CRISPR-based oligo recombineering prioritizes apicomplexan cysteines for drug discovery.

Nucleophilic amino acids are important in covalent drug development yet underutilized as anti-microbial targets. Chemoproteomic technologies have been developed to mine chemically accessible residues via their intrinsic reactivity towards electrophilic probes but cannot discern which chemically reactive sites contribute to protein function and should therefore be prioritized for drug discovery. To address this, we have developed a CRISPR-based oligo recombineering (CORe) platform to support the rapid identification, functional prioritization and rational targeting of chemically reactive sites in haploid systems. Our approach couples protein sequence and function with biological fitness of live cells. Here we profile the electrophile sensitivity of proteinogenic cysteines in the eukaryotic pathogen Toxoplasma gondii and prioritize functional sites using CORe. Electrophile-sensitive cysteines decorating the ribosome were found to be critical for parasite growth, with target-based screening identifying a parasite-selective anti-malarial lead molecule and validating the apicomplexan translation machinery as a target for ongoing covalent ligand development.

Effects of propofol on ischemia and reperfusion in the isolated rat heart compared with thiamylal.

The aim of the present study was to investigate whether clinical doses of propofol and thiamylal affect oxygen free radical production and intracellular calcium concentration ([Ca2+]i) in the post-ischemic reperfused heart. Forty-eight rat hearts were perfused with a Langendorff system and loaded with Fura-2 / AM as a [Ca2+]i marker. The hearts were divided into 6 groups as follows (each group: n = 8); Group S (saline), Group TL (thiamylal 100 microM), Group TH (thiamylal 300 microM), Group I (Intralipid), Group PL (propofol 3 microM), and Group PH (propofol 10 microM). All hearts were initially perfused for 5 min as control aerobic perfusion. Afterwards, no-flow ischemia was induced for 15 min, followed by reperfusion for 20 min. The formation of hydroxyl radicals in the coronary effluent was measured with high performance liquid chromatography using salicylic acid. At the beginning of the ischemia and reperfusion periods, increases in systolic and diastolic [Ca2+]i were observed in all groups except Group TH. The high dose of thiamylal significantly suppressed this initial increase in cytosolic [Ca2+]i (Group S 1.30+/-0.15; Group TL 0.99+/-0.17; Group TH 0.70+/-0.09, at 1 min after reperfusion; systolic [Ca2+]i : p < 0.05). Total DHBAs in the coronary effluent of all groups increased significantly 1 min after reperfusion, however, there were no significant differences among the groups. Clinical doses of propofol had no significant effect on myocardial function and [Ca2+]i before and after ischemia, whereas thiamylal suppressed the increase in [Ca2+]i during ischemia and reperfusion. However, free radical formation during reperfusion was unaffected by thiamylal and propofol.

[Effect of pre-mixed lidocaine with propofol on propofol injection pain in elderly patients].

The purpose of this study was to compare the younger and older patients in the incidence and the severity of the pain during injection of propofol. Thirty-four, elderly patients (60-80-yr-old) and 52 patients (20-40-yr-old) scheduled to undergo elective surgery were studied. We conducted a prospective, randomized and double-blinded trial. All patients were randomly allocated to one of two groups according to the agents added to 1% propofol 20 ml; Group S, normal saline 2 ml, and Group L, 2% lidocaine 2 ml. The pain on injection was rated as none, mild, moderate, or severe. Seventy percent of patients in the S group of elderly patients experienced pain, while 22% of patients experienced pain in the L group in elderly patients. The incidence of pain on injection in the S group of older patients was comparable with S group of younger patients. The severity of pain in elderly patients was significantly decreased after premixing with lidocaine. There were no significant differences between older and younger patients in the severity of propofol injection pain in both S group and L group. In conclusion, elderly patients suffered the pain on injection of propofol with the same incidence as the younger patients did. Lidocaine premixed with propofol significantly reduces the incidence and the severity of pain associated with propofol in elderly patients.

[Premixing of 5% dextrose in Ringer's acetate solution with propofol reduces incidence and severity of pain on propofol injection].

The purpose of this study was to compare the effect of premixed 5% dextrose in Ringer's acetate solution and premixed lidocaine with propofpl on the reduction of pain during injection of propofol in adult patients. We conducted a prospective, randomized, double-blinded trial. Ninety-six patients were randomly allocated to one of three groups according to the agents added to 1% propofol 20 ml; Group C, normal saline 2 ml, Group L, 2% lidocaine 2 ml, and Group A, 5% dextrose in Ringer's acetate solution 2 ml. The pain on injection was rated as none, mild, moderate, or severe. Seventy percent of patients in the C group experienced pain, while 33% and 25% of patients experienced pain in the A group and the L group, respectively. Forty-two percent of patients in the C group complained moderate to severe pain but only one patient in both A group and L group. In conclusion, 5% dextrose in Ringer's acetate solution premixed with 200 mg propofol significantly reduces incidence and severity of pain associated with propofol injection and is easier to use than premixed lidocaine.

Green tea suppresses D-galactosamine-induced liver injury in rats.

Dietary supplementation with powder of a green tea extract suppressed the enhancement of plasma alanine aminotransferase and aspartate aminotransferase activities induced by D-galactosamine, but not by carbon tetrachloride, in a dose-dependent manner in rats. The minimum dose to cause a significant effect was 1 to 2%. Drinking green tea also suppressed plasma enzyme activities. These results indicate that green tea had a liver injury-preventive effect.