Biomedical subjects

Yang Lu

Publications and source records attributed to Yang Lu.

97 records · Page 6Linked to original sources

PubMed2002

Cardiovascular effects of urotensin II in different brain areas.

It has been shown that intracerebroventricular injection of urotensin II (UII)-induced hypotensive and bradycardiac responses. Here, we tested the cardiovascular roles of UII in different brain areas by microinjection of UII into the A1 and A2 areas (noradrenergic cells found in the lower part of the medulla that have been designated either A1 or A2 areas), the paraventricular and the arcuate nucleus. In urethane-anaesthetized rats, we observed that: (1) microinjection of UII into the A1 area induced dose-related depressor and bradycardiac responses; (2) mean arterial blood pressure (mABP) and heart rate (HR) did not change significantly after microinjection of UII into the A2 area; and (3) significant increases in mABP and HR were induced after microinjection of 10 pmol UII into either the paraventricular or arcuate nucleus. The above results suggest that UII, in different brain areas, plays different roles in cardiovascular regulation and the A1 area is a very important action site for UII in cardiovascular regulation.

Animals↗

PubMed2002

Beesiosides G, H, and J-N, seven new cycloartane triterpene glycosides from Beesia calthifolia.

Seven new cycloartane glycosides (1-7), beesiosides G, H, and J-N, together with beesioside I (8) and beesioside A, were isolated from the rhizomes of Beesia calthifolia, and their structures were established by spectroscopic and chemical methods. Beesiosides G, H, and J-N were assigned as 20xi(1),24xi(2)-epoxy-9,19-cyclolanostane-3beta,16beta,18,25-tetraol-3-O-beta-D-glucopyranoside (1), 20xi(1),24xi(2)-epoxy-9,19-cyclolanostane-3beta,16beta,18,25-tetraol-3-O-[beta-D-glucopyranosyl-(1-->6)]-beta-D-glucopyranoside (2), (20S,24R)-15alpha,16beta-diacetoxy-20,24-epoxy-9,19-cyclolanostane-3beta,18,25-triol-3-O-beta-D-xylopyranoside (3), (20S,24S)-16beta-acetoxy-18,24;20,24-diepoxy-9,19-cyclanostane-3beta,15beta,25-triol-3-O-beta-D-xylopyranoside (4), (20S,24S)-16beta-acetoxy-18,24;20,24-diepoxy-9,19-cyclanostane-3beta,25-diol-3-O-beta-D-xylopyranoside (5), 20xi(1),24xi(2)-epoxy-15alpha-acetoxy-9,19-cyclolanostane-3beta,16beta,25-triol-3-O-beta-D-xylopyranoside (6), and 20xi(1),24xi(2)-epoxy-9,19-cyclolanostane-3beta,12alpha,15alpha,16beta,25-pentaol-3-O-beta-D-xylopyranoside (7), respectively.

Chromatography, Thin Layer↗

PubMed2002

Isolation and characterization of Brachystemidines A-E, novel alkaloids from Brachystemma calycinum.

Five novel alkaloids, brachystemidines A-E (1-5), were isolated from the roots of Brachystemma calycinum. Their structures were established by spectral data, especially by 1D and 2D NMR techniques. The crystal structure of brachystemidine D was determined via X-ray diffraction analysis.

Alkaloids↗

PubMed2002

Construction of pGFP-FL plasmid and its application in preparing FL-secreting tumor vaccine.

OBJECTIVE: To construct a plasmid containing a green fluorescent protein (GFP) reporter gene as the effective vector for preparing fms-like tyrosine kinase receptor-3 ligand (FL)-secreting tumor vaccines. METHODS: A pGFP-FL plasmid, harboring a FL gene and a GFP gene, was designed and constructed by routine molecular cloning techniques. In this plasmid, FL gene was under the control of cytomegalovirus promoter, while EF-1a promoter acted to drive GFP gene. A prokaryotic/eukaryotic selective gene Kan(R)/neo was also introduced into the plasmid. After structure identification by restriction analysis, pGFP-FL plasmid was further transferred into Hepa1-6 cells, and the expression of GFP and FL genes was examined by way of fluorescent microscopy and reverse transcriptase-PCR respectively. RESULTS: Restriction analysis showed that the structure of pGFP-FL plasmid was exactly the same as anticipated. Further results indicated that both GFP and FL genes were simultaneously expressed in Hepa1-6 cells. CONCLUSION: A new plasmid has been established as the vector for studying the FL-secreting tumor vaccines, in which GFP gene can serve as a reporter gene reflecting the expression of FL gene.

Animals↗

PubMed2002

Synthesis of targeted drug delivery system for fluorouracil using sulfadiazine as the carrier.

OBJECTIVE: To synthesize a targeted drug delivery system for 5-fluorouracil (5Fu) using sulfadiazine (SF) as a carrier with reduced side-effects and strong antitumor activity. METHODS: SF-poly (ethylene glycol) (PEG) conjugate was initially synthesized. 5Fu was subjected to reaction with trichloromethyl chloroformate to prepare chloroformyl 5Fu, which was linked to a spacer hydroxyl group of PEG that served as a macromolecular linking arm between SF and 5Fu. The content of 5Fu in the conjugate was determined by ultraviolet spectrophotometry. Spectrum of ultraviolet and infrared along with differential scanning calorimetry were employed to identify the structure of the conjugate of SFPEG-end capped 5Fu. RESULTS: The drug loading content of the conjugate was 3.2 %, and structural analysis confirmed the linkage between 5Fu and SF via PEG. CONCLUSION: Targeted drug delivery system for 5Fu using SF as a carrier has been successfully synthesized by this means.

Antimetabolites, Antineoplastic↗

PubMed2002

[Induction of immune responses in mice by hepatitis B virus large envelope DNA vaccine delivered by attenuated Salmonella typhimurium].

The enhanced green fluorescent protein (EGFP) expression plasmid was transformed into an attenuated AroA- autotrophic mutant of Salmonella typhimurium SL7207, the resultant bacteria was administered orally to BALB/c mice. EGFP expressed in spleen cells was detected by flow cytometry. A DNA vaccine encoding HBV large envelope protein was immunized BALB/c mice by oral delivery through SL7207 or by direct intramuscular injection. The serum antibodies, T lymphocyte proliferative response and cytotoxic T lymphocyte response of mice were detected. The results showed that both DNA immunization methods could induce cellular and humoral immune responses, whereas oral vaccination elicited stronger immune responses than intramuscular vaccination did. Therefor, oral administration with HBV DNA vaccine using attenuated Salmonella may be a simple and effective method for the therapy of hepatitis B.

Animals↗

PubMed2002

[Chemical constituents from Alyxia sinensis (II)].

OBJECTIVE: To demonstrate the chemical constituents of Alyxia sinensis. METHOD: The constituents were isolated by column chromatography and identified by advanced physical and spectral analysis. RESULT: Eight compounds have been isolated and elucidated as bauereny acetate(18), scopletin(19), liriodendrin(20), pinoresinol-di-O-beta-D-glucopyranoside(21), daucosterol(22), flaxetin(23), esculin(24), aseculin(25). CONCLUSION: These compounds were found from the plant for the first time, and compound 20,21,23-25 were found from Alyxiae genis for the first time, and compound 18 is firstly been isolated from natural source.

Apocynaceae↗