34 research outputs found
Association of Ficolin-3 with Severity and Outcome of Chronic Heart Failure
BACKGROUND: Inflammatory mechanisms involving complement activation has been shown to take part in the pathophysiology of congestive heart failure, but the initiating mechanisms are unknown. We hypothesized that the main initiator molecules of the lectin complement pathway mannose-binding lectin (MBL), ficolin-2 and ficolin-3 were related to disease severity and outcome in chronic heart failure. METHODS AND RESULTS: MBL, ficolin-2 and ficolin-3 plasma concentrations were determined in two consecutive cohorts comprising 190 patients from Hungary and 183 patients from Norway as well as controls. Disease severity and clinical parameters were determined at baseline, and all-cause mortality was registered after 5-years follow-up. In univariate analysis a low level of ficolin-3, but not that of MBL or ficolin-2, was significantly associated with advanced heart failure (New York Heart Association Class IV, p<0.001 for both cohorts) and showed inverse correlation with B- type natriuretic peptide (BNP) levels (r = -0.609, p<0.001 and r = -0.467, p<0.001, respectively). In multivariable Cox regression analysis, adjusted for age, gender and BNP, decreased plasma ficolin-3 was a significant predictor of mortality (HR 1.368, 95% CI 1.052-6.210; and HR 1.426, 95% CI 1.013-2.008, respectively). Low ficolin-3 levels were associated with increased complement activation product C3a and correspondingly decreased concentrations of complement factor C3. CONCLUSIONS: This study provides evidence for an association of low ficolin-3 levels with advanced heart failure. Concordant results from two cohorts show that low levels of ficolin-3 are associated with advanced heart failure and outcome. The decrease of ficolin-3 was associated with increased complement activation
High circulating osteoprotegerin levels are associated with non-zero blood groups
Background: Osteoprotegerin (OPG) and von Willebrand factor (VWF) form complex within endothelial cells and following secretion. The nature of blood group antigens strongly influences the levels of circulating VWF, but there is no available data concerning its ascendancy on OPG levels. We aimed to assess the relationship of AB0 blood groups with OPG, VWF levels (VWF: Ag) and collagen binding activity (VWF: CB) in peripheral arterial disease (PAD) patients. Methods: Functional and laboratory parameters of 105 PAD patients and 109 controls were examined. Results of OPG, VWF: Ag, VWF: CB (ELISA-s) were analysed by comparative statistics, together with clinical data. Results: OPG levels were higher in patients than in controls (4.64 ng/mL vs. 3.68 ng/mL, p < 0.001). Among patients elevation was marked in the presence of critical limb ischemia (5.19 ng/mL vs. 4.20 ng/mL, p = 0.011). The OPG in patients correlated positively with VWF: Ag and VWF: CB (r = 0.26, p = 0.008; r = 0.33, p = 0.001) and negatively with ankle-brachial pressure index (r = -0.22, p = 0.023). Furthermore, OPG was significantly elevated in non-0 blood groups compared to 0-groups both in patients and controls (4.95 ng/mL vs. 3.90 ng/mL, p = 0.012 and 4.09 ng/mL vs. 3.40 ng/mL, p = 0.002). Conclusions: OPG levels are associated to blood group phenotypes and higher in non-0 individuals. Increased OPG levels in PAD characterize disease severity. The significant correlation between OPG and VWF: CB might have functional importance in an atherothrombosis-prone biological environment
Hypertrophy of Rat Skeletal Muscle Is Associated with Increased SIRT1/Akt/mTOR/S6 and Suppressed Sestrin2/SIRT3/FOXO1 Levels
Despite the intensive investigation of the molecular mechanism of skeletal muscle hypertrophy, the underlying signaling processes are not completely understood. Therefore, we used an overload model, in which the main synergist muscles (gastrocnemius, soleus) of the plantaris muscle were surgically removed, to cause a significant overload in the remaining plantaris muscle of 8-month-old Wistar male rats. SIRT1-associated pro-anabolic, pro-catabolic molecular signaling pathways, NAD and H2S levels of this overload-induced hypertrophy were studied. Fourteen days of overload resulted in a significant 43% (p < 0.01) increase in the mass of plantaris muscle compared to sham operated animals. Cystathionine-β-synthase (CBS) activities and bioavailable H2S levels were not modified by overload. On the other hand, overload-induced hypertrophy of skeletal muscle was associated with increased SIRT1 (p < 0.01), Akt (p < 0.01), mTOR, S6 (p < 0.01) and suppressed sestrin 2 levels (p < 0.01), which are mostly responsible for anabolic signaling. Decreased FOXO1 and SIRT3 signaling (p < 0.01) suggest downregulation of protein breakdown and mitophagy. Decreased levels of NAD+, sestrin2, OGG1 (p < 0.01) indicate that the redox milieu of skeletal muscle after 14 days of overloading is reduced. The present investigation revealed novel cellular interactions that regulate anabolic and catabolic processes in the hypertrophy of skeletal muscle
Enhancement of entorhinal-dentate evoked potentials following repeated electroconvulsive shock seizures in the rat, neuroprotection studies
grantor:
University of TorontoBurnham and colleagues have recently shown that repeated ECS long-lasting and perhaps permanent enhancement in entorhinal-dentate evoked potentials (EPs) in rats. These studies, however, involved "unmodified" ECS, whereas, in clinical practice, ECT is now given in its "modified" form. Experiment 1, therefore, repeated the study of Burnham et al. (1995) using "modified" ECS. Despite the use of the "modified" procedure, a significant and long-lasting (up to 3 months) enhancement in population spike amplitude was seen in the ECS group. Stewart and Reid (1994) have reported that ketamine protects against EP enhancement following "unmodified" ECS. Experiment 2 was designed to confirm and extend the findings of Stewart and Reid (1994). Despite the use of ketamine, a significant enhancement in population spike amplitude was seen in the ECS groups. The "therapeutic" effect of ECS, however, as indexed by the Porsolt test, was diminished in animals receiving either ketamine or PB.M.Sc
Expression of erythropoietin and its receptor increases in colonic neoplastic progression: The role of hypoxia in tumorigenesis
Background: Tissue hypoxia is a characteristic patho-physiologic property of colorectal cancer. This process may also add to a therapeutic problem of solid tumor resistance to chemo- and radiation therapy. Erythropoietin (Epo) expression is induced by tissue hypoxia. Acting via its receptor (EpoR), Epo inhibits apoptosis of erythroid cells and has been shown to rescue neurons from hypoxic damage. Increased Epo and EpoR expression has been recently described in human breast, renal and cervical carcinoma. Given the characteristic tumor diathesis present in majority of colorectal cancers, we examined whether Epo signaling may play a role in colonic neoplastic progression. Materials and Methods: Expression of Epo and EpoR was examined using immunohistochemistry in 24 cases of primary colorectal and metastatic adenocarcinomas versus adenomas and normal colonic mucosa. Immunohistochemical stains were evaluated semiquantitatively based on a four-tiered scale. Based on the combination of extent and intensity of immunoreactivity, an immunostaining score (0-300) was determined for each sample. Expression of Epo and EpoR protein and mRNA was examined using Western blot and reverse transcriptase-polymerase chain reaction (RT-PCR), respectively, in both normal colonic tissue and carcinoma specimens in five cases. Results: Epo expression was sequentially increased in normal colonic mucosa (8.3 ± 5.6, mean ± SEM), adenoma (26.4 ± 9.1), primary carcinoma (96.1 ± 12.8) and metastatic carcinoma (122 ± 51.3). EpoR expression was also sequentially increased in normal colonic mucosa (22.3 ± 11.8), adenoma (108.7 ± 24.2), primary carcinoma (178.7 ± 16.6) and metastatic carcinoma (220 ± 58.3) (P< 0.05 for all results). Epo and EpoR showed enhanced expression in the areas adjacent to ischemia/necrosis. Western blot and RT-PCR analysis revealed increased EpoR protein and mRNA levels in carcinoma compared to normal mucosal colon specimens. Focal stromal Epo and EpoR immunoreactivity was present in 10 and 12 cases, respectively. Conclusions: The uniform increase in the expression of Epo and EpoR along the colonic neoplastic sequence and further increase in ischemic/necrotic areas indicates that the Epo signaling pathway is an important component in colon carcinogenesis including possible epithelial-stromal interactions
Induction of polyunsaturated fatty-acid synthesis enhances tolerance of a <i>cyanobacterium, Cylindrospermopsis raciborskii, </i>to low-temperature photoinhibition
470-476Acyl-lipid desaturation introduces double bonds (unsaturated bonds)
at specifically defined positions of fatty acids that are esterified to the
glycerol backbone of membrane glycerolipids. Desaturation pattern of the glycerolipids
of Cylindrospermopsis raciborskii (C.
raciborskii) , a filamentous cyanobacterial strain, was determined in
cells grown at 35°C and 25 °C. The lowering of the growth
temperature from 35°C to 25°C resulted in a considerable
accumulation of polyunsaturated octadecanoic fatty acids in all lipid classes.
Lipid unsaturation of C. raciborskii
was also compared to Synechocytis PCC6803. In C. raciborskii cells,
a shift in growth temperature induced a much more pronounced alteration in the
desaturation pattern of all lipid classes than in Synechocystis PCC6803.
The tolerance to low-temperature photoinhibition of the C. raciborskii cells
grown at 25uC and 35°C was al so compared to the tolerance of Synechocystis cells
grown at the same
temperatures. Lower growth temperature increased
the tolerance of C. raciborskii cells but not that of Synechocystis cells.
These results strengthen the importance of polyunsaturated glycerolipids in the
tolerance to environmental stresses and may give a physiological explanation
for the determinative role of C. raciborskii
strain in algal blooming in the Lake Balaton (Hungary).</span
Fluorescence lifetime imaging microscopy of synechocystis WT cells — variation in photosynthetic performance of individual cells in various strains of sp. PCC 6803
The FLIM (fluorescence lifetime imaging microscopy) technique allows picosecond fluorescence measurements at the level of the individual cell. Using this technique we were able to observe heterogeneity of cyanobacterial cells in a culture grown under controlled conditions and we were able to resolve structural variations within individual cells. It can be concluded that on the one hand the inhomogeneous distribution of photosynthetic pigments within the cell leads to variation of the fluorescence intensity, whereas on the other hand it is impossible to detect variation in the relative amounts of photosystem I and II throughout the cell. Different Synechocystis sp. PCC 6803 strain lines were compared to each other and differences were observed in the average fluorescence lifetimes obtained for individual cells of the various cell lines. The differences can be traced back to variable efficiency of excitation energy transfer from the phycobilisome antenna to the photosystems. We could successfully demonstrate that there is heterogeneity inside individual cells, within individual cultures, and between various wild-type cell lines