Human VH4-34 antibodies derived from B1 cells are more frequently autoreactive than VH4-34 antibodies derived from memory cells.

Human B1 cells produce natural antibodies characterized by overutilization of heavy chain variable region VH4-34 in comparison to other B cell populations. VH4-34-containing antibodies have been reported to be autoreactive and to be associated with lupus and other autoimmune dyscrasias. However, it has been unclear to what extent VH4-34 antibodies manifest autoreactivity in B1 cells or other B cell populations-in other words, are VH4-34 containing antibodies autoreactive wherever found, or mainly within the B1 cell population? To address this issue we sort purified single human B1 and memory B cells and then amplified, sequenced, cloned and expressed VH4-34-containing antibodies from 76 individual B cells.

A comparison of the effect of X and gamma irradiation on red cell storage quality.

Background And Objectives: Irradiation of red cell components is indicated for recipients at risk of transfusion-associated graft vs. host disease. Current technologies available comprise of a gamma (γ) or an x source of radiation.

Tear osmolarity is sensitive to exercise-induced fluid loss but is not associated with common hydration measures in a field setting.

Unlabelled: This investigation (i) examined changes in tear osmolarity in response to fluid loss that occurs with exercise in a field setting, and (ii) compared tear osmolarity with common field and laboratory hydration measures.  Sixty-three participants [age 27.8 ± 8.

A LC-MS/MS Method for Quantifying Adenosine, Guanosine and Inosine Nucleotides in Human Cells.

Purpose: To develop and validate a method for the simultaneous measurement of adenosine, guanosine, and inosine derived from mono (MP) and triphosphate (TP) forms in peripheral blood mononuclear cells (PBMCs), red blood cells (RBCs) and dried blood spots (DBS).

Methods: Solid phase extraction of cell lysates followed by dephosphorylation to molar equivalent nucleoside and LC-MS/MS quantification.

Results: The assay was linear for each of the three quantification ranges: 10-2000, 1.

Plasma and intracellular ribavirin concentrations are not significantly altered by abacavir in hepatitis C virus-infected patients.

Objectives: The objective of this study was to evaluate the effects of abacavir on intracellular ribavirin triphosphate and plasma ribavirin trough concentrations.

Methods: Hepatitis C virus-infected subjects who had been cured or failed prior treatment were randomized to 8 weeks of ribavirin alone (N = 14; weight-based dosing) or weight-based ribavirin + abacavir (N = 14; 300 mg orally every 12 h). Ribavirin trough concentrations were measured on days 14, 28, 42 and 56; PBMCs for ribavirin triphosphate determination were sampled on days 28 and 56, pre-dose and at 6 and 12 h post-dose.

Measurement of intracellular ribavirin mono-, di- and triphosphate using solid phase extraction and LC-MS/MS quantification.

Ribavirin (RBV) is a nucleoside analog used to treat a variety of DNA and RNA viruses. RBV undergoes intracellular phosphorylation to a mono- (MP), di- (DP), and triphosphate (TP). The phosphorylated forms have been associated with the mechanisms of antiviral effect observed in vitro, but the intracellular pharmacology of the drug has not been well characterized in vivo.

Pharmacokinetic interaction between boceprevir and etravirine in HIV/HCV seronegative volunteers.

Objective: The primary aim of this study was to determine the bioequivalence of boceprevir, an HCV protease inhibitor and etravirine, an HIV non-nucleoside reverse transcriptase inhibitor; area under the concentration time curve (AUC(0,τ)); maximum concentration (C(max)); and trough concentration (C(8) or C(min)) when administered in combination versus alone.

Design: Open-label crossover study in healthy volunteers.

Methods: Boceprevir, etravirine, and the combination were administered for 11-14 days with intensive sampling between days 11 and 14 of each sequence.

Determination of nucleoside analog mono-, di-, and tri-phosphates in cellular matrix by solid phase extraction and ultra-sensitive LC-MS/MS detection.

An ultra-sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) assay was developed and validated to facilitate the assessment of clinical pharmacokinetics of nucleotide analogs from lysed intracellular matrix. The method utilized a strong anion exchange isolation of mono-(MP), di-(DP), and tri-phosphates (TP) from intracellular matrix. Each fraction was then dephosphorylated to the parent moiety yielding a molar equivalent to the original nucleotide analog intracellular concentration.

Effect of antacids on the pharmacokinetics of raltegravir in human immunodeficiency virus-seronegative volunteers.

Raltegravir's divalent metal ion chelating motif may predispose the drug to interactions with divalent cations. We determined whether a divalent cation-containing antacid interacted with raltegravir. Twelve HIV-1-seronegative subjects were enrolled in this randomized, prospective, crossover study of single-dose raltegravir (400 mg) with and without an antacid.

Atazanavir pharmacokinetics in genetically determined CYP3A5 expressors versus non-expressors.

Objectives: The objective of this study was to compare atazanavir pharmacokinetics in genetically determined CYP3A5 expressors versus non-expressors.

Methods: HIV-negative adult volunteers were pre-screened for CYP3A5 *3, *6 and *7 polymorphisms and enrollment was balanced for CYP3A5 expressor status, gender and race (African-American versus non-African-American). Participants received atazanavir 400 mg daily for 7 days followed by atazanavir/ritonavir 300 mg/100 mg daily for 7 days with pharmacokinetic studies on days 7 and 14.

Liquid chromatography-tandem mass spectrometric determination of tenofovir-diphosphate in human peripheral blood mononuclear cells.

To facilitate the evaluation of drug safety, virologic activity, and pharmacokinetics, an anion exchange isolation of tenofovir-diphosphate (TFV-DP) from human peripheral blood mononuclear cells (hPBMCs), coupled with dephosphorylation, desaltation, and detection by LC-MS-MS was validated. hPBMCs were harvested from whole blood, lysed, and a suspension of intracellular tenofovir moieties was produced. TFV-DP was isolated from TFV-monophosphate (TFV-MP) and tenofovir (TFV), dephosphorylated with acid phosphatase to form TFV and then desalted and concentrated, making it possible for tandem mass spectral detection.

Quantitation of zidovudine triphosphate concentrations from human peripheral blood mononuclear cells by anion exchange solid phase extraction and liquid chromatography-tandem mass spectroscopy; an indirect quantitation methodology.

To facilitate the assessment of drug safety and determination of phamacokinetics, an anion exchange isolation of zidovudine triphosphate (ZDV-TP) from human peripheral blood mononuclear cells (hPBMC), coupled with dephosphorylation, desaltation, and detection by liquid chromatography-tandem mass spectroscopy (LC-MS-MS) was validated. hPBMCs were harvested from whole blood, lysed, and a suspension of intracellular ZDV-TP was produced. ZDV-TP was isolated from ZDV, ZDV-monophosphate (ZDV-MP), and ZDV-diphosphate (ZDV-DP), which were all present in the cell lysate, by performing a salt gradient anion exchange SPE.

Can textbook covers be used to increase poison center utilization?

An education program was implemented at a regional poison center to increase use of a new nationwide 800 number (800/222-1222) in counties in our region that had low rates of utilization. We identified 10 counties with the lowest utilization rates and provided textbook covers to the elementary and secondary schools in these areas. The covers contained the poison help logo and information about what to do if a poisoning occurs.