126
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Choi ME, Sohn HY, Ahmed YMZ, Mohamed FM, Han G, Shalabi MEH. Effect of CaSO4 Pelletization Conditions on a Novel Process for Converting SO2 to Elemental Sulfur by Reaction Cycles Involving CaSO4/CaS – Part II: Reduction of SO2 with CaS. Chem Eng Technol 2007. [DOI: 10.1002/ceat.200700047] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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127
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Eob Choi M, Sohn HY, Ahmed YMZ, Mohamed FM, Han G, Shalabi MEH. Effect of CaSO4 Pelletization Conditions on a Novel Process for Converting SO2 to Elemental Sulfur by Reaction Cycles involving CaSO4/CaS – Part I. CaSO4 Pellet Strength and Reducibility by Hydrogen. Chem Eng Technol 2007. [DOI: 10.1002/ceat.200700046] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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128
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Sohn H, Savic M, Padilla R, Han G. A novel reaction system involving BaS and BaSO4 for converting SO2 to elemental sulfur without generating pollutants: Part I. Feasibility and kinetics of SO2 reduction with BaS. Chem Eng Sci 2006. [DOI: 10.1016/j.ces.2006.03.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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129
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Naidich MJ, Walker MT, Gottardi-Littell NR, Han G, Chandler JP. Cerebellar pleomorphic xanthoastrocytoma in a patient with neurofibromatosis type 1. Neuroradiology 2005; 46:825-9. [PMID: 15289955 DOI: 10.1007/s00234-004-1216-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
We describe a case of cerebellar pleomorphic xanthoastrocytoma (PXA) occurring in a patient with neurofibromatosis type 1 (NF1). The histomorphology of this uncommon glial (astrocytic) neoplasm is discussed. The occurrence of this tumor within the posterior fossa is extremely rare. To our knowledge, this is the first reported case of a cerebellar PXA in a patient with NF1.
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130
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Hsu R, Taylor JR, Newton SS, Alvaro JD, Haile C, Han G, Hruby VJ, Nestler EJ, Duman RS. Blockade of melanocortin transmission inhibits cocaine reward. Eur J Neurosci 2005; 21:2233-42. [PMID: 15869520 PMCID: PMC2694749 DOI: 10.1111/j.1460-9568.2005.04038.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Melanocortins and the melanocortin-4 receptor (MC4-R) are enriched in the nucleus accumbens, a brain region that has been implicated in the rewarding action of cocaine and other drugs of abuse. In the present study we use a number of rat behavioral models to show that infusion of a melanocortin peptide antagonist into the nucleus accumbens blocks the reinforcing, incentive motivational, and locomotor sensitizing effects of cocaine. We also show that locomotor responses to repeated cocaine exposure are completely blocked in MC4-R null mutant mice and reduced in Agouti mice that overexpress an endogenous inhibitor of melanocortins in the brain. The results also demonstrate that cocaine administration increases the expression of MC4-R in the nucleus accumbens and striatum, and that MC4-R is co-localized with prodynorphin in medium spiny neurons in the nucleus accumbens. Together, these findings indicate that the behavioral actions of cocaine are dependent on activation of MC4-R, and suggest that upregulation of this receptor by drug exposure may contribute to sensitization of these behavioral responses. Modulation of cocaine reward is a novel action of the melanocortin-MC4-R system and could be targeted for the development of new medications for cocaine addiction.
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MESH Headings
- Agouti Signaling Protein
- Animals
- Behavior, Animal
- Cocaine/administration & dosage
- Conditioning, Operant/drug effects
- Dopamine Uptake Inhibitors/administration & dosage
- Dose-Response Relationship, Drug
- Drug Interactions
- Enkephalins/genetics
- Enkephalins/metabolism
- In Situ Hybridization/methods
- Intercellular Signaling Peptides and Proteins/deficiency
- Melanocyte-Stimulating Hormones/antagonists & inhibitors
- Melanocyte-Stimulating Hormones/pharmacology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Motor Activity/drug effects
- Motor Activity/physiology
- Nucleus Accumbens/drug effects
- Protein Precursors/genetics
- Protein Precursors/metabolism
- RNA, Messenger/metabolism
- Rats
- Rats, Mutant Strains
- Receptor, Melanocortin, Type 4/antagonists & inhibitors
- Receptor, Melanocortin, Type 4/deficiency
- Receptor, Melanocortin, Type 4/genetics
- Receptor, Melanocortin, Type 4/metabolism
- Reward
- Self Administration
- Time Factors
- alpha-MSH/antagonists & inhibitors
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131
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Huang YZ, Han G, Wang H, Liang WQ. Cationic niosomes as gene carriers: preparation and cellular uptake in vitro. DIE PHARMAZIE 2005; 60:473-4. [PMID: 15997841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Cationic niosomes of sorbitan monoesters were prepared using film hydration method and tested for their effect on delivery of antisense oligonucleotides (OND) in a COS-7 cell line. These formulations showed positive results on cellular uptake of antisense oligonucleotides. Especially, cationic niosomes of Span 40 and 60 have a more significant effect.
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132
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Song L, Wang J, Wang R, Yu M, Sun Y, Han G, Li Y, Qian J, Scott DW, Kang Y, Soukhareva N, Shen B. Retroviral delivery of GAD-IgG fusion construct induces tolerance and modulates diabetes: a role for CD4+ regulatory T cells and TGF-beta? Gene Ther 2004; 11:1487-96. [PMID: 15343360 DOI: 10.1038/sj.gt.3302327] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Previous studies have demonstrated that antigen-specific tolerance could be induced by lipopolysaccharide (LPS)-stimulated B cells retrovirally transduced with an immunoglobulin-antigen (or epitope-containing peptide) fusion construct. To investigate the mechanism of this gene therapy system, we now adapted this approach to immunotherapy of spontaneous diabetes in nonobese diabetic (NOD) mice, a T-cell-mediated autoimmune disease triggered, in part, by a pathogenic response to glutamate decarboxylase (GAD) 65. We demonstrate that LPS-stimulated splenocytes, retrovirally transfected with GAD-IgG fusion construct, induce a significant antigen-specific hyporesponsiveness at both cellular and humoral levels and reduce the incidence of diabetes in female NOD mice. Parallel with disease protection, we observed a prolonged increase of the numbers of CD4+CD25+ T cells in the periphery of GAD-IgG-treated mice, compared to those treated with a control IgG vector, both in the prediabetic period and persisting even 8 months after gene therapy. This increase appeared to be induced by the repeated stimulation of the antigen in the periphery instead of a result of differentiation of T-cell precursor in the thymus. Moreover, CD4+CD25+ T cells induced by GAD-IgG fusion construct were capable of suppressing the proliferative response of CD4+CD25- T cells in vitro; and ablation of the activity of CD4+CD25+ T cells by blocking antibody against CD25 could reverse GAD-specific T-cell hyporesponsiveness. These results suggested that CD4+CD25+ T-cell subset induced in GAD-IgG-treated NOD mice represented the regulatory or suppressive CD4+CD25+ T cells (Treg) and might play an important role in the induction and maintenance of tolerance in NOD mice. Furthermore, the numbers of splenic CD4+CD62L+ regulatory T cells in GAD-IgG-treated mice during the prediabetic period and serum TGF-beta levels in 34-38-week-old GAD-IgG-protected mice were also increased, compared to control IgG-treated ones. Therefore, we propose that the induction of tolerance and the prevention of diabetes incidence in NOD female mice induced by the GAD-IgG fusion construct may require CD4+ regulatory T cells, and the possible mediation of TGF-beta.
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133
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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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134
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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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135
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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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136
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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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137
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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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138
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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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139
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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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140
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141
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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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142
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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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143
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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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144
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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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145
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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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146
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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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147
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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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148
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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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149
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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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150
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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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