PubMed Health⌕ Search

Biomedical subjects

P Spence

Publications and source records attributed to P Spence.

10 recordsLinked to original sources
PubMed1999

From genome to drug--optimising the drug discovery process.

Current drug discovery and development practices are technologically sophisticated and highly efficient. At the same time the failure rate of compounds in both preclinical and clinical development is high. These failures can be attributed to many factors. Two predominant causes of failure are lack of efficacy and toxicity. Often lack of efficacy is only determined late in the clinical trial process and can be difficult if not impossible to explain, as well as being expensive. Toxicity accounts for many failures during preclinical development, which are less costly, but it also occurs in the clinic. Often the underlying cause of clinical toxicity is never identified. Studies of the structure and activity of the human and other genomes has over the last decade lead to a revolution in biological and medical research. Disease associated genes can now be identified through the application of human genetics, whole genomes have been sequenced and tools have been developed that allow the complete characterization of an organism's gene expression profile in a single experiment. These tools are now being applied to pharmaceutical research and development with the aim to increase the efficiency of the process and the quality of the product.

Animals↗
PubMed1999

Genomics: the race is on.

'ellipsisgenomics has started a race in the pharmaceutical and biotechnology industryellipsis'

Journal Article↗
PubMed1998

Structure-activity relationships of the Kvbeta1 inactivation domain and its putative receptor probed using peptide analogs of voltage-gated potassium channel alpha- and beta-subunits.

Certain beta-subunits exert profound effects on the kinetics of voltage-gated (Kv) potassium channel inactivation through an interaction between the amino-terminal "inactivation domain" of the beta-subunit and a "receptor" located at or near the cytoplasmic mouth of the channel pore. Here we used a bacterial random peptide library to examine the structural requirements for this interaction. To identify peptides that bind Kv1.1 we screened the library against a synthetic peptide corresponding to the predicted S4-S5 cytoplasmic loop of the Kv1.1 alpha-subunit (residues 313-328). Among the highest affinity interactors were peptides with significant homology to the amino terminus of Kvbeta1. We performed a second screen using a peptide from the amino terminus of Kvbeta1 (residues 2-31) as "bait" and identified peptide sequences with significant homology to the S4-S5 loop of Kv1.1. A series of synthetic peptides containing mutations of the wild-type Kvbeta1 and Kv1.1 sequences were examined for their ability to inhibit Kvbeta1/Kv1.1 binding. Amino acids Arg20 and Leu21 in Kvbeta1 and residues Arg324 and Leu328 in Kv1.1 were found to be important for the interaction. Taken together, these data provide support for the contention that the S4-S5 loop of the Kv1.1 alpha subunit is the likely acceptor for the Kvbeta1 inactivation domain and provide information about residues that may underlie the protein-protein interactions responsible for beta-subunit mediated Kv channel inactivation.

Amino Acid Sequence↗
PubMed1996

Evaluation of the long-term effectiveness of extraluminal and intraluminal vasodilators in an in vitro porcine model of arterial graft spasm.

OBJECTIVE: Postoperative graft spasm is a concern when arterial conduits are used because there may be insufficient arterial graft flow. Intraoperatively, vasodilators are used to increase flow and prevent spasm, but little is known about their duration of effectiveness. METHODS: To examine this we attached porcine gastroepiploic and internal thoracic arteries (GEA, n = 48; ITA, n = 24, 10-12 cm long) to a computer-controlled perfusion system (constant inflow pressure 80 mm Hg) with a fixed outflow resistance. Norepinephrine (10(-9)-10(-5) M) was incrementally added to the perfusate at baseline (B), then immediately (h+0) and 2 h (h+2) after the vessels were treated with 30 min of extraluminal or intraluminal nitroglycerin, nitroprusside, verapamil or papaverine. RESULTS: At (B), norepinephrine caused a dose-dependent decrease in flow in both the ITAs and GEAs. In the ITAs, at (h+0), both extraluminal and intraluminal papaverine and, to a lesser extent nitroprusside, increased initial flow and decreased graft sensitivity to norepinephrine. At (h+2), only extraluminal papaverine sustained this maximal effect (ED50 for extraluminal papaverine at (B) 2.6 E(-7) vs. (h+2) 1.3 E(-6), P = 0.01). For the GEAs, at (h+0), both extraluminal and intraluminal verapamil, papaverine, nitroprusside and nitroglycerin attenuated flow reduction due to norepinephrine. At (h+2), only extraluminal papaverine, extraluminal verapamil and intraluminal verapamil were effective in preventing norepinephrine-induced spasm (ED50 for extraluminal papaverine at (B) 1.0 E(-7) vs. (h+2) 6.4 E(-6) (P = 0.004); extraluminal verapamil at (B) 1.2 E(-7) vs. (h+2) 4.0 E(-6); intraluminal verapamil at (B) 5.8 E(-7) vs. (h+2) 5.7 E(-6), P = 0.005). CONCLUSION: Verapamil-and papaverine-treated arteries have a greater duration of efficacy in resisting spasm than arteries treated with nitroglycerin and nitroprusside. In the ITA, extraluminal administration of papaverine is most efficacious, possibly due to the prolonged exposure afforded by this route of administration. The effects of verapamil and papaverine are more prolonged in the GEA when administered extraluminally, potentially due to absorption in the perivascular fat-pad and subsequent slow release. The results of this study suggest that extraluminally administered verapamil and papaverine appear to be the preferred vasodilators for preventing arterial graft spasm in the postoperative period. This may be especially important when multiple arterial grafts are used.

Animals↗
PubMed1992

Expression of the mouse c-abl type IV proto-oncogene product in the insect cell baculovirus system.

The cellular gene c-abl is the normal homologue of the transforming gene (v-abl) within the genome of the Abelson leukaemia virus. The cDNA sequence coding for the cellular form of the murine abl gene (c-abl type IV) has been inserted into the baculovirus transfer vector, pAc36C, so that the c-abl gene is under the control of the polyhedrin promoter of Autographa californica nuclear polyhedrosis virus (AcNPV). Spodoptera frugiperda cells infected with the recombinant transfer vector in the presence of wild type AcNPV DNA yielded recombinant, polyhedrin negative virus that expressed moderate levels of the c-Abl protein (representing approx. 0.5-1% of the stained cellular proteins as determined by densitometric scanning). The insect derived c-Abl protein was compared to the P210-BCR/ABL protein from K562 cells, a cell line derived from a patient with chronic myelogenous leukaemia. Antibodies raised against synthetic peptides based on c-abl encoded peptides react with the insect derived c-Abl. In addition, the baculovirus derived c-Abl protein has a tyrosine kinase activity as demonstrated by phosphorylation of a synthetic polypeptide and also by autophosphorylation. Phosphoamino acid analysis of immunoprecipitated, autophosphorylated baculovirus derived c-Abl protein indicates that the majority of label incorporated is on the tyrosine residues. Immunofluorescence microscopy has been used to show that the majority of the c-Abl protein expressed in cells infected with recombinant virus is located in the nuclear and plasma membranes.

Animals↗
PubMed1987

Identification of human papillomavirus type 18 E6 polypeptide in cells derived from human cervical carcinomas.

We recently reported the expression of human papillomavirus type 18 (HPV-18) E6 protein in bacteria and the production of anti-E6 polyclonal antibodies. This work has now been extended with the production of a panel of monoclonal antibodies against the HPV-18 E6 protein. These antibodies demonstrate that there is little antigenic conservation in the E6 protein between HPV-16 and HPV-18, with only one antibody recognizing a cross-reactive epitope. We have used both the monoclonal and the polyclonal antibodies to look for E6 expression in a number of HPV DNA-containing cell lines. These reagents specifically detected a 16.5K mol. wt. polypeptide in cells derived from a human cervical carcinoma.

Antibodies, Monoclonal↗
PubMed1986

The expression of human papillomavirus type 18 E6 protein in bacteria and the production of anti-E6 antibodies.

Human papillomavirus type 18 (HPV-18) has recently been closely linked with human malignant cervical lesions. The early region of the genome of the related bovine papillomavirus (BPV) has been shown to be important for the production of the transformed phenotype. BPV E6 has been shown to be a transforming protein. We report the primary structure of the HPV-18 E6 open reading frame and its predicted amino acid sequence. Both E6 protein and E6-beta-galactosidase fusion protein were synthesized in bacteria. Antisera were raised against the E6-beta-galactosidase fusion protein and against an E6 N-terminal peptide which was 14 amino acids long. We show that these antisera reacted on Western blots against E6 synthesized in bacteria. The HPV E6 antigen and antibodies described here will be useful in understanding HPV expression and its association with human malignancies and may also be diagnostically useful.

Amino Acid Sequence↗
PubMedDate not supplied

All tired out.

Explore the source record for details and available documents.

Adaptation, Psychological↗