水解蛋黄粉Bonepep对骨代谢的影响

在小鼠和人体预实验水平上,作者旨在研究源于鸡蛋蛋黄的水解蛋黄粉(Bonepep)对骨质代谢的影响。给SD小鼠喂食10 mg/(kg·d)和100 mg/(kg·d)的Bonepep,使小鼠胫骨伸长提高了4.5%和10.3%。SD小鼠在长时间高剂量喂食后,其喂食期间各项生理生化指标与对照组比较未发生显著变化。而摄食Bonepep的小鼠尿样中脱氧吡啶啉(Dpyr)含量与未喂食的对照组降低了84.6%,其大腿端部断面中海绵骨明显减少。女性志愿者连续服用5周水解蛋黄粉后,其尿样中反映骨吸收指标的脱氧吡啶啉(DPD)与、尿中I型胶原交联N末端肽(NTx)水平无显著变化,但反映骨形成指标的骨碱性磷酸酶(BALP)活性则提高了14.6%。上述结果表明,水解蛋黄粉能够有效地抑制破骨分化和促进成骨生长。     

多种钙剂对大鼠骨代谢影响的初探

目的：比较不同钙剂对大鼠骨代谢影响的差异。方法：以断乳SD雌性大鼠为模型,随机分为7个实验组与2个对照组,分别为纳米螯合钙组、L-天门冬氨酸钙组、柠檬酸苹果酸钙组、牦牛骨钙组、牛骨钙组、珊瑚钙组、鱼骨钙组以及碳酸钙对照组、低钙对照组,各组饲以用不同种钙剂配制的饲料以及低钙饲料,测量各组大鼠股骨骨密度、骨钙含量等指标。结果：在股骨远心端,纳米螯合钙、柠檬酸苹果酸钙、L-天门冬氨酸钙组骨密度高于低钙对照组与碳酸钙对照组（P〈0.05）。L-天门冬氨酸钙组骨钙含量高于碳酸钙对照组（P〈0.05）。牦牛骨钙组大鼠血清碱性磷酸酶含量高于碳酸钙对照组（P〈0.05）。结论：L-天门冬氨酸钙改善大鼠骨代谢的效果较好,可作为钙补充剂的较好选择。     

乳清碱性蛋白对骨代谢影响的研究进展

牛乳碱性蛋白（Milk Basic Protein,MBP）是从牛奶乳清中分离出来的一组成分,是乳蛋白质的碱性部分。研究证实,MBP可直接作用于骨细胞,通过促进骨形成和抑制骨吸收作用,从而预防骨质疏松的发生;进一步的研究证实,MBP在骨骼模型重建的过程中起重要作用。本文概述SMBP对骨代谢影响的研究进展。     

婴幼儿配方食品中矿物元素的检测

为解决部分婴幼儿配方食品中矿物元素检测不均的问题,采用干法、湿法、微波法和复溶-微波法对样品进行消解检测,结果表明：干法消解的数据质量最差;湿法与微波消解法检测的结果相比,铜、铁、钾、镁、锰和钠的含量差异不显著（P>0.05）,部分矿物元素（铜、铁、钾、钠、磷、锌）检测结果的相对标准偏差（relative standard deviation,RSD）减小,但未达到预期。样品复溶后进行微波消解检测发现,用水复溶后的大部分元素含量偏低,特别是铁,且检测的矿物元素RSD均较大,而用5%硝酸复溶后,元素含量均没有明显偏高和偏低,且RSD均明显减小。因此,通过5%硝酸复溶样品后进行微波消解检测婴幼儿配方食品中的矿物元素,可以解决样品中矿物元素测定结果不均的问题。     

乳清蛋白组分及其对骨代谢的影响

乳清蛋白是干酪加工过程中产生的副产品,由于其组成成分的异质性和丰富性,成就了其在生物学功能上的多样性。乳清蛋白中的成分主要分为两大类：骨桥蛋白、酪蛋白磷酸肽和糖巨肽属活性蛋白等乳清酸性蛋白,及IGF-I、TGF-β和EGF等生长因子、半胱氨酸蛋白酶抑制剂C、HMG样蛋白和激肽原片断等乳清碱性蛋白。它们通过参与破骨细胞介导的骨吸收和成骨细胞介导的骨形成或者改变钙离子的溶解状态等方式影响骨代谢,在延缓由于年龄增长或雌激素减退引起的骨丢失、增强骨骼生物力度等方面发挥积极作用。     

高糖-氧化应激相关信号通路对各系统疾病的影响

高糖对机体健康具有较大影响.血糖浓度偏高会引起机体氧化应激,而信号通路调控紊乱是高糖引起氧化应激的主要原因之一.随着糖尿病患病率的持续增高,由高糖引起的相关疾病广受关注.目前有关高糖引起的氧化应激及其相关细胞信号通路在各系统疾病中的研究尚未见报道.本文从细胞类型出发,结合糖尿病及其相关并发症给机体不同系统带来的影响,对...     

食品试样中矿物元素分析的实验预处理

本文介绍食品试样中矿物元素实验处理的常用方法，指出了这些方法的适用范围。     

稀土元素镧代谢动力学及对血液元素谱的影响

目的 探讨镧经口暴露后在大鼠体内的吸收、分布、蓄积、排泄规律以及镧对大鼠血液元素谱的影响。方法 48只雌性SPF级大鼠随机分为8组进行单次经口暴露实验,一次性灌胃700 mg/kg·BW硝酸镧溶液。于灌胃后1、2、4、8、16、32、64、128 h采用电感耦合等离子体质谱仪（ICP-MS）测定大鼠全血、心、肝、脾、肺、肾、脑、股骨、粪便镧含量。48只SPF级大鼠随机分为4组（雌雄各半）进行重复经口暴露实验,每组含1个对照组和1个实验组。实验组重复灌胃镧含量66 mg/kg·BW的硝酸镧溶液,对照组灌胃等量生理盐水,每天1次,在第7、14、21和28 d时,各取1组（含对照组和实验组）,采用ICP-MS法测定大鼠全血44种元素含量以及肝、肾、股骨、粪便和尿液镧含量。结果 大鼠单次经口暴露镧后,镧在全血中达峰时间为2 h,消除半衰期为69.315 h,总体清除率为1.733 L/h/kg;镧随血液广泛分布于心、肝、脾、肺、肾、脑和股骨,以股骨中含量最高（P<0.05）;大鼠重复经口暴露镧14、21和28 d后,与肾含量相比,大鼠肝和股骨镧含量显著升高（P<0.05）,且实验组大鼠粪便镧含量显著高于尿液（P<0.001）。大鼠重复给予镧处理后,与对照组相比,实验组大鼠全血中除了镧含量显著升高（P<0.05）外,其余元素（钙、钠、钾、镁、铁、铜、锌、硒、钴、钼、铅、砷）含量在对照组和实验组间未见统计学差异（P>0.05）。结论 本试验镧经口暴露后可快速吸收入血,并广泛分布于心、肝、脾、肺、肾、脑和股骨,重复暴露后易沉积于肝和股骨,且以粪便排泄为主;未观察到镧对大鼠血液元素谱产生影响。     

基于TLR-4/NF-κB信号通路探究金花茶提取物对非酒精性脂肪肝的作用

探讨金花茶提取物对非酒精性脂肪肝病（NAFLD）大鼠模型的改善作用及其机制。随机选取10只SD大鼠为空白组,剩余50只则灌服高糖高脂乳剂复制非酒精性脂肪肝模型,14 d后造模大鼠按血清中总胆固醇（TC）水平随机分为模型组、辛伐他汀组（8 mg/kg）及金花茶高、中、低剂量组（260、130、65 mg/kg）。分组后连续给药6周,于末次给药前进行口服葡萄糖耐量试验（OGTT）并计算血糖曲线下面积（AUC）,末次给药后采集血清及肝组织,检测血脂指标总胆固醇（TC）、三酰甘油（TG）、高密度脂蛋白（HDL-C）、低密度脂蛋白（LDL-C）及游离脂肪酸（FFA）,肝脂指标TC及TG,肝功能指标谷丙转氨酶（ALT）及谷草转氨酶（AST）,肝脏脂质过氧化指标丙二醛（MDA）及超氧化物歧化酶（SOD）;测定大鼠血清炎症因子指标白介素6（IL-6）、白介素8（IL-8）及肿瘤坏死因子（TNF-α）;检测血清胰岛素（FINS）并计算胰岛素抵抗指数（HOMA-IR）;HE染色法观察肝脏病理形态学变化并进行非酒精性脂肪肝病活动度积分（NAS）评分;测定肝组织中Toll样受体4（TLR-4）和核因子κB（NF-κB）的基因及蛋白的表达。结果表明：与模型组相比,金花茶药物组AUC、HOMA-IR及血清中FINS、TG、TC、LDL-C、FFA、ALT、AST、IL-6、IL-8、TNF水平显著降低（P<0.05）,HDL-C水平明显升高（P<0.05）;肝组织TG、TC、MDA中含量显著降低（P<0.05）,SOD活性显著升高（P<0.05）;肝脏脂肪肝病样变减轻,肝细胞形态异常及炎症浸润明显改善,NAS评分显著下降（P<0.05）;TLR-4、NF-κB蛋白及mRNA表达降低,差异均有统计学意义（P<0.05）,其中以金花茶高剂量的改善效果最佳。综上所述,金花茶提取物可通过TLR-4/NF-κB信号通路来调节糖脂代谢紊乱,降低炎症反应和减轻炎症浸润,改善NAFLD大鼠肝脏病变。     

基于宏基因组技术分析传统红茶菌中菌群组成及其主要代谢通路

由于传统红茶菌发酵过程中,微生物的种类及数量随时间延长而不断变化,导致红茶菌发酵液代谢产物难以控制。采用高通量测序技术对发酵7 d的传统红茶菌进行宏基因组测序,获得65771178个clean reads数据,经拼接组装,获得93449个Unigene片段。以BLAST(E-value<1.0e^-5)将Unigene对NR、KEGG数据库进行比对,与NR库比对共65515个Unigene得到注释信息,再将得到的注释信息根据GI(GenInfo Identifier)与物种分类的关系得到物种分类信息,分为细菌、真菌2个界,细菌界占96.57%,真菌界占3.40%,细菌的主要优势菌种是Gluconacetobacter sp. SXCC-1(29.17%)、Komagataeibacter medellinensis(7.84%)、Komagataeibacter xylinus(7.58%),真菌的优势菌种是Brettanomyces bruxellensis(1.86%);与KEGG数据库比对,共47234 个Unigene注释到KEGG的代谢通路中,分属338类代谢通路,其中有2475个Unigene参与氨基酸代谢过程,307个属于次生代谢途径。序列已提交至GenBank数据库,登录号SRP103682。利用宏基因组技术将传统红茶菌中的微生物鉴定到     

Dietary calcium has little effect on mineral balance and bone mineral metabolism through twenty weeks of lactation in Holstein cows

Calcium and P balance and mobilization from bone were evaluated through 20 wk of lactation to determine the timing and extent of net resorption of bone mineral and mineral balance in lactating dairy cows. Eighteen Holstein cows were blocked by parity and calving date and randomly assigned to 1 of 3 dietary treatments: high (1.03%, HI), medium (0.78%, MED), or low (0.52%, LOW) dietary Ca. Dietary P was 0.34% in all diets. Cows consumed treatment diets from calving to 140 DIM. Total collection of milk, urine, and feces was conducted 2 wk before expected calving and in wk 2, 5, 8, 11, and 20 of lactation. Blood samples were collected at 14 and 10 d before expected calving and 0, 1, 3, 5, 10, 14, 21, 28, 35, 56, 70, 84, 98, and 140 d after calving. Blood samples were analyzed for Ca, P, and parathyroid hormone concentration. Serum concentrations of osteocalcin (OC), a marker of bone formation, and deoxypyridinoline (DPD), a marker of bone resorption, were measured to assess bone mobilization. Rib bone biopsies were conducted within 10 d postcalving and during wk 11 and 20 of lactation. Dietary Ca concentration affected Ca balance, with cows consuming the HI Ca diet in positive Ca balance for all weeks with the exception of wk 11. Interestingly, all cows across all treatments had a negative Ca balance at wk 11, possibly the result of timed estrous synchronization that occurred during wk 11. At wk 20, Ca balances were 61.2, 29.9, and 8.1 g/d for the HI, MED, and LOW diets, respectively. Phosphorus balances across all treatments and weeks were negative. Bone Ca content on a fat-free ash weight basis was least in cows consuming the MED diet, but bone P was not different. Serum Ca and P were not affected by treatment. Dietary Ca concentration did not affect P balance in the weeks examined, but there was a clear effect of parity on balance, markers of bone metabolism, and bone P. Primiparous cows had greater serum OC and DPD concentrations than multiparous cows. Regardless of dietary treatment, serum OC concentration peaked around d 35 of lactation. Simultaneously, DPD concentration began to decrease, which may indicate a switch from net bone resorption to formation after d 35. However, this was not reflected in balance measures. This information may help refine dietary mineral recommendations for lactating dairy cows and suggests that dietary P requirements are independent of dietary Ca.     

Influence of calcium and phosphorus feeding on markers of bone metabolism in transition cows

A study was carried out to verify the effect of Ca and P levels on production, digestibility, and serum bone metabolism biomarkers in dairy cows. Fifty-two nonlactating multiparous cows (≥3 lactations) were confined in a free-stall barn approximately 20 d before calving. A standard close-up diet was fed to cows once daily until d 2 postpartum. Cows were randomly assigned to 1 of 4 dietary treatments arranged in a 2 × 2 factorial approach averaging 0.64% Ca for high Ca (HCa), 0.46% Ca for low Ca (LCa), 0.47% P for high P (HP), and 0.38% P for low P (LP) on a dry matter basis. Experimental diets were fed twice daily from 3 d in milk (DIM) until 31 DIM. Intake and milk yield were recorded daily. Milk samples were collected on d 28, 29, and 30 postpartum for components analyses. Blood samples were drawn 10 d before expected calving, at calving, and at 15 and 30 DIM for serum analyses of osteocalcin, a biomarker of bone accretion, and pyridinoline, a biomarker of bone resorption. Total fecal collection was conducted when cows in a block averaged 20 DIM. Intake and production traits were not significantly affected by any of the dietary treatments. Cows averaged nearly 21 kg/d dry matter intake and 44 kg/d milk yield from 6 to 31 DIM. There were no significant differences across treatments in body weight or body condition score loss. Phosphorus intake, P fecal output, P digestibility, and P apparent absorption were affected by dietary P content. Calcium intake was higher with HCa, but Ca fecal output, digestibility, and apparent absorption showed an interaction between dietary Ca and dietary P. Calcium fecal output was 100.6 g/d for cows fed HCaHP, intermediate for cows on the HCaLP diet (89 g/d), and similar among cows fed the 2 LCa diets (70 g/d with LCaHP and 75 with LCaLP). There was no significant effect of Ca or P on osteocalcin measurements. Pyridinoline concentrations were affected by dietary Ca levels and tended to have a significant dietary Ca × dietary P interaction. Phosphorus apparent digestibility occurred independently of dietary Ca levels. Results of this study suggest that more bone was mobilized in cows fed LCa diets, but excess dietary P caused greater and prolonged bone mobilization regardless of dietary Ca content.     

牛骨粉品质及其生物利用率研究

通过相关的分析方法,分别对高压蒸煮工艺、低温冷冻工艺制备的牛腿骨、肋骨、椎骨骨粉中的钙磷含量、水分含量、溶解度和钙的生物利用率进行分析测定。结果显示:牛骨粉中钙含量高达17%~28%;磷的含量为3%~7%;水分含量较低,为0.9%~1.6%;溶解度为11%~25%;钙的生物利用率较高,为21%~38%。并将测定结果分别与鹿骨粉、市场上的牦牛骨粉固体颗粒的相应成分进行比较,结果表明:牛骨粉中的钙含量略高于鹿骨粉,磷含量、水分含量、溶解度和钙生物利用率都比较接近;比较蒸煮与冷冻两种工艺,结果显示:冷冻法制得的骨粉的钙磷含量、生物利用率较高,水分含量和溶解度都较低。     

Vitamin D status in growing dairy goats and sheep: Influence of ultraviolet B radiation on bone metabolism and calcium homeostasis

The aim of this study was to investigate how controlled UVB irradiation in combination with reduced nutritional vitamin D (vitD) supply affects vitD status and Ca metabolism of growing goats and sheep. The hypothesis was that, like dairy cows, goats and sheep are able to compensate for the missing nutritional supply of vitD through endogenous production in the skin, with the consequence of a high vitD status and a balanced Ca homeostasis. Sixteen lambs and 14 goat kids aged 3 and a half months were housed in an UVB free environment and fed hay and a vitD-free concentrate over a period of 13 wk. One group of each species was exposed to UVB lamps daily during individual feeding; the other groups served as controls. Serum, urine, and feces samples were taken at the start and at a monthly interval. Serum was analyzed for vitD metabolites, bone markers, growth hormone, insulin-like growth factor I, Ca, and P. Apparent digestibility and urinary excretion of Ca and P were determined. The left metatarsus was analyzed by peripheral quantitative computer tomography for bone mineral density before starting and at the end of the trial. In wk 13, all animals were slaughtered and samples of skin, rumen, duodenum, kidney, and bone (metatarsus) were collected. Content of sterols of vitD synthesis in the skin, Ca flux rates in rumen and duodenum, expression of vitD receptor in duodenum and kidney, renal and intestinal gene expression of Ca transport proteins, and renal enzymes related to vitD metabolism were determined. The UVB exposure led to lower 7-dehydrocholesterol content in the skin and a better vitD status (higher serum 25-hydroxyvitamin D), but no signs of vitD deficiency were seen in the control groups and no effect of irradiation was detected in the analyzed parameters of Ca homeostasis. Differences between the 2 species were detected: lambs had a higher increase of bone mineral density, lower values of bone markers, growth hormone, and insulin-like growth factor I in serum and higher tachysterol and lower lumisterol content in skin compared with goat kids. The results indicated that growing lambs and goat kids are able to compensate for a vitD-reduced diet by cutaneous vitD synthesis when exposed to UVB irradiation and therefore to keep a high vitD status. In contrast, when a reduced vitD diet is combined with missing UVB exposure, the vitD status drops, but the experimental time was probably too short to induce a vitD deficiency or an effect on Ca homeostasis.     

乳酸菌发酵猪骨粉中游离钙的研究

本实验利用保加利亚乳杆菌和嗜热链球菌混合菌种对猪骨粉进行发酵,以期提高发酵液中游离钙的含量。通过单因素试验和正交试验,确定发酵猪骨粉的最佳工艺条件为：保加利亚乳杆菌:嗜热链球菌为菌浓度之比2:1,蔗糖添加量为6%、乳酸菌接种量为7%、骨粉添加量为6%,此时发酵液中游离钙的含量为0.9942%,钙磷比为2.3:1。利用乳酸菌发酵猪骨粉,能显著提高发酵液中游离钙的含量。     

植物多酚通过Wnt/β-catenin信号通路抗肿瘤作用研究进展

Wnt信号传导通路是传递生长、发育信息的重要通路,与胚胎发育,细胞存活、生长、增殖、分化关系密切。此条通路的激活或抑制对肿瘤的发生发展有重要作用。植物多酚因其抗肿瘤潜能而成为开发防癌物质的重要来源。本文通过介绍Wnt/β-catenin信号通路的组成、调节机制及其与肿瘤的关系,总结植物多酚对肿瘤细胞中Wnt信号通路的作用机制,明确植物多酚对Wnt通路的有效靶点,为植物多酚保健食品(或药物)的开发提供新的依据。     

菊糖对大鼠钙吸收利用的影响

菊糖是从菊芋中提取的一种水溶性天然多糖,在中性和弱碱性的环境下可提高钙的溶解度和钙溶液的稳定性。取SD大鼠16只,分成对照组和实验组两组,对照组喂予基础饲料;实验组为基础饲料并灌胃2mL菊糖液(150mg/mL),喂养2周,并进行4天钙代谢试验。结果表明:实验组的钙吸收率比对照组提高10·60%,差别有显著性意义,血钙含量无显著差异。