Melatonin treatment for prevention of oxidative stress: involving histopathological changes

This study was undertaken to test the effect of irradiation on the histopathology of the hypothalamus and cerebral cortex. In addition, the probable effects of radiotherapy on the activities of antioxidant enzymes and levels of nitric oxide (NO) in the plasma were investigated as well. The effects of melatonin treatment on radiotherapy-based central nervous system (CNS) damage were also studied. For this purpose, the rats were randomized into four groups. The first group was the control group (sham-exposed group), the second group received only melatonin, the third group was irradiated and the fourth group received both melatonin and irradiation. Plasma samples of rats were collected for measuring the activities of superoxide dismutase (SOD), catalase (CAT) and the levels of NO. 24 h after the interventions, tissue samples were obtained from the hypothalamus and the cerebral cortex for the light microscopic investigations. These tissues were mostly affected by radiation. The results indicated that the application of radiation significantly enhanced the levels of plasma SOD and NO. On the other hand, melatonin pretreatment prevented the decrease in plasma CAT activity induced by irradiation. It was found that the application of melatonin could significantly prevent the irradiation-induced damages. Light microscopic results revealed that the damage of the CNS by radiation was prevented by the application of melatonin.     

Molecular sieves provoke multiple substitutions in the enzymatic synthesis of fructose oligosaccharide–lauryl esters

The cause of discrepancies in the literature regarding the specificity of immobilized Candida antarctica lipase B in the acylation of oligosaccharides was examined. Molecular sieves, generally used to control the water content during acylation reactions, turned out to have an important role in this. It was proven that molecular sieves alone can catalyze the acylation of fructose oligomers using vinyl laurate, leading to multiple substitution of the oligomers. This effect was the most profound at conditions unfavorable for the enzyme, because this resulted in a relatively high concentration of the chemically produced adducts. The enzyme alone catalyzed the formation of monosubstituted oligomers. It was proven that even solvent pre-drying by molecular sieves already causes the release of catalyzing compounds to the liquid, leading to subsequent catalysis. These findings should be taken into account when applying molecular sieves in this type of reactions in the future. Molecular sieves could, moreover, be used as a catalyst when multiple substitution is desired.     

Phylogeography of Y-chromosome haplogroup I reveals distinct domains of prehistoric gene flow in europe

To investigate which aspects of contemporary human Y-chromosome variation in Europe are characteristic of primary colonization, late-glacial expansions from refuge areas, Neolithic dispersals, or more recent events of gene flow, we have analyzed, in detail, haplogroup I (Hg I), the only major clade of the Y phylogeny that is widespread over Europe but virtually absent elsewhere. The analysis of 1,104 Hg I Y chromosomes, which were identified in the survey of 7,574 males from 60 population samples, revealed several subclades with distinct geographic distributions. Subclade I1a accounts for most of Hg I in Scandinavia, with a rapidly decreasing frequency toward both the East European Plain and the Atlantic fringe, but microsatellite diversity reveals that France could be the source region of the early spread of both I1a and the less common I1c. Also, I1b*, which extends from the eastern Adriatic to eastern Europe and declines noticeably toward the southern Balkans and abruptly toward the periphery of northern Italy, probably diffused after the Last Glacial Maximum from a homeland in eastern Europe or the Balkans. In contrast, I1b2 most likely arose in southern France/Iberia. Similarly to the other subclades, it underwent a postglacial expansion and marked the human colonization of Sardinia ~9,000 years ago.     

A Study on the Anticarcinogenic Effects of Calcium Fructoborate

Evidences about the preventive and therapeutic effects of boron compounds on cancer have been increasing in the last years. Although calcium fructoborate (CaFB) is used as a nutritional supplement, data about its preventive and therapeutic effects on neoplastic transformations are limited. In the present study, the various concentrations of CaFB were applied to the MDA-MB-231 metastatic breast cancer cell line. First, we examined the cytotoxic effect and IC₅₀ value of CaFB by MTT assay. For the evaluation of the DNA damage, apoptosis and metastatic potential, expression levels of ATM, pATM, PARP, p53, p-p53, caspase-3, caspase-9, and VEGF were investigated by using immunoblotting and immunohistochemical methods. Cell viability was significantly reduced at 50 μM CaFB treatment. pATM, p-p53, and caspase-9 levels increased significantly in all groups; furthermore, there was approximately 12.5-, 2.4-, and 10.7-fold increase, respectively, for 100 μM CaFB treatment. ATM and p53 levels did not change with CaFB treatment, but PARP levels significantly 2.5-fold decreased. While VEGF immunoreactivity decreased in all groups, significant increase in caspase-3 immunoreactivity was observed only in the group treated with 50 μM CaFB (p < 0,001). Our results imply that CaFB may have therapeutic potential as well as preventive benefits in cancer.     

Characterization of some bread wheat genotypes using molecular markers for drought tolerance

Because of its wide geographical adaptation and importance in human nutrition, wheat is one of the most important crops in the world. However, wheat yield has reduced due to drought stress posing threat to sustainability and world food security in agricultural production. The first stage of drought tolerant variety breeding occurs on the molecular and biochemical characterization and classification of wheat genotypes. The aim of the present study is characterization of widely grown bread wheat cultivars and breeding lines for drought tolerance so as to be adapted to different regions in Turkey. The genotypes were screened with molecular markers for the presence of QTLs mapped to different chromosomes. Results of the molecular studies identified and detected 15 polymorphic SSR markers which gave the clearest PCR bands among the control genotypes. At the end of the research, bread wheat genotypes which were classified for tolerance or sensitivity to drought and the genetic similarity within control varieties were determined by molecular markers. According to SSR based dendrogram, two main groups were obtained for drought tolerance. At end of the molecular screening with SSR primers, genetic similarity coefficients were obtained that ranged from 0.14 to 0.71. The ones numbered 8 and 11 were the closest genotypes to drought tolerant cultivar Gerek 79 and the furthest genotypes from this cultivar were number 16 and to drought sensitive cultivar Sultan 95. The genotypes as drought tolerance due to their SSR markers scores are expected to provide useful information for drought related molecular breeding studies.     

Starfish oocytes form intracellular ice at unusually high temperatures

Starfish oocytes, eggs, and embryos are popular models for studying meiotic maturation, fertilization, and embryonic development. Their large (170- to 200-microm) oocytes are obtainable in copious amounts and are amenable to manipulations that mammalian oocytes are not. The most formidable obstacle to working with marine oocytes is their seasonal availability, yet a successful means of preserving them for use during the nonreproductive season has not been reported. The aim of this study was to investigate the response of starfish oocytes to freezing with rapid and slow cooling rates under a variety of conditions to develop a cryopreservation protocol for these cells. Cryomicroscopic observation revealed that starfish oocytes in isotonic medium undergo intracellular ice formation (IIF) at very high subzero temperatures, such that the mean difference between the temperature of extracellular ice formation (T(EIF)) and IIF (TI(IF)) was less than 3 degrees C and the average T(IIF) was approximately between -4 and -6 degrees C. Neither partial cellular dehydration nor addition of the cryopreservative dimethyl sulfoxide significantly depressed the T(IIF). Under some conditions, we observed ice nucleation at multiple locations within the cytoplasm, suggesting that several factors contribute to the unusually high T(IIF) during controlled-rate freezing and thus vitrification may be a more suitable method for cryopreserving these cells.     

Polyphenolic compounds from Geranium pratense and their free radical scavenging activities

Two new polyphenolic compounds, myricetin 3-O-(2"-O-galloyl)-beta-D-glucopyranoside and (-)-6-chloroepicatechin, were isolated from the aerial parts of Geranium pratense subsp. finitimum (Woronow) Knuth, along with three known polyphenolic compounds [quercetin 3-O-(2"-O-galloyl)-beta-D-glucopyranoside, quercetin 3-O-(2"-O-galloyl)-beta-D-galactopyranoside, methyl gallate] and tryptophan. Quercetin 3-O-beta-D-glucopyranoside, quercetin 3-O-beta-D-galactopyranoside, quercetin 3-O-(2"-O-galloyl)-beta-D-glucopyranoside and quercetin 3-O-(2"-O-galloyl)-beta-D-galactopyranoside were found to be effective against free radical induced impairment of endothelium-dependent relaxation in isolated rat aorta.