No abstract available.
Humans ; Staphylococcal Protein A*

the ability to biosynthesis of protein A from some Staphylococcus aureus strains isolated from the patients of Bach Mai Hospital was studied in the years 2001-2002. The results showed that there were 3 strains (25, 28 and 55) have the ability to synthesize protein A in the highest levels among 8 strains investigated. Using ELISA technique with protein A served as an antigen from Staphylococcus strain 25 to analyse IgG from sera of 32 healthy subjects has determined that the average IgG level from human serum is 14.37mg/ml. This result was supported by the same technique using commercial foreign bio-kit. It is proven that protein A preparation can be used as an antigen in bio-kit capturing specifically IgG from human serum in clinical diagnosis and in immuno-pathological research using ELISA technique
Staphylococcal Protein A ; biosynthesis ; Enzyme-Linked Immunosorbent Assay

BACKGROUND: Instead of hepatitis C virus (HCV) RNA test using RT-PCR, an enzyme immunoas-say for detection of HCV core protein as a simple, rapid method for the detection of HCV viremia has been developed recently. In this study, we investigated the usefulness of HCV core protein for the detection of HCV viremia by comparing the results of HCV RNA. METHODS: The study group included 71 patients; some of whom showed anti-HCV Ab. The HCV core protein assay was performed by enzyme immunoassay (Ortho Clinical Diagnostics, Raritan, NJ, USA). RESULTS: The concordance rate between HCV RNA and HCV core protein assay was 75%. Compared with the HCV RNA results, HCV core protein assay showed 50% sensitivity and 97% specificity. Among 17 patients whose results for HCV RNA were positive and those of HCV core protein were negative, all of them had anti-HCV Ab. CONCLUSIONS: Although the sensitivity of HCV core protein was not high in cases with anti-HCV Ab, the positive results for HCV core protein suggests the presence of HCV viremia. So, HCV core protein may be used as a simple and rapid method for detection of HCV viremia.
Hepacivirus ; Humans ; Immunoenzyme Techniques ; RNA ; Sensitivity and Specificity ; Staphylococcal Protein A ; Viremia*

We investigated the role of Ca2+ and protein kinases/phosphatases in the stimulatory effect of insulin on glucose transport. In isolated rat adipocytes, the simple omission of CaCl2 from the incubation medium significantly reduced, but did not abolish, insulin-stimulated 2-deoxy glucose (2-DG) uptake. Pre-loading adipocytes with intracellular Ca2+ chelator, 5,5'-dimethyl bis (o-aminophenoxy)ethane-N,N,N'N' tetraacetic acetoxymethyl ester (5,5'-dimethyl BAPTA/AM) completely blocked the stimulation. Insulin raised intracellular Ca2+ concentration ((Ca2+)i) about 1.7 times the basal level of 72+/-5 nM, and 5,5'-dimethyl BAPTA/AM kept it constant at the basal level. This correlation between insulin-induced increases in 2-DG uptake and (Ca2+)i indicates that the elevation of (Ca2+)i may be prerequisite for the stimulation of glucose transport. Studies with inhibitors (ML-9, KN-62, cyclosporin A) of Ca2+-calmodulin dependent protein kinases/phosphatases also indicate an involvement of intracellular Ca2+. Additional studies with okadaic acid and calyculin A, protein phosphatase-1 (PP-1) and 2A (PP-2A) inhibitors, indicate an involvement of PP-1 in insulin action on 2-DG uptake. These results indicate an involvement of Ca2+-dependent signaling pathway in insulin action on glucose transport.
Adipocytes* ; Animals ; Cyclosporine ; Glucose* ; Insulin* ; Okadaic Acid ; Rats ; Staphylococcal Protein A

Enterotoxins ; analysis ; Humans ; Microbial Sensitivity Tests ; Staphylococcal Food Poisoning ; microbiology ; Staphylococcal Protein A ; analysis ; Staphylococcus aureus ; isolation & purification

This study was aimed to observe the distribution of Mas-related G protein-coupled receptor A (MrgA) in cerebrospinal fluid (CSF)-contacting nucleus of normal rats and its expression in neuropathic pain, and to provide morphological evidence for CSF-contacting nucleus to participate in neuropathic pain. The model of neuropathic pain with chronic constriction injury (CCI) of the sciatic nerve was made in Sprague-Dawley rats. The thermal withdrawal latency (TWL) and mechanical withdrawal threshold (MWT) were measured. The expressions of MrgA in the CSF-contacting nucleus were examined by double labeling with immunofluorescent staining. The results showed that on the 5th, 7th, 10th and 14th days, the values of MWT and TWL in CCI group were all lower than those in sham group (P < 0.05). MrgA was found to be distributed in CSF-contacting nucleus of normal rats; and the expression was markedly up-regulated in rats at the peak of neuropathic pain. Our data suggest that CSF-contacting nucleus may participate in neuropathic pain through the MrgA-mediated signaling pathway.
Animals ; Neuralgia ; Rats ; Rats, Sprague-Dawley ; Receptors, G-Protein-Coupled/metabolism* ; Staphylococcal Protein A/metabolism* ; Up-Regulation

PURPOSE: Dengue virus infection is now a global problem. Currently, there is no licensed vaccine or proven antiviral treatment against this virus. All four serotypes (1-4) of dengue virus can infect human. An effective dengue vaccine should be tetravalent to induce protective immune responses against all four serotypes. Most of dengue vaccine candidates are monovalent, or in the form of physically mixed multivalent formulations. Recently envelope protein domain III of virus is considered as a vaccine candidate, which plays critical roles in the most important viral activities. Development of a tetravalent protein subunit vaccine is very important for equal induction of immune system and prevention of unbalanced immunity. Here, we have presented and used a rational approach to design a tetravalent dengue vaccine candidate. MATERIALS AND METHODS: We designed a multi domain antigen by fusing four consensus domain III sequences together with appropriate hydrophobic linkers and used several types of bioinformatics software and neural networks to predict structural and immunological properties of the designed tetravalent antigen. RESULTS: We designed a tetravalent protein (EDIIIF) based on domain III of dengue virus envelope protein. According to the results of the bioinformatics analysis, the constructed models for EDIIIF protein were structurally stable and potentially immunogenic. CONCLUSION: The designed tetravalent protein can be considered as a potential dengue vaccine candidate. The presented approach can be used for rational design and in silico evaluation of chimeric dengue vaccine candidates.
Computational Biology ; Computer Simulation* ; Consensus ; Dengue Virus ; Dengue* ; Humans ; Immune System ; Protein Structure, Tertiary ; Protein Subunits ; Staphylococcal Protein A*

PURPOSE: There is a need to broaden protective coverage of M protein–based vaccines against group A streptococci (GAS) because coverage of the current 30-valent M protein vaccine does not extend to all emm types. An additional GAS antigen and virulence factor that could potentially extend vaccine coverage is M-related protein (Mrp). Previous work indicated that there are three structurally related families of Mrp (MrpI, MrpII, and MrpIII) and peptides of all three elicited bactericidal antibodies against multiple emm types. The purpose of this study was to determine if a recombinant form containing Mrp from the three families would evoke bactericidal antiserum and to determine if this antiserum could enhance the effectiveness of antisera to the 30-valent M protein vaccine. MATERIALS AND METHODS: A trivalent recombinant Mrp (trMrp) protein containing N-terminal fragments from the three families (trMrp) was constructed, purified and used to immunize rabbits. Anti-trMrp sera contained high titers of antibodies against the trMrp immunogen and recombinant forms representing MrpI, MrpII, and MrpIII. RESULTS: The antisera opsonized emm types of GAS representing each Mrp family and also opsonized emm types not covered by the 30-valent M protein–based vaccine. Importantly, a combination of trMrp and 30-valent M protein antiserum resulted in higher levels of opsonization of GAS than either antiserum alone. CONCLUSION: These findings suggest that trMrp may be an effective addition to future constructs of GAS vaccines.
Antibodies ; Humans ; Immune Sera ; Peptides ; Rabbits ; Staphylococcal Protein A* ; Streptococcal Vaccines* ; Streptococcus pyogenes ; Vaccines ; Virulence ; Virulence Factors

Considerable effort has been directed at understanding the structure and function of HIV-1 envelope glycoproteins. It has been difficult to characterize HIV-1 envelope glycoproteins due to the limited availability of these proteins from virus particles or infected cells. To facilitate the structural and functional analysis of HIV-1 envelope glycoproteins, recombinant baculoviruses were generated to express wild type or mutant HIV-1 envelope glycoproteins. The gp160 precursor protein as well as the gp120 glycoprotein were detected in the cell infected with recombinant BacENVw.t containing wild type HIV-1 envelope gene. In the insect cells infected with recombinant BacENVc with mutations at the cleavage site of gp160, a precursor form of envelope glycoprotein was produced, but not secreted into the culture medium. However, the insect cells infected with recombinant BacENVc/t containing both mutations at the cleavage site and membrane spanning region produced mutant envelope glycoproteins that were efficiently secreted into the culture medium in the form of precursor. Therefore the recombinant HIV-1 envelope glycoproteins produced in this system would be useful as immunogens in the development of a vaccine against AIDS.
Baculoviridae* ; Glycoproteins* ; HIV* ; HIV-1* ; Humans* ; Insects ; Membranes ; Staphylococcal Protein A ; Virion

Gastric cancer cells express large amounts of galectin-3 on the cell surface. This fact may provide the possibility to use galectin-3 protein as a surface target for delivering cytotoxic anticancer agents. To investigate the possibility of application of galectin-3 protein as a target protein in delivering cytotoxic anticancer agents, we synthesized doxorubicin immunoconjugate by using maleimidocaproic acid and conjugated doxorubicin immunoconjugate to anti-galectin-3 mAb. The anticancer effect of immunotoxin was assayed on NIH3T3, AGS and KATO III cell lines. The anticancer effect of immunotoxin on AGS cell line is highest and that of KATO III is higher than that of NIH3T3. This results relate to that of flow cytometry analysis previously shown and indicate that galectin-3 protein can be used as a target protein on the surface of gastric cancer cell for delivering cytotoxic anticancer agents.
Antineoplastic Agents* ; Cell Line ; Doxorubicin ; Flow Cytometry ; Galectin 3 ; Galectins* ; Immunoconjugates ; Immunotoxins ; Staphylococcal Protein A ; Stomach Neoplasms