[Determination of four hydroxyl polycyclic aromatic hydrocarbons in urine by solid-phase extraction with monolithic column coupled with high performance liquid chromatography].

A method based on monolithic column solid-phase extraction (SPE) coupled with high performance liquid chromatography (HPLC) was developed for the simultaneous determination of four hydroxyl polycyclic aromatic hydrocarbons (OH-PAHs) in urine.A poly (butyl methacrylate-co-ethylene dimethacrylate) monolithic column was prepared in a syringe and was used as the sorbent.The parameters influencing SPE, such as loading volume, washing solvent, eluent, and elution volume, were investigated in detail.Under the optimized conditions, the linearities were obtained in range of 1.2-200.0 ng/mL, and the LODs and LOQs of the analytes were 0.06-0.09 ng/mL and 0.20-0.30 ng/mL, respectively.The intra-day and inter-day relative standard deviations were 1.4%-5.3% and 2.6%-7.3%, respectively.The recoveries evaluated using the spiked (3 ng/mL) urine samples of coke oven workers ranged from 78.2% to 117.0%.The feasibility of the developed method was further demonstrated for the analysis of the real samples.The results indicated that the reusable monolithic column enabled effective purification and enrichment of the four OH-PAHs in urine, and can be applied to the analysis of OH-PAHs in urine due to its simplicity and accuracy.

Fully human broadly neutralizing monoclonal antibodies against influenza A viruses generated from the memory B cells of a 2009 pandemic H1N1 influenza vaccine recipient.

Whether the 2009 pandemic H1N1 influenza vaccine can induce heterosubtypic cross-protective anti-hemagglutinin (HA) neutralizing antibodies is an important issue. We obtained a panel of fully human monoclonal antibodies from the memory B cells of a 2009 pandemic H1N1 influenza vaccine recipient. Most of the monoclonal antibodies targeted the HA protein but not the HA1 fragment. Among the analyzed antibodies, seven mAbs exhibited neutralizing activity against several influenza A viruses of different subtypes. The conserved linear epitope targeted by the neutralizing mAbs (FIEGGWTGMVDGWYGYHH) is part of the fusion peptide on HA2. Our work suggests that a heterosubtypic neutralizing antibody response primarily targeting the HA stem region exists in recipients of the 2009 pandemic H1N1 influenza vaccine. The HA stem region contains various conserved neutralizing epitopes with the fusion peptide as an important one. This work may aid in the design of a universal influenza A virus vaccine.

Immune protection induced on day 10 following administration of the 2009 A/H1N1 pandemic influenza vaccine.

BACKGROUND: The 2009 swine-origin influenza virus (S-OIV) H1N1 pandemic has caused more than 18,000 deaths worldwide. Vaccines against the 2009 A/H1N1 influenza virus are useful for preventing infection and controlling the pandemic. The kinetics of the immune response following vaccination with the 2009 A/H1N1 influenza vaccine need further investigation. METHODOLOGY/PRINCIPAL FINDINGS: 58 volunteers were vaccinated with a 2009 A/H1N1 pandemic influenza monovalent split-virus vaccine (15 µg, single-dose). The sera were collected before Day 0 (pre-vaccination) and on Days 3, 5, 10, 14, 21, 30, 45 and 60 post vaccination. Specific antibody responses induced by the vaccination were analyzed using hemagglutination inhibition (HI) assay and enzyme-linked immunosorbent assay (ELISA). After administration of the 2009 A/H1N1 influenza vaccine, specific and protective antibody response with a major subtype of IgG was sufficiently developed as early as Day 10 (seroprotection rate: 93%). This specific antibody response could maintain for at least 60 days without significant reduction. Antibody response induced by the 2009 A/H1N1 influenza vaccine could not render protection against seasonal H1N1 influenza (seroconversion rate: 3% on Day 21). However, volunteers with higher pre-existing seasonal influenza antibody levels (pre-vaccination HI titer ≥1∶40, Group 1) more easily developed a strong antibody protection effect against the 2009 A/H1N1 influenza vaccine as compared with those showing lower pre-existing seasonal influenza antibody levels (pre-vaccination HI titer <1∶40, Group 2). The titer of the specific antibody against the 2009 A/H1N1 influenza was much higher in Group 1 (geometric mean titer: 146 on Day 21) than that in Group 2 (geometric mean titer: 70 on Day 21). CONCLUSIONS/SIGNIFICANCE: Recipients could gain sufficient protection as early as 10 days after vaccine administration. The protection could last at least 60 days. Individuals with a stronger pre-existing seasonal influenza antibody response may have a relatively higher potential for developing a stronger humoral immune response after vaccination with the 2009 A/H1N1 pandemic influenza vaccine.