桑叶黄酮对腺嘌呤诱导大鼠高尿酸血症肾损伤的防治作用

本文研究了桑叶黄酮(mulberry leaf flavonoids,MLF)对腺嘌呤诱导大鼠高尿酸血症、肾损伤的防治作用.采用腺嘌呤灌胃法诱导SD大鼠制备高尿酸血症和肾损伤模型,MLF预防治疗3w,测定与高尿酸血症和肾衰相关的各项组织器官和血液生化指标.结果显示桑叶总黄酮可显著降低血清尿酸水平,与别嘌醇的降尿酸效果相当;并能显著降低尿酸氮、肌酐、丙二醛、甘油三酯、游离脂肪酸水平和肝脏系数、肾脏系数.上述结果表明桑叶总黄酮有干预腺嘌呤诱导高尿酸血症和肾损伤的作用.     

Uric Acid Metabolism in Patients with Primary Gout and the Metabolic Syndrome

Forty-four patients (40 males) with a mean age of 58 years were included in this pilot study. Mean serum urate concentration in patients with and without the metabolic syndrome (MS) was 8.8 mg/dL and 8.1 mg/dL, respectively. Urinary uric acid excretion was 543 mg/day/1.73m² in the former and 609 mg/day/1.73m² in the latter. Uric acid to creatinine ratio was 0.37 mg/mg in patients with the MS and 0.42 mg/mg in those without the MS. Mean serum urate increased from 8.6 mg/dL in subjects with three or more MS components to 10.3 mg/dL in those with five MS components. Serum urate was markedly lower in patients with mild MS (9 patients, 8.6 mg/dL) as compared to severe MS (10 patients, 9.2 mg/dL). In contrast, urinary uric acid to creatinine ratio was 0.42 mg/mg in patients with gout and mild MS and 0.33 mg/mg in gout patients with severe MS. Uric acid underexcretion appears to be more severe in gout patients with the MS. This disturbance appears to be related to the severity of the MS.     

Effect of Acarbose on the Increased Plasma Concentration of Uric Acid Induced by Sucrose Ingestion

Sucrose is converted fructose and glucose, which may increase plasma uric acid concentration (pUA) through increased purine degradation and/or decreased uric acid (UA) excretion. To investigate effects of acarbose, an inhibitor of alpha-glucosidase, on the increased pUA from sucrose administration, we measured pUA and urinary UA excretion in 6 healthy subjects before and after administering sucrose, with and without co-administration of acarbose. Sucrose raised pUA by 10% (p < 0.01). However, excretion and fractional clearance of UA were unchanged. Sucrose and acarbose coadministration also increased pUA, but less than did sucrose alone (sucrose: 4.9 to 5.4 mg/dl; sucrose + acarbose, 4.7 to 4.9 mg/dl, p < 0.05) without changes in urinary excretion and fractional clearance of UA. Acarbose appears to attenuate the rise in pUA by sucrose ingestion by inhibiting sucrose absorption.     

基于合成生物学治疗高尿酸血症的活体生物药研究进展

高尿酸血症(hyperuricemia, HUA)是一种常见的代谢性疾病,尿酸过高时会积聚在关节内形成尿酸盐结晶,引发痛风,并可能触发其他健康问题。目前市售降尿酸药物种类繁杂,但普遍存在肾功能损害等副作用。相比之下,活体生物药治疗高尿酸血症的安全性更高、见效更快且具有调节肠道菌群生态等优点。本文主要阐述了基于合成生物学技术开发治疗高尿酸血症的活体生物药的研究进展,重点介绍了降解嘌呤前体物质、创建新嘌呤代谢途径、优化尿酸氧化酶表达、尿酸氧化反应的辅助强化等功能模块的构建方式及表达,为高尿酸血症的活体生物药开发提供了新的思路。     

Determination of phytic acid by gas chromatography–mass spectroscopy: application to biological samples

A GC–MS method is reported for the determination of phytic acid based on purification by anion-exchange chromatography, enzymatic hydrolysis of phytic acid to myo-inositol and derivation to trimethylsilyl derivative, with scyllo-inositol as an internal standard. Analytical features of the method are: limit of detection 9 μg l⁻¹ phytic acid, linear working range 18–500 μg l⁻¹ phytic acid, and coefficient of variation 1.9%. The method has been successfully applied to a variety of biological samples: various rat organs (kidney, liver, brain and bone), human plasma and urine and kidney stones. A comparative study of sample treatments, including deproteization, lipid extraction and the presence of a chelator, is also reported. Phytic acid amounts found in rat organs ranged from 1.07 g kg⁻¹ for bone to 32.0 g kg⁻¹ for brain. Phytic acid in human plasma was of the order of 0.14 mg l⁻¹. In kidney stones, phytic acid was found in calcium containing stones.     

尿酸代谢失衡与心血管疾病及药物干预

尿酸是体内嘌呤代谢的终末产物,与各类心血管疾病的发生发展密切相关,是心血管疾病的重要危险因子之一。综述尿酸的代谢及生理病理意义,尿酸代谢失衡与急性心肌梗死、高血压、胰岛素抵抗、肥胖症等心血管疾病的关联以及尿酸代谢失衡的药物干预与心血管保护作用。     

塔吉克族高原人群高尿酸血症与慢性高原病关系的探讨

目的：研究帕米尔高原地区血尿酸（SUA）水平与慢性高原病（CMS）的关系,为该地区CMS防治提供新策略。方法：以海拔、年龄、性别为匹配条件,进行1：1配对的病例对照研究,纳入30例通过国际CMS诊断记分系统确诊的CMS人群作为病例组,其中男性22例,女性8例,平均年龄为（41.87±6.05）岁。收集30例非CMS人群作为对照组,平均年龄为（41.37 ±5.54）岁,两组均为世居帕米尔高原塔吉克族。分析两组人群中体质指数、心率、血氧饱和度、SUA、血压及血脂的差异性。校正混杂因素后比较两组人群中SUA的差异,研究高尿酸血症（HUA）与CMS的关系。结果：病例组与对照组间人群的SUA、低密度脂蛋白（LDL-C）及载脂蛋白B （APOB）存在统计学差异（P<0.05）,校正混杂因素后,SUA是CMS的危险因素（OR：1.015,95% CI：1.004-1.026,P<0.01）。HUA在两组间的优势比为6.882（95% CI：1.707-27.7 52,P<0.01）。结论：SUA水平同CMS关系密切,HUA可能为塔吉克族高原人群CMS的一个危险因素。     

转基因植物表达植酸酶研究进展

植酸是植物体内磷的主要存在形式,其绝大部分不能被单胃动物消化吸收,而随粪便排出体外造成环境污染;同时,植酸又是一种抗营养因子,它通过络合植物体内的一些营养成分而降低植物的营养价值。通过植物转基因方法使植物自身表达足量的植酸酶,以减小植酸带来的不利影响,是提高植物性饲料营养价值和控制环境磷污染的一种经济有效的措施。就转基因植物植酸酶的优势、研究现状、存在的问题及其发展前景进行了综述。     

高龄老年男性高血压患者腔隙性脑梗死与血清尿酸水平的相关性研究

目的：探讨男性高龄高血压患者腔隙性脑梗死（LI）与血清尿酸水平的相关性。方法：以98例男性高龄高血压患者为对象,均行颅脑磁共振成像（MRI）检查和血清尿酸水平测定,同时收集患者的临床和其他实验室数据。根据患者尿酸水平分为1、2、3三组（n=32、32、34）。结果：以尿酸水平分组的患者一般资料比较,单因素方差分析提示,随着尿酸水平的增高,三组的LI个数、血肌酐、尿素水平增高,而高密度脂蛋白（HDL）水平降低,差异有统计学意义（P〈0.05）。三组患者的24 h收缩压、舒张压、年龄、总胆固醇（TC）、甘油三酯（TG）、低密度脂蛋白（LDL）和空腹血糖比较,差异无统计学意义（P〉0.05）;LI个数与影响因素的Spearman相关分析提示尿酸及尿素水平与腔梗个数相关（P〈0.05）;LI个数与影响因素的多元线性回归分析提示血清尿酸水平是影响LI个数的独立危险因素（P〈0.01）。结论：在高龄高血压患者中,尿酸水平的增高可能是LI的危险因素之一。     

植酸切花保鲜剂的研究

本文报道以植酸作保鲜剂,对切花保鲜作用机理的研究。实验结果表明,植酸作为保鲜剂具抗氧化和抑制多酚氧化酶作用,从而显著延长切花保鲜期,为深层次开发利用植酸资源提供了重要依据。     

Barley (Hordeum vulgare L.) inositol monophosphatase: gene structure and enzyme characteristics

The cellular myo-inositol (Ins) pool is important to many metabolic and signaling pathways in plants. Ins monophosphatase (IMPase; EC 3.1.3.25) activity is essential for the de novo synthesis of myo-Inositol (Ins), and for recycling of Ins in Ins(1,4,5)P3. However, proteins encoded by at least one family of IMP genes also have L-galactose-1-P phosphatase activity important to ascorbic acid synthesis, indicating a bifunctionality that links these two branches of carbon metabolism. As part of research into the regulation of Ins synthesis and supply during seed development, the barley IMP-1 gene and gene products were studied. The 1.4 kb barley IMP-1 promoter contains one low temperature response element (RE), two heat shock REs, one gibberellin and two auxin REs, and five sugar REs. Barley IMP-1 is expressed in all tissues assayed, and expression levels were not greatly altered by abiotic stress treatments. Reduced use of Ins for Ins P6 synthesis in developing seed of barley low phytic acid (lpa) mutants results in Ins accumulation, and IMP-1 expression is reduced in proportion to the increase in Ins level. The barley recombinant enzyme had a lower Km, indicating higher affinity, for D/L-Ins(3)P1 (Km = 9.7 microM) as compared with reported Km (Ins P1) values for other eukaryotic IMPases (43-330 microM) or with a reported Km (L-Gal-1P) of 150 microM for a kiwifruit (Actinidia deliciosa) enzyme. These and other data indicate that the barley IMP-1 gene is regulated at least in part in response to Ins metabolic needs, and that the enzyme it encodes displays catalytic properties well suited for a role in Ins synthesis, in addition to other roles as an L-gal-1-P phosphatase important to ascorbate synthesis, or as an IMPase important to Ins(1,4,5)P3 signal recycling.     

Bone and faecal minerals and scanning electron microscopic assessments of femur in rats fed phytic acid extract from sweet potato (<Emphasis Type="Italic">Ipomoea batatas</Emphasis>)

Phytic acid was extracted from sweet potato (Ipomoea batatas) and fed to Wistar rats with or without zinc for 3 weeks. Animals were then sacrificed and bone and faecal minerals were assessed. The ultra-structure of the bones was examined via scanning electron microscopy. Phytic acid extract or commercial phytic acid supplemented diets (D + Zn + PE or D + PE) displayed reduced bone calcium levels (101.27 ± 59.11 and 119.27 ± 45.36 g/kg) compared to the other test groups. Similarly, reduced calcium were observed in the control groups (D + Zn and D) fed formulated diets with or without zinc supplementation (213.14 ± 15.31 and 210 ± 6.88 g/kg) compared to the other test groups. The group fed supplemented commercial phytic acid diet (D + CP) demonstrated the lowest femur magnesium (3.72 ± 0.13 g/kg) while the group fed phytic acid extract supplementation (D + PE) recorded the highest level (4.84 ± 0.26 g/kg) amongst the groups. Femur iron was highest in the group fed commercial phytic acid supplemented diet (D + CP −115.74 ± 2.41 g/kg) compared to the other groups. Faecal magnesium levels were significantly higher in the two test groups fed phytic acid extract with or without zinc (D + Zn + PE or D + PE) compared to all other groups. All the groups which had phytic acid supplemented diets had significantly thinner bone in the trabecular region, compared to the groups fed formulated diet or zinc supplemented formulated diet (D or D + Zn). These observations suggest that the consumption of foods high in phytic acid may contribute to a reduction in the minerals available for essential metabolic processes in rats.