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Department of Gastroenterology, İstanbul University Cerrahpaşa Medical School İstanbul/Turkey. hulyauzunismail@gmail.com.
Background/aims: This study was designed to assess the role of foods with raised IgG antibodies and additives on the symptoms and inflammation of Crohn's disease. Methods: Eight patients with Crohn's disease in remission were studied. They followed a strict diet during phase I. Then, provocations with two, three-day periods (phases II and III) followed: in phase II, pure forms of foods with high IgG antibodies and in phase III, off-the-shelf forms of those foods were added. Stool samples were collected for fecal calprotectin assay. Blood samples were taken on the 11th and 17th days for highly sensitive C-reactive protein, ferritin, erythrocyte sedimentation rate, white blood cells, and platelets. Patients kept a diet-symptom diary. Results: Increased Crohn's disease activity index scores were found statistically significant (p=0.012) between pre- and during the provocation weeks. There were significant increases according to Harvey-Bradshaw Index when the highest values during the phases I, II (p=0.027) and I, III (p=0.027) were compared. The increases in highly sensitive C-reactive protein (p=0.025) and white blood cells (p= 0.036) were found statistically significant. Fecal calprotectin levels showed day-to-day variability. When compared, the levels of fecal calprotectin increased in all patients on the last day of the restriction (10th day) and the first day of the provocation (11th day) with the exception of one patient. Conclusions: Foods with raised IgG antibody levels and food additives can provoke the symptoms and may stimulate the inflammation in patients with Crohn's disease. Addition of a proper diet with restriction of those foods may be beneficial in the medical treatment.
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ABSTRACT Replication Protein A (RPA) is known to interact with G-rich sequences that adopt G-quadruplex (GQ) structures. Most studies in the literature have been performed on GQ formed by homogenous sequences, such as the human telomeric repeat, and RPA's ability to unfold GQ structures of differing stability is not known. We compared the thermal stability of three potential GQ forming DNA sequences (PQS) to their stability against RPA mediated unfolding using single molecule FRET and bulk biophysical and biochemical experiments. One of these sequences is the human telomeric repeat and the other two located in the promoter region of tyrosine hydroxylase gene are highly heterogeneous sequences, which better represent PQS in the genome. The three GQ constructs have thermal stabilities that are significantly different from each other. Our measurements showed that the most thermally stable structure (Tm= 86 °C) was also the most stable against RPA mediated unfolding, although the least thermally stable structure (Tm= 69 ºC) had at least an order of magnitude higher stability against RPA mediated unfolding compared to the structure with intermediate thermal stability (Tm= 78 ºC). The significance of this observation becomes more evident when considered within the context of cellular environment where protein-DNA interactions can be an important determinant of GQ viability. Considering these, we conclude that thermal stability is not necessarily an adequate criterion for predicting physiological viability of GQ structures. Finally, we measured the time it takes for an RPA molecule to unfold a GQ from a fully folded to a fully unfolded conformation using a single molecule stopped-flow type method. All three GQ structures were unfolded within Δt≈0.30±0.10 sec, a surprising result as the unfolding time does not correlate with thermal stability or stability against RPA mediated unfolding. These results suggest that the limiting step in G-quadruplex unfolding by RPA is simply the accessibility of the structure to the RPA protein.
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Obstetrics and Gynecology Department of Cerrahpaşa Medical Faculty, Istanbul University, Istanbul, Turkey Department of Genetics, Cerrahpaşa Medical Faculty, Istanbul University, Istanbul, Turkey.
Citation Karata S, Aydin Y, Ocer F, Buyru A, Balci H. Hereditary Thrombophilia, anti-beta2 glycoprotein 1 IgM, and anti-annexin V antibodies in recurrent pregnancy loss. Am J Reprod Immunol 2011 Problem We investigated the beta2-glycoprotein I and anti-annexin V antibodies as anti-phospholipid-cofactor antibodies; and factor V G1691A Leiden, prothrombin G20210A, and methylenetetrahydrofolate reductase (MTHFR) C677T mutations as hereditary thrombophilia in recurrent pregnancy losses (RPL). Method of study Study group consisted of 84 women with recurrent pregnancy loss and control group consisted of 84 women having at least one live birth. Results Methylenetetrahydrofolate reductase C677T homozygous mutation was detected in 28.5% of the study group and in 14.2% of the controls, and the difference was highly significant (P < 0.001). Heterozygous mutation of this gene was found in 64.3% of the study population and in 38.1% of the controls, and difference in heterozygous mutation frequency was also significant (P < 0.001). Both homozygous and heterozygous mutations of PT G20210A and factor V G1691A were not different between the groups. There was no significant difference in anti-annexin V levels and anti-beta2-gp 1 levels of the groups. Conclusion We concluded that both homozygous and heterozygous mutations of MTHFR C677T were related with RPL in Caucasian women.
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Physics Department, University of Illinois, Urbana, Illinois, USA.
The conformational states of Escherichia coli Rep helicase undergoing ATP hydrolysis while bound to a partial-duplex DNA (pdDNA) were studied using single-molecule FRET. Crystallographic studies showed that Rep bound to single-stranded DNA can exist in open and closed conformations that differ in the orientation of the 2B subdomain. FRET measurements between eight Rep mutants donor-labeled at different residues and pdDNA acceptor-labeled at the junction were conducted at each of the four nucleotide states. The positions of donor-labeled residues, based on crystal structure, and FRET measurements between these donor molecules and the acceptor fluorophore at the DNA junction were used to predict the most likely position for the DNA junction using a triangulation algorithm. These predicted junction positions are compared with the crystal structure to determine whether the open or closed conformation is more consistent with the FRET data. Our data revealed that there are two distinct Rep-pdDNA conformations in the ATPγS and ADP states, an unexpected finding. The primary conformation is similar to that observed in nucleotide-free and ADP.Pi states, and the secondary conformation is a novel conformation where the duplex DNA and 2B subdomain moved as a unit by 13 Å relative to the rest of the protein. The primary conformation found in all nucleotide states is consistent with the closed conformation of the crystal structure however; the secondary conformation is a new conformation that has not been observed before. We discuss the possible implications of this newly observed conformation.
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Department of Nephrology, Haydarpasa Numune Training and Research Hospital, Istanbul, Turkey. canbakbil@gmail.com
Liver biopsy is an imperfect gold standard for assessing the disease severity in hemodialysis patients with chronic hepatitis C. Our purpose was to compare the accuracy of the FibroTest (FT) and ActiTest (AT) with liver biopsy and the AST-to-platelet ratio index (APRI) in determining hepatic fibrosis and necroinflammatory activity in hemodialysis patients with hepatitis C virus (HCV). The FT-AT index combining 6 biochemical markers was assessed in 33 hemodialysis patients with HCV. Liver fibrosis and necroinflammatory activity was staged and graded according to the METAVIR scoring system. The accuracy of FT-AT versus biopsy was 0.46 for significant fibrosis and 0.36 for severe necroinflammatory activity. The FT index had a positive predictive value of 20% for scores greater than 0.6 and a negative predictive value of 45% for scores less than 0.2. Eleven of the 33 patients had scores ≤0.2, 6 had significant fibrosis on biopsy. Four out of 5 patients with FT scores >0.6 had mild fibrosis. APRI correlated well with the biopsy. The FT-AT test does not seem to be a reliable noninvasive marker for the prediction of necroinflammatory activity and fibrosis in hemodialysis patients with HCV and cannot be used as an alternative to either liver biopsy or APRI.
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Cerrahpasa Medical Faculty of Istanbul University, Department of Gastroenterology, Fatih, 34303 Istanbul, Turkey. canbakbil@gmail.com.
Aim: To evaluate the serum alanine aminotransferase (ALT) variabilities in nonalcoholic fatty liver disease (NAFLD) and correlate it with hepatocyte apoptosis and oxidative stress parameters. Methods: 24 patients with NAFLD and normal ALT were compared with 26 subjects with NAFLD and elevated ALT. Liver oxidative stress was estimated on the basis of malondialdehyde, superoxide dismutase and glutathione. Immunohistochemistry was performed for activated caspase 3 and 8, nuclear factor-kappaB, antiapoptotic Bcl-2 protein and serum TNF receptor levels were measured. Results: The mean caspase 3 and 8 activity scores, oxidative stress parameters, necroinflammatory grade and prevalence of severe fibrosis were comparable across the groups with normal versus elevated ALT. Patients with nonalcoholic steatohepatitis had significantly higher caspase 3 and 8 activity (percentage of cells with positive staining per high power field), and serum malondialdehyde (mmol/l) levels than those with simple steatosis. ALT elevation was not a risk factor for advanced necroinflammatory grade and fibrosis. A receiver operating characteristic curve did not demonstrate sensitivity and specificity for discriminative power of ALT. Conclusion: Apoptosis and oxidative stress are the main processes contributing to disease progression in NAFLD. ALT values do not correlate with the parameters of apoptosis and oxidative stress. The disease severity can only be determined by liver biopsy.
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From the Cerrahpasa Medical Faculty, University of Istanbul, Turkey.
OBJECTIVE:: The effect of ezetimibe on blood lipids, oxidative stress, and fibrinolytic activity in hyperlipidemic patients was investigated after three months of therapy. METHODS:: Thirty hyperlipidemic patients were treated for twelve weeks with ezetimibe 10 mg/day. A healthy control group with matching age and gender was also included. Fasting blood glucose, lipid parameters, paraoxonase (PON1), protein carbonyl (PCO), oxidized LDL (oxLDL), 8-isoprostane (ISOPR), total antioxidant capacity (TAC) levels, tissue-type plasminogen activator (tPA), plasminogen activator inhibitor type-1 (PAI-1), and PAI-1/t-PA levels were evaluated. RESULTS:: Ezetimibe therapy for twelve weeks led to changes in lipid profile in accordance with the literature. Fibrinolytic activity parameters, PAI-1/tPA and tPA-1 decreased, whereas PAI-1 levels did not change significantly. Antioxidant parameters, serum PON1 activity, and TAC levels increased significantly compared with the basal values. Oxidant parameters, oxLDL, ISOPR, and PCO (which is an indicator of oxidative protein damage) decreased significantly after therapy. CONCLUSIONS:: Ezetimibe therapy has beneficial effects on fibrinolytic activity and homeostasis between oxidant and antioxidant activity in hyperlipidemic patients This may be through lowering lipid levels or other mechanisms such as decreasing insulin resistance and the pleiotropic effects of the drug.
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Department of Biochemistry, Faculty of Dentistry, Marmara University, Istanbul, Turkey.
Aim: Tissue factor (TF) is a low-molecular-weight glycoprotein responsible for the initiation of the coagulation cascade. The relation between oxidized low-density lipoprotein (Ox-LDL), that has been shown to be involved in atherogenesis, and TF has not been evaluated before in circulating plasma. The aim of this study was to determine plasma levels of TF and Ox-LDL in acute coronary syndrome (ACS) and stable coronary artery disease (SCAD). Methods: The study group consisted of 41 patients with ACS and 26 patients with SCAD. Among the ACS patients, 12 were diagnosed with unstable angina pectoris (UAP) and 29 were diagnosed with acute myocardial infarction (AMI). The control group consisted of 30 healthy volunteers. TF and Ox-LDL levels were evaluated by ELISA kits. Results: Ox-LDL levels were significantly higher in UAP and AMI patients compared with the control (p < 0.001) and SCAD (p < 0.01 and p < 0.001, respectively) groups. TF levels were significantly higher in the UAP, AMI and SCAD groups compared with the control group (p < 0.001, p < 0.001 and p < 0.01, respectively). In the AMI group a significant increase was observed in TF levels when compared with the SCAD group (p < 0.01). Plasma Ox-LDL levels were significantly and positively correlated with TF levels in the UAP and AMI groups (p < 0.05, r = 702, and p < 0.0001, r = 0.679, respectively). Conclusion: Thepotential link between Ox-LDL and TF in circulating blood in ACS may strengthen the evidence supporting a relationship between oxidant stress, lipids and thrombosis and consequently may contribute to understanding the mechanism through which Ox-LDL and TF may mediate the pathogenesis of CAD.
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Istanbul University Medical School, Istanbul, Turkey. dr@erkalbilen.com
We retrospectively evaluated the results after ulnar lengthening and radial deformity correction using an external fixator for forearm deformities caused by osteochondromas. Eight forearms were treated surgically in seven patients with multiple hereditary osteochondroma. The mean follow-up time was 40 months (range, 20 to 60 months). The average radial articular angle improved from 43 degrees to 35.5 degrees (range, 28 to 56 degrees) and the carpal slip improved from 69.5% to 55%(range, 40 to 60%) postoperatively. The average shortening of the ulna was reduced from 2.06 cm to 0.44 cm (range 0 to 1 cm) after the treatment. There were no serious complications associated with the surgery; two minor pin track infections were successfully treated by local wound care and antibiotics. Although technically demanding, ulnar osteotomy and gradual lengthening by an external fixator provided promising results in the treatment of forearm deformities in children with multiple osteochondroma.
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2012-05-17 09:30:00 © BioInfoBank Institute