Importance of the lumpy skin disease virus (LSDV) LSDV126 gene in differential diagnosis and epidemiology and its possible involvement in attenuation.

Examination of lumpy skin disease virus (LSDV) isolates from different geographic regions and times revealed that assays developed in our laboratory for differentiating between virulent Israeli viruses and Neethling vaccine virus (NVV) are generally useful in most, if not all, endemic areas in which NVV-based vaccines are used. Recently it was revealed that the LSDV126 gene of field isolates contains a duplicated region of 27 bp (9 aa), while the vaccine viruses have only one copy. Phylogenetic analysis of a 532-bp segment carrying the LSDV126 gene and whole virus genome sequences revealed that LSDV isolates formed two groups: virulent and vaccine viruses. In this analysis, all of the capripox viruses that lack the ability to efficiently infect cattle were found to carry only one copy of the 27-bp fragment, suggesting that the LSDV126 gene plays an important role in the ability of capripox viruses to infect cattle. In silico analysis of potential antigenic sites in LSDV126 revealed that LSDV126 variants with only one copy of the repeat lack a potentially important antigenic epitope, supporting its possible significance in cattle infection. This study provides new information about the nature of the LSDV126 gene and its possible role in the life cycle of LSDV.

Adsorption of sulfur dioxide on natural clinoptilolite chemically modified with salt solutions.

Various ion exchange forms of preliminary partly decationised zeolite (hydrogen forms) were obtained by indirect modification with metal salt solutions, as well as by direct treatment of natural clinoptilolite taken from Bulgarian deposits. Direct modification leads to a higher extent of samples enrichment with corresponding ion. Independently of the conditions, the alkaline and alkaline earth metal ions (especially sodium and calcium) were inserted at a greater extent, while the transitional metals-at a comparatively lower extent. The cationic forms of clinoptilolite were used for adsorption and desorption experiments. The breakthrough adsorption curves and the concentration curves at temperature-programmed desorption were obtained and compared. The breakthrough and saturation times, the adsorption capacity, the distribution coefficient, the adsorbed SO(2), the portions desorbed as SO(2) and SO(3), respectively, as well as the not desorbed portion of SO(2), were determined using these curves. It was established that a definite quantity of undesorbed SO(2) has remained in the zeolite forms modified with transitional metal cations. This statement was proved not only by the comparison between the adsorbed and desorbed quantities, but also by three-cycle adsorption-desorption experiments for the Cu(2+)-form. The results demonstrate a decrease in the capacity for each following cycle in an extent similar to the undesorbed SO(2) quantity. It was not observed a visible difference in the values of the distribution coefficients for adsorption on identical cation forms, directly or indirectly obtained. However, the breakthrough time of the samples obtained by ion exchange of the hydrogen form was longer in all cases. Definite quantities of desorbed SO(3) were registered for all forms, except for the natural clinoptilolite and the samples enriched with alkaline and alkaline earth metal cations.

A plant polyphenol-rich extract restores the suppressed functions of phagocytes in influenza virus-infected mice.

Influenza infection was induced in white ICR mice by intranasal (i.n.) inoculation of the virus A/Aichi/2/68 (H3N2). The number, migration and phagocyte indices of alveolar and peritoneal macrophages (pMØ) and of blood polymorphonuclear leukocytes (PMNs), as well as the inhibition of the PMN adherence in the presence of a specific antigen were followed for 9 days after infection. The effect of the i.n. application of a polyphenol-rich extract, designated as polyphenolic complex (PC), isolated from the medicinal plant Geranium sanguineum L., on the inspected immune parameters was studied in parallel with the virological parameters of the infection, e.g. rate of mortality, mean survival time (MST), infectious lung virus titre and consolidation of the lungs. It was found that the application of PC induced a continuous 2- to 2.5-fold rise in the number of both peritoneal and alveolar macrophages (aMØ) in the infected and healthy controls. The migration of both peritoneal and aMØ increased 1.5- to 2-fold in the group of infected PC-treated animals and four to fivefold in the control group, the maximum being on day 9. PC stimulated phagocyte activities of blood PMNs in both infected and healthy mice. The leukocyte adherence inhibition (LAI) index decreased in the infected and PC-treated animals. The restoration of the suppressed functions of phagocytes in influenza virus-infected mice (VIM) was consistent with a prolongation of MST and reduction in mortality rate, infectious virus titre and lung consolidation. The immunoenhancing properties of PC apparently contribute to the overall protective effect of the plant preparation in the lethal murine experimental influenza A/Aichi infection.

Effect of Cu/Zn-superoxide dismutase from the fungal strain Humicola lutea 103 on antioxidant defense of Graffi tumor-bearing hamsters.

A novel Cu/Zn-containing superoxide dismutase (SOD) was isolated from the fungal strain Humicola lutea 103. Previously, a protective effect of this enzyme (HLSOD) against tumor growth and also superoxide production in Graffi tumor-bearing hamsters (TBH) were established. The aim of the present study was to investigate the effect of HLSOD on the activity of endogenous SOD and catalase in the cells from TBH during tumor progression. Our results point out that transplantation of Graffi tumor causes a significant decrease in SOD activity in the cells from liver of the hosts (from 35 to 59% compared to the control). In the tumor cells relatively low levels of SOD (about 7 U mg protein(-1)) were found, and Cu/ZnSOD was the main isoenzyme in total SOD activity. Tumor growth resulted in a reduction of catalase activity, which correlated with the process of tumor progression. A single dose (65 U) treatment with HLSOD caused an increase in endogenous SOD and catalase activity in healthy animals and resulted in restoration of the antioxidant ability in liver cells of the hosts at the early stage of tumor progression. The results show the possible participation of HLSOD in the host oxidant-antioxidant balance, which is probably one of the factors of its immunoprotective action established earlier.

A novel glycosylated Cu/Zn-containing superoxide dismutase: production and potential therapeutic effect.

The fungal strain Humicola lutea 103 produces a naturally glycosylated Cu/Zn SOD. To improve its yield, the effect of an increased concentration of dissolved oxygen (DO) on growth and enzyme biosynthesis by the producer, cultivated in a 3 l bioreactor, was examined. Exposure to a 20% DO level caused a 1.7-fold increase of SOD activity compared to the DO-uncontrolled culture. Maximum enzyme productivity of SOD was approximately 300 x 10(3) U (kg wet biomass)(-1). The novel enzyme was purified to electrophoretic homogeneity. The presence of Cu and Zn were confirmed by atomic absorption spectrometry. The molecular mass of H. lutea Cu/Zn SOD was calculated to be 31870 Da for the whole molecule and 15936 Da for the structural subunits. The N-terminal sequence revealed a high degree of structural homology with Cu/Zn SOD from other prokaryotic and eukaryotic sources. H. lutea Cu/Zn SOD was used in an in vivo model for the demonstration of its protective effect against myeloid Graffi tumour in hamsters. Comparative studies revealed that the enzyme (i) elongated the latent time for tumour appearance, (ii) inhibited tumour growth in the early stage of tumour progression (73-75% at day 10) and (iii) increased the mean survival time of Graffi-tumour-bearing hamsters. Moreover, the fungal Cu/Zn SOD exhibited a strong protective effect on experimental influenza virus infection in mice. The survival rate increased markedly, the time of survival rose by 5.2 d and the protective index reached 86%. The H. lutea SOD protected mice from mortality more efficiently compared to the selective antiviral drug ribavirin and to commercial bovine SOD. In conclusion, our results suggest that appropriate use of the novel fungal SOD, applied as such or in combination with selective inhibitors, could outline a promising strategy for the treatment of myeloid Graffi tumour and influenza virus infection.