Objective To explore the protective effect of L-carnitine on myocardial systolic dysfunction in sepsis and its underlying mechanism.Methods A mouse sepsis model was established by cecal ligation and puncture(CLP).Ten-week-old male SPF-grade C57BL/6 mice(body weight 20～30 g)were randomly divided into 5 groups via random number table:Sham group,Sepsis group,L-carnitine group,L-carnitine+Etomoxir(Eto)group,and Eto group.Echocardiography assessed cardiac function,ELISA measured serum creatine kinase isoenzyme MB(CK-MB)levels,and 72-hour survival rates were recorded to evaluate L-carnitine's effects on cardiac function.Cardiomyocytes were isolated,and a cell microtensiometer was used to detect cardiomyocyte contractile function and calcium transients.Myocardial tissues were collected from each group,and ELISA was used to determine the contents of triglyceride(TG),free fatty acid(FFA),and adenosine triphosphate(ATP).An in vitro sepsis model was constructed by stimulating HL-1 cardiomyocytes with lipopolysaccharide(LPS)for 12 hours,which was divided into 5 groups:control(CTRL)group,LPS group,L-carnitine group,L-carnitine+Eto group,and Eto group.ELISA was used to detect the contents of TG,FFA,and ATP as well as the activity of carnitine palmitoyltransferase 1A(CPT1A)in cardiomyocytes.A cellular energy metabolism analysis system was employed to measure fatty acid oxidation capacity,and Western blot was used to detect the protein expression of CPT1A in cardiomyocytes.BODIPY-FL-C16(green fluorescently labeled palmitic acid)was utilized to detect the distribution of fatty acids in the cytoplasm and mitochondria via immunofluorescence technology,thereby observing the ability of cells to transport fatty acids into mitochondria.Results Compared with the Sham group,cardiac function was significantly impaired in the Sepsis group,as evidenced by decreased ejection fraction and mean arterial pressure(P<0.05),along with elevated levels of the cardiac injury marker CK-MB(P<0.05).Treatment with L-carnitine significantly improved myocardial function,restored blood pressure in septic mice,and increased their survival rate from 12.50%to 81.25%(P<0.05).Compared with the Sham group,the contractile function and calcium transients of acutely isolated single cardiomyocytes were significantly reduced in the Sepsis group(P<0.05),while L-carnitine treatment remarkably restored the contractile function and calcium release capacity of septic cardiomyocytes(P<0.05).Both in vivo and in vitro experiments showed that TG and FFA levels were significantly increased(P<0.05),and ATP levels was significantly decreased(P<0.05)in the Sepsis and LPS groups—effects significantly reversed by L-carnitine treatment.Compared with the CTRL group,the basal oxidation rate and maximum oxidation capacity of fatty acids in cardiomyocytes of the LPS group were significantly reduced(P<0.05),and L-carnitine treatment notably improved these indicators.Compared with the CTRL group,the expression and activity of CPT1A in cardiomyocytes of the LPS group were significantly decreased(P<0.05),while L-carnitine treatment significantly increased the expression and activity of CPT1A(P<0.05).In LPS group cardiomyocytes,green fluorescently labeled palmitic acid primarily formed numerous granular/clumpy aggregates in the cytoplasm with minimal mitochondrial colocalization.In the L-carnitine group,the green fluorescent granules in the cytoplasm of cardiomyocytes were smaller,and colocalization with mitochondria was increased.However,the L-carnitine+Eto group exhibited similar phenomena to the LPS group.In addition,both in vivo and in vitro experiments demonstrated that treatment with the CPT1A inhibitor Eto reversed the effect of L-carnitine.Compared with the L-carnitine group,the ATP content in the L-carnitine+Eto group was significantly decreased(P<0.05),while the FFA content was significantly increased(P<0.05).Conclusion L-carnitine facilitates fatty acid entry into mitochondria for β-oxidation via a CPT1A-dependent mechanism,thereby ameliorating fatty acid oxidation dysfunction in septic cardiomyocytes and improving myocardial contractile function.

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.

Objective To determine the therapeutic effect of fasciotomy+hypertonic saline flushing for crush syndrome(CS)in rats.Methods SD rats(weighing 250±20 g)were randomly divided into normal control group(NC group,n=10)and CS group(n=14).Rat CS model was established by compressing the buttocks and both hindlimbs with a weight of 7.5 kg for 4 h,and the presence of hematuria or anuria was defined as success of modeling.In 6 h after modeling,the fluid exuded from the compressed tissues was collected,and the contents of potassium ions(K+),calcium ions(Ca2+),myoglobin(Mb),and lactic acid(Lac)in the exudate of each group were detected.Another 63 male SD rats(weighing 250±20 g)were randomly and equally divided into blank control group(NC group),CS group,CS+fasciotomy group(CSO group),and CS+fasciotomy+difference doses of NaCl solution irrigation groups(0.9％,3.0％,5.0％and 7.0％NaCl,respectively).At 6 h after modeling,the renal blood flow was measured,the contents of K+,Ca2+,Mb,Lac,AST,ALT,Cr,and urea in the plasma of each group were detected,and the compressed tissues and kidney tissues were observed for pathological changes.Results Detection of exudates showed the contents of K+,Mb,and Lac were significantly higher,while that of Ca2+content was obviously decreased in the CS group than the NC group(P＜0.01).Plasma detection indicated that simple fasciotomy had no therapeutic effect,while it combined with NaCl solution flushing decreased the contents of K+,Mb,Lac,AST,ALT,urea and Cr,and increased the Ca2+content in the blood of the CS group(P＜0.05).Laser speckle contrast imaging revealed that simple fasciotomy could not increase renal blood flow,while the combination of fasciotomy and NaCl solution flushing notably increased the renal blood flow in the CS rats(P＜0.05).In addition,the combination treatment reduced the pathological damage in the kidneys induced by CS,but fasciotomy alone had no such effect(P＜0.5).Conclusion Fasciotomy combined with hypertonic NaCl solution(3％)flushing can significantly reduce the damage caused by CS in rats.

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.

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.

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: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