Objective:To investigate the effect of β-Ecdysterone (β-Ecd), an active ingredient in cow′s knee, on hormonal femoral head necrosis in young rabbits and explore the mechanism involved.Methods:An animal study.Sixty New Zealand young rabbits were divided into control, model and intervention groups by random number table method, with 20 rabbits in each group.Prednisolone acetate (7.5 mg/kg) was injected bilaterally into the gluteal muscle of rabbits in both model and intervention groups twice a week.β-Ecd (0.5 mg/kg) was injected subcutaneously at the time of the first injection of Prednisolone acetate in the intervention group for 5 times a week.An equal amount of saline was injected into rabbits in control and model groups.Eight weeks after modelling, animals were put to death, and femoral heads were taken from both sides for gross observation.Micro computed tomography(Micro-CT) was used to analyze the microstructure of bone trabeculae and to measure bone microstructural parameters.Histological staining was used to detect changes in the morphology of bone tissues.Immunohistochemistry and Western blot were used to examine the expression of osteogenic and lipogenic factors and proteins in the femoral head tissue.Rabbit bone marrow mesenchymal stem cells (BMSCs) were divided into a blank control group, a Dexamethasone group and a β-Ecd intervention group.Cell damage was induced by Dexamethasone in Dexamethasone group and β-Ecd intervention group, and the β-Ecd intervention group was given the optimal concentration of β-Ecd.Western blot was used to detect the expression of osteogenic and lipogenic proteins in the cells of each group.Real-time quantitative polymerase chain reaction (RT-qPCR) was used to determine the mRNA expression of osteogenic and lipogenic marker genes.Results:After excluding 9 rabbits that died during the experimental period, 51 rabbits were finally included in the study, with 19 in the control group, 15 in the model group and 17 in the intervention group.Gross observation and Micro-CT showed that compared with that of the control group, the femoral head of the model group was obscure and greyish, with dark red necrotic areas.The bone trabeculae of the model group were sparse, thinned, disordered, and partially fractured, compared with those of the control group.The changes in the femoral head and bone trabeculae of the intervention group were between those of control and model groups.The bone mineral density, the number, thickness and relative volume of bone trabeculae significantly decreased and trabecular separation significantly increased in both model and intervention groups, compared with those in the control group ( F=12.78, 45.52, 32.74, 64.08, 8.83, all P<0.05).However, these symptoms in the intervention group were better than those in the model group.Pathological histology showed that in the control group, bone trabeculae were neatly arranged, robust and full, with a high number of osteoclasts and occasional empty bone sockets.In the model group, bone trabeculae were sparsely arranged and broken, with fewer osteoclasts, and the number of empty bone sockets increased and enlarged.In the intervention group, bone trabeculae had a more complete morphology, with fewer necrotic osteoclasts and reduced empty bone sockets, compared with the model group.Immunohistochemistry results showed that compared with the control group, the model group and intervention group had increased content of fatty acid binding proteins (FABP) and CCAAT/enhancer binding proteins α (CEBP) in the femoral head bone tissue, and decreased content of osteopontin (OPN) and Runt-related transcription factor 2 (RUNX2) .The changes in each index were greater in the model group than those in the intervention group ( F=21.07, 24.06, 17.92, 21.36, all P<0.05). Western blot detection showed that compared with the control group, the CEBP protein expression content of the femoral head in the model group and the intervention group was increased and the RUNX2 protein expression content was decreased. The changes of CEBP and RUNX2 were greater in the model group than those in the intervention group( F=73.43, 197.87, all P<0.05).Western blot detection of BMSCs showed that compared with the blank control group, the Dexamethasone group and β-Ecd intervention group had decreased expression of OPN and RUNX2 proteins and increased expression of FABP and CEBP proteins ( F=161.61, 358.01, 91.18, 69.04, all P<0.05).The changes in each index in the β-Ecd intervention group were smaller than those in the Dexamethasone group.RT-qPCR detection of BMSCs showed that in the Dexamethasone group had lower expression of OPN and RUNX2 and higher expression of CEBP and FABP than the blank control group ( F=19.71, 45.08, 61.46, 15.12, all P<0.05).The changes in each index in the β-Ecd intervention group were smaller than those in the Dexamethasone group. Conclusions:β-Ecd can attenuate the pathological changes of hormonal femoral head necrosis in young rabbits by promoting osteogenic differentiation of BMSCs, inhibiting lipogenic differentiation of BMSCs, and improving bone microstructure.

Objective:To investigate the effect of β-Ecdysterone (β-Ecd), an active ingredient in cow′s knee, on hormonal femoral head necrosis in young rabbits and explore the mechanism involved.Methods:An animal study.Sixty New Zealand young rabbits were divided into control, model and intervention groups by random number table method, with 20 rabbits in each group.Prednisolone acetate (7.5 mg/kg) was injected bilaterally into the gluteal muscle of rabbits in both model and intervention groups twice a week.β-Ecd (0.5 mg/kg) was injected subcutaneously at the time of the first injection of Prednisolone acetate in the intervention group for 5 times a week.An equal amount of saline was injected into rabbits in control and model groups.Eight weeks after modelling, animals were put to death, and femoral heads were taken from both sides for gross observation.Micro computed tomography(Micro-CT) was used to analyze the microstructure of bone trabeculae and to measure bone microstructural parameters.Histological staining was used to detect changes in the morphology of bone tissues.Immunohistochemistry and Western blot were used to examine the expression of osteogenic and lipogenic factors and proteins in the femoral head tissue.Rabbit bone marrow mesenchymal stem cells (BMSCs) were divided into a blank control group, a Dexamethasone group and a β-Ecd intervention group.Cell damage was induced by Dexamethasone in Dexamethasone group and β-Ecd intervention group, and the β-Ecd intervention group was given the optimal concentration of β-Ecd.Western blot was used to detect the expression of osteogenic and lipogenic proteins in the cells of each group.Real-time quantitative polymerase chain reaction (RT-qPCR) was used to determine the mRNA expression of osteogenic and lipogenic marker genes.Results:After excluding 9 rabbits that died during the experimental period, 51 rabbits were finally included in the study, with 19 in the control group, 15 in the model group and 17 in the intervention group.Gross observation and Micro-CT showed that compared with that of the control group, the femoral head of the model group was obscure and greyish, with dark red necrotic areas.The bone trabeculae of the model group were sparse, thinned, disordered, and partially fractured, compared with those of the control group.The changes in the femoral head and bone trabeculae of the intervention group were between those of control and model groups.The bone mineral density, the number, thickness and relative volume of bone trabeculae significantly decreased and trabecular separation significantly increased in both model and intervention groups, compared with those in the control group ( F=12.78, 45.52, 32.74, 64.08, 8.83, all P<0.05).However, these symptoms in the intervention group were better than those in the model group.Pathological histology showed that in the control group, bone trabeculae were neatly arranged, robust and full, with a high number of osteoclasts and occasional empty bone sockets.In the model group, bone trabeculae were sparsely arranged and broken, with fewer osteoclasts, and the number of empty bone sockets increased and enlarged.In the intervention group, bone trabeculae had a more complete morphology, with fewer necrotic osteoclasts and reduced empty bone sockets, compared with the model group.Immunohistochemistry results showed that compared with the control group, the model group and intervention group had increased content of fatty acid binding proteins (FABP) and CCAAT/enhancer binding proteins α (CEBP) in the femoral head bone tissue, and decreased content of osteopontin (OPN) and Runt-related transcription factor 2 (RUNX2) .The changes in each index were greater in the model group than those in the intervention group ( F=21.07, 24.06, 17.92, 21.36, all P<0.05). Western blot detection showed that compared with the control group, the CEBP protein expression content of the femoral head in the model group and the intervention group was increased and the RUNX2 protein expression content was decreased. The changes of CEBP and RUNX2 were greater in the model group than those in the intervention group( F=73.43, 197.87, all P<0.05).Western blot detection of BMSCs showed that compared with the blank control group, the Dexamethasone group and β-Ecd intervention group had decreased expression of OPN and RUNX2 proteins and increased expression of FABP and CEBP proteins ( F=161.61, 358.01, 91.18, 69.04, all P<0.05).The changes in each index in the β-Ecd intervention group were smaller than those in the Dexamethasone group.RT-qPCR detection of BMSCs showed that in the Dexamethasone group had lower expression of OPN and RUNX2 and higher expression of CEBP and FABP than the blank control group ( F=19.71, 45.08, 61.46, 15.12, all P<0.05).The changes in each index in the β-Ecd intervention group were smaller than those in the Dexamethasone group. Conclusions:β-Ecd can attenuate the pathological changes of hormonal femoral head necrosis in young rabbits by promoting osteogenic differentiation of BMSCs, inhibiting lipogenic differentiation of BMSCs, and improving bone microstructure.

During his studies at the Peking Union Medical College(1921-1929),Chen Zhiqian formed his thoughts on public health under the influences of modern medical education and the advanced thinking of the times,which laid an ideological foundation for his later engagement in rural health care and reflected the medical progress in China at that time.In the 1920s,Chen Zhiqian's thoughts on public health mainly encompassed five aspects.First,health was a cornerstone of the country's wealth and people's well-being.Second,he belived in comprehensive"big medicine"which emphasized the combination of prevention and treatment.Third,he advoca-ted the return of medicine to the state and the building of a medical system covering all people.Fourth,he advo-cated maternal training and institutional standardization,emphasizing child health protection.Fifth,he was com-mitted to the popularization of health science and advocated health education reform.Summarizing the above five aspects is of great significance for enriching and improving the academic evaluation about Chen Zhiqian and pro-vides a reference for today's work on public health.

Objective: : To investigate the epidemiology of newly-diagnosed, histologically-confirmed (NDHC) central nervous system (CNS) tumours and its changes over a 21-year period in a regional hospital in Hong Kong. Methods: : This is a single-institute retrospective descriptive study of patients undergoing surgery for CNS tumours in a regional hospital of Hong Kong in the period from January 1996 to December 2016. The histological definition of CNS tumours was according to the World Health Organization classification, while the site definition for case ascertainment of CNS tumours was as set out by the Central Brain Tumour Registry of the United States. Patients of any age, who had NDHC CNS tumours, either primary or secondary, were included. The following parameters of the patients were retrieved : age at diagnosis, gender, tumour location, and histological diagnosis. Population data were obtained from sources provided by the Government of Hong Kong. The incident rate, estimated by the annual number of cases per 100000 population, for each histology grouping was calculated. Statistical analyses, both including and excluding brain metastases, were performed. Statistical analysis was performed with Microsoft Excel, 2016 (Microsoft, Redmond, WA, USA). Results: : Among the 2134 cases of NDHC CNS tumours, there were 1936 cases of intracranial tumours and 198 cases of spinal tumours. The annual number of cases per 100000 population of combined primary intracranial and spinal CNS tumours was 3.6 in 1996, and 11.1 in 2016. Comparing the 5-year average annual number of cases per 100000 population of primary CNS tumours from the period 1996–2000 to 2011–2015, there was an 88% increase, which represent an increase in the absolute number of cases by 4.52 cases/100000 population. This increase was mainly contributed by benign histologies. In the aforementioned periods, meningiomas increased by 1.45 cases/100000 population; schwannomas by 1.05 cases/100000 population, and pituitary adenomas by 0.91 cases/100000 population. While gliomas had a fluctuating 5-year average annual number of cases per 100000 population, it only had an absolute increase of 0.51 cases/100000 population between the 2 periods, which was mainly accounted for by the change in glioblastomas. Conclusion : This retrospective study of CNS tumour epidemiology revealed increasing trends in the incidences of several common CNS tumour histologies in Hong Kong, which agrees with the findings in large-scale studies in Korea and the United States. It is important for different geographic locations to establish their own CNS tumour registry with well-defined and structured data collection and analysis system to meet the international standards.