Development and evaluation of QCM sensors for the detection of influenza virus from clinical samples

The Quartz crystal microbalance (QCM) is a very sensitive mass-detecting device which is based on changes in to the vibrational frequency of quartz crystals after adsorption of substances to a modified crystal surface. In this study a QCM-based biosensor was developed for the rapid diagnosis of influenza viruses and its suitability and limitations were compared with currently available diagnostic methods on 67 clinical samples (nasal washes) received during the 2005 Australian winter. The type-specific and conserved viral M1 proteins of both A/PR/8/34 and B/Lee/40 viruses were used to prepare polyclonal antisera for the development of an ELISA. The limits of detection of ELISAs for the detection of purified A/PR/8/34 and B/Lee/40 ƒnviruses were 20ƒÝg/mL ƒnand 14 ƒÝg/mL using polyclonal antibodies, and 30 ƒÝg/mL and 20 ƒÝg/mL for monoclonal antibodies, respectively. The limit for detection of each virus was 104 pfu/mL, irrespective of whether antisera or monoclonal antibodies were used for capture. Non-purified cell culture-grown preparations of either virus could be detected at 103 pfu/mL The QCM utilised the same reagents used in ELISAs. However, a number of parameters were then further optimised to improve the sensitivity of the tests. These included blocking of non-specific binding, examination of the effects of flow-cell compression, the role of pH, flow rate, antibody concentration and the addition of protein A to the crystal surfaces of the biosensor. The lowest virus concentration that could be detected with the QCM was 104 pfu/mL for egg-grown preparations of both A/PR/8/34 and B/Lee/40, which could be detected within 30 min. However, conjugation of 13 nm gold nanoparticles to a second detector antibody resulted in a 10-fold increase in sensitivity and a detection limit of 103 pfu/mL that could be determined within 1 h. The direct detection of the influenza viruses in nasal samples was not possible by QCM because of the significant frequency fluctuation that was probably caused by the viscosity of the samples. Therefore, an additional culture step of 12 h was required, which increased the processing time to 2 days. The QCM/nanoparticle method was shown to be as sensitive as the standard cell culture method, and the QCM method as sensitive as the shell vial method. The QCM and QCM/nanoparticle methods were shown to be 81 and 87% as sensitive and both were 100% as specific as the real-time polymerase chain reaction. However, for use in rapid diagnosis, improvements are required to remove frequency fluctuation resulting from the direct use of nasal samples

MABGEL 1: C2F5, C4E10 & C2G12 as a vaginal microbicide

Topical microbicides are being developed as a female-controlled method for preventing HIV-1 infection. Non-antiretroviral (ARV)-based candidates may be advantageous given increasing levels of ARV resistance in low and middle- income countries. MABGEL 1 was a phase 1 trial designed to evaluate the pharmacokinetics and safety of a vaginal microbicide containing the broadly HIV-1 neutralizing monoclonal antibodies (mAbs) C2F5, C4E10 and C2G12 in a hydroxyethylcellulose-based gel vehicle. It was the first study of topical mAb application to the human female genital tract. Twenty-eight healthy women were randomised to apply either high dose Mabgel (containing 20mg/g of each mAb) (n= 10), low dose Mabgel (containing 10mg/g of each mAb) (n=9) or placebo gel (n=9). Doses (2.5ml) were applied over 12 consecutive days. Genital tract sampling was performed at baseline, 1 hour, 8 hours and 24 hours post 1st dose and 12 and 36 hours post 12th dose with serum samples collected at baseline, 8 hours post 1st dose and 12 hours post 12th dose. Safety was assessed through participant report and clinical examination, including colposcopy. Residence half-lives (t ½) in vaginal secretions (Weck-Cel samples) were estimated to be between 4 and 5.5 hours for C4E10 and C2F5. In contrast, vaginal levels of C2G12 did not conform to a single overall exponential decay, displaying a more rapid initial rate of decline, which then slowed at lower concentrations. The estimated early t ½ of C2G12 was 1.4 hours (95% CI 1.2 to 1.8). There was no evidence of systemic absorption. Daily vaginal application of up to 50g of each mAb over 12 days was safe. Although adverse events (AEs) were reported by all but 1 participant, 95 % were mild, none were serious and only 4 were moderate. There was no statistically significant difference in the number of AEs reported per participant between the 3 study arms. Although there are a number of caveats, results demonstrate ‘proof of principle’ of the potential for combinations of HIV-1 neutralizing mAbs to be used as a coitally-dependent microbicide

MABGEL 1: C2F5, C4E10 & C2G12 as a vaginal microbicide

Topical microbicides are being developed as a female-controlled method for preventing HIV-1 infection. Non-antiretroviral (ARV)-based candidates may be advantageous given increasing levels of ARV resistance in low and middle- income countries.MABGEL 1 was a phase 1 trial designed to evaluate the pharmacokinetics and safety of a vaginal microbicide containing the broadly HIV-1 neutralizing monoclonal antibodies (mAbs) C2F5, C4E10 and C2G12 in a hydroxyethylcellulose-based gel vehicle. It was the first study of topical mAb application to the human female genital tract.Twenty-eight healthy women were randomised to apply either high dose Mabgel (containing 20mg/g of each mAb) (n= 10), low dose Mabgel (containing 10mg/g of each mAb) (n=9) or placebo gel (n=9). Doses (2.5ml) were applied over 12 consecutive days. Genital tract sampling was performed at baseline, 1 hour, 8 hours and 24 hours post 1st dose and 12 and 36 hours post 12th dose with serum samples collected at baseline, 8 hours post 1st dose and 12 hours post 12th dose. Safety was assessed through participant report and clinical examination, including colposcopy.Residence half-lives (t ½) in vaginal secretions (Weck-Cel samples) were estimated to be between 4 and 5.5 hours for C4E10 and C2F5. In contrast, vaginal levels of C2G12 did not conform to a single overall exponential decay, displaying a more rapid initial rate of decline, which then slowed at lower concentrations. The estimated early t ½ of C2G12 was 1.4 hours (95% CI 1.2 to 1.8). There was no evidence of systemic absorption.Daily vaginal application of up to 50g of each mAb over 12 days was safe. Although adverse events (AEs) were reported by all but 1 participant, 95 % were mild, none were serious and only 4 were moderate. There was no statistically significant difference in the number of AEs reported per participant between the 3 study arms.Although there are a number of caveats, results demonstrate ‘proof of principle’ of the potential for combinations of HIV-1 neutralizing mAbs to be used as a coitally-dependent microbicide

Life Sciences Program Tasks and Bibliography

This document includes information on all peer reviewed projects funded by the Office of Life and Microgravity Sciences and Applications, Life Sciences Division during fiscal year 1995. Additionally, this inaugural edition of the Task Book includes information for FY 1994 programs. This document will be published annually and made available to scientists in the space life sciences field both as a hard copy and as an interactive Internet web pag

Antioxidant and DPPH-Scavenging Activities of Compounds and Ethanolic Extract of the Leaf and Twigs of Caesalpinia bonduc L. Roxb.

Antioxidant effects of ethanolic extract of Caesalpinia bonduc and its isolated bioactive compounds were evaluated in vitro. The compounds included two new cassanediterpenes, 1α,7α-diacetoxy-5α,6β-dihydroxyl-cass-14(15)-epoxy-16,12-olide (1)and 12α-ethoxyl-1α,14β-diacetoxy-2α,5α-dihydroxyl cass-13(15)-en-16,12-olide(2); and others, bonducellin (3), 7,4’-dihydroxy-3,11-dehydrohomoisoflavanone (4), daucosterol (5), luteolin (6), quercetin-3-methyl ether (7) and kaempferol-3-O-α-L-rhamnopyranosyl-(1Ç2)-β-D-xylopyranoside (8). The antioxidant properties of the extract and compounds were assessed by the measurement of the total phenolic content, ascorbic acid content, total antioxidant capacity and 1-1-diphenyl-2-picryl hydrazyl (DPPH) and hydrogen peroxide radicals scavenging activities.Compounds 3, 6, 7 and ethanolic extract had DPPH scavenging activities with IC50 values of 186, 75, 17 and 102 μg/ml respectively when compared to vitamin C with 15 μg/ml. On the other hand, no significant results were obtained for hydrogen peroxide radical. In addition, compound 7 has the highest phenolic content of 0.81±0.01 mg/ml of gallic acid equivalent while compound 8 showed the highest total antioxidant capacity with 254.31±3.54 and 199.82±2.78 μg/ml gallic and ascorbic acid equivalent respectively. Compound 4 and ethanolic extract showed a high ascorbic acid content of 2.26±0.01 and 6.78±0.03 mg/ml respectively.The results obtained showed the antioxidant activity of the ethanolic extract of C. bonduc and deduced that this activity was mediated by its isolated bioactive compounds

The EBMT Handbook

This Open Access edition of the European Society for Blood and Marrow Transplantation (EBMT) handbook addresses the latest developments and innovations in hematopoietic stem cell transplantation and cellular therapy. Consisting of 93 chapters, it has been written by 175 leading experts in the field. Discussing all types of stem cell and bone marrow transplantation, including haplo-identical stem cell and cord blood transplantation, it also covers the indications for transplantation, the management of early and late complications as well as the new and rapidly evolving field of cellular therapies. This book provides an unparalleled description of current practices to enhance readers’ knowledge and practice skills

Emerg Infect Dis

PMC4550154611