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Biomedical subjects

A Hayward

Publications and source records attributed to A Hayward.

61 records · Page 4Linked to original sources

Microchimerism and tolerance following intrauterine transplantation and transfusion for alpha-thalassemia-1.

A fetus homozygous for alpha-thalassemia-1 was given haploidentical paternal CD34 cells at 13, 19 and 24 weeks' gestation and supported through pregnancy by blood transfusion. The fetal hematocrit ranged between 27 and 47% and between one half and three quarters of this hemoglobin was of recipient (Bart's) type. Intrauterine growth proceeded normally and no significant fetal hydrops was detected. Tests for donor HLA antigens, and alpha-globin DNA, were negative on fetal blood samples drawn before birth. A positive signal for alpha-globin DNA was obtained from cord blood and from marrow obtained at 3 months of age, suggesting that some donor stem cells had persisted in the recipient. The infant's blood mononuclear cells showed little proliferative and no cytotoxic response to the donor while responses to a third party were present. Additional paternal CD34 cells given at 3 months age did not reduce transfusion dependency in the subsequent 6 months. Our results show that repeated transfusions can support an alpha-thalassemia-1 fetus through pregnancy, in this instance without significant birth defects or apparent hypoxic tissue injury. The donor stem cells did not have a survival advantage compared with endogenous stem cells, but appeared to survive in the recipient as judged by the persistence of an alpha-globin DNA signal. In vitro studies of alloreactivity suggest tolerization of the host to the donor's MHC disparity. Future efforts will focus on exploiting this tolerance to improve the level of donor chimerism.

Antigens, CD34↗

Joint hypermobility: the use of a new assessment tool to measure lower limb hypermobility.

OBJECTIVES: The aim of the study was to compare the use of a new assessment tool for diagnosis of hypermobility in the lower limb to the Beighton score for generalised hypermobility. METHODS: Three groups of children were compared (n = 225) and included a "normal" population of 116 school children, a "possible hypermobile" group of 88 children attending afoot and gait clinic and a "known hypermobile" group of 21 children referred from a paediatrician or rheumatologist. The Beighton score was used to measure generalised hypermobility. The Lower Limb Assessment Score was used to measure hypermobility in the lower limbs. RESULTS: The Lower Limb Assessment Score was able to distinguish between the three groups of children better than the Beighton score. At a threshold of 5/9 indicating hypermobility, the Beighton score identified hypermobility in 34% of school children; the lower limb score identified hypermobility in 21% of school children after a threshold was identified. There was disagreement between the scores in school children where 26.7% of children appeared to have a positive Beighton score that was not accompanied by a positive lower limb score. In the "known hypermobile" group the Beighton score was positive in only 10% of children when the lower limb score was negative for hypermobility. CONCLUSION: In this group of school children, the Beighton score appeared to over-diagnose hypermobility at the threshold of 5/9. Specific thresholds for diagnosis need to be set dependant on the age and ethnic group of the population being studied. The Lower Limb Assessment Score may be a useful score for health professionals specifically interested in lower limb hypermobility.

Adolescent↗

Pathophysiological basis of burn management.

Despite increased public awareness of the dangers of fire, burns remain a part of everyday life. Most accident departments will see one or more burn victims each day and, although not common, major burns still occur. In this and a second article we review the pathophysiology of thermal injury and describe the early treatment of a major burn victim.

Burns↗

The early management of large burns.

The first article in this series (Vol 52 (11), p.583) discussed the pathophysiological processes involved in burn injury. This article describes the early management of large burns, in which treatment is considered in four stages: resuscitation, assessment, further care and transfer. The mnemonic 'RAFT' is suggested as a means of assisting recall of the management process.

Burn Units↗