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

Overcoming yield limitations when resolving racemates by combination of crystallization and/or chromatography with racemization

The major drawback of using enantioseparation techniques when resolving racemates is a yield of maximum 50%. To prevail over this disadvantage new approaches are explored for manufacturing single enantiomers. The work presented in this thesis is dedicated in particular to this challenge. In this work two integrated processes for production of optically pure enantiomers are studied. Each one couples a separation technique with a racemization reaction. The principle of work consists of resolution of the racemate and racemization of the unwanted enantiomer, whereby the yield of the target enantiomer can be significantly increased - at best to 100%. The engagement of the racemization which should offer minimum of no loss of optically active material should considerably contribute to the process economics. Based on the information obtained from studying each single unit, more detailed scenarios for both integrated processes are suggested and general outlook is given regarding their potentials and critical aspects. The applicability of one of the examined integrated processes is experimentally proven

Legal status of the pharmacy practice in the European Union and the Republic of Macedonia

From a historical point of view, one can notice that the role of the pharmacists employed in community and hospital pharmacies became more complex. Today, they do not only supply, store, prepare and dispense medicines with ensured quality, but they also provide professional services based on the concept of pharmaceutical care and good pharmacy practice. In this paper, detailed review on the current legislative regulating the status and practice of the community and hospital pharmacies in some EU-member countries and in Macedonia is given. The implementation of the concept of pharmaceutical care and good pharmacy practice in selected EU member-countries, Great Britain, Germany and Slovenia, and in Croatia as a future EU member as well as in Macedonia is also discussed. In addition, set of recommendations for establishing the good pharmacy practice standards is prepared and presented. At the end, an attempt is made to establish a basis for development a modern Law on Pharmacy Practice in the Republic of Macedonia

Enzyme-assisted physicochemical enantioseparation processes - part III: Overcoming yield limitations by dynamic kinetic resolution of asparagine via preferential crystallization and enzymatic racemization

The application of enantioseparation methods alone can only yield up to 50% of the desired chiral product. Thus enantioseparation becomes more attractive when accompanied by the racemization of the counter-enantiomer. Here we present first results of dynamic kinetic resolution of L-asparagine (L-Asn) via preferential crystallization and enzymatic racemization from a racemic, supersaturated solution on a 20 mL scale. An enzyme lyophilisate (WT amino acid racemase from P. putida KT2440 (E.C. 5.1.1.10), overexpressed in E. coli BL21(DE3)) was used for in situ racemization (enzyme concentrations varying from 0 to 1 mg/mL). When preferential crystallization was applied without any enzyme, a total of 31 mg of L-Asn monohydrate could be crystallized, before crystal formation of d-Asn started. Crystallization experiments accompanied by enzymatic racemization led to a significant increase of crystallized L-Asn (198 mg L-Asn monohydrate; >92%ee) giving the first experimental proof for this new process concept of dynamic kinetic resolution via preferential crystallization and enzymatic racemization. Measurements of the racemase activity before and after the crystallization process showed no significant differences, which would allow for enzyme recovery and recycling

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

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