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B Murphy

Publications and source records attributed to B Murphy.

At least 37 records · Page 2Linked to original sources
PubMed1992

Differential expression of clusterin in inducible models of apoptosis.

Apoptosis (programmed cell death) and necrosis can be readily distinguished morphologically and biochemically. The most striking biochemical change observed in apoptotic cells is the cleavage of the genomic DNA into discrete nucleosome sized fragments, producing a laddering pattern when the DNA is examined electrophoretically. It has recently been shown that RNA and protein products of the testosterone-repressed prostate message-2 gene are induced, coordinate with the onset of cell death. This gene has been isolated from a variety of species and tissues, it is highly conserved, and collectively referred to as clusterin. We have examined a number of inducible leucocyte models of apoptosis, including glucocorticoid and calcium ionophore induced thymocyte death, 'aged' neutrophils and cytotoxic T cells, and found that in these situations that cell death is not associated with up-regulation of clusterin gene expression. The finding that clusterin is not expressed in all cells undergoing apoptosis would suggest that this molecule is not critical to the mechanism of cell death. It does, however, provide the first example of a readily detectable marker which is differentially expressed in cells undergoing apoptosis and adds further weight to the argument that apoptosis is not a uniform phenomena, but is dependent on the nature of the cells involved and the means of induction.

Animals↗
PubMed1992

Antibodies against cortisol block suppressive effects of corticosteroids on lymphocytes in vitro.

Lymphocyte transformation assays were used to test the ability of antibodies against cortisol to reduce bioactivity of corticosteroids in vitro. Mononuclear cells were separated from whole bovine blood and cultured in the presence of PHA alone, PHA + steroid, PHA + steroid + anticortisol, or PHA + steroid + anti-bovine serum albumin. Tritiated thymidine uptake was determined for all groups during the last 24 hr of a 72-hr culture period by scintillation counting. Polyclonal anticortisol against cortisol-bovine serum albumin conjugated in the 21 position was more effective in blocking cortisol activity than monoclonal anticortisol built against conjugates in the 3 position. The steroids that suppressed PHA-induced lymphocyte proliferation in a concentration-dependent manner were: cortisol, corticosterone, dexamethasone, prednisolone, 11-deoxycortisol, and 11-deoxycorticosterone. Aldosterone, cortisone, cholesterol, estradiol, and progesterone did not exhibit concentration-dependent effects and, thus, were not considered suppressive. These concentration-independent steroids were also the least suppressive (with the exception of aldosterone). Anticortisol was able to reduce bioactivity of suppressive corticosteroids that had an 11-hydroxy group, suggesting the antibody was primarily made against this site. Anti-BSA was not effective in blocking corticosteroid activity, but it did enhance proliferation of lymphocytes if added in combination with weakly suppressive steroids. Anticortisol also had an enhancing effect when added with some weakly suppressive steroids. We conclude that antibodies against cortisol are capable of reducing bioactivity of steroids that strongly suppress lymphocyte proliferation. Additionally, the 11-hydroxy group may be an important antigenic determinant of steroid molecules.

Adrenal Cortex Hormones↗
PubMed1991

The apolipoprotein A-I binding protein of placenta and the SP-40,40 protein of human blood are different proteins which both bind to apolipoprotein A-I.

A complement-associated protein SP-40,40, which is a normal constituent of human blood, binds to the main apoprotein, apoA-I, of high density lipoprotein (HDL). This protein, which is identical to apolipoprotein J, was compared to another apoA-I binding protein purified from human placenta. Immunologically the two apoA-I binding proteins are different.

Amino Acid Sequence↗
PubMed1991

Abbott prism: a multichannel heterogeneous chemiluminescence immunoassay analyzer.

We describe a multichannel heterogeneous immunoassay analyzer in which a sample is split between disposable reaction trays in a group of linear tracks. The system's pipettor uses noninvasive sensing of the sample volume and disposable pipet tips. Each assay track has (a) a conveyor belt for moving reaction trays to predetermined functional stations, (b) temperature-controlled tunnels, (c) noncontact transfer of the reaction mixture between incubation and detection wells, and (d) single-photon counting to detect a chemiluminescence (CL) signal from the captured immunochemical product. A novel disposable reaction tray, with separate reaction and detection wells and self-contained fluid removal, is used in conjunction with the transfer device on the track to produce a carryover-free system. The linear immunoassay track has nine predetermined positions for performing individual assay steps. Assay step sequence and timing is selected by changing the location of the assay modules between these predetermined positions. The assay methodology, a combination of microparticle capture and direct detection of a CL signal on a porous matrix, offers excellent sensitivity, specificity, and ease of automation. Immunoassay configurations have been tested for hepatitis B surface antigen and for antibodies to hepatitis B core antigen, hepatitis C virus, human immunodeficiency virus I and II, and human T-cell leukemia virus I and II.

Binding, Competitive↗
PubMed1991

Reaction tray and noncontact transfer method for heterogeneous chemiluminescence immunoassays.

We describe a reaction tray for a heterogeneous chemiluminescence (CL) immunoassay having the following features: separate sample incubation and signal detection wells; a design that allows for noncontact transfer of the reaction mixture from incubation wells to detection wells; surface features to mate with a detector and create a light-tight seal for CL detection; and self-contained means for liquid removal. The reaction mixture is transferred by injecting a wash solution from a group of nozzles into the incubation well. Quantitative transfer of microparticles (transfer efficiencies greater than 95% and CV less than 5%) is achieved by injecting two 300-microL pulses of transfer solution at a rate of 2.1 m/s. The performance of the tray and method of transfer is tested by determining the precision of CL signal for a sample containing a concentration of anti-hepatitis B core antigen (anti-HBc) or hepatitis B surface antigen (HBsAg) close to the cutoff value for the assay.

Binding, Competitive↗
PubMed1991

Lid flora in blepharitis.

The microbiologic evaluations of 332 consecutive patients with the primary diagnosis of chronic blepharitis were reviewed and compared to those of 160 control patients. The most commonly isolated organisms from lids with blepharitis were Staphylococcus epidermidis (95.8%), Propronibacterium acnes (92.8%), Corynebacterium sp. (76.8%), Acinetobacter sp. (11.4%), and Staphylococcus aureus (10.5%). Compared to controls, S. epidermidis (p less than 0.01), P. acnes (p less than 0.02), and Corynebacterium sp. (p less than 0.001) were present significantly more often. S. aureus and the isolation of more than one microbial species were not more common in blepharitis patients. Quantitatively, heavy growth, by total and individual species, was significantly more common in blepharitis patients (total, p less than 0.001; S. epidermidis, p less than 0.001, P. acnes, p less than 0.001). These data demonstrate that patients with blepharitis are more likely to have normal skin bacteria on their lids and in greater quantities than nonblepharitis patients.

Bacteria↗
PubMed1990

Patterns of out-patients non-steroidal anti-inflammatory drug prescribing in two teaching hospital rheumatology units--implications for post-marketing surveillance.

Patterns of prescriptions or recommendations for non-steroidal anti-inflammatory drugs (NSAIDs) were examined in the out-patient departments of two teaching hospital rheumatology units [The General Infirmary, Leeds (n = 140), and Musgrave Park Hospital, Belfast (n = 77)]. In both units four drugs accounted for over 80% of prescriptions/recommendations (diclofenac, indomethacin, ibuprofen and naproxen in Leeds and flurbiprofen, nabumetone, ibuprofen and diclofenac in Belfast). In Leeds patients with pre-existing upper gastrointestinal problems were more likely to receive diclofenac whereas in Belfast they were more likely to receive nabumetone or ibuprofen. In Leeds, patients who received indomethacin tended to be young males with seronegative arthritis. These differences between drugs and between centres could have important implications for cost, design and interpretation of studies of post-marketing surveillance.

Adolescent↗
PubMed1990

Bilateral mammary artery bypass and sternal dehiscence. A favorable outcome.

The efficacy of mammary artery bypass for coronary artery disease has been well established. The present retrospective series of consecutive patients was scrutinized to assess the incidence of sternal dehiscence following myocardial revascularization using the right and left internal mammary arteries. For comparison, the consecutive group of patients undergoing myocardial revascularization with unilateral internal mammary artery bypass was analyzed for similar sternal complications. In a consecutive series of patients, 277 patients underwent myocardial revascularization using the right and left internal mammary arteries for bypass. The overall operative mortality in this group of patients was 0.722 per cent. In this group there was an overall incidence of seven sternal dehiscences, both partial and complete for an incidence of 2.52 per cent. Upon analysis, it was shown that the female sex and diabetes were the conditions that most likely predisposed to the occurrence of sternal dehiscence whether partial or complete. For comparison, a consecutive group of 413 patients were analyzed for similar demographic data and results. The overall operative mortality in this group was 1.21 per cent. The overall incidence of sternal dehiscence both partial and complete, was 0.484 per cent. Both instances of sternal dehiscence occurred in diabetic patients and the data indicates, as in the bilateral internal mammary artery group, the presence of diabetes predisposed to the occurrence of this complication. The low overall incidence of sternal dehiscence in the expanded use of the mammary arteries should not deter the surgeon from aggressive use of the mammary arteries. One should use caution, however, in using bilateral mammary artery grafts in diabetics, women, and to a lesser extent, patients more than 70 years of age.

Adult↗
PubMed1989

Regulation of gene expression at the translational level. The rescue factor reverses thermosensitive protein synthesis in N4316, a conditionally-lethal mutant of Escherichia coli defective in translation.

Extracts of the conditionally-lethal mutant Escherichia coli N4316 are defective in a newly described translation factor, the rescue protein. We have analyzed the in vitro translation products of this mutant by gel electrophoresis during normal and arrested synthesis at the permissive and non-permissive temperatures. Translation programmed with MS2 bacteriophage RNA at the non-permissive temperature results in highly reduced synthesis of the coat protein with no detectable levels of the maturation and replicase products. Thus the relative number of copies of proteins synthesized by the ribosomes is altered in this mutant. In addition, there is mistranslation of the coat gene which results in the overproduction of the phage encoded no. 7 protein. Aberrant synthesis is also reflected in the increased read-through of termination codons during synthesis directed by phage RNAs harbouring amber mutations in the coat cistron. The rescue protein, purified from the parental strain, is able to complement the thermosensitive defect and restore proper synthesis. Biochemical characterization of the defect in the absence of rescue shows no detectable deficiency in the extent of initiation complex formation in reactions inhibited with sparsomycin. Peptidyltransferase is fully active as judged by the kinetics of formylmethionine-puromycin formation. However, rescue does exert an effect at the level of termination. In addition, the thermolability of the mutant can be reversed by dissociating 70S ribosomes into 30S and 50S subunits. Based on these and other observations, we propose tht rescue mediates a novel function in the association/dissociation of ribosomal subunits which is essential to the accuracy and efficiency of translation.

Bacterial Proteins↗
PubMed1989

Molecular cloning and characterization of the novel, human complement-associated protein, SP-40,40: a link between the complement and reproductive systems.

The cDNA sequence encoding the human complement-associated protein, SP-40,40, is reported. The two chains of SP-40,40 are coded in a single open reading frame on the same mRNA molecule, indicating the existence of a biosynthetic precursor protein which matures post-synthetically by the proteolysis of at least one peptide bond. The precursor is preceded by a signal sequence for vectorial export and contains six N-linked glycosylation sites distributed equally between the two chains of the structure. The sequence of the SP-40,40 precursor bears a 77% identity to a rat sulphated glycoprotein-2 (SGP-2) which is the major secreted product of Sertoli cells. The presence of SP-40,40 within human seminal plasma at levels comparable to those in serum was demonstrated, indicating that SP-40,40 and SGP-2 are serum and seminal forms of the same protein. A sequence of 23 amino acids within the beta-chain of SP-40,40 exhibited significant homology to corresponding segments located within complement components C7, C8 and C9. The short cysteine-containing motif represented the only evidence of a possible vestigial relationship between SP-40,40 and other complement components. The precise role of SP-40,40 is not known in either blood or semen but the present findings document an intriguing link between the immune and the reproductive systems.

Amino Acid Sequence↗
PubMed1989

Nucleotide sequence of the avian influenza A/Mallard/NY/6750/78 virus polymerase genes.

The avian influenza A/Mallard/NY/6750/78 virus is currently being evaluated as a donor of attenuating genes in the construction of live avian-human influenza A reassortant virus vaccines for use in humans. We determined the nucleotide sequences of the three polymerase gene segments of this virus. This completes the nucleotide sequence of the six transferrable genes of the avian donor virus. Comparison of the nucleotide and deduced amino acid sequences of the non-glycoprotein genes of the avian A/Mallard/78 virus with representative avian and human influenza A viruses suggests that the PB1 gene of H2N2 subtype human influenza A viruses may have been derived from a non-human, possibly avian influenza A virus by genetic reassortment. In addition, several regions of conserved amino acids with potential functional significance were identified in the deduced amino acid sequences of the polymerase proteins.

Amino Acid Sequence↗