肾炎康复片对糖尿病肾病小鼠粪便中短链脂肪酸的调节作用

[目的] 研究经肾炎康复片干预的糖尿肾病小鼠粪便中肠道菌群的代谢产物短链脂肪酸含量变化情况,从肠道微生态代谢物的角度解释肾炎康复片改善糖尿病肾病的作用机制。[方法] 基于气质联用系统（GC-MS/MS）和标准曲线法检测db/db小鼠粪便中短链脂肪酸含量水平,并进行统计学分析及与肠道菌群变化的相关性分析。以db/db基因缺陷小鼠为糖尿病肾病的模型鼠,以m/m小鼠为正常组,将db/db小鼠随机分为模型组、二甲双胍组和肾炎康复片高、低剂量组。给药3个月后,收集每只小鼠的粪便并称质量记录。造模和用药前后定期监测小鼠血糖和体质量。[结果] 在程序升温、1.2 mL/min载气流量的气相色谱-质谱条件下,粪便中乙酸、丙酸、异丁酸、丁酸、异戊酸、己酸和戊酸得到有效分离,结果显示与模型组相比,各给药组中短链脂肪酸的含量都呈下降的趋势,并且模型组丙酸的含量与各给药组相比,差异有统计学的意义（P<0.05）,与肠道菌群拟杆菌的相对丰度降低相互印证。[结论] 本实验建立了有效测定小鼠粪便中的短链脂肪酸的含量的方法,并且发现经肾炎康复片干预后的db/db小鼠短链脂肪酸中的丙酸含量呈下降的趋势,且现有研究指出,丙酸在能量代谢和炎症反应中发挥着重要作用。该结果为肾炎康复片治疗糖尿病肾病的作用机制提供了数据支持,为糖尿病肾病治疗药物的研发提供了参考。     

不同产地阳春砂总酚与总黄酮测定及抗氧化活性研究

目的:测定不同产地阳春砂总酚、总黄酮含量,比较抗氧化活性差异,为天然抗氧化剂的开发提供实验依据。方法:采用福林酚比色法测定总酚含量;采用硝酸铝比色法测定总黄酮含量;通过1,1-二苯基-2-三硝基苯肼(DPPH)自由基、羟自由基清除能力和还原能力评价砂仁抗氧化活性。结果:没食子酸线性范围为0.2~1.6mg/mL(r=0.9973),平均加样回收率为100.52%(RSD=2.53%,n=9);芦丁线性范围为0~0.7mg/mL(r=0.9997),平均加样回收率为99.97%(RSD=2.61%,n=9)。DPPH清除率最强为(92.45±1.79)%(S9),羟自由基清除率最强为(84.52±0.51)%(S3),还原能力最强为OD700(1.23±0.01)(S13)。结论:不同产地阳春砂药材在总黄酮、总酚含量和抗氧化活性方面存在较大差异,建立的方法简单、准确、重复性好,可用于测定阳春砂中总酚、总黄酮的含量。     

急性脑梗死患者血、脑脊液兴奋性氨基酸的变化与意义

目的 研究急性脑梗死后谷氨酸（Glu)、甘氨酸（Gly)的变化规律及与梗死恶化进展的关系。方法 采用高效液相色谱技术测定112例发病24h内的急性脑梗死患者及32例正常对照组血和脑脊液（CSF）中Glu、Gly浓度的变化。结果 脑梗死患者血和CSF中Glu、Gly浓度在发病24h内明显升高，其变化与神经功能缺损程度呈显著相关。恶化进展性脑梗死Glu、Gly浓度较稳定性脑梗死升高更为显著。结论 Glu和Gly在脑梗死的发生、发展过程中起着重要作用，血和CSF中Glu、Gly浓度不仅与发病24h内神经功能缺损程度有关，并可作为脑梗死后48h病情恶化进展的一个临床观察直接客观的指标。     

Free amino acids in plasma and muscle during 24 hours post-operatively – a descriptive study

Summary. Intracellular amino acids in skeletal muscle show a specific concentration pattern on the third post-operative day. The temporal development of these changes has not been clarified. Here the amino acid concentrations in skeletal muscle were studied during the first post-operative day in fourteen patients undergoing elective abdominal surgery. Muscle amino acids were determined pre-operatively, as well as at 12 and 24 h post-operatively. In muscle the concentrations of glutamine and the basic amino acids decreased gradually during the first 24 h after surgery to 79% (P< 0 001) and 67% (P< 001) respectively. The sum of the essential amino acids decreased to 73% (P<0 001) at 12 h, but thereafter rose to 91% (P<0 05) at 24 h. The sum of the BCAA decreased to 84% (P<0.05) at 12 h but then increased to 116% (P<0 05) at 24 h. The alanine concentration increased to 122% (P<0 001) during the first postoperative day. In plasma the alanine concentration increased at 12 h while most other amino acids declined. At 24 h post-operatively the plasma concentrations of all amino acids had returned to normal or showed a tendency towards normalization except for phenylalanine, which increased. At the end of the first post-operative day the concentrations of amino acids in muscle were consistent with the alterations previously observed three days after surgery. The changes in plasma amino acid concentrations only partly reflected those in muscle.     

n-3多不饱和脂肪酸对哮喘小鼠白三烯B4及5脂氧合酶基因表达的影响

目的：探讨n-3多不饱和脂肪酸（n-3PUFA）对哮喘小鼠支气管肺泡灌洗液（bronchoalveolar lavage fluid，BALF）中白三烯B4（LTB4）水平、肺组织5脂氧合酶（5-LO）mRNA表达的影响及其可能的机制.方法：建立小鼠卵蛋白哮喘模型．分别灌胃不同剂量的n-3PUFA干预．用ELISA的方法检测BALF中LTB4含量；用RT—PCR的方法检测肺组织中5-LO mRNA表达的变化．结果：哮喘小鼠BALF中LTB4水平、肺组织5-LO基因表达水平较正常对照组显著升高（P〈0．01）；灌胃n-3PUFA干预的3个剂量组与模型组相比，LTB4含量、5-LO基因表达水平下降（P〈0．05）.结论：LTB4在气道里的高浓度及5LO基因表达的上调在哮喘小鼠发病中起重要作用，n—3PUFA可以降低哮喘小鼠BALF中LTB4的浓度，抑制肺组织5-LO mRNA表达，从而起到对抗哮喘气道炎症的作用.     

The Mechanism of Action of Clofibrate and Tetranicotinoylfructose (Bradilan) on the Kinetics of Plasma Free Fatty Acid and Triglyceride Transport in Type IV und Type V Hypertriglyceridaemia

Abstract. The kinetics of plasma free fatty acid and triglyceride transport were assessed in 20 patients with idiopathic hypertriglyceridaemia. These patients were subdivided according to lipoprotein pattern into Type IV and Type V patients. The effects of clofibrate therapy on plasma free fatty acid and triglyceride kinetics were assessed in these patients. Clofibrate produced a marked reduction in serum triglyceride associated with a significant reduction in triglyceride turnover as well as enhancement of triglyceride clearance. The reduction in triglyceride concentration produced by clofibrate was found to correlate with the reduction in free fatty acid turnover indicating that this drug decreased the availability of free fatty acid turnover indicating that this drug decreased the availability of free fatty acids for hepatic esterification. Clearance of endogenous plasma triglyceride was markedly enhanced in those patients in whom it was markedly impaired before treatment. – Having discontinued clofibrate for six weeks the same patients received bradilan (tetranicotinoylfructose) and kinetic measurements were repeated. It was evident that bradilan had a greater hypotriglyceridaemic effect than clofibrate in both groups of patients. The effect of bradilan was the result of inhibition of free fatty acid turnover and consequently a marked reduction in triglyceride turnover. Bradilan, unlike clofibrate, did not affect the mechanisms responsible for the clearance of plasma triglycerides.     

Protein and amino acid metabolism after severe cerebral trauma

Fourteen patients (20–48 years) suffering from severe head injury were followed for changes in amino acid and protein metabolism during the first 8 days after trauma. All patients received a standardized intravenous nutrition containing 15.7 g of nitrogen per day and additional carbohydrates. Electrolytes, free water, and blood constitutuents were given as needed. Additional treatment included surgical decompression of space-occupying hematomas, high dose dexamethasone therapy, and controlled hyperventilation for at least 5 days. Gross changes of protein metabolism were observed particularly on the days 5 and 6. The duration and chronological sequence of these changes are different from those usually found in patients with multiple injuries.     

Selective amino acid solutions in hepatic encephalopathy treatment

Summary Hepatic encephalopathy may complicate chronic liver diseases and portosystemic shunting. Recently it has been suggested that a change in the blood amino acid pattern (with elevated phenylalanine, tyrosine, methionine and depressed branched chain amino acids) and increased levels of octopamine and phenylethanolamine (a false neurotransmitter) are related causally to neurological symptoms. Previous works have suggested that an amino acid mixture of special formulation (enriched in branched chain amino acids and poor in aromatic amino acids) can normalize the plasma amino acid levels and consequently improve the neurological state. In order to test the actual therapeutic effect of these specially formulated solutions, the following therapeutic protocols were administered to 3 groups of cirrhotic patients: group 1 (15 cases): lactulose; group 2 (8 cases): special amino acid solutions; group 3 (8 cases): special amino acid solutions and lactulose. Clinical, laboratory and EEG examinations in a preliminary experiment, before and after treatment, showed that the best effect was obtained by the combined treatment with amino acid solutions and lactulose.     

Cutis laxa,exocrine pancreatic insufficiency and altered cellular metabolomics as additional symptoms in a new patient with ATP6AP1-CDG

Congenital disorders of glycosylation (CDG) are genetic defects in the glycoconjugate biosynthesis. > 100 types of CDG are known, most of them cause multi-organ diseases. Here we describe a boy whose leading symptoms comprise cutis laxa, pancreatic insufficiency and hepatosplenomegaly. Whole exome sequencing identified the novel hemizygous mutation c.542 T > G (p.L181R) in the X-linked ATP6AP1, an accessory protein of the mammalian vacuolar H⁺-ATPase, which led to a general N-glycosylation deficiency. Studies of serum N-glycans revealed reduction of complex sialylated and appearance of truncated diantennary structures. Proliferation of the patient's fibroblasts was significantly reduced and doubling time prolonged. Additionally, there were alterations in the fibroblasts' amino acid levels and the acylcarnitine composition. Especially, short-chain species were reduced, whereas several medium- to long-chain acylcarnitines (C14-OH to C18) were elevated. Investigation of the main lipid classes revealed that total cholesterol was significantly enriched in the patient's fibroblasts at the expense of phophatidylcholine and phosphatidylethanolamine. Within the minor lipid species, hexosylceramide was reduced, while its immediate precursor ceramide was increased. Since catalase activity and ACOX3 expression in peroxisomes were reduced, we assume an ATP6AP1-dependent impact on the β-oxidation of fatty acids. These results help to understand the complex clinical characteristics of this new patient.     

Fatty acid incorporation in endothelial cells and effects on endothelial nitric oxide synthase

BACKGROUND: The nature of fatty acids provided by the diet as well as plasma lipid metabolism can modify the composition and properties of plasma membrane and thus the activity of membrane proteins. In humans, as well as in experimental models, diabetes is associated with both an alteration in serum lipid profile and a documented endothelial dysfunction. This in vitro study investigated on an immortalized human endothelial cell line (EA.hy 926) the specific effects of several free fatty acids (FFAs) on the composition of cellular membranes and the regulation of endothelial nitric oxide synthase (eNOS). MATERIALS AND METHODS: 0.1% of lipid deprived serum was added to the incubation medium with 25 mM glucose in order to study the effects of individual fatty acids: myristic acid, palmitic acid, stearic acid, oleic acid or linoleic acid at 100 microM bound with albumin. The effects of the FFAs on the endothelial nitric oxide synthase were investigated on mRNA level by quantitative PCR, on protein level and Ser1177 phosphorylation by Western blot and on enzymatic activity on living cells using radiolabelled arginine. RESULTS: Free linoleic acid increased the membrane content in n-6 fatty acids (mainly C18: n-6 and its metabolites) with a decrease in saturated and monounsaturated fatty acids. These conditions decreased the basal eNOS activity and reduced the phosphorylation of eNOS-Ser1177 due to activation by histamine. Free palmitic acid enriched the membranes with 16 : 0 with a slight decrease in monounsaturated fatty acids. These conditions increased eNOS activation without increasing Ser1177 phosphorylation upon histamine activation. The addition of the other FFAs also resulted in modifications of membrane composition, which did not to affect eNOS-Ser1177 phosphorylation. CONCLUSION: Among the fatty acids used, only modification of the membrane composition due to linoleic acid supply disturbed the basal enzymatic activity and Ser1177 phosphorylation of eNOS in a way that limited the role of histamine activation. Linoleic acid might involve the dysfunction of both eNOS basal activity and its phosphorylation status and may then contribute to an impaired vasodilatation in vivo.