Prevention of group B streptococcal neonatal disease revisited. The DEVANI European project.

The purpose of this paper was to present the current knowledge on the prevention of group B streptococcus (GBS) neonatal infections and the status of prevention policies in European countries and to present the DEVANI pan-European program, launched in 2008. The aim of this program was to assess the GBS neonatal infection burden in Europe, to design a new vaccine to immunize neonates against GBS infections, to improve the laboratory performance for the diagnosis of GBS colonization and infection, and to improve the methods for the typing of GBS strains. The current guidelines for GBS prevention in different countries were ascertained and a picture of the burden before and after the instauration of prevention policies has been drawn. After the issue of the Centers for Disease Control and Prevention (CDC) guidelines, many European countries have adopted universal screening for the GBS colonization of pregnant women and intrapartum prophylaxis to colonized mothers. Nevertheless, some European countries continue advocating the risk factor approach to GBS prevention. Most European countries have implemented policies to prevent GBS neonatal infections and the burden of the disease has decreased during the last several years. Nevertheless, further steps are necessary in order to develop new strategies of prevention, to improve microbiological techniques to detect GBS colonization and infection, and to coordinate the prevention policies in the EU.

Outcome of repeat ERCP after initial failed use of a needle knife for biliary access.

INTRODUCTION: A needle knife is often used to gain bile duct access when standard techniques have failed. If unsuccessful, the next step may involve either radiological- or endoscopic ultrasound-guided biliary access. However, repeat endoscopic retrograde cholangiopancreatography (ERCP) may be an option if the patient's clinical condition permits. AIM: To determine the success of repeat ERCP after failed use of a needle knife to gain biliary access. METHODS: Retrospective analysis of all patients who underwent initial unsuccessful biliary cannulation after use of a needle knife between 2007 and 2010. RESULTS: Seventy five patients were identified. Of these, 51 (68%) underwent repeat ERCP, and biliary cannulation was successful in 38 (75%). The median time to repeat ERCP was 7.7 days (range 1-28 days). Complications developed in two (4%) patients. These included one case each of wire-guided perforation and mild pancreatitis, both of which were resolved by conservative management. CONCLUSIONS: Repeat ERCP within a few days after failed use of a needle knife for biliary access is associated with acceptable success and acceptable incidence of complications, and therefore obviates the need for alternative approaches for biliary access for most patients.

An investigation of the inclusion complex of cyclomaltoheptaose (beta-cyclodextrin) with N-methylanthranilic acid in the solid state.

A 2:1 complex between cyclomaltoheptaose (beta-cyclodextrin) and N-methylanthranilic acid has been studied in the solid state. The inclusion complex belongs to the triclinic system (space group P1) with unit cell dimensions a=15.2773(15)A, b=15.4710(15)A, c=17.9627(18)A, alpha=99.632(5) degrees , beta=113.416(5) degrees , and gamma=102.818(5) degrees . The complex forms a head-to-head channel-type structure with the N-methylanthranilic acid lying between the beta-cyclodextrin groups in a sandwich fashion, which is held in place by an extensive hydrogen-bonding network between the cyclodextrin molecules.

Add-on cases in the endoscopy unit: Factors that affect volume.

BACKGROUND: Although most procedures in the endoscopy clinic are elective, emergency add-on cases in hospital-based endoscopy clinics are common, frequently consuming a great deal of time and resources relative to elective endoscopy procedures. OBJECTIVE: To determine which specific factors correlate with the high volume of add-on emergency cases in a tertiary care, hospital-based endoscopy unit. METHODS: A retrospective chart review of all gastrointestinal add-on, and electively booked cases of esophagastroduodenoscopy (EGD), colonoscopy(C) and flexible sigmoidoscopy(FS)procedures from September 2006 to May 2007, was conducted. The day of the week, month, type of procedure and physician were recorded. Emergency add-on procedures performed during the weekends were not assessed. These cases were then compared with elective cases during a similar time frame to determine differences in the aspects of add-on cases versus those that were elective. RESULTS: Seven hundred twenty-one add-on cases were reviewed (mean patient age 57.4 years; 46% women) and compared with 736 elective cases (mean age 56 years; 49% women; P not significant). Of the add-on cases, 377 (52%) were EGD, 216 C (30%) and 105 (15%) were FS, with 23 combined procedures (3.2%) versus 202 (27%) EGD, 442 (60%) C and 74 (10%) FS in the elective group. Add-on cases were more likely to be EGDs than elective cases (OR 2.7; 95% CI 1.8 to 4.3; P<0.0001) and less likely to be Cs (OR 0.24; 95% CI 0.15 to 0.38; P<0.0001). There were significantly more add-on cases on Mondays (OR 1.7; 95% CI 1.0 to 2.28; P>0.03). Conversely, there were significantly fewer procedures added on Fridays (OR 0.31; 95% CI 0.16 to 0.57; P=0.0001). There were statistically fewer add-on cases in September compared with the other months that were evaluated (OR 0.31; 95% CI 0.11 to 0.78; P=0.0006). CONCLUSION: With the present system of performing only emergency cases on the weekend, Monday tends to have more add-on cases. Consistent with the fact that upper gastrointestinal bleeding is the most common emergency condition, EGD is more common in add-on cases than with elective cases. Although speculative, the reasons for Friday having fewer add-on cases may be the result of a change of physician on call that day; consequently, most cases may be performed earlier in the week. For unknown reasons, fewer cases tend to be added on in September than in the other months evaluated. These data demonstrate that even in the same institution with similar patients, variability in the number of add-on cases likely is a result of many additional factors governing add-on cases, which require appropriate resource planning to ensure adequate allocation of services to ensure ideal patient care.

The physico-chemical characterization of a boiling stable antifreeze protein from a perennial grass (Lolium perenne).

We have characterized a cold-induced, boiling stable antifreeze protein. This highly active ice recrystallization inhibition protein shows a much lower thermal hysteresis effect and displays binding behavior that is uncharacteristic of any AFP from fish or insects. Ice-binding studies show it binds to the (1 0 1 0) plane of ice and FTIR studies reveal that it has an unusual type of highly beta-sheeted secondary structure. Ice-binding studies of both glycosylated and nonglycosylated expressed forms indicate that it adsorbs to ice through the protein backbone. These results are discussed in light of the currently proposed mechanisms of AFP action.

How the loop and middle regions influence the properties of Helicobacter pylori VacA channels.

VacA is a pore-forming cytotoxin produced by Helicobacter pylori in several strain-specific isoforms, which have been classified in two main families, m1 and m2, according to the sequence of a variable "midregion." Both forms are associated with gastric pathologies and can induce vacuolation of cultured cells. The comparison of two representative toxins, m1 17874 and m2 9554, has indicated that the m2 form is less powerful in vacuolation assays and that its effects are more strongly cell type dependent. To rationalize these differences and to investigate structure-function relationships in this toxin, we have compared the properties of the channels formed by these two variants and by a construct derived from 17874 by deleting a loop that connects the two toxin domains, which is shorter in 9554 than in 17874. Although the channels formed by all three proteins are similar, m2 9554 channels have, on average, a lower conductance and are less anion-selective and more voltage-dependent than the m1 pores. Furthermore, the rate of incorporation of 9554 VacA into planar bilayers depends on lipid composition much more strongly than that of 17874. The comparison with the behavior of the loop deletion mutant indicates that this latter property, as well as a portion of the conductance decrease, may be attributed to the reduction in loop length. The differences in pore properties are proposed to account in part for the different cytotoxicity exhibited by the two toxin isoforms. We furthermore present evidence suggesting that the conformation of the membrane-embedded toxin may be influenced by the lipid composition of the membrane itself.

Automated cardiac auscultation for detection of pathologic heart murmurs.

Experienced cardiologists can usually recognize pathologic heart murmurs with high sensitivity and specificity, although nonspecialists with less clinical experience may have more difficulty. Harsh, pansystolic murmurs of intensity grade > or = 3 at the left upper sternal border (LUSB) are likely to be associated with pathology. In this study, we designed a system for automatically detecting systolic murmurs due to a variety of conditions and examined the correlation between relative murmur intensity and likelihood of pathology. Cardiac auscultatory examinations of 194 children and young adults were recorded, digitized, and stored along with corresponding echocardiographic diagnoses, and automated spectral analysis using continuous wavelet transforms was performed. Patients without heart disease and either no murmur or an innocent murmur (n = 95) were compared to patients with a variety of cardiac diagnoses and a pathologic systolic murmur present at the LUSB (n = 99). The sensitivity and specificity of the automated system for detecting pathologic murmurs with intensity grade > or = 2 were both 96%, and for grade > or = 3 murmurs they were 100%. Automated cardiac auscultation and interpretation may be useful as a diagnostic aid to support clinical decision making.

Identification and characterization of a novel nuclear factor of activated T-cells-1 isoform expressed in mouse brain.

The nuclear factor of activated T-cells (NFAT) family transcription factors play a key role in the control of cytokine gene expression in T-cells. Although initially identified in T-cells, recent data have unveiled unanticipated roles for NFATs in the development, proliferation, and differentiation of other tissues. Here we report the identification, cDNA cloning, and functional characterization of a new isoform of NFAT1 highly expressed in mouse brain. This isoform, which we named NFAT1-D, is identical to NFAT1 throughout the N-terminal regulatory domain and the portion of the Rel domain which includes the minimal region required for specific binding to DNA and interaction with AP-1. The homology stops sharply upstream of the 3'-boundary of the Rel homology domain and is followed by a short unique C-terminal region. NFAT1-D was expressed at high levels in all brain districts and was found as a constitutively active transcription complex. Transfection of a NFAT/luciferase reporter in the neuronal cell line PC12, which also expresses NFAT1-D, showed that these cells expressed a constitutive NFAT activity that was enhanced after nerve growth factor-induced differentiation but was resistant to the immunosuppressant cyclosporin A. NFAT1-D was, however, inducibly activated in a cyclosporin A-sensitive manner when expressed in T-cells, suggesting that the activity of NFAT proteins might be controlled by their specific cellular context.

The design of vaccines against Helicobacter pylori and their development.

Helicobacter pylori is a gram negative, spiral, microaerophylic bacterium that infects the stomach of more than 50% of the human population worldwide. It is mostly acquired during childhood and, if not treated, persists chronically, causing chronic gastritis, peptic ulcer disease, and in some individuals, gastric adenocarcinoma and gastric B cell lymphoma. The current therapy, based on the use of a proton-pump inhibitor and antibiotics, is efficacious but faces problems such as patient compliance, antibiotic resistance, and possible recurrence of infection. The development of an efficacious vaccine against H. pylori would thus offer several advantages. Various approaches have been followed in the development of vaccines against H. pylori, most of which have been based on the use of selected antigens known to be involved in the pathogenesis of the infection, such as urease, the vacuolating cytotoxin (VacA), the cytotoxin-associated antigen (CagA), the neutrophil-activating protein (NAP), and others, and intended to confer protection prophylactically and/or therapeutically in animal models of infection. However, very little is known of the natural history of H. pylori infection and of the kinetics of the induced immune responses. Several lines of evidence suggest that H. pylori infection is accompanied by a pronounced Th1-type CD4(+) T cell response. It appears, however, that after immunization, the antigen-specific response is predominantly polarized toward a Th2-type response, with production of cytokines that can inhibit the activation of Th1 cells and of macrophages, and the production of proinflammatory cytokines. The exact effector mechanisms of protection induced after immunization are still poorly understood. The next couple of years will be crucial for the development of vaccines against H. pylori. Several trials are foreseen in humans, and expectations are that most of the questions being asked now on the host-microbe interactions will be answered.

The African enigma: low prevalence of gastric atrophy, high prevalence of chronic inflammation in West African adults and children.

BACKGROUND: Helicobacter pylori infection is very common in Africa, yet peptic ulcer disease and gastric malignancy are rare. AIM: The aim of this study was to quantify mucosal responses to H. pylori in Gambian adults and children and to estimate the prevalence of antibodies to bacterial virulence factors (cagA and vacA) in a symptomatic population. PATIENTS AND METHODS: Adults (mean 36 SD 12 years) with dyspepsia and children (mean 1.4 years SD 0.4 years) with malnutrition underwent gastroscopy with biopsy. Blood was simultaneously drawn for cagA and vacA antibody status. Histopathological scoring used the modified Sydney classification. RESULTS: Both adults (n = 45) and children (n = 37) mainly demonstrated chronic mild antral inflammation. Only 2/83 cases of focal atrophy (GA) and 4/83 cases of intestinal metaplasia (IM) were observed. Adults tended to demonstrate more frequent acute (AI) and chronic inflammation (CI) (38% compared with 18% and 85% compared with 72%, respectively). Sixty-seven percent of children were cagA IgG+ and 21% vacA IgG+ and 93% of adults were IgG cagA+ and 86% vacA+. There were no differences in mucosal responses between those who were cagA or vacA positive compared with those who were negative. CONCLUSION: Gambian adults and children mount a CI response to H. pylori but GA, IM and AI are uncommon. cagA and vacA are commonly expressed in Gambian strains of H. pylori. Further studies are needed in order to confirm that GA and IM are not late findings in old age.

Developing a nurse-led service for COPD patients.

A rise in the rate of hospital admissions for patients with COPD has led to the development of nurse-led home care. A study in which a nurse-led team provided domiciliary treatment with ongoing follow-up, was found to be cost-effective and reduced the need for hospital care.

A structural overview of the Helicobacter cytotoxin.

VacA, the major exotoxin produced by Helicobacter pylori, is composed of identical 87-kDa monomers that assemble into flower-shaped oligomers. The monomers can be proteolytically cleaved into two moieties of 37 and 58 kDa, or P37 and P58. The most studied property of VacA is the alteration of intracellular vesicular trafficking in eukaryotic cells leading to the formation of large vacuoles containing markers of late endosomes and lysosomes. However, VacA also causes a reduction in trans-epithelial electrical resistance in polarized monolayers and forms ion channels in lipid bilayers. The ability to induce vacuoles is localized mostly but not entirely in P37, while P58 is involved in cell targeting. Here, we review the structural aspects of VacA biology.

In vivo measurement of tumor conductiveness with the magnetic bioimpedance method.

A noninvasive electromagnetic method has been developed that can effectively measure the in-vivo conductivity difference between rat tumor lines having a low and high metastatic potential. These tumor lines are used in the study of human prostate tumor.

Temporally regulated assembly of a dynamic signaling complex associated with the activated TCR.

TCR triggering promotes multiple tyrosine kinase-dependent interactions involving proteins with one or more protein binding modules. Reported interactions mostly exceed the binding potential of these proteins. A solution to this paradox is the temporally regulated recruitment of alternative ligands. We have tested this hypothesis by analyzing the time course of protein/protein interactions triggered by TCR engagement. We show that a short-lived and dynamic multimolecular complex is assembled on tyrosine-phosphorylated CD3zeta. Specific components of this complex are recruited and shed in a temporal sequence distinct for each of the proteins analyzed. The temporally regulated assembly of a higher order structure at the activated TCR is likely to be crucial in achieving both signal longevity and signal specificity.

Defective recruitment and activation of ZAP-70 in common variable immunodeficiency patients with T cell defects.

We have previously identified a subset of common variable immunodeficiency (CVID) patients with defective T cell function associated with impaired activation of the TCR-dependent tyrosine phosphorylation cascade. Here we have assessed the structural and functional integrity of the principal components involved in coupling the TCR/CD3 complex to intracellular tyrosine kinases in two of these patients. We show that ZAP-70 fails to bind the signaling-competent CD3zeta tyrosine phosphorylation isoform and to become activated following TCR engagement, suggesting that defective recruitment of ZAP-70 might underlie the TCR signaling dysfunction in these patients. Determination of the nucleotide sequences encoding the intracellular domains of the CD3/zeta subunits and ZAP-70 did not reveal any mutation. Furthermore, ZAP-70 from these patients could interact in vitro with recombinant phospho-zeta, ruling out genetic defects at the immunoreceptor tyrosine-based activation motif/SH2 domain interface responsible for ZAP-70 recruitment to the activated TCR. No defect was found in expression, activity or subcellular localization of Lck, which is thought to be primarily responsible for CD3zeta phosphorylation. Hence, while the T cell defect in these CVID patients can be pinpointed to the interaction between ZAP-70 and CD3zeta, the integrity in the components of the signaling machinery involved in this process suggests that additional components might be required for completion of this step.

Membrane topology of VacA cytotoxin from H. pylori.

The interaction of VacA with membranes involves: (i) a low pH activation that induces VacA monomerization in solution, (ii) binding of the monomers to the membrane, (iii) oligomerization and (iv) channel formation. To better understand the structure-activity relationship of VacA, we determined its topology in a lipid membrane by a combination of proteolytic, structural and fluorescence techniques. Residues 40-66, 111-169, 205-266, 548-574 and 723-767 were protected from proteolysis because of their interaction with the membrane. This last peptide was shown to most probably adopt a surface orientation. Both alpha-helices and beta-sheets were found in the structure of the protected peptides.