In order to improve the teaching quality of epidemiology and better serve the situation of disease prevention and control,problem-based learning (PBL) teaching method was applied in the teaching of epidemiology. This paper introduced the implementation of PBL and its advantages and disad-vantages. PBL teaching method can improve students' self-learning ability,communication skills,team cooperation,practical ability and capability of integrating knowledge of many subjects.

Objective: To investigate the current prevalence of excessive weight gain during pregnancy among pregnant and lying-in women in Xining City and to identify the influencing factors, so as to provide insights into reasonable weight control during pregnancy. Methods: The pregnant and lying-in women who were registered and delivered in the Red Cross Hospital of Qinghai Province, the Affiliated Hospital of Qinghai University and the First People's Hospital of Xining City from August 2021 to July 2022 were enrolled. Women's demographics, health status during pregnancy, diet, sleep and exercise were collected through prenatal testing data and questionnaires. Excessive weight gain during pregnancy was identified according to "Weight monitoring and evaluation during pregnancy of Chinese Women" (T/CNSS 009-2021), and the factors affecting excessive weight gain during pregnancy were identified using a multivariable logistic regression model. Results: A total of 902 questionnaires were allocated and 882 valid questionnaires were recovered, with an effective recovery rate of 97.78%. The pregnant and lying-in women had a mean age of (29.06±4.16) years, mean pregestational body mass index of (20.44±2.20) kg/m2 and mean gestational weight gain of (14.17±3.11) kg, and there were 447 primiparas (50.68%) and 360 women with excessive weight gain during pregnancy (40.82%). Multivariable logistic regression analysis identified an educational level of senior high school/technical secondary school (OR=1.400, 95%CI: 1.037-1.889), annual household income of >200 000 Yuan (OR=2.385, 95%CI: 1.924-2.956), a family history of diabetes (OR=1.475, 95%CI: 1.180-1.844), pregestational overweight/obesity (OR=4.079, 95%CI: 2.471-6.734), gestational hypertension (OR=2.061, 95%CI: 1.027-4.136), anxiety (OR=1.315, 95%CI: 1.139-1.518) and preference for sour foods (OR=1.715, 95%CI: 1.237-2.376) as risk factors for excessive weight gain during pregnancy, and early pregnancy reaction as a protective factor (OR=0.636, 95%CI: 0.546-0.742). Conclusions The prevalence of excessive weight gain during pregnancy was high in Xining City, and educational level, annual household income, family history of diabetes, pregestational body mass index, pregnant complications and dietary habits are factors affecting excessive weight gain during pregnancy.

Objective To evaluate the diagnostic value of conventional ultrasound and contrastenhanced ultrasound(CEUS) in calcified thyroid nodules.Methods 122 cases of calcified thyroid nodules confirmed by pathology were underwent conventional ultrasound and CEUS.The sensitivity,specificity,positive predictive,negative predictive and diagnostic coincidence rate of conventional ultrasound and CEUS were evaluated.Receiver operating characteristic (ROC) curve was constructed to assess the differential diagnosis value of conventional ultrasound and CEUS in calcified thyroid nodules.Results There were 73 benign and 49 malignant nodules among 122 calcified thyroid nodules.The sensitivity,specificity,positive predictive,negative predictive and diagnostic coincidence rate of conventional ultrasound were 49.98％,76.71％,58.54％,69.14％ and 65.57％,while for CEUS were 89.80％,91.78％,88.00％,93.06％ and 90.98％,respectively.There was statistical difference for each index between the two methods (all P ＜0.05).The area under ROC curve of CEUS was 0.908,which was bigger than conventional ultrasound.Conclusions Compared with conventional ultrasound,CEUS has higher value in differential diagnosis of benign and malignant calcified thyroid nodules.

AIM: To explore the influence of Huqi San on the Hedgehog signaling pathway in rats with prehe-patocarcinoma.METHODS: The model of prehepatocarcinoma in the rats was established by a modified solt-farber method.The rats were intragastric administrated with Huqi San solution for 3 d after subtotal hepatectomy.Four weeks after administration of the Huqi San solution, the hepatic damage was observed by histopathological analysis.The protein expression of glutathione S-transferase-π (GST-π), alpha-fetoprotein (AFP), OV6, albumin (ALB) and glioma-associated oncogene homolog 2 (Gli2) was detected by immunohistochemistry and immunofluorescence staining.The expression of Sonic hedgehog (Shh), Smoothened (Smo), Gli2, cyclin D and cyclin E at mRNA and protein levels in the rats was determined by RT-qPCR and Western blot, respectively.The serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyltransferase (GGT) were assayed using diagnostic kits.RESULTS: Compared with model group, Huqi San decreased the serum levels of ALT, AST and GGT, and alleviated the pathological changes in prehepatocarcinoma rats.Huqi San inhibited the protein expression of GST-π and AFP (P<0.05) in the prehepatocarcinoma rats.Huqi San also promoted the protein expression of OV6 and ALB (P<0.05).Furthermore, Huqi San activated Hedgehog signaling pathway and its downstream targeting molecules such as Shh, Smo, Gli2, cyclin D and cyclin E.In addition, the results in vitro showed that Huqi San may activate Hedgehog signaling pathway and promoted oval cell proliferation.CONCLUSION: Huqi San not only promotes hepatic progenitor cell proliferation, but also induces hepatic progenitor cell differentiation and inhibits prehepatocarcinoma in the rats probably via activating Hedgehog signaling pathway.

Aim To investigate the role of endothe-lium in the enhancement of phenylephrine-mediated vasoconstriction by bupivacaine in the isolated rat aor-ta.Methods The isolated rat aortic rings were pre-pared, and the vascular endothelium was removed chemically or physically .Phenylephrine-mediated vas-oconstriction was recorded .Results A pretreatment with bupivacaine at 30 μmol · L-1 for 20 min signifi-cantly increased the Emax value of vasoconstrictive re-sponses to phenylephrine from 2.22 ±0.07 g of sol-vent-controlled group to 2.50 ±0.05 g ( P<0.01 ) in the isolated endothelium-intact rat aorta.However, the Emax value was not significantly changed by a pretreat-ment with bupivacaine at 30 μmol · L-1 for 5 , 10 or 15 min ( P>0.05 ) .A pretreatment with bupivacaine at 30 μmol · L-1 for 20 min slightly but significantly inhibited the vasoconstrictive responses to low concen-tration of phenylephrine in the isolated endothelium-de-nuded rat aorta (P<0.05).In the isolated endotheli-um-intact rat aorta under a combined treatment with in-dometacin, ChTX, apamin and L-NAME, the vasodi-lator responses to acetylcholine were completely sup-pressed , and a pretreatment with bupivacaine at 30μmol· L-1 for 20 min did not significantly affect the vasoconstrictive responses to phenylephrine ( P >0.05 ) .Conclusion Bupivacaine enhances α1-adre-noceptor-mediated vasoconstriction by inhibiting vascu-lar endothelium in the isolated endothelium-intact rat aorta, Which potentiates indirectly the vasoconstrictive responses to phenylephrine .

Aim To investigate the selective inhibition of ethanol on muscarinic receptor-or 5-HT receptor-me-diated contractile responses in the circular smooth mus-cle strips isolated from the different regions of rat stom-ach. Methods Circular muscle strips isolated from the rat gastric fundus, body, cardia and pylorus were prepared, and the contractile responses to carbachol ( CCh ) or 5-HT were recorded. Results Ethanol (0. 000 05~0. 000 5, V/V) did not affect the contrac-tile response to CCh in circular muscle strips from the rat gastric fundus and cardia, and that to 5-HT in the strips from rat gastric fundus and body ( P >0. 05 ) . However, ethanol(0. 000 1 and 0. 000 5) significantly inhibited the Emax value of the contraction by CCh from (12. 18 ± 0. 33) g of control level to (10. 88 ± 0. 41) g and -lgEC50 value from ( 6. 33 ± 0. 05 ) of control level to (6. 12 ± 0. 06)(P <0. 05) in the strips from rat gastric body. Ethanol(0. 000 1 and 0. 000 5) also significantly inhibited the Emax value of the contraction by CCh from (2. 87 ± 0. 15) g of control level to (2. 2 ± 0. 13) g and -lgEC50 value from (6. 49 ± 0. 10) of control level to (6. 05 ± 0. 09)(P<0. 01) in the strips from rat gastric pylorus. Moreover, ethanol ( 0. 000 1 and 0. 000 5) significantly inhibited the Emax value of the contraction by 5-HT from (2. 93 ± 0. 35) g of con-trol level to ( 2. 1 ± 0. 30 ) g ( P<0. 05 ) , but did not affect the -lgEC50 value in the strips from rat gastric cardia. Conclusions Ethanol inhibits the contractile responses to 5-HT only in the circular muscle strips of rat gastric cardia, and it inhibits the contractile respon-ses to CCh more strongly in the circular muscle strips of gastric pylorus than gastric body. In those gastric circular muscle strips, ethanol decreases both the ac-tivity and affinity of CCh to muscarinic receptors, but decreases only the activity of 5-HT to its receptors.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease affecting both upper and lower motor neurons in the brain and spinal cord. One important aspect of ALS pathogenesis is superoxide dismutase 1 (SOD1) mutant-mediated mitochondrial toxicity, leading to apoptosis in neurons. This study aimed to evaluate the neural protective synergistic effects of ginsenosides Rg1 (G-Rg1) and conditioned medium (CM) on a mutational SOD1 cell model, and to explore the underlying mechanisms. We found that the contents of nerve growth factor, glial cell line-derived neurotrophic factor, and brain-derived neurotrophic factor significantly increased in CM after human umbilical cord mesenchymal stem cells (hUCMSCs) were exposed to neuron differentiation reagents for seven days. CM or G-Rg1 decreased the apoptotic rate of SOD1^G93A-NSC34 cells to a certain extent, but their combination brought about the least apoptosis, compared with CM or G-Rg1 alone. Further research showed that the anti-apoptotic protein Bcl-2 was upregulated in all the treatment groups. Proteins associated with mitochondrial apoptotic pathways, such as Bax, caspase 9 (Cas-9), and cytochrome c (Cyt c), were downregulated. Furthermore, CM or G-Rg1 also inhibited the activation of the nuclear factor-kappa B (NF-κB) signaling pathway by reducing the phosphorylation of p65 and IκBα. CM/G-Rg1 or their combination also reduced the apoptotic rate induced by betulinic acid (BetA), an agonist of the NF-κB signaling pathway. In summary, the combination of CM and G-Rg1 effectively reduced the apoptosis of SOD1^G93A-NSC34 cells through suppressing the NF-κB/Bcl-2 signaling pathway (Fig. 1 is a graphical representation of the abstract).
Humans ; NF-kappa B/metabolism* ; Ginsenosides/pharmacology* ; Amyotrophic Lateral Sclerosis/genetics* ; Culture Media, Conditioned/pharmacology* ; Superoxide Dismutase-1 ; Neurodegenerative Diseases ; Neurons/metabolism* ; Apoptosis