Design of protease-resistant myelin basic protein-derived peptides by cleavage site directed amino acid substitutions

Multiple Sclerosis (MS) is considered to be a T cell-mediated autoimmune disease. An attractive strategy to prevent activation of autoaggressive T cells in MS, is the use of altered peptide ligands (APL), which bind to major histocompatibility complex class II (MHC II) molecules. To be of clinical use, APL must be capable of resisting hostile environments including the proteolytic machinery of antigen presenting cells (APC). The current design of APL relies on cost- and labour-intensive strategies. To overcome these major drawbacks, we used a deductive approach which involved modifying proteolytic cleavage sites in APL. Cleavage site-directed amino acid substitution of the autoantigen myelin basic protein (MBP) resulted in lysosomal protease-resistant, high-affinity binding peptides. In addition, these peptides mitigated T cell activation in a similar fashion as conventional APL. The strategy outlined allows the development of protease-resistant APL and provides a universal design strategy to improve peptide-based immunotherapeutics.     

Failure of MTT as a toxicity testing agent for mesoporous silicon microparticles

In this work, it is shown that the common toxicity indicator, MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide), will fail to predict the toxicity of porous silicon (PSi) microparticles. This is due to the spontaneous redox reactions where the MTT is reduced and the PSi particle surfaces are oxidized simultaneously. MTT was shown to even react with thermally oxidized and carbonized forms of PSi particles, although the treatment did give an enhanced protection against the unwanted reactions as compared to as-anodized PSi particles. The observed levels of cellular viability with the MTT assay were much higher than expected in the presence of Caco-2 cells, even considering the spontaneous reduction of MTT at PSi surfaces. The results indicate that the redox reaction is further enhanced inside living cells. Thus, we recommend that MTT should not be used to test the cytotoxicity of drug formulations containing PSi microparticles. The study also shows that since PSi particles are capable of reducing the MTT, they will also be able to reduce other species as well. This should be taken into account when considering future applications for the porous silicon particles. The completely oxidized SiO2 particles (MCM-41 and SBA-15) were shown to work as expected with the MTT assay and showed no inherent oxidation/reduction.     

Air pollution and inflammatory response in myocardial infarction survivors: gene-environment interactions in a high-risk group

Ambient air pollution has been associated with an increased risk of hospital admission and mortality in potentially susceptible subpopulations, including myocardial infarction (MI) survivors. The multicenter epidemiological study described in this report was set up to study the role of air pollution in eliciting inflammation in MI survivors in six European cities, Helsinki, Stockholm, Augsburg, Rome, Barcelona, and Athens. Outcomes of interest are plasma concentrations of the proinflammatory cytokine interleukin 6 (IL-6) and the acute-phase proteins C-reactive protein (CRP) and fibrinogen. In addition, the study was designed to assess the role of candidate gene polymorphisms hypothesized to lead to a modification of the short-term effects of ambient air pollution. In total, 1003 MI survivors were recruited and assessed with at least 2 repeated clinic visits without any signs of infections. In total, 5813 blood samples were collected, equivalent to an average of 5.8 repeated clinic visits per subject (97% of the scheduled 6 repeated visits). Subjects across the six cities varied with respect to risk factor profiles. Most of the subjects were nonsmokers, but light smokers were included in Rome, Barcelona, and Athens. Substantial inter- and intraindividual variability was observed for IL-6 and CRP. The study will permit assessing the role of cardiovascular disease risk factors, including ambient air pollution and genetic polymorphisms in candidate genes, in determining the inter- and the intraindividual variability in plasma IL-6, CRP, and fibrinogen concentrations in MI survivors.     

Division of the hepatic branch of the anterior vagus nerve in fundoplication: effects on gallbladder function

Background

Cutting the hepatic branch of the anterior vagus nerve makes laparoscopic fundoplication technically easier; however, there is little data about the effect of cutting the nerve on gallbladder function.

Methods

One surgeon (MPä) preserved this nerve until March 2001 when he changed the technique. We investigated patients consecutively operated on before and after this date. A symptom questionnaire was returned by 59 patients, of whom 19 in both groups were successfully further investigated. The follow-up varied from 4 to 9 years postoperatively. The volume of the gallbladder was measured by ultrasonography before and after a fatty test meal. Alkaline phosphatase (ALP), alanine aminotransferase (ALAT), bilirubin, and amylase were determined from plasma.

Results

There was no difference in symptoms or use of antireflux medication between the groups. No difference was found in the levels of bilirubin, ALAT, or ALP. A mild elevation in plasma amylase was noted after nerve division (p = 0.041). The gallbladder ejection fraction did not differ between groups, but the fasting gallbladder volume was smaller when the nerve was cut (median 18.1 (range, 6–57.7) ml versus median 23.2 (range, 7.9–66.7) ml; p = 0.049). Both differences in plasma amylase and gallbladder fasting volume were clearer in male patients.

Conclusions

Cutting the hepatic branch of the anterior vagus nerve during fundoplication may reduce the size of gallbladder, but it has no effect on the ejection fraction. No clinical significance has been noted to date. Prospective trials will be necessary to confirm these findings.     

RotaTeq,a pentavalent rotavirus vaccine: Efficacy and safety among infants in Europe

A pentavalent human–bovine reassortant oral rotavirus vaccine, RotaTeq^®, was evaluated among nearly 70,000 infants in the Rotavirus Efficacy and Safety Trial (REST), of which 30,523 were from Europe. All infants were followed for serious adverse events as well as hospitalizations and emergency department (ED) visits. All adverse events, health care utilization, and RVGE regardless of severity were evaluated in the clinical efficacy cohort (N = 2686) in Finland. RotaTeq^® was 98.3% (95% CI, 90.2–100%) and 68.0% (95% CI 60.3–74.4%) efficacious against severe rotavirus gastroenteritis (RVGE) and all RVGE due to any serotype for two rotavirus seasons post-vaccination. The combined rate of hospitalizations and ED visits due to RVGE of any serotype was reduced by 94.5% (95% CI, 91.3–96.8%) for up to 2 years after vaccination. There were no statistically significant differences between RotaTeq^® and placebo for any of the safety outcomes. In Europe, RotaTeq^® was highly efficacious and well tolerated.     

Ultra-short echo time spectroscopic imaging in rats: implications for monitoring lipids in glioma gene therapy

We demonstrate the feasibility of using ultra-short echo time (TE = 2 ms) magnetic resonance spectroscopic imaging (MRSI) to detect intracranial mobile lipids in the rat brain. High-performance outer volume suppression and pre-localization were demonstrated in phantoms and by the total absence of signals arising from extra-cranial lipids in MRSI spectra from control rats. The sequence performance was tested on glioma-bearing BDIX rats. Fast-relaxing lipid signals were spatially varied within a glioma during herpes simplex virus thymidine kinase-mediated gene therapy, demonstrating the potential application of this method.     

Self-reported sleep duration in Finnish general population

Self-reported short or long sleep duration has been repeatedly found to be associated with increased mortality and health risks. However, there is still an insufficient amount of detailed knowledge available to characterize the short and long sleep duration groups in general population. Consequently, the underlying mechanisms potentially explaining the health risks associated with short and long sleep duration are unclear. In the present study, the self-reported sleep duration in a sample of Finnish general population was studied, and its possible associations with such factors as self-perceived health, sociodemographic characteristics, lifestyle, sleep difficulties and daytime concomitants were analyzed. In particular, an effort was made to define mutually statistically-independent determinants of sleep duration. In the Finnish Health 2000 Survey, a representative sample of 8,028 subjects of 30 years of age or older and a sample of 1,894 subjects of 18-29 years of age were invited to take part in the health interview and health examination. The participation rate of the study was over 80%. The most important and statistically-independent determinants of short and long sleep duration were gender, physical tiredness, sleep problems, marital status, main occupation and physical activity. However, in the multivariable model they only accounted for approximately 16% of the variance in sleep duration in short and long sleepers, suggesting multiple sources of variance. The present study also suggests a dose-response like relationship between the sleep duration and many of its determinants within both short and long sleepers. A more detailed analysis of the clinical status of the short and long sleep duration groups is needed to evaluate the possible importance of these findings for health risks associated with sleep duration.