188 research outputs found
ACTIVE DYNAMICS OF THE ENZYMES OF THE ANTIRADICAL PROTECTION AND THE GENERAL ANTIOXIDATIVE ACTIVITY BY THE DEVELOPMENT OF THE EXPERIMENTAL ISCHEMIC REPERFUSION OF LIVER
The purpose of the study: to research the active changes in several enzymes of the antioxidative protection within the dynamical development of the liver reperfusion in rats. Materials and methods: the study has been performed on 95 white non-lineal male rats with the mass of 240-280 g divided into groups, the biological material of which has been sampled within 5-20 minutes of the ischemic period and 5-20 minutes of the reperfusion period with the interval of 5 minutes. To evaluate the changes of the antioxidative system the activity of the superoxide dismutase, the erythrocyte catalase and the liver homogenate as well as the general antioxidative activity have been determined. Results: the performed study has demonstrated the imbalance development for the relation between the activity of catalase and superoxide dismutase by the development of the ischemic reperfusion syndrome with the change of this relation to the prevalence of the catalase activity on the systemic level and the superoxide dismutase activity on the organic level after the circulatory restoration. Besides the increase in activity of the studied enzymes from the erythrocyte, meal by 2 times in comparison with the control group has been determined especially at the ischemic period as well as the tendencies to the progressive activity decrease of the same enzymes in the liver tissue. The general antioxidative activity in the period of ischemic reperfusion has been decreasing to the fifth minute of ischemia by 2 times and has lasted on the same level (0.04-0.05 mg/l of vitamin C in terms of 1 gram of homogenate protein) during the entire experiment. Conclusion: the received results have demonstrated the possibility for the evaluation of the functional state for the system of oxidative restorative homeostasis in an animal by ischemic reperfusion of the liver against the background of the lowered general antioxidative activity. It was marked also the necessity of the metabolic support of this link within the system of non-specific resistance for the correction of the developing disorders
New biological model of moderate inhibition of tumor and metastases growth with prolonged leukopenia in mice
A new biological model of moderate inhibition of tumor growth and metastases with prolonged leukopenia on C57BI/6 mice with the Lewis Lung Carcinoma was designed. The model was created by the injection of cyclophosphamide (dose 83.3 mg/kg) on 6th, 12th, 18th days after tumor cells transplantation on animals. Experiment showed that 3-fold cyclophosphamide use leads to growth of primary tumor and metastases inhibition. Tumor growth inhibition was 34 % on 21st day after cyclophosphamide inject. The number of metastases decreased by 4.7 times (p < 0,01). Metastatic area reduced. Metastasis frequency made 100 %. In addition, the course of cyclophosphamide application caused inhibition of granulocytic and lymphoid hematopoiesis. The reducing the number of segmented neutrophils and lymphocytes was showed on the 3rd day after 1, 2 and 3 injections of cyclophosphamide. The model can be used to study the efficacy of drugs in tumor therapy and in correction of such toxic manifestation of chemotherapy as leukopenia
Red fluorescent genetically encoded indicator for intracellular hydrogen peroxide
Reactive oxygen species (ROS) are conserved regulators of numerous cellular functions, and overproduction of ROS is a hallmark of various pathological processes. Genetically encoded fluorescent probes are unique tools to study ROS production in living systems of different scale and complexity. However, the currently available recombinant redox sensors have green emission, which overlaps with the spectra of many other probes. Expanding the spectral range of recombinant in vivo ROS probes would enable multiparametric in vivo ROS detection. Here we present the first genetically encoded red fluorescent sensor for hydrogen peroxide detection, HyPerRed. The performance of this sensor is similar to its green analogues. We demonstrate the utility of the sensor by tracing low concentrations of H2O2 produced in the cytoplasm of cultured cells upon growth factor stimulation. Moreover, using HyPerRed we detect local and transient H2O2 production in the mitochondrial matrix upon inhibition of the endoplasmic reticulum Ca(2+) uptake
КОСТНЫЙ ОБМЕН И МИНЕРАЛЬНАЯ ПЛОТНОСТЬ КОСТНОЙ ТКАНИ ПОЯСНИЧНЫХ ПОЗВОНКОВ У ЖЕНЩИН С ПЕРВИЧНЫМ БИЛИАРНЫМ ЦИРРОЗОМ ДО И ПОСЛЕ ОРТОТОПИЧЕСКОЙ ТРАНСПЛАНТАЦИИ ПЕЧЕНИ
Aim. To elucidate the role of cholestasis and menopausal status in the development of osteoporosis in women with primary biliary cirrhosis (PBC) before and after orthotopic liver transplantation (OLT). Methods and re- sults. There were fulfilled 74 estimations of biochemical markers of bone metabolism, estrogen (E2), parathy- roid hormone (PTH) endogenous secretion so as mineral content of lumbar vertebras in 21 women with PBC (10 women before and 17 in different terms after OLT). Bone turnover disturbances were characterized by delay of bone formation associated with hyperbilirubinaemia before OLT while increased bone turnover following OLT. Bone resorption markers correlated inversely with E2 in postmenopausal women and positively with PTH in premenopausal women. Conclusion. Bone wastes degree depended on hard and duration of disease before OLT so as menopausal status after OLT. In postmenopausal women bone wastes were associated with degree of endogenous E2 decreasing, increased bone turnover, and graft dysfunction. Цель исследования: изучение роли холестаза и менопаузального статуса в развитии остеопороза у женщин с первичным билиарным циррозом (ПБЦ) до и после ортотопической трансплантации печени (ОТП). Методы и результаты. У 21 женщины с ПБЦ (у 10 до и у 17 в различные сроки после ОТП) исследовали в динамике (74 исследования) биохимические маркеры костного обмена, минеральную плотность кости поясничных по- звонков, а также эндогенную секрецию эстрадиола (Е2) и паратиреоидного гормона (ПТГ). Нарушения кост- ного обмена до ОТП характеризовались подавлением костного формирования, связанным с гипербилируби- немией, после ОТП – ускорением костного обмена. Маркеры костной резорбции коррелировали обратно с секрецией Е2 у женщин в постменопаузе и прямо с секрецией ПТГ у женщин в пременопаузе. Заключение. До ОТП выраженность костных потерь была связана с тяжестью и продолжительностью холестаза, а после ОТП, кроме того, и с менопаузальным статусом. Костные потери у женщин в постменопаузе зависели от степени снижения эндогенной секреции Е2, ускорения костного обмена и дисфункции трансплантата.
Predicting Functional Alternative Splicing by Measuring RNA Selection Pressure from Multigenome Alignments
High-throughput methods such as EST sequencing, microarrays and deep sequencing have identified large numbers of alternative splicing (AS) events, but studies have shown that only a subset of these may be functional. Here we report a sensitive bioinformatics approach that identifies exons with evidence of a strong RNA selection pressure ratio (RSPR) —i.e., evolutionary selection against mutations that change only the mRNA sequence while leaving the protein sequence unchanged—measured across an entire evolutionary family, which greatly amplifies its predictive power. Using the UCSC 28 vertebrate genome alignment, this approach correctly predicted half to three-quarters of AS exons that are known binding targets of the NOVA splicing regulatory factor, and predicted 345 strongly selected alternative splicing events in human, and 262 in mouse. These predictions were strongly validated by several experimental criteria of functional AS such as independent detection of the same AS event in other species, reading frame-preservation, and experimental evidence of tissue-specific regulation: 75% (15/20) of a sample of high-RSPR exons displayed tissue specific regulation in a panel of ten tissues, vs. only 20% (4/20) among a sample of low-RSPR exons. These data suggest that RSPR can identify exons with functionally important splicing regulation, and provides biologists with a dataset of over 600 such exons. We present several case studies, including both well-studied examples (GRIN1) and novel examples (EXOC7). These data also show that RSPR strongly outperforms other approaches such as standard sequence conservation (which fails to distinguish amino acid selection pressure from RNA selection pressure), or pairwise genome comparison (which lacks adequate statistical power for predicting individual exons)
ОСНОВНЫЕ ЗАКОНОМЕРНОСТИ И ИНДИВИДУАЛЬНЫЕ ОСОБЕННОСТИ ЦИТОКИНОВОГО СТАТУСА ПРИ ИСКУССТВЕННОМ КРОВООБРАЩЕНИИ
The basic variants of cytokines reactions defining type of organ dysfunctions are revealed in the course of car- diopulmonary bypass and in the early postoperative period. Their character and expression, depends on gravity preoperative an immunodeficiency and initial degree of heart insufficiency. Diphasic dynamics of development of system inflammatory reaction is confirmed after cardiopulmonary bypass: increase of levels proinflammatory cytokines is in the first phase and anti-inflammatory cytokines with development immunodepression and cellular anergy in is the second phase. Also, key role IL-1Ra is revealed in restraint of hyperactivation of system inflam- matory reaction. Blood whey levels IL-6, IL-8, G-CSF, TNF-α and IL-1Ra should be defined to cardiopulmonary bypass, in 10–12 hours, 24 hours and 3 days after cardiopulmonary bypass and may be used as prognostic criteria of development of postoperative complications. В процессе искусственного кровообращения и в раннем послеоперационном периоде выявлены основ- ные варианты цитокиновых реакций, определяющих тип органных дисфункций, характер и выражен- ность которых зависят от тяжести дооперационного иммунодефицита и исходной степени сердечной не- достаточности. Подтверждена двухфазная динамика развития системной воспалительной реакции после искусственного кровообращения: повышение уровней провоспалительных цитокинов в первой фазе и сменой их на противовоспалительные цитокины с развитием иммунодепрессии и клеточной анергии во второй фазе, а также ключевая роль IL-1Ra в сдерживании гиперактивации системной воспалительной реакции. Сывороточные уровни IL-6, IL-8, G-CSF, TNF-α и IL-1Ra должны определяться до ИК, через 10–12 часов, 24 часа и 3 суток после ИК и могут быть использованы в качестве прогностических крите- риев развития послеоперационных осложнений.
Width of Gene Expression Profile Drives Alternative Splicing
Alternative splicing generates an enormous amount of functional and proteomic diversity in metazoan organisms. This process is probably central to the macromolecular and cellular complexity of higher eukaryotes. While most studies have focused on the molecular mechanism triggering and controlling alternative splicing, as well as on its incidence in different species, its maintenance and evolution within populations has been little investigated. Here, we propose to address these questions by comparing the structural characteristics as well as the functional and transcriptional profiles of genes with monomorphic or polymorphic splicing, referred to as MS and PS genes, respectively. We find that MS and PS genes differ particularly in the number of tissues and cell types where they are expressed.We find a striking deficit of PS genes on the sex chromosomes, particularly on the Y chromosome where it is shown not to be due to the observed lower breadth of expression of genes on that chromosome. The development of a simple model of evolution of cis-regulated alternative splicing leads to predictions in agreement with these observations. It further predicts the conditions for the emergence and the maintenance of cis-regulated alternative splicing, which are both favored by the tissue specific expression of splicing variants. We finally propose that the width of the gene expression profile is an essential factor for the acquisition of new transcript isoforms that could later be maintained by a new form of balancing selection
- …