PubMed Health⌕ Search

Biomedical subjects

M Newton

Publications and source records attributed to M Newton.

At least 19 recordsLinked to original sources
PubMed1992

Bone composition measured by x-ray scattering.

Ten composite samples consisting of cortical bone and adipose tissue, in known proportions, were made. The intensity of monochromatic x-rays (energy 8 keV) scattered by these samples was determined as a function of the modulus of the scattering vector, K. The ratio of the heights of peaks at K values of around 134 and 22 nm-1 provided a measure of the ratio of adipose tissue to bone mineral in these samples. This method was then used to determine the ratio of adipose tissue to mineral in samples of trabecular bone from 16 vertebral bodies. The results were correlated with measurements of the bone composition determined by ashing (r = 0.66) and histomorphometry (r = 0.66). Furthermore, the ashing and histomorphometry results were correlated with each other (r = 0.68). The feasibility of using higher energy x-rays (35-80 keV) for obtaining the same information from bone within the body is briefly discussed.

Adipose Tissue↗
PubMed1992

Objective clinical evaluation of physical impairment in chronic low back pain.

The aim of this study was to investigate physical impairment in patients with chronic low back pain, to develop a method of clinical evaluation suitable for routine use, and to consider the relationship between pain, disability, and physical impairment. Twenty-seven physical tests were investigated. Permanent anatomic and structural impairments of spinal deformities, spinal fractures, surgical scarring, and neurologic deficits were excluded as not relevant to the patient with low back pain in the absence of nerve root involvement or previous surgery. Three consecutive 20-patient reproducibility studies were used to develop reliable methods of examination for 23 of the tests. Only four tests were excluded as unreliable: sacral angle, pelvic tilt, and separate lumbar and pelvic extension, none of which are part of routine clinical examination or have any proven relationship to disability. The remaining 23 physical tests were evaluated in 70 asymptomatic subjects and 120 patients with chronic low back pain. Passive knee flexion, passive hip flexion, hip flexion strength, hip abduction strength, pain reproduction on each of these tests, and the prone extension strength test were excluded because they were too closely related to nonorganic and behavioral responses to examination. Eight tests successfully discriminated patients with low back pain from normal subjects and were significantly related to self-report disability in activities of daily living: pelvic flexion, total flexion, total extension, lateral flexion, straight leg raising, spinal tenderness, bilateral active straight leg raising, and sit-up. Factor analysis failed to demonstrate an underlying statistical dimension of physical impairment. However, an empirical combination of total flexion, total extension, average lateral flexion, average straight leg raising, spinal tenderness, bilateral active straight leg raising, and sit-up provided an equally satisfactory alternative. Simple cut-offs from normal subjects made the scale simple and quick to use. This final scale successfully discriminated 78% of patients and normal subjects and explained 25% of the variance of disability, with a specificity of 86% and sensitivity of 76%. This scale provides an objective clinical evaluation that meets the criteria for evaluating physical impairment, yet is simple, reliable, and suitable for routine clinical use. It should, however, be emphasized that all the tests included in the final scale are measures of current functional limitation rather than of permanent anatomic or structural impairment. This raises questions about the physical basis of permanent disability due to chronic low back pain.

Activities of Daily Living↗
PubMed1992

The effect of transplantation site and islet mass on long-term survival and metabolic and hormonal function of canine purified islet autografts.

Determination of the long-term function of islet transplantation in relation to the implantation site and the numbers of islets is of scientific interest and, with human islet transplant trials in progress, is a pressing clinical question. In this study, highly purified canine islets were isolated by collagenase digestion and Ficoll purification, and autotransplanted into either the spleen (in 10 dogs) or the liver (in 12 dogs). Dogs transplanted with islets into the spleen or liver received 264,300 +/- 20,300 (mean +/- SEM) and 158,600 +/- 15,000 islet equivalents (150-microns-sized islets) respectively. Graft survival at 1 yr was 86% in intrasplenic islet autografts (ISTx) and 50% in intraportal islet autografts (IPTx). Intravenous glucose tolerance tests and mixed meal-oral glucose tests were performed 1-12 mo from islet transplantation. Compared to controls, ISTx and IPTx dogs showed a similar decrease of glucose tolerance after both intravenous glucose tolerance tests and mixed meal-oral glucose tests. On intravenous glucose tolerance tests, plasma insulin levels were lower in ISTx than in IPTx dogs and controls. On mixed meal-oral glucose tests, insulin values were higher in IPTx dogs than in controls. There was a positive correlation (r = .56, p < 0.05) between the number of transplanted islet equivalents and the K values. These results demonstrate that, in dogs with islet transplant: 1) long-term islet survival can be achieved in the spleen better than in the liver; 2) islet survival is related to the mass of transplanted islets in the spleen, but not in the liver, where other factors probably affect islet survival; 3) the ability of metabolizing glucose is reduced after both intrasplenic and intraportal islet autografts; 4) both reduced insulin secretion (predominant in ISTx dogs on intravenous glucose tolerance testing) and insulin resistance (predominant in IPTx dogs on mixed meal-oral glucose tests) are the probable causes of the decreased glucose tolerance.

Animals↗
PubMed1991

Use of the polymerase chain reaction for homology probing of butyrylcholinesterase from several vertebrates.

Genomic blots from man, monkey, cow, sheep, pig, rabbit, dog, rat, mouse, guinea pig, and chicken DNA were hybridized with probes derived from the four exons of the human butyrylcholinesterase gene (BCHE) (Arpagaus, M., Kott, M., Vatsis, K. P., Bartels, C. F., La Du, B. N., and Lockridge, O. (1990) Biochemistry 29, 124-131). Results showed that the BCHE gene was present in a single copy in the genome of all these vertebrates. The polymerase chain reaction was used to amplify genomic DNA from these animals with oligonucleotides derived from the human BCHE coding sequence. The amplified segment contained 423 bp of BCHE sequence including the active site serine of the enzyme (amino acid 198) and a component of the anionic site, aspartate 70. Amplification was successful for monkey, pig, cow, dog, sheep, and rabbit DNA, but unsuccessful for rat, guinea pig, mouse, and chicken DNA. Amplified segments were cloned in M13 and sequenced. The mouse sequence was obtained by sequencing a genomic clone. The highest identity of the human amino acid sequence was found with monkey (100%) and the lowest with mouse (91.5%). The sequence around the active site serine 198, Phe-Gly-Glu-Ser-Ala-Gly-Ala, was conserved in all eight animals as was the anionic site component, aspartate 70. A phylogenetic tree of mammalian butyrylcholinesterases was constructed using the partial BCHE sequences.

Amino Acid Sequence↗
PubMed1991

The effects of exercise in a coronary rehabilitation programme.

Twenty-two male and female patients who had recently suffered a myocardial infarction were randomly assigned to a treatment group who participated in a 10-week exercise-based cardiac rehabilitation programme or a routine care group who did not participate in the rehabilitation programme. Physiological and psychological function were assessed before the programme started and after it finished. Results indicated that the treatment group did not improve physiological functioning more than the control group but they did evidence statistically significant improved psychological functioning. This investigation appears to be the first attempt to assess the potential benefits of an exercise-based cardiac rehabilitation programme in Glasgow and supports the suggestion that exercise-based cardiac rehabilitation has psychological benefits.

Aged↗
PubMed1979

Quality of life for the gynecologic oncology patient.

An attempt is made to define the quality of life in terms of the patient with gynecologic cancer. The effect of the diagnosis of cancer and its recurrence or its terminal state on the quality of life is considered. Possible methods of assessing the patient's individual feelings about the quality of her life are reviewed and suggestions made for incorporating these into plans of management at all stages of the disease.

Activities of Daily Living↗
PubMed1977

A fluorescence polymorphism associated with Down's syndrome?

Fluorescence polymorphism frequencies have been determined for a group of 85 Down's syndrome cases and 164 controls. For one class of polymorphism, that of positive satellites of chromosome 21, the frequency in the Down's cases was significantly higher than in the controls; the distribution of positive satellites in the mongols indicates that in the majority the extra chromosome arose by first meiotic non-disjunction. The possibility that positive satellites on chromosome 21 could be a causative factor in Down's syndrome is discussed, and the implications of this possibility on the assessment of the risk of producing a Down's child are examined.

Adolescent↗