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Khorram O, Garthwaite M, Johnson MS, Denessiouk KA, Han G, Guo T, McPhaul LW, Magee TR, Westerman B, Golos TG. Identification and characterization of a novel luciferase-like protein in the human female reproductive tract. J Clin Endocrinol Metab 2004; 89:5837-46. [PMID: 15531550 DOI: 10.1210/jc.2004-0022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A novel cDNA was cloned from human endometrium, matching a human gene with the interim name KIAA1463. An mRNA identified by 5'-rapid amplification of cDNA ends was found to be 3349 nt in length. PCR analysis also identified another transcript of 6626 nt, with an open reading frame encoding a 900 amino acid protein. A fold recognition program identified similarity to firefly luciferase containing an AMP-binding motif; hence, we refer to the predicted protein as the AMP binding/luciferase-like protein (ALLP). ALLP mRNA and protein were expressed throughout the female reproductive tract with the highest levels found in the ovary and uterus. In situ hybridization and immunohistochemistry showed predominant localization of the ALLP mRNA/protein in endometrial glandular epithelium and within the theca and granulosa cells in the ovary. In the endometrium expression of ALLP, mRNA and protein were higher during d 16-21 of the secretory phase of the cycle. Western blot analysis showed decreased expression of ALLP in the postmenopausal endometrium, and hormone replacement therapy increased the expression of ALLP. Endometrial adenocarcinoma cell lines expressed more ALLP, compared with cultured primary endometrial cells or normal endometrial tissue. The ubiquitous expression of ALLP in reproductive and nonreproductive tissues suggests that this protein, which is probably regulated by ovarian steroids, plays an important metabolic role and may be involved in such processes as implantation and tumorigenesis.
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Desapriya EBR, Joshi P, Han G, Rajabali F. Demographic risk factors in pesticide related suicides in Sri Lanka. Inj Prev 2004; 10:125. [PMID: 15066981 PMCID: PMC1730054 DOI: 10.1136/ip.2003.004283] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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153
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Han G, Li AG, Owens P, Wang X. 036 Overexpression of Smad7 in Keratinocytes Accelerates Cutaneous Wound Healing. Wound Repair Regen 2004. [DOI: 10.1111/j.1067-1927.2004.0abstractai.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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154
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Grieco P, Balse-Srinivasan P, Han G, Weinberg D, MacNeil T, Van der Ploeg LHT, Hruby VJ. Extensive structure-activity studies of lactam derivatives of MT-II and SHU-9119: their activity and selectivity at human melanocortin receptors 3, 4, and 5. ACTA ACUST UNITED AC 2003; 62:199-206. [PMID: 14531843 DOI: 10.1034/j.1399-3011.2003.00087.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The melanocortin system is involved in the regulation of several diverse physiologic pathways. Recently we have demonstrated that replacing His6 by Pro6 in the well-known antagonist SHU-9119 resulted in a potent agonist at the hMC5R (EC50 = 0.072 nm) with full antagonist activity at the hMC3R and the hMC4R. We have designed, synthesized, and pharmacologically characterized a series of peptide analogs of MT-II and SHU-9119 at the human melanocortin receptors MC3R, MC4R and MC5R. All these peptides were modified at position 6 with a Pro instead of a His residue. In this study, we have identified new scaffolds which are antagonists at the hMC4R and hMC3R. Additionally, we have discovered a new selective agonist at the hMC4R, Ac-Nle-c[Asp-Pro-D-Phe-Arg-Trp-Lys]-Pro-Val-NH2 (6, PG-931) which will be useful in further biologic investigations of the hMC4R. PG-931 was about 100-fold more selective for the hMC4R vs. the hMC3R (IC50 = 0.58 and 55 nm, respectively). Some of these new analogs have exceptional biologic potencies at the hMC5R and will be useful in further efforts to differentiate the substructural features responsible for selectivity at the hMC3R, hMC4R, and hMC5R.
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MESH Headings
- Animals
- CHO Cells
- Cell Membrane/drug effects
- Cell Membrane/metabolism
- Cricetinae
- Drug Design
- Histidine/chemistry
- Humans
- Inhibitory Concentration 50
- Lactams/chemical synthesis
- Lactams/pharmacology
- Melanocyte-Stimulating Hormones/chemical synthesis
- Melanocyte-Stimulating Hormones/pharmacology
- Peptides, Cyclic/chemical synthesis
- Peptides, Cyclic/pharmacology
- Proline/chemistry
- Receptor, Melanocortin, Type 3/agonists
- Receptor, Melanocortin, Type 3/antagonists & inhibitors
- Receptor, Melanocortin, Type 3/drug effects
- Receptor, Melanocortin, Type 4/agonists
- Receptor, Melanocortin, Type 4/antagonists & inhibitors
- Receptor, Melanocortin, Type 4/drug effects
- Receptors, Corticotropin/agonists
- Receptors, Corticotropin/antagonists & inhibitors
- Receptors, Corticotropin/drug effects
- Receptors, Melanocortin
- Structure-Activity Relationship
- alpha-MSH/analogs & derivatives
- alpha-MSH/chemical synthesis
- alpha-MSH/pharmacology
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155
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Wessells H, Hruby VJ, Hackett J, Han G, Balse-Srinivasan P, Vanderah TW. Ac-Nle-c[Asp-His-DPhe-Arg-Trp-Lys]-NH2 induces penile erection via brain and spinal melanocortin receptors. Neuroscience 2003; 118:755-62. [PMID: 12710982 DOI: 10.1016/s0306-4522(02)00866-7] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Penile erection induced by alpha-melanocyte-stimulating hormone and melanocortin receptors (MC-R) in areas of the spinal cord and periphery has not been demonstrated. To elucidate sites of the proerectile action of melanocortin peptides, in awake male rats we administered the MC-R agonist Ac-Nle-c[Asp-His-DPhe-Arg-Trp-Lys]-NH(2) (MT-II) i.c.v., intrathecal (i.th.) and i.v. and scored penile erection and yawning. Injection of the MC-R antagonist Ac-Nle-c[Asp-His-DNal(2')-Arg-Trp-Lys]-NH(2) (SHU-9119) i.c.v. or i.th. in combination with i.th. MT-II differentiated spinal from supraspinal effects. To exclude a site of action in the penis, we recorded intracavernous pressure responses to intracavernosal injection of MT-II in the anesthetized rat.I.c.v., i.th., and i.v. MT-II induced penile erections in a dose-dependent fashion. Yawning was observed with i.c.v. and i.v. MT-II, while spinal injection did not produce this behavior. Intrathecal delivery of MT-II to the lumbosacral spinal cord was more efficacious in inducing erections than i.c.v. or i.v. administration; SHU-9119 blocked the erectile responses to i.th. MT-II when injected i.th. but not i.c.v. Intracavernosal MT-II neither increased intracavernous pressure nor augmented neurostimulated erectile responses. We confirmed the central proerectile activity of MT-II and demonstrated that in addition to a site of action in the brain, the distal spinal cord contains melanocortin receptors that can initiate penile erection independent of higher centers. These results provide new insight into the central melanocortinergic pathways that mediate penile erection and may allow for more efficacious melanotropin-based therapy for erectile dysfunction.
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156
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Han G, Quillan JM, Carlson K, Sadée W, Hruby VJ. Design of novel chimeric melanotropin-deltorphin analogues. Discovery of the first potent human melanocortin 1 receptor antagonist. J Med Chem 2003; 46:810-9. [PMID: 12593660 DOI: 10.1021/jm020355o] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A number of novel alpha-melanotropin (alpha-MSH) analogues have been designed, synthesized, and assayed for bioactivity at the melanocortin-1 (MC1) receptor from Xenopus frog skin, and selected potent analogues were examined at recombinant human MC1, MC3, and MC4 receptors expressed in human embryonic kidney (HEK) cells. These ligands were designed from Deltorphin-II, by a new hybrid approach, which incorporates the hydrophobic tail and the address sequence of Deltorphin-II (Glu-Val-Val-Gly-NH(2)) and key pharmacophore elements of melanotropins. Some of the ligands designed, c[Xxx-Yyy-Zzz-Arg-Trp-Glu]-Val-Val-Gly-NH(2) [XXX = nothing, Gly, beta-Ala, gamma-Abu, 6-Ahx; YYY = His, His(3-Bom), (S)-cyclopentylglycine (Cpg); ZZZ = Phe, d-Phe; d-Nal(2')], show high potency at melanocortin receptors. One ligand, GXH-32B-c[beta-Ala-His-d-Nal(2')-Arg-Trp-Glu]-Val-Val-Gly-NH(2), the most potent of the chimeric analogues tested, displayed agonist activity at each of the MC receptor subtypes analyzed, with an EC(50) of 2 nM at the amphibian MC1 receptor. In contrast, GXH-38B-c[Gly-Cpg-d-Nal(2')-Arg-Trp-Glu]-Val-Val-Gly-NH(2) (Cpg = cyclopentyl glycine) was an antagonist with a IC(50) of 43 nM at the amphibian receptor, and among the human subtypes tested, was the most potent at the MC1 receptor subtype where it also acted as an antagonist (K(i) = 53 nM), which is the first potent antagonist discovered for the human MC1 receptor. These results provide strong evidence supporting our hypothesis that ligand scaffolds for different G-protein coupled receptors (GPCRs) can be used to design ligands for other GPCRs and to design more potent ligands to treat diseases associated with the human MC1 receptor.
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157
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Grieco P, Balse-Srinivasan P, Han G, Weinberg D, MacNeil T, Van der Ploeg LHT, Hruby VJ. Synthesis and biological evaluation on hMC3, hMC4 and hMC5 receptors of gamma-MSH analogs substituted with L-alanine. THE JOURNAL OF PEPTIDE RESEARCH : OFFICIAL JOURNAL OF THE AMERICAN PEPTIDE SOCIETY 2002; 59:203-10. [PMID: 11966977 DOI: 10.1034/j.1399-3011.2002.01966.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
To elucidate the molecular basis of the interaction of the native dodecapeptide gamma-MSH with the melanocortin receptors, we performed a structure-activity study in which we systematically replaced l-Ala in each position of this peptide. Here we report the binding affinity and agonist potency on human MC3R, MC4R and MC5R. Intracellular cAMP concentration was measured on CHO cells, and binding assays were carried out using membranes prepared from these cell lines which stably express hMC3R, hMC4R and hMC5R. Our results indicate that the last four amino acids in the C-terminal region of gamma-MSH are not important determinants of biological activity and selectivity at human melanocortin receptors. Interesting results were obtained when l-Ala was substituted for His6, Phe7, Arg8 and Trp9. For these peptides, the affinity and activity at all three human receptors (MC3R, MC4R and MC5R) decreased significantly, demonstrating that the His-Phe-Arg-Trp sequence in gamma-MSH is important for activity at these three melanocortin receptors. Similar results were obtained when Met3 was replaced with l-Ala, suggesting the importance of this position in the interaction with all three receptors. This study highlights the role played by the His-Phe-Arg-Trp sequence in receptor binding and in agonist activity of gamma-MSH.
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158
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159
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Zhang H, Bai C, Wang J, Han G, Guo X, Zhou X, Wu K, Ding J, Fan D. [Significance of lung perfusion scanning with technetium labeled macroaggregated albumin and pulmonary function assay for diagnosis of early hepatopulmonary syndrome]. ZHONGHUA GAN ZANG BING ZA ZHI = ZHONGHUA GANZANGBING ZAZHI = CHINESE JOURNAL OF HEPATOLOGY 2001; 9:331-3. [PMID: 11782297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To evaluate the values of pulmonary function assay and dynamic pulmonary perfusion imaging with technetium labeled macroaggregated albumin ((99m)TcMAA) in the early diagnosis of hepatopulmonary syndrome (HPS). METHODS The pulmonary function assay and (99m)TcMAA scans were performed in 28 patients with HPS, 30 cirrhotic patients (CP) without HPS, and 21 healthy controls (HC). RESULTS In the patients with HPS, PaO(2), SaO(2) and diffusion capacity for carbon monoxide of lungs (DLco) was significantly lower than that in CP (P<0.01) and HC (P<0.01), and alveolar-arterial gradient [P((A-a))O(2)] was significantly increased (P<0.001). Results from (99m)TcMAA scans showed that the radionuclides were distributed over the spleen, kidney, liver and brain, and the ratios of arterivenous shunt were significantly higher than that in CP (P<0.001) and NC (P<0.001). In cirrhotic patients, DLco significantly decreased (P<0.05), P((A-a))O(2) and shunt ratios increased (P<0.01 and 0.001). CONCLUSIONS Pulmonary function assay and dynamic pulmonary perfusion imaging with (99m)TcMAA are sensitive methods for diagnosis of the early HPS.
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160
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Ma Z, Wang G, Han G. [Synthesis of hapten 3-phenoxybenzyl-2,2-dimetheyl-cyclopropane-1,3-dicarboxylate]. WEI SHENG YAN JIU = JOURNAL OF HYGIENE RESEARCH 2001; 30:367-8. [PMID: 12561624] [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 order to establish the immunoassay for insecticides of pyrethroids, hapten (3-phenoxybenzyl-2,2-dimethyleyclopropane-1,3-dicarboxylate) has been synthesized from chrysanthemumcarboxylic acid via chloridization, esterification and oxidation. The structure of the product was determined by IR, 1HNMR and MS analysis.
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161
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Miller AW, Dimitropoulou C, Han G, White RE, Busija DW, Carrier GO. Epoxyeicosatrienoic acid-induced relaxation is impaired in insulin resistance. Am J Physiol Heart Circ Physiol 2001; 281:H1524-31. [PMID: 11557540 DOI: 10.1152/ajpheart.2001.281.4.h1524] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
We assessed the effect of epoxyeicosatrienoic acids (EETs) in intact mesenteric arteries and Ca(2+)-activated K(+) (BK(Ca)) channels of isolated vascular smooth muscle cells from control and insulin-resistant (IR) rats. The response to 11,12-EET and 14,15-EET was assessed in small mesenteric arteries from control and IR rats in vitro. Mechanistic studies were performed in endothelium intact or denuded arteries and in the presence of pharmacological inhibitors. Moreover, EET-induced activation of the BK(Ca) channel was assessed in myocytes in both the cell-attached and the inside-out (I/O) patch-clamp configurations. In control arteries, both EET isomers induced relaxation. Relaxation was impaired by endothelium denudation, N(omega)-nitro-L-arginine, or iberiotoxin (IBTX), whereas it was abolished by IBTX + apamin or charybdotoxin + apamin. In contrast, the EETs did not relax IR arteries. In control myocytes, the EETs increased BK(Ca) activity in both configurations. Conversely, in the cell-attached mode, EETs had no effect on BK(Ca) channel activity in IR myocytes, whereas in the I/O configuration, BK(Ca) channel activity was enhanced. EETs induce relaxation in small mesenteric arteries from control rats through K(Ca) channels. In contrast, arteries from IR rats do not relax to the EETs. Patch-clamp studies suggest impaired relaxation is due to altered regulatory mechanisms of the BK(Ca) channel.
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162
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Han G, Tamaki M, Hruby VJ. Fast, efficient and selective deprotection of the tert-butoxycarbonyl (Boc) group using HCl/dioxane (4 m). THE JOURNAL OF PEPTIDE RESEARCH : OFFICIAL JOURNAL OF THE AMERICAN PEPTIDE SOCIETY 2001; 58:338-41. [PMID: 11606219 DOI: 10.1034/j.1399-3011.2001.00935.x] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Fast, efficient and selective deprotection of the tert-butoxycarbonyl (Boc) group of various amino acids and peptides was achieved by using hydrogen chloride (4 m) in anhydrous dioxane solution for 30 min at room temperature. In the cases studied in our laboratory, this protocol provided superior selectivity to deprotect Nalpha-Boc groups in the presence of tert-butyl esters and tert-butyl ethers, including thio-tert-butyl ethers, but not phenolic tert-butyl ethers.
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163
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Wan YJ, Poland RE, Han G, Konishi T, Zheng YP, Berman N, Lin KM. Analysis of the CYP2D6 gene polymorphism and enzyme activity in African-Americans in southern California. PHARMACOGENETICS 2001; 11:489-99. [PMID: 11505219 DOI: 10.1097/00008571-200108000-00004] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Despite its importance in drug metabolism and disease susceptibility, CYP2D6 activity and genetic polymorphism have rarely been investigated in African-American populations. In order to bridge this gap, we examined the genotype and phenotype of the enzyme in 154 African-American (AA) and 143 Caucasian (C) normal volunteers. AAs are significantly more likely to possess *17 and *5, but less likely to have *4. Overall, the two groups were similar in their CYP2D6 activity as measured with dextromethorphan as the probe (metabolic ratio 2.21 +/- 0.78 for AAs; 2.11 +/- 0.86 for Cs; t = 1.02, NS). Two of four AAs and six of seven Cs were classified as poor metabolizers and have two nonfunctioning alleles. CYP2D6 activity is determined by *17, *4, *5 and age in AAs (r2 = 0.33, f = 18.8, P < 0.001) and by *4 and *XN in Cs (r2 = 0.14, f = 10.8, P < 0.001). These results support previous findings demonstrating the importance of *17 in determining CYP2D6 activity in AAs.
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164
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Han G, Liu B, Zhang J, Zuo W, Morris NR, Xiang X. The Aspergillus cytoplasmic dynein heavy chain and NUDF localize to microtubule ends and affect microtubule dynamics. Curr Biol 2001; 11:719-24. [PMID: 11369237 DOI: 10.1016/s0960-9822(01)00200-7] [Citation(s) in RCA: 133] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Cytoplasmic dynein is a multisubunit, minus end-directed microtubule motor that uses dynactin as an accessory complex to perform various in vivo functions including vesicle transport, spindle assembly, and nuclear distribution [1]. We previously showed that in the filamentous fungus Aspergillus nidulans, a GFP-tagged cytoplasmic dynein heavy chain (NUDA) forms comet-like structures that exhibited microtubule-dependent movement toward and back from the hyphal tip [2]. Here we demonstrate that another protein in the NUDA pathway, NUDF, which is homologous to the human LIS1 protein involved in brain development [3, 4], also exhibits such dynamic behavior. Both NUDA and NUDF are located at the ends of microtubules, and this observation suggests that the observed dynamic behavior is due to their association with the dynamic microtubule ends. To address whether NUDA and NUDF play a role in regulating microtubule dynamics in vivo, we constructed a GFP-labeled alpha-tubulin strain and used it to compare microtubule dynamics in vivo in wild-type A. nidulans versus temperature-sensitive loss-of-function mutants of nudA and nudF. The mutants showed a lower frequency of microtubule catastrophe, a lower rate of shrinkage during catastrophe, and a lower frequency of rescue. The microtubules in the mutant cells also paused longer at the hyphal tip than wild-type microtubules. These results indicate that cytoplasmic dynein and the LIS1 homolog NUDF affect microtubule dynamics in vivo.
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165
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Abstract
The family of Ser/Thr and/or Tyr kinases and that of His kinases play essential roles in signal transduction. For a long time, the former has been found in eukaryotes, the latter in prokaryotes. Studies in the last decade have shown, however, that most bacteria possess from one to more than 10 genes encoding Ser/Thr kinases. This observation raises an important question concerning the evolutionary origin of Ser/Thr kinases found in bacteria. To answer this question, we have analyzed a family of 11 genes encoding Ser/Thr kinases in the cyanobacterium Synechocystis sp. PCC 6803. This bacterium contains the largest number of Ser/Thr kinases among all bacteria whose genomic sequences have been released so far. In this study, we have developed a user-friendly computer program for statistical analysis of codon usages and GC content. The results demonstrate that Ser/Thr kinases have similar codon usages and GC contents as the average of all possible open reading frames (ORFs) deduced from the genome. In contrast, ORFs encoding transposases, as a control in our analysis, display a disparity in both codon usage and GC content, confirming their multiple origin and genetic promiscuity. In light of our results, we propose that Ser/Thr kinases existed before the divergence between prokaryotes and eukaryotes during evolution, or were laterally transferred into prokaryotes at the early stages of bacterial evolution. If Ser/Thr kinases have persisted ever since in prokaryotes under evolutionary pressure, it is then expected that they play important, possibly even essential roles in regulating bacterial activities as do their counterparts in eukaryotes.
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Han G, Li X, Tian H, Tong N, Ouyang Q, Yin P. [Study on gastric motility and its relevant factors in type 2 diabetes]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 2001; 32:296-9. [PMID: 12600114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
OBJECTIVE In this study radionuclide semi-liquid gastric emptying (GE) study was adopted to test the gastric motility in 129 patients with type 2 diabetes. Further study was made to explore the relationship between gastric motility disorder of diabetes and the influential factors. METHODS The variables to be measured and analyzed were age, BMI, duration of illness, level of glycemia, HbAlc, plasma insulin, motilin, gastrin, glucagon and Mg2+. RESULTS Of the 129 cases, 80 had delayed GE with an occurrence of 62.02%, and there was a close correlation between gastric motility disorder and the duration of illness, BMI, FPG, PPG, serum insulin, motilin levels and HbAlc as well. CONCLUSION These findings imply that gastric motility disorder of diabetes is influenced by multiple factors. The results also suggest that gastric motiligy disorder is much more common than expected, and radionuclide gastric emptying test is a useful aid for the early detection of this clinical entity.
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167
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Xiao H, Xie SP, Fan JX, Yao H, Han G. [Analysis of olanzapine in human plasma with reversed-phase high performance liquid chromatography]. Se Pu 2001; 19:281-2. [PMID: 12541820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2023] Open
Abstract
Olanzapine is a novel antipsychotic drug. Recently it has been applied to clinical research. For the determination of olanzapine in plasma a reversed-phase HPLC method has been established. An aqueous solution of 0.25% ascorbic acid was added into the plasma sample and kept at -20 degrees C. Olanzapine can be separated on a Zorbax ODS column with a mobile phase of 50 mmol/L sodium phosphate (pH 7.2)-methanol-acetonitrile(12:10:3, volume ratios) and detected at 270 nm. The flow rate was 1.0 mL/min. The linear range was 15 micrograms/L-1,200 micrograms/L, r = 0.9988. The limited concentration of detection was 3 micrograms/L. The average recovery was (97.02 +/- 3.11)%. The intra-day and inter-day coefficients of variation were 3.86% (n = 15) and 4.12% (n = 15) respectively. The method has been used to determine olanzapine concentration in patient's plasma. The data obtained show that the sensitivity and selectivity of this method are adequate for drug monitoring in clinical research.
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168
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Han G, Foster BA, Mistry S, Buchanan G, Harris JM, Tilley WD, Greenberg NM. Hormone status selects for spontaneous somatic androgen receptor variants that demonstrate specific ligand and cofactor dependent activities in autochthonous prostate cancer. J Biol Chem 2001; 276:11204-13. [PMID: 11063747 DOI: 10.1074/jbc.m008207200] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have used the autochthonous transgenic adenocarcinoma of mouse prostate (TRAMP) model to investigate the relationship between somatic mutation in the androgen receptor (AR) and the emergence of androgen-independent prostate cancer. Here we report the identification, isolation, and characterization of distinct classes of AR variants from spontaneous prostate tumors in the TRAMP model. Using cDNA cloning, single stranded conformation polymorphism and sequencing strategies, 15 unique somatic mutations in the AR were identified in prostate tumors obtained from eight TRAMP mice between 24 and 29 weeks of age. At least one mutation was isolated from each mouse. All mutations were single base substitutions, 10 were missense and 5 were silent. Nine mutations in the AR were identified in tumors of four mice that were castrated at 12 weeks of age. Interestingly, the majority of mutations (seven out of nine, 78%) identified in the androgen-independent tumors colocalized in the AR transactivation domain. The remaining mutations colocalized in the AR ligand binding domain. In general, the AR variants demonstrated promoter-, cell-, and cofactor-specific activities in response to various hormones. All AR variants isolated in this study maintained strong sensitivity for androgens, and four AR variants isolated from castrated mice demonstrated increased activities in the absence of ligand. The K638M and F677S variants demonstrated increased activities in response to androgen, and K638M also demonstrated increased response to estradiol. In the presence of AR coactivator ARA70 the E231G variant demonstrated increased activity in response to both androgen and estradiol. However, in the presence of AR coactivator ARA160 the E231G variant was selectively responsive to androgen. Collectively these analyses not only indicate that somatic mutations in the AR gene occur spontaneously in TRAMP tumors but also how changes in the hormonal environment may drive the selection of spontaneous somatic mutations that provide a growth advantage.
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169
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Tamaki M, Han G, Hruby VJ. Practical and efficient synthesis of orthogonally protected constrained 4-guanidinoprolines. J Org Chem 2001; 66:1038-42. [PMID: 11430070 DOI: 10.1021/jo005626m] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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170
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Buchanan G, Yang M, Harris JM, Nahm HS, Han G, Moore N, Bentel JM, Matusik RJ, Horsfall DJ, Marshall VR, Greenberg NM, Tilley WD. Mutations at the boundary of the hinge and ligand binding domain of the androgen receptor confer increased transactivation function. Mol Endocrinol 2001; 15:46-56. [PMID: 11145738 DOI: 10.1210/mend.15.1.0581] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The androgen receptor (AR), a member of the steroid receptor superfamily of nuclear transcription factors, mediates androgen signaling in diverse target tissues. Here we report AR gene mutations identified in human prostate cancer and the autochthonous transgenic adenocarcinoma of the mouse prostate model that colocate to residues (668)QPIF(671) at the boundary of the hinge and ligand-binding domain, resulting in receptors that exhibit 2- to 4-fold increased activity compared with wild-type AR in response to dihydrotestosterone, estradiol, progesterone, adrenal androgens, and the AR antagonist, hydroxyflutamide, without an apparent effect on receptor levels, ligand binding kinetics, or DNA binding. The expression of these or similar variants could explain the emergence of hormone refractory disease in a subset of patients. Homology modeling indicates that amino acid residues (668)QPIF(671) form a ridge bordering a potential protein-protein interaction surface. The naturally occurring AR gene mutations reported in this study result in decreased hydrophobicity of this surface, suggesting that altered receptor-protein interaction mediates the precocious activity of the AR variants.
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171
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Peng Z, Tang H, Ling Y, Han G. Apoptosis and Fas system are significantly involved in the process of liver cirrhosis converting into hepatocellular carcinoma. Curr Med Sci 2001; 21:126-9, 148. [PMID: 11523216 DOI: 10.1007/bf02888075] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2000] [Indexed: 10/19/2022]
Abstract
To investigate the roles of apoptosis and the Fas system (Fas, Fas ligand, soluble Fas) in the process of liver cirrhosis (LC) converting into hepatocellular carcinoma (HCC), expression of Fas and Fas ligand (FasL) in 49 LC and 36 HCC samples was detected by immunohistochemical method. Apoptosis was detected by terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) method. Serum soluble Fas (sFas) levels in 28 cases of LC and 27 cases of HCC were measured by enzyme-linked immunosorbent assay (ELISA) method. Compared with LC, apoptotic indices (AI) in HCC tissues were significantly reduced (P < 0.001), expression of Fas was decreased (P < 0.05), and that of FasL was increased (P < 0.05). Serum sFas levels in HCC patients were significantly higher than those in normal controls. Down-regulation of Fas expression, up-regulation of FasL expression in hepatocytes and elevation of sFas level in serum might contribute to tumor escape from immune surveillance of the body. Apoptosis and the Fas system are significantly involved in the process of liver cirrhosis converting into hepatocellular carcinoma.
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Han G, LaPorte MG, Folmer JJ, Werner KM, Weinreb SM. Total syntheses of the Securinega alkaloids (+)-14,15-dihydronorsecurinine, (-)-norsecurinine, and phyllanthine. J Org Chem 2000; 65:6293-306. [PMID: 11052071 DOI: 10.1021/jo000260z] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new strategy for enantiospecific construction of the Securinega alkaloids has been developed and applied in total syntheses of (+)-14,15-dihydronorsecurinine (8), (-)-norsecurinine (6), and phyllanthine (2). The B-ring and C7 absolute stereochemistry of these biologically active alkaloids originated from trans-4-hydroxy-L-proline (10), which was converted to ketonitrile 13 via a high-yielding eight-step sequence. Treatment of this ketonitrile with SmI2 afforded the 6-azabicyclo[3.2.1]octane B/C-ring system 14, which is a key advanced intermediate for all three synthetic targets. Annulation of the A-ring of (-)-norsecurinine (6) with the required C2 configuration via an N-acyliminium ion alkylation was accomplished using radical-based amide oxidation methodology developed in these laboratories as a key step, providing tricycle 33. Annulation of the D-ring onto alpha-hydroxyketone 33 with the Bestmann ylide 45 at 12 kbar gave (+)-14,15-dihydronorsecurinine (8). In the securinine series, the D-ring was incorporated using an intramolecular Wadsworth-Horner-Emmons olefination of phenylselenylated alpha-hydroxyketone 47. The C14,15 unsaturation was installed late in the synthesis by an oxidative elimination of the selenoxide derived from tetracyclic butenolide 50 to give (-)-norsecurinine (6). The A-ring of phyllanthine (2) was formed from hydroxyketone 14 using a stereoselective Yb(OTf)3-promoted hetero Diels-Alder reaction of the derived imine 34 with Danishefsky's diene, affording adduct 35. Conjugate reduction and stereoselective equatorial ketone reduction of vinylogous amide 35 provided tricyclic intermediate 36, which could then be elaborated in a few steps to stable hydroxyenone 53 via alpha-selenophenylenone intermediate 52. The D-ring was then constructed, again using an intramolecular Wadsworth-Horner-Emmons olefination reaction to give phyllanthine (2).
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Schroeder JW, Honeycutt RL, Rooney AP, Han G, Begall S, Gallardo MH. Microsatellites from the South American coruro, Spalacopus cyanus. Mol Ecol 2000; 9:1447-9. [PMID: 10972791 DOI: 10.1046/j.1365-294x.2000.01019-9.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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174
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Balse PM, Kim HJ, Han G, Hruby VJ. Evaluation of new base-labile 2-(4-nitrophenylsulfonyl) ethoxycarbonyl (Nsc)-amino acids for solid-phase peptide synthesis. THE JOURNAL OF PEPTIDE RESEARCH : OFFICIAL JOURNAL OF THE AMERICAN PEPTIDE SOCIETY 2000; 56:70-9. [PMID: 10961541 DOI: 10.1034/j.1399-3011.2000.00759.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The 2-(4-nitrophenylsulfonyl)ethoxycarbonyl (Nsc) group is a new base-labile protecting group for solid-phase peptide synthesis, completely interchangeable with the fluorenylmethoxycarbonyl (Fmoc) protecting group, but with certain advantages. In this paper, we report a methodology with Nalpha-Nsc-protected amino acids for the synthesis of some melanotropins important to our research, namely, gamma-melanocyte-stimulating hormone (gamma-MSH), its [Nle3]-analogue, and a cyclic alpha-MSH/beta-MSH hybrid. We developed an efficient protocol for the synthesis of the cyclic MSH analogue that yielded this peptide in >98% purity. The gamma-MSH synthesis, which gave problems with both the Boc and Fmoc strategies, yielded the desired peptide by Nsc-chemistry but was accompanied by side products. Finally, the Nle3-gamma-MSH analogue was synthesized more efficiently using the Fmoc strategy, suggesting that Nsc-chemistry might not be the best methodology for certain sequences.
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Han G, Yao Q, Li H. [Inhibitory effect of panicoin on platelet activation and its mechanism]. ZHONGGUO ZHONG XI YI JIE HE ZA ZHI ZHONGGUO ZHONGXIYI JIEHE ZAZHI = CHINESE JOURNAL OF INTEGRATED TRADITIONAL AND WESTERN MEDICINE 2000; 20:527-9. [PMID: 11789213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To explore the inhibitory pathway and the possible mechanism of panicoin on platelet activation. METHODS The effect of panicoin on platelet aggregation, thromboxane B2 release, P-selectin (GMP-140) count, levels of cyclic AMP and cyclic GMP induced by ADP, epinephrine, arachidonic acid (AA) or thrombin were observed. RESULTS (1) Panicoin significantly inhibits platelet aggregation induced by ADP, arachidonic acid and epinephrine in a dose-dependent manner; (2) It reduces the P-selectin number on platelet surface which was stimulated by thrombin; (3) It inhibits TXB2 release induced by AA and increases the platelet cyclic AMP level, while cyclic GMP level was not changed. CONCLUSION Panicoin shows a potent inhibition on platelet activation and antithrombotic effect. The mechanisms seem to be related with the elevation of platelet cyclic AMP.
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Han G. Synthesis and biological evaluation of phosphonate analogues of 1alpha,25-dihydroxyvitamin D3. Arch Pharm Res 2000; 23:206-10. [PMID: 10896049 DOI: 10.1007/bf02976446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
A new series of phosphonate side chain analogues of 1alpha,25-dihydroxyvitamin D3 (1) have been synthesized. Antiproliferative activities of theses analogues (8a,b and 9a,b) using human keratinocyte cell shows that analogues which have natural A-ring show higher activity than unnatural A-ring series and almost equally active to 1alpha,25-Dihydroxyvitamin D3 (1) at 1 microM level.
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Xiang X, Han G, Winkelmann DA, Zuo W, Morris NR. Dynamics of cytoplasmic dynein in living cells and the effect of a mutation in the dynactin complex actin-related protein Arp1. Curr Biol 2000; 10:603-6. [PMID: 10837229 DOI: 10.1016/s0960-9822(00)00488-7] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Cytoplasmic dynein is a minus-end-directed microtubule motor that participates in multiple cellular activities such as organelle transport and mitotic spindle assembly [1]. To study the dynamic behavior of cytoplasmic dynein in the filamentous fungus Aspergillus nidulans, we replaced the gene for the cytoplasmic dynein heavy chain, nudA, with a gene encoding a green fluorescent protein (GFP)-tagged chimera, GFP-nudA. The GFP-NUDA fusion protein is fully functional in vivo: strains expressing only the GFP-tagged nudA grow as well as wild-type strains. Fluorescence microscopy showed GFP-NUDA to be in comet-like structures that moved in the hyphae toward the growing tip. Retrograde movement of some GFP-NUDA comets after they arrived at the tip was also observed. These dynamics of GFP-NUDA were not observed in cells treated with a microtubule-destabilizing drug, benomyl, suggesting they are microtubule-dependent. The rate of GFP-NUDA tip-ward movement is similar to the rate of cytoplasmic microtubule polymerization toward the hyphal tip, suggesting that GFP-NUDA is associated and moving with the polymerizing ends of microtubules. A mutation in actin-related protein Arp1 of the dynactin complex abolishes the presence of these dynamic GFP-NUDA structures near the hyphal tip, suggesting a targeting role of the dynactin complex.
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White RE, Kryman JP, El-Mowafy AM, Han G, Carrier GO. cAMP-dependent vasodilators cross-activate the cGMP-dependent protein kinase to stimulate BK(Ca) channel activity in coronary artery smooth muscle cells. Circ Res 2000; 86:897-905. [PMID: 10785513 DOI: 10.1161/01.res.86.8.897] [Citation(s) in RCA: 140] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
cAMP-dependent vasodilators are used to treat a variety of cardiovascular disorders; however, the signal transduction pathways and effector mechanisms stimulated by these agents are not fully understood. In the present study we demonstrate that cAMP-stimulating agents enhance the activity of the large-conductance, calcium-activated potassium (BK(Ca)) channel in single myocytes from coronary arteries by "cross-activation" of the cGMP-dependent protein kinase (protein kinase G, PKG). Single-channel patch-clamp data revealed that 10 micromol/L isoproterenol, forskolin, or dopamine opens BK(Ca) channels in coronary myocytes and that this effect is attenuated by inhibitors of PKG (KT5823; Rp-8-pCPT-cGMPS), but not by inhibiting the cAMP-dependent protein kinase (protein kinase A, PKA). In addition, a membrane-permeable analog, CPT-cAMP, also opened BK(Ca) channels in these myocytes, and this effect was reversed by KT5823. Direct biochemical measurement confirmed that dopamine or forskolin stimulates PKG activity in coronary arteries but does not elevate cGMP. Finally, the stimulatory effect of cAMP on BK(Ca) channels was reconstituted in a cell-free, inside-out patch by addition of purified PKG activated by either cGMP or cAMP. In contrast, channel gating was unaffected by exposure to the purified catalytic subunit of PKA. In summary, findings from on-cell and cell-free patch-clamp experiments provide direct evidence that cAMP-dependent vasodilators open BK(Ca) channels in coronary myocytes by cross-activation of PKG (but not via PKA). Biochemical assay confirmed this cross-activation mechanism of cAMP action in these arteries. This signaling pathway is a novel mechanism for regulation of potassium channel activity in vascular smooth muscle and other cells.
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179
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Peng J, Han G. [Thoughts on the TCM literature research on infectious disease]. ZHONGHUA YI SHI ZA ZHI (BEIJING, CHINA : 1980) 2000; 30:121-3. [PMID: 11624640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
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180
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Peltekova V, Han G, Soleymanlou N, Hampson DR. Constraints on proper folding of the amino terminal domains of group III metabotropic glutamate receptors. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 2000; 76:180-90. [PMID: 10719229 DOI: 10.1016/s0169-328x(00)00029-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The glutamate binding site of the G-protein coupled metabotropic glutamate receptors (mGluRs) is contained within the large extracellular amino terminal domain (ATD) of the receptor. In this study, we examined the ligand binding properties and cellular dispositions of the membrane-bound mGluR4 and mGluR8 subtypes of mGluRs, and a series of truncated versions of these receptors. Truncation of the ATDs of mGluR4 and mGluR8 40 amino acids upstream of the first transmembrane domain produced soluble proteins that were secreted into the cell culture media of transfected human embryonic kidney cells. The soluble receptors retained ligand binding capabilities. Additional constructs of the ATDs of mGluR4 and mGluR8 were assessed for their ability to bind the agonist [(3)H]L-AP4 and for secretion from cells. A shorter mGluR4 construct truncated 98 amino acids upstream from the first transmembrane domain failed to bind [(3)H]L-AP4, while the analogous mGluR8 construct displayed a low level of binding. Unlike the full-length receptors, which were expressed on the cell surface, or the soluble constructs which were secreted, the shorter constructs were primarily associated with intracellular membranes. These observations suggest that the cysteine-rich region may be important for efficient secretion, but not absolutely obligatory for ligand binding. Surprisingly, longer constructs encoding the entire ATDs of mGluR4 and mGluR8 failed to bind ligand and were localized intracellularly. Together, these findings demonstrate that there are strict limitations on the proper folding of truncated versions of the ATDs of mGluR4 and mGluR8. Specifically, all of the leucine-isoleucine-valine binding protein homology region, and part of the cysteine-rich region is required for optimal secretion in a soluble form that retains ligand binding activity.
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181
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Han G, Du J, Li J. [Mating behavioral ecology of Ancylis sativa adult]. YING YONG SHENG TAI XUE BAO = THE JOURNAL OF APPLIED ECOLOGY 2000; 11:99-102. [PMID: 11766601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
The study shows that the mating peak of the overwintering generation adults of Ancylis sativa appeared at 6.0-8.0 hours in their scotophase and the mating activity was more intensive during 2-3 days after eclosion. The higher the temperature was, the later the adults began to mate. For most adults, the duration of mating was 3-4 hours, with a mean frequency of 3.3 times for males and 1.59 for females. The mating behavior of 2-days old adults shifted from photoperiod 14L:10D to continuous dark was similar to that at 14L:10D, all showing an obvious rhythm. When the adults were shifted to continuous light, their mating became inacitive and irregular. The sex pheromone titer of virgin female decreased significantly after mating 1 hour, and remained low until 48 hours after mating.
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Hohmann JG, Teal TH, Clifton DK, Davis J, Hruby VJ, Han G, Steiner RA. Differential role of melanocortins in mediating leptin's central effects on feeding and reproduction. Am J Physiol Regul Integr Comp Physiol 2000; 278:R50-9. [PMID: 10644621 DOI: 10.1152/ajpregu.2000.278.1.r50] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Leptin serves as a humoral link coupling the status of energy reserves to the functional activity of the reproductive system. Leptin is thought to act through melanocortinergic pathways in the brain to regulate ingestive behaviors; however, whether melanocortins mediate leptin's actions on the neuroendocrine-reproductive axis is unknown. We tested this hypothesis first by determining whether the effects of leptin on feeding behavior and reproduction in the ob/ob mouse could be blocked by the melanocortin receptor (MC-R) antagonist SHU9119 and second, by examining the effects of the MC-R agonist MTII on feeding and the endocrine-reproductive system. Administered by intracerebroventricular injections, leptin inhibited food intake, raised plasma gonadotropin levels, and increased seminal vesicle weights compared with controls; SHU9119 (intracerebroventricularly) attenuated leptin's effects on food intake and body weight but did not alter leptin's stimulatory effect on the reproductive axis. MTII (intracerebroventricularly and intraperitoneally) decreased food intake and increased body temperature compared with controls but had no effect on the reproductive-endocrine axis. These results suggest that although leptin acts centrally through melanocortinergic pathways to inhibit ingestive behaviors and stimulate metabolism, leptin's activational effect on the reproductive axis is likely to be mediated by other, unknown neuroendocrine circuits.
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183
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Han G, LaPorte MG, Folmer JJ, Werner KM, Weinreb SM. A New Enantioselective Approach to Total Synthesis of the Securinega Alkaloids: Application to (-)-Norsecurinine and Phyllanthine. Angew Chem Int Ed Engl 2000; 39:237-240. [PMID: 10649387 DOI: 10.1002/(sici)1521-3773(20000103)39:1<237::aid-anie237>3.0.co;2-b] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
An inexpensive proline derivative and chiral control feature in the total synthesis of securinega alkaloids (-)-norsecurinine (1) and phyllanthine (2). Key steps in the synthesis of 1 include an intramolecular ketonitrile coupling and application of a radical-based generation of N-acylimines. The total synthesis of 2 utilizes a stereoselective imino Diels - Alder construction of the methoxypiperidine ring.
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Gonzales O, Han G, de Gyvez J, Sanchez-Sinencio E. Lorenz-based chaotic cryptosystem: a monolithic implementation. ACTA ACUST UNITED AC 2000. [DOI: 10.1109/81.873879] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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185
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186
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Han G, Kryman JP, McMillin PJ, White RE, Carrier GO. A novel transduction mechanism mediating dopamine-induced vascular relaxation: opening of BKCa channels by cyclic AMP-induced stimulation of the cyclic GMP-dependent protein kinase. J Cardiovasc Pharmacol 1999; 34:619-27. [PMID: 10547076 DOI: 10.1097/00005344-199911000-00001] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Dopamine dilates the coronary, renal and other vascular beds; however, the signaling pathway underlying this effect is unclear. In this study the signal-transduction process mediating dopamine-induced relaxation of porcine coronary arteries was investigated in isolated vessels and single arterial myocytes. Dopamine-induced relaxation of arteries was mediated through the DA- receptor and involved K+ efflux, and subsequent patch-clamp studies demonstrated that either dopamine or fenoldopam, a selective DA-1 agonist, increased the opening probability of the large-conductance, calcium- and voltage-activated K+ (BKCa) channel in coronary myocytes. Moreover, blockade of this channel by iberiotoxin prevented dopamine-induced coronary relaxation. Dopamine stimulation of BKCa channels was completely prevented by a DA-1-receptor antagonist, but was unaffected by propranolol. Furthermore, inhibiting adenylyl cyclase activity prevented stimulation of BKCa channel activity, whereas chlorophenylthio (CPT)-cyclic adenosine monophosphate (AMP), a membrane-permeable analog of cyclic AMP, mimicked the effects of dopamine. Interestingly, inhibiting the cyclic AMP-dependent protein kinase (PKA) did not affect the response to dopamine, whereas dopamine-induced channel activity was completely blocked by inhibiting the activity of the cyclic guanosine monophosphate (GMP)-dependent protein kinase (PKG). These findings demonstrate that activation of DA-1 receptors causes stimulation of BKCa channel activity by a mechanism involving cyclic AMP-dependent stimulation of PKG, but not PKA, and further suggest that this cross-reactivity mediates dopamine-induced coronary vasodilation.
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187
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Posner GH, Wang Q, Han G, Lee JK, Crawford K, Zand S, Brem H, Peleg S, Dolan P, Kensler TW. Conceptually new sulfone analogues of the hormone 1alpha, 25-dihydroxyvitamin D(3): synthesis and preliminary biological evaluation. J Med Chem 1999; 42:3425-35. [PMID: 10479276 DOI: 10.1021/jm990267c] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A conceptually new series of vitamin D(3)-like nonfluorinated and fluorinated 16-ene side chain tert-butyl sulfones 3-7 has been synthesized. Even though these novel C,D-ring side chain analogues of the hormone 1alpha,25-dihydroxyvitamin D(3) (1,1,25D(3)) lack a terminal OH group, thought previously to be essential for high biological activity, they are highly antiproliferative and, in several cases, transcriptionally active in vitro but desirably noncalcemic in vivo. The side chain sulfone group may be binding to the nVDR as a hydrogen-bond acceptor, in contrast to the hydrogen-bond donor function of the 25-OH group of natural 1,25D(3).
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188
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Li S, Zhang X, Han G. [Case-control studies on risk factors for pulmonary tuberculosis in servicemen of China]. ZHONGHUA LIU XING BING XUE ZA ZHI = ZHONGHUA LIUXINGBINGXUE ZAZHI 1999; 20:208-11. [PMID: 10682496] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
OBJECTIVE To study the risk factors for pulmonary tuberculosis (PTB) in the servicemen of armed forces and lay a basis for its prevention and control. METHODS A 1:2 matched case-control study was carried cut in the servicemen, with 86 cases and 153 controls. Data were analyzed with conditional logistic regression with EGRET software. Odds ratios (ORs) were calculated for the relevant factors. RESULTS Single-variable analysis showed that schooling, history of exposure to PTB, history of Bacille Calmette-Guérin (BCG) vaccination and BCG vaccination scar all associated with the incidence of PTB, with ORs of 2.19, 2.03, 0.38 and 0.54, respectively, and P < 0.05. Multiple logistic regression analysis showed that BCG vaccination scar, history of exposure to PTB and schooling all entered the final regression model, with ORs of 0.36, 1.94 and 2.33, respectively. CONCLUSION It suggested that BCG vaccination could play a role in the prevention of TB in the servicemen, and history of exposure to PTB was a potential risk factor for TB as well.
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189
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Lu Y, Wang S, Wu B, Zheng Q, Han G. [Structural disorder and conformation difference in the organic molecular crystals]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 1999; 21:288-92. [PMID: 12567452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE Investigating multiple configuration nature of natural organic molecules through study on atom disorder in crystal state molecules. METHODS Three-dimensional determination for four natural organic compound samples by using single crystal X-ray diffraction. RESULTS Through disorder analysis on molecules in crystal state, we have found that the disorder of some atoms may cause conformation difference for molecules, bring about multiple conformation in crystal state hence reducing the symmetry of molecules in crystal cells. CONCLUSIONS There can be two or three molecules, even two different compounds in an asymmetrical unit of structure cell because of partial disorder or configuration difference in organic molecule crystals.
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190
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Han G, Hampson DR. Ligand binding to the amino-terminal domain of the mGluR4 subtype of metabotropic glutamate receptor. J Biol Chem 1999; 274:10008-13. [PMID: 10187777 DOI: 10.1074/jbc.274.15.10008] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The metabotropic glutamate receptor (mGluR) 4 subtype of metabotropic glutamate receptor is a presynaptic receptor that modulates neurotransmitter release. We have characterized the properties of a truncated, epitope-tagged construct containing part of the extracellular amino-terminal domain of mGluR4. The truncated receptor was secreted into the cell culture medium of transfected human embryonic kidney cells. The oligomeric structure of the soluble truncated receptor was assessed by gel electrophoresis. In the presence of high concentrations of a reducing agent, the truncated receptor migrated as a monomer; at lower concentrations of the reducing agent, only higher molecular weight oligomers were observed. Competition binding experiments using the radiolabeled agonist [3H]L-2-amino-4-phosphonobutyric acid revealed that the rank order of potency of metabotropic ligands at the truncated receptor was similar to that of the full-length membrane-bound receptor. However, the truncated receptor displayed higher affinities for agonists and lower affinities for antagonists compared with the full-length receptor. Deglycosylation produced a shift in the relative molecular weight of the soluble protein from Mr = 71,000 to Mr = 63,000; deglycosylation had no effect on the binding of [3H]L-2-amino-4-phosphonobutyric acid, indicating that the asparagine-linked carbohydrates are not necessary for agonist binding. These results demonstrate that although the primary determinants of ligand binding to mGluR4 are contained within the first 548 amino acids of the receptor, additional amino acids located downstream of this region may influence the affinity of ligands for the binding site.
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191
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Han J, Clark C, Han G, Chu TC, Han P. Preparation of 2-nitro-5-thiobenzoic acid using immobilized Tris(2-carboxyethyl)phosphine. Anal Biochem 1999; 268:404-7. [PMID: 10075833 DOI: 10.1006/abio.1998.3054] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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192
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Liu C, Han G, Li K, Si J, Liu S, Song G. [Research on the oncogenesis of cervical epithelial cells co-induced by human papillomavirus and human cytomegalovirus]. ZHONGHUA BING LI XUE ZA ZHI = CHINESE JOURNAL OF PATHOLOGY 1999; 28:24-7. [PMID: 11869507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE The carcinogenesis of the human cervical carcinoma is known closely associated with human papillomavirus (HPV). The purpose of this article is to identify whether another sexually transmitted factor, human cytomegalovirus (HCMV) plays as a co-factor role in the carcinogenesis. METHODS Human cervical epithelial cells immortalized by HPV16 were transfected with IE gene of HCMV. The condition and efficiency of IE gene were examined. RESULTS It was showed that the cervical epithelial cells could be completely transformed into malignant by HPV 16 and IE gene of HCMV and tumor was formed by injecting the transformed cells in nude mice. CONCLUSION The co-operation effect of HPV and HCMV auailed the oncogenesis of human cervical carcinoma and moreover, the cellular and molecular biological mechanism was discussed.
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Chu TC, Han P, Han G, Potter DE. Intraocular pressure lowering by S-allylmercaptocysteine in rabbits. J Ocul Pharmacol Ther 1999; 15:9-17. [PMID: 10048343 DOI: 10.1089/jop.1999.15.9] [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: 11/13/2022] Open
Abstract
The purpose of this study was to examine the actions of a garlic-derived compound, S-allylmercaptocysteine (SAMC) on intraocular pressure (IOP) and to determine the possible involvement of sulfhydryl reactivity, sympathetic neuronal activity and atrial natriuretic peptide (ANP) in the IOP response. Topical, unilateral application of SAMC (20, 100, 200 microg) elicited dose-dependent decreases in IOP. The magnitude of the IOP-lowering effect induced by SAMC was between four to six mmHg. The ocular hypotensive responses were unilateral, peaked at one to three hours and lasted from two to four hours. The IOP-lowering effect by SAMC (100 microg) was enhanced modestly by topical, bilateral pretreatment with a reducing agent, tris(2-carboxyethyl) phosphine (100 microg) which itself produced no change in IOP. No alteration of pupil diameter was observed following topical application of either SAMC or tris(2-carboxyethyl) phosphine. Thus, alteration of sulfhydryl reactivity does not seem to be a major mechanism of action for SAMC. SAMC caused no change of basal and electrically stimulated norepinephrine release in rabbit iris-ciliary bodies, ruling out a prejunctional effect on sympathetic nerve activity. However, SAMC increased the ANP levels in aqueous humor by five-fold. It is concluded that the ocular hypotensive response induced by SAMC in rabbits could involve the elevation of ANP levels in aqueous humor.
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Süzer O, Köseoğlu S, Han G. No beneficial effects of isocolloidoosmotic synthetic colloid addition to St. Thomas Hospital cardioplegic solution in ischemia-reperfusion injury in isolated perfused rat hearts. GENERAL PHARMACOLOGY 1999; 32:101-5. [PMID: 9888261 DOI: 10.1016/s0306-3623(98)00091-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
1. Cardioplegic solutions provide the opportunity to operate on a nonbeating heart and to protect the heart against ischemic injury during cardiac surgery. The components of these solutions are constantly being modified in an effort to find the optimal solution. We studied the effects of colloidal volume replacers such as dextran, HES and gelatin as an isocolloidoosmotic addition to St. Thomas Hospital cardioplegic solution in ischemia-reperfusion injury of isolated rat hearts. 2. In the control group, after a stabilization period of 20 min, the hearts were arrested with St. Thomas Hospital cardioplegic solution for 3 min, then subjected to 30 min of global ischemia. Hearts then were reperfused for 10 min. In the experimental groups, the protocol was the same, but either HES 200/0.5 (50 g/L), modified fluid gelatin (30 g/l) or dextran 70 (25 g/L) were added to the St. Thomas Hospital solution. 3. All hearts were compared for their preischemic and postischemic contractility, heart rate, contractility rate product, coronary flow, lactate dehydrogenase, creatine phosphokinase enzyme leakage and wet/dry weight ratio. 4. All groups had similar contractility (for control, HES, gelatin and dextran groups the values at minute 10 of reperfusion were 59+/-9, 56+/-11%, 61+/-14%, 49+/-14% of initial values [P>0.05, respectively]) and enzyme leakage (lactate dehydrogenase 4.1+/-1.0, 8.1+/-1.5, 5.8+/-1.4, 3.7+/-1.2 [P>0.05] and for creatine phosphokinase 3.9+/-2.5, 6.4+/-3.7, 5.5+/-1.3, 5.5+/-0.8, P>0.05] IU xmin(-1) x g dry tissue(-1) in the reperfusion period, respectively) results as compared with the control group. 5. The addition of isocolloidoosmotic colloids to the cardioplegic solution did not appear to enhance the effectiveness of the crystalloid St. Thomas Hospital cardioplegic solution. If a colloid is to be chosen as a plasma replacer or an additive to priming solution in the preoperative period, or during open-heart surgery, it should be modified fluid gelatin-for no sign of cardiodepression was determined with the use of this agent.
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Capodici C, Pillinger MH, Han G, Philips MR, Weissmann G. Integrin-dependent homotypic adhesion of neutrophils. Arachidonic acid activates Raf-1/Mek/Erk via a 5-lipoxygenase- dependent pathway. J Clin Invest 1998; 102:165-75. [PMID: 9649570 PMCID: PMC509078 DOI: 10.1172/jci592] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
AA stimulates integrin-dependent neutrophil adhesion, a critical early step in acute inflammation. However, neither the signaling pathway(s) of AA-stimulated adhesion, nor whether AA acts directly or through the generation of active metabolites, has been elucidated. Previously, we have observed a tight association between neutrophil Erk activation and homotypic adhesion in response to chemoattractants acting through G protein-linked receptors. We now report a similar association between homotypic adhesion and Erk activation in response to AA. Erk activation was cyclooxygenase independent and required AA metabolism to 5(S)- hydroperoxyeicosatetraenoic acid (5-HpETE) via 5-lipoxygenase, but not the further lipoxygenase-dependent metabolism of 5-HpETE to leukotrienes. AA stimulation of Erk was accompanied by Raf-1 activation and was sensitive to inhibitors of Raf-1 and Mek. Whereas activation of Erk by AA was pertussis toxin sensitive, [3H]-AA binding to neutrophils was not saturable, suggesting that an AA metabolite activates a G protein. Consistent with this hypothesis, Erk activation by 5(S)-hydroxyeicosatetraenoic acid (5-HETE; lipoxygenase-independent metabolite of 5-HpETE) was also pertussis toxin sensitive. These data suggest that a 5-lipoxygenase metabolite of AA, e.g., 5-HETE, is released from AA-treated cells to engage a plasma membrane-associated, pertussis toxin-sensitive, G protein-linked receptor, leading to activation of Erk and adhesion via the Raf-1/Mek signal transduction pathway.
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Han G, Chen J, Ding L. [The sensitivity of carcinogenic initiation effect of regenerated liver induced by diethylnitrosamine in rats]. ZHONGHUA BING LI XUE ZA ZHI = CHINESE JOURNAL OF PATHOLOGY 1998; 27:23-6. [PMID: 11244937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
OBJECTIVE To compare the sensitivity of carcinogenic initiation effect of regenerated liver with normal liver induced by diethylnitrosamine (DEN) in rats. METHODS Experimental group was composed of rats that had 2/3 of their liver excised 8 weeks previously, normal rats were used as controls to study: (1) weight of their livers, conventional histological examination and 3H-TdR incorporation test; (2) a modified Solt-Farber carcinogenesis scheme was applied in order to detect the degree of carcinogenic initiation effect by stereologic study of GGT positive preneoplastic liver cell foci; (3) damage of DNA in hepatocytes were detected by in situ nick translation test after DEN treatment both in vivo and in primary cultured liver cells. RESULTS (1) the regenerative process in liver was completed by the end of the 8th post-operative week and no proliferation of hepatocytes was detected. (2) both the number and volume density of GGT positive foci in the experimental group were higher than those in control group. (3) DNA damage in hepatocytes of experimental group were more severe than in the control group. CONCLUSION Even after the regeneration process was completed, the regenerated liver still possessed higher sensitivity to carcinogenic initiation effect than normal liver, this sensitivity was related with the severity of DNA damage in hepatocytes of the regenerated liver after DEN attack.
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Pillinger MH, Capodici C, Han G, Weissmann G. Inflammation and anti-inflammation: gating of cell/cell adhesion at the level of mitogen-activated protein kinases. Ann N Y Acad Sci 1997; 832:1-12. [PMID: 9704032 DOI: 10.1111/j.1749-6632.1997.tb46232.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Lu X, Xu W, Shen J, Han G. [Chemical studies on Campylotropis hirtella (Franch. Schindl.)]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1997; 22:680-2, 704. [PMID: 11243186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
From the roots of Campylotropis hirtella 6 compounds were isolated. Based on the extensive spectrae analysis their chemical structures were identified as beta-sitosterol, oleanolic acid, ursolic acid, euscaphic acid, tomentic acid and rosamultin.
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Iwatsuki K, Ohtsuka M, Harada H, Han G, Kaneko F. Clinicopathologic manifestations of Epstein-Barr virus-associated cutaneous lymphoproliferative disorders. ARCHIVES OF DERMATOLOGY 1997; 133:1081-6. [PMID: 9301584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To elucidate clinicopathologic manifestations of cutaneous lymphoproliferative disorders associated with Epstein-Barr virus (EBV) infection. DESIGN Retrospective survey of case series. SETTING University hospital medical center. PATIENTS Sixty-five patients with cutaneous lymphomas and related disorders. MAIN OUTCOME MEASURES Detection of EBV genes and EBV-encoded small nuclear RNAs. RESULTS Evidence of latent EBV infection was demonstrated in 15 patients: 3 had malignant lymphoma with clinical features mimicking cytophagic histiocytic panniculitis, 6 had facial vesiculopapular eruptions mimicking hydroa vacciniforme, 4 had angiocentric lymphoma, 1 had histiocytoid lymphoma associated with hemophagocytosis, and 1 had plasmacytoma. Hypersensitivity to mosquito bites was noted in a patient with hydroa vacciniforme-like eruptions and another with histiocytoid lymphoma. Angiocentric infiltration of atypical lymphoid cells was a common histological feature in the patients with hydroa vacciniforme-like eruptions and angiocentric lymphoma. No evidence of EBV infection was apparent in 19 patients with mycosis fungoides or Sézary syndrome, 7 with adult T-cell leukemia or lymphoma, 3 with lymphomatoid papulosis (type A), and 2 with lymphocytoma cutis. CONCLUSION Patients with EBV-associated cutaneous lymphoproliferative disorders present with unique and diagnostic clinicopathologic features distinct from those of mycosis fungoides or Sézary syndrome.
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Iwatsuki K, Harada H, Ohtsuka M, Han G, Kaneko F. Latent Epstein-Barr virus infection is frequently detected in subcutaneous lymphoma associated with hemophagocytosis but not in nonfatal cytophagic histiocytic panniculitis. ARCHIVES OF DERMATOLOGY 1997; 133:787-8. [PMID: 9197840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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