Phylogenetic Analysis of the Flavivirus-associated Encephalitis Syndromes, Development and Application of a New Molecular Marker for the Rapid Characterization of Flaviviruses

Flaviviruses are arthropod transmitted viruses belonging tothe family Flaviviridae, and the genus Flavivirus includesmore than 70 species of single stranded viruses bearing re sponsibility of considerable morbidity and mortality of thisviral infection. So…     

Molecular Typing of “Candidatus Bartonella ancashi,” a New Human Pathogen Causing Verruga Peruana

A recently described clinical isolate, “Candidatus Bartonella ancashi,” was obtained from a blood sample of a patient presenting with verruga peruana in the Ancash region of Peru. This sample and a second isolate obtained 60 days later from the same patient were molecularly typed using multilocus sequence typing (MLST) and multispacer sequence typing (MST). The isolates were 100% indistinguishable from each other but phylogenetically distant from Bartonella bacilliformis and considerably divergent from other known Bartonella species, confirming their novelty.     

The Cysteine-Cysteine Family of Chemokines RANTES,MIP-1α, and MIP-1β Induce Trypanocidal Activity in Human Macrophages via Nitric Oxide

This paper describes a new role for the cysteine-cysteine (CC) chemokines RANTES, MIP-1α, and MIP-1β on human macrophage function, which is the induction of nitric oxide (NO)-mediated trypanocidal activity. In a previous report, we showed that RANTES, MIP-1α and MIP-1β enhance Trypanosoma cruzi uptake and promote parasite killing by human macrophages (M. F. Lima, Y. Zhang, and F. Villalta, Cell. Mol. Biol. 43:1067–1076, 1997). Here we study the mechanism by which RANTES, MIP-1α, and MIP-1β activate human macrophages obtained from healthy individuals to kill T. cruzi. Treatment of human macrophages with different concentrations of RANTES, MIP-1α, and MIP-1β enhances T. cruzi trypomastigote phagocytosis in a dose peak response. The optimal response induced by the three CC chemokines is attained at 500 ng/ml. The macrophage trypanocidal activity induced by CC chemokines can be completely inhibited by l-N-monomethyl arginine (l-NMMA), a specific inhibitor of the l-arginine:NO pathway, but not by its d-enantiomer. Culture supernatants of chemokine-treated human macrophages contain increased NO₂⁻ levels, and NO₂⁻ production is also specifically inhibited by l-NMMA. The amount of NO₂⁻ induced by these chemokines in human macrophages is comparable to the amount of NO₂⁻ induced by gamma interferon. The killing of trypomastigotes by NO in cell-free medium is blocked by an NO antagonist or a NO scavenger. This data supports the hypothesis that the CC chemokines RANTES, MIP-1α, and MIP-1β activate human macrophages to kill T. cruzi via NO, which is an effective trypanocidal mechanism.As the role of the cysteine-cysteine (CC) family of chemokines in immunological processes continues to be defined, it is clear that their cellular influence and biological activities are broader and encompass more than simply chemoattraction. In fact, other functions beside chemotaxis, such as their participation in angiogenesis and neovascularization, resistance to human immunodeficiency virus type 1 (HIV-1), T-cell costimulatory activities (reviewed in references 2 and 46), and enhancement of NK-mediated cytolysis (45), have been reported. The mechanism by which CC chemokines activate human macrophages to exert cytotoxicity is unknown. In this study, we have explored the role of the CC chemokines RANTES, MIP1-α, and MIP-1β on human macrophage cytotoxic cell function against the human parasite Trypanosoma cruzi by examining their mechanism of trypanosome toxicity within macrophages.T. cruzi, the causative agent of Chagas’ disease, is an obligate intracellular pathogen of several cells including cells of the monocyte/macrophage lineage (4). This organism is now viewed as an emerging human pathogen of HIV-1-infected individuals, since it induces dramatic pathologic changes in the brain and results in earlier death when associated with HIV-1 infections (9, 39). The possible emergence of T. cruzi as an opportunistic infection of HIV-1-infected individuals in the United States has recently been considered (30). Inflammatory molecules have been postulated to play a role in the clearance of T. cruzi, since control of the acute phase of Chagas’ disease is critically dependent on cytokine-mediated macrophage activation. For instance, treatment of macrophages with gamma interferon (IFN-γ) (36), granulocyte-macrophage colony-stimulating factor (33, 37), or tumor necrosis factor alpha (TNF-α) (27) induces T. cruzi killing whereas transforming growth factor β (TGF-β) and interleukin-10 (IL-10) inhibit the trypanocidal action of IFN-γ-activated macrophages (14).Chemokines mediate inflammatory reactions (3, 40–42) and show potential leukocyte activation and/or chemotactic activity (11). CC chemokines act primarily on monocytes but also have been shown to act on basophils, eosinophils, lymphocytes including Th2 cells, astrocytes, dendritic cells, fibroblasts, and hematopoietic cells (reviewed in references 2 and 46). CC chemokines include MIP-1α and MIP-1β (macrophage inflammatory proteins 1α and 1β), RANTES (regulated upon activation, normal T expressed and secreted), MCP-1 through MCP-3 (7), I-309, Eotaxin, C10, HCC-1 (2, 46), and 6Ckine (16). The proinflammatory activities of CC chemokines overlap but are not identical (8); MIP-1α, MIP-1β, and RANTES bind to a common receptor, suggesting that there are structural similarities among them (8).Chemokines play important roles in immunopathogenesis and may selectively recruit cells into sites of antigenic challenge (7). They are active on lymphocytes and monocytes/macrophages upon binding to G-protein-coupled seven-transmembrane-domain surface receptors (13, 31). It was recently shown that HIV-1 entry into human macrophages is inhibited by MIP-1α, MIP-1β, and RANTES (6, 21) and that CCKR5, the RANTES, MIP-1α, and MIP-1β receptor, functions as a coreceptor for macrophage-tropic HIV-1 (1).The objective of this study was to investigate the microbicidal mechanism induced by these inflammatory secreted proteins in human macrophages infected with infective trypomastigote forms of T. cruzi. In this work, we describe a new role for the CC chemokines RANTES, MIP-1α, and MIP-1β on human macrophage function, which is the induction of microbicidal activity of these cells via NO.     

The Molecular Mechanism of Human Resistance to HIV-1 Infectionin Persistently Infected Individuals—A Review,Hypothesis and Implications

Resistance to HIV-1 infection in Europeans is associated with a mutation in the gene that codes for the CCR5 protein that is present in Th2 cells and serves as a coreceptor for HIV-1 R5 strain. A deletion of 32 amino acids from the cytokine receptor prevents infection. This mutation prevails in Europeans and is absent in Africans. However, duplication of a gene that codes for a chemokine that binds to the CCR5 was discovered in Africans (mean gene copy 6 while in non-Africans the mean gene copy is 3). Higher expression of these genes protects T cells against HIV-1 infection in vitro. It should be noted that resistance to HIV-1 R5 variant does not protect against HIV-1 R4 variant. It was reported that a minority of highly HIV-1 exposed African professional sex workers (APSW) were resistant to the virus infection during a 10 years period. Recently, the analysis of the cytokines in the serum of the persistently infected seronegative women revealed that the latter hypo-expresses the cytokine IL-4. Since the molecular events during HIV-1 infection are associated with a marked increase in the levels of IL-4 and IgE in the sera of the infected individuals, it suggests that AIDS is an allergy. Thus, a very low level of IL-4 production may abrogate the virus infection. Studies on the human IL-4 gene revealed that together with the IL-4 mRNA a spliced variant with a deletion of exon 2 is synthesized. The latter is a natural antagonist of IL-4 and when expressed in an individual at a level higher than IL-4, the person will resist a microbial infection (e.g. Mycobacterium tuberculosis) or asthma. The present hypothesis suggests that the HIV-1 resistant APSWs produce more IL-4 delta 2 molecules than IL-4 molecules. The binding of IL–4 delta 2 to IL-4 receptors on T and B cells prevents their functions and the infection by HIV-1. The implications of these studies are that treatment of HIV-1 infected people with drugs that will block the IL-4 receptors will stop HIV-1 infections and the determination of the levels of IL-4 and IL-4 delta 2 in the sera of HIV-1+ patients will enable to identify the individuals that have a natural resistance to HIV-l/AIDS and those who need treatments.     

Molecular Characterization of HE, M, and E Genes of Winter Dysentery Bovine Coronavirus Circulated in Korea During 2002–2003

The different bovine coronavirus (BCoV) strains or isolates exhibited various degrees of substitutions, resulting in altered antigenicity and pathogenicity of the virus. In the previous our study, we demonstrated that the spike glycoprotein gene of Korean winter dysentery (WD) BCoV had a genetic property of both enteric (EBCV) and respiratory BCoV (RBCV) and were significantly distinct from the ancestral enteric strains. In the present study, therefore, we analyzed the other structure genes, the hemagglutinin/esterase (HE) protein, the transmembrane (M) protein and the small membrane (E) protein to characterize 10 WD BCoV circulated in Korea during 2002–2003 and compared the nucleotide and deduced amino acid sequences with the other known BCoV. Phylogenetic analysis indicated that the HE gene among BCoV could be divided into three groups. The first group included only RBCV, while the second group contained calf diarrhea BCoV, RBCV, WD and EBCV, respectively. The third group possessed only all Korean WD strains which were more homologous to each other and were sharply distinct from the other known BCoV, suggesting Korean WD strains had evolutionary distinct pathway. In contrast, the relative conservation of the M and E proteins of BCoV including Korean WD strains and the other coronaviruses suggested that structural constraints on these proteins are rigid, resulting in more limited evolution of these proteins. In addition, BCoV and human coronavirus HCV-OC43 contained four potential O-glycosylation sites in the M gene. However, the M gene sequence of both BCoV and HCV-OC43 might not contain a signal peptide, suggesting the M protein might be unlikely to be exposed to the O-glycosylation machinery in vivo. Nucleotide sequence data reported is available in the GenBank database under the accession no. HE, M and E genes: KWD1; AH014866, KWD2; AH014867; KWD3; AH014868, KWD4; AH014869, KWD5; AH014870, KWD6; AH014871, KWD7; AH014872, KWD8; AH014873, KWD9; AH014874, and KWD10; AH014875.     

LDL Receptor–Related Protein-1: A Regulator of Inflammation in Atherosclerosis,Cancer, and Injury to the Nervous System

Low-density lipoprotein receptor–related protein-1 (LRP1) is an endocytic receptor for numerous proteins that are both structurally and functionally diverse. In some cell types, LRP1-mediated endocytosis is coupled to activation of cell signaling. LRP1 also regulates the composition of the plasma membrane and may, thereby, indirectly regulate the activity of other cell-signaling receptors. Given the scope of LRP1 ligands and its multifunctional nature, it is not surprising that numerous biological activities have been attributed to this receptor. LRP1 gene deletion is embryonic-lethal in mice. However, elegant studies using Cre-LoxP recombination have helped elucidate the function of LRP1 in mature normal and pathological tissues. One major theme that has emerged is the role of LRP1 as a regulator of inflammation. In this review, we will describe evidence for LRP1 as a regulator of inflammation in atherosclerosis, cancer, and injury to the nervous system.Low-density lipoprotein (LDL) receptor–related protein-1 (LRP1/CD91) is a type 1 transmembrane protein, which is processed by furin-like endoproteases in the trans-Golgi compartment to generate the mature two-chain structure.^1,2 The 515-kDa α-chain is entirely extracellular and coupled to the cell surface through strong noncovalent interactions with the transmembrane 85-kDa β-chain. Although LRP1 may localize transiently in lipid rafts, the receptor migrates in the plasma membrane to clathrin-coated pits, where it undergoes constitutive endocytosis and recycling with extremely high efficiency.^3–5 In most cells, including macrophages, hepatocytes, and neurons, LRP1-associated ligands dissociate in acidified endosomes and are transferred to lysosomes.^3,4,6 In endothelial cells, LRP1 ligands may undergo transcytosis.^7,8LRP1 is a member of the LDL receptor gene family, which includes receptors such as megalin/LRP2, apolipoprotein E receptor 2/LRP8, and the VLDL receptor. These receptors demonstrate similarities in domain organization and, in some cases, partially overlapping function.⁹ As shown in Figure 1A, the LRP1 α-chain includes four clusters of complement-like repeats (CCRs), numbered from the N-terminus.^9,10 CCR2 and CCR4 contain 8 and 11 complement-like repeats, respectively, and are responsible for most of the ligand-binding activity of LRP1.¹⁰ The LRP1 β-chain includes YxxL and dileucine motifs that serve as principal endocytosis signals¹¹ and two NPxY motifs that function as secondary endocytosis signals and as binding sites for signaling adapter proteins.^11–13Open in a separate windowFigure 1Molecular models showing the organization of structural domains in LRP1 and the docking of a representative ligand to complement-like repeats in LRP1. A: The depicted domains in LRP1 are common to the LDL receptor family. Stars are present in the intracellular region of LRP1 to represent motifs that function as endocytosis signals and/or as docking sites for cell-signaling proteins including NPXY, YxxL, and dileucine. B: A representative LRP1 ligand, the 18-kDa receptor-binding domain of α₂-macroglobulin, which is a free-standing domain in the activated state of the protein, is shown in pink. Two lysine residues in a single α-helix, highlighted in blue, are essential for binding to LRP1. These lysine residues interact with acidic amino acids in the LRP1 complement-like repeats. The fourth and fifth complement-like repeats in CCR2 are shown in orange, and the acidic amino acids in these domains are highlighted in black. The approximate positions of calcium are shown. EGF, epidermal growth factor.The first identified LRP1 ligand was apolipoprotein E–containing β-VLDL.¹⁴ Subsequently, LRP1 was identified as the receptor for activated α₂-macroglobulin (α₂M),¹⁵ bringing forward a considerable body of literature in which LRP1 was referred to as the activated α₂M receptor. Figure 1B shows a model in which the 18-kDa LRP1-binding domain of α₂M (called the receptor-binding domain or RBD) is engaging tandem complement-like repeats from CCR2 of LRP1. As is typical for LRP1-ligand interactions, Lys residues in the structure of the RBD, positioned in parallel orientation within the same α-helix, interact with negatively charged amino acids in the complement-like repeats.^16,17 Hydrophobic residues exposed on the surface of the RBD also may be involved.¹⁶ The integral association of calcium with the complement-like repeats is necessary for structural integrity and function.^1,17Currently identified LRP1 ligands include proteases, protease inhibitor complexes, extracellular matrix proteins, growth factors, toxins, and viral proteins.⁹ LRP1 ligands are present in myelin, including myelin basic protein and myelin-associated glycoprotein (MAG),^18,19 explaining why in the injured central nervous system, LRP1 may participate in the phagocytosis of myelin debris.¹⁸ By binding calreticulin, LRP1 associates with members of the collectin family, including C1q and mannose-binding lectin, and participates in the phagocytosis of apoptotic cells.^20,21 LRP1 also serves as an endocytic receptor for many intracellular proteins released by necrotic cells.²² These LRP1 activities are important because failure to efficiently clear intracellular proteins, apoptotic cells, and cell debris may be associated with the onset of autoimmune disease.²³     

Coexpression of Ang1 and Tie2 in Odontoblasts of Mouse Developing and Mature Teeth—A New Insight into Dentinogenesis

Angiopoietin-1 regulates vascular angiogenesis and stabilization, and is reported to promote bone formation by facilitating angiogenesis. To estimate the role of Ang1 in odontogenesis, we explored the distribution of Ang1 and the receptor, Tie2 in the mouse developing and mature first molar of the mandible. At embryonic day 18, when differentiation of odontoblasts begins, immunosignals for Ang1 were intensely detected in the basement membrane and the distal side, which faced the basement membrane of odontoblasts. In situ hybridization revealed that Ang1 was expressed in odontoblasts and ameloblasts facing the basement membrane. Tie2 was localized in the distal side of odontoblasts. After birth, Ang1 was detected in the predentin, whereas both Ang1 and Tie2 were colocalized in odontoblasts and odontoblast processes. These distributions were retained up to 8 weeks. In contrast to odontoblasts, ameloblasts, cementoblasts and osteoblasts expressed Ang1 but did not express Tie2. Colocalization of Ang1 and Tie2 in odontoblasts and selective expression of Tie2 in odontoblasts among cells responsible for calcified tissue formation suggested the involvement of autocrine signals of Ang1-Tie2 in dentinogenesis.     

TLR stimulation of human neutrophils lead to increased release of MCP-1, MIP-1α, IL-1β, IL-8 and TNF during tuberculosis

Neutrophils inform and shape immune responses. Toll-like receptors (TLRs) play an essential part in the perception of microbes and shape the complex host responses that occur during infection. The TLRs present on neutrophils play an indispensable role in neutrophil mediated pathogen recognition and elimination. This study was done to identify the role of significant TLRs in immune responses leading to differences in cytokine/chemokine release following stimulation. We evaluated the concentrations of various significant cytokines (IL-1β, TNF, MIP-1α, MCP-1 and IL-8) secreted by neutrophils from healthy donors and pulmonary tuberculosis patients following TLR ligand stimulation. TLR stimulation increased the release of such cytokines in both the groups. Thus it is noted that TLR stimulation of neutrophils definitely lead to increased cytokine response. Also, the release of all the studied cytokines are found to be greatly increased in patient neutrophils, affirming that neutrophils undergo secretory level modifications during tuberculosis infection.     

GABAergic Neurons from Mouse Embryonic Stem Cells Possess Functional Properties of Striatal Neurons In Vitro, and Develop into Striatal Neurons In Vivo in a Mouse Model of Huntington’s Disease

Huntington's disease (HD) is a neurodegenerative disease where GABAergic medium spiny neurons (MSNs) in the striatum degenerate. Embryonic stem cell-derived neural transplantation may provide an appropriate therapy for HD. Here we aimed to develop a suitable protocol to obtain a high percentage of functional GABAergic neurons from mouse embryonic stem cells (mESCs), and then tested their differentiation potential in vivo. The monolayer method was compared with the embryoid body and five stage method for its efficiency in generating GABAergic neurons from mESCs. All three methods yielded a similar percentage of GABAergic neurons from mESCs. Monolayer method-derived GABAergic neurons expressed the MSN marker dopamine- and cyclic AMP-regulated phosphoprotein (DARPP32). The pluripotent stem cell population could be eliminated in vitro by treating cells with puromycin and retinoic acid. Using patch-clamp recordings, the functional properties of GABAergic neurons derived from mESCs were compared to GABAergic neurons derived from primary lateral ganglionic eminence. Both types of neurons showed active membrane properties (voltage-gated Na(+) and K(+) currents, Na(+)-dependent action potentials, and spontaneous postsynaptic currents) and possessed functional glutamatergic receptors and transporters. mESC-derived neural progenitors were transplanted into a mouse model of HD. Grafted cells differentiated to mature neurons expressing glutamate decarboxylase, dopamine type 1 receptors, and DARPP32. Also, neural precursors and dividing populations were found in the grafts. In summary, mESCs are able to differentiate efficiently into functional GABAergic neurons using defined in vitro conditions, and these survive and differentiate following grafting to a mouse model of HD.     

Molecular Diagnosis of Severe Combined Immunodeficiency��Identification of IL2RG, JAK3, IL7R, DCLRE1C, RAG1, and RAG2 Mutations in a Cohort of Chinese and Southeast Asian Children

Severe combined immunodeficiencies (SCID) are a group of rare inherited disorders with profound defects in T cell and B cell immunity. From 2005 to 2010, our unit performed testing for IL2RG, JAK3, IL7R, RAG1, RAG2, DCLRE1C, LIG4, AK2, and ZAP70 mutations in 42 Chinese and Southeast Asian infants with SCID adopting a candidate gene approach, based on patient's gender, immune phenotype, and inheritance pattern. Mutations were identified in 26 patients, including IL2RG (n?=?19), IL7R (n?=?2), JAK3 (n?=?2), RAG1 (n?=?1), RAG2 (n?=?1), and DCLRE1C (n?=?1). Among 12 patients who underwent hematopoietic stem cell transplantation, eight patients survived. Complications and morbidities during transplant period were significant, especially disseminated bacillus Calmette-Guérin disease which was often difficult to control. This is the first cohort study on SCID in the Chinese and Southeast Asian population, based on a multi-centered collaborative research network. The foremost issue is service provision for early detection, diagnosis, management, and definitive treatment for patients with SCID. National management guidelines for SCID should be established, and research into an efficient platform for genetic diagnosis is needed.     

Efficacy, Pharmacokinetics, Safety, and Tolerability of Flebogamma® 10% DIF, a High-Purity Human Intravenous Immunoglobulin, in Primary Immunodeficiency

Background

Flebogamma® 10% DIF represents an evolution of intravenous immune globulin from the previous 5% product to be administered at higher rates and with smaller infusion volumes. Pathogen safety is enhanced by the combination of multiple methods with different mechanisms of action.

Objective

The objective of this study as to evaluate the efficacy, pharmacokinetics, and safety of Flebogamma® 10% DIF for immunoglobulin replacement therapy in primary immunodeficiency diseases (PIDD).

Methods

Flebogamma® 10% DIF was administered to 46 subjects with well-defined PIDD at a dose of 300–600 mg/kg every 21–28 days for 12 months.

Results

Serious bacterial infection rate was 0.025/subject/year. Half-life in serum of the administered IgG was approximately 35 days. No serious treatment-related adverse event (AE) occurred in any patient. Most of the potentially treatment-related AEs occurred during the infusion, accounting for 20% of the 601 infusions administered.

Conclusions

Flebogamma® 10% DIF is efficacious and safe, has adequate pharmacokinetic properties, and is well-tolerated for the treatment of PIDD.     

Molecular characterization of Echinococcus granulosus in south-eastern Romania: evidence of G1–G3 and G6–G10 complexes in humans

Echinococcus granulosus is the aetiological agent of cystic echinococcosis (CE), which is a public health problem in many eastern European countries, particularly in Romania, where the infection causes a high number of human and animal cases. To shed light on the transmission patterns of the parasite, we performed a genotyping analysis on 60 cyst samples obtained from patients who live in south-eastern Romania and who underwent surgery for liver or lung CE. DNA was extracted from the endocysts or the cyst fluids, and fragments of cytochrome c oxidase subunit 1 and NADH dehydrogenase subunit 1 mitochondrial genes (cox1 and nd1, respectively) were amplified by PCR and sequenced. We found that most of the samples analysed (59/60) belonged to the G1–G3 complex (E. granulosus sensu stricto), which contains the most widespread and infective strains of the parasite. We also identified the first human patient infected by a non-G1–G3 genotype of E. granulosus in this country. As the DNA sequence of this cyst sample showed maximum homology with the G6–G10 complex (Echinococcus canadensis), this is, in all likelihood, a G7 genotype, which is often found in pigs and dogs in most countries of eastern and south-eastern Europe.     

Cultural–Ecological Theory of Academic Disengagement Used to Explain a Story of Race,Culture and Education

Students of African ancestry often share an experience of being a racialized minority in the context of the educational institution. Late Professor of Anthropology John Ogbu’s Cultural-ecological Theory of Academic Disengagement is employed to describe the negative responses encountered by peers in the name of academic achievement.The late Nigerian-American anthropologist John Ogbu described that it is often socially disadvantageous for black youth to prosper academically in formal education. Black students are often seen as betraying their cultural identities by aspiring to academic success and scholastic achievement and are met with repugnance by black peers.The notion of “acting white” is unnecessary, impertinent should be abandoned outright as achievement should have no color.     

Characterization of hLF1–11 immobilization onto chitosan ultrathin films,and its effects on antimicrobial activity

hLF1–11 (GRRRRSVQWCA) is an antimicrobial peptide (AMP) with high activity against methicillin-resistant Staphylococcus aureus (MRSA), the most prevalent species in implant-associated infection. In this work, the effect of the surface immobilization on hLF1–11 antimicrobial activity was studied. Immobilization was performed onto chitosan thin films as a model for an implant coating due to its reported osteogenic and antibacterial properties. Chitosan thin films were produced by spin-coating on gold surfaces. hLF1–11 was immobilized onto these films by its C-terminal cysteine in an orientation that exposes the antimicrobial activity-related arginine-rich portion of the peptide. Two levels of exposure (with and without a polyethylene glycol (PEG) spacer) were analyzed. Covalent immobilization was further compared with the AMP physical adsorption onto chitosan films. Surfaces were characterized using ellipsometry, contact angle measurements, atomic force microscopy, infrared and X-ray photoelectron spectroscopies and using a fluorimetric assay for hLF1–11 quantification. Surface antimicrobial activity was assessed through surface adhesion and viability assays using an MRSA (S. aureus ATCC 33591). The incorporation of hLF1–11 increased significantly bacterial adhesion to chitosan films. However, the presence of hLF1–11, namely when immobilized through a PEG spacer, decreased the viability of adherent bacteria with regard to the control surface. These results demonstrated that hLF1–11 after covalent immobilization by its cysteine can maintain activity, particularly if a spacer is applied. However, further studies, exploring the opposite orientation or the same C-terminal orientation, but non-cysteine related, can help to clarify the potential of the hLF1–11 immobilization strategy.     

Synthesis,Characterization and Photopolymerization of a New Dimethacrylate Monomer Based on (α-Methyl-benzylidene)bisphenol Used as Root Canal Sealer

Methacrylate resin-based sealers have attracted wide attention because of their easy handling, superior aesthetic qualities, good mechanical properties and excellent adhesive ability with dentin. 2,2-Bis[4-(2′-hydroxy-3′-methacryloyloxypropoxy)-phenyl]-propane (Bis-GMA) is the main component of the newly developed commercial root canal sealer 'Epiphany', which is one of the methacrylate resin-based sealers. In order to further reduce the polymerization volume shrinkage of Bis-GMA, 4,4′-(α-methylbenzylidene)-bis(2′-hydroxy-3′-methacryloyloxy-propoxy)benzene (4,4′-AMBHMB) with higher molecular weight and larger molecular volume was synthesized to replace Bis-GMA as one of the components of the root canal sealer used in this study. The structure of monomer 4,4′-AMBHMB was confirmed by FT-IR, ¹H-NMR, mass spectrum and elemental analysis. The photopolymerization behavior of mixture of 4,4′-AMBHMB and triethylene glycol dimethacrylate (TEGDMA) was investigated by FT-IR. Degree of double bond conversion, volume shrinkage, water sorption and solubility, diffusion coefficient value, flexure strength and glass transition temperature of 4,4′-AMBHMB/TEGDMA system with a mass ratio of 50:50 were measured. A 50:50 Bis-GMA/TEGDMA formulation was used as reference. The results illustrated that 4,4′-AMBHMB/TEGDMA system had the same double bond conversion and water sorption with Bis-GMA/TEGDMA system. Polymerization shrinkage, water solubility and diffusion coefficient of 4,4′-AMBHMB/TEGDMA system were lower than that of the Bis-GMA/TEGDMA system, whereas the flexural strength and glass-transition temperature of 4,4′-AMBHMB/TEGDMA system were higher than that of the Bis-GMA/TEGDMA system.     

Antigenic and Molecular Analyses Reveal that the Equine Rotavirus Strain H-1 is Closely Related to Porcine,but not Equine,Rotaviruses: Interspecies Transmission from Pigs to Horses?

We have sequenced the genes encoding the inner capsid protein VP6 and the outer capsid glycoprotein VP7 of the subgroup (SG) I equine rotavirus strain H-1 (P9[7], G5). The VP6 and VP7 proteins of the equine rotavirus strain H-1 shared a high degree of sequence and deduced amino acid identity with SG I porcine strains and serotype G5 porcine strains, respectively. Previous sequence analyses of the genes encoding the outer capsid spike protein VP4 and the nonstructural proteins NSP1 and NSP4 of equine H-1 strain also revealed a high degree of sequence and deduced amino acid homology with the prototype porcine rotavirus strain OSU (P9[7], G5). We have also confirmed and extended the VP4 and VP7 antigenic relatedness of equine rotavirus strain H-1 to porcine strains of P9[7] and G5 serotype specificities isolated in the United States, Venezuela, Argentina, and Australia based on cross-neutralization studies. In addition, the pathogenicity of tissue culture-adapted equine H-1, H-2, FI-14, FI-23, and L338, and porcine OSU rotavirus strains was compared in the neonatal mouse model. The 50% diarrhea dose (DD₅₀) of equine H-1 was similar to that of porcine OSU and equine H-2 and L338 strains, while the DD₅₀ of equine H-2 was50 or 315-fold lower than those of equine FI-14 or FI-23, respectively. Our sequence comparison of NSP4 of the rotavirus strains tested potentially identified amino acid residue 136, within the variable region spanning amino acids 130 to 141, as playing a role in virulence. Taken together, there is strong support to suggest that the equine rotavirus strain H-1 may represent an example of interspecies transmission from pigs to horses.