Establishment Of Adrenal VX₂ Tumor Model And Experiment Research Of Injury Effect Of Ho: YAG Laser

Adrenal tumor is a serious disease that threatens to human health, one of the most common symptoms is irregular fluctuations of blood pressure, such as refractory hypertension. Hypertensive crisis is a major cause of death. The current study is mainly small-scale clinical trials with fewer cases. Further research could not be performed because of the relative shortage of sample. This study established a model of adrenal tumors, which will provide an ideal platform to adrenal tumor therapy study and help carry out some large sample animal experiments. Secondly, we studied damage effect of holmium laser on adrenal tumors in the models, which provides an experimental basis to establish a new minimally invasive treatment technology of adrenal tumors.PARTⅠ:Establishment of Adrenal VX₂ Tumor Model and Ultrasonography Study in Rabbits[Abstract] Objectives : To establish an adrenal tumor model in rabbit and investigate its manifestation using ultrasonography. Methods: 60 New Zealand rabbits were randomly divided into 4 groups: 7d group, 14d group, 21d group and 28d group. VX₂ tumor cell suspension was injected into left adrenal gland of rabbit under euthyphoria to establish an adrenal tumor model. The tumor growing status of models was observed by ultrasonography. The median artery blood pressure of rabbit ear in each group was measured before and after grafting and the incidence of hypertension was calculated. Mean tumor volume of each group was calculated and an ANOVA was carried out. The rate of successful model establishment was calculated. All tumor specimens were stained in HE and observed under the optical microscope to survey cytological change of tumor tissue. Results: tumor can be found and located accurately by ultrasound imaging two weeks after grafting. Blood pressure in each group was among normal range. The rate of successful model establishment was 93.3%. The tumor volume grew with the increase of time after grafting, which is of statistical significance（F=2413.72,df=3,P<0.01）. The tumor model of 14d group was the best model. Conclusions: Adrenal tumor model in rabbit was established successfully, and with this model, therapeutic research for adrenal tumor can be carried out efficiently.PARTⅡ:Injury Effect of Ho: YAG Laser Ablation in an Adrenal Tumor model in Rabbits[Abstract] Objectives: To explore the injury effect of Ho YAG laser ablation on adrenal tumors. Methods: Rabbits was used as adrenal VX₂ Tumor Model in this research. Firstly, irradiation experiment: 25 rabbits were executed immediately after their tumors were thoroughly irradiated by Ho YAG laser with different powers in vivo under euthyphoria. Then the pathological changes of the tumor and tissue around adrenal after irradiation were observed. Next, control experiment: 10 rabbits from the Irradiation Group and the Control Group are executed respectively two weeks after the operation. The tumors’growing condition of the two groups were also observed and compared. Results: In the irradiation experiment, adrenal tumor cells experience coagulation necrosis. Slight inflammatory reaction was observed in tissue around adrenal. No side injury is observed on the important organs, such as abdominal aorta, inferior vena cava and renal. There is a linear relationship between the volume of irradiation lesion and corresponding power of HO YAG Laser. The volume grows with the increase of power, which is of statistics significance （r=0.965,p<0.001,a=0.3618,b=-0.4012）. In the control experiment,the primary tumors in irradiation group had been eradicated completely, which didn’t occurred in the control group. The average volume of tumors in the irradiation group （1522.0±520.1 mm3） was larger than that in the control group （7031.3±1312.2 mm3） （t test, P<0.01）.Conclusion: Ho YAG laser is an effective therapeutic method for adrenal tumor and the size of ablation lesion can be accurately controlled and handled. Objectives: The ultimate objective is reconstruction of the structure and function of nonfunctioning kidney in situ. This experiment is only a preliminary study to explore the optimal dose of decellular agents and perfusion programs by a semi-automatic renal perfusion to elute parts of cells and matrix of renal. Methods: Different decellular agents in 10-15ml/min velocity and temperature conditions were perfused into healthy rabbit kidneys through renal artery by semi-automatic pump perfusion system. All decellular agents and perfusion schemes included: 1%SDS（25℃,1h/2h）,1%Triton-100（25℃,1h/2h）, Non-ionized water（25℃,1h/2h）、1mol/l NaCL（25℃,1h/2h）、80% PEG（25℃,1h/2h）、0.125% trypsin（25℃,1h/2h）、0.5% trypsin（25℃,1h/2h）、0.5% trypsin（37℃,10min/20min）、0.05% collagenaseⅣ（37℃,10min/20min）、0.1% collagenaseⅣ（37℃,10min/20min）. Changes in the course of renal perfusion should be observed. Kidneys were dissected and underwent HE stain to observe the general histological examination, focusing on glomerular and tubular cell structure changes. Results: The best decellular agent and perfusion scheme is 1% collagenaseⅣat 37℃for 20min, the enzyme can elute renal parenchyma cells within a relatively little time without side injury to renal matrix, and it can reduce the warm ischemia time of renal, which contributes to kidney regeneration. The better decellular agent and perfusion scheme is 0.5% trypsin at 25℃for 2h, which can elute more glomerular cells, leave only the matrix part and have little effect on renal tubular, but this perfusion scheme with a longer time, has reached the resistance limit of kidney in vitro to ischemia. So it is not recommended. The most powerful decellular agent is SDS, but the renal caused irreversible damage, especially the damage of basement membrane is not conducive to regeneration of renal. Other perfusion schemes are not ideal. Conclusion: By selecting the appropriate decellular agent, with a suitable temperature, concentration, perfusion pressure and other conditions, parts of renal cells and matrix can be eluted, which will provide an experimental basis for the reconstruction of the structure and function of nonfunctioning kidney.