How can we predict ureteral obstruction after gynecological surgery? The changes in Doppler resistive index and plasma creatinine and magnesium concentrations after surgical, unilateral ureteral obstruction in a rabbit model

The aim of this study is to evaluate the changes in Doppler resistive index (RI) and plasma creatinine and magnesium concentrations after unilateral ureteral obstruction in a rabbit model. Fourteen adult female rabbits were used in this study. In seven rabbits, the left ureter was ligated with silk suture, and the control group was sham operated. Before surgery and on the second and seventh days after surgery, blood samples were obtained to measure plasma creatinine and magnesium concentrations. Doppler RIs of both kidneys were also measured before surgery and on the second and seventh days after the surgical procedure. With regard to magnesium levels, there was a significant within-subjects sessions difference [F(2, 20) = 15.21, P= 0.001] indicating a decrease through sessions. Magnesium concentrations decreased significantly at the postoperative second and seventh days compared to preoperative baseline levels (P= 0.003 and P= 0.001, respectively). Multifactorial analysis of variance was applied for each session separately with laterality, and groups as factors. The Doppler RI and the creatinine level did not show any significant differences or interactions for all sessions (P > 0.05). The decreasing plasma magnesium concentration after surgery may indicate ureteral injury; however, Doppler studies and creatinine levels may not be useful as well.     

Renal function in relation to three candidate genes in a Chinese population

We recently found in a white population that the genes encoding angiotensin-converting enzyme (ACE, I/D polymorphism), -adducin (Gly460Trp), and aldosterone synthase (–344C/T) jointly influence renal function. We therefore investigated in a Chinese population the associations between the serum concentrations of creatinine and uric acid and these three genetic polymorphisms. We genotyped 471 ethnic Han Chinese subjects from 125 nuclear families recruited in northern China via random population sampling (75%) and at specialized hypertension clinics (25%). We performed population-based and family-based association analyses using generalized estimating equations (GEE) and quantitative transmission disequilibrium test (QTDT), respectively, while controlling for covariables. The participants were 39.7 years old and included 235 women (49.9%). The blood pressure measured at the subjects homes averaged 126/80 mmHg. Mean values were 71 µmol/l for serum creatinine, 111 ml min^–1 1.73 m^–2 for calculated creatinine clearance, and 236 µmol/l for serum uric acid. With adjustment for covariables, GEE analyses of single genes demonstrated that serum uric acid, but not serum creatinine, was positively associated with the ACE D allele. Serum uric acid concentrations were 15.8 µmol/l (95% confidence interval 3.3–28.2) and 25.7 µmol/l (11.1–40.2) higher in DD homozygotes than in ID and II subjects, respectively. Further GEE analyses of the three genes combined showed that the association between serum uric acid and the ACE polymorphism was confined to carriers of the -adducin Gly and/or aldosterone synthase C alleles. Sensitivity analyses in parents and offspring separately as well as QTDT analyses were confirmatory. Among 114 informative offspring carrying the -adducin Gly allele serum uric acid was significantly and positively associated with the transmission of the ACE D allele (=20.7 µmol/l). In conclusion, the present study extends our previous findings on the combined effects of the three candidate genes and supports the concept that these genetic polymorphisms jointly influence renal function.     

高效毛细管电泳法分离多巴胺和5-羟色胺

建立毛细管电泳分离分析多巴胺和 5一羟色胺的方法。采用自由区带电泳法 (CZE) ,4 0mmol/L硼砂缓冲液 2 0PSI气压进样 5s ,定电流 75 μA分离 10min ,二极管阵列PDA检测器检测 ,应用 2 0 0nm检测波长 ,结果显示两种物质完全分离。     

Association of Creatinine-to-Cystatin C Ratio with Myosteatosis and Physical Performance in Older Adults: The Japan Shimanami Health Promoting Program

ObjectiveSarcopenia is a risk factor for poor outcomes in older adults. Identification of plasma markers may facilitate screening of sarcopenia. We previously reported that creatinine-to-cystatin C ratio is a simple marker of muscle mass. To further assess the clinical relevance of the creatinine-to-cystatin C ratio, we investigated its association with myosteatosis and physical performance.DesignObservational study.Setting and ParticipantsCross-sectional analysis of the dataset obtained from a Japanese population consisting of 1468 older (≥60 years of age) community residents.MethodsThe mean attenuation values of the skeletal muscle calculated from computed tomography images of the midthigh were used as an index of myosteatosis, while the cross-sectional area of the muscle was used as a proxy for muscle mass. Physical performance was assessed by 1-leg standing time.ResultsCreatinine-to-cystatin C ratio was positively associated with the cross-sectional area of muscle fiber-rich muscles, while it showed an inverse association with fat-rich muscle areas, resulting in the positive association between creatinine-to-cystatin C ratio and the mean attenuation value of the skeletal muscle [creatinine-to-cystatin C ratio quartiles (Q), Q1: 47.4 ± 4.8, Q2: 48.9 ± 4.4, Q3: 49.8 ± 4.1, Q4: 50.9 ± 3.7, P < .001]. The results of the linear regression analysis adjusted for major covariates (including muscle cross-sectional area) identified creatinine-to-cystatin C ratio as an independent determinant of the mean attenuation value (Q1: reference, Q2: β = 0.07, P = .019, Q3: β = 0.11, P < .001, Q4: β = 0.16, P < .001). Low creatinine-to-cystatin C ratio was independently associated with 1-leg standing time, although the association was attenuated substantially by adjusting for skeletal muscle cross-sectional area and mean attenuation value.Conclusion and ImplicationsCreatinine-to-cystatin C ratio was associated with myosteatosis in older adults, independent of the muscle mass. Creatinine-to-cystatin C ratio may serve as a convenient marker of sarcopenia.     

三种血清肌酐测定方法的评价

目的：寻找一个简便,特异,准确的检测肌酐的方法,方法：使用三种方法Jaffe-FIXED,E-RATE,E-PAP进行方法学评价,包括准确度,精密度,线性范围,干扰试验,对比试验,结果：每各方法匀有自己的优,缺点,相比而言Jaffe-FIXE,E-RATE法更优于E－PAP,结论：根据实验室情况,使用试剂盒前进行方法学评价并选择方法,了解其性能,以便克服其缺陷。     

Laboratory tests of renal function

The kidneys are vital organs in the management of fluid balance, waste product removal, electrolyte homeostasis, acid–base balance and endocrine function. Waste products removed by the kidney are urea, uric acid and creatinine; other foreign products with similar physiochemical properties are also excreted. Urea and uric acid are by products of protein metabolism and creatinine is generated by the metabolism of creatine compounds from muscle. The kidney regulates fluid and electrolyte balance through controlling the composition and volume of urine. In the proximal convoluted tubule and the loop of Henle, 90% of sodium, potassium, calcium and magnesium are reabsorbed. Acid–base balance is achieved by regulating the excretion of hydrogen ions and bicarbonate buffering. The kidney also has a number of endocrine functions including the production of renin and erythropoietin as well as hydroxylation of vitamin D. The kidneys receive 25% of cardiac output, generating 170–200 litres of ultrafiltrate per day. Urine output is approximately 1.5 litres per day, which is concentrated ultrafiltrate through selective reabsorption of solutes and water. In this article we will discuss tests frequently used to assess renal function.     

皮肤电导率在早期糖尿病肾病筛查中的应用价值

目的 探讨皮肤电导率（ESC）在早期糖尿病肾病筛查中的应用价值。方法 选取2022年10月至2023年2月于安徽医科大学第二附属医院分泌科住院的176例2型糖尿病患者,根据尿白蛋白/肌酐比值（UACR）和肾小球滤过率（eGFR）将其分为两组,糖尿病肾病组（DKD组,n=68）和糖尿病非肾病组（non-DKD组,n=108）,所有患者均完善SUDOSCAN仪检测,获得双手、双足ESC(HESC、FESC),肾病风险分数（SUDOSCAN-DN）,采用Spearman相关性分析UACR与SUDOSCAN各指标的关系。采用受试者工作特征（ROC）曲线判断SUDOSCAN各指标对糖尿病肾病的诊断效能。结果 与non-DKD组相比,DKD组年龄较大,病程较长,收缩压较高,三酰甘油（TG）、血尿酸及肌酐、促甲状腺激素（TSH）水平较高,HbA1c水平偏低,HESC、FESC、SUDOSCAN-DN值均较低,差异有统计学意义（P<0.05）;Spearman相关分析显示,UACR与TC、LDL-C、血肌酐、TSH呈正相关（r值分别为0.202、0.207、0.378、0.174,P<0....