Impact of dietary fat on gut microbiota and low-grade systemic inflammation: mechanisms and clinical implications on obesity

Dietary fat strongly affects human health by modulating gut microbiota composition and low-grade systemic inflammation. High-fat diets have been implicated in reduced gut microbiota richness, increased Firmicutes to Bacteroidetes ratio, and several changes at family, genus and species levels. Saturated (SFA), monounsaturated (MUFA), polyunsaturated (PUFA) and conjugated linolenic fatty acids share important pathways of immune system activation/inhibition with gut microbes, modulating obesogenic and proinflammatory profiles. Mechanisms that link dietary fat, gut microbiota and obesity are mediated by increased intestinal permeability, systemic endotoxemia, and the activity of the endocannabinoid system. Although the probiotic therapy could be a complementary strategy to improve gut microbiota composition, it did not show permanent effects to treat fat-induced dysbiosis. Based upon evidence to date, we believe that high-fat diets and SFA consumption should be avoided, and MUFA and omega-3 PUFA intake should be encouraged in order to regulate gut microbiota and inflammation, promoting body weight/fat control.     

不同种质金线莲氨基酸和矿物质元素量的比较

目的比较不同种质金线莲中氨基酸和矿物质元素的差异。方法采用全自动氨基酸分析仪和原子吸收光谱仪测定11个不同种质金线莲中氨基酸和矿物质元素的量。结果不同种质金线莲必需氨基酸为2.81%~4.47%,总氨基酸量为11.38%~17.06%,其中天门冬氨酸、谷氨酸和精氨酸的量明显高于其他氨基酸组分。矿物质元素中钾元素的量最高,其顺序为KCaMgFeMnZnCrCuPbCd。主成分分析表明丙氨酸、丝氨酸、谷氨酸、天门冬氨酸、苏氨酸、异亮氨酸、丙氨酸、苯丙氨酸、亮氨酸为金线莲的特征性氨基酸,Fe、Zn、Mn、Ca、Cr、Mg为金线莲的特征性元素。结论金线莲中氨基酸和矿物质元素量存在地域性差异。     

人工牛黄薄层指纹图谱多元图像分析及化学计量学研究

建立了人工牛黄薄层指纹图谱,对其图像进行数字化和化学计量学研究。首先采用以环己烷-乙酸乙酯-乙酸-甲醇(2∶7∶1∶2)为展开剂,10%硫酸乙醇溶液为显色剂,105℃加热至斑点清晰,并在366 nm下采集数码图像。然后将该图像转换成为灰度图像,得到指纹图谱的灰度曲线图多元数据,并采用主成分分析法对多元数据进行分析。结果表明薄层指纹图谱可表征不同生产企业生产的人工牛黄,并且分析得到图谱上表征来源的特征区域。该方法简便,快速,适合用于不同来源的人工牛黄质量差异的评价。     

栀子金花丸化学成分的UPLC-Q-TOF-MS/MS快速鉴定与分析

目的:采用超高效液相色谱串联四极杆飞行时间高分辨率质谱技术(UPLC-Q-TOF-MS/MS)对栀子金花丸整方的化学成分进行定性分析。方法:采用Waters ACQUITY BEH C_(18)超高效液相色谱柱(2.1 mm×100 mm,1.7μm),流动相0.1%甲酸乙腈溶液-0.1%甲酸水溶液梯度洗脱,流速0.4 m L·min~(-1),以正、负离子模式扫描的一级和二级质谱信息,结合文献报道,对栀子金花丸的主要色谱峰进行归属鉴别。结果:根据质谱裂解规律、保留时间及参考文献等信息,初步推测鉴定出65个化学成分,其中,20个黄酮类成分,9个环烯醚萜类成分,8个有机酸类成分,6个生物碱类成分,6个蒽醌类成分,4个甾体皂苷类成分,3个鞣质类成分,3个二萜色素类成分,3个双苯吡酮类成分,1个单萜类成分,1个二蒽酮类成分和1个柠檬苷素类成分。结论:建立的方法分离度好、灵敏度高,可同时对栀子金花丸不同类型化合物进行快速分析,有助于开展进一步的活性成分和质量控制研究。     

Local application of n-3 or n-6 polyunsaturated fatty acids in the treatment of human experimental gingivitis

BACKGROUND: Polyunsaturated fatty acids have the potential to attenuate inflammation by the synthesis of mediators of the 15-lipoxygenase pathways, which show opposite effects to the pro-inflammatory arachidonic acid metabolites such as leukotriene B4 (LTB4). AIMS: The aim of this clinical study was to evaluate the effects of topical application of n-6 or n-6 polyunsaturated fatty acids in patients with experimental gingivitis. METHODS: In each subject, similar teeth served as experimental and control over a 21-day non-hygiene phase and a 9-day resolving phase. Efficacy assessment was based on the bleeding on probing frequency (BOP) and the gingivocrevicular fluid volume (GCF). GCF was determined by inserting a filter paper strip for 30 s and measurements were performed on a Periotron 8000. The LTB4 concentration was analyzed by reversed-phase high-pressure liquid chromatography. RESULTS: After 21 days of plaque growth, the BOP, GCF and LTB4 levels were significantly increased in all groups, with no differences between the control and experimental side. Rinsing of an area with established gingivitis for a 9-day period significantly reduced the GCF in the n-6 group (71.9 (18.7) versus 47.4 (11.4) Periotron Units, median (inter quartile range)). CONCLUSION: The topical application of n-6 or n-6 fatty acids failed to inhibit the development of experimental gingivitis. Rinsing with n-6 fatty acids could reduce the level of GCF in established experimental gingivitis.     

Non-viral-mediated gene therapy approaches for bone repair

OBJECTIVES: Bone repair strategies continue to be developed for alternatives to autografting, allogeneic implants of banked bone, and other bone substitutes. Efforts have included the delivery of potent growth and/or differentiation factors and the use of gene therapy. For bone regeneration, gene therapy is the delivery, uptake and expression of DNA that has been localized to a wound bed. The objective of the current study is to investigate methods to enhance non-viral-mediated means of gene uptake and expression for use in bone regeneration. METHODS: Several types of DNA-polymer complexes, either applied directly to baby hamster kidney (BHK) cells, or released from a porous, resorbable gene-activated matrix (GAM), were evaluated in vitro for their ability to transfect cells with a circular plasmid DNA construct expressing green fluorescent protein. Complexes included conjugates containing a lipophilic reagent, liposomes, poly-ethyl-oxazoline, and poly-ethyleneimine (PEI). Data were subjected to analysis of variance and Fisher's protected least significant difference for multiple comparisons with significance established at p < 0.05. RESULTS: Transfection efficiencies of the liposome and PEI complexes improved in vitro when released from resorbable GAMs. The lipophilic reagent FuGene 6 demonstrated abundant uptake and expression in the initial 1- and 2-day evaluation periods. In contrast, the DNA-liposome and PEI GAM complexes demonstrated a sustained release, uptake and expression by the BHK cells at the 2-, 4-, and 7-day, and 4- and 7-day evaluation intervals, respectively. CONCLUSION: GAM technology appears to improve the functional stability and release duration of incorporated DNA-polymer complexes in the present in vitro studies. The ongoing objective of our research is to develop a localized treatment to improve the uptake and expression of plasmid DNA by non-viral-mediated gene therapy.     

The coupling of diffusion,migration and chemical equilibrium during the voltammetric reduction of weak polyprotic acids1

A theoretical model is presented for the coupling of diffusion, migration and chemical equilibrium during the voltammetric reduction of weak polyprotic acids. The dissociation reaction of a neutral acid is assumed to influence only the apparent diffusion coefficients of the hydrogen ion and its conjugate base anions. For typical values of equilibrium constants of dissociation reactions and analytical concentration, polyprotic acids behave as either monoprotic acids or diprotic acids, which agrees well with experimental results. A semi-quantitative explanation based on a diffusion layer treatment is proposed for this phenomenon. It is also shown that the ratio of limiting current at low concentration of supporting electrolyte to diffusion-limited current depends on the initial equilibrium concentrations of all species in the solution but not on the kinetics of the dissociation reactions. Furthermore the movement of the uncharged species (the neutral acid) can be influenced by an electric field through the coupling effected by the chemical equilibrium.     

Effects of transforming growth factor beta1 (TGFbeta-1) and dentin non-collagenous proteins (DNCP) on human embryonic ectomesenchymal cells in a three-dimensional culture system

Cranial neural crest-derived ectomesenchymal cells represent a population of pluripotent stem cells giving rise to many of the various oro-facial and dental tissues. The factors determining the terminal fate of these cells are still unclear. The potentiality of human embryonic ectomesenchymal cells from the first branchial arch have been investigated when isolated and grown in a three-dimensional (3D)-collagen gel culture system in the presence of dentin matrix-derived non-collagenous proteins (DNCP) and TGFbeta-1. Functional differentiation of cells showing some characteristics of odontoblast-like cells could be observed when the cells were cultured with DNCP+TGFbeta-1 or DNCP, however, only cytological differentiation was observed during culture with TGFbeta-1 alone. The characteristics of these cells was assessed by morphological appearance, expression of the odontoblast phenotype marker dentin sialophosphoprotein (DSPP), increased alkaline phosphatase levels and formation of mineralised nodules in vitro. The results indicate that these embryonic cells from the first branchial arch are capable of responding to the inductive stimulus of DNCP or DNCP+TGFbeta-1 when isolated and grown in the 3D collagen gel culture system. The capacity of the isolated cells to differentiate into mineralizing cells showing some characteristics of odontoblast-like cells under these growth conditions highlights the potential of such approaches for tissue engineering strategies for hard-tissue regeneration after injury.     

Separation of the outer membrane and identification of major outer membrane proteins from Porphyromonas gingivalis

The outer membrane of Porphyromonas gingivalis, an oral strict anaerobe, was isolated by sucrose density gradient centrifugation. The outer membrane obtained by the differential detergent extraction method, previously reported, showed an essentially similar protein pattern on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), confirming that the latter method is suitable for the study of outer membrane proteins in this organism. N-terminal amino acid sequence analysis revealed that major outer membrane proteins in this organism included Arg-gingipain, Lys-gingipain, RagA (a TonB-linked receptor), and putative porins that were homologous to Escherichia coli OmpA.     

Amino acid utilization by Fusobacterium nucleatum grown in a chemically defined medium

The present investigation evaluated amino acid utilization by 120 strains of Fusobacterium nucleatum in a chemically defined medium and attempted to relate the patterns to 3 proposed subspecies of F. nucleatum. Strains were inoculated into a chemically defined medium, with and without 2 g/l glucose, consisting of 14 inorganic salts, 21 amino acids, 23 vitamins and cofactors, and 7 purines and pyrimidines. After 7 days of anaerobic incubation, the spent culture medium, as well as the uninoculated control medium, were analyzed for amino acid content by ion chromatography. Amino acid utilization was determined by the differences in concentrations of amino acids found in inoculated and uninoculated samples. If greater than 34% of the amino acid was removed from the medium, the amino acid was considered to be utilized. Of the 21 amino acids present in the chemically defined medium, 8 amino acids, lysine, glutamine, asparagine, histidine, threonine, serine, glutamate and cysteine were consistently utilized. Four amino acids, tyrosine, tryptophan, methionine and aspartate were utilized by some strains but not others. Nine amino acids, alanine, leucine, isoleucine, glycine, valine, phenylalanine, proline, ornithine, and arginine were not utilized by any of the strains. The utilization patterns did not relate to subspecies formed on the basis of SDS-PAGE and DNA hybridization.