Immunoblastic morphology as a possible prognostic indicator for the outcome of the patients with diffuse large B cell lymphoma in era of the rituximab based treatment: single centre experience

Recently the results from one large prospective study indicated that immunoblastic morphology and not immunohistohemical features predict the outcome of the Diffuse large B lymphoma (DLBL). In order to investigate the prediction value of the immunoblastic morphology (IB) as a possible prognostic indicator for the outcome of our DLBL patient treated with the Rituximab (R)-CHOP regimen we conducted a retrospective study. Our study enrolled 192 DLBL patients diagnosed and treated at the University Clinic of Hematology in the period between February 2002 and December 2007. They were all treated with R-CHOP regimen and the median follow-up of the patient was 36 months. We analyzed the biopsy samples immunohistochemically for markers of germinal center (BCL6), post-germinal center (MUM1) and apoptosis (BCL2).The patients were categorized as DLBL(132; 68.7%), IB(60; 31.2). The median overall survival time (OS) were 59.3 months in DLBL group and 42.2 months in IB group, and time to treatment (TT) were 56.8 and 30.6 months respectively for the IB group. The DLBL and IB groups were comparable regarding the age, gender distributions and all others already established prognostic parameters as performance status, advanced IPI, albumin level except for the low IPI 0-2 which was statistically associated with the DLBL group (p=.024). Our results did not show any statistical survival advantage and better outcome for the patient classified as DLBL when treated with R-CHOP and indicate that immunohistohemical markers do not really reflect the molecular diversity of the tumor.  Our work shows that IB morphology is a major risk factor in DLBL patients treated with R-CHOP. Therefore this morphology appears to capture some adverse molecular events that a currently hard to detect with routine diagnostic procedures.

Hepatobiliary neuroendocrine carcinoma: a case report

<p>Abstract</p> <p>Introduction</p> <p>Neuroendocrine carcinoma of the gallbladder is a rather uncommon disease. We report a case of a neuroendocrine tumor that was located in the wall of the gallbladder and that extended into the liver.</p> <p>Case presentation</p> <p>A 52-year-old Caucasian woman presented with right-sided abdominal pain, ascites and jaundice. An MRI scan revealed a tumor mass located in the gallbladder wall and involving the liver. A partial hepatectomy and cholecystectomy were performed. Histology revealed a neuroendocrine tumor, which showed scattered Grimelius positive cells and immuno-expressed epithelial and endocrine markers. Our patient is undergoing chemotherapy treatment.</p> <p>Conclusion</p> <p>Gastroenteropancreatic neuroendocrine tumors need a multidisciplinary approach, involving immunohistochemistry and molecular-genetic techniques.</p

The benzene metabolite para-benzoquinone is genotoxic in human, phorbol-12-acetate-13-myristate induced, peripheral blood mononuclear cells at low concentrations

Benzene is one of the most prominent occupational and environmental pollutants. The substance is a proven human carcinogen that induces hematologic malignancies in humans, probably at even low doses. Yet knowledge of the mechanisms leading to benzene-induced carcinogenesis is still incomplete. Benzene itself is not genotoxic. The generation of carcinogenic metabolites involves the production of oxidized intermediates such as catechol, hydroquinone and para-benzoquinone (p-BQ) in the liver. Further activation to the ultimate carcinogenic intermediates is most probably catalyzed by myeloperoxidase (MPO). Yet the products of the MPO pathway have not been identified. If an oxidized benzene metabolite such as p-BQ was actually the precursor for the ultimate carcinogenic benzene metabolite and further activation proceeds via MPO mediated reactions, it should be possible to activate p-BQ to a genotoxic compound in vitro. We tested this hypothesis with phorbol-12-acetate-13-myristate (PMA) activated peripheral blood cells exposed to p-BQ, using the cytokinesis-block micronucleus test. Addition of 20–28 ng/ml PMA caused a significant increase of micronuclei at low and non-cytotoxic p-BQ concentrations between 0.04 and 0.2 μg/ml (0.37–1.85 μM). Thus with PMA or p-BQ alone no reproducible elevation of micronuclei was seen up to toxic concentrations. PMA and p-BQ induce micronuclei when administered jointly. Our results add further support to the hypothesis that MPO is a key enzyme in the activation of benzene

Preferential Crystallization of L-Asparagine in Water

Because of its simplicity and cost-effectiveness, preferential crystallization (PC) can be considered as one of the most attractive techniques available for enantioseparation. In this paper,the enantioseparation of the nonessential amino acid DL-asparagine (DL-Asn), which belongs to the group of conglomerate forming systems, is studied experimentally and theoretically. Goals of this work are to investigate the applicability of PC of L-Asn·H2O from an aqueous solution of racemic DL-Asn using simple isothermal batch preferential crystallization (SIB-PC) and to provide a reliable database for model validation based on essential model parameters identified. To further improve the performance of PC, two crystallizers can be connected in order to exchange continuously the mother liquors (CIB-PC, coupled isothermal batch preferential crystallization). This new configuration is tested and assessed. Copyright © 2011 American Chemical Society [accessed 27th May 2011

Enzyme supported preferential crystallization of enantiopure amino acids

The production of enantiopure substances has drawn a lot of interest during the last decades. Especially intermediates for the pharmaceutical industry, fine chemicals and feed additives like L-amino acids are of great scientific and economic relevance [1, 2]. Despite an increasing number of stereoselective synthesis there are still a lot of reactions that lead to racemic mixtures of the desired homochiral products. Numerous separation techniques have been developed [3-5], but a major drawback of them is the principal yield limitation to a maximum of 50 %. We present a new approach for the production of enantiopure amino acids (AA) with a theoretical yield of 100 % that integrates preferential crystallization (PC) of a conglomerate and enzymatic in situ racemization (Fig. 1). Starting from a racemic oversaturated AA solution one enantiomer can be crystallized by seeding with homochiral crystals, which leads to an increasing enantiomeric excess (ee) of the counter enantiomer in the crystallization medium. PC is only possible as long as the medium composition remains in the metastable zone of the ternary phase system, thus crystallization of the counter enantiomer will start at a certain point. In order to prevent this, enzymatic in situ racemization can be applied which keeps the ee in the medium at a minimum. By continuous feeding of racemic AA into the system a stationary process can be obtained

Novel Integrated Concepts for Preferential Crystallization

Driven by the policy of regulatory authorities such as US Food and Drug Administration and the EU Committee for Proprietary Medical Products the production of pure enantiomers is considerably increasing in several industrial branches, e.g. pharmaceutical, agrochemical, food industries as well as in cosmetic and fragrance industries [1]. An attractive process for gaining pure enantiomers from racemic mixtures is the so-called preferential crystallization [2-4]. The principle of this batch process is quite simple: the tank is filled with a supersaturated solution of the racemate (Ep+Ec as 50%:50% mixture). After addition of homochiral seeds (e.g. Ep) merely Ep is crystallizing within a limited time period. In order to gain this enantiomer as a product of high purity, the process must be stopped before the undesired counter-enantiomer occurs [3]. During this batch crystallization, the concentration of the desired enantiomer in the solution is decreasing, whereas the concentration of the counter-enantiomer remains constant. This phenomenon leads to an arrangement which might provide a better performance where two crystallizers are coupled via the liquid phase, i.e. the crystal free mother-liquor is exchanged between these two vessels. Because of this exchange, the liquid phase shows a higher overall concentration of the preferred enantiomer in that vessel in which the preferred enantiomer was seeded. The supersaturation level which corresponds to the crystallization driving force is higher during the whole process in comparison to the case without an exchange (decoupled simple batch mode). Additionally, the concentration of the counter-enantiomer in the liquid phase for each of the vessels decreases. For the borderline case of infinite exchange flow rate racemic composition is reached in the fluid phase of both vessels. The described effect of decreasing the counter-enantiomer concentration in that crystallizer in which the preferred enantiomer shall be gained makes the probability for primary nucleation lower. This corresponds to higher product purity at the end of the process and enhances also the productivity. This more attractive and effective operation mode using two batch crystallizers coupled via their liquid phases has been investigated theoretically and experimentally for the amino acid threonine in water [5-7]. The influence of specific process parameters, like e.g. the size distribution and the mass of the seeds, and different temperature profiles has been analyzed. The effect of racemization by exchanging the fluid phase allows the specific manipulation of concentration profiles and seems to be a suitable lever for process intensification on the apparatus level. Similar manipulation of the concentration profiles during the crystallization process can be also realized on molecular level if the racemization is achieved by an enzymatic reaction in which an excess of the counter-enantiomer in the liquid phase is transformed to the preferred one [8, 9]. By coupling crystallization (for conglomerate sys-tems) and racemization (for conversion of the unwanted enantiomer) expected theoretical yield of a pure enantiomer can lead up to 100%. Our goal is to develop a comprehensive study for each operating unit and their subsequent integration in a hybrid process. As a model component for the investigation, the amino acid asparagine in water has been chosen. The first configuration will be usually applied if there is a need for both enantiomers in pure form (with yields up to 50% for each enantiomer), whereas the second configuration provides just one enantiomer with very high yield (up to 100%). These different configurations for productivity enhancement with regard to preferential crystallization will be presented in this contribution. [1] CANER, H.; GRONER, E.; LEVY, L.; AGRANAT, I. (2004): Trends in the development of chiral drugs. Drug Discovery Today. 9 (3), 105-110 [2] JACQUES, J.; COLLET, A.; WILEN, S.H. (1994): Enantiomers, racemates and resolutions. Krieger, Malabar [3] ELSNER, M.P., FERNÁNDEZ MENÉNDEZ, D., ALONSO MUSLERA, E., SEIDEL-MORGENSTERN, A. (2005): Experimental study and simplified mathematical description of preferential crystallization. Chirality 17 (S1), S183-S195 [4] LORENZ, H., PERLBERG, A., SAPOUNDJIEV, D., ELSNER, M.P., SEIDEL-MORGENSTERN, A., (2006): Crystallization of enantiomers. Chem. Eng. and Proc. 45(10), 863-873 [5] ELSNER, M.P.; ZIOMEK, G.; SEIDEL-MORGENSTERN, A. (2007): Simultaneous preferential crystallization in a coupled, batch operation mode. Part I: Theoretical analysis and optimization. Chem. Eng. Sci. 62 (17), 4760-4769 [6] ELSNER, M.P.; ZIOMEK, G.; SEIDEL-MORGENSTERN, A. (2008): Efficient separation of enantiomers by preferential crystallization in two coupled vessels. AIChE Journal (submitted) [7] ZIOMEK, G.; ELSNER, M.P.; SEIDEL-MORGENSTERN, A. (2008): Simultaneous preferential crystallization in a coupled, batch operation mode – Part II: Experimental investigations. Chem. Eng. Sci. (in preparation) [8] LÜTZ, S.; WANDREY, C.; SEIDEL-MORGENSTERN, A.; ELSNER, M.P. (2006): Verfahren zur Herstellung chiraler Substanzen durch selektive Kristallisation unterstützt durch eine enzymatische Racemisierungsreaktion. DE 10 2006 013 725.6 (24.03.2006) [9] WÜRGES, K.; PETRUSEVSKA, K.; SERCI, S.; WILHELM, S.; WANDREY, C.; SEIDEL-MORGENSTERN, A.; ELSNER, M.P.; LÜTZ, S. (2008): Enzyme-assisted physicochemical enantioseparation processes – part I: Production and characterization of a recombinant amino acid racemase. Journal of Molecular Catalysis B: Enzymatic (submitted) © 2008 American Institute of Chemical Engineers [accessed December 11, 2008