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E Stanley

Publications and source records attributed to E Stanley.

15 recordsLinked to original sources
PubMed1992

Effect of inflammation of enteric nerves. Cytokine-induced changes in neurotransmitter content and release.

The results of our previously published work provide evidence of inflammation-induced functional disturbances in the enteric nervous system. Data presented in this paper describe our preliminary results indicating that the altered function in enteric nerves in the nematode-infected rat model of intestinal inflammation is mediated by interleukin-1. This is based on the ability of the exogenous cytokine to mimic changes observed in the model, and on the ability of a specific IL-1 antagonist to attenuate these changes. In addition, we have identified mechanisms underlying the actions of IL-1 in the myenteric plexus. Our data are consistent with a direct interaction between the cytokine and neural membranes. In addition, the delayed effect of IL-1 beta on neurotransmitter release appears to be due to the release of endogenous IL-1, most likely from macrophage-like cells in the myenteric plexus (Fig. 3). If such cells possess receptors for neuropeptides, as has been found with macrophages elsewhere in the gut, a neuroimmune axis would exist in the myenteric plexus. Thus, the finding of a source of IL-1 in the plexus of the noninflamed intestine invites speculation on a neuromodulatory role of the cytokine within the enteric nervous system.

Animals↗
PubMed1992

Lipopolysaccharide- and interferon-gamma-induced expression of hck and lyn tyrosine kinases in murine bone marrow-derived macrophages.

We have examined the role of tyrosine phosphorylation during the course of macrophage activation. Initial experiments indicated that vanadate, a known phosphotyrosine phosphatase inhibitor, enhanced the phorbol 12-myristate 13-acetate (PMA)-triggered respiratory burst and potentiated the priming effects of bacterial lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma), suggesting that tyrosine phosphorylation may be important in these end cell functions. As src-related kinases have been implicated in the activation of cells of other haemopoietic lineages, we examined the relationship between the activity of two such kinases, hck and lyn, and priming of the respiratory burst. We found that the level of hck and lyn is increased following exposure of bone marrow-derived macrophages (BMM) to LPS or IFN-gamma. The induction of both of these kinases follows similar kinetics with maximal activity occurring at 24-48 h. Interestingly, the kinetics of induction of hck and lyn kinase activity in BMM demonstrated a close temporal relationship with the priming effects of LPS and IFN-gamma on the macrophage respiratory burst. Collectively, these observations raise the possibility that modulation of expression of hck and lyn is involved in the regulation of the respiratory burst.

Animals↗
PubMed1991

Alternatively spliced murine lyn mRNAs encode distinct proteins.

Two lyn proteins of 56 and 53 kDa have been observed in immunoprecipitates from a variety of murine and human cell lines and tissues. We report the cloning and nucleotide sequence of two distinct murine lyn cDNAs isolated from an FDC-P1 cDNA library. One of the cDNAs, designated lyn11, encodes a protein of 56 kDa which shares 96% similarity with human lyn. The other cDNA, designated lyn12, encodes a protein of 53 kDa. The proteins differ in the presence or absence of a 21-amino-acid sequence located 24 amino acids C terminal of the translational initiation codon. Using RNase protection analysis, we have identified mRNAs corresponding to both cDNAs in murine cell lines and tissues. Sequence analysis of murine genomic clones suggests that the distinct mRNAs are alternatively spliced transcripts derived from a single gene. Expression of both cDNAs in COS cells leads to the production of lyn proteins with the same molecular weight as the two forms of lyn proteins immunoprecipitated from extracts of FDC-P1 cells and mouse spleen. Subcellular fractionation studies and Western immunoblotting analysis suggest that both isoforms of lyn are membrane associated. The association of both lyn isoforms with the membrane fraction supports the notion that lyn, like other src-related kinases, may interact with the intracellular domain of cell surface receptors.

Amino Acid Sequence↗
PubMed1991

Two isoforms of murine hck, generated by utilization of alternative translational initiation codons, exhibit different patterns of subcellular localization.

Mammalian hck, a member of the src family of tyrosine kinases, is expressed predominantly in cells of the myeloid and B-lymphoid lineages. Using mutational analysis, we have investigated the molecular basis of two immunoreactive forms of murine hck of 56 and 59 kDa found in numerous hemopoietic cell types. Our results indicate that translation of murine p59hck initiates from a CTG codon located 21 codons 5' of an ATG that is utilized to generate p56hck. We provide evidence that two human hck isoforms are generated by the same mechanism. Subcellular fractionation studies reveal that while p59hck and p56hck are associated with membranes of various murine B-lymphoid and myeloid cell lines, p59hck alone is also located in the cytosol. In contrast to membrane-associated p59hck, which is metabolically labeled with [3H]myristic acid and exhibits amphiphilic properties in Triton X-114 detergent, cytosolic p59hck is hydrophilic, suggesting that it is not acylated. Possible mechanisms are proposed to account for these observations.

Amino Acid Sequence↗
PubMed1990

Functional analysis and nucleotide sequence of the promoter region of the murine hck gene.

The structure and function of the promoter region and exon 1 of the murine hck gene have been characterized in detail. RNase protection analysis has established that hck transcripts initiate from heterogeneous start sites located within the hck gene. Fusion gene constructs containing hck 5'-flanking sequences and the bacterial Neor gene have been introduced into the hematopoietic cell lines FDC-P1 and WEHI-265 by using a self-inactivating retroviral vector. The transcriptional start sites of the fusion gene are essentially identical to those of the endogenous hck gene. Analysis of infected WEHI-265 cell lines treated with bacterial lipopolysaccharide (LPS) reveals a 3- to 5-fold elevation in the levels of endogenous hck mRNA and a 1.4- to 2.6-fold increase in the level of Neor fusion gene transcripts, indicating that hck 5'-flanking sequences are capable of conferring LPS responsiveness on the Neor gene. The 5'-flanking region of the hck gene contains sequences similar to an element which is thought to be involved in the LPS responsiveness of the class II major histocompatibility gene A alpha k. A subset of these sequences are also found in the 5'-flanking regions of other LPS-responsive genes. Moreover, this motif is related to the consensus binding sequence of NF-kappa B, a transcription factor which is known to be regulated by LPS.

Animals↗
PubMed1988

Murine epidermal growth factor: structure and function.

Murine epidermal growth factor (EGF), a 53 amino acid protein, has been modified by enzymic digestion, site-specific chemical reactions, and recombinant DNA technology. After trypsin digestion the EGF derivatives EGF1-48 (called EGF-T) and EGF1-45 (called EGF-T2) were separated from the residual EGF and the C-terminal pentapeptide by reversed-phase high-performance liquid chromatography. EGF-T competes for binding to EGF receptors with the same efficiency as EGF. The EGF-T2 derivative had no detectable receptor binding activity even at 100 nM. The in vitro mitogenic potencies of EGF and EGF-T for Balb/c 3T3 cells were indistinguishable. Treatment of EGF-T with carboxypeptidase Y yielded two derivatives, EGF-T-(des-Arg48) and EGF-T-des(Leu47-Arg48). There was only a 3-7-fold diminution in the binding efficiency and mitogenic potency for EGF-T-(des-Arg48). However, there was more than a 100-fold decrease in the binding efficiency and mitogenic activity of EGF-T-des (Leu47-Arg48). These results indicated that Leu47 is intimately involved in the formation of the ligand-receptor complex. Studies with a number of proteases indicated that the C-terminus of EGF was susceptible to enzymic digestion; however, the N-terminus appears to be folded into a conformation which prevents access to proteolytic digestion. Consequently, the N-terminus was modified by preparing an analogue with recombinant DNA technology. Oligonucleotides corresponding to EGF(3-48). Met3 Lys21 residues were ligated in frame to a beta-galactosidase expression vector. The beta-Gal-EGF fusion protein was cleaved with cyanogen bromide and EGF(4-48).Lys21 purified.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1987

Transgenic mice expressing a hemopoietic growth factor gene (GM-CSF) develop accumulations of macrophages, blindness, and a fatal syndrome of tissue damage.

Transgenic mice carrying the murine granulocyte-macrophage colony stimulating factor (GM-CSF) gene expressed from a retroviral promoter exhibit elevated levels of GM-CSF in the serum, urine, peritoneal cavity, and eye. The eyes of transgenic mice are opaque, contain accumulations of macrophages, and develop retinal damage. Similarly, lesions containing macrophages develop in striated muscle. The mice also display an accumulation of large, often multinucleate, activated macrophages in the peritoneal and pleural cavities. The transgene is transcribed in peritoneal cells, as well as in eyes and infiltrated striated muscle. A high proportion of transgenic mice die with muscle wasting when aged 2-4 months, possibly because of macrophage activation resulting from the high levels of GM-CSF.

Animals↗
PubMed1985

The structure and expression of the murine gene encoding granulocyte-macrophage colony stimulating factor: evidence for utilisation of alternative promoters.

Two overlapping genomic clones containing the murine granulocyte-macrophage colony stimulating factor (GM-CSF) gene have been isolated. On the basis of transfection experiments, we have established that a 9-kb BamHI fragment from one of these recombinants encodes biologically active GM-CSF. As deduced from nucleotide sequence analysis, the GM-CSF gene comprises four exons encompassing 2.5 kb of genomic DNA. Primer extension analysis of GM-CSF mRNA identifies a transcriptional initiation site 35 bp upstream of a single translational initiation codon in-frame with the GM-CSF coding sequences and 28 bp downstream of a TATA promoter consensus sequence. Pre-GM-CSF molecules encoded by mRNAs originating from this promoter would include a hydrophobic leader sequence typical for a secreted protein. Intriguingly, sequences present at the 5' end of a GM-CSF cDNA clone previously isolated in our laboratory are not contained within either of the genomic clones and must therefore be transcribed from a promoter located at least 10 kb 5' of the main body of the gene. mRNAs transcribed from this alternative upstream promoter possess an additional initiating codon and potentially encode a pre-GM-CSF polypeptide with an atypical NH2-terminal leader peptide. Comparison of the nucleotide sequence of the GM-CSF gene with that of other haemopoietic growth factor genes has revealed a common decanucleotide (5'-GPuGPuTTPyCAPy-3') within their respective 5'-flanking regions which may be involved in their co-ordinate regulation.

Amino Acid Sequence↗
PubMed1978

An introduction to sexuality in the medical curriculum.

An educational procedure is described for increasing comfort and clinical objectiveness when interviewing patients with sexual problems. It is based on the viewing of sexually explicit films interspersed with small group discussions. Judging from questionnaires completed by 329 students in four British medical schools, most felt that the procedure had benefited them both personally and professionally, and that it provided a good foundation for a course in human sexuality.

Audiovisual Aids↗
PubMed1977

Altered peripheral nerve function resulting from haemodialysis.

The amplitudes of muscle and nerve action potentials evoked median nerve stimulation were recorded just before and immediately after haemodialysis. These revealed a growht of action potential amplitude during dialysis. It is suggested that some component of the defective peripheral nerve function that inevitably accompanies uraemia is temporarily improved during dialysis.

Adolescent↗
PubMed1976

Improvement in peripheral nerve function immediately after haemodialysis.

During haemodialysis there is a growth in the amplitude of muscle and nerve action potentials evoked by median nerve stimulation. It is therefore suggested that even a single period of haemodialysis causes some temporary improvement in the defective peripheral nerve function that accompanies uraemia.

Adolescent↗