[Pathogenic characteristics and influence factors of bloodstream infection-induced severe sepsis in pediatric intensive care unit]

Objective: To summarize the pathogenic characteristics of bloodstream infection (BSI)-induced severe sepsis and analyze the influence factors in pediatric intensive care unit (PICU). Methods: Pediatric patients who were diagnosed with severe sepsis caused by BSI in the PICU of Children's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from January 2016 to December 2021 were retrospectively selected and divided into survival group and death group according to their discharge outcomes. Clinical characteristics, laboratory parameters, pathogenic characteristics and drug resistance of the patients were collected. The characteristics of pathogens, clinical and laboratory indicators were summarized, and the influencing factors of death in children with severe sepsis caused by BSI were analyzed based on binary multivariate logistic regression. Results: A total of 132 patients, aged [M (Q1, Q3)] 36 (10, 119) months, with BSI-induced severe sepsis were enrolled in this study, including 81 males and 51 females. There were 38 cases aged 36 (15, 120) months in the death group, including 23 males and 15 females. There were 94 cases, aged 36 (8, 108) months, in the survival group, including 58 males and 36 females. A total of 132 strains of pathogens were isolated, including 87 strains (65.9%) of Gram-negative bacteria. The top 5 pathogens were Klebsiella pneumoniae (24 cases, 18.2%), Escherichia coli (17 cases, 12.9%), Acinetobacter baumannii (13 cases, 9.8%), Pseudomonas aeruginosa (10 cases, 7.6%) and Staphylococcus aureus (10 cases, 7.6%). The proportion of multi-drug resistant bacteria in hospital-acquired BSI was higher than that in community-acquired BSI [52.9% (36/68) vs 15.6% (10/64), P=0.001]. The proportions of community-acquired infection were 58.5% (55/94) and 23.7% (9/38) in the survival and death groups, respectively, the difference was statistically significant (P<0.001). The proportion of central venous catheter insertion before bloodstream infection in the death group was higher than that in the survival group [63.2% (24/38) vs 42.6% (40/94), P=0.034]. According to the binary multivariate logistic regression analysis, hospital-acquired infection (OR=4.80, 95%CI: 1.825-12.621, P=0.001), absolute neutrophil count (ANC) (OR=0.93, 95%CI: 0.863-0.993, P=0.030) and decreased albumin (OR=0.89, 95%CI: 0.817-0.977, P=0.014) were risk factors for death. Conclusions: The common pathogen of BSI-induced severe sepsis in PICU is Gram-negative bacteria. The proportion of multi-drug resistant organisms of BSI obtained in hospitals is high. Children with severe sepsis due to BSI with nosocomial acquired infection, ANC and decreased albumin have a high risk of death.

Simplified Rapid Hydration Prevents Contrast-Associated Acute Kidney Injury Among CKD Patients Undergoing Coronary Angiography

BACKGROUND

Patients with chronic kidney disease (CKD) undergoing coronary angiography (CAG) are at high risk of contrast-associated acute kidney injury (CA-AKI) and mortality. Therefore, there is a clinical need to explore safe, convenient, and effective strategies for preventing CA-AKI.

OBJECTIVES

This study sought to assess whether simplified rapid hydration is noninferior to standard hydration for CA-AKI prevention in patients with CKD.

METHODS

This multicenter, open-label, randomized controlled study was conducted across 21 teaching hospitals and included 1,002 patients with CKD. Patients were randomized to either simplified hydration (SH) (SH group, with normal saline from 1 hour before to 4 hours after CAG at a rate of 3 mL/kg/h) or standard hydration (control group, with normal saline 12 hours before and 12 hours after CAG at a rate of 1 mL/kg/h). The primary endpoint of CA-AKI was a ≥25% or 0.5-mg/dL rise in serum creatinine from baseline within 48 to 72 hours.

RESULTS

CA-AKI occurred in 29 of 466 (6.2%) patients in the SH group and in 38 of 455 (8.4%) patients in the control group (relative risk: 0.8; 95% CI: 0.5-1.2; P = 0.216). In addition, the risk of acute heart failure and 1-year major adverse cardiovascular events did not differ significantly between the groups. However, the median hydration duration was significantly shorter in the SH group than in the control group (6 vs 25 hours; P < 0.001).

CONCLUSIONS

In CKD patients undergoing CAG, SH is noninferior to standard hydration in preventing CA-AKI with a shorter hydration duration.

[Analysis of risk factors of central nervous system complications supported on extracorporeal membrane oxygenation]

Objective: To investigate the risk factors of central nervous system (CNS) complications in children undergoing extracorporeal membrane oxygenation (ECMO) support. Methods: The clinical data, ECMO parameters, laboratory examination and outcome (follow-up to 90 d after discharge) of 82 children treated with ECMO in the pediatric intensive care unit (PICU) of Shanghai Children's Hospital from December 2015 to December 2021 were analyzed retrospectively in this study. The patients were divided into CNS complication group and non-CNS complication group. The ECMO mode, ECMO catheterization mode, clinical and laboratory indicators pre-ECMO and 24 h after ECMO initiation, in-hospital mortality and 90-day mortality were compared with Chi-square test, t test and nonparametric rank sum test. Kaplan-Meier method was used to draw survival curve, and Log-rank test was used to compare the difference in survival rate. The receiver operating characteristic (ROC) curve was used to evaluate the power of variables to predict CNS complications. Results: A total of 82 children were treated with ECMO, including 49 males and 33 females, aged 34 (8, 80) months. There were 18 cases suffering CNS complications, including cerebral hemorrhage in 8 cases, epilepsy in 6 cases, simple cerebral infarction in 3 cases, and cerebral hemorrhage combined with cerebral infarction in 1 case. Veno-arterial ECMO accounted for a greater proportion in CNS complication group (17/18 vs. 67% (43/64), χ²=4.02, P=0.045). A higher percentage of children with CNS complications underwent surgical cannulation compared to those in non-CNS complication group (16/18 vs. 53% (34/64), χ²=7.55, P=0.006). The laboratory results indicated that lower pre-ECMO pH value (7.24 (7.15, 7.28) vs. 7.35 (7.26, 7.45), Z=-3.65, P<0.001) and platelet count 24 h after ECMO initiation (66 (27, 135) ×10⁹/L vs. 107 (61, 157) ×10⁹/L, Z=-2.04, P=0.041) were associated with CNS complications. In the CNS complication group, 7 children died during hospitalization and 7 died during 90-day after admission, and there was no significant difference compared with those in the non-CNS complication group (7/18 vs. 31% (20/64), 7/18 vs. 34% (22/64), both P>0.05). The ROC curve analysis indicated that the area under the ROC curve for pre-ECMO pH value was 0.738 (95%CI 0.598-0.877), and the optimal cut-off value was 7.325. Conclusions: CNS complications in children undergoing ECMO support are common. Pre-ECMO pH value <7.325 is a risk factor for CNS complications. Reducing the veno-arterial ECMO and surgical cannulation can help reduce the occurrence of CNS complications.

[Ultrasound-guided percutaneous cannulation for extracorporeal membrane oxygenation in children]

Objective: To evaluate the effectiveness and safety of ultrasound-guided percutaneous cannulation for extracorporeal membrane oxygenation (ECMO) in children. Methods: In this retrospective observational study, 66 cases who underwent non-cardiac surgery ECMO in pediatric intensive care unit (PICU) of Shanghai Children's Hospital from May 2016 to April 2021 were collected. The demographics, model of ECMO support, type and size of arteriovenous cannulas, way of catheterization and complications were recorded and summarized. Patients were divided into percutaneous cannulation group and surgical cannulation group according to catheterization strategies. The demographics, duration of cannulation and ECMO support, ECMO weaning rate and hospital survival rate were compared among two groups. χ² and nonparametric rank sum test were used for comparison. Results: Among the 66 patients who received ECMO, 38 were male and 28 were female, with age 44.5 (12.0, 83.5) months and weight 15.0 (10.0, 25.0) kg; 21 patients underwent percutaneous cannulation, with a success rate of 95% (20 cases). Point-of-care ultrasound was performed for all percutaneous cannulation cases. The duration of percutaneous cannulation was significantly shorter than that of surgical cannulation (26.0 (23.3, 30.3) vs. 57.0 (53.8, 64.0) min, Z=6.31, P<0.001). Successful percutaneous cannulation cases were aged 70.5 (23.8, 109.5) months, and their weight was 23.2 (13.6, 37.0) kg. Ten cases were initially given veno-venous (VV) ECMO support, and 10 cases were given veno-arterial (VA) ECMO support. ECMO arterial cannulas were sized from 8 F to 17 F, and venous cannulas sized from 10 F to 19 F. For VV-ECMO, the right internal jugular and femoral veins were used as vascular access, while VA-ECMO used right internal jugular vein-femoral artery or right femoral vein-left femoral artery approach. Only one patient suffered severe complication (superior vena cava perforation). There was no catheter-related bloodstream infection. Conclusion: Ultrasound-guided percutaneous cannulation for ECMO can be performed with a high rate of success and safety in children.

[Efficacy of high flow nasal oxygen therapy in children with acute respiratory failure]

Objective: To investigate the efficacy of high flow nasal cannula (HFNC) in children with acute respiratory failure. Methods: A prospective study was conducted. A total of 153 patients aged from 1 to 14 years with acute respiratory failure were enrolled, who were admitted to pediatric intensive care unit (PICU) of Shanghai Children's Hospital from January 2018 to December 2019. HFNC success was defined as no need for invasive mechanical ventilation and successfully withdrawn from HFNC, while HFNC failure was defined as need for invasive mechanical ventilation. HFNC at a flow rate of 2 L/(kg·min) (maximum ≤ 60 L/min) with inhaled oxygen concentration (FiO₂) between 0.30 and 1.00 was applied to maintain percutaneous oxygen saturation (SpO₂) of 0.94-0.97. Parameters including arterial partial pressure of oxygen (PaO₂), partial pressure of carbon dioxide in artery (PaCO₂), SpO₂ and PaO₂/FiO₂ were collected before and during the application of HFNC at 1 h, 6 h, 12 h, 24 h and 48 h, as well as over 48 h after HFNC withdrawn. Comparison between the groups was performed by student t test, Mann-Whitney U test or chi-square test. The sensitivity and specificity of the above parameters in predicting HFNC success were evaluated by receiver operating characteristic (ROC) curve. Results: A total of 153 children (70 males and 83 females) were enrolled. Among them, 131 (85.6%) cases were successfully weaned off from HFNC and 22 (14.4%) failed. The duration of HFNC was 57 (38, 95) hours in the successful group, and the PaO₂/FiO₂ before HFNC application and after HFNC was withdrawn were 187 (170, 212) mmHg (1 mmHg=0.133 kPa) and 280 (262, 292) mmHg, respectively. The duration of HFNC in the failure group was 19 (9, 49) hours, and the PaO₂/FiO₂ before HFNC application and after HFNC withdrawn were 176 (171, 189) mmHg and 159 (156, 161) mmHg, respectively. The values of PaO₂/FiO₂ were significantly higher in the successful group than those in the failed group at using HFNC initially 1 h (196 (182, 211) vs. 174 (160, 178) mmHg, Z =-5.105, P<0.01), 6 h (213 (203, 220) vs. 168 (157, 170) mmHg, Z =-6.772, P<0.01), 12 h (226 (180, 261) vs. 165 (161, 170) mmHg, Z =-4.308, P<0.01), 24 h (229 (195, 259) vs. 165 (161, 170) mmHg, Z=-4.609, P<0.01) and 48 h (249 (216, 273) vs. 163 (158, 169) mmHg, Z =-4.628, P<0.01) after the HFNC application, and over 48 h after HFNC was withdrawn (277 (268, 283) vs. 157 (154, 158) mmHg, Z=-3.512, P<0.01). Moreover, the PaO₂ levels were significantly higher in the successful group than those in the failed group using HFNC initially at 1 h (73.7 (71.0, 76.7) vs. 70.0 (66.2, 71.2) mmHg, Z=-4.587, P<0.01) and 6 h (79.0 (75.0, 82.0) vs. 71.0 (62.0, 72.0) mmHg, Z=-5.954, P<0.01) after HFNC application. Also, the SpO₂ levels showed the same differences at 1 h (0.96 (0.95, 0.96) vs. 0.94 (0.92, 0.94), Z =-4.812, P<0.01) and 6 h (0.96 (0.95, 0.97) vs. 0.94(0.91, 0.95), Z=-5.024, P<0.01) after HFNC application. Forty eight hours after HFNC was withdrawn, the PaO₂ (88.0 (81.7, 95.0) vs. 63.7 (63.3, 66.0) mmHg, Z =-3.032, P<0.01) and SpO₂ (0.96 (0.94, 0.98) vs. 0.91 (0.90, 0.92), Z=-3.957, P<0.01) were also significantly higher in the successful group. Regarding the HFNC complications, there was one case with atelectasis and one with pneumothorax in the failure group. HFNC was used as sequential oxygen therapy after extubation in 79 children, successful in all. ROC curve showed that the area under curve of PaO₂/FiO₂ in predicting HFNC success was 0.990, and the optimal cut-off value was 232 mmHg with the 95%CI of 0.970-1.000 (P<0.01). Conclusions: HFNC could be used as a respiratory support strategy for children with mild to moderate respiratory failure and as a sequential oxygen therapy after extubation. The PaO₂/FiO₂ when HFNC withdrow is the optimal index to evaluate the success of HFNC application.

[Role of cardiac magnetic resonance imaging in myocarditis patients with biopsy negative: a retrospective case series study]

Objective: To analyze the cardiac magnetic resonance (CMR) imaging feature of clinically diagnosed myocarditis patients with negative endocardial biopsy (EMB) results, and to further demonstrate the diagnostic value of CMR in these patients. Methods: This was a retrospective case series study. Fourteen patients, who were clinically diagnosed as myocarditis according to 2013 European Society of Cardiology (ESC) clinical diagnostic criteria for myocarditis, but with negative EMB results, were enrolled. All patients underwent CMR examinations. The morphological, functional and histological changes of the heart were assessed based on black blood sequence, cine sequence, T2W-STIR sequence and contrast agent late gadolinium enhancement,(LGE). Results: There were 10 males and 4 females in this cohort, the age was (25.6±13.2) years. The interval between symptom onset and CMR was 21 (13, 60) days, and the interval between symptom onset and EMB was 19 (9, 40) days. There were 13 patients with abnormal CMR results including myocardial oedema, fibrosis, decreased ejection fraction, pericardial effusion or increased cardiac chamber dimension. Nine out of 14 patients had CMR morphological and/or functional abnormalities, including 1 case of left atrium enlargement, 1 case of left ventricle enlargement, 3 cases of right ventricle enlargement, 4 cases of increased left ventricular end diastolic volume index. Left ventricular ejection fraction was<50% in three cases, right ventricular ejection fraction was<40% in 5 cases, and pericardial effusion depth>3 mm was detected in 3 cases. Of the 14 patients, 11 had histological changes, of which 6 had T2 ratio≥2. Among the 10 patients (10/14) with positive LGE, the most common patterns were subepicardial LGE of the lateral wall and/or midwall LGE of the septum (n=9); 2 cases showed extensively subendocardial LGE of the left ventricular wall. No LGE involved in the right ventricular wall in the whole cohort. Conclusion: CMR plays a complementary role in the diagnosis of myocarditis in clinically diagnosed myocarditis patients with negative EMB findings.

[Clinical features and outcomes of cancer-related versus non-cancer-related sepsis in pediatric intensive care unit]

Objective: To compare the clinical features and outcomes of cancer-related and non-cancer-related sepsis in children who were admitted pediatric intensive care unit (PICU). Methods: The clinical history of patients with sepsis, who were admitted to PICU in Shanghai Children's Hospital, Shanghai Jiao Tong University from August 2016 to July 2019, were retrospectively reviewed. A total of 768 patients were divided into the cancer-related sepsis group (135 cases) and the non-cancer-related sepsis group (633 cases). The patients in the cancer-related group were further categorized into three subgroups including hematological malignancy (80 cases), solid tumor (43 cases) and hemophagocytic lymphohistiocytosis (HLH) (12 cases). The variables of clinical features, laboratory tests, pathogens, management strategies and in-hospital mortality were compared between the two groups by student t test, Mann-Whitney U test or Chi-square test. Results: The patients with cancer-related sepsis accounted for 17.6% of all patients (135/768). Regarding the site of initial infection, the incidence of gastrointestinal infection (43.0% (58/135) vs. 28.6% (181/633), χ(2)=10.718, P=0.001), blood stream infection (29.6% (40/135) vs. 17.1% (108/633), χ(2)=11.297, P=0.001) and skin and soft tissue infection (22.2% (30/135) vs. 4.1% (26/633), χ(2)=54.013, P<0.01) were higher in the patients with cancer-related sepsis than in those with non-cancer-related sepsis. On first PICU admission, the levels of hemoglobin (71 (61, 83) vs. 106 (92, 116) g/L, Z=13.594, P<0.01), white blood cell (1.4 (0.3, 5.2) vs. 9.8 (5.8, 15.1)×10(9)/L, Z=11.213, P<0.01), platelet count (51 (15, 121) vs. 286 (192, 384)×10(9)/L, Z=13.336, P<0.01), CD19(+)cells (0.106 (0.008, 0.274) vs. 0.325 (0.224, 0.454), Z=6.555, P<0.01), and neutrophil (0.449 (0.170, 0.730) vs. 0.683 (0.537, 0.800), Z=5.974, P<0.01) were significantly lower in patients with cancer-related sepsis; however, the levels of C-reactive protein (82 (25, 155) vs. 36 (11, 86) mg/L, Z=-5.257, P<0.01), procalcitonin (1.5 (0.3, 12.0) vs. 0.8 (0.2, 4.0) μg/L, Z=-2.767, P=0.006), CD8(+)cells (0.329 (0.253, 0.514) vs. 0.209 (0.156, 0.275), Z=-5.699, P<0.01), interleukin (IL) -6 (0.1 (0.1, 522.4) vs. 0.1 (0.1, 0.1) ng/L, Z=-2.747, P=0.006), IL-8 (0.1 (0.1, 177.0) vs. 0.1 (0.1, 4.5) ng/L, Z=-2.087, P=0.037), and IL-10 (0.1 (0.1, 42.7) vs. 0.1 (0.1, 6.6) ng/L, Z=-2.148, P=0.032) were significantly higher in patients with cancer-related sepsis. Similarly, the rate of continuous renal replacement therapy (CRRT) (34.8% (47/135) vs. 16.9% (107/633), χ(2)=26.267, P<0.01) and the use of intravenous immunoglobulin (IVIG) (83.0% (112/135) vs. 66.2% (419/633), χ(2)=14.667, P<0.01) were significantly higher in cancer-related sepsis group. Moreover, the incidence of co-infection with fungi was also higher in cancer-related sepsis group (14.1% (19/135) vs. 0.5%(3/633), χ(2)=73.965, P<0.01), and so was the number of multiple organ dysfunction (3 (2, 5) vs. 2 (1, 3), Z=-6.988, P<0.01). Finally, the in-hospital mortality rate of cancer-related sepsis and non-cancer-related sepsis were 36.3% (49/135) and 9.3% (59/633), respectively, also significantly different (χ(2)=67.000, P<0.01). There was no difference in the in-hospital mortality among children with hematologic tumors, solid tumors and HLH (35.0% (28/80) vs. 32.6% (14/43) vs. 7/12, χ(2)=2.838, P=0.242). Conclusions: The site of initial infection, inflammatory markers on PICU admission, and co-infection pathogen during hospitalization are different between patients with cancer-related sepsis and non-cancer-related sepsis. Besides, the in-hospital mortality of cancer-related sepsis is about 4-fold that of non-cancer-related sepsis. The monitoring of clinical features and organ dysfunction, and timely treatment are crucial for cancer-related sepsis.

Ethnicity and health inequalities: an empirical study based on the 2010 China survey of social change (CSSC) in Western China

BACKGROUND

In China, ethnic minorities often live in frontier areas and have a relatively small population size, and tremendous social transitions have enlarged the gap between eastern and western China, with western China being home to 44 ethnic minority groups. These three disadvantages have health impacts. Examining ethnicity and health inequality in the context of western China is therefore essential.

METHODS

This paper is based on data from the 2010 China Survey of Social Change (CSSC2010), which was conducted in 12 provinces, autonomous regions and province-level municipalities in western China and had a sample size of 10,819. We examined self-rated health and disparities in self-rated health between ethnic minorities and Han Chinese in the context of western China. Self-rated health was coded as poor or good, and ethnicity was coded as ethnic minority or Han Chinese. Ethnic differences in self-rated health was examined by using binary logistic regression. Associations among sociodemographic variables, SES variable, health behaviour variable, health problem variables and self-rated health were also explored.

RESULTS

Fourteen percent of respondents reported their health to be poor. A total of 15.75% of ethnic minorities and 13.43% of Han Chinese respondents reported their health to be poor, indicating a difference in self-rated health between ethnic minorities and Han Chinese. Age, gender, marital status, education, alcohol, and health problems were the main factors that affected differences in self-rated health.

CONCLUSION

In western China, there were obvious ethnic disparities in self-rated health. Elderly ethnic minorities, non-partnered ethnic minorities, ethnic minorities with an educational level lower than middle school, and ethnic minorities with chronic disease had higher odds of poor self-rated health.

[Clinical features and outcomes of pediatric acute fulminant myocarditis requiring extracorporeal membrane oxygenation]

Objective: To observe the clinical features and effects of extracorporeal membrane oxygenation (ECMO) in critically ill children with acute fulminant myocarditis (AFM). Methods: A retrospective analysis was performed in pediatric patients with AFM requiring ECMO, from December 2015 to December 2018, who were admitted to the Pediatric Intensive Care Unit (PICU) in Shanghai Children's Hospital. According to whether patient was alive at least 48 hours after weaning, the children were divided into successful weaning group (9 cases) and unsucessful weaning group (3 cases). The factors related to successful ECMO weaning were explored. The changes of clinical and biochemical parameters before and after ECMO treatment in successful weaning group were analyzed. Continuous variables were presented as median (inter quartile range) for abnormal distribution data, and Mann-Whitney U test was used to compare the data. Results: A total of 12 pediatric patients including 4 males and 8 females were enrolled in this study. The median body weight was 20 (17, 36) kg, and the median age was 66 (48, 103) months. Nine cases were successfully weaned from ECMO, and 8 cases survived to discharge, and 4 cases died in the hospital. The median interval between symptoms onset and ECMO establishment was 3.0 (2.2, 4.0) days, the median duration of ECMO support was 120 (68, 152) hours. In the unsuccessful weaning group, patients displayed higher levels of initiallactic acid (LA), higher vasoactive-inotropic score (VIS), and longer QRS duration before ECMO establishment when compared with those in the successful weaning group (all P<0.05). After ECMO establishment, mean arterial pressure (MAP), systemic central venous oxygen saturation, LA, myocardial injury markers and left ventricular ejection fraction were all significantly improved in the successful weaning group (all P<0.05). Conclusion: In pediatric AFM patients, serum LA level, VIS and QRS duration before ECMO establishment are associated with successful ECMO weaning.

[Continuous renal replacement therapy combined with extracorporeal membrane oxygenation for pediatric cardiopulmonary failure]

Objective: To explore the effectiveness and safety of continuous renal replacement therapy (CRRT) combined with extracorporeal membrane oxygenation (ECMO) on rescuing pediatric patients with cardiopulmonary failure. Methods: The medical records of patients treated with ECMO admitted to pediatric intensive care unit (PICU) in Shanghai Children's Hospital from December 2015 to November 2017 were retrospectively extracted. There were 14 patients treated with ECMO combined with CRRT (ECMO+ CRRT group) due to acute kidney injury (AKI) or fluid overload, while 11 cases treated with ECMO only. The demographics and clinical characteristics of patients, the indications, details and complications of ECMO and CRRT support, and the survival rates were analyzed. Results: A total of 25 cases including 15 boys and 10 girls with cardiopulmonary failure treated with ECMO were enrolled in this study, whose median age and body weight were 9 (1-117) months and 10 (2-42) kg. The median duration of ECMO support was 199.2 h, and the median duration of CRRT was 78.6 h. Among the 14 cases in ECMO + CRRT group, 12 cases were treated with CRRT connected to ECMO pipeline, and 2 other cases were treated with independently operated CRRT. The serum level of creatinine was significantly higher in ECMO+ CRRT group than that in ECMO group (53 (22- 126) vs. 29 (12- 92) μmol/L, Z=-2.208, P=0.043). There was no significant difference in running time between ECMO+CRRT group and ECMO group ((257±203) vs. (122± 83) h, t=-2.062, P=0.051). And the incidence of thrombocytopenia was higher in ECMO+CRRT group than that in ECMO group (10/14 vs. 3/11 , χ(2)=4.812, P=0.028). There were no differences in the successful weaning rate and discharge survival rate between ECMO + CRRT and ECMO group (9 vs. 8, χ(2)= 0.203, P= 0.652 and 8 vs. 8, χ(2)= 0.659, P= 0.417, respectively). Conclusion: The combination of CRRT and ECMO is an effective and safe treatment to alleviate fluid overload and improve kidney function in pediatric patients with cardiopulmonary failure.

[Review of sixty years of Department of Burns of the 159th Hospital of PLA]

This paper describes the development of Department of Burns of the 159th Hospital of PLA in the past 60 years and shows their spirit of hard working and achievements of several generations.

[Comparison of effects of oleic acid and palmitic acid on lipid deposition and mTOR / S6K1 / SREBP-1c pathway in HepG2 cells]

Objective: To explore the effects of oleic acid and palmitic acid on lipid deposition and mTOR/S6K1/SREBP-1c pathways in HepG2 cells. Methods: The model of steatosis was established with induction of oleic acid and palmitic acid and was intervened by rapamycin. The changes in lipid droplets were observed after staining the cells with oil Red O. Intracellular triglyceride (TG) contents in cells were measured by TG kit. mTOR, S6K1, and SREBP-1c mRNA expression levels were detected using QRT-PCR. Western blot was used to determine protein expression levels of mTOR, S6K1 and SREBP-1c. Results: Both fatty acids increased lipid droplets in HepG2 cells. Fatty degeneration with elevated TG occurred with significant changes in oleic acid group lipids. Rapamycin alleviated lipid deposition caused by oleic acid and palmitic acid and inhibited their induction of increased expression of mTOR, S6K1, and SREBP-1c. QRT-PCR and Western blot results showed that mRNA and protein expressions of mTOR, S6K1, and SREBP-1c in oleic acid and palmitic acid group were significantly higher than the control group (P < 0.05). The increase was more pronounced in the palmitic acid group (P < 0.05); however, after rapamycin intervention, the expression of mRNA and protein in the three groups were significantly lower (P < 0.05), and the change in palmitic acid group was more pronounced (P < 0.05). Conclusion: Oleic acid and palmitic acid can induce lipid deposition in HepG2 cells and increase expression of every component of mTOR/S6K1/SREBP-1c pathway; however, Oleic acid-induced lipid deposition is more pronounced, and the mTOR, S6K1, and SREBP-1c pathway change is more obvious in palmitic acid. Rapamycin has high potent inhibitory effect on palmitic acid-induced lipid deposition. These results specify that lipid synthesis involved in the mTOR/S6K1/SREBP-1c pathways are mainly associated to palmitic acid in HepG2 cells, whereas other signaling pathway may mediate oleic acid-induced lipid synthesis.

[The research advances of microRNA-184 and related ocular diseases]

microRNA-184 (miR-184) is a small, non-coding, endogenic RNA molecule of 22 nucleotides in length. It is a highly conserved sequence throughout many different species. Multiple studies have demonstrated that miR-184 is an important factor in regulating gene expression at the post-transcriptional level. miR-184 plays vital roles in many biological processes, including development and differentiation in many tissues and organs. Meanwhile, the research on the physiological and pathological role of miR-184 in eyes draws more and more attention lately. Recent research indicates that miR-184 is highly expressed in the cornea and lens of mice. miR-184 plays crucial regulatory roles in several ocular diseases, such as neovascularization, keratoconus, endothelial dystrophy-iris hypoplasia-congenital cataract-stromal thinning syndrome, corneal squamous cell carcinoma, age-related macular degeneration and cataract. Here we summarize and discuss the recent findings of miR-184 in its gene structure, gene expression and regulation, biological function and its relevance with ocular diseases. (Chin J Ophthalmol, 2017, 53: 950-955).

[The combined effects of family history of cardiovascular disease and overweight on ischemic stroke incidence among the Mongolian population]

Objective: To investigate the cumulative effect of family history of cardiovascular disease(CVD)and overweight on ischemic stroke events in the Mongolian population. Methods: Study participants were recruited from 32 villages from May 2002 to August 2012 in Kezuohou Banner(county)and Naiman Banner in Inner Mongolia, China. Among 3 457 Mongolian people aged ≥20 years old living in these villages, 2 589 were selected to participate in this study. None of the participants had chronic kidney disease, malignant tumor, thyroid disease or adrenalopathy, or acute infectious disease. The 2 589 participants were followed for a mean of 9.2 years. Six participants were lost to follow up, resulting in a follow-up rate of 99.8%. Information collected included demographic characteristics, lifestyle risk factors, alcohol consumption, cigarette smoking, history of disease, family history of CVD, and physical examination. Ischemic stroke incidence information was collected during follow-up. All participants were categorized into four subgroups according to family history of CVD and overweight status. Cox proportional hazards models were used to estimate the hazard ratios(HR)and 95% CI of ischemic stroke events among subgroups, compared with the subgroup with no family history of CVD and body mass index(BMI)<24 kg/m²(the reference group). Results: Among 2 589 participants, 76 ischemic stroke events occurred after follow-up, and 8 were excluded because of lack of key data. Finally, 2 581 participants were included in the analysis, and the incidence density was 323/100 000 person-years. The cumulative incidence rates of ischemic stroke were 2.48%, 1.86%, 6.67% and 9.00% in the no family history of CVD and BMI <24 kg/m², no family history of CVD and BMI ≥24 kg/m², family history of CVD and BMI <24 kg/m² and family history of CVD and BMI ≥ 24 kg/m² subgroups, respectively. Using the Cox proportional hazards model, after further adjustment for age, gender, smoking, drinking, FPG, hypertension, total cholesterol, triglycerides, and heart rate, the risk of ischemic stroke in the subgroup with a family history of CVD and BMI ≥24 kg/m² was higher than the reference group(HR: 2.61, 95% CI: 1.16-5.87). However, the risk of ischemic stroke in other two groups was not statistically significant compared with the reference group. The HR(95% CI)values in the no family history of CVD and BMI ≥24 kg/m²and family history of CVD and BMI <24 kg/m² subgroups were 1.18(0.5- 2.39)and 1.27(0.67- 2.42), respectively. Conclusion: In the Mongolian population, a family history of CVD and coexistent overweight may increase the risk of ischemic stroke events, suggesting that in people with family history of cardiovascular disease, weight control is conducive to the prevention of ischemic stroke.

Time-specific blockade of PDGFR with Imatinib (Glivec®) causes cataract and disruption of lens fiber cells in neonatal mice

This study aimed at investigating the response of lens epithelial cells in postnatal mice to Imatinib (Glivec®, a potent inhibitor of platelet-derived growth factor receptor (PDGFR)) treatment. Mouse eyes were sampled 10 days after administration of Imatinib (0.5 mg·g(-1)·day(-1)) for 3 days, at either 7, 14, or 21 days postpartum. Structural changes of lens were revealed by routine H.E. staining. Levels of proliferation and apoptosis were revealed by BrdU incorporation and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, respectively, and immunofluorescent staining with anti-PDGFRα antibody was carried out on the sections of eyeball. PDGFRα and p-PDGFRαprotein levels were evaluated by Western blot. Our results indicated that administration of Imatinib led to blockade of PDGFR signaling. Formation of cataracts was found only in those mice where treatment started from 7 days postpartum (P7), but was not observed in those samples from P14 nor P21. Fiber cells were disorganized in cataract lens core as observed histologically, and migration of epithelial cells was also inhibited. No apoptosis was detected with the TUNEL method. Our results indicated blockade of PDGFR at the neonatal stage (P7) would lead to cataracts and lens fiber cells disorganization, suggesting that PDGFR signaling plays a time-specific and crucial role in the postnatal development of lens in the mouse, and also may provide a new approach to produce a congenital cataract animal model.

Ginseng berry reduces blood glucose and body weight in db/db mice

In this study, we observed anti-diabetic and anti-obesity effects of Panax ginseng berry in adult C57BL/Ks db/db mice and their lean littermates. Animals received daily intraperitoneal injections of Panax ginseng berry extract at 150 mg/kg body wt. for 12 consecutive days. On Day 5, the extract-treated db/db mice had significantly lower fasting blood glucose levels as compared to vehicle-treated mice (180.5+/-10.2 mg/dl vs. 226.0+/-15.3 mg/dl, P < 0.01). On day 12, the extract-treated db/db mice were normoglycemic (134.3+/-7.3 mg/dl) as compared to vehicle-treated mice (254.8+/-24.1 mg/dl; P < 0.01). Fasting blood glucose levels of lean mice did not decrease significantly after treatment with extract. After 12 days of treatment with the extract, glucose tolerance increased significantly, and overall blood glucose exposure calculated as area under the curve (AUC) decreased 53.4% (P < 0.01) in db/db mice. Furthermore, db/db mice treated with extract (150 mg/kg body wt.) showed weight loss from 51.0+/-1.9 g on Day 0, to 46.6+/-1.7 g on Day 5, and to 45.2+/-1.4 g on Day 12 (P < 0.05 and P < 0.01 compared to Day 0, respectively). The body weight of lean littermates also decreased at the same dose of extract. These data suggest that Panax ginseng berry extract may have therapeutic value in treating diabetic and obese patients.

Calpains play a role in insulin secretion and action

Studies of the genetic basis of type 2 diabetes suggest that variation in the calpain-10 gene affects susceptibility to this common disorder, raising the possibility that calpain-sensitive pathways may play a role in regulating insulin secretion and/or action. Calpains are ubiquitously expressed cysteine proteases that are thought to regulate a variety of normal cellular functions. Here, we report that short-term (4-h) exposure to the cell-permeable calpain inhibitors calpain inhibitor II and E-64-d increases the insulin secretory response to glucose in mouse pancreatic islets. This dose-dependent effect is observed at glucose concentrations above 8 mmol/l. This effect was also seen with other calpain inhibitors with different mechanisms of action but not with cathepsin inhibitors or other protease inhibitors. Enhancement of insulin secretion with short-term exposure to calpain inhibitors is not mediated by increased responses in intracellular Ca2+ or increased glucose metabolism in islets but by accelerated exocytosis of insulin granules. In muscle strips and adipocytes, exposure to both calpain inhibitor II and E-64-d reduced insulin-mediated glucose transport. Incorporation of glucose into glycogen in muscle also was reduced. These results are consistent with a role for calpains in the regulation of insulin secretion and insulin action.

Cytotoxic 7,20-epoxy ent-kauranoids from Isodon xerophilus

Four 7,20-epoxy ent-kaurane diterpenoids, xerophilusins G (1) and I-K (2-4), were isolated from the leaves of Isodon xerophilus, along with four known ones, enanderianin C (5), rosthorin A (6), longikaurin B (7), and rabdoternin D (8). Their structures were determined primarily using NMR spectroscopic techniques. The structure and stereochemistry of 3 were confirmed by X-ray crystallography. Compounds 4 and 7 exhibited broad cytotoxicity against four kinds of human tumor cells (K562, HL-60, HCT, and MKN-28 cells) in the range of 2.23-15.35 and 0.30-8.61 microg/ml, respectively.

New 7,20:14,20-diepoxy ent-kauranoids from Isodon xerophilus

Three new 7,20:14,20-diepoxy-ent-kaurane diterpenoids, xerophilusins A-C (1-3), together with a known one, macrocalin B (4), were isolated from the leaves of Isodon xerophilus. Their structures were elucidated on the basis of their spectral properties and X-ray crystallographic analysis. Compounds 1, 2, and 4 showed significant cytotoxic activity against K562, HL-60, and MKN-28 cells.

An experimental study on systemic inflammatory response syndrome induced by subeschar tissue fluid

OBJECTIVE

To investigate the biological activity of subeschar tissue fluid (STF) and its probable mechanism in the genesis of systemic inflammatory response syndrome(SIRS).

METHODS

The changes of heart rate (HR), respiratory rate (RR), white blood cell count (WBCC) as well as the major organ function were observed in the animals injected with STF. The inflammatory mediators TNF-alpha and IL-1 in the supernatants of macrophages cultured with STF were assayed.

RESULTS

The HR, RR and WBCC were elevated in animals after injection with STF. STF showed a deleterious effect on function and structure of the major visceral organs. Macrophages were activated to produce excessive TNF-alpha and IL-1.

CONCLUSION

The findings suggest that STF may be one of the inducing factors involved in the genesis of SIRS and the development of MODS in the early postburn stage.

Overexpression of Bcl-x(L) in beta-cells prevents cell death but impairs mitochondrial signal for insulin secretion

To study effects of Bcl-x(L) in the pancreatic beta-cell, two transgenic lines were produced using different forms of the rat insulin promoter. Bcl-x(L) expression in beta-cells was increased 2- to 3-fold in founder (Fd) 1 and over 10-fold in Fd 2 compared with littermate controls. After exposure to thapsigargin (10 microM for 48 h), losses of cell viability in islets of Fd 1 and Fd 2 Bcl-x(L) transgenic mice were significantly lower than in islets of wild-type mice. Unexpectedly, severe glucose intolerance was observed in Fd 2 but not Fd 1 Bcl-x(L) mice. Pancreatic insulin content and islet morphology were not different from control in either transgenic line. However, Fd 2 Bcl-x(L) islets had impaired insulin secretory and intracellular free Ca(2+) ([Ca(2+)](i)) responses to glucose and KCl. Furthermore, insulin and [Ca(2+)](i) responses to pyruvate methyl ester (PME) were similarly reduced as glucose in Fd 2 Bcl-x(L) islets. Consistent with a mitochondrial defect, glucose oxidation, but not glycolysis, was significantly lower in Fd 2 Bcl-x(L) islets than in wild-type islets. Glucose-, PME-, and alpha-ketoisocaproate-induced hyperpolarization of mitochondrial membrane potential, NAD(P)H, and ATP production were also significantly reduced in Fd 2 Bcl-x(L) islets. Thus, although Bcl-x(L) promotes beta-cell survival, high levels of expression of Bcl-x(L) result in reduced glucose-induced insulin secretion and hyperglycemia due to a defect in mitochondrial nutrient metabolism and signaling for insulin secretion.

Basal insulin hypersecretion in insulin-resistant Zucker diabetic and Zucker fatty rats: role of enhanced fuel metabolism

The biochemical mechanisms responsible for basal hyperinsulinemia in insulin-resistant states have not been fully defined. We therefore studied pancreatic beta-cell function in vitro to characterize the relative importance of fuel metabolism or secretion via a constitutive pathway in the maintenance of high basal insulin secretion in Zucker diabetic fatty (ZDF) and Zucker fatty (ZF) rats. Insulin secretion from ZF (10+/-1.8 v 5+/-0.6 pmol/ng DNA/h) and ZDF (30+/-4 v 7+/-0.8 pmol/ng DNA/h) islets at 2.8 mmol/L glucose was two to four times greater than secretion from islets of lean littermate control rats. In response to a decreasing glucose concentration (from 12 to 0 mmol/L), a paradoxical increase in insulin secretion was observed in perfused ZDF rat pancreas. Insulin secretion at 2.8 mmol/L glucose was suppressed approximately 70% to 80% in islets from ZDF and ZF rats following exposure to diazoxide, a K+-adenosine triphosphate (K(ATP)) channel opener that inhibits membrane depolarization, or rotenone and oligomycin, agents that inhibit ATP production, or by incubation at 23 degrees C. Inhibition of glycolysis with mannoheptulose, 2-deoxyglucose, and iodoacetate or fatty acid oxidation with a carnitine palmitoyltransferase I inhibitor also significantly inhibited basal insulin secretion in islets of ZDF and ZF rats but not their lean littermates. Furthermore, the glycolytic flux at 2.8 mmol/L glucose was significantly higher in ZDF islets versus ZDF lean littermate (ZLC) islets (2.2+/-0.1 v 3.7+/-0.3 pmol/ng DNA/2 h, P < .01) and was suppressed by mannoheptulose. In ZDF and ZF islets, high basal insulin secretion was maintained despite a 50% reduction in the rate of proinsulin/insulin biosynthesis at 2.8 mmol/L glucose. The rate of proinsulin to insulin conversion and the ratio of proinsulin to insulin secretion by islets of ZDF rats were similar to the values in the lean littermates. Thus, basal hypersecretion in these two insulin-resistant models appears to be related to enhanced fuel metabolism rather than the contribution of a constitutive pathway of secretion.

Defective pancreatic beta-cell glycolytic signaling in hepatocyte nuclear factor-1alpha-deficient mice

Mutations in the hepatocyte nuclear factor-1alpha (HNF-1alpha) gene cause maturity onset diabetes of the young type 3, a form of type 2 diabetes mellitus. In mice lacking the HNF-1alpha gene, insulin secretion and intracellular calcium ([Ca2+]i) responses were impaired following stimulation with nutrient secretagogues such as glucose and glyceraldehyde but normal with non-nutrient stimuli such as potassium chloride. Patch clamp recordings revealed ATP-sensitive K+ currents (KATP) in beta-cells that were insensitive to suppression by glucose but normally sensitive to ATP. Exposure to mitochondrial substrates suppressed KATP, elevated [Ca2+]i, and corrected the insulin secretion defect. NAD(P)H responses to glucose were substantially reduced, and inhibitors of glycolytic NADH generation reproduced the mutant phenotype in normal islets. Flux of glucose through glycolysis in islets from mutant mice was reduced, as a result of which ATP generation in response to glucose was impaired. We conclude that hepatocyte nuclear factor-1alpha diabetes results from defective beta-cell glycolytic signaling, which is potentially correctable using substrates that bypass the defect.

Apoptosis in insulin-secreting cells. Evidence for the role of intracellular Ca2+ stores and arachidonic acid metabolism

This study investigated the role of intracellular free Ca2+ concentration ([Ca2+]i) in apoptosis in MIN6 cells, an insulin secreting cell line, and in mouse islets. Thapsigargin, an inhibitor of sarcoendoplasmic reticulum Ca2+-ATPases (SERCA), caused a time- and concentration-dependent decrease in the viability of MIN6 cells and an increase in DNA fragmentation and nuclear chromatin staining changes characteristic of apoptosis. Two structurally distinct SERCA inhibitors, cyclopiazonic acid and 2,5-di-[t-butyl]-1,4-hydroquinone also caused apoptosis, but agents that increased [Ca2+]i by other mechanisms did not induce apoptosis in MIN6 cells. Carbachol- or ionomycin-releasible intracellular Ca2+ stores were completely depleted in cells treated by SERCA inhibitors, but not by other agents that increase [Ca2+]i. The ability of thapsigargin to induce cell death was not affected by blocking Ca2+ influx or by clamping [Ca2+]i with a cytosolic Ca2+ buffer suggesting that the process did not depend on changes in [Ca2+]i per se. However, application of the lipoxygenase inhibitors 5,8,11-eicosatrienoic acid and nordihydroguaiaretic acid partially prevented MIN6 cell apoptosis, while exposure of cells to the product of lipoxygenase, 12-hydroxy-[5,8,10,14]-eicosatetraenoic acid, caused apoptosis. In contrast, inhibition of cyclooxygenase with indomethacin did not abolish thapsigargin-induced apoptosis in MIN6 cells. Our findings indicate that thapsigargin causes apoptosis in MIN6 cells by depleting intracellular Ca2+ stores and leading to release of intermediate metabolites of arachidonic acid metabolism.

Successful recovery of 14 patients afflicted with full-thickness burns for more than 70 per cent body surface area

Fourteen cases suffering full-thickness burns of more than 70 per cent total body surface area (TBSA) have been successfully treated during the last 8 years (1988-1995). Among these patients, 10 cases suffered from burns of more than 90 per cent TBSA. Five cases had full-thickness burns of 80-90 per cent TBSA. Escharectomy, followed by coverage of wounds with a homograft to the lower surface of which, adjacent to the wound bed, microautoskin grafts had been attached was employed to close wounds in the early stages after burn. The remaining non-surgically treated wound was treated by exposure and topical silver sulfadiazine. The temperature and humidity of the ward was controlled by air conditioning and dehumidification. Aggressive excision of eschar and auto-skingrafting was carried out 3 weeks post-injury. Strictly limiting the uncovered wound to less than 5 per cent appeared to be the major effective measure in preventing burn infection.

[Effect of electroacupuncturing heart meridian on arterial blood pressure with myocardial ischemia in rabbits]

OBJECTIVE

To explore the relationship between Heart Meridian (HM) and cardiac function.

METHODS

Forty-eight rabbits with acute myocardial ischemia resulting from intravenous pituitrin injection was conducted. Electroacupunture(EA) on the HM and the Lung meridian, 3 points for each, was applied and their change of arterial pressure was observed.

RESULTS

The distinct difference existed in the improvement of arterial pressure on the HM and Lung Meridian with EA. The regulatory action of EA in HM on the cardiac function was significantly better than that of EA in Lung Meridian.

CONCLUSION

HM was closely related to the cardiac function.

Insulin mediators in man: effects of glucose ingestion and insulin resistance

Insulin mediators (inositol phosphoglycans) have been shown to mimic insulin action in vitro and in intact mammals, but it is not known which mediator is involved in insulin action under physiological conditions, nor is it known whether insulin resistance alters the mediator profile under such conditions. We therefore investigated the effects of glucose ingestion on changes in the bioactivity of serum inositol phosphoglycan-like substances (IPG) in healthy men and insulin resistant (obese, non-insulin-dependent diabetic) men. Two classes of mediators were partially purified from serum before and after glucose ingestion. The first was eluted from an anion exchange resin with HCl pH 2.0, and bioactivity was determined by activation of pyruvate dehydrogenase in vitro. The second was eluted with HCl pH 1.3, and bioactivity was determined by inhibition of cyclic AMP-dependent protein kinase. In healthy men, the bioactivity of the pH 1.3 IPG was not altered by glucose ingestion, whereas bioactivity of the pH 2.0 IPG increased to approximately 120% of the pre-glucose ingestion value at 60-240 min post-glucose ingestion (p < 0.05 vs pre-glucose). There was no change in either IPG after glucose ingestion in the insulin-resistant group. These data suggest that the pH 2.0 IPG plays an important role in mediating insulin's effect on peripheral glucose utilization in man under physiological conditions. The data further show, for the first time, a defective change in the bioactivity of an insulin mediator isolated from insulin-resistant humans after hyperinsulinaemia, suggesting that inadequate generation/release of IPGs is associated with insulin resistance.

Inhibitory effects of fatty acids on glucose-regulated B-cell function: association with increased islet triglyceride stores and altered effect of fatty acid oxidation on glucose metabolism

Long-term exposure to fatty acids (FA) inhibits B-cell function. We tested whether the inhibitory effects are associated with increased islet triglycerides (TG). Rat pancreatic islets were cultured for 48 hours in RPMI 1640 medium with 10% fetal calf serum (FCS) and 11 mmol/L glucose in the presence or absence of the long-chain FA, palmitate. Palmitate (0.125 mmol/L) exposure successively increased islet TG 70% after 6 hours and 200% after 48 hours of culture. The dose-response for palmitate was similar for the increase in TG and inhibition of glucose-induced insulin secretion. Reversal of elevated islet TG in RPMI medium (after 48 hours of palmitate) was 29% after 6 hours and 84% after 24 hours. A more rapid decline of TG was observed in Krebs-Ringer bicarbonate (KRB) medium in the absence of nutrients. This decline was totally prevented by 1 mumol/L of the carnitine palmitoyl transferase-I (CPT-I) inhibitor, etomoxir. Etomoxir enhanced glucose-induced insulin secretion from palmitate-cultured islets; however, this effect was lost when TG were normalized. Under conditions when oxidation of FA from islet TG stores was blocked with etomoxir, we tested the effects of octanoate, the oxidation of which is not blocked by etomoxir. Oxidation of [1-14C]octanoate from islets precultured with palmitate (48 hours) did not differ from that in control islets. Conversely, after palmitate, octanoate inhibited glucose oxidation (14CO2 production from [U-14C]glucose, 613 +/- 41 pmol/10 islets/90 min v 1,129 +/- 87 after control conditions, P < .01). In conclusion, (1) palmitate induces increases in islet TG that are associated with inhibition of B-cell function, and (2) long-term exposure to palmitate also induces an inhibitory effect of FA oxidation on glucose metabolism that is independent of TG.

[An epidemiologic study on the aetiological factors of primary liver cancer in Shunde City of Guangdong province]

In order to investigate the aetiological factors of Primary Liver Cancer (PLC) in Shunde City of Guangdong province, 96 clinically diagnosed PLC patients and 144 matched hospital controls were interviewed and their blood samples were examined for HBV, HCV and other seven indices. Monofactorial and multifactorial analyses were fitted by using Non-conditional Logistic Regression model. The findings confirmed the strong association between HBV infection and PLC. Histories of hepatitis and histories of eating raw fish, shrimp or salt fish were also noticed. The history of alcohol intake might have associated with PLC. The present study did not find associations between PLC and drinking water, histories of blood transfusion and injection- or exposure to insecticides. Antibody of HBV surface antigen seemed to be a protective factor with a relative risk of 0.3064 (0.1647-0.5701). The results showed that the combined effects of HBsAg infection and HCV infection were worthy for further study.

Fasting and decreased B cell sensitivity: important role for fatty acid-induced inhibition of PDH activity

Fasting inhibits glucose-induced insulin secretion. We investigated the role of a glucose fatty acid cycle for such inhibition and its molecular basis in pancreatic islets from 48-h fasted rats. The fasting-impaired insulin response to 27 mM glucose was restored by 41% with a carnitine palmitoyltransferase I inhibitor, etomoxir. Etomoxir also restored (by 50%) impaired glucose oxidation in islets from fasted rats and increased the ratio of oxidation to glycolytic flux from 33 to 43%. Fasting decreased total pyruvate dehydrogenase (PDH) activity (active, unphosphorylated plus inactive, phosphorylated form) by 29%, as well as the percentage of active form (54 +/- 5 vs. 79 +/- 2% in fed rats, P < 0.001). Fasting increased islet PDH kinase activity as follows: PDH-bound activity by 36% and free (not PDH bound) PDH kinase by 70%. Fasting failed to affect PDH kinase content when assayed by an enzyme-linked immunoabsorbent assay with antibodies raised against 45 kDa PDH kinase alpha-chain. We conclude that fasting impairs B cell function to a major extent through the operation of a glucose fatty acid cycle and that decreased PDH activity resulting from increased specific activity of PDH kinase constitutes an important molecular mechanism.

A fatty acid-induced decrease in pyruvate dehydrogenase activity is an important determinant of beta-cell dysfunction in the obese diabetic db/db mouse

We studied the effects of fatty acid oxidation on insulin secretion of db/db mice and underlying molecular mechanisms of these effects. At 2-3 months of age, db/db mice were markedly obese, hyperglycemic, and hyperinsulinemic. Serum free fatty acid (FFA) levels were increased in 2-month-old (1.5 +/- 0.1 vs. 1.1 +/- 0.1 mmol/l, P < 0.05) and 3-month-old (1.9 +/- 0.1 vs. 1.2 +/- 0.1 mmol/l, P < 0.01) mice compared with the age and sex-matched db/+ mice serving as controls. Glucose-induced insulin release from db/db islets was markedly decreased compared with that from db/+ islets and was specifically ameliorated (by 54% in 2-month-old and 38% in 3-month-old mice) by exposure to a carnitine palmitoyltransferase I inhibitor, etomoxir (1 micromol/l). Etomoxir failed to affect the insulin response to alpha-ketoisocaproate. The effect of etomoxir on glucose-induced insulin release was lost after culturing db/db islets in RPMI medium containing 22 mmol/l glucose but no fatty acid. Culture of db/+ islets with 0.125 mmol/l palmitate led to a decrease in glucose-induced insulin secretion, which was partially reversible by etomoxir. Both islet glucose oxidation and the ratio of glucose oxidation to utilization were decreased in db/db islets. Etomoxir significantly enhanced glucose oxidation by 60% and also the ratio of oxidation to glucose utilization (from 27 +/- 2.5 to 37 +/-3.0%, P < 0.05). Pyruvate dehydrogenase (PDH) activity was decreased in islets of db/db mice (75 +/-4.2 vs. 91 +/- 2.9 nU/ng DNA, P < 0.01), whereas PDH kinase activity was increased (rate of PDH inactivation -0.25 +/- 0.02 vs. - 0.11 +/- 0.02/min, P < 0.0 1). These abnormalities were partly but not wholly reversed by a 2-h preexposure to etomoxir. In conclusion, elevated FFA levels in the db/db mouse diminish glucose-induced insulin secretion by a glucose-fatty acid cycle in which fatty acid oxidation inhibits glucose oxidation by decreasing PDH activity and increasing PDH kinase activities.

Deficiency of pyruvate dehydrogenase activity in pancreatic islets of diabetic GK rats

We investigated the role of islet pyruvate dehydrogenase (PDH) enzyme activity and fatty acid oxidation in the impaired insulin secretion in spontaneously diabetic GK rats. Blood glucose levels were elevated in 2- to 3-month-old GK rats (8.7 +/- 0.5 vs. 6.5 +/- 0.3 mM in control Wistar rats; P < 0.01), whereas serum insulin levels were comparable to those in control rats. Insulin and DNA contents were similar in freshly isolated islets from GK and control rats, whereas insulin responses to 27 mM glucose from GK islets were reduced by 52%. The effect of acetate or pyruvate on insulin responses evoked by succinate monomethylester (SAM) were compared to indirectly assess deficient generation of acetyl-coenzyme A from pyruvate. Acetate potentiated SAM-induced insulin secretion similarly in GK and control islets, whereas 10 mM pyruvate (which supplies acetyl-coenzyme A through PDH enzyme activity) failed to normally potentiate insulin secretion in GK islets (92% of SAM-induced response in GK vs. 154% in control islets). The PDH activity (active form) was decreased in GK islets by 35% (P < 0.001). The proportion of active form PDH to total PDH activity was reduced in GK islets (56% vs. 71% in control islets; P < 0.01). The activity of PDH kinase (which inactivates PDH by phosphorylation) was increased in GK islets, the rate of ATP-dependent inactivation of PDH was -0.29 +/- 0.02 vs. -0.19 +/- 0.02/min in control islets (P < 0.05). Culturing GK islets for 48 h at 5.5 mM glucose failed to correct the impaired insulin response to glucose and the decreased PDH activity. Serum FFA levels and islet triglyceride contents did not differ between GK and control rats. Etomoxir (1.0 and 10 microM), a carnitine palmitoyl transferase I inhibitor, failed to enhance glucose-induced insulin release in GK islets. The following conclusions were reached: 1) a kinase-mediated decrease in PDH activity in islets of GK rats may in part account for the decreased ratio of oxidized to utilized glucose and impaired insulin release in these islets; and 2) impaired insulin release in the GK rats is not linked to an inhibitory influence of islet fatty acid oxidation.

Long term exposure to fatty acids and ketones inhibits B-cell functions in human pancreatic islets of Langerhans

We previously demonstrated in the rat that long term exposure to fatty acids inhibits B-cell function in vivo and in vitro. To further assess the clinical significance of these findings, we tested in human islets the effects of fatty acids on glucose-induced insulin release and biosynthesis and on pyruvate dehydrogenase (PDH) activity. Human islets were obtained from the beta-Cell Transplant Unit (Brussels, Belgium). Exposure to 0.125 mmol/L palmitate or oleate for 48 h during tissue culture (RPMI-1640 and 5.5 mmol/L glucose) inhibited the postculture insulin response to 27 mmol/L glucose by 40% and 42% (P < 0.01 for difference). Inhibition was partly prevented by coculture with 1 mumol/L etomoxir, a carnitine-palmitoyl-transferase-I inhibitor (P < 0.05 for effect of etomoxir). Inhibitory effects on glucose-induced insulin secretion by previous palmitate were additive to the inhibitory effects exerted by previous high glucose (11 and 27 mmol/L). Palmitate-induced inhibition of insulin secretion was evident after exposure to 25 mumol/L added fatty acid. The insulin content of islets exposed to fatty acids was significantly reduced, and glucose-induced proinsulin biosynthesis was inhibited by 59% after palmitate addition and by 51% after oleate exposure (P < 0.01). These effects were partly prevented by etomoxir (P < 0.05). The activity of PDH in mitochondrial extracts of islets preexposed for 48 h to palmitate was decreased by 35% (P < 0.05) vs. that in control islets, whereas the activity of PDH kinase (which inactivates PDH) was significantly increased in the same preparations (P < 0.05). The effects of ketones were tested by 48-h exposure to beta-hydroxybutyrate (beta-D-OHB). Ten millimoles of D-beta-OHB per L inhibited the subsequently tested insulin response to 27 mmol/L glucose by 56% (P < 0.001). Half-maximal inhibitory effects of D-beta-OHB on insulin secretion and insulin content were seen at concentrations between 0.5-2.5 mmol/L. Inhibition by D-beta-OHB was partially reversed by etomoxir, whereas exposure to D-beta-OHB failed to affect PDH and PDH kinase activities. We conclude that fatty acids as well as ketone bodies diminish B-cell responsiveness to glucose in human islets by way of a glucose-fatty acid cycle. Increased plasma concentrations of fatty acids and ketones are likely to be important factors behind the negative influences on B-cell function exerted by a diabetic state in both type 1 and type 2 diabetes.

Palmitate-induced beta-cell insensitivity to glucose is coupled to decreased pyruvate dehydrogenase activity and enhanced kinase activity in rat pancreatic islets

We previously found that long-term exposure to fatty acids impairs glucose-induced insulin release. In the present study, we investigated whether impairment is related to decreased pyruvate dehydrogenase (PDH) and increased PDH kinase activity. Rat pancreatic islets were cultured for 48 h in RPMI-1640 medium with or without 0.125 mmol/l palmitate. Potentiation of insulin responses to succinic acid monomethylester (SAM) by 10 mmol/l acetate and pyruvate were subsequently compared in order to assess whether generation of acetyl-coenzyme A (CoA) from pyruvate was deficient in the intact beta-cell. Potentiation by acetate was similar in control and palmitate-preexposed islets. In contrast, pyruvate potentiated SAM-induced response by 122% in control but by only 39% in palmitate-exposed islets (P < 0.001). In extracts of palmitate-exposed islets, the active (unphosphorylated) form of PDH was decreased by 50% and total PDH activity (assessed after phosphatase treatment) by 25%. The proportion of active form to total PDH activity was also reduced (42.7 +/- 2.6% after palmitate vs. 66.6 +/- 4.3% in control islets, P < 0.01). In the same preparations, PDH kinase activity was enhanced 1.7-fold by palmitate in terms of the rate constant of ATP-dependent inactivation of PDH (P < 0.05). To test for a role of free (not PDH-bound) kinase, a PDH-free mitochondrial fraction was prepared, and its kinase activity was tested against a pig heart PDH preparation. Free kinase activity was increased 1.9-fold in palmitate-treated islets (P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term exposure of rat pancreatic islets to fatty acids inhibits glucose-induced insulin secretion and biosynthesis through a glucose fatty acid cycle

We tested effects of long-term exposure of pancreatic islets to free fatty acids (FFA) in vitro on B cell function. Islets isolated from male Sprague-Dawley rats were exposed to palmitate (0.125 or 0.25 mM), oleate (0.125 mM), or octanoate (2.0 mM) during culture. Insulin responses were subsequently tested in the absence of FFA. After a 48-h exposure to FFA, insulin secretion during basal glucose (3.3 mM) was several-fold increased. However, during stimulation with 27 mM glucose, secretion was inhibited by 30-50% and proinsulin biosynthesis by 30-40%. Total protein synthesis was similarly affected. Conversely, previous palmitate did not impair alpha-ketoisocaproic acid (5 mM)-induced insulin release. Induction and reversibility of the inhibitory effect on glucose-induced insulin secretion required between 6 and 24 h. Addition of the carnitine palmitoyltransferase I inhibitor etomoxir (1 microM) partially reversed (by > 50%) FFA-associated decrease in secretory as well as proinsulin biosynthetic responses to 27 mM glucose. The inhibitory effect of previous palmitate was similar when co-culture was performed with 5.5, 11, or 27 mM glucose. Exposure to palmitate or oleate reduced the production of 14CO2 from D-[U-14C]glucose, and of 14CO2 from D-[3,4-14C]-glucose, both effects being reversed by etomoxir.

CONCLUSIONS

long-term exposure to FFA inhibits glucose-induced insulin secretion and biosynthesis probably through a glucose fatty acid cycle.

[Effects of silybin on red blood cell sorbitol and nerve conduction velocity in diabetic patients]

The effects of silybin on red blood cell (RBC) sorbitol and nerve conduction velocity in 14 non-insulin dependent diabetic patients (female 9, male 5; average age 58.2 years) were reported. Their RBC sorbitol levels averaged 72.55 +/- 21.61 nmol/g.Hb, a value almost two times of non-diabetic controls (33.31 +/- 7.82 nmol/g.Hb). After 4 weeks of silybin (231 mg/d) therapy, RBC sorbitol dropped to 39.53 +/- 14.94 nmol/g.Hb, a highly significant reduction than that before silybin therapy. Silybin treatment had no effect on fasting blood glucose. In addition, silybin treatment slightly improved nerve conduction velocity, but statistically not significant. This report suggests that silybin may be a potent aldose reductase inhibitor, and valuable in the prophylaxis and treatment of diabetic complications.

1079.5- and 1341.4-nm: larger energy from a dual-wavelength Nd:YAIO(3) pulsed laser

On the basis of oscillation conditions of simultaneous multiple-wavelength lasing that we have established, a larger-energy (1079.5 and 1341.4 nm) dual-wavelength Nd:YAlO(3) pulsed laser has been developed. Output energies of 3.71 and 1.39 J with efficiencies of 1.29% and 0.48% for the 1341.4-and 1079.5-nm wavelengths, respectively, have been achieved. To our knowledge, this is the best result among simultaneous dual-wavelength solid-state lasers to date. The temporal and spatial distributions of these beams obtained from a free-running dual-wavelength Nd:YAlO3 pulsed laser have also been measured. Experimental results show that the temporal and spatial overlap of the two beams is quite good for this type of laser.

Burns complicated with gastrointestinal haemorrhage--an analysis of 70 cases

Clinical data concerning the age, burn surface area and depth, burn shock, the time and location of haemorrhage, amount of blood lost and prognosis are described in 70 burn patients who developed gastrointestinal haemorrhage. The relevant morbidity, diagnosis and treatment is discussed.

[Inhibition of aldose reductase from rat lens by some Chinese herbs and their components]

Nearly 20 herbs or herbal components were screened for the inhibitory effect of rat lens aldose reductase(AR) with a fluorometric assay of AR activity. Among these Glycyrrhiza uralensis, Salvia miltiorrhiza, Radix astragali, Gentiana scabra, silybin, puerarin and baicalin were found to exhibit markedly inhibitory effects on AR comparable to Sorbinil. The authors suggest that some of the Chinese herbs used in the control of diabetic complications may act through the pharmacologic action of inhibiting AR.

Oral baicalin and liquid extract of licorice reduce sorbitol levels in red blood cell of diabetic rats

Intracellular accumulation of sorbitol, resulting from the increased glucose flux through polyol pathway with the action of aldose reductase, has been found pathogenic to chronic diabetic complications. It has been reported that baicalin and Glycyrrhiza uralensis Fisch can inhibit rat lens aldose reductase in vitro. In order to determine whether the said medicinal herbs give the inhibitive effect in vivo, 10 streptozotocin induced diabetic rats were treated with baicalin 150 mg/kg.d and liquid extract of licorice (LEL) 7.5 ml/kg.d for a week. RBC sorbitol was determined by a fluorometric assay before and after the treatment, as well as one week afterwards. It was found that oral baicalin and licorice dramatically reduced sorbitol levels in RBC without affecting blood glucose levels. The sorbitol levels was restored to its original values one week after discontinuing the treatment. The present study has demonstrated the effectiveness of baicalin and licorice in reducing RBC sorbitol levels in diabetic rats. Its mechanism is presumably through inhibition of aldose reductase. The feasibility of its clinical application for the control of diabetic complications is under investigation.