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Biomedical subjects

R E West

Publications and source records attributed to R E West.

27 records · Page 2Linked to original sources
PubMed1985

Pertussis toxin-catalyzed ADP-ribosylation of transducin. Cysteine 347 is the ADP-ribose acceptor site.

Pertussis toxin catalyzes the transfer of ADP-ribose from NAD to the guanine nucleotide-binding regulatory proteins Gi, Go, and transducin. Based on a partial amino acid sequence for a tryptic peptide of ADP-ribosylated transducin, asparagine had been characterized as the site of pertussis toxin-catalyzed ADP-ribosylation. Subsequently, cDNA data for the alpha subunit of transducin indicated that the putative asparagine residue was, in fact, not present in the protein. To determine the amino acid that served as the ADP-ribose acceptor, radiolabel from [adenine-U-14C]NAD was incorporated, in the presence of pertussis toxin, into the alpha subunit of transducin (0.3 mol/mol). An ADP-ribosylated, tryptic peptide was purified and fully sequenced by automated Edman degradation. The amino acid sequence, Glu-Asn 343-Leu-Lys-Asp 346-X-Gly 348-Leu-Phe, corresponds to the cDNA sequence coding the carboxyl-terminal nonapeptide, Glu 342-Phe 350, which includes by cDNA sequence cysteine at position 347. Neither Asn 343 nor Asp 346 appeared to be modified; residue 347 adhered to the sequencing resin. Cysteine, the missing residue, was eluted from the sequencing resin with acetic acid along with 76% of the peptide-associated radioactivity, half of which, presumably ADP-ribosylcysteine, eluted from an anion exchange column between NAD and ADP-ribose; the other half had a retention time corresponding to 5'-AMP. We conclude that Cys 347 and not Asn 343 or Asp 346 is the site of pertusis toxin-catalyzed ADP-ribosylation in transducin.

Adenosine Diphosphate Ribose↗
PubMed1984

Productivity analysis as a method of fiscal accountability for therapeutic recreation.

This article reviews increasing pressures for fiscal accountability and describes productivity analysis and measurement as a method of demonstrating fiscal accountability for therapeutic recreation. The article reviews various aspects of productivity analysis and measurement, including definitions for productivity, a description of why productivity measurement is important to therapeutic recreation as a method of demonstrating fiscal accountability, and facts and myths about productivity analysis and measurement. A process of developing a productivity measurement system for therapeutic recreation is presented for consideration.

Efficiency↗
PubMed1983

[3H]ethylketocyclazocine binding to NCB-20 hybrid neurotumor cells.

Ethylketocyclazocine (EKC) binds to two sites on NCB-20 neuroblastoma X Chinese hamster brain hybrid cells (KDH = 2 nM, Bmax = 21,000 sites/cell; KDL = 27 nM, Bmax = 140,000 sites/cell. The high-affinity site has been characterized as a delta opiate receptor. The low-affinity site is relatively benzomorphan-specific; opioid peptides, morphine, etorphine, and naloxone do not compete at it. Rank order of potency among benzomorphans is (+)-EKC greater than Mr 2267 greater than (+)-ketocyclazocine greater than (+)-SKF 10047 greater than bremazocine greater than cyclazocine. Among other drugs of interest that inhibit [3H]EKC binding are phencyclidine and its analogues, Ki values for which are 0.2-40 microM. Stereoselectivity is the reverse of other opioid receptors: (+)-EKC much much greater than (-)-EKC, Mr 2267 greater than Mr 2266, (+)-SKF 10047 greater than (-)-SKF 10047. The site is sensitive to trypsin, but not to N-ethylmaleimide. Binding is insensitive to nucleotides, slightly sensitive to physiological concentrations of sodium, magnesium, and manganese ions and to EDTA but not EGTA.

Animals↗
PubMed1981

Distinct high-affinity binding sites for benzomorphan drugs and enkephalin in a neuroblastoma--brain hybrid cell line.

The high-affinity binding of benzomorphan drugs (ethylketocyclazocine and N-allylnorcyclazocine) and [DAla2,DLeu5] enkephalin was examined in a mouse neuroblastoma--Chinese hamster brain clonal hybrid cell line (NCB-20). Scatchard analysis of saturation binding isotherms indicated the presence of a single binding site for 3H-labeled [DAla2,DLeu5]enkephalin (Kd = 3 nM) and multiple binding sites for [3H]ethylketocyclazocine (Kd = 4 and 20 nM) and N-[3H]allylnorcyclazocine (Kd = 0.5 and 15 nM). Both ethylketocyclazocine and N-allylnorcyclazocine competed (Ki = 10 and 30 nM, respectively) with [3H][DAla2,DLeu5]enkephalin binding in NCB-20 cells but neither [DAla2,DLeu5]enkephalin nor morphine could completely inhibit the specific binding of [3H]ethylketocyclazocine (7 nM) or N-[3H]allylnorcyclazocine (3 nM). Furthermore, not all benzomorphan drugs (e.g., ethylketocyclazocine) were totally efficacious in displacing 3 nM N-[3H]allylnorcyclazocine binding in the presence or absence of high concentrations of [DAla2,DLeu5]enkephalin. The data presented suggest that benzomorphan drugs interact with three distinct high-affinity binding sites: (i) a site that binds enkephalin and morphine in addition to ethylketocyclazocine and N-allylnorcyclazocine; (ii) a site that binds both ethylketocyclazocine and N-allylnorcyclazocine but not enkephalin and morphine; and (iii) a site that binds N-allylnorcyclazocine but not enkephalin, morphine, or ethylketocyclazocine. The first of these sites was comparable to the delta opiate receptor expressed in NG108-15 and N4TG1 cell lines based on the potency series obtained for various opiates and benzomorphan drugs in competition studies with [3H][DAla2,DLeu5]-enkephalin. However, the specific high-affinity benzomorphan binding sites thus far are unique and may represent biochemical correlates of kappa and sigma opiate receptors which have been proposed to exist on the basis of physiological studies.

Analgesics, Opioid↗
PubMedDate not supplied

Rapid establishment of therapeutic serum concentrations of salicylates.

A minimum serum salicylate concentration of 150 microgram/ml is required to control certain inflammatory disease processes. A loading regimen designed to rapidly achieve this minimal level was evaluated in six normal volunteers (age 22 to 27 years, weight 70.5 to 84.1 kg) using a randomized crossover design. The control group received 650 mg aspirin (ASA) every 4 hours for 48 hours. The loading regimen was 2600 mg ASA divided into two equal doses 4 hours apart. Maintenance dosing of 650 mg ASA every 4 hours was then started 4 hours after the completion of the loading regimen and continued for 40 hours. Serum samples were drawn at 0, 2, 4, 6, 8, 12, 24, 36, and 48 hours after initiation of the study and were assayed for salicylate concentration by UV spectrophotometry. Loading with aspirin produced serum concentrations which were significantly higher (P less than 0.01) for the first 24 hours and reduced the time to reach 150 microgram/ml (15.3 +/- 5.9 hours versus 30.4 +/- 8.65 hours, P less than 0.001) for five of six subjects when compared to a conventional regimen. One subject did not achieve 150 microgram/ml at 48 hours with either regimen. Considerable intersubject variation in serum concentration was noted at 48 hours for both regimens. We suggest that a loading regimen for aspirin may have utility for patients in whom rapid attainment of a therapeutic antiinflammatory serum concentration is desirable.

Adult↗
PubMedDate not supplied

Delta and sigma sites of clonal NCB20 cells do not modulate calcium uptake.

Opiate alkaloids and peptides are reported to inhibit 45Ca2+ binding to synaptic plasma membranes and uptake into brain synaptosomes. We have examined the effects of a number of opiates on 45Ca2+ uptake in a clonal cell line NCB20 which expresses multiple opioid binding sites. The cells express voltage-dependent calcium channels that are blocked by verapamil and nifedipine. In contrast to brain, 45Ca2+ uptake in these cells, in normal or high potassium medium, is unaffected by opiates. This difference may be due to the particular receptor types; the delta and sigma sites of these cells do not inhibit 45Ca2+ uptake.

Animals↗
PubMedDate not supplied

GC/MS analysis of five common benzodiazepine metabolites in urine as tert-butyl-dimethylsilyl derivatives.

A method for the GC/MS confirmation of oxazepam, nordiazepam, desalkylflurazepam, temazepam, and alpha-hydroxyalprazolam in urine is described. The method incorporates a solid phase extraction technique developed by Varian which was found to extract all five metabolites with recoveries exceeding 73%. The extracted metabolites were derivatized with N-methyl-N-(tert-butyldimethylsilyl)-trifluoroacetamide (MTBSTFA), resulting in the formation of stable tert-butyldimethylsilyl (TBDMS) derivatives. Quantitation was performed by GC/MS using oxazepam-D5, nordiazepam-D5, and alpha-hydroxyalprazolam-D5 as internal standards. The method was found to be linear over the range of 50-2000 ng/mL. Within-run precision, measured as the coefficient of variation at 100 ng/mL, was less than 3% for all analytes except temazepam which was 6% (N = 20).

Benzodiazepines↗