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Biomedical subjects

T A Hall

Publications and source records attributed to T A Hall.

At least 73 records · Page 4Linked to original sources
PubMed1977

Zinc distribution in injured myocardium. EMMA-4 examinations of dogs' hearts after coronary ligation.

Electron microscopic X-ray microanalysis and atomic absorption spectrophotometry were used to determine changes in zinc concentration after myocardial ischemic injury by coronary ligature in dogs. The zinc concentration increased in the damaged myocardium especially in specific intracellular locations identified by means of the microprobe. It was concluded that the selective zinc augmentation was related to proliferative and biosynthetic reactive processes in the myocardium.

Animals↗
PubMed1977

Origin, structure, composition and age-dependence of mineralized dense bodies (concretions) in the midgut epithelium of the adult housefly, Musca domestica.

The epithelial cells of the midgut in 1-40 day old adult female houseflies were examined by electron microscopic X-ray microalnalytic and histochemical techniques in order to study the mode of genesis, chemical nature and age-associated distribution of dense bodies. Dense bodies contain high concentration of phosphorus sulphur, chlorine, calcium, iron and copper; they are therfore termed concretions. Concretionary material is initially deposited within Golgi vesicles, lamellar bodies and residual bodies. The average size of the concretion granules and the concentration of the sequestered material increases with age, while new concretions are continually formed throughout life. With advancing age, concretions accumulate in the epithelial cells and occupy a considerable proportion of the cytoplasm in old flies. It is postulated that the concretions sequester superfluous minerals and may play an important role in the excretory system of the adult housefly.

Acid Phosphatase↗
PubMed1976

Fine structure and x-ray microanalysis of mineralized concretions in the malpighian tubules of the housefly, Musca domestica.

The epithelium and the lumen of the Malpighian tubules of the housefly contains mineralized dense bodies called concretions. The morphological characteristics, mode of origin, nature of the sequestered elements and the age-associated changes in the distribution of concretions are reported. There are three types of concretions in the cytoplasm, which have been designated as type A, type B, and type C. Type A concretions are membrane-bound spherical structures which may arise by the gradual intravacuolar accumulation of dense material. Type B concretions appear to be related to multivesicular bodies. Type C concretions are heteromorphic and morphologically resemble the residual bodies. They show a positive localization of acid phosphatase reaction product. X-ray microanalysis of intracytoplasmic and intraluminal concretions revealed the presence of phosphorus, sulphur, chlorine, calcium, iron, zinc and copper. There was no evidence suggesting the extrusion of the intracytoplasmic concretions into the lumen of the Malpighian tubules. There is an age-associated increase in the distribution of type C concretions. It is hypothesized that the sequestration of metal ions within the concretions may provide a means for the effective excretion of these elements.

Aging↗
PubMed1976

Electron microscopic x-ray microanalysis of normal and leukemic human lymphocytes.

A comparative study of the elemental content of normal and leukemic cells was undertaken on a few subjects, using electron microscopic x-ray microanalysis. Phosphorus, sulfur, chlorine, calcium, copper, and zinc were detected in intracellular loci. The concentration of some of the above elements appeared to be disease related. In leukemic lymphocytes, the nuclear zinc was significantly lower than that recorded in normal lymphocytes, while the phosphorus was only moderately decreased. This suggests a faulty zinc uptake or binding in leukemic cells. The possible consequences of intracellular zinc deficiency are discussed.

Calcium↗
PubMed1976

Gold tracer studies of muscle regeneration.

Rabbits were injected with soluble gold, and cold injury was inflicted upon their extraocular muscles. Following the typical freeze-thaw damage in which the myofiber basement membrane is preserved, a polymorphonuclear granulocyte exudation occurred. At this stage only a few interstitial cells with long processes contained gold. At one and two days abundant mononuclear cells with gold were observed at the site of injury. In subsequent stages of muscle regeneration the amount of tracer decreased but myoblasts, and even fully formed myotubes, often contained detectable gold. Some data on "in vivo" gold salt kinetics and the specificity of gold localization were utilised in the study of the relation between mononuclear interstitial cells and myoblasts.

Animals↗
PubMed1976

Aurothiomalate as an ultrastructural marker. Electron microscopy and x-ray microanalysis of various tissues after in vivo gold injections.

Rabbits and rats were given single injections of aurothiomalate by different routes. The animals were killed at progressive intervals, and sections from various organs were examined by electron microscopic x-ray microanalysis. Ultrastructurally, characteristic material was regularly found in vacuoles, dense and heterogeneous bodies of macrophages, hepatocytes and renal epithelial cells. Occasionally, other mesenchymal cells also contained gold. Histochemical and analytical tests showed that the gold-containing organelles were devoid of acid phosphatase activity. The generalized rapid spread, retention and selectivity of localization after a single small dose make aurothiomalate a useful marker substance for ultrastructural studies.

Acid Phosphatase↗
PubMed1976

Sulphure in epidermal keratohyalin granules: a quantitative assay by x-ray microanalysis.

The elemental composition of different types of keratohyalin granules from the epidermis of newborn and adult rats was studied by means of an EMMA-4 analytical electron microscope, equipped with an energy-dispersive X-ray spectrometer. An absolute quantitation of the sulphur concentration in keratohyalin granules was performed. The results demonstrate that epidermal keratohyalin granules are chemically heterogeneous. A type of keratohyalin granule present in the nuclei and cytoplasm of epidermal cells from both newborn and adult rats - termed single granules - is rich in sulphur, having a content of 2-5-3-6%. Other types of keratohyalin granules, which differ in newborn and adult rats, contain a sulphur-poor component; they often have a sulphur-rich component as well. The sulphur-poor keratohyalin contains 0-6-0-9% sulphur. It is suggested that the sulphur-rich keratohyalin granules are the source of the peripheral envelope protein of cornified cells.

Animals↗
PubMed1976

Spread of gold injected into the joints of healthy rabbits.

This study shows that after intra-articular injection, aurothiomalate and colloidal gold of small (200 A) particle size were rapidly absorbed from joints while the larger, 300 A, particle size colloidal radioactive gold could not be found outside them. Larger particle size suspensions seem therefore more likely to remain localised in the joint and its lining synovium after intra-articular injection, the systemic absorption from the joint cavity diminishing with increasing particle size. It was also found that the intra-articular injection of small amounts of aurothiomalate, of colloidal gold and of colloidal radioactive gold produces identical degenerative lesions in the lining cells of the proximal convoluted tubules of the kidneys. These lesions were always found, although gold particles were demonstrated only in sampled kidney tissues of the animals injected with the soluble gold preparation whereas no gold could be detected in the tissues of animals injected with colloidal non-radioactive or radioactive gold. Electron microscopic evidence is presented to suggest the possibility that the mitochondria are the "target" organelles of the gold-induced cellular damage. Mitochondrial damage was demonstrated in liver and spleen in addition to the already described kidney damage. The correlation between structure and function of the mitochondrial changes is not clear, and ionic shifts may be both a cause and a result of damage.

Animals↗
PubMed1975

X-ray microanalysis of mast cells in rat's muscle.

Mast cells from rat's tongue muscles, fixed with glutaraldehyde only, were examined with an electron microscopic microanalyzer - the EMMA-4. With the preparatory method used, high emissions of a number of elements were obtained in various intracellular spots. The granules of mast cells were found to contain strictly localized high concentrations of sulphur, calcium and zinc.

Animals↗
PubMed1975

A simplified method of specimen preparation for X-ray microanalysis of muscle and blood cells.

The effect of various steps in the preparation of muscle and blood cells for electron microscopic X-ray microanalysis, was studied with reference to calcium, zinc and copper levels. It was found that these elements are readily detectable in material fixed in glutaraldehyde and embedded directly in Epon 812. Alcohol dehydration, buffer rinses and post-osmication caused marked depletion of all elements examined.

Animals↗
PubMed1975

Microprobe measurements of calcium binding in the contractile spasmoneme of a vorticellid.

By means of an electron microprobe, the calcium content of isolated contractile organelles (spasmonemes) from the ciliate Zoothamnium was compared in extension and contraction. By using calcium buffers of different total concentrations, it was shown that the calcium in extended organelles was almost entirely due to concentration of solute during the drying of the specimen. Contracted organelles contained 1-7 g more calcium per kg of dry mass than extended ones, and this extra calcium was bound strongly. The quantity of calcium bound in this way is consistent with the theory that the energy for contraction is derived from the chemical potential of calcium ions. Stoichiometry suggests that between 1-4 and 2-1 calcium ions become bound to each molecule of a spasmonemal calcium-binding protein.

Animals↗
PubMed1975

Nephrotoxic effect of parenteral and intraarticular gold. Ultrastructure and electron microprobe examination of clinical and experimental material.

The presence of gold in the kidney of a 58-year-old woman was confirmed by use of ultrastructural and microprobe examinations. A series of animal experiments were performed in which small single doses of gold were administered systemically and intraarticularly in rabbits. Both the colloidal suspension and the soluable salt gold sodium thiomalate (Myochrysine) were used. Selective lesions occurred in the proximal convoluted tubules and the mitochondria appeared to be the target organelle. They contained gold after gold sodium thiomalate but not after colloidal gold.

Animals↗