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Biomedical subjects

D Hull

Publications and source records attributed to D Hull.

At least 91 records · Page 5Linked to original sources
PubMed1988

The gamete and embryo compatibility of various synthetic polymers.

Several popular and well-characterized polymeric materials were evaluated for their biocompatibility toward the cells unique to reproduction. To accomplish these studies, several in vitro tests were developed that evaluated biocompatibility between the polymers and spermatozoa, ova, and embryos. The data indicated significant differences between the materials with respect to their biocompatibility toward sperm motility, the sperm's ability to penetrate zona-free hamster eggs, and the ability of two-cell mouse embryos to divide. Polytetrafluoroethylene (PTFE-Teflon; PTFE, Chemplast Inc., Wayne, NJ), polyethylene glycol (PEG), and polyhydroxyethyl methacrylate (PHEMA) appear to be the most inert of the materials studied. Polyvinyl chloride (PVC; Tygon-Norton, Akron, OH) was found to be the most detrimental material toward gametes and embryos, with gross physiologic and morphologic changes observed in the PVC-exposed cells.

Animals↗
PubMed1988

Evaluation of the Nottingham birth scoring system.

A case-control study of postneonatal deaths occurring in 1974-1976 in the City of Nottingham, England, revealed that most were attributable to respiratory infections and SIDS, and primarily occurred in wintertime, at home, in the less well-off parts of Nottingham. By means of a step-wise discriminant analysis, 9% of the infant population was identified as a high-risk group in whom 53% of postneonatal deaths could be expected to occur. From January 1, 1978, this group of infants was followed up more intensively by health visitors and general practitioners, who gave advice on the early recognition of respiratory symptoms. Although the postneonatal mortality rate fell from 6.5 per 1,000 live births in 1977 to 5.2 per 1,000 in 1983, it is not possible to show that the rate of improvement was any faster after the introduction of the system. The system was discontinued on March 31, 1985. Birth scoring systems are not recommended; instead, resources should be concentrated on general improvements in services and symptom recognition, and basic research into the causes of SIDS.

Child Health Services↗
PubMed1988

Renal transplantation at Hartford Hospital: results of combined and flexible immunosuppression.

1. Three groups of first cadaver kidney transplant recipients at Hartford Hospital were analyzed. All received AZA and P, and most received pretransplant blood transfusions. The first group, 41 patients transplanted from 1977-1979, had a 2 year graft survival of 49%; the second group, 72 patients transplanted from 1980 to 1984 had an emphasis on DR typing and 2-year graft survival of 61%. The third group had the addition of CsA (triple immunosuppression) from 1984 to October, 1988. These 200 patients had a 2-year graft survival of 87%. The 2-year patient survival was 82%, 85%, and 94% for the 3 groups, respectively. 2. Triple immunosuppression resulted in less frequent and less severe rejection activity. There was no increase in serious infection and no significant elevation in mean serum creatinine at a 2-year follow-up, when compared to a control group receiving AZA and P. 3. DST was used selectively for one haplotype living-related donor kidney transplants, and in HLA-identical sibling kidney transplantation. Triple immunosuppression was also used in living-related donor kidney transplants, but in a very low-dose range. Only 3 of 58 grafts in living-related donor kidney transplants have been lost in the past 4 years; none due to rejection. 4. OKT3 therapy has been used primarily for steroid-resistant rejection, usually resulting in reversal, but also in a significant increase in CMV infection. When an "OKT3 available" group of cadaver kidney transplant recipients was compared to a previous control group, OKT3 therapy did not appear to improve the overall results. 5. Patients receiving retransplantation experienced a better success rate than reported at many other centers, (72% graft survival at 2 years). The use of OKT3 or ATG and DR matching contributed to the success. 6. The average ATN rate for all perfused kidneys was 36%; 50% for those preserved longer than 28 hours. Imported kidneys preserved with Euro Collins solution had a 63% ATN rate versus 36% for locally procured kidneys. There was no significant difference in graft survival in patients with or without posttransplant ATN.

Adolescent↗
PubMed1988

The effect of limit feeding on thermogenesis and thermoregulation in genetically obese (ob/ob) mice during cold exposure.

Thermogenesis and thermoregulation in ad-lib-fed and limit-fed lean (+/ob or +/+) and obese (ob/ob) mice during acute cold exposure were studied by measuring oxygen consumption and body temperature. No significant differences in oxygen consumption were found between the lean ad-lib, obese ad-lib- or obese limit-fed groups. The oxygen consumption of the lean-limit-fed group was decreased by 25-30 per cent compared with the other groups. The body temperature of the obese ad-lib-fed group fell at a rate of at least twice that of any other group. The weight, total cytochrome c oxidase activity and protein content of the brown adipose tissue (BAT) of the lean groups was similar, and there appeared to be little difference in cell size or fat content. The BAT of both obese groups showed a several-fold increase in weight, and a 50 per cent increase in total protein, compared with the lean groups. The limit-fed obese group showed a significant increase in cytochrome c oxidase activity compared with all other groups. The BAT cells of both obese groups were much enlarged and contained considerable amounts of fat. These observations indicate that the susceptibility of obese mice to hypothermia is not due to a reduced capacity for thermogenesis, but to a failure to conserve heat. Failure of thermoregulation in obese animals may be due to postural constraints that result in increased heat loss by radiation. The results are discussed in relation to the accredited role of BAT thermogenesis in rodents exposed to the cold.

Adipose Tissue, Brown↗
PubMed1987

Fatty acid composition of the plasma lipids of the maternal and newborn horse.

The fatty acid composition of the plasma free fatty acid, triacylglycerol and phospholipid fractions was measured in blood and milk samples taken daily from 3 mares and their foals on Days 1-9 post partum inclusive, and from a total of 12 mares and foals on Days 22, 30 and 51. A rise in the plasma concentrations of triacylglycerol and phospholipid similar to that well documented in other species occurred in the neonatal period. Alterations in the composition of the foal plasma phospholipid after birth lend support to the view that the placenta rather than the fetus could be responsible for the elongation and desaturation of the essential fatty acids to provide long-chain polyunsaturated fatty acids for the fetus.

Animals↗
PubMed1986

Children intoxicated by alcohol in Nottingham and Glasgow, 1973-84.

The circumstances of ingestion, clinical course, and long term sequelae were examined retrospectively in 143 children (108 boys, 35 girls) admitted with acute alcohol intoxication in Glasgow and Nottingham over the 12 years 1973-84. Fifty three of the children were aged less than 7 years and 90 were aged 7-14. Twelve of the children were hypoglycaemic on arrival at hospital. Trauma related to intoxication occurred in 14 cases, and nine boys became drunk under duress, which in four cases was associated with sexual abuse.

Age Factors↗
PubMed1986

The nucleotide sequence of the mRNA encoding the fusion protein of measles virus (Edmonston strain): a comparison of fusion proteins from several different paramyxoviruses.

Membrane fusion is the primary cytopathic effect observed in cells infected with measles virus. The viral protein responsible for this process has previously been defined as the fusion (F) protein. Fusion is activated by the proteolytic cleavage of a precursor molecule (F0) to yield two disulfide-linked polypeptides (F1 and F2). In this paper the mRNA for the membrane fusion protein has been cloned and the resulting cDNAs were sequenced. A mRNA composed of 2377 nucleotides was found to contain one open reading frame which could potentially code for a protein of 550 amino acids. This corresponding gene product was identified as the fusion protein through use of antibodies directed against a synthetic peptide which was constructed from the deduced amino acid sequence. A long and rather G-C rich 5' terminus was found on the mRNA and this noncoding region may play some role in regulation of protein synthesis at the translational level. Protein sequence data derived from the cDNA clones revealed a highly conserved F1 amino terminus which is characteristic of most paramyxoviruses. Very little amino acid homology (except for the conservation of the F1 terminus and 9 cysteines) was evident when the sequence was compared to other paramyxovirus fusion proteins. However an overall hydrophobic nature was characteristic of all the F proteins and hydrophobicity plots for the fusion proteins of 4 different paramyxoviruses were very similar. Computer analysis was also employed to analyze the secondary structure of the measles virus F protein. Large stretches of alpha helix were characteristic of the regions which purportedly interact with membranes. The functional domains of the F protein and their similarity to those of the influenza hemagglutinin protein are discussed in this communication. We concluded that the distribution of hydrophobic regions capable of spanning biological membranes determines the fusogenic nature of the F protein.

Amino Acid Sequence↗
PubMed1986

Evaluation of a special low birth weight formula, with and without the use of medium chain triacylglycerols.

A special low birth weight formula containing 1.8 g/100 ml of medium chain triacylglycerols (Nenatal) was compared with 'modified' Nenatal (medium chain triacylglycerols (MCT) replaced by long chain triacylglycerols (LCT)) and standard modified baby milk (Cow and Gate Premium). 22 infants of birth weight less than 1500 g and gestational age less than 33 weeks were studied for three weeks when enteral feeds were well tolerated. Nenatal was given to all infants for the first and third weeks, during the middle week 11 infants received Premium and 11 infants received modified Nenatal. On Nenatal there was a significant elevation of serum beta-hydroxybutyrate and small amounts of medium chain fatty acids were detected in the serum. Glucose and long chain triacylglycerol levels were similar on all feeds. Incremental weight gain and energetic efficiency of weight gain was significantly greater on Nenatal than on Premium, but there was no difference in this respect between Nenatal and modified Nenatal. We conclude that the use of a special low birth weight formula is associated with increased weight gain, but this is not dependent on the presence of MCT in the feed. Therefore although feeds containing MCT are well tolerated, there seems little advantage in including MCT in the formulation of low birth weight feeds.

Body Weight↗
PubMed1986

Prevention of postneonatal mortality.

Studies of postneonatal mortality in Nottingham between 1974 and 1977 showed a familiar pattern of high death rates in socially deprived parts of the city. A birth scoring system was devised, which identified at birth 9% of infants in whom 53% of postneonatal deaths could be expected to occur From 1 January 1978 this group was identified by midwives and followed up intensively by health visitors. The postneonatal mortality in the city of Nottingham fell from 8.7/1000 live births in 1974 to 3.6/1000 in 1981. It was not possible, however, to show that the rate of improvement after the introduction of the birth scoring system was greater than the trend present before its introduction. The causes of postneonatal death, and their geographical and seasonal distribution, were similar in 1978-81 and 1974-77, despite an absolute fall in numbers. By 1981 the important risk factors were either recorded on the birth notification or known to the health visitor in any case. Although nurse managers and most health visitors have found the scheme useful in other respects--for example, resource allocation--it was considered that these could be achieved without a formal scoring system. Therefore, the birth scoring system was stopped at the end of March 1985. Health visitors are still being encouraged to pay more attention to high risk cases as a part of normal clinical practice.

Birth Weight↗
PubMed1986

The preferred environmental temperature of newborn rabbits.

The preferred environmental temperature (TE) and rates of oxygen consumption (VO2) around the thermal neutral range were measured in rabbits on the day of birth and 2, 7 and 14 days after birth. On day 0, the preferred TE was 38.0 +/- 0.8 degrees C, and it fell to 30.4 +/- 0.5 degrees C by day 14. Day-0 rabbits kept for 1 h in a warm (41 degrees C), neutral 39 degrees C) or cool (28 degrees C) environment selected a different TE at 39.8, 39.5 and 37.3 degrees C, giving colonic temperatures (TC) of 40.8, 39.9 and 37.7 degrees C, respectively. A similar phenomenon occurred on day 2, but not on day 7. It was concluded that newborn rabbits select a TE to match that which they experienced in utero and that this preferred TE changes after birth depending on the temperature of their surroundings and the development of their thermoregulatory control.

Aging↗