Cross-Linking GPVI-Fc by Anti-Fc Antibodies Potentiates Its Inhibition of Atherosclerotic Plaque- and Collagen-Induced Platelet Activation

To enhance the antithrombotic properties of recombinant glycoprotein VI fragment crystallizable (GPVI-Fc), the authors incubated GPVI-Fc with anti-human Fc antibodies to cross-link the Fc tails of GPVI-Fc. Cross-linking potentiated the inhibition of human plaque- and collagen-induced platelet aggregation by GPVI-Fc under static and flow conditions without increasing bleeding time in vitro. Cross-linking with anti-human-Fc Fab2 was even superior to anti-human-Fc immunoglobulin G (IgG). Advanced optical imaging revealed a continuous sheath-like coverage of collagen fibers by cross-linked GPVI-Fc complexes. Cross-linking of GPVI into oligomeric complexes provides a new, highly effective, and probably safe antithrombotic treatment as it suppresses platelet GPVI-plaque interaction selectively at the site of acute atherothrombosis.

Performance and Value of IFN-Lambda3 and IFN-Lambda4 Genotyping in Patients with Chronic Hepatitis C (CHC) Genotype 2/3 in a Real World Setting

BACKGROUND

SNPs near the interferon lambda (IFNL) 3 gene are predictors for sustained virological response (SVR) in patients with chronic hepatitis C genotype (GT) 1. In addition, a dinucleotide frame shift in ss469415590 was described, which generates IFNL4. In this study, we compared the role of IFNL4 variants with IFNL3-(rs12979860) and IFNL3-(rs8099917) on response to pegylated (PEG)-IFN and Ribavirin (RBV) in patients with chronic hepatitis C GT2/3.

METHODS

We recruited 1006 patients with chronic hepatitis C and GT2/3 in a large German registry. A treatment with PEG-IFN and Ribavirin was started by 959 patients. We performed genotyping of IFNL3 (rs12979860, n = 726; rs8099917, n = 687) and of IFNL4 (ss469415590; n = 631).

RESULTS

Both preferable IFNL3 genotypes were associated with RVR (both p<0.0001) rather than with SVR (rs12979860: p = 0.251; rs8099917: p = 0.447). Only RVR was linked to SVR in univariate and multivariate analyzes (both p<0.001). Concordance of genotyping in patients with available serum samples and EDTA blood samples (n = 259) was more than 96% for both IFNL3 SNPs. IFNL3-(rs12979860) correlated with IFNL4: 99.2% of patients with IFNL3-(rs12979860)-CC were IFNL4-(ss469415590)-TT/TT. IFNL3-(rs12979860)-CT was linked with IFNL4-(ss469415590)-TT/ΔG (98.0%) and IFNL3-(rs12979860)-TT was associated with IFNL4-(ss469415590)-ΔG/ΔG (97.6%).

CONCLUSION

IFNL3 genotyping from serum was highly efficient and can be used as an alternative if EDTA whole blood is not available. In Caucasian GT2/3 patients genotyping for INFL4-(ss469415590) does not lead to additional information for the decision-making process. Importantly, IFNL3 SNPs were not associated with SVR but with RVR. Even in the era of new direct acting antiviral (DAA) therapies, IFNL3 testing may therefore still be considered for naïve GT2/3 patients to decide if dual Peg-IFN/RBV therapy is an option in resource limited regions.

The Antibody Light-Chain Linker Is Important for Domain Stability and Amyloid Formation

The association of light chains (LCs) and heavy chains is the basis for functional antibodies that are essential for adaptive immune responses. However, in some cases, LCs and especially fragments consisting of the LC variable (VL) domain are pathologically deposited in fatal aggregation diseases. The two domains of the LC are connected by a highly conserved linker. We show here that, unexpectedly, the linker residue Arg108 affects the conformational stability and folding of both VLκ and LC constant (CLκ) domains. Interestingly, the extension of VL by Arg108 results in its resistance to amyloid formation, which suggests that the nature of the truncation of the LC plays a crucial role in disease progression. Increased solvation due to the exposed charged C-terminal Arg108 residue explains its stabilizing effects on the VL domain. For the CL domain, the interaction of N-terminal loop residues with Arg108 is important for the integrity of the domain, as the disruption of this interaction results in fluctuation, partial opening of the protein's interior and the exposure of hydrophobic residues that destabilize the domain. This establishes new principles for antibody domain architecture and amyloidogenicity.

Asymmetrical flow field-flow fractionation for the analysis of PEG-asparaginase

Monomethoxypolyethylene glycol L-asparaginase (PEG-ASNASE) is the PEGylated version of the enzyme L-asparaginase (ASNASE). Both are used for remission induction in acute lymphoblastic leukemia (ALL) and non-Hodgkin's lymphoma (NHL). The treatment control is generally carried out by performing activity assays, though methods to determine the actual enzyme rather than its activity are rare. Using asymmetrical flow field-flow fractionation (AF4) offered the chance to develop a method capable of simultaneously measuring PEG-ASNASE and PEG. A method validation was performed in accordance with FDA guidelines for PEG-ASNASE from non-biological solutions. The method unfolded a linearity of 15-750 U/mL with coefficients of correlation of r(2)>0.99. The coefficients of variation (CV) for within-run and between-run variability were 1.18-10.15% and 2.43-8.73%, respectively. Furthermore, the method was used to perform stability tests of the product Oncaspar® (PEG-ASNASE) and estimation of the molecular weight by multi-angle light scattering (MALS) of stressed samples to correlate them with the corresponding activity. The findings indicate that Oncaspar® stock solution should not be stored any longer than 24 h at room temperature and cannot be frozen in pure aqueous media. The validated method might be useful for the pharmaceutical industry and its quality control of PEG-ASNASE production.

Screening for autoantibodies in chronic hepatitis C patients has no effect on treatment initiation or outcome

Autoantibodies in hepatitis C virus-infected patients may indicate autoimmune hepatitis or other immune-mediated diseases. This may impact safety and efficacy of interferon-based therapy of chronic hepatitis C. We investigated the association between a positive test result for a variety of autoantibodies and the initiation and efficacy of therapy for chronic hepatitis C. We analysed an observational cohort of 24 306 patients for an association between autoantibodies and treatment outcome. 8241 patients were tested simultaneously for antinuclear antibodies (ANA), liver kidney microsomal antibodies (LKM), smooth muscle antibodies (SMA) and antimitochondrial antibodies (AMA). Matched-pair analysis was performed matching one autoantibody-positive patient to three controls. Control patients had negative tests for all four antibodies. Analyses were performed for patients with a single positive autoantibody test and for patients with multiple positive autoantibody tests. A positive test result for ANA, LKM, SMA or AMA did not affect the physician's decision to initiate therapy with pegylated interferon and ribavirin. In addition, a positive test for one or multiple autoantibodies did not adversely affect sustained virologic response. There was no difference in fibrosis stage or alanine transaminase at baseline or during therapy irrespective of antibody status. Thyroid dysfunction was more frequent in patients with positive LKM antibodies (P = 0.004). Initiation of therapy for chronic hepatitis C and outcome were not affected by the presence of ANA, LKM, SMA or AMA. Routine testing of these autoantibodies seems not warranted. Determination of autoantibodies should be guided by individualized clinical decisions.

Estimating the likelihood of sustained virological response in chronic hepatitis C therapy

The likelihood of a sustained virological response (SVR) is the most important factor for physicians and patients in the decision to initiate and continue therapy for chronic hepatitis C (CHC) infection. This study identified predictive factors for SVR with peginterferon plus ribavirin (RBV) in patients with CHC treated under 'real-life' conditions. The study cohort consisted of patients from a large, retrospective German multicentre, observational study who had been treated with peginterferon alfa-2a plus RBV or peginterferon alfa-2b plus RBV between the years 2000 and 2007. To ensure comparability regarding peginterferon therapies, patients were analysed in pairs matched by several baseline variables. Univariate and multivariate logistic regression analyses were used to determine the effect of nonmatched baseline variables and treatment modality on SVR. Among 2378 patients (1189 matched pairs), SVR rates were 57.9% overall, 46.5% in HCV genotype 1/4-infected patients and 77.3% in genotype 2/3-infected patients. In multivariate logistic regression analysis, positive predictors of SVR were HCV genotype 2 infection, HCV genotype 3 infection, low baseline viral load and treatment with peginterferon alfa-2a. Negative predictors of SVR were higher age (≥40 years), elevated baseline gamma-glutamyl transpeptidase (GGT) and low baseline platelet count (<150,000/μL). Among patients treated with peginterferon plus RBV in routine clinical practice, genotype, baseline viral load, age, GGT level and platelet levels all predict the likelihood of treatment success. In patients matched by baseline characteristics, treatment with peginterferon alfa-2a may be a positive predictor of SVR when compared to peginterferon alfa-2b.

Raman Characterization of Nitrogen Doped Multiwalled Carbon Nanotubes

N-type multi-walled nanotubes were synthesized by nitrogen doping using pyridine and pyridine-melamine mixtures in chemical vapor deposition, and their donor states were verified by Scanning Tunneling Spectroscopy. Tunneling Electron Microscopy reveals small amounts of residual catalyst and Scanning Electron Microscopy show well aligned mats of the Nitrogen doped nanotubes. Nitrogen is present in the lattice of these MWNTs as pyridine structures and CNx structures. Raman scattering measurements were performed as a function of increasing growth temperature and the results compared to previously studied boron doped multiwalled nanotubes.

Knowledge and treatment practices of malaria among mothers and caregivers of children in an urban slum in Jos, Nigeria

BACKGROUND

Malaria is a public health problem in more than 90 countries, inhabited by a total of 2.4 billion people, representing about 40% of the world's population. Major trends over the last few decades point to a worsening situation if effective action is not taken. Sadly, this is in spite of enormous efforts and resources that have been invested in its control. The objective of this study was to describe the level of knowledge of malaria as a disease and the practice of its treatment by mothers and caregivers of under five children in Gangare, an urban slum of Jos City, Nigeria.

METHODOLOGY

A cross-sectional descriptive study design, a cluster sampling technique and an interviewer administered questionnaire were used to collect information on socio demographic profiles as well as knowledge and treatment practices of malaria from mothers and caregivers of under five children in Gangare, Jos North Local Government Area of Plateau State, central Nigeria. The data was then analyzed using Epi info2002 epidemiological software.

RESULTS

The study revealed a low level of knowledge of malaria with 248 (49.6%) being able to recognize the disease and only 124 (24.9%) attributing it to the mosquito bite. The attitude of most respondents towards malaria as an illness was however good as 275 (55%) viewed it as a very serious illness and most of them 328 (65.6%) would use hospitals/clinics for treatment. Majority of them; 462 (92.4%) have not heard of Artemisinin Combination Therapy (ACT) and only 19 (50%) of those who had heard of ACT had ever used it for the treatment of malaria. Generally their knowledge of malaria and treatment seeking practice are influenced by cost of treatment, perceived safety and level of their education. (p < 0.05).

CONCLUSION

Among mothers and caregivers living in slums in Jos, their ability to recognize malaria is poor. So also is their awareness and use of Artemisinin Combination Therapy. An improvement in their level of education and their economic power could improve their knowledge and treatment practices.

Materials: protein single crystal growth under microgravity

The preparation of suitably large protein single crystals is essentially the rate-determining step of protein x-ray structure determinations. Attempts to produce single crystals with two model compounds-beta-galactosidase and lysozyme-under conditions of microgravity were successful. Crystals formed by salting out from solutions kept free of convection were 27 and 1000 times larger in volume, respectively, than those produced in the same apparatus but exposed to terrestrial gravitation.

Efficacy and tolerability of peginterferon alfa-2a or alfa-2b plus ribavirin in the daily routine treatment of patients with chronic hepatitis C in Germany: the PRACTICE study

In randomized clinical trials, treatment with peginterferon plus ribavirin (RBV) results in a sustained virological response (SVR) in around half of hepatitis C virus genotype 1-infected and 80% of genotype 2/3-infected individuals. This study aimed to evaluate efficacy and tolerability of peginterferon alfa-2a plus RBV compared with peginterferon alfa-2b plus RBV for the treatment of chronic hepatitis C in routine clinical practice. The intent-to-treat cohort consisted of 3414 patients treated with either peginterferon alfa-2a plus RBV (Group A) or peginterferon alfa-2b plus RBV (Group B) in 23 centres participating in the large, multicentre, observational PRACTICE study. Collected data included baseline characteristics, treatment regimen, RBV dose and outcome. Rates of early virological response, end of treatment response and SVR were 76.6%, 75.7% and 52.9% in Group A, and 70.2%, 65.6% and 50.5% in Group B, respectively. In patients matched by baseline parameters, 59.9% of patients in Group A and 55.9% in Group B achieved an SVR (P < or = 0.051). In genotype 1-infected patients matched by baseline parameters and cumulative RBV dose, SVR rates were 49.6% and 43.7% for Group A and Group B, respectively (P < or = 0.047); when matched by baseline parameters and RBV starting dose, SVR rates were 49.9% and 44.6%, respectively (P = 0.068). Overall, 21.8% of group A and 29.6% of group B patients discontinued treatment (P < or = 0.0001). The efficacy and tolerability of peginterferon plus RBV in this large cohort of patients treated in routine daily practice was similar to that in randomized clinical trials. In matched pairs analyses, more patients achieved an SVR with peginterferon alfa-2a compared with peginterferon alfa-2b.

The influence of HAART on the efficacy and safety of pegylated interferon and ribavirin therapy for the treatment of chronic HCV infection in HIV-positive Individuals

Objective

This study was performed to investigate the impact of HAART versus no HAART and nucleoside free versus nucleoside containing HAART on the efficacy and safety of pegylated interferon and ribavirin therapy for the treatment of chronic HCV infection in HIV/HCV co-infected patients. In addition a control group of HCV mono-infected patients undergoing anti-HCV therapy was evaluated.

Methods

Multicenter, partially randomized, controlled clinical trial. HIV-negative and -positive patients with chronic HCV infection were treated with pegylated interferon alfa-2a and ribavirin (800 - 1200 mg/day) for 24 - 48 weeks in one of four treatment arms: HIV-negative (A), HIV-positive without HAART (B) and HIV-positive on HAART (C). Patients within arm C were randomized to receive open label either a nucleoside containing (C1) or a nucleoside free HAART (C2).

Results

168 patients were available for analysis. By intent-to-treat analysis similar sustained virological response rates (SVR, negative HCV-RNA 24 weeks after the end of therapy) were observed comparing HIV-negative and -positive patients (54% vs. 54%, p = 1.000). Among HIV-positive patients SVR rates were similar between patients off and on HAART (57% vs. 52%, p = 0.708). Higher SVR rates were observed in patients on a nucleoside free HAART compared to patients on a nucleoside containing HAART, though confounding could not be ruled out and in the intent-to-treat analysis the difference was not statistically significant (64% vs. 46%, p = 0.209).

Conclusions

Similar response rates for HCV therapy can be achieved in HIV-positive and -negative patients. Patients on nucleoside free HAART reached at least equal rates of sustained virological response compared to patients on standard HAART.

[Ilya Ilich Metchnikov and Paul Ehrlich: 1908 Nobel Prize winners for their research on immunity]

The Nobel Prize in Physiology or Medicine in 1908 was awarded to Ilya I. Mechnikov and Paul Ehrlich for recognition of their work on immunity. Mechnikov have discovered phagocytes and phagocytosis as the basis of natural cellular immunity. His ,,phagocytic theory" is the principle of immunological concept "self and not self" as the prerequisition of physiological inflammation, and selfmaintaining of organism. Ehrlich developed the methods for standardization of antibody activity in immune sera, described neutralizing and complement-depending effect of antibodies and enunciated the ,"ide-chain" theory of the formation of antibodies. Their concept of the key-stone of immunity was different, but they expressed the basic paradigma of immunology: immunity imply the protection of identity and guarantee the integrity of organism. Both are the founders of immunology as the scientific discipline. Discoveries and conceptions of I. Mechnikov and P. Ehrlich exceedingly influenced development of immunology and are also applicable, instructive and suggestive in contemporary immunology and microbiology.

[Epidemiology of chronic hepatitis C in Germany--an analysis of 10,326 patients in hepatitis centres and outpatient units]

Little is known about the epidemiology of chronic hepatitis C (CHC) in Germany and especially about the importance of transmission, duration of infection, genotypes, symptoms and quality of life of the patients. The current study prospectively evaluates epidemiological and clinical data of patients infected with the hepatitis C virus (HCV). Using online data entry, various characteristics of 10,326 untreated patients with CHC were documented from March 2003 until May 2006 in 352 centres all over Germany. Mean age of patients was 43.4 years. Patients infected by i.v. drug abuse were considerably younger (36.5 years) than the remaining patients (49.2 years). As indicated by their native language, 64.4% of the patients came from Germany and 19.2% from Russia. 61.7% were infected with genotype 1 and 34.9% with genotype 2 or 3. 45.5% of the patients had been infected by i.v. drug abuse. In at least 5.4% of the patients liver cirrhosis had been proved by biopsy. 63.5% of the patients felt an impairment of quality of life caused by CHC. In many patients infected with hepatitis C socio-economic issues are existent. This is reflected, i.e., in very high rates of unemployment in special subpopulations. Coinfections with hepatitis B and HIV occurred in 1.5% and 4.7%, respectively. Nearly 80% of patients were managed near their homes. The data of the 10 326 patients represent about 2% of all German patients with CHC. This database is up to now the largest of its kind and gives a representative insight into the epidemiological situation of CHC in Germany.