Quality Control and Risk Management of Carbon Nanomaterials

Our atmosphere contains a substantial number of nanoparticles in which some are unintentionally produced, whereas others are intentionally produced engineered nanoparticle. Among all ENPs, the single-walled and multi-walled carbon nanotubes, spherical fullerenes, and dendrimers are attracting attention for biomedical applications, such as biosensor design, drug delivery, tumor therapy, and tissue engineering. Because of the inert nature of pristine carbon nanotubes (CNTs), it needs to be functionalized to make it reactive with other organic and inorganic materials. The functionalization leads to the addition of functional groups, e.g., C‖O, C▬O, ▬OH, and ▬COOH, to CNTs, which make them dispersible in solvents and suitable for numerous applications. Functionalized CNTs and their composite need to be tested for biocompatibility before real-time applications. Various toxicity mechanisms have been suggested for CNTs, including interference of transmembrane electron transfer, interruption/penetration of the cell envelope, oxidation of cell elements, and formulation of secondary products such as dissolved heavy metal ions or reactive oxygen species (ROS). Numerous studies have insinuated that well-functionalized CNTs are innoxious to animal cells, while raw CNTs or CNTs without functionalization manifest toxicity to cells at even modest dosage

Tactics to patients with acute colangitis and mechanical jaundice

Catedra Chirurgie nr.1 “Nicolae Anestiadi”, Laboratorul Chirurgie Hepato-Pancreato-Biliară, Universitatea de Stat de Medicină şi Farmacie „Nicolae Testemiţanu”, Institutul de Medicină Urgentă, Chișinău, Republica Moldova, Al XIII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” și al III-lea Congres al Societății de Endoscopie, Chirurgie miniminvazivă și Ultrasonografie ”V.M.Guțu” din Republica MoldovaIntroducere: Colangita acută severă și icterul mecanic decurge concomitent cu afectarea și organelor zonei hepato-bilio-pancreatoduodenale şi a schimbărilor la nivelul papilei duodenale mari. Scopul: Importanța tratamentului minim-invazit în diagnosticul și tratamentul colangitei acute și icterului mecanic. Material și metode: Analiza retrospectivă efectuată a 470 pacienți, în IMSP IMU, în perioada 2016-2017. Selecţia pacienţilor s-a efectuat în baza diagnosticului clinico-imagistic de icter obstructiv și anamneză. Rezultate: A predominat sexul masculin în raport de 1:1,3 (femei:bărbați), după vârstă a predominat grupa de vârstă 61 – 70 ani - 136 pacienți (29%), urmată de 71 – 80 ani - 106 pacienți (22,5%) și de 41 – 50 ani - 106 pacienți (22,5%), peste 80 ani - 24 pacienți (5%). Adresarea tardivă, în mare majoritate peste 72 ore - 348 pacienți (74%). Pacienţii cu colangită acută și icter mecanic au necesitat o atitudine promtă, în primile 24 – 48 ore efectuarea decompresiei biliare prin: (1) colangiopancreatografie retrogradă endoscopică cu sfincterotomie endoscopică (ERCP cu STE) la 380 pacienți (81%), cu amplasarea drenajului biliar intern – 48 pacienți (12,6%); (2) drenare transparietohepatică (TPH) la 19 pacienți (4%); (3) iar la 71 pacienți (15%) a fost imposibil tratamentului minim-invaziv. Cauzile ce au provocat icterul mecanic și colangitei au fost următoarele: coledocolitiaza -133 pacienți (35%), diverticuli parapapilari - 65 pacienți (17%), Tumora Klatskin - 10 pacienți (3%), stenoza papilei duodenale mari 152 pacienți (40%), neo cap de pancreas - 19 pacienți (5%). Concluzii: Examenul endoscopic ne permite determinarea cauzei și rezolvarea ei unimomental, indiferent de gradul severității colangitei acute și nivelul de obstrucție al căilor biliare. Necesitatea în specialiști și tehnică endoscopică este considerabilă, pentru a acoperi problema dată.Background: Severe acute cholangitis and mechanical jaundice develops concomitant with other impairments of the hepato-biliopancreato-duodenal region and changes in the large duodenal papillary. Purpose: The importance of minimally invasive treatment in the diagnosis and treatment of acute cholangitis and mechanical jaundice. Methods and materials: The retrospective analysis of 470 patients in the IMSP IMU during 2016-2017. Patient selection was performed according to the clinical-imaging diagnosis of obstructive jaundice and anamnesis. Results: Male predominates in relation to 1: 1.3 (women: men), age group 61-70 years predominated - 136 patients (29%), followed by 71-80 years - 106 patients (22 , 5%) and 41-50 years - 106 patients (22,5%), over 80 years - 24 patients (5%). The late referral, mostly over 72 hours - 348 patients (74%). Patients with acute cholangitis and mechanical jaundice required a prompt attitude in the first 24 to 48 hours and biliary decompression was performed: (1) endoscopic retrograde cholangiopancreatography with endoscopic sphincterotomy (ERCP with spincterotomy) in 380 patients (81%) and internal biliary drainage insertion - 48 patients (12,6%); (2) trans-parieto-hepatic drainage in 19 patients (4%); (3) and in 71 patients (15%), minim-invasive treatment was impossible. Causes of jaundice and cholangitis were: cholecystitis - 133 patients (35%), parapapillary diverticulitis - 65 patients (17%), Klatskin Tumor - 10 patients (3%), high duodenal duct stenosis 152 patients (40%), neo pancreas head - 19 patients (5%). Conclusion: The endoscopic examination allows us to determine the cause and solve it unimodal regardless to the severity of the acute cholangitis and the level of obstruction of the bile ducts. The need for specialists and endoscopic technicians is considerable in order to cover the problem

New Stability-Indicating RP-HPLC Method for Determination of Diclofenac Potassium and Metaxalone from their Combined Dosage Form

A simple, precise and accurate isocratic RP-HPLC stability-indicating assay method has been developed to determine diclofenac potassium and metaxalone in their combined dosage forms. Isocratic separation was achieved on a Hibar-C18, Lichrosphere-100® (250 mm × 4.6 mm i.d., particle size 5 μm) column at room temperature in isocratic mode, the mobile phase consists of methanol: water (80:20, v/v) at a flow rate of 1.0 ml/min, the injection volume was 20 μl and UV detection was carried out at 280nm. The drug was subjected to acid and alkali hydrolysis, oxidation, photolysis and heat as stress conditions. The method was validated for specificity, linearity, precision, accuracy, robustness and system suitability. The method was linear in the drug concentration range of 2.5–30 μg/ml and 20–240 μg/ml for diclofenac potassium and metaxalone, respectively. The precision (RSD) of six samples was 0.83 and 0.93% for repeatability, and the intermediate precision (RSD) among six-sample preparation was 1.63 and 0.49% for diclofenac potassium and metaxalone, respectively. The mean recoveries were between 100.99–102.58% and 99.97–100.01% for diclofenac potassium and metaxalone, respectively. The proposed method can be used successfully for routine analysis of the drug in bulk and combined pharmaceutical dosage forms

Identification of a Contiguous 6-Residue Determinant in the MHV Receptor That Controls the Level of Virion Binding to Cells

AbstractMurine carcinoembryonic antigens serve as receptors for the binding and entry of the enveloped coronavirus mouse hepatitis virus (MHV) into cells. Numerous receptor isoforms are now known, and each has extensive differences in its amino terminal immunoglobulin-like domain (NTD) to which MHV binds via its protruding spike proteins. Some of these receptor alterations may affect the ability to bind viral spikes. To identify individual residues controlling virus binding differences, we have used plasmid and vaccinia virus vectors to express two forms of MHV receptor differing only in their NTD. The two receptors, designated biliary glycoproteins (Bgp) 1aand 1bNTD, varied by 29 residues in the 107 amino acid NTD. When expressed from cDNAs in receptor-negative HeLa cells, these two Bgp molecules were displayed on cell surfaces to equivalent levels, as both were equally modified by a membrane-impermeant biotinylation reagent. Infectious center assays revealed that the 1aisoform was 10 to 100 times more effective than 1bNTDin its ability to confer sensitivity to MHV (strain A59) infection. Bgp1awas also more effective than Bgp1bNTDin comparative virus adsorption assays, binding 6 times more MHV (strain A59) and 2.5 times more MHV (strain JHMX). Bgp1awas similarly more effective in promoting the capacity of viral spikes to mediate intercellular membrane fusion as judged by quantitation of syncytia following cocultivation of spike and receptor-bearing cells. To identify residues influencing these differences, we inserted varying numbers of 1bresidues into the Bgp1abackground via restriction fragment exchange and site-directed mutagenesis. Analysis of the resulting chimeric receptors showed that residues 38 to 43 of the NTD were key determinants of the binding and fusion differences between the two receptors. These residues map to an exposed loop (C-C′ loop) in a structural model of the closely related human carcinoembryonic antigen