On square roots of the Haar state on compact quantum groups

The paper is concerned with the extension of the classical study of probability measures on a compact group which are square roots of the Haar measure, due to Diaconis and Shahshahani, to the context of compact quantum groups. We provide a simple characterisation for compact quantum groups which admit no non-trivial square roots of the Haar state in terms of their corepresentation theory. In particular it is shown that such compact quantum groups are necessarily of Kac type and their subalgebras generated by the coefficients of a fixed two-dimensional irreducible corepresentation are isomorphic (as finite quantum groups) to the algebra of functions on the group of unit quaternions. An example of a quantum group whose Haar state admits no nontrivial square root and which is neither commutative nor cocommutative is given.     

Approximate innerness and central triviality of endomorphisms

We introduce the notions of approximate innerness and central triviality for endomorphisms on separable von Neumann factors, and we characterize them for hyperfinite factors by Connes-Takesaki modules of endomorphisms and modular endomorphisms which are introduced by Izumi. Our result is a generalization of the corresponding result obtained by Kawahigashi-Sutherland-Takesaki in automorphism case.     

CHLORPROMAZINE PHOTOSENSITIZATION–II. FAILURE TO DETECT ANY EVIDENCE FOR INVOLVEMENT OF DNA DAMAGE IN THE PHOTODYNAMIC KILLING OF ESCHERICHIA COLI IN THE PRESENCE OF CHLORPROMAZINE

Abstract— When a suspension of Escherichia coli was irradiated with near-UV light in the presence of chlorpromazine (at a concentration below a cytotoxic level), the cells were killed. Efficiency of the photodynamic killing was not influenced by the deficiency of the uvrA gene or the recA gene. Neither phenotypic reversion of E. coli Hs30R (arginine auxotroph) nor induction of lambda prophage in lysogenic bacteria was detected after this treatment.     

Development of an on-line immobilized-enzyme reversed-phase HPLC method for protein digestion and peptide separation

This paper describes use of a novel glass bead-based immobilized-enzyme micro column for simple and swift on-line protein digestion then peptide separation by reversed-phase HPLC. The inexpensive and easily made immobilized-enzyme micro column was prepared from aminopropyl controlled-pore glass that was reacted first with glutaraldehyde then with trypsin in the presence of phosphate buffer. Tryptic digestion of bovine serum albumin (BSA) was achieved simply by passing pretreated protein solution through the laboratory made immobilized-trypsin column; the tryptic fragments were then separated by reversed-phase HPLC. The peptide separation was found to be identical to separation of a sample which had undergone conventional enzymatic protein digestion in solution. Digestion of BSA by the immobilized-trypsin column decreased with increasing flow rate of the solution through the column, and 1.0 μL min⁻¹ was found to be the optimum flow rate for on-line protein digestion with our system. It was also found that the sample required pretreatment with urea before injection, because of a change in the properties of the protein in the presence of urea, and the immobilized-trypsin column lost its function in the presence of acetonitrile. This on-line proteomics system enables simple and rapid protein digestion and was successfully applied to partially micro two-dimensional (2D) chromatographic separation of proteins.     

UPLC-MS/MS detection of disaccharides derived from glycosaminoglycans as biomarkers of mucopolysaccharidoses

Mucopolysaccharidoses (MPSs) are a group of disorders resulting from primary defects in lysosomal enzymes involved in the degradation of glycosaminoglycans (GAGs). Depending on the specific enzyme defect, the catabolism of one or more GAGs is blocked leading to accumulation in tissues and biological fluids. GAG measurements are important for high-risk screening, diagnosis, monitoring treatment efficacy, and patient follow up. The dimethylmethylene blue (DMB) spectrophotometric method commonly used in most biochemical genetics laboratories relies on a non-specific total GAG analysis which has led to false positive results, and even false negative results (mainly for MPS III and IV patients). The main objective of our project was to devise and validate a reliable tandem mass spectrometry multiplex analysis for the urine quantitation of four GAGs (dermatan sulfate (DS), heparan sulfate (HS), keratan sulfate (KS), and chondroitin sulfate (CS)) for an eventual technological transfer to the clinic. The developed methodology is rapid (7 min) and our results showed good intraday and interday precision (RSDs ≤ 8.7%) and accuracy (Biases range: −12.0%–18.4%). Linearity was good (r² > 0.995) for DS, HS, CS, and KS calibration curves. In comparison with the DMB spectrophotometric method, this multiplex tandem mass spectrometry method allows GAG fractionation, thus a differentiation of MPS types, except for MPS I and II which are characterized by the same GAG profile. The devised method is a useful and reliable tool for diagnosis of MPS patients, as well as their monitoring and follow up, as shown by longitudinal studies.     

Analytical method for determination of disaccharides derived from keratan sulfates in human serum and plasma by high-performance liquid chromatography/turbo-ionspray ionization tandem mass spectrometry

We established a highly sensitive LC/MS/MS method for the analysis of the disaccharides produced from keratan sulfates (KS). It was revealed that the disaccharides produced by keratanase II enzymatic digestion of KS could be determined with high sensitivity by negative ion mode of multiple reaction monitoring. Furthermore, monosulfated and disulfated disaccharides can be separated using a Hypercarb (2.0 mm i.d. x 150 mm, 5 microm) with a gradient elution of acetonitrile-0.01 m ammonium bicarbonate (pH 10). This method was applied to the determination of KS in serum and plasma of control subjects. The intra-day precision expressed as %CV was within 6.8% for five replicate analyses with three different control serum. The inter-day (overall, n = 15) precision was within 7.3% for three days. This method is sensitive, reproducible and would be useful for clinical analysis.