Objective To study the morphological types of the retinal ganglion cells (RGCs) projecting to tectum in the chick. Methods The tectal projecting RGCs in the chick were identified by retrograde axonal transport of Fast blue and their dendrites were labeled by intracellular injection of Lucifer Yellow.The retinotectal projecting ganglion cells were classified according to somal areas,dendritic field sizes and dendritic branching pattern. Results Retinotectal projecting ganglion cells were divided into 3 groups and 5 subgroups,Group Ic/Is,Group IIc/IIs,Group IVc.Group I cells had small somal area and small dendritic field.They contained 2 subgroups of Is(simple)and Ic(complex).Group II cells had medium sized soma and dendritic field,and also included 2 subgroups of IIs and IIc.Group IV cells had large soma and dendritic field,and only contained a subgroup IVc.The proportion of each subgroup was 27.7%(Ic),33.6%(Is),2.5%(IIc),24.4%(IIs),and 11.8%(IVc),respectively. Conclusion The types of retinotectal projecting ganglion cell were prominently composed of small to medium sized neurons(88.2%)and some large neurons(11.8%).Ofthese,subgroup Ic cells which were very similar to ? cells were found in the chick and subgroup Is and IIs were not reported in the mammalin retina.The cells in group Ⅲ,which were found in the chick central retina,did not project to the tectum. [

Objective To study the effect of monochromatic light on the distribution of retinal ganglion cells in chicks. Methods Sixty One-day-old male broilers were reared under four light treatments,red(660nm),green(560nm),blue(480nm) and white(400-760nm) by using LED(light-emitting diodes) as light sources until the 49th day(n=15).Light intensity was 15 lux at the height of birds' heads and scheduled for 23hours of light and 1hour of darkness during the entire experiment.The retinas were stained by Nissl-staining and DiI-labeling.The retinal area,cell size and density in ganglion cell layer were estimated by image analysis. Results The retinal area and RGCs' number in the blue and green light groups were higher than that in the red and white light groups(10.35% and 17.07%,P

Objective To prove the mechanism of diethylstibestrol(DES) induced abnormal spermatogenesis,this study on the changes of proto-oncogenes bcl-2 and p53 proteins as well as cadherin adherens molecules expression in adult male hamster spermatogenic cells. Methods Adult male golden hamsters were treated daily olive oil vehicle either alone(control)or containing 1 mg/kg body weight of DES (experiment)by subcutaneous injection for 7 days.The changes of testes histological morphology were observed under light and electron microscope.The expressions of bcl-2 and p53 and cadherin in the testes seminiferous epithelium were detected by immunohistochemistry. Results DES induced adult hamster testes abnormal spermatogenesis.As compared to the control group animals,in DES-treated group animals the expression of both bcl-2 and p53 significantly increased in spermatogenic cells,especially in spermatocytes and round spermatids.However,the expression of cadherin adherens molecules obviously decreased.Conclusion It is one of reasons of DES inducing abnormal spermatogenesis that DES can result in increasing in the expression of proto-oncogenes bcl-2 and p53,and reducing cadherin adherens molecules expression.

Objective Few reports are seen on the methods of establishing the rabbit model of pancreatic cancer .This study was to compare the effect of Panc-1 cell suspension orthotopic implantation with that of VX-2 tissue orthotopic implantation in construc-ting the rabbit model of pancreatic cancer . Methods Using the random number table method , we divided 30 healthy rabbits into a tissue suspension group ( n=15) and a cell suspension group ( n=15) , VX-2 tissue suspension employed for in-situ implanting in the former group and panc-1 cell suspension utilized in the latter .Then we evaluated the two modeling methods by B-ultrasonography , 3.0T MRI, and CT. Results In the third week after modeling , transpla-ntive metastasis of lots of tumor tissues was observed in the duode-num, colon, appendix, and peritoneal wall in 5 rabbits of the tissue suspension group , but only in the greater omentum of 3 rabbits in the cell suspension group , with high signals of MR T 2 in the posterior gastric body .One case of duodenal metastasis was seen in the cell suspension group , with slightly high signals of MR LAVA in the posterior gastric body .The model of pancreatic cancer was successfully established in all the 15 rabbits of the tissue suspension group , but only in 3 of the cell suspension group .The success rate of tumor im-planting at 3 and 4 weeks was significantly higher in the former ( 46.66%and 100%) than in the latter group ( 6.67%and 20.00%) (P<0.05). Conclusion VX-2 tissue orthotopic implantation is a more feasible and convenient method than Panc -1 cell suspension orthotopic implantation for establishing the rabbit model of pancreatic cancer .

Objective To explore the application value of magnetic resonance molecular functional imaging diffusion weighted imaging(DWI) in the identification of pancreatic carcinoma and mass-type pancreatitis of animal model.Methods Each 8 cases of laboratory pancreatic head transplantation tumor model,chronic mass-type pancreatitis model and normal rabbits were selected and performed the MR DWI molecular functional imaging,the b values were 333,667,1 000 s/mm2 respectively.The apparent diffusion coefficients(ADC) of pancreatic carcinoma model,mass-type pancreatitis model and normal pancreas under different b values were observed.Then the change situation of ADC values of pancreatic carcinoma model,mass-type pancreatitis model and normal pancreas under different b values and difference of ADC(DADC) was analyzed.Moreover the differences in molecular diffusion,tissue perfusion among various groups were observed.Results Throughout the study period,the mortality rate of pancreatic head transplantation tumor model was 50%;the mass-type pancreatitis model and 8 normal rabbits were normally survival.The ADC value of pancreatic carcinoma under the same b value was significantly lower than that of chronic inflammation and normal pancreas area.The ADC value in each group was decreased with the increase of b value,and there was significant difference in ADC value when the b value was 333 s/mm2(F=6.662,P=0.014),in the pairwise comparison among groups,the difference between pancreatic cancer and pancreatitis (t=6.773,P=0.003) and between pancreatic cancer and normal pancreas(t=5.883,P=0.016) had statistical significance (P<0.05).The b value was increased,DADC was smaller,the difference change of DADC between pancreatic cancer area and chronic pancreatitis mass area,between pancreatic cancer area and normal pancreatic head area had statistical significance (P<0.05).Conclusion Rationally selecting the molecular functional imaging DWI technology of b value can better distinguish pancreatic cancer from mass-type pancreatitis,which may be promoted and applied in the evaluation of animal pancreatic head cancer model.

The study was carried out to understand the changes in the ethical cognition status of laboratory animals and the effectiveness of laboratory animal ethics education among medical students in Xiangya School of Medicine of Central South University (CSU), and provide new enlightenment for further strengthening the ethical education of laboratory animals. In the study, the same self-compiled questionnaire was used to investigate the ethical cognition of experimental animals among medical students in Xiangya School of Medicine of CSU in 2011 and 2021, and 359 and 363 questionnaires were collected respectively. Through comparative analysis of the questionnaire results before and after ten years, it was found that medical students’ animal experiment operation and attitudes towards laboratory animals, cognition of experimental animal ethics knowledge and their attitude to animal experiment ethics education were significantly improved. It showed that the state of experimental animal ethics cognition among medical students in Xiangya School of Medicine of CSU had improved significantly in recent 10 years, but the cognition of experimental animal ethics knowledge was higher than the actual behavior of caring for experimental animals, and there was the phenomenon of "separation of knowledge and action". The ethics education of experimental animals needs to pay more attention to the development of students’ behavior of caring for experimental animals.

The study was carried out to understand the changes in the ethical cognition status of laboratory animals and the effectiveness of laboratory animal ethics education among medical students in Xiangya School of Medicine of Central South University (CSU), and provide new enlightenment for further strengthening the ethical education of laboratory animals. In the study, the same self-compiled questionnaire was used to investigate the ethical cognition of experimental animals among medical students in Xiangya School of Medicine of CSU in 2011 and 2021, and 359 and 363 questionnaires were collected respectively. Through comparative analysis of the questionnaire results before and after ten years, it was found that medical students’ animal experiment operation and attitudes towards laboratory animals, cognition of experimental animal ethics knowledge and their attitude to animal experiment ethics education were significantly improved. It showed that the state of experimental animal ethics cognition among medical students in Xiangya School of Medicine of CSU had improved significantly in recent 10 years, but the cognition of experimental animal ethics knowledge was higher than the actual behavior of caring for experimental animals, and there was the phenomenon of "separation of knowledge and action". The ethics education of experimental animals needs to pay more attention to the development of students’ behavior of caring for experimental animals.