Removal of N-terminal blocking groups from proteins.

Two enzymatic methods commonly used in N-terminal sequence analysis of blocked proteins are presented: one uses pyroglutamate aminopeptidase for N(α)-pyrrolidone carboxyl-proteins in solution or blotted onto a membrane, and the other uses acylaminoacyl-peptide hydrolase for N(α)-acyl-proteins blocked with other acyl groups. A Support Protocol describes a colorimetric assay for pyroglutamate aminopeptidase activity. Sequencing with acylaminoacyl-peptide hydrolase must include fragmentation of the protein before unblocking, so procedures are provided for chemically blocking newly generated peptides with either succinic anhydride or phenylisothiocyanate/performic acid.

Reduced labor force participation among primary care patients with headache.

Objective: To assess the long-term impact of headache on labor force participation among primary care patients with headache.

Design: A 2-year cohort study comparing employment status of primary care patients with headache and that of patients with back pain.

Participants: Patients with headache (n = 662) or back pain (n = 1,024) sampled from persons visiting a primary care physician who completed baseline, 1-year and 2-year follow-up interviews.

Apoptosis in a Fas-resistant, T-cell receptor-sensitive human leukaemic T-cell clone.

The Fas (CD95) antigen plays a key role in regulating T-cell activation and survival. We have generated a Fas-resistant subclone of the human T-cell leukaemia line, H9, which is still able to undergo apoptosis in response to T-cell receptor ligation. Molecular analyses revealed that resistance to Fas-mediated apoptosis was due to a heterozygous mutation in the death domain of the Fas gene which generates a stop codon, and thus encodes a truncated Fas molecule.

Discovery of ligands for the nuclear peroxisome proliferator-activated receptors.

The identification of high-affinity ligands for PPAR gamma has revealed the role of this receptor as the molecular target for the antidiabetic activity of the thiazolidinediones. The surprising observation that agonists of an adipogenic transcription factor reverse the obesity-associated disease of diabetes highlights the power of using potent and selective ligands to study receptor-mediated biology. Similarly, the observation that PGD2 and its cyclopentenone metabolites compounds are microM PPAR ligands suggests that these receptors may have a physiological role in mediating prostaglandin signaling in the spleen.

Fluticasone Propionate Reduces Oral Prednisone Use While it Improves Asthma Control.

This study examined the effect of fluticasone propionate aerosol on oral prednisone requirements in patients with severe asthma. Ninety-six patients dependent on oral prednisone were treated with placebo or fluticasone propionate aerosol (750 or 1000 &mgr;g twice daily) for 16 weeks. The dosage of oral prednisone was adjusted weekly according to predetermined criteria.

Phosphorylation of a cAMP-specific phosphodiesterase (HSPDE4B2B) by mitogen-activated protein kinase.

A cAMP-specific phosphodiesterase, HSPDE4B2B, was found to be phosphorylated when expressed in Sf9 cells or yeast. Deletion of amino acids 81-151 and 529-564 had no effect on the phosphorylation of HSPDE4B2B. Mass spectrometric analysis of purified HSPDE4B2B(1-564).

Ranitidine 300 mg twice daily and 150 mg four-times daily are effective in healing erosive oesophagitis.

Background: Ranitidine 150 mg q.d.s.

Ethanol Pharmacodynamics at Low Blood Concentrations.

Ranitidine has been shown to produce increases in blood alcohol concentration (BAC) after low doses of alcohol. The objective of this study was to reproduce, in a controlled setting, the BACs seen after low oral doses of ethanol in the presence and absence of ranitidine and to assess the effect of these concentrations on cognitive performance. An active control group (0.

Determination of alosetron in human plasma or serum by high-performance liquid chromatography with robotic sample preparation.

A method of analysis for the determination of alosetron in human plasma or serum has been developed. The method was fully automated using a laboratory robot in order to improve analytical precision, efficiency and safety. The assay involved solid-phase extraction with reversed-phase HPLC separation and fluorescence detection.

Activation of stimulus-secretion coupling in pancreatic beta-cells by specific products of glucose metabolism. Evidence for privileged signaling by glycolysis.

The energy requirements of most cells supplied with glucose are fulfilled by glycolytic and oxidative metabolism, yielding ATP. In pancreatic beta-cells, a rise in cytosolic ATP is also a critical signaling event, coupling closure of ATP-sensitive K+ channels (KATP) to insulin secretion via depolarization-driven increases in intracellular Ca2+ ([Ca2+]i). We report that glycolytic but not Krebs cycle metabolism of glucose is critically involved in this signaling process.

Migraine headache in a prepaid health plan: ascertainment, demographics, physiological, and behavioral factors.

Background: Migraine is a prevalent disorder whose relationship to other conditions remains poorly understood.

Methods: Associations between migraine and physiological, behavioral, and demographic characteristics were assessed in a retrospective cohort study of 79,588 enrollees in a large prepaid health maintenance organization who underwent a multiphasic preventive health checkup in 1971-1973.

Results: Migraine was found to be inversely associated with age and education and strongly associated with the female sex.

A matrixed approach to long-term stability testing of pharmaceutical products.

A matrixed approach to long-term stability testing of pharmaceutical products is presented. The basic matrix design, suitable for testing three lots at one storage condition, may be extended to multiple product presentations or storage conditions. The design has full testing at the endpoints (0 and 36 months) and partial testing at the interim time points (3, 6, 9, 12, 18, and 24 months).

Overexpression of an Agouti cDNA in the skin of transgenic mice recapitulates dominant coat color phenotypes of spontaneous mutants.

The classical mouse fancy Agouti gene is responsible for the wild-type coat color where hairs are banded black and yellow. The Agouti gene encodes a 131-amino-acid secreted protein product that regulates phaeomelanin synthesis by melanocytes in mice. Mice with a dominant mutation at this locus, Ay, develop a yellow coat color, obesity, and diabetes, as the result of a deletion that results in ectopic overexpression of the Agouti gene mRNA in all tissues examined.

Flow cytometric assay of modulation of P-glycoprotein function in whole blood by the multidrug resistance inhibitor GG918.

We sought to develop an assay for measuring the inhibition of P-glycoprotein (Pgp) function in whole blood as an indicator of in vivo drug activity. Since the CD56(+) subset of peripheral blood lymphocytes (PBLs) has been shown to express functional Pgp, the changes in rhodamine 123 (R123) uptake by CD56(+) PBLs from GG918-treated and untreated whole blood were used as the basis for these studies. In an ex vivo study, heparin-treated whole blood was obtained from normal volunteers, and GG918 and R123 were added at various concentrations for time course analyses of dye loading.

Dual and triple therapy regimens of antisecretory agents and antibiotics for the eradication of Helicobacter pylori: an overview.

Background: Studies evaluating therapeutic regimens that combine antisecretory agents with antibiotics for the eradication of H. pylori have reported significant variations in efficacy.

Methods: We reviewed the published literature to compare H.

The pharmacokinetics and extra-hepatic clearance of remifentanil, a short acting opioid agonist, in male beagle dogs during constant rate infusions.

Remifentanil is a mu opioid receptor agonist, structurally related to fentanyl, being developed for use in anesthesia. Remifentanil was designed to be cleared rapidly by ester hydrolysis. To determine the pharmacokinetics of remifentanil in conscious beagle dogs, venous blood was collected at various times during and after the end of a 25 min intravenous infusion of the compound (0.

Improvements in health-related quality of life with sumatriptan treatment for migraine.

Background: The debilitating effects of migraine might be reduced in patients using an effective migraine medication. The serotonin (5HT1) receptor agonist sumatriptan has been shown in clinical trials to alleviate headache and associated symptoms in the majority of patients treated.

Methods: Three hundred forty-four (344) patients with migraine were allowed to treat an unlimited number of migraine attacks for up to 24 months with subcutaneous sumatriptan (6 mg).

Pharmacokinetics, absolute bioavailability, and absorption characteristics of lamivudine.

Lamivudine is a novel cytosine nucleoside analog, reverse transcriptase inhibitor that has shown activity against human immunodeficiency virus (HIV) types 1 and 2 and hepatitis B virus in vitro. This study was conducted to compare the absolute bioavailability, pharmacokinetics, and absorption characteristics of oral solution, 100-mg capsule, and 100-mg tablet formulations of lamivudine with those of intravenous lamivudine. Twelve patients with HIV were enrolled in a single-center, randomized, open-label, four-way cross-over study.

A canine model for determination of the therapeutic index of cytokine inhibitors.

Using tumor necrosis factor (TNF) inhibition in dog blood as a measure of efficacy, and canine emesis as a measure of toxicity, we were able to assign a therapeutic index to rolipram, a prototypic anti-inflammatory compound. Because both assays were performed in the same species, the ambiguities associated with comparing the physiologic effects of drugs on various species was avoided. Rolipram, a standard phosphodiesterase type IV inhibitor, was a prototypic test compound characterized by a number of cardiovascular and central nervous system side effects, as well as its in vitro and in vivo inhibition of TNF.

A prostaglandin J2 metabolite binds peroxisome proliferator-activated receptor gamma and promotes adipocyte differentiation.

Prostaglandins (PGs) of the J2 series form in vivo and exert effects on a variety of biological processes. While most of PGs mediate their effects through G protein-coupled receptors, the mechanism of action for the J2 series of PGs remains unclear. Here, we report the PGJ2 and its derivatives are efficacious activators of peroxisome proliferator-activated receptors alpha and gamma (PPAR alpha and PPAR gamma, respectively), orphan nuclear receptors implicated in lipid homeostasis and adipocyte differentiation.

Catalytic activity of the SH2 domain of human pp60c-src; evidence from NMR, mass spectrometry, site-directed mutagenesis and kinetic studies for an inherent phosphatase activity.

During solution structural studies it was apparent that the human recombinant pp60c-src SH2 domain (srcSH2, residues 144-249) possessed an inherent phosphatase (Pase) activity. Complexes of U[13C,15N]srcSH2 with unlabeled Ac-pYEEIE (I) were examined using 31P and 1H-detected isotope filtered NMR methods. The presence of a high-affinity complex in equimolar solutions of I and U[13C, 15N]-srcSH2 was demonstrated by chemical shift perturbations, line broadening, and the observation of intermolecular nuclear Overhauser effects from the pY and Ile side-chain protons of I to protons on amino acid residues present in the binding pocket of srcSH2.

Cyclic AMP signaling pathways are important in IL-1 beta transcriptional regulation.

An intact cAMP response element (CRE) in the upstream regulatory sequence of IL-1 beta (-2755/-2762) has been shown to be essential for maintaining full IL-1 beta inducibility following treatment with LPS, PMA, or TNF-alpha. In the present study, using the recombinant plasmid pIL-1(4.0 kb)-chloramphenicol acetyltransferase, containing 4.

Examination of the dephosphorylation reactions catalyzed by pp60c-src tyrosine kinase explores the roles of autophosphorylation and SH2 ligand binding.

pp60c-src tyrosine kinase (srcTK) catalyzes the dephosphorylation of phosphotyrosine-containing peptides, including phosphopeptides that bind with high affinity to the src SH2 domain. The mechanism for these dephosphorylation reactions was investigated. Dephosphorylation was inhibited by a competitive inhibitor for the ATP binding site.

Characterization of pp60c-src tyrosine kinase activities using a continuous assay: autoactivation of the enzyme is an intermolecular autophosphorylation process.

A continuous assay for pp60c-src tyrosine kinase (srcTK) was developed. A lag in phosphorylation of the peptide RRLIEDAEYAARG was observed that could be eliminated by preincubation with MgATP. The induction time for this lag was dependent upon MgATP and srcTK concentrations.

Exploration of the sequence specificity of pp60c-src tyrosine kinase. Minimal peptide sequence required for maximal activity.

The minimum length required for phosphorylation of a peptide by pp60c-src tyrosine kinase (srcTK) was delineated in this work. Budde (M.D.