Objective To study the impacts of dynamic compressive stress on the mRNA expression of osteopontin ( OPN ),runt related gene 2 ( Runx2 ),osteocalcin ( OC ),osterix,alkaline phosphatase (ALP) and bone morphogenetic protein 2 (BMP-2) in the osteoblasts of Sprague-Dawley (SD) rats. Methods Osteoblasts extracted from skull periosteum tissue of neonatal SD rats were digested using trypsin and collagenase （Ⅰ）,then were subcultured and amplified in vitro.ALP staining and alizarin red staining were performed to identify the purified cells.The cells were treated with compressive stress at 20,50 or 100 mmHg for 24 h.The expression levels of OPN,Runx-2,OC,osterix,ALP and BMP-2 were measured and quantitatively analysed using a real-time quantitative polymerase chain reaction. Results Under 20 mmHg of dynamic compressive stress the expression levels of OPN,Runx2,OC,osterix,ALP and BMP-2 all were elevated compared with the control group.The peak expression oecured under 50 mmHg pressure. The expression levels did not change significantly compared with the control group under 100 mmHg pressure. Conclusions Moderate dynamic compressive stress can promote the expression of OPN,Runx-2,OC,osterix,ALP and BMP-2 mRNA in osteoblasts,which might be an important mechanism for promoting the union of fractures.

BACKGROUND:Silk fibroin/mesoporous glass ceramic composites have been reported to exert satisfactory repair outcomes in bone defects and hold good biocompatibility. However, the biosafety and preparation methods are rarely reported. OBJECTIVE:To investigate the preparation method and treatment outcomes of silk fibroin/mesoporous bioactive glass ceramic in skul repair. METHODS:Thirty-two Sprague-Dawley rats were enrol ed to establish the skul defect models and were thenrandomized into two groups:fibroin/mesoporous glass ceramic materials and silk fibroin were respectively implanted into the defect region in experimental and control groups. At 4 and 8 weeks after implantation, the CT examination and histological observation were performed. RESULTS AND CONCLUSION:CT examination showed that at 4 weeks after implantation, the defect area in the experimental group diminished in size, showing more dense new bones. The defect area of the control group was reduced, and a smal amount of new bones were observed. At 8 weeks after implantation, bone defect repair was completed in the experimental group, but not in the control group. The bone volume in the experimental group was significantly larger than that in the control group at different time points after implantation (P<0.05). Hematoxylin-eosin staining found that at 4 weeks after implantation, in the experimental group, there was new bone between the implant and the bone, which did not cause inflammation;there were few new bones and fibrous tissues in the control group. At 8 weeks after implantation, many new bones formed in the experimental group, with similar morphology to the host bone and the scaffold was degraded completely. Conversely, the implant material stil existed in the control group. In conclusion, the silk fibroin/mesoporous glass ceramic composite can promote bone repair.

BACKGROUND:Schwann cell is one of the major seed cells In peripheral nervous system and plays an important role in neural injury and neural disease.However,the source of Schwann cells is limited.And the purity of Schwann cells is affected due to the pollution of fibroblasts.Many purified methods have been proposed,but every one has its defect to satisfy the clinical demand.OBJECTIVE:To compare the differences among differential adhesion purified method,cold jet purified method,immunomagnetic beads selection purified method and G418 selection purified method to purify Schwann cells of neonatal rat in vitro.METHODS:Bilateral sciatic nerves of SD rats were harvested under sterile condition.Schwann cells were purified respectively using differential adhesion purified method,cold jet purified method,immunomagnetic beads selection purified method and G418 selection purified method.Cell viability was compared,and cell purity was determined by immunohistochemistry.RESULTS AND CONCLUSION:The purity of Schwann cells separated by differential adhesion method was low,but the viability was fair.The purity and viability of cells following cold jet method immunomagnetic beads selection method was high.The purity of cells separated by immunomagnetic beads selection methods was similar to that of cold jet method immunomagnetic beads selection method,but the cell viability was worse.The cell viability following G418 selection method was bad,but the purity was high.

OBJECTIVETo evaluate the down stream involvement of the bile duct in hepatolithiasis.

METHODSMechanical damage to bile duct epithelia and long standing cholangitis as result of hepatolithiasis play an important role in the carcinogenesis of bile duct epithelia and stricture of the intra- and extra-hepatic bile duct. Macromorphological and microscopic changes in bile duct mucosa of 100 consecutive patients with hepatolithiasis were investigated using intra- or post-operative cholangioscopy. Biopsy specimens of lesions obtained during cholangioscopy were studied with immunohistochemical staining and flow cytometry to determine proliferative activity and DNA content. Five cases of well-proven cholangiocarcinoma were simultaneously studied as controls.

RESULTSOf the 100 patients, those with chronic cholangitis accounted for 86% (86/100), proliferative lesions 11% (11/100), adenomatous polyps 1% (1/100), and adenocarcinoma 2% (2/100). The obvious mucosal lesion associated with hepatolithiasis was located down-stream of the bile duct, predominantly in the hilar region, e.g. orifices of the right/left hepatic duct and common hepatic duct (73% mucosa lesions in the hilar region). The intensity of cancer embryonic antigen stain and the proliferative cell nuclear antigen index increased with the development of bile duct lesions. Aneuploid DNA presented mainly in the high degree malignant adenocarcinomas (> 80% of cases).

CONCLUSIONSThe obvious mucosal lesions associated with hepatolithiasis were located down-stream of the bile duct, predominantly in the hilar region (73% of mucosal lesions). The proliferative activity of examined bile duct mucosa lesions increased with the development of pathological deterioration, which may contribute to the development of hilar bile duct stricture and hilar cholangiocarcinoma.

Adult ; Aged ; Bile Ducts ; pathology ; Carcinoembryonic Antigen ; analysis ; Cholangiocarcinoma ; etiology ; Humans ; Lithiasis ; complications ; pathology ; Liver Diseases ; complications ; pathology ; Middle Aged ; Proliferating Cell Nuclear Antigen ; analysis

Objective:To analyze the changes of serum metabolomics in rats with combined injuries caused by gas explosion and explore its possible mechanism.Methods:In April 2018, the large coal mine gas explosion test roadway and explosion test system were used to simulate the gas explosion experiment. All 32 SD rats were randomly divided into four groups, control group (not involved in the explosion) , close range (40 m) group, medium range (160 m) group and long range (240 m) group, 8 in each group. The respiratory function at 2 hours and the neural behavior at 48 hours were detected after the explosion. The rats were anesthetized and sacrificed after 48 hours, and the serum, lung, liver and other tissues of the rats were isolated and histopathological changes of lung and liver tissues were observed by HE staining. Serum samples were detected by liquid chromatography-high resolution mass spectrometry (UPLC-Orbitrap Elite/MS) , and metabolic spectrum differences between groups were evaluated by principal component analysis. Differential metabolites were screened and identified, and metabolic pathways were analyzed.Results:Compared with control group, respiratory function indexes (respiratory frequency, minute ventilation, peak inspiratory flow rate, peak expiratory flow rate and 1/2 tidal volume expiratory flow) of rats in different explosion groups were significantly decreased ( P<0.05) , but respiration pause, inspiratory time and 2/3 tidal volume required time were significantly increased ( P<0.05) in 2 hours after the explosion. However, the residence times of the neurobehavioral indicators of the 40 m group and 160 m group were significantly increased ( P<0.05) , and the movement distances were significantly decreased ( P<0.05) in 48 hours after the explosion. HE staining results showed that the lung and liver tissues of the rats in the gas explosion group structurally damaged, and the cells were disordered, with inflammatory cell infiltration, bleeding and edema. Metabonomics analysis showed that there were significant differences in metabolic profiles between groups. A total of 18 differential metabolites were identified in serum samples, including aconitum acid, citric acid, niacinamide and pyruvate, which involved in 12 major metabolic pathways, including the glutamic acid and glutamine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, glyoxylic acid and dicarboxylic acid metabolism, phenylalanine metabolism, nicotinic acid and nicotinamide metabolism, citric acid cycle (TCA cycle) . Conclusion:Gas explosion can cause multi-organ system damage in rats, the mechanism of which may be related to the biosynthesis of alanine, tyrosine and tryptophan, metabolism of niacin and niacinamide, metabolism of acetaldehyde and dicarboxylic acid, and TCA cycle, etc.

Objective:To analyze the changes of serum metabolomics in rats with combined injuries caused by gas explosion and explore its possible mechanism.Methods:In April 2018, the large coal mine gas explosion test roadway and explosion test system were used to simulate the gas explosion experiment. All 32 SD rats were randomly divided into four groups, control group (not involved in the explosion) , close range (40 m) group, medium range (160 m) group and long range (240 m) group, 8 in each group. The respiratory function at 2 hours and the neural behavior at 48 hours were detected after the explosion. The rats were anesthetized and sacrificed after 48 hours, and the serum, lung, liver and other tissues of the rats were isolated and histopathological changes of lung and liver tissues were observed by HE staining. Serum samples were detected by liquid chromatography-high resolution mass spectrometry (UPLC-Orbitrap Elite/MS) , and metabolic spectrum differences between groups were evaluated by principal component analysis. Differential metabolites were screened and identified, and metabolic pathways were analyzed.Results:Compared with control group, respiratory function indexes (respiratory frequency, minute ventilation, peak inspiratory flow rate, peak expiratory flow rate and 1/2 tidal volume expiratory flow) of rats in different explosion groups were significantly decreased ( P<0.05) , but respiration pause, inspiratory time and 2/3 tidal volume required time were significantly increased ( P<0.05) in 2 hours after the explosion. However, the residence times of the neurobehavioral indicators of the 40 m group and 160 m group were significantly increased ( P<0.05) , and the movement distances were significantly decreased ( P<0.05) in 48 hours after the explosion. HE staining results showed that the lung and liver tissues of the rats in the gas explosion group structurally damaged, and the cells were disordered, with inflammatory cell infiltration, bleeding and edema. Metabonomics analysis showed that there were significant differences in metabolic profiles between groups. A total of 18 differential metabolites were identified in serum samples, including aconitum acid, citric acid, niacinamide and pyruvate, which involved in 12 major metabolic pathways, including the glutamic acid and glutamine metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, glyoxylic acid and dicarboxylic acid metabolism, phenylalanine metabolism, nicotinic acid and nicotinamide metabolism, citric acid cycle (TCA cycle) . Conclusion:Gas explosion can cause multi-organ system damage in rats, the mechanism of which may be related to the biosynthesis of alanine, tyrosine and tryptophan, metabolism of niacin and niacinamide, metabolism of acetaldehyde and dicarboxylic acid, and TCA cycle, etc.

Objective:To investigates the role and mechanism of ferroptosis in combined burn-blast injury with acute lung injury in rats.Methods:This study was an experimental study. Twenty-four 8-week-old male Sprague-Dawley rats were divided into control group and experimental group by random number table method, each containing 12 animals. The rats in experimental group were anesthetized and subjected to explosion treatment to create the model of combined burn-blast injury with acute lung injury, whereas the rats in control group underwent sham injury. At 24 hours post injury, the pathological morphology of lung tissue was observed by hematoxylin-eosin staining and immunohistochemical staining. The levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6 in the supernatant of bronchoalveolar lavage fluid (BALF) were detected by enzyme-linked immunosorbent assay. The arterial partial pressure of oxygen (PaO 2) and arterial partial pressure of carbon dioxide (PaCO 2) of abdominal aortic blood were measured by automatic animal blood gas analyzer. The lung tissue was weighed and the wet-dry weight ratio was calculated. The total protein concentration in BALF was measured by bicinchoninic acid assay. Lung injury was scored based on hematoxylin-eosin staining. The levels of oxidative stress factors, such as reactive oxygen species, malondialdehyde, superoxide dismutase (SOD), glutathione, and ferrous ion in lung tissue homogenate of rats were detected by related kits. The expression levels of ferroptosis-related molecule glutathione peroxidase 4 (GPX4), lipid peroxidation-related molecule 4-hydroxynonenal (4-HNE), and oxidative DNA damage-related molecule 8-hydroxydeoxyguanosine (8-OHdG) in lung tissue were detected by immunofluorescence and immunohistochemistry methods. Mitochondrial morphology in lung tissue cells was observed under transmission electron microscopy. The sample number was all 6. Results:At 24 hours post injury, the lung tissue structure of rats in control group was clear and complete, and the alveolar wall was normal; in experimental group, the lung tissue edema of rats was obvious, the alveolar wall became thicker, and the structure was not clear. At 24 hours post injury, compared with those in control group, the levels of TNF-α, IL-1β, and IL-6 in BALF supernatant of rats in experimental group were significantly increased (with t values of 3.96, 9.84, and 10.60, respectively, P<0.05); the wet-dry weight ratio of lung tissue, lung injury score, and total protein concentration in BALF of rats in experimental group were significantly increased (with t values of 6.91, 6.64, and 10.04, respectively, P<0.05), PaO 2 of abdominal aortic blood decreased significantly ( t=8.85, P<0.05) while PaCO 2 did not change significantly ( P>0.05); the levels of SOD and glutathione in the lung tissue homogenate of rats in experimental group were significantly decreased (with t values of 4.36 and 8.56, respectively, P<0.05), while the levels of reactive oxygen species, malondialdehyde, and ferrous ion were significantly increased (with t values of 11.55, 9.78, and 14.77, respectively, P<0.05). At 24 hours post injury, immunofluorescence staining and immunohistochemical staining showed that the expression levels of GPX4 in lung tissue of rats in experimental group were 0.245±0.024 and 0.786±0.240, respectively, which were significantly lower than 1.000±0.305 and 1.000±0.200 in control group (with t values of 6.05 and 2.60, respectively, P<0.05); the expression levels of 4-HNE in lung tissue of rats in experimental group were 5.93±1.05 and 2.21±0.23, respectively, which were significantly higher than 1.00±0.29 and 1.00±0.23 in control group (with t values of 11.13 and 9.16, respectively, P<0.05); the expression levels of 8-OHdG in lung tissue of rats in experimental group were 2.08±0.40 and 1.61±0.29, respectively, which were significantly higher than 1.00±0.40 and 1.00±0.26 in control group (with t values of 4.72 and 3.87, respectively, P<0.05). At 24 hours post injury, compared with that in control group, the density of mitochondrial double-layer membrane in the lung tissue cells of rats in experimental group increased, the outer membrane ruptured, and the crista decreased. Conclusions:In rats with combined burn-blast injury with acute lung injury, there is oxidative DNA damage in lung tissue cells, the imbalance of antioxidant system in lung tissue, and a decrease in the expression of GPX4, the key molecule against ferroptosis, suggesting that ferroptosis is involved in the pathophysiological process of this disease.