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Biomedical subjects

M Jones

Publications and source records attributed to M Jones.

At least 883 records · Page 49Linked to original sources
PubMed1978

The effects of triton WR1339 and asialo-fetuin on the hepatic uptake of circulating native and asialo-carcinoembryonic antigen.

Uptake of carcinoembryonic antigen from the circulation of the mouse is inhibited by treatment of the animal with Triton WR1339, but not by asialo-fetuin. Uptake of asialo-carcinoembryonic antigen is inhibited by asialo-fetuin, but not by Triton WR1339. These results reflect the different mechanisms of uptake of the glycoproteins. The presence or absence of sialic acid does not seem to be important in governing Kupffer-cell uptake, but when terminal galactoses are exposed on a glycoprotein, uptake by hepatocytes is preferred. Kupffer-cell uptake of carcinoembryonic antigen is not due to the formation of high-molecular-weight complexes in the blood stream. The effect of asialo-fetuin and Triton WR1339 on the biliary excretion of carcinoembryonic antigen and asialo-carcinoembryonic antigen is discussed.

Animals↗
PubMed1978

Visceral calcification and the CaXP product.

The authors studied the presence of visceral calcification as evidenced by the visceral uptake of bone-seeking radionuclides during the course of a bone scan among 22 patients with terminal renal failure maintained on dialysis, nine patients with hypercalcemia secondary to malignancy, and nine patients with primary hyperparathyroidism. Uptake by the lungs or stomach was observed in 11 renal failure patients (50%) and in four of those with malignancy and hypercalcemia (44%). None of the patients with primary hyperparathyroidism had evidence of visceral calcification. The serum CaXP product was significantly higher among those with visceral calcification than those without. The results of this study indicate that a CaXP product of 60 represents the saturation product of calcium phosphate in serum above which spontaneous precipitation of this salt may occur in such viscera as stomach and lungs.

Adult↗
PubMed1978

Amino acid and protein metabolism in renal failure.

There are many cAUSES OF ALTERED AMINO ACID AND PROTEIN METABOLISM IN UREMIA WHICH MAY Lead to impaired growth, wasting, malnutrition, and other aspects of the uremic syndrome. These causes have complex interrelationships that are not well understood. The factors include altered nutrition due to poor intake, losses of nutrients during dialysis, and abnormal metabolism of many nutrients. Uremic toxins, superimposed catabolic illnesses, elevated or reduced serum hormone levels, reduced capacity of the kidney to synthesize certain amino acids and to degrade other amino acids, peptides, and small proteins, and decreased excretion of certain amino acids and peptides may also contribute to altered amino acid and protein metabolism. The response of certain plasma amino acids to protein restriction appears to differ in uremic patients as compared to normal subjects. Increased plasma levels of many products of amino acids and proteins in renal failure are due primarily to decreased urinary clearance by the kidney. However, for some metabolites, increased synthesis or decreased degradation may also contribute to elevated levels. These latter compounds include guanidinosuccinic acid, methylguanidine, certain middle molecules, and in some patients, phenylpyruvic acid.

Amino Acids↗
PubMed1978

External layers of Rickettsia prowazekii and Rickettsia rickettsii: occurrence of a slime layer.

Using a simple specific-antibody stabilization procedure on organisms gently liberated from their host cells, we have demonstrated by electron microscopy that Rickettsia prowazekii and Rickettsia rickettsii possess a coat of variable thickness, external to the outer leaflet of the cell wall and the structure designated by others as a "microcapsule," which corresponds most closely to the slime layer of certain other bacteria. Reactions in the methenamine silver and ruthenium red staining procedures and the failure to be visualized by standard procedures suggest that the slime layer is largely polysaccharide in nature. It is postulated that this slime layer accounts in large part for the large, electron-lucent, halo-like zone which is found by electron microscopy to surround organisms of the typhus and spotted fever groups in the cytoplasm of their host cells, that it may be the locus of some major group-specific antigens, and that it may function as an antiphagocytic mechanism, as an aid for attachment of rickettsiae to potential host cells, or both. Moreover, because the attenuated E strain of R. prowazekii has been shown to possess a substantial slime layer, the basis for attenuation is not likely to be a simple smooth-to-rough variation.

Antigens, Bacterial↗
PubMed1978

Comparison of selected intravenous infusion pumps and rate regulators.

Selected intravenous infusion pumps and rate regulators were compared to determine the relative advantages and disadvantages and to formulate guidelines for purchase of these devices. Three basic types of devices were studied: infusion rate regulators, nonvolumetric (peristaltic) infusion pumps and volumetric infusion pumps. Simple syringe-type infusion pumps were not studied. After use and close study of the devices, both in the laboratory and in the clinical area, desirable features were identified. Ideally, the infusion device should operate over a wide rate range, use standard administration sets, be easy to assemble and service, have an internal battery of good power for several hours, have appropriate malfunction alarms, have an automatic keep-open device in alarm situations, be accurate under a variety of situations, and be easy for the nurse to understand and operate. All devices tested were accurate within the limits claimed by the manufacturer, although a couple of models have features which can cause gross volume errors. Overall evaluation resulted in preference of some devices over others. Cost of infusion devices and administration sets can vary widely, and this should be a factor in the final choice of intravenous infusion equipment.

Evaluation Studies as Topic↗
PubMed1978

Ultrastructure of the fibrous ring in patient with discrete subaortic stenosis.

Histologic and ultrastructural studies disclosed the presence of five tissue layers in fibrous rings excised at operation from five patients with discrete subaortic stenosis. These layers were: (1) a surface monolayer of endothelial cells; (2) a subendothelial layer rich in acid mucopolysaccharides and basement membrane-like material; (3) a fibroelastic layer containing collagen and small (1 micrometer or less in diameter) elastic fibers; (4) a layer of smooth muscle cells with thickened basement membranes, and (5) a central fibrous layer with large amounts of collagen and small amounts of elastic fibers. The connective tissue layers in the rings frequently were discontinuous. The layered arrangement of these rings resembles that of normal endocardium in the left ventricular outflow tract.

Adolescent↗