Connexin 26 (GJB2) mutations in the Turkish population: implications for the origin and high frequency of the 35delG mutation in Caucasians

Mutations in the Connexin 26 (GJB2/Cx26) gene are responsible for more than half of all cases of prelingual non-syndromic recessive deafness in many Caucasian populations. To determine the importance of Cx26 mutations as a cause of deafness in Turks we screened 11 families with prelingual non-syndromic deafness, seven (64%) of which were found to carry the 35delG mutation. We subsequently screened 674 Turkish subjects with no known hearing loss and found twelve 35delG heterozygotes (1.78%; 95% confidence interval: 0.9%-3%) but no examples of the 167delT mutation. To search for possible founder effects, we typed chromosomes carrying the 35delG mutation for closely linked polymorphic markers in samples from Turkey and United States and compared the allele frequencies with those of hearing subjects. The data showed a modest degree of disequilibrium in both populations. Analyses of two pedigrees from Turkey demonstrated both conserved and different haplotypes, suggesting possible founder effects and multiple origins of the 35delG mutation.     

Investigation of the Effects of the Fenoxaprop-p-Ethyl Herbicide and Salicylic Acid on the Ascorbic Acid and Vitamin B6 Vitamers in Wheat Leaves

Journal of Plant Growth Regulation - Herbicides inhibit plant growth and development by various mechanisms, and oxidative stress is a common plant response to herbicide treatment. In a limited...     

The Effects of Chromium Picolinate and Chromium Histidinate Administration on NF-κB and Nrf2/HO-1 Pathway in the Brain of Diabetic Rats

The objective of this experiment was to investigate the effects of supplemental chromium picolinate (CrPic) and chromium histidinate (CrHis) on nuclear factor-kappa B (NF-??B p65) and nuclear factor (erythroid-derived 2)-like 2 (Nrf2) signaling pathway in diabetic rat brain. Nondiabetic (n?=?45) and diabetic (n?=?45) male Wistar rats were either not supplemented or supplemented with CrPic or CrHis via drinking water to consume 8???g elemental chromium (Cr) per day for 12?weeks. Diabetes was induced by streptozotocin injection (40?mg/kg i.p., for 2?weeks) and maintained by high-fat feeding (40?%). Diabetes was associated with increases in cerebral NF-??B and 4-hydroxynonenal (4-HNE) protein adducts and decreased in cerebral nuclear factor of kappa light polypeptide gene enhancer in B cells inhibitor, alpha (I??B??) and Nrf2 levels. Both Cr chelates were effective to decrease levels of NF-??B and 4-HNE protein adducts and to increase levels of I??B?? and Nrf2 in the brain of diabetic rats. However, responses of these increases and decreases were more notable when Cr was supplemented as CrHis than as CrPic. In conclusion, Cr may play a protective role in cerebral antioxidant defense system in diabetic subjects via the Nrf2 pathway by reducing inflammation through NF-??B p65 inhibition. Histidinate form of Cr was superior to picolinate form of Cr in reducing NF-??B expression and increasing Nrf2 expression in the brain of diabetic rats.     

Possible role of adenosine in the CNS effects of ethanol

The ability of adenosine to modify the CNS effects of acute and chronic ethanol was studied by using theophylline, an adenosine antagonist, and dipyridamole, a blocker of adenosine reuptake. We also studied the binding characteristics of adenosine using crude membranes of whole brain. Theophylline pretreatment prior to acute ethanol administration markedly reduced the duration of ethanol-induced sleep and similarly decreased the intensity and duration of motor incoordination. In chronic ethanol treated mice the effect of theophylline on ethanol-induced hypnosis and motor incoordination was similar to the acute experiment. Dipyridamole markedly prolonged the duration of ethanol-induced hypnosis and potentiated the motor incoordination produced by acute ethanol. However, in chronic ethanol treated mice dipyridamole was not able to potentiate the motor incoordinating effect of ethanol although it was able to prolong ethanol hypnosis similar to the results obtained in the acute ethanol study. Neither drug had any effect on ethanol-induced hypothermia, in either the acute or chronic studies.After 10 days of ethanol ingestion the adenosine dissociation constant was unchanged whereas the number of brain adenosine receptors was increased 28% although the increase did not reach statistical significance. The number of the adenosine receoptors was reduced 40% at 24 and 48 h after withdrawal and returned to prewithdrawal levels at 72 h. The dissociation constant was reduced at 24 and 48 h but by 72 h had returned to prewithdrawal levels. The marked changes in adenosine binding characteristics as well as the modification of some CNS effect of ethanol by drugs which influence either adenosine binding to its receptor or the availability of adenosine suggest that adenosine may be involved in the expression of some of the CNS effects of ethanol.     

Diversity and metabolic potential of culturable bacteria from the rhizosphere of Turkish tea grown in acidic soils

The purpose of this study was to investigate the diversity of cultivable phosphate solubilising (PSB) and total bacteria originated from 384 rhizospheric acidic soils samples of tea plants grown at 32 locations. Over 900 rhizoplane bacteria were randomly selected from agar-solidified trypticase soy broth, and identified using fatty acid methyl ester (FAME) profiles. Based on FAME profiles, 53 bacterial genera were identified with a similarity index >0.3, but 60.3% of the identified isolates belonged to five genera: Bacillus (34.6%), Pseudomonas (8.9%), Stenotrophomonas (6.1%), Paenibacillus (5.9%) and Arthrobacter (4.8%). The bacilli group comprised many different species, with the most abundant being B. cereus, B. megaterium and B. sphaericus. The main identified Pseudomonads included P. fluorescens, P. putida, and P. alcaligenes. About 30.4% of the bacterial isolates could not be classified to genus since their similarity indices were <0.3 indicating no close matches. Most of the total and P-solubilizing bacteria isolated were Gram positive (61.3 and 52.3%), and Gram negative constituted only 38.7 and 47.7%. Out of the 214 PSB from a pool of 506 bacterial isolates recovered on the selective media from the rhizosphere of tea, 74 of them were characterized by carbon sources using BIOLOG^M GN2 and GP2 plates. Bacillus, Pseudomonas, Paenibacillus and Stenotrophomonas genera were the most prominent P-solubilizing groups in the rhizosphere and soil populations analyzed. B. cereus, P. fluorescens, S. maltophilia, B. megaterium, P. putida, B. sphaericus and Paenibacillus polymyxa were the most frequent P-solubilizing species in the acidic tea rhizosohere soils. Selected Gram-positive PSB appeared to favour carbohydrates, and Gram-negative bacteria appeared to favour carboxylic acids, amino acids and carbohydrates as carbon sources. Selected phosphate solubilizing acid tolerant strains showed high variability in utilizing various carbon sources.