Inflammation-driven deaminase deregulation fuels human pre-leukemia stem cell evolution

Inflammation-dependent base deaminases promote therapeutic resistance in many malignancies. However, their roles in human pre-leukemia stem cell (pre-LSC) evolution to acute myeloid leukemia stem cells (LSCs) had not been elucidated. Comparative whole-genome and whole-transcriptome sequencing analyses of FACS-purified pre-LSCs from myeloproliferative neoplasm (MPN) patients reveal APOBEC3C upregulation, an increased C-to-T mutational burden, and hematopoietic stem and progenitor cell (HSPC) proliferation during progression, which can be recapitulated by lentiviral APOBEC3C overexpression. In pre-LSCs, inflammatory splice isoform overexpression coincides with APOBEC3C upregulation and ADAR1p150-induced A-to-I RNA hyper-editing. Pre-LSC evolution to LSCs is marked by STAT3 editing, STAT3β isoform switching, elevated phospho-STAT3, and increased ADAR1p150 expression, which can be prevented by JAK2/STAT3 inhibition with ruxolitinib or fedratinib or lentiviral ADAR1 shRNA knockdown. Conversely, lentiviral ADAR1p150 expression enhances pre-LSC replating and STAT3 splice isoform switching. Thus, pre-LSC evolution to LSCs is fueled by primate-specific APOBEC3C-induced pre-LSC proliferation and ADAR1-mediated splicing deregulation.

The occurrence of Listeria species in pâté: the Cardiff experience 1989

Samples of 216 pâtés were examined for the presence of Listeria spp. between May and August 1989; 35% were contaminated with L. monocytogenes, 5% of samples having counts of greater than 10(4)/g. L. innocua was recovered from 2% of samples but no other species was isolated. Five serotypes of L. monocytogenes were represented (1/2, 4b, 4b(X), 4 not 4b or 4b(X), and NT), 4b was the predominant serotype and multiple serotypes were found in eight pâtés. The incidence of contamination with L. monocytogenes was greater in stored pâté (46%) than display pâté (30%). Sampling over a 21-day period showed an apparent increase in numbers of L. monocytogenes in 6 of 7 samples with multiple serotypes represented. There was no correlation between contamination of pâté by L. monocytogenes and the presence of coliforms. Comparisons are made between the contamination of soft cheese and pâté.

The early bacterial colonization of acrylic palates in man

Adhesive tape applied to the fitting surface was used to study the early colonization of acrylic palates in six subjects. Streptococci were major constituents of the plaque accumulated on the tape over the first 3 days. Bacterial colonization of the tape discs was selective in that dextran-producing streptococci constituted a greater proportion of the total streptococcal count after 15 min compared with that of the initial sample and saliva, while the converse was true for Streptococcus salivarius. Scanning electron microscopy showed that denture plaque development started in grooves and depressions on the surface of the tape, and became more extensive with time. Comparison of the colonization of tape and acrylic discs in one individual demonstrated that the tape was a suitable model for in vivo colonization of dentures or orthodontic appliances.

Coenzyme A: pKa and g values

The pKa and γ values at 25°, I 0.1 M, of the mercapto group of coenzyme A were calculated to be 10.35�0.15 and 0.70�0.02 respectively. The γ value was calculated from differences in the partition coefficient of quinazoline between cyclohexane and aqueous buffers and that between cyclohexane and aqueous buffers which contained coenzyme A. The described procedure could be used to obtain γ values of other nucleophilic reagents which, like coenzyme A, absorb u.v, energy strongly.

Covalent Additions of Glutathione, Cysteine, Homocysteine, Cysteamine and Thioglycolic Acid to Quinazoline Cation

A linear relationship with a gradient of 0�38 was found to exist between the γ values of thiols and the pKa values of their mercapto groups. The γ value of a nucleophilic reagent is a relative measure of the extent to which it will covalently add across >C=N-,>C=O and >C=C< groups, γ values for the thiols were calculated from the equilibrium constants for their covalent addition to quinazoline cation at 25�, l 0.1 M. The results indicate that substituents in a thiol influence both the pKa value of the mercapto group and the γ value in a similar manner but they have a significantly greater effect on the pKa value.

Hydroxyisothiazoles. II. Preparation of isothiazolin-3-ones and their methylated derivatives from the oxidation of cyano-substituted dithioacetate salts

The hydrogen peroxide oxidation of α-cyanoaryldithioacetate salts (3) affords substituted isothiazol-3-ols (isothiazolin-3-ones) (4) in moderate yields. Methylation of the products yields mainly N-methyl derivatives. 4-Arylisothiazol-3-ols can be further oxidized to saccharin analogues (7).