Regulated Intramembrane Proteolysis of the Virulence Activator TCPP in Vibrio cholerae.

In Vibrio cholerae, direct activation of genes that encode cholera toxin (CT) and toxin-coregulated pilus (TCP) requires the ToxT transcription activator, whose expression is regulated by a complex of membrane regulatory proteins including ToxR and TcpP. TcpP, with a cytoplasmic domain similar to that found in OmpR and a periplasmic domain that may respond to specific environmental signals, is degraded in a two-step proteolytic pathway known as regulated intramembrane proteolysis (RIP), which eliminates the expression of CT and TCP. Under specific conditions, degradation is inhibited by another membrane-bound periplasmic protein, TcpH. I applied forward and reverse genetic approaches to determine the site-1 protease of TcpP. Through these analyses, I found that a C-terminal protease called Tsp catalyzes TcpP degradation to a truncated yet still active species that we termed TcpP*, which is the substrate for the previously identified site-2 protease, YaeL. Moreover, my results indicate a role of TcpH in protecting full-length TcpP from spurious degradation by YaeL. I investigate the possibility of RIP regulating steady-state levels of TcpH and present evidence that TcpP confers stability to TcpH. Furthermore, in vivo studies in infant mice suggest that YaeL, but not Tsp, is required for intestinal colonization. These results expand our knowledge about RIP and the unorthodox mechanism of gene activation by membrane-bound transcription factors.PhDMicrobiology and ImmunologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/113400/1/teoh_1.pd

Carbon monoxide-Releasing Molecule-2 (CORM-2) attenuates acute hepatic ischemia reperfusion injury in rats

<p>Abstract</p> <p>Background</p> <p>Hepatic ischemia-reperfusion injury (I/Ri) is a serious complication occurring during liver surgery that may lead to liver failure. Hepatic I/Ri induces formation of reactive oxygen species, hepatocyte apoptosis, and release of pro-inflammatory cytokines, which together causes liver damage and organ dysfunction. A potential strategy to alleviate hepatic I/Ri is to exploit the potent anti-inflammatory and cytoprotective effects of carbon monoxide (CO) by application of so-called CO-releasing molecules (CORMs). Here, we assessed whether CO released from CORM-2 protects against hepatic I/Ri in a rat model.</p> <p>Methods</p> <p>Forty male Wistar rats were randomly assigned into four groups (n = 10). Sham group underwent a sham operation and received saline. I/R group underwent hepatic I/R procedure by partial clamping of portal structures to the left and median lobes with a microvascular clip for 60 minutes, yielding ~70% hepatic ischemia and subsequently received saline. CORM-2 group underwent the same procedure and received 8 mg/kg of CORM-2 at time of reperfusion. iCORM-2 group underwent the same procedure and received iCORM-2 (8 mg/kg), which does not release CO. Therapeutic effects of CORM-2 on hepatic I/Ri was assessed by measuring serum damage markers AST and ALT, liver histology score, TUNEL-scoring of apoptotic cells, NFkB-activity in nuclear liver extracts, serum levels of pro-inflammatory cytokines TNF-α and IL-6, and hepatic neutrophil infiltration.</p> <p>Results</p> <p>A single systemic infusion with CORM-2 protected the liver from I/Ri as evidenced by a reduction in serum AST/ALT levels and an improved liver histology score. Treatment with CORM-2 also up-regulated expression of the anti-apoptotic protein Bcl-2, down-regulated caspase-3 activation, and significantly reduced the levels of apoptosis after I/Ri. Furthermore, treatment with CORM-2 significantly inhibited the activity of the pro-inflammatory transcription factor NF-κB as measured in nuclear extracts of liver homogenates. Moreover, CORM-2 treatment resulted in reduced serum levels of pro-inflammatory cytokines TNF-α and IL-6 and down-regulation of the adhesion molecule ICAM-1 in the endothelial cells of liver. In line with these findings, CORM-2 treatment reduced the accumulation of neutrophils in the liver upon I/Ri. Similar treatment with an inactive variant of CORM-2 (iCORM-2) did not have any beneficial effect on the extent of liver I/Ri.</p> <p>Conclusions</p> <p>CORM-2 treatment at the time of reperfusion had several distinct beneficial effects on severity of hepatic I/Ri that may be of therapeutic value for the prevention of tissue damage as a result of I/Ri during hepatic surgery.</p

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

TG18 management strategies for gallbladder drainage in patients with acute cholecystitis: Updated Tokyo Guidelines 2018 (with videos)

Since the publication of the Tokyo Guidelines in 2007 and their revision in 2013, appropriate management for acute cholecystitis has been more clearly established. Since the last revision, several manuscripts, especially for alternative endoscopic techniques, have been reported; therefore, additional evaluation and refinement of the 2013 Guidelines is required. We describe a standard drainage method for surgically high-risk patients with acute cholecystitis and the latest developed endoscopic gallbladder drainage techniques described in the updated Tokyo Guidelines 2018 (TG18). Our study confirmed that percutaneous transhepatic gallbladder drainage should be considered the first alternative to surgical intervention in surgically high-risk patients with acute cholecystitis. Also, endoscopic transpapillary gallbladder drainage or endoscopic ultrasound-guided gallbladder drainage can be considered in high-volume institutes by skilled endoscopists. In the endoscopic transpapillary approach, either endoscopic naso-gallbladder drainage or gallbladder stenting can be considered for gallbladder drainage. We also introduce special techniques and the latest outcomes of endoscopic ultrasound-guided gallbladder drainage studies. Free full articles and mobile app of TG18 are available at: . Related clinical questions and references are also include

Regulated intramembrane proteolysis of the virulence activator TcpP in Vibrio cholerae is initiated by the tail‐specific protease (Tsp)

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113117/1/mmi13069.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/113117/2/mmi13069-sup-0001-si.pd

Customer satisfaction on the usage of Singlish in the service industry.

This project aims to examine the impact of the usage of Singlish, which is colloquial English spoken in Singapore. It is an amalgamation of many dialects and languages like English, Teochew, Hokkien, and Malay and it is understood by all Singaporeans. There have been both advocates and critics of using Singlish, with some supporting Singlish as being a fundamental part of building a nation-identity because it is a distinct trait only of people living in Singapore and hence it helps foster a cultural common bond. This is so distinct that it has become a way that Singaporeans who travel or live overseas identify a fellow Singaporean. On the other hand, the critics, mainly made up of the Singaporean government and many English-educated Singaporeans think that the acceptable national norm should only be Standard English since this is the English that is being taught in schools. They believe this form of English is more professional since has existed for hundreds of years, and it is widely used around the world. Hence, the government has tried to create a change by launching the Speak Good English movement as well as discouraging its usage in mass media. Hence, this study aims to examine the actual attitudes of Singaporeans toward the use of Singlish versus English by people, with the focus being on the service industry. This industry was chosen because the primary mode of communication is verbal and Singlish is widely used. The other variables in this study are the gender and attractiveness of the service staff. This is because we would like to find out if the expectations of customers differ if it is a male or female service staff, or if the person serving is deemed attractive or unattractive. The results of this study are based on 240 students from Nanyang Technological University aged 19-25. The reason for choosing these students of this age range is because they tend to be versatile in terms of dining choices. They tend to dine in a variety of different ambiences and have no qualms about eating in a noisy hawker center and yet are able to adapt to a fine dining setting with quiet music playing in the background only a few hours later. Hence, this group is well aware of the different expectations of choice of words and tone used in different dining settings. Therefore, this group would provide a reasonably accurate portrayal of whether the type of spoken communication used by service staff in a fine dining restaurant would affect their overall impression of the person. We have found in this study that the differences in standard of English used by the service staff (pertaining to English and Singlish), gender and attractiveness of the service staff does play a part in the overall impression of customers and especially when these variables interact together, there are significant differences in the overall impression of customers. In our study, service staff using Singlish has been found to generate a significantly lower level of perceived service standard. We will discuss our methodologies and also the implications of our findings in the rest of this report.BUSINES

An Attempt to Maximize the Use of Used Cooking Oil and Fly Ash in the Production of Green Roofing Tile

This study introduces a novel attempt of utilizing used cooking oil (UCO) and fly ash in the production of green roofing tile, namely UCO-GRT. UCO was utilized as an alternative binder to fully replace the cement and clay, while fly ash was used as a fine aggregate instead of virgin sand. This can maximize the percentage of waste substitution in the manufacturing process, consequently reducing the waste disposal issues encountered in Malaysia. The optimization process was carried out to investigate the optimal manufacturing parameters, by considering the curing duration, the composition of UCO and fly ash, and the composition of catalyst incorporated. The mechanical properties of UCO-GRT produced, including density, dry and wet transverse strength, percentage of water absorption, and permeability have been investigated. Findings reveal that the utilization of catalysed UCO and fly ash solely in the production of roofing tiles is feasible. The optimized UCO-GRT fulfilled the basic requirements of a high-profile roofing tile as per ASTM standards. The embodied carbon and embodied energy of the novel roofing tile were also studied and compared with the cementitious and clay roofing tiles