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Biomedical subjects

J Blake

Publications and source records attributed to J Blake.

At least 91 records · Page 5Linked to original sources
PubMed1986

Is Metaphit a phencyclidine antagonist? Studies with ketamine, phencyclidine and N-methylaspartate.

The dissociative anaesthetics, phencyclidine and ketamine, block excitation of central neurones by N-methylaspartate. Using the technique of microelectrophoresis on rat spinal neurones in vivo Metaphit, a phencyclidine receptor acylating agent, was tested to see whether it would antagonise this effect of dissociative anaesthetics. The predominant effect of Metaphit was, however, to reduce N-methylaspartate induced excitation. It is concluded that Metaphit has mixed agonist/antagonist effects at the phencyclidine receptor.

Action Potentials↗
PubMed1986

Total synthesis of S-carbamoylmethyl bovine apocytochrome c by segment coupling.

Three peptide segments corresponding to the complete sequence of the 104 amino acid protein bovine apocytochrome c were synthesized by the solid-phase method. The peptides Ac-[Cys(Cam)14,17, GlyS23]-apocytochrome c-(1-23) (I), CF3CO-[GlyS60]-apocytochrome c-(24-60) (II), and CF3CO-apocytochrome c-(61-104) (III) were purified by chromatography on CM-cellulose, partition chromatography and/or HPLC. Each of the peptides was reacted with citraconic anhydride to block all of the lysine side chains, and the 61-104 peptide was treated with 10% hydrazine to remove the trifluoroacetyl group, to give the corresponding peptides Ia, IIa, and IIIa. Peptides IIa and IIIa were coupled together by reaction with silver nitrate/N-hydroxysuccinimide to give the 24-104 sequence. After removal of the trifluoroacetyl group from the amino terminus, peptide Ia was also coupled. Treatment of the peptide mixture with aqueous acetic acid removed the citraconyl groups, and purification by chromatography on CM-cellulose and HPLC gave a 0.6% yield of [Cys(Cam)14,17]-apocytochrome c. The synthetic product was shown to be identical to a sample derived from native bovine cytochrome c by paper or gel electrophoresis, HPLC and by chymotryptic or tryptic map.

Amino Acid Sequence↗
PubMed1986

Chemical synthesis of alpha-inhibin-92 by the thiocarboxyl segment coupling method.

The amino acid residue peptide, alpha-inhibin-92 (alpha-IB-92), has been synthesized by the thiocarboxyl segment strategy. Three segments were synthesized by the solid phase method, purified, and characterized: [GlyS34]-alpha-IB-92-(1-34) (I), CF3CO-[GlyS65]-alpha-IB-92-(35-65) (II), and Msc-alpha-IB-92-(66-92) (III). All were reacted with citraconic anhydride followed by removal of the Msc group in III to give Ia, IIa, and IIIa, respectively. Peptide IIIa was coupled to IIa by the silver nitrate/N-hydroxysuccinimide procedure and, after removal of uncoupled segments and the trifluoroacetyl group, Ia was coupled followed again by removal of uncoupled segments. Final deblocking to remove citraconyl groups was accomplished under exceptionally mild conditions in aqueous acetic acid. The synthetic product was identical to natural alpha-IB-92 in amino acid analysis, HPLC, gel electrophoresis, and tryptic mapping. The synthetic peptide was indistinguishable from natural alpha-IB-92 in a radioimmunoassay and in an in vitro mouse pituitary assay for measuring suppression of FSH release in the presence of LHRH.

Amino Acid Sequence↗
PubMed1986

Lacrimal sac mucoepidermoid carcinoma.

A single case of mucoepidermoid carcinoma of the lacrimal sac was considered worth reporting as there are only four other cases described in the literature. The importance of the correct histological diagnosis and the management are discussed. This appears to be the first study of the ultrastructure of lacrimal sac mucoepidermoid tumour.

Aged↗
PubMed1985

Successful Whipple's operation for pancreatic injury.

A case is presented of severe pancreatic injury in a 30-year-old man following a road traffic accident. A Whipple's operation was performed successfully. Despite some postoperative complications, the patient is well and back at work 1 year after the operation.

Adult↗
PubMed1985

Topological mapping of acetylcholine receptor: evidence for a model with five transmembrane segments and a cytoplasmic COOH-terminal peptide.

Antibodies were raised against two synthetic peptides whose sequences correspond respectively to the COOH-terminal end (residues 501-516) of the protein encoded by the gene for the delta chain and to a proposed cytoplasmic region (residues 350-358) of the beta chain of the acetylcholine receptor from Torpedo californica. Binding of the COOH-terminal antibody to the acetylcholine receptor in intact, receptor-rich vesicles was tested by radioimmunoassay and by precipitation with immobilized protein A. In both cases, binding was detected only after treatment of the vesicles with detergent, suggesting that the segment of the receptor that is recognized by this antibody is on the cytoplasmic side of the membrane. Electron microscopy of tissue from Torpedo electric organ labeled with colloidal gold-conjugated second antibodies established that both anti-receptor antibodies bind to the cytoplasmic surface of the postsynaptic membrane. These experiments give ultrastructural evidence that the COOH-terminal segment of the delta chain as well as residues 350-358 of the beta chain are on the cytoplasmic surface. They strongly support a model in which each of the receptor subunits crosses the membrane five times in which one transmembrane segment of each chain contributes to the formation of a central ion channel.

Amino Acid Sequence↗
PubMed1985

Beta-endorphin. Synthesis and biological activity of analogs with disulfide bridges.

Two analogs of human beta-endorphin (beta-EP) which contain cystine bridges, [Cys15-Cys26,Phe27,Gly31]-beta-EP (I) and [Cys16-Cys26,Phe27,Gly31]-beta-EP (II), were synthesized by the solid-phase method. Peptides I and II were shown to contain 2-2.5 times the opiate receptor binding activity of beta-endorphin. We also synthesized two analogs with reduced alkylated cysteine residues and these peptides, [Arg9,19,24,28,29 Cys(Cam)11,26,Phe27,Gly31] and [Arg9,19,24,28,29,Cys-(Cam)12,26,Phe27,Gly31], were shown to have approximately the same opiate receptor activity as beta-endorphin.

Brain↗
PubMed1984

Synthesis of human pancreatic growth hormone-releasing factor and two omission analogs by segment-coupling method in aqueous solution.

The human growth hormone-releasing factor (GRF) peptides [GlyS15]-GRF-(1-15) (IV), trifluoroacetyl-GRF-(20-44) (VI), trifluoroacetyl-GRF-(18-44) (VIII), and trifluoroacetyl-GRF-(16-44) (X) were synthesized by the solid-phase method. Each of the peptides was reacted with citraconic anhydride and the trifluoroacetyl group was removed by reaction with 10% hydrazine in water. The citraconylated GRF-(1-15) peptide was coupled to the (20-44), (18-44) or (16-44) peptides by reaction with silver nitrate/N-hydroxysuccinimide to give GRF-(1-15)-(20-44) (XII), GRF-(1-15)-(18-44) (XIII), or GRF-(1-44), respectively. GRF-(1-44) was shown to stimulate the release of rat growth hormone from rat pituitary cells with an ED50 = 8.8 X 10(-11)M. Peptides XII and XIII were inactive, either as agonists or as antagonists of the action of GRF-(1-44).

Animals↗
PubMed1983

Road blindness.

Explore the source record for details and available documents.

Accidents, Traffic↗
PubMed1983

Road blindness.

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Accidents, Traffic↗
PubMed1983

Total synthesis of human beta-lipotropin.

The total synthesis of human beta-lipotropin has been accomplished by the new segment-coupling method in aqueous solution. The peptides Ac-Arg-beta-lipotropin-(61-89) (I) and [GlyS60]-beta-lipotropin-(1-60) (II) were synthesized by the solid-phase method. Reaction of peptide I with citraconic anhydride followed by brief digestion with trypsin to remove the acetylarginyl group, gave Ia. Reaction of peptide II with citraconic anhydride gave the citraconyl peptide IIa. Ia and IIa were coupled together in 50% dimethylformamide by reaction with silver nitrate/N-hydroxysuccinimide. After removal of the citraconyl groups in 25% acetic acid, a 10% yield of synthetic beta-lipotropin could be isolated. The synthetic product was shown to be identical to native human beta-lipotropin by paper electrophoresis, isoelectric focusing, HPLC, lipolytic activity in isolated rabbit fat cells, and radioimmunoassay.

Amino Acid Sequence↗
PubMed1983

Pacemaker-induced pseudotricuspid regurgitation.

A patient with aortic stenosis and ventricular pacemaker had clinical findings suggesting tricuspid regurgitation. Her presentation was actually caused by regular and constant cannon waves resulting from ventriculoatrial conduction of paced beats. The correct diagnosis was confirmed by abolition of hepatic pulsations during atrial pacing at the time of cardiac catheterization. Therapy consisted of restoring antegrade atrioventricular conduction.

Aged↗
PubMed1983

Dietetic performance indicators: a new management tool.

The need for dietetic performance indicators that more accurately reflect the performance of the department of dietetics has led to the development of an effective tool for directors of dietetics to use in monitoring departmental performance, planning departmental activities, services and programs, and budgeting. To follow-up on the work initiated by a group of directors of dietetics in Metropolitan Toronto, the joint Ontario Dietetic Association-Ontario Hospital Association (ODA-OHA) Steering Committee on Alternative Dietetic Performance Indicators (SCADPI) was established. The work of this Committee has involved identifying relevant dietetic performance indicators based on three areas of departmental activity: patient meal service, non-patient meal service, and clinical nutrition service; developing the methodology of allocating food, sundry, and labor costs to these three areas of departmental activity; and testing the validity and feasibility of the methodology among hospitals of varying sizes and levels of dietary department management personnel.

Dietetics↗
PubMed1982

The use of adenosine deaminase assays in the diagnosis of tuberculosis.

We describe a rapid method for the estimation of adenosine deaminase (ADA) activity in cerebrospinal, pleural, peritoneal, and pericardial fluids. Tuberculous effusions show significantly higher levels of ADA activity compared with effusions due to other underlying lesions such as neoplasms, bacterial and viral infections and simple transudates. Similarly, tuberculous meningitis results in raised ADA activity in the cerebrospinal fluid (CSF) when compared with the CSF from patients with other neurological disorders and from normal subjects. The results in 359 cases studied indicated the value of ADA assays in the diagnosis of tuberculous diseases. Levels above 30 IU/I in effusions and above 6 IU/I in the CSF indicate probable tuberculosis.

Adenosine Deaminase↗