Biomedical subjects

S H Wu

Publications and source records attributed to S H Wu.

At least 37 records · Page 2Linked to original sources

PubMed2001

Function and regulation of cholecystokinin octapeptide, beta-endorphin and gastrin in anorexic infantile rats treated with ErBao Granules.

AIM: To study the role of cholecystokinin octapeptide (CCK-8),beta endorphin (beta EP), and gastrin in an anorexic infantile rat model and no subsequent regulation of nose peptides by the Yunpi complex prescription ErBao Granule. METHODS: We fed infantile rats with special prepared forage. A liquid extract of ErBao Granule was administered to the rats daily for 3 weeks, CCK-8, beta-EP, and gastrin concentrations in hypothalamus, gastric antrum, and plasma of the rats were measured by radioimmunoassay, and were compared with controls. RESULTS: Treatment of rats with ErBao Granule inhibited CCK-8 secretion and increased beta-EP and gastrin secretion. CCK-8 concentration in hypothalamus and plasma of model control group increased significantly and correlated negatively with food intake of models, respectively. beta-EP concentration in gastric antrum and plasma of model control group decreased significantly and showed a positive correlation with food intake of models, respectively. Hypothalamus concentration of beta-EP was similar in models and controls. Gastrin concentration in gastric antrum of models was lower than in the blank control group, and correlated positively to food intake of models. Finally, CCK-8 concentrations in plasma of rats showed a positive correlation with plasma beta-EP (r=-0.68, P<0.05). CONCLUSION: The increased plasma and hypothalamus concentration of CCK-8, decreased gastric antrum and plasma level of beta-EP, and decreased gastric antrum concentration of gastrin are associated significantly with the anorexia of infantile anorexic rat models produced by special for-age. ErBao Granule can reverse these changes, which may be the major mechanisms of ErBao Granule simulating feeding.

Animals↗

PubMed2001

Increased soluble Fas ligand concentration in tuberculous pleural effusion.

BACKGROUND AND PURPOSE: Tuberculous (TB) pleurisy results from a delayed hypersensitivity reaction involving macrophages, T-cells, and many cytokines (including tumor necrosis factor, interferon-gamma, and interleukin 1 and 2). Infection by Mycobacterium tuberculosis induces apoptosis in gamma/delta T-cells and macrophages. Fas ligand (FasL) is a type II membrane protein that plays an important role in the regulation of apoptosis and has an intimate relation with these cells and cytokines. A soluble form of FasL (sFasL) exists in a variety of human body fluids, including serum, pleural effusion, cerebral spinal fluid, and ocular fluid. Therefore, we hypothesized that Fas activity is elevated in TB pleurisy. This study investigated the concentration of sFasL in TB pleural effusions and compared it with expression of sFasL in various other pleural effusions. METHODS: Using an enzyme-linked immunosorbent assay, we investigated the sFasL concentrations of 80 pleural effusions from patients with various diagnoses. RESULTS: The median sFasL concentration in the TB pleural effusion group was 104.91 pg/mL (n = 32). This was significantly higher than values in the transudate group (median value, 20.02 pg/mL, n = 9, p < 0.001) and patients with malignant effusion associated with adenocarcinoma of the lung (median value, 23.29 pg/mL, n = 14, p < 0.001). Lymphoproliferative disease could not be distinguished from TB based on sFasL concentrations in pleural effusion. CONCLUSIONS: The sFasL concentration in TB pleural effusions is significantly higher than that in adenocarcinomatous pleural effusions, which are the most common malignant pleural effusions. This difference may serve as a diagnostic tool to differentiate these two most commonly encountered unexplained pleural effusions. Determination of the cellular source and the actual role of the abundant sFasL in TB pleurisy will require further investigation.

Adenocarcinoma↗

PubMed2001

[Structural and functional study of prokaryotic enhancer-like element VV1 from vaccinia virus].

Enhancer VV1 (about 283 bp) is selected as the target to analyze its structure and function systemically. Stepwise deletion experiment is used to identify the functional domain of VV1 element. The results suggest that the 20 bp at 5' terminal and 20 bp at 3' terminal are important to the activity of VV1, for without either of them its activity decreased greatly. Furthermore, the 30-50 bp at 5' terminal is essential to its activity, without which will lead to complete loss of its activity. By random mutagenesis assay it is found that base mutation can regulate the activity of enhancer VV1 positively or negatively. The more the activities of mutants descend, the more mutations take place. For singlebase mutation, the activities change relatively little, and most of the mutations always occur in the 50 bp at the 5' terminal.

Base Sequence↗

PubMed2001

Genotype and allele frequency of the 27-bp tandem repeat polymorphism in the endothelial nitric oxide synthase gene in Chinese population.

Genotype and allele frequency of the polymorphic 27-bp repeat, a variable number of tandem repeats (VNTR) located in intron 4 of the endothelial nitric oxide synthase gene, were analyzed in 316 healthy Chinese individuals. Four genotypes, namely 6/5-repeats heterozygous, 5/5-repeats homozygous, 5/4-repeats heterozygous and 4/4-repeats homozygous, were identified. Both observed genotype and allele frequencies of this VNTR in Chinese were similar to those of Japanese, while the 4/4-repeats genotype differed significantly from that of Caucasians in Spain, and all ones did from those of African-American in United States.

Alleles↗

PubMed2000

Defining the bilin lyase domain: lessons from the extended phytochrome superfamily.

Through pattern searches of genomic databases, new members of the growing family of phytochrome-related genes were identified and used to construct a 130-180 amino acid motif that delimits the bilin lyase domain, a subdomain of the extended phytochrome family that is sufficient for covalent attachment of linear tetrapyrroles (bilins). To test this hypothesis, portions of locus sll0821, a novel phytochrome-related gene from Synechocystis sp. PCC6803 that encodes a large protein with two potential bilin binding sites, were amplified, and the recombinant apoproteins were tested for bilin binding and phytochrome photoactivity. Our experiments indicated that both sites of this protein, termed Cph2 for cyanobacterial phytochrome 2, possessed bilin lyase activity, revealing two distinct classes of bilin lyase domains--those whose bilin adducts are red, far-red reversible and a second class whose bilin adducts are nonphotochromic. Spectroscopic analysis of photochromic phycocyanobilin and fluorescent phycoerythrobilin adducts of a 24-kDa fragment of Cph2 definitively established that the motif identified by pattern searches represents a bona fide bilin lyase domain. Site-directed mutagenesis of highly conserved charged residues within bilin lyase domains of nearly all members of the extended phytochrome superfamily has identified a glutamate residue critical for bilin binding.

Amino Acid Sequence↗

PubMed2000

Alkaloid-fullerene systems through photocycloaddition reactions.

The photocycloaddition of tertiary amines to ¿60fullerene (C(60)) is an interesting and useful reaction. We wished to extend the applications of this type of reaction through an investigation of the photoaddition of alkaloids to C(60) for the purpose of synthesizing novel and complex photoadducts that are difficult to obtain by usual methods. Irradiation of tazettine (2) or gramine (3) with C(60) in toluene leads to formation of one monoadduct (6 or 7), whereas scandine (1a) or 10-hydroxyscandine (1b) reacts with C(60) photochemically to give two products, the expected ¿6,6 monoadduct (5a, 5b) and a new type of monoadduct with a bis-¿6, 6 closed structure (4a, 4b). These new structures were characterized by UV-vis, FT-IR, (1)H NMR, (13)C NMR, (1)H-(1)H COSY, ROESY, HMQC (heteronuclear multiple-quantum coherence), and HMBC (heteronuclear multiple-bond connectivity) spectroscopy. The techniques of time-of-flight secondary ion MS (TOF-SIMS) and field desorption MS (FD-MS) were used for the mass determination. (3)He NMR analysis of the product mixture from photoaddition of 1a to C(60) containing a (3)He atom ((3)He@C(60)) led to two peaks at -9.091 and -11.090 ppm relative to gaseous (3)He, consistent with formation of a ¿6, 6-closed monoadduct and a bis-¿6,6 closed adduct. Presumably, the bis-¿6, 6 closed adducts are formed by an intramolecular ¿2 + 2 cycloaddition of the vinyl group to the adjacent 6,6-ring junction of C(60) after the initial photocycloaddition.

Alkaloids↗

PubMed2000

Tirucallane triterpenoids from Dysoxylum hainanense.

Four tirucallane derivatives, 3beta,22S-dihydroxy-tirucalla-7,24-dien-23-one, 22,23-epoxy-tirucalla-7-ene-3beta,24,25-triol, 3beta,25-dihydroxy-tirucalla-7,23-diene, 23,26-dihydroxy-tirucalla-7,24-dien-3-one, together with two known triterpenoids, 24,25-epoxy-3beta,23-dihydroxy-7-tirucallene, tirucalla-7,24-diene-3beta,23-diol, were isolated from Dysoxylum hainanense. Their structures were elucidated on the basis of spectroscopic evidence.

Magnoliopsida↗

PubMed2000

Components of Cipadessa baccifera.

Four compounds were isolated from dry seeds of Cipadessa baccifera (Roth) Miq. along with the known 2beta,3beta,4beta-trihydroxypregnan-16-one, febrifugin, and khaysin T. Their structures were elucidated on the basis of spectral analysis to be cipadesin, 17alpha,20R-dihydroxypregnan-3,16-dione, 1,4-epoxy-16-hydroxyheneicos-1,3,12,14,18-pentaene and 1,4-epoxy-16-hydroxyheneicos-1,3,12,14-tetraene.

Ketones↗

PubMed2000

Synthesis and cytotoxic effect of 1,3-dihydroxy-9,10-anthraquinone derivatives.

1,3-Dihydroxy-9,10-anthraquinone (4) was reacted with epichlorohydrin or 1,omega-dibromo-alkane to yield 1-hydroxy-3-(2,3-epoxypropoxy)-9,10-anthraquinone (5) and 1-hydroxy-3-(3-chloro-2-hydroxypropoxy)-9,10-anthraquinone (6) or 1-hydroxy-3-(omega-bromoalkoxy)-9,10-anthraquinone. Ring-opening of the epoxide (5) or 1-hydroxy-3-(omega-bromoalkoxy)-9,10-anthraquinones with appropriate amines, afforded various 1-hydroxy-3-(3-alkylamino-2-hydroxypropoxy)-9,10-anthraquinones. The synthetic compounds were tested in vitro inhibition of human T-24, Hep 3B, Hep G2, SiHa, HT-3, PLC/PRF/5 and 212 cells. Almost all compounds showed significant inhibitory activity against several different cancer cell lines. Structure-activity analysis indicated epoxidation of the hydroxyanthraquinone increased cytotoxicity against tumour cells, but ring-opening of the epoxide group with amine did not enhance the cytotoxic activity. The phosphatidylserine (PS) externalization and DNA fragmentation in SiHa cells were significantly observed after 48 h incubation with selected compound 19. The results show that 19 cause cell death by apoptosis.

Anthraquinones↗

PubMed2000

Limonoids and phytol derivatives from Cedrela sinensis.

Two new compounds, cedrellin (1) and 2,6,10,15-phytatetraene-14-ol (2), together with five known compounds, 7 alpha-obacunyl acetate, 6-acetoxyobacunol acetate, 7 alpha-acetoxydihydronomilin, 2,6,10-phytatriene-1,14,15-triol and phytol were isolated from leaves of Cedrela sinensis. Their structures were elucidated on the basis of combined one- and two-dimensional spectral techniques.

Drugs, Chinese Herbal↗

PubMed2000

A new triterpenoid from Azadirachta indica.

A new triterpenoid, 1 alpha,7 alpha-diacetoxyapotirucall-14-en e-3 alpha, 21,22,24,25-pentaol (1), and the two known compounds odoratone (2) and 2 beta,3 beta,4 beta-trihydroxypregnan-16-o ne (3) were isolated from a methanolic extract of the seed kernels of Azadirachta indica. Their structures were elucidated on the basis of spectral methods.

Cholestenes↗

PubMed2000

Long-term potentiation in the inferior colliculus studied in rat brain slice.

The purpose of this study is to determine whether long-term potentiation (LTP) can be induced in the central nucleus of the inferior colliculus (ICC) by electrical stimulation of the lateral lemniscus. If LTP can be induced, is it mediated by N-methyl-D-aspartate (NMDA) and/or other receptors? Brain slices of the ICC were obtained from 14-35 day old Wistar rats. The field potentials were recorded from the ICC after GABAergic and glycinergic inhibition was suppressed. Following tetanic stimulation (50 Hz, 20 s), the amplitude of the response was increased to about 146% of control response for at least 30 min. LTP was observed in about 78% of the cases tested. Induction of LTP in the ICC required activation of both NMDA and gamma-aminobutyric acid (GABA)(B) receptors. GABAergic inhibitory postsynaptic potentials (IPSPs) were blocked by the GABA(A) receptor antagonist, but not by the GABA(B) receptor antagonist. The IPSPs were decreased by the GABA(B) receptor agonist, baclofen. The intrinsic postsynaptic membrane properties were not affected by baclofen. These results suggest that GABAergic inhibition in the ICC is mediated only by GABA(A) receptors, but that it is modulated by presynaptic GABA(B) receptors. The GABA(B) receptors in the ICC may suppress GABAergic inhibition and promote induction of LTP.

Animals↗

PubMed2000

Developmental changes in physiological properties in the rat's dorsal nucleus of the lateral lemniscus.

To better understand the development of the dorsal nucleus of the lateral lemniscus (DNLL), intrinsic membrane properties and synaptic responses of DNLL neurons in brain slice preparations were examined. Intracellular recordings were taken from DNLL neurons of rat pups at postnatal days 4-8 (early group), 10-12 (intermediate group) and 16-18 (late group). In response to positive current injection, neurons in the early group displayed firing with lower frequency and a longer action potential duration in comparison to the intermediate and late groups. The action potential amplitude of DNLL neurons increased during development. Postsynaptic potentials (PSPs), with excitatory predominance, were elicited by electrical stimulation of the lateral lemniscus and commissure of Probst throughout the three age groups. Neurons showed a longer latency and rise time of the PSPs in the early group in comparison with those in the intermediate and late groups. These results suggest that the early DNLL neurons display physiological characteristics associated with immature neurons, while the other two groups tend to illustrate mature-like neuronal properties. Furthermore, it seems that the neurons at day 10-12 are in a transitional period of development, which coincides with the onset of hearing.

Action Potentials↗

PubMed2000

Two novel secoergosterols from the fungus Tylopilus plumbeoviolaceus.

Two novel secoergosterols, 3beta-hydroxy-8alpha,9alpha-oxido-8, 9-secoergosta-7,9(11),22-triene (tylopiol A) (1) and 3beta-hydroxy-8alpha,9alpha-oxido-8,9-secoergosta-7,22 -dien-12-one (tylopiol B) (2), were isolated from the fresh fruit bodies of Tylopilus plumbeoviolaceus, along with three known compounds, ergosta-7,22-dien-3beta-ol, uridine, and allitol. Their structures were elucidated by NMR techniques, including (1)H NMR, (13)C NMR, HMQC, HMBC, and MS. The structure and stereochemistry of compound 1 were demonstrated by X-ray crystallography.

Agaricales↗

PubMed2000

Tetranortriterpenoids from Walsura yunnanensis.

Five new tetranortriterpenoids-walsurin (1), isowalsuranolide (2), walsuranolide (3), 11beta-acetoxywalsuranolide (4), and 20, 22-dihydro-22,23-epoxywalsuranolide (5)-and three new natural tetranortriterpenoids-11beta-hydroxydihydrocedrelone (6), 11beta-acetoxydihydrocedrelone (7), and 11beta-hydroxycedrelone (8)-together with a known tetranortriterpenoid, cedrelone (9), were isolated from the bark of Walsura yunnanensis. The structures of 1-8 were determined on the basis of spectral evidence.

Plants↗

PubMed2000

Structure of human erythrocyte catalase.

Catalase (E.C. 1.11.1.6) was purified from human erythrocytes and crystallized in three different forms: orthorhombic, hexagonal and tetragonal. The structure of the orthorhombic crystal form of human erythrocyte catalase (HEC), with space group P2(1)2(1)2(1) and unit-cell parameters a = 84.9, b = 141.7, c = 232.5 A, was determined and refined with 2.75 A resolution data. Non-crystallographic symmetry restraints were employed and the resulting R value and R(free) were 0.206 and 0.272, respectively. The overall structure and arrangement of HEC molecules in the orthorhombic unit cell were very similar to those of bovine liver catalase (BLC). However, no NADPH was observed in the HEC crystal and a water was bound to the active-site residue His75. Conserved lattice interactions suggested a common growth mechanism for the orthorhombic crystals of HEC and BLC.

Animals↗

PubMed2000

Purification and properties of ornithine racemase from Clostridium sticklandii.

Ornithine racemase has been purified to homogeneity from Clostridium sticklandii, as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This is the first racemase known to be highly specific to ornithine. This PLP-dependent enzyme has an M(r) of 92, 000, with a K(m) for L-ornithine of 0.77 +/- 0.05 mM and a k(cat) of 980 +/- 20 s(-1).

Amino Acid Isomerases↗

PubMed2000

[Functional and structural analysis of a prokaryotic enhancer-like element in Escherichia coli MC1061 strain].

Cat and lacZ genes were used as reporter gene and three prokaryotic enhancer-like element (MC2, MC8 and MC9) were identified in the genomic DNA of MC1061 strain. All three fragments can improve the expression of lacZ gene by 2-5 times with the orientation independence. The results of in vivo transcription and Dot blot hybridization assays suggested that MC8 regulated the expression of lacZ at transcription level. Stepwise deletion expreriments showed the functional domain of MC8 located at 450-950 bp, and in regions 450-600 bp and 840-950 bp contain at least one functional loci. Sequence data indicated three are 3 A + T rich sections in MC8, 2 of them are in the functional loci.

Enhancer Elements, Genetic↗