Evaluation of a new antigen for diagnosis of Helicobacter pylori infection in stool of adult and children

Background: Nowadays, there is an increasing interest in noninvasive methods to diagnose Helicobacter pylori infection. Indeed, they can profitably replace endoscopy in predicting the diagnosis. The stool antigen test for H. pylori is a noninvasive immunoassay to diagnose active infection with this bacterium in human fecal samples. The aim of this study was detection of alkyl hydroperoxide reductase protein (AhpC) antigen by immunoblotting in stool samples for diagnosis of H. pylori. Materials and Methods: Chromosomal DNA from H. pylori was isolated. AhpC gene was amplified by PCR, These amplicons were cloned into pTZ57R/T cloning vector then subcloned into pQE30 expression vector and overexpressed using isopropyl‐beta‐D‐thiogalactopyranoside in E. coli M15. AhpC protein was purified by affinity chromatography. Rabbits were immunized with the purified AhpC protein for the production of antibodies. To determine the accuracy of the test for diagnosing H. pylori infection from stool, we evaluated 84 patients (6–81 years old) using Western blot analysis by rabbit anti‐AhpC antibody. Positive rapid urease test on biopsy samples was considered as the gold standard. Results: AhpC gene was overexpressed, and AhpC protein was purified. Rabbit anti‐AhpC antibody produced after immunization with the purified AhpC protein. By immunoblotting, we detected AhpC protein in the positive stool samples. The test showed a 83.3% sensitivity (95% CI: 69.8–92.5%) and a 91.7% specificity (95% CI: 77.5–98.2). Among the children, the sensitivity was 88.2% (95% CI: 63.6–98.5) and the specificity was 100% (95% CI: 69.2–100); in adults, the sensitivity and specificity were 80.6% (95% CI: 62.5–92.5) and 88.5% (95% CI: 69.8–97.6), respectively. Conclusions: Using of AhpC antigen for diagnosis of H. pylori infection is a useful noninvasive method, accurate in adolescents and children, and can be used for the development of a stool antigen detection kit for H. pylori.     

Mutations in Fanconi anemia genes and the risk of esophageal cancer

The incidence of esophageal squamous cell carcinoma (ESCC) is very high in northeastern Iran. Previously, we reported a strong familial component of ESCC among Turkmens, who constitute approximately one-half of the population of this region. We hypothesized that the genes which cause Fanconi anemia might be candidate genes for ESCC. We sequenced the entire coding regions of 12 Fanconi anemia genes in the germline DNA of 190 Turkmen cases of ESCC. We identified three heterozygous insertion/deletion mutations: one in FANCD2 (p.Val1233del), one in FANCE (p.Val311SerfsX2), and one in FANCL (p.Thr367AsnfsX13). All three patients had a strong family history of ESCC. In addition, four patients (out of 746 tested) were homozygous for the FANCA p.Ser858Arg mutation, compared to none of 1,373 matched controls (OR?=?16.7, 95% CI?=?6.2-44.2, P?=?0.01). The p. Lys3326X mutation in BRCA2 (also known as Fanconi anemia gene FANCD1) was present in 27 of 746 ESCC cases and in 16 of 1,373 controls (OR?=?3.38, 95% CI?=?1.97-6.91, P?=?0.0002). In summary, both heterozygous and homozygous mutations in several Fanconi anemia-predisposing genes are associated with an increased risk of ESCC in Iran.     

Anthropometric measures and risk of ovarian cancer among BRCA1 and BRCA2 mutation carriers

Studies conducted among women in the general population suggest that various anthropometric measures, including height and weight, may be associated with the risk of developing ovarian cancer. Whether such an association exists among women who carry a BRCA1 or BRCA2 mutation has not been evaluated. Thus, we investigated the association between height, weight, changes in body weight, and BMI, and the risk of developing ovarian cancer among 938 women carrying a BRCA1 or BRCA2 mutation. A matched case-control study was conducted in 469 pairs of women carrying a deleterious mutation in either BRCA1 (n = 403 pairs) or BRCA2 (n = 66 pairs). Information about height and weight at ages 18, 30, and 40 was collected from a questionnaire routinely administered to women during the course of genetic counseling. Conditional logistic regression was used to estimate the association between these body size measures and the risk of ovarian cancer. Height, weight, and BMI were not associated with the risk of ovarian cancer (P-trend ≥ 0.15). Also, there was no association between changes in body weight between ages 18-30, or ages 30-40, or ages 18-40 and the risk of ovarian cancer (P-trend ≥ 0.28). The results from this study suggest that height, weight, or weight gain do not influence the risk of ovarian cancer among carriers of a BRCA1 or BRCA2 mutation.     

Impact of Bulk and Nanosized Titanium Dioxide (TiO<Subscript>2</Subscript>) on Wheat Seed Germination and Seedling Growth

The impacts of different concentrations of bulk and nanosized TiO₂ on seed germination and seedling growth of wheat were studied in a randomized completely design with four replications in the College of Agriculture, Ferdowsi University of Mashhad, Iran, in 2011. The experimental treatments included five concentrations of bulk (1, 2, 10, 100, and 500 ppm), five concentrations of nanosized TiO₂ (1, 2, 10, 100, and 500 ppm), and control (without any TiO₂). Results indicated that among the wheat germination indices, only mean germination time was affected by treatments. The lowest and the highest mean germination time (0.89 vs. 1.35 days) were obtained in 10 ppm concentration of nanosized TiO₂ and control treatments, respectively. In addition, shoot length, seedling length, and root dry matters were affected by bulk and nanosized TiO₂ concentrations, significantly. Shoot and seedling lengths at 2 and 10 ppm concentrations of nanosized TiO₂ were higher than those of the untreated control and bulk TiO₂ at 2 and 10 ppm concentrations. Employing nanosized TiO₂ in suitable concentration could promote the seed germination of wheat in comparison to bulk TiO₂ but in high concentrations had inhibitory or any effect on wheat.     

A fluorescent aptasensor for sensitive analysis oxytetracycline based on silver nanoclusters

A fluorescent aptasensor for detection of oxytetracycline (OTC) was presented based on fluorescence quenching of DNA aptamer‐templated silver nanoclusters (AgNCs). The specific DNA scaffolds with two different nucleotides fragments were used: one was enriched with a cytosine sequence fragment (C12) that could produce DNA–AgNCs via a chemical reduction method, and another was the OTC aptamer fragment that could selectively bind to the OTC antibiotic. Thus, the as‐prepared AgNCs could exhibit quenched fluorescence after binding to the target OTC. The fluorescence ratio of the DNA–AgNCs was quenched in a linearly proportional manner to the concentration of the target in the range of 0.5 nM to 100 nM with a detection limit of 0.1 nM. This proposed nanobiosensor was demonstrated to be sensitive, selective, and simple, introducing a viable alternative for rapid determination of toxin OTC in honey and water samples. Copyright © 2016 John Wiley & Sons, Ltd.     

Lumbar Disk Degeneration Disease and Aggrecan Gene Polymorphism in Northern Iran

Aggrecan is the major component of intervertebral disk matrix proteoglycan with multiple functional domains. To understand the role of aggrecan polymorphism in a part of exon 12 encoding the CS1 domain in lumbar disk degeneration disease, we have analyzed genomic DNA from 71 patients with the disease and 108 healthy individuals in northern Iran. The AGC1 alleles were determined by PCR followed by gel electrophoresis. Twelve AGC1 alleles ranging from 18 to 29 repeats were detected in patients and controls. The most frequent AGC1 allele was 27, followed by 28 in patients and controls. The shorter AGC1 alleles (≤24 repeats) were more frequent in patients than in controls (37 vs. 16%, P < 0.001). The odds ratio for lumbar disk degeneration was 3.28 (95% confidence interval 1.62–6.65) in carriers of the shorter AGC1 alleles. Our data suggest that carrying shorter AGC1 alleles with less than 24 repeats could predispose a subject to lumbar disk degeneration disease in northern Iran.     

Processing and secretion of a mutant yolk polypeptide in Drosophila

Flies homozygous for the female sterile mutation fs(1)1163 produce eggs deficient in YP1, one of the three major yolk polypeptides. Genetic studies showed that fs(1)1163 is cis acting on YP1 quantity, so that mutation does not control a diffusible substance regulating YP1 production. The sterility and YP1 quantity phenotypes were not genetically separated from each other or from the structural gene for YP1, indicating that the mutation is located in or near Yp1. The amount of translatable YP1 message in mutant and wild-type cells was approximately equal, but the primary translation products were different in size and, hence, different in structure. The signal peptide was cleaved normally from the mutant polypeptide, and phosphorylation and glycosylation of the mutant YP1 also occur. However, YP1 processing intermediates that are transient in wild-type cells become major species in fs(1)1163 cells. We conclude that fs(1)1163 alters the primary structure of YP1 in a way that does not block signal-peptide cleavage but does alter later processing steps and hence its rate of secretion, leading to the YP1 deficiency found in the hemolymph and eggs.