Search PubMed⌕ Search

Biomedical subjects

H Song

Publications and source records attributed to H Song.

At least 181 records · Page 10Linked to original sources
PubMed1997

[Effect of Yang-warming and Qi-tonifying natural products on neuroendocrine of deficiency-cold rats].

The rat fed with the compound drug Zhi Mu and Shi Gao was made into an animal model of deficiency cold syndrome. The deficiency cold state was kept for more than 7 days after stopping the drug. So the animal model is good for studing the therapeutic effect of products of heat nature. After 3 therapeutic days with Fu Jiang and Shen Qi compounds, the D beta H activity in serum, cortisone in adrenal gland and NE, DA amount in brain were increased, but serotonin was decreased, and after 7 days the effect was increased significantly. Both compounds could excite the sympathetic nerve and endocrine system in the peripheral and central nervous systems. Shen Qi compound acts quickly, but does not last as long as Fu Jiang. The effect will be better if the two compounds are used together.

Adrenal Glands↗
PubMed1997

[The effects of Gu Chi Gao on IL-8 in GCF of periodontitis].

In order to find a new treatment of periodontitis, this paper studied the effects of Gu Chi Gao on IL-8 in gingival crevicular fluid (GCF) of periodontitis. One tooth was selected from every patient in 24 patients with adult periodontitis. After supragingival scaling, the patients were divided into two groups randomly. One group was treated with Gu Chi Gao, while the other group was untreated as control group. All patients were examined after one month. GCF samples were collected with 2 mm x 20 mm Whatman I filter paper stripes and IL-8 in the GCF samples were detected by the method of ELISA. The result demonstrated that the levels of GCF and IL-8 in the treated group were lower than that of control group (P < 0.01), it suggests that Gu Chi Gao may inhibit the production of IL-8 and GCF.

Adult↗
PubMed1997

[The expression of IL-1 alpha gene in gingival tissue].

IL-1 is secreted by a variety of cells and plays an important role in the network of cytokines. In this study, the expression of IL-1 alpha in gingival tissue was determined with reverse transcription-polymerase chain reaction (RT-PCR). The PCR-product was confirmed by DNA sequencing. The results showed that IL-1 alpha transcription was detected in all 5 inflammatory gingival tissue samples, but it was not delected in the normal gingival tissue samples and in the samples after treatment. These findings suggested that IL-1 alpha may be a specific indicator of periodontal disease, and a potential mediator in pathogenesis of periodontitis.

Gene Expression↗
PubMed1997

[Preparation and characterization of recombinant retroviral vector containing t-PA cDNA].

A recombinant retroviral vector containing tissue-type plasminogen activator (t-PA) cDNA was constructed and transfected into PA317 viral packaging cells, forming intact virus particles. Under electron microscope the recombinant retroviral particles were composed of envelope, capsid and core. These viral particles were spherical with a diameter of 90-180nm, and spread dispersely in the cells. NIH3T3 cell infected by retrovirus particles were screened with G418. The virus titer of 6 x 10(8) CFU/L was verified by counting the positive clones two weeks after screening. The expression of t-PA was demonstrated in the NIH3T3 cells infected with the recombinant virus.

DNA, Complementary↗
PubMed1997

[Nucleotide sequence of gltB gene encoding the large subunit of Rhodobacter sphaeroides glutamate synthase].

The complete nucleotide sequence of a 5.4-kb chromosomal EcoRI-SalI fragment was determined, which contains the structural gene (gltB) for the large subunit of Rhodobacter sphaeroides glutamate synthase, as well as the 5'- and 3'- flanking regions. A open reading frame of 4636 base pairs was identified as R. sphaeroides gltB gene. The MW of the large subunit, as deduced from the nucleotide sequence, was estimated as 164kD. Comparision of the nucleotide sequences revealed a high similarity among gltB genes of R. sphaeroides, Azospirillum brasilense and Escherichia coli. The deduced amino acid sequence of R. sphaeroides GltB showed a high similarity with that of A. brasilense GltB.

Amino Acid Sequence↗
PubMed1997

[Clinical significance of changes of fibrillation potential amplitude following denervation of human skeletal muscle].

To evaluate the value of clinical application of examination of fibrillation potential amplitude, 110 patients, 97 males and 13 females, were examined and only the maximum fibrillation potential amplitudes were recorded in 420 muscles. The results showed that there was no significant difference between sexes, ages and sides. However, significant difference was evident between the groups of different frequency (1+ to 4+). The fibrillation potential amplitude was maximum at 3 to 4 months after denervation and still remained at relatively high level for years in certain patients. No significant difference was showed between the time groups in incomplete nerve injuries. Surgery did not affect the course of fibrillation potential amplitude change. It was suggested that the muscle cells sustained their property for years after denervation in some patients, thus it might explain that satisfactory result could be obtained from operative repair in some late cases. The changes of fibrillation potential amplitude might indicate that the changes from muscle denervation was still reversible and might be more accurate than traditional method of examination.

Action Potentials↗
PubMed1996

Fibroblast growth factor 2 can replace ectodermal signaling for feather development.

The initiation and morphogenesis of cutaneous appendages depend on a series of reciprocal signaling events between the epithelium and mesenchyme of the embryonic skin. In the development of feather germs, early dermal signals induce the formation of epidermal placodes that in turn signal the mesoderm to form dermal condensations immediately beneath them. We find a spatially and temporally restricted pattern of transcription for the genes that encode fibroblast growth factor (FGF) 2 and FGF receptor (FGFR) 1 in developing feather germs of the chicken embryo. FGF-2 expression is restricted to the epidermal placodes, whereas FGFR-1 expression is limited to the dermal condensations. Transcription of these genes could not be detected in skins of scaleless (sc/sc) embryos that fail to develop feathers as a result of an ectodermal defect. Treatment of sc/sc skins with FGF-2 results in the formation of feathers at the site of application of the growth factor and the induced feathers express FGFR-1 in their dermal condensations. Thus, we have established FGF-2 as an epidermal signal in early feather germ formation. The observation that FGF-2 can rescue the mutant phenotype of sc/sc embryos suggests that FGF-2 either is, or is downstream from, the signal that the sc/sc mutant ectoderm fails to generate.

Animals↗
PubMed1996

Binding sites on microtubules of kinesin motors of the same or opposite polarity.

The kinesin motor proteins translocate toward either the plus or minus end of microtubules (MTs). Competitive microtubule binding assays were carried out with monomeric motor domains of the minus-end-directed nonclaret disjunctional (Ncd) and Kar3 and the plus-end-directed kinesin heavy chain (KHC) to determine whether motors of the same or opposite polarity compete for binding sites on MTs and to test the idea that motor polarity is determined by differences in binding sites on MTs of the motors. The stoichiometries of binding were approximately 1 motor:1 tubulin heterodimer for all three motors. Ncd and Kar3, both minus-end motors, severely inhibited the binding of one another to MTs, as predicted theoretically for binding of the two motors to the same site on MTs, indicating that the binding sites on MTs of Ncd and Kar3 are the same or overlap extensively. Motors of opposite polarity, KHC and Ncd or KHC and Kar3, showed partial or complete inhibition of binding to MTs under different experimental protocols. The differences in binding behavior could be due to experimental conditions or be inherent in the nature of motor binding to MTs. Alternatively, differences in KHC and Ncd or Kar3 binding sites on MTs may exist such that the motors bind to partially overlapping but nonidentical sites on MTs. These differences in binding sites may be related to the opposite polarity of translocation on MTs of the motors.

Animals↗
PubMed1996

A point mutation in the microtubule binding region of the Ncd motor protein reduces motor velocity.

Non-claret disjunctional (Ncd) is a kinesin-related microtubule motor protein in Drosophila that functions in meiotic spindle assembly in oocytes and spindle pole maintenance in early embryos. The partial loss-of-function mutant ncdD retains mitotic, but not meiotic, function. The predicted NcdD mutant protein contains a V556-->F mutation in the putative microtubule binding region of the Ncd motor domain. Here we report an analysis of the properties of recombinant Ncd and NcdD proteins. A GST-NcdD fusion protein translocated microtubules approximately 10-fold more slowly than the corresponding wild-type protein in gliding assays. The maximum microtubule-stimulated ATPase activity of an NcdD motor domain protein was reduced approximately 3-fold and an approximately 3-fold greater concentration of microtubules was required for half-maximal stimulation of ATPase activity, compared with the corresponding wild-type protein. The Km for ATP and basal rate of ATP turnover were, in contrast, similar for the NcdD mutant and wild-type Ncd motor domain proteins. Pelleting assays demonstrated that the binding of the mutant NcdD motor protein to microtubules was reduced in the absence of nucleotide, relative to wild-type. The reduced velocity of NcdD translocation on microtubules is therefore correlated with reductions in microtubule-stimulated ATPase activity and affinity of the mutant motor for microtubules. The characteristics of the NcdD motor explain its meiotic loss of function, and are consistent with partial motor activity of Ncd being sufficient for its mitotic, but not its meiotic, role.

Adenosine Triphosphatases↗
PubMed1996

Crystallization and preliminary X-ray diffraction studies of recombinant staphylokinase.

Staphylokinase, a fibrin-specific plasminogen activator, was highly expressed in Escherichia coli and purified by ion-exchange and gel-filtration chromatography. The purified recombinant staphylokinase was fully active and readily crystallized against 1.2 M sodium citrate in 100 mM Tris-HCl buffer at pH 8.0 using the hanging-drop method. Crystals of staphylokinase diffract to better than 2.2 A resolution. The crystal belongs to the tetragonal space group P4(1)2(1)2 or its enantiomorph with unit-cell parameters a = b = 67.5, c = 150.1 A. There are two molecules in the asymmetric unit. In this paper, we described the first crystallization of a kind of plasminogen activator and present the results of preliminary X-ray diffraction data from the native protein.

Journal Article↗
PubMed1996

Crystallization and preliminary crystallographic analysis of RepA1, a replication control protein of the RepFIC replicon of enterotoxin plasmid EntP307.

RepA1 protein is essential for replication of the RepFIC replicon of enterotoxin plasmid EntP307 and is thought to interact directly with the origin of replication. We have purified RepA1 from an over-producing expression system and have prepared single crystals using a macroseeding technique. The crystals belong to space group P2(1)2(1)2(1) or P2(1)2(1)2, with cell dimensions a = 61 A, b = 67 A, and c = 243 A. They diffract X-rays to 3.3 A resolution and probably contain two 40,000 molecular weight RepA1 molecules per asymmetric unit.

Bacterial Proteins↗
PubMed1996

Predominance of defective proviral sequences in an HIV + long-term non-progressor.

We examined the accessory genes and envelope V3 region of provirus obtained over a 5 year period from an HIV+ long-term non-progressor with very low viral load and no in vitro recoverable virus during that same time span. LTR sequences supported normal Tat-mediated promoter activity. Multiple clones of nef sequences were highly conserved with < 10% containing frame shift or stop codon mutations. Functional analysis of the predominant nef sequence indicated wild type downregulation of surface CD4 and good function in a complementation infectivity assay. By contrast, inactivating mutations were found in 64% of amplicons containing vif, vpr, vpu, tat1, and rev1, and in 41% of amplicons containing env V3. Identical inactive sequences were obtained at an interval of 2 years, suggesting persistence of quiescent defective provirus in a long-lived clonal cell population. Furthermore, genetic distance versus time analysis revealed an absence of progressive evolution or arborization of quasispecies over time. This contrasts with data generated from other asymptomatic HIV+ individuals. The non-progressive pattern of env sequence diversity and low R2 for genetic divergence over time suggests that the defective provirus circulating in the periphery of this patient represents a randomly sampled 'fossil record' of earlier replication competent HIV-1 genomes.

Defective Viruses↗
PubMed1996

A role of PDI in the reductive cleavage of mixed disulfides.

We previously reported that protein disulfide isomerase (PDI) can dissociate the glutathione molecule in vitro from the mutant human lysozyme (hLZM) C77A-a, which is modified with glutathione at Cys95; however, it seems structurally difficult for PDI to attack either the disulfide bond or the side chain of the cysteine residue of a mixed disulfide. To investigate the function of PDI, we introduced several glutathione and cysteine derivatives at Cys95, instead of the glutathione of C77A-a. Using thiol compounds modified by 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), we could easily modify the free thiol group of C77A-b (C77A with no glutathionylation), without denaturation. For all of the modifications we tested, a negative correlation was found between the initial rate and the acceleration ratio of the reductive cleavage of mixed disulfides with PDI. A mutant PDI (hPDIM), which has no thiol-disulfide exchange activity, suppressed the reductive cleavage of the mixed disulfide of C77A-a with hPDI, suggesting that hPDI non-covalently interacted with the substrates. Taking account of the results of the structural analysis, we conclude that one of the functions of PDI in vivo lies in relaxing the structure around the disulfide bond, as well as in exchanging the thiol-disulfide bonds.

Amino Acid Sequence↗
PubMed1996

[Purification and properties of polysaccharide PPIII from Sterculia lychnophora Hance].

Polysaccharide PP III was isolated and purified from aqueous extract of the seeds of Sterculia lychnophora. It is composed of galactose, arabinose and rhamnose, the molar ratio being 1 : 1.67 : 1.01 and molecular weight 162200. Rhamnoses in the main chain are linked by alpha-(1-->3) glycoside linkage. PP III C is its major fragment, and is composed of galactose and rhamnose with a molar ratio of 1 : 2. 78 and MW 62500.

Arabinose↗
PubMed1996

Selective arterial embolization in the management of internal bleeding caused by trophoblastic diseases.

OBJECTIVE: To evaluate the efficacy and safety of selective arterial embolization in the management of internal bleeding caused by trophoblastic diseases. PATIENTS AND METHODS: Four patients with internal bleeding caused by trophoblastic diseases were diagnosed with arteriography and treated with selective arterial embolization as a life-saving measure. Effect of controlling bleeding was assessed by follow-up arteriogram and clinical observation. RESULTS: The embolization successfully controlled the bleeding in all patients. Operation time was short with a mean of 42 minutes. The shock was corrected dramatically. Fever and pain were common complications. CONCLUSION: Selective arterial embolization is a life-saving measure in the management of internal bleeding caused by trophoblastic diseases.

Adult↗
PubMed1996

[Experimental study of human micro-urokinase gene therapy].

OBJECTIVE: To determine the feasibility and efficiency of gene therapy to thrombotic disease. METHODS: The retroviral vectors containing 982 bp mUKcDNA were constructed and transfected into PA317 viral packaging cells. Recombinant retroviral particles collected from media of PA317 cells were injected into mice subcutaneous tissue, abdominal cavity and quadriceps muscle, respectively. mUK activity of plasma was measured with a synthetic substrate S-2390. Six mice were sacrificed after injection for immunofluorohistochemical staining. RESULTS: The mUK activity in plasma was obviously increased (P < 0.01) and the expression of mUKcDNA was observed at local sites of injection by immunofluorohistochemical staining. The mUK activity was raised for 4 months. CONCLUSION: The injection of recombinant viral particles containing transcriptional unit of mUKcDNA might be applied to the prevention and treatment of thrombotic disease.

Animals↗