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Biomedical subjects

D Murphy

Publications and source records attributed to D Murphy.

At least 307 records · Page 17Linked to original sources

The assignment of chain specificities for anti-Ia monoclonal antibodies using L cell transfectants.

The chain specificities of 18 Ak and 26 Ab-reactive anti-Ia monoclonal antibodies have been determined. L cells were transfected with haplotype-matched (A alpha k:A beta k, A alpha b:A beta k) or haplotype-mismatched (A alpha k:A beta b, A alpha b:A beta k) cDNA pairs, lines expressing high levels of surface A complex were selected, and antibody reactivity with a panel of reagents was assessed by cytofluorimetric analysis. Most of the antibodies recognized a determinant specified by one chain, either alpha or (more commonly) beta. A few examples of more complex determinants were also observed. A knowledge of the chain specificities of anti-Ia monoclonal antibodies should prove useful for a variety of studies aimed at dissecting Ia structure-function relationships.

Animals↗

Developmental and transformation-sensitive expression of the Sparc gene on mouse chromosome 11.

SPARC is a Mr 43,000 secreted, acidic, cysteine-rich glycoprotein homologous to 43K bovine endothelial 'culture shock' protein. We show here that it is encoded by a single gene localized to the central region of mouse chromosome 11. During development SPARC mRNA is expressed at higher levels in all the extra-embryonic tissues than in the fetus. Highest levels are found in the parietal endoderm, while visceral endoderm has approximately 6-fold less. This differential expression is also seen in F9 teratocarcinoma cells treated with retinoic acid under conditions in which they give rise to either parietal or visceral endoderm. The 20-fold increase seen during differentiation into parietal endoderm is due, at least in part, to an increase in gene transcription. We also report SPARC expression in a variety of adult tissues and cultured cells, and present evidence that a decrease accompanies the transformation of fibroblast cell lines.

Animals↗

Drug use patterns: implications for the acquired immunodeficiency syndrome.

The acquired immunodeficiency syndrome (AIDS) represents a major public health concern for society. Intravenous drug users continue to be the second largest risk group. While needle sharing has been demonstrated to play a prominent role in the higher risk experienced by illicit drug users, serious evaluations of the inherent immunologic aberrancies attendant to drug abuse have been limited. Partly responsible are the small study sample sizes and inadequate examinations of the role of particular patterns of drug abuse in the development of immunologic dysfunction. The present study represents the preliminary findings of an ongoing investigation to assess the contribution of an array of behaviors on various indicators of immunologic status.The results in 97 patients investigated demonstrate that route of administration and duration of drug use were the factors most significantly associated with a greater prevalence of immunologic abnormalities. There was also a suggestion that abnormal liver function may contribute to altered immune status.

Acquired Immunodeficiency Syndrome↗

Development of a measure of extraversion and neuroticism for mentally retarded persons.

A conventional British questionnaire for measuring extraversion and neuroticism of EMR individuals was reexamined for its application to adolescents in a special school for EMR students in Edmonton, Canada. The items were revised on the basis of principal axes factor analysis and alpha reliabilities. Using this revised scale, we found that EMR female students had significantly higher neuroticism scores than did EMR male students, whereas their extraversion scores were comparable. Likewise, mental age variations appeared to be related to neuroticism but not to extraversion. Subsequent studies were suggested for developing a video form to test these two basic personality traits so that TMR persons may be assessed.

Adolescent↗

The regulation of cellular transcription by Simian virus 40 large T-antigen.

The transforming protein of Simian virus 40 (SV40), large T-antigen, regulates transcription both positively and negatively during the productive infection cycle. We have isolated a number of cellular genes which are expressed at elevated levels in SV40-transformed cells and have used these to study the mechanism or mechanisms by which the viral transforming protein regulates cellular gene expression. Small RNAs homologous to the mouse B2 repetitive sequence family are found at higher levels in transformed cells than in normal cells and we have shown that pure large T-antigen stimulates transcription of such repeats by RNA polymerase III. A class I major histocompatibility complex (MHC) gene is also activated as a result of SV40 transformation and we have used DNA-mediated gene transfer to study how this gene is regulated by large T-antigen.

Animals↗

Functional wrist motion: a biomechanical study.

A triaxial electrogoniometer was used to measure functional wrist motion. Wrist motion was evaluated in 10 normal subjects who performed 52 standardized tasks. The wrist joint was found to have three degrees of freedom (flexion-extension, radioulnar deviation, and rotation). The normal functional range of wrist motion is 5 degrees of flexion, 30 degrees of extension, 10 degrees of radial deviation, and 15 degrees of ulnar deviation.

Activities of Daily Living↗

Expression of c-fos in parietal endoderm, amnion and differentiating F9 teratocarcinoma cells.

The expression of the cellular proto-oncogene, c-fos, in extra-embryonic tissues of the mouse was investigated using a v-fos DNA probe and an affinity-purified antiserum raised against a C-terminal synthetic peptide. At 13.5 days of development, parietal endoderm--a tissue not previously studied using these methods--was found to express c-fos RNA at a higher level than the amnion or placenta. The previously reported dramatic increase in c-fos RNA levels in extra-embryonic membranes during gestation was found to be confined to the amnion. The antipeptide serum specifically recovered proteins with Mr values of 46,000 and 39,000 from extracts of parietal endoderm and amnion cells labelled for 15 min with 35S-methionine. On sodium-dodecyl-sulphate/polyacrylamide gel electrophoresis these proteins co-migrated with proteins immunoprecipitated using serum from rats inoculated with FBJ-MuSV-transformed cells (tumour-bearing rat serum). Pulse-chasing and 32P-labelling experiments showed that the protein with an Mr of 46,000 was rapidly converted into higher-molecular-weight phosphorylated derivatives. F9 teratocarcinoma stem cells differentiated into parietal-endoderm-like cells in response to treatment with retinoic acid and dibutyryl cyclic AMP. However, this differentiation was not accompanied by any large transient increase in c-fos RNA expression.

Amnion↗

The effects of dopamine agonists on human cardiovascular and sympathetic nervous systems.

We gave people four different dopamine agonists and monitored blood pressure, heart rate and circulating catecholamine levels. Bromocriptine decreased blood pressure and plasma norepinephrine levels. Dopamine increased pulse pressure, heart rate and circulating epinephrine (E) and norepinephrine (NE) levels. Dopamine agonists tend to diminish blood pressure by inhibiting sympathetic neuronal discharge of NE and, to a lesser extent, by stimulating dopamine vascular receptors. However, dopamine and L-dopa can be converted to NE and E, both of which have pressor effects. The complex cardiovascular effects of dopamine agonists are the result of stimulation of dopamine vascular and neuronal receptors and the production of NE and E.

Adult↗