Analyse structurale des fractions polysaccharidiques extraites de laparoi cellulaire d’Hypnea musciformis (Rhodophyceae, Gigartinales)

Structural analyze of polysaccharidic fractions extracted from the cellular wall of Hypnea musciformis (Rhodophyceae, Gigartinales)In Morocco, the industry of carrageenans (gelling and thickening) polysaccharides is not yet developed and the activity is reduced to the harvest and to the export in the raw state of some species of Gigartinaceae. Polysaccharides fractions of the cell wall of the carrageenophyte Hypnea  musciformis extracted according to their degree of solubility in water at various temperatures and increasing of ethanol concentration were analyzed quantitatively and qualitatively. Both methods of extraction show the homogeneity of the polymers extracted. The chemical composition of the phycocolloïds does not show important variations as regards the galactose and 3.6 anhydrogalactose which are the main constituents of the polysaccharide chain. Besides, sulfates are bound (connected) to the light fractions of carrageenans extracted according to the temperature and do not appear simultaneously during their synthesis according to the extraction to the ethanol. The IR and RMN of 13C spectroscopic analysis showed that the fractions extracted at different temperatures and concentrations of ethanol have de same structure. The carrageenans extracted from the wall of Hypnea musciformis is  omogenize of kappa type

NOX2, p22phox and p47phox are targeted to the nuclear pore complex in ischemic cardiomyocytes colocalizing with local reactive oxygen species.

BACKGROUND: NADPH oxidases play an essential role in reactive oxygen species (ROS)-based signaling in the heart. Previously, we have demonstrated that (peri)nuclear expression of the catalytic NADPH oxidase subunit NOX2 in stressed cardiomyocytes, e.g. under ischemia or high concentrations of homocysteine, is an important step in the induction of apoptosis in these cells. Here this ischemia-induced nuclear targeting and activation of NOX2 was specified in cardiomyocytes. METHODS: The effect of ischemia, mimicked by metabolic inhibition, on nuclear localization of NOX2 and the NADPH oxidase subunits p22(phox) and p47(phox), was analyzed in rat neonatal cardiomyoblasts (H9c2 cells) using Western blot, immuno-electron microscopy and digital-imaging microscopy. RESULTS: NOX2 expression significantly increased in nuclear fractions of ischemic H9c2 cells. In addition, in these cells NOX2 was found to colocalize in the nuclear envelope with nuclear pore complexes, p22(phox), p47(phox) and nitrotyrosine residues, a marker for the generation of ROS. Inhibition of NADPH oxidase activity, with apocynin and DPI, significantly reduced (peri)nuclear expression of nitrotyrosine. CONCLUSION: We for the first time show that NOX2, p22(phox) and p47(phox) are targeted to and produce ROS at the nuclear pore complex in ischemic cardiomyocytes

СОВРЕМЕННЫЕ МЕТОДЫ ЛЕЧЕНИЯ РЕЦИДИВНОГО НЕОПЕРАБЕЛЬНОГО ПЛОСКОКЛЕТОЧНОГО РАКА ГОРТАНИ (ОБЗОР ЛИТЕРАТУРЫ)

The literature review presents the modern methods of treatment of inoperable recurrent squamous cell cancer of the larynx. The application of radiation and chemotherapy.В обзоре литературы представлены данные о современных методах лечения неоперабельного рецидивного плоскоклеточного рака гортани. Рассматриваются вопросы применения лучевой и лекарственной терапии

Современные возможности консервативного и комбинированного лечения местнораспространенного рака гортани

The comparative analysis of results of conservative and combined treatment was carried out. The study group consisted of 400 patients with stage T3–4N0–3M0 laryngeal cancer who received concurrent chemotherapy and radiation therapy in combination with various physical radiomodifyers. The control group comprised 920 patients treated with the same technique but without systemic polychemotherapy. The 5-year relapse-free and overall survival rates were significantly higher in the study group than in the control group  (concervative treatment: 71 % and 86 % versus 37 % and 64.8 %, respectively, р<0,001 and combined treatment: 80 % and 83 % versus 47.4 % and 52 %, respectively(р<0,001). The functional organ was preserved in 71.2 % of locally advanced laryngeal cancer patients treated conservatively compared to 37.0 % of the control group patients. Oprgan-preserving surgeries were performed in 30.5% and 23%, respectively. The total number of patients with the larynx preservation was 50 % of the stydy group and 31.6 % of the control group.Проведен сравнительный анализ результатов консервативного и комбинированного лечения 400 больных (основная группа) раком гортани T3–4N0–3M0 стадии, которым применялась одновременная химиолучевая терапия в сочетании с различными физиче-скими радиомодификаторами и 920 пациентов (контрольная группа), пролеченных по аналогичным методикам, но без применения системной полихимиотерапии. Получено значимое повышение 5-летней безрецидивной и общей выживаемости в основной группе как при консервативном – 71 % и 86 %, в контрольной группе – 37 % (р<0,001) и 64,8 % (р<0,001), так и при комбинированном лечении – 80 % и 83 %, в контрольной группе – 47,4 % (р<0,001) и 52 % (р<0,001) соответственно. Сохранен функционирующий орган у 71,2 % больных местнораспространенным раком гортани при консервативном лечении по сравнению с 37,0 % в контроле, органосохраняющие хирургические вмешательства удалось провести у 30,5 % и 23,0 % пациентов соответственно. Всего гортань сохранена у 50 % больных основной группы, в  контрольной – у 31,6 %

Anthrax Lethal Toxin Suppresses Murine Cardiomyocyte Contractile Function and Intracellular Ca2+ Handling via a NADPH Oxidase-Dependent Mechanism

OBJECTIVES: Anthrax infection is associated with devastating cardiovascular sequelae, suggesting unfavorable cardiovascular effects of toxins originated from Bacillus anthracis namely lethal and edema toxins. This study was designed to examine the direct effect of lethal toxins on cardiomyocyte contractile and intracellular Ca(2+) properties. METHODS: Murine cardiomyocyte contractile function and intracellular Ca(2+) handling were evaluated including peak shortening (PS), maximal velocity of shortening/ relengthening (± dL/dt), time-to-PS (TPS), time-to-90% relengthening (TR(90)), intracellular Ca(2+) rise measured as fura-2 fluorescent intensity (ΔFFI), and intracellular Ca(2+) decay rate. Stress signaling and Ca(2+) regulatory proteins were assessed using Western blot analysis. RESULTS: In vitro exposure to a lethal toxin (0.05-50 nM) elicited a concentration-dependent depression on cardiomyocyte contractile and intracellular Ca(2+) properties (PS, ± dL/dt, ΔFFI), along with prolonged duration of contraction and intracellular Ca(2+) decay, the effects of which were nullified by the NADPH oxidase inhibitor apocynin. The lethal toxin significantly enhanced superoxide production and cell death, which were reversed by apocynin. In vivo lethal toxin exposure exerted similar time-dependent cardiomyocyte mechanical and intracellular Ca(2+) responses. Stress signaling cascades including MEK1/2, p38, ERK and JNK were unaffected by in vitro lethal toxins whereas they were significantly altered by in vivo lethal toxins. Ca(2+) regulatory proteins SERCA2a and phospholamban were also differentially regulated by in vitro and in vivo lethal toxins. Autophagy was drastically triggered although ER stress was minimally affected following lethal toxin exposure. CONCLUSIONS: Our findings indicate that lethal toxins directly compromised murine cardiomyocyte contractile function and intracellular Ca(2+) through a NADPH oxidase-dependent mechanism

Concerted Regulation of cGMP and cAMP Phosphodiesterases in Early Cardiac Hypertrophy Induced by Angiotensin II

Left ventricular hypertrophy leads to heart failure and represents a high risk leading to premature death. Cyclic nucleotides (cAMP and cGMP) play a major role in heart contractility and cyclic nucleotide phosphodiesterases (PDEs) are involved in different stages of advanced cardiac diseases. We have investigated their contributions in the very initial stages of left ventricular hypertrophy development. Wistar male rats were treated over two weeks by chronic infusion of angiotensin II using osmotic mini-pumps. Left cardiac ventricles were used as total homogenates for analysis. PDE1 to PDE5 specific activities and protein and mRNA expressions were explored

Intermittent Hypoxia-Induced Cognitive Deficits Are Mediated by NADPH Oxidase Activity in a Murine Model of Sleep Apnea

Background: In rodents, exposure to intermittent hypoxia (IH), a hallmark of obstructive sleep apnea (OSA), is associated with neurobehavioral impairments, increased apoptosis in the hippocampus and cortex, as well as increased oxidant stress and inflammation. Excessive NADPH oxidase activity may play a role in IH-induced CNS dysfunction. Methods and Findings: The effect of IH during light period on two forms of spatial learning in the water maze and well as markers of oxidative stress was assessed in mice lacking NADPH oxidase activity (gp91phox _/Y) and wild-type littermates. On a standard place training task, gp91phox _/Y displayed normal learning, and were protected from the spatial learning deficits observed in wild-type littermates exposed to IH. Moreover, anxiety levels were increased in wild-type mice exposed to IH as compared to room air (RA) controls, while no changes emerged in gp91phox _/Y mice. Additionally, wild-type mice, but not gp91phox _/Y mice had significantly elevated levels of NADPH oxidase expression and activity, as well as MDA and 8-OHDG in cortical and hippocampal lysates following IH exposures. Conclusions: The oxidative stress responses and neurobehavioral impairments induced by IH during sleep are mediated, at least in part, by excessive NADPH oxidase activity, and thus pharmacological agents targeting NADPH oxidase may provid

Over-expression of mitochondrial creatine kinase in the murine heart improves functional recovery and protects against injury following ischaemia–reperfusion

Aims Mitochondrial creatine kinase (MtCK) couples ATP production via oxidative phosphorylation to phosphocreatine in the cytosol, which acts as a mobile energy store available for regeneration of ATP at times of high demand. We hypothesized that elevating MtCK would be beneficial in ischaemia–reperfusion (I/R) injury. Methods and results Mice were created over-expressing the sarcomeric MtCK gene with αMHC promoter at the Rosa26 locus (MtCK-OE) and compared with wild-type (WT) littermates. MtCK activity was 27% higher than WT, with no change in other CK isoenzymes or creatine levels. Electron microscopy confirmed normal mitochondrial cell density and mitochondrial localization of transgenic protein. Respiration in isolated mitochondria was unaltered and metabolomic analysis by 1 H-NMR suggests that cellular metabolism was not grossly affected by transgene expression. There were no significant differences in cardiac structure or function under baseline conditions by cine-MRI or LV haemodynamics. In Langendorff-perfused hearts subjected to 20 min ischaemia and 30 min reperfusion, MtCK-OE exhibited less ischaemic contracture, and improved functional recovery (Rate pressure product 58% above WT; P < 0.001). These hearts had reduced myocardial infarct size, which was confirmed in vivo: 55 ± 4% in WT vs. 29 ± 4% in MtCK-OE; P < 0.0001). Isolated cardiomyocytes from MtCK-OE hearts exhibited delayed opening of the mitochondrial permeability transition pore (mPTP) compared to WT, which was confirmed by reduced mitochondrial swelling in response to calcium. There was no detectable change in the structural integrity of the mitochondrial membrane. Conclusions Modest elevation of MtCK activity in the heart does not adversely affect cellular metabolism, mitochondrial or in vivo cardiac function, but modifies mPTP opening to protect against I/R injury and improve functional recovery. Our findings support MtCK as a prime therapeutic target in myocardial ischaemia