Evaluation of the chicken embryo chorioallantoic membrane model for laryngeal tumor transplantation

The laryngeal squamous cell carcinoma is the second common malignant tumor of the respiratory tract and together with recurrent respiratory papillomas represents the most common tumors of the larynx. Many experimental models are used to study the morphology of malignant tumors. The chicken chorioallantoic membrane (CAM) model is one of them. The CAM has all the nutrition needed for the piece of the transplanted tumor to survive. The aim of this study was to investigate whether the laryngeal papilloma and the laryngeal squamous cell carcinoma tissues transplanted on the chick CAM survive with their main histological features, and to determine the morphological changes of the CAM with different transplants. For the preparation of the CAM, fertilized hen eggs were put into an incubator for 3 days. Then the windows in the shell were opened. The fresh samples of tumors were transplanted on the CAM on the 7th day of incubation. After 3 days after transplantation the CAM with onplants were excised and fixed in the 10% formalin solution. Morphological changes in the control CAM and in the CAM with tumor onplants were observed using the digital camera on the OLYMPUS microscope. The results showed that the CAM with the laryngeal squamous cell carcinoma onplant was distinctly thicker than that of the control group and than the CAM with the papilloma onplant; the chorionic epithelium was thickened and appeared stratified of up to 5–6 layers and in some locations squamous keratinized; the mesenchymal cells were densely arranged under the tumor transplants. We observed that morphological changes in the thickness of the CAM and the chorionic epithelium were more obvious in the CAM under the carcinoma transplants. After 72 hours of the tumor tissue transfer onto the membrane, the tumor cells retained their vitality and also their influence on the CAM tissues could be observed

Lyginamoji gyvūnų morfologija : mokymo priemonė

Vytauto Didžiojo universiteta

Histological analysis of electrochemotherapy influence on Lewis Lung Carcinoma

Stipriais elektriniais laukais veikiant navikines ląsteles, jų plazminėje membranoje atsiranda mikroporų, per kurias citotoksinis preparatas lengviau prasiskverbia į ląstelės vidų ir dėl to pastebimai sustabdo naviko augimą. Šis reiškinys buvo pavadintas elektrochemoterapiniu veikimu. Tyrinėjant elektrochemoterapijos poveikio sukeltus plaučių epidermoidinės karcinomos, įskiepytos pelėms į poodį, histologinius pakitimus optinės ir elektroninės mikroskopijos metodais, nustatyta, kad po gydymo naviko ląstelių ir branduolių membranos praranda vientisumą, nutrūksta ryšiai tarp ląstelių, audinyje susidaro nekrozės židiniai, atsiranda bebranduolių ląstelių – “šešėlių”. Nekrozės sričių plotas priklauso nuo elektrinio lauko stiprumoUnder the influence of strong electric fields the permeability of tumor cell membranes to poor permeating drugs increases and as a result the tumor growth is inhibited. This new tumor treatment method is named electrochemotherapy. We investigated the electrochemotherapy influence of bleomycin upon mice Lewis Lung Carcinoma by using optical histological and electron microscopic tumor analysis. It was shown that due to electrochemotherapy tumor necrosis area is significantly increased, intercellular gaps enlarge, and a big amount of cells is destroyed. Cell and nucleus membranes break as well as hemorrhage are very often. The observable histological tumor change was noted when electrical pulses of 1300 V/cm and 0.1 ms duration were applied. Pulses of 1700 V/cm and 0.1 ms duration induce total tumor destructionKauno medicinos universitetasVytauto Didžiojo universiteta

Effectiveness of electrochemotherapy in dependence of combinations of pulse strength and duration

Biologijos katedraVytauto Didžiojo universiteta

Extent of cell electrofusion in vitro and in vivo is cell line dependent

Background: Electric pulses delivered to cells that are in close contact may induce cell fusion, by a process termed electrofusion. Recently it has been shown that electrofusion in tumours in vivo depends on tumour type. The aim of this work was to examine the differences in electrofusion in various cell lines, both in vivo and in vitro. Materials and Methods: LPB, B16F10 and DC-3F cells in vitro and LLC tumours in vivo were exposed to various electric pulses. The number of fused cells was then evaluated. Results: Cell electropermeabilization was confirmed to be a necessary but non-exclusive condition to obtain a high level of cell electrofusion. The extent of electrofusion depends both on the degree of permeabilization and cell type. Conclusion: It was observed that metastatic tumour cells easily electrofuse, suggesting that cell type-specific membrane properties and/or secretion of proteases determine the extent of electrofusionBiologijos katedraKauno medicinos universitetasVytauto Didžiojo universiteta

Optimization of a gene electrotransfer method for mesenchymal stem cell transfection

Gene electrotransfer is an efficient and reproducible nonviral gene transfer technique useful for the nonpermanent expression of therapeutic transgenes. The present study established optimal conditions for the electrotransfer of reporter genes into mesenchymal stem cells (MSCs) isolated from rat bone marrow by their selective adherence to tissue-culture plasticware. The electrotransfer of the lacZ reporter gene was optimized by adjusting the pulse electric field intensity, electric pulse type, electropulsation buffer conductivity and electroporation temperature. LacZ electrotransfection into MSCs was optimal at 1500 V cm-1 with pre-incubation in Spinner's minimum essential medium buffer at 22 °C. Under these conditions -galactosidase expression was achieved in 293% of adherent cells 48 h post transfection. The kinetics of -galactosidase activity revealed maintenance of -galactosidase production for at least 10 days. Moreover, electroporation did not affect the MSC potential for multidifferentiation; electroporated MSCs differentiated into osteoblastic, adipogenic and chondrogenic lineages to the same extent as cells that were not exposed to electric pulses. Thus, this study demonstrates the feasibility of efficient transgene electrotransfer into MSCs while preserving cell viability and multipotencyVytauto Didžiojo universiteta