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

Traffic Network Control from Temporal Logic Specifications

We propose a framework for generating a signal control policy for a traffic network of signalized intersections to accomplish control objectives expressible using linear temporal logic. By applying techniques from model checking and formal methods, we obtain a correct-by-construction controller that is guaranteed to satisfy complex specifications. To apply these tools, we identify and exploit structural properties particular to traffic networks that allow for efficient computation of a finite state abstraction. In particular, traffic networks exhibit a componentwise monotonicity property which allows reach set computations that scale linearly with the dimension of the continuous state space

On the diophantine equation x2+2a3b73c=ynx^2+2^a3^b73^c=y^n

summary:In this paper, we find all integer solutions $(x, y, n, a, b, c)$ of the equation in the title for non-negative integers $a, b$ and $c$ under the condition that the integers $x$ and $y$ are relatively prime and $n \ge 3$. The proof depends on the famous primitive divisor theorem due to Bilu, Hanrot and Voutier and the computational techniques on some elliptic curves

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

TÜRKİYE’DE YAT İÇMEKAN TASARIMININ MALZEME SEÇİMİNE ETKİLERİ

Bu çalışmada, Türkiye’de inşa edilmiş üç farklı yatın tasarımı ile kullanılan malzemeleri arsındaki ilişkisi incelenmiştir. Türkiye, son yıllarda 24m üzeri yat inşasında (toplam boya göre) dünyada ilk sıralardadır. Yatlar genellikle ihraç edilerek döviz girdisi sağlanmaktadır. Bu girdiler, işçilik ve malzeme temelinde değerlendirilmelidir. Çünkü inşa maliyetinin %40’ını işçilik, %60’ını malzeme oluşturmaktadır. Yat sektörü, Türkiye’de, işçilik bakımından Batı Ülkeleri’nden görece ucuz fakat dünya kalitesinde hizmet sunarken katma değeri yüksek ürünlerin kullanımında ithal ağırlıklı bir faaliyet sergilemektedir. İthal ürün yoğunluklu üretim, sektör için bir tehdit unsuru olarak görülmelidir. Üretimi şekillendiren süreçlerin en önemli aşaması olan tasarım faaliyetinin bu tehdidi ortadan kaldırabilme potansiyeli vardır. Çünkü malzeme seçimi ve ürün detaylarının belirlenmesi bu aşamada gerçekleşir. Bu tehdide yönelik farkındalık oluşturma amacıyla, incelenen yatlarda kullanılan malzemeler, Tablo 1’deki 23 maddede ithal ve yerli ayrımıyla ortaya konularak önerilerde bulunulmuştur

Exchange processes and watermass modifications along the subarctic front in the North Pacific: Oxygen consumption rates and net carbon flux

Exchange processes along the subarctic front and the modification of subpolar water in the North Pacific are investigated using tracer data from World Ocean Circulation Experiment P14N and P17N lines. The North Pacific Current transports water on both sides of the subarctic front from the western to eastern North Pacific. During this transport, subpolar water from the western subpolar gyre becomes warmer and saltier through the main thermocline via isopycnal mixing with subtropical water. It is shown that this modified subpolar water of western origin is the primary source of well-ventilated water to the eastern subpolar gyre. The isopycnal mixing along the subarctic front is quantified with a two end-member linear mixing analysis using potential temperature, which allowed estimates of oxygen consumption and nitrate remineralization on intermediate layers. Based on the oxygen consumption estimates and temporal information from transient tracers, the vertically integrated oxygen consumption rate is calculated to be 2.1 ± 0.4 M m-2y-1 in the 132-706 m depth range. This implies a net carbon flux of approximately 19 ± 4 gC m-2y-1 out of the euphotic zone