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1.
Heliyon ; 5(9): e02516, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31687603

ABSTRACT

The impact of corruption on carbon emissions is one of the main objectives of empirical studies on environmental economics. Recently, a theoretical discussion was conducted on the significant impact of reducing the level of corruption on environmental quality in developing rather than in developed countries. In this study, an empirical investigation of this claim was conducted using panel data which included 61 countries, between 2003 and 2016. The effects of corruption on carbon emission were considered using a panel threshold model. The threshold variable included human development index (HDI) which divided countries into developing and developed ones endogenously. According to the results, the value of threshold (γ = 0.753) was consistent with the categorization of UNDP countries by HDI. In developing countries, for each unit of increase in the corruption index -which means a decrease in corruption levels- we observe a 0.08 unit decrease in carbon emission while carbon emission is no longer affected by the corruption levels in developed countries and decrease in corruption does not have a significant effect on carbon emission levels.

2.
Microb Pathog ; 98: 106-11, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27377430

ABSTRACT

Hap, an auto-transporter protein, is an antigenically conserved adhesion protein which is present on both typeable and nontypeable Haemophilus influenzae. This protein has central role in bacterial attachment to respiratory tract epithelial cells. A 1000bp C-terminal fragment of Hap passenger domain (HapS) from nontypeable Haemophilus influenzae was cloned into a prokaryotic expression vector, pET-24a. BALB/c mice were immunized subcutaneously with purified rC-HapS. Serum IgG responses to purified rC-HapS, serum IgG subclasses were determined by ELISA and functional activity of antibodies was examined by Serum Bactericidal Assay. The output of rC-HapS was approximately 62% of the total bacterial proteins. Serum IgG responses were significantly increased in immunized group with rC-HapS mixed with Freund's adjuvant in comparison with control groups. Analysis of the serum IgG subclasses showed that the IgG1 subclass was predominant after subcutaneous immunization in BALB/c mice (IgG2a/IgG1 < 1). The sera from rC-HapS immunized animals were strongly bactericidal against nontypeable Haemophilus influenzae. These results suggest that rC-HapS may be a potential vaccine candidate for nontypeable Haemophilus influenzae.


Subject(s)
Adhesins, Bacterial/immunology , Antigens, Bacterial/immunology , Haemophilus Vaccines/immunology , Haemophilus influenzae/immunology , Recombinant Proteins/immunology , Adhesins, Bacterial/genetics , Animals , Antibodies, Bacterial/blood , Antigens, Bacterial/genetics , Blood Bactericidal Activity , Cloning, Molecular , Enzyme-Linked Immunosorbent Assay , Freund's Adjuvant/administration & dosage , Gene Expression , Genetic Vectors , Haemophilus Vaccines/administration & dosage , Haemophilus Vaccines/genetics , Haemophilus influenzae/genetics , Immunoglobulin G/blood , Injections, Subcutaneous , Mice, Inbred BALB C , Microbial Viability , Recombinant Proteins/genetics , Vaccines, Synthetic/administration & dosage , Vaccines, Synthetic/genetics , Vaccines, Synthetic/immunology
3.
Mol Biotechnol ; 56(6): 487-97, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24619477

ABSTRACT

Protein antigens have drawn a lot of attention from investigators working on tuberculosis vaccines. These proteins can be used to improve the immunogenicity of the new generation BCG vaccines or even replace them completely. Recombinant technology is used to insure the production of pure mycobacterial antigens in high quantities. Mycolyl transferase 85B (Ag85B) is a potent, mycobacterial antigen that significantly stimulates immune responses. Since Ag85B is an apolar protein, production of the water-soluble antigen is of interest. In this work, we report a systematic optimization strategy concerning cloning systems and purification methods, aiming at increasing the yield of recombinant Ag85B. Our optimized method resulted in a yield of 8 mg of recombinant Ag85B from 1 liter of induced culture (400 µg/ml) by using pET32a(+), Escherichia coli Rosseta-gami™(DE3) pLysS and a Ni-NTA agarose-based procedure and on-column re-solubilization. The purified recombinant Ag85B showed strong immunostimulating properties by inducing high levels of TNF-α, IFN-γ, IL-12, and IgG2a in immunized mice, therefore it can effectively be applied in TB vaccine researches.


Subject(s)
Acyltransferases/genetics , Antigens, Bacterial/genetics , Bacterial Proteins/genetics , Tuberculosis/drug therapy , Acyltransferases/biosynthesis , Acyltransferases/immunology , Acyltransferases/isolation & purification , Animals , Antigens, Bacterial/biosynthesis , Antigens, Bacterial/immunology , Antigens, Bacterial/isolation & purification , Bacterial Proteins/biosynthesis , Bacterial Proteins/immunology , Bacterial Proteins/isolation & purification , Cloning, Molecular , Gene Expression Regulation, Bacterial , Immunoglobulin G/immunology , Immunoglobulin G/metabolism , Interferon-gamma/metabolism , Interleukin-12/immunology , Interleukin-12/metabolism , Mice , Mycobacterium tuberculosis/enzymology , Mycobacterium tuberculosis/immunology , Tuberculosis/genetics , Tuberculosis/prevention & control , Tuberculosis Vaccines/genetics , Tuberculosis Vaccines/immunology , Tumor Necrosis Factor-alpha/immunology , Tumor Necrosis Factor-alpha/metabolism
4.
J Infect Dev Ctries ; 6(10): 721-6, 2012 Oct 19.
Article in English | MEDLINE | ID: mdl-23103894

ABSTRACT

INTRODUCTION: This study involved 300 Pseudomonas aeruginosa strains isolated from patients admitted in four Tehran hospitals. Using standard O-specific typing sera, they were all grouped into 16 strains out of 17 known P. aeruginosa. The strains were lyophilized and each was given a code according to the Collection of Standard Bacteria, Pasteur Institute of Iran (CSBPI) for further investigations. METHODOLOGY: Among all clinical samples, CSBPI: 16-190 was the most prevalent P. aeruginosa serotype which showed a high agglutination titer (4+, 320) against homologous O-specific typing sera. This serotype was selected for extraction of P. aeruginosa major outer membrane vesicles (OMP-F). OMP-F vesicles were extracted and purified according to the Deoxycholate Ultracentrifuge Differentiation Technique. Purity and molecular weight of OMP-F were determined by SDS-PAGE and the ability of OMP-F vesicles to induce high titers of antibody in rabbit, which was shown as a sharp antibody-antigen precipitation line in the agarose gel immune-diffusion technique. RESULTS: Passive immunization of mice with anti-rabbit OMP-F antisera induced a high level of protection when the mice were post-challenged with 2×LD50 of live P. aeruginosa CSBPI: 16-190. Furthermore, active immunization of mice with 50 µg of OMP-F could protect mice against 2xLD50 of live homologous (100% protection) and 15 heterologous native Iranian P. aeruginosa serotypes with 50-100% level of protection. CONCLUSIONS: These investigations indicate that purified OMP-F of CSBPI: 16-190 can be regarded as a safe protective immunogen in vaccinothrapy against all P. aeruginosa immunotype isolated in Iran.


Subject(s)
Porins/immunology , Pseudomonas Infections/prevention & control , Pseudomonas Vaccines/immunology , Pseudomonas aeruginosa/immunology , Animals , Antibodies, Bacterial/blood , Antibodies, Bacterial/therapeutic use , Disease Models, Animal , Humans , Immunization, Passive/methods , Iran/epidemiology , Mice , Porins/isolation & purification , Pseudomonas Infections/epidemiology , Pseudomonas Infections/immunology , Pseudomonas Vaccines/administration & dosage , Pseudomonas aeruginosa/classification , Pseudomonas aeruginosa/isolation & purification , Rabbits , Secretory Vesicles/immunology , Serotyping , Survival Analysis , Vaccination/methods
5.
Clin Vaccine Immunol ; 17(4): 524-8, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20106999

ABSTRACT

Some patients with common variable immunodeficiency (CVID) can generate an antibody response following vaccination with Neisseria meningitidis polysaccharide, but the duration of this protection is unknown. In this study, serum bactericidal antibody (SBA) responses to serogroup C N. meningitidis of 23 patients with CVID and 23 sex- and age-matched controls were measured 1 year after vaccination with the plain A/C meningococcal polysaccharide vaccine. The fold rise in serum bactericidal antibody geometric mean titers of the control group from prevaccination to 1 year postvaccination was significantly higher than that of the patient group (5.41- versus 2.96-fold, P = 0.009). Of 23 CVID patients, 8 had a poor response to vaccine (<4-fold rise) 3 weeks after vaccination, and low titers remained when measured 1 year later. Of the 15 CVID patients who had a normal response to vaccine (>/=4-fold rise) 3 weeks after vaccination, 6 cases failed to maintain protective SBA titers, whereas the remaining 9 had protective titers 1 year after vaccination. Only one of the 23 controls, who developed protective SBA titers after 3 weeks, lost the protective titers after 1 year. Among the patients, the presence of bronchiectasis and/or splenomegaly at enrollment was associated with poor SBA response to vaccine at 3 weeks and/or failure to maintain protective levels at 1 year. The results of this study demonstrate that a number of CVID patients can produce protective antibody titers that can persist for 1 year after vaccination, which lends strong support to the inclusion of polysaccharide vaccine in the immunization program for CVID patients.


Subject(s)
Antibodies, Bacterial/blood , Blood Bactericidal Activity , Common Variable Immunodeficiency/immunology , Meningococcal Vaccines/immunology , Neisseria meningitidis, Serogroup C/immunology , Adolescent , Adult , Child , Female , Humans , Immunologic Memory , Male , Middle Aged , Time Factors , Young Adult
6.
Clin Vaccine Immunol ; 15(4): 607-11, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18235041

ABSTRACT

Common variable immunodeficiency (CVID) is a heterogeneous group of disorders characterized by hypogammaglobulinemia and increased susceptibility to recurrent pyogenic infections. This study was performed to subclassify CVID on the basis of the bactericidal antibody responses of patients to polysaccharide meningococcal vaccine. Twenty-five patients with CVID (18 male and 7 female) and 25 healthy volunteers received meningococcal polysaccharide vaccine A + C. Serum bactericidal antibody (SBA) titers were measured at baseline and after 3 weeks. Response was correlated with clinical and immunological manifestations of CVID. Twenty-four (96%) of the 25 normal controls had a protective SBA titer of > or = 8 postvaccination, whereas only 16 (64%) of the 25 CVID patients had a protective titer (P value = 0.013). Among the patients with CVID who were nonresponders, there were significantly increased rates of bronchiectasis (P = 0.008), splenomegaly (P = 0.016), and autoimmunity (P = 0.034) in comparison with patients who had protective SBA titers. A reversed CD4/CD8 ratio was more common in the nonresponder group of patients (P = 0.053). We conclude that individuals with CVID who cannot produce protective postvaccination titers after receiving meningococcal polysaccharide vaccine are more likely to exhibit bronchiectasis, splenomegaly, and autoimmune diseases. Vaccination response may define subgroups of patients with CVID, enabling more effective monitoring and therapeutic strategies.


Subject(s)
Common Variable Immunodeficiency/classification , Common Variable Immunodeficiency/immunology , Meningococcal Vaccines/immunology , Serum Bactericidal Test/methods , Adolescent , Adult , Antibody Formation , Case-Control Studies , Child , Child, Preschool , Female , Humans , Immunoglobulins/blood , Male , Meningococcal Vaccines/blood , Middle Aged
7.
Vaccine ; 25(29): 5308-14, 2007 Jul 20.
Article in English | MEDLINE | ID: mdl-17574314

ABSTRACT

Primary antibody deficiencies are characterized by decreased serum levels of immunoglobulin isotypes and increased susceptibility to infection by various microorganisms including encapsulated bacteria. This study was performed in order to evaluate bactericidal antibody response of these patients to polysaccharide meningococcal vaccine. Twenty-four antibody deficient children of mean age 11.2+/-3.5 years, and 15 sex and age-matched healthy volunteers were enrolled. All subjects received meningococcal polysaccharide vaccine A+C; blood samples were collected before vaccination and 3 weeks after vaccination. Following vaccination, the serum bactericidal antibody (SBA) geometric mean titre was significantly increased compared to the prevaccination level in the patient group (8.98 versus 1.63, P<0.001) and the control group (12.13 versus 1.26, P<0.001). All controls had a protective SBA response (SBA titre of >or=8 post-vaccination or rise of >or=4-fold from pre- to post-vaccination), whereas only 16 of 24 patients (66.6%) had a protective response (P=0.014). The non-responder patients included 5 cases with common variable immunodeficiency, two cases with hyper IgM syndrome, and one case with IgG subclass deficiency. This study indicates that some patients with primary antibody deficiencies can produce protective post-vaccination titres similar to the normal population, despite the common perception that patients with primary antibody deficiencies respond poorly to vaccination. This supports the use of polysaccharide-containing vaccines in these patients.


Subject(s)
Antibodies, Bacterial/blood , Immunologic Deficiency Syndromes/complications , Meningococcal Vaccines/immunology , Microbial Viability , Neisseria meningitidis, Serogroup C/immunology , Adolescent , Child , Child, Preschool , Female , Humans , Male
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