WRN mutations in Werner syndrome patients: genomic rearrangements, unusual intronic mutations and ethnic-specific alterations

Werner syndrome (WS) is an autosomal recessive segmental progeroid syndrome caused by null mutations at the WRN locus, which codes for a member of the RecQ family of DNA helicases. Since 1988, the International Registry of Werner syndrome had enrolled 130 molecularly confirmed WS cases from among 110 worldwide pedigrees. We now report 18 new mutations, including two genomic rearrangements, a deep intronic mutation resulting in a novel exon, a splice consensus mutation leading to utilization of the nearby splice site, and two rare missense mutations. We also review evidence for founder mutations among various ethnic/geographic groups. Founder WRN mutations had been previously reported in Japan and Northern Sardinia. Our Registry now suggests characteristic mutations originated in Morocco, Turkey, The Netherlands and elsewhere.     

Evaluating the diagnostic significance of nuclear grooves in thyroid fine needle aspirates with a semiquantitative approach

OBJECTIVE: To clarify the diagnostic significance of nuclear grooves in thyroid fine needle aspirates, to search for other associated nuclear features and to identify possible diagnostic pitfalls. STUDY DESIGN: In total, 67 fine needle aspiration cases were retrospectively reviewed for selected nuclear features, including grooves, intranuclear cytoplasmic invaginations, enlargement, pleomorphism and status of nucleoli. A semiquantitative method was used to estimate the percentage of nuclear grooves in 5 high-power fields with the most frequent nuclear grooves. RESULTS: Unequivocal intranuclear cytoplasmic invaginations were a specific diagnostic feature of papillary carcinoma. In the absence of intranuclear cytoplasmic invaginations, the presence of > or = 20% nuclear grooves was virtually diagnostic of thyroid neoplasms, predominantly papillary carcinoma. Less than 10% of nuclear grooves virtually eliminated the possibility of papillary carcinoma. However, 10-19% of nuclear grooves may be seen in papillary carcinoma and benign lesions; therefore, such cases fell into the diagnostic category of "atypical cytology" or "indeterminate" cytology. Nuclear enlargement with elongation was a readily identifiable feature usually associated with nuclear grooves. Significant pleomorphism was more commonly seen in papillary carcinoma than in benign lesions. CONCLUSION: A semiquantitative method is helpful when nuclear grooves are encountered in thyroid cytology in the absence of other diagnostic features. It can significantly improve the diagnostic specificity of nuclear grooves for papillary carcinoma.     

Morphological,karyological and palynological investigation of endemic Centaurea kurdica Reichardt from Turkey

The purpose of this study was to determine the morphological, morphometrical, karyological and palynological features of the endemic Centaurea kurdica Reichardt species from East Anatolian region. Some morphological features of the species like morphology of capitula, involucra, involucral leaves (phyllaries) and achene have been investigated. The chromosome number of Centaurea kurdica was found as 2n = 18 and haploid karyotype formula 6m+2sm+1M. Metaphase chromosome length ranged from 5.81 to 3.91 μm and the total haploid chromosome length was 41.09 μm. The results of the light microscope investigation of pollen revealed that it is radially symmetrical, isopolar tricolporate and has spheroid-type pollen, and exine ornamentation was also determined as scabrate.     

The influence of Helicobacter pylori infection on the prevalence of endoscopic erosive esophagitis

OBJECTIVES: This study aimed to determine the frequency of endoscopic esophagitis and Helicobacter pylori infection in a large Turkish population over a 6-year period. METHODS: We studied a consecutive series of 14,380 patients who had been newly referred for diagnostic esophagogastroduodenoscopy from 2000 to 2006. The mean age value was 45 +/- 10 (18-89) years. All endoscopic findings were retrospectively evaluated. Two antral and two corpus biopsies were taken from patients for rapid urease test. Endoscopic esophagitis was defined as the presence of erosions and/or ulceration. The relationship between erosive esophagitis and various relevant factors was analyzed. RESULTS: The overall prevalence of endoscopic esophagitis was 7.8% (95% CI, 6.9-8.1). The prevalence of positive rapid urease test was 49% (95% CI, 38-53) in patients with esophagitis and 85% (95% CI, 70-96) in patients without esophagitis (p < .001). From 2000 to 2006, the frequency of endoscopic esophagitis and the rate of positive rapid urease test remained unchanged. After adjusting for the effects of mean age, male gender, and percentage of hiatal hernia, there was a 0.785% risk reduction in esophagitis with every 1% increase in the rate of positive rapid urease test result. CONCLUSIONS: The frequency of endoscopic esophagitis is significantly lower in patients with a positive rapid urease test result. This negative correlation with H. pylori infection reflects a protective effect of H. pylori from endoscopic esophagitis in a Turkish population and deserves further investigation.     

Ammonium oxidation via nitrite accumulation under limited oxygen concentration in sequencing batch reactors

In this study, the effects of sludge retention time (SRT) on NH(4)-N oxidation and NO(x)-N accumulation in the nitritation reactors were studied. The gradually decrease of SRT also caused long reaction time to achieve 99% NH(4)-N removal. Although the target NH(4)-N removal was achieved in a short reaction time at 40 days of SRT, decreasing of SRT from 40 to 30, 25, 20 days, increase the reaction time from 168 to 240 and 265 h, respectively. The inlet NH(4)-N was almost oxidized and the concentration of NO(2)-N accumulated to a high level of 177 mg/l, while NO(2)-N/(NO(3)-N+NO(2)-N) ratio was about 0.9 at SRT of 40 days. However, the concentration of NO(3)-N increased slightly and NO(2)-N/(NO(x)-N) ratio dropped to 0.8 when the SRT was lower than 40 days. During the operation in a cycle, free ammonia concentration in the SBR was decreased from 2.8 to 0.7 mg/l which is below the lowest concentration causing inhibition of nitrite oxidizing bacteria (NOB). It was assumed that combined dissolved oxygen limitation and NH(3)-N inhibition on NOB caused NO(2)-N accumulation under the experimental conditions.     

Purification of heterotrimeric G protein alpha subunits by GST-Ric-8 association: primary characterization of purified G alpha(olf)

Ric-8A and Ric-8B are nonreceptor G protein guanine nucleotide exchange factors that collectively bind the four subfamilies of G protein α subunits. Co-expression of Gα subunits with Ric-8A or Ric-8B in HEK293 cells or insect cells greatly promoted Gα protein expression. We exploited these characteristics of Ric-8 proteins to develop a simplified method for recombinant G protein α subunit purification that was applicable to all Gα subunit classes. The method allowed production of the olfactory adenylyl cyclase stimulatory protein Gα(olf) for the first time and unprecedented yield of Gα(q) and Gα(13). Gα subunits were co-expressed with GST-tagged Ric-8A or Ric-8B in insect cells. GST-Ric-8·Gα complexes were isolated from whole cell detergent lysates with glutathione-Sepharose. Gα subunits were dissociated from GST-Ric-8 with GDP-AlF(4)(-) (GTP mimicry) and found to be >80% pure, bind guanosine 5'-[γ-thio]triphosphate (GTPγS), and stimulate appropriate G protein effector enzymes. A primary characterization of Gα(olf) showed that it binds GTPγS at a rate marginally slower than Gα(s short) and directly activates adenylyl cyclase isoforms 3, 5, and 6 with less efficacy than Gα(s short).     

Induction of <Emphasis Type="Italic">Gentiana cruciata</Emphasis> hairy roots and their secondary metabolites

Gentiana cruciata L. (cross gentian) is a medicinal and ornamental plant. The root extracts of this species are known to exhibit many curative properties. The natural Gentiana populations are exposed to great danger because of their uncontrolled usage. In this study, hairy roots from Gentiana cruciata L. stem and leaf explants belonging to three different clones were induced by inoculation with four different Agrobacterium rhizogenes wild strains namely A4, 15834, 8196 and R1000. Induction of the root transformation was significantly dependent on the explant type used. On the other hand, the genotype and bacterial strain had no significant effect on hairy root formation. Hairy root formation percentages of the explants varied between 5.6–33.3% in the stem explants, and between 0.0–6.7% in the leaf explants. Transformations of the hairy roots were confirmed by PCR using rolC specific primers, and revealed the absence of contaminating A. rhizogenes with virC primers. Total of twelve hairy root clones were obtained, and their secondary metabolite content was also analyzed by HPLC. Quantitative results exhibited that gentiopicroside was the most abundant compound in all root samples. Furthermore, metabolites such as loganic acid, swertiamarin, and sweroside were also identified and quantified in the samples.     

Loss of UCP2 Attenuates Mitochondrial Dysfunction without Altering ROS Production and Uncoupling Activity

Although mitochondrial dysfunction is often accompanied by excessive reactive oxygen species (ROS) production, we previously showed that an increase in random somatic mtDNA mutations does not result in increased oxidative stress. Normal levels of ROS and oxidative stress could also be a result of an active compensatory mechanism such as a mild increase in proton leak. Uncoupling protein 2 (UCP2) was proposed to play such a role in many physiological situations. However, we show that upregulation of UCP2 in mtDNA mutator mice is not associated with altered proton leak kinetics or ROS production, challenging the current view on the role of UCP2 in energy metabolism. Instead, our results argue that high UCP2 levels allow better utilization of fatty acid oxidation resulting in a beneficial effect on mitochondrial function in heart, postponing systemic lactic acidosis and resulting in longer lifespan in these mice. This study proposes a novel mechanism for an adaptive response to mitochondrial cardiomyopathy that links changes in metabolism to amelioration of respiratory chain deficiency and longer lifespan.