Infiltrating growing pattern xenografts induced by glioblastoma and anaplastic astrocytoma derived tumor stem cells.

OBJECTIVE: The number of evidences regarding the role of tumor stem cells (TSC) in the initiation and progression of high-grade astrocytomas became more and more numerous in the last years. This issue has been intensively tested in glioblastoma, but little attention has been paid for anaplastic astrocytoma. The main objective of this paper was to study the morphological characteristics of the xenografts developed from glioblastoma and anaplastic astrocytoma derived cancer stem cells. METHODS: The authors of this study successfully isolated and partial characterized primary cultures of glioblastoma and anaplastic astrocytoma derived TSC. Tumors stem cells have been stereotactically inoculated in nude mice brains and the xenografts have been studied using morphological and imunohistochemistry techniques. RESULTS: The tumor xenografts which have been established in nude mice using TSC had different characteristics when compared with U87 xenografts previously developed by our group, and depend of the origin type of the tumors (glioblastoma versus anaplastic astrocytoma). The diffuse growing pattern and cells infiltration have been more pronounced in both anaplastic astrocytoma and glioblastoma derived TSC xenografts compared with U87 line xenografts. CONCLUSION: Our results support the hypothesis regarding the role of TSC in the infiltration process of glioblastoma and anaplastic astrocytoma. The extensive infiltration growing patterns of these types of xenografts make them useful models for studying the invasion mechanisms in gliomas.

Effects of lithium carbonate on rat seminiferous tubules: an ultrastructural study.

Lithium salts are commonly used for treatment of bipolar disorder but prolonged treatment with therapeutic doses induces substantial toxic effects. In the present study we examined the effects of lithium carbonate on the ultrastructure of rat seminiferous tubules. Rats were exposed to lithium carbonate at doses of 35 mg/kg/day for 21 days. After lithium treatment, the tunica propria widened and folded together with convolutions of the basement membrane, myoid cells and lymphatic endothelium. In the seminiferous epithelium loss of germ cell attachment and appearance of expanded intercellular spaces between spermatogenic cells were observed. Early stages of spermatogenic cells showed nuclear protrusions or swellings because of an extensive enlargement of the outer nuclear membrane. Round spermatids exhibited abnormally shaped acrosomes and dilation of the subacrosomal space. Many abnormal, degenerated late spermatids with random orientation were seen towards the basal and adluminal compartments of the seminiferous epithelium. In addition, spermatids exhibited alteration in F-actin bundle ectoplasmic specialization and contained many mitochondria-associated granular bodies.

[The effects of cicatrizant wound compresses]. / Efectele compreselor cicatrizante asupra plagilor (nota preliminara).

Cicatrisant collagen compress are biomaterials performed from type I collagen purified. Experimental studies including trials carried out in vitro and in vivo, demonstrated the biocompatibility of these biomaterials and their effect on accelerating the process of dermic wound re-epithelization. A subsequent stage of our investigations consisted in clinical trial of these cicatrisant compresses. These were applied to post-traumatismal wounds of variable areas or to 2nd and 3rd degree of deeper burns. The obtained results demonstrated that collagen biomaterials as cicatrizing compresses are well tolerated by human organism, they do not cause inflammations, necroses or other undesirable phenomena at the site of application. Also it was found that these biomaterials are not antigenic, since anticollagen type I antibodies were not present in nome of the treated patients' serum and accelerate the epitelization.