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Biomedical subjects

R Kennett

Publications and source records attributed to R Kennett.

44 records · Page 3Linked to original sources
PubMed1980

A monoclonal antibody identifying a cell surface antigen shared by common acute lymphoblastic leukemias and B lineage cells.

A monoclonal antibody designated PI153/3, which reacts with neuroblastoma and fetal brain, is shown to identify also a cell surface determinant shared by pre-B and mature B cells and their corresponding leukemias including chronic lymphocytic leukemia, non-Hodgkin's lymphoma, B acute lymphoblastic leukemia, and hairy cell leukemia, but not plasmacytoma. Almost all non-T, non-B acute "lymphoid" leukemias bind PI153/3. The latter includes 71 of 74 common ALL tested, most but not all "unclassified" or "null" ALL and cases of both acute undifferentiated leukemia and Ph1 positive chronic myeloid leukemia in blast crisis with common ALL phenotypes. The antigen is absent or present at very low density on normal and leukemic T lymphocyte, myeloid and erythroid cells. The determinant appears to co-redistribute with cell surface immunoglobulin in B lymphocytes and segregates independently of other cell surface antigens associated with B cells and/or cALL including HLA-DR (Ia-like antigens) and the cALL (gp 100) antigen.

Antibodies↗
PubMed1977

Assignment of the structural genes for the alpha subunit of hexosaminidase A, mannosephosphate isomerase, and pyruvate kinase to the region q22-qter of human chromosome 15.

Concordant segregation of the expression of the alpha subunit of human hexosaminidase A, human mannosephosphate isomerase, and pyruvate kinase was observed in somatic cell hybrids between either thymidine kinase-deficient mouse cells or thymidine kinase-deficient Chinese hamster cells and human white blood cells carrying a translocation of the distal half (q 22-qter) of the long arm of chromosome 15 to chromosome 17. A positive correlation was established between the expression of these human phenotypes and the presence of the distal half of the long arm of human chromosome 15.

Carbohydrate Epimerases↗
PubMed1976

Permanent lymphoid lines from genetically marked lymphocytes: success with lymphocytes recovered from frozen storage.

Permanent human lymphoid cell lines were established successfully from peripheral blood lymphocytes which had been separated for HL-A typing and stored in liquid nitrogen for two years. Frozen lymphocytes were chosen from two siblings who were homozygous at the LA and FOUR HL-A loci. Thawed lymphocytes were transformed with EB virus produced by the marmoset lymphoid line B95-8. No chromosome abnormalities were seen on karyotypes prepared on cells from the established human lymphoid lines using G and Q banding techniques. HL-A typing showed the expected HL-A antigens plus a considerable number of additional reactions. Separation of lymphocytes and freezing them for possible future use requires a relatively small investment. This method of preserving cells can be applied to patients with interesting genetic disorders or other biochemical markers to provide cells which can be transformed and propagated years later.

Blood Preservation↗
PubMed1975

Human intraspecific somatic cell hybrids: a genetic and karyotypic analysis of crosses between lymphocytes and D98/AH-2.

A number of human intraspecific hybrids were produced by fusing the 8-azaguanine-resistant cell line D98/AH-2 with PHA-stimulated lymphocytes from a normal human male, followed by selection in HAT medium. The parent cells differed in zymogram patterns for 4 enzyme systems. Hypoxanthine-guanine phophoribosyltransferase was missing in D98/AH-2 and was determined in the hybrids by the normal gene derived from the lymphocyte donor's X chromosome. The HL-A antigens of the lymphocyte donor as well as the W28 specificity from HeLa were easily recognized by a cytotoxicity assay on the hybrid cells, while D98/AH-2 itself was not killed in the normal way by any HL-4 typing sera. The initial hybrid karyotype in all lines was relatively stable, but slow loss of chromosomes occurred following extended growth in culture. The importance of the culture conditions for the rate of chromosome loss was demonstrated. The behavior of several chromosomes was followed in the hybrids and their derivatives. There was relatively nonspecific loss of small numbers of chromosomes, showing that loss of chromosomes from both the D98/AH-2 and the normal lymphocyte parent can occur. Cell lines resistant to 6-thioguanine were selected from the sensitive hybrids. Most had lost the lymphocyte donor's X chromosome, thereby losing the only active allele for HGPRT present in the initial hybrids. However, one line, DMR41, apparently retained the X chromosome and may have a mutated allele for HGPRT. Two lines that are the products of spontaneous segregation are also described. DM4CS and DM17A.

Acid Phosphatase↗
PubMed1971

Extrinsic Cotton effects in hapten--carrier and hapten--antibody interactions.

Two homogeneous univalent hapten-protein conjugates, prepared by the covalent attachment of a single 2,4-dinitrophenyl (DNP-) or 2,4,6-trinitrophenyl (TNP-) side chain to the cysteine-SH in the active site of the enzyme papain, have been found to exhibit large Cotton effects in the wavelength region of the absorption bands of the DNP or TNP groups. This indicates that the DNP or TNP groups are noncovalently bound to some asymmetric region(s) of the papain molecule. These homogeneous papain conjugates are antigens that can elicit anti-DNP or anti-TNP antibody production in mice or rabbits. It is suggested that the noncovalent binding of a hapten to the surface of its carrier protein may profoundly affect the characteristics of the anti-hapten antibodies that are elicited. It has also been observed that the specific binding of these papain conjugates, and of the simple haptens DNP-lysine or TNP-lysine, to anti-hapten antibodies produces characteristic extrinsic Cotton effects.

Antibody Formation↗
PubMedDate not supplied

Osmotic balance in the eggs of the turtle Chelodina rugosa during developmental arrest under water.

The tropical Australian turtle Chelodina rugosa normally lays its hard-shelled eggs in mud, under shallow freshwater, during the monsoon season. The eggs undergo developmental arrest until the water recedes and oxygen is able to diffuse into the embryo. This period of arrest can exceed 12 wk without embryonic mortality. To understand how the eggs avoid osmotic absorption of water leading to shell rupture and embryonic death, this study investigates the solute concentrations and volumes of the albumen and yolk compartments during submergence in distilled water. The albumen loses considerable sodium through the shell, particularly during the first week, and its osmotic concentration drops from 234 mmol/kg at laying to about 23 mmol/kg. Meanwhile, water from the albumen slowly moves through the vitelline membrane into the yolk compartment, which enlarges at a constant rate until it approaches the inside of the shell at about 22 wk. Osmotic uptake dilutes yolk solutes, decreasing the osmotic concentration from 281 mmol/kg at laying to 132 mmol/kg at 157 d. Loss of embryonic viability is associated with contact of the vitelline membrane with the inside of the shell. The principal adaptation of this species for protracted developmental arrest under water is a vitelline membrane of such low permeability to water that the expansion of the yolk compartment occurs about 10 times more slowly than in other chelonians.

Animals↗