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Qingwei Luo Firdausi Qadri Rita Kansal David A. Rasko Alaullah Sheikh James M. Fleckenstein 《PLoS neglected tropical diseases》2015,9(1)
BackgroundEnterotoxigenic Escherichia coli (ETEC) are common causes of diarrheal morbidity and mortality in developing countries for which there is currently no vaccine. Heterogeneity in classical ETEC antigens known as colonization factors (CFs) and poor efficacy of toxoid-based approaches to date have impeded development of a broadly protective ETEC vaccine, prompting searches for novel molecular targets.MethodologyUsing a variety of molecular methods, we examined a large collection of ETEC isolates for production of two secreted plasmid-encoded pathotype-specific antigens, the EtpA extracellular adhesin, and EatA, a mucin-degrading serine protease; and two chromosomally-encoded molecules, the YghJ metalloprotease and the EaeH adhesin, that are not specific to the ETEC pathovar, but which have been implicated in ETEC pathogenesis. ELISA assays were also performed on control and convalescent sera to characterize the immune response to these antigens. Finally, mice were immunized with recombinant EtpA (rEtpA), and a protease deficient version of the secreted EatA passenger domain (rEatApH134R) to examine the feasibility of combining these molecules in a subunit vaccine approach.ConclusionsCollectively, these data suggest that novel antigens could significantly complement current approaches and foster improved strategies for development of broadly protective ETEC vaccines. 相似文献
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Antoine G. Almonte Laura H. Qadri Faraz A. Sultan Jennifer A. Watson Daniel J. Mount Gavin Rumbaugh J. David Sweatt 《Journal of neurochemistry》2013,124(1):109-122
Protease‐activated receptor‐1 (PAR1) is an unusual G‐protein coupled receptor (GPCR) that is activated through proteolytic cleavage by extracellular serine proteases. Although previous work has shown that inhibiting PAR1 activation is neuroprotective in models of ischemia, traumatic injury, and neurotoxicity, surprisingly little is known about PAR1's contribution to normal brain function. Here, we used PAR1?/? mice to investigate the contribution of PAR1 function to memory formation and synaptic function. We demonstrate that PAR1?/? mice have deficits in hippocampus‐dependent memory. We also show that while PAR1?/? mice have normal baseline synaptic transmission at Schaffer collateral‐CA1 synapses, they exhibit severe deficits in N‐methyl‐d ‐aspartate receptor (NMDAR)‐dependent long‐term potentiation (LTP). Mounting evidence indicates that activation of PAR1 leads to potentiation of NMDAR‐mediated responses in CA1 pyramidal cells. Taken together, this evidence and our data suggest an important role for PAR1 function in NMDAR‐dependent processes subserving memory formation and synaptic plasticity. 相似文献
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Influence of Temperature of Incubation and Type of Growth Medium on Pigmentation in Serratia marcescens 总被引:16,自引:3,他引:13 下载免费PDF全文
Robert P. Williams Cora L. Gott S. M. Hussain Qadri Randolph H. Scott 《Journal of bacteriology》1971,106(2):438-443
Maximal amounts of prodigiosin were synthesized in either minimal or complete medium after incubation of cultures at 27 C for 7 days. Biosynthesis of prodigiosin began earlier and the range of temperature for formation was greater in complete medium. No prodigiosin was formed in either medium when cultures were incubated at 38 C; however, after a shift to 27 C, pigmentation ensued, provided the period of incubation at 38 C was not longer than 36 hr for minimal medium or 48 hr for complete medium. Washed, nonpigmented cells grown in either medium at 38 C for 72 hr could synthesize prodigiosin when suspended in saline at 27 C when casein hydrolysate was added. These suspensions produced less prodigiosin at a slower rate than did cultures growing in casein hydrolysate at 27 C without prior incubation at 38 C. Optimal concentration of casein hydrolysate for pigment formation by suspensions was 0.4%; optimal temperature was 27 C. Anaerobic incubation, shift back to 38 C, killing cells by heating, or chloramphenicol (25 mug/ml) inhibited pigmentation. Suspensions of washed cells forming pigment reached pH 8.0 to 8.3 rapidly and maintained this pH throughout incubation for 7 days. Measurements of viable count and of protein, plus other data, indicated that cellular multiplication did not occur in suspensions of washed cells during pigment formation. By this procedure utilizing a shift down in temperature, biosynthesis of prodigiosin by washed cells could be separated from multiplication of bacteria. 相似文献
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Iqra Farooq Z.A. Qadri Z.A. Rather Imtiyaz T. Nazki Neelofar Banday Sadaf Rafiq Khalid Z. Masoodi Ahmed Noureldeen Sheikh Mansoor 《Saudi Journal of Biological Sciences》2021,28(7):3701-3709
An efficient protocol for in-vitro propagation of an important ornamental crop, Petunia hybrida Vilm. Cv. “Bravo” was developed. The explants that were used to carry out the experiment were Leaf segments, nodal segments and shoot tips. Nodal segments recorded highest per cent asepsis followed by shoot tips and leaf segments. Asepsis was found to be highest when the explants were sterilized with Fungicide (Carbendazim) 0.02% for the duration of 30 min followed by 0.1% HgCl2 for duration of 10 min and then ethanol 70% for 10 s. Longer duration of the sterilant treatment showed more necrotic effects on the explants, thus mercuric chloride treatment when given for 5 min proved to be more effective in terms of survival of the explants. Maximum establishment per cent was recorded in Murashige and Skoog (MS) media fortified with BAP (1.5 mg L−1) and IBA (0.5 mg L−1) in shoot tips and nodal segments, i.e. 97.90 and 95.74% respectively. Callus was efficiently induced and developed when PGR amalgamation of BAP (0.1 mg L−1) and 2,4-D (1.5mg L−1) was used. Kinetin at the concentration of 2.0 mg L−1 along with IBA at 0.5mg L−1 recorded highest callus regeneration in both leaf and internodal segment derived callus. Maximum proliferation percent of shoots (97.90%), highest number of shoots (20.50 explant−1) and maximum length of shoot (2.70 cm) was recorded in PGR combination of IBA and BAP both at 0.5 mg L−1 concentration level. Rhizogenesis was recorded to be highest in the MS media containing IBA 1.00 mg L−1. Best hardening media which recorded maximum survival per cent 92.50% was noticed on the media formulation comprised of equal ratio of perlite and vermiculite mix, under poly house conditions. 相似文献
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Amjad Ullah Ivana Tlak Gajger Arnold Majoros Showket Ahmad Dar Sanaullah Khan Ayesha Haleem Shah Muhammad Nasir Khabir Riaz Hussain Hikmat Ullah Khan Mehwish Hameed Syed Ishtiaq Anjum 《Saudi Journal of Biological Sciences》2021,28(1):523-530
Honey bee is vital for pollination and ecological services, boosting crops productivity in terms of quality and quantity and production of colony products: wax, royal jelly, bee venom, honey, pollen and propolis. Honey bees are most important plant pollinators and almost one third of diet depends on bee’s pollination, worth billions of dollars. Hence the role that honey bees have in environment and their economic importance in food production, their health is of dominant significance. Honey bees can be infected by various pathogens like: viruses, bacteria, fungi, or infested by parasitic mites. At least more than 20 viruses have been identified to infect honey bees worldwide, generally from Dicistroviridae as well as Iflaviridae families, like ABPV (Acute Bee Paralysis Virus), BQCV (Black Queen Cell Virus), KBV (Kashmir Bee Virus), SBV (Sacbrood Virus), CBPV (Chronic bee paralysis virus), SBPV (Slow Bee Paralysis Virus) along with IAPV (Israeli acute paralysis virus), and DWV (Deformed Wing Virus) are prominent and cause infections harmful for honey bee colonies health. This issue about honey bee viruses demonstrates remarkably how diverse this field is, and considerable work has to be done to get a comprehensive interpretation of the bee virology. 相似文献
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Jonathan D. Sugimoto Amanda A. Koepke Eben E. Kenah M. Elizabeth Halloran Fahima Chowdhury Ashraful I. Khan Regina C. LaRocque Yang Yang Edward T. Ryan Firdausi Qadri Stephen B. Calderwood Jason B. Harris Ira M. Longini Jr. 《PLoS neglected tropical diseases》2014,8(11)