Application of 3D printing models to clinical teaching in otolaryngology / 基础医学与临床

Objective To apply three-dimensional(3D) printing techniques to the clinical anatomy teaching of otolar-yngology. Methods We reconstructed the three-dimensional models of temporal bones and paranasal sinuses based on CT scan data,and divided them into sub-models according to several interested planes on CT scan. Sub-models were printed with 3D printer.The CT images of interested planes were printed by normal printer and pasted to the appropri-ate sub-models. We also checked the accuracy of the anatomy models. Results We successfully made the digital and 3D printing models of temporal bones and paranasal sinuses. The CT scan images were compounded to the models. The key anatomy structures outside and inside of the temporal bone and paranasal sinuses can be shown clearly and exactly on the models. Conclusions The 3D printing models help the medical students to understand and master the clinical anatomy and radiology knowledge of otolaryngology as a supplement for traditional teaching methods.

Action of NO and TNF-alpha release of rats with cadmium loading in malfunctiion of multiple system organ / 生理学报

Thirty-six healthy Sprague-Dawley male rats were used and divided randomly into a control group (group C), a medium-dose cadmium loading group (group M) and a high-dose cadmium loading group (group H). Cadmium chloride was diluted with saline to contain 0.4 mg/ml of autoclaved cadmium solution. Groups M and H were injected in the abdominal cavity with 0.5 and 1.0 mg of cadmium per kg body weight respectively, and group C with saline of the same dosage as in group H over 7 d. Six rats of each group were killed on the 4th day and 7th day after cadmium loading, respectively, and blood, testis, liver and heart were collected. Cadmium content, changes in nitric oxide and tumor necrosis factor-alpha were studied in blood and the tissues of testis, liver and heart. Results showed that during the entire experimental period, body weight in groups M and H decreased significantly as compared with that in group C; cadmium concentration increased significantly in testis, heart and liver of groups M and H, and rose with increased dosage and time of cadmium loading; there was no obvious difference in plasma nitric oxide between groups M and C, though nitric oxide was higher in group M than in group C. Nitric oxide in group H was significantly superior to that in group C. Plasma tumor necrosis factor-alpha was markedly higher in groups M and H than in group C. Nitric oxide contents in the rat s testis, liver and heart homogenates with cadmium loading were higher than those in group C or significantly superior to group C. The same changes in tumor necrosis factor-alpha in the tissue homogenates of the testis and heart were found, but no obvious difference in tumor necrosis factor-alpha in the liver between the three groups was observed. It is suggested that the massive release of nitric oxide and tumor necrosis factor-alpha induced by cadmium loading may play an important role in the induction of malfunction of multiple systems or organs in rats.

Effects of chronic cadmium loading on the testis and endocrine function of reproduction in male rats / 生理学报

Sixty healthy Sprague-Dawley male rats were used and divided randomly into control group (group C), cadmium loading group with medium dose (group M) and cadmium loading group with high dose (group H). Groups C, M and H were orally dosed daily with 0, 5 and 10 mg/kg of cadmium for over 6 weeks. Effects of cadmium loading on testis and endocrine function of reproduction in male rats were studied. The results showed that the zinc content decreased slightly in testis and plasma, and the cadmium concentration increased significantly in the testis of groups M and H; while the plasma levels of cadmium and zinc had no obvious difference as compared with those of group C; daily sperm production in the testis of group H decreased markedly during week 3 of cadmium loading, and was significantly lower in groups M and H as compared to that in group C during week 6; alkaline phosphatase (ALP) in group H and lactate dehydrogenase-X (LDH-X) in groups M and H were markedly lower compared to those of group C; plasma testosterone (T) level in both cadmium loading groups decreased and was low or significantly lower than that in group C; follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels had no apparent difference between the three groups. It is suggested that the gradual accumulation of cadmium in testis tissue induced by chronic cadmium loading results in changes in some enzyme activity, a decrease in sperm production, and defect of endocrine function activity in the testis.