离子液体-分散液液微萃取/高效液相色谱法用于猪肾脏中3种四环素类抗生素的检测

建立了分散液液微萃取(DLLME)技术进行样品前处理,高效液相色谱(HPLC)法测定猪肾脏中土霉素(OTC)、四环素(TC)、金霉素(CTC)3种四环素类抗生素(TCs)残留量的方法。考察了分散剂种类、离子液体用量、分散剂用量、样品溶液pH值、萃取时间、盐效应等因素对萃取效率的影响。优化后的实验条件为：以丙酮为分散剂,离子液体(［BMIM］PF6)用量为50μL,分散剂用量为140μL,样品溶液pH值为3.0,萃取时间为15min,不添加盐。该方法在0.1~10.0mg/L范围内线性关系良好(r2≥0.9995),土霉素、四环素和金霉素的相对标准偏差(RSD)为2.2%~3.1%,检出限(LOD)为54~93μg/L,富集倍数为7.0~27.8,且样品的加标回收率达99.5%~101.1%。该法准确度和精密度均满足分析方法的要求,实现了对猪肾脏中土霉素、四环素、金霉素3种四环素类抗生素残留量的快速、绿色、灵敏和准确检测。     

超高效液相色谱-串联质谱法检测猪肉和猪肾中残留的10种镇静剂类药物

建立了猪肉和猪肾中安眠酮、氯丙嗪、异丙嗪、地西泮、硝西泮、奥沙西泮、替马西泮、咪达唑仑、三唑仑和唑吡旦10种镇静剂类药物残留检测的超高效液相色谱-串联质谱分析方法。样品经酶解后,调节pH值呈碱性,分别用乙酸乙酯和叔丁基甲醚进行萃取,高速冷冻离心去除脂肪等杂质。提取液经Waters Acquity UPLC BEH C18色谱柱分离,以0.1%甲酸乙腈溶液和0.1%甲酸水溶液为流动相进行梯度洗脱。电喷雾正离子(ESI+)模式电离,多反应监测(MRM)模式检测,基质匹配标准溶液法进行定量。结果表明: 10种镇静剂在2～100 μg/L范围内呈良好的线性关系,相关系数(r)均大于0.998; 10种镇静剂的检出限(S/N＞3)为0.5 μg/kg,定量限(S/N＞10)为1 μg/kg。3个添加水平的回收率为64.5%～111.4%,批内、批间相对标准偏差(RSD)均小于15%。该方法具有简便快捷、灵敏度高、定性准确等特点。     

A preliminary study of blood-oxygen-level-dependent MRI in patients with chronic kidney disease

Background

Blood-oxygen-level-dependent (BOLD) magnetic resonance imaging (MRI) can provide regional measurements of oxygen content using deoxyhemoglobin paramagnetic characteristics. The apparent relaxation rate or R2*(=1/T2*) can be determined from the slope of log (intensity) versus echo time and is directly proportional to the tissue content of deoxyhemoglobin. Thus, as the level of deoxyhemoglobin increases, T2* will decrease, leading to an increase in R2*. Chronic kidney disease (CKD) can affect oxygenation levels in renal parenchyma, which influences the clinical course of the disease. The goal of this study was to detect and assess renal oxygenation levels in CKD using BOLD MRI.

Methods

Fifteen healthy subjects and 11 patients with CKD underwent a renal scan using multigradient-recalled-echo sequence with eight echoes. R2* (1/s) of the renal cortex and medulla was measured on BOLD images. Of the 11 patients, nine had biopsy-proven chronic glomerulonephritis, and two had a similar diagnosis based on clinical symptoms and investigations.

Results

Mean medullary R2* (MR2*) and cortex R2* (CR2*) levels were significantly higher in patients (22 kidneys, MR2*=24.79±4.84 s⁻¹, CR2*=18.97±2.72 s⁻¹) than in controls (30 kidneys, MR2*=19.98±1.19 s⁻¹, CR2*=16.03±1.23 s⁻¹) (P<.01), and MR2* was increased more than CR2*. Medullary to cortical R2* ratios (MCR2*) of patients were significantly increased when compared with those of controls (P<.01). In the patient group, estimated glomerular filtration rate levels were greater than or equal to 60 ml/min/1.73 m² in six patients (12 kidneys), whose MR2* and CR2* were also significantly higher than those of controls (P<.01). Serum creatinine levels were normal in seven patients (14 kidneys), whose MR2*, CR2* and MCR2* were also higher than those of controls (P<.01).

Conclusions

BOLD MRI can be used to evaluate changes in renal oxygenation in CKD, suggesting that it has the potential to be an excellent noninvasive tool for the evaluation of renal function.     

Production of Ammonia From Hippurate in the Kidney of Different Species Including Man. an in vitro Study with 15N-Hippurate

Hippurate, synthetized from benzoate and glycine in the liver and in the kidney of several species modulates the activity of renal γ-glutamyl-transpeptidase. By this mechanism hippurate interferes with renal intra-luminal ammonia production. Besides, in the rat hippurate serves as a minor substrate for renal ammoniagenesis as well. Hippurate may yield ammonia from its glycine moiety either after cleavage by hippuricase, or after condensation with an aldehyde according to Erlenmeyer's reaction. This reaction results in producing equimolar amounts of ammonia, benzoate and an α-keto acid, thus in a net gain of an acid equivalent. -In order to evaluate variability and extent of renal ammonia production from hippurate in different species, experiments were carried out on isolated tubular segments of the rat and on cortical kidney slices of rat, cow, man and cat. The incubation medium was enriched with J0mmol/1 hippurate spiked with 5% of ¹⁵N-hippurate, some of the known inhibitors of hippuricase and γGT as well as glyceraldehyde or propional-dehyde. Factors known to affect hippuricase or γGT did not interfere with renal ammonia production from hippurate, but glyceraldehyde and propionaldehyde (up to 1mmol/1) had a stimulating effect. Renal ammoniagenesis from hippurate as well as production of benzoate was lowest in the cow (～ 0.1%), amounted to 1–2% in rat and man and reached high values in the cat (up to 15% of the total ammonia production). These results indicate that hippurate could have physiological significance in the renal metabolism of some species.     

B cell-associated immune profiles in patients with end-stage renal disease (ESRD)

Most of the previous studies on immune dysregulation in end-stage renal disease (ESRD) have focused on T cell immunity. We investigated B cell subpopulations in ESRD patients and the effect of hemodialysis (HD) on B cell-associated immune profiles in these patients. Forty-four ESRD [maintenance HD patients (n = 27) and pre-dialysis patients (n = 17)] and 27 healthy volunteers were included in this study. We determined the percentage of B cell subtypes, such as mature and immature B cells, memory B cells, and interleukin (IL)-10+ cells, as well as B cell-producing cytokines (IL-10, IL-4 and IL-21) by florescent activated cell sorting (FACS). B cell-associated gene expression was examined using real-time PCR and B cell producing cytokines (IL-10, IL-4 and IL-21) were determined using an enzyme- linked immunosorbent assay (ELISA). The percentage of total B cells and mature B cells did not differ significantly among the three groups. The percentages of memory B cells were significantly higher in the pre-dialysis group than in the HD group (P < 0.01), but the percentage of immature B cells was significantly lower in the pre-dialysis group than in the other groups. The percentages of IL-10-expressing cells that were CD19+ or immature B cells did not differ significantly (P > 0.05) between the two subgroups within the ESRD group, but the serum IL-10 concentration was significantly lower in the pre-dialysis group (P < 0.01). The results of this study demonstrate significantly altered B cell-associated immunity. Specifically, an imbalance of immature and memory B cells in ESRD patients was observed, with this finding predominating in pre-dialysis patients.     

Preparation and properties of immobilized pig kidney aminoa cylase and optical resolution of N-acyl-dl-alanine

Aminoacylase (EC 3.5.1.14) was immobilized into DEAE-Sephadex A-25 by ion-exchange absorption for optical resolution of N-acyl-dl-alanine. The effects of pH, temperature, and Co²⁺ concentration on the activity of free and immobilized enzymes were in vestigated along with the operational and the thermal stability of the immobilized enzyme. The immobilized enzyme retained high catalytic activity. The optimum pH and temperature for the hydrolysis of N-acyl-l-alanine in the dl-isomer mixture were 8.0 and 65°C, respectively. Co²⁺ was an activator for the immobilized enzyme in a similarroleas for the free enzyme. Nosignificant loss of activity was observed for at least 300 h of continuous operation. The yield of l-alanine was about 70% of the theoretical yield. The immobilized aminoacylase column decayed over a very long period of operation, but could be completely reactivated by regeneration.     

Determination of bile acids in pig liver, pig kidney and bovine liver by gas chromatography-chemical ionization tandem mass spectrometry with total ion chromatograms and extraction ion chromatograms

An effective method has been developed for quantitative determination of six bile acids including lithocholic acid (LCA), deoxycholic acid (DCA), chenodeoxycholic acid (CDCA), hydodeoxycholic acid (HDCA), cholic acid (CA) and ursodeoxycholic acid (UDCA) in biological tissues including pig liver, pig kidney and bovine liver by gas chromatography-chemical ionization/tandem mass spectrometry (GC-CI/MS/MS). Camphor-10-sulphonic acid (CSA) was proposed as effective catalyst for bile acid derivatization. Reactions were accelerated ultrasonically. The effects of different catalysts and reaction times on derivatization efficiency were evaluated and optimized. Bile acids were determined as methyl ester-trimethylsilyl ether and methyl ester-acetate derivatives. The efficiency of trimethylsilylation and acetylation was evaluated. Trimethylsilylation was done with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) as the trimethylsilyl donating reagent in a ultrasonic bath for 20 min. Acetylation was done in pyridine with acetic anhydride at 40-45°C for 4 h. The former reaction was faster than the latter. Thus, trimethylsilylation was employed for the quantitative analysis. Negligible interferences from sterols in biological matrices were observed when the biological samples were treated with solid phase extraction before GC-CI/MS/MS. The linearity, reproducibility, detection limit and recovery were evaluated under the optimized conditions. Satisfactory results were obtained when bile acid derivatives of LCA, CDCA, HDCA, and UDCA were determined with total ion chromatograms (TIC) while DCA and CA were determined with extracted ion chromatograms (EIC), respectively. The detection limits (S/N=3) for six bile acids in biological tissues were ranging from 0.40 to 1.6 ng/mL and the recoveries indicated that the proposed method was feasible for the determination of trace bile acids in the biological samples studied. The experimental results for the animal tissues purchased from five different markets were compared. Interestingly, all of the six bile acids were present in pig liver while only the dihydroxy bile acids, DCA, CDCA and HDCA were found in pig kidney. In addition to DCA and CDCA, trihydroxy bile acid, CA, are the major bile acids in bovine liver.     

Ultrasound-assisted adsorption of Pb ions by carbonized/activated date stones from singles/mixed aqueous solutions

This work aims to assess the adsorption efficiency of date stones biowaste subjected to carbonization and activation processes for the removal of Pb ions from single and mixed solutions. Several techniques have been used for characterization of adsorbents such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), methylene blue index and point of zero charge (pHpzc). An excellent adsorption capacity of 97.43% is achieved at an initial concentration of 300 ?mg/L, solution volume 75 ?mL of Pb nitrate, adsorbent mass of 0.7 ?g, temperature of 30 ?°C, a stirring speed of 500 ?rpm/min, a contact time of 180 ?min and pH 6. Specifically, a comparison has been conducted between carbonized/activated date stones “CADS” and commercial activated carbon “CAC” besides investigating the influence of the presence of Co ions and the utilization of ultrasound radiation. A higher adsorption rate of 98.16% is reached under ultrasound radiation at Pb(II) initial concentration of 100 ?mg/L for a contact time of 3 ?h. Nevertheless, the temperature has shown a negative effect; the adsorption rate decreases from 98.31% at 18 ?°C to 92.70% at 60 ?°C. The modeling of the experimental adsorption data manifests a type-L isotherm characteristic of Langmuir and Freundlich models. The kinetic study has shown that the experimental data are well described by a pseudo-second-order rate model and controlled by the internal diffusion, a limiting-step that controls the transfer rate of Pb(II) to the adsorbent surface. The calculated thermodynamic parameters (ΔG⁰, ΔH⁰, ΔS⁰) indicate that the adsorption of Pb(II) is spontaneous and exothermic process.     

双倍剂量生血宁片治疗慢性肾脏病3～4期肾性贫血的疗效观察

目的分析在慢性肾脏病3~4期肾性贫血患者治疗中,双倍剂量生血宁片的临床应用疗效。方法选取江西省九江市中医院于2014年2月至2015年2月收治的62例慢性肾脏病3~4期肾性贫血患者为研究对象,将其随机分为对照组与观察组,对照组患者服用常规剂量的生血宁片接受治疗,观察组患者则在对照组患者基础上服用双倍剂量生血宁片,对比两组患者的临床治疗效果及Hb、SF、TAST等指标情况。结果观察组患者的临床治疗效果明显好于对照组,主要生理指标改善情况也比对照组患者更为明显,两组患者数据经对比后差异具有统计学意义(P0.05)。结论在慢性肾脏病3~4期肾性贫血患者的治疗中,双倍剂量生血宁片的应用效果较好,值得推广应用。     

聚苯乙烯磺酸钙防治慢性肾脏病(CKD)患者服用RAAS-I致高钾血症的效果

目的 探讨因服用肾素-血管紧张素-醛固酮系统抑制剂(RAAS-I)致高钾血症的慢性肾脏病(CKD)患者应用聚苯乙烯磺酸钙进行防治的临床效果.方法 选取惠州市第三人民医院诊治的CKD患者80例作为研究对象,所有患者均服用RAAS-I 4周以上.将其随机分为观察组和对照组.对照组给予常规治疗,观察组给予聚苯乙烯磺酸钙联合治疗.统计观察组患者治疗前以及治疗2个月后24 h尿蛋白、血肌酐以及血钾变化,并对两组患者不同时段血钾水平进行统计分析.结果 治疗后观察组24 h尿蛋白水平明显高于治疗前(P<0.05),血钾水平明显低于治疗前(P<0.05);观察组治疗1、3以及6个月时血钾水平均低于对照组(P<0.05).结论 聚苯乙烯磺酸钙治疗CKD患者服用RAAS-I所致的高钾血症效果显著,血钾水平控制良好.