Tityus stigmurus venom causes genetic damage in blood and testicular cells and affects the number and morphology of gametogenic lineage cells in mice.

Scorpion envenomation represents an important health problem in many parts of the world, due to the high number and severity of accidents. Recent studies demonstrated that some species can produce venoms with genetic damage potential. Here, we evaluated whether Tityus stigmurus venom causes genetic damage in blood and testicular cells of Swiss mice. We also analyzed the effect of the venom on the number of spermatogenic lineage cells. Five groups of mice received 0.387 mg/kg of the venom, intraperitoneally; one group received saline solution (control group). Blood and testicular cells were collected for comet assay and histological analysis at different times after treatment (1, 2, 6, 12, and 48 h). Blood was also collected 48 h after treatment for the micronucleus test in erythrocytes. Histological analysis was performed by counting cells of the spermatogenic lineages; the nuclear area of elongated spermatocytes was also evaluated. Treatment with the venom induced DNA damage that endured from 1 h to 48 h, as confirmed by the comet assay. The micronucleus test demonstrated that the venom induced mutations in erythrocytes. The number of spermatogonia and rounded spermatids decreased in some groups; the number of elongated spermatids increased, and their nuclear size decreased 1 h after treatment. Genetic damage can be caused directly by the venom, but we suggested that reactive oxygen species that result from inflammatory process caused by the envenomation may have an important role in the DNA damage. Genetic damage and apoptosis may explain the changes in the number of spermatogenic cells. Furthermore, the decrease in nuclear area may result from chromatin loss. Genetic damage in testicular cells, associated with alterations in the number and morphology of spermatogenic cells, can result in reproduction disorders in animals, or humans, stung by T. stigmurus.

Immunophenotypic and ultrastructural validation of a new human glioblastoma cell line.

1. A human glioma cell line, NG97, was established by Grippo et al. in 2001 from tissue obtained from a grade III astrocytoma (WHO, 2000). In this first study, the cell line grew as two morphologically distinct subpopulations: dendritic/spindle cells and small round cells. The injection of NG97 cells into nude mice induced an aggressive tumor characterized by: severe cytological atypia, vascular proliferation and pseudopalisading necrosis (glioblastoma multiforme features). 2. The purpose of the present study was to characterize the immunophenotype and ultrastructural aspects of this cell line, using the parental tumor, cultured cells and the xenotransplant, in order to assess its glial nature and possible divergent differentiation. 3. NG97 cells and xenotransplant expressed the main neuroglial markers (GFAP, S-100 protein, NSE and Leu-7) and showed no aberrant expression of other histogenetic markers. GFAP was similarly expressed in the parental tumor and in the cells in culture, but decreased in the xenotransplant. NSE expression was reduced in NG97 cells, but substantially recovered in the xenotransplant. This variability in expression of GFAP and NSE was interpreted as either a phenomenon of dedifferentiation or to microenvironmental selection of specific subclones. S-100 was equally expressed in the three contexts. The xenotransplant's ultrastructural features were those of a highly undifferentiated tumor. No significant immunophenotypic or ultrastructural differences between the two morphologically distinct populations were found. 4. Thus, our data demonstrate that NG97 cells constitute a pure glial-committed cell line, which may prove useful as a malignant glioma model in studies addressing pathophysiological, diagnostic and therapeutic issues.