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Biomedical subjects

E L Cooper

Publications and source records attributed to E L Cooper.

At least 109 records · Page 6Linked to original sources
PubMed1983

Aging changes in lymphopoietic and myelopoietic organs of the annual cyprinodont fish, Nothobranchius guentheri.

The thymus of aging annual, cyprinodont fish, Nothobranchius guentheri and Cynolebias adloffi begins to undergo senescent changes at approximately four months. At this time, the histopathology reveals increased amounts of connective tissue, epithelial cysts and myoid cells, but decreased numbers of thymocytes. At 12 months, of the 50 fish observed at 10 stages from day 15 and 1, 2, 4, 6, 8, 9, 10, 11, 12 months the maximum time of senescence, there was an increased incidence of tumors in the oral cavity, connective tissue, kidney and liver in all 5 fish. At least in the kidney, the malignant transformation was classified as nodular-type histiocytic lymphoma. It is of interest that development of these tumors occurs during peak senescent changes in the thymus, supporting the view that as fish age, accompanied by atrophy of the thymus, the immune system is less vigorous and there is an increase in the incidence of cancer.

Aging↗
PubMed1982

Agglutinins in the earthworm Lumbricus terrestris: naturally occurring and induced.

A naturally occurring hemagglutinin against rabbit and rat erythrocytes is contained in the coelomic fluid of the earthworm Lumbricus terrestris. The hemagglutinin reacts with some chicken and human erythrocytes, but not others, and does not react with the erythrocytes of seven other vertebrates. Hemagglutinins appear in increased amounts within 24 hr after injection of rat, rabbit, horse and sheep erythrocytes, and some chicken and human erythrocytes, and are the highest (approximately four- to sevenfold) with rabbit erythrocytes. The response is brief, and increased or more rapid responses do not occur after multiple injections. Cross reactivity and absorption data indicate a close or possibly identical relationship between agglutinins induced against different erythrocyte types. Effects of heating, enzyme and chemical treatment on induced anti-rabbit erythrocyte agglutinins indicate at least two and perhaps three different agglutinins. Two of the agglutinins are protein, one trypsin-sensitive and the other trypsin-resistant. Agglutinin activity is reduced in the absence of divalent cations. Sensitivity to heat varies with the type of agglutinin. The naturally occurring agglutinin is a protein, trypsin-resistant and unaffected by heating at 100 degrees C for 30 min. These hemagglutinins constitute one of the earthworm's humoral factors that may participate in immune responses.

Absorption↗
PubMed1982

Agglutinins and proteins in the earthworm, Lumbricus terrestris, before and after injection of erythrocytes, carbohydrates, and other materials.

Agglutinin activity and total protein concentration in earthworm coelomic fluid were determined 24 hours after injecting different erythrocyte types and carbohydrates. Agglutinin titers increased from 14 to 1216 after a single injection of erythrocytes. At the same time, protein concentrations increased by variable amounts, suggesting an indirect correlation between increased agglutinin titer and protein concentration. To understand the nature of erythrocyte determinants responsible for inducing agglutinins and other proteins, separate groups of earthworms were injected with different carbohydrates. At 24 hours, coelomic fluid was assayed for agglutinin titer and protein concentration. The injection of different carbohydrates, amino acids, nucleotides and protein (BSA), like erythrocytes, also increased protein concentration and agglutinin titers. Changes in the protein concentration and composition of coelomic fluid were studied by standard and bidimensional immunoelectrophoresis. Different patterns and numbers of components were found before and after injection. At least two different components were present after injecting carbohydrates or erythrocytes, which may be related specifically to the agglutinins. Clearly, earthworms can synthesize and shed these molecules at rapid rates into the coelomic fluid. These molecules may be involved in earthworm defense.

Agglutinins↗
PubMed1981

Simultaneous determination of niacinamide, pyridoxine, riboflavin, and thiamine in multivitamin products by high-pressure liquid chromatography.

A high-pressure liquid chromatographic assay was developed for the determination of four water-soluble vitamins: niacinamide, pyridoxine, thiamine, and riboflavin. The four vitamins are assayed simultaneously in multivitamin products not containing minerals. Thiamine currently is not quantitated in formulations containing minerals because it is not stable under the extraction conditions. The method was applied to the analysis of at least 12 different multivitamin products, including various formulations of sterile products, fluids, compressed tablets, and coated, compressed tablets. The method is stability indicating and is applicable to single-tablet assays.

Chromatography, High Pressure Liquid↗
PubMed1981

Ultrastructure of the jugular body of Rana pipiens.

The jugular bodies in adult Rana pipiens, are surrounded by a capsule of mesothelium and connective tissue, and their parenchyma consists of cell cords arranged in a sinusoidal network. The cell cords are formed by irregular reticular cells, showing numerous filaments and joined together by zonulae adherents. The intercellular spaces are filled by reticular fibres and free cells. These latter are small and medium lymphocytes, lymphoblasts, and developing and mature plasma cells. Additionally, free macrophages, neutrophils and acidophils also occur. Sinusoidal blood vessels show thin walls with numerous filaments and pinocytotic vesicles. They exhibit a discontinuous basement membrane, and tight junctions frequently occur between endothelial cells. Occasionally, lymphatic vessels are found and the innervation is principally vasomotor, although nerve endings appear remarkably near reticular cells and lymphocytes. The jugular bodies of adult R. pipiens are plasma cell and antibody-forming organs, whose functional significance is discussed in relation to their ultrastructural organization.

Animals↗