Cloning of the gene coding for chitobiase ofSerratia marcescens

Summary A λ phage DNA library ofSerratia marcescens was constructed and a clone carrying the gene coding for chitobiase (E.C.3.2.1.29) was isolated and characterized. Deletion analysis limited the cloned region to 4.5 kb that is capable of efficient expression of chitobiase.Escherichia coli cells harboring a plasmid carrying the cloned gene express chitobiase constitutively. The molecular weight of the protein is about 95000 daltons. In exponentially growingE. coli cells the chitobiase enzyme was found to be secreted into the periplasm.     

Vacuoles release sucrose via tonoplast-localised SUC4-type transporters

Arabidopsis thaliana has seven genes for functionally active sucrose transporters. Together with sucrose transporters from other dicot and monocot plants, these proteins form four separate phylogenetic groups. Group-IV includes the Arabidopsis protein SUC4 (synonym SUT4) and related proteins from monocots and dicots. These Group-IV sucrose transporters were reported to be either tonoplast- or plasma membrane-localised, and in heterologous expression systems were shown to act as sucrose/H(+) symporters. Here, we present comparative analyses of the subcellular localisation of the Arabidopsis SUC4 protein and of several other Group-IV sucrose transporters, studies on tissue specificity of the Arabidopsis SUC4 promoter, phenotypic characterisations of Atsuc4.1 mutants and AtSUC4 overexpressing (AtSUC4-OX) plants, and functional comparisons of Atsuc4.1 and AtSUC4-OX vacuoles. Our data show that SUC4-type sucrose transporters from different plant families (Brassicaceae, Cucurbitaceae and Solanaceae) localise exclusively to the tonoplast, demonstrating that vacuolar sucrose transport is a common theme of all SUC4-type proteins. AtSUC4 expression is confined to the stele of Arabidopsis roots, developing anthers and meristematic tissues in all aerial parts. Analyses of the carbohydrate content of WT and mutant seedlings revealed reduced sucrose content in AtSUC4-OX seedlings. This is in line with patch-clamp analyses of AtSUC4-OX vacuoles that characterise AtSUC4 as a sucrose/H(+) symporter directly in the tonoplast membrane.     

Use of a Novel Probiotic Formulation to Alleviate Lactose Intolerance Symptoms—a Pilot Study

Probiotics and Antimicrobial Proteins - Lactose intolerance is a common condition caused by lactase deficiency and may result in symptoms of lactose malabsorption (bloating, flatulence, abdominal...     

Ethnic groups and high sensitivity C-reactive protein in Israel

Abstract

High-sensitivity C-reactive protein (hs-CRP) is a biomarker that correlates with atherothrombotic risk and outcome. hs-CRP is influenced by various modifiable and non-modifiable factors. We studied the relationship between ethnic background and hs-CRP level, among the Jewish population in Israel. A total of 3659 men and 2180 women were divided into two ethnic groups (Ashkenazi and Sephardic Jews), based on the knowledge of Jewish immigration patterns throughout the centuries. Mean hs-CRP levels were calculated for each group and were adjusted for various factors known to influence hs-CRP. Sephardic Jews were found to have higher adjusted mean hs-CRP levels (2.0 mg l^?1 for men and 3.9 mg l^?1 for women) compared with Ashkenazi Jews (1.5 mg l^?1 for men and 2.9 mg l^?1 for women). Ethnic background emerged as an independent significant predictor of hs-CRP levels. We demonstrated that ethnicity is an important factor when considering hs-CRP as a marker of atherothrombotic risk.     

Comparing in-lab full polysomnography for diagnosing sleep apnea in children to home sleep apnea tests (HSAT) with an online video attending technician

Sleep and Biological Rhythms - The main study aim was to compare the validity of children sleep apnea data obtained from standard polysomnography (PSG) to a home sleep apnea test (HSAT) accompanied...     

The effects of leflunomide on clinical parameters and serum levels of IL-6, IL-10, MMP-1 and MMP-3 in patients with resistant rheumatoid arthritis

OBJECTIVE: The purpose of this open pilot study was to assess possible mechanisms of the effects of leflunomide by studying the influence of the drug on the serum levels of MMP-1, MMP-3, IL-10, IL-6 and their possible correlation with clinical disease parameters. PATIENTS AND METHODS: Thirty patients with long standing active rheumatoid arthritis were enrolled in this study. All patients failed at least 5 DMARDs in the past and were on stable treatment for at least 3 months before starting the protocol. The patients received a loading dose of 100 mg for 3 days followed by 20 mg/day thereafter and followed up monthly for 6 months. Disease activity was assessed at baseline, 2 weeks, and every month of therapy thereafter using the following variables: tender joint count, swollen joint count, morning stiffness duration, pain, tiredness, physician's and patient's global assessment, using VAS, ESR and CRP. Clinical effects of the treatment regimen were calculated using the American College of Rheumatology (ACR) criteria for clinical response. Adverse events were recorded. Serum levels of MMP-1, MMP-3, IL-10 and IL-6 were measured before and 3 months after starting the protocol. RESULTS: Except for tiredness, a statistically significant improvement in all clinical and laboratory parameters of disease activity was reached after 3 months. At this time point the ACR-20 response rate was 46.2%. The levels of MMP-1, MMP-3, IL-6 and IL-10 decreased significantly after 3 months. A statistically significant correlation between serum levels of MMP-1, IL-10 and IL-6 and clinical and laboratory parameters was also shown. After 6 months, 16 out of 30 patients withdrew from the study [adverse events (35.4%), lack of efficacy (9.7%), and low compliance (6.4%)]. CONCLUSIONS: Leflunomide was clinically efficacious in this group of long standing resistant RA in an open study "real life" design. These results comply with those reported in previous clinical trials. Serum MMP-1, MMP-3, IL-10 and IL-6 levels decreased significantly. Despite high withdrawal rate, no serious adverse effects were recorded.     

Structure-toxicity relationship of aminoglycosides: correlation of 2'-amine basicity with acute toxicity in pseudo-disaccharide scaffolds

A new pseudo-disaccharide NB23 with a 3',4'-methylidene protection was designed and its properties were evaluated in comparison to other two structurally related pseudo-disaccharides. The basicity of the 2'-amine was found to be well correlated to acute toxicity data in mice: the increase in the basicity is associated with the toxicity increase. Based on these data, a new pseudo-trisaccharide NB45 was constructed. NB45 exhibited significant antibacterial activity while at the same time retained low acute toxicity.     

The Effect of Chemical Chaperones on the Assembly and Stability of HIV-1 Capsid Protein

Chemical chaperones are small organic molecules which accumulate in a broad range of organisms in various tissues under different stress conditions and assist in the maintenance of a correct proteostasis under denaturating environments. The effect of chemical chaperones on protein folding and aggregation has been extensively studied and is generally considered to be mediated through non-specific interactions. However, the precise mechanism of action remains elusive. Protein self-assembly is a key event in both native and pathological states, ranging from microtubules and actin filaments formation to toxic amyloids appearance in degenerative disorders, such as Alzheimer''s and Parkinson''s diseases. Another pathological event, in which protein assembly cascade is a fundamental process, is the formation of virus particles. In the late stage of the virus life cycle, capsid proteins self-assemble into highly-ordered cores, which encapsulate the viral genome, consequently protect genome integrity and mediate infectivity. In this study, we examined the effect of different groups of chemical chaperones on viral capsid assembly in vitro, focusing on HIV-1 capsid protein as a system model. We found that while polyols and sugars markedly inhibited capsid assembly, methylamines dramatically enhanced the assembly rate. Moreover, chemical chaperones that inhibited capsid core formation, also stabilized capsid structure under thermal denaturation. Correspondingly, trimethylamine N-oxide, which facilitated formation of high-order assemblies, clearly destabilized capsid structure under similar conditions. In contrast to the prevailing hypothesis suggesting that chemical chaperones affect proteins through preferential exclusion, the observed dual effects imply that different chaperones modify capsid assembly and stability through different mechanisms. Furthermore, our results indicate a correlation between the folding state of capsid to its tendency to assemble into highly-ordered structures.