Biological Activity Alterations of Human Amniotic Membrane Pre and Post Irradiation Tissue Banking.

BACKGROUND AND OBJECTIVE: Innate immunity of Human Amniotic Membrane (HAM) and its highly active secretome that rich with various types of growth factors and anti-inflammatory substances proposed it as a promising material for many medical studies and applications. METHODOLOGY: This study evaluate the biological activity of cultivated HAM pre and post tissue banking process in which freeze-dried HAM was sterilized by 25 KGray (kGy) dose of γ radiation. The HAM's antimicrobial activity, viability, growth of isolated human amniotic epithelial cells (HAECs), hematopoietic stimulation of co-cultivated murine bone marrow cells (mammalian model), scaffold efficiency for fish brain building up (non-mammalian model) and self re-epithelialization after trypsin denuding treatment were examined as supposed biological activity features. RESULTS: Native HAM revealed viability indications and was active to kill all tested microorganisms; 6 bacterial species (3 Gram-positive and 3 Gram-negative) and Candida albicans as a pathogenic fungus. Also, HAM activity promoted colony formation of murine hematopoietic cells, Tilapia nilotica brain fragment building-up and self re-epithelialization after trypsin treatment. In contrary, radiation-based tissue banking of HAM caused HAM cellular death and consequently lacked almost all of examined biological activity features. CONCLUSION: Viable HAM was featured with biological activity than fixed HAM prepared by irradiation tissue banking.

Multiplication of Spodoptera littoralis granulosis virus in a cell line established from Phthorimaea operculella.

A complete replication of the Spodoptera littoralis granulosis virus (SpliGV) was obtained, in vitro by both virus infection and DNA transfection in the ORS-Pop-95 (Pop-95) cell line established from embryonic cells of the potato tuber moth, Phthorimaea operculella. SpliGV multiplied significantly during several passages in Pop-95 cells at 19 degrees C. When the cells were infected and kept at 19 degrees C for the first 4 hrs and then at 27 degrees C for the rest of the experiment (20 days), the viral multiplication proceeded at the same rate. Comparison of SpliGV progenies, multiplied either in vivo or in vitro, using electron microscopy and restriction profile analysis, showed their identity.

The potato mitochondrial initiator methionine tRNA gene and its flanking regions: an illustration of the diversity of mitochondrial genome rearrangements among plant species.

The initiator methionine transfer RNA (tRNA(fMet)) gene was identified on a 347 bp Eco RI-Hind III DNA fragment of the potato mitochondrial (mt) genome. The sequence of this gene shows 1 to 7 nucleotide differences with the other plant mt tRNAs(fMet) or tRNA(fMet) genes studied so far. Whereas the tRNA(fMet) gene is present as a single copy in the potato mt genome, a tRNA 'pseudogene' corresponding to 60% of a complete tRNA (from the 5' end to the variable region) and located at 105 nucleotides upstream of the tRNA(fMet) gene on the opposite strand was shown to be repeated at least three times. Furthermore, the physical environment of the tRNA(fMet) gene in the mt genome is very different among plants, which suggests that the tRNA(fMet) gene region has often been implicated in recombination events of plant mt genomes leading to important rearrangements in gene order.