Prevalence and characteristics of Epstein-Barr virus-associated gastric cancer in Iran.

BACKGROUND/AIMS: Gastric cancer (GC) is the second leading cause of cancer-related deaths worldwide and is the most frequent cancer in Iran. Epstein-Barr virus (EBV) has been shown to be associated with gastric cancer. The present study was carried out to investigate the prevalence of Epstein-Barr virus (EBV) associated gastric cancer among Iranian patients. METHODS: Ninety formalin fixed paraffin-embedded cases of gastric cancer were studied. The specimens were investigated for the presence of the EBV genome by quantitative real-time polymerase chain reaction. RESULTS: Of ninety specimens, EBV was detected in six cases (6.66%). The mean age for patients EBV-positive gastric carcinomas was 72.1 years, whereas the mean age for the entire group was 65.7 years. Four out of 64 (6.25%) male patients and 2 out of 26 (7.69%) female cases were positive for EBV. According to anatomic location, EBV was detected in 4 out of 39 (10.25% ) gastric cancer were located in cardia and 2 out of 26 (7.69%) gastric cancer were located in middle/corpus. CONCLUSIONS: The present study shows that the frequency of EBV-associated gastric carcinoma in Iran is  low. Differences of EBV-associated gastric carcinoma incidence in different countries may reflect the epidemiologic factors and dietary habits. Further analysis of clinical pathology features of EBV-associated gastric carcinoma using a larger number of cases would give invaluable insights into its etiology.

Hepatitis B virus surface antigen (HBsAg) mutations are rare but clustered in immune epitopes in chronic carriers from Sistan-Balouchestan Province, Iran.

BACKGROUND: Hepatitis B virus (HBV) gene and protein variations have frequently been observed in chronic patients. The aims of this study were to determine the genotypes as well as the patterns of HBsAg variations in chronically-infected patients from the south-eastern part of Iran. METHODS: Twenty- one chronic inactive HBV carriers from Sistan-Balouchestan Province (an area with a low prevalence of HBV complications such as cirrhosis and hepatocellular carcinoma [HCC]) were enrolled. The surface genes were amplified, sequenced, and subsequently aligned using international and national Iranian database. RESULTS: All strains belonged to genotype D, subgenotype D1, and subtype ayw2. Of all 39 mutations occurred at 31 nucleotide positions, 15 (38.5%) were missense (amino acid altering) and 24 (61.5%) were silent (no amino acid changing). At the amino acid level, 15 substitutions occurred; 10 (66.67%) were distributed in different immune epitopes, five of which (33.33%) were in B cell epitopes; four (36.27%) were distributed in T helper epitopes, and one (6.67%) occurred inside CTL epitopes. CONCLUSION: A narrowly-focused immune pressure has been on the surface proteins, especially at the B cell level, led to the emergence of escape mutants in these patients that might be related to the pathogenicity of HBV chronic infection. Also, due to the negative selection imposed on HBV genome and the uniqueness of genotype D in this ethnic group, complications (cirrhosis and HCC) are lower than other published studies.

Expression of recombinant HAO3 from an Iranian isolate of Hyalomma anatolicum anatolicum in Pichia pastoris and evaluation of its antigenicity.

Hyalomma anatolicum anatolicum tick is considered as one of the main problem of ruminants' productivity in endemic countries such as parts of Africa, the Middle East and India. The disease is economically important and hence, its control and eradication is a priority. This problem reinforces the need for alternative approach like vaccine to control tick infestations instead of continuous application of acaricide which led to the natural selection of the acaricide-resistant ticks. Therefore, the present study provided evidence for the construction of transformant containing the chromosomally integrated multi-copy expression cassettes of HAO3, its successful and efficient expression in Pichia pastoris yeast and purification of the secreted protein by ultrafiltration (UF) system in a high level yield and purity. The result of antigenicity assay for the rHAO3 protein pointed well toward its capability for the elicitation of antibody response in immunized rabbits. Interestingly, the results indicated that the expressed HAO3 protein reacted well with mid gut antigen (MGAg) and rBm86 (Gavac) antisera in ELISA and western blot assays making it evident that the epitopes present in expressed protein are well recognized by the antibodies against MGAg and rBm86 proteins. Moreover, the presence of cross-reactive epitopes between rHAO3 protein with its native antigen from mid gut cells was also determined.