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Tripathi PK, Qin H, Deng S, Xu C, Bhattacharya-Chatterjee M, Foon KA, Chatterjee SK. Antigen mimicry by an anti-idiotypic antibody single chain variable fragment. Mol Immunol 1998; 35:853-63. [PMID: 9839554 DOI: 10.1016/s0161-5890(98)00072-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
For the therapy of cancer patients whose disease is positive for Carcinoembryonic Antigen (CEA), we developed an active specific immunotherapy based on the idiotypic network. The anti-idiotype monoclonal antibody (mAb), 3H1 was generated by immunization of mice with the anti-CEA mAb, 8019. 3H1 mimics CEA both functionally and structurally and acts as a surrogate for CEA. To define the minimum structural requirements for antigen mimicry by 3H1, we constructed plasmid vectors for expression of single chain Fv (scFv) variants of 3H1 in Escherichia coli. Variable heavy (VH) and variable light (VL) chain domains of 3H1 were linked by a 15 amino acid linker (Ln), (Gly4Ser)3 in two constructs, VH-Ln-VL and VL-LnVH. Ln was omitted in two constructs, VH-VL and VL-VH. Each of the scFv constructs has a tag of six His [(His)6 tag] for purification by metal chelate affinity chromatography and detection by enzyme-linked immunoabsorbent assay (ELISA). Comparisons of the binding of 8019 to purified scFv proteins by ELISA and immunoblot experiments showed that only VH-Ln-VL had significant activity. VH-Ln-VL also showed maximum inhibition of binding of 8019 to CEA. Immunization of mice with naked VH-Ln-VL and VH-Ln-VL conjugated to keyhole limpet hemocyanin induced anti-CEA antibodies in mouse sera. Sera from immunized mice inhibited the binding of 8019 to 3H1 as well as CEA. Induction of anti-CEA antibodies in the immunized mice was confirmed by flow cytometric analysis using CEA positive MC-38cea cells. These results demonstrate that for antigen mimicry of 3H1 scFv, the presence of Ln is necessary and the domain order should be VH followed by VL.
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Qin H, Xia X, Li Z. [Effects of polysaccharide of Polygala aureocauda on the immunnity functions of normal mouse]. ZHONG YAO CAI = ZHONGYAOCAI = JOURNAL OF CHINESE MEDICINAL MATERIALS 1998; 21:467-9. [PMID: 12569840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
The effects of polysaccharide of polygala aureocauda on the immunity functions of the normal mouse were researched by the tests of clearing away carbon granules, hemolysin antibodies production and lymphocyte transformation. The results showed that the polysaccharide of polygala aureocauda Dunn. (PADTP) could strengthen the phagocytosis of the single nucleus phagocytes, promote the production of the antibodies, and raise the transformable rate of the lympocytes. That proved the PADTP could strengthen immunity function of the normal mouse.
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Gao F, Qin H, Knaff DB, Zhang L, Yu L, Yu CA, Ondrias MR. Q-band resonance Raman spectra of oxidized and reduced mitochondrial bc1 complexes. Biochemistry 1998; 37:9751-8. [PMID: 9657688 DOI: 10.1021/bi9800653] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Recently published crystallographic studies of mitochondrial bc1 complexes have stimulated renewed interest in the active site architecture of these important integral membrane proteins. We present resonance Raman spectra obtained via variable excitation within the heme Q-band from samples poised in several different net redox states. Appropriate subtraction and polarization analysis allows the vibrational behavior of the individual heme bL,bH, and c1 sites to be assessed. The spectra of the b hemes are particularly noteworthy. They exhibit evidence for a protonation equilibrium involving heme axial ligands and reveal a marked structural heterogeneity at the heme bH site that most likely involves nonplanar distortions of the macrocycle. The possible implications of these findings for heme functionality are discussed.
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Dong J, Xu L, Qin H, Li L, Xu D, Ji Z. [Synthesis and antiinflammatory activity of 2-(E)-(4-hydroxy-3-methoxybenzylidene)-5-(N-substituted aminomethyl) cyclopentanones]. YAO XUE XUE BAO = ACTA PHARMACEUTICA SINICA 1998; 33:548-52. [PMID: 12016891] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
In search for new antiinflammatory agents, a series of 2-(E)-(4-hydroxy-3-methoxybenzylidene)-5-(N-substituted aminomethyl) cyclopentanones was synthesized via Stork reaction, Mannich reaction and amine exchange reaction. All of the fifteen target compounds were characterized by spectral analysis and elemental analysis. Preliminary pharmacological tests showed that several target compounds exerted appreciable effect on xylene-induced ear edema in mice and that alteration of the substituents of anilines showed significant influence on antiinflammatory potency.
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155
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Chen W, Qin H, Reese VA, Cheever MA. CTLs specific for bcr-abl joining region segment peptides fail to lyse leukemia cells expressing p210 bcr-abl protein. J Immunother 1998; 21:257-68. [PMID: 9672847 DOI: 10.1097/00002371-199807000-00003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The aim of the current study was to determine whether immunization with synthetic peptides corresponding to the joining region segment of p210 bcr-abl chimeric protein can elicit CD8+ cytotoxic T lymphocytes (CTLs) capable of specifically lysing leukemia cells. BALB/c mice were immunized with peptides identical to the joining region segment of p210 bcr-abl protein. Class I major histocompatibility complex (MHC)-restricted bcr-abl peptide-specific CD8+ CTLs were elicited. The CTL clones were H-2 Kd restricted and specifically recognized a nonamer peptide of the combined sequence of bcr-abl amino acids but neither bcr nor abl amino acid sequence alone. Despite specificity and substantial lytic potential against syngeneic cell line incubated with exogenously supplied peptides, the bcr-abl peptide-specific CTLs failed to lyse syngeneic murine leukemia cells expressing human p210 bcr-abl protein containing the same bcr-abl joining region peptide sequence. Similarly, the bcr-abl peptide-specific CTLs did not lyse human bcr-abl-positive chronic myelogenous leukemia cells expressing murine class I MHC antigen (i.e., K562 cells infected with vaccinia virus expressing H-2 Kd). The appropriateness of the joining region segment of bcr-abl protein to serve as a T cell target depends upon whether that segment is presented by class I MHC in a concentration high enough to stimulate CTLs. The current experiments using murine peptide-specific CTLs could not establish that the joining region of bcr-abl protein is processed and presented by class I MHC antigen-processing pathway, but the possibility was not ruled out. Alternative models and/or strategies are necessary.
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Arya P, Kutterer KM, Qin H, Roby J, Barnes ML, Kim JM, Roy R. Diversity of C-linked neoglycopeptides for the exploration of subsite-assisted carbohydrate binding interactions. Bioorg Med Chem Lett 1998; 8:1127-32. [PMID: 9871721 DOI: 10.1016/s0960-894x(98)00182-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Diversity of alpha-galactose based C-linked neoglycopeptides (1b, 2b, 3c, 4d, and 5d) has been developed to explore the importance of subsite-assisted carbohydrate binding interactions. Deprotected C-linked neoglycopeptides (1b, 2b, 3c, 4d, and 5d) were synthesized and tested in competitive inhibition assays using a model enzyme-linked lectin (e.g., Maclura pomifera). Compound 2b, with two alpha-galactoside units on the side chain of the lysine residue of the dipeptide backbone, exhibited a remarkable effect with a 2.82-fold increase in its inhibitory properties (IC50 1.48 mM) in comparison to 1b (IC50 4.18 mM).
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Dong J, Xu L, Qin H, Chen S, Ji Z, Wang M. [Synthesis and antiinflammatory activity of 2-(E)-benzylidene-5-(N-substituted aminomethyl) cyclopentanones]. YAO XUE XUE BAO = ACTA PHARMACEUTICA SINICA 1998; 33:344-9. [PMID: 12017001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Nineteen kinds of 2-(E)-benzylidene-5-(N-substituted aminomethyl) cyclopentanones were synthesized via Mannich reaction or amine exchange reaction and identified spectrometrically. One compound exhibited significant antiinflammatory activity, showing obvious inhibitory effect on xylene-induced mice ear swelling, carrageenin-induced rats paw edema and increased capillary permeability induced with acetic acid in mice. Its ED50 values in these inflammatory models were calculated to be 67.8 mg.kg-1, 25.3 mg.kg-1 and 41.8 mg.kg-1 respectively, nearly equal to those of ibuprofen and aspirin.
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Wang P, Chen H, Qin H, Sankarapandi S, Becher MW, Wong PC, Zweier JL. Overexpression of human copper, zinc-superoxide dismutase (SOD1) prevents postischemic injury. Proc Natl Acad Sci U S A 1998; 95:4556-60. [PMID: 9539776 PMCID: PMC22528 DOI: 10.1073/pnas.95.8.4556] [Citation(s) in RCA: 197] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Superoxide and superoxide-derived oxidants have been hypothesized to be important mediators of postischemic injury. Whereas copper, zinc-superoxide dismutase, SOD1, efficiently dismutates superoxide, there has been controversy regarding whether increasing intracellular SOD1 expression would protect against or potentiate cellular injury. To determine whether increased SOD1 protects the heart from ischemia and reperfusion, studies were performed in a newly developed transgenic mouse model in which direct measurement of superoxide, contractile function, bioenergetics, and cell death could be performed. Transgenic mice with overexpression of human SOD1 were studied along with matched nontransgenic controls. Immunoblotting and immunohistology demonstrated that total SOD1 expression was increased 10-fold in hearts from transgenic mice compared with nontransgenic controls, with increased expression in both myocytes and endothelial cells. In nontransgenic hearts following 30 min of global ischemia a reperfusion-associated burst of superoxide generation was demonstrated by electron paramagnetic resonance spin trapping. However, in the transgenic hearts with overexpression of SOD1 the burst of superoxide generation was almost totally quenched, and this was accompanied by a 2-fold increase in the recovery of contractile function, a 2.2-fold decrease in infarct size, and a greatly improved recovery of high energy phosphates compared with that in nontransgenic controls. These results demonstrate that superoxide is an important mediator of postischemic injury and that increasing intracellular SOD1 dramatically protects the heart from this injury. Thus, increasing intracellular SOD1 expression may be a highly effective approach to decrease the cellular injury that occurs following reperfusion of ischemic tissues.
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Qin H, Gunning P. The 3'-end of the human beta-actin gene enhances activity of the beta-actin expression vector system: construction of improved vectors. JOURNAL OF BIOCHEMICAL AND BIOPHYSICAL METHODS 1997; 36:63-72. [PMID: 9507373 DOI: 10.1016/s0165-022x(97)00045-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The human beta-actin promoter has been widely used to drive expression of genes of interest in mammalian cell lines and transgenic mice. The original form of the human beta-actin expression vector contains upstream sequences, 5'UTR (untranslated region) and intron 1 from the beta-actin gene linked to a three restriction site polylinker and SV40 (Simian Virus 40) 3'UTR. We have modified this vector now to contain the highly conserved beta-actin 3'UTR plus flanking region which replaces the SV40 sequences. An additional modification has removed the mRNA peripheral localization sequences present in the beta-actin 3'UTR. The new vectors also contain an improved polylinker. The activity of these two new vectors has been compared with that of the original vector and that of a vector using the popular cytomegalovirus (CMV) promoter. Mouse C2 myoblasts were transfected with each vector driving expression of enhanced green fluorescent protein (EGFP) and analyzed for EGFP mRNA levels. We find that both new vectors drive twice the level of mRNA accumulation of the original vector and over 30-times that of the CMV promoter. This suggests that these new vectors will provide a substantial elevation in levels of expression by virtue of inclusion of the beta-actin 3'UTR plus flanking region.
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Abstract
BACKGROUND Gastrin-releasing peptide receptors (GRPR) are overexpressed in small cell lung carcinoma and some other human cancers. Small molecule peptides with antagonistic activities toward these receptors are potential radiotherapeutic agents. METHODS A 7-amino acid analogue of bombesin (BBN) was synthesized through solid-phase techniques. The peptide was conjugated to trisuccin prior to cleavage from the resin. The conjugate was hydrogenated to remove the hydroxamate-protecting benzyl groups followed by purification through reversed-phase high performance liquid chromatography (RP-HPLC). Rhenium-188 (188Re)-labeling of the trisuccin-peptide conjugate was performed by a SnCl2-reduced radioisotope and the labeled product was purified by RP-HPLC. The labeled conjugate was incubated with BNR-11 (3T3 mouse fibroblast cells stably transfected with murine GRPR) and PC-3 human prostate carcinoma GRPR positive cells. The nonradioactive peptide analogue was used as a competitive inhibitor and 125I-[Tyr4]-BBN was used as a positive control. RESULTS Solid-phase and solution phase synthesis afforded the conjugates of the hydroxamate ligand trisuccin with the 7-amino acid BBN analogue. The molecules differed by either a direct attachment of the trisuccin to the peptide (TrisBBN) or connection through a 6-carbon linker (TrisC6BBN). The overall yield for each synthesis was approximately 20%. Both conjugates showed the correct molecular weights on mass spectroscopy. Radiolabeling of the conjugates with 188Re were performed in > or = 90% yield. Cell-binding assays performed with BNR-11 (TrisBBN and TrisC6BBN) and PC-3 (TrisBBN) cell lines resulted in positive binding. CONCLUSIONS The synthesis and radiolabeling of Tris-BBN conjugates with 188Re were shown to be feasible. The yields of chemical syntheses and radiolabeling and positive binding of the radiolabeled conjugates to GRPR-positive tumor cells reveal promise in the use of these molecules for cancer imaging and therapy. More work is needed and is in progress to optimize the cell-binding properties.
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161
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Xu R, Guo D, Qin H, Guan X. [Electroacupuncture along meridians activating subcutaneous primary afferents in acupoints--CB-HRP tracing study]. ZHEN CI YAN JIU = ACUPUNCTURE RESEARCH 1997; 21:54-8. [PMID: 9388320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The experiment was performed to observe the segmental distribution of sensory afferent nerves in acupoints and the influence of electroacupuncture (EA) along meridians on it. 1% CB-HRP solution (5 microliters) was injected subcutaneously at unilateral "Zusanli" or "Ruzhong" acupoint of rats. The HRP labeled cells were counted in the related spinal dorsal root ganglia (DRG). The results were as follows: the sensory nerve terminals of "Zusanli" acupoint mainly projected to the neurons of L4 and L5 DRG and that of "Ruzhong" acupoint projected to the neurons of T4, T5 and T6 DRG; sensory nerve terminals of "Zusanli" or "Ruzhong" acupoint were activated by the EA stimulation along meridians, their ability of uptaking HRP was enhanced, so the HRP labeled cells increased in the related DRG, the HRP labeled DRG segments spread. This study provides a new morphological evidence for the mechanism's explanation of propagated sensation along the meridians.
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162
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Xu B, Järvelin MR, Xu X, Wang Z, Qin H, Rimpelä A. Maternal menstrual history and small-for-gestational-age births in a population-based Chinese birth cohort. Early Hum Dev 1997; 49:183-92. [PMID: 9378080 DOI: 10.1016/s0378-3782(97)00031-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The relationship between maternal menstrual history and small-for-gestational-age (SGA) births is examined in a population-based birth cohort of 5291 mothers with singleton births and 28 completed gestational weeks in Qingdao, China, in 1992. Multivariate analyses suggest that the length of the menstrual cycle and age at menarche had independent effects on SGA after controlling for sex of the infant, physical size of the mother, blood pressure at the first antenatal visit, parity, gestational week at the first antenatal visit, number of antenatal visits, number of previous spontaneous abortions and maternal educational attainment and occupation. The relative risk (RR) of SGA among thin mothers (BMI < = 21) is 1.63 (95% confidence interval (CI) 1.16-2.29) if the mother's menarche started after 14 years (reference to < = 14 years), 1.75 (95% CI 0.96-3.20) if the mother's menstrual cycle was 29-30 days and 2.92 (95% CI 1.42-6.03) if the menstrual cycle > = 31 days ( < = 28 as a reference category for both). Among normal weight mothers (BMI 21-24), only a menstrual cycle equal or longer than 31 days still had a significant effect on SGA (RR 2.17, 95% CI 1.18-4.08), and among fat mothers no significant effects were observed. The results encourage further evaluation of the association between maternal menstrual background and fetal development among other ethnic populations and exploration of the possible biological mechanisms behind this relationship.
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Safavy A, Sanders A, Qin H, Buchsbaum DJ. Conjugation of unprotected trisuccin, N-[tris[2-[(N-hydroxyamino)carbonyl]ethyl]methyl]succinamic acid, to monoclonal antibody CC49 by an improved active ester protocol. Bioconjug Chem 1997; 8:766-71. [PMID: 9327144 DOI: 10.1021/bc970127m] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
For the conjugation of the trihydroxamate bifunctional chelating agent N-[tris[2-[[N-(benzyloxy)amino]-carbonyl]ethyl]methyl]succinamic acid (trisuccin, 1) to antibodies, we originally used the corresponding 2,3,5,6-tetrafluorophenyl active ester followed by the postconjugation removal of the benzyl protecting groups by catalytic hydrogenation. It was of interest to us to design a conjugation protocol capable of incorporating deblocked hydroxamates into peptides and proteins. Reported procedures that were expected to be compatible with the functionalities present in trisuccin were used with no success, as judged by the lack of ability of the products to radiolabel with 188Re. A simple conjugation method was then developed utilizing the o-nitrophenol (ONP) activated ester of the unprotected trisuccin, N-[tris[2-[(N-hydroxyamino)carbonyl]ethyl]methyl]succinamic acid, 3, which eliminates the need for the postconjugation deblocking. An assay for indirect estimation of the active ester content, based on the concentration of its decomposition byproduct, ONP-OH, was developed. Comparison of the indirectly estimated concentrations with those obtained directly from purified products showed > 90% accuracy for this assay. This procedure has the advantage of rapidly using the unpurified active ester, eliminating the possibilities of its decomposition through solvolysis or self-condensation by the unprotected hydroxamate functions. A colorimetric assay was developed for estimation of the number of ligands per molecule of protein. This assay and the fact that all conjugates consistently radiolabeled with 188Re show that this procedure conjugated the unprotected hydroxamate ligands to the CC49 monoclonal antibody. These results indicate the potential applicability of this technique to conjugation of unprotected hydroxamate derivatives with other proteins and peptides.
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Aho S, Rouda S, Kennedy SH, Qin H, Tan EM. Regulation of human interstitial collagenase (matrix metalloproteinase-1) promoter activity by fibroblast growth factor. EUROPEAN JOURNAL OF BIOCHEMISTRY 1997; 247:503-10. [PMID: 9266691 DOI: 10.1111/j.1432-1033.1997.00503.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Basic fibroblast growth factor (bFGF) is a pleiotropic factor that is implicated in tissue remodeling. The growth factor is capable of up-regulating the expression of the interstitial collagenase (matrix metalloproteinase-1 or MMP-1) gene. In this study, the full-length human MMP-1 promoter, spanning 4.3 kb, was sequenced and the regulatory control of its activity by bFGF was examined in NIH3T3 fibroblasts. Several regulatory sequences, including five activator protein-1 (AP-1), five activator protein-2 (AP-2), five glucocorticoid-response elements and multiple ets/polyoma enhancer-binding 3 elements, were identified. Deletion constructs were prepared and transiently transfected into fibroblast cultures incubated with and without bFGF. The results showed that bFGF enhanced the activity of the deletion promoter fragments and the full-length MMP-1 promoter by sixfold or more in the cell cultures. Stimulation of the MMP-1 promoter activity by bFGF was reflected in substantial increase of the collagenase mRNA levels. A bFGF-responsive element appeared to be the AP-1 consensus sequence. Mutation of the first AP-1 site resulted in major reduction of the basal level of the MMP-1 promoter activity, supporting the notion that the AP-1 consensus sequence is essential for the constitutive expression of the MMP-1 gene. Furthermore, bFGF induction of the activity of the promoter constructs containing a mutant AP-1 site was essentially absent, suggesting that the regulatory element is necessary for the induction of the promoter activity by the growth factor. Thus, bFGF up-regulates MMP-1 gene expression in NIH3T3 fibroblasts via induction of its promoter activity that is dependent on an AP-1 consensus sequence.
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Wang J, Qin H, Zhang H, Wang M, Zhang L, Wang Y, Guo M, Mao H. [Inhibition of 5 compounds from Bidens bipinnata on leukemia cells in vitro]. ZHONG YAO CAI = ZHONGYAOCAI = JOURNAL OF CHINESE MEDICINAL MATERIALS 1997; 20:247-9. [PMID: 12572466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
In vitro, inhibition of 5 compounds from Bidens bipinnata on two leukemia cells HL-60 and V397 is presented by determination of MTT living cell in this paper. The result show that the compounds have the action of inhibition, IC50 on V937 < or = 60 micrograms/ml.
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Kennedy SH, Rouda S, Qin H, Aho S, Selber J, Tan EM. Basic FGF regulates interstitial collagenase gene expression in human smooth muscle cells. J Cell Biochem 1997; 65:32-41. [PMID: 9138078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Basic fibroblast growth factor (bFGF) is a mitogenic factor that is implicated in smooth muscle cell growth in atherosclerosis and vascular restenosis. In this study, we examined the effect of bFGF on the expression of the interstitial collagenase gene in human vascular smooth muscle cells. Results from Northern transfer analysis showed that bFGF increased collagenase mRNA levels greater than threefold as early as 24 h. Collagenase pre-mRNA levels were elevated approximately threefold by bFGF, according to RT-PCR analysis. Transient transfections of the smooth muscle cells with a 4.4-kb human collagenase promoter-CAT reporter gene, however, failed to show upregulation of the promoter activity by bFGF. Interestingly, transfections with deleted fragments containing promoter sequences from -1047 to -2271 resulted in modest stimulation of the collagenase-CAT promoter activity by bFGF, bFGF did not alter the stability of the collagenase mRNA, as demonstrated by degradation studies. The enhanced collagenase mRNA levels elicited by bFGF were reflected in increased amounts of collagenase protein that were detected by Western blot analysis. In summary, bFGF upregulates the interstitial collagenase expression, resulting in turnover of the extracellular matrix, an event that could facilitate smooth muscle cell migration and proliferation during the early stages of atherosclerosis and restenosis.
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Lee YJ, Han Y, Lu HT, Nguyen V, Qin H, Howe PH, Hocevar BA, Boss JM, Ransohoff RM, Benveniste EN. TGF-beta suppresses IFN-gamma induction of class II MHC gene expression by inhibiting class II transactivator messenger RNA expression. THE JOURNAL OF IMMUNOLOGY 1997. [DOI: 10.4049/jimmunol.158.5.2065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
Recently, a non-DNA binding protein, class II transactivator (CIITA), has been shown to be required for constitutive and IFN-gamma-inducible class II MHC transcription. The cytokine TGF-beta inhibits IFN-gamma-induced class II MHC expression at the transcriptional level. In this study, we provide evidence that TGF-beta blocks IFN-gamma-induced CIITA mRNA accumulation. TGF-beta down-regulates class II MHC and CIITA mRNA accumulation in human astroglioma and fibrosarcoma cell lines, but TGF-beta does not destabilize the CIITA message, suggesting an effect at the transcriptional level. In cells that stably overexpressed CIITA, leading to a constitutive class II MHC-positive phenotype, the inhibitory effect of TGF-beta on class II MHC was abrogated, but the cells remained responsive for expression of TGF-beta-inducible genes. Cell lines that possessed defects in TGF-beta signaling also became refractory to inhibition of IFN-gamma-induced CIITA and class II MHC expression. Our data indicate that TGF-beta suppresses IFN-gamma-induced class II MHC expression by inhibiting accumulation of CIITA mRNA.
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Lee YJ, Han Y, Lu HT, Nguyen V, Qin H, Howe PH, Hocevar BA, Boss JM, Ransohoff RM, Benveniste EN. TGF-beta suppresses IFN-gamma induction of class II MHC gene expression by inhibiting class II transactivator messenger RNA expression. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1997; 158:2065-75. [PMID: 9036950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Recently, a non-DNA binding protein, class II transactivator (CIITA), has been shown to be required for constitutive and IFN-gamma-inducible class II MHC transcription. The cytokine TGF-beta inhibits IFN-gamma-induced class II MHC expression at the transcriptional level. In this study, we provide evidence that TGF-beta blocks IFN-gamma-induced CIITA mRNA accumulation. TGF-beta down-regulates class II MHC and CIITA mRNA accumulation in human astroglioma and fibrosarcoma cell lines, but TGF-beta does not destabilize the CIITA message, suggesting an effect at the transcriptional level. In cells that stably overexpressed CIITA, leading to a constitutive class II MHC-positive phenotype, the inhibitory effect of TGF-beta on class II MHC was abrogated, but the cells remained responsive for expression of TGF-beta-inducible genes. Cell lines that possessed defects in TGF-beta signaling also became refractory to inhibition of IFN-gamma-induced CIITA and class II MHC expression. Our data indicate that TGF-beta suppresses IFN-gamma-induced class II MHC expression by inhibiting accumulation of CIITA mRNA.
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Qin H, Zhao G, Wu H. [A study on lens epithelial cell DNA damage induced by hydrogen peroxide in rat and its repair]. [ZHONGHUA YAN KE ZA ZHI] CHINESE JOURNAL OF OPHTHALMOLOGY 1996; 32:453-6. [PMID: 9590817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE The induction and repair of DNA single-strand breaks (SSBs) were measured in primary cultured infant rat lens epithelial cells (RLECs) following hydrogen peroxide (HP) exposure, and the influential factors were detected. METHODS Utilizing nick translation methodology which utilizes incorporation of labeled nucleotides at the sites of DNA SSBs to sensitively quantitate the damage, we studied the effects of temperature, doses of HP and trace amount of selenium on cell survival. RESULTS The number of DNA SSBs at 37 degrees was higher than that at 4C (P < 0.01). Significant numbers of SSBs were detected after being insulted by as low as 36.4 mumol/L hydrogen peroxide for 12 minutes 4 degrees (P < 0.05). Repair rapidly initiated and almost completed in 60 minutes after mild damage, and it was unable to repair when the DNA damage was induced by HP at toxic concentration. Trace selenium was added to the culture and incubated for 24 hours, then the number of SSBs was significantly decreased (P < 0.01). CONCLUSIONS At 37 degrees HP may induce DNA SSBs in RLECs. HP induces the SSBs in a dose dependent manner. The DNA SSBs can not be repaired after severe damage. Trace selenium can decrease the degree of susceptibility to oxidative damage in infant RLECs.
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Chen W, Qin H, Chesebro B, Cheever MA. Identification of a gag-encoded cytotoxic T-lymphocyte epitope from FBL-3 leukemia shared by Friend, Moloney, and Rauscher murine leukemia virus-induced tumors. J Virol 1996; 70:7773-82. [PMID: 8892898 PMCID: PMC190847 DOI: 10.1128/jvi.70.11.7773-7782.1996] [Citation(s) in RCA: 122] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
FBL-3 is a highly immunogenic murine leukemia of C57BL/6 origin induced by Friend murine leukemia virus (MuLV). Immunization of C57BL/6 mice with FBL-3 readily elicits CD8+ cytotoxic T lymphocytes (CTL) capable of lysing FBL-3 as well as syngeneic leukemias induced by Moloney and Rauscher MuLV. The aim of this current study was to identify the immunogenic epitope(s) recognized by the FBL-3-specific CD8+ CTL. A series of FBL-3-specific CD8+ CTL clones were generated from C57BL/6 mice immunized to FBL-3. The majority of CTL clones (32 of 38) were specific for F-MuLV gag-encoded antigen. By using a series of recombinant vaccinia viruses expressing full-length and truncated F-MuLV gag genes, the antigenic epitope recognized by the FBL-3 gag-specific CTL clones, as well as by bulk-cultured CTL from spleens of mice immune to FBL-3, was localized to the leader sequence of gPr80gag protein. The precise amino acid sequence of the CTL epitope in the leader sequence was identified as CCLCLTVFL (positions 85-93) by examining lysis of targets incubated with a series of synthetic leader sequence peptides. No evidence of other CTL epitopes in the gPr80gag or Pr65gag core virion structural polyproteins was found. The identity of CCLCLTVFL as the target peptide was validated by showing that immunization with the peptide elicited CTL that lysed FBL-3. The CTL elicited by the Gag peptide also specifically lysed syngeneic leukemia cells induced by Moloney and Rauscher MuLV (MBL-2 and RBL-5). The transmembrane peptide was shown to be the major gag-encoded antigenic epitope recognized by bulk-cultured CTL derived from C57BL/6 mice immunized to MBL-2 or RBL-5. Thus, the CTL epitope of FBL-3 is localized to the transmembrane anchor domain of the nonstructural Gag polyprotein and is shared by leukemia/lymphoma cell lines induced by Friend, Moloney, and Rauscher MuLV.
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Qin H, Chatterjee SK. Cancer gene therapy using tumor cells infected with recombinant vaccinia virus expressing GM-CSF. Hum Gene Ther 1996; 7:1853-60. [PMID: 8894677 DOI: 10.1089/hum.1996.7.15-1853] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The efficacy of a recombinant vaccinia virus (rvv-mGM-CSF) expressing murine granulocyte-macrophage colony stimulating factor (GM-CSF) for use in cancer gene therapy was evaluated. C57BL/6 mice with established B16-F10 melanoma were treated by s.c. injection of irradiated B16 cells infected with two different recombinant vaccinia virus (rvv) constructs. Mice treated with rvv-mGM-CSF vaccine survived longer (p < 0.05), were free of palpable tumors (> 4 mm) longer (p < 0.02), and had smaller mean tumor volumes (p < 0.005) compared to those treated with irradiated B16 cells infected with a control rvv (rvv-lacZ) expressing Escherichia coli beta-galactosidase or irradiated uninfected B16 cells. The vaccine appeared to be B16 tumor cell specific, because there was no therapeutic effect when heterologous but syngeneic (H-2b) colon adenocarcinoma cells, MC-38 infected with rvv-mGM-CSF were used as vaccine. In this model, rvv expressing interleukin-2 (IL-2) was ineffective. In addition, experimental lung metastasis of B16 tumor cells was significantly inhibited by rvv-mGM-CSF vaccine compared to several control vaccines when the vaccine was applied either by i.p. route (p < 0.006) or by s.c. injection (p < 0.0008). B16 cells expressing mGM-CSF after infection with rvv-mGM-CSF or transduction with a retroviral vector, were equally effective (p > 0.14) as vaccines against lung metastasis. Inhibition of metastasis was also B16 tumor cell specific. These data suggest that this approach of cancer gene therapy has a potential for use in cancer patients.
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172
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Gao F, Qin H, Simpson MC, Shelnutt JA, Knaff DB, Ondrias MR. Isolation and characterization of vibrational spectra of individual heme active sites in cytochrome bc1 complexes from Rhodobacter capsulatus. Biochemistry 1996; 35:12812-9. [PMID: 8841124 DOI: 10.1021/bi960419v] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Resonance Raman spectra of bc1 complexes and isolated c1 subunit from Rhodobacter capsulatus have been obtained using a variety of excitation wavelengths. Spectra obtained via Q-band excitation of bc1 complexes in different redox states were separated to yield the individual vibrational spectra of each of the three heme active sites. Hemes bH and c1 exhibit vibrational spectra typical of b- and c-type hemes, respectively. In contrast, the spectrum of heme bL is anomalous with respect to those of other hemes b. The isolated spectra were also used to assess the effects of inhibitor binding on the local structural environments of the hemes. Neither antimycin nor myxothiazol binding produces dramatic structural perturbations at the hemes. Heme c1 is completely unaffected by the presence of either inhibitor. The vibrational spectra of hemes bH and bL are slightly altered by antimycin and myxothiazol binding, respectively.
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173
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Finnegan MG, Knaff DB, Qin H, Gray KA, Daldal F, Yu L, Yu CA, Kleis-San Francisco S, Johnson MK. Axial heme ligation in the cytochrome bc1 complexes of mitochondrial and photosynthetic membranes. A near-infrared magnetic circular dichroism and electron paramagnetic resonance study. BIOCHIMICA ET BIOPHYSICA ACTA 1996; 1274:9-20. [PMID: 8645697 DOI: 10.1016/0005-2728(95)00155-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The combination of EPR and low-temperature near-IR magnetic circular dichroism spectroscopies have been used to investigate the axial ligation of the cytochromes in the cytochrome bc1 complexes from bovine heart mitochondria, Rhodobacter capsulatus, Rhodobacter sphaeroides, and Rhodospirillum rubrum, and the purified cytochromes c1 from bovine heart mitochondria, Rb. capsulatus and Rb. sphaeroides. The possibility of axial ligation of cytochrome c1 by the amino terminus of the polypeptide was also assessed by acetylating the N-terminus of Rb. capsulatus cytochrome c1 and comparing the properties of the acetylated and unmodified samples. The results are consistent with bis-histidine axial ligation for the high- and low-potential b-type cytochromes and histidine/methionine axial ligation for the c1-type cytochrome in the intact cytochrome bc1 complexes. Purified samples of cytochrome c1 are mixtures of two forms, one with histidine/methionine and the other with bis-histidine axial ligation. The form with bis-histidine axial ligation is also assembled in the M183L mutant of the Rb. capsulatus cyt bc1 complex in which the methionine residue coordinating cyt c1 is replaced by a leucine. The bis-histidine form appears to be an artifact of dissociation of cytochrome c1 from the cytochrome bc1 complex and is greatly enhanced particularly in the bacterial cytochromes c1 by sample handling and the addition of 50% (v/v) ethylene glycol or glycerol.
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174
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Qin H, Chatterjee SK. Recombinant vaccinia expressing interleukin-2 for cancer gene therapy. Cancer Gene Ther 1996; 3:163-7. [PMID: 8725880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Use of a recombinant vaccinia virus expressing human interleukin-2 (IL-2) was evaluated for preparation of tumor vaccines. A/J mice were immunized against neuroblastoma (C1300) cells using a preparation of C1300 cells infected/transfected with the recombinant virus, vCF13, expressing IL-2. A second recombinant vaccinia, vSC8, expressing Escherichia coli beta-galactosidase, was used as a control. After three weekly immunizations with virus-transfected cells, the mice were challenged with 1 x 10(6) unmodified C1300 cells and tumor development was monitored. Tumor development in the mice was inhibited by immunization with vCF13-transfected cells, compared to those vaccinated with vSC8-transfected cells (P < .008). A group of mice (7/15) immunized with vCF13-transfected cells followed by tumor challenge survived more than 60 days, at which time all mice immunized with the control vaccine were dead (p < .006). Five of the mice treated with the vCF13 vaccine were alive for more than 75 days (P < .05), after which they were rechallenged with another dose of 1 x 10(6) unmodified tumor cells. Tumor development was not apparent in these mice for more than 45 days following the second challenge, suggesting that these mice were completely protected by this immunization. These results demonstrate that recombinant vaccinia virus expressing IL-2 may be useful for cancer gene therapy.
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175
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Qin H, Chen W, Takahashi M. [CD4+ T-cell immunity and Ab responses to mutant ras protein in pancreas and colon cancer patients]. ZHONGHUA ZHONG LIU ZA ZHI [CHINESE JOURNAL OF ONCOLOGY] 1996; 18:173-6. [PMID: 9387247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Mutated p21 ras protein contains single substituted amino acid residue. It can be considered as cancer-specific protein. The current study examined whether T-cell and Ab responses to mutant p21 ras protein and/or peptide can be detected in patients with pancreatic or colon cancer. Studies focused on the aspartic acid substitution in amino acid position 12(ras D12) as the commonest mutation in gastrointestinal malignancy. IgA antibodies directed against mutated ras D12 protein were detected in 51 of 160 (31.8%) colon cancer patients, but only in 1 of 40 (2.5%) normals. The greater incidence of antibody in cancer patients provides evidence that immunization to the ras proteins occurred as a result of the malignancy. Seven of sixteen (43.7%) pancreas cancer patients responded to ras D12 peptide. T cell responses to ras D12 peptides were detected in only 2 of 25 (8.0%) colon cancer patients. None of the 11 normal individuals tested had positive responses to normal or mutant ras p21 proteins and/or peptides. Thus, Ab and CD4+ T cell immunity to the mutated segment of ras protein is present in some patients with gastrointestinal cancer.
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176
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Ju TZ, Chen HL, Gu JX, Qin H. Regulation of N-acetylglucosaminyltransferase V by protein kinases. Glycoconj J 1995; 12:767-72. [PMID: 8748153 DOI: 10.1007/bf00731237] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
When 7721 human hepatocarcinoma cells were treated with 100 nM phorbol-12-myristate-13-acetate (PMA), the activity of N-acetylglucosaminyltransferase V(GnT-V) in the cells varied in accordance with the activity of membranous protein kinase C (PKC), but not with that of cytosolic PKC. Quercetin, a non-specific inhibitor of Ser/Thr protein kinase, and D-sphingosine and staurosporine, two specific inhibitors of PKC, blocked the activation of membranous PKC and GnT-V by PMA. Among the three inhibitors, quercetin was least effective. The inhibitory rates of quercetin and staurosporine toward membranous PKC and GnTV were proportional to the concentrations of the two inhibitors. The activities of GnTV and membranous protein kinase A (PKA) were also induced in parallel by dibutyryl cAMP (db-cAMP) and this induction was blocked by a specific PKA inhibitor. When cell free preparations of 7721 cells and human kidney were treated with alkaline phosphatase (ALP) to remove the phosphate groups, the GnTV activities were decreased. These results suggest that GnTV may be activated by membranous PKC or PKA, indirectly or directly, via phosphorylation of Ser/Thr residues.
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177
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Huang B, Qin H. [Changes of lung function in ex-smokers]. ZHONGHUA YU FANG YI XUE ZA ZHI [CHINESE JOURNAL OF PREVENTIVE MEDICINE] 1995; 29:354-5. [PMID: 8697941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Lung function in 31 ex-smokers, 17 with six to eight and 14 with 11 to 15 years of cigarette smoking, and pair-matched controls were studied. Results showed smoking could cause prolongation of mean through time and partial mean through time in forced expiratory volume scheme, which increased with length of smoking, and multiple abnormal in lung function tests. Lung function could improve apparently after the cease of smoking. It suggested quitting of smoking could prevent lung function from further damage, or reverse the damaged lung function.
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Takahashi M, Chen W, Byrd DR, Disis ML, Huseby ES, Qin H, McCahill L, Nelson H, Shimada H, Okuno K. Antibody to ras proteins in patients with colon cancer. Clin Cancer Res 1995; 1:1071-7. [PMID: 9815896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The current study examined sera from 160 colon cancer patients and 60 normal individuals to determine whether antibody to mutated p21 ras protein was present. Studies focused on the aspartic acid substitution at amino acid position 12 (denoted D12), one of the most common mutations in colon adenocarcinoma. IgA antibodies directed against mutated p21 ras-D12 protein were detected in 51 (32%) of 160 colon cancer patients, but only in 1 (2.5%) of 40 normal individuals. The greater incidence of antibody in cancer patients provides presumptive evidence that immunization to the ras proteins occurred as a result of the malignancy. Examination of sera for antibody reactivity to wild-type p21 ras protein (denoted p21 ras-G12) as well as p21 ras proteins bearing the D12, V12, S12, or L61 mutations showed that antibody detected was largely to normal segments of the p21 ras protein. Epitope mapping, using peptide neutralization assays with mutated or normal ras peptides as competitors, demonstrated that in 10 (67%) of 15 sera examined the antibody reactivity to p21 ras-G12 protein was neutralized by peptides near the carboxyl terminus of p21 ras protein, but not by peptides spanning the specific point mutation region. Antibody reactivities correlated with peripheral blood lymphocyte count, but did not correlate with patient age, sex, histology, stage, tumor locus, lymph node metastasis, or serum carcinoembryonic antigen.
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179
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Tan EM, Qin H, Kennedy SH, Rouda S, Fox JW, Moore JH. Platelet-derived growth factors-AA and -BB regulate collagen and collagenase gene expression differentially in human fibroblasts. Biochem J 1995; 310 ( Pt 2):585-8. [PMID: 7654198 PMCID: PMC1135935 DOI: 10.1042/bj3100585] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Platelet-derived growth factor (PDGF) is a mitogen associated with tissue repair, a process involving collagen synthesis and remodelling by interstitial collagenase. This study examines and compares the regulation of interstitial collagenase and collagen gene expression by PDGF-AA and -BB in human fibroblasts. Time-course analysis showed that neither PDGF-AA or -BB had a consistent effect on the expression of pro-alpha 1(I) or pro-alpha 2(I) type-I collagen genes. In contrast, interstitial collagenase gene expression was found to be consistently up-regulated severalfold by PDGF-BB. Enhanced expression of the collagenase gene was not apparently due to up-regulation of its promoter activity in human dermal fibroblasts, as indicated by transient and stable transfection experiments. Unlike PDGF-BB, PDGF-AA did not alter collagenase mRNA levels under low-serum culture conditions. Thus, the biological activities of the PDGF homodimers are different, with PDGF-BB being clearly more potent than PDGF-AA in its regulation of collagenase gene expression.
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180
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Qin H, Chen W, Takahashi M, Disis ML, Byrd DR, McCahill L, Bertram KA, Fenton RG, Peace DJ, Cheever MA. CD4+ T-cell immunity to mutated ras protein in pancreatic and colon cancer patients. Cancer Res 1995; 55:2984-7. [PMID: 7606715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Mutated p21 ras proteins contain single substituted amino acid residues and represent cancer-specific proteins. The current study examined whether primed T cell immunity to mutant p21 ras proteins and/or peptides can be detected in patients with pancreatic or colon cancer. Studies focused on the aspartic acid substitution in amino acid position 12 (denoted D12) as the commonest mutation in gastrointestinal malignancy. Peripheral blood lymphocytes from patients or normal individuals were tested for the ability to proliferate in response to normal or mutated ras peptides or proteins. T-cell responses were defined as a stimulation index of > 2.0. Results showed that 7 of 16 (44%) pancreatic cancer patients responded to ras-D12 peptide. Responses to ras-D12 protein were studied in only the last four patients that responded to D12 peptides. Three of the 4 patients that responded to ras-D12 peptide showed a substantial response to p21 ras-D12 protein (stimulation indices of 12, 8, and 24). Specificity was validated by examining responses to normal and alternate ras peptides and proteins. T-cell responses to ras-D12 peptides were detected in only 2 of 25 (8%) colon cancer patients. None of 11 normal individuals tested had positive responses to normal or mutant ras p21 proteins and/or peptides. Thus, CD4+ T-cell immunity to the mutated segment of ras protein is present in some patients with gastrointestinal cancer.
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181
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Liu Z, Qin H, Xiao C, Wen C, Wang S, Sui SF. Specific binding of avidin to biotin containing lipid lamella surfaces studied with monolayers and liposomes. EUROPEAN BIOPHYSICS JOURNAL : EBJ 1995; 24:31-8. [PMID: 7635091 DOI: 10.1007/bf00216828] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The interaction of avidin (from egg white) with phospholipid (monolayer and bilayer) model membranes containing biotin-conjugated phospholipids has been studied. In the first part, using surface sensitive techniques (ellipsometry and surface plasmon resonance) we demonstrated that the nonspecific adsorption of avidin to phospholipid lamella could be abolished by adding an amount of Ca2+, Mg2+ or Ba2+ that led to an electrostatic interaction. The specific binding of avidin to lipid mixtures containing biotin-conjugated phospholipids was obviously composition dependent. The ratio 1:12 of a B-DPPE/DPPE mixture was found to be the optimum molar ratio. When we compared the results from the surface sensitive techniques with those from the electron micrographs of a two dimensional crystal of avidin (obtained in our laboratory), the optimum ratio was found to be determined by the effect of lateral steric hindrance. In the second part, we observed the pattern of the layers of fluorescently labeled phospholipid and adsorbed proteins with a home-made micro fluorescence film balance. The fluorescence images showed that avidin was preferentially bound to the receptors that were in the fluid domains. Further, with a sensitive fluorescence assay method, the effect of the phase behavior of liposomes on the specific binding of avidin was measured. This showed that avidin interacted with biotinlipid more weakly in the gel state liposome than in the liquid state liposome. The major conclusion was that the binding of avidin to a membrane bound model receptor was significantly restricted by two factors: one was the lateral steric hindrance and the other was the fluidity of the model membrane.
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Abstract
Two-dimensional crystals of avidin were obtained on mixed lipid monolayers containing biotinylated lipids (N-biotinyl-dipalmitoyl-L-alpha-phosphatidyl ethanolamine and dioleoyl phosphatidyl choline) by specific interaction. Image analysis of electron micrographs of these crystals revealed p2 symmetry with the unit cell parameters a = 66 +/- 2 A, b = 68 +/- 1 A, and gamma = 121 +/- 4 degrees. The projection map showed, at a resolution of about 27 A, that the four subunits within one avidin molecule are separated into two parts. Comparison between avidin and streptavidin reveals that avidin molecule binds to the lipid monolayer in an orientation similar to that of streptavidin.
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183
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Kennedy SH, Qin H, Lin L, Tan EM. Basic fibroblast growth factor regulates type I collagen and collagenase gene expression in human smooth muscle cells. THE AMERICAN JOURNAL OF PATHOLOGY 1995; 146:764-71. [PMID: 7887456 PMCID: PMC1869161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Basic fibroblast growth factor (bFGF) is a multifunctional peptide well known for angiogenic, neurotropic, and mesoderm-inducing effects. In the present study, we have investigated the effects of bFGF on collagen and collagenase gene expression in human iliac arterial smooth muscle cells. We report that bFGF inhibits type I collagen gene expression and collagen biosynthesis, with concomitant stimulation of collagenase gene expression. The smooth muscle cells incubated with human recombinant bFGF decreased the mRNA steady state levels of pro-alpha 1(I) type I collagen by as much as 72%. [3H]Hydroxyproline synthesis was also suppressed by 59% compared with untreated control cultures. Indirect immunofluorescence confirmed corresponding changes at the protein level. In contrast to the down-regulation of type I collagen gene expression, collagenase gene expression was found to be up-regulated severalfold by bFGF. The data suggest that bFGF is capable of regulating collagen and collagenase gene expression divergently in human smooth muscle cells and that the effects appear to be mediated at a pretranslational level.
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184
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Qin H, Morris BJ, Hoh JF. Isolation and structure of cat superfast myosin light chain-2 cDNA and evidence for the identity of its human homologue. Biochem Biophys Res Commun 1994; 200:1277-82. [PMID: 8185576 DOI: 10.1006/bbrc.1994.1589] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A full-length cDNA clone coding for superfast myosin light chain-2 (MyLC2) was isolated from an expression cDNA library prepared from cat masseter muscle and was fully characterized. The deduced amino acid sequence shares 58% overall identity with limb fast MyLC2, whereas homologies of the latter among higher vertebrates show 90% identity, indicating that superfast MyLC2 has diverged considerably from limb fast MyLC2 during evolution. Superfast MyLC2 cDNA has 89% nucleotide homology and 93% amino acid homology with a published novel human MyLC2 (MYL5), suggesting that MYL5 is a human homologue of the cat superfast MyLC2. Hybridization of a superfast MyLC2 isoform-specific probe reveals that expression of superfast MyLC2 in cat is confined to jaw-closing muscles. In conclusion, the present paper describes for the first time the cloning of a superfast myosin light chain coding sequence.
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185
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Lei ZY, Qin H, Liao JZ. [Action of Astragalus membranaceus on left ventricular function of angina pectoris]. ZHONGGUO ZHONG XI YI JIE HE ZA ZHI ZHONGGUO ZHONGXIYI JIEHE ZAZHI = CHINESE JOURNAL OF INTEGRATED TRADITIONAL AND WESTERN MEDICINE 1994; 14:199-202, 195. [PMID: 7950192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The action on left ventricular function of Astragalus Membranaceus (AM), a Qi-tonic, in 20 patients with angina pectoris was studied by means of Doppler Echocardiogram (DEC). It showed that cardiac output increased from 5.09 +/- 0.21 to 5.95 +/- 0.18 L/min 2 weeks after AM was administered (P < 0.01), and no improvement of left ventricular diastolic function appeared. Adenosine triphosphatase activity was not inhibited by using AM, which was different from that of digitalis.
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186
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Cheng TJ, Qin H, Zhang PY. [Protection against experimental hepatic injury by fengxiang yigankang capsule]. ZHONGGUO ZHONG XI YI JIE HE ZA ZHI ZHONGGUO ZHONGXIYI JIEHE ZAZHI = CHINESE JOURNAL OF INTEGRATED TRADITIONAL AND WESTERN MEDICINE 1994; 14:162-4, 134. [PMID: 7950188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Protective effect of Fengxiang Yigankang (FXYGK) capsule against hepatotoxicity induced by CCl4 and acetaminophen (AAP) was studied. It was found that the FXYGK capsule inhibited markedly malonic aldehyde (MDA) formation of liver induced by CCl4 and AAP. It blocked also depletion of reduced form of glutathione (GSH) of damaged liver induced by AAP. In addition, FXYGK could decrease serum alanine aminotransferase levels induced by CCl4 (P < 0.05). The results of histopathological examination showed that the FXYGK capsule (0.45, 0.9 and 1.8 g/kg) could also reduce significantly fatty degeneration of liver (P < 0.05).
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187
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Elbein SC, Hoffman M, Qin H, Chiu K, Tanizawa Y, Permutt MA. Molecular screening of the glucokinase gene in familial type 2 (non-insulin-dependent) diabetes mellitus. Diabetologia 1994; 37:182-7. [PMID: 8163053 DOI: 10.1007/s001250050091] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The glucokinase locus has been implicated by linkage studies in several Caucasian pedigrees with early onset, autosomal dominant diabetes, and mutations have been identified in a large number of these pedigrees. Although mutations have been reported in some pedigrees with late onset Type 2 (non-insulin-dependent) diabetes mellitus, linkage studies of typical familial Type 2 diabetes did not suggest a major role for this locus. Nonetheless, linkage studies were consistent with the hypothesis that mutations of the glucokinase gene were responsible for the pathogenesis of Type 2 diabetes in a minority of pedigrees or one gene in a polygenic disorder. To systematically address this hypothesis, we examined 60 diabetic members of 18 pedigrees ascertained for two or more Type 2 diabetic siblings and eight unrelated diabetic spouses. Initially, the coding regions from each of the 11 glucokinase exons were examined by the sensitive technique of single strand conformation polymorphism analysis to screen for single nucleotide substitutions. Subsequently, we also sequenced each exon from an affected member of the single pedigree in which a glucokinase allele was most likely to segregate with diabetes. Single strand conformation polymorphism analysis detected only three variants, none of which altered the amino acid sequence. No coding or splice site mutations were detected. Likewise, no additional mutations were detected upon direct sequence analysis. However, additional screening of promoter and 3' untranslated regions detected a variant pattern in the untranslated region of exon 10 which appeared to segregate with diabetes and impaired glucose tolerance in one pedigree.(ABSTRACT TRUNCATED AT 250 WORDS)
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188
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Lou YK, Qin H, Molodysky E, Morris BJ. Simple microwave and thermal cycler boiling methods for preparation of cervicovaginal lavage cell samples prior to PCR for human papillomavirus detection. J Virol Methods 1993; 44:77-81. [PMID: 8227280 DOI: 10.1016/0166-0934(93)90009-g] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Sample preparation is an important step in the detection of viral DNA by the polymerase chain reaction (PCR) technique. The method used should achieve release of cellular DNA with the minimum of manipulation steps so as to reduce the possibility of contamination. The present report demonstrates that either microwaving or 20 min of boiling in the heating block of a thermal cycler lead to satisfactory results in the detection by PCR of human papillomavirus in cervicovaginal epithelial cell specimens obtained by lavage. Since each of these methods uses only one step the possibility of contamination is greatly reduced compared to the widely used proteins K/nonionic detergent extraction procedure.
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189
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Qin H, Chen YH, Yip MY, Lam-Po-Tang PR, Morris BJ. Reassignment of human renin gene to chromosome 1q32 in studies of a (1;4)(q42;p16) translocation. Hum Hered 1993; 43:261-4. [PMID: 8344672 DOI: 10.1159/000154142] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The human renin gene (REN) has been assigned to chromosome 1q42. Linkage studies are, however, inconsistent with this localization. We therefore reexamined the question of the location of REN using a patient whose distal chromosome 1q arm was translocated to chromosome 4 [(1;4)(q42;p16)]. In situ hybridization using a 3H-labelled REN probe demonstrated hybridization signals confined to the q32 band of chromosome 1, with radioactivity in the translocated 1q42 region being similar to the low levels along all other chromosomes.
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190
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Qin H, Fu J, Zhang Y, Hu Y, Zhao X. Intelligence function in children with acute lymphoblastic leukemia after treatment. CHINESE MEDICAL SCIENCES JOURNAL = CHUNG-KUO I HSUEH K'O HSUEH TSA CHIH 1993; 8:91-4. [PMID: 8292807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In order to evaluate the effects of chemotherapy and central nervous system prophylaxis on the intelligence function of children with acute lymphoblastic leukemia (ALL), 147 patients were divided into 2 groups according to their different treatment regimens. Group A included 75 patients with ALL who were diagnosed and treated from 1981 to 1986. Group B included 72 ALL patients diagnosed and treated from 1988 to 1990. A control group included 73 healthy children who shared the same education and environmental background with the patients. Chinese revisions of Wechsler measures of intelligence quotient were used to estimate verbal IQ, performance IQ and total IQ in the 3 groups. American-produced Systate software was used to analyze the data. Results showed that IQ distribution, verbal IQ, performance IQ and total IQ of group A were obviously lower than those in the control group. Verbal IQ and total IQ of group B were also reduced. Significant differences of verbal IQ and performance IQ as well as total IQ were also found between groups A and B. Multiple regression analysis showed negative correlations between IQ and cranial irradiation dosage, times of intrathecal MTX and time after irradiation.
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Qin H, Welker DL, Youssef NN. Isolation and characterization of a linear plasmid from the entomopathogenic fungus Ascosphaera apis. Plasmid 1993; 29:19-30. [PMID: 8441766 DOI: 10.1006/plas.1993.1003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
An extrachromosomal DNA plasmid was isolated from both mating types of the entomopathogenic fungus Ascosphaera apis and named pAaL. The subculture in which pAaL was first identified originated from mummified honey bee larvae from an apiary in Wyoming. Very similar, homologous plasmids were found in 9 out of 10 of isolates collected from diverse geographic locations. The plasmid is found inside the mitochondria, has the same buoyant density as mitochondrial DNA in bisbenzamide--CsCl gradients, and does not contain sequences homologous to either mitochondrial DNA or genomic DNA. The plasmid is linear, double-stranded, of 12 kilobase pair, and has a higher copy number than the mitochondrial DNA. Endonuclease and exonuclease digestions suggest that an inverted repeat is probably present at each terminus and that pAaL has two blocked 5' ends, probably due to the presence of terminal binding proteins. Restriction site data showed pAaL to be AT-rich. There were no apparent differences in the growth rate, culture appearance, and reproductive cycle of plasmid-bearing or plasmid-free A. apis isolates. pAaL was stably inherited in the plasmid-free strains, but it was lost in the progeny of crosses and reciprocal crosses between the plasmid-free strain and plasmid-bearing strains. The biological function of this plasmid has not yet been determined.
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192
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Qin H, Li SC. [Case control study on risk factors of cerebral thrombosis]. ZHONGHUA LIU XING BING XUE ZA ZHI = ZHONGHUA LIUXINGBINGXUE ZAZHI 1991; 12:354-6. [PMID: 1811895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In order to explore the pathogenic risk factors or protective factors of cerebral thrombosis, 1:1 matched case control study was done in 110 cases diagnosed by computerized tomography (CT). Both cases and controls were selected from several provincial and municipal hospitals in Jinan, Shandong Province, China. Every case was matched with one control on sex, race, age, occupation, residential area, educational level and economic status. 31 factors were analysed and 9 risk or protective factors were found by univariate analysis and multiple stepwise regression. Using the same 9 factors as independent variables, conditional logistic regression was performed and 4 factors were confirmed as pathogenic risk factors or protective factor of cerebral thrombosis (alpha = 0.01). They are high blood pressure (beta = 3.46, OR = 7.57), abdominal skinfold thickness (beta = 3.21, OR = 3.77), familial aggregation of stroke (beta = 2.25, OR = 12.64) and high level HDL2-C (beta = -2.99, OR = 0.16). Moreover, reliability of collective data and control o: bias were evaluated and discussed.
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Qin H, Kemp J, Yip MY, Lam-Po-Tang PR, Morris BJ. Localization of human glandular kallikrein-1 gene to chromosome 19q13.3-13.4 by in situ hybridization. Hum Hered 1991; 41:222-6. [PMID: 1783409 DOI: 10.1159/000154005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Humans possess 3 fully characterized kallikrein-like genes. The gene expressed in kidney, pancreas and salivary gland (KLK), and the gene encoding prostate-specific antigen (APS) have been localized to chromosome 19q13.2-qter. The present study describes the localization of the remaining gene, hGK-1, which has highest homology to and a similar tissue specificity of expression as the APS gene. Using a [3H]-labeled probe derived from a hGK-1 genomic clone, we demonstrated hybridization confined to the q13.3 and q13.4 bands of chromosome 19 and suggest that kallikrein genes may possibly be located near the border of these two bands.
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194
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Dowse GK, Qin H, Collins VR, Zimmet PZ, Alberti KG, Gareeboo H. Determinants of estimated insulin resistance and beta-cell function in Indian, Creole and Chinese Mauritians. The Mauritius NCD Study Group. Diabetes Res Clin Pract 1990; 10:265-79. [PMID: 2073874 DOI: 10.1016/0168-8227(90)90070-a] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Associations with insulin resistance and islet beta-cell function have been studied cross-sectionally in a population-based sample of 4278 Mauritians comprising Asian Indian, Creole and Chinese subjects. Insulin resistance and beta-cell function were estimated by a computer solved model based on fasting plasma glucose and insulin concentrations. Insulin resistance increased with declining glucose tolerance, whereas beta-cell function was highest in subjects with impaired glucose tolerance (IGT) and lowest in those with non-insulin-dependent diabetes mellitus (NIDDM). Indian subjects had the highest beta-cell function, while ethnic differences in insulin sensitivity were less marked. This may indicate that deranged beta-cell function rather than insulin resistance is the primary determinant of hyperinsulinaemia and glucose intolerance in Asian Indians. beta-Cell function declined with age more sharply than did insulin sensitivity, suggesting that the age-related decline in glucose tolerance is primarily related to loss of beta-cell function. Body mass index, waist/hip ratio, physical inactivity and female sex were independently associated with insulin resistance and beta-cell function. Subjects with a family history of diabetes had increased insulin resistance, irrespective of glucose tolerance. This or similar models may have application in longitudinal population-based studies which seek to determine the relative contributions of insulin resistance and beta-cell function to the aetio-pathogenesis of NIDDM.
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Deng K, Qin H, Liang C, Hong B. [Diagnosis value of lateral pharyngeal roentgenography in snoring disease]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1990; 21:213-5. [PMID: 2391108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In this paper, X-ray findings of the lateral pharynx before uvulopalatopharyngoplasty in 14 cases of snoring disease were studied. The results are as follows. There is less than 5 mm in anterior-posterior airway of pharyngeal cavity (13 cases), and 8 mm (1 case), in diameter. Minimum 2 mm, average 4.4 mm. There is less than 25 mm length of uvula (7 cases), 28-35 mm (7 cases). Minimum 22 mm, average length is 27.9 mm. Shape of uvula is thick and long (12 cases), thick and short 1 case, thin and long 1 case. The etiology, abnormal X-ray finding and X-ray examination of the lateral pharynx, etc. in snoring disease have been discussed.
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Qin H, Kemp J, Yip MY, Lam-Po-Tang PR, Hoh JF, Morris BJ. Localization of human cardiac beta-myosin heavy chain gene (MYH7) to chromosome 14q12 by in situ hybridization. CYTOGENETICS AND CELL GENETICS 1990; 54:74-6. [PMID: 2249479 DOI: 10.1159/000132961] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The genes coding for each human cardiac myosin heavy chain (alpha-MHC and beta-MHC, MYH6 and MYH7, respectively) are tightly linked and the alpha-MHC gene has been assigned to chromosome 14. In order to provide a more precise regional localization, in situ hybridization experiments were carried out using a 3H-labeled probe derived from a beta-MHC genomic clone. The results demonstrated that the human cardiac MHC genes are located within the q12 band of chromosome 14.
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