Biomedical subjects

Ji Wang

Publications and source records attributed to Ji Wang.

23 records · Page 2Linked to original sources

PubMed2004

[Therapy for Graves' ophthalmopathy].

Graves' ophthalmopathy (GO) is also called thyroid-related eye disease, infiltrative ophthalmopathy, which is related with the autoimmunity of thyroid, especially hyperthyroidism. Its morbidity ragnes from five percent to ten percent of hyperthyroidism, and the morbidity of male patients is higher than that of the female patients. The treatment of severe GO is a difficult task for doctors. The therapeutic effect is not always satisfactory. In order to solve this knotty problem, researchers have been devoting themselves to the development of new therapeutic methods. Here, the development of the therapies for GO is introduced, and the trends of treatments are prospected.

Combined Modality Therapy↗

PubMed2003

A monovalent anion affected multi-functional cellulase EGX from the mollusca, Ampullaria crossean.

A cellulose hydrolytic enzyme was isolated from the stomach juice of Ampullaria crossean, a kind of herbivorous mollusca. The enzyme was purified 45.3-fold to homogenety by ammonium sulfate precipitation, DEAE-Sephadex A-50 column, Bio-gel P-100 gel filtration column, and phenyl-Sepharose CL-4B column chromatography. The enzyme was designated as cellulase EGX. The purified enzyme is a multi-functional enzyme with the activities of exo-beta-1,4-glucanase (14.84 U/mg for p-nitrophenyl beta-D-cellobioside), endo-beta-1,4-glucanase (40.3 U/mg for carboxymethyl cellulose), and endo-beta-1,4-xylanase (196 U/mg for soluble xylan from birchwood). The monovalent anions such as F(-), Cl(-), Br(-), I(-), and NO(3)(-) are essential for its exo-beta-1,4-glucanase activity but have no effect on the activity for xylan, while I(-) higher than 5mM would inhibit the exo-beta-1,4-glucanase activity. The monovalent anions Cl(-) and Br(-) activate its endo-beta-1,4-glucanase activity. Binding of Cl(-) enhances the thermostability of EGX, but does not affect its fluorescence emission spectrum. The molecular mass of EGX is 41.5 kDa, as determined by SDS-PAGE. The pI value is about pH 7.35. The xylan hydrolytic activity of EGX reaches to the maximum between pH 4.8 and 6.0 and the pNPC hydrolytic activity reaches the maximum between pH 4.8 and 5.6, while that for CMC hydrolytic activity is between pH 4.4 and 4.8. Preliminary results showed that the enzyme was secreted by the mollusca itself.

Ammonium Sulfate↗

PubMed2003

Isolation of a multi-functional endogenous cellulase gene from mollusc, Ampullaria crossean.

The cellulase genes of some animals, most coding for endo-beta-1,4-glucanases, were found and cloned. There has been no reports about genes encoding exo-beta-1,4-glucanase or endo- -1,4-xylanase from animal. Here we cloned the cDNA of a cellulase designated as EGX from mollusc, Ampullaria crossean, and expressed it in Pichia pastoris for the first time. The cellulase EGX is a multi-functional beta cellulase with the activities of exo-beta-1,4-glucanase, endo-beta-1,4-glucanase and endo-beta-1,4-xylanase. The opening reading frame of EGX cDNA is 1185 bp and encodes 395 amino acids. The EGX gene can also be amplificated from the genomic DNA by PCR, which verified the endogenous origin of this gene. This EGX gene was the first multi-functional cellulase gene that was directly isolated from animals.

Amino Acid Sequence↗

PubMed2003

[Establishment of a method with micro-channel electrophoresis for detecting the mutations of isoniazid-resistant genes in Mycobacterium tuberculosis].

OBJECTIVE: To establish a method for the detection of isoniazid resistance-associated mutations in katG gene and inhA gene in Mycobacterium tuberculosis with single-stranded conformation polymorphism (SSCP) analysis by the micro-channel electrophoresis chip system. METHODS: The polymer solutions of acrylamide and its derivatives were used for sieving matrices with small amount of acridine orange as the fluorescent tag. A novel pair of primers was designed to link an extra segment that could be base paired with the mutation region to the PCR products of wild type inhA gene, which made the single strands of wild type inhA fragments present a unique conformation. RESULTS: The wild type fragments of katG gene and the fragments with mutation at codon 315 can be distinguished, and the inhA fragments with wild type and mutated regulatory sequence can be distinguished by this method. Twenty-two out of the 23 resistant strains were detected from 30 clinical isolates, the efficiency being 95%. CONCLUSION: It is demonstrated the high speed and sensitivity in detecting the mutations of isoniazid-resistant genes in Mycobacterium tuberculosis by micro-channel electrophoresis, and this method may be applicable in clinical detection of isoniazid-resistant strains.

Antitubercular Agents↗

PubMed2003

[Influence of bondage stress on Th1/Th2 cytokines and growth of tumors in mice bearing S180 tumor cells].

AIM: To observe the influence of bondage stress on Th1/Th2 cytokines and growth of tumor in mice bearing S180 tumor cells. METHODS: 2 x 10(6) S180 tumor cells were injected subcutaneously into the murine right oxter,and bondage stress was imposed on mice for 8 hours per day,ten days running. Then T lymphocyte proliferation was detected by MTT colorimetry. IFN-gamma and IL-2 secreted by splenocytes was measured by mitogen-activating lymphoblast assay and macrophage NO production assay. At the same time, the levels of IL-4 and IL-10 in serum were detected by ELISA, and the weight of the tumors and thymuses were measured. RESULTS: Compared with mice only injected with S180 tumor cells, tumor bearing mice suffered from bondage stress showed decreased T lymphocyte proliferation, thymus index, and levels of IFN-gamma and IL-2, but increased levels of IL-4 and IL-10(P<0.05), and tumor weight (P<0.01). CONCLUSION: Bondage stress could aggravate the suppression of cellular immunity in mice bearing S180 tumor and promote the T cells to shift towards Th2 type cells, which may be one of the mechanisms of promoting tumor growth by bondage stress.

Animals↗