Home  About us  Contact
 

Strong Protection (strong + protection)

Distribution by Scientific Domains
Medical Sciences71%

Selected Abstracts

Dual Economies and International Total Factor Productivity Differences: Channelling the Impact from Institutions, Trade, and Geography

ECONOMICA, Issue 300 2008
AREENDAM CHANDA
This paper provides a framework that decomposes aggregate total factor productivity (TFP) into a component reflecting relative efficiency across sectors, and another component that reflects the absolute level of efficiency. A development accounting analysis suggests that as much as 85% of the international variation in aggregate TFP can be attributed to variation in relative efficiency across sectors. Estimation results show that recent findings highlighting the importance of strong protection of property rights, financial development and geographical advantage for the level of TFP, can be explained by their impact on relative efficiency. [source]

,-Galactosylceramide-loaded, antigen-expressing B cells prime a wide spectrum of antitumor immunity

INTERNATIONAL JOURNAL OF CANCER, Issue 12 2008
Yeon-Jeong Kim
Abstract Most of the current tumor vaccines successfully elicit strong protection against tumor but offer little therapeutic effect against existing tumors, highlighting the need for a more effective vaccine strategy. Vaccination with tumor antigen-presenting cells can induce antitumor immune responses. We have previously shown that NKT-licensed B cells prime cytotoxic T lymphocytes (CTLs) with epitope peptide and generate prophylactic/therapeutic antitumor effects. To extend our B cell vaccine approach to the whole antigen, and to overcome the MHC restriction, we used a nonreplicating adenovirus to transduce B cells with antigenic gene. Primary B cells transduced with an adenovirus-encoding truncated Her-2/neu (AdHM) efficiently expressed Her-2/neu. Compared with the moderate antitumor activity induced by vaccination with adenovirus-transduced B cells (B/AdHM), vaccination with ,-galactosylceramide-loaded B/AdHM (B/AdHM/,GalCer) induced significantly stronger antitumor immunity, especially in the tumor-bearing mice. The depletion study showed that CD4+, CD8+ and NK cells were all necessary for the therapeutic immunity. Confirming the results of the depletion study, B/AdHM/,GalCer vaccination induced cytotoxic NK cell responses but B/AdHM did not. Vaccination with B/AdHM/,GalCer generated Her-2/neu -specific antibodies more efficiently than B/AdHM immunization. More importantly, B/AdHM/,GalCer could prime Her-2/neu -specific cytotoxic T cells more efficiently and durably than B/AdHM. CD4+ cells appeared to be necessary for the induction of antibody and CTL responses. Our results demonstrate that, with the help of NKT cells, antigen-transduced B cells efficiently induce innate immunity as well as a wide range of adaptive immunity against the tumor, suggesting that they could be used to develop a novel cellular vaccine. © 2008 Wiley-Liss, Inc. [source]

Evaluation of the immune response against Strongyloides venezuelensis in antigen-immunized or previously infected mice

PARASITE IMMUNOLOGY, Issue 3 2008
A. FERNANDES
Summary The present study was carried out to investigate the immune response against Strongyloides venezuelensis infection in Balb/c mice previously immunized with larva-antigens or primed with live-larvae. Our results indicate that all primed mice developed a strong protection against challenge infection that remained active for 45 days. In mice primed with live-larvae the challenge infection resulted in great reduction of migrating larvae and the worms were completely eliminated from the small intestine before maturation. The protection pattern did not alter when the primary infection was aborted by drug treatment. In these experimental groups, the challenge infection was accompanied by a type-2 predominant immune response, intense IgE and reactive IgG1 production, and granulocyte infiltration in skin, lungs and intestine. The challenge infection in antigen-immunized mice also resulted in great reduction of migrating larvae. However, the worms that reached the host intestine matured, produced eggs and were eliminated similarly to the ones from nonimmunized mice. Protective mechanisms after immunization with larva antigen were migrating larva-specific and associated with a strong and mixed Th1 and Th2 response, without tissue granulocyte infiltration. In conclusion, protective immunity induced by a previous infection or antigen-immunization are stage-specific and operate through different effector mechanisms. [source]

GRA7 provides protective immunity in cocktail DNA vaccines against Toxoplasma gondii

PARASITE IMMUNOLOGY, Issue 9 2007
E. JONGERT
SUMMARY In a previous study, single-gene vaccination with GRA1, GRA7 or ROP2 was shown to elicit partial protection against Toxoplasma gondii. In this study, the contribution of each antigen in the evoked humoral and cellular immune responses was evaluated after vaccination with plasmid mixtures containing GRA1, GRA7 and ROP2. Cocktail DNA vaccinated mice developed high antibody titers against the antigens from two-gene DNA vaccine cocktails, but lower titres when immunized with the three-gene cocktail. High numbers of IFN-, secreting splenocytes were generated predominantly against GRA7. Brain cyst burden was reduced by 81% in mice vaccinated with the three-gene mixture and they were completely protected against acute toxoplasmosis. Similar high levels of brain cyst reductions were obtained after vaccination with cocktails composed of GRA1 and GRA7 (89% reduction), or GRA7 and ROP2 (79% reduction), but not with the cocktail composed of GRA1 and ROP2. In low dose single-gene vaccinations, IFN-, and strong protection could only be elicited by GRA7. Hence, the presence of GRA7 in the DNA vaccine formulation was important for optimal protection and this was correlated with GRA7-specific IFN-, production. We propose GRA7 as a main component in cocktail DNA vaccines for vaccination against T. gondii. [source]

Inhibitory effects of Keishi-bukuryo-gan on free radical induced lysis of rat red blood cells

PHYTOTHERAPY RESEARCH, Issue 4 2002
Nobuyasu Sekiya
Abstract Keishi-bukuryo-gan (KBG) prevents the progression of atherosclerosis in cholesterol-fed rabbits by its antioxidative effect. The present study was to test our hypothesis that ingestion of KBG would protect red blood cell (RBC) membranes from free radical induced oxidation if polyphenolic antioxidants in KBG could be absorbed and circulated in the blood. When incubated with a RBC suspension, KBG and four of five herb medicines constituting KBG provided strong protection for RBC membranes against haemolysis induced by 2,2-azo-bis (2-amidinopropane) dihydrochloride (AAPH), an azo free radical initiator. The inhibitory effect was dose dependent at concentrations of 100,1000 ,g/mL. Furthermore, the ingestion of 200,mg of KBG was associated with a significant decrease in susceptibility of RBC to haemolysis in rats. Copyright © 2002 John Wiley & Sons, Ltd. [source]

SRFR1, a suppressor of effector-triggered immunity, encodes a conserved tetratricopeptide repeat protein with similarity to transcriptional repressors

THE PLANT JOURNAL, Issue 1 2009
Soon Il Kwon
Summary Effector-triggered immunity provides plants with strong protection from pathogens. However, this response has the potential to be highly deleterious to the host and needs to be tightly controlled. The molecular mechanisms in the plant that regulate the balance between activation and suppression of resistance are not fully understood. Previously, we identified Arabidopsis suppressor of rps4-RLD 1 (srfr1) mutants with enhanced resistance to the bacterial effector AvrRps4. These mutants were recessive and retained full susceptibility to virulent bacteria, suggesting that SRFR1 functions as a negative regulator and that AvrRps4-triggered immunity was specifically enhanced in the mutants. Consistent with this, we show here that the response to flagellin, an elicitor of basal resistance, is unaltered in srfr1-1. In contrast, resistance to AvrRps4 in srfr1-1 requires EDS1, a central regulator of effector-triggered immunity via multiple resistance genes. SRFR1 is a single-copy gene encoding a pioneer tetratricopeptide repeat protein conserved between plants and animals. The SRFR1 tetratricopeptide repeat domain shows sequence similarity to those of transcriptional repressors in Saccharomyces cerevisiae and Caenorhabditis elegans. Indeed, a sub-pool of SRFR1 transiently expressed in Nicotiana benthamiana leaf cells localizes to the nucleus. Identification of SRFR1 may therefore provide insight into the regulation of the transcriptional reprogramming that is activated by effector-triggered immunity. [source]

Association of the interleukin-23 receptor gene variant rs11209026 with Crohn's disease in German children

ACTA PAEDIATRICA, Issue 5 2010
M Lacher
Abstract Aim:, Genome-wide association studies have described variants within the interleukin-23 receptor (IL23R) locus to be associated with Crohn's disease (CD) and ulcerative colitis (UC). We investigated the association of rs11209026 (p.Arg381Gln) and rs7517847 (c.799-3588T>G) into German paediatric inflammatory bowel disease (IBD) patients and analysed IL23R transcriptional activity in colonic tissues. Methods:, The rs11209026 and rs7517847 nucleotide substitutions were determined in 353 German children with IBD (221 CD, 132 UC) and 253 controls using pre-designed TaqMan® SNP genotyping assays. In selected IBD patients and controls, IL23R mRNA expression was measured using real-time PCR. Results:, The prevalence of the rs11209026 A allele was lower in CD patients, but not in UC patients, when compared with controls (1.8% vs 7.1%, p < 0.01). The rs7517847 variant, in contrast, was associated neither with CD nor with UC. IL23R expression was variable in IBD patients compared with controls without significant overexpression or downregulation. Conclusion:, Our study provides additional support for the strong protection of the rs11209026 (p.Arg381Gln) variant against paediatric CD. IL23R was expressed in both CD and UC with a great variability. However, expression levels showed no significant association with the disease. [source]