Some coumarins and benzoxazinones as potent paraoxonase 1 inhibitors

In this study, we aimed to investigate the effect of some coumarin and benzoxazinone derivatives on the activity of human PON1. Human serum paraoxonase 1 was purified from fresh human serum blood by two-step procedures that are ammonium sulfate precipitation (60–80%) and then hydrophobic interaction chromatography (Sepharose 4B, L-tyrosine and 1-napthylamine). The enzyme was purified 232-fold with a final specific activity of 27.1?U/mg. In vitro effects of some previously synthesized ionic coumarin or benzoxazinone derivatives (1–21) on purified PON1 activity were investigated. Compound 14 (1-(2,3,4,5,6)-pentamethylbenzyl-3-(6,8-dimethyl-2H-chromen-2-one-4-yl))benzimidazolium chloride was found out as the strongest inhibitor (IC₅₀?=?7.84?μM) for PON1 among the compounds. Kinetic investigation and molecular docking study were evaluated for one of the most active compounds (compound 12) and obtained data showed that this compound is competitive inhibitor of PON1 and interact with Leu262 and Ser263 in the active site of PON1. Moreover, coumarin derivatives were found out as the more potent inhibitors for PON1 than benzoxazinone derivatives.     

Development of a fast and low-cost qPCR assay for diagnosis of acute gas pharyngitis

Background

Group A streptococci (GAS) are the most common bacterial cause of acute pharyngitis and account for 15–30 % of cases of acute pharyngitis in children and 5–10 % of cases in adults. In this study, a real-time quantitative PCR (qPCR) based GAS detection assay in pharyngeal swab specimens was developed.

Methods

The qPCR assay was compared with the gold standard bacterial culture and a rapid antigen detection test (RADT) to evaluate its clinical performance in 687 patients. The analytical sensitivity of the assay was 240 cfu/swab. Forty-five different potential cross-reacting organisms did not react with the test. Four different laboratories for the reproducibility studies were in 100 % (60/60) agreement for the contrived GAS positive and negative swab samples.

Results

The relative sensitivities of the RADT and the qPCR test were 55.9 and 100 %; and the relative specificities were 100 and 96.3 %, respectively. Duration of the total assay for 24 samples including pre-analytical processing and analysis changed between 42 and 55 min depending on the type of qPCR instrument used. A simple DNA extraction method and a low qPCR volume made the developed assay an economical alternative for the GAS detection.

Conclusion

We showed that the developed qPCR test is rapid, cheap, sensitive and specific and therefore can be used to replace both antigen detection and culture for diagnosis of acute GAS pharyngitis.

     

Efficient top-<Emphasis Type="Italic">k</Emphasis> similarity document search utilizing distributed file systems and cosine similarity

Document similarity has important real life applications such as finding duplicate web sites and identifying plagiarism. While the basic techniques such as k-similarity algorithms have been long known, overwhelming amount of data, being collected such as in big data setting, calls for novel algorithms to find highly similar documents in reasonably short amount of time. In particular, pairwise comparison of documents’ features, a key operation in calculating document similarity, necessitates prohibitively high storage and computation power. In this paper, we propose a new filtering technique that decreases the number of comparisons between the query set and the search set to find highly similar documents. The proposed filtering technique utilizes Z-order prefix, based on the cosine similarity measure, in which only the most important features are used first to find highly similar documents. We propose a three-phase approach, where the phases are near duplicate detection, common important terms and join phase. We utilize the Hadoop distributed file system and the MapReduce parallel programming model to scale our techniques to big data setting. Our experimental results on real data show that the proposed method performs better than the previous work in the literature in terms of the number of joins, and therefore, speed.     

Rural and Urban Students’ Perceptions of and Attitudes toward Brown Bears in Turkey

Many studies have examined adults’ perceptions of and attitudes toward large carnivores to assess human–wildlife conflict and inform conservation strategies, but there have been few studies concerning children. I studied secondary school students’ perceptions of and attitudes toward brown bears (Ursus arctos) and other large mammals in Turkey via a questionnaire survey. The questionnaire, consisting of 18 questions, was completed by 215 rural and 98 urban secondary school students. Both sets of students liked bears; they were also afraid of them and unsure about living with them in the future. While there were no gender differences in attitudes and perceptions, there were marked differences between urban and rural students. Urban students had less contact with nature, gained more of their knowledge about bears from documentaries, and had less positive attitudes toward bears. They were also more likely to be afraid of species not present in Turkey, for example, anaconda, while rural students were most afraid of wild boars. Factor analysis identified three important themes: familiarity with bears, conservation of bears, and experiencing conflict with bears, which explained 49.8% of the variance in attitudes toward bears. The most important factor for the development of negative attitudes toward bears was personal experience of human–bear conflict, suggesting that measures to reduce human–bear conflict in rural areas may help to sustain students’ positive attitudes toward the conservation of bears.     

Hatchery performance in a major rainbow trout (Oncorhynchus mykiss,Walbaum, 1792) seed production area of Turkey

This study aims to determine the production characteristics and performance of rainbow trout hatcheries in Seydikemer, Mu?la, Turkey where over half of the total production of eyed eggs and juveniles take place. For this purpose six hatcheries with different production scales were selected and coded A, B, C, D, E and F (with capacities of 60, 15, 5.6, 4, 0.95 and 0.6 million juveniles per year, respectively). From each hatchery, 20 females were selected and their egg qualities (egg number, diameter and weight, fertilization, eyed egg, hatching, swim‐up fry and survival rates at 120 days after hatching) and juvenile growth rates were monitored until the 120^th day after hatching under each farms own conditions. The sperm characteristics of 10 broodstock males from each hatchery were also examined. Although fertilization and eyed egg rates were similar among the farms, hatching, swim‐up fry, and survival rates at the 120^th day after hatching differed significantly. The average eyed egg, hatching and survival rates (calculated from selected 20 females) were 72, 55, and 32%, respectively. While sperm characteristics except duration of motility (s), were significantly different among the farms, average sperm concentration (per ml), motility (%) and duration of motility (s) in the region were 11.8 × 10⁹, 55.3, and 56.4, respectively. The best hatchery performance was observed in Farm A because of better records and management applications than in the other farms.     

The effect of resveratrol on surgery-induced peritoneal adhesions in an experimental model

Adhesion formation is a common cause of complications following surgery. The aim of this study was to investigate the effect of resveratrol on intra-abdominal adhesion prevention in a rat model. Twenty one Wistar-Albino rats weighing 200-250 g were assigned to three groups, of 7 rats each. After a midline laparotomy was performed, a 1 cm area of the ceacum was abraded in two of the groups. They were then given either resveratrol (Group 1), or saline (Group 2) intraperitoneally. Group 3 rats (sham operation) received no treatment, without the serosal damage. On the 14th day, the rats were killed and the adhesion score was determined according to Mazuji's adhesion grade scale. The tissue levels of malondialdehyde (MDA), nitric oxide (NO), and reduced glutathione (GSH) were measured. The mean Mazuji's adhesion grade in the resveratrol group was 1.0 +/- 0.0, in the saline group 2.57 +/- 1.51, and zero in the sham operated group (p < 0.05 between the resveratrol group and saline group comparison). The levels of MDA and NO in the resveratrol group were significantly lower than those of the saline group (p < 0.001). The level of GSH in the resveratrol group was significantly higher than in the saline and sham operated groups (p < 0.001 and p < 0.001, respectively). Introduction of resveratrol into the peritoneal cavity at the time of surgery reduced adhesion formation effectively in this model. Resveratrol probably acts through reduction of lipid peroxidation products.     

Effects of vitamin K1 supplementation on vascular responsiveness and oxidative stress in a rat femoral osteotomy model

The main function of vitamin K1 is to act a co-factor for gamma-glutamyl carboxylase. However, it has also been shown to lessen oxidative stress. This study was aimed to evaluate the effect of vitamin K1 supplementation on vascular responsiveness and oxidative status in rats that underwent femoral osteotomy. Twenty-four male rats were divided into three groups to serve as sham, osteotomy and vitamin K1 groups. Indices of oxidative stress (catalase), and oxidative damage (malondialdehyde) were analysed in erythrocytes. In order to evaluate vascular reactivity, concentration-response curves to phenylephrine, angiotensin II, 5-hydroxytryptamine, bradykinin and histamine were constructed. The findings of this study clearly show that oxidative stress clearly increases after femoral osteotomy in rats. Also, this operation causes a significant depression in vascular responsiveness to contracting agents and endothelium-dependent vasodilators. However, vitamin K1 supplementation prevents vascular hyporeactivity by reducing oxidative stress and may represent a novel approach during osteotomy healing.