ORNITHOCHOLANIC ACIDS AND CHOLELITHIASIS IN MAN

Ornithocholanic acids and small soft gall stones were found in the bile of patients from which Klebsiella pneumoniae was also isolated. Cholelithiasis may be initiated by metabolic disturbances in the conjugation of bile acids in liver tissue and the subsequent precipitation of cholesterol and bile pigment.     

LFA3降低大鼠血清胆固醇作用机理的探讨

以含ＬＦＡ３０（对照组）和１００ｇ／ｋｇ（试验组）日粮饲喂Ｗｉｓｔａｒ大鼠８周。试验组血清ＴＣ含量下降２３．４５％，ＨＤＬ－Ｃ上升７．０９％，肝ＴＣ下降４．５％。胆管插管，引流胆汁试验，试验组肝胆汁分泌量上升５１％。结果提示，ＬＦＡ３有较高的降血脂作用，这种作用可能同ＬＦＡ３能引起ＨＤＬ－Ｃ含量上升，肝脏对胆固醇代谢转化作用加强，以及通过增加胆汁分泌而加速胆固醇的排泄有关     

饲喂益生菌Lactobacillus casei Zhang对高脂日粮大鼠肝脏脂质代谢的作用

【目的】研究不同剂量益生菌L. casei Zhang（2.0×1010 CFU/d、2.0×109 CFU/d和2.0×108 CFU/d）及其发酵乳饮料（2.0×108 CFU/mL/d）对高胆固醇血症大鼠肝脏脂质的治疗作用。【方法】采用高脂饲料诱导高脂血症,采用相应试剂盒测定肝脏总胆固醇水平（TC）和甘油三酯（TG）水平、粪便总胆汁酸水平与胆固醇水平以及血清载脂蛋白ApoAⅠ与ApoB水平。【结果】益生菌各剂量组和发酵饮料组与高脂模型组相比,肝脏总胆固醇水平（TC）和甘油三酯（TG）水平均显著降低(P＜0.05 或P＜0.01)。各试验组均可显著增加高血脂大鼠粪便总胆汁酸水平和血清载脂蛋白ApoAⅠ水平以及显著降低血清载脂蛋白ApoB水平(P＜0.01),但对粪便胆固醇水平影响不明显(P＞0.05)。【结论】益生菌L. casei Zhang主要通过增加总胆汁酸的排出和调节载脂蛋白水平来改善高血脂大鼠肝脏脂质水平。     

Diet-induced hypercholesterolemia in mice: prevention by overexpression of LDL receptors

The current studies were designed to determine whether chronic overexpression of low density lipoprotein (LDL) receptors in the liver would protect mice from the increase in plasma LDL-cholesterol that is induced by high-fat diets. A line of transgenic mice was studied that express the human LDL receptor gene in the liver under control of the transferrin promoter. When fed a diet containing cholesterol, saturated fat, and bile acids for 3 weeks, the transgenic mice, in contrast to normal mice, did not develop a detectable increase in plasma LDL. The current data indicate that unregulated overexpression of LDL receptors can protect against diet-induced hypercholesterolemia in mice.     

Regulation of absorption and ABC1-mediated efflux of cholesterol by RXR heterodimers

Several nuclear hormone receptors involved in lipid metabolism form obligate heterodimers with retinoid X receptors (RXRs) and are activated by RXR agonists such as rexinoids. Animals treated with rexinoids exhibited marked changes in cholesterol balance, including inhibition of cholesterol absorption and repressed bile acid synthesis. Studies with receptor-selective agonists revealed that oxysterol receptors (LXRs) and the bile acid receptor (FXR) are the RXR heterodimeric partners that mediate these effects by regulating expression of the reverse cholesterol transporter, ABC1, and the rate-limiting enzyme of bile acid synthesis, CYP7A1, respectively. Thus, these RXR heterodimers serve as key regulators of cholesterol homeostasis by governing reverse cholesterol transport from peripheral tissues, bile acid synthesis in liver, and cholesterol absorption in intestine.     

Niemann-Pick C1 Like 1 protein is critical for intestinal cholesterol absorption

Dietary cholesterol consumption and intestinal cholesterol absorption contribute to plasma cholesterol levels, a risk factor for coronary heart disease. The molecular mechanism of sterol uptake from the lumen of the small intestine is poorly defined. We show that Niemann-Pick C1 Like 1(NPC1L1) protein plays a critical role in the absorption of intestinal cholesterol. NPC1L1 expression is enriched in the small intestine and is in the brush border membrane of enterocytes. Although otherwise phenotypically normal, NPC1L1-deficient mice exhibit a substantial reduction in absorbed cholesterol, which is unaffected by dietary supplementation of bile acids. Ezetimibe, a drug that inhibits cholesterol absorption, had no effect in NPC1L1 knockout mice, suggesting that NPC1L1 resides in an ezetimibe-sensitive pathway responsible for intestinal cholesterol absorption.     

猪源降胆固醇肠球菌的分离鉴定

为了筛选益生菌并评价其对血清胆固醇的降解作用,从健康猪胃肠道分离鉴定12株肠球菌,进行体外降胆固醇,对酸和胆盐的耐受性试验,结果表明：分离菌均具有体外降解血清胆固醇的作用,降解率为16．67～48．00％,对pH3．0和0．4％的胆盐具有抵抗力,综合评价E1和E7可以作为降胆固醇的备选益生菌株。     

Inhibition of cholesterol crystal formation by apolipoproteins in supersaturated model bile

Apolipoproteins A-1 and A-2 were purified from human plasma. At concentrations present in human bile these proteins prolonged the nucleation time of cholesterol monohydrate crystals when added to model systems of supersaturated bile. In contrast, apolipoprotein C-3 and other serum proteins did not have this effect. Also, when human gallbladder bile was fractionated by gel filtration chromatography, apolipoproteins A-1 and A-2 were among the proteins present in a fraction of bile enriched in potent inhibitors of cholesterol crystal nucleation. These findings suggest that apolipoproteins A-1 and A-2 in supersaturated human gallbladder bile could inhibit the rate of formation of solid cholesterol crystals and thus help to prevent spontaneous cholesterol gallstone formation in humans.     

Nuclear receptor-dependent bile acid signaling is required for normal liver regeneration

Liver mass depends on one or more unidentified humoral signals that drive regeneration when liver functional capacity is diminished. Bile acids are important liver products, and their levels are tightly regulated. Here, we identify a role for nuclear receptor-dependent bile acid signaling in normal liver regeneration. Elevated bile acid levels accelerate regeneration, and decreased levels inhibit liver regrowth, as does the absence of the primary nuclear bile acid receptor FXR. We propose that FXR activation by increased bile acid flux is a signal of decreased functional capacity of the liver. FXR, and possibly other nuclear receptors, may promote homeostasis not only by regulating expression of appropriate metabolic target genes but also by driving homeotrophic liver growth.     

饲料中胆汁酸对红鳍东方鲀脂肪酸组成及抗氧化能力的影响

为研究饲料中添加胆汁酸对红鳍东方鲀脂肪酸组成及抗氧化能力的影响,以鱼油为主要脂肪源,配制五种等氮饲料,以初始体重14g的红鳍东方鲀进行为期56天的投喂养殖实验。设置适宜脂肪含量(8%)的对照组,并在对照组添加0.02%及0.10%的胆汁酸,分别获得低胆汁酸添加组(BA)和高胆汁酸组(HBA)。另设一高脂组(脂肪含量12.5%,HL组)及高脂+0.02%胆汁酸组(HLBA组)。结果表明,添加胆汁酸的处理组肌肉和肝脏MUFA均低于对照组,其中HBA组显著低于对照组(P<0.05)。肌肉中n-6PUFA含量在HLBA和HL组显著低于其他组(P<0.05)。在适宜脂肪含量的三个处理组间,肝脏中的C20:0、C16:1n-7、C18:1n-9、C18:2n-6、C20:4n-6、C18:3n-3、C18:4n-3、C20:5n-3和C22:6n-3都呈现随着胆汁酸添加量增加而降低的趋势。血清超氧化物歧化酶活性和谷胱甘肽过氧化物酶活性都有随着胆汁酸添加而升高的趋势,且在高脂组显著高于对照组(P<0.05);血清谷胱甘肽还原酶则呈现相反的趋势。肝脏中谷胱甘肽过氧化物酶1的mRNA相对表达量在对照组显著高于其他组,而BA组氧化还原酶1的基因表达量显著高于对照组;在高脂组添加胆汁酸显著升高了过氧化氢酶的基因表达量。综上所述,饲料中胆汁酸的添加降低了饲料及鱼体组织中一系列长链脂肪酸的含量;胆汁酸对血清抗氧化蛋白活性的影响与其对肝脏抗氧化相关基因表达的影响结果不一致。     

Multiple effects of grape seed polyphenolics to prevent metabolic diseases

Obesity is increasing in developing countries. Population studies show a relationship between affluence and obesity. Changing food intake patterns with affluence such as preference for foods with less astringent polyphenolic compounds and dietary fibers may increase risk of metabolic dysfunctions due to caloric imbalance. Animal models of obesity consistently show that grape seed procyanidins prevent increases in body and abdo- minal adipose weight gain, plasma cholesterol, liver weight gain and inflammation in animals on high fat diets. The mechanisms are not clear because the oral intake of procyanidins results in pleiotropic interactions with proteins in the mouth, stomach, small intestine, cecum and colon that affect the rate of digestion of bioavailability of macronutrients, sterols, and dietary fiber. Procyanidins also bind bile acids and reduce intestinal permeability to inflammatory bacterial cell wall fragment. Procyanidins are not degraded or metabolized until reaching the lower gut where they can be metabolized into phenolic acids by gut bacteria. While they are metabolized by gut bacteria, they also alter total numbers and distribution of phyla and species of gut bacteria. Gut bacteria are recognized as significant contributors to obesity and obesity related metabolic diseases. The review examines the different pleiotropic effects of grape seed procyanidins that have a significant effect on metabolic disease in animal models of obesity.     

Cholesterol solubility in lecithin-bile salt systems

The method of sample preparation can markedly influence the rate of dissolution and attainment of supersaturated states of cholesterol. The equilibrium solubility of cholesterol, studied as a function of its physical state in a model bile system, is almost half that of previously accepted values. Slow attainment of the equilibrium state may have acted to bias previous studies. Extrapolation of our data to the clinical situation reveals that many persons considered normal by present standards actually possess bile that is supersaturated with respect to cholesterol and are thus potential gallstone formers.     

箬竹叶水提取物化学成分研究

御江箬竹和阔叶箬竹叶水提取物的得率分别为９．６９％和１１．９０％。组成糖中前者以果糖为最多，其次为葡萄糖和甘露糖；后者以阿拉伯糖为最多，其次为果糖和甘露糖。组成氨基酸中两者均以谷氨酸、精氨酸、丙氨酸、天门冬氨酸和丝氨酸较多。水溶性维生素，御江箬竹以Ｖ＿ｃ、烟酸、叶酸和Ｖ＿（Ｂ１）较多，Ｖ＿（Ｂ６）、胆碱和泛酸未检出；阔叶箬竹则以烟酸、Ｖ＿ｃ和Ｖ＿（Ｂ１）较多，Ｖ＿（Ｂ６）、Ｖ＿（Ｂ２）、叶酸、泛酸和胆碱未检出。本研究还测定了箬竹部分微量和常量元素的含量。     

筇竹笋生长过程中营养成分的变化1）

筇竹是优良的笋材两用竹种,为了解筇竹笋在生长过程中营养成分的变化,分析测定了3个不同出土高度（5～10 cm1、0～20 cm2、0～30 cm）筇竹笋的几种主要营养成分。结果表明：筇竹笋的水分、粗脂肪、蛋白质、可溶性糖的质量分数随着出土高度的增加逐渐下降;粗纤维质量分数随着出土高度的增长而增加;维生素C、总灰分质量分数随着出土高度的增长呈先上升后下降的趋势。筇竹笋含有17种常见氨基酸,氨基酸总量随着出土高度的增长呈先上升后下降,呈味类氨基酸的质量分数由高到低的顺序为：鲜味类、苦味类、甜味类、芳香类。筇竹笋营养成分丰富,是一种高蛋白、低脂肪、富含纤维素的健康食品,其中出土高度为10～20 cm的筇竹笋的营养品质和口感最优,食用价值和经济价值最高。     

贵州石阡苔茶生化成分分析

通过分析石阡苔茶群体品种鲜叶和成品茶的主要生化成分,结果表明：石阡苔茶群体品种鲜叶中,氨基酸、咖啡碱、可溶性糖和Vc的含量高于福鼎大白茶鲜叶,其中B样点鲜叶中咖啡碱、可溶性糖、茶多酚、氨基酸含量均高于A、C样点,A样点Vc含量最高达1.13%;成品茶茶多酚含量低于福鼎大白茶,而咖啡碱、水浸出物、Vc含量明显高于福鼎大白茶。说明作为贵州地方又一群体品种,石阡苔茶具有较大的开发利用前景。     

钙对酸性土壤不同品种莴笋产量和品质的效应

通过盆栽试验研究了施钙对酸性土壤5个品种莴笋（润农、挂丝红、双尖、二白皮、尖叶）产量和品质的影响.结果表明,增施钙肥使各品种莴笋产量提高且达显著（极）差异;施用钙肥二白皮莴笋品质提高明显,硝酸盐含量在5个品种中最低,维生素C在低肥、高肥处理中含量最高,可溶性糖、氨基酸含量在施钙水平下有所降低;挂丝红莴笋在4个处理中产量均为最高,并以N20P5K15Ca37处理的莴笋品质好,硝酸盐含量降低8.5%,维生素C含量增加32.9%,可溶性糖含量增加45.3%,氨基酸含量增加125.2%.     

Vitamin D receptor as an intestinal bile acid sensor

The vitamin D receptor (VDR) mediates the effects of the calcemic hormone 1alpha,25-dihydroxyvitamin D3 [1,25(OH)2D3]. We show that VDR also functions as a receptor for the secondary bile acid lithocholic acid (LCA), which is hepatotoxic and a potential enteric carcinogen. VDR is an order of magnitude more sensitive to LCA and its metabolites than are other nuclear receptors. Activation of VDR by LCA or vitamin D induced expression in vivo of CYP3A, a cytochrome P450 enzyme that detoxifies LCA in the liver and intestine. These studies offer a mechanism that may explain the proposed protective effects of vitamin D and its receptor against colon cancer.     

酸牦牛乳中乳酸菌降胆固醇作用及胆盐耐受性研究

为了从分离自甘肃酸牦牛乳中的23株乳酸菌中筛选能够同时降低胆固醇并耐受胆盐的乳酸菌,通过邻苯二甲醛法测定降胆固醇能力,并比较各菌株对三种形式的胆盐:牛胆汁、胆酸、甘胆酸钠的耐受性。结果表明,这些菌株在不同条件下的降胆固醇能力差异显著(P<0.05),多数菌株在不含牛胆汁的培养基中培养比添加牛胆汁时有着更好的对胆固醇的去除能力;死菌体对胆固醇的去除能力较弱;对各菌株对不同形式的胆盐耐受能力比较分析得出,各种形式的胆盐对乳酸菌的生长均有抑制作用,抑制顺序由强到弱依次为:甘胆酸钠>胆酸>牛胆汁;各菌株对胆盐的耐受力与降胆固醇能力没有相关性。通过比较选择出H1,I10和W2三株菌,作为功能性菌株为开发应用进行深入研究。     

不同沙棘品种果实营养成分的比较分析

本试验对卡图尼礼品、８９１１、巨人、ＭＨ、Ｍ４、中国沙棘６个沙棘品种的维生素Ｃ、维生素Ｅ、类胡萝卜素及游离氨基酸等指标进行了分析。结果表明，巨人含维生素Ｃ量最高，８９１１含维生素Ｅ量最高，ＭＨ含类胡萝卜素量最高；同时，氨基酸含量ＭＨ、８９１１含１７种，卡图尼礼品、中国沙棘含１６种，Ｍ４含１５种，巨人含１４种。其中，人体必需氨基酸ＭＨ、８９１１、卡图尼礼品含９种，中国沙棘、Ｍ４含８种，巨人含７种。     

甘南地区河曲马肉营养价值的研究

本文研究了河曲马肉的营养成分及营养价值。该品种肉蛋白质含量(22.87％)较高,脂肪含量(4.96％)较低。人类所需的各种必需氨基酸总量占全部氨基酸总量的12.67％。各种必需氨基酸的含量与人需要的“理想蛋白质”中的建议标准量相比较,仅缬氨酸(46.6mg/g蛋白质)略低于标准(50mg/g蛋白质)外,其他各种均不同程度地超过标准量。其中赖氨酸量为建议标准量的1.52倍。说明其肉蛋白质的质量较优。马脂中的多不饱和脂肪酸占脂肪酸总量的22.64％,多不饱和脂肪酸:饱和脂肪酸(P/S比)为0.6∶1,这是表明食物营养价值较高的另一主要方面。本试验测定出河曲马肉的胆固醇含量为101mg/100g鲜肉,总维生素C含量为20.20mg/100g鲜肉。