ИССЛЕДОВАНИЕ ДИНАМИЧЕСКОГО ДИАПАЗОНА ЦИФРОВОЙ КАМЕРЫ НА ОСНОВЕ ТЕХНОЛОГИЙ ОБРАБОТКИ ЦИФРОВЫХ ИЗОБРАЖЕНИЙ

Digital images provide to determine photometric and colorimetric properties of objects subject to validation all elements of a measuring channel (digital camera, software, display) and solve the problem of their limited dynamic ranges. The aim of the study was to explore the dynamic range of a digital camera for use in photometric and colorimetric measurements.The Laboratory of Photonics at the Institute of Microelectronics and Optoelectronics (Warsaw Technical University, Poland) conducted a comparative experiment to determine the threshold of sensitivity, linearity and range of application the digital camera. Color target sets with certified brightness and chromaticity were created at the terminals and recorded with a digital camera with different exposure times. The authors propose a method to extend the dynamic range of a digital camera for red, green and blue color channel of intensities by pairing the calibration dependencies, and determine the true brightness and color of a point on the object by calculation.Calibration dependencies (triads) of digital camera for red, green and blue color channels intensities were constructed. These dependences allow determining lower and upper bounds of the dynamic range. Each triad has a form of the hysteresis loop. The experiment showed that the accuracy of this method is ± 3–5 %. Цифровые изображения позволяют определять фотометрические и колориметрические свойства объектов при условии валидации всех элементов измерительного канала (цифровой камеры, программного обеспечения, дисплея) и решения проблемы ограничения их динамических диапазонов. Целью работы являлось исследование динамического диапазона цифровой камеры для ее дальнейшего использования в фотометрических и колориметрических измерениях.Лаборатория фотоники в Институте микроэлектроники и оптоэлектроники (Варшавский технический университет, Польша) проводила сличительный эксперимент для определения порога чувствительности, линейности и диапазона применения цифровой камеры. Цветовые мишени были созданы на дисплее в виде аттестованных цветовых однородных полей и регистрировались с помощью цифровой камеры с пошагово увеличивающимся временем экспозиции, а затем осуществлялась обработка изображений и калибровка камеры в красном, зеленом и синем цветовых каналах для получения калибровочных зависимостей. Авторами предложен метод расширения динамического диапазона цифровой камеры для красного, зеленого и синего цветовых каналов интенсивностей посредством сопряжения градуировочных зависимостей и определения истинной яркости точки на объекте расчетным путем.Полученные калибровочные зависимости (триады) имели форму петли гистерезиса и позволили расчетным путем расширить динамический диапазон. Эксперименты показали, что точность данного метода составляет ± 3–5 %.

B cells and monocytes from patients with active multiple sclerosis exhibit increased surface expression of both HERV-H Env and HERV-W Env, accompanied by increased seroreactivity

<p>Abstract</p> <p>Background</p> <p>The etiology of the neurogenerative disease multiple sclerosis (MS) is unknown. The leading hypotheses suggest that MS is the result of exposure of genetically susceptible individuals to certain environmental factor(s). Herpesviruses and human endogenous retroviruses (HERVs) represent potentially important factors in MS development. Herpesviruses can activate HERVs, and HERVs are activated in MS patients.</p> <p>Results</p> <p>Using flow cytometry, we have analyzed HERV-H Env and HERV-W Env epitope expression on the surface of PBMCs from MS patients with active and stable disease, and from control individuals. We have also analyzed serum antibody levels to the expressed HERV-H and HERV-W Env epitopes. We found a significantly higher expression of HERV-H and HERV-W Env epitopes on B cells and monocytes from patients with active MS compared with patients with stable MS or control individuals. Furthermore, patients with active disease had relatively higher numbers of B cells in the PBMC population, and higher antibody reactivities towards HERV-H Env and HERV-W Env epitopes. The higher antibody reactivities in sera from patients with active MS correlate with the higher levels of HERV-H Env and HERV-W Env expression on B cells and monocytes. We did not find such correlations for stable MS patients or for controls.</p> <p>Conclusion</p> <p>These findings indicate that both HERV-H Env and HERV-W Env are expressed in higher quantities on the surface of B cells and monocytes in patients with active MS, and that the expression of these proteins may be associated with exacerbation of the disease.</p

Non-Raft AC2 Defines a cAMP Signaling Compartment That Selectively Regulates IL-6 Expression in Airway Smooth Muscle Cells

Adenylyl cyclase (AC) isoforms differ in their tissue distribution, cellular localization, regulation, and protein interactions. Most cell types express multiple AC isoforms. We hypothesized that cAMP produced by different AC isoforms regulates unique cellular responses in human bronchial smooth muscle cells (BSMC). Overexpression of AC2, AC3, or AC6 had distinct effects on forskolin (Fsk)-induced expression of a number of known cAMP-responsive genes. These data show that different AC isoforms can differentially regulate gene expression. Most notable, overexpression and activation of AC2 enhanced interleukin 6 (IL-6) expression, but overexpression of AC3 or AC6 had no effect. IL-6 production by BSMC was induced by Fsk and select G protein-coupled receptor (GPCR) agonists, though IL-6 levels did not directly correlate with global cAMP levels. Treatment with PKA selective 6-Bnz-cAMP or Epac selective 8-CPT-2Me-cAMP cAMP analogs revealed a predominant role for PKA in cAMP-mediated induction of IL-6. IL-6 promoter mutations demonstrated that AP-1 and CRE transcription sites were required for Fsk to stimulate IL-6 expression. Our present study defines an AC2 cAMP signaling compartment that specifically regulates IL-6 expression in BSMC via Epac and PKA and demonstrates that other AC isoforms are excluded from this pool

Novel Mouse Xenograft Models Reveal a Critical Role of CD4+ T Cells in the Proliferation of EBV-Infected T and NK Cells

Epstein-Barr virus (EBV), a ubiquitous B-lymphotropic herpesvirus, ectopically infects T or NK cells to cause severe diseases of unknown pathogenesis, including chronic active EBV infection (CAEBV) and EBV-associated hemophagocytic lymphohistiocytosis (EBV-HLH). We developed xenograft models of CAEBV and EBV-HLH by transplanting patients' PBMC to immunodeficient mice of the NOD/Shi-scid/IL-2Rγnull strain. In these models, EBV-infected T, NK, or B cells proliferated systemically and reproduced histological characteristics of the two diseases. Analysis of the TCR repertoire expression revealed that identical predominant EBV-infected T-cell clones proliferated in patients and corresponding mice transplanted with their PBMC. Expression of the EBV nuclear antigen 1 (EBNA1), the latent membrane protein 1 (LMP1), and LMP2, but not EBNA2, in the engrafted cells is consistent with the latency II program of EBV gene expression known in CAEBV. High levels of human cytokines, including IL-8, IFN-γ, and RANTES, were detected in the peripheral blood of the model mice, mirroring hypercytokinemia characteristic to both CAEBV and EBV-HLH. Transplantation of individual immunophenotypic subsets isolated from patients' PBMC as well as that of various combinations of these subsets revealed a critical role of CD4+ T cells in the engraftment of EBV-infected T and NK cells. In accordance with this finding, in vivo depletion of CD4+ T cells by the administration of the OKT4 antibody following transplantation of PBMC prevented the engraftment of EBV-infected T and NK cells. This is the first report of animal models of CAEBV and EBV-HLH that are expected to be useful tools in the development of novel therapeutic strategies for the treatment of the diseases

HIV infection and HERV expression: a review

The human genome contains multiple copies of retrovirus genomes known as endogenous retroviruses (ERVs) that have entered the germ-line at some point in evolution. Several of these proviruses have retained (partial) coding capacity, so that a number of viral proteins or even virus particles are expressed under various conditions. Human ERVs (HERVs) belong to the beta-, gamma-, or spuma- retrovirus groups. Endogenous delta- and lenti- viruses are notably absent in humans, although endogenous lentivirus genomes have been found in lower primates. Exogenous retroviruses that currently form a health threat to humans intriguingly belong to those absent groups. The best studied of the two infectious human retroviruses is the lentivirus human immunodeficiency virus (HIV) which has an overwhelming influence on its host by infecting cells of the immune system. One HIV-induced change is the induction of HERV transcription, often leading to induced HERV protein expression. This review will discuss the potential HIV-HERV interactions

Natural anti-CCR5 antibodies in HIV-infection and -exposure

Natural antibodies constitute a first-line of defence against pathogens; they may also play other roles in immune regulation and homeostasis, through their ability to bind host antigens, surface molecules and receptors. Natural anti-CCR5 antibodies can be decisive in preventing HIV infection in mucosal tissues and offer prompt and effective protection just at major sites of virus entry. Among natural anti-CCR5 antibodies, IgG and IgA to the ECL1 domain have been shown to block HIV effectively and durably without causing harm to the host. Their biological properties and their uncommon generation in subsets of HIV-infected and HIV-exposed individuals (so called ESN) will be introduced and discussed, with the aim at exploiting their potential in therapy and prevention