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Biomedical subjects

J Walton

Publications and source records attributed to J Walton.

At least 127 records · Page 7Linked to original sources
PubMed1979

Absorption of inorganic phosphate in the human small intestine.

1. Intestinal phosphate absorption in human subjects was studied by the technique of triple lumen intestinal perfusion in vivo. 2. Ileal phosphate absorption increased as the intraluminal phosphate concentration was increased. 3. Ileal rates of phosphate absorption were lower at any given intraluminal phosphate concentration than previously described jejunal rates. Acidification of the ileal lumen did not increase phosphate absorption. 4. Phosphate absorption was shown in the jejunum to be dependent on the intraluminal sodium concentration. 5. Phosphate absorption in the human small intestine consists of at least two components, one directly proportional to water movement and the second apparently independent of water movement.

Adult↗
PubMed1979

Lead aspartate, an en bloc contrast stain particularly useful for ultrastructural enzymology.

Lead aspartate is a new en bloc stain for electron microscopy. Its predictable staining depends on chelation that results from the interaction of the two stain components, lead nitrate and aspartic acid, which must be present in a specific ratio. Lead aspartate stain is 0.02 M in lead nitrate and 0.03 M in aspartic acid, adjusted to pH 5.5. Cells or tissues are stained at 60 degrees C for 30 to 60 min. Cells stained en bloc with lead aspartate closely resemble cells stained on grids by lead citrate, except that the former seldom have contamination. En bloc staining with lead aspartate bypasses the grid-staining step so that samples can be viewed and photographed immediately after they are thin-sectioned. The lower pH of the lead aspartate solution allows counterstaining of enzyme reaction products that dissolve in the highly alkaline lead citrate stain. Lead aspartate en bloc staining to enhance contrast should especially benefit studies of ultrastructure requiring a clean and predictably lead stain.

Animals↗
PubMed1977

Stimulation of cell division in ectopic kidney grafts following unilateral removal of the lung.

Small fragments of kidney tissue were grafted into the right lung (Xenopus laevis) and the left lung was subsequently removed. This stimulated compensatory hyperplasia (increased mitotic rate) in alveolar tissue of the right lung and in the kidney graft. This suggests that the stimulus to compensatory hyperplasia is location-specific rather than tissue- or organ-specific. After implantation into the lung the kidney grafts are revascularized by the surrounding pulmonary supply. Damage or functional impairment of an organ usually produces a localized increase in the rate of blood flow and we therefore propose that this may lead to an increased rate of cell division in one of two ways: by permitting an increased functional capacity in the tissue concerned, or by causing a more rapid local clearance of mitotic control factors.

Animals↗
PubMed1977

Primary hyperparathyroidism presenting as anticonvulsant-induced osteomalacia.

A patient presented with the classic features of anticonvulsant-induced osteomalacia. Following discontinuance of diphenylhydantoin therapy and repletion with physiologic quantities of vitamin D, hypercalcemia and persistent biochemical hyperparathyroidism developed, and a parathyroid adenoma was removed. A history of nephrolithiasis and hypercalcemia preceding the institution of drug therapy allowed this patient's underlying parathyroid disease to be defined as primary hyperparathyroidism, which had been obscured by anticonvulsant therapy.

Adenoma↗
PubMed1975

Effects of calcium infusions in patients with postmenopausal osteoporosis.

From earlier studies, it appeared that postmenopausal women with osteoporosis may not be so responsive to therapeutic calcium infusions as younger men. A study of seven women with postmenopausal osteoporosis revealed that only one had a good therapeutic response as judged by sustained decrease in bone pain and improvement in calcium balance. It is concluded that a series of calcium infusions is unlikely to be therapeutically useful in postmenopausal osteoporosis.

Aged↗