Molecular epidemiology of macrolide resistance in neonatal bloodstream isolates of group B streptococci

Pulsed-field gel electrophoresis (PFGE) was performed on 122 neonatal bloodstream isolates of group B streptococci (GBS) to further examine the relationship between macrolide resistance and serotype V GBS (GBS-V). Over one-third (35%) of macrolide-resistant GBS belonged to a single PFGE subtype of GBS-V, which was also the most common GBS-V subtype noted in previous Centers for Disease Control and Prevention surveillance studies. Erm methylase (ermA and ermB) was the most common resistance mechanism detected, present in 12 of 20 macrolide-resistant GBS.     

The prevalence, cost and basis of food allergy across Europe

The development of effective management strategies to optimize the quality of life for allergic patients is currently hampered by a lack of good quality information. Estimates of how many individuals suffer from food allergy and the major foods involved vary widely and inadequacies of in vitro diagnostics make food challenges the only reliable means of diagnosis in many instances. The EuroPrevall project brings together a multidisciplinary partnership to address these issues. Cohorts spanning the main climatic regions of Europe are being developed in infants through a birth cohort, community surveys in school-age children and adults and an outpatient clinic study. Confirmatory double-blind placebo-controlled food challenge diagnosis is being undertaken using foods as they are eaten with titrated doses to allow no-effect and lowest-observable effect levels for allergenic foods to be determined. The cohorts will also facilitate validation of novel in vitro diagnostics through the development of the EuroPrevall Serum Bank. Complementary studies in Ghana, western Siberia, India and China will allow us to gain insights into how different dietary patterns and exposure to microorganisms affect food allergies. New instruments to assess the socioeconomic impact of food allergy are being developed in the project and their application in the clinical cohorts will allow, for the first time, an assessment to be made of the burden this disease places on allergy sufferers and their communities.     

(Photo)crosslinkable Smectic LC Main‐Chain Polymers

This paper presents the synthetic route to SmA LC main‐chain polymers, that can be (photo)crosslinked without solvent in the bulk phase. They are based on soluble polymalonates, in which higher ordered phases can be suppressed by copolymerization with a laterally brominated biphenyl. Two routes were developed to incorporate the crosslinkable groups into the polyester backbone. The first consists in the incorporation of phenols into the polyester. These phenols are not reactive enough to participate in the transesterification reaction used to build up the polymer, but they can be esterified afterwards with acrylates. Thermally or photochemically created radicals then start the crosslinking. The second route is based on the incorporation of benzophenone as side group. It allows a photochemical crosslinking. Crosslinked fibers (monodomains) show the potential of the smectic LC main‐chain elastomers as actuators.

     

Identification of sequential IgE-binding epitopes on bovine alpha(s2)-casein in cow's milk allergic patients

BACKGROUND: Caseins are the major allergens responsible for cow's milk allergy (CMA). We have previously identified the IgE-binding epitopes of the major cow's milk (CM) proteins except for alpha(s2)-casein. METHODS: Overlapping decapeptides representing the entire length of alpha(s2)-casein were synthesized on a cellulose-derivatized membrane. Sera from 13 CM-allergic children, 4-15 years of age, with a median level of CM-specific IgE >100 kU/l (range 33.7 to > 100 kU/l) were used to identify IgE-binding epitopes. RESULTS: Four major and six minor sequential IgE-binding regions were identified on alpha(s2)-casein. The first major region is located in the middle of the protein at amino acids (AA) 83-100, and the other three major regions are located in the carboxy terminal portion of the protein at AA 143-158, 157-172 and 165-188. The minor IgE-binding regions were identified at AA 31-44, 43-56, 93-106, 105-114, 117-128, and 191-200. CONCLUSION: We identified 10 sequential IgE-binding regions on alpha(s2)-casein and performed the first crucial step in the development of immunotherapeutic interventions for CMA.     

Utility of the ratio of food-specific IgE/total IgE in predicting symptomatic food allergy in children

BACKGROUND: Double-blind, placebo-controlled food challenges are time-consuming, expensive and not without risk to patients. Therefore, an in vitro test that could accurately diagnose food allergy would be of great value. OBJECTIVE: To evaluate the utility of the ratio of specific immunoglobulin E (IgE)/total IgE compared with specific IgE (sIgE) alone in predicting symptomatic food allergy. METHODS: We retrospectively analysed 992 controlled oral food challenges performed in 501 children (median age 13 months). The ratio of sIgE/total IgE was calculated and tested for correlation with the outcome of food challenges. Receiver operator characteristics (ROC)-curves were performed; predicted probabilities and predictive decision points were calculated. RESULTS: A significant correlation was found between the ratio and the outcome of food challenges for cow's milk (CM), hen's egg (HE), and wheat, but not for soy. The ROC and predicted probability curves as well as sensitivity and specificity of the decision points of the ratio were similar to those of sIgE levels for CM, HE and wheat. CONCLUSION: In view of the greater effort needed to determine the ratio, without benefit compared with the sIgE alone, the calculation of the ratio of sIgE/total IgE for diagnosing symptomatic food allergy offers no advantage for CM, HE, wheat or soy. For the majority of cases controlled oral food challenges still remain the method of choice.     

Sequence comparison of human and yeast telomeres identifies structurally distinct subtelomeric domains

We have sequenced and compared DNA from the ends of three human chromosomes: 4p, 16p and 22q. In all cases the pro-terminal regions are subdivided by degenerate (TTAGGG)n repeats into distal and proximal sub- domains with entirely different patterns of homology to other chromosome ends. The distal regions contain numerous, short (<2 kb) segments of interrupted homology to many other human telomeric regions. The proximal regions show much longer (approximately 10-40 kb) uninterrupted homology to a few chromosome ends. A comparison of all yeast subtelomeric regions indicates that they too are subdivided by degenerate TTAGGG repeats into distal and proximal sub-domains with similarly different patterns of identity to other non-homologous chromosome ends. Sequence comparisons indicate that the distal and proximal sub-domains do not interact with each other and that they interact quite differently with the corresponding regions on other, non- homologous, chromosomes. These findings suggest that the degenerate TTAGGG repeats identify a previously unrecognized, evolutionarily conserved boundary between remarkably different subtelomeric domains.