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

Near-field direct antenna modulation

NFDAM systems provide a unique solution for transmitting highly secured direction-dependent data and hence preventing eavesdroppers from properly demodulating the signal. A 60-GHz proof-of-concept chip was designed and measured

Transmitter Architectures Based on Near-Field Direct Antenna Modulation

A near-field direct antenna modulation (NFDAM) technique is introduced, where the radiated far-field signal is modulated by time-varying changes in the antenna near-field electromagnetic (EM) boundary conditions. This enables the transmitter to send data in a direction-dependent fashion producing a secure communication link. Near-field direct antenna modulation (NFDAM) can be performed by using either switches or varactors. Two fully-integrated proof-of-concept NFDAM transmitters operating at 60 GHz using switches and varactors are demonstrated in silicon proving the feasibility of this approach

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

The short-time Dynamics of the Critical Potts Model

The universal behaviour of the short-time dynamics of the three state Potts model in two dimensions at criticality is investigated with Monte Carlo methods. The initial increase of the order is observed. The new dynamic exponent $\theta$ as well as exponent $z$ and $\beta/\nu$ are determined. The measurements are carried out in the very beginning of the time evolution. The spatial correlation length is found to be very short compared with the lattice size.Comment: 6 pages, 3 figure

Multinational Corporations and Governance of Political Activity

This article builds a conceptual framework to help explain the political behavior of multinational corporations (MNCs). I build on three streams of literature, i.e. heterogenous firms, global value chains, and governance, and provide an overarching framework to help understand firms’ political activities undertaken across value chain networks. I put forward a model that outlines MNCs’ coordination of political mobilization using their affiliates and subsidiaries in different jurisdictions and demonstrate models of governance they have at their disposal to reach political goals. I argue that the spread of global value chains allows firms to develop legal links with enterprises across borders through which they orchestrate political activity or delegate policy goals. The degree of flexibility between MNCs and associated firms determine the model of governance they undertake with corporations in their network. They engage in such costly coordination either to obtain legal standing in foreign jurisdictions or to cultivate a sort of critical mass that goes after a policy objective. I demonstrate the plausibility of my propositions with anecdotal evidence and identify future lines of research

Determination of the Critical Point and Exponents from short-time Dynamics

The dynamic process for the two dimensional three state Potts model in the critical domain is simulated by the Monte Carlo method. It is shown that the critical point can rigorously be located from the universal short-time behaviour. This makes it possible to investigate critical dynamics independently of the equilibrium state. From the power law behaviour of the magnetization the exponents $\beta / (\nu z)$ and $1/ (\nu z)$ are determined.Comment: 6 pages, 4 figure

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

Growth and feed utilization of goldfish (Carassius auratus) fed graded levels of brewers yeast (Saccharomyces cerevisiae)

In this study, a feeding trial was conducted to examine the potential of replacing fish meal with brewers yeast in practical diet of goldfish (Carassius auratus). Five isoproteic (37% CP) and isocaloric (3350 kcal/kg) diets were formulated to contain graded levels of brewers yeast. Fish meal protein was replaced by 0%, 15%, 25%, 35%, and 45% of yeast. Each diet was randomly allocated to triplicate groups of 20 fish (initial average weight of 0.56 g fish^-1) in glass aquarium (65L). Fish were fed three times per day to apparent satiation for 84 days. At the end of the experiment, weight gain, specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER), condition factor (CF), survival rate (SR), hepatosomatic indices (HSI) and body composition of goldfish fry were determined. According to the results, weight gain, SGR, FCR and PER of fish fed the diet including yeast replaced 35% of the fish meal were better than those of fish fed the other diets. There were no significant differences in SR and HSI values among fish fed diets (p>0.05). However, CF among fish fed the experimental diets was significantly different (p>0.05). Whole body composition was similar among fish fed different diets. The optimal replacement level of fishmeal protein by brewers yeast was determined by second-order polynomial regression to be (y= 2, 2237- 0,0004x^2 + 0,0279x; R² = 0,9977) 34.875%, on the basis of SGR