Helicobacter pylori Infection and Recurrent Abdominal Pain in Turkish Children

Background. Helicobacter pylori infection is primarily acquired in childhood. However, the association between H. pylori infection and recurrent abdominal pain (RAP) remains unclear. Materials and methods. One hundred and forty-one children with and 21 without RAP underwent upper gastrointestinal endoscopy. At least five antral gastric biopsies were obtained from each patient and the presence of H. pylori infection was accepted when at least two out of four tests (histology, direct antral smear, culture, and rapid urease test) were positive. Patients with H. pylori infection underwent triple therapy with omeprazole, clarithromycin, and metronidazole. Results. Eighty-five out of 141 (60.3%) patients with RAP were H. pylori positive whereas 5 out of 21 (20.8%) patients without RAP were (p = .0037). Symptoms were disappeared in 87% of children whose H. pylori infection was eradicated compared with 41% of those in whom the infection was not eradicated (p = .0035). Conclusions. It was concluded that children with RAP and H. pylori infection appear to benefit from eradication therapy in Turkey.     

Three new G6PD variants,G6PD Adana,G6PD Samandağ, and G6PD Balcali in Çukurova,Turkey

Summary Glucose-6-phosphate dehydrogenase (G6PD) enzyme from cases known to be completely or mildly deficient were analyzed. The enzymes were purified from blood samples by utilizing DEAE-52 cellulose pH 7.0 column chromatography and ammonium sulphate precipitation. Biochemical and electrophoretic properties of G6PD were studied in these partially purified enzymes. In this study wer report three new variants from Çukurova, named Adana, Samanda, and Balcali. Variant I (G6PD Adana) had a high K_m for G6P (210 M) and NADP (13M). Utilization of 2d-G6P was 38%. It had a slow electrophoretic mobility, a biphasic pH optimum curve, and abnormal heat stability. Variant II (G6PD Samanda) had a low K_m for G6P (25M) and a high K_m for NADP (18M). The rate of utilization of 2d-G6P was normal. G6PD Samanda deviated from the normal enzyme by its biphasic pH optimum curve and its slow electrophoretic mobility. Variant III (G6PD-Balcali) had a normal K_m G6P, NADP and rate of utilization of 2d-G6P. However, it showed a biphasic pH optimum curve and slow electrophoretic mobility.     

Interaction of diphtheria toxin (fragment A) with actin

It was shown by gel filtration and viscosity measurements that N‐terminal fragment (FA) of diphtheria toxin (DT) can interact with both G‐ and F‐actin (filamentous actin). Elution profiles on Sephadex G‐100 indicated the formation of a binary complex of fragment A (FA) with globular actin monomer (G‐actin), which was inhibited by gelsolin. Deoxyribonuclease I (DNase I) in turn appeared to interact with this complex. Tritiated FA was found to bind to F‐actin stoichiometrically. This binding was inhibited again by gelsolin and G‐actin, but not by DNase I. The binding of FA inhibited polymerization of G‐actin and induced a time‐dependent breakdown of F‐actin under polymerization conditions. Inhibition of its ADP‐ribosyltransferase activity did not have any effect on the interactions of FA with actin. FA interacted with actin also in the cell. After treatment of human umbilical vein endothelial cells (HUVEC) with biotin‐labeled DT, Western blot analysis revealed predominantly the presence of actin in affinity‐isolated complexes of the labeled FA. Similarly, FA was found in immunoaffinity‐isolated complexes of actin. Copyright © 2009 John Wiley & Sons, Ltd.     

Conformation and tautomerizm of the 2-methyl-4-pyridin-2′-yl-1,5-benzodiazepine molecule. An ab initio study

The protomeric tautomerizm and conformation of the 2-methyl-4-pyridin-2′-yl-1,5-benzodiazepine molecule were investigated, and its three neutral tautomers (B₁,B₂,B₃) and their rotamers (C₁,C₂,C₃) were considered. Full geometry optimizations were carried out at the HF/6-31G* and B3LYP/6-31G* levels in gas phase and in water. The tautomerization processes in water (ɛ = 78.54) were studied by using self-consistent reaction field theory. The calculation showed that the boat conformation is dominant for the seven-membered diazepine ring in all of the structures, even with different double bond positions. The calculated relative free energies (ΔG) showed that the tautomer C₁ was the most stable structure, and its conformer B₁ was the second most stable in the gas phase and in water. Figure 2-Methyl-4-pyridin-2′-yl-1,5-benzodiazepine     

Effect of Aloe vera (L.) Burm. fil. leaf gel and pulp extracts on kidney in type-II diabetic rat models

Significant degenerative changes were observed in the kidney tissue of untreated neonatal streptozotocin (n0STZ)-induced type-II diabetic rats. These degenerative changes were diminished in the kidney tissue of diabetic animals given glibenclamide and Aloe leaf gel and pulp extracts. Kidney lipid peroxidation levels were increased in diabetic rats compared to healthy rats; these levels were higher in rats treated with glibenclamide than in those which received Aloe extracts. Serum urea and creatinine levels were higher in diabetic rats in comparison to healthy rats. The administration of Aloe gel extract and glibenclamide decreased serum urea and creatinine levels in comparison to diabetic controls. Only A. vera leaf gel extract showed improvement both in histological and biochemical parameters suggesting a protective effect of A. vera on mild damage caused by type-II diabetes on kidney tissue.     

Helicobacter pylori infection in Turkish children: comparison of diagnostic tests, evaluation of eradication rate, and changes in symptoms after eradication

BACKGROUND: Helicobacter pylori infection is most frequently acquired in childhood. After this organism is eradicated, the rate of reinfection is low. Thus, it is very important to diagnose and treat the disease appropriately in childhood, and to be able to assess eradication with certainty. Eradication of H. pylori infection is reported to reduce or eliminate abdominal pain and dyspeptic symptoms in children. PATIENTS AND METHODS: The study involved 102 children who had already been diagnosed with symptomatic H. pylori infection based on gastric histopathological examination, urea breath test, rapid urease test, serology and culture. Each patient's symptoms and family history of gastrointestinal problems were recorded. Using histology as the gold standard for identifying H. pylori infection, we determined the diagnostic sensitivity of each of the other methods. Omeprazole or lansoprazole, amoxicillin and clarithromycin were administered as eradication treatment, and each patient was re-evaluated by urea breath test 8 weeks later. Each child was re-interviewed about symptoms after treatment. These answers and the results of drug sensitivity testing were recorded. Cases of failed eradication were re-treated with a quadruple-drug regimen of tetracycline, metronidazole, bismuth subsalicylate and omeprazole. RESULTS: The most frequent symptom was abdominal pain (89.2%). Fifty-four per cent of the subjects had a family history of dyspeptic symptoms. Sixty-six patients (64.7%) exhibited nodularity in the antral mucosa. The sensitivities of the diagnostic tests in histologically proven cases were as follows: urea breath test 100%, rapid urease test 89.2%, serology 71.9%, and culture 54.9%. Metronidazole had the highest frequency of resistance (36.4%) and the rate of clarithromycin resistance was 18.2%. The eradication rate after first-line therapy was 75.5%, and abdominal pain and dyspeptic symptoms were reduced or completely resolved in 75.7% of the successful-eradication cases. The proportion of failed-eradication cases that responded well to quadruple-drug therapy was 93.8%. CONCLUSION: Symptomatic H. pylori infection in a child should always be treated. The urea breath test is an accurate and reliable way to identify H. pylori-positive patients and to determine the response to treatment. Triple-agent therapy is effective for eradicating H. pylori infection in children and usually helps reduce or eliminate dyspeptic symptoms. The level of H. pylori resistance to metronidazole is high in our region. The significant rate of resistance to clarithromycin (18.1%) may explain the treatment failure observed in this study.     

Serum zinc and copper levels in southeastern Turkish children with giardiasis or amebiasis

Alterations of serum zinc (Zn) and copper (Cu) concentrations are commonly found in patients suffering from gastrointestinal infections and with hepatic, renal, cardiovascular, and malignant diseases. In this study, the serum Zn and Cu levels in 20 children with giardiasis and in 40 children with amebiasis were evaluated. The serum Zn levels showed a significant decrease when compared to controls (p<0.001). After metronidazole therapy, a significant increase in Zn levels was observed (p<0.001). There was no significant difference in serum Cu levels between patients and controls before therapy. Before therapy, the serum Cu/Zn ratio in children with either giardiasis or amebiasis was significantly higher than that of the control group. After therapy, the Cu/Zn ratio was found to be back to normal. There were no significant differences in serum Zn levels and Cu/Zn ratios between children with and without diarrhea and there was no significant difference in children with or without failure to thrive. We concluded that Zn deficiency and elevated Cu/Zn ratio could be acute-phase responses to parasitic infections in children with giardiasis or amebiasis and that a successful treatment of the primary disorder will lead to complete recovery. Further studies are in progress to confirm the benefit of Zn supplementation during the acute phase of the disease, particularly in zinc-deficient regions of the world, such as in the case of Turkey.     

Physical and functional interactions between Werner syndrome helicase and mismatch-repair initiation factors

Werner syndrome (WS) is a severe recessive disorder characterized by premature aging, cancer predisposition and genomic instability. The gene mutated in WS encodes a bi-functional enzyme called WRN that acts as a RecQ-type DNA helicase and a 3′-5′ exonuclease, but its exact role in DNA metabolism is poorly understood. Here we show that WRN physically interacts with the MSH2/MSH6 (MutSα), MSH2/MSH3 (MutSβ) and MLH1/PMS2 (MutLα) heterodimers that are involved in the initiation of mismatch repair (MMR) and the rejection of homeologous recombination. MutSα and MutSβ can strongly stimulate the helicase activity of WRN specifically on forked DNA structures with a 3′-single-stranded arm. The stimulatory effect of MutSα on WRN-mediated unwinding is enhanced by a G/T mismatch in the DNA duplex ahead of the fork. The MutLα protein known to bind to the MutS α–heteroduplex complexes has no effect on WRN-mediated DNA unwinding stimulated by MutSα, nor does it affect DNA unwinding by WRN alone. Our data are consistent with results of genetic experiments in yeast suggesting that MMR factors act in conjunction with a RecQ-type helicase to reject recombination between divergent sequences.