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Objective:To evaluate the value of preoperative prediction of vessel invasion (VI) of locally advanced gastric cancer by machine learning model based on the venous phase enhanced CT radiomics features.Methods:A retrospective analysis of 296 patients with locally advanced gastric cancer confirmed by pathology in the First Affiliated Hospital of Zhengzhou University from July 2011 to December 2020 was performed. The patients were divided into VI positive group ( n=213) and VI negative group ( n=83) based on pathological results. The data were divided into training set ( n=207) and test set ( n=89) according to the ratio of 7∶3 with stratification sampling. The clinical characteristics of patients were recorded, and the independent risk factors of gastric cancer VI were screened by multivariate logistic regression. Pyradiomics software was used to extract radiomic features from the venous phase enhanced CT images, and the minimum absolute shrinkage and selection algorithm (LASSO) was used to screen the features, obtain the optimal feature subset, and establish the radiomics signature. Four machine learning algorithms, including extreme gradient boosting (XGBoost), logistic, naive Bayes (GNB), and support vector machine (SVM) models, were used to build prediction models for the radiomics signature and the screened clinical independent risk factors. The efficacy of the model in predicting gastric cancer VI was evaluated by the receiver operating characteristic curve. Results:The degree of differentiation (OR=13.651, 95%CI 7.265-25.650, P=0.003), Lauren′s classification (OR=1.349, 95%CI 1.011-1.799, P=0.042) and CA199 (OR=1.796, 95%CI 1.406-2.186, P=0.044) were independent risk factors for predicting the VI of locally advanced gastric cancer. Based on the venous phase enhanced CT images, 864 quantitative features were extracted, and 18 best constructed radiomics signature were selected by LASSO. In the training set, the area under the curve (AUC) of XGBoost, logistic, GNB and SVM models for predicting gastric cancer VI were 0.914 (95%CI 0.875-0.953), 0.897 (95%CI 0.853-0.940), 0.880 (95%CI 0.832-0.928) and 0.814 (95%CI 0.755-0.873), respectively, and in the test set were 0.870 (95%CI 0.769-0.971), 0.877 (95%CI 0.788-0.964), 0.859 (95%CI 0.755-0.961) and 0.773 (95%CI 0.647-0.898). The logistic model had the largest AUC in the test set. Conclusions:The machine learning model based on the venous phase enhanced CT radiomics features has high efficacy in predicting the VI of locally advanced gastric cancer before the operation, and the logistic model demonstrates the best diagnostic efficacy.
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Endoscopic anterior fundoplication with the MUSE is an endoscopic therapy that combines ultrasound and endoscopic anti-reflux technology for moderate to severe gastroesophageal reflux disease. Training and learning procedures are required to obtain qualifications for this endoscopic therapy before clinical operations. At present, there is limited high-quality evidence-based medical evidence on MUSE treatment, and lack of expert consensus or guidance for training and the standard of MUSE therapy procedure. This consensus is based on the published literature, and formulated by experts with MUSE clinical experience in China, to provide guidance for the training and clinical standard operation of this technique.
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Objective:To analyze the difference and clinical significance of reflux related parameters between patients with reflux asthma (RA) and typical gastroesophageal reflux disease (TGERD).Methods:From June 2017 to June 2020, at PLA Rocket Force Characteristic Medical Center, the clinical data of 120 patients with gastroesophageal reflux disease (GERD) who underwent gastroscopy, high-resolution esophageal manometry (HREM) and 24 h pH-impedance monitoring contemporaneously were retrospectively analyzed. The GERD patients were divided into RA group and TGERD group according to the symptom correlated indexes, 60 cases in each group. The reflux related indexes of two groups were compared, which included reflux esophagitis (RE) score, esophageal hiatal hernia, Hill grade score of gastroesophageal flap valve, upper esophageal sphincter (UES) pressure, DeMeester score, and reflux episodes. Mann-Whitney U test and chi-square test were used for statistical analysis. Results:There were no significant differences in RE score and Hill grade score between TGERD group and RA group (0.0, 0.0 to 1.0 vs. 0.0, 0.0 to 1.8; 3.0, 2.0 to 3.0 vs. 3.0, 2.0 to 3.0) (both P>0.05). The detection rate of UES pressure less than 34 mmHg (1 mmHg=0.133 kPa) of RA group was higher than that of TGERD group (41.7%, 25/60 vs. 23.3%, 14/60), and the difference was statistically significant ( χ2=4.596, P=0.032). The UES pressure of RA group was lower than that of TGERD group (51.7 mmHg, 23.6 mmHg to 70.1 mmHg vs. 62.0 mmHg, 37.4 mmHg to 77.4 mmHg), and the difference was statistically significant ( Z=-2.105, P=0.035). There were no significant differences in other parameters of HREM between TGERD group and RA group (all P>0.05). The detection rates of DeMeester score more than 14.7, acid exposure time more than 4.5% and total reflux episodes more than 73 episodes of RA group were all higher than those of TGERD group (41.7%, 25/60 vs. 23.3%, 14/60; 40.0%, 24/60 vs. 21.7%, 13/60; 38.3%, 23/60 vs. 20.0%, 12/60, respectively), and the differences were all statistically significant ( χ2=5.546, 4.728 and 4.881, all P<0.05). The total reflux episodes and weak acid gas reflux episodes of RA group were both higher than those of TGERD group (60 episodes, 43 episodes to 98 episodes vs. 52 episodes, 34 episodes to 69 episodes; 12 episodes, 6 episodes to 21 episodes vs. 9 episodes, 3 episodes to 14 episodes), and the differences were statistically significant ( Z=-2.323 and -2.053, both P<0.05). There were no significant differences in other parameters of 24 h pH-impedance monitoring between TGERD group and RA group (all P>0.05). Conclusion:Low UES pressure, abnormal esophageal acid exposure and increased reflux episodes, especially weak acid gas reflux episodes, may be more likely to induce RA.
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This exploratory study attempted to establish the rules in diagnosis and treatment of diabetic foot, through interpretation and comparison of the guidelines for diabetic foot from domestic with international ones. The document provided comparison between Guidelines of International Working Group on Diabetic Foot (IWGDF) and Chinese Diabetes Society (CDS) in 2019, related to diabetic foot disease on: methodology, content, prevention, offloading, peripheral artery disease (PAD), infection, wound healing interventions, and classification of diabetic foot ulcers. Prevention of ulcers in persons with diabetes foot is very important, and a non-removable offloading device is the first-choice of offloading treatment; Surgical indications and reasonable treatment should be mastered in PAD; Different anti-infection treatments, including surgical debridement, should be used base on the severity of foot infection; There are lots of treatments to improve healing, however the Grand Standard of medical evidence is not very high; There are a larger number of proposed classifications and scoring systems for diabetic foot, but none of them could cover all the needs of diagnosis and treatment. Thus, the principles outlined have to be adapted or modified by our health care professionals, based on local circumstances, to develop a standardizated procedure in diagnosis and treatment of diabetic foot.
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Objective To investigate the protective effect of safflower extract on hepatocyte mitochondria in hepatic fibrosis rats.Methods Rat model of hepatic fibrosis was induced by diethyl nitrosamine.Oral safflower extract was taken orally in the experimental group.Hepatic mitochondria were isolated from each group.Morphological changes of hepatocyte mitochondria were observed and MDA and SOD were detected in the level hepatocyte mitochondria.Observe changes in mitochondrial membrane potential and mitochondrial ATP levels and observe changes in mitochondrial respiratory function to investigate whether safflower extract has protective effects on hepatocyte mitochondria in rats with hepatic fibrosis or not.Results In the normal group,the rat mitochondria were arranged neatly and the morphology was normal.In the control group,the mitochondria of the rats were swollen with irregular morphology,the borders were unclear,and the sizes were inconsistent.In the experimental group,the mitochondria were swollen,the structures were not clear,and the sizes were different.The above condition is significantly improved;liver fibrosis in rats' mitochondria MDA levels increased significantly,while SOD content decreased significantly,safflower extract treatment can significantly reduce mitochondrial MDA levels,and it can increase SOD content.Compared with the normal group,the mitochondrial membrane potential of liver fibrosis rats was significantly reduced,while the safflower extract treatment can increase the mitochondrial membrane potential;due to liver fibrosis,rats can increase the consumption of ATP in liver mitochondria and safflower extract can significantly reduce ATP consumption in rat mitochondria.Consistent with this,the phosphor-to-oxygen ratio in the rat mitochondria of the experimental group was significantly higher than that of the control group.Conclusion The safflower extract can significantly reduce the hepatocyte mitochondrial oxidative stress induced by hepatic fibrosis in rats.It can maintain mitochondrial ATP level,respiratory control rate and phosphorus-oxygen ratio to protect mitochondrial function.
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Distortion will occur when testing medical microwave products, due to its high power, high frequency, in the existing radiated emission testing process which will cause saturation non-linear of the pre-amplifier. It will lead to test distorted, the test results are not accurate. This article will improve the original test method by adding some suppressing-frequency devices to suppress the main frequency energy and avoid pre-amplifier saturation, eliminate distortion. All of this will ensure the test results are effective and relia ble.
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Amplifiers, Electronic , Equipment Design , Equipment and Supplies , Materials Testing , MicrowavesABSTRACT
Spinal cord injury (SCI) is a common traumatic disease. SCI causes nutritional and metabolic abnormalities including malnu-trition and overnutrition. This article reviewed nutritional metabolism assessments, the changes and reasons after SCI. Spinal Nutrition Screening Tool (SNST) and Malnutrition Universal Screening Tool (MUST) are commonly used to evaluate malnutrition in adult. Screening Tool for the Assessment of Malnutrition in Paediatrics (STAMP) is used to evaluate malnutrition in child. Body mass index, waist circumfer-ence and dual-energy X-ray are used to evaluate overnutrition. SCI causes increasement of total caloric intake, disturbance of carbohydrate metabolism, disturbance of fat and protein metabolism, increasement of metabolic syndrome incidence, high risk of coronary heart disease, and abnormal bone metabolism. Individual diet program should be provided to SCI patients for balanced nutrition. Periodic assessments are also necessary.
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Objective To evaluate the effectiveness and complications of laparoscopic repair for hiatal hernia.Methods The clinical data of 992 patients with hiatal hernia undergoing laparoscopic repair from Jan 2008 to June 2014 were collected and analyzed.Postoperative symptom scores,postoperative complications,recurrence rate and satisfaction were evaluated.Results 858 cases were followed up,including type Ⅰ HH accounting for 79.8％,type Ⅱ for 1.3％,type Ⅲ for 17.1％,type Ⅳ for 1.8％ respectively.HH repaired with mesh in 520 cases.The overall improvement rate was 96.2％.Postoperative symptom scores significantly decreased.Recurrence of anatomy and symptoms were 31 and 15 cases respectively.Short-term and long-term of postoperative complications were 35.8％ and 5.6％ respectively.Excellent,fair and poor result were achieved in 91.8％,4.3％,3.9％ of postoperatively follow-up cases,respectively.Conclusion The laparoscopic approach for repair of hiatal hernias is of minimally invasive,lower recurrence rate,less complications and high satisfaction.
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Objective To investigate the clinical effect and immunologic function of Moxifloxacin combined with small dose of hormone in the treatment of Ventilator pneumonia in elder.Methods 64 cases of Ventilator pneumonia in our hospital were collected and randomly divided into experiment group and control group, 32 cases each.Two groups were given conventional treatment, the control group received Methylprednisolone Sodium Succinate 1 mg/kg qd, the experiment group was given Methylprednisolone Sodium Succinate 1 mg/kg qd, and Moxifloxacin Hydrochloride and Sodium Chloride Injection 400 mg qd.Two groups of patients were continuous treated for 10 days.After treatment,T lymphocyte subsets, NK cells, white blood cell count, C reactive protein, clinical symptoms disappeared time, mechanical ventilation time, ICU length of stay and mortality rate were compared. Results After treatment, the total effective rate in the experiment group 75% was higher than the control group 50%( P <0.05 ).The levels CD3 +, CD4 +, CD4 +/CD8 +and NK cell in two groups increased(P<0.05), levels of CD8 +decreased(P<0.05),levels of WBC, CPR and PCT decreased in the two groups(P<0.05), and compared with the control group, the levels CD3 +, CD4 +, CD4 +/CD8 +and NK cell in the experiment group were higher(P<0.05), levels of CD8 + were lower(P<0.05),levels of WBC,CPR and PCT were lower(P <0.05), the rales disappeared time, cough disappeared time, fever disappeared time were significantly shorter than the control group(P <0.05), the duration of mechanical ventilation and the length of hospital stay were significantly shorter(P<0.05).Conclusion Moxifloxacin combined with small dose of hormone in the treatment of Ventilator pneumonia in elder was significantly effective, and it can relieve inflammation, prevention of infection control, enhance immune function.
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<p><b>OBJECTIVE</b>To investigate the efficacy and safety of laparoscopic fundoplication for gastroesophageal reflux disease (GERD)-related cough.</p><p><b>METHODS</b>Retrospective review of 70 patients with GERD-related cough who received laparoscopic fundoplication in GERD Department of The Second Artillery General Hospital during June 2008 to June 2013 was carried out. GERD-related symptoms (reflux, heartburn, cough, expectoration, globus sensation and hoarseness) before and after surgery were compared through questionnaire, and the symptom remission rate (preoperative symptom score - postoperative symptom score)/preoperative symptom score×100%) was calculated. Complication morbidity and satisfaction degree of patients were investigated.</p><p><b>RESULTS</b>The GERD-related symptom scores of regurgitation, heartburn, cough, expectoration, globus sensation and hoarseness all significantly decreased (all P<0.01) after the anti-reflux laparoscopic fundoplication, with the corresponding symptom remission rates as (79.4±23.2)%, (82.0±21.5)%, (72.2±28.5)%, (62.6±28.9)%, (76.1±31.5)% and (70.8±39.3)% respectively. No major complication and death occurred. Five cases (7.1%) had pneumoperitoneum-related chest or neck subcutaneous emphysema, 17 cases (24.3% ) had various degree of early and late dysphagia, 6 cases (8.6%) had increased flatus and 2 cases had bloating after surgery. All the complications could be cured by appropriate treatment. Among all the patients, 16 cases (15.7%) felt very satisfied, 37 cases (52.9%) felt satisfied, 11 cases (15.7%) felt acceptable, 4 cases (5.7%) felt unsatisfied and 2 cases felt very unsatisfied with the surgery.</p><p><b>CONCLUSION</b>Laparoscopic fundoplication is safe and effective for GERD-related cough, with quite high satisfaction degree form patients.</p>
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Humans , Cough , Deglutition Disorders , Fundoplication , Gastroesophageal Reflux , Laparoscopy , Retrospective Studies , Surveys and QuestionnairesABSTRACT
With the enforcement of YY 0505-2012 standard,more attention has been paid to the electromagnetic compatibility test of medical electrical equipment.In all the test items involved in YY 0505-2012,the radiation emission test is the most complicated and the hardest to be passed,so it is very important to master the test method.Microwave therapy equipment is a kind of equipment using microwave radiation energy to treat diseases,and is supervised as class Ⅲ medical equipment.According to the requirements of the relevant standards,all the electromagnetic compatibility testing items of microwave equipment are listed,and the test difficulty and the test focus of the equipment are studied.In the frequency band of the radiation emission experiment,microwave treatment equipment is divided into different categories according to the purpose and environment of the application.By comparing the data of the tests,the differences of different classes of microwave treatment equipment in the radiation emission tests are summarized.
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[Summary] To investigate the effect of microRNA126 on glucose metabolism in the normal liver cell lines. In vitro, the chang liver cell lines were cultured. Under the most effective transfection conditions ascertained above, microRNA126 mimic, microRNA126 inhibitor, and relative negative control were transfected into the cultured normal liver cells. And the transfection efficiency was tested by realtime fluorescent quantitative PCR. After 48 hours, the cells were stimulated with synthetic insulin ( 100 nmol/L ) and respective substrates for 2 hours. Then the glycogenesis, gluconeogenesis, and glycolysis in cells were measured. The level of microRNA126 of the microRNA126 mimic group was higher than the other groups, and the difference was statistically significant ( P<0. 05 ). MicroRNA126 mimic group significantly decreased glucose utilization, reduced glycogen synthesis, effectively increased the account of gluconeogenesis, reduced lactate production, and pyruvate kinase activity ( all P<0. 05). The over-expressing microRNA126 in hepatocytes may reverse the function of glucose metabolism, and enhance output of hepatic glucose.
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[Summary] As the gradual deepening understanding of gastroesophageal reflux disease ( GERD ) , more extraesophageal symptoms are noted .The concept and therapeutic strategy for GERD has also undergone a quiet revolution over recent years .The application of proton pump inhibitor ( PPI) has been a landmark of medical treatment for GERD , and the invention of laparoscopic fundoplication and endoscopic radiofrequency energy delivery to the lower esophageal sphincter are marking a new era of comprehensive therapy for GERD .Good short and long term outcomes have been obtained since endoscopic radiofrequency energy delivery to the lower esophageal sphincter was applied on typical symptoms of GERD .Furthermore, the technique has also been successfully used in treating extraesophageal symptoms induced by proximal reflux in China .With more simple and less invasive features compared with anti-reflux surgery, the radiofrequency procedure has broad application prospects .
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Objective To evaluate the effectiveness of thoracic electrical bioimpedance(TEB)in monitoring the cardiac function of peritoneal dialysis patients.Methods One hundred and one patients with continuous ambulatory peritoneal dialysis (CAPD) and 30 healthy persons (control group)were included in the study.Thoracic electrical bioimpedance (TEB) noninvasive hcmodynamic monitoring and echocardiography were taken to analyze the correlation between indexes.Results Echocardiography showed that left atrial diameter (LAD),left ventricular end diastolic diameter (LVDd),left ventricular end systolic diameter (LVDs),interventricular septal thickness （IVST),interventricular septal thickness (PAP),left ventricle weight index (LVMI) of CAPD group were higher than that of the control group (all P ＜ 0.05),early and late wave of mitral valve flow (E/A) of CAPD group was lower than that of control group (P ＜ 0.05).TEB monitoring showed that cardiac output (CO),stroke volume (SV),acceleration index (ACI),ejection fraction (EF),velocity index (Ⅵ) of CAPD group were significantly lower than that of control group (all P ＜ 0.01),systolic time ratio (STR),SVR,TFC of CAPD group were significantly higher than that of control group (P ＜ 0.01).Correlation analysis show that left ventricular ejection fraction (LVEF) was negatively correlated with BNP (r =-0.467,P ＜ 0.01),LVMI was positively correlated with BNP (r=0.416,P ＜ 0.01),PEP,STR and TFC were positively correlated with BNP (r =0.404,P ＜ 0.01; r =0.572,P ＜ 0.01; r=0.471,P ＜ 0.01),EF was negatively correlated with BNP (r =-0.664,P ＜ 0.01).Correlation analysis between echocardiogaphy and TEB monitoring index showed there was significant correlation between EF and LVEF (r =0.451,P ＜ 0.01),SVR and TFC were positively correlated with LVMI (r =0.232,P ＜ 0.05; r =0.284,P ＜ 0.05),SV was positively correlated with E/A (r =0.285,P ＜ 0.05),pre-ejection period (PEP) and STR were negatively correlated with LVEF (r =-0.389,P ＜ 0.01; r =-0.446,P ＜ 0.01),TFC was positively correlated with LAD (r=0.279,P ＜ 0.05).Conclusion TEB monitoring can accurately evaluate the cardiac function with the advantage of dynamic monitoring and simple operation.It can partly replace the echocardiography test.
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Objective To observe the influence of spine kyphotic deformity on postmenopausal osteoporosis patients' pulmonary function and physical activity,and then provide a guide for the rehabilitation training of patients with osteoporosis and a kyphotic spine.Methods Sixty postmenopausal women with osteoporosis were recruited from the osteoporosis outpatients of the Third Hospital of Peking University.Half of them suffered from spine kyphosis (the spine kyphosis group) and the other half did not (the non-spine kyphosis group).There was no significant difference in the average ages and body mass indexes of the two groups.The research applied Cobb's angle and wall-occiput distance (WOD) to assess kyphosis severity,a visual analogue scale (VAS) to evaluate the patient's pain level,plus pulmonary function assessments and thoracic expansion assessments in both groups simultaneously,and the 6-minute walking test (6-MWT) to assess the patients' physical activity.Results The spine kyphosis group said they experienced significantly more pain than the non-kyphosis group,and they had worse pulmonary function and poorer physical activity.These differences were statistically significant.Pulmonary function was significantly correlated with the severity of spine kyphosis,back ache,thoracic expansion as well as physical activity.Conclusion Spine kyphosis deformity can aggravate back ache among postmenopausal osteoporosis patients,and affect their pulmonary function and physical activity.When planning clinical exercise training for such patients,physicians should pay attention to respiratory function training so as to improve the patients' pulmonary function,physical activity and endurance as much as possible,and thus improve their quality of life.
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To investigate whether peroxisome proliferators-activated receptor-y (PPARγ) ligand Troglitazone can reduce endothelial injury and activation during storage of harvested saphenous vein grafts. Segments of human saphenous vein graft were collected from 9 patients undergoing coronary bypass surgery and then divided into two equal parts of control and test specimens, were stored in ei-ther heparinized blood (control group) or heparinized blood containing 20 μmol/L troglitazone (test group) for 1 h at room temperature. Tissue distribution and protein expression of VCAM-1, ICAM-1, and endothelial nitric oxide synthase (eNOS) were compared using immunohistochemistry and West-ern blot analysis. Myeloperoxidase (MPO) activity, a marker of neutrophil sequestration in human saphenous vein grafts, was also measured in each group. The expression of ICAM-1 (753±132 versus 7201±934; P<0.01) , VCAM-1 (3731±294 versus 8292±793; P<0.01), and MPO activity (1.52±0.42 U/g, 5.04±1.26 U/g P<0.01) were significantly lower in test group. In contract, eNOS expression (7983±834 versus 3989±1008; P<0.01) was significantly higher in test group. PPARγ ligand troglita- zone might reduce endothelial injury during the storage period of human saphenous vein grafts.
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In order to study the cardioprotective effects of diazoxide on the myocardial ischemia/reperfusion injury of rats and mechanisms, the healthy SD rats were randomly divided into 2groups: the rats in the experimental group were injected with diazoxide for preconditioning with the dosage of 12.5 mg/kg through the right femoral vein and those in the control group was only administered with the equal volume of media. After 10 min, a left thoracotomy was performed and the left anterior descending branch was occluded for 2 h. Two h later, the left anterior descending branch was reperfused for 2 h and then the heart was quickly excised to be used for measurement of MDA, SOD and the infarct size, in situ cell apoptosis detection and observation of the cell ultrastructure by electron microscopy. The results showed that as compared with the control group, MDA, the infarct size and cell apoptosis in the experimental group were greatly reduced (P＜0.05). And the cell ultrastructure was obviously improved. But the activity of SOD had no change (P＞0.05). It was concluded that diazoxide could protect the rats from myocardial ischemia/reperfusion injury, which might be contributed to the reduction of lipid peroxidation and cell apoptosis.
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In order to study the cardioprotective effects of diazoxide on the myocardial ischemia/reperfusion injury of rats and mechanisms, the healthy SD rats were randomly divided into 2 groups: the rats in the experimental group were injected with diazoxide for preconditioning with the dosage of 12.5 mg/kg through the right femoral vein and those in the control group was only administered with the equal volume of media. After 10 min, a left thoracotomy was performed and the left anterior descending branch was occluded for 2 h. Two h later, the left anterior descending branch was reperfused for 2 h and then the heart was quickly excised to be used for measurement of MDA, SOD and the infarct size, in situ cell apoptosis detection and observation of the cell ultrastructure by electron microscopy. The results showed that as compared with the control group. MDA, the infarct size and cell apoptosis in the experimental group were greatly reduced (P0.05). It was concluded that diazoxide could protect the rats from myocardial ischemia/reperfusion injury, which might be contributed to the reduction of lipid peroxidation and cell apoptosis.
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This study was designed to investigate the cardioprotective effects of preconditioning with 3-nitropropionic acid, an inhibitor of mitochondrial succinate dehydrogenase. 16 isolated rat hearts were randomly divided into two groups, a treatment group and a control group. The rats of the treatment group were treated intraperitoneally with 3-nitropropionic acid (3-NPA, 4 mg/kg)and the rats of the control group were treated with saline. 24 h after the treatment, the isolated hearts were mounted on a Langendorff apparatus. After 30 min, the hearts were subjected to 30-min ischemia and 60-min reperfusion. The HR, LVDP and ±dp/dtmax were measured at pre-ischemia and 30 min, 60 min after the reperfusion. Coronary effluent was collected 15 min after the reperfusion for the determination of CK and LDH. At the end of the 60-min reperfusion the heart was removed for the determination of myocardial SOD and MDA. Our results showed that in the 3-NPA group LVDP and ±dp/dtmax recovered significantly better, myocardial MDA, CK and LDH were significantly lower and the myocardial SOD was significantly higher than in the control group.It is concluded that chemical preconditioning by 3-nitropropionate has cardioprotective effects against ischemia-reperfusion injury.
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Summary: The effects of diazoxide treatments on electrophysiologyic properties in guinea pig papillary muscles undergoing ischemia/reperfusion was studied using intracellular microelectrode technique. Twenty-four guinea pigs were randomly divided into three groups (n=8 in each group). In control group, St.Thomas solution was given. In experimental group, St.Thomas solution with diazoxide (100 mol/L) was given. In pretreatment group, the muscle was treated with diazoxide 20 min before arrested with St.Thomas cardioplegia. The results showed that the APD50 and APD90 in experimental and pretreatment groups were significantly shorter after 5 and 10 min reperfusion (P<0.01, P<0.05), but longer after 30 min reperfusion (P<0.01, P<0.05) than in control group. In experimental and pretreatment groups, APA, OS, Vmax recovered more quickly than those in control group. The time to re-systole after reperfusion in control group was longer than that in experimental and pretreatment groups. There was no significant difference in RP among three groups. The time of arrest in pretreatment group was longer than that in experimental and pretreatment group (P<0.05). This study indicates that protective effects of St.Thomas solution with diazoxide is better than that of pretreatment with diazoxide or St.Thomas solution alone.