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The cytoskeleton, a dynamic network of structural proteins within cells, is essential for cellular deformation and responds to external mechanical cues. Here, based on the structure of the cytoskeleton, combined with the biochemical reactions of the activator RhoA and the inhibitor F-actin, we develop a novel mechanochemical cytoskeleton model to investigate the mechanical behavior of cells. Interestingly, we find that active stress fibers exhibit diverse dynamical modes at specific inhibitor concentration thresholds. The existence of concentration differences and sustained mechanochemical feedback in activators and inhibitors trigger a global oscillation of isolated cells. In addition, under uniaxial and biaxial stretches, activators and inhibitors preferentially diffuse toward the more significantly deformed cytoskeletal elements, and their dynamic interactions regulate the cell to align with the main stretching direction. Our findings, consistent with many experimental results, provide fundamental insights into cytoskeletal remodeling and cellular mechanosensing mechanisms. [ABSTRACT FROM AUTHOR]

Objective: To investigate the prevalence and risk factors of functional dyspepsia (FD) and irritable bowel syndrome (IBS) among college students in China., Methods: An online questionnaire survey of college students aged 17-35 from across China was conducted. The online questionnaire survey was supplemented by an offline survey. A total of 2025 valid samples were included for statistical analysis. χ 2 test and logistic regression were performed for statistical analysis., Results: The prevalence of FD among college students who met the Rome Ⅳ diagnostic criteria was 5.5% (112/2025), with most of them, or 66.1% (74/112), suffering from postprandial discomfort syndrome (PDS). Smoking (odds ratio [ OR ]=2.334, 95% confidence interval [ CI ]: 1.187-4.589, P =0.014), depression ( OR =2.447, 95% CI : 1.421-4.214, P =0.001), and insomnia ( OR =1.947, 95% CI : 1.291-2.937, P =0.001) were positively correlated with the prevalence of FD. The prevalence of IBS was 1.9% (38/2025), with IBS-diarrhea dominant (IBS-D) being the most important subtype that accounted for 44.7%. Anxiety ( OR =3.63, 95% CI : 1.34-9.88, P =0.012) and insomnia ( OR =2.35, 95% CI : 1.18-4.68, P =0.015) were positively correlated with the prevalence of IBS., Conclusion: Based on Rome Ⅳ criteria, IBS and FD are not uncommon among Chinese university students. Psychological disorders and some related lifestyle factors may be related to the development of the disease. In the future, more series of studies based on different diagnostic criteria, different regions, and multiple factors should be conducted in China., (Copyright© by Editorial Board of Journal of Sichuan University (Medical Sciences).)

Objective: To explore the inhibitory effect of estrogen against metastasis of human hepatocellular carcinoma MHCC97H cells and explore the molecular mechanism., Methods: The inhibitory effect of estrogen on the migration and invasion of MHCC97H cells was evaluated with wound healing assay and Transwell assay. Western blotting was used for investigating the expression of MMP-2, MMP-9, AKT and p-AKT in the cells treated with estrogen., Results: Estrogen treatment significantly inhibited the migration and invasion of MHCC97H cells in a dose-dependent manner. Estrogen significantly down-regulated the protein expressions of MMP-2 and MMP-9 and lowered the phosphorylation level of AKT., Conclusion: The anti-metastatic effect of estrogen involves inhibition of MMP-2 and MMP-9 in MHCC97H cells probably by regulating AKT signal pathway.

Objective: To analyze the clinical features of interstitial pneumonitis (IP) associated with interferon therapy for chronic hepatitis C., Methods: We report the first case of IP in China resulting from pegylated interferon alpha-2a in combination with ribavirin for treatment of hepatitis C viral infection. A statistical analysis of the related literatures documenting such IP cases was performed using SPSS 11.5 software., Results: Of the 22 patients reported to develop IP after interferon therapy alone or in combination with ribavirin, 83%, 72% and 56% of the patients had the symptoms of dyspnoea, dry cough and fever, respectively. Twenty of these cases presented with restrictive pulmonary functional impairment and/or hypoxemia, and diffuse infiltration on chest radiography and/or CT. Complications were documented in 71% of the cases within 12 weeks of the treatment. The majority (85%) of the patients had favorable prognoses with an average recovery time of 7.5 weeks. Compared with the patients with mild and moderate pulmonary function impairment, 8 patients with severe pulmonary functional impairment had early onset of IP during the interferon therapy (6.6 vs 14.1 weeks, P<0.05), and a higher rate of corticosteroid treatment (75% vs 54%, P>0.05)., Conclusion: IP is a rare pulmonary complication associated with IFN therapy, and patients with chronic hepatitis C should be followed up closely in the first 12 weeks of interferon therapy. Prompt discontinuation of medication is mandatory in the presence of IP, and corticosteroid therapy may not be essential for patients with mild or moderate pulmonary functional impairment under close monitoring. The severity of pulmonary damage is associated with the time of complication occurrence, and corticosteroids are required when obvious pulmonary toxicity occurs in early stage of the treatment (within 6 weeks) to reduce the pulmonary damage.

Objective: To examine the expressions of E-cadherin, beta-catenin and cyclin D1 in the skin lesions of patients with psoriasis vulgaris, and understand their possible roles in keratinocyte hyperproliferation in these patients., Methods: Immunohistochemistry was performed to detect the expressions of E-cadherin, beta-catenin and cyclin D1 in the normal skin tissues and psoriatic lesions., Results: In normal skin tissues, positive staining for E-cadherin and beta-catenin was detected in all layers of the normal epidermis at the sites of cell-cell junctions, and downregulation of E-cadherin and beta-catenin expression was found in the granular layer and basal layer of the psoriatic lesions. Cyclin D1 overexpression was observed mainly in the basal layer of the lesions, which was correlated to abnormal expression of beta-catenin., Conclusion: Downregulation of E-cadherin and beta-catenin expression and cyclin D1 overexpression in psoriatic skin are probably involved in keratinocyte hyperproliferation in psoriasis vulgaris.

Objective: To investigate the involvement of E-cadherin-catenin adhesion system in Bowen's disease (BD) and cutaneous squamous cell carcinoma (SCC)., Methods: Fifteen normal skin, 28 BD and 18 SCC specimens were stained with monoclonal antibodies against E-cadherin and beta-catenin. Evaluation of the staining results was performed with semi-quantification of the pattern and intensity of staining, percentage of positive cells, and cytoplasmic staining., Result: Normal skins strongly expressed membranous E-cadherin and beta-catenin, but their expression was remarkably reduced in BD and SCC. Abnormal staining of beta-catenin was observed in the cytoplasm or cell nuclei of BD and SCC., Conclusion: Abnormal expression of the E-cadherin/catenin complex is common in SCC and BD.