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131.
Amna Al-Otaiba Annie John Thekra Al-Belooshi Haider Raza 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2010,180(8):1121-1132
We have previously reported the occurrence of multiple forms of drug-metabolizing enzymes in camel tissues. Here, we investigate
glutathione (GSH)-dependent redox homeostasis, reactive oxygen species (ROS) production and mitochondrial respiratory functions
in camel tissues and compare them with imported domestic goats and laboratory rats and mice. Cytochrome P450 2E1 (CYP 2E1)
and GSH-metabolizing enzymes were differentially expressed in the liver and kidney of these animals. Camel liver has significantly
lower GSH pool than that in goats, rats and mice. Mitochondria isolated from the tissues of these animals showed a comparable
ability to metabolize specific substrates for respiratory enzyme complexes I, II/III and IV. These complexes were metabolically
more active in the kidney than in the liver of all the species. Furthermore, the activity of complex IV in camel tissues was
significantly lower than in other species. On the other hand, complex II/III activity in camel kidney was higher compared
to the other species. In addition, as expected, we observed that inhibitors of these enzyme complexes augment the production
of mitochondrial ROS in camel and goat tissues. These results help to better understand the metabolic ability and adaptation
in desert camels in comparison with domestic goats and laboratory rats and mice since they are exposed to different environmental
and dietary conditions. Our study may also have implications in the pharmacology and toxicology of drugs and pollutants in
these species. 相似文献
132.
Marina L Kozak Alejandro Chavez Weiwei Dang Shelley L Berger Annie Ashok Xiaoge Guo F Brad Johnson 《The EMBO journal》2010,29(1):158-170
Changes in telomere chromatin have been linked to cellular senescence, but the underlying mechanisms and impact on lifespan are unclear. We found that inactivation of the Sas2 histone acetyltransferase delays senescence in Saccharomyces cerevisiae telomerase (tlc1) mutants through a homologous recombination‐dependent mechanism. Sas2 acetylates histone H4 lysine 16 (H4K16), and telomere shortening in tlc1 mutants was accompanied by a selective and Sas2‐dependent increase in subtelomeric H4K16 acetylation. Further, mutation of H4 lysine 16 to arginine, which mimics constitutively deacetylated H4K16, delayed senescence and was epistatic to sas2 deletion, indicating that deacetylated H4K16 mediates the delay caused by sas2 deletion. Sas2 normally prevents the Sir2/3/4 heterochromatin complex from leaving the telomere and spreading to internal euchromatic loci. Senescence was delayed by sir3 deletion, but not sir2 deletion, indicating that senescence delay is mediated by release of Sir3 specifically from the telomere repeats. In contrast, sir4 deletion sped senescence and blocked the delay conferred by sas2 or sir3 deletion. We thus show that manipulation of telomere chromatin modulates senescence caused by telomere shortening. 相似文献
133.
Ja-an Annie Ho Li-Chen Wu Li-Hui Chang Kuo-Chu Hwang Jih-Ru Reuben Hwu 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2010,878(2):172-176
Immunoglobulin E (IgE)-mediated type I allergies affect over 25% of the world's population; they are among the most common diseases in developed countries. Therefore, simple and rapid in vivo and in vitro methods for diagnosing allergies are becoming increasingly important. In this paper, we demonstrate the feasibility of using sulforhodamine B, a fluorescent dye, entrapped inside immunoliposomes, the outer surfaces of which were sensitized with IgE, as a signal amplifier for the development of a simple, rapid, and inexpensive colorimetric affinity chromatographic immunoassay for the detection of total IgE in serum. This assay operates based on competition between standards (or human serum samples) containing IgE and IgE-sensitized immunoliposomes for the limited number of antigen binding sites of immobilized anti-IgE antibodies at the antigen capture (AC) zone on the nitrocellulose membranes. The color density of the AC zone is indirectly proportional to the number of IgE units present in the test sample. The detection limit of this liposome-based immunoaffinity chromatographic assay was 0.37 ng in IgE-free serum solution (equivalent to 20 μL of a 18.5 ng mL−1 solution). A commercially available ELISA kit was used as a reference method to validate the proposed assay through the analysis of three human serum samples. 相似文献
134.
Th-cytotoxic T-lymphocyte chimeric epitopes extended by Nepsilon-palmitoyl lysines induce herpes simplex virus type 1-specific effector CD8+ Tc1 responses and protect against ocular infection 总被引:1,自引:0,他引:1 下载免费PDF全文
Zhang X Issagholian A Berg EA Fishman JB Nesburn AB BenMohamed L 《Journal of virology》2005,79(24):15289-15301
Molecularly defined vaccine formulations capable of inducing antiviral CD8+ T-cell-specific immunity in a manner compatible with human delivery are limited. Few molecules achieve this target without the support of an appropriate immunological adjuvant. In this study, we investigate the potential of totally synthetic palmitoyl-tailed helper-cytotoxic-T-lymphocyte chimeric epitopes (Th-CTL chimeric lipopeptides) to induce herpes simplex virus type 1 (HSV-1)-specific CD8+ T-cell responses. As a model antigen, the HSV-1 glycoprotein B498-505 (gB498-505) CD8+ CTL epitope was synthesized in line with the Pan DR peptide (PADRE), a universal CD4+ Th epitope. The peptide backbone, composed solely of both epitopes, was extended by N-terminal attachment of one (PAM-Th-CTL), two [(PAM)2-Th-CTL], or three [(PAM)3-Th-CTL] palmitoyl lysines and delivered to H2b mice in adjuvant-free saline. Potent HSV-1 gB498-505-specific antiviral CD8+ T-cell effector type 1 responses were induced by each of the palmitoyl-tailed Th-CTL chimeric epitopes, irrespective of the number of lipid moieties. The palmitoyl-tailed Th-CTL chimeric epitopes provoked cell surface expression of major histocompatibility complex and costimulatory molecules and production of interleukin-12 and tumor necrosis factor alpha proinflammatory cytokines by immature dendritic cells. Following ocular HSV-1 challenge, palmitoyl-tailed Th-CTL-immunized mice exhibited a decrease of virus replication in the eye and in the local trigeminal ganglion and reduced herpetic blepharitis and corneal scarring. The rational of the molecularly defined vaccine approach presented in this study may be applied to ocular herpes and other viral infections in humans, providing steps are taken to include appropriate Th and CTL epitopes and lipid groups. 相似文献
135.
Gilbert G. G. Donders Christophe E. Depuydt John-Paul Bogers Annie J. Vereecken 《PloS one》2013,8(12)
Objective
Is Trichomonas vaginalis (TV) an inducing factor for the development of (pre-)cancerous lesions of the cervix?Design
Cross sectional study.Setting
Screening healthy Belgian women with low infection risk.Sample
63,251 consecutive liquid based cervical samples.Methods
Real time quantitative PCR for presence of TV, 18 HPV types and Pap smear analysis of cytologic abnormalities.Main Outcome Measures
Association of TV and HPV with cervix dysplasiaResults
The overall prevalence of TV DNA was 0.37%, of low risk HPV 2%, of high risk HPV 13.2%, and 8.8 % had cytological abnormalities. Both LR-HPV and HR-HPV were significantly associated with all cytological abnormalities. Presence of TV was associated with LR- and HR-HPV, ASC-US and HSIL, but not with other abnormalities. All women with TV and HSIL also had HR-HPV, while the latter was present in only 59% of women with TV and ASC-US. Amongst HPV negative women, TV was found in 1.3% of women with ASC-US, but only in 0.03% of women with normal cytology (OR 4.2, CL95% 2.1-8.6). In HR-HPV positive women, presence of TV increased the likelihood of cytological abnormalities somewhat (P=0.05), mainly due to an increase in ASC-US and LSIL, but not HSIL.Conclusions
We conclude that TV infection is associated with both LR and HR-HPV infection of the cervix, as well as with ASC-US and HSIL. TV is a concomitant STI, but is not thought to be a co-factor in the causation of HSIL and cervical cancer. However, TV may cause false positive diagnoses of ASC-US. 相似文献136.
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139.
Bonavita-Cougourdan A Provost E Riviere G Bagneres AG Dusticier G 《Journal of insect physiology》2004,50(4):285-293
The purpose of this study was to compare cuticular hydrocarbon profiles of slave-making Polyergus rufescens ants reared alone or with their Formica rufibarbis slaves. Chemical analyses showed that due to the close contacts occurring when the Formica were tending the Polyergus, the synthesis of the cuticular hydrocarbons carried by the slaves was enhanced in the slave-makers. The postpharyngeal hydrocarbon levels increased during the first 15 days of life, whether or not the Polyergus were exposed to Formica. Our findings suggest that Polyergus is able to secrete all components of their cuticular hydrocarbon blend and that none are acquired through contact with Formica. In addition to presenting our experimental evidence, several hypotheses are proposed to explain the synthesis and regulation of hydrocarbon blends borne when these two species cohabitate within a single colony. 相似文献
140.
NO and CO differentially activate soluble guanylyl cyclase via a heme pivot-bend mechanism 下载免费PDF全文
Diatomic ligand discrimination by soluble guanylyl cyclase (sGC) is paramount to cardiovascular homeostasis and neuronal signaling. Nitric oxide (NO) stimulates sGC activity 200-fold compared with only four-fold by carbon monoxide (CO). The molecular details of ligand discrimination and differential response to NO and CO are not well understood. These ligands are sensed by the heme domain of sGC, which belongs to the heme nitric oxide oxygen (H-NOX) domain family, also evolutionarily conserved in prokaryotes. Here we report crystal structures of the free, NO-bound, and CO-bound H-NOX domains of a cyanobacterial homolog. These structures and complementary mutational analysis in sGC reveal a molecular ruler mechanism that allows sGC to favor NO over CO while excluding oxygen, concomitant to signaling that exploits differential heme pivoting and heme bending. The heme thereby serves as a flexing wedge, allowing the N-terminal subdomain of H-NOX to shift concurrent with the transition of the six- to five-coordinated NO-bound state upon sGC activation. This transition can be modulated by mutations at sGC residues 74 and 145 and corresponding residues in the cyanobacterial H-NOX homolog. 相似文献