RAPD analysis of selected local Turkish grape cultivars (Vitis vinifera)

Turkey is very rich in local grape varieties. The solution to the problem of identifying local cultivars, which is considered an important deficiency for the region, will only be possible when they can be defined with molecular markers. Forty-nine local grapevine cultivars from ?anl?urfa (Turkey) were characterized with RAPD markers. Twenty-five decamer primers selected from 60 primers were used in this analysis. A total of 171 bands were obtained with the 25 primers, of which 112 were polymorphic; the level of DNA polymorphism was 65.49% in these local cultivars. Among the selected primers, OPA-18, OPO-07 and P-123 gave the maximum number of polymorphic bands (seven). Genetic relationships among these cultivars were determined with a similarity index and using a dendogram. Among the grape cultivars, the lowest similarity ratio (0.578) was observed among the Külahi-K?z?lbanki cultivars and the highest similarity ratio (0.908) was observed for the ?ilorut-D?külgen combination. The high similarity ratio among the grape cultivars of ?anl?urfa Province was also reflected in the dendogram. In general, no relationships were encountered between the genetic identification of the cultivars and their ampelographic properties.     

Mapping of MN1 Sequences Necessary for Myeloid Transformation

The MN1 oncogene is deregulated in human acute myeloid leukemia and its overexpression induces proliferation and represses myeloid differentiation of primitive human and mouse hematopoietic cells, leading to myeloid leukemia in mouse models. To delineate the sequences within MN1 necessary for MN1-induced leukemia, we tested the transforming capacity of in-frame deletion mutants, using retroviral transduction of mouse bone marrow. We found that integrity of the regions between amino acids 12 to 458 and 1119 to 1273 are required for MN1’s in vivo transforming activity, generating myeloid leukemia with some mutants also producing T-cell lympho-leukemia and megakaryocytic leukemia. Although both full length MN1 and a mutant that lacks the residues between 12–228 (Δ12–228 mutant) repressed myeloid differentiation and increased myeloproliferative activity in vitro, the mutant lost its transforming activity in vivo. Both MN1 and Δ12–228 increased the frequency of common myeloid progentiors (CMP) in vitro and microarray comparisons of purified MN1-CMP and Δ12–228-CMP cells showed many differentially expressed genes including Hoxa9, Meis1, Myb, Runx2, Cebpa, Cebpb and Cebpd. This collection of immediate MN1-responsive candidate genes distinguishes the leukemic activity from the in vitro myeloproliferative capacity of this oncoprotein.     

Does N‐acetyl Cystein Affect the Sensitivity and Specificity of Helicobacter pylori Stool Antigen Test?

Background. N‐acetyl cystein, a mucolytic agent, might make Helicobacter pylori antigens shed more easily to stool, and might therefore contribute to the diagnostic accuracy of the Helicobacter pylori stool antigen test. The aim of this study is to investigate if N‐acetyl cystein contributes to the diagnostic accuracy of the Helicobacter pylori stool antigen test by increasing the sensitivity and specificity of the test. Materials and Methods. 107 patients were separated into treatment and placebo groups. The AC group (n = 53) was given 5 ml of acetyl cystein (4%) t.i.d. and the Placebo group (n = 54) was given placebo, for 3 days. Helicobacter pylori status was determined by both histology and CLOtest. Stool samples were assayed using a specific ELISA kit for Helicobacter pylori stool antigen. Results. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of Helicobacter pylori stool antigen test were 76%, 79%, 90%, 55%, and 77%, respectively, in AC group; and 85%, 89%, 93%, 76% and 86%, respectively, in placebo group. Conclusions. N‐acetyl cystein did not increase, and actually decreased, the sensitivity and specificity of the Helicobacter pylori stool antigen test according to our results. We believe that this finding can be taken into consideration when setting up the exclusion criteria for future studies, which will use Helicobacter pylori stool antigen tests.     

Subcellular distribution of accumulated heavy metals in Saccharomyces cerevisiae and Kluyveromyces marxianus

Summary Kluyveromyces spp. have been found to be more efficient than a CUP1^R strain of S. cerevisiae in heavy metal resistance and accumulation. The present study describes the subcellular distribution of the accumulated metals (Ag, Cd, Cu) in S. cerevisiae and K. marxianus. Absorption by insoluble cellular material of the metals appears as the main mechanism of metal accumulation in both organisms.     

The effect of L-NAME administrations after oral mucosal incision on wound NO level in rabbit

The aim of the current study was to comparatively investigate the effect of inhibition of nitric oxide (NO) production by N-nitro-L-arginine methyl ester (L-NAME), an isoform non-specific inhibitor of nitric oxide synthase (NOS), after oral mucosal incision on wound tissue NO levels. A standard incision was applied to the oral mucosa of rabbits. After oral mucosal incision, rabbits were divided into five groups as follows: (1) Untreated incisional group (control); (2) Titanium (Ti) implanted group; (3) Ti + Polyethylene glycol (PEG) 4000 implanted group; (4) Ti + PEG 4000 + L-NAME (2 × 10⁻⁴ M) implanted group and (5) i.p. L-NAME administrated group (10 mg/kg). At 5 days after oral incision operations, wound tissue strips and plasma were obtained from rabbits. Oral wound tissue and plasma nitric oxide, plasma thiobarbituric acid reactive substances (TBARS) and total sulfhydryl group (RSH) levels were investigated. Plasma TBARS and NOx levels decreased after i.p. L-NAME administration. Total RSH group levels were not changed in all groups (p>0.05). This means that L-NAME inhibits the deteriorating effects of free radicals without affecting healing. L-NAME in PEG and titanium also has no effect on tissue and plasma NOx levels. These findings indicate that NO generation will not be affected both Ti and local nitric oxide synthase (NOS) inhibitor. (Mol Cell Biochem 278: 65–69, 2005)     

A novel biosensor based on Lactobacillus acidophilus for determination of phenolic compounds in milk products and wastewater

Different branches of industry need to use phenolic compounds (PCs) in their production, so determination of PCs sensitively, accurately, rapidly, and economically is very important. For the sensitive determination of PCs, some biosensors based on pure polyphenol oxidase, plant tissue and microorganisms were developed before. But there has been no study to develop a microbial phenolic compounds biosensor based on Lactobacillus species, which contain polyphenol oxidase enzyme. In this study, we used different forms of Lactobacillus species as enzyme sources of biosensor and compared biosensor performances of these forms for determination of PCs. For this purpose, we used lyophilized Lactobacillus cells (containing L. bulgaricus, L. acidophilus, Streptococcus thermophilus), pure L. acidophilus, pure L. bulgaricus, and L. acidophilus- and L. bulgaricus adapted to catechol in Lactobacilli MRS Broth. The most suitable form was determined and optimization studies of the biosensor were carried out by using this form. For preparing the bioactive layer of the biosensor, the Lactobacillus cells were immobilized in gelatin by using glutaraldehyde. In the study, we used catechol as a substrate. Phenolic compound determination is based on the assay of the differences on the respiration activity of the cells on the oxygen meter in the absence and the presence of catechol. The microbial biosensor response depends directly on catechol concentration between 0.5 and 5.0 mM with 18 min response time. In the optimization studies of the microbial biosensor the most suitable microorganism amount was found to be 10 mg, and also phosphate buffer (pH 8.0; 50 mM) and 37.5 °C were obtained as the optimum working conditions. In the characterization studies of the microbial biosensor some parameters such as substrate specificity on the biosensor response and operational and storage stability were examine. Furthermore, the determination of PC levels in synthetic wastewater, industrial wastewater, and milk products was investigated by using the developed biosensor under optimum conditions.     

Investigation of N-acyl homoserine lactone (AHL) molecule production in Gram-negative bacteria isolated from cooling tower water and biofilm samples

In this study, 99 Gram-negative rod bacteria were isolated from cooling tower water, and biofilm samples were examined for cell-to-cell signaling systems, N-acyl homoserine lactone (AHL) signal molecule types, and biofilm formation capacity. Four of 39 (10 %) strains isolated from water samples and 14 of 60 (23 %) strains isolated from biofilm samples were found to be producing a variety of AHL signal molecules. It was determined that the AHL signal molecule production ability and the biofilm formation capacity of sessile bacteria is higher than planktonic bacteria, and there was a statistically significant difference between the AHL signal molecule production of these two groups (p?<?0.05). In addition, it was found that bacteria belonging to the same species isolated from cooling tower water and biofilm samples produced different types of AHL signal molecules and that there were different types of AHL signal molecules in an AHL extract of bacteria. In the present study, it was observed that different isolates of the same strains did not produce the same AHLs or did not produce AHL molecules, and bacteria known as AHL producers did not produce AHL. These findings suggest that detection of signal molecules in bacteria isolated from cooling towers may contribute to prevention of biofilm formation, elimination of communication among bacteria in water systems, and blockage of quorum-sensing controlled virulence of these bacteria.     

Purification of fucoxanthin from the diatom Amphora capitellata by preparative chromatography after its enhanced productivity via oxidative stress

Journal of Applied Phycology - Microalgae with high growth rates represent a potential source of carotenoids including fucoxanthin. For commercial fucoxanthin production, choosing the cultivation...