Development of guidelines on good manufacturing of biomedical cell products

The article presents the essence of draft of the Guidance of good manufacturing practices of biomedical cell products (BMCP) (GMP/GTP guideline) harmonized with the international requirements, which contains the basic quality and safety standards of clinical application of these products. These regulations prescribe the requirements for institutions engaged in one or more stages of BMCP production and allow to avoid any risk of contamination of cells, tissues and finished product. The aim of this work is to develop a methodology for BMCPs' quality assurance framework. Materials and methods. The main subjects of research are national and international laws and regulations, publications on quality assurance systems of cell products, problems of BMCP manufacturing and validation. Results. The draft Guidance of good manufacturing practices of BMCP (GMP/GTP guideline), including specific requirements to donor determination, biomaterial sampling and its transportation to the manufacture, to risk management system, traceability system, to processing, definition of minimally manipulated BMCP, requirements to incoming control, continuous in-process control and control of finished BMCP, to pharmacovigilance system were developed. Specific features of the manufacture of test products for non-clinical and clinical studies are described. Assessment elements for certification prior to release of each batch of test BMCP were clarified. Recommendations on the introduction of a product coding system according to ISBT 128 Standard are given in this work

Применение численного моделирования в исследовании мемристивных структур на основе оксидов и халькогенидов

Models that describe bipolar resistive switching in planar microstructures based on oxide compounds (Bi2Sr2CaCu2O8+x, Nd2-xCexCuO4-y) and bismuth selenide are considered. Metal-isolator-metal planar-type meristor heterostructures were investigated, in which the micro-size is formed by an electrode whose diameter is much smaller than the total size of the structure (it can be both Chervinsky-type microjunctions and film electric electrodes). Another important feature of these heterostructures is the presence of a surface layer several tens of nanometers thick with specific conductivity significantly reduced relative to volume. The change in the resistive properties of such heterostructures is caused by the formation or destruction of the conductive channel through the above-mentioned layer. Numerical simulation has shown that the bipolar resistive switching is significantly influenced by the electrical field distribution topology. A “critical field” model is proposed to describe experimentally observed memristor effects in investigated heterostructures. In this model it is assumed that the change in specific conductivity occurs in those parts of the surface layer where the electric field strength exceeds some critical value. The model of the “critical field” is based on the numerical calculation of the distribution of electrical potential on the distribution of specific conductivity in the structure. In addition, the model allowing to analyze the influence of electrodiffusion of oxygen ions on resistive switching in heterostructures based on Bi2Sr2CaCu2O8+x is considered. At numerical realization of the models a combination of the integro-differential approximation of the differential equations, the multi-grid approach for localization of heterogeneities of physical characteristics, the iterative decomposition method and composite adaptive meshes was used. It allowed tracking the processes under investigation with necessary accuracy. The comparison of simulation results with experimental data is presented.Рассмотрены модели, которые описывают биполярные резистивные переключения в планарных микроструктурах, созданных на основе оксидных соединений (Bi2Sr2CaCu2O8+x, Nd2-xCexCuO4-y) и селенида висмута. Исследованы мемристивные гетероструктуры металл—изолятор—металл планарого типа, в которых микроразмер формируется электродом, диаметр которого значительно меньше общего размера структуры (это могут быть и микроконтакты шарвинского типа, и пленочные электрические электроды). Другой важной особенностью этих гетероструктур является наличие поверхностного слоя толщиной несколько десятков нанометров с удельной проводимостью, значительно пониженной относительно объемной. Изменение резистивных свойств подобных гетероструктур обусловлено формированием или разрушением проводящего канала через указанный слой. Численное моделирование показало, что при этом на биполярные резистивные переключения значительное влияние оказывает топология распределения электрического поля. Предложена модель «критического поля» для описания экспериментально наблюдаемых мемристивных эффектов в исследуемых гетероструктурах. В этой модели предполагается, что изменение удельной проводимости происходит в тех частях поверхностного слоя, где напряженность электрического поля превышает некоторое критическое значение. Модель «критического поля» основана на численном расчете распределения электрического потенциала по распределению удельной проводимости в структуре. Кроме того, рассмотрена модель позволяющая проанализировать влияние электродиффузии ионов кислорода на резистивные переключения в гетероструктурах на основе Bi2Sr2CaCu2O8+x. При численной реализации моделей использовалось сочетание интегро-разностной аппроксимации дифференциальных уравнений, многосеточного подхода для локализации неоднородностей физических характеристик, итерационного метода декомпозиции и составных адаптивных сеток. Это позволило с необходимой точностью отслеживать исследуемые процессы. Приведено сравнение результатов моделирования с экспериментальными данными

Evaluation of the influence of environmental factors on formation of oncologic morbidity of the Orenburg region

The aim of research is a studying of the cancer pathology in Orenburg and in some separate administrative areas. Areas with a high level of a morbidity of malignant neoplasms have been identified in children and adults. The risk’s evaluation of influence of certain carcinogens in ambient air and drinking water on health has been spent. Territories with a high level of risk have been established and priority pollutants have been identified that is causing high levels of risk.Целью исследования являлось изучение онкопатологии в Оренбуржье и в отдельных административных территориях. Выявлены территории с высоким уровнем заболеваемости злокачественными новообразованиями среди детей и взрослых. Проведена оценка риска влияния отдельных канцерогенов атмосферного воздуха и питьевой воды на состояние здоровья населения. Установлены территории с высоким уровнем риска, выявлены приоритетные поллютанты, обусловливающие высокие уровни риска

Centrosome misorientation reduces stem cell division during ageing

Asymmetric division of adult stem cells generates one self- renewing stem cell and one differentiating cell, thereby maintaining tissue homeostasis. A decline in stem cell function has been proposed to contribute to tissue ageing, although the underlying mechanism is poorly understood. Here we show that changes in the stem cell orientation with respect to the niche during ageing contribute to the decline in spermatogenesis in the male germ line of Drosophila. Throughout the cell cycle, centrosomes in germline stem cells ( GSCs) are oriented within their niche and this ensures asymmetric division. We found that GSCs containing misoriented centrosomes accumulate with age and that these GSCs are arrested or delayed in the cell cycle. The cell cycle arrest is transient, and GSCs appear to re- enter the cell cycle on correction of centrosome orientation. On the basis of these findings, we propose that cell cycle arrest associated with centrosome misorientation functions as a mechanism to ensure asymmetric stem cell division, and that the inability of stem cells to maintain correct orientation during ageing contributes to the decline in spermatogenesis. We also show that some of the misoriented GSCs probably originate from dedifferentiation of spermatogonia.University of Michigan ; March of Dimes Basil O'Conner Starter Scholar Research Award ; Searle Scholar Program ; NIH [P01 DK53074, R01GM072006]We thank C. Gonzalez, D. McKearin, N. Rusan, M. Peifer and the Bloomington Stock Center for fly stocks; R. Lehmann, C. Field and the Developmental Studies Hybridoma Bank for antibodies; M. Kiel and D. Nakada for help with X-ray irradiation; and S. Morrison and T. Mahowald for comments on the manuscript. This research was supported by a University of Michigan start-up fund, March of Dimes Basil O'Conner Starter Scholar Research Award and the Searle Scholar Program (to Y.M.Y.), and NIH grants P01 DK53074 (to M.T.F.) and R01GM072006 (to A.J.H.).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62879/1/nature07386.pd

Efficiency of Spermatogonial Dedifferentiation during Aging

Adult stem cells are critical for tissue homeostasis; therefore, the mechanisms utilized to maintain an adequate stem cell pool are important for the survival of an individual. In Drosophila, one mechanism utilized to replace lost germline stem cells (GSCs) is dedifferentiation of early progenitor cells. However, the average number of male GSCs decreases with age, suggesting that stem cell replacement may become compromised in older flies.Using a temperature sensitive allelic combination of Stat92E to control dedifferentiation, we found that germline dedifferentiation is remarkably efficient in older males; somatic cells are also effectively replaced. Surprisingly, although the number of somatic cyst cells also declines with age, the proliferation rate of early somatic cells, including cyst stem cells (CySCs) increases.These data indicate that defects in spermatogonial dedifferentiation are not likely to contribute significantly to an aging-related decline in GSCs. In addition, our findings highlight differences in the ways GSCs and CySCs age. Strategies to initiate or enhance the ability of endogenous, differentiating progenitor cells to replace lost stem cells could provide a powerful and novel strategy for maintaining tissue homeostasis and an alternative to tissue replacement therapy in older individuals

Differential Roles of HOW in Male and Female Drosophila Germline Differentiation

The adult gonads in both male and female Drosophila melanogaster produce gametes that originate from a regenerative pool of germline stem cells (GSCs). The differentiation programme that produces gametes must be co-ordinated with GSC maintenance and proliferation in order to regulate tissue regeneration. The HOW RNA-binding protein has been shown to maintain mitotic progression of male GSCs and their daughters by maintenance of Cyclin B expression as well as suppressing accumulation of the differentiation factor Bam. Loss of HOW function in the male germline results in loss of GSCs due to a delay in G2 and subsequent apoptosis. Here we show that female how mutant GSCs do not have any cell cycle defects although HOW continues to bind bam mRNA and suppress Bam expression. The role of HOW in suppressing germ cell Bam expression appears to be conserved between sexes, leading to different cellular outcomes in how mutants due to the different functions of Bam. In addition the role in maintaining Cyclin B expression has not been conserved so female how GSCs differentiate rather than arrest