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Leukemia cutis (LC) is an extramedullary manifestationof leukemia owing to cutaneous infiltration ofneoplastic cells resulting in characteristic firm,erythematous nodules. Most cases of LC occur inpatients with acute myelogenous leukemia andchronic myelogenous leukemia. However in rarecases, LC has presented in patients with acutelymphoblastic leukemia (ALL). In these rare ALLassociatedcases, only 10 cases of precursor-B-ALL(pre-B-ALL) have been described in the literature.We report a case of a 22-year-old man with relapsingpre-B-ALL who presented with a 4-day history ofmultiple asymptomatic, soft, dome-shaped, lipomalikemounds on his scalp and chin, which exhibitedcutaneous involvement by leukemic cells. To date, thisis the first case of pre-B-ALL associated leukemia cutispresenting as soft, dome-shaped mounds resemblinglipomas.

Introduction: Glycopeptides contain carbohydrate moieties (glycans) covalently attached to the side chain and/or terminal peptide units. Since glycans are present on cell surfaces, these constructs can potentially address a wide array of therapeutic functions. To overcome the deficiencies associated with current synthetic routes to glycopeptides, such as costly processes and toxic reagents, this work aimed to develop versatile environmentally friendly protease-catalyzed peptide synthesis routes to peptides decorated with a glycan at their N-terminus. Methods: "Grafters" were first synthesized that consist of a glycan conjugated directly, or through a spacer, to the amine group of L-Phe-ethyl ester (Phe-OEt). The role of Phe-OEt is to increase the conjugate's recognition by the protease (papain) catalytic active site. A series of grafters were synthesized with variation of the glycan structure, linkage-chemistry, and presence of an oligo (ethylene glycol) "spacer" of varied length between the glycan and Phe-OEt moiety. High grafter efficiency will result by the successful acceptance of the grafter at the enzymes S1/S2 subsites, formation of an acyl enzyme complex and subsequent conversion to glycan-terminated oligo(Leu)x (x = 1), as opposed to construction of non-glycan N-terminated oligo(Leu)x. Results and discussion: While glycan-Phe-OEt grafters without a spacer between the glycan and Phe-OEt resulted in low grafter efficiency (8.3% ± 2.0%), insertion of a short oligo (ethylene glycol) spacer between the glycan and Phe-OEt moieties (glycan-PEGn-Phe-OEt, n = 3) increased the grafter efficiency by 3-fold-24.5% ± 1.8%. In addition, computational modeling was performed using Rosetta software provided insights on a molecular level of how grafter efficiency is influenced by the PEG spacer length. [ABSTRACT FROM AUTHOR]

Directed enzyme evolution has led to significant application of biocatalysis for improved chemical transformations throughout the scientific and industrial communities. Biocatalytic reactions utilizing evolved enzymes immobilized within microporous supports have realized unique advantages, including notably higher enzyme stability, higher enzyme load, enzyme reusability, and efficient product-enzyme separation. To date, limited analytical methodology is available to discern the spatial and chemical distribution of immobilized enzymes, in which techniques for surface visualization, enzyme stability, or activity are instead employed. New analytical tools to investigate enzyme immobilization are therefore needed. In this work, development, application, and evaluation of an analytical methodology to study enzyme immobilization is presented. Specifically, Raman hyperspectral imaging with principal component analysis, a multivariate method, is demonstrated for the first time to investigate evolved enzymes immobilized onto microporous supports for biocatalysis. Herein we demonstrate the ability to spatially and spectrally resolve evolved pantothenate kinase (PanK) immobilized onto two commercially-available, chemically-diverse porous resins. This analytical methodology is able to chemically distinguish evolved enzyme, resin, and chemical species pertinent to immobilization. As such, a new analytical approach to study immobilized biocatalysts is demonstrated, offering potential wide application for analysis of protein or biomolecule immobilization. [ABSTRACT FROM AUTHOR]

The erection of the Goddess of Democracy statue in Tiananmen Square in Beijing, China, in 1989 was an exhilarating moment of the Beijing spring initiative. The monument was more than a reminder of the US-inspired street demonstrations in that Chinese city in May 1989 but was also to become the China democracy movement's angel of death. In the decade that was to follow the Tiananmen massacre the Goddess of Democracy came to symbolize that tragedy and also to serve as a reminder that loving the US and democracy too openly can be considered subversive.

Abstract: Therapeutic drugs and environmental pollutants may exhibit high reactivity toward DNA bases and backbone. Understanding the mechanisms of drug–DNA binding is crucial for predicting their potential genotoxicity. We developed a fluorescence analytical method for the determination of the preferential binding mode for drug–DNA interactions. Two nucleic acid dyes were employed in the method: TO-PRO-3 iodide (TP3) and 4′,6-diamidino-2-phenylindole (DAPI). TP3 binds DNA by intercalation, whereas DAPI exhibits minor groove binding. Both dyes exhibit significant fluorescence magnification on binding to DNA. We evaluated the DNA binding constant, K b, for each dye. We also performed fluorescence quenching experiments with 11 molecules of various structures and measured a C 50 value for each compound. We determined preferential binding modes for the aforementioned molecules and found that they bound to DNA consistently, as indicated by other studies. The values of the likelihood of DNA intercalation were correlated with the partition coefficients of the molecules. In addition, we performed nuclear magnetic resonance (NMR) studies of the interactions with calf thymus DNA for the three molecules. The results were consistent with the fluorescence method described above. Thus, we conclude that the fluorescence method we developed provides a reliable determination of the likelihoods of the two different DNA binding modes. [Copyright &y& Elsevier]