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Biomedical subjects

D Hull

Publications and source records attributed to D Hull.

At least 37 records · Page 2Linked to original sources

Malignant lymphoma in congenital dyserythropoietic anaemia type III.

A 60 year old woman with congenital dyserythropoietic anaemia (CDA) type III developed a malignant T cell lymphoma with cutaneous and widespread nodal involvement. Bone marrow aspirates showed erythroid hyperplasia and dyserythropoiesis with multinucleate erythroblasts and gigantoblasts, in keeping with CDA type III. Electron microscopy showed multinucleate erythroblasts with notably irregular nuclear outlines and intranuclear clefts. The development of malignant lymphoma in this patient, together with a documented high prevalence of monoclonal gammopathy and multiple myeloma and a single case of Hodgkin's disease, may indicate an increased incidence of lymphoproliferative disease in CDA type III.

Anemia, Dyserythropoietic, Congenital↗

Breast milk for preterm infants.

The breast-feeding intentions and achievements of mothers of babies born prematurely were investigated in a prospective enquiry, a postal survey and by interview. The prospective inquiry was conducted from April 19 1993 to March 19 1994 on all 686 infants admitted to the two neonatal units in Nottingham. The aim was to see how many infants were offered mother's breast milk by any route. Feeding records were available for 593 infants of whom 64% were offered mother's breast milk. Gestation did not affect the mother's ability to produce milk. Infants of 24-28 weeks' gestation received breast milk for 4 to 5 weeks on average. The postal questionnaire was sent to 114 mothers whose infants were in the units for over seven days between April and October 1994. The aim was to learn how they felt about producing milk and feeding their preterm infant. 64 [59%] responded. 54% of responders and 49% of non-responders had intended to breast feed. Of the responders 65% produced some milk and 46% were home fully breast feeding. The home interviews were conducted 2-6 weeks after discharge with 16 mothers who fulfilled the criteria for the postal enquiry. The aim was to learn from mothers how the service might be improved and what motivated their choice of feeding. They requested clear guidance, agreed by all the professionals involved; a warm, comfortable and private environment; and a ready supply of breast pumps. Their choice of feeding was motivated primarily by previous experience and family pressure, not by advice from health-care professionals. CONCLUSIONS. Many mothers succeed in supplying milk for their preterm infants and many more might do so if the benefits of human milk to preterm infants were more actively advocated and the support service in the neonatal units developed.

Breast Feeding↗

Organ transplantation at the Hartford Transplant Center.

Over 1,243 organ transplants have been performed at the Hartford Transplant Center over the past two decades. Survival in kidney, heart, liver, and pancreas patients is at or above the national average. Hartford was one of the first centers to use triple immunosuppression, which significantly improved survival in kidney transplantation. For recipients of kidneys from living related donors and cadaveric kidneys, two-year actuarial graft survival has been 98% and 83%, respectively, over the last five years. For heart and liver transplants, two-year survival has been 79% and 67%, respectively. Despite high success rates at most transplant centers, donor organs remain scarce. This problem needs to be addressed through increased cooperative efforts in the health-care community and the general public.

Adolescent↗

Deficits in lower extremity muscle and gait performance among renal transplant candidates.

This study was performed to determine the reliability and convergent validity of two lower extremity muscle performance (LEMP) measurements and to describe deficits in and determinants of LEMP and gait performance. Cross-sectional case series and criterion standard designs were used. The study took place at a tertiary care center. The subjects were referred from a volunteer sample of 110 renal transplant candidates. There were no interventions. The main outcome measures were knee extension strength measured by hand-held dynamometry and a sit-to-stand-to-sit (STSTS) test; gait independence on level surfaces and stairs; comfortable and maximum gait speed. Dynamometer measurements were reliable within (intraclass correlation coefficient (ICC) > or = .976) and between (ICC > or = .953) testers. Repeated STSTS measurements were also reliable (ICC > or = .843). The LEMP measures correlated significantly (p < .001) with one another (r > or = .406, R > or = .445). Compared with values predicted by regression equations derived from healthy individuals, transplant candidates showed significant deficits in knee extension force (33.2% to 34.6%) and gait speed (20.5% to 22.7%). Consistent as determinants of LEMP were sex, weight, and diabetic status. STSTS performance was the most consistent determinant of gait performance. The results of this study support the use of the STSTS test to characterize LEMP in kidney transplant candidates, particularly those who are diabetic or have deficits in gait performance.

Adolescent↗

Fetal and maternal plasma lipids in chronically catheterized mares in late gestation: effects of different nutritional states.

The effects of different nutritional states on plasma lipid concentrations have been examined in pregnant mares and their fetuses. Maternal and fetal arterial catheters were inserted into 12 pony mares between 244-303 days' gestation (term 320-360 days) and observations made from 5 days following the insertion of catheters. After recovery from surgery maternal and fetal arterial samples were withdrawn from 7 mares with normal feeding patterns (Group IA), from four of these mares at the end of a 30 h fast and 3 h later following refeeding (Group IB) and six mares who failed to re-establish normal feeding patterns (Group II). The fatty acid concentrations and composition of the plasma free fatty acid (FFA), triacylglycerol and phospholipid fractions were analysed. Maternal FFA, triacylglycerol and phospholipid concentrations were significantly raised in the fasted (Group IB) and under-fed (Group II) mares. Fetal concentrations of FFA and phospholipid increased significantly in the group of under-fed (Group II) mares but not in the fasted (Group IB) mares. In the fetal plasma the proportions of polyunsaturated fatty acids derived from essential fatty acids in the FFA and phospholipid fractions were much higher than those in the mare. In the fasted (IB) and under-fed (II) groups the relative amounts of the polyunsaturated fatty acids in each fraction remained unchanged (P > 0.05). These results show a short fast or prolonged undernutrition result in raised maternal plasma lipid concentrations which in turn can effect the total amount of lipid in the fetal circulation. However any increases in polyunsaturated fatty acids in the fetus (e.g. in Group II) are unlikely to come from the maternal circulation; likely sources of these fatty acids are the placenta or fetal tissues.

Animals↗

Sclerosing IgA multiple myeloma.

A case of IgA multiple myeloma associated with myelofibrosis and radiological evidence of diffuse osteosclerosis from the disease onset is reported. Bone marrow trephine biopsies performed before and after chemotherapy treatment for myeloma showed grade 4 collagen fibrosis of the bone marrow, thickened bony trabeculae and the presence of plasma cells, both mature and immature. Serum electrophoresis revealed an IgA lambda-paraprotein. Throughout the course of the disease, there was persistent radiological evidence of osteosclerosis, although several lytic lesions appeared late in the disease process. The patient died 5 years after presentation, during an episode of septicaemic shock. It is speculated that cytokine(s) released by the neoplastic plasma cells may stimulate a fibroblastic reaction within the marrow, which subsequently undergoes bony metaplasia resulting in osteosclerosis.

Bone Marrow Examination↗

Effect on placental transfer of exogenous lipid administered to the pregnant rabbit.

The transfer of lipids across the placenta was measured after infusion of an emulsion of triacylglycerol and phospholipid (intralipid) into 10 anesthetized rabbits. Maternal and umbilical venous and arterial samples were collected at 10-min intervals. All samples were analyzed for concentration and fatty acid composition of FFA, triacylglycerol, and phospholipid fractions. At the end of the infusion period of intralipid, there was a significant increase in the maternal concentrations of total triacylglycerol (p < 0.01) and of total phospholipid (p = 0.01) but not of total FFA (p > 0.05). Maternal plasma triacylglycerol and phospholipid altered in composition to match that of the infused Intralipid by the end of the infusion. Despite the significant rise in maternal triacylglycerol and phospholipid concentrations, the umbilical vein-artery difference for these lipid fractions remained unchanged and very low. In contrast, the umbilical vein-artery difference for FFA (p < 0.02) rose gradually throughout the experiments. There was no significant change in the fatty acid composition of the maternal FFA, but the fatty acid composition of the umbilical vein-artery difference for FFA changed to reflect the composition of Intralipid. These experiments show that exogenous triacylglycerol and phospholipid dramatically alter the lipid fractions presented to the placenta in the maternal plasma but do not cross the placenta intact. However, the composition of the FFA crossing the placenta is modulated to become more similar to that of the exogenous lipid.

Animals↗

Albumin improves islet isolation: specific versus nonspecific effects.

1. BSA-containing solutions improve islet yields using standard collagenase digestion techniques. 2. The BSA effect on islet isolation is independent of source and lot of collagenase. 3. The BSA effect on islet isolation is not due solely to its colloid action, as HES failed to achieve the same level of improvement seen with albumin. 4. BSA can protect islets from warm ischemic injury, and the protective action appears to be unique to albumin, as HES was not as effective.

Animals↗

Release of lipid from the equine placenta during in vitro incubation.

An in vitro incubation technique was used to examine release of lipids from the equine placenta. Placental tissue was obtained at term (n = 5, term = 320-365 days) and earlier in gestation (n = 8, mean = 266 days). Term placentae were incubated at two temperatures, 4 degrees C (control) and 37 degrees C for 2 h. Pre-term placentae were incubated at 37 degrees C with two different concentrations of fatty acid in the medium. Tissues and media were analysed for their lipid concentrations. Term and pre-term placentae released free fatty acid (FFA) and phospholipid into the incubation medium during incubation at 37 degrees C. Long chain polyunsaturated fatty acids derived from the essential fatty acids were released into the media. The fatty acid profiles of the lipids released during incubation more closely resembled those of fetal plasma than maternal plasma lipids as measured in previous studies. These data are consistent with the view that the equine placenta is a source of both FFA and phospholipid for the fetus and that the placenta may provide long chain polyunsaturated fatty acids for the fetal foal.

Animals↗

Muscle strength impairments and gait performance deficits in kidney transplantation candidates.

The purposes of this study of patients referred for renal transplant were to describe muscle strength impairments and deficits in gait performance and to establish the relationship between them. Twenty-six patients were tested. Muscle strength measurements included grip, elbow flexion, and shoulder abduction in the upper extremities, and ankle dorsiflexion, knee extension, hip abduction, and timed sit-to-stands in the lower extremities. Gait performance (level ground and stair) was quantified using ordinal scales and speed. Compared with healthy control subjects, patients demonstrated impairments in muscle strength and deficits in gait performance. Patients with diabetes demonstrated greater impairments and deficits than patients without diabetes. Patients with an active fistula demonstrated better grip strength in their upper extremity without the fistula. Gait performance was correlated significantly with lower extremity strength, with knee extension strength and weight providing the best prediction of gait speed (R2 = 0.478 to 0.617). The results of this study suggest that patients referred for renal transplantation possess both strength impairments and deficits in gait performance, the latter being related to the former. The clinician wishing to efficiently monitor strength impairments among patients referred for transplantation can obtain a reasonable indication of them from dynamometric grip and knee extension strength measurements.

Adult↗

Management of cholelithiasis in heart and kidney transplant patients: with review of laparoscopic cholecystectomy.

The purpose of this study was to determine the incidence of cholelithiasis among heart and kidney transplant recipients. Since recommendations for cholecystectomy in transplant recipients varies widely, we discuss guidelines for surgery including laparoscopic techniques. We reviewed the records of 114 patients who underwent heart transplantation from 1984 to 1993 and 539 kidney transplant patients from 1972 to 1993. Recipients of heart and kidney transplants were found to have an incidence of cholelithiasis of 12% and 3% respectively. Pretransplantation ultrasound surveillance was used in heart transplant recipients and 64% of these with asymptomatic cholelithiasis have not required surgery with close follow-up from six months to six years. Thirty-six percent of the heart patients underwent cholecystectomy. All symptomatic renal transplant patients undergoing ultrasound with the findings of cholelithiasis underwent cholecystectomy. Open cholecystectomies were performed prior to the advent of laparoscopic surgery in six of the first seven attempts. Laparoscopic cholecystectomy on heart and kidney transplant recipients was well tolerated with admission the same day of surgery, a one to two day hospital stay and maintenance of oral immunosuppression. There was a single complication of leg thrombophlebitis, no mortality, and allograft rejection did not occur.

Adult↗

The effect of endotoxin-induced fever on thermoregulation in the newborn rabbit.

1. Metabolic responses of endotoxin-injected newborn rabbits were measured in a closed circuit calorimeter at a constant environmental temperature within their thermoneutral range. Oxygen consumption and colonic temperatures were then measured over a range of environmental temperatures from 21.0 to 40.0 degrees C and the responses of endotoxin-injected rabbits compared with non-injected litter mates. 2. To measure their preferred thermal environment, endotoxin-injected and non-injected litter mates were allowed to settle on a thermal gradient and their colonic temperatures measured. 3. In a constant environmental temperature of 37 degrees C, rises in oxygen consumption and colonic temperature following endotoxin injection were found to be biphasic. Oxygen consumption rose from 21 ml kg-1 min-1 to a maximum 35 ml kg-1 min-1 and colonic temperature rose from 39.0 to 39.8 degrees C. 4. The maximal rate of oxygen consumption was the same in both injected and non-injected animals, 53 ml kg-1 min-1, being provoked at the same environmental temperature of 24 degrees C. Minimal rates of oxygen consumption were also similar for the two groups but in the injected animals they were achieved at an environmental temperature of 39 degrees C, 2 degrees C higher than for non-injected animals. 5. We conclude that newborn rabbits challenged with a pyrogen have both behavioural and physiological responses. The thermogenic response is consistent with a change in sensitivity to feedback information rather than a simple shift in the central thermoregulatory set point. We find no evidence to support the view that in the febrile response a higher body temperature necessitates an increase in metabolic rate, the so-called Q10 effect.

Animals↗

Placental transfer of free fatty acids: importance of fetal albumin concentration and acid-base status.

Free fatty acids (FFA) are the main class of naturally occurring lipids transferred across the placenta, irrespective of species. In order to study the importance of fetal plasma albumin concentration and pH on placental transfer of FFA, in situ perfusion of the rabbit placenta in late gestation was used as an experimental model. Increasing albumin concentration on the fetal side of the placenta from 1 to 6% significantly increased transfer of FFA across the placenta. However, alteration of the umbilical perfusate pH in the range 7.0-7.5 had no significant effect.

Acid-Base Equilibrium↗

Age-related changes in endotoxin sensitivity and the febrile response of newborn rabbits.

Thermoregulatory responses to pyrogens in the immediate newborn period have been reported suppressed or undeveloped. In this study we investigated these responses in the newborn rabbit. Endotoxin (Escherichia coli LPS) was injected intraperitoneally in rabbits at different doses on day 0 (day of delivery), 1 or 3 of life, each animal being used only once. Oxygen consumption (VO2) and colonic temperature (Tc) were measured continuously for up to 5 h following endotoxin administration. On all days, a thermogenic response of a similar pattern was seen. At a low dose of endotoxin, there was a monophasic rise in VO2 that reached a peak at 2 h, followed by a plateau phase lasting a further 2-3 h. At an intermediate dose the response was biphasic with an initial smaller peak after 45-60 min and a second more sustained peak developing by about 2 h. At a higher dose the depression between the two peaks became deeper and longer with the second peak becoming more delayed and weaker. As animals got older, the doses needed to produce this sequence increased. On day 0 the increased VO2 caused by endotoxin was not accompanied by an increase in Tc. By day 3, Tc rose with the increase in VO2. We conclude that rabbits on the day of delivery respond to endotoxin with an increase in VO2 and by day 3 this is accompanied by an increase in Tc. The pattern of VO2, changes from monophasic to biphasic with increasing doses of endotoxin and the sensitivity to endotoxin decreases over the first 3 days of life.

Age Factors↗