Lipopolysaccharide

Luận văn Thạc sĩ Y học: Đánh giá độc tính cấp, bán trường diễn và tác dụng chống đông máu của “Trân Châu Ngưu Hoàng Hoàn” trên động vật thực nghiệm được nghiên cứu nhằm xác định độc tính cấp, bán trường diễn của “Trân châu ngưu hoàng hoàn” trên động vật thực nghiệm; Đánh giá tác dụng chống đông máu của “Trân châu ngưu hoàng hoàn”trên mô hình gây đông bằng lipopolysaccharid trên động vật thực nghiệm.

102p visystrom 22-11-2023 11 7   Download

Mục tiêu của đề tài là đánh giá được tác dụng hạ sốt của cao chiết toàn phần, cao chiết phân đoạn và cao chiết tiêu chuẩn lá Bàng biển trên mô hình thỏ được gây sốt bằng lipopolysaccharid (LPS); đánh giá được độc tính cấp của cao chiết tiêu chuẩn lá Bàng biển trên chuột nhắt trắng.

55p closefriend03 13-10-2021 35 10   Download

Những đóng góp của luận án là lần đầu tiên nghiên cứu về thành phần hóa học và hoạt tính sinh học của loài hải miên Smenospongia cerebriformis ở vùng biển miền Trung Việt Nam. Đã phân lập xác định cấu trúc của 8 hợp chất mới từ loài hải miên S.cerebriformis. Lần đầu tiên các hợp chất phân lập được từ loài hải miên S.cerebriformis được đánh giá hoạt tính kháng viêm dựa trên khả năng ức chế NO trong đại thực bào được kích thích bởi Lipopolysaccharide.

27p acacia2510 11-05-2021 14 4   Download

Nguyên nhân Qua hình dạng phóng đại của kính hiển vi điện tử một số tác giả đã cho rằng tác nhân gây bệnh u nang biểu bì ở mang cá là những loài của Rickettsia (Paperna và CTV, 1981) hoặc Chlamydia (Wolf, 1981). Trong một số ký chủ, hình thái cấu tạo của chúng giống với những loài của Clarmydia, tuy nhiên một số ít nó giống những loài khác. Trong 2 kết quả nghiên cứu (Turnbull, 1987 và Bradley và CTV, 1988) đã xác định được kháng nguyên của giống Chlamydia là Lipopolysaccharide. Do đó tác nhân gây...

4p nhonnhipnp 13-06-2013 73 2   Download

Bacteroides vulgatus has been shown to be involved in the aggravation of colitis. Previously, we separated two potent virulence factors, capsular polysaccharide (CPS) and lipopolysaccharide (LPS), from a clinical isolate of B. vulgatus and characterized the structure of CPS. In this study, we elucidated the structures of O-antigen polysaccharide (OPS) and lipid A in the LPS. LPS was subjected to weak acid hydrolysis to produce the lipid A fraction and polysaccharide fraction.

7p system191 01-06-2013 50 8   Download

The structure of the O-polysaccharide of the lipopolysaccharide from a diarrheal strain isolated in Bangladesh was studied with sugar, and methylation analysis, NMR spectroscopy, mass spectrometry and partial acid hydrolysis. The strain was first designated as Hafnia alvei, but later found to be a possible new species in the genus Escherichia. Two different polysaccharides were detected, a major and a minor one. The structure of the major polysaccharide is given below, while the structure of the minor one was not investigated. ...

7p system191 01-06-2013 35 6   Download

Agrobacterium tumefaciens is a Gram-negative, phytopathogenic bacterium and is characterized by an unique mode of action on dicotyledonous plants: it is able to genetically modify the host, and because of this feature, it is used as a tool for transgenic plants. Many experiments have demonstrated that lipopolysaccharides (LPSs) play an important role for the disease development, as they are involved in the adhesion process of the bacterium on the plant cell wall.

4p system191 01-06-2013 32 4   Download

The effect of a-tocopheryl hemisuccinate (TS) on lipopolysaccharide (LPS)/interferon-c (IFN)-induced nitric oxide production in rat vascular smooth muscle cells (VSMC) was examined. The LPS/IFN-induced NO production was enhanced by TS but not by the other a-tocopherol (a-T) derivatives a-tocopheryl acetate (TA) and a-tocopheryl nicotinate (TN), or a-T itself. a-T, TA and TN inhibited the enhancement by TS of LPS/IFNinduced NO production.

6p research12 01-06-2013 39 4   Download

The structure of the lipopolysaccharide (LPS) of Pseudomonas aeruginosa immunotype 1 was studied after mild acid and strong alkaline degradations by MS and NMR spectroscopy. Three types of LPS molecules were found, including those with an unsubstituted glycoform 1 core (A) or an isomeric glycoform 2 core substituted with one O-polysaccharide repeating unit (B) or with a long-chain O-polysaccharide. Therefore, of two core glycoforms, only glycoform 2 accepts the O-polysaccharide. LPS molecules, an O-acetyl group is present in the outer core region at unknown position....

10p research12 01-06-2013 36 4   Download

From the lipopolysaccharide of the deep rough mutant I-69 Rd–/b+ of Haemophilus influenzae two oligosaccharides were obtained after de-O-acylation and separation by high-performance anion exchange chromatography. Their chemical structures were determined by one- and two-dimensional 1H-, 13C- and 31P-NMR spectroscopy as aKdo-4P-(2 fi 6)-bGlcN-4P-(1 fi 6)-aGlcN-1P and aKdo-5P-(2 fi 6)-bGlcN-4P-(1 fi 6)-aGlcN-1P.

6p research12 01-06-2013 31 4   Download

The CD spectra of SMAP-29, an antimicrobial peptide from sheep, showed disordered structure in aqueous buffers, and significant helicity in membrane-like environments, including SDS micelles, lipopolysaccharide (LPS) dispersions, and trifluoroethanol buffer systems. A structure determined by NMR in 40% perdeuterated trifluoroethanol indicated that residues 8–17 were helical, residues 18–19 formed a hinge, and residues 20–28 formed an ordered, hydrophobic segment.

9p research12 01-06-2013 36 4   Download

Structural analysis of the lipopolysaccharide (LPS) of nontypeableHaemophilus in¯uenzaestrain 1003 has been achieved by the application of high-®eld NMR techniques, ESI-MS, capillary electrophoresis coupled to ESI-MS, composition and linkage analyses on O-deacylated LPS and core oligosaccharide material. It was found that the LPS contains the common structural element of H.

11p research12 01-06-2013 47 7   Download

The chemical structure of lipid A from the lipopolysaccha-ride of the mushroom-associated bacterium Pseudomonas reactans,a pathogen of cultivated mushroom, was elucida-ted by compositional analysis and spectroscopic methods (MALDI-TOF and two-dimensional NMR). The sugar backbone was composed of theb-(1¢fi6)-linkedD-gluco-samine disaccharide 1-phosphate.

8p research12 29-04-2013 43 3   Download

TheO-chainpolysaccharide of the lipopolysaccharide (LPS) of a previously nonclassi®ed strain ofProteus mirabilis termed G1 was studied by sugar analysis and 1 Hand13 C NMR spectroscopy, including 2D COSY, TOCSY, rota-ting-frameNOE(ROESY),H-detected 1 H, 13 CHMQC,and heteronuclear multiple-bond correlation (HMBC) experi-ments.

7p research12 29-04-2013 48 5   Download

Recent studies have shown that the Porifera, with the examples of the demosponges Suberites domunculaand Geodia cydonium, comprise a series of pathways found also in the immune systemofDeuterostomia, suchas vertebrates, but are absent in Protostomia, with insects or nematodes as examples. One pathway is the (2¢)5¢)oligoadenylate syn-thetase [(2±5)A synthetase] system.

11p research12 29-04-2013 41 2   Download

Mild acid degradation of the lipopolysaccharide ofCitro-bacter gilleniiO9a,9b released a polysaccharide (PS), which was found to consist of a single monosaccharide, 4-acetamido-4,6-dideoxy-D-mannose (D-Rha4NAc,N-acetyl-D-perosamine). PS was studied by methylation analysis and 1 H-NMR and 13 C-NMR spectroscopy, using two-dimen-sional 1 H, 1 H COSY, TOCSY, NOESY, and H-detected 1 H, 13 C heteronuclear correlation experiments.

7p research12 29-04-2013 33 4   Download

The binding of lipopolysaccharide (LPS, also known as bacterial endotoxin) to human hemoglobin is known to result in oxidation of hemoglobin to methemoglobin and hemichrome. We have investigated the effects of the LPSs from smooth and rough Escherichia coliandSalmonella minnesotaon the rate of oxidation of native oxyhemoglobin A0and hemoglobin cross-linked between thea-99 lysines.

6p research12 23-04-2013 44 3   Download

Xanthomonas campestrispv.vitians is a Gram-negative plant-associated bacterium that acts as causative agent of bacterial leaf spot and headrot in lettuce. The lipopolysac-charide of this bacterium is suspected to be an important molecule for adhesion to and infection of the plants. The lipopolysaccharide has been isolated from the phenol phase and the O-specific chain characterized by compositional analysis, high fieldNMRandMALDI-TOFMS.

9p research12 23-04-2013 45 2   Download

The amino acid glycine is identified as a component of the inner core oligosaccharide in meningococcal lipopolysac-charide (LPS). Ester-linked glycine residues were consis-tently foundbymass spectrometry experiments tobe located on the distal heptose residue (HepII) in LPS from several strainsofNeisseriameningitidis.Nuclearmagnetic resonance studies confirmedand extended this observation locating the glycine residue at the 7-position of theHepIImolecule inL3 and L4 immunotype strains.

7p research12 23-04-2013 41 2   Download

A sialylated lacto-N-neotetraose (Sial-lNnT) structural unit was identified and structurally characterized in the lipo-polysaccharide (LPS) from the genome-sequenced strain Road (RM118) of the human pathogenHaemophilus influ-enzaegrown in the presence of sialic acid. A combination of molecular genetics, MS and NMR spectroscopy techniques showed that this structural unit extended from the proximal heptose residue of the inner core regionof theLPSmolecule.

11p research12 23-04-2013 36 2   Download