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Biomedical subjects

J L Abraham

Publications and source records attributed to J L Abraham.

At least 73 records · Page 4Linked to original sources
PubMed1980

Biomedical microanalysis--putting it to work now in diagnostic pathology.

Based on a review of seven years' experience with microanalysis in human pathology, the emphasis of this keynote paper is that currently available microanalytic instrumentation and methodology are of great use diagnostically. The appropriate diagnostic questions which must be posed for microanalysis center around those seeking the cause of the disease (etiologic diagnosis). The preventive and forensic aspects of etiologic diagnosis are stressed. Pathologists analyse not only tissues but also material samples. The backscattered electron (BSE) image with compositional contrast has been essential in making efficient diagnostic use of microanalysis in the scanning electron microscope (SEM). From the 454 specimens seen in the four years 1976-1979, examples are presented to illustrate several aspects of microanalysis: e.g., documentation of the identity and source of toxic dust in lungs; identification of particulate materials in liver, kidney, salivary glands, lymph nodes, etc.; problems of contamination of specimens; use of high vs low magnification analysis; relative volume of tissue sampled using thick (5 micrometer) vs thin (100nm) sections; time required for analysis; and use of fresh frozen, cryo-sectioned tissue for analysis of soluble materials. For practical diagnostic microanalysis, SEM with BSE and x-ray microanalysis of 5 micrometer thick tissue sections at present seems to be the most efficient procedure.

Electron Probe Microanalysis↗
PubMed1980

Uptake of iodinated contrast material in ischemic myocardium as an indicator of loss of cellular membrane integrity.

Differential uptake of iodine containing radiographic contrast medium (I) in myocardial infarcts compared with normal mycardium has been detected by computerized transmission tomography (CTT). In this study the histologic and cellular distribution of I in ischemically damaged canine myocardium after intravenous administration of contrast material was examined by the use of scanning electron microscopy and energy dispersive X-ray microanalysis of fresh frozen cryosections. Analysis of individual cells in 6-mu thick sections mounted on carbon substrates showed that I was detectable in the ischemically damaged but not the normal myocardial cells. A decline in the potassium-to-sodium ratio confirmed the loss of membrane integrity in the ischemically damaged cells that accumulated I. These results indicate that I enters ischemically damaged but not normal myocardial cells suggesting that CTT scans after intravenous administration of contrast material may be capable of defining the area of the myocardium in which cells have lost membrane integrity after an ischemic injury.

Animals↗
PubMed1979

Molecular microanalysis of pathological specimens in situ with a laser-Raman microprobe.

A laser-Raman microprobe has been used to identify microscopic inclusions of silicone polymer in standard paraffin sections of lymph node. This example of organic chemical microanalysis in situ in pathological tissue represents an extension of microanalytical capabilities from elemental analysis, performed with electron and ion microprobes, to compound-specific molecular microanalysis.

Electron Probe Microanalysis↗
PubMed1979

Documentation of environmental particulate exposures in humans using SEM and EDXA.

There is increasing awareness of health hazards from environmental and occupational exposures to particulates. Scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDXA) can document these exposures by analysis of small portions of cells, tissues and environmental samples. Previous work is briefly reviewed and special attention is given to discussion, with examples, of the various types of particulates which may be found in tissues (exogenous, endogenous, inhaled, injected, ingested, inorganic, organic), the different tissues in which they may be found (lung, heart, liver, skin, brain, kidney, lymph nodes, etc.), methods of tissue sampling (e.g. pulmonary lavage, transbronchial biopsy, open biopsy, percutaneous biopsy, autopsy), specimen preparation (fixation, embedding, sectioning, choice of substrate), SEM and EDXA data collection (backscattered electron imaging, etc.) data interpretation (artefacts, limitations of SEM and EDXA) and other new techniques (ion microprobe, laser Raman microprobe).

Air Pollutants↗
PubMed1979

Silicate pneumoconiosis of farm workers.

Abnormal numbers of birefringent particles have been found in the lungs of seven patients (five vineyard workers, one farmer, and one rural resident) in association with a spectrum of early to late interstitial inflammation and fibrosis. Nodular granulomas of the type seen in silicosis were absent. Scanning electron microscopy and energy dispersive x-ray analysis of 177 individual particles (less than 5 micrometer.) in situ in the lungs of four of the patients showed mostly silicates (notably aluminum, silicon, and potassium), with 5 to 10 per cent silicon dioxide. An analysis of particles less than 5 micrometer. from both vineyard and non-vineyard soil showed lung and soil particles to have a similar composition. The presence of large amounts of silicates in the lung tissues, in association with chronic inflammation and fibrosis, implicates the silicates in the causation of the fibrosis. The silicate deposits may, in large part, be a marker, reflecting a mixture of toxic soil additives or pesticides found in commercial clay silicate products or in dusts from the soil itself. The findings do not exclude lung pathology of a similar nature in regions outside of the farm.

Aged↗
PubMed1979

Diagnostic applications of scanning electron microscopy and microanalysis in pathology.

Microanalytical technology developed within the last decade provides important information in diagnostic pathology. Scanning electron microscopy, including backscattered electron imaging and energy dispersive X-ray analysis should become at least as valuable as polarized light microscopy, histochemistry and conventional transmission electron microscopy. Other as yet less available techniques such as the ion microprobe and laser Raman microprobe are also valuable. The pathologist should consider the use of microanalytic techniques in any disease process in which endogenous or exogenous materials may be present in the tissues, in the same manner in which one would perform stains for microorganisms. Cases are presented illustrating the tissue preparation and results of scanning electron microscopy and energy dispersive X-ray analysis in diagnosis.

Electron Probe Microanalysis↗
PubMed1979

Scanning electron microscope surface morphometry of type II alveolar lung cell response to urethane in strain A mice.

Quantitative scanning electron microscope (SEM) examination of the time course of type II cell hyperplasia in mice exposed to a single i.p. injection of urethane is presented. Counts of type II cells from random alveoli suggest that, compared to controls, a significant depression in type II cell numbers occurs during the first week, followed by a doubling in the next 3 to 4 week period. This supports conclusions of earlier studies done with thin sections and light morphometric techniques. The use of a SEM as the morphometric tool is statistically more efficient, however, since initial sample preparation is easier, samples are larger in area, resolution is higher and, most importantly, the amount of surface area available for examination is many times greater than that presented by light microscope examination of cross sections with equivalent magnification.

Animals↗
PubMed1978

Silicon identification in prosthesis-associated fibrous capsules.

The use of correlated microscopic techniques, including the scanning electron microscopic modes of backscattered electron imaging and energy dispersive x-ray analysis, aid in defining the process of dispersion of silicon-containing material around silicone rubber (polydimethylsiloxane) prosthetic devices.

Breast↗
PubMed1978

Particulate concentrations in pulmonary alveolar proteinosis.

Quantitative birefringent particle counts per 10 high-power fields in lung tissue were correlated with age, sex, and occupational exposure in 37 cases of pulmonary alveolar proteinosis. Counts were significantly higher in pulmonary alveolar proteinosis cases in both regions of alveolar proteinosis (47 +/- 11) and perivascular and peribronchiolar areas (dust retention areas) (275 +/- 65) than in 13 controls (5 +/- 3 and 79 +/- 23, respectively). Of a total of 8619 particles, 4817 were less than 1 micron, and 3771 were 1 to 10 microns in diameter. Fifty-nine percent were round, 19% fibrous, and 22% irregular. When analyzed individually, 20 of 37 cases (78%) had alveolar particle counts significantly higher than controls, and 10 of 26 cases had dust-retention area counts greater than controls (P less than 0.050). Known or possible occupational exposure was ascertained in 13 cases. In the remaining 24 cases insufficient occupational information was available. The mean age of the pulmonary alveolar proteinosis patients was 33 +/- 4 years, and of the controls, 40 +/- 7 years, and there was a male-to-female ratio of approximately 3:1. We propose that many cases of pulmonary alveolar proteinosis will ultimately be shown to be associated with environmental exposures to fine dusts or fumes.

Adolescent↗
PubMed1978

Microscopic diagnoses.

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Microscopy, Electron, Scanning↗