The assessment of commercial beef and chicken bouillons in terms of heterocyclic aromatic amines and some of their precursors

Herein, the assessment of commercial beef and chicken bouillons in terms of heterocyclic aromatic amines (HAAs) and some of their precursors was evaluated. Creatine and creatinine levels were ranged between 0.57–0.80 and 0.28–0.94 mg g⁻¹, respectively. Glutamic acid was found to be the most abundant amino acid in both bouillons. 2-amino-3,7,8-trimethylimidazo[4,5-ƒ]quinoxaline (7,8-DiMeIQx, up to 0.03 ng g⁻¹) was the only quantified analyte in beef bouillons, whereas it (up to 0.08 ng g⁻¹) was determined in addition to 2-amino-3-methylimidazo[4,5-ƒ]quinoxaline (IQx, up to 0.08 ng g⁻¹) in chicken bouillons. Creatine, creatinine and free amino acid composition did not have the capacity to initiate the formation of HAAs. Therefore, bouillons do not pose risk in terms of HAAs. However, it should be noted that multiple factors, such as the substrate amount and production conditions, may affect the results. Glutamic acid content is remarkable in commercial bouillons sold in Turkey.     

The Effect of Cadmium on GFR Is Clarified by Normalization of Excretion Rates to Creatinine Clearance

Erroneous conclusions may result from normalization of urine cadmium and N-acetyl-β-D-glucosaminidase concentrations ([Cd]_u and [NAG]_u) to the urine creatinine concentration ([cr]_u). In theory, the sources of these errors are nullified by normalization of excretion rates (E_Cd and E_NAG) to creatinine clearance (C_cr). We hypothesized that this alternate approach would clarify the contribution of Cd-induced tubular injury to nephron loss. We studied 931 Thai subjects with a wide range of environmental Cd exposure. For x = Cd or NAG, E_x/E_cr and E_x/C_cr were calculated as [x]_u/[cr]_u and [x]_u[cr]_p/[cr]_u, respectively. Glomerular filtration rate (GFR) was estimated according to the Chronic Kidney Disease (CKD) Epidemiology Collaboration (eGFR), and CKD was defined as eGFR < 60 mL/min/1.73m². In multivariable logistic regression analyses, prevalence odds ratios (PORs) for CKD were higher for log(E_Cd/C_cr) and log(E_NAG/C_cr) than for log(E_Cd/E_cr) and log(E_NAG/E_cr). Doubling of E_Cd/C_cr and E_NAG/C_cr increased POR by 132% and 168%; doubling of E_Cd/E_cr and E_NAG/E_cr increased POR by 64% and 54%. As log(E_Cd/C_cr) rose, associations of eGFR with log(E_Cd/C_cr) and log(E_NAG/C_cr) became stronger, while associations of eGFR with log(E_Cd/E_cr) and log(E_NAG/E_cr) became insignificant. In univariate regressions of eGFR on each of these logarithmic variables, R² was consistently higher with normalization to C_cr. Our tabular and graphic analyses uniformly indicate that normalization to C_cr clarified relationships of E_Cd and E_NAG to eGFR.     

老年高血压患者脉压指数与尿微量白蛋白/尿肌酐、血清视黄醇结合蛋白的关系

目的 探讨老年原发性高血压（EH）患者脉压指数（PPI）与尿微量白蛋白/尿肌酐（尿mAlb/尿Cr）、血清视黄醇结合蛋白（RBP）的关系.方法 选取血肌酐（Cr）正常的老年EH患者50例（EH组,根据PPI分为PPI＆lt;0.5组及≥0.5组）及健康体检的老年人20例（对照组）.比较各组尿mAlb/尿Cr比值、血清RBP的变化及与PPI的相关性.结果 尿mAlb/尿Cr比值、血清RBP值比较：EH组高于对照组,PPI≥0.5组高于PPI＆lt;0.5组（均P＆lt;0.05）;尿mAlb/尿Cr比值联合血清RBP值阳性率比较：PPI≥0.5组高于PPI＆lt;0.5组（63.64%比28.57%,P＆lt;0.05）;PPI与尿mAlb/尿Cr比值、血清RBP值呈正相关（r=0.425,P=0.019;r=0.401,P=0.032）.结论 老年EH患者PPI与尿mAlb/尿Cr、血清RBP密切相关,联合检测可作为老年EH患者早期肾功能损害的一个评估指标.     

The Urinary Level of Injury Biomarkers Is Not Univocally Reflective of the Extent of Toxic Renal Tubular Injury in Rats

Nephrotoxicity is a major cause of intrinsic acute kidney injury (AKI). Because renal tissue damage may occur independently of a reduction in glomerular filtration rate and of elevations in plasma creatinine concentration, so-called injury biomarkers have been proposed to form part of diagnostic criteria as reflective of tubular damage independently of renal function status. We studied whether the urinary level of NGAL, KIM-1, GM2AP, t-gelsolin, and REGIIIb informed on the extent of tubular damage in rat models of nephrotoxicity, regardless of the etiology, moment of observation, and underlying pathophysiology. At a time of overt AKI, urinary biomarkers were measured by Western blot or ELISA, and tubular necrosis was scored from histological specimens stained with hematoxylin and eosin. Correlation and regression studies revealed that only weak relations existed between biomarkers and tubular damage. Due to high interindividual variability in the extent of damage for any given biomarker level, urinary injury biomarkers did not necessarily reflect the extent of the underlying tissue injury in individual rats. We contended, in this work, that further pathophysiological contextualization is necessary to understand the diagnostic significance of injury biomarkers before they can be used for renal tubular damage severity stratification in the context of nephrotoxic and, in general, intrinsic AKI.     

液相色谱-同位素稀释质谱法准确测定血清中肌酸酐含量

利用液相色谱-同位素稀释质谱法准确测定血清中的肌酸酐含量。该方法特异性高、重复性好，可实现肌酸酐与肌酸的完全分离。利用该方法参加国际物质量咨询委员会(CCQM)2005年组织的关键比对CCQM-K12.1，测定血清中肌酸酐含量的准确定值。实验结果与其他各国一致，验证并提高了我国血清中肌酸酐含量准确定值的化学计量能力，为建立相应权威性方法及其参考系统提供了技术支持。     

以生物相容性微球为基质制备的接枝微球CPVA-g-PMAA对肌酐的吸附性能

在生物相容性微球交联聚乙烯醇(CPVA)微球表面实施甲基丙烯酸(MAA)的接枝聚合,制备了高接枝度(30g/100g)的接枝微球CPVA-g-PMAA。研究了接枝微球CPVA-g-PMAA对肌酐分子的吸附性能,分析了吸附机理。结果表明,在较大的pH范围内,CPVA-g-PMAA的Zeta电位为绝对值较大的负值。在强静电相互作用和氢键相互作用的协同下,CPVA-g-PMAA对肌酐分子表现出很强的吸附能力。随介质pH的增高,吸附容量先增大后减小,pH=8.0时,吸附容量最大(40mg/g);温度升高,吸附容量减小;CPVA-g-PMAA的接枝度增大,吸附容量升高。     

肌酸长期服用的毒性机理及关键酶抑制剂的研究

肌酸是一种普遍流行的能量增强剂。尽管短期服用肌酸不会对健康产生不良影响,但长期使用肌酸的安全性逐渐为人们所关注。本实验以研究肌酸的副面效应为出发点,建立大鼠模型,通过检测大鼠血清中SSAO活性以及各项生理指标来验证肌酸是否具有毒性伤害。结果表明外源性肌酸的摄入,会引起大鼠体内血清SSAO活性的升高,肌酸与X共同作用,可明显降低血清中SSAO活性。且长期服用肌酸可能会引发肾功能的轻微损伤以及肝脏的炎症。313swiss细胞与不同浓度肌酸共培养后,细胞存活率明显降低。初步证明了长期大量服用肌酸会造成一定的毒性伤害,对口服肌酸的长期毒性给予了肯定的评价。     

Nitrogenous constituents in the urine of cattle,sheep and goats

Ten samples of urine from dairy cows, five from sheep and four from goats were analysed to assess the distribution of urinary nitrogen (N) among various chemical constituents in order to gain a better understanding of the reactions undergone by urinary N in soil. Total N in the cow urine ranged from 6.8 to 21.6 g N litre^?1, of which an average of 69% was present as urea, 7.3% as allantoin, 5.8% as hippuric acid, 3.7% as creatinine, 2.5% as creatine, 1.3% as uric acid, 0.5% as xanthine plus hypoxanthine, 1.3% as free amino acid N and 2.8% as ammonia. In the sheep urine, total N ranged from 3.0 to 13.7 g litre^?1 of which an average of 83 % was present as urea; creatine accounted for 5.3% of the N; hippuric acid and allantoin both accounted for 4.3%, while each of the other constituents amounted to less than 1% of the total N. The goat urine was similar to the sheep urine but with a lower ratio of creatine to creatinine and a somewhat higher proportion (2.0 %) of the total N as amino acid.     

马齿苋降尿酸及肾脏保护作用的研究

目的:研究马齿苋降尿酸和肾脏保护作用,为临床研究提供参考。方法:将雄性ICR小鼠随机分为5组,空白组（CON）、模型组（HUA）、别嘌呤醇阳性药对照组（ALLOP,0.02 g/kg/d）、马齿苋高剂量组（PO-H,1.48 g/kg/d）、马齿苋低剂量组（PO-L,0.5 g/kg/d）。每组按相应给药剂量连续灌胃21 d,第7 d开始,除空白组外,每组腹腔注射次黄嘌呤（HX,0.3 g/kg）联合氧嗪酸钾（OAPS,0.3 g/kg）以建立高尿酸血症模型。观察小鼠血清尿酸值（SUA）、丙二醛（MDA）水平;收集肝脏检测黄嘌呤氧化酶（XOD）、超氧化物歧化酶（SOD）水平;收集肾脏检测谷胱甘肽（GSH）、谷胱甘肽过氧化酶（GSH-PX）水平;实验结束前一天收集24 h尿液检测尿尿酸（UUA）、尿肌酐（UCr）水平;对小鼠肾脏HE染色进行病理学观察。结果:与CON组比较,HUA组极显著（P<0.01）升高MDA、SUA、XOD水平,极显著（P<0.01）降低SOD、GSH、GSH-PX、UUA、UCr水平,说明高尿酸血症建模成功。与HUA组比较,PO-H组可极显著（P<0.01）降低SUA、MDA、XOD水平,极显著（P<0.01）升高SOD、GSH、GSH-PX、UCr水平;PO-L组可显著（P<0.05或P<0.01）降低SUA、MDA、XOD水平,显著（P<0.05或P<0.01）升高GSH、GSH-PX、UCr水平;HE染色结果显示PO可明显改善HUA小鼠肾组织的病理变化。结论:马齿苋提取物对高尿酸血症小鼠具有一定的降尿酸和肾保护功能。