Nagwa Aref

This study aimed to assess radioprotective efficacy of zinc oxide nanoparticles (nano-ZnO) against γ-radiation induced DNA lesions in Vicia faba employing flow cytometry (FCM), comet assay, and RAPD-PCR bioassays. Each dose of γ-irradiated seeds was post-treated with three nano-ZnO concentrations. Exposure time pre- and post-ZnO treatments were 24 h. Dose-dependent nano-ZnO and γ-ray treatments showed specific interference with DNA. Three bioassays could successfully detect positive action of two nano-ZnO concentrations (500 and 2000 mg L^-1) on DNA compared to control while high concentration nano-ZnO showed a negative interference with DNA. On the contrary, three doses of γ-ray induced major lesions in V. faba DNA. Data obtained illustrated that combination of 2000 mgL^-1 nano-ZnO concentration with each γ-ray dose had a good ability to protect DNA against their damaging when compared to the equivalent γ-ray doses prior nano-ZnO treatment. This was evident through the significant amelioration of DNA parameters which manifested in increasing nuclear DNA content and genome size, reduction the DNA damage (tail length, Tailed DNA% and tail moment), and scoring new amplified DNA bands and increasing their number. This study concluded that nano-ZnO can be used as potent mutant and an efficient nano-radioprotector for the protection of crop plants DNA.

Background/Aim: To assess the correlation between serum HBsAg titers and hepatitis B virus (HBV) DNA levels in patients with hepatitis B envelop antigen-negative (HBeAg −ve) HBV genotype-D (HBV/D) infection. Patients and Methods: A total of 106 treatment- naïve, HBeAg −ve HBV/D patients were included; 78 in the inactive carrier (IC) state and 28 in the active hepatitis (AH) stage. HBV DNA load and HBsAg titers were tested using TaqMan real-time polymerase chain reaction (PCR) and automated chemiluminescent microparticle immunoassay, respectively. Results: The median (range) log10 HBsAg titer was significantly lower in the IC group compared with AH group, 3.09 (−1 to -4.4) versus 3.68 (−0.77 to 5.09) IU/mL, respectively; P < 0.001. The suggested cutoff value of HBsAg titer to differentiate between the two groups was 3.79 log10 IU/mL. In addition, there was a significant positive correlation between HBsAg and HBV DNA levels in the whole cohort, AH, and IC groups (r = 0.6, P < 0.0001; r = 0.591, P = 0.001; and r = 0.243, P = 0.032, respectively). Conclusion: Serum HBsAg titers may correlate with HBV DNA in treatment-naïve HBeAg -ve HBV/D patients, and supports the use of HBsAg levels in clinical practice as a predictor of serum HBV DNA levels.

The newly introduced castor bean whitefly (CBW) Trialeurodes ricini (Misra) has become an important pest which is widely spread all over Egypt. Biochemical studies were conducted to distinguish the different T. ricini biotypes and to determine the biotype economic threshold based on its ability to transmit plant viruses. Forty‐five samples of T. ricini adults were collected from castor bean (Ricinus communis) at different geographical locations representing the Egyptian Delta and Nile valley governorates. Esterase banding patterns were investigated to evaluate the extent of variation among the tested populations of the castor bean whitefly. Electrophoresis of homogenates of individual T. ricini females showed that there are five different biotypes (C₁–C₅). The predominant biotype (C₁ type) was found in about 80% of the tested locations. In transmission studies, the polymerase chain reaction (PCR) was used to detect geminiviruses in nucleic acid extracted from the different castor bean whitefly biotypes. PCR revealed that the five biotypes of T. ricini are viruliferous. To evaluate the efficiency of the predominant T. ricini biotype for transmitting the tomato yellow leaf curl virus (TYLCV), acquisition and inoculation access periods were determined. PCR indicated that 50% of whitefly adults collected from castor bean, acquired the virus after 10 h exposure to TYLCV infected tomato. Experimentally, the rate of transmission increased as the inoculation access period was lengthened and reached a maximum after 4 h. The obtained symptomatological results were also confirmed by PCR.