Genetic diversity of HCV genotype 2 strains in south western France

Hepatitis C virus (HCV) is a major cause of chronic hepatitis and liver disease worldwide. The genetic heterogeneity of HCV and its spread among infected patients can be examined accurately by nucleotide sequencing. The diversity of HCV genotype 2 strains (HCV-2) was studied in a large cohort of patients in the Midi Pyrénées area of southern France. Phylogenetic analysis was performed on 344 NS5B sequences from patients infected with HCV-2. These included 145 strains whose E2 region was also analyzed, and epidemiological data were collected for the corresponding patients. HCV-2 accounts for 11.3% of HCV infections in this area. Phylogenetic analysis of NS5B sequences revealed eight subtypes, while that of the E2 region provided congruent results for 100% of strains. The most frequent subtypes were 2i (24.7%), 2k (22.4%) 2c (17.4%), and 2a (10.8%). The mean age of HCV-2-infected patients was 55.5 years. Epidemiological data showed that blood transfusion is the major route of infection, but it was not associated with any particular subtype. By contrast, intravenous drug users were infected predominantly with genotype 2a. HCV-2a-infected patients were younger than patients infected with other subtypes (48 vs. 56.5 years, P < 0.01). This study shows substantial genetic diversity of HCV-2 subtypes in the south of France and the spread of 2a strains via intravenous drug users.     

Campylobacter coli isolates derived from chickens in Senegal: Diversity, genetic exchange with Campylobacter jejuni and quinolone resistance

We used the multilocus sequence typing (MLST) method to study the genetic diversity of Campylobacter coli isolated from chickens in Senegal, and to check the presence of genetic exchange with Campylobacter jejuni. In addition, we assessed the resistance of the isolates to ciprofloxacin and nalidixic acid, and their gyrA sequences. MLST revealed a low level of diversity and the absence of lineages among C. coli isolates. In addition, an exchange of alleles with C. jejuni was found. Twenty percent of the ciprofloxacin-resistant isolates lacked mutations within the quinolone resistance-determining region (QRDR) of GyrA. There was no link between quinolone resistance and sequence type (ST).     

CD8+ T lymphocytes specific for glutamic acid decarboxylase 90-98 epitope mediate diabetes in NOD SCID mouse

During the past decade, glutamic acid decarboxylase (GAD) has been considered a crucial beta-cell autoantigen involved in type 1 diabetes in the NOD mouse and human. Recently, the etiological role of GAD has remained controversy. In the NOD mouse, some previous studies argued in favor of a regulatory role for GAD-specific CD4+ T cells, and no diabetogenic CD8+ T cells specific for GAD have been identified so far, discrediting the importance of GAD in beta-cell injury. Here, we identified, in the NOD model, a relevant GAD CD8+ T cell epitope (GAD(90-98)) using immunization with a plasmid encoding GAD, a protocol relying on in vivo processing of peptides from the autoantigenic protein. In pancreatic lymph nodes of na?ve female NOD mice, CD8+ T lymphocytes recognizing GAD(90-98) peptide were detected during the initial phase of invasive insulitis (between 4 and 8 weeks of age), suggesting an important role for these cells in the first stage of the disease. GAD(90-98) specific CD8+ lymphocytes lysed efficiently islet cells in vitro and transferred diabetes into NOD(SCID) mice (100%). Finally, diabetes was accelerated greatly in 3-week-old female NOD mice injected i.p. with GAD(90-98), strengthening the role of GAD-specific CTLs in diabetes pathogenesis.     

DiC14-amidine cationic liposomes stimulate myeloid dendritic cells through Toll-like receptor 4

DiC14-amidine cationic liposomes were recently shown to promote Th1 responses when mixed with allergen. To further define the mode of action of diC14-amidine as potential vaccine adjuvant, we characterized its effects on mouse and human myeloid dendritic cells (DC). First, we observed that, as compared with two other cationic liposomes, only diC14-amidine liposomes induced the production of IL-12p40 and TNF-alpha by mouse bone marrow-derived DC. DiC14-amidine liposomes also activated human DC, as shown by synthesis of IL-12p40 and TNF-alpha, accumulation of IL-6, IFN-beta and CXCL10 mRNA, and up-regulation of membrane expression of CD80 and CD86. DC stimulation by diC14-amidine liposomes was associated with activation of NF-kappaB, ERK1/2, JNK and p38 MAP kinases. Finally, we demonstrated in mouse and human cells that diC14-amidine liposomes use Toll-like receptor 4 to elicit both MyD88-dependent and Toll/IL-1R-containing adaptor inducing interferon IFN-beta (TRIF)-dependent responses.     

Medical applications of poly(styrene-block-isobutylene-block-styrene) ("SIBS")

Poly(Styrene-block-IsoButylene-block-Styrene) ("SIBS") is a biostable thermoplastic elastomer with physical properties that overlap silicone rubber and polyurethane. Initial data collected with SIBS stent-grafts and coatings on metallic stents demonstrate hemocompatibility, biocompatibility and long-term stability in contact with metal. SIBS has been used successfully as the carrier for a drug-eluting coronary stent; specifically Boston Scientific's TAXUS stent, and its uses are being investigated for ophthalmic implants to treat glaucoma, synthetic heart valves to possibly replace tissue valves and other applications. At present, researchers developing medical devices utilizing SIBS have found the following: (1) SIBS does not substantially activate platelets in the vascular system; (2) polymorphonuclear leukocytes in large numbers are not commonly observed around SIBS implants in the vascular system or in subcutaneous implants or in the eye; (3) myofibroblasts, scarring and encapsulation are not clinically significant with SIBS implanted in the eye; (4) embrittlement has not been observed in any implant location; (5) calcification within the polymer has not been observed; and (6) degradation has not been observed in any living system to date. Some deficiencies of SIBS that need to be addressed include creep deformation in certain load-bearing applications and certain sterilization requirements. The reason for the excellent biocompatibility of SIBS may be due to the inertness of SIBS and lack of cleavable moieties that could be chemotactic towards phagocytes.     

Characterization and use of Equine Bone Marrow Mesenchymal Stem Cells in Equine Cartilage Engineering. Study of their Hyaline Cartilage Forming Potential when Cultured under Hypoxia within a Biomaterial in the Presence of BMP-2 and TGF-ß1

Articular cartilage presents a poor capacity for self-repair. Its structure-function are frequently disrupted or damaged upon physical trauma or osteoarthritis in humans. Similar musculoskeletal disorders also affect horses and are the leading cause of poor performance or early retirement of sport- and racehorses. To develop a therapeutic solution for horses, we tested the autologous chondrocyte implantation technique developed on human bone marrow (BM) mesenchymal stem cells (MSCs) on horse BM-MSCs. This technique involves BM-MSC chondrogenesis using a combinatory approach based on the association of 3D–culture in collagen sponges, under hypoxia in the presence of chondrogenic factors (BMP-2 + TGF-β₁) and siRNA to knockdown collagen I and HtrA1. Horse BM-MSCs were characterized before being cultured in chondrogenic conditions to find the best combination to enhance, stabilize, the chondrocyte phenotype. Our results show a very high proliferation of MSCs and these cells satisfy the criteria defining stem cells (pluripotency-surface markers expression). The combination of BMP-2 + TGF-β₁ strongly induces the chondrogenic differentiation of MSCs and prevents HtrA1 expression. siRNAs targeting Col1a1 and Htra1 were functionally validated. Ultimately, the combined use of specific culture conditions defined here with specific growth factors and a Col1a1 siRNAs (50 nM) association leads to the in vitro synthesis of a hyaline-type neocartilage whose chondrocytes present an optimal phenotypic index similar to that of healthy, differentiated chondrocytes. Our results lead the way to setting up pre-clinical trials in horses to better understand the reaction of neocartilage substitute and to carry out a proof-of-concept of this therapeutic strategy on a large animal model.     

Performance of a New MicroScan WalkAway PC30 panel and disk diffusion method for detection of oxacillin resistance in Staphylococcus spp

The performance of the MicroScan WalkAway PC30 panel for detection of oxacillin resistance was evaluated by use of a collection of 420 staphylococcus isolates. The addition of a cefoxitin test (4 mg/liter) to the oxacillin MIC determination increased its raw performance for Staphylococcus aureus; additional data were required for coagulase-negative staphylococci.     

Are isofurans and neuroprostanes increased after subarachnoid hemorrhage and traumatic brain injury?

Current diagnostic tools to assess neurological injury after aneurysmal subarachnoid hemorrhage (aSAH) and traumatic brain injury (TBI) have poor discriminatory abilities. Free radicals are associated with the pathophysiology of secondary damage after brain trauma. We examined cerebrospinal fluid (CSF) lipid markers of oxidative stress, isofurans (IsoFs), F(4)-neuroprostanes (F(4)-NeuroPs), and F(2)-isoprostanes (F(2)-IsoPs), in two case-controlled studies in patients with aSAH or severe TBI. Patients with aSAH (n=18) or TBI (n=18) were age and gender matched with separate control groups. CSF samples were collected from patients within 24?h of the injury. CSF IsoFs and F(4)-NeuroPs were increased in aSAH patients compared with their controls. In TBI patients, IsoFs and F(4)-NeuroPs were increased compared with their controls. F(2)-IsoPs were increased in aSAH patients, but not in TBI patients, compared with their respective controls. CSF IsoFs and F(4)-NeuroPs are consistently increased after a catastrophic central nervous system injury. These results suggest their measurement may enhance the management of unconscious patients in neurological care.     

Peanut-induced anaphylaxis in children and adolescents: Data from the European Anaphylaxis Registry

Background

Peanut allergy has a rising prevalence in high-income countries, affecting 0.5%–1.4% of children. This study aimed to better understand peanut anaphylaxis in comparison to anaphylaxis to other food triggers in European children and adolescents.

Methods

Data was sourced from the European Anaphylaxis Registry via an online questionnaire, after in-depth review of food-induced anaphylaxis cases in a tertiary paediatric allergy centre.

Results

3514 cases of food anaphylaxis were reported between July 2007 - March 2018, 56% in patients younger than 18 years. Peanut anaphylaxis was recorded in 459 children and adolescents (85% of all peanut anaphylaxis cases). Previous reactions (42% vs. 38%; p = .001), asthma comorbidity (47% vs. 35%; p < .001), relevant cofactors (29% vs. 22%; p = .004) and biphasic reactions (10% vs. 4%; p = .001) were more commonly reported in peanut anaphylaxis. Most cases were labelled as severe anaphylaxis (Ring&Messmer grade III 65% vs. 56% and grade IV 1.1% vs. 0.9%; p = .001). Self-administration of intramuscular adrenaline was low (17% vs. 15%), professional adrenaline administration was higher in non-peanut food anaphylaxis (34% vs. 26%; p = .003). Hospitalization was higher for peanut anaphylaxis (67% vs. 54%; p = .004).

Conclusions

The European Anaphylaxis Registry data confirmed peanut as one of the major causes of severe, potentially life-threatening allergic reactions in European children, with some characteristic features e.g., presence of asthma comorbidity and increased rate of biphasic reactions. Usage of intramuscular adrenaline as first-line treatment is low and needs to be improved. The Registry, designed as the largest database on anaphylaxis, allows continuous assessment of this condition.