Biomedical subjects

K E Carr

Publications and source records attributed to K E Carr.

At least 91 records · Page 5Linked to original sources

PubMed1979

A preliminary study of scanning electron microscopic changes of the duodenum during healing of duodenal ulcers.

Using the scanning electron microscope, changes in the rat duodenum have been studied during the healing of gastric secretagogue-induced duodenal ulcers on the 1st, 3rd, 7th and 10th days post-infustion. A montage technique with fine resolution has allowed both the entire area of the duodenum and the cellular organization in individual villi in proximity to the ulcers to be investigated. There was a considerable range of appearances noted at any one time point due to the variations in the size and depth of the original area of ulceration. On day 1, there was acute destruction of the mucosal surface with distortion of the villi at the ulcer margin. By the 3rd day, some specimens already showed full epithelialization over the defects whereas others up to day 10 revealed persistent areas of ulceration. Occasional specimens showed areas suggestive of gastric surface metaplasia on the villous surface adjacent to these ulcers.

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PubMed1979

Scanning electron microscopy of macrophages: a bibliography.

In this bibliography an attempt has been made to gather together as much as possible of the widely spread literature on the scanning electron microscopic appearances of macrophages. The primary source for these references was a medline search, supplemented by any secondary references obtained. The listed references have all been examined in detail by the compilers. In the subject index, an attempt has been made to draw the reference together into broad categories of biologic interest, as well as indexing for specific anatomic sites, pathologic conditions, toxic agents and so on. We hope that this compilation may be of some help to those seeking information on the surface morphology of the mononuclear phagocytes.

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PubMed1978

Hypersensitivity reactions in the small intestine. IV. Influence of allograft rejection on small intestinal mucosal architecture: a scanning and transmission electron microscope study.

The effect of a local delayed hypersensitivity reaction (allograft rejection) on small intestinal architecture has been examined by using scanning electron microscopy of the mucosal surface. In isografts, regarded as a morphological basis for normality of the system, the villi appeared normal and finger like. In allografts the appearances ranged from fairly normal areas to others with stunted and ridged villi, and flat areas in which crypt mouths opened on to the flat mucosal surface. The fine structure of epithelial cells was studied further by transmission electron microscopy. There was an apparent reduction in the size of the microvillous border in allografts but no other consistent abnormality. The similarities between this model of allograft rejection, and untreated coeliac disease in man, are highlighted and contrasted with the effects of acute radiation injury on the intestine.

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PubMed1976

Scanning electron microscopy of mouse intestinal mucosa after cobalt 60 and D-T neutron irradiation.

The stem-cell population of the intestinal crypt is an important model system in experimental radiobiology. Standardized techniques have been developed to allow quantitation of the response of crypt cells to radiation injury following doses of 0-2 krad of D-T neutrons or 60Co gamma rays. These techniques rely on the identification of regenerating crypt cells three-and-a-half days after irradiation. The results are expressed as the number of regenerating crypts per circumference of small intestine, as determined by conventional histological examination; the more profound the injury, the smaller the crypt count. The practical relevance of crypt-counting techniques to clinical radiotherapy is limited by their relative insensitivity; the dose levels commonly used in fractionated radiotherapy produce no detectable response. Scanning electron microscopy of the mucosal surface provides a more sensitive measure of radiation injury. The earliest detectable changes occur at the level of 300 rad of gamma radiation, well below the threshold of the crypt-counting technique. At around 1,000 rad, where the first drop in crypt counts occurs, there are well-marked morphological changes which become more severe with increasing dose levels. Some differences have been observed between the morphological effects of gamma and neutron irradiation at points of radiobiological equivalence in terms of crypt counts (using an RBE value of about 2). The changes observed may reflect more than the disruption of epithelial cell kinetics. Mucosal morphology is the total expression of many different biological parameters of which the regenerative ability of the crypt cells is only one. The surface microanatomy of the gut may be the most sensitive indicator of radiation injury which is conveniently available for study.

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PubMed1975

Cardiac effects of lead in drinking water of rats.

1. There is no known cause for the increased mortality due to ischaemic heart disease in soft water areas. Since the lead concentration of soft water is elevated in houses with lead plumbing, studies have been carried out to determine the effects of lead on the heart of rats. 2. Rats were given drinking water containing lead for 1 year at concentrations similar to those found previously in Glasgow, which has a soft water supply. 3. There was increasing deposition of lead in the heart and a fall in the cardiac levels of the enzymes ferrochelatase and delta-aminolaevulinic acid dehydratase. These changes are maximal after 6 months, when there were marked electron-microscopic changes in the myocardium and myocardial mitochondria. 4. Further studies are needed to determine whether lead is a cause of the increased mortality from ischaemic heart disease in soft water areas.

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PubMed1974