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131.
132.
Wouter L. W. Hazenbos Kimberly K. Kajihara Richard Vandlen J. Hiroshi Morisaki Sophie M. Lehar Mark J. Kwakkenbos Tim Beaumont Arjen Q. Bakker Qui Phung Lee R. Swem Satish Ramakrishnan Janice Kim Min Xu Ishita M. Shah Binh An Diep Tao Sai Andrew Sebrell Yana Khalfin Angela Oh Chris Koth S. Jack Lin Byoung-Chul Lee Magnus Strandh Klaus Koefoed Peter S. Andersen Hergen Spits Eric J. Brown Man-Wah Tan Sanjeev Mariathasan 《PLoS pathogens》2013,9(10)
Infection of host tissues by Staphylococcus aureus and S. epidermidis requires an unusual family of staphylococcal adhesive proteins that contain long stretches of serine-aspartate dipeptide-repeats (SDR). The prototype member of this family is clumping factor A (ClfA), a key virulence factor that mediates adhesion to host tissues by binding to extracellular matrix proteins such as fibrinogen. However, the biological siginificance of the SDR-domain and its implication for pathogenesis remain poorly understood. Here, we identified two novel bacterial glycosyltransferases, SdgA and SdgB, which modify all SDR-proteins in these two bacterial species. Genetic and biochemical data demonstrated that these two glycosyltransferases directly bind and covalently link N-acetylglucosamine (GlcNAc) moieties to the SDR-domain in a step-wise manner, with SdgB appending the sugar residues proximal to the target Ser-Asp repeats, followed by additional modification by SdgA. GlcNAc-modification of SDR-proteins by SdgB creates an immunodominant epitope for highly opsonic human antibodies, which represent up to 1% of total human IgG. Deletion of these glycosyltransferases renders SDR-proteins vulnerable to proteolysis by human neutrophil-derived cathepsin G. Thus, SdgA and SdgB glycosylate staphylococcal SDR-proteins, which protects them against host proteolytic activity, and yet generates major eptopes for the human anti-staphylococcal antibody response, which may represent an ongoing competition between host and pathogen. 相似文献
133.
Tomohiro Nishimura Shinya Sato Wittaya Tawong Hiroshi Sakanari Keita Uehara Md Mahfuzur Rahman Shah Shoichiro Suda Takeshi Yasumoto Yohsuke Taira Haruo Yamaguchi Masao Adachi 《PloS one》2013,8(4)
Background
The marine epiphytic dinoflagellate genus Gambierdiscus produce toxins that cause ciguatera fish poisoning (CFP): one of the most significant seafood-borne illnesses associated with fish consumption worldwide. So far, occurrences of CFP incidents in Japan have been mainly reported in subtropical areas. A previous phylogeographic study of Japanese Gambierdiscus revealed the existence of two distinct phylotypes: Gambierdiscus sp. type 1 from subtropical and Gambierdiscus sp. type 2 from temperate areas. However, details of the genetic diversity and distribution for Japanese Gambierdiscus are still unclear, because a comprehensive investigation has not been conducted yet.Methods/Principal Finding
A total of 248 strains were examined from samples mainly collected from western and southern coastal areas of Japan during 2006–2011. The SSU rDNA, the LSU rDNA D8–D10 and the ITS region were selected as genetic markers and phylogenetic analyses were conducted. The genetic diversity of Japanese Gambierdiscus was high since five species/phylotypes were detected: including two reported phylotypes (Gambierdiscus sp. type 1 and Gambierdiscus sp. type 2), two species of Gambierdiscus (G. australes and G. cf. yasumotoi) and a hitherto unreported phylotype Gambierdiscus sp. type 3. The distributions of type 3 and G. cf. yasumotoi were restricted to the temperate and the subtropical area, respectively. On the other hand, type 1, type 2 and G. australes occurred from the subtropical to the temperate area, with a tendency that type 1 and G. australes were dominant in the subtropical area, whereas type 2 was dominant in the temperate area. By using mouse bioassay, type 1, type 3 and G. australes exhibited mouse toxicities.Conclusions/Significance
This study revealed a surprising diversity of Japanese Gambierdiscus and the distribution of five species/phylotypes displayed clear geographical patterns in Japanese coastal areas. The SSU rDNA and the LSU rDNA D8–D10 as genetic markers are recommended for further use. 相似文献134.
Megha Kaushik Chen Yu Wang Michael H. Barnett Raymond Garrick John Parratt Stuart L. Graham Prema Sriram Con Yiannikas Alexandr Klistorner 《PloS one》2013,8(10)
Aim
To examine the relationship between retinal ganglion cell loss and changes in the inner nuclear layer (INL) in optic neuritis (ON).Methods
36 multiple sclerosis (MS) patients with a history of ON and 36 age and sex-matched controls underwent Optical Coherence Tomography. The paramacular retinal nerve fiber layer (RNFL), combined ganglion cell and inner plexiform layers (GCL/IPL) and inner nuclear layer (INL) thickness were measured at 36 points around the fovea. To remove inter-subject variability, the difference in thickness of each layer between the ON and fellow eye of each patient was calculated. A topographic analysis was conducted.Results
The INL of the ON patients was thicker than the controls (42.9µm versus 39.6µm, p=0.002). ON patients also had a thinner RNFL (27.8µm versus 32.2µm, p<0.001) and GCL/IPL (69.3µm versus 98.1µm, p<0.001). Among the controls, there was no correlation between RNFL and GCL/IPL as well as RNFL and INL, but a positive correlation was seen between GCL/IPL and INL (r=0.65, p<0.001). In the ON group, there was a positive correlation between RNFL and GCL/IPL (r=0.80, p<0.001) but a negative correlation between RNFL and INL (r=-0.61, p<0.001) as well as GCL/IPL and INL (r=-0.44, p=0.007). The negative correlation between GCL/IPL and INL strengthened in the ON group when inter-subject variability was removed (r=-0.75, p<0.001). Microcysts within the INL were present in 5 ON patients, mainly in the superior and infero-nasal paramacular regions. While patients with microcysts lay at the far end of the correlation curve between GCL/IPL and INL (i.e. larger INL and smaller GCL/IPL compared to other patients), their exclusion did not affect the correlation (r= -0.76, p<0.001).Conclusions
INL enlargement in MS-related ON is associated with the severity of GCL loss. This is a continuous relationship and patients with INL microcysts may represent the extreme end of the scale. 相似文献135.
<i>Aspergillus tubingensis</i> Causes Leaf Spot of Cotton (<i>Gossypium hirsutum</i> L.) in Pakistan
Maria Khizar Urooj Haroon Musrat Ali Samiah Arif Iftikhar Hussain Shah Hassan Javed Chaudhary Muhammad Farooq Hussain Munis 《Phyton》2020,89(1):103-109
Cotton (Gossypium hirsutum L.) is a key fiber crop of great commercial
importance. Numerous phytopathogens decimate crop production by causing
various diseases. During July-August 2018, leaf spot symptoms were recurrently
observed on cotton leaves in Rahim Yar Khan, Pakistan and adjacent areas. Infected
leaf samples were collected and plated on potato dextrose agar (PDA) media.
Causal agent of cotton leaf spot was isolated, characterized and identified as
Aspergillus tubingensis based on morphological and microscopic observations.
Conclusive identification of pathogen was done on the comparative molecular
analysis of CaM and β-tubulin gene sequences. BLAST analysis of both sequenced
genes showed 99% similarity with A. tubingensis. Koch’s postulates were followed
to confirm the pathogenicity of the isolated fungus. Healthy plants were inoculated
with fungus and similar disease symptoms were observed. Fungus was re-isolated
and identified to be identical to the inoculated fungus. To our knowledge, this is the
first report describing the involvement of A. tubingensis in causing leaf spot disease
of cotton in Pakistan and around the world. 相似文献
136.
137.
Kamal Osama M. Shah Sayyed Hamad Ahmad Li Yan Hou Xilin Li Ying 《Molecular biology reports》2020,47(9):6887-6897
Molecular Biology Reports - The objective of the present work was the selection of cultivar, suitable medium and explant type for callus, root production, ascorbic acid, total ascorbic acid,... 相似文献
138.
Mohammad Badrul Anam Shah Adil Ishtiyaq Ahmad Mikiko Kudo Arif Istiaq Athary Abdulhaleem M. Felemban Naofumi Ito Kunimasa Ohta 《Development, growth & differentiation》2020,62(2):97-107
Specialized microenvironment, or neurogenic niche, in embryonic and postnatal mouse brain plays critical roles during neurogenesis throughout adulthood. The subventricular zone (SVZ) and the dentate gyrus (DG) of hippocampus in the mouse brain are two major neurogenic niches where neurogenesis is directed by numerous regulatory factors. Now, we report Akhirin (AKH), a stem cell maintenance factor in mouse spinal cord, plays a pivotal regulatory role in the SVZ and in the DG. AKH showed specific distribution during development in embryonic and postnatal neurogenic niches. Loss of AKH led to abnormal development of the ventricular zone and the DG along with reduction of cellular proliferation in both regions. In AKH knockout mice (AKH−/−), quiescent neural stem cells (NSCs) increased, while proliferative NSCs or neural progenitor cells decreased at both neurogenic niches. In vitro NSC culture assay showed increased number of neurospheres and reduced neurogenesis in AKH−/−. These results indicate that AKH, at the neurogenic niche, exerts dynamic regulatory role on NSC self-renewal, proliferation and differentiation during SVZ and hippocampal neurogenesis. 相似文献
139.
Aman Shah Abdul Majid Amin Malik Shah Abdul Majid Zheng Qin Yin Dan Ji 《Neurochemical research》2013,38(7):1375-1393
Hydrogen sulphide (H2S) is one of three gaseous signaling molecules after nitric oxide and carbon monoxide. Various H2S donor compounds have been synthesized to study its physiological function. Among these compounds sodium hydrosulphide (NaHS), a donor of releasing H2S rapidly have shown to be protective in certain neuronal cell line but several in vivo studies have generated conflicting data. Furthermore several slow releasing H2S donors have been shown to have positive effects on cells in culture. The intracellular concentration of H2S and hence its rate of production may be a factor in keeping the balance between its neuroprotective and toxic effects. The present study was undertaken to deduce how a rapid releasing H2S donor (NaHS) as opposed to a slow releasing donor (ADTOH), affect oxidative stress related intracellular components and survival of RGC-5 cells. It was concluded that when RGC-5 cells are exposed to the toxic effects of glutamate in combination with buthionine sulfoxime (Glu/BSO), ADTOH was more efficacious in inhibiting apoptosis, scavenging reactive oxygen species (ROS), stimulation of glutathione (GSH) and gluthathione-S-transferase (GST). Western blot and qPCR analysis showed ADTOH increased the levels of Nrf2, HO-1, PKCα, p-Akt, Bcl-2 and XIAP but caused a decrease of Nfκβ and xCT greater than NaHS. This study is first to compare the efficacy of two H2S donor drugs as potential neuroprotectants and demonstrate that slow regulated release of H2S to cell culture can be more beneficial in inhibiting oxidative stress induced cell death. 相似文献
140.
Don Vu Prashant Sakharkar Eglis Tellez-Corrales Tariq Shah Ian Hutchinson David I. Min 《Molecular biology reports》2013,40(2):933-939
Polymorphism of genes encoding components of the vitamin D pathway including vitamin D receptor (VDR) and vitamin D binding protein (VDBP), have been widely explored due to the complex role played by vitamin D in renal transplant outcomes. In this study, we investigated whether polymorphisms of genes encoding VDR and VDBP were associated with allograft survival or acute rejection (AR) among a Hispanic kidney transplant population. A total of 502 Hispanic renal allograft recipients at the St. Vincent Medical Center between 2001 and 2010 were genotyped for four different single nucleotide polymorphisms of VDR: FokI C>T (rs2228570), BsmI G>A (rs1544410), ApaI T>G (rs7975232), and TaqI T>C (rs731236). We also performed genotyping for one common polymorphism in the VDBP gene (rs4588). Survival was significantly improved for patients who were homozygous GG for the rs4588 G>T allele in the VDBP gene (GG vs. GT + TT, OR = 0.63, p = 0.02) while GT genotype was associated with a higher risk of graft loss (GT vs. GG + TT, OR = 1.67, p = 0.01). We found no association for polymorphic markers in VDR with allograft survival and AR. The frequency of the haplotype GTCG (in the order of VDR FokI C>T, BsmI G>A, ApaI T>G, and TaqI T>C), was significantly different in the patients with graft rejection compared to the control (p = 0.007) while ACCA haplotype was found to be associated with graft loss (p = 0.02). Hence, the VDBP G>T polymorphism (rs4588) and two haplotypes (GTCG and ACCA) of VDR appear to be associated with renal allograft outcomes among Hispanic allograft recipients. 相似文献