Resolution of (±)‐β‐methylphenylethylamine by a novel chiral stationary phase for Pirkle‐type column chromatography

In this study, a new Pirkle‐type chiral column stationary phase for resolution of β‐methylphenylethyl amine was described by using activated Sepharose 4B as a matrix, L ‐tyrosine as a spacer arm, and an aromatic amine derivative of L ‐glutamic acid as a ligand. The binding capacities of the stationary phase were determined at different pH values (pH = 6, 7, and 8) using buffer solutions as mobile phase, and enantiomeric excess (ee) was determined by HPLC equipped with chiral column. The ee was found to be 47%. Chirality, 2010. © 2009 Wiley‐Liss, Inc.     

Drought-induced oxidative damage and antioxidant responses in peanut (<Emphasis Type="Italic">Arachis</Emphasis><Emphasis Type="Italic">hypogaea</Emphasis> L.) seedlings

Two cultivars of peanut (Arachis hypogaea L.) which were designated as resistant (Florispan) and sensitive (Gazipasa) according to their growth retardation under drought stress conditions were compared for their oxidative damage and antioxidant responses. Sixteen days-old peanut seedlings were subjected to PEG-6000 solutions of two different osmotic potentials; −0.4 and −0.8 MPa, and various growth parameters, photosystem II activity, changes in malondialdehyde (MDA), hydrogen peroxide (H₂O₂) and proline levels, activities of ascorbate peroxidase (APX), catalase (CAT), peroxidase (POX) and gluthatione reductase (GR) enzymes were determined. Both cultivars exhibited water deficit at −0.8 MPa osmotic potential of PEG-6000 and H₂O₂ levels significantly increased during exposure to −0.4 MPa osmotic potential. However, H₂O₂ levels were under control in both cultivars at exposure to −0.8 MPa osmotic potential. Significant proline accumulation was observed in the tissues of cv. Florispan at −0.8 MPa osmotic potential, whereas proline accumulation did not appear to be an essential part of the protection mechanism against drought in cv. Gazipasa. No significant variation in chlorophyll fluorescence values were detected in neither of the cultivars. Enzyme activity measurements revealed that Gazipasa copes well with lesser magnitudes of drought stress by increasing the activity of mainly APX, and during harsh stress conditions, only APX maintains its activity in the tissues. In cultivar Florispan, GR activity appears to take role in lesser magnitudes of drought stress, whereas CAT and APX activities appear to be very crucial antioxidative defenses during intense stress conditions. The results indicate that, the level of proline and activities of the enzymes CAT and APX are important mechanisms for the maintenance of drought tolerance in peanut plants.     

Seleno <Emphasis Type="SmallCaps">l-</Emphasis>Methionine Acts on Cyclophosphamide-Induced Kidney Toxicity

The anticancer drug cyclophosphamide (CP) has nephrotoxic effects besides its urotoxicity, which both in turn limit its clinical utility. The nephrotoxicity of CP is less common compared to its urotoxicity, and not much importance has been given for the study of mechanism of CP-induced nephrotoxicity so far. Overproduction of reactive oxygen species (ROS) during inflammation is one of the reasons of the kidney injury. Selenoproteins play crucial roles in regulating ROS and redox status in nearly all tissues; therefore, in this study, the nephrotoxicity of CP and the possible protective effects of seleno l-methionine (SLM) on rat kidneys were investigated. Forty-two Sprague–Dawley rats were equally divided into six groups of seven rats each. The control group received saline, and other rats were injected with CP (100 mg/kg), SLM (0.5 or 1 mg/kg), or CP + SLM intraperitoneally. Malondialdehyde (MDA) and glutathione (GSH) levels in kidney homogenates of rats were measured, and kidney tissues were examined under the microscope. CP-treated rats showed a depletion of renal GSH levels (28% of control), while CP + SLM-injected rats had GSH values close to the control group. MDA levels increased 36% of control following CP administration, which were significantly decreased after SLM treatment. Furthermore, these biochemical results were supported by microscopical observations. In conclusion, the present study not only points to the therapeutic potential of SLM in CP-induced kidney toxicity but also indicates a significant role for ROS and their relation to kidney dysfunction.     

Two Novel Missense Mutations in the Connexin 26 Gene in Turkish Patients with Nonsyndromic Hearing Loss

Most nonsyndromic hearing losses are caused by mutations in the GJB2 gene, and studies have revealed that the forms and frequencies of these mutations are largely dependent on ethnic origin. In the present study, we aimed to characterize the mutation profiles of 151 patients with hearing loss in Turkey. The entire coding region of the GJB2 was directly sequenced in all patients. We found 35 (23.2%) individuals carrying GJB2 mutations. Seven different mutations were identified, five of which were previously known (35delG, delE120, R184P, M163V, L90P), the remaining two being novel variants (M34V, L205V). The most common mutation was 35delG followed by delE120. The 35delG mutation was homozygous in 22 cases (14.5%) and heterozygous in 4 cases (2.6%). Compound heterozygosity for 35delG was also observed. The delE120 mutation was found in three patients in homozygous form. A homozygous L90P and heterozygous mutations M163V and M34V were found in single cases.     

Genetic Relationships Among Some Hawthorn (Crataegus spp.) Species and Genotypes

The genus Crataegus is well distributed in Turkey as a wild plant, with numerous, inherently variable species and genotypes. RAPD markers were used to study 17 hawthorn genotypes belonging to Crataegus monogyna ssp. monogyna Jacq (2 genotypes), C. monogyna ssp. azarella Jacq (1), Crataegus pontica K.Koch (3), Crataegus orientalis var. orientalis Pallas Ex Bieb (3), Crataegus pseudoheterophylla Pojark (1), Crataegus aronia var. dentata Browicz (1), C. aronia var. aronia Browicz (4), and Crateagus × bornmuelleri Zabel (2). The 10 RAPD primers produced 72 polymorphic bands (88% polymorphism). A dendrogram based on Jaccard’s index included four major groups and one outgroup according to taxa. The lowest genetic variability was observed within C. aronia var. aronia genotypes. The study demonstrated that RAPD analysis is efficient for genotyping wild-grown hawthorns.     

Temtamy preaxial brachydactyly syndrome is caused by loss-of-function mutations in chondroitin synthase 1, a potential target of BMP signaling

Altered Bone Morphogenetic Protein (BMP) signaling leads to multiple developmental defects, including brachydactyly and deafness. Here we identify chondroitin synthase 1 (CHSY1) as a potential mediator of BMP effects. We show that loss of human CHSY1 function causes autosomal-recessive Temtamy preaxial brachydactyly syndrome (TPBS), mainly characterized by limb malformations, short stature, and hearing loss. After mapping the TPBS locus to chromosome 15q26-qterm, we identified causative mutations in five consanguineous TPBS families. In zebrafish, antisense-mediated chsy1 knockdown causes defects in multiple developmental processes, some of which are likely to also be causative in the etiology of TPBS. In the inner ears of zebrafish larvae, chsy1 is expressed similarly to the BMP inhibitor dan and in a complementary fashion to bmp2b. Furthermore, unrestricted Bmp2b signaling or loss of Dan activity leads to reduced chsy1 expression and, during epithelial morphogenesis, defects similar to those that occur upon Chsy1 inactivation, indicating that Bmp signaling affects inner-ear development by repressing chsy1. In addition, we obtained strikingly similar zebrafish phenotypes after chsy1 overexpression, which might explain why, in humans, brachydactyly can be caused by mutations leading either to loss or to gain of BMP signaling.     

Protective Effects of Antioxidants Against Cadmium-induced Oxidative Damage in Rat Testes

The protective effects of melatonin, vitamin E, and selenium alone or in combination were tested against cadmium-induced oxidative damage in rat testes. A total of 60 male rats were equally divided into five study groups, one of which acted as control receiving subcutaneous injections of physiological saline. The remaining four groups were treated with subcutaneous injections of cadmium chloride at a dose of 1 mg/kg weight. The first study group received no treatment. The second group was treated with a combination of 60 mg/kg vitamin E and 1 mg/kg sodium selenite. Group 3 was treated with 10 mg/kg melatonin, and the fourth group received a combination of vitamin E, sodium selenite, and melatonin at the doses mentioned above. After 1 month, the animals were killed, and the testes were excised for histological inspection and determination of tissue malondialdehyde and the activity of superoxide dismutase. The animals receiving no treatment showed significantly higher malondialdehyde levels and reduced activity of the enzyme (p < 0.05). Treatment with antioxidants resulted in a significant reduction in malondialdehyde when compared to the nontreated animals (p < 0.05) and an increase in the superoxide dismutase activity that was almost the same as the controls. The combination of melatonin, vitamin E, and selenium appears to have the more profound effect against cadmium-induced testicular injury.     

Effects of Selenium and Vitamin E,in Addıtıon to Melatonin,Against Oxidative Stress Caused by Cadmium in Rats

The present study was carried to evaluate the protective effects of melatonin alone and vitamin E with selenium combination against high dose cadmium-induced oxidative stress in rats. The control group received subcutanous physiological saline. The first study group administered cadmium chloride (CdCl₂) by subcutaneous injection of dose of 1 mg/kg. The second study group administered cadmium plus vitamin E with selenium (1 mg/kg sodium selenite with 60 mg/kg vitamin E); the third study group administered cadmium plus 10 mg/kg melatonin (MLT); the fourth study group administered CdCl₂ plus a combination of melatonin in addition to vitamin E and selenium for a month. Determination levels of plasma malondialdehyde (MDA), glutathione peroxidase (GSH-Px), blood superoxide dismutase (SOD), creatinine alanine transaminase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), blood urea nitrogen (BUN), and urea were measured in serum. In only CdCl₂ administered group, the MDA, creatinine, ALT, AST, ALP, and urea levels in the serum were significantly higher than the control group (p < 0.05). Whereas in all other groups, this values were significantly lower than the only CdCl₂ administered group (p < 0.05). Erythrocytes GSH-Px, serum SOD activities of only CdCl₂ received group were significantly lower than the control group (p < 0.05). In conclusion, vitamin E + Se, melatonin and vitamin E, and Se, in addition to MLT combinations, had protective effects against high dose cadmium-induced oxidative damage.