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Biomedical subjects

J B Wu

Publications and source records attributed to J B Wu.

At least 19 recordsLinked to original sources
PubMed2006

Siegesbeckia yellow vein virus is a distinct begomovirus associated with a satellite DNA molecule.

Leaf samples of Siegesbeckia glabrescens showing yellow vein, enation, and stunting symptoms were collected in Guangdong province, China. A specific 500-bp product was consistently detected in total DNA extracts, amplified with universal primers specific for members of the genus Begomovirus. Comparison of partial DNA sequences revealed that these virus isolates were identical, and therefore isolates GD13, GD24 and GD27 were selected for further sequence analysis. The complete nucleotide sequences of GD13, GD24 and GD27 were all found to be 2768 nucleotides (nts) long, with two open reading frames (ORFs) in the virion-sense strand and four ORFs in the complementary-sense strand, typical of the Old World begomoviruses. Sequence identities among the three isolates ranged from 99.7 to 99.8%. When compared with other reported sequences of begomoviruses, GD13 was most closely related to papaya leaf curl China virus (AJ876548), with a sequence identity of 76.8%. In addition, all isolates were found to be associated with DNAbeta molecules. The complete DNAbeta sequences of isolates GD13, GD24 and GD27 were determined. Sequence analysis showed that they had highest sequence identity with DNAbeta of Eupatorium yellow vein virus (AJ438938) (44.0, 43.9 and 45.6% identity). GD13, GD24 and GD27 are considered to be isolates of a distinct begomovirus species for which the name Siegesbeckia yellow vein virus (SgYVV) is proposed.

Asteraceae↗
PubMed2006

Mutations in the ATP2C1 gene in Chinese patients with Hailey-Hailey disease.

Hailey-Hailey disease (HHD; MIM 16960) is a rare autosomal dominant hereditary disorder characterized by recurrent eruption of vesicles and bullae, predominantly involving the body folds. It is caused by heterozygous mutations in the ATP2C1 gene, encoding the human secretory pathway Ca2+/Mn2+-ATPase protein 1 (hSPCA1). When we studied Chinese patients with HHD, we found two different heterozygous mutations, Q506X and G353V, the former previously reported in a Hungarian patient, and the latter being a novel mutation. In a 38-year-old patient from a four-generation pedigree with a 3-year history of severe recurrent blisters, we identified a C-->T transition at nucleotide 1696, c(1696C-->T), in exon 17 of ATP2C1, resulting in a nonsenes mutation, Gln506X, which resulted in a premature termination codon. In the second patient, who represented a occurrence of sporadic Hailey-Hailey disease, a G-->T transversion of nucleotide, c(G1238T), in exon 13 of ATP2C1 was detected, which resulted in a Gly353-->Val amino acid substitution (G353V). Our molecular findings further demonstrate that the mutational events in the human ATP2C1 gene encoding the hSPCA1 pump play an important role in the pathogenesis of HHD.

Adult↗
PubMed2001

[Study on the structural property of polysacchrides 139A--a kind of IL-1R antagonists from microorganism].

AIM: To study the structural property of the bioactive component from the fermentation broth of Streptomyces 139 which can inhibit IL-1R. METHODS: Polysaccharide 139A is extracted and purified by means of macroreticular resin Diaion HP-20, cation exchange and DEAE Sephadex A-25 chromatography. The sugar compositions were analyzed with GC, the linkage positions of 139A were determined by methylation and GC-MS. RESULTS: The bioactive component which can inhibit IL-1R is a kind of polysaccharides. CONCLUSION: The components of 139A repeat units are conjectured.

Gas Chromatography-Mass Spectrometry↗
PubMed1995

Potent antiplatelet, anti-inflammatory and antiallergic isoflavanquinones from the roots of Abrus precatorius.

Five isoflavanquinones have been isolated from the roots of Abrus precatorius L. (Leguminosae). Three of them are new and designated as abruquinones D, E, and F. The pharmacological activities of the isoflavanquinones have been evaluated. The results indicated that abruquinones A, B, and D exhibited remarkable inhibitory effects on the platelet aggregation. The IC50 of abruquinones A and B for the inhibition of the platelet aggregation induced by arachidonic acid (AA) and collagen were less than 5 micrograms/ml, and of abruquinone D, was less than 10 micrograms/ml for that induced by AA. On the other hand, abruquinones A, B, D, and F showed strong anti-inflammatory and antiallergic effects. The IC50 of abruquinones A, B, D, and F for the inhibition of superoxide formation were less than 0.3 micrograms/ml, for the inhibition of the release of both beta-glucuronidase and lysozyme from rat neutrophils and the release of both beta-glucuronidase and histamine from mast cells were less than 1 microgram/ml.

Animals↗
PubMed1993

Isolation of FSH from bovine pituitary glands.

An improved method is described for the isolation of FSH from bovine pituitary glands. The purification procedure consisted of an initial ammonium sulphate precipitation step followed by triazine-dye chromatography, immobilized metal affinity chromatography, high-performance anion-exchange chromatography and gel filtration. Three highly purified bovine FSH preparations (designated bFSH-A, -B and -C) were obtained, giving yields of approximately 5.7 mg FSH/kg bovine pituitary glands (wet weight), with specific radioreceptor activities for bFSH-A, -B and -C of 61, 25 and 29 units (NIH-FSH-S1)/mg protein respectively. The corresponding biological activities were 217 (bFSH-A), 62 (bFSH-B) and 86 (bFSH-C) units/mg, as measured by an FSH in-vitro bioassay. LH levels were found to be < 1% (w/w) as determined by an LH in-vitro bioassay. SDS-PAGE of these bFSH preparations under reducing conditions in 16% polyacrylamide gels showed two major silver-staining bands of apparent molecular masses 19.5 kDa and 15.8 kDa. Their amino acid compositions were in close agreement with the expected composition, based on the bFSH cDNA sequence and results reported by other investigators. N-terminal sequencing of the bFSH-A preparation yielded two major sequences consistent with alpha- and beta-subunits, and a third minor (< 20%) sequence consistent with the alpha-subunit clipped at amino acid residue 6. It was concluded that the bFSH purification procedure reported here is a rapid method which produces bFSH in high yield and high purity, with radioreceptor and in-vitro specific activities comparable with those previously reported by other investigators.

Animals↗
PubMed1992

Platelet activating factor (PAF) antagonists contained in medicinal plants: lignans and sesquiterpenes.

Hot aqueous extracts of medicinal plants were tested for their inhibitory effect on the binding of platelet activating factor (PAF) to rabbit platelets. The extracts of Forsythia suspensa VAHL. (Oleaceae), Arctium lappa L. (Compositae) and Centipeda minima (L.) A. BRAUN et ASCHERS (Compositae) showed significant activities. Since the main constituents of F. suspensa and A. lappa are lignans, 30 lignans were tested for their inhibitory effects on PAF binding to platelets and 9 lignans were found active. Four sesquiterpenes were isolated as active compounds from C. minima. In particular 6-O-angeloylplenolin and 6-O-senecioyplenolin are the most potent and specific PAF antagonists found in this study.

Lignin↗
PubMed1992

[Preparation and biological activities of monoclonal antibody-streptonigrin immunoconjugates].

The clinic use of streptonigrin (114B), a highly active antitumor antibiotic, is limited by its detrimental effects on normal tissues. In an attempt to improve its specificity streptonigrin was conjugated to anti-human hepatoma monoclonal antibody 3A5 by four different chemical linkage methods. The first method was via water-soluble carbodiimide (EDCI) to create conjugates (1); in the second, an active ester of streptonigrin was applied as a reactive intermediate (2); and in the other two, spacers were put to use for coupling streptonigrin to McAb 3A5-Dextran T-40 (3) or McAb 3A5-bovin serum albumin (BSA) (4). The conjugates showed biological activities and UV spectral characteristics of streptonigrin and 3A5. As determined by clonogenic assay with human hepatoma BEL-7402 cells for 1 hour exposure, the IC50 for conjugate (2), conjugate (3) and streptonigrin were 0.355 ng/ml, 1.23 ng/ml and 22.4 ng/ml, respectively. The potency of conjugates (2) and (3) were 63-fold and 18-fold stronger than that of free streptonigrin. Clonogenic assay with KB cells which weakly react with 3A5 by Elisa showed that the potency of conjugate (2) and (3) were 11-fold and 13-fold weaker than free streptonigrin, respectively. The results suggest that the conjugates of McAb 3A5 and streptonigrin show specific cytotoxicity to target liver cancer cails. The linkage groups of streptonigrin were also discussed.

Antibodies, Monoclonal↗
PubMed1991

6-Pentadecylsalicylic acid: an antithrombin component isolated from the stem of Rhus semialata var. roxburghii.

Bioassay-directed fractionation of the n-hexane extract of the stem of Rhus semialata Murr. var. roxburghii DC (Anacardiaceae) has led to the isolation of 6-pentadecylsalicylic acid. It showed antithrombin activity at 50 micrograms/ml in the amidolytic method. It also prolonged the clotting time in a dose-dependent manner in the clotting assay of thrombin-fibrinogen interaction.

Amino Acid Sequence↗
PubMed1991

Biologically active constituents of Centipeda minima: sesquiterpenes of potential anti-allergy activity.

Ether, methanol and aqueous extracts of Centipeda minima (Compositae) herbs were found to have significant anti-allergy activities in passive cutaneous anaphylaxis (PCA) test. Three flavonoids, two sesquiterpene lactones and an amide were isolated from this plant material as inhibitors to induced histamine release from mast cells. The sesquiterpenes were identified as isobutyroylplenolin and senecioylplenolin by spectral investigations. The flavonoids and sesquiterpenes exhibited significant anti-allergy activity in PCA test with p.o. administration.

Animals↗
PubMed1988

Analysis of the open-closing movement of the human temporomandibular joint.

By using X-ray cinemographic techniques and biomechanical methods, the open-closing movement of the human temporomandibular joint was investigated in 14 living subjects. The theory of the instantaneous center of rotation (IRC) of the mandibular movement is strongly recommended and the position and the tendency of the IRC are also roughly determined. Moreover, a two-step model of the joint is put forward.

Humans↗