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Biomedical subjects

M Thomas

Publications and source records attributed to M Thomas.

At least 775 records · Page 43Linked to original sources
PubMed1985

Duplex scanning with continuous wave Doppler for carotid disease.

Duplex scanning with the use of continuous wave Doppler instrumentation was used for the evaluation of carotid disease and compared to angiography. In twenty such patients 100% accuracy for diagnosis of total occlusion by Duplex scanning with continuous wave Doppler, was obtained. The sensitivity for those patients with 50%-99% stenosis was 92% and for those patients with 20%-49% stenosis was 75%. The overall accuracy for this diagnostic test for all groups of stenosis was 85%. This compares favorably with other noninvasive vascular techniques and is felt to be an accurate and useful technique for the detection of carotid stenosis. Several advantages of this technique are pointed out.

Angiography↗
PubMed1985

Functional selection and analysis of yeast centromeric DNA.

A direct selection procedure has been used to isolate 11 distinct yeast genomic DNA fragments that eliminate the extreme segregation bias characteristic of autonomously replicating yeast plasmids. The selection scheme takes advantage of the fact that the cloned ochre suppressing tRNA gene, SUP11, is lethal at high copy number and therefore causes cell death when present on an ARS plasmid that lacks a cis-acting partition function. Each of the cloned DNA sequences was mapped to specific yeast chromosomes by hybridization to chromosome-sized DNA molecules separated by alternating field electrophoresis. Ten of the cloned fragments correspond to chromosomal centromeres; one fragment corresponds to the cis-acting locus required for endogenous 2 mu plasmid stability. Nucleotide sequence comparison of the ten centromere DNAs gives a new picture of conserved centromere DNA elements.

Base Sequence↗
PubMed1985

[Familial myeloma. Apropos of a case].

2 cases of multiple myeloma, both with IgG kappa, are reported in a man and his daughter. 33 other cases of myeloma involving two or more first degree relatives have been reported in the literature. Reported cases showed no major specific characteristics of the myelomas involved. Monoclonal protein family members were rarely identical. Our observation of identical monoclonal protein in two family members has only been found in 4 other reports. Occurrence of several cases of myeloma in one family is unlikely to be due to chance alone and the possibility of familial myeloma must be considered. Reports of benign monoclonal gammapathy in other members of the family of a patient with myeloma is also in favor of genetic factors. HLA-typing has shown an increase in frequency of the 4c complex and HLA-A9 in myeloma, and the latter was present in our patients. A genetic predisposition is further supported by experimental observations in mice. Finally, the short delay between onsets of myeloma in family members, less than 5 years in 20 families out of 27, and 4 years in our case, suggests a possible role of environmental factors.

Aged↗
PubMed1985

Effect of plasma levels of parathyroid hormone on NADPH pathways in kidney and liver.

NADPH available for mixed function oxidations (pathway 1) or biosynthetic processes (pathway 2) has been evaluated in different cells from rat liver and kidney. In addition, changes of the proportion of NADPH utilized in each pathway were demonstrated in the same cells from rats showing different circulating levels of parathyroid hormone (PTH). Quantitative levels of NADPH directed into each of these pathways have been measured and histologically located in sections from rat liver and kidney using quantitative cytochemistry and scanning and integrating microdensitometry. Centrilobular hepatocytes utilize the major amount of NADPH, either via pathway 1 or 2. Kidney cells utilize most NADPH via pathway 2, particularly in the distal part of the nephron. The cells of the pars recta have shown the highest capacity to utilize NADPH via pathway 1, which is about half that of centrilobular hepatocytes. In centrilobular cells, the presence of high plasma levels of PTH results in a significant increment of NADPH utilization either via pathway 1 or 2. In kidneys from rats showing high plasma levels of PTH, a selective increase in NADPH utilized via pathway 2 was observed in the distal convoluted tubule whereas a selective increase in NADPH utilized via pathway 1 was demonstrated in cells of the pars recta. These observations provide further information in the understanding of the physiology of kidney and liver cells.

Animals↗
PubMed1985

The contribution of spectral analysis to the diagnosis of carotid artery disease.

Pulsed and continuous-wave Doppler examinations with spectral analysis were performed on 258 carotid arteries in 220 patients and compared with multiplane contrast angiography. Each artery was examined for stenosis and assigned to one of four groups: normal to 19%, 20% to 49%, 50% to 99%, and occlusion. The incidence of disease was 70%. Diagnostic sensitivity with all noninvasive techniques varied from 76% to 90% depending on the degree of stenosis, with an overall accuracy rate of 86%. In an attempt to evaluate the diagnostic contribution of spectral analysis, stenosis classification by peak frequency alone was compared with that of the full laboratory profile, including spectral analysis. In the 147 carotid arteries in which such data were available, diagnostic sensitivity was improved with spectral analysis by 8% to 29% depending on the degree of stenosis. Detection of occlusions was unchanged. The major contribution of spectral analysis was in detecting non-flow-limiting stenoses of 20% to 49%. Spectral analysis added little to the diagnostic ability of peak frequency to detect lesions with greater than 50% stenosis. Spectral analysis of either pulsed Doppler or continuous-wave Doppler signals is an accurate noninvasive method for evaluating carotid bifurcation disease, which particularly improves the detection of non-flow-limiting stenoses.

Arterial Occlusive Diseases↗
PubMed1985

The results of a selective surgical policy on the cognitive abilities of children with spina bifida.

A cohort of spina-bifida children born between 1973 and 1978 and subjected to selection for surgery was divided into those who met specific physical criteria at birth and were offered immediate treatment, and those who had delayed treatment because of adverse criteria. There was a significantly higher level of intelligence among children treated immediately but a fifth of those given delayed treatment had normal levels of intelligence. There were negligible differences in intelligence between the children given delayed treatment and an unselectively treated series of children born between 1964 and 1966, suggesting that postponing surgery for a period does not necessarily have a disastrous effect upon ability.

Child↗
PubMed1985

Postpartum cervical myofascial pain syndrome: review of four patients.

Four postpartum patients with complaints of headache and neck pain were examined. All had received epidural analgesia and had a long second stage associated with prolonged pushing. Many similarities to postdural puncture headache were noted. The headache started the day after delivery and involved the occipital region primarily, along with the neck and shoulder girdle areas. However, the pain did not change with positional changes and was associated with marked tenderness of muscles at specific anatomic points. A diagnosis of cervical myofascial pain was made. All patients responded quickly to physical therapy. The authors suggest that many patients initially considered to have postdural puncture headache may actually have postpartum cervical myofascial pain.

Adult↗
PubMed1985

Granuloma annulare of the eyelid.

A five-year-old patient presented with nodular lesions on the left upper lid, index finger and thigh. Biopsy revealed granuloma annulare. The lesions resolved without treatment. This entity should be considered in the differential diagnosis of eyelid nodules.

Biopsy↗