This study sought to elucidate the effect of mechanical strain on the differentiation of mesenchymal stem cells into osteoblasts. Under the conditons of inducing osteoblasts, Immunohistochemical methods and RT-PCR technology were applied in osteogenic supplements medium to detect: (1) the expression of Alkaline phosphatase (ALP), Type I collagen (COL I ), Osterx (Osx) and Osteocalcin (OCN) mRNA, with cyclic strain (3%, 0.5 Hz) applied for 15 min, 30 min, 1 h, 2 h, 4 h, 3 d, 7 d, 14 d; (2) the expression of Osx mRNA and OCN mRNA with 3% strain for 1 h. The results showed: (1) ALP mRNA expression was higher at 7 days; COL I mRNA expression was greater obviously at 7 days and 14 days than that at 3 days and that of the unstrained cells; (2) the expression of Osx mRNA was up-regulated after 15min by strain stimulation,which was significantly increased at 30 min and 1 h in the unstrained cells. The expression of OCN mRNA was not affected in the unstrained cells at 15 min, whereas strain could promote the expression of OCN mRNA at this period. The expression of OCN mRNA was more obviously upregulated in the strained cells at 30 min and 1 h when compared with that in the unstrained cells; (3) the strain (1% and 3%) significantly promoted the expression of Osx mRNA; 10% strain had a little effect on Osx mRNA expression. The expression of OCN mRNA was up-regulated by 3% strain, whereas it had little effect at 1% and 10% strain. In summary, mechanical strain can promote the differentiation of mesenchymal stem cells into osteoblasts.
Animals ; Bone Marrow Cells ; cytology ; Cell Differentiation ; Cells, Cultured ; Mechanoreceptors ; physiology ; Mechanotransduction, Cellular ; physiology ; Mesenchymal Stromal Cells ; cytology ; Mice ; Osteoblasts ; cytology ; Osteocalcin ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Sp7 Transcription Factor ; Stress, Mechanical ; Transcription Factors ; genetics ; metabolism

OBJECTIVES: To analyze the clinical characteristics of fecal severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid-positive in patients with coronavirus dasease 2019 (COVID-19) and to provide a scientific basis for the prevention and control of this disease. METHODS: The clinical data of 16 patients with fecal SARS-CoV-2 nucleic acid positive, who hospitalized in the North Branch of the First Hospital of Changsha (Changsha Public Health Rescue Center) from January to February 2020, were retrospectively analyzed. Their clinical manifestations, laboratory data and imaging data were summarized. RESULTS: Among the 16 patients, there were 9 males (56.25%) and 7 females (43.75%), the ratio of males to females was 1∶1.29. The age of onset was (43.3±14.6) years. There were 15 patients with contact history of Wuhan, 1 patient with contact history of local patient.Twelve patients were common type (75%), and 4 patients were severe type (25%). Clinical symptoms included fever in 14 patients (87.5%), cough in 12 patients (75%), shortness of breath in 5 patients (31.25%), pharyngalgia in 10 patients (62.5%), fatigue in 7 patients (43.75%), and diarrhea in 4 patients (25%). There were 14 patients (87.5%) with normal or decreased white blood cell count, 11 patients (68.75%) with decreased lymphocyte count, 15 patients (93.75%) with increased erythrocyte sedimentation rate, 13 patients (81.25%) with increased hypersensitivity C-reactive protein, 5 patients (31.25%) with increased procalcitonin, and 8 patients (50%) with increased serum ferritin in peripheral blood, and stool routine was basically normal. Compared with the common type, there was significant difference in the white blood cell and lymphocyte counts in the severe type (<0.01); the infection indicators, such as hypersensitivity C-reactive protein and serum ferritin, were significantly increased, with significant difference (all <0.01); but the procalcitonin and erythrocyte sedimentation rate was not significantly different (both >0.05). Chest CT mainly showed patchy shadows and interstitial changes. According to imaging examination, 4 patients (25%) showed unilateral pneumonia and 12 patients (75%) showed bilateral pneumonia. CONCLUSIONS The patients have the clinical symptoms of COVID-19, but gastrointestinal symptoms (such as diarrhea) are more common, and the changes of white blood cell count, lymphocyte count, hypersensitivity C-reactive protein, ferritin are more obvious in severe patients.The positivity of fecal nucleic acid suggests the possibility of digestive tract transmission of SARS-CoV-2, and fecal nucleic acid testing can be used as a routine testing method in clinical practice.
Adult ; Betacoronavirus ; isolation & purification ; C-Reactive Protein ; analysis ; China ; Coronavirus Infections ; diagnosis ; physiopathology ; Diarrhea ; virology ; Feces ; virology ; Female ; Ferritins ; analysis ; Humans ; Leukocyte Count ; Male ; Middle Aged ; Pandemics ; Pneumonia, Viral ; diagnosis ; physiopathology ; Retrospective Studies