthetic impingement. The surgeon is currently confronted with a variety of prostheses with different head-neck diameter ratios and neck lengths. When choosing the optimal prosthesis for a particular patient, the surgeon is often restricted by various anatomical constraints. While a large head diameter cannot always be chosen, an adequate range of motion without prosthetic impingement can still be achieved by ensuring that head-neck diameter ratio is optimum. A sufficient neck length to ensure adequate range of motion is desirable, but the neck should not be so long that neck-socket impingement is of concern. Optimum clinical range of motion, with minimal prosthetic impingement, may be achieved with a large head size and a medium neck length.

Biomechanical Phenomena↗
PubMed1982

Familial Hibernian fever.

An Irish family with an unusual periodic syndrome is described. Attacks consist of fever with localized myalgia and painful erythema. Other features include abdominal pain and pleurisy, with leucocytosis and a high ESR. The syndrome resembles classical familial Mediterranean fever (FMF) but differs from it in its prompt response to steroids and its autosomal dominant pattern of inheritance. The disease appears to have a benign course and no patient has developed amyloid.

Adult↗
PubMed1981

Interpretation of the contraindications to whooping cough vaccination.

The official recommendations on the contraindications to whooping cough immunisation are currently couched in general terms. The results of a simple inquiry made to directors of public health laboratories, general paediatriciains, paediatric neurologists, medical officers, general practitioners, and health visitors to see how they would interpret the contraindications in certain specific cases suggest that there is considerable uncertainty on how the contraindications should be interpreted. This is probably one factor responsible for the fall in the rate of whooping cough immunisation in the United Kingdom.

Allied Health Personnel↗
PubMed1981

Fat content of expressed breast milk: a case for quality control.

Expressed breast milk used to feed preterm infants is precious and so, despite heterogeneity of composition, all available milk is used. A study of 274 samples of expressed breast milk supplied by preterm mothers and National Childbirth Trust donors showed pronounced variation in fat content as measured by the "creamatocrit" method. This was not due to differences between term and preterm mothers or between transitional and mature milk. The composition was affected by diurnal variation and method of collection. Substantial amounts of fat were also wasted as a result of continuous nasogastric feeding. Several milk samples did not contain enough fat to supply even a fraction of the recommended energy requirements of these infants. Some type of quality control over samples of expressed breast milk is clearly essential. The creamatocrit method is simple and feasible.

Female↗
PubMed1981

Prolactin, maternal oestrogens, and breast development in the newborn.

To investigate the influence of maternal oestrogens on the fetal breast development, maternal urinary oestriol excretion, maternal plasma oestriol concentrations, and cord venous plasma oestradiol and oestriol concentrations were related to the size of the neonatal breast. A significant positive association between oestriol excretion and neonatal breast size was demonstrated, but the relationship was not strong and might be due to both measures having a positive relationship with birthweight. The infants' circulating concentrations of prolactin at birth and during the first weeks of life were also related to breast size. There was no cord venous-arterial difference in prolactin concentrations, and neither related to breast diameter. However there was a strong association between breast size and prolactin concentrations in mature infants aged between 5 and 7 days. In preterm infants breast tissue often develops after birth. Prolactin levels in preterm infants were higher between 2 and 6 weeks than they were in the first week of life. It would appear that the early development of the breast is influenced more by the infants's than the mother's endocrine activity.

Anthropometry↗
PubMed1981

Breast development in the newborn.

Breast size and milk secretion was studied in term and preterm infants. Breast nodules were palpable in most of the mature infants, both boys and girls. In 6 term infants without palpable breast tissue there was a high incidence of complications during late pregnancy or delivery. In light-for-gestational age infants the breast diameter was generally appropriate for gestation. None of the infants under 31 weeks' gestation had palpable breast tissue at birth, but some in the first weeks of life developed breast tissue and secreted milk. Milk had been secreted by most of the mature infants by age 7 days, and the onset was earlier in light-for-dates infants. The breast does not regress rapidly after birth. The nodules persist into the second half of the first year by which time sex differences have emerged. Clearly the growth and activity of the neonatal breast cannot be explained solely in terms of the influence of maternal hormones towards the end of gestation. Further studies on early breast tissue development may indicate the other endocrine factors concerned.

Anthropometry↗
PubMed1981

Reduction of skin water loss in the newborn. I. Effect of applying topical agents.

The waterproofing effect of a number of creams, oils, and greases was examined by measuring water loss from adult skin before and after topical application. Creams had a high water content and were ineffective, oils produced a modest fall in water loss, but paraffin in grease form had a pronounced, sustained waterproofing effect. A paraffin mixture (80% soft, 20% hard paraffin (BP) was then applied to the skin of 3 preterm babies nursed naked in incubators. Overall skin water loss fell by 40 to 60% after application and was still lower than pretreatment levels 6 hours later. The topical application of paraffin offers a new approach to reduction of the high evaporative water and heat losses of preterm babies.

Administration, Topical↗
PubMed1981

Reduction of skin water loss in the newborn. II. Clinical trial of two methods in very low birthweight babies.

Two methods of reducing evaporative water and heat loss in the newborn, the thermal blanket and topical paraffin, were compared in a clinical trial. Forty-four babies weighing less than 1.5 kg, nursed in incubators since birth, were either covered with a plastic bubble blanket or had a paraffin mixture applied to their skin at 6- and 8-hour intervals for the first 2 weeks of life. There was no significant difference between the two groups in terms of mortality, morbidity, weight gain or loss, and temperature control. Two babies in the blanket group were removed from the study because of persistently low body temperatures. Five babies in the paraffin group had minor skin rashes and a further 2 had more extensive rashes which led to their removal from the study. Both methods resulted in good temperature control in babies after the first day of life. In the first 24 hours however, neither method of treatment could prevent subnormal body temperatures in the babies weighing less than 1.0 kg, even though the incubator air temperature was on average more than 1 degree C above the rectal temperature. Other methods are necessary to achieve normal body temperatures in these vulnerable babies.

Bedding and Linens↗
PubMed1981

Investigation of [14C] linoleic acid conversion into [14C] arachidonic acid and placental transfer of linoleic and palmitic acids across the perfused human placenta.

In five separate experiments in which single placental lobes were perfused, [14C] antipyrine, [3H] dextran and a fatty acid mixture containing [14C] linoleic and [3H] palmitic acids were added to the maternal circuit. Samples of fetal and maternal perfusate, taken at intervals, were analysed for radioactivity and fatty acid content. The relative placental transport rates of antipyrine, linoleic and palmitic acids and the changes in maternal and fetal circuit content of linoleic, palmitic and arachidonic acids were measured. Mean transfer rates of 150, 0.023 and 0.034 mumol min-1 were obtained for [14C] antipyrine, [3H] palmitic and [14C] linoleic acids, respectively. The transfer of [3H] dextran was negligible. The transfer rates of linoleic and palmitic acids did not differ significantly from one another. The maternal circuit content of palmitic and arachidonic acids increased, whereas linoleic acid content decreased. The fetal content of all three acid increased but in the case of arachidonic and palmitic acids the increase was not as great as that seen in the maternal circuit. In no experiment was radioactivity detected in maternal or fetal perfusate arachidonic acid. It is concluded that linoleic and palmitic acids cross the placenta from the maternal to the fetal side. This transfer appears to be non-selective. The large amounts of arachidonic acid that are released into the perfusate probably originate from placental lipids other than free linoleic acid.

Antipyrine↗
PubMed1981

The development of cold-induced thermogenesis in hamsters.

The onset of the thermogenic response to cold exposure in hamsters was studied in relation to the development of brown adipose tissue. The daily weight increment of hamsters reared in animal house conditions was first determined. Organ weights in animals with body weights within +/- 1 SD of mean were obtained at intervals between 0 and 20 days of age. Adipose tissue increased rapidly in weight between days 10 and 15, but the fat content of cervical adipose tissue fell. Electronmicroscopic studies reveal that there had been a dramatic increase in the number and size of the mitochondria. Serial measurement of the rate of oxygen consumption showed an initial increase in minimal rate over the first 4 days of life followed by a larger increment from 8 to 16 days of age. On day 12 most hamsters shivered vigorously but had a poor and variable thermogenic response to cold. By day 16 all showed an impressive increase in heat production in the cold. It would appear that thermogenesis in response to cold exposure awaits the development of brown adipose tissue.

Adipose Tissue↗
PubMed1980

Mode of delivery and survival in babies weighing less than 2000 g at birth.

A retrospective study of babies weighing less than 2000 g at birth admitted over a four-year period to Nottingham City Hospital Neonatal Unit showed a higher incidence of lower Apgar scores and the need for intubation in babies born by caesarean section and breech deliveries. Mortality in those delivered by the breech (35%) was statistically higher than those by caesarean section (10%) or vertex (14%). It is concluded that small babies born by breech delivery have a higher mortality than when delivered vaginally and should have the benefit of caesarean section.

Apgar Score↗
PubMed1980

Plasma free fatty acid umbilical venous-arterial concentration differences and placental transfer of [14C]palmitic acid in pigs.

The passage of plasma free fatty acids across the pig placenta was investigated in four anaesthetized sows with a total of 41 fetal piglets. The plasma free fatty acid concentrations in fetal piglets were very low and appeared independent of maternal concentrations. In each piglet there was a small positive umbilical venous-arterial concentration difference. There were large differences between the composition of maternal and fetal plasma free fatty acid. The fetal free fatty acid contained relatively large amounts of arachidonic and docosahexaenoic acids. [14C]palmitic acid given intravenously to the sows appeared rapidly in fetal plasma free fatty acids but the amount of radioactivity was low. Analysis of the specific activity of palmitic acid in fetal and maternal blood indicated that little more than 10% of fatty acids coming from the placenta were derived directly from maternal plasma free fatty acids. It is concluded that, in the anaesthetized pig at Caesarean section, fatty acids enter the fetal circulation from the placenta and are taken up by the fetus at rates exceeding the requirements for structure and storage, but the major part of these free fatty acids are not derived directly from maternal free fatty acids.

Animals↗