23 research outputs found
Implementation of Quality Management System in Iranian Medical Laboratories
"nReference health Laboratory of Iran (RHL) has been established under the Secretary of Health in 2007. This organization has been developed from integration of Reference laboratories of Iran, Directorate of General Affairs and Laboratory de­partment of CDC. In accordance with policies of Ministry of Health and Medical Education, also Millennium Development Goals and requirements of IHR the RHL has highlighted his main goal as "Quality Improvement of Medical Laboratory Net­work". In order to achieve this goal as soon and efficient as possible, RHL has tried to launch Quality Management sys­tem in medical laboratories. After studying and analyzing the situation in the country RHL has tried by using ISO 15189 which is an successful international standard to draw national standards and write necessary manuals, guidelines and check­lists. For a successful implementation and detailed managerial observance, three phases were designed: Training, Stepwise imple­mentation of standard requirements in the laboratories, accreditation of laboratories. After one year of training and send­ing out national standards and guidelines, the RHL is in the middle of the second phase "implementation"
Activity, stability and structure of laccase in betaine based natural deep eutectic solvents
Natural deep eutectic solvents (NADES) play a role as alternative media to water in living organisms. They are formed by mixing two or more natural compounds in certain ratios producing a liquid having a lower melting point than those of the individual NADES components. Although, the eutectics medium bring several advantages as enhanced solubility of non-polar substrates and/or products, however, these advantages would often be limited by a lower stability of biocatalysts in these systems. To examine this matter, biochemical characterization, thermal stability and tertiary structure of laccase from Bacillus HR03 was investigated as a model in betaine and choline based NADES. In eutectics containing choline, a sudden drop in enzyme activity and stability was observed. Betaine based eutectics exhibited a better media for the laccase stability in comparison with the aqueous buffer and choline chloride eutectics. The enzyme highest activity was observed in 20 (v/v) glycerol:betaine (2:1). Among betaine based eutectics, the enzyme exhibited its highest stability in sorbitol:betaine:water (1:1:1) and glycerol:betaine (2:1) compared to the aqueous buffer at 80 and 90 °C. Associated conformational changes caused by solvents were monitored using fluorescence technique. Finally, the effects of NADES on the enzyme activity and stability were discussed. © 2017 Elsevier B.V
Activity, stability and structure of laccase in betaine based natural deep eutectic solvents
Natural deep eutectic solvents (NADES) play a role as alternative media to water in living organisms. They are formed by mixing two or more natural compounds in certain ratios producing a liquid having a lower melting point than those of the individual NADES components. Although, the eutectics medium bring several advantages as enhanced solubility of non-polar substrates and/or products, however, these advantages would often be limited by a lower stability of biocatalysts in these systems. To examine this matter, biochemical characterization, thermal stability and tertiary structure of laccase from Bacillus HR03 was investigated as a model in betaine and choline based NADES. In eutectics containing choline, a sudden drop in enzyme activity and stability was observed. Betaine based eutectics exhibited a better media for the laccase stability in comparison with the aqueous buffer and choline chloride eutectics. The enzyme highest activity was observed in 20 (v/v) glycerol:betaine (2:1). Among betaine based eutectics, the enzyme exhibited its highest stability in sorbitol:betaine:water (1:1:1) and glycerol:betaine (2:1) compared to the aqueous buffer at 80 and 90 °C. Associated conformational changes caused by solvents were monitored using fluorescence technique. Finally, the effects of NADES on the enzyme activity and stability were discussed. © 2017 Elsevier B.V
Challenges of Implementing Iranian National Laboratory Standards
After four years of publishing the Iranian National Laboratory Standard and following a strategic plan to implement its requirements, it was decided to review the taken actions, evaluating the achievements and the failures, as well as analyzing the gaps and planning the interventional activities to resolve the problems. A thorough evaluation revealed that the progress of implementation process varies considerably in different provinces, as well as in laboratories in different public and private sectors. Diversity and heterogeneousity of laboratories throughout the country is one of unresolvable problems. Although we encounter shortage of resources in the country, improper allocation or distribution of resources and budgets make the problems more complicated. Inadequacy of academic training in laboratory sciences has resulted in necessity of holding comprehensive post-graduate training courses. Revising academic curriculum of laboratory sciences could be mostly helpful, moreover there should be organized, training courses with pre-determined practical topics. providing specific technical guidelines, to clarify the required technical details could temporarily fill the training gaps of laboratory staff. Inadequate number of competent auditors was one of the difficulties in universities. Another important challenge returns to laboratory equipment, developing the national controlling system to manage the laboratory equipment in terms of quality and accessibility has been planned in RHL. At last cultural problems and resistance to change are main obstacles that have reduced the pace of standardization, it needs to rationalize the necessity of establishing laboratory standards for all stakeholders
Eukaryotic DNA Polymerases in Homologous Recombination
Homologous recombination (HR) is a central process to ensure genomic stability in somatic cells and during meiosis. HR-associated DNA synthesis determines in large part the fidelity of the process. A number of recent studies have demonstrated that DNA synthesis during HR is conservative, less processive, and more mutagenic than replicative DNA synthesis. In this review, we describe mechanistic features of DNA synthesis during different types of HR-mediated DNA repair, including synthesis-dependent strand annealing, break-induced replication, and meiotic recombination. We highlight recent findings from diverse eukaryotic organisms, including humans, that suggest both replicative and translesion DNA polymerases are involved in HR-associated DNA synthesis. Our focus is to integrate the emerging literature about DNA polymerase involvement during HR with the unique aspects of these repair mechanisms, including mutagenesis and template switching
Benchmarked approaches for reconstruction of in vitro cell lineages and in silico models of C. elegans and M. musculus developmental trees.
The recent advent of CRISPR and other molecular tools enabled the reconstruction of cell lineages based on induced DNA mutations and promises to solve the ones of more complex organisms. To date, no lineage reconstruction algorithms have been rigorously examined for their performance and robustness across dataset types and number of cells. To benchmark such methods, we decided to organize a DREAM challenge using in vitro experimental intMEMOIR recordings and in silico data for a C. elegans lineage tree of about 1,000 cells and a Mus musculus tree of 10,000 cells. Some of the 22 approaches submitted had excellent performance, but structural features of the trees prevented optimal reconstructions. Using smaller sub-trees as training sets proved to be a good approach for tuning algorithms to reconstruct larger trees. The simulation and reconstruction methods here generated delineate a potential way forward for solving larger cell lineage trees such as in mouse