多壁碳纳米管表面甘草酸分子印迹聚合物的制备及其应用

目的:研制甘草酸为模板的固相萃取柱,并将其应用到药草中高纯度甘草酸的分离富集方面。方法:以丙烯酰胺修饰的碳纳米管为载体,甘草酸为模板,丙烯酰胺为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,N,N-二甲基甲酰胺(DMF)为致孔剂,采用沉淀聚合技术,在碳纳米管表面成功接枝甘草酸印迹聚合材料。采用红外光谱、扫描电镜和热重分析对印迹材料的性能进行表征。结果:当功能单体为丙烯酰胺,沉淀聚合温度为60℃,致孔剂是DMF,EGDMA与溶剂比例为1∶20时,能够在在碳纳米管表面印迹一层稳定、均匀的印迹材料;Scatchard模型表明,多壁碳纳米管-分子印迹聚合物(MWCNTs-MIP)对甘草酸有着不同亲和力的2种结合位点,即高结合位点的平衡常数(Kd)1.17 mmol·L-1,最大表观吸附量(Qmax)741.5μg·g-1,低结合点的Kd 3.96 mmol·L-1,Qmax1 668.5μg·g-1,并且MWCNTs-MIP对甘草酸有特异性识别能力。结论:优化条件合成的分子印迹聚合物具有更好的形态结构,对目标分子具有很好的吸附效率,故作为固相萃取材料应用于药草中甘草酸的分离富集方面有一定研究价值。     

Right Ventricular Dysfunction and the Incidence of Implantable Cardioverter‐Defibrillator Therapies

Introduction: Implantable cardioverter‐defibrillator (ICD) therapy is well established in preventing sudden cardiac death in patients with left ventricular dysfunction. The influence of right ventricular (RV) function on ICD therapy for sudden cardiac death (SCD) is not known. Methods: We retrospectively studied 222 patients receiving an ICD for primary prevention of SCD. Baseline clinical and echocardiographic data were gathered. RV systolic function was qualitatively assessed as normal or abnormal (described as mildly, moderately, or severely reduced). Primary endpoint was combined ICD therapy or death and secondary endpoint was ICD therapy alone. Results: The mean follow‐up was 940 ± 522 days. The mean left ventricular ejection fraction was 0.23 ± 0.07. By Kaplan‐Meier analysis, RV dysfunction was predictive of combined ICD therapy or death when comparing between normal and abnormal RV function (P = 0.008) and among qualitative ranges of RV function (P = 0.012). RV dysfunction was not predictive of ICD therapy alone with either type of classification. After adjusting for clinical covariates, severe RV dysfunction was predictive of the combined endpoint of ICD therapy or death (HR 2.02, 95% CI 1.04–3.92, P = 0.037). Conclusion: Severe RV dysfunction appears to be an independent predictor of the combined endpoint of ICD therapy or death. RV dysfunction does not reliably predict the incidence of ICD therapy alone.     

Plasma and urinary platelet activating factor concentrations and leukotriene releasing activity of leukocytes in steroid sensitive nephrotic syndrome of childhood

Platelet activating factor (PAF) is synthesized and secreted by glomerular mesangial and endothelial cells. It increases glomerular basement membrane permeability and induces proteinuria. Leukotrienes (LT) are mediators released by either leukocytes or glomerular cells under the PAF effect. The possible role of PAF in steroid sensitive nephrotic syndrome (SSNS) of childhood was studied in 8 children with SSNS in the acute stage, 5 children in remission and 8 healthy controls. The PAF concentrations in urine and plasma were determined. Leukocytes were stimulated in vitro and the LT release in response to stimulation was determined. The urinary and plasma concentrations of PAF were significantly higher in the acute phase than in remission and in control patients. Children with SSNS were found to have peripheral leukocytes with increased LT releasing activity in vitro. These results are in accordance with clinical and experimental observations indicating that PAF originates in the kidney and plays a role in normal kidney physiology. Urinary PAF concentrations may be related to proteinuria because they were strongly correlated in the present study. Elevated plasma PAF concentrations in the acute stage of SSNS could result from either its secretion from the circulating leukocytes or decreased acetyl hidrolase activity needed for its hydrolysis in plasma. The increased LT release in vitro suggests that these cells might have been activated by PAF secreted from glomeruli. It is proposed that PAF and different LT in systemic and glomerular circulation are important mediators in childhood SSNS.     

Long‐term prognosis of nonalcoholic fatty liver disease: Is pharmacological therapy actually necessary?

Background and Aim: Nonalcoholic fatty liver disease (NAFLD) comprises a wide spectrum of liver injury, ranging from steatosis and steatohepatitis to cirrhosis. Reasons for the different natural course in individuals with NAFLD are still unclear. The aim of this study was to describe the natural course of disease in individuals with NAFLD who did not receive pharmacological therapy. Methods: A total of 27 individuals with NAFLD (male/female ratio: 10/17, mean age 49.7 years) were prospectively enrolled. Management after diagnosis consisted of establishment of an appropriate diet and exercise (walking and jogging) program, treatment of associated metabolic conditions such as diabetes and dyslipidemia, and discontinuation of potentially hepatotoxic drugs if the patient was taking these. Liver tests were performed at diagnosis and at 3‐month intervals during the follow‐up period. Mean follow‐up period was 43.3 months (range 36–49 months). Results: From baseline to the end of the follow‐up period, although there was no significant difference observed in terms of the mean body mass index, serum aminotransferase levels significantly improved (48.8 ± 29.9 U/L to 31.6 ± 16.0 U/L for aspartate aminotransferase [AST] and 66.3 ± 38.3 U/L to 39.6 ± 22.9 U/L for alanine aminotransferase [ALT]; P < 0.05). No significant differences in platelet counts, serum albumin level or prothrombin time were observed (P > 0.05). No patient developed signs of advanced liver disease during the follow‐up period. Conclusion: A treatment strategy comprising diet, exercise and management of associated metabolic conditions is associated with improvement in aminotransferases among patients with NAFLD. Further investigation is needed to examine the long‐term efficacy of this approach on liver histology and clinical outcomes.     

Possible effect of leptin on renal magnesium excretion in adolescent patients with type 1 diabetes

BACKGROUND: Hypomagnesaemia and hyperleptinemia are common in patients with diabetes. Moreover, it has been demonstrated that leptin stimulates diuresis and natriuresis. The aim of this study was to evaluate the relationship between serum leptin, serum magnesium (Mg) and urinary Mg/urinary creatinine levels in patients with type 1 diabetes. METHODS: Serum leptin and Mg and urinary Mg/urinary creatinine levels were measured in 67 patients with diabetes (33 girls and 34 boys). The age, diabetes duration, anthropometric and metabolic parameters of the subjects were matched between girls and boys. The relation of serum leptin levels to serum and urinary Mg/urinary creatinine levels was assessed. RESULTS: Serum leptin levels of girls with diabetes were higher than those of the boys (14 +/- 5.3 microg/L vs 5.8 +/- 1.5 microg/L, P < 0.001, respectively). The differences for serum Mg and for urinary Mg/urinary creatinine levels were not significant between girls and boys with diabetes. Leptin levels were correlated with urinary Mg/urinary creatinine levels in both girls and boys (r = 0.39, P = 0.02 and r = 0.37, P = 0.03, respectively). In a multivariate regression model, leptin emerged as independent correlates for mean urinary Mg/urinary creatinine in both girls and boys with the total variance explained being 14%, and 15%, respectively. CONCLUSION: The data suggest that serum leptin might be related to increased urinary Mg loss in patients with type I diabetes.     

Retrospective analysis of 135 renal trauma cases

BACKGROUND: We review our trauma cases over the last 11 years and discuss our diagnosis and treatment modalities. METHODS: One hundred and thirty-five patients with renal injuries who had been hospitalized in the Urology and General Surgery clinics of Dicle University hospital between 1990 and 2001 were reviewed retrospectively. Patients were evaluated with regard to age, sex, cause of trauma, transport time, diagnostic methods, grade of injuries, associated organ injuries, treatments and complications. RESULTS: One hundred and forty-one renal injuries were established in 135 patients. The patients were between 5 and 65 years old; 114 (84.4%) were male and 21 (15.6%) were female. The most common cause of injuries (99 patients) was penetrating injuries. The transport time to hospital after injury was approximately 116 min. Immediate laparotomy was performed in 95 hemodynamically unstable patients. Radiological investigations were carried out in the remaining 40 patients. Most of the injuries were grade 4 (28, 19.86%) or 5 (60, 42.55%). Isolated renal injury was established in only 22 of 135 patients. Nephrorrhaphy was performed in 45 of 141 kidneys. Twelve injured kidneys were managed conservatively. Nephrectomy was performed in 66 of 141 kidneys. The remaining injured kidneys were managed with different treatment methods. Twenty-nine (21.48%) patients were lost intraoperatively or during the early postoperative period. CONCLUSION: We believe that our rates of nephrectomy and mortality were high because of the long transport time, unsuitable transport type, frequent high grade and high rate of associated organ injuries.