Objective To determine the normal range of hematological and visceral weight parameters of F 1 4-week and 8-week old, male and female transgenic CB6F1 mice.The influence of gender and week age on the biochemical parameters was assessed .Methods 4-week and 8-week old CB6F1 mice, half male and half female ( n=20 in each group) , were weighed alive , dissected to weigh the main viscera , and blood samples were collected to test the physiological and biochemical parameters .Results When 4-week old and 8-week old CB6F1 mice were compared , there were significant differences in 22 parameters (body weight, heart, liver, spleen, left ovary, left testis, right testis, WBC, RBC, HGB, HCT, MCV, MCH, PCT, MPV, PDW, LYM, TP, ALT, ALB, P and TG) (P<0.01 for all), and in 8 parameters (left kidney, right kidney, right adrenal, thymus, left ovary, RDW, MON%and BUN) (P<0.05 for all). When male and female 4-week CB6F1 mice were compared, there were significant differences in 14 parameters ( body weight, heart, liver, spleen, lung, left kidney, right kidney, MCHC, LYM, ALT, ALP, GLU, P and CHO) (P<0.01 for all), and in 6 parameters (right adrenal, WBC, PCT, MPV, TP and BUN) (P<0.05 for all).For male and female 8-week old CB6F1 mice, there were significant differences in 15 parameters (body weight, heart, liver, lung, left kidney, right kidney, MCV, PCT, LYM, LYM%, NEUT%, ALT, GLU, P and CHO) (P<0.01 for all), and in 5 parameters (WBC, RBC, MPV, NEUT and TP) (P<0.05 for all).Conclusions The normal range of hematological and visceral weight parameters of 4-week and 8-week old male and female CB6F1 mice are determined.Our study establishes normal detection indexes of CB6F1 mice and provides useful reference for its application .

Objective To improve the gene targeting efficiency with C57BL/6 embryonic stem ( ES) cells.Meth-ods Three different genetically modified C57BL/6 ES cell lines, named TLX3, Ai3K and SL, were microinjected into ICR, B6( Cg)-Tyrc-2J and BALB/c mouse blastocysts, respectively.The efficiency was statistically evaluated according to three aspects:blastocyst collection, chimera production and germline transmission.Results None of the three ES cell lines was germline transmitted with B6(Cg)-Tyrc-2J mice as blastocyst donors, while it was achieved with both BALB/c and ICR mouse blastocysts.Compared in the aspect of blastocysts collection, ICR mouse was much better than BALB/c mouse (P<0.05), and the chimera production efficiency of ICR mouse was comparable to that of BALB/c mouse (P =0.115). As to the germline transmission efficiency, that of BALB/c mice is significantly higher than that of the ICR mice ( P<0.01).Conclusions The germline transmission efficiency of BALB/c mouse is highest among these three mouse strains. However, it has the disadvantages of blastocyst collection, developmental delay and zona pellucida fragility, compared with ICR mouse.Therefore, ICR mouse is also a good candidate as blastocyst donor for embryonic stem cell microinjection.

Objective To establish a simple , fast and economic total DNA extraction method to serve the rapid identification of model mouse genotype in large number of mice .Methods Three methods, i.e.phenol extraction, isopropyl alcohol precipitation and mouse ear boiling methods were used to extract the total DNA from ten C 57-rasmodel mice.The purity and yield of DNA obtained by the three methods were compared , and polymerase chain reaction ( PCR) assay was used to compare the efficacy of the three extraction methods .Results Among the three methods , phenol extraction was the best and isopropyl alcohol precipitation was the poorest in DNA yield .In terms of DNA purity , the phenol extraction was the best and the mouse ear boiling method was the poorest .All the three methods could be used to extract the total DNA from mice serving as template of PCR reaction for the mouse genotype identification .The time consumption of three methods are 12.5 hr ,13 hr and 0.18 hr.Mouse ear boiling method was significantly lower than that of the other two methods ( P <0.01 ) ,.The obtained total DNA can be stored at conventional -20℃for 7 days and 30 days later still can be used as a template for PCR reaction .Conclusions Among the three methods studied , the mouse ear boiling method is simple and with the lowest cost , so it is feasible for total DNA extraction in scaled genotyping experiments .

Objective To discuss the effect of in vitro fertilization ( IVF) and mouse sperm cryopreservation , to establish a simple and economic frozen system for the genetically engineering mice preservation .Methods Sperm from genetically engineering mice were cryopreserved , IVF was performed using post-thawed sperm, then embryo transfer, to compare the effects of cryopreservation medium、age of male mice and sperm preincubation medium .Results Using CPA as sperm cryopreservation medium , when PM was used thawed-sperm preincubation in IVF , the fertility rates were from 82.49%to 91.43%, when HTF was used thawed-sperm preincubation in IVF , the fertility rates were from14.46%to 27.38%, there was a signification difference between PM and HTF sperm preincubation medium;10 to 35 weeks male genetically engineering mice sperm were succeed cryopreservation , and positive mice were procreated after 2-cell embryos were transferred;R18S3、CPM and CPA was used to freeze sperm , the fertility rates were 75.85%、88.89%to 94.27%, positive mice were procreated after 2-cell embryos were transferred;2-cell embryos after IVF were freezed , then thawed and positive mice were procreated after 2-cell embryos were transferred .Conclusion Using CPA as sperm cryopreservation medium , when PM was used thawed-sperm preincubation in IVF , genetically engineering mice sperm were succeed cryopreservation .

Objective To obtain the basic growth parameters of a self-established F1 hybrid CB6F1 C57-ras transgenic mouse model, and to provide basic information for commercialization of this mouse model. Methods F1 hybrid mice (CB6F1) were produced by crossing C57-ras heterozygous transgenic (c-Ha-ras+/-) male mice and wild-type BALB/cJ female mice.The average litter size, weaning rate, sex ratio, growth performance and C57-ras transgenic positive rate were recorded and analyzed.Results The average litter size was eight, weaning rate was 90%, and sex ratio was approximately in accordance with prediction.The average body weight of newborn mice was 1.73 ±0.05 g.The average body weight of 10-week old c-Ha-ras transgenic female and male mice in CB6F1 background was 24.38 ±1.74 g and 29.42 ±1.72g, respectively, which had a significant difference (P<0.01).The c-Ha-ras transgenic positive rate was 46.9%. which was in accordance with genetic rules.Conclusions The F1 hybrid mice (CB6F1) produced by crossing C57-ras heterozygous transgenic ( c-Ha-ras +/-) male mice and wild-type BALB/cJ female mice show normal growth performance and development characteristics, and it can be used for large-scale commercial supply.

Objective:To investigate the change trend of etiological burden of disease of liver cancer in the Chinese population from 1990 to 2019.Methods:The descriptive epidemiologic method was conducted. Based on the Global Burden of Disease data from the Institute for Health Metrics and Evaluation at the University of Washington, the data related to liver cancer burden caused by hepatitis B virus (HBV) infection, hepatitis C virus (HCV) infection, alcohol, nonalcoholic steatohepatitis (NASH) and other factors, including number of new cases, the crude incidence rate, age-specific incidence rate, number of deaths, crude mortality rate and age-specific mortality rate, in the Chinese population from 1990 to 2019 were collected. The age-standardized rate was calculated based on the world standardized population structure in 2019 from the Global Burden of Disease data. Observation indicators: (1) the incidence of liver cancer caused by different etiologies in the Chinese population from 1990 to 2019; (2) the mortality of liver cancer caused by different etiologies in the Chinese population from 1990 to 2019; (3) the change trend of age-specific incidence rate of liver cancer caused by different etiologies in the Chinese population from 1990 to 2019; (4) the age-specific mortality rate of liver cancer caused by different etiologies in the Chinese population from 1990 to 2019. Count data were expressed as absolute numbers, percentages and ratio. Based on the junction point regression model, the Joinpoint software (V.4.9.1.0) was used to calculate the annual percentage change, average annual percentage change (AAPC) and 95% confidence intervals ( CI) of age-specific incidence rate and age-specific mortality rate of liver cancer caused by different etiologies. Results:(1) The incidence of liver cancer caused by different etiologies in the Chinese population from 1990 to 2019. From 1990 to 2019, the number of new cases of liver cancer in Chinese population decreased from 236 825 to 210 462, and the crude incidence rate decreased from 20.01/100,000 to 14.80/100,000. The new cases of liver cancer caused by HBV infection, HCV infection and other factors showed a downward trend, and the absolute change rates were ?14.76%, ?3.98% and ?26.67%, respectively. The new cases of liver cancer caused by alcohol and NASH showed a increase trend, and the absolute change rates were 9.31% and 13.91%, respectively. (2) The mortality of liver cancer caused by different etiologies in the Chinese population from 1990 to 2019. From 1990 to 2019, the number of deaths of liver cancer in Chinese population decreased from 232 449 to 187 700, and the crude mortality rate decreased from 19.64/100,000 to 13.20/100,000. The number of deaths of liver cancer caused by HBV infection, HCV infection and other factors showed a down-ward trend, and the absolute change rates were ?23.34%, ?10.99% and ?33.75%, respectively. The number of deaths of liver cancer caused by alcohol showed a slow downward trend, and the absolute change rate was ?0.51%. The number of deaths of liver cancer caused by NASH showed a increase trend, and the absolute change rate was 6.03%. (3) The change trend of age-specific incidence rate of liver cancer caused by different etiologies in the Chinese population from 1990 to 2019. From 1990 to 2019, the AAPC of age-specific incidence rate of liver cancer caused by HBV infection, HCV infection, alcohol, NASH and other factors was ?3.61%(95% CI as ?4.10% to ?3.11%), ?3.57%(95% CI as ?3.99% to ?3.14%), ?2.79%(95% CI as ?3.24% to ?2.33%), ?2.65%(95% CI as ?3.09% to ?2.21%) and ?3.62%(95% CI as ?4.05% to ?3.19%), respectively. (4) The age-specific mortality rate of liver cancer caused by different etiologies in the Chinese population from 1990 to 2019. From 1990 to 2019, the AAPC of age-specific mortality rate of liver cancer caused by HBV infection, HCV infection, alcohol, NASH and other factors was ?3.92%(95% CI as ?4.42% to ?3.41%), ?3.90%(95% CI as ?4.45% to ?3.35%), ?3.15%(95% CI as ?3.71% to ?2.58%), ?2.86%(95% CI as ?3.34% to ?2.38%) and ?4.09%(95% CI as ?4.64% to ?3.55%), respectively. Conclusions:From 1990 to 2019, the liver cancer burden of the Chinese population shows an overall downward trend, in which the liver cancer burden caused by HBV and HCV infection decreases the most, but HBV and HCV infection is still the main reason for the heavy burden of liver cancer. The age-specific incidence rate and age-specific mortality rate of liver cancer caused by alcohol and NASH show a downward trend, but the number of new cases of liver cancer caused by alcohol and NASH shows significant growth. The liver cancer burden caused by other factors shows a downward trend.

BACKGROUND: Large disparities exist in liver cancer burden trends across countries but are poorly understood. We aimed to investigate the global trajectories of liver cancer burden, explore the driving forces, and predict future trends. METHODS: Data on the liver cancer burden in 204 countries and territories from 1990 to 2019 were extracted from the Global Burden of Disease Study. The age-standardized incidence rate (ASIR) and age-standardized mortality rate (ASMR) trajectories were defined using growth mixture models. Five major risk factors contributing to changes in the ASIR or ASMR and socioeconomic determinants were explored using the identified trajectories. A Bayesian age-period-cohort model was used to predict future trends through 2035. RESULTS: Three trajectories of liver cancer burden were identified: increasing, stable, and decreasing groups. Almost half of the American countries were classified in the decreasing group (48.6% for ASIR and ASMR), and the increasing group was the most common in the European region (ASIR, 49.1%; ASMR, 37.7%). In the decreasing group, the decrease of liver cancer due to hepatitis B contributed 63.4% and 60.4% of the total decreases in ASIR and ASMR, respectively. The increase of liver cancer due to alcohol use, hepatitis C, and hepatitis B contributed the most to the increase in the increasing group (30.8%, 31.1%, and 24.2% for ASIR; 33.7%, 30.2%, and 22.2% for ASMR, respectively). The increasing group was associated with a higher sociodemographic index, gross domestic product per capita, health expenditure per capita, and universal health coverage (all P <0.05). Significant variations in disease burden are predicted to continue through 2035, with a disproportionate burden in the decreasing group. CONCLUSION Global disparities were observed in liver cancer burden trajectories. Hepatitis B, alcohol use, and hepatitis C were identified as driving forces in different regions.
Humans ; Bayes Theorem ; Liver Neoplasms ; Risk Factors ; Hepatitis C/complications* ; Hepatitis B ; Hepacivirus ; Incidence

BACKGROUND: The cancer burden in the United States of America (USA) has decreased gradually. However, China is experiencing a transition in its cancer profiles, with greater incidence of cancers that were previously more common in the USA. This study compared the latest cancer profiles, trends, and determinants between China and USA. METHODS: This was a comparative study using open-source data. Cancer cases and deaths in 2022 were calculated using cancer estimates from GLOBOCAN 2020 and population estimates from the United Nations. Trends in cancer incidence and mortality rates in the USA used data from the Surveillance, Epidemiology, and End Results program and National Center for Health Statistics. Chinese data were obtained from cancer registry reports. Data from the Global Burden of Disease 2019 and a decomposition method were used to express cancer deaths as the product of four determinant factors. RESULTS: In 2022, there will be approximately 4,820,000 and 2,370,000 new cancer cases, and 3,210,000 and 640,000 cancer deaths in China and the USA, respectively. The most common cancers are lung cancer in China and breast cancer in the USA, and lung cancer is the leading cause of cancer death in both. Age-standardized incidence and mortality rates for lung cancer and colorectal cancer in the USA have decreased significantly recently, but rates of liver cancer have increased slightly. Rates of stomach, liver, and esophageal cancer decreased gradually in China, but rates have increased for colorectal cancer in the whole population, prostate cancer in men, and other seven cancer types in women. Increases in adult population size and population aging were major determinants for incremental cancer deaths, and case-fatality rates contributed to reduced cancer deaths in both countries. CONCLUSIONS The decreasing cancer burden in liver, stomach, and esophagus, and increasing burden in lung, colorectum, breast, and prostate, mean that cancer profiles in China and the USA are converging. Population aging is a growing determinant of incremental cancer burden. Progress in cancer prevention and care in the USA, and measures to actively respond to population aging, may help China to reduce the cancer burden.
Adult ; Breast Neoplasms ; China/epidemiology* ; Female ; Humans ; Incidence ; Liver Neoplasms ; Male ; Neoplasms/epidemiology* ; Registries ; United States/epidemiology*

Objective To overcome the limitations of existing human respiratory syncytial virus(hRSV)animal models,such as semi-permissiveness and short duration of infection,this study established an IL2rg gene knockout(IL2rg-/-)rat model using TALEN gene editing technology.Methods The animal model was infected with hRSV intranasally.Clinical characteristics,body weight,and temperature changes were observed over the infection period(0～35 days).The total viral loads in respiratory organs,such as the nasal tissue,trachea,and lungs,were measured at various time points(4,11,20,and 35 days post-infection).Pathological analysis was conducted on target organs at the endpoint of observation(35 days post-infection).Changes in peripheral blood T,B,NK,and NKT cells and various cytokines were assessed at various time points(4,20,and 35 days post-infection).Results(1)IL2rg/-knockout rats sustained high viral loads in the nasal cavity upon intranasal inoculation with hRSV.The average peak titer rapidly reached 1 × 1010 copies/g in nasal tissue and 1 × 107 copies/g up to 5 weeks post-infection.(2)However,no significant pathological changes were noted in nasal,tracheal,or lung tissues.(3)An increase was observed in the content of peripheral blood B cells in hRSV-infected IL2rg--rats.(4)IL-6 and MCP-1 were increased in the early stage of infection and then decreased at the end of the observation period.Conclusions This study established a new IL2rg-/-rat model using TALEN technology and found that this model effectively supported high-level replication and long-term infection of hRSV,providing a good basis for antiviral drug screening and in vivo efficacy evaluation of anti-hRSV antibodies.

ObjectiveThrough improving the potential of vascular endothelial growth factor receptor (VEGFR)-humanized mouse model (hKDR^+/+) with C57BL/6N background to allow the growth of different mouse tumor cell lines, to establish novel tumor-bearing mouse models which can support in vivo tumorigenesis of different mouse tumor cell lines and be used to evaluate drugs targeting VEGFR.MethodsFirstly, a method to evaluate the in vivo activity of antibody targeting VEGFR based on the hKDR^+/+ humanized mouse model was established. Recombinant activating gene 1 (Rag1) knockout mice (Rag1^-/-) were established using CRISPR/Cas9 technology. Then these Rag1^-/- mice were crossed with hKDR^+/+ mice to get a double gene modified homozygous hKDR^+/+/Rag1^-/- mouse model by screening. Finally, tumor cell lines derived from different mouse strains were tested on the double gene-modified mouse model to compare the differences in tumor growth. ResultsAntibodies designed for VEGFR showed significant anti-tumor activity in hKDR^+/+ mice, which significantly reduced tumor volume and weight compared with the PBS group (P<0.01, P<0.05). The number of B cells and T cells in the peripheral blood of Rag1^-/- mice and hKDR^+/+/Rag1^-/- mice decreased (P<0.05, P<0.001). Tumors were observed in hKDR^+/+/Rag1^-/-, Rag1^-/-, wild-type, and hKDR^+/+ mice after 7 d of inoculation of MC38 cells derived from C57BL/6 mice. Tumors were only observed in groups of hKDR^+/+/Rag1^-/- and Rag1^-/- mice, but not in the wild-type and hKDR^+/+ mice after 10 d of inoculation with CT26 cells derived from BALB/c mice. After 3 weeks of inoculation, the tumor volume of hKDR^+/+/Rag1^-/- mice was significantly larger than that of Rag1^-/- mice (P<0.01). ConclusionRag1 knockout mice were obtained and a novel hKDR^+/+/Rag1^-/- double genes modified mouse model was further screened. The tumor cell lines from different mouse strain origins were more prone to growth in mice with Rag1 gene deficiency. The results suggest that the reduced immune response of hKDR^+/+ humanized mice will improve the capacity of supporting the growth of mouse tumor lines in the model. As a result, more tumor-bearing mouse models may be constructed for the evaluation of drugs targeting VEGFR in this way.