The relationship between L-arginine/ADMA ratio and coronary collateral development in patients with low glomerular filtration rate

Background: It is yet to be established which factors are responsible for differences among patients with the same degree of coronary artery disease in terms of coronary collateral development (CCD). Methods: Patients who had a greater than or equal to 95% stenosis in at least one epicardial coronary artery were classified into two groups according to their glomerular filtration rate (GFR) level. Afterwards, the degree of CCD was evaluated according to their plasma concentration of asymmetric dimethylarginine (ADMA) and GFR levels. Results: Rentrop grade 2&#8211;3 was found more frequently in patients with GFR > 60 mL/min than in patients with GFR < 60 mL/min (68.6% vs 41.4%, p = 0.032). Then we divided patients into four groups according to their GFR levels and Rentrop grades; whereas we did not find any significant difference for L-arginine or ADMA levels (respectively p = 0.629 and p = 0.076), we did find a statistically significant difference between groups for L-arginine/ /ADMA ratio (p = 0.003) and this statistically significant difference was evident between patients with GFR 60 mL/min and Rentrop 2&#8211;3 (1.23 vs 1.69, p < 0.001). Multivariate logistic regression analysis revealed that L-arginine/ADMA ratio was the only variable which had a significant effect on CCD (OR = 1.016; 95% CI 1.001&#8211;1.031, Wald = 4.565; p = 0.033). Conclusions: These results showed that CCD was poor in patients with GFR < 60 mL/min, presumably because of the adverse effect of decreased L-arginine/ADMA ratio on endothelial cells and angiogenesis. (Cardiol J 2012; 19, 1: 29&#8211;35

A Fusion-Based Framework for Wireless Multimedia Sensor Networks in Surveillance Applications

Multimedia sensors enable monitoring applications to obtain more accurate and detailed information. However, the development of efficient and lightweight solutions for managing data traffic over wireless multimedia sensor networks (WMSNs) has become vital because of the excessive volume of data produced by multimedia sensors. As part of this motivation, this paper proposes a fusion-based WMSN framework that reduces the amount of data to be transmitted over the network by intra-node processing. This framework explores three main issues: 1) the design of a wireless multimedia sensor (WMS) node to detect objects using machine learning techniques; 2) a method for increasing the accuracy while reducing the amount of information transmitted by the WMS nodes to the base station, and; 3) a new cluster-based routing algorithm for the WMSNs that consumes less power than the currently used algorithms. In this context, a WMS node is designed and implemented using commercially available components. In order to reduce the amount of information to be transmitted to the base station and thereby extend the lifetime of a WMSN, a method for detecting and classifying objects on three different layers has been developed. A new energy-efficient cluster-based routing algorithm is developed to transfer the collected information/data to the sink. The proposed framework and the cluster-based routing algorithm are applied to our WMS nodes and tested experimentally. The results of the experiments clearly demonstrate the feasibility of the proposed WMSN architecture in the real-world surveillance applications

DNA Repair Based Therapy in Oncology and Neurodegeneration

WOS: 000378333000015

POTENTIAL PROTECTIVE ROLE OF SDF-1 AND CXCR4 GENE VARIANTS IN THE DEVELOPMENT OF DEMENTIA

Background: The aim of this study was to evaluate the role of polymorphisms of stromal cell-derived factor-1 (SDF-1) and chemokine receptor-4 (CXCR4) genes in dementia susceptibility in a Turkish population. Subjects and methods: The study group included 61 dementia patients, while the control group comprised 82 healthy individuals. Gene polymorphisms of SDF-1 3’A G801A (rs1801157) and CXCR4 C138T (rs2228014) were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. Results: A significantly reduced risk for developing dementia was found for the group bearing an A allele for SDF-1 3’A polymorphism (p=0.009; x2=6.812; OR=0.626; 95%CI= 0.429-0.913). The frequency of the CXCR4 TT and TC genotype was significantly lower in patients with dementia compared to controls (p=0.028; x2=5.583; OR=0.215; 95%CI=0.05-0.914); (p=0.027; x2=4.919; OR=0.484; 95% CI= 0.246-0.955). Additionally, combined genotype analysis showed that the frequency of SDF1 GACXCR4 CC was significantly lower in patients with dementia in comparison with those of controls (p=0.049; OR=0.560; 95% CI= 0.307±1.020). Conclusions: Our study provides new evidence that SDF1 A and CXCR4 T alleles may be associated with a decreased dementia risk. The present study is important because to our knowledge, it is the first one to be conducted in a Turkish population to date, but we believe that more patients and controls are needed to obtain statistically significant results

Comparative in vitro studies on PBN loaded nanoparticles prepared by biodegradable chitosan, PLGA polymers and their PEGylated block copolymers

α-phenyl-N-tert-butyl nitrone (PBN) is a neuroprotective free radical scavenger however it has low in vivo stability and blood residence time. Aim. of this study is to develop a nanoparticle formulation by using different polymeric system which enhance the blood residence time and in vivo stability of PBN and characterize in terms of particle size, zeta potential, morphology, encapsulation efficiency, in vitro release profiles. Chitosan (CS), poly(D,L-lactide-co-glycolide) (PLGA) and their poly(ethylene glycol) (PEG) block co-polymers were used for comparative study. Results showed that particle sizes of CS, CS-PEG, PLGA and PLGA-PEG nanoparticles are between 142-356 nm. PLGA nanoparticles and their block copolymers' nanoparticle have greatly monodisperse distribution. CS and CS-PEG nanoparticles have zeta potential values between 17-40 mV related to amine groups, contrariwise PLGA and PLGA-PEG nanoparticles have negative zeta potential in the range of (-8)-(-19) mV. Encapsulation efficiency and loading capacity for all formulations are between 12-54 %, 9-68 %, respectively. PLGA-PEG nanoparticles are promising for further studies due to their sufficient encapsulation efficiency and in vitro release profilesAuthors would like to acknowledge that this project was financially supported by Tubitak (Scientific Research Project Number: 110S460)S

An aquaporin 4 antisense oligonucleotide loaded, brain targeted nanoparticulate system design

Aquaporins (AQPs), members of the water-channel protein family, are highly expressed in brain tissue especially in astrocytic end-feet. They are important players for water hemostasis during development of cytotoxic as well as vasogenic edema. Increased expression of AQPs is important in pathophysiology of neurological diseases such as neuroinflammation and ischemia. Unfortunately, there are a few pharmacological inhibitors of AQP4 with several side effects limiting their translation as a drug for use in clinical conditions. Another therapeutic approach is using antisense oligonucleotides (ASOs) to block AQP4 activity. These are short, synthetic, modified nucleic acids that bind RNA to modulate its function. However, they cannot pass the blood brain barrier (BBB). To overcome this obstacle we designed a nanoparticulate system made up of chitosan nanoparticles surface modified with PEG and conjugated with monoclonal anti transferrin receptor-1 antibody via streptavidin-biotin binding. The nanocarrier system could be targeted to the transferrin receptor-1 at the brain endothelial capillaries through monoclonal antibodies. It is hypothesized that the nanoparticles could pass the BBB via receptor mediated transcytosis and reach brain parenchyma. Particle size, zeta potential, loading capacity and release profiles of nanoparticles were investigated. It was observed that all types of chitosau (CS) nanoparticles had positive zeta potential values and nanoparticle particle size distribution varied between 100 and 800 nm. The association efficiency of ASOs into the nanoparticles was between 80–97% and the release profiles of the nanoparticles exhibited an initial burst effect followed by a controlled release. The results showed that the designed chitosan based nanocarriers could be a promising carrier system to transport nucleic acid based drugs to brain parenchymaThis study is supported by The Scientific and Technological Research Council of Turkey (TUBITAK, Project Number: 110S460)S

Systemically Administered Brain-Targeted Nanoparticles Transport Peptides across the Blood—Brain Barrier and Provide Neuroprotection

Although growth factors and anti-apoptotic peptides have been shown to be neuroprotective in stroke models, translation of these experimental findings to clinic is hampered by limited penetration of peptides to the brain. Here, we show that a large peptide like the basic fibroblast growth factor (bFGF) and a small peptide inhibitor of caspase-3 (z-DEVD-FMK) can effectively be transported to the brain after systemic administration by incorporating these peptides to brain-targeted nanoparticles (NPs). Chitosan NPs were loaded with peptides and then functionalized by conjugating with antibodies directed against the transferrin receptor-1 on brain endothelia to induce receptor-mediated transcytosis across the blood—brain barrier (BBB). Pre-ischemic systemic administration of bFGF- or z-DEVD-FMK-loaded NPs significantly decreased the infarct volume after 2-hour middle cerebral artery occlusion and 22-hour reperfusion in mice. Co-administration of bFGF- or z-DEVD-FMK-loaded NPs reduced the infarct volume further and provided a 3-hour therapeutic window. bFGF-loaded NPs were histologically detected in the brain parenchyma and also restored ischemia-induced Akt dephosphorylation. The neuroprotection was not observed when receptor-mediated transcytosis was inhibited with imatinib or when bFGF-loaded NPs were not conjugated with the targeting antibody, which enables them to cross the BBB. Nanoparticles targeted to brain are promising drug carriers to transport large as well as small BBB-impermeable therapeutics for neuroprotection against strokeTurgay Dalkara’s work is supported by the Turkish Academy of Sciences. This study is supported by The Scientific and Technological Research Council of Turkey (TUBITAK, Project Number: 109S017)S

Safety and efficacy of PNL vs RIRS in the management of stones located in horseshoe kidneys: A critical comparative evaluation

Aim: To assess the efficacy and safety of two different techniques (Percutaneous nephrolithotomy (PNL) vs Retrograde intrarenal surgery (RIRS)) in the management of stones in patients with horseshoe kidneys (HSK). Patients and methods: Departmental files of 88 cases with radiopaque kidney stones in horseshoe kidneys undergoing two different approaches (PNL vs RIRS) were evaluated with respect to the success and complication rates of in a retrospective manner. In addition to the factors related with the procedures (success and complication rates, additional procedures), patient and stone characteristics were all well evaluated. Findings obtained in both groups were evaluated in a comparative manner with respect to the statistical significance. Results: Stone free rates were comparable in both groups after 1-week period (81.6% PNL vs 80% RIRS). As well as 3 months evaluation (84.2% PNL and 82.0% RIRS). The percentage of the cases with residual fragments (> 4 mm) were similar in both groups and while all PNL procedures were completed in one session, mean number of RIRS sessions was higher (1.22 ± 0.05). Mean duration of the procedure was slightly higher in RIRS group and based on Clavien scoring system, despite a higher risk of Hb drop noted in patients treated with PNL, all complication rates were found to be similar in both groups. Conclusion: Our results demonstrate that of the available minimally invasive treatment alternatives, both PNL and RIRS could be safe and effective alternatives for renal stone removal in patients with HSK