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Biomedical subjects

A M Wilson

Publications and source records attributed to A M Wilson.

At least 127 records · Page 7Linked to original sources
PubMed1996

Treatment of acute superficial digital flexor tendon injury in horses with polysulphated glycosaminoglycan.

Horses with acute injuries of the superficial digital flexor tendon were treated with a course of seven intramuscular injections of 500 mg of polysulphated glycosaminoglycan at four-day intervals. Clinical assessments of the lesions were made by a veterinary surgeon at the time of each injection and 14 and 28 days after the last injection. A total of 150 courses of the drug were administered and adequately completed assessment forms were returned for 80 cases. Long-term follow-up data were obtained for 19 cases. The subjective assessments by the veterinary surgeons showed that in 80 per cent of cases the drug was felt to be of value in the treatment of acute tendon injury.

Animals↗
PubMed1996

Role of image-guided core-needle biopsy in the management of patients with lymphoma.

PURPOSE: The results of 106 radiologically guided core needle biopsies in 96 patients were analyzed retrospectively to evaluate the accuracy, safety, and role of this technique in the management of patients with lymphoma and to determine factors predictive of success. PATIENTS AND METHODS: Biopsies were performed in 51 patients with low-grade non-Hodgkin's lymphoma (NHL), 24 with high-grade NHL, 16 with previously diagnosed Hodgkin's disease (HD), and 15 with no previous history of lymphoma. Disease was infradiaphragmatic in 92 patients and supradiaphragmatic in 14. Computed tomography (CT) guidance was used in 98 biopsies and ultrasonography (US) in eight. RESULTS: The biopsy was diagnostic and yielded information on the basis of which treatment was started in 88 of 106 patients. The procedure was well tolerated and there were no major complications. Small size of the sample or inappropriate tissue sampled were the main causes of failure. The technique was equally successful in the diagnosis of HD and both high-grade and low-grade NHL as in nonlymphoproliferative disorders. The procedure was equally successful at diagnosis as at suspected recurrence or progression. In 33 of 80 cases in which the biopsy was performed at the time of recurrence or progression, the histology had changed; in 31 of 33, this influenced treatment. The technique was efficient at diagnosing transformation of follicular NHL in 16 of 18 patients, which allowed early adjustment of treatment at recurrence. CONCLUSION: At St Bartholomew's Hospital (SBH), image-guided core-needle biopsy has proven to be a quick, safe, and efficient alternative to excisional biopsy in the evaluation of lymphoproliferative disorders at presentation, recurrence, or progression. It should become the procedure of choice for histologic sampling in the absence of peripheral lymphadenopathy.

Adolescent↗
PubMed1995

The response of the skeleton to physical training: a biochemical study in horses.

In this study we tested the hypothesis that exercise induces an adaptive response in the developing skeleton which may be monitored in vivo by measuring biochemical markers of bone metabolism. The effects of exercise on two biochemical markers of bone formation were determined; the carboxy-terminal propeptide of type I procollagen (PICP), and the bone-specific isoenzyme of alkaline phosphatase (BAP), and one putative marker of resorption, the pyridinoline crosslinked telopeptide domain of type I collagen (ICTP). All three markers were measured for a year in 2-year-old thoroughbred horses exercised three times a week on a treadmill, and values compared to a control group of age-matched animals. Levels of all three markers fell in both exercised and control groups over the 12-month period reflecting normal age changes. However, there were differences between groups in the pattern of this decrease. When expressed as a percentage of baseline values, BAP was higher (p < 0.05) at 2 months and both BAP and the PICP were higher at 4 months (p < 0.01 and p < 0.05, respectively) in the exercised group, reflecting an increase in bone turnover in this group in the early stages of training. PICP levels were also elevated in the exercised group at 10 months and this result indicates an increase in bone turnover at this time. The changes in ICTP were different; at 2 months, levels were higher in exercised animals than in controls, but there was no significant difference between the two groups at 4 and 6 months. After 8 months, ICTP levels in the exercised group increased returning to near baseline values at 10 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1995

Nodular type of lymphocyte predominant Hodgkin's disease. A clinical study of 50 cases.

BACKGROUND: Lymphocyte predominant Hodgkin's disease (LP-HD), particularly that with a nodular pattern has been suggested to constitute a distinct disorder within the spectrum of Hodgkin's disease, this issue being based on clinical, morphological and immunological observations. Furthermore, the nodular LP-HD (N-LP-HD) has been considered to differ from the diffuse subtype (D-LP-HD), although the data are conflicting. The question addressed in this study was whether the clinical course of N-LP-HD differs from that of the D-LP-HD as well as the other subtypes of Hodgkin's disease. PATIENTS AND METHODS: 90 cases diagnosed as LP-HD at St. Bartholomew's Hospital (SBH) were reviewed. The histopathological classification was based on the original Lukes and Butler criteria for classical N-LP-HD. Clinical data were retrieved from case notes and a computer database. Stage was determined by the Ann Arbor criteria. Survival and remission duration analyses were performed for the group of patients with N-LP-HD and compared with an histological control group of patients with the other subtypes of Hodgkin's disease and the cases of LP-HD that have been reclassified. RESULTS: 1. 50/90 cases (56%) originally diagnosed as N-LP-HD qualified as N-LP-HD. No case with the diffuse subtype, could be identified. Twenty-three percent of the cases were reclassified as Mixed Cellularity and 11% as Nodular Sclerosis HD, whilst 10% as non-Hodgkin's lymphomas. 2. The majority of cases (78%) presented with early stage (I + II). Bone marrow and liver involvement were rare. 3. 92% of cases achieved complete remission. Recurrence developed in only 6/46 patients within 5-12 years. A second complete remission was achieved in 5/6 (83%) cases. Further recurrences have not yet occurred. 4. The overall survival of the 50 cases with N-LP-HD was 92% at 4 years and did not differ significantly from the 40 cases that have been reclassified. Remission duration however, was significantly better for the group of N-LP-HD being 81% at 12 years. 5. Second malignancies were common and developed in 6/50 cases (12%) with N-LP-HD within 10-15 years. These included: ALL (1 case), high grade B-NHL (2 cases), squamous cell carcinoma (1 case), glioma (1 case), lung carcinoma (1 case). 6. 12/50 patients died within a period of follow-up, up to 21 years. 1/3 of the deaths was attributed to the development of second malignancy. CONCLUSIONS: The diffuse variant of LP-HD is rare, having not been seen at St. Bartholomew's Hospital during this time period. The 50 cases with N-LP-HD showed a favourable course with presentation at an early stage, good response to treatment, late recurrences and remission duration other than the other subtypes of HD. The latter could be attributable to the early stage at presentation of N-LP-HD, since the remission duration on a matching on stage analysis was superficially better in favour of N-LP-HD (p = 0.06). The indolent course of the disease in combination with the risk of second malignancy cases raises the question whether histology should be taken into consideration in the development of new protocols for HD.

Adolescent↗
PubMed1994

Exercise-induced hyperthermia as a possible mechanism for tendon degeneration.

Mathematical modelling of tendon thermodynamics predicted that the temperature of the central core of the equine superficial digital flexor tendon would plateau at 11 degrees C above the tendon surface temperature during a sustained gallop. A mean temperature differential (between tendon core and surface) of 5.4 (S.E. +/- 1.0) degrees C was demonstrated in vivo in four horses. Peak intra-tendinous temperatures in the range 43-45 degrees C were recorded. Temperatures above 42.5 degrees C are known to result in fibroblast death in vitro [Hall (1988) Radiobiology for the Radiologist, 3rd Edn., pp. 294-329]. These in vivo recordings provide a possible aetiology for the degenerative changes that are observed in the central core of tendons in both equine and human athletes.

Achilles Tendon↗
PubMed1994

The pathobiology and repair of tendon and ligament injury.

Injury of the collagenous structures comprising tendons and ligaments, either from acute trauma or from repetitive strain lesions, results in protracted periods of disability. The resolution of such injuries often fails to restore the normal morphologic and functional characteristics of the structure and, therefore, either compromises the future performance of the individual or predisposes to an increased risk of recurrent injury.

Animals↗
PubMed1994

Integration of physical, genetic and cytogenetic maps of human chromosome 7: isolation and analysis of yeast artificial chromosome clones for 117 mapped genetic markers.

An important goal for the human genome project is to assemble fully integrated physical, genetic and cytogenetic maps for each human chromosome. Towards that end, we have isolated yeast artificial chromosome (YAC) clones containing 117 of the 119 genetic markers that constitute a recently constructed, detailed genetic map of human chromosome 7. Analysis of these clones reveals numerous examples where adjacent genetic markers have been physically connected, either in individual YACs or in multi-YAC contigs. At present, the 117 genetic markers are contained in fewer than 80 YAC contigs, with most of these contigs uniquely ordered relative to one another based on the genetic map positions of the corresponding markers. These YACs and YAC contigs are estimated to contain approximately 60-85% of the DNA from human chromosome 7. YACs representing 36 genetic markers were mapped by fluorescence in situ hybridization (FISH) to metaphase chromosomes, allowing assignment of these genetic markers to cytogenetic bands along chromosome 7 and placement of the centromere within the genetic map. Together, these studies provide genetically and cytogenetically anchored YAC clones covering the majority of chromosome 7 that will be useful both for the positional cloning of genes and as a framework for assembling a complete YAC-based physical map of the chromosome.

Chromosome Mapping↗
PubMed1993

Issues in intensive care visiting.

In order to obtain a contemporary view of the visiting hour regimes in intensive care units (ICUs) in the UK, a national telephone survey was performed. 122 geographically representative units were contacted, representing 42% of the total number of units in the UK. 107 units gave consent to participate in the study, of which 66 units allowed visiting at any time of the day. Many of these units however restricted the number or kind of visitors and only 19% could be regarded as having 'true' open visiting, that is, visiting at any time of the day for any age of child, any member of the family, or friends. Several of the topics arising from the study are discussed in more detail, for example the childhood risk of infection and/or psychological trauma and the needs of the family. Based on the available research evidence, a more liberated view of hospital visiting is necessary, with relaxation of what often amount to restricted visiting regimes. Several recommendations for further research are made.

Adolescent↗
PubMed1992

Functional significance of the morphology and micromechanics of collagen fibres in relation to partial rupture of the superficial digital flexor tendon in racehorses.

The high incidence of partial rupture of the superficial digital flexor tendor in the equine athlete represents a major cause for concern in the racing industry. Frequently, the lesion is localised to the central core of the tendon. This study tested the hypothesis that the site specific structural failure results from differences in the collagen fibre morphology and associated micromechanics between central and peripheral regions of the tendon. Bundles of collagen fibres were dissected from central and peripheral sites in the mid-metacarpal region of the tendon. Crimp morphology was quantified by polarised light microscopy and mechanical characteristics determined using a fibre tensometer. In older horses, centrally located fibres showed significantly lower values for crimp angle, crimp length and toe limit strain than seen peripherally. There were no significant differences in these features between corresponding sites in the younger horses. No significant difference between sites was found in elastic modulus in either group. These data indicate a non-uniform functional stress distribution which may result from ageing or be related to the exercise history as a feature of accumulated damage. These observations may explain the location of central core lesions seen on clinical examination.

Aging↗
PubMed1991

Turtle cortical neurons survive glutamate exposures that are lethal to mammalian neurons.

Glutamate is an excitatory neurotransmitter in turtle and mammalian cortex. In high concentrations it is toxic to mammalian neurons and is an important mediator in the pathway that leads to neuronal death from anoxia. Turtle neurons are remarkably resistant to anoxic injury and we sought to determine whether part of this resistance could be attributed to the sensitivity of turtle neurons to glutamate toxicity. Embryonic turtle cortical neurons were grown for 25 days in dissociated cell culture using a modification of a method developed for murine cortical cell culture. Turtle neurons in dissociated culture were found to express glutamate receptors which include both N-methyl-D-aspartate (NMDA) and non-NMDA receptor types. Remarkably, these neurons survive 5 minute exposures to glutamate in concentrations up to 3 mM, doses 30 times the LD50 and 6 times the LD100 for mouse cortical neurons. Elucidating the mechanism for this resistance may suggest new strategies for brain protection.

Animals↗