Hepatitis B Virus Vaccine immune response in Egyptian children 15-17 years after primary immunization; should we provide a booster dose?

Background: Few studies have evaluated the seroprotection of HBV vaccines among healthy Egyptian children after receiving the primary immunization. Yet, up to our knowledge none of them has evaluated the immune status to HBV vaccine among Egyptian children older than 15 years.Objective: To assess the seroprotection as well as immunological memory against HB virus more than 15 years after receiving the primary set of vaccination.Methods: Serum anti-HB surface antibody was measured in 225 healthy adolescents. Their ages ranged from 16-18 year with a definite history ofreceiving the primary immunization for HBV at infancy. A booster dose ofthe HB vaccine was given to 56 of the candidates in whom serum level ofanti-HB surface antibody was not protective (less than 10 mIU/ml). Asecond evaluation of anti-HBs was done in those 56 one month after thebooster dose.Results: Only 8.9% of our cohort have a protective anti-HBs antibody when measured 15-17 years after primary vaccination set. On the other hand, 100% of the 56 children who received the booster dose showed excellent anamnestic response.Conclusion: Despite the loss of protective levels of anti-HBs antibody among healthy low risk adolescents 15-17 years after primary HB immunization set, strong anamnestic response indicates the presence of good immunological memory.Keywords: Hepatitis B, vaccine, booste

An in vitro L-band EPR study with whole human teeth in a surface coil resonator. Radiat

Abstract L-band EPR measurements were done in vitro on extracted human teeth with the objective to evaluate the feasibility of retrospective in vivo EPR dosimetry. In a recent study, the relative contributions of individual tooth components (enamel, crown dentin and root) to the total response of a whole tooth inside an L-band surface coil resonator was investigated. In the present work, the gamma-dose response curves were evaluated for di erent EPR signal evaluation methods, using 35 whole teeth with absorbed doses in the range 1-100 Gy. The paper reports on the ÿrst attempt to deconvolute the single composite L-band EPR line in components due to CO − 2 and native radicals. The L-band EPR spectrum of teeth could be approximated by combining powder-simulated spectra of orthorhombic and quasi-axial signals of the CO − 2 radical and an isotropic signal of the native radicals. Among the applied EPR signal evaluation methods, the evaluation by spectrum deconvolution revealed the lowest detection limit for absorbed dose. A detection limit of about 0:5 Gy was estimated for the currently available L-band equipment

Evaluation of the Native Killer Yeasts against the Postharvest Phytopathogenic mould of Balady Orange Fruits

Yeasts are some of the most important postharvest biocontrol agents (BCAs). Postharvest oranges frequently deteriorate due to green and blue moulds, leading to significant economic losses. The purposes of the present study were to isolate blue and green moulds from infected orange fruits, to assess the ability of killer yeasts isolated from healthy orange fruits and leaves from orange orchards to control blue and green moulds and to evaluate the additive effect of BCAs in combination with 2% sodium bicarbonate (SBC), 2%, sodium benzoate (SB), 2% calcium chloride, 0.2% salicylic acid (SA) or 0.5% chitosan. Among eight fungi isolated from orange fruits showing symptoms of green and blue mulds infection, two were identified as P. digitatum and P. italicum and selected for in vitro assays. Twenty eight yeast isolates were obtained from orange leaves and from the surface of fruits. All yeasts exhibited high killer activity. Twelve yeasts reduced 22.5 –70% of P. digitatum growth while seven isolates reduced 21.1- 68.5% of P. italicum growth. The most potent yeast isolates were identified as Candida pseudotropicalis, Candida salmanticensis, Candida membranifaciens and Pichia guilliermondii. Combination of the BCAs, C. pseudotropicalis, C. salmanticensis and P. guilliermondii with SBC, CaCl2 or chitosan increased their effectiveness against P. digitatum. While combination of C. pseudotropicalis, C. membranifaciens and P. guilliermondii with these natural compounds decreased their effectiveness against P. italicum. Combination of C. membranifaciens with SA increased its effectiveness against P. digitatum. Sodium benzoate has additive effect on C. pseudotropicalis against P. digitatum and C. pseudotropicalis and P. guilliermondii against P. italicum

Estimation of radiation levels by EPR measurement of tooth enamel in Indian populations.

Enamel from 34 molars from 22 individuals in the general population are used to evaluate the background radiation in six cities in India. The estimation of the background dose for each tooth is evaluated using two EPR methods: the calibration-curve method and the additive-dose method. The variation of the estimated EPR dose with tooth position is investigated by using eight teeth taken from the same person. Contribution of the dental X-ray treatments to the enamel-absorbed dose was evaluated using another 17 teeth exposed from 1 to 10 times

Comparison of gamma- and UV-light-induced EPR spectra of enamel from deciduous molar teeth.

From previous work, it is known that CO2− radicals in tooth enamel are induced by gamma as well as by UV-light exposure. The parameters of the EPR signal of the CO−2 radical were found to be independent of the source of exposure. However, it would be desirable for retrospective dosimetry to identify other characteristic features of the EPR spectrum of tooth enamel, which would allow differentiation between the two sources of exposure. In the present work, enamel of deciduous molars was exposed to γ-radiation from a 60Co-source and 254 nm UV-light from a low-pressure mercury lamp. The resulting EPR spectra were deconvoluted, and the native spectrum simulated from spectra of the CO−2 radical, and two further EPR lines. Both EPR signals of the native spectrum were located at g=2.0046, but were different in line shape and width. One was a 1 mT wide isotropic signal of Gaussian line shape while the other was a 0.7 mT wide axial signal of Lorentzian line shape. A comparable study of the amplitudes of the native and CO2− signals was done before and after γ- and UV-light exposure. While the native signals were found to be only slightly sensitive to γ-radiation, their amplitude increased significantly on UV-light exposure. Feasibilities are discussed to distinguish different radiation sources by exposure-induced alterations of the native EPR spectrum