101 research outputs found
Plankton lattices and the role of chaos in plankton patchiness
Spatiotemporal and interspecies irregularities in planktonic populations have been widely observed. Much research into the drivers of such plankton patches has been initiated over the past few decades but only recently have the dynamics of the interacting patches themselves been considered. We take a coupled lattice approach to model continuous-in-time plankton patch dynamics, as opposed to the more common continuum type reaction-diffusion-advection model, because it potentially offers a broader scope of application and numerical study with relative ease. We show that nonsynchronous plankton patch dynamics (the discrete analog of spatiotemporal irregularity) arise quite naturally for patches whose underlying dynamics are chaotic. However, we also observe that for parameters in a neighborhood of the chaotic regime, smooth generalized synchronization of nonidentical patches is more readily supported which reduces the incidence of distinct patchiness. We demonstrate that simply associating the coupling strength with measurements of (effective) turbulent diffusivity results in a realistic critical length of the order of 100 km, above which one would expect to observe unsynchronized behavior. It is likely that this estimate of critical length may be reduced by a more exact interpretation of coupling in turbulent flows
Murine hematopoietic stem cell activity is derived from pre-circulation embryos but not yolk sacs.
The embryonic site of definitive hematopoietic stem cell (dHSC) origination has been debated for decades. Although an intra-embryonic origin is well supported, the yolk sac (YS) contribution to adult hematopoiesis remains controversial. The same developmental origin makes it difficult to identify specific markers that discern between an intraembryonic versus YS-origin using a lineage trace approach. Additionally, the highly migratory nature of blood cells and the inability of pre-circulatory embryonic cells (i.e., 5-7 somite pairs (sp)) to robustly engraft in transplantation, even after culture, has precluded scientists from properly answering these questions. Here we report robust, multi-lineage and serially transplantable dHSC activity from cultured 2-7sp murine embryonic explants (Em-Ex). dHSC are undetectable in 2-7sp YS explants. Additionally, the engraftment from Em-Ex is confined to an emerging CD31+CD45+c-Kit+CD41- population. In sum, our work supports a model in which the embryo, not the YS, is the major source of lifelong definitive hematopoiesis
Humoral regulation of the immune answer at tuberculosis of lungs
The main task of immunological researches at tuberculosis - an assessment of a condition of the patient, definition of changes in immune system, studying of patogenesis of diseases. Concentration studying cytokines at the patients infected with M. tuberculosis, definition of regulation of the immune answer became the purpose of work. Research is conducted with participation of 39 people. They were united in three groups: 10 healthy people, 15 patients with lung tuberculosis, tuberculoma, 14 patients with infiltrative tuberculosis. Determined concentration cytokines by IL-1p, IL-4, IL-6, TNF-a, structure of leukocytes and lymphocytes, and also phagocyte activity of monocytes, neutrophils. It is established that balance change between cytokines is strategy of a survival for M. tuberculosis. One of main cytokines, defining resistance of immune system to tuberculosis, is TNF-a. Concentration of IL-ip in blood correlates with weight of infectious process at tuberculosis of lungs.Основная задача иммунологических исследований при туберкулезе - оценка состояния больного и выявление изменений в иммунной системе для выявления патогенеза заболевания. Целью работы стало изучение цитокинового профиля у больных, инфицированных М. tuberculosis для оценки гуморальной регуляции иммунного ответа. Исследование проведено с участием 39 человек, составивших три группы: 10 здоровых людей, 15 больных с диагнозом туберкулез легкого, туберкулома, 14 пациентов с инфильтративным туберкулезом. Определяли концентрацию цитокинов IL-1p, IL-4, IL-6, TNF-a, популяционный состав лейкоцитов и лимфоцитов, а также фагоцитарную активность моноцитов, нейтрофилов. Установлено, что изменение баланса между цитокинами является стратегией выживания для М. tuberculosis. Одним из основных цитокинов, определяющим устойчивость иммунной системы к туберкулезу является TNF-a. Концентрация IL-1p в крови коррелирует с тяжестью инфекционного процесса при туберкулезе легких
New approach to the assessment of functional and metabolic activity of phagocytes in phtisyotrytic practice
Phagocytosis - the protective mechanism of the person from pathogens. New ways of an assessment of metabolic activity of phagocytes cells give the chance to study reaction of an organism to M. tuberculosis. Studying of a new way of determination of metabolic activity of phagocytes of blood by a method of a flowing cellular flyuorimetriya became a research objective. Research was conducted with participation of 25 people: 15 patients with the diagnosis tuberculoma a lung and 10 donors of blood. Statistical processing is carried out with Microsoft Office Excel 2007 program and STATISTICA use. Changes of phagocytes activity of cages, the main indicators of a cellular link of immune system at patients with tuberculoma are noted. The quantity of phagocytes cells cages decreases. Reduction of quantity of NK-, В - and T-cells and their subpopulations is noted. Decrease multidirectional also depends on a sex of the person.Фагоцитоз - универсальный защитный механизм организма человека от патогенов. Новые способы оценки функционально-метаболической активности фагоцитов позволяют изучать реакцию организма на М. Tuberculosis, что лежит в основе патогенетической терапии. Целью исследования стало изучение возможностей нового способа определения функционально-метаболической активности фагоцитов крови с применением метода проточной цитофлюориметрии. Данное исследование проводилось с участием 25 человек: 15 больных с диагнозом туберкулома легкого и 10 доноров крови. Статистическая обработка проведена с использованием программы Microsoft Office Excel 2007 и STATISTICA v 6.0. Установлены изменения фагоцитарной активности клеток и основных показателей клеточного звена иммунной системы у пациентов с туберкуломами. Отмечалось значительное снижение числа фагоцитирующих клеток, уменьшение количества основных иммунокопетентных клеток - NK-, В- и Т-клеток, а также их субпопуляций. Снижение было разнонаправленным и зависело от гендерного признака
Impact of the phase of activity of tuberculosis on treatment outcomes in renal cavity (poly-cavity) tuberculosis cases
The goal of the study was to investigate the ways of efficiency increasing of treatment and to develop of differential surgical tactics, estimate the volume of operations, its abilities and ef-ficacy to use them in patients with cavity (poly-cavity) forms of renal tuberculosis. With the help of morphology the activity of renal tuberculosis was estimated. The results of surgical treatment in patients (n=107) with cavity and poly-cavity renal tuberculosis (ТВ), operated at different phases of ТВ activity. Detected that frequency of ТВ process progressing was the less low the longer was the conservative anti-ТВ therapy. It’s necessary to notice that in the case of isolated locus of destruction or “closed" cavity (cavern) in renal parenchyma the ade-quate and standardized long-term conservative anti-ТВ treatment was not the guarantee for treatment success. Only operation for ТВ locus sanitation in complex with long-term anti-ТВ chemotherapy was the right way to reach the satisfactory results of treatment.Целью настоящей работы явилось изучение путей повышения эффективности лечения, разработка дифференцированной тактики хирургического лечения, объема операций, возможности и эффективности их выполнения у больных с кавернозными (поликавернозными) формами туберкулеза почек. С помощью морфологических исследований изучена направленность активности туберкулезного процесса. Изучены результаты хирургического лечения больных туберкулезом мочевых органов (ТМО) у 107 больных кавернозным и поликавернозным туберкулезом почек, оперированных в различные фазы активности туберкулезного процесса. Установлено, чем длительнее, консервативная противотуберкулезная терапия, тем меньше частота выявления прогрессирования туберкулезного процесса. Однако следует подчеркнуть, что при наличии изолированного очага деструкции почечной ткани или «замкнутой» каверны, проведение адекватного и длительного курса туберкулостатической терапии по стандартным режимам не является гарантий излечения туберкулеза. Лишь оперативное вмешательство, направленное на санацию очага инфекции в сочетании с длительной туберкулостатической терапией позволяет добиться положительных результатов лечения
The European Hematology Association Roadmap for European Hematology Research. A Consensus Document
Abstract
The European Hematology Association (EHA) Roadmap for European Hematology Research highlights major achievements in diagnosis and treatment of blood disorders and identifies the greatest unmet clinical and scientific needs in those areas to enable better funded, more focused European hematology research. Initiated by the EHA, around 300 experts contributed to the consensus document, which will help European policy makers, research funders, research organizations, researchers, and patient groups make better informed decisions on hematology research. It also aims to raise public awareness of the burden of blood disorders on European society, which purely in economic terms is estimated at Euro 23 billion per year, a level of cost that is not matched in current European hematology research funding. In recent decades, hematology research has improved our fundamental understanding of the biology of blood disorders, and has improved diagnostics and treatments, sometimes in revolutionary ways. This progress highlights the potential of focused basic research programs such as this EHA Roadmap. The EHA Roadmap identifies nine sections in hematology: normal hematopoiesis, malignant lymphoid and myeloid diseases, anemias and related diseases, platelet disorders, blood coagulation and hemostatic disorders, transfusion medicine, infections in hematology, and hematopoietic stem cell transplantation. These sections span 60 smaller groups of diseases or disorders. The EHA Roadmap identifies priorities and needs across the field of hematology, including those to develop targeted therapies based on genomic profiling and chemical biology, to eradicate minimal residual malignant disease, and to develop cellular immunotherapies, combination treatments, gene therapies, hematopoietic stem cell treatments, and treatments that are better tolerated by elderly patients.
Received December 15, 2015.
Accepted January 27, 2016.
Copyright © 2016, Ferrata Storti Foundatio
The European Hematology Association Roadmap for European Hematology Research: a consensus document
The European Hematology Association (EHA) Roadmap for European Hematology Research highlights major achievements in diagnosis and treatment of blood disorders and identifies the greatest unmet clinical and scientific needs in those areas to enable better funded, more focused European hematology research. Initiated by the EHA, around 300 experts contributed to the consensus document, which will help European policy makers, research funders, research organizations, researchers, and patient groups make better informed decisions on hematology research. It also aims to raise public awareness of the burden of blood disorders on European society, which purely in economic terms is estimated at €23 billion per year, a level of cost that is not matched in current European hematology research funding. In recent decades, hematology research has improved our fundamental understanding of the biology of blood disorders, and has improved diagnostics and treatments, sometimes in revolutionary ways. This progress highlights the potential of focused basic research programs such as this EHA Roadmap.
The EHA Roadmap identifies nine ‘sections’ in hematology: normal hematopoiesis, malignant lymphoid and myeloid diseases, anemias and related diseases, platelet disorders, blood coagulation and hemostatic disorders, transfusion medicine, infections in hematology, and hematopoietic stem cell transplantation. These sections span 60 smaller groups of diseases or disorders.
The EHA Roadmap identifies priorities and needs across the field of hematology, including those to develop targeted therapies based on genomic profiling and chemical biology, to eradicate minimal residual malignant disease, and to develop cellular immunotherapies, combination treatments, gene therapies, hematopoietic stem cell treatments, and treatments that are better tolerated by elderly patients
Surgical management of tuberculous ureteritis
We compared long-term outcome in 73 patients with tuberculous ureteritis treated with early urine derivation (EUD) and antituberculous drug therapy (ADT) versus only ADT. 46 patients underwent EUD: 22 - percutaneous nephrostomy, 17 — open one, 14 -ureteral stenting, 27 - received only ADT. Rates of renal function preservation obtained with EUD and ADT was not equally good: 70,8-94,4% and 37,0% consequently. It was shown that EUD increase the opportunity for later reconstructive surgery and decrease the likelihood of renal loss in tuberculous ureteritis.С целью оптимизации результатов комплексного лечения туберкулеза почки и мочеточника изучены отдаленные исходы у 73 больных. Чрескожная пункционная нефростомия выполнена 22, циркулярная -1 7 , стентирование мочеточника - 14 и из них, только консервативную терапию получали 27. Установлено, что своевременное отведение мочи позволяет сохранить функцию почек в 70,8-94,4% случаев и только в 37,0% - без декомпрессии почки. Применение ранней декомпрессии почки приводит к снижению количества органоуносящих и увеличению числа реконструктивно-восстановительных операций при туберкулезном уретерите
Inductive interactions mediated by interplay of asymmetric signalling underlie development of adult hematopoietic stem cells
During embryonic development, adult haematopoietic stem cells (HSCs) emerge preferentially in the ventral domain of the aorta in the aorta-gonad-mesonephros (AGM) region. Several signalling pathways such as Notch, Wnt, Shh and RA are implicated in this process, yet how these interact to regulate the emergence of HSCs has not previously been described in mammals. Using a combination of ex vivo and in vivo approaches, we report here that stage-specific reciprocal dorso-ventral inductive interactions and lateral input from the urogenital ridges are required to drive HSC development in the aorta. Our study strongly suggests that these inductive interactions in the AGM region are mediated by the interplay between spatially polarized signalling pathways. Specifically, Shh produced in the dorsal region of the AGM, stem cell factor in the ventral and lateral regions, and BMP inhibitory signals in the ventral tissue are integral parts of the regulatory system involved in the development of HSCs
Intrinsic factors and the embryonic environment influence the formation of extragonadal teratomas during gestation
Background: Pluripotent cells are present in early embryos until the levels of the pluripotency regulator Oct4 drop at the beginning of somitogenesis. Elevating Oct4 levels in explanted post-pluripotent cells in vitro restores their pluripotency. Cultured pluripotent cells can participate in normal development when introduced into host embryos up to the end of gastrulation. In contrast, pluripotent cells efficiently seed malignant teratocarcinomas in adult animals. In humans, extragonadal teratomas and teratocarcinomas are most frequently found in the sacrococcygeal region of neonates, suggesting that these tumours originate from cells in the posterior of the embryo that either reactivate or fail to switch off their pluripotent status. However, experimental models for the persistence or reactivation of pluripotency during embryonic development are lacking.
Methods: We manually injected embryonic stem cells into conceptuses at E9.5 to test whether the presence of pluripotent cells at this stage correlates with teratocarcinoma formation. We then examined the effects of reactivating embryonic Oct4 expression ubiquitously or in combination with Nanog within the primitive streak (PS)/tail bud (TB) using a transgenic mouse line and embryo chimeras carrying a PS/TB-specific heterologous gene expression cassette respectively.
Results: Here, we show that pluripotent cells seed teratomas in post-gastrulation embryos. However, at these stages, induced ubiquitous expression of Oct4 does not lead to restoration of pluripotency (indicated by Nanog expression) and tumour formation in utero, but instead causes a severe phenotype in the extending anteroposterior axis. Use of a more restricted T(Bra) promoter transgenic system enabling inducible ectopic expression of Oct4 and Nanog specifically in the posteriorly-located primitive streak (PS) and tail bud (TB) led to similar axial malformations to those induced by Oct4 alone. These cells underwent induction of pluripotency marker expression in Epiblast Stem Cell (EpiSC) explants derived from somitogenesis-stage embryos, but no teratocarcinoma formation was observed in vivo.
Conclusions: Our findings show that although pluripotent cells with teratocarcinogenic potential can be produced in vitro by the overexpression of pluripotency regulators in explanted somitogenesis-stage somatic cells, the in vivo induction of these genes does not yield tumours. This suggests a restrictive regulatory role of the embryonic microenvironment in the induction of pluripotency
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