Objective To study the protective effects of ischemic preconditioning(IP) duration against ischemic reperfusion injury of skeletal muscle. Methods Thirty-six Wister rats were made amputation-like models, which underwent temporary amputation at the level of the femur, excluding the femoral vessels. They were divided into 6 groups(n=6) according to different treatments before ischemiareperfusion: group A(4 hours of ischemiareperfusion); groups B, C, D, E(5, 10,15, 20 minutes of ischemia and 5, 10, 15, 20 minutes of reperfusion respectively, for 3 cycles, 4 hours ischemiareperfusion ); group F (no ischemia-reperfusion). The malondialdehyde(MDA), the extent of edema and necrosis of skeletal muscle were measured to observe protective effects of different ischemic preconditioning duration. Results Five minutes of ischemic preconditioning（IP5）could protect skeletal muscle of ischaemia against necrosis and the survival area of the muscle was 82.47%.The effects of IP10 and IP 15 were significantly superior to that of IP5 and the survival areas of the muscle were 89.03% and 89.49%. The effect of IP20(78.27%) was significantly inferior to that IP5. IP5 could reduce edema of skeletal muscle, the effect of IP10 was significantly superior to that of IP5. IP5, IP 10,and IP 15 could decrease the level of MDA, but IP20 did not decrease it. Conclusion The trend of protective effect of IP on ischemia-reperfusion injury of themuscle in rats first rise to the peak and then go down,10minutes ofIPis optimal.
To explore the relationship between the drug-seeking behavior, motivation of conditioned place preference (CPP) rats and the frontal association cortex (FrA) electroencephalogram (EEG) sample entropy, we in this paper present our studies on the FrA EEG sample entropy of control group rats and CPP group rats, respectively. We invested different behavior in four situations of the rat activities, i.e. rats were staying in black chamber of videoed boxes, those staying in white chamber of videoed boxes, those shuttling between black-white chambers and those shuttling between white-black chambers. The experimental results showed that, compared with the control group rats, the FrA EEG sample entropy of CPP rats staying in black chamber of video box and shuttling between white-black chambers had no significant difference. However, sample entropy is significantly smaller (P < 0.01) when heroin-induced group rats stayed in white chamber of video box and shuttled between black-white chambers. Consequently, the drug-seeking behavior and motivation of CPP rats correlated closely with the EEG sample entropy changes.
ObjectiveTo summarize recent researches on mechanism of the hepatic ischemic preconditioning (IPC) and its clinical applications on hepatectomy and liver transplantation. MethodsRelevant references about basic and clinical researches of hepatic IPC were collected and reviewed. ResultsRecent experimental researches indicated that IPC could relieve hepatic ischemiareperfusion injury (IRI) by remaining and improving energy metabolism of liver, regulating microcirculation disorder, decreasing the production of lipid peroxidation and oxyradical. It could also inhibit the activation of inflammatory cells and the release of cytokine, suppress cell apoptosis and induce the release of endogenous protective substance. Till now, most of the clinical researches had confirmed the protective function of hepatic IPC, but there were still some references with opposite opinions. ConclusionHepatic IPC could relieve liver IRI, but its clinical application value on hepatectomy and liver transplantation still need more researches to prove.
Objective To analyze the clinical characteristics and the treatment of 20 confirmed A/H1N1 flu cases of serious conditions. Methods The 20 confirmed A/H1N1 flu cases of serious conditions were collected and we analyzed their Clinical characteristics, treatment and prognosis. Results The 20 cases of serious conditions were given Oseltamivir, endotrachealintubation, ventilator ventilator assistant, high dose intravenous injection of Gamma-globulin/ albuminum/plasam of A/H1N1 flu rehabilitation, appropriate liquid recovery and hypothermic treatment, etc. A total of 19 of 20 confirmed A/H1N1 flu cases of serious conditions were cured and 1 case died. Conclusion The intent observation, early detection and early intervention are very helpful for A/H1N1 flu cases of serious conditions.
ObjectiveTo investigate the effect of simvastatin and mechanical pretreatment on intimal hyperplasia of venous graft and its mechanism.MethodsTwelve New Zealand rabbits were selected and randomly divided into 4 groups: a blank control group, a simvastatin topical treatment group, a mechanical precondition group and a combined group (n=3 in each group). Ultrasound was used to evaluate the changes of graft wall and blood flow velocity in the graft, and pathological section was used to evaluate the intimal hyperplasia. Human umbilical cord endodermal cells were cultured in vitro. A simvastatin group and a solvent control group were set to detect YAP phosphorylation, downstream target gene expression and cell proliferation.ResultsVascular ultrasound showed that except the simvastatin topical treatment group, the flow velocity in vein grafts in the other three groups significantly increased 21 days after surgery compared with 7 days after surgery (P<0.01). Pathological sections showed that the thickness of new intima in the simvastatin topical treatment group, mechanical precondition group, combined group and blank control group were 45.56±4.11 μm, 201.28±16.71 μm, 143.57±7.82 μm, 249.45±13.33 μm, respectively, and there were statistical differences compared with the blank control group (P<0.05). In vitro results showed that compared with the solvent control group, cell death was observed in high concentration simvastatin (5 mmol/L) group, cell proliferation was inhibited in low concentration simvastatin (2.5 mmol/L) group (P<0.05), the expression of YAP protein in the simvastatin group was unchanged, but the expression of phosphorylated YAP protein significantly increased (P<0.05), and the expression of downstream target gene ccn1 was down-regulated (P<0.001).ConclusionIntravascular local application of simvastatin and mechanical preconditioning alone or in combination can inhibit intimal hyperplasia of venous graft. High concentration of simvastatin has cytotoxicity, while low concentration of simvastatin has inhibitory effect on cell proliferation. Simvastatin can inhibit the formation of new intima by inhibiting the entry of YAP into the nucleus and reducing the transcription of cell proliferation-related target gene ccn1.
Objective To study the diagnostic and prognostic value of serum soluble triggering receptor expressed on myeloid cell-1 (sTREM-1) and cyclooxygenase-2 (COX-2) in abdominal infection-caused sepsis. Methods A total of 170 patients with abdominal infection treated in the First Hospital of Qinhuangdao between January 2019 and March 2022 were retrospectively selected and divided into sepsis group (n=76) and non-sepsis group (n=94) according to whether they were combined with abdominal infection-caused sepsis. In addition, 80 healthy people in the same period were selected as the control group. The levels of serum sTREM-1 and COX-2 in the three groups were detected and the differences were compared. The laboratory indexes, including white blood cell count, high-sensitivity C-reactive protein, and procalcitonin of patients with abdominal infection-caused sepsis were detected. The Sequential Organ Failure Assessment score, Acute Physiology and Chronic Health Evaluation System Ⅱ and prognosis (survival or death) of patients with abdominal infection-caused sepsis were evaluated. The correlations of serum sTREM-1 and COX-2 with the severity of sepsis were analyzed, and the diagnostic and prognostic value of sTREM-1 and COX-2 in abdominal infection-caused sepsis was assessed. Results The levels of serum sTREM-1 and COX-2 in the sepsis group were higher than those in the control group and the non-sepsis group (P<0.05). The levels of serum sTREM-1 and COX-2 in the sepsis group were positively correlated with white blood cell count, high-sensitivity C-reactive protein, procalcitonin, Sequential Organ Failure Assessment score, Acute Physiology and Chronic Health Evaluation System Ⅱ score (P<0.05). The serum levels of sTREM-1 and COX-2 of patients who died during hospitalization in the sepsis group were higher than those of the surviving patients. The areas under the receiver operating characteristic curves of the serum sTREM-1 and COX-2 levels for diagnosing sepsis caused by abdominal infection were 0.814 [95% confidence interval (CI) (0.746, 0.882), P<0.001] and 0.848 [95%CI (0.788, 0.905), P<0.001], respectively, with critical values of 1.879 pg/mL and 18.75 ng/mL, respectively, and those for predicting the prognosis of patients with sepsis caused by abdominal infection were 0.775 [95%CI (0.659, 0.890), P<0.001] and 0.784 [95%CI (0.679, 0.889), P<0.001], respectively, with critical values of 2.283 pg/mL and 23.02 ng/mL, respectively (P<0.05). Conclusion The serum levels of sTREM-1 and COX-2 have certain value in the diagnosis and prognosis prediction of abdominal infection-caused sepsis.
Objective To investigate the protection on the intrahepatic cholangiocyte mediated by hypoxic preconditioning (HP) after liver transplantation and the role of vascular endothelial growth factor (VEGF). Methods The model of autologous liver transplantation was established, and the rats were divided into 3 groups: autologous liver transplantation group, hypoxic preconditioning before operation group (HP group) and sham operation group. At 6, 12, 24, 48 h after operation, blood samples were collected for examination of the serum total bilirubin (TBIL), direct bilirubin (DBIL) and alkaline phosphatase (ALP), and the expression of VEGF was detected by immunohistochemical method. The pathological changes of cholangiocytes were observed by light microscope. Results As compared with autologous liver transplantation group, the levels of seurm TBIL, DBIL and ALP in HP group were lower (P＜0.05), while the expression of VEGF in HP group was higher at the whole process (P＜0.05). The degrees of billiary epithelium damage and inflammatory infiltration in autologous liver transplantation group were more severe than those in HP group. Conclusion HP has protective effect on cholangiocytes after liver transplantation, in which VEGF may play an important role.
Objective Isoflurane has an acute preconditioning effectiveness against ischemia in kidney, but this beneficial effectiveness can only last for 2-3 hours. To investigate whether isoflurane produces delayed preconditioningagainst renal ischemia/reperfusion (I/R) injury, and whether this process is mediated by hypoxia inducible factor 1α(HIF- 1α). Methods A total of 52 male C57BL/6 mice were randomly assigned to 4 groups (n=13 in each group): the controlgroup (group A), PBS/isoflurane treated group (group B), scrambled small interference RNA (siRNA)/isoflurane treated group (group C), and HIF-1α siRNA/isoflurane treated group (group D). In groups C and D, 1 mL RNase-free PBS containing 50 μg scrambled siRNA or HIF-1α siRNA was administered via tail vein 24 hours before gas exposure, respectively. Equivalent RNasefree PBS was given in groups A and B. Then the mice in groups B, C, and D were exposed to 1.5% isoflurne and 25%O2 for 2 hours; while the mice in group A received 25%O2 for 2 hours. After 24 hours, 5 mice in each group were sacrificed to assesse the expressions of HIF-1α and erythropoietin (EPO) in renal cortex by Western blot. Renal I/R injury was induced with bilateral renal pedicle occlusion for 25 minutes followed by 24 hours reperfusion on the other 8 mice. At the end of reperfusion, the serum creatinine (SCr), the blood urea nitrogen (BUN), and the histological grading were measured. Results The expressions of HIF-1α and EPO in groups B and C were significantly higher than those in group A (P lt; 0.01). The concentrations of SCr and BUN in groups B and C were significantly lower than those in group A, as well as the scores of tubules (P lt; 0.01), and the injury of kidney was amel iorated noticeably in groups B and C. The expressions of HIF-1α and the concentrations of SCr and BUN in group D were significantly lower than those in group A (P lt; 0.01). Compared with groups B and C, the expression of HIF- 1α and EPO in group D decreased markedly (P lt; 0.01), the concentrations of SCr and BUN were increased obviously, as well asthe scores of tubules (P lt; 0.01), and the renal injury was aggratived significantly. Conclusion Isoflurane produces delayed preconditioning against renal I/R injury, and this beneficial effectiveness may be mediated by HIF-1α.
Objective To explore the best centrifuge condition for preparing rabbit leukocyte-poor platelet-rich plasma (LP-PRP) by using single centrifugation method. Methods Sixteen healthy New Zealand rabbits, aged 3-4 months, were utilized in the investigation. A total of 15 mL anticoagulated blood was extracted from the central ear artery of each rabbit, with a repeat of the blood collection procedure after 1 and 2 months. The obtained blood specimens were individually subjected to centrifugation at a radius of 16.7 cm and speeds of 1 200, 1 300, 1 400, and 1 500 r/min (equivalent to centrifugal forces of 269×g, 315×g, 365×g, and 420×g) for durations of 2, 3, 4, and 5 minutes, resulting in a total of 16 groups. Following centrifugation, collect plasma from each group to a distance of 1.5 mL from the separation plane. The volumes, platelet enrichment coefficient, and platelet recovery rates of LP-PRP in each group, under varying centrifugation conditions, were methodically computed and subsequently compared. Results The volume of LP-PRP obtained under all centrifugation conditions ranged from 1.8 to 7.6 mL. At a consistent centrifugal speed, an extension of centrifugation time leaded to a significant increase in the volume of LP-PRP, accompanied by a declining trend in the platelet enrichment coefficient of LP-PRP. When centrifuged for 2 minutes, the volume of LP-PRP at speeds of 1 200 and 1 300 r/min was less than 2.0 mL, while the volume of LP-PRP obtained under other conditions was more than 2.0 mL. When centrifuged for 4 and 5 minutes, the volume of LP-PRP obtained at each speed was more than 4 mL. LP-PRP with a platelet enrichment coefficient more than 2.0 could be prepared by centrifuging at 1 200 r/min for each time group and 1 300 r/min for 2 and 3 minutes, and the highest LP-PRP platelet enrichment coefficient could be obtained by centrifugation for 2 minutes at a speed of 1 200 r/min. The platelet recovery rates of LP-PRP obtained by centrifugation at 1 200 r/min for 4 and 5 minutes, as well as centrifugation at 1 400 r/min for 5 minutes, were both greater than 60%. There was no significant difference between the groups when centrifuged at 1 200 r/min for 4 and 5 minutes (P>0.05). Conclusion In the process of preparing rabbit LP-PRP using a single centrifugation method, collecting 15 mL of blood and centrifuging at a radius of 16.7 cm and speed of 1 200 r/min for 4 minutes can prepare LP-PRP with a volume exceeding 2.0 mL, platelet enrichment coefficient exceeding 2.0, and platelet recovery rate exceeding 60%. This centrifugal condition can achieve the optimal LP-PRP action parameters in the shortest possible time.
Objective To investigate the protective effects of ischemic postconditioning (IPo) on ischemiareperfusion (I/R) myocardium and the relationship with mitochondrial adenosine triphosphate (ATP) sensitive K+ channels (mitoKATP) and provide evidences to the development of druginduced postconditioning. Methods Langendorff models were established in 40 Wistar rats which were divided into 5 groups by random number table with 8 rats in each group. Normal control group(NC group): the rat hearts were continuously reperfused by KrebsHenseleit bicarbonate buffer (K-HB) for 100 min without any other treatment; I/R group: the rat hearts underwent a 40-min global ischemia followed by a 60-min reperfusion; IPo group: after a 40-min global ischemia, the process of 10-second reperfusion followed by a 10-second ischemia was repeated 6 times, then there was a continuous 58min reperfusion; 5-hydroxydecanoic acid(5-HD) group: after a 40min global ischemia, hearts with 5HD(100 μmol/L) K-HB were reperfused for 15min and then perfused without 5HD for 45min；IPo+5-HD group: after a 40-min global ischemia, the process that the isolated hearts with 5-HD(100 μmol/L) KHB were reperfused for 10second followed by a 10second ischemia was repeated 6 times, then the hearts with 5-HD(100 μmol/L) KHB were continuously [CM(159mm]perfused for 13-min followed by reperfusion without 5-HD(100 μmol/L) K-HB for 45-min. The cardiac function,coronary flow(CF), cardiac troponin I(cTnI) content in coronary effluent, the area of acute myocardial infarction (AMI) and myocardial ultrastructure were observed. Results Left ventricular developed pressure(74.3±3.3 mm Hg vs. 57.1±3.3 mm Hg,t=1300, P=0.000),+dp/dtmax(1 706.6±135.6 mm Hg/s vs. 1 313.3±96.2 mm Hg/s,t=6.28,P=0.000),－dp/dtmax(1 132.8±112.1 mm Hg/s vs. 575.7±67.7 mm Hg/s,t=13.48, P=0.000) and CF(6.49±0.30 ml/min vs. 3.70±0.24 ml/min,t=28.6,P=0.000) in IPo group were higher than those in I/R group. Left ventricular enddiastolic pressure(10.9±1.7mm Hg vs. 26.2±1.5 mm Hg,t=－19.21, P=0000)and cTnI content in coronary effluent (0.62±0.01 ng/ml vs. 0.71±0.01 ng/ml, t=-12.00,P=0.000) were lower than those in I/R group; the area of AMI decreased 20.8％ compared with that in I/R group (Plt;0.05). The myocardial protective effect in IPo+5HD group was similar with that in IPo group, but lower than that in IPo group. The electron microscope showed that IPo and IPo+5HD could reduce myocardial fiber damage and mitochondrial damage caused by I/R. Conclusion IPo can protect I/R myocardium, which is achieved mainly by activating mitoK-ATP channels.