In a previous work, CcrM was reported to be highly processive [Berdis et al. (1998) Proc. Natl Acad. Sci. USA 95: 2874-2879]. However upon review of this work, we identified a technical error in the setup of a crucial experiment in this publication, which prohibits making any statement about the processivity of CcrM. In this study, we performed a series of in vitro experiments to study CcrM processivity. We show that it distributively methylates six target
sites on the pUC19 plasmid as well as two target sites located on a 129-mer DNA fragment both in unmethylated ON-01910 chemical structure and hemimethylated state. Reaction quenching experiments confirmed the lack of processivity. We conclude that the original statement that CcrM is processive is no longer valid.”
“BACKGROUND\n\nA high throughput, high pressure liquid chromatographic (HPLC) method with triple quadrupole mass spectral detection (LC/MS/MS) was validated for the measurement of 5 endogenous androgens in human plasma and serum and applied to various in vivo and in vitro study samples to pursue find more a better understanding of the interrelationship of the androgen axis, intracrine metabolism, and castration-recurrent prostate cancer (CaP).\n\nMETHODS\n\nA Shimadzu HPLC system interfaced with a Sciex QTRAP 5500 mass spectrometer with electrospray ionization was used with inline column-switching. Samples were liquid/liquid extracted and
chromatographed on a Luna C18(2) column at 60 degrees C with a biphasic gradient using a 15-min run time.\n\nRESULTS\n\nThe method was validated for five androgens in human plasma and serum, and applied to four sets of samples. Plasma (n = 188) and bone marrow aspirate (n = 129) samples from patients with CaP, who received abiraterone acetate plus prednisone for up
to 945 days (135 weeks), had undetectable androgens after 8 weeks of treatment. Plasma dehydroepiandrosterone (DHEA) concentrations were higher in African Americans than Caucasian Americans with newly diagnosed CaP. Analysis of prostate tumor tissue homogenates demonstrated reproducible testosterone (T) and dihydrotestosterone (DHT) concentrations with a minimal sample size of similar to 1.0-2.0 mg of tissue. Finally, cell pellet and media samples from the LNCaP C4-2 cell line showed conversion of T to DHT.\n\nCONCLUSION\n\nThe proposed PF-6463922 LC/MS/MS method was validated for quantitation of five endogenous androgens in human plasma and serum, and effectively profiles androgens in clinical specimens and cell culture samples. Prostate 74:722-731, 2014. (c) 2014 Wiley Periodicals, Inc.”
“Objective: To determine whether phenobarbital (PB) given before therapeutic hypothermia to infants with hypoxic-ischemic encephalopathy (HIE) augments the neuroprotective efficacy of hypothermia.\n\nStudy Design: Records of 68 asphyxiated infants of >= 36 weeks’ gestation, who received hypothermia for moderate or severe HIE were reviewed. Some of these infants received PB prophylactically or for clinical seizures.