BACKGROUND: Because of complicated physiological environment and difficulty to control experimental conditions, it is difficult to get satisfactory results from in vivo studies of cell mechanics.OBJECTIVE: To study the action and mechanism of p38MAPK signaling pathways on myoblast apoptosis based on successful construction of in vitro mechanical stimulation models.METHODS: The C2C12 cells cultured in vitro were divided into control group and SB203580 treatment group. Cyclic tensile stress was applied on the C2C12 myoblast cells for 0, 6, 12 and 24 hours in each group. The Flexcell Strain Unit-5000T was used to expose C2C12 myoblast cell to an equiaxial cyclic of 15% magnitude and a frequency of 10 cycles/min, each cycle including the 3 s stretch and 3 s relaxation. Hoechst 33258 fluorescent staining and optical microscope were used to detect cell apoptosis. RT-PCR, flow cytometric analysis were used to observe the apoptosis of C2C12 myoblast cells and Western blotting were used to detect the activity of p38MAPK and p-p38MAPK. RESULTS AND CONCLUSION: The optical microscope tested the change in the morphology. Hoechst 33258 staining showed that after treatment with cyclic stress, the cell took the typical appearance of apoptosis with chromatin condensation and apoptotic bodies. RT-PCR and flow cytometry showed that with the extension of time the rate of the apoptosis of C2C12 myoblast cell increased. And cells imposed SB203580 before imposing cyclical tensile stress, the results showed that the apoptosis was markedly affected, and the p-p38MAPK expression declined apparently. These findings demonstrate that p38MAPK signaling pathways in stress mediated into C2C12 myoblast cell apoptosis plays an important role.

Objective To study the incidence of lactase deficiency and the risk factors affecting intestinal lactase secretion in newborns with lactase deficiency.Method From February to December 2016,newborns admitted to the neonatal ward of the Affiliated Hospital of Hangzhou Normal University were enrolled in this prospective study.Urine samples were taken within one to two hours after feeding for galactose qualitative tests,and the related clinical data were recorded.The newborns were assigned into lactase deficient group and non-lactase deficient group according to the test results.Then the risk factors of lactase deficiency were analyzed comparing the clinical data between the two groups.Result A total of 1 022 newborns were hospitalized during the research period,of whom 213 were enrolled in this study according to the inclusion criteria.154 cases had positive results in the urine galactose qualitative tests,yielding the incidence of lactase deficiency of 72.3 ％.42 cases had lactose intolerance symptoms,and the incidence of lactose intolerance was 27.3 ％ (42/154).Age and positive family history in lactase deficient group were higher than non-lactase deficient group (10.3 ±6.4 d vs.8.1 ±5.8 d and 23.4％ vs.10.2％),while the gestational age of lactase deficient group was lower than non-lactase deficient group (37.8 ±2.9 weeks vs.39.0 ± 1.7 weeks),and the differences between the two groups were statistically significant (P ＜ 0.05).No significant differences existed in gender,birth weight,antibiotics use and feeding volumes between the two groups (P ＞ 0.05).Multivariate Logistic regression analysis showed that age (OR =1.065,95％CI 1.007 ～ 1.127) and positive family history (OR =2.912,95％ CI 1.053 ～ 8.056) were the risk factors of lactase deficiency.Gestational age (OR =0.747,95％ CI 0.617 ～ 0.904) was the protective factor of lactase deficiency in newborns.Conclusion The incidence of lactase deficiency in newborns is high,but not all the newborns manifest lactose intolerance symptoms.Age and positive family history were the risk factors while gestational age was the protective factor for lactase deficiency in newborns.

Objective To discuss the application of gelatin sponge-hemocoagulase plugging agent in patients with pulmonary puncture bleeding.Methods The clinical data of 43 patients with hemorrhage caused by DSA-guided lung puncture biopsy,who received gelatin sponge-hemocoagulase plugging agent treatment at the Jining Municipal First People's Hospital of China between September 2021 and May 2023,were collected,and the hemostatic effect of gelatin sponge-hemocoagulase plugging agent was analyzed.Results Successful lung puncture needle biopsy was achieved in all the 43 patients.The puncture needle channel occlusion was accomplished by using gelatin sponge-hemocoagulase plugging agent.Five minutes after occlusion treatment,in one patient,whose moderate hemoptysis with moderate bleeding shadow before puncture needle biopsy changed to bloody sputum,the intrapulmonary bleeding shadow displayed on image became slightly enlarged when compared the size five minutes ago,while in all the remaining patients successful hemostasis was achieved,the hemoptysis disappeared and the pulmonary hemorrhage shadow was similar to that five minutes ago.No occlusion-related complications occurred in all patients.Conclusion For the treatment of pulmonary hemorrhage caused by DSA-guided lung puncture biopsy,gelatin sponge-hemocoagulase plugging agent is clinically safe and effective.