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Biomedical subjects

Q Song

Publications and source records attributed to Q Song.

At least 37 records · Page 2Linked to original sources

[Historical investigation of dentifrice in China].

A herbal literature survey was carried out on data concerning historical pharmacognostical changes of "dentifrice" in China and how diseases of the teeth and gums had been treated there in ancient times. It had been considered to be a matter of utmost importance that to prevent teeth from decaying, only the brushing of teeth with a toothbrush was necessary. Over time, various tooth agents have been found to treat oral diseases the teeth and gums. Glycyrrhizae Radix, Ginseng Radix, Scutellariae Radix, Menthae Herbal, and salt were widely used materials. Investigations from all approaches are being carried out to develop remedies for oral diseases, including Kampo medicine and the pharmacological effects of numerous crude drugs. When tracing the pharmacognostical changes of dentifrice in ancient China, we felt wonder at and admiration for the abundance of clinical experiences described in the old herbal and medical literature we researched.

China↗

Urokinase-type plasminogen activator stimulates the Ras/Extracellular signal-regulated kinase (ERK) signaling pathway and MCF-7 cell migration by a mechanism that requires focal adhesion kinase, Src, and Shc. Rapid dissociation of GRB2/Sps-Shc complex is associated with the transient phosphorylation of ERK in urokinase-treated cells.

Urokinase-type plasminogen activator (uPA) stimulates MCF-7 cell migration by binding to the UPA receptor and activating the Ras-extracellular signal-regulated kinase (Ras-ERK) signaling pathway. Studies presented here show that soluble uPA receptor and a peptide derived from the linker region between domains 1 and 2 of the uPA receptor also stimulate cellular migration via a mitogen-activated protein kinase/ERK kinase (MEK)-dependent pathway. Signaling proteins that function upstream of Ras in uPA- stimulated cells remain undefined. To address this problem, we transfected MCF-7 cells to express the noncatalytic carboxylterminal domain of focal adhesion kinase (FAK), FAK(Y397F), kinase-defective c-Src, or Shc FFF, all of which express dominant-negative activity. In each case, ERK phosphorylation and cellular migration in response to uPA were blocked. Both activities were rescued by co-transfecting the cells to express constitutively active MEK1, indicating that FAK, c-Src, and Shc are upstream of MEK. Shc was tyrosine-phosphorylated in uPA-treated cells. The level of phosphorylated Shc was increased within 1 min and remained increased for at least 30 min. Sos co-immunoprecipitated with Shc in cells that were treated with uPA for 1-2.5 min, probably reflecting the formation of Shc-Grb2/Sos complex; however, by 10 min, co-immunoprecipitation of Sos with Shc was no longer observed. Rapid dissociation of Sos from Shc represents a possible mechanism for the transient phosphorylation of ERK in uPA-treated MCF-7 cells.

Adaptor Proteins, Signal Transducing↗

Kallistatin stimulates vascular smooth muscle cell proliferation and migration in vitro and neointima formation in balloon-injured rat artery.

Kallistatin, a serine proteinase inhibitor (serpin), is expressed in the endothelial and smooth muscle cells of blood vessels. The potential function of kallistatin in vascular biology was investigated by studying its role in the proliferation and migration of cultured primary aortic vascular smooth muscle cells (VSMCs) in vitro and in neointima formation in rat artery after balloon angioplasty in vivo. Exogenous kallistatin induced a >2-fold increase of VSMC proliferation and cell growth as measured by [(3)H]thymidine incorporation and cell counts and a 2.3-fold increase of cell migration in modified Boyden chambers. In balloon-injured vessels, endogenous kallistatin mRNA and protein levels increased up to 10-fold as determined by competitive polymerase chain reaction and by ELISA. Intense staining of kallistatin mRNA was identified in the proliferating VSMCs of balloon-injured arteries during cell migration from media to neointima by in situ hybridization histochemistry and immunohistochemistry. We observed an induction of kallistatin expression by platelet-derived growth factor (PDGF) and upregulation of p42/44 mitogen-activated protein kinase (MAPK) activity by kallistatin in cultured VSMCs. Conversely, adenovirus-mediated transfer of kallistatin antisense cDNA into cultured VSMCs inhibited PDGF-induced p42/44 MAPK activity and cell proliferation. Furthermore, local delivery of adenovirus carrying kallistatin antisense cDNA significantly downregulated kallistatin mRNA levels and attenuated neointima formation in balloon-injured rat arteries in vivo. These results indicate that kallistatin may play an important role in mediating PDGF-induced MAPK pathway on VSMC proliferation and in neointima formation after balloon angioplasty.

Adenoviridae↗

Dibenzocyclooctadiene-type lignans from Magnolia pyramidata.

Eight dibenzocyclooctadiene-type lignans, pyramidatin A-H, were isolated from the leaves of Magnolia pyramidata. Their structures were established by spectral methods, mainly 2D NMR spectroscopic techniques, which involved combined applications of COSY, DEPT. 1H, 13C correlations, COLOC, INAPT and long-range inverse 1H, 13C NMR correlations. The molecular structures of pyramidatin A and B were determined by single crystal X-ray diffraction. The absolute configurations of all eight lignans were derived from CD spectral correlations with structurally related dibenzocyclooctadienes of known absolute configuration.

Circular Dichroism↗

Effects of Astragali root and Hedysari root on the murine B and T cell differentiation.

It has traditionally been known in Asian countries that the Astragali and Hedysari roots have similar beneficial effects. They have been applied in clinical practice for immunological diseases, we investigated their effects on specific antibody production, B cells and T cells in BALB/c mice immunized with ovalbumin (OVA). Both the Astragali and Hedysari roots reduced the production of IgG2a in the primary response to OVA. Hedysari root reduced the production of IgG2a in the secondary response. Both reduced the production of IgM, suppressed IL-6 production in spleen cells. It was presumed that the suppression of IgG2a production was induced by the suppression of IL-6, which is an antibody production inducer. It was found that the Hedysari root increased the B cells and activated them, and the Astragali root also tended to increase them. In addition, Hedysari root decreased the proportions of IFN-gamma-producing cells in splenic CD4(+) T lymphocytes. It was shown that the Astragali and Hedysari roots could act as a growth factor of B cells by increasing the proportion of the total B cells and activated B cells. In conclusion, both the Astragali and Hedysari roots showed the same actions, but the latter was more effective.

Animals↗

Dynamic regulation of prothoracic gland ecdysteroidogenesis: Manduca sexta recombinant prothoracicotropic hormone and brain extracts have identical effects.

Multiple assays were conducted in order to determine if the recently available recombinant prothoracicotropic hormone (rPTTH) from Manduca sexta is identical, or similar, to the natural hormone and if results from its use in a variety of assays confirm, or are inconsistent with, previous studies over the past 20years on PTTH action using brain extract. Brain extracts and rPTTH showed similar, if not identical, effects on the cell biology of Manduca prothoracic gland cells with the following results: increased levels of cAMP (adenosine 3':5' cyclic monophosphate) synthesis; requirement for extracellular Ca(2+) in in vitro studies; ecdysteroidogenesis stimulation in vitro; stimulation of general and specific protein synthesis; immunocytochemical identification of the two lateral cells in each brain hemisphere as the source of PTTH (the prothoracicotropes); the ability of antibodies to rPTTH to inhibit ecdysteroidogenesis stimulation in vitro; and the multiple phosphorylation of the ribosomal protein S6. The data revealed that brain extract and rPTTH show equivalent effects in all of the assays, indicating that this rPTTH is the natural PTTH of Manduca and that the data generated with brain extracts over the past two decades are indeed relevant.

Animals↗

Helicobacter pylori in the oral cavity: high prevalence and great DNA diversity.

To test the hypothesis that Helicobacter pylori may be transmitted by the oral-oral route, we applied nested PCR and DNA sequencing to detect and analyze H. pylori DNA in the oral cavity of 20 adult patients undergoing endoscopy. Dental plaques of molars, premolars, and incisors and saliva were collected. Additional paraffin-embedded gastric biopsies were analyzed in four patients. Two sets of highly sensitive and specific primers, EHC-U/EHC-L and ET5-U/ET-5L directed to a 860-bp fragment of H. pylori DNA, were used in the nested PCR. Eight patients had an active infection in the stomach determined with the [13C]urea breath test and the other 12 were negative. Nested PCR showed that all 20 subjects (100%) were positive for H. pylori in the oral cavity. DNA sequencing demonstrated that all tested PCR products of the expected size from the oral samples have more than 97% identity with that from H. pylori type strain ATCC 43629. However, sequences differed in oral samples from different subjects as well as between different oral locations and gastric biopsies within the same individuals. In conclusion, the oral cavity may be a permanent reservoir for H. pylori and can harbor multiple H. pylori strains at the same time.

Adult↗

Plasminogen activator inhibitor-1 fused with erythropoietin (EPO) mimetic peptide (EMP) enhances the EPO activity of EMP.

Erythropoietin (EPO) mimetic peptide (EMP) encoding sequence was inserted into the gene of plasminogen activator inhibitor-1 (PAI-1) between Ala348 and Pro349 (P2'-P3'), generating a novel gene, PAI-1/EMP (PMP). This was cloned into pET32a expression vector, fused with TrxA peptide in the vector, and a 63-kDa protein was expressed in inclusion bodies with an expression level >50%. The TrxA/PMP protein was purified by Ni-NTA-agarose metal-ligand affinity chromatography to a purity >90%, showing a single, silver-stained band on SDS-PAGE. Using a reticulocyte counting assay, the EPO activity of PMP was determined to be 5,000 IU/mg, 2,500-fold that of EMP.

Amino Acid Sequence↗

Endogenous fatty acid synthesis in squamous cell carcinomas of the oral cavity.

We measured the synthesis of endogenous fatty acids in oral squamous cell carcinoma, its adjacent tissue, and normal oral tissues that were collected fresh from surgical specimens. The tissues were minced in Roswell Park Memorial Institute Medium 1640 (RPMI 1640) and incubated in [1(2)-(14)C] acetic acid, sodium salt ((14)CH(3)(14)CO(2)Na). Total lipids were then extracted and(14)C was measured by scintillation counter. We found that incorporation of(14)C in the total lipids of squamous cell carcinoma was significantly higher than in the other tissues.

Carbon Radioisotopes↗

Developmental expression of thyroid hormone receptors in the rat testis.

Sertoli cell proliferation in the rat is completed by Days 15-20 postnatally. Thyroid hormones appear to regulate the duration of Sertoli cell proliferation, affecting adult Sertoli cell number and hence the capacity of the testis to produce sperm. In the present study, a combination of immunohistochemistry, immunoblot analysis, and reverse transcription-polymerase chain reaction was used to demonstrate the expression pattern of thyroid hormone receptors (TR) in the juvenile and adult rat testis. The results indicated that TRalpha1 was expressed in proliferating Sertoli cell nuclei, its expression decreasing coincident with the cessation of proliferation. TRalpha2, TRalpha3, and TRbeta1 mRNAs were expressed at low levels during development; however, the corresponding protein was not detected by immunoblot analysis. In addition, TRalpha1 was found to be expressed in germ cells from intermediate spermatogonia to mid-cycle pachytene spermatocytes. Immunohistochemistry also demonstrated TR expression in a subset of interstitial cells. The demonstration of TR expression in germ cells undergoing spermatogenic differentiation suggests a possible role for thyroid hormones in the adult testis.

Animals↗

Characteristic distribution pattern of Helicobacter pylori in dental plaque and saliva detected with nested PCR.

The precise mode of transmission and the natural reservoir for Helicobacter pylori are unknown. PCR assays have proved to be highly sensitive and specific and are regarded as the method of choice for detecting H. pylori DNA in the oral cavity. The aim of this study was to investigate the prevalence and distribution of H. pylori in the oral cavity. Forty-two patients undergoing gastroscopy were investigated for the presence of H. pylori in dental plaque and saliva by nested PCR, and in the stomach by the 13C-urea breath test. Samples tested comprised dental plaque from molars, premolars and incisors and saliva. Two sets of primers homologous to the 860-bp fragment of H. pylori DNA, which have been shown previously to be highly sensitive and specific, were used for nested PCR. Eleven patients (26.2%) were infected with H. pylori in the stomach. H. pylori DNA was identified in dental plaque samples from 41 patients (97%) and in 23 saliva samples (55%). The prevalence in dental plaque from molars, premolars and incisors was 82%, 64% and 59%, with an odds ratio of 3.18, 1.24 and 1 (reference), respectively. In conclusion, H. pylori was present in the oral cavity of 97% of tested patients, with a characteristic distribution that was independent of the infection status of the stomach. Thus H. pylori may belong to the normal oral microflora.

Adult↗

Quantitation of Helicobacter pylori in dental plaque samples by competitive polymerase chain reaction.

AIM: To establish a competitive PCR (cPCR) assay for quantitation of H pylori organisms in dental plaque samples. METHODS: The cPCR co-amplified target H pylori DNA and a known amount of internal standard template in the same tube with the same primers directed to 0.86 kb DNA of H pylori. The internal standard was a synthesised DNA bearing the same primer recognition sites at two ends and a non-homologous core sequence as the target DNA fragment. Quantitation was based on determination of the relative, not absolute, amounts of the differently sized and [32P]-dCTP labelled products derived from H pylori DNA and the competitive internal standard after gel electrophoresis separation. RESULTS: A significant correlation between known amounts of H pylori added to dental plaque samples and the results of the cPCR was found, and a standard line was developed which allowed quantitation of H pylori in the plaque samples. cPCR was performed on supragingival plaque samples from 10 adult patients with H pylori infection in the stomach, and from five adults and six children without H pylori infection in the stomach. The ranges of H pylori numbers were 1-213 (median 25), 6-76 (10), and 4-94 (14) cells/mg of dental plaque in the three groups, respectively. CONCLUSIONS: cPCR is useful for quantitation of H pylori in supragingival dental plaque samples; however, the number of the organisms in dental plaque samples seems very low.

Adolescent↗

Enhanced renal function in bradykinin B(2) receptor transgenic mice.

The tissue kallikrein-kinin system has been recognized as a paracrine and/or autocrine hormonal system that regulates arterial pressure, renal hemodynamics, and electrolyte excretion. We have created a transgenic mouse model overexpressing human bradykinin B(2) receptor, and the mice developed lifetime hypotension. With this animal model, we further analyzed the potential role of B(2) receptors in regulation of renal function. Baseline urinary excretion, urinary potassium excretion, and pH were significantly increased in transgenic mice, whereas urinary sodium excretion and serum sodium concentration were unaltered. Transgenic mice exhibited increased renal blood flow, glomerular filtration rate, and urine flow. Enhanced renal function was accompanied by significant increases in urinary nitrate/nitrite, cGMP, and cAMP levels with unaltered urinary kinin levels in transgenic mice compared with control siblings. Renal cGMP and cAMP content was also significantly increased in transgenic mice. Because the renin-angiotensin system exerts vasoconstriction buffering vasodilation of the kallikrein-kinin system, expression of renin-angiotensin components was examined by Northern blot analysis. We found a significant increase in hepatic angiotensinogen expression with no changes in renal renin and pulmonary angiotensin-converting enzyme mRNA levels in B(2) receptor transgenic mice. These studies showed that overexpression of B(2) receptors in transgenic mice resulted in hypotension and enhanced renal function through activation of nitric oxide-cGMP and cAMP signal transduction pathways.

Animals↗

[An occlusive evaluation proposal to intra-saccular embolization of intracranial aneurysm].

OBJECTIVE: To explore the imaging criteria for evaluating intracranial aneurysm embolization. METHODS: Angiographic occlusive criteria for intracranial aneurysm embolization (aneurysm not opcified angiographically after embolization, 100% occlusion; a little part of aneurysm neck residual, 95%; neck residual, 90%; neck and a little part of aneurysm cavity residual, 80%; some cavity residual, < 80%) were used by 6 specialists to evaluate 121 aneurysms embolized with MDS (mechanical detachable spiral) and/or GDC (guglielmi detachable coil) from March 1995 to July 1999. The rationality, feasibility and limitation of the criteria were discussed. RESULTS: Among the 121 aneurysms, 100% occlusion was reached in 53 aneurysms (43.8%), 95% in 27 (22.3%), 90% in 16 (13.2%), 80% in 15 (12.4%), and less than 80% in 10 (8.3%) respectively. Good accordance was obtained among different doctors in the occlusive evaluation of aneurysm embolization. CONCLUSIONS: The suggesting criteria are simple and feasible in clinical practice, although the effect of imaging follow-up of embolized aneurysm is unknown and the numerical value of occlusive percentage is arbitrary.

Adult↗

[Preparation and identification of monoclonal antibodies against human apoptosis-related protein TFAR19].

OBJECTIVE: To obtain mouse anti-human TFAR19 monoclonal antibodies for further study of the structure and function of the apoptosis-related protein TFAR19. METHODS: BALB/c mice were immunized with recombinant human TFAR19, hybridoma cells were screened by cell fusion and subcloning approach. The monoclonal antibodies were identified by ELISA and Western blotting. RESULTS: Three hybridoma cells (C1, C10, 2C12) stable in secreting anti-TFAR19 monoclonal antibodies were obtained. The monoclonal antibodies showed high specificity and high titer to TFAR19 with various affinity. All of them belong to IgG1 subclass. CONCLUSIONS: These monoclonal antibodies could bind specifically to TFAR19 protein.

Animals↗

[Effect of Tripterygium Wilfordii Hook T4 monomer on proliferation and interleukin-6 production of synovial fibroblasts of patients with rheumatoid arthritis].

OBJECTIVE: Tripterygium Wilfordii Hook multi-glycosides T2 has been wildly used in China in treatment of RA. T4 was abstracted from T2 and was reported much more efficient in anti-inflammatory and immune suppression than T2. This study was to investigate the effect Tripterygium Wilfordii Hook T4 monomer on proliferation and interleukin-6 production of synovial fibroblasts of patients with rheumatoid arthritis. METHODS: Synovium was obtained from patients with rheumatoid arthritis undergoing synovectomies or joint replacement. Cultures of synovial fibroblasts were established. After 3 generations, cultured synovial fibroblasts were stimulated with IL-1. Then 1.5 ng/ml, 5 ng/ml and 15 ng/ml T4 were added, and synovial fibroblasts were cultured in the presence of T4 for 48 hours. Cell proliferation was assayed using MTT method. IL-6 level of supernatant was measured by ELISA. RESULTS: Proliferation of synovial fibroblasts was inhibited by T4. The proliferation inhibition effect of T4 was dose dependent and inhibition rate was 5.18%, 10.95% and 21.37%, respectively. And T4 had no effect on IL-6 production by IL-1 stimulated synovial fibroblasts. CONCLUSIONS: T4 might control the disease activity of RA by inhibiting the proliferation of synoviocyte. And T4 might not influence the concentration of IL-6 in synovial fluid, as a central effect, since IL-6 has protective effect on articular cartilage.

Anti-Inflammatory Agents, Non-Steroidal↗