Objective To investigate the expressions of transforming growth factor-?1(TGF-?1)and ?-smooth muscle actin(?-SMA)in the lungs of mice with intra-amniotic endotoxin priming and exposed to 60% hyperoxia after born in order to elucidate the possible relationship with bronchopulmonary dysplasia(BPD).MethodsFifty C57 pregnant mice were divided into 2 groups:lipopolysaccharide(LPS,40 ?g/L)group and saline solution group,and then received an intra-amniotic injection of corresponding solution on E15.The neonatal mice of each group were randomized to be set in 60% oxygen exposure or in room air.So there were 4 subgroups,LPS+air,LPS+hyperoxia,saline+air and saline+hyperoxia groups.On days 1,3,7,10 and 14 after birth(8 rats each time point),the lung histological changes was assessed with hematoxylin and eosin(HE)staining for radial alveolar counting(RAC).The expressions of TGF-?1 and ?-SMA proteins were detected by immunohistochemical and immunofluorescence staining,and the expressions of TGF-?1 and ?-SMA mRNA by real-time polymerase chain reaction(RT-PCR).ResultsIn the LPS+hyperoxia group and saline+hyperoxia group,RAC began to decrease on day 3,and then further declined in a time-dependent manner.Compared with saline+hyperoxia group,LPS+hyperoxia group had significantly lower RAC(P

Objective To explore the conditions and methods for cryopreservation and proliferation of mouse spermatogonial stem cells (SSCs). Methods SSCs were isolated from six-day-old Kunming mouse using two-step enzymatic digestion and Percoll discontinuous density gradient centrifugation. Cells were frozen with different freezing medium and cooling rate. After thaw, they were cultured in mimimum essential medium alpha (MEMα) supplemented with 10% fetal calf serum (FCS) and 100μg/L glial cell line-derived neurotrophic factor (GDNF). The survived and proliferating SSCs were examined by WST-8 colorimetric assay. Alkaline phosphatase andreverse transcription-polymerase chain reaction (RT-PCR) were performed to confirm if the cultured 96 hours germ cells were still stem cells. Results The best method to cryopreserve SSCs is using cryoprotector containing 10% dimethyl sulfoxide(DMSO), 10% FCS, 0.07mol/L sucrose and 1℃/min cooling rate, and the viability of cells in this method is more than 84%;Although the cell viability in non-programmed freezing method is less than that in the programmed freezing method, it is a simple and effective cropreservation method for mouse SSCs. What is more, the anchoring time of SSCs in this method is 8-12 hours after thaw, SSCs begin to proliferate 24 hours later, and rapid proliferation appears on the 48 hours, colonies are composed by 20-25 cells in 96 hours, when SSCs proliferated nearly 5 times.Conclusion The culture condition we used is suitable for proliferation of frozen-thawed SSCs.

Objective To investigate the clinical features,early diagnosis and individualized treatment of renal hypophosphatemia and osteomalacia induced by adefovir dipivoxil (ADV) in patients with chronic hepatitis B (CHB).Methods Thirty-nine CHB or hepatitis B virus (HBV)-related cirrhosis patients of renal hypophosphatemia and osteomalacia induced by ADV were consecutively collected.The clinical features were analyzed and treatment outcome was followed up.Results The mean age of the 39 patients was 54 (27-71) years old.There were 26 male and 13 female patients,and 19 patients with cirrhosis.The mean ADV treatment duration was 69 (range 18-116) months,and 31 patients were treated for 36-96 months.The mean serum phosphate was 0.68 (0.42-0.79) mmol/L.Twenty-six cases developed renal hypophosphatemic osteomaolacia,of which 14 had bone pain and 19 had abnormally elevated alkaline phosphatase (ALP).Three patients had increased serum creatinine and 24 patients had decreased estimated glomerular filtration rate (eGFR).After individualized treatment,patients gained normal serum phosphate in mean of 2.0 (range 0.5-6.0) months,and had bone pain remission in the mean of 0.8 (range 0.2-1.0) month and bone pain disappeared in the mean of 1.5 (range 0.5-5.0) months.Function indices of liver and kidney were improved gradually,and the bone mineral density examination improved slowly.Conclusions CHB and HBV-related cirrhosis patients treated with longterm ADV could develop renal hypophosphatemia and hypophosphatemic osteomalacia,which is partially reversible.Monitoring serum phosphate,creatinine and cystatin C is necessary during long-term ADV therapy.After confirmed diagnosis,withdrawal or dosage reduction of ADV,and switch to telbivudine or entecavir should be considered.Meanwhile,serum phosphate and HBV DNA level should be monitored.

Objective: To explore the relationship between behavioral problems and accidental injuries among preschoolers, and to provide evidence for the targeted prevention of children s accidental injuries. Methods: During September to October 2019, parent of 2 062 children aged 3 to 6 selected from 8 kindergartens in Hefei through stratified clustering method were investigated. The prevalence of accidental injuries and behavioral problems among preschoolers was collected by questionnaire survey. Results: The prevalence of accidental injury during the past year was 14.55%(300), and behavioral problems 14.21%(293). Total rate of behavioral problems and rate of each dimensions in children with accidental injury were 32.67%, 2.33%, 19.67%, 15.00%, 2.00%, 1.00 % and 5.00%, compared to 11.07%, 0.45%, 6.41%, 4.88%, 0.40%, 0.17% and 0.79% in children without accidental injury ( χ 2=98.11, 12.54, 58.90, 44.12, 10.51, 6.08, 32.68, P <0.01). Multivariate Logistic regression analysis showed that psychosomatic problems( OR =3.13, 95% CI =2.11-4.66), learning problems( OR =2.73, 95% CI =1.86-3.99), abnormal hyperactivity index ( OR =3.16, 95% CI =1.40-7.14) and left behind children ( OR =1.53, 95% CI =1.13-2.07) were associated with higher risk of accidental injuries( P <0.05). Conclusion Behavioral problems are significantly associated with unintentional injuries among preschool children, which deserved further attention and intervention when formulating prevention and control measures for childhood accidental injury.

In this study, we amplified human lysosomal acid beta-glucosidase (GlcCerase) gene by RT-PCR from human placenta, and analyzed the sequence of the PCR product cloned in pMD-19T. The gene identity was 99% comparable to that of the reported human GlcCerase cDNA sequence in GenBank. The GlcCerase gene digested with Xho I was subcloned into eukaryotic express vector pEGFP-C1 to generate recombinant expression vector pEGFP-GlcCerase. After identified the recombinant plasmid by restriction enzyme digestion, we transfected pEGFP-GlcCerase into COS7 cells by liposome. GlcCerase mRNA was expressed and the activity of GlcCerase was also detected in COS7 cells. This study would lay a foundation for the function of GlcCerase and its production by transgenic bioreactor.
Animals ; COS Cells ; Cercopithecus aethiops ; Cloning, Molecular ; Genetic Vectors ; genetics ; Glucosylceramidase ; genetics ; metabolism ; Green Fluorescent Proteins ; genetics ; Humans ; Lysosomes ; enzymology ; Recombination, Genetic ; Transfection

Abstract The prevalence of overweight and obesity among children in China has entered a new phase of pandemic, with substantial regional differences. There are diverse and complex determinants for overweight and obesity in school age children, it is necessary to take targeted measures towards children of different ages and regions, comprehensively consider the effects of physiological, social, household and behavioral factors and simultaneously strengthen connections between schools, medical institutions and families, so as to actively respond to the severe situation of childhood obesity epidemic.

Formative assessment emphasizes timely feedback to guide and improve the learning process, benefiting both students and teachers through the evaluation–feedback–improvement–reevaluation mechanism. The Pediatric College of Chongqing Medical University has widely applied formative assessment to standardized residency training, and at the same time, has actively researched this method in undergraduate education to employ various formative assessment tools to establish a formative assessment-based pediatric education model that has specialized characteristics and can be popularized. We have demonstrated that the formative assessment-based education model can improve the teaching quality of pediatric medical education, and better meet the requirements of higher education and the new situation of medical education in the age of new medicine.

The aim of this study was to construct a mammary gland-specific expressional vector pBC1-hLF-Neo for Human Lactoferrin (hLF) gene and then investigate its expression in the mammary gland epithelium cells. The constructed vector contained the 6.2 kb long 5' flank regulation region including promoter, other elements and the 7.1 kb long 3' flank regulation region including transcriptional ending signal of a goat's beta-casein gene. A cassette of Neo gene was also inserted into the vector which gave a total length of 26.736 kb identified by restriction fragment analysis and partial DNA sequencing. The results revealed that the structure of the final constructed vector accords with the designed plasmid map. In order to analyze the bioactivity of the vector, we transfected the lined vector DNA into the dairy goat's mammary gland epithelium cells and C127 cells of a mouse's mammary epithelium by Lipofectamine. After selection with G418 for 8-10 days, G418-risistant clones were obtained. PCR analysis demonstrated that hLF gene cassette had been integrated into the genomic DNA of G418-risistant clones. After proliferation culture, the two kinds of transgenic cells were cultured in serum-free DMEM-F12 medium with prolactin, insulin and hydrocortisone- a medium capable of inducing recombinant hLF expression. RT-PCR, Western blotting and anti-bacteria bioactivity experiments demonstrated that the constructed mammary gland specific vector pBC1-hLF-Neo possessed the desirable bioactivity to efficiently express and could secrete hLF in both mammary gland cells and have the effect of E. coli proliferation inhibition. Paramount to everything, this study laid a firm foundation for preparing the hLF gene transgenic goat fetal-derived fibroblast cells.
Animals ; Base Sequence ; Breast Neoplasms ; metabolism ; pathology ; Caseins ; genetics ; Cell Line, Tumor ; DNA, Complementary ; biosynthesis ; genetics ; Epithelial Cells ; metabolism ; Female ; Genetic Vectors ; genetics ; Goats ; Humans ; Lactoferrin ; biosynthesis ; genetics ; Mammary Glands, Animal ; cytology ; metabolism ; Mice ; Molecular Sequence Data ; Mutagenesis, Insertional ; Promoter Regions, Genetic ; genetics

Objective: To understand sexual orientation and characteristics of sexual behaviors related with HIV infection among HIV positive male college students in Beijing and to provide suggestions for development of sexual health education and HIV prevention strategy for student population. Methods: HIV positive male college students diagnosed from 2016 to June 30, 2019 in Beijing were recruited. Questionnaire was used to retrospectively investigate sexual orientation and characteristics of sexual behaviors before HIV infection. Behaviors related to HIV infection were compared between absolutely homosexual and others sexual orientation. Results: The average age of male students firstly identified to be HIV positive was (22.18±2.70) years old, 61.5%(123) of them were undergraduate, 69.5%(139) were not registered permanent residency in Beijing, 38.5%(77) of their interviewed sexual partners were from online chat and 83.0%(166) had homosexual behaviors. Sexual orientation score analysis showed that 50.0% of the participants self identified as exclusively homosexual. Compared with other sexual oriental group, exclusively homosexual group had lower mean age of their HIV infection firstly identified（ t =2.77， P =0.01）, higher rate of Rush use, firstly insertive sexual behavior with male, firstly insertive sexual behavior before 18 years old, sexual partners more than three persons, having regular partners, nonpersistent use of condom, being diagnosed of sexual transmitted disease and the frequency of homosexual behaviors more than 1 time per month （ χ 2=5.15,28.06,4.16,5.34,5.89,7.39,6.68, P <0.05）. Rush users had higher rate of STD diagnosis than non users in exclusively homosexual group ( χ 2=6.26， P =0.01). Conclusion Risky sexual behaviors associated with HIV infection were higher in exclusively homosexual group then other sexual orientation groups among HIV positive male college students. Family and school should concern with sexual health education byreinforcing health education via network media to improve college students’ awarenees on HIV/AIDS.

Objective:To analyze the feasibility of developing clinical pediatrics curriculum for pediatric students at the pre-clinical stage, and to provide a basis for the subsequent curriculum construction.Methods:A total of 90 pediatric medical students were enrolled, including pre-clinical group (G1, third semester of the second year, n=47) and the clinical clerkship group (G2, seventh semester of the fourth year, n=43). A questionnaire survey was conducted to compare the two groups from three aspects: clinical interest, learning methods and learning ability. And 24 and 20 students were randomly selected from the two groups to participate a clinical course respectively. Both of the formative evaluation and in-class test were carried out to compare the learning performance and learning effect between G1 and G2. SPSS 22.0 was used for data analysis. The counting data were described by case number and rate, and the frequency between groups was compared by chi-square test. When the chi-square test condition is not met, Fisher's exact test was performed. Normal distribution test was carried out for measurement data. Two independent sample t test was conducted for the comparison between groups of normal distribution data and Mann-Whitney U test for the comparison between groups of skewed distribution respectively. Results:There was no significant difference in clinical interest and pre-clinical interest between the two groups (Fisher's exact probability method, P=0.252, 1.000). There were partial differences in learning methods: G1 spent more time learning after class ( Z=-2.36, P=0.018), learned more in spare time ( Z=2.53, P=0.011), learned more on the homework ( P=0.020), and had a higher preview rate ( Z=-5.07, P < 0.001). There were also partial differences in learning ability: G2 had better literature retrieval ability ( χ2=10.57, P=0.001); G2 had higher scores on class and extended class performance ( t=-3.18, P=0.004; t=-10.14, P<0.001). In terms of learning effect, G2 scored higher scores on only one multiple choice question ( t=-2.46, P=0.022). Conclusion:The pediatrics students at the pre-clinical stage have certain interest and ability to receive clinical pediatrics courses. Sufficient pre-class preparation and appropriate curriculum design are helpful to the early cultivation of student's clinical thinking.