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Chang A, Cheang S, Espanel X, Sudol M. Rsp5 WW domains interact directly with the carboxyl-terminal domain of RNA polymerase II. J Biol Chem 2000; 275:20562-71. [PMID: 10781604 DOI: 10.1074/jbc.m002479200] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
RSP5 is an essential gene in Saccharomyces cerevisiae and was recently shown to form a physical and functional complex with RNA polymerase II (RNA pol II). The amino-terminal half of Rsp5 consists of four domains: a C2 domain, which binds membrane phospholipids; and three WW domains, which are protein interaction modules that bind proline-rich ligands. The carboxyl-terminal half of Rsp5 contains a HECT (homologous to E6-AP carboxyl terminus) domain that catalytically ligates ubiquitin to proteins and functionally classifies Rsp5 as an E3 ubiquitin-protein ligase. The C2 and WW domains are presumed to act as membrane localization and substrate recognition modules, respectively. We report that the second (and possibly third) Rsp5 WW domain mediates binding to the carboxyl-terminal domain (CTD) of the RNA pol II large subunit. The CTD comprises a heptamer (YSPTSPS) repeated 26 times and a PXY core that is critical for interaction with a specific group of WW domains. An analysis of synthetic peptides revealed a minimal CTD sequence that is sufficient to bind to the second Rsp5 WW domain (Rsp5 WW2) in vitro and in yeast two-hybrid assays. Furthermore, we found that specific "imperfect" CTD repeats can form a complex with Rsp5 WW2. In addition, we have shown that phosphorylation of this minimal CTD sequence on serine, threonine and tyrosine residues acts as a negative regulator of the Rsp5 WW2-CTD interaction. In view of the recent data pertaining to phosphorylation-driven interactions between the RNA pol II CTD and the WW domain of Ess1/Pin1, we suggest that CTD dephosphorylation may be a prerequisite for targeted RNA pol II degradation.
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Flandin L, Chang A, Nazarenko S, Hiltner A, Baer E. Effect of strain on the properties of an ethylene-octene elastomer with conductive carbon fillers. J Appl Polym Sci 2000. [DOI: 10.1002/(sici)1097-4628(20000509)76:6<894::aid-app16>3.0.co;2-k] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Flandin L, Chang A, Nazarenko S, Hiltner A, Baer E. Effect of strain on the properties of an ethylene-octene elastomer with conductive carbon fillers. J Appl Polym Sci 2000. [DOI: 10.1002/(sici)1097-4628(20000509)76:6%3c894::aid-app16%3e3.0.co;2-k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Johnson TM, Chang A, Redman B, Rees R, Bradford C, Riba M, Lowe L. Management of melanoma with a multidisciplinary melanoma clinic model. J Am Acad Dermatol 2000; 42:820-6. [PMID: 10775861 DOI: 10.1067/mjd.2000.105947] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Yousef GM, Chang A, Diamandis EP. Identification and characterization of KLK-L4, a new kallikrein-like gene that appears to be down-regulated in breast cancer tissues. J Biol Chem 2000; 275:11891-8. [PMID: 10766816 DOI: 10.1074/jbc.275.16.11891] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Kallikreins are a subgroup of serine proteases and these proteolytic enzymes have diverse physiological functions in many tissues. Growing evidence suggests that many kallikreins are implicated in carcinogenesis. In rodents, kallikreins constitute a large multigene family, but in humans, only three genes were identified. By using the positional candidate gene approach, we were able to identify a new kallikrein-like gene, tentatively named KLK-L4 (for kallikrein-like gene 4). This new gene maps to chromosome 19q13. 3-q13.4, is formed of five coding exons and four introns, and shows structural similarity to other kallikreins and kallikrein-like genes. KLK-L4 is expressed in a variety of tissues including prostate, salivary gland, breast, and testis. Our preliminary results show that KLK-L4 is down-regulated, at the mRNA level, in breast cancer tissues and breast cancer cell lines. Its expression is regulated by steroid hormones in the breast cancer cell line BT-474. This gene may be involved in the pathogenesis and/or progression of breast cancer and may find applicability as a novel cancer biomarker.
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Cu-Uvin S, Caliendo AM, Reinert S, Chang A, Juliano-Remollino C, Flanigan TP, Mayer KH, Carpenter CC. Effect of highly active antiretroviral therapy on cervicovaginal HIV-1 RNA. AIDS 2000; 14:415-21. [PMID: 10770544 DOI: 10.1097/00002030-200003100-00015] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES To determine the frequency of cervicovaginal lavage and plasma HIV-1 RNA levels that are below detectable levels (< 400 copies/ml) among women on highly active antiretroviral therapy (HAART), non-HAART and on no therapy. To compare the effect of initiating HAART on the timing of HIV-1 RNA suppression in the blood plasma and genital tract among antiretroviral-naïve women. METHODS Data were obtained from 205 HIV-infected women with paired plasma and cervicovaginal lavage viral load measurements. Seven antiretroviral-naïve women starting HAART had viral load measurements performed daily for one week, at 2 weeks and at 1 month after initiating therapy. Viral load quantification was carried out by nucleic acid sequence-based amplification assay. The lower limit of detection was 400 copies/ml. RESULTS Plasma and cervicovaginal HIV-1 RNA was detectable in 71 and 26% of the women, respectively. Among women with plasma viral loads less than 400, 400-9999, and 10,000 copies/ml or over, genital tract HIV-1 RNA was detected in 3, 17 and 48%, respectively (P < 0.001). Fifty-one per cent of the women with CD4 cell counts of less than 200/mm3 had detectable cervicovaginal viral loads compared with 18% among women with CD4 cell counts of 200/mm3 or over (P < 0.001). Cervicovaginal HIV-1 RNA was less than 400 copies/ml in 85% of those on HAART, 69% of those on non-HAART and 69% of those on no therapy (P < 0.045). In seven antiretroviral-naïve women initiating HAART, cervicovaginal HIV-1 RNA decreased by 0.7-2.1 log10 within 1-14 days of starting therapy. CONCLUSION The cervicovaginal HIV-1 RNA level was positively correlated with plasma HIV-1 RNA and negatively with the CD4 cell count. The use of HAART was significantly associated with below-detectable levels of HIV-1 RNA in both plasma and the genital tract. HIV-1 RNA suppression in the genital tract may occur rapidly after initiating therapy.
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Levitan N, Dowlati A, Shina D, Craffey M, Mackay W, DeVore R, Jett J, Remick SC, Chang A, Johnson D. Multi-institutional phase I/II trial of paclitaxel, cisplatin, and etoposide with concurrent radiation for limited-stage small-cell lung carcinoma. J Clin Oncol 2000; 18:1102-9. [PMID: 10694563 DOI: 10.1200/jco.2000.18.5.1102] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE To determine the feasibility of adding paclitaxel to standard cisplatin/etoposide (EP) and thoracic radiotherapy. PATIENTS AND METHODS Thirty-one patients were enrolled onto this study. During the phase I section of this study, the dose of paclitaxel was escalated in groups of three or more patients. Cycles were repeated every 21 days. For cycles 1 and 2, paclitaxel was administered according to the dose-escalation schema at doses of 100, 135, or 170 mg/m(2) intravenously over 3 hours on day 1. Once the maximum-tolerated dose (MTD) of paclitaxel (for cycles 1 and 2, concurrent with radiation) was determined, that dose was used in all subsequent patients entered onto the phase II section of this study. For cycles 3 and 4, the paclitaxel dose was fixed at 170 mg/m(2) in all patients. On day 2, cisplatin 60 mg/m(2) was administered for all cycles. On days 1, 2, and 3, etoposide 60 mg/m(2)/d (cycles 1 and 2) or 80 mg/m(2)/d (cycles 3 and 4) was administered. Chest radiation was given at 9 Gy/wk in five fractions for 5 weeks beginning on day 1 of cycle 1. Granulocyte colony-stimulating factors were used during cycles 3 and 4 only. RESULTS Twenty-eight patients were assessable. The MTD of paclitaxel was 135 mg/m(2), with the dose-limiting toxicity being grade 4 neutropenia. Cycles 1 and 2 were associated with grade 4 neutropenia in 32% of courses, with fever occurring in 7% of courses and grade 2/3 esophagitis in 13%. Cycles 3 and 4 were complicated by grade 4 neutropenia in 20% of courses, with fever occurring in 6% of courses and grade 2/3 esophagitis in 16%. The overall response rate was 96% (complete responses, 39%; partial responses, 57%). After a median follow-up period of 23 months (range, 9 to 40 months), the median survival time was 22.3 months (95% confidence interval, 15.1 to 34.3 months) CONCLUSION The MTD of paclitaxel with radiation and EP treatment is 135 mg/m(2) given over 3 hours. In this schedule of administration, a high response rate and acceptable toxicity can be anticipated.
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Strachan BK, van Wijngaarden WJ, Sahota D, Chang A, James DK. Cardiotocography only versus cardiotocography plus PR-interval analysis in intrapartum surveillance: a randomised, multicentre trial. FECG Study Group. Lancet 2000; 355:456-9. [PMID: 10841126 DOI: 10.1016/s0140-6736(00)82012-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND There is a need to improve the sensitivity and specificity of fetal monitoring during labour. We compared the gold standard, cardiotocography, with cardiotocography plus time-interval analysis of the fetal electrocardiogram in fetal surveillance. The aim was to find out whether time-interval analysis decreased the need for operative intervention due to fetal distress. METHODS We did a randomised, prospective trial in five hospitals in the UK, Hong Kong, the Netherlands, and Singapore. 1038 women undergoing high-risk labours were randomly assigned fetal monitoring by cardiotocography alone, or cardiotocography plus fetal electrocardiography (ECG). Outcomes measured were rates of operative intervention, and neonatal outcome. Analysis was by intention to treat. FINDINGS 515 women were assigned management by cardiotocography, and 523 cardiotocography plus fetal ECG. There was a trend towards fewer operative interventions for presumed fetal distress in the time-interval analysis plus cardiotocography group (63 [13%] vs 78 [16%]), but this was not significant (relative risk 0.80 [95% CI 0.59-1.08], p=0.17). There was no significant difference between groups in the proportion of babies who had an umbilical arterial pH of 7.15 or less (51 [11%] vs 49 [11%]; 1.01 [0.7-1.47]), or in the frequency of unsuspected acidaemia (42 [9%] vs 35 [8%]; 1.17 [0.76-1.79]). INTERPRETATION The addition of time-interval analysis of the fetal electrocardiogram during labour did not show a significant benefit in decreasing operative intervention. There was no significant difference in neonatal outcome.
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Luo WJ, Chang A. An endosome-to-plasma membrane pathway involved in trafficking of a mutant plasma membrane ATPase in yeast. Mol Biol Cell 2000; 11:579-92. [PMID: 10679016 PMCID: PMC14795 DOI: 10.1091/mbc.11.2.579] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The plasma membrane ATPase, encoded by PMA1, is delivered to the cell surface via the secretory pathway. Previously, we characterized a temperature-sensitive pma1 mutant in which newly synthesized Pma1-7 is not delivered to the plasma membrane but is mislocalized instead to the vacuole at 37 degrees C. Several vps mutants, which are defective in vacuolar protein sorting, suppress targeting-defective pma1 by allowing mutant Pma1 to move once again to the plasma membrane. In this study, we have analyzed trafficking in the endosomal system by monitoring the movement of Pma1-7 in vps36, vps1, and vps8 mutants. Upon induction of expression, mutant Pma1 accumulates in the prevacuolar compartment in vps36 cells. After chase, a fraction of newly synthesized Pma1-7 is delivered to the plasma membrane. In both vps1 and vps8 cells, newly synthesized mutant Pma1 appears in small punctate structures before arrival at the cell surface. Nevertheless, biosynthetic membrane traffic appears to follow different routes in vps8 and vps1: the vacuolar protein-sorting receptor Vps10p is stable in vps8 but not in vps1. Furthermore, a defect in endocytic delivery to the vacuole was revealed in vps8 (and vps36) but not vps1 by endocytosis of the bulk membrane marker FM 4-64. Moreover, in vps8 cells, there is defective down-regulation from the cell surface of the mating receptor Ste3, consistent with persistent receptor recycling from an endosomal compartment to the plasma membrane. These data support a model in which mutant Pma1 is diverted from the Golgi to the surface in vps1 cells. We hypothesize that in vps8 and vps36, in contrast to vps1, mutant Pma1 moves to the surface via endosomal intermediates, implicating an endosome-to-surface traffic pathway.
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Pan YX, Xu J, Bolan E, Chang A, Mahurter L, Rossi G, Pasternak GW. Isolation and expression of a novel alternatively spliced mu opioid receptor isoform, MOR-1F. FEBS Lett 2000; 466:337-40. [PMID: 10682855 DOI: 10.1016/s0014-5793(00)01095-4] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The MOR-1 gene is large, with a recent study reporting nine exons spanning 250 kb which combine to yield six different mu opioid receptor splice variants. We now report the isolation of exon 10, which is contained within yet another splice variant, MOR-1F, which is composed of exons 1, 2, 3, 10, 6, 7, 8 and 9. Exon 10 comprises 186 bp which predict a unique 58 amino acid sequence extending beyond exon 3. It has been mapped between exons 4 and 6 and has flanking consensus splice sequences. On Northern blot analysis, the MOR-1F mRNA is smaller than the other MOR-1 mRNAs. When expressed in CHO cells, MOR-1F binds the mu opioid radioligand [3H]DAMGO with high affinity (K(D) = 1.04+/-0.03 nM). Competition studies demonstrated the selectivity of the variant for mu opioid ligands, supporting its classification within the mu opioid receptor family.
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Grace MJ, Xie L, Musco ML, Cui S, Gurnani M, DiGiacomo R, Chang A, Indelicato S, Syed J, Johnson R, Nielsen LL. The use of laser scanning cytometry to assess depth of penetration of adenovirus p53 gene therapy in human xenograft biopsies. THE AMERICAN JOURNAL OF PATHOLOGY 1999; 155:1869-78. [PMID: 10595917 PMCID: PMC1866932 DOI: 10.1016/s0002-9440(10)65506-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
SCH58500 is an agent for gene therapy of cancer, consisting of a replication-deficient type 5 adenovirus (Ad5) expressing the human p53 tumor suppressor gene (Ad5/p53). An important question about the use of Ad5/p53 gene therapy is how to achieve the therapeutically effective delivery of an Ad5/p53 vector to the tumor. We wanted to determine the effective depth of penetration of an Ad5/p53 vector by dosing the vector in an experimental human xenograft/SCID model. To assess depth of penetration, we developed a novel methodology for scanning tissue sections by laser scanning cytometry (LSC). SCID mice were given intraperitoneal injections of either p53(null) SK-OV-3 human ovarian tumor cells or p53(mut) DU-145 human prostate tumor cells to establish xenograft solid tumors. Mice were then dosed once or twice at 24-hour intervals by intraperitoneal injection with SCH58500 (Ad5/p53), an adenovirus construct expressing beta-galactosidase (Ad5/beta-gal), or a buffer control. Additional groups of mice received a single intraperitoneal dose of 10 mg/kg paclitaxel either alone or coadministered with Ad5/p53. Twenty-four hours after each last dose, the human solid tumor xenograft and relevant mouse tissue were removed from each mouse for the analysis of Ad5/p53 penetration. Immunohistochemistry (IHC) for beta-galactosidase protein revealed a depth of penetration of between 1 and 10 cells from the tumor surface. In some mice, hepatocytes in the periportal regions of liver lobules were also positive, indicating systemic absorption of adenovirus from the peritoneal cavity. IHC staining for p53 and p21 proteins in SK-OV-3 solid tumor xenografts revealed similar Ad/p53 penetration. LSC was used to map and quantitate apoptosis in both tumor and liver tissue biopsies, with over 450,000 nuclei from liver tissue and 150,000 nuclei from tumor tissue being evaluated. LSC analysis demonstrated a high level of apoptosis in the tumors that had been removed from Ad5/p53-dosed mice (12.7-19.7%). This level of apoptosis was significantly higher (P < 0.05) than was observed for liver tissues taken from Ad5/p53-dosed mice (2.7-8.0%) or tumor tissues taken from either Ad5/beta-gal-dosed mice (3.0-6.4%) or buffer control-dosed mice (3.0-5.3%). Scan bit maps from the extensive LSC analyses confirmed that apoptosis was present to about the same depth (1-10 cells) as had been identified by IHC for beta-galactosidase, p53, and p21 proteins. Paclitaxel coadministered with Ad5/p53 had no effect on Ad5 penetration into solid tumors in vivo as measured by IHC for p53 or p21 protein. However, the combination therapy did cause an elevation in the number of tumor cells undergoing apoptosis.
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Nishiyama A, Chang A, Trapp BD. NG2+ glial cells: a novel glial cell population in the adult brain. J Neuropathol Exp Neurol 1999; 58:1113-24. [PMID: 10560654 DOI: 10.1097/00005072-199911000-00001] [Citation(s) in RCA: 214] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
We describe a major glial cell population in the central nervous system (CNS) that can be identified by the expression of 2 cell surface molecules, the NG2 proteoglycan and the alpha receptor for platelet-derived growth factor (PDGF alphaR). In vitro and in the developing brain in vivo, NG2 and PDGF alphaR are expressed on oligodendrocyte progenitor cells but are down-regulated as the progenitor cells differentiate into mature oligodendrocytes. In the mature CNS, numerous NG2+/PDGF alphaR+ cells with extensive arborization of their cell processes are found ubiquitously long after oligodendrocytes are generated. NG2+ cells in the mature CNS do not express antigens specific to mature oligodendrocytes, astrocytes, microglia, or neurons, suggesting that they are a novel population of glial cells. Recently NG2+ cells in the adult CNS have been shown to undergo proliferation and morphological changes in response to a variety of stimuli, such as demyelination and inflammation, suggesting that they are dynamic cells capable of responding to changes in the environment. Furthermore, high levels of NG2+ and PDGF alphaR are expressed on oligodendroglioma cells, raising the possibility that the NG2+/PDGF alphaR+ cells in the mature CNS contribute to glial neoplasm.
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Abstract
PMA1 is an essential gene encoding the yeast plasma membrane [H(+)]ATPase. A pma1-D378N mutant has a dominant-negative effect on cell growth because both newly synthesized mutant and wild-type Pma1 molecules are retained and degraded in the endoplasmic reticulum (ER). Like other substrates for ER-associated degradation, Pma1-D378N is stabilized in mutants defective in components of the ubiquitination machinery. A genetic selection was performed for eps (ER-retained pma1 suppressing) mutants in which the growth defect caused by the D378N allele is suppressed. In an eps1 mutant, both mutant and wild-type Pma1 molecules are allowed to travel to the plasma membrane; however, normal retention of resident ER proteins Shr3 and Kar2 is not perturbed. Eps1 is a novel membrane protein belonging to the protein disulfide isomerase (PDI) family, and Eps1 co-localizes with Pma1-D378N in the ER. In the absence of Pma1-D378N, ER export of wild-type Pma1 is not affected by eps1 deletion, but export of the plasma membrane protein Gas1 is delayed. Because Eps1 is required for retention and degradation of Pma1-D378N, we propose a model in which Eps1 acts as a novel membrane-bound chaperone in ER quality control.
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Chen MS, Tung KS, Coonrod SA, Takahashi Y, Bigler D, Chang A, Yamashita Y, Kincade PW, Herr JC, White JM. Role of the integrin-associated protein CD9 in binding between sperm ADAM 2 and the egg integrin alpha6beta1: implications for murine fertilization. Proc Natl Acad Sci U S A 1999; 96:11830-5. [PMID: 10518536 PMCID: PMC18372 DOI: 10.1073/pnas.96.21.11830] [Citation(s) in RCA: 181] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
CD9 is a tetraspan protein that associates with several beta1 integrins, including alpha6beta1. Because alpha6beta1 is present on murine eggs and interacts with the sperm-surface glycoprotein ADAM 2 (fertilin beta), we first asked whether CD9 is present on murine eggs and whether it functions in sperm-egg binding and fusion. CD9 is present on the plasma membrane of oocytes in the ovary as well as on eggs isolated from the oviduct. The anti-CD9 mAb, JF9, potently inhibits sperm-egg binding and fusion in vitro in a dose-dependent manner. JF9 also disrupts binding of fluorescent beads coated with native fertilin or a recombinant fertilin beta disintegrin domain. (Both ligands bind to the egg via alpha6beta1.) Immunohistochemistry showed that CD9 is undetectable in the uterine epithelium, appears basolaterally and as prominent apical patches on the epithelium in the region between the uterus and the oviduct, and then persists apically in the oviduct. The integrin alpha6A subunit is found in similar apical patches in the region between the uterus and oviduct, but is confined to the basal aspect of the epithelium in the uterus and oviduct. Hence, alpha6A and CD9 both are expressed on the apical epithelial surface at the uterine-oviduct junction. These findings correlate with the observation that fertilin beta "knockout" sperm traverse the uterus but do not progress into the oviduct, contributing to the infertility of fertilin beta(-/-) male mice. Our results suggest that high-avidity binding between fertilin beta (ADAM 2) and alpha6beta1 requires cooperation between alpha6beta1 and CD9. Such cooperation may assist sperm passage into the oviduct as well as sperm-egg interactions.
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Abstract
Prolactin secretion from the anterior pituitary gland is regulated by multiple factors including prolactin-release inhibiting factors (PIFs) and prolactin releasing factors. PIFs, however, usually dominate to exert a tonic inhibition in the biological system, and the physiological PIF is believed to be dopamine. However, there is accumulating evidence that dopamine can not only inhibit but also stimulate prolactin release. Many investigators believe that this is achieved by activating inhibitory and stimulatory subtypes of dopamine receptors. We tried to demonstrate that one subtype of dopamine receptors is capable of both inhibiting or stimulating prolactin release using GH(4)ZR(7) cells. GH(4)ZR(7) cells express only a short form of dopamine D(2) receptors (D(2s)). Low concentrations of three well-established D(2) receptor agonists (dopamine, apomorphine and bromocriptine) stimulated prolactin release from GH(4)ZR(7) cells while high concentrations inhibited the release. Haloperidol, a D(2) receptor antagonist, blocked the inhibitory action, but was unable to block the dopamine-induced stimulatory action. Pretreatment of cells with phenoxybenzamine, a receptor alkylating agent, abolished both the dopamine-induced stimulatory and inhibitory actions. Our results support the thesis that the stimulation of prolactin release induced by dopamine is mediated through dopamine D(2s) receptors since the GH(4)ZR(7) cells have only D(2s) receptors among dopamine receptors. We have concluded that the D(2s) receptor is capable of both stimulating and inhibiting prolactin release, probably via the activation of a G(s) protein by low concentrations and a G(i) protein by high concentrations of dopaminergic agents.
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Mann EA, Blair EA, Levy AJ, Chang A. Effect of topical antibiotic therapy on recovery after tonsillectomy in adults. Otolaryngol Head Neck Surg 1999; 121:277-82. [PMID: 10471871 DOI: 10.1016/s0194-5998(99)70185-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Systemic antibiotics given during the first week after tonsillectomy appear to be effective in reducing postoperative morbidity. We assessed the effectiveness of perioperative topical antibiotic rinses in reducing posttonsillectomy morbidity. METHODS A randomized, double-blinded, placebo-controlled pilot study of 36 patients undergoing tonsillectomy was used to evaluate the effects of a standard 7-day systemic regimen of perioperative intravenous ampicillin/oral amoxicillin and 2 single-day topical antibiotic regimens: (1) clindamycin (Cleocin) and (2) amoxicillin/clavulanate (Augmentin) and ticarcillin/clavulanate (Timentin). RESULTS Mean aerobic and anaerobic oral bacterial counts were decreased in both topical treatment groups compared with the placebo group on the first postoperative day, achieving statistical significance with Augmentin/Timentin (aerobic and anaerobic bacterial counts) and Cleocin (aerobic counts). Significantly less postoperative pain and mouth odor were reported for both Cleocin (P = 0.014 and P = 0.005, respectively) and Augmentin/Timentin (P = 0.026 and P = 0.05, respectively) topical treatment groups when compared with the placebo group. CONCLUSIONS Preliminary results indicate a reduction in oral bacterial counts and postoperative morbidity in adult patients receiving topical antibiotics compared with patients receiving placebo; further investigation is warranted.
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Bagavant H, Adams S, Terranova P, Chang A, Kraemer FW, Lou Y, Kasai K, Luo AM, Tung KS. Autoimmune ovarian inflammation triggered by proinflammatory (Th1) T cells is compatible with normal ovarian function in mice. Biol Reprod 1999; 61:635-42. [PMID: 10456839 DOI: 10.1095/biolreprod61.3.635] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
The detection of noninfectious ovarian inflammation (oophoritis) and serum ovarian autoantibodies in a patient with premature ovarian failure is indicative of an autoimmune etiology. The mechanisms of autoimmune ovarian injury leading to loss of function are currently unknown. In this study we investigated the impact of oophoritis on ovarian function based on two murine autoimmune ovarian disease (AOD) models. AOD can be induced by thymectomy at Day 3 after birth (d3tx). D3tx mice develop ovarian inflammation and atrophy with loss of oocytes. In these mice, ovarian atrophy and not oophoritis correlated with abnormal estrous cyclicity. The second AOD model is induced by active immunization of adult mice with a murine ZP3 peptide (pZP3) in adjuvant. After active immunization, the zona pellucida antibody titer, not oophoritis, correlated with reduced fertility. To investigate the effect of oophoritis in the absence of antibody response or ovarian atrophy, pZP3-specific T cells were passively transferred into naive syngeneic mice. This recruited cytokine-producing cells into the ovaries so that elevated cytokine production and its effect on ovarian function could be examined. Recipients of pZP3-specific T cells developed severe granulomatous oophoritis, and the diseased ovaries had elevated ovarian mRNA levels of interferon-gamma, interleukin-1beta, and tumor necrosis factor alpha. Despite these changes, fertility rates and gonadotropin-induced follicular development remained essentially normal. Therefore, normal ovarian function is compatible with severe ovarian inflammation mediated by autoreactive T cells.
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Shoshan Y, Nishiyama A, Chang A, Mörk S, Barnett GH, Cowell JK, Trapp BD, Staugaitis SM. Expression of oligodendrocyte progenitor cell antigens by gliomas: implications for the histogenesis of brain tumors. Proc Natl Acad Sci U S A 1999; 96:10361-6. [PMID: 10468613 PMCID: PMC17893 DOI: 10.1073/pnas.96.18.10361] [Citation(s) in RCA: 147] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The early events in neoplastic transformation can be understood only by comparison of the neoplastic cell with its nontransformed counterpart. The most common central nervous system gliomas traditionally are thought to arise from mature astrocytes and oligodendrocytes. We examined the possibility that gliomas arise from a population of glia that has properties of oligodendrocyte progenitors. These glial cells express the NG2 chondroitin sulfate proteoglycan and the alpha receptor of platelet-derived growth factor in vivo. We identified NG2 and the alpha receptor of platelet-derived growth factor expression in tissue from seven of seven oligodendrogliomas, three of three pilocytic astrocytomas, and one of five glioblastoma multiforme. These data provide evidence that glial tumors arise from glial progenitor cells. Molecules expressed by these progenitor cells should be considered as targets for novel therapeutics.
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Pan YX, Xu J, Bolan E, Abbadie C, Chang A, Zuckerman A, Rossi G, Pasternak GW. Identification and characterization of three new alternatively spliced mu-opioid receptor isoforms. Mol Pharmacol 1999; 56:396-403. [PMID: 10419560 DOI: 10.1124/mol.56.2.396] [Citation(s) in RCA: 208] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We have identified four new mu-opiod receptor (MOR)-1 exons, indicating that the gene now contains at least nine exons spanning more than 200 kilobases. Replacement of exon 4 by combinations of the new exons yields three new receptors. When expressed in Chinese hamster ovary cells, all three variants displayed high affinity for mu-opioid ligands, but kappa and delta drugs were inactive. However, there were subtle, but significant, differences in the binding profiles of the three variants among themselves and from MOR-1. Immunohistochemically, the major variant, MOR-1C, displayed a regional distribution quite distinct from that of MOR-1. Region-specific processing also was seen at the mRNA level. Antisense mapping revealed that the four new exons were all involved in morphine analgesia. Together with two other variants generated from alternative splicing of exon 4, there are now six distinct MOR-1 receptors.
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MESH Headings
- Alternative Splicing
- Animals
- Brain/metabolism
- Cloning, Molecular
- Cricetinae
- Exons/genetics
- Male
- Mice
- Mice, Inbred ICR
- Protein Isoforms/biosynthesis
- Protein Isoforms/genetics
- Protein Isoforms/isolation & purification
- RNA, Messenger/biosynthesis
- RNA, Messenger/metabolism
- Receptors, Opioid, mu/biosynthesis
- Receptors, Opioid, mu/genetics
- Receptors, Opioid, mu/isolation & purification
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295
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Abstract
Localized heat urticaria is one of the rarest of the physical urticarias, characterized by well-defined urticarial lesions sharply confined to sites of heat exposure. We describe a case of localized heat urticaria in a 40-year-old woman. Because of the rarity of this disorder, much remains to be elucidated. The clinical features, pathogenesis and therapy are reviewed.
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296
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Chen YJ, Dai YS, Chen BF, Chang A, Chen HC, Lin YC, Chang KH, Lai YL, Chung CH, Lai YJ. The effect of tetrandrine and extracts of Centella asiatica on acute radiation dermatitis in rats. Biol Pharm Bull 1999; 22:703-6. [PMID: 10443466 DOI: 10.1248/bpb.22.703] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Radiation injury to the skin is one of the major limiting factors in radiotherapy. We designed this study using Sprague-Dawley rats to evaluate the reduction in skin injury achieved using natural products from plant extracts as protection. The acute skin reaction in tetrandrine- and Madecassol-treated animals appeared earlier, but was significantly less severe, than in the control group. The peak skin reactions in the tetrandrine group were less serious than those of the control group at three different radiation doses. At a high dose irradiation, the healing effect of tetrandrine is better than Madecassol and vaseline. The histologic findings indicate that tetrandrine and Madecassol are able to reduce acute radiation reactions by their anti-inflammatory activity.
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297
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Abstract
Multiple sclerosis (MS) is an inflammatory disease of the central nervous system. The primary pathological target in multiple sclerosis is myelin. Most MS patients follow a relapsing-remitting (RR-MS) course for 10 to 15 years that transforms into a chronic or secondary progressive disease (SP-MS). This review summarizes studies from our laboratory that implicate activated microglia and astrocytes in early stages of myelin destruction in MS brain. In addition, we review evidence that indicates that axonal transection is a major pathological process in multiple sclerosis. Our data support the hypothesis that neurological disability in RR-MS is due to inflammatory demyelination while axonal loss plays a significant role in the irreversible neurological decline in SP-MS. Further elucidation of the pathological targets and pathological mechanisms of tissue destruction in MS brain will help identify new therapeutics.
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298
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Luetteke NC, Qiu TH, Fenton SE, Troyer KL, Riedel RF, Chang A, Lee DC. Targeted inactivation of the EGF and amphiregulin genes reveals distinct roles for EGF receptor ligands in mouse mammary gland development. Development 1999; 126:2739-50. [PMID: 10331984 DOI: 10.1242/dev.126.12.2739] [Citation(s) in RCA: 374] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Targeted mice lacking functional EGF or amphiregulin (AR) were derived and bred to the TGFalpha-knockout to generate mice lacking various combinations of the three ligands. In contrast to EGF receptor (EGFR) knockout mice, triple null mice lacking half of the EGFR ligand family were healthy and fertile, indicative of overlapping or compensatory functions among EGF family members. Nevertheless, pups born to triple null dams frequently died or were runted, suggesting a mammary gland defect. Comparison of individual and combinatorial knockouts established that specific loss of AR severely stunted ductal outgrowth during puberty, consistent with dramatic expression of AR transcripts in normal developing ducts. Surprisingly, loss of all three ligands did not significantly affect cellular proliferation, apoptosis, or ERK activation within terminal end buds. Following pregnancy, most AR single null females, but few triple null females could nurse their young, revealing collaborative roles for EGF and TGFalpha in mammopoiesis and lactogenesis. In triple null glands, alveoli were poorly organized and differentiated, and milk protein gene expression was decreased. Additionally, Stat5a activation was frequently reduced in AR single and combinatorial nulls in association with impaired lactation. Collectively, our results provide genetic confirmation of a requirement for EGFR signaling throughout the development of the mouse mammary gland, and reveal stage-dependent activities for different EGFR ligands. Finally, the additional loss of growth factors from pups nursed by triple null dams further worsened their survival and growth, establishing functions for both maternal- and neonatal-derived growth factors.
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299
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Valencia IC, Chang A, Kirsner RS, Kerdel FA. Eosinophilic fasciitis responsive to treatment with pulsed steroids and cyclosporine. Int J Dermatol 1999; 38:369-72. [PMID: 10369548 DOI: 10.1046/j.1365-4362.1999.00695.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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300
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Vogel C, O'Rourke M, Winer E, Hochster H, Chang A, Adamkiewicz B, White R, McGuirt C. Vinorelbine as first-line chemotherapy for advanced breast cancer in women 60 years of age or older. Ann Oncol 1999; 10:397-402. [PMID: 10370781 DOI: 10.1023/a:1008364222793] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Older patients with advanced breast cancer are less likely to receive chemotherapy than younger patients. Vinorelbine is an attractive alternative in this setting because of its clinical activity and low frequency of side effects. This multicenter, phase II trial was designed to assess the safety and efficacy of intravenous vinorelbine as first-line therapy in women > or = 60 years old. PATIENTS AND METHODS Fifty-six women (median age, 72 years; range 60-84 years), with measurable advanced breast cancer and no prior chemotherapy for metastatic disease, were enrolled and included in the analysis. Vinorelbine 30 mg/m2 was administered weekly for 13 weeks and then every two weeks until development of progressive disease; doses were reduced or delayed to manage toxicity. RESULTS The objective response rate was 38% (95% confidence interval (95% CI): 24%-51%); median duration of response, nine months; median time to disease progression in all patients, six months. The major dose-limiting toxicity was hematologic, which led to a median dose intensity of 20.6 mg/m2/week. Grade 3-4 nonhematologic toxicity consisted of asthenia (7%); nausea and generalized pain (5%); vomiting, chest pain, abdominal pain, and elevated AST (4%); fever, diarrhea, constipation, and injection site reaction (2%). Neurotoxicity and alopecia were grade 1-2 and relatively infrequent. CONCLUSIONS Vinorelbine offers a promising alternative for the management of advanced breast cancer in elderly patients who are concerned about the subjective side effects of cytotoxic chemotherapy. The dose-limiting toxicity is neutropenia, which is readily managed with dose adjustment. Nonhematologic toxicity, including gastrointestinal side effects, is minimal. Randomized studies are warranted to compare the activity of vinorelbine with that of other regimens in elderly patients.
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