Background: More than two billion people have been exposed to hepatitis B virus (HBV) worldwide. Furthermore, four hundred million of them are infected with chronic HBV infection. The predominant mutation of the precore region involves a G to A change at nucleotide1896, which creates a premature stop codon at codon 28. Two mutations of A1762T and G1764A are reported as the most prevalent mutations in the basal core promoter (BCP). Objectives: The purpose of this study was to investigate the relationship between mutations in precore (PC) and basal core promoter regions, and the viral load. Patients and Methods: Fifty serum samples from patients with hepatitis B were used. Levels of liver enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured at the same time of serological markers of hepatitis B by ELISA. HBV-DNA was extracted from the sera, and then PCR performed on the HBV-DNA extracted with the use of specific primer of gene C. HBV viral load was determined by real-time PCR. The PC/ BCP mutations were determined by applying Line Probe Assay technique. The data were analyzed using SPSS software, version 20. Results: Only 82% of the patients were HBeAb positive and 76% of the patients had basal core/ precore mutations and mean viral load was 3/7 × 106 ± 9/7 × 105 IU/ml. Prevalence of mutations in the precore and basal core promoter regions were 46% and 30%, respectively. Conclusions: Our data indicated that there is a statistically significant relationship between HBV viral load and mutations in precore region (P < 0.05). Keywords: Mutations; Hepatitis B Virus; Viral Load

Introduction: Since the beginning of the COVID-19 pandemic, a wide clinical spectrum, from asymptomatic infection to mild or severe disease and death, have been reported in COVID-19 patients. Studies have suggested several possible factors, which may affect the clinical outcome of COVID-19. A pro-inflammatory state and impaired antiviral response have been suggested as major contributing factors in severe COVID-19. Considering that mitochondria have an important role in regulating the immune responses to pathogens, pro-inflammatory signaling, and cell death, it has received much attention in SARS-CoV-2 infection. Recent studies have demonstrated that high levels of cell-free mitochondrial DNA (cf-mtDNA) are associated with an increased risk of COVID-19 intensive care unit (ICU) admission and mortality. However, there have been few studies on cf-mtDNA in SARS-CoV-2 infection, mainly focusing on critically ill COVID-19 cases. In the present study, we investigated cf-mtDNA copy number in COVID-19 patients and compared between asymptomatic and symptomatic cases, and assessed the clinical values. We also determined the cf-nuclear DNA (cf-nDNA) copy number and mitochondrial transcription factor A (TFAM) mRNA level in the studied groups.Materials and methods: Plasma and buffy coat samples were collected from 37 COVID-19 patients and 33 controls. Briefly, after total DNA extraction, plasma cf-mtDNA, and cf-nDNA copy numbers were measured by absolute qPCR using a standard curve method. Furthermore, after total RNA extraction from buffy coat and cDNA synthesis, TFAM mRNA levels were evaluated by qPCR.Results: The results showed that cf-mtDNA levels in asymptomatic COVID-19 patients were statistically significantly higher than in symptomatic cases (p value = 0.01). However, cf-nDNA levels were higher in symptomatic patients than in asymptomatic cases (p value = 0.00). There was no significant difference between TFAM levels in the buffy coat of these two groups (p value > 0.05). Also, cf-mtDNA levels showed good diagnostic potential in COVID-19 subgroups.Conclusion: cf-mtDNA is probably important in the outcome of SARS-CoV-2 infection due to its role in inflammation and immune response. It can also be a promising candidate biomarker for the diagnosis of COVID-19 subgroups. Further investigation will help understanding the COVID-19 pathophysiology and effective diagnostic and therapeutic strategies.

Background and Objectives: In recent years, active packaging has been introduced as a new method to better preserve food. Chitosan and nanoclay have been used for preparation of an active nanocomposite with respect to their antimicrobial properties to investigate its effects on the microbial limitation in Gouda cheese. Materials and Methods: Nanoclay film, chitosan film, chitosan-based nanocomposites and nanoclay-based nanocompos- ites were prepared and their antimicrobial properties were evaluated to the microbial limitations of Gouda cheese con- sist of coliforms, Escherichia coli, Salmonella spp., coagulase-positive Staphylococcus, mold and yeast by agar diffusion method. Results: The results indicated, the best antimicrobial effect belonged to nanocomposite film with the composition of chitosan 3 wt% by adding nanoclay 1 wt%, which can prevent microbial characteristics of Gouda cheese. Conclusion: The chitosan and nanoclay nanocomposite had excellent antibacterial activity and performed well against microbial limitations (coliforms, E. coli, Salmonella spp., coagulase-positive Staphylococcus, mold and yeast) of Gouda cheese. Therefore, the nanocomposite may be possibly used as a surface coating in addition to Gouda cheese as well as sim- ilar cheeses and other food to enhance microbial characteristics and extend shelf life.

• The present study investigated HLA-DQB1 polymorphisms in three generations (Grandmother, mother and offspring) of patients with hepatitis B in their families. • The typing of HLA-DQB1 showed that HLA-DQB1*04:01 has the most frequent allele in patients with chronic hepatitis B is considered a risk factor for susceptibility to hepatitis B infection. • HLA-DQB1*06:04 that was observed only in one case in the control group, was suggesting a protective role in HBV infection and spontaneous clearance of the virus. • HLA-DQB1*03:03 was reported in recovered and healthy groups was correlated with viral clearance and suppression of CHB formation. • HLA-DQB1*05:02 is a polymorphism associated with a higher risk of liver cirrhosis; it was observed in three-generation, two-generation, and intra-familial groups, as well as in one healthy subject in fifth group. • HLA-DQB1*05 that associated with increased susceptibility to HBV infection, its persistence, and the development of CHB, was the most common HLA allele in three generations, two generations, and other groups.