The effect of melatonin on bacterial translocation following ischemia/reperfusion injury in a rat model of superior mesenteric artery occlusion

Background: Acute mesenteric ischemia is a life-threatening vascular emergency resulting in tissue destruction due to ischemia-reperfusion injury. Melatonin, the primary hormone of the pineal gland, is a powerful scavenger of reactive oxygen species (ROS), including the hydroxyl and peroxyl radicals, as well as singlet oxygen, and nitric oxide. In this study, we aimed to investigate whether melatonin prevents harmful effects of superior mesenteric ischemia-reperfusion on intestinal tissues in rats. Methods: Rats were randomly divided into three groups, each having 10 animals. In group I, the superior mesenteric artery (SMA) was isolated but not occluded. In group II and group III, the SMA was occluded immediately distal to the aorta for 60 minutes. After that, the clamp was removed and the reperfusion period began. In group III, 30 minutes before the start of reperfusion, 10 mg/kg melatonin was administered intraperitonally. All animals were sacrified 24 hours after reperfusion. Tissue samples were collected to evaluate the I/R-induced intestinal injury and bacterial translocation (BT). Results: There was a statistically significant increase in myeloperoxidase activity, malondialdehyde levels and in the incidence of bacterial translocation in group II, along with a decrease in glutathione levels. These investigated parameters were found to be normalized in melatonin treated animals (group III). Conclusion: We conclude that melatonin prevents bacterial translocation while precluding the harmful effects of ischemia/reperfusion injury on intestinal tissues in a rat model of superior mesenteric artery occlusion. © 2015 Ozban et al.; licensee BioMed Central

Analytical solutions of the Klein-Fock-Gordon equation with the Manning-Rosen potential plus a Ring-Shaped like potential

In this work, on the condition that scalar potential is equal to vector potential, the bound state solutions of the Klein-Fock-Gordon equation of the Manning-Rosen plus ring-shaped like potential are obtained by Nikiforov-Uvarov method. The energy levels are worked out and the corresponding normalized eigenfunctions are obtained in terms of orthogonal polynomials for arbitrary $l$ states. The conclusion also contain central Manning-Rosen, central and non-central Hulth\'en potential.Comment: 14 pages. arXiv admin note: substantial text overlap with arXiv:1210.537

The place of D-dimer and L-lactate levels in the early diagnosis of acute mesenteric ischemia

INTRODUCTION: Acute mesenteric ischemia (AMI) is an abdominal-vascular emergency which is rare and has high mortality rates (60-80 %) due to late diagnosis (1-3). Although it is known that extravascular reasons like intestinal intussusception, volvulus, strangulated hernias and obstructions can cause intestinal gangrene, these are rarely the cause of AMI (1). MATERIALS AND METHODS: In this study, we used male Wistar-Albino rats weighing 250-300 grams obtained from Pamukkale University Experimental Research Laboratory. Animals were exposed to light-dark cycles for 12 hours and had free access to food and water. They were kept in cages for 7 days to stabilise their intestinal flora. In animals of group I, nothing was made other than taking 0.5 ml blood intracardially. In other animals, abdomen was reached with midline laparotomy and superior mesenteric artery (SMA) was located. In group II (operative control group), SMA was isolated and manipulated but was not ligated. In Group III (intestinal ischemia group), SMAwas isolated and ligated with 3/0 silk tie distally to the aorta. After this process, intestinal ischemia was achieved which was confirmed by paleness and pulselessness of intestines, caecum and right colon. Later on, abdomen was closed with double 3/0 polyglactin sutures. At postoperative 1st, 4th and 6th hours 0.5 ml blood was taken intracardially from the animals in groups II and III in order to quantify D-dimer and L-lactate levels. LABORATORY TESTS: D-dimer: Blood samples which were put into tubes containing sodium citrate, were seperated from plasma with centrifugation at 4000 rpm for 7 minutes. L-lactate: Blood L-lactate levels were determined from blood taken into capillary tubes with the help of immobilised enzyme electrode technology using YSI 1500 Sport portative lactate analyzer (Yellow Springs Instruments Inc., Ohio-USA). HISTOPATHOLOGIC VERIFICATION: Two cm long intestinal samples were taken from animals in which SMA was ligated in order to achieve mesenteric ischemia and these samples were fixed in 10 % formol. DISCUSSION: As a result, in rats with SMA occlusion serum D-dimer levels were not increased significantly when compared either in the group or with the basal values of the control group and values in operative control group. Therefore, it is concluded that D-dimer is not a useful marker for early diagnosis of AMI. On the other hand, it is revealed that blood L-lactate levels began to increase significantly following 4th hour of mesenteric ischemia and it is shown that this increase continued at the 6th hour. In addition, considering the utmost importance of the early diagnosis in patients with the clinical suspicion of AMI, L-lactate seems to be a suitable marker to use in emergency departments because it is achieved with a portable device that gives fast and accurate results. Nevertheless, our results are need to be supported by clinical studies with larger patient series (Tab. 2, Fig. 11, Ref. 39). Text in PDF www.elis.sk

Isotropic three-dimensional left-handed meta-materials

We investigate three-dimensional left-handed and related meta-materials based on a fully symmetric multi-gap single-ring SRR design and crossing continuous wires. We demonstrate isotropic transmission properties of a SRR-only meta-material and the corresponding left-handed material which possesses a negative effective index of refraction due to simultaneously negative effective permeability and permittivity. Minor deviations from complete isotropy are due to the finite thickness of the meta-material.Comment: 4 pages, 6 figure

The Strong Decay Patterns of the 1−+1^{-+} Exotic Hybrid Mesons

We calculate the coupling constants of the decay modes $1^{-+}\rightarrow\rho\pi, f_1\pi, b_1\pi, \eta\pi, \eta'\pi, a_1\pi, f_1\eta$ within the framework of the light-cone QCD sum rule. Then we calculate the partial width of these decay channels, which differ greatly from the existing calculations using phenomenological models. For the isovector $1^{-+}$ state, the dominant decay modes are $\rho\pi, f_1\pi$. For its isoscalar partner, its dominant decay mode is $a_1\pi$. We also discuss the possible search of the $1^{-+}$ state at BESIII, for example through the decay chains $J/\psi (\psi')\to \pi_1 +\gamma$ or $J/\psi (\psi')\to \pi_1 +\rho$ where $\pi_1$ can be reconstructed through the decay modes $\pi_1\to \rho\pi\to \pi^+\pi^-\pi^0$ or $\pi_1\to f_1(1285)\pi^0$. Hopefully the present work will be helpful to the experimental establishment of the $1^{-+}$ hybrid meson.Comment: 14 pages, 10 figure

Role of Alpha Oscillations During Short Time Memory Task Investigated by Graph Based Partitioning

In this study, we investigate the clustering pattern of alpha band (8 Hz - 12 Hz) electroencephalogram (EEG) oscillations obtained from healthy individuals during a short time memory task with 3 different memory loads. The retention period during which subjects were asked to memorize a pattern in a square matrix is analyzed with a graph theoretical approach. The functional coupling among EEG electrodes are quantified via mutual information in the time-frequency plane. A spectral clustering algorithm followed by bootstrapping is used to parcellate memory related circuits and for identifying significant clusters in the brain. The main outcome of the study is that the size of the significant clusters formed by alpha oscillations decreases as the memory load increases. This finding corroborates the active inhibition hypothesis about alpha oscillations