排序方式: 共有49条查询结果,搜索用时 15 毫秒
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Ahmad S Yousuf S Ishrat T Khan MB Bhatia K Fazli IS Khan JS Ansari NH Islam F 《Life sciences》2006,79(20):1921-1928
Oxidative stress may be regarded as an imbalance between free radical production and opposing antioxidant defenses. Free radical oxidative stress is implicated in rat cerebral ischemia and naturaceutical antioxidants are dietary supplements that have been reported to have neuroprotective activity. Many studies have reported dietary sesame oil (SO) as an effective antioxidant. In the present study the neuroprotective effect of dietary SO was evaluated against middle cerebral artery occlusion (MCAO)-induced cerebral ischemia injury in rats. Rats were fed on diet (20% SO) for 15 days. The middle cerebral artery of adult male Wistar rat was occluded for 2 h and reperfused for 22 h. The antioxidant properties of brain were measured as levels of reduced glutathione (GSH), glutathione-S-transferase (GST), glutathione peroxide (GPx), glutathione reductase (GR), catalase (CAT), superoxide dismutase (SOD) and thiobarbituric acid reactive substance (TBARS). A decrease in the activity of all the enzymatic and non-enzymatic antioxidants was observed along with an increase in lipid peroxidation (LPO) in MCAO group. The neurobehavioral activity of rats was also observed by using videopath analyzer. Dietary SO improved the antioxidant status in MCAO+SO group when compared with MCAO group. The results of neurobehavioral activity also support our biochemical data. The results obtained suggest protective effect of SO against cerebral ischemia in rat brain through their antioxidant properties. 相似文献
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Yong He Robert Fisher Soma Chowdhury Ishrat Sultana Claudia P. Pereira Mike Bray Jennifer L. Reed 《PloS one》2014,9(11)
Rationale
Humans with a dominant negative mutation in STAT3 are susceptible to severe skin infections, suggesting an essential role for STAT3 signaling in defense against cutaneous pathogens.Methods
To focus on innate antiviral defenses in keratinocytes, we used a standard model of cutaneous infection of severe combined immunodeficient mice with the current smallpox vaccine, ACAM-2000. In parallel, early events post-infection with the smallpox vaccine ACAM-2000 were investigated in cultured keratinocytes of human and mouse origin.Results
Mice treated topically with a STAT3 inhibitor (Stattic) developed larger vaccinia lesions with higher virus titers and died more rapidly than untreated controls. Cultured human and murine keratinocytes infected with ACAM-2000 underwent rapid necrosis, but when treated with Stattic or with inhibitors of RIP1 kinase or caspase-1, they survived longer, produced higher titers of virus, and showed reduced activation of type I interferon responses and inflammatory cytokines release. Treatment with inhibitors of RIP1 kinase and STAT3, but not caspase-1, also reduced the inflammatory response of keratinocytes to TLR ligands. Vaccinia growth properties in Vero cells, which are known to be defective in some antiviral responses, were unaffected by inhibition of RIP1K, caspase-1, or STAT3.Conclusions
Our findings indicate that keratinocytes suppress the replication and spread of vaccinia virus by undergoing rapid programmed cell death, in a process requiring STAT3. These data offer a new framework for understanding susceptibility to skin infection in patients with STAT3 mutations. Interventions which promote prompt necroptosis/pyroptosis of infected keratinocytes may reduce risks associated with vaccination with live vaccinia virus. 相似文献4.
Growth performance, chromium (Cr) accumulation potential and induction of antioxidative defence system and phytochelatins
(PCs) were studied in hydroponically grown Brassica juncea (Indian mustard) and Vigna radiata (mungbean) at various levels of Cr treatments (0, 50, 100, 200 μM Cr). B. juncea accumulated twofolds and threefolds higher Cr in root and shoot, respectively than in V. radiata. Compared to B. juncea, V. radiata was found to be particularly sensitive to Cr as observed by the severity and development of Cr toxicity symptoms and decreased
growth. Induction of PC and enzymes of antioxidant defence system were monitored as plant’s primary and secondary metal detoxifying
responses, respectively. There was induction of PC and enzymes of antioxidant defence system in both the plants. PCs were
induced significantly in roots and shoot of both the plants at all the levels of Cr treatments. Significantly higher activities
of superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and glutathione reductase (GR) were observed in
shoot of B. juncea than V. radiata at all the levels of Cr treatments. Induction of PCs along with antioxidant defence system in response to Cr stress suggests
the cumulative role of PCs and antioxidants in conferring tolerance against accumulated Cr in B. juncea, and thereby signifies the suitability of this plant as one of the potential remediators of Cr. 相似文献
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Bihl F Frahm N Di Giammarino L Sidney J John M Yusim K Woodberry T Sango K Hewitt HS Henry L Linde CH Chisholm JV Zaman TM Pae E Mallal S Walker BD Sette A Korber BT Heckerman D Brander C 《Journal of immunology (Baltimore, Md. : 1950)》2006,176(7):4094-4101
Immunodominance is variably used to describe either the most frequently detectable response among tested individuals or the strongest response within a single individual, yet factors determining either inter- or intraindividual immunodominance are still poorly understood. More than 90 individuals were tested against 184 HIV- and 92 EBV-derived, previously defined CTL epitopes. The data show that HLA-B-restricted epitopes were significantly more frequently recognized than HLA-A- or HLA-C-restricted epitopes. HLA-B-restricted epitopes also induced responses of higher magnitude than did either HLA-A- or HLA-C-restricted epitopes, although this comparison only reached statistical significance for EBV epitopes. For both viruses, the magnitude and frequency of recognition were correlated with each other, but not with the epitope binding affinity to the restricting HLA allele. The presence or absence of HIV coinfection did not impact EBV epitope immunodominance patterns significantly. Peptide titration studies showed that the magnitude of responses was associated with high functional avidity, requiring low concentration of cognate peptide to respond in in vitro assays. The data support the important role of HLA-B alleles in antiviral immunity and afford a better understanding of the factors contributing to inter- and intraindividual immunodominance. 相似文献
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Ancuta P Autissier P Wurcel A Zaman T Stone D Gabuzda D 《Journal of immunology (Baltimore, Md. : 1950)》2006,176(10):5760-5771
The CD16(+) monocyte (Mo) subset produces proinflammatory cytokines and is expanded in peripheral blood during progression to AIDS, but its contribution to HIV pathogenesis is unclear. In this study, we investigate the capacity of human CD16(+) and CD16(-) Mo subsets to render resting CD4(+) T cells permissive for HIV replication. We demonstrate that CD16(+) Mo preferentially differentiate into macrophages (Mphi) that activate resting T cells for productive HIV infection by producing the CCR3 and CCR4 ligands CCL24, CCL2, CCL22, and CCL17. CD16(+), but not CD16(-), Mo-derived Mphi from HIV-infected and -uninfected individuals constitutively produce CCL24 and CCL2. Furthermore, these chemokines stimulate HIV replication in CD16(-) Mo:T cell cocultures. Engagement of CCR3 and CCR4 by CCL24 and CCL2, respectively, along with stimulation via CD3/CD28, renders T cells highly permissive for productive HIV infection. Moreover, HIV replicates preferentially in CCR3(+) and CCR4(+) T cells. These findings reveal a new pathway of T cell costimulation for increased susceptibility to HIV infection via engagement of CCR3 and CCR4 by chemokines constitutively produced by CD16(+) Mo/Mphi. Thus, expansion of CD16(+) Mo in peripheral blood of HIV-infected patients and their subsequent recruitment into tissues may contribute to chronic immune activation and establishment of viral reservoirs in resting T cells. 相似文献
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Yamazaki H Naito M Ghani FI Dang NH Iwata S Morimoto C 《Biochemical and biophysical research communications》2012,419(3):529-536
Malignant mesothelioma (MM) is an asbestos-related malignancy characterized by rapid growth and poor prognosis. In our previous study, we have demonstrated that several cancer stem cell (CSC) markers correlated with CSC properties in MM cells. Among these markers, we focused on two: CD24, the common CSC marker, and CD26, the additional CSC marker. We further analyzed the CSC properties of CD24 and CD26-positve MM cells. We established RNAi-knockdown cells and found that these markers were significantly correlated with chemoresistance, proliferation, and invasion potentials in vitro. Interestingly, while Meso-1 cells expressed both CD24 and CD26, the presence of each of these two markers was correlated with different CSC property. In addition, downstream signaling of these markers was explored by microarray analysis, which revealed that their expressions were correlated with several cancer-related genes. Furthermore, phosphorylation of ERK by EGF stimulation was significantly affected by the expression of CD26, but not CD24. These results suggest that CD24 and CD26 differentially regulate the CSC potentials of MM and could be promising targets for CSC-oriented therapy. 相似文献
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Manoucher Shahamat Morris Levin Ishrat Rahman Christopher Grim John Heidelberg Gerard Stelma Rita Colwell 《Aerobiologia》1997,13(4):219-226
Disease transmission by airborne bacteria is well known. Bacterial burden in indoor air is estimated by sampling the air and
estimating Colony Forming Units (CFU) using a variety of media. In this study, the recovery of bacteria, after aerosolization
in an aerosol chamber, and employing a variety of media, was compared to that achieved using Tryptic Soy Agar medium. The
total number of cells present was determined by direct microscopy. All trials were conducted at approximately the same relative
humidity (RH) and temperature using the same collection device. Twelve species of bacteria were tested and a total of 120
media or media combinations were evaluated. Recovery on 64 media formulations was significantly lower for all strains examined,
and therefore, excluded from further consideration for the purposes of this study. Data for 56 of the media are presented.
Three species (Bacillus subtilis, Staphylococcus aureus andSerratia marcescens) were selected as representative for reporting and testing recovery success. It is concluded that, for the media included
in the study, there are large differences in recovery and successful recovery is related both to the effect of aerosolization
and the type of medium employed for recovery. Brain Heart Infusion Agar (with horse serum), Tryptic Soy Agar and Mueller Hinton
Agar yielded the best recoveries of aerosolized cultures. The most important finding was that only a small fraction of the
airborne bacterial populations, enumerated by direct microscopy, could be recovered on any of the media tested, suggesting
that culturable bacterial count is not a satisfactory means of estimating air microbial pollution. 相似文献
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Jannah Tauheed Marco Sanchez-Guerra Jane J. Lee Ligi Paul Md Omar Sharif Ibne Hasan Quazi Quamruzzaman 《Epigenetics》2017,12(6):484-491
Arsenic exposure may contribute to disease risk in humans through alterations in the epigenome. Previous studies reported that arsenic exposure is associated with changes in plasma histone concentrations. Posttranslational histone modifications have been found to differ between the brain tissue of human embryos with neural tube defects and that of controls. Our objectives were to investigate the relationships between plasma histone 3 levels, history of having an infant with myelomeningocele, biomarkers of arsenic exposure, and maternal folate deficiency. These studies took place in Bangladesh, a country with high environmental arsenic exposure through contaminated drinking water. We performed ELISA assays to investigate plasma concentration of total histone 3 (H3) and the histone modification H3K27me3. The plasma samples were collected from 85 adult women as part of a case-control study of arsenic and myelomeningocele risk in Bangladesh. We found significant associations between plasma %H3K27me3 levels and risk of myelomeningocele (P<0.05). Mothers with higher %H3K27me3 in their plasma had lower risk of having an infant with myelomeningocele (odds ratio: 0.91, 95% confidence interval: 0.84, 0.98). We also found that arsenic exposure, as estimated by arsenic concentration in toenails, was associated with lower total H3 concentrations in plasma, but only among women with folate deficiency (β = ?9.99, standard error = 3.91, P=0.02). Our results suggest that %H3K27me3 in maternal plasma differs between mothers of infants with myelomeningocele and mothers of infants without myelomeningocele, and may be a marker for myelomeningocele risk. Women with folate deficiency may be more susceptible to the epigenetic effects of environmental arsenic exposure. 相似文献