PubMed Health⌕ Search

Biomedical subjects

D Kenney

Publications and source records attributed to D Kenney.

17 recordsLinked to original sources
PubMed1992

Activation and facilitation in the lexicon of schizophrenics.

45 schizophrenic patients of three different subtypes (chronic undifferentiated, schizoaffective and paranoid) and 15 normal control subjects completed a semantic priming version of the lexical decision task. Schizophrenic subjects demonstrated longer reaction times relative to normal controls; however, all of the subjects showed semantic facilitation effects. No significant differences in reaction times were found among the three schizophrenic subtype groups. These results suggest that initial sensory-perceptual processing is unimpaired in schizophrenia and thus provide evidence of intact automatic processing. The similarity in performance among the schizophrenic subtype groups refutes the theory of a paranoid/non-paranoid dimension at the initial level of automatic processing.

Arousal↗
PubMed1990

Partition coefficients and capacity factors of some nucleoside analogues.

The AIDS epidemic has brought into focus the development of antiviral agents, of which nucleoside analogues are an important class. The single most important physico-chemical property of a chemotherapeutic agent is its hydrophobicity. This paper reports the hydrophobicity, determined as log partition coefficient (P) by the shake-flask method, of 25 nucleoside analogues. The capacity factors (k') of these analogues were also obtained by reversed-phase liquid chromatography. There is a very strong linear correlation between the log P and the log k' values of all the nucleoside analogues, indicating that hydrophobicity of nucleosides can be determined by liquid chromatography. Examination of the P data indicates that an empirical mathematical relationship exists between the partition coefficient value and the molecular structure of the nucleoside analogues. A table of constants and an equation is proposed to estimate the P of nucleoside analogues.

Antiviral Agents↗
PubMed1987

Biosynthesis of human sialophorins and analysis of the polypeptide core.

Biosynthesis was examined of sialophorin (formerly called gpL115) which is altered in the inherited immunodeficiency Wiskott-Aldrich syndrome. Sialophorin is greater than 50% carbohydrate, primarily O-linked units of sialic acid, galactose, and galactosamine. Pulse-labeling with [35S]methionine and chase incubation established that sialophorin is synthesized in CEM lymphoblastoid cells as an Mr 62,000 precursor which is converted within 45 min to mature glycosylated sialophorin, a long-lived molecule. Experiments with tunicamycin and endoglycosidase H demonstrated that sialophorin contains N-linked carbohydrate (approximately two units per molecule) and is therefore an N,O-glycoprotein. Pulse-labeling of tunicamycin-treated CEM cells together with immunoprecipitation provided the means to isolate the [35S]-methionine-labeled polypeptide core of sialophorin and determine its molecular weight (58,000). This datum allowed us to express the previously established composition on a "per molecule" basis and determine that sialophorin molecules contain approximately 520 amino acid residues and greater than or equal to 100 O-linked carbohydrate units. A recent study showed that various blood cells express sialophorin and that there are two molecular forms: lymphocyte/monocyte sialophorin and platelet/neutrophil sialophorin. Biosynthesis of the two forms was compared by using sialophorin of CEM cells and sialophorin of MOLT-4 cells (another lymphoblastoid line) as models for lymphocyte/monocyte sialophorin and platelet/neutrophil sialophorin, respectively. The time course of biosynthesis and the content of N units were found to be identical for the two sialophorin species. [35S]Methionine-labeled polypeptide cores of CEM sialophorin and MOLT sialophorin were isolated and compared by electrophoresis, isoelectrofocusing, and a newly developed peptide mapping technique.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylglucosaminidase↗
PubMed1987

Relationship of declines in grain consumption and milk yield to estrus in dairy cattle.

A retrospective study was done to determine if a reduction in daily grain consumption or decline in daily milk yield were accurate indicators of estrus in 25 Holstein cows. A computer automatically identified all cows that left more than 10% of their daily grain allocation in the feed stall or that gave less than 85% of their most current 7-d daily average milk yeild. By retrospectively analyzing breeding records, grain refusal and milk declines were identified as either occurring in conjunction with estrus or nonestrus. Declines in grain consumption and milk yield were frequently associated with estrus, but many cows in estrus did not exhibit such declines. While such declines hold promise as estrous detection aids, it was concluded that refusals of daily grain allocation or declines in daily milk yield were not sufficiently accurate to supplant other methods of estrous detection in dairy cattle.

Journal Article↗
PubMed1987

Expression on blood cells of sialophorin, the surface glycoprotein that is defective in Wiskott-Aldrich syndrome.

Sialophorin, previously called gpL115, is the heavily sialylated surface protein that is defective in lymphocytes of Wiskott-Aldrich syndrome patients. Using the monoclonal antibody L10 as a probe, sialophorin expression was detected on isolated T lymphocytes and thymocytes, B cell lines, monocytes, neutrophils, and platelets, but not on erythrocytes, fibroblasts, and glioblastoma cells. This unusual distribution pattern suggests that sialophorin is expressed on all circulating cells except erythrocytes. Trace amounts of the sialophorin molecules on lymphocytes are incompletely sialylated, but significant amounts of the molecules on thymocytes are incompletely sialylated. The molecular form of sialophorin on T lymphocytes, thymocytes, and monocytes is the previously characterized species of apparent mol wt 115,000. A newly described sialophorin species of apparent mol wt 135,000 was found on neutrophils and platelets. The 115,000 lymphocyte/monocyte form and the 135,000 platelet/neutrophil form were shown to be substantially similar. The two forms have approximately the same content of sialylated O-linked carbohydrate units since both undergo the same atypical shift in electrophoretic mobility on desialylation. Both contain the epitope recognized by the monoclonal antibody L2 and the epitope recognized by L10 antibody. Moreover, evidence from another study indicates that the polypeptide portions are identical, cumulatively suggesting that 115,000 sialophorin and 135,000 sialophorin are identical except for the presence on the latter of additional neutral saccharide residues.

Antibodies, Monoclonal↗
PubMed1986

Purification and chemical composition of gpL115, the human lymphocyte surface sialoglycoprotein that is defective in Wiskott-Aldrich syndrome.

gpL115, the surface sialoglycoprotein that is defective in lymphocytes of Wiskott-Aldrich syndrome patients has been purified from large scale cultures of the lymphoblastoid line CEM. The purification entails cell lysis and solubilization of gpL115 with the detergent Nonidet P-40, sequential affinity chromatography on lentil lectin-Sepharose, wheat germ lectin-Sepharose, and, after treatment with sialidase, on peanut lectin-Sepharose. Sepharose CL-6B gel filtration removes residual protein contaminants and transfers asialo-gpL115 from Nonidet P-40-containing to sodium dodecyl sulfate-containing buffer. The yield, 1300 micrograms of homogeneous protein/10(11) cells, represents greater than 60% recovery. The amino acid composition of gpL115 has several atypical features including low lysine content, high proline content, and very high content of hydroxyamino acids (12.5 residues of serine and 12.5 residues of threonine/100 amino acids). Total carbohydrate content of gpL115 is very high, i.e. 52% for the asialo-molecule. The major carbohydrate residues of asialo-gpL115 are galactose and N-acetylgalactosamine in approximately equimolar amounts (25 and 22 residues/100 amino acids, respectively) plus severalfold lower amounts of N-acetylglucosamine, fucose, and mannose.

Amino Acids↗
PubMed1986

Morphological abnormalities in the lymphocytes of patients with the Wiskott-Aldrich syndrome.

Lymphocytes from 18 patients with the Wiskott-Aldrich Syndrome (WAS) were examined by scanning electron microscopy (SEM). Most peripheral blood lymphocytes from normal individuals are covered with slender microvillus projections, but a large proportion of lymphocytes from WAS patients were found to be relatively devoid of microvilli. A lymphocyte morphology scoring system was developed to quantify the density of microvilli: Grade 4 classified those lymphocytes with greater than 75% of the surface covered with microvilli with progressive decrements to grade 1, which were those without microvilli. The mean lymphocyte morphology score of eight normal individuals was 3.62 +/- .22. The mean lymphocyte score of WAS patients was substantially lower (2.89 +/- .27, P less than .001). In addition, WAS lymphocytes often were qualitatively abnormal, with short, blunted microvilli. These morphological criteria were used to diagnose WAS from the cord blood lymphocytes of one "at-risk" patient. Thus, WAS is the first primary immunodeficiency in which morphological abnormalities have been identified that can aid in diagnosis.

Cell Membrane↗
PubMed1981

Thrombin inhibition by malignant and normal cells: a cell-bound antithrombin effect.

Analysis of fresh surgical specimens of normal tissue and tumor tissue show a cellular antithrombin activity to be present in certain organs. In normal tissues it was noted chiefly in normal colon, testes, breast, and uterus. In malignant tissues it was prominent in adenocarcinomas of the colon, breast, and lung. No epidermoid tumors showed evidence of thrombin binding. The thrombin- binding activity required the presence of intact cells and was distinct from the soluble antithrombins normally present in plasma and serum. There is growing evidence to suggest an interrelationship between clotting and the growth and dissemination of cancer. The implications of cellular antithrombins are reviewed in this context.

Adenocarcinoma↗
PubMed1969

Antibacterial activity of 2'-esters of erythromycin.

The effect of esterification at the 2'-position of desosamine on the antibacterial activity of erythromycin was investigated by determining the bacteriostatic and bactericidal activities of erythromycin and a number of its 2'-esters on S. aureus and relating these activities to the hydrolysis rates of the esters. These studies, together with comparison of the inhibition of protein synthesis in a cell-free system isolated from S. aureus, lead to the conclusion that 2'-esters of erythromycin are inactive until hydrolyzed. Loss of activity appears to result from inability of erythromycin esters to bind to bacterial ribosomes and thus inhibit synthesis of protein.

Bacterial Proteins↗