Search PubMed⌕ Search

Biomedical subjects

I Thomas

Publications and source records attributed to I Thomas.

At least 91 records · Page 5Linked to original sources
PubMed1981

[Effect of clonidine on plasma-catecholamine levels at rest and on ergometric exercise (author's transl)].

The effect of clonidine on peripheral venous-plasma catecholamine concentration was assessed in ten subjects with normal circulation, at rest and on submaximal bicycle exercise. Three hours after oral intake of 300 micrograms clonidine in single dose there was significant lowering of the plasma adrenaline and noradrenaline levels. Six hours after intake the lowest plasma catecholamine level was reached, but after 24 hours the clonidine effect had largely disappeared. The sympatholytic effect of clonidine was relatively less marked with bicycle exercise than at rest. When clonidine had been given for only a short period at moderate dosage, there was no exaggerated catecholamine rise. Clonidine administration did not effect plasma dopamine levels. These results indicate that clonidine decreases plasma adrenaline and noradrenaline levels without significant effect on circulatory regulation.

Adult↗
PubMed1980

Vascularized rib-periosteal and osteocutaneous reconstruction of the maxilla and mandible: an assessment.

Three approaches to provide rib-periosteal or osteocutaneous composite tissue in maxillary or mandibular reconstruction are presented. All methods appear to be useful in replacing viable osteocytes and improving vascularity of maxillary or mandibular defects. Disadvantages include the bulk of the transplanted tissue, volume deficiency of bone, and the unreliability in viability of the associated cutaneous tissue, especially with the posterior and posterolateral approach. Significant patient morbidity and pulmonary complications in our series should indicate caution when considering these methods of reconstruction. At present, rib-periosteal transplantation is most often indicated to replace segmental defects of mandibular continuity when the recipient bed is avascular but the quantity of cutaneous cover is adequate. In those patients with deficient soft tissue and a small segmental mandibular loss, reconstruction with musculocutaneous flaps and nonvascularized bone grafts is indicated. With extensive deficiencies of both soft tissue cover and mandibular or maxillary continuity, an iliac osteocutaneous flap based on the deep circumflex iliac vessels may be the most effective. Lower patient morbidity statistics should be anticipated.

Evaluation Studies as Topic↗
PubMed1979

Hypertrophic obstructive cardiomyopathy and coronary artery spasm.

Three patients had hypertrophic obstructive cardiomyopathy and coronary artery spasm. The clinical diagnosis of hypertrophic obstructive cardiomyopathy, in all patients, was confirmed by echocardiography and angiography. Significant spasm of the right coronary artery was demonstrated in each patient by selective coronary arteriography. One patient had atherosclerotic obstructive three vessel disease, while the other two showed no evidence of any fixed organic narrowing of the coronary arteries. ST segment elevation in the inferior ECG leads was documented in two of the patients in association with coronary spasm.

Cardiomegaly↗
PubMed1978

Ultrastructure of the skin of patients treated with sodium aurothiomalate.

Skin biopsies from cases of rheumatoid arthritis treated with sodium aurothiomalate were examined with the electron microscope. Intralysosomal gold deposits were found in the macrophages of both normal-looking skin and from areas of erythematous rash that had developed as a toxic manifestation of gold therapy. The main difference between affected and normal-looking skin was the presence of numerous mast cells in the former. It is hence suggested that the dermatologic side-effects of gold are probably mediated by the release of vasoactive substances from mast cells and that vigorous administration of antihistamines to neutralise the liberated products of mast cells or an agent that interferes with degranulation of mast cells might have a palliative effect on the skin rash that sometimes develops during chrysotherapy.

Adult↗
PubMed1978

Long-term effects of myochrysine on the synovial membrane and aurosomes.

Mysochrysine injected into the rabbit knee joint produced regressive and destructive changes in the synovial membrane, ultimately leading to fibrosis. Aurosomes, containing characteristic electron-dense deposits indicating the presence of gold, formed in the synovial intimal cells and subsynovial macrophages. The number of aurosomes decreased with the passage of time but some were found even 2 yr after the injection of Myochrysine. Electron-probe X-ray analysis showed that the aurosomes contain gold, sulphur and phosphorus. A comparison was made between the atomic ratios of these elements in 3-day and 18-mth-old aurosomes but no significant difference was detected.

Animals↗
PubMed1978

Ultrastructure of rabbit semilunar cartilages.

A light and transmission electron microscopical study of 6 to 8 months old rabbit semilunar cartilages has shown that the cells in this tissue resemble chondrocytes more than fibroblasts. The prominent organelles in these cells were rough endoplasmic reticulum and the Golgi complex. An unusual finding was the occurrence of filamentous material in Golgi sacs and vesicles, and collagen fibrils within smooth membrane-bound tubular structures, apparently within the cells. Collagen fibrils forming fibres, fibre bundles and lamellae constituted the major component of the menisci. Protein-polysaccharide particles and associated fine filaments were found in the interfibrillary matrix and in the sparse territorial matrix adjacent to the chondrocytes. Numerous immature elastic fibrils, and rare mature elastic fibres with an electorn-lucent amorphous core, were also found in the general matrix amongst the collagen fibrils.

Animals↗
PubMed1977

Aurosomes produced in the synovial membrane by the oral administration of a gold compound SK & F 36914.

Chlorotriethylphosphine gold (SK & F 36914) administered orally to rabbits produced aurosomes in the synovial membrane. These aurosomes were similar to aurosomes produced by parenteral or intra-articular injections of soluble gold salts such as sodium aurothiomalate and aurothioglucose. This study shows, (1) that an orally administered gold compound is capable of producing gold deposits in the synovial membrane, and (2) that such compounds may have a future in the treatment of rheumatoid arthritis.

Administration, Oral↗
PubMed1977

Long-term results of superficial defects in articular cartilage: a scanning electron-microscope study.

Superficial defects produced in rabbit articular cartilage were studied with the scanning electron microscope over a period of 2 yr. It would appear that at first a new layer of matrix forms on the injured surface but that this is abraded away by joint movement so that even after 2 yr the defect does not heal. In some instances the general articular surface developed superficial fissures, deep ravines, and foci of fibrillation.

Animals↗
PubMed1977

Comparative ultrastructural morphology of aurosomes produced by colloidal gold and soluble gold salts.

Intra-articular administration of colloidal gold produced aurosomes which contained spherical electron-dense granules and also often some very fine electron-dense particles. Intra-articular administration of aurothioglucose produced aurosomes of a morphology similar to that reported to occur after administration of sodium aurothiomalate. These aurosomes produced by soluble gold salts are characterised by particle and granule-studded membranous formations which present in profile as rod-like and curled filamentous structures. On the basis of morphological differences two types of aurosomes should be recognised, the "Type I or granular aurosome" and the "Type II or membranous aurosome".

Animals↗
PubMed1977

Humps on young human and rabbit articular cartilage.

Scanning electron microscopic studies revealed numerous humps on the surface or articular cartilage from a 7 years old boy and from 1 month old rabbits. This shows that the surface topography of articular cartilage in young individuals is different from that of older individuals (human and rabbit) where the surface is beset by numerous pits. In 2 months old rabbits an intermediate situation was witnessed, for both shallow pits and occasional humps were present. Ridges and undulations were not seen on the articular surface of the 7 years old boy, except near the cut edge of the specimen. They were, however, found on air-dried specimens of 1 month old rabbit cartilage, but were absent from specimens dried by the critical-point method. The collective evidence supports the idea that ridges and undulations are not a constant feature of the normal articular surface, but that such features are artefactual, a typical or pathological.

Animals↗