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Rosser E, Buckner E, Avedissian T, Cheung DSK, Eviza K, Hafsteinsdóttir TB, Hsu MY, Kirshbaum MN, Lai C, Ng YC, Ramsbotham J, Waweru S. The Global Leadership Mentoring Community: building capacity across seven global regions. Int Nurs Rev 2020; 67:484-494. [PMID: 32869285 DOI: 10.1111/inr.12617] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 06/30/2020] [Accepted: 07/13/2020] [Indexed: 11/29/2022]
Abstract
AIM The purpose of this paper is to report on the evaluation of the online Global Leadership Mentoring Community, a programme designed to build relationships across seven global regions and promote leadership development for emerging nurse leaders. BACKGROUND There is a pressing need and opportunity for sustainable global leadership mentoring programmes. This programme of Sigma Theta Tau International (Sigma) brought mentors and mentees together from across the world to build leadership capacity, understand global leadership issues and build networks. Community coordinators purposively selected mentors from each of Sigma's seven Global Regions, and mentees were chosen through a process of snowball sampling. Mentors and mentees met monthly with quarterly group calls. METHODS The study followed a programme evaluation, outcomes-focused approach. All eleven pairs of mentors-mentees were invited to complete online surveys at the outset and end of programme capturing both quantitative and qualitative data. Quantitative data were analysed using descriptive statistics and for qualitative data, a thematic analysis. FINDINGS Quantitative data confirmed that all 22 participants gained from the experience. From qualitative analysis, themes emerged illustrating the scope of achievements: 1. facilitation of successful outcomes for both mentors and mentees, 2. challenges of global mentoring and 3. strategies for successful global mentoring. DISCUSSION/CONCLUSION Participants reported that creating global leadership is a longitudinal process that needs sustained attention to effect change. This evaluation identified many strengths of the programme and recommended its continuation to help further development of global leaders, particularly through focusing more purposefully on policy issues. IMPLICATIONS FOR NURSING POLICY Empowerment of nurses globally through a Global Leadership Mentoring Community can improve leadership at all levels, thus emboldening their voices to influence nursing and health policy and ultimately improve patient care.
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Affiliation(s)
- E Rosser
- Faculty of Health and Social Sciences, Bournemouth University, Poole, UK
| | - E Buckner
- Ida Moffett School of Nursing, Samford University, Birmingham, AL, USA
| | - T Avedissian
- Hariri School of Nursing, American University of Beirut, Beirut, Lebanon
| | - D S K Cheung
- School of Nursing, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - K Eviza
- Sentara Martha Jefferson Hospital, Charlottesville, VA, USA
| | - T B Hafsteinsdóttir
- Department of Nursing Science, University Medical Center Utrecht, Utrecht, The Netherlands
| | - M Y Hsu
- Department of Nursing, Chung Shan Medical University, Taichung, Taiwan.,Department of Nursing, Chung Shan Medical University Hospital, Taichung, Taiwan
| | | | - C Lai
- School of Nursing, The Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Y C Ng
- University of Alabama in Hunstville, Huntsville, AL, USA
| | - J Ramsbotham
- School of Nursing, Queensland University of Technology, Kelvin Grove, QLD, Australia
| | - S Waweru
- USA College of Nursing, South Alabama, Mobile, AL, USA
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Garcia RA, Lupisella JA, Zhang R, Carson NL, Wang Z, Hsu MY, Fernando G, Ryan CS, Dierks E, Asahina Y, Kohno Y, Wurtz NR, Ostrowski J, Ito BR, Villarreal FJ. 2420Effects of a selective small-molecule formyl peptide receptor 2 agonist on post myocardial inflammation and left ventricular structure-function relationships. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz748.0168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background/Introduction
Dysregulated inflammation following myocardial infarction (MI) can lead to maladaptive infarct healing, myocardial damage and heart failure. Formyl peptide receptor 2 (FPR2) plays an important role in the ligand-dependent regulation of inflammation resolution. Stimulation of resolution via FPR2 activation is hypothesized to preserve left ventricular (LV) structure-function relationships thereby preventing pathological cardiac remodeling, and heart failure.
Purpose
We evaluated a selective 4-phenylpyrrolidinone FPR2 agonist in rodent MI models by assessing the impact on LV and infarct scar remodeling and cardiac function.
Methods
The FPR2 agonist was evaluated in phagocytosis, chemotaxis and cytokine response assays. In vivo, following permanent occlusion of the left anterior descending (LAD) artery, C57BL/6 mice or Sprague-Dawley rats were treated with the FPR2 agonist or vehicle; PO gavage, QD. Treatment began 24 hours after occlusion (0.3 and 3 mg/kg) and continued for three days to assess early inflammation or four weeks to evaluate LV and infarct structure and function. Rats subjected to permanent MI were treated 48 hours after occlusion (0.01, 0.1. 1, 10 mg/kg) for six weeks to assess structure-function relationships. A parallel study in rats evaluated compound treatment (0.01, 0.1. 1, 10 mg/kg) following 60 minutes occlusion and reperfusion of the LAD artery.
Results
The FPR2 agonist enhanced cellular phagocytosis and chemotaxis, and stimulated IL-10 and MCP-1 gene expression in isolated human whole blood. In mice, FPR2 agonist treatment improved survival post MI, reduced LV chamber area and infarct size (26% and 55% vs. vehicle, respectively, P<0.05) and preserved infarct wall thickness (59% vs. vehicle, P<0.05). Treatment increased macrophage arginase 1 levels three days post-MI in the infarct border zone and CD206 levels in the whole heart, indicating a shift towards a pro-resolution phenotype. In rats, FPR2 agonist treatment preserved infarct wall thickness (maximal at 10 mg/kg, 96% vs. vehicle, P<0.05) and increased LV ejection fraction at all doses (+9% vs. vehicle, P<0.05). Following occlusion and reperfusion of the LAD artery, treatment preserved viable myocardium across the infarct wall at multiple doses (25–41%, P<0.05) resulting in increased ejection fraction (14% and 19% vs vehicle at 0.01 and 1 mg/kg, respectively, P<0.05).
Conclusion(s)
Improvements in cardiac structure-function versus vehicle treated animals support the concept that agonism of FPR2 improves post-MI wound healing, limiting adverse post-MI LV remodeling, thereby preserving cardiac function. These preclinical results suggest targeting FPR2 may present an innovative approach towards development of effective drug therapies to prevent heart failure post-MI.
Acknowledgement/Funding
Bristol-Myers Squibb Company
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Affiliation(s)
- R A Garcia
- Bristol-Myers Squibb Co., Cardiovascular and Fibrosis Drug Discovery, Pennington, United States of America
| | - J A Lupisella
- Bristol-Myers Squibb Co., Cardiovascular and Fibrosis Drug Discovery, Pennington, United States of America
| | - R Zhang
- Bristol-Myers Squibb Co., Cardiovascular and Fibrosis Drug Discovery, Pennington, United States of America
| | - N L Carson
- Bristol-Myers Squibb Co., Cardiovascular and Fibrosis Drug Discovery, Pennington, United States of America
| | - Z Wang
- Bristol-Myers Squibb Co., Cardiovascular and Fibrosis Drug Discovery, Pennington, United States of America
| | - M Y Hsu
- Bristol-Myers Squibb Co., Cardiovascular and Fibrosis Drug Discovery, Pennington, United States of America
| | - G Fernando
- Bristol-Myers Squibb Co., Cardiovascular and Fibrosis Drug Discovery, Pennington, United States of America
| | - C S Ryan
- Bristol-Myers Squibb Co., Cardiovascular and Fibrosis Drug Discovery, Pennington, United States of America
| | - E Dierks
- Bristol-Myers Squibb Co., Cardiovascular and Fibrosis Drug Discovery, Pennington, United States of America
| | - Y Asahina
- Kyorin Pharmaceutical Co., LTD., Tokyo, Japan
| | - Y Kohno
- Kyorin Pharmaceutical Co., LTD., Tokyo, Japan
| | - N R Wurtz
- Bristol-Myers Squibb Co., Cardiovascular and Fibrosis Drug Discovery, Pennington, United States of America
| | - J Ostrowski
- Bristol-Myers Squibb Co., Cardiovascular and Fibrosis Drug Discovery, Pennington, United States of America
| | - B R Ito
- University of California San Diego, San Diego, United States of America
| | - F J Villarreal
- University of California San Diego, San Diego, United States of America
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Nesbit M, Schaider H, Berking C, Shih DT, Hsu MY, McBrian M, Crombleholme TM, Elenitsas R, Buck C, Herlyn M. Alpha5 and alpha2 integrin gene transfers mimic the PDGF-B-induced transformed phenotype of fibroblasts in human skin. J Transl Med 2001; 81:1263-74. [PMID: 11555674 DOI: 10.1038/labinvest.3780340] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Platelet-derived growth factor (PDGF)-B is a proto-oncogene capable of transforming fibroblasts. Using adenoviral vectors, we tested whether endogenous PDGF-B expression in human skin xenotransplants leads to changes in the expression of alpha5 and alpha2 integrin subunits and whether integrin overexpression leads to PDGF-related changes in the skin. In vitro, transduction of fibroblasts with PDGF-B or the integrin alpha5 subunit stimulated multilayered growth and spindle-type morphology, both markers of mesenchymal cell transformation. In vivo, PDGF-B transduction of the human dermis was associated with up-regulation of collagen and fibronectin synthesis, increases in alpha5 and alpha2 integrin subunit expression, vessel formation, and proliferation of fibroblasts, keratinocytes, and pericytes. A similar stromal response was induced when alpha5 and alpha2 integrin subunits were overexpressed in the human dermis, suggesting that integrins play a major role in the induction of a transformed phenotype of fibroblasts by PDGF-B.
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Affiliation(s)
- M Nesbit
- The Wistar Institute, Philadelphia, Pennsylvania 19104, USA
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5
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Inouye S, Jain R, Ueki T, Nariya H, Xu CY, Hsu MY, Fernandez-Luque BA, Munoz-Dorado J, Farez-Vidal E, Inouye M. A large family of eukaryotic-like protein Ser/Thr kinases of Myxococcus xanthus, a developmental bacterium. Microb Comp Genomics 2001; 5:103-20. [PMID: 11087177 DOI: 10.1089/10906590050179783] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Myxococcus xanthus is a gram-negative bacterium that forms multicellular fruiting bodies upon starvation. Here, we demonstrate that it contains at least 13 eukaryotic-like protein Ser/Thr kinases (Pkn1 to Pkn13) individually having unique features. All contain the kinase domain of approximately 280 residues near the N-terminal end, which share highly conserved features in eukaryotic Ser/Thr kinases. The kinase domain is followed by a putative regulatory domain consisting of 185 to 692 residues. These regulatory domains share no significant sequence similarities. The C-terminal regions of 11 kinases contain at least 1 transmembrane domain, suggesting that they function as transmembrane sensor kinases. From the recent genomic analysis, protein Ser/Thr kinases were found in various pathogenic bacteria and coexist with protein His kinases. Phylogenetic analysis of these Ser/Thr kinases reveals that all bacterial Ser/Thr kinases were evolved from a common ancestral kinase together with eukaryotic Tyr and Ser/Thr kinases. Coexistence of both Ser/Thr and His kinases in some organisms may be significant in terms of functional differences between the two kinases. We argue that both kinases are essential for some bacteria to adapt optimally to severe environmental changes.
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Affiliation(s)
- S Inouye
- Department of Biochemistry, Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA.
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Hsu MY, Meier FE, Nesbit M, Hsu JY, Van Belle P, Elder DE, Herlyn M. E-cadherin expression in melanoma cells restores keratinocyte-mediated growth control and down-regulates expression of invasion-related adhesion receptors. Am J Pathol 2000; 156:1515-25. [PMID: 10793063 PMCID: PMC1876923 DOI: 10.1016/s0002-9440(10)65023-7] [Citation(s) in RCA: 251] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/06/2000] [Indexed: 02/08/2023]
Abstract
In human epidermis, functional symbiosis requires homeostatic balance between keratinocytes and melanocytes. Compelling evidence from co-culture studies demonstrated a sophisticated, multileveled regulation of normal melanocytic phenotype orchestrated by undifferentiated, basal-type keratinocytes. Keratinocytes control cell growth and dendricity, as well as expression of melanoma-associated cell surface molecules of normal melanocytes. In contrast, melanoma cells are refractory to the keratinocyte-mediated regulation. The loss of regulatory dominance by keratinocytes occurs in concert with down-regulation of E-cadherin expression in melanoma cells. To investigate the potential role of E-cadherin in melanoma-keratinocyte interaction, we transduced E-cadherin-negative melanoma cells with full-length E-cadherin cDNA using an adenoviral vector. Our results show that functional E-cadherin expression in melanoma cells leads to cell adhesion to keratinocytes rendering them susceptible for keratinocyte-mediated control. In a skin reconstruction model, ectopic E-cadherin expression inhibits invasion of melanoma cells into dermis by down-regulating invasion-related adhesion receptors, MelCAM/MUC18 and beta3 integrin subunit, and by induction of apoptosis. Thus, disruption of the E-cadherin-mediated, normal regulatory control from keratinocytes may represent one of the mechanisms accounting for melanocyte transformation.
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Affiliation(s)
- M Y Hsu
- Wistar Institute, Philadelphia, Pennsylvania 19104, USA
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Satyamoorthy K, Meier F, Hsu MY, Berking C, Herlyn M. Human xenografts, human skin and skin reconstructs for studies in melanoma development and progression. Cancer Metastasis Rev 2000; 18:401-5. [PMID: 10721493 DOI: 10.1023/a:1006333627271] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Melanoma develops from a series of architectural and phenotypically distinct stages and becomes progressively aggressive. Considerable progress has been made in understanding the biological, pathological, and immunological aspects of human melanoma. Genetic and cytogenetic studies have revealed broad chromosomal abnormalities and wide mutational spectra. Precise biological and molecular determinants responsible for melanoma progression are not yet known. This is in part due to lack of experimental models that mimic human melanomas. Experimental models in melanoma should not only identify cause and origin of malignancy, but also should represent the ordered progression steps that culminate in metastasis to distant organs. Currently, there are several mouse and other vertebrate melanoma models under investigation; several of them promise to shed light on mechanisms of melanomagenesis. However, many of them suffer from lack of context to human skin architecture and hence, are of basic interest. The lack of appropriate models impeded the efforts to understand origin, etiology, progression and ultimately therapeutic benefits to humans. Development of human skin-mouse chimeric models has appeal because it mimics human diseases. In addition, human artificial skin constructs in vitro promises to be a versatile and efficient model to study not only origin and mechanisms of melanoma, but also progression. This review will focus on the recent progress in establishing tumor models in melanoma in general and their relevance to human melanoma as molecular determinants of tumor progression.
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Choi MM, Hsu MY, Wong SL. Determination of cyclamate in low-calorie foods by high-performance liquid chromatography with indirect visible photometry. Analyst 2000; 125:217-20. [PMID: 10885077 DOI: 10.1039/a906852j] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A rapid and simple method using reversed-phase high-performance liquid chromatography combined with indirect visible photometry at 433 nm was developed to determine cyclamate in some food samples. Cyclamate was not detected in these chosen samples as its use is banned in Hong Kong. Cyclamate can easily be detected in spiked samples using a mobile phase consisting of 30 mumol dm-3 Methyl Red and 0.02 mol dm-3 phosphate buffer (pH 7.0)-methanol in a volume ratio of 3:2. The column temperature was set at 23 degrees C. The detection limit was 0.14 mmol dm-3 and the relative standard deviation of the peak area response was 0.58% for a solution containing 5.0 mmol dm-3 of cyclamate (n = 8). This method was successfully applied to the analysis of eight spiked food samples and the cyclamate recoveries for these samples ranged from 93 to 99%.
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Affiliation(s)
- M M Choi
- Department of Chemistry, Hong Kong Baptist University, SAR, China.
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9
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Meier F, Nesbit M, Hsu MY, Martin B, Van Belle P, Elder DE, Schaumburg-Lever G, Garbe C, Walz TM, Donatien P, Crombleholme TM, Herlyn M. Human melanoma progression in skin reconstructs : biological significance of bFGF. Am J Pathol 2000; 156:193-200. [PMID: 10623667 PMCID: PMC1868639 DOI: 10.1016/s0002-9440(10)64719-0] [Citation(s) in RCA: 173] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/29/1999] [Indexed: 12/14/2022]
Abstract
Human skin reconstructs are three-dimensional in vitro models consisting of epidermal keratinocytes plated onto fibroblast-contracted collagen gels. Cells in skin reconstructs more closely recapitulate the in situ phenotype than do cells in monolayer culture. Normal melanocytes in skin reconstructs remained singly distributed at the basement membrane which separated the epidermis from the dermis. Cell lines derived from biologically early primary melanomas of the radial growth phase proliferated in the epidermis and the basement membrane was left intact. Growth and migration of the radial growth phase melanoma cells in the dermal reconstruct and tumorigenicity in vivo were only observed when cells were transduced with the basic fibroblast growth factor gene, a major autocrine growth stimulator for melanomas. Primary melanoma cell lines representing the more advanced stage vertical growth phase invaded the dermis in reconstructs and only an irregular basement membrane was formed. Metastatic melanoma cells rapidly proliferated and aggressively invaded deep into the dermis, with each cell line showing typical invasion and growth characteristics. Our results demonstrate that the growth patterns of melanoma cells in skin reconstructs closely correspond to those in situ and that basic fibroblast growth factor is critical for progression.
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Affiliation(s)
- F Meier
- Wistar Institute, Philadelphia, Pennsylvania 19104, USA
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Nesbit M, Nesbit HK, Bennett J, Andl T, Hsu MY, Dejesus E, McBrian M, Gupta AR, Eck SL, Herlyn M. Basic fibroblast growth factor induces a transformed phenotype in normal human melanocytes. Oncogene 1999; 18:6469-76. [PMID: 10597249 DOI: 10.1038/sj.onc.1203066] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Basic fibroblast growth factor (bFGF or FGF-2) is produced by nearly all melanomas in vitro and in vivo but not by normal melanocytes, which require exogenous bFGF for growth. In this study, we transduced normal human melanocytes to overexpress two forms of bFGF: (bFGF-Long and bFGF-Short) using replication-deficient adenovirus 5 vectors. bFGF-Long induced the 17.8, 22.5, 23.1 and 24.2 kDa forms of bFGF, whereas bFGF-Short induced only the 17.8 kDa mature form. Growth of cultured melanocytes transduced with either vector was similar to that of nevus and melanoma cells and was independent of exogenous bFGF and of insulin/insulin-like growth factor 1, and cyclic AMP enhancers, requiring only phorbol ester as an exogenous mitogen. Like primary melanoma cells, transduced normal melanocytes grew anchorage independently in soft agar. When injected into the dermis of human skin grafted to mice, bFGF-transduced melanocytes proliferated for at least 20 days, whereas cells from control cultures showed poor survival and no proliferation. These results demonstrate that bFGF upregulation is a critical component in melanoma progression.
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Affiliation(s)
- M Nesbit
- Wistar Institute, Philadelphia, Pennsylvania, PA 19104, USA
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Hsu JY, Hsu MY, Sorger T, Herlyn M, Levine EM. Heparin/endothelial cell growth supplement regulates matrix gene expression and prolongs life span of vascular smooth muscle cells through modulation of interleukin-1. In Vitro Cell Dev Biol Anim 1999; 35:647-54. [PMID: 10614876 DOI: 10.1007/s11626-999-0105-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Vascular smooth muscle cells produce and respond to interleukin-1, a cytokine which modifies inflammation-associated vascular activities including the synthesis of extracellular matrix proteins. We have established vascular smooth muscle cells culture conditions in which heparin, in the presence of endothelial cell growth supplement, promotes cell proliferation and inhibits interleukin-1 and matrix protein expression. To test whether interleukin-1 mediates growth and matrix modulation by heparin/endothelial cell growth supplement, vascular smooth muscle cells were transfected with an Epstein-Barr virus-derived expression vector designed to express interleukin-1 antisense transcripts. RNase protection and ELISA assays demonstrated a complete block of interleukin-1 transcription and protein synthesis. Northern blot analysis also showed that interleukin-1 antisense decreased the expression of matrix genes such as type I collagen, fibronectin, and decorin similar to downregulation after heparin/endothelial cell growth supplement treatment. In contrast, the expression of versican was not affected, indicating a selective suppression of matrix proteins. In addition, interleukin-1 antisense significantly prolonged the life span of vascular smooth muscle cells in culture. Our data suggest that heparin/endothelial cell growth supplement induces matrix remodeling and controls growth and senescence of vascular smooth muscle cells through down-regulation of interleukin-1.
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Affiliation(s)
- J Y Hsu
- The Wistar Institute, Philadelphia, Pennsylvania 19104-4268, USA
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Inouye S, Hsu MY, Xu A, Inouye M. Highly specific recognition of primer RNA structures for 2'-OH priming reaction by bacterial reverse transcriptases. J Biol Chem 1999; 274:31236-44. [PMID: 10531319 DOI: 10.1074/jbc.274.44.31236] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A minor population of Escherichia coli contains retro-elements called retrons, which encode reverse transcriptases (RT) to synthesize peculiar satellite DNAs called multicopy single-stranded DNA (msDNA). These RTs recognize specific RNA structures in their individual primer-template RNAs to initiate cDNA synthesis from the 2'-OH group of a specific internal G residue (branching G residue). The resulting products (msDNA) consist of RNA and single-stranded DNA, sharing hardly any sequence homology. Here, we investigated how RT-Ec86 recognizes the specific RNA structure in its primer-template RNA. On the basis of structural comparison with HIV-1 RT, domain exchanges were carried out between two E. coli RTs, RT-Ec86 and RT-Ec73. RT-Ec86 (320 residues) and RT-Ec73 (316 residues) share only 71 identical residues (22%). From the analysis of 10 such constructs, the C-terminal 91-residue sequence of RT-Ec86 was found to be essential for the recognition of the unique stem-loop structure and the branching G residue in the primer-template RNA for retron-Ec86. Using the SELEX (systematic evolution of ligands by exponential enrichment) method with RT-Ec86 and primer RNAs containing random sequences, the identical stem-loop structure (including the 3-U loop) to that found in the retron-Ec86 primer-template RNA was enriched. In addition, the highly conserved 4-base sequence (UAGC), including the branching G residue, was also enriched. These results indicate that the highly diverse C-terminal region recognizes specific stem-loop structures and the branching G residue located upstream of the stem-loop structure. The present results with seemingly primitive RNA-dependent DNA polymerases provide insight into the mechanisms for specific protein RNA recognition.
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Affiliation(s)
- S Inouye
- Department of Biochemistry, Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA
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Abstract
Ephrin-A1, formerly called B61, is a new melanoma growth factor; it is angiogenic and chemoattractant for endothelial cells. EPH-A2, or ECK (a receptor for ephrin-A1), is ectopically expressed in most melanoma cell lines; the pathology where this expression is first manifested and the possible role of the receptor in tumor progression are unknown. To determine these, we studied the expression of this ligand and receptor in biopsies of benign and malignant melanocytic lesions. EPH-A2 was not detected in normal melanocytes, benign compound nevi or advanced melanomas, though it was found in 2 of 9 biopsies of malignant melanoma in situ. Ephrin-A1 was present in occasional early lesions and in advanced primary melanomas (43%) and metastatic melanomas (67%). Expression of ephrin-A1 was induced in melanoma cells by pro-inflammatory cytokines. Our findings are consistent with 2 possible roles for ephrin-A1 in melanoma development: it may promote melanocytic cell growth or survival and induce vascularization in advanced melanomas. Both effects may be potentiated by inflammatory responses. Our data are consistent with earlier observations that an inflammatory infiltrate is associated with poor prognosis in thin primary melanomas.
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Affiliation(s)
- D J Easty
- St. George's Hospital Medical School, London, UK.
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Abstract
Ephrin-A1, formerly called B61, is a new melanoma growth factor; it is angiogenic and chemoattractant for endothelial cells. EPH-A2, or ECK (a receptor for ephrin-A1), is ectopically expressed in most melanoma cell lines; the pathology where this expression is first manifested and the possible role of the receptor in tumor progression are unknown. To determine these, we studied the expression of this ligand and receptor in biopsies of benign and malignant melanocytic lesions. EPH-A2 was not detected in normal melanocytes, benign compound nevi or advanced melanomas, though it was found in 2 of 9 biopsies of malignant melanoma in situ. Ephrin-A1 was present in occasional early lesions and in advanced primary melanomas (43%) and metastatic melanomas (67%). Expression of ephrin-A1 was induced in melanoma cells by pro-inflammatory cytokines. Our findings are consistent with 2 possible roles for ephrin-A1 in melanoma development: it may promote melanocytic cell growth or survival and induce vascularization in advanced melanomas. Both effects may be potentiated by inflammatory responses. Our data are consistent with earlier observations that an inflammatory infiltrate is associated with poor prognosis in thin primary melanomas.
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Affiliation(s)
- D J Easty
- St. George's Hospital Medical School, London, UK.
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Abstract
Ephrin-A1, formerly called B61, is a new melanoma growth factor; it is angiogenic and chemoattractant for endothelial cells. EPH-A2, or ECK (a receptor for ephrin-A1), is ectopically expressed in most melanoma cell lines; the pathology where this expression is first manifested and the possible role of the receptor in tumor progression are unknown. To determine these, we studied the expression of this ligand and receptor in biopsies of benign and malignant melanocytic lesions. EPH-A2 was not detected in normal melanocytes, benign compound nevi or advanced melanomas, though it was found in 2 of 9 biopsies of malignant melanoma in situ. Ephrin-A1 was present in occasional early lesions and in advanced primary melanomas (43%) and metastatic melanomas (67%). Expression of ephrin-A1 was induced in melanoma cells by pro-inflammatory cytokines. Our findings are consistent with 2 possible roles for ephrin-A1 in melanoma development: it may promote melanocytic cell growth or survival and induce vascularization in advanced melanomas. Both effects may be potentiated by inflammatory responses. Our data are consistent with earlier observations that an inflammatory infiltrate is associated with poor prognosis in thin primary melanomas.
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Affiliation(s)
- D J Easty
- St. George's Hospital Medical School, London, UK.
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Hsu MY, Shih DT, Meier FE, Van Belle P, Hsu JY, Elder DE, Buck CA, Herlyn M. Adenoviral gene transfer of beta3 integrin subunit induces conversion from radial to vertical growth phase in primary human melanoma. Am J Pathol 1998; 153:1435-42. [PMID: 9811334 PMCID: PMC1853416 DOI: 10.1016/s0002-9440(10)65730-6] [Citation(s) in RCA: 166] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/22/1998] [Indexed: 12/22/2022]
Abstract
Expression of the beta3 subunit of the alphavbeta3 vitronectin receptor on melanoma cells is associated with tumor thickness and the ability to invade and metastasize. To address the role of alphavbeta3 in the complex process of progression from the nontumorigenic radial to the tumorigenic vertical growth phase of primary melanoma, we examined the biological consequences of overexpressing alphavbeta3 in early-stage melanoma cells using an adenoviral vector for gene transfer. Overexpression of functional alphavbeta3 in radial growth phase primary melanoma cells 1) promotes both anchorage-dependent and -independent growth, 2) initiates invasive growth from the epidermis into the dermis in three-dimensional skin reconstructs, 3) prevents apoptosis of invading cells, and 4) increases tumor growth in vivo. Thus, alphavbeta3 serves diverse biological functions during the progression from the nontumorigenic radial growth phase to the tumorigenic and-invasive vertical growth phase primary melanoma.
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Affiliation(s)
- M Y Hsu
- Wistar Institute, University of Pennsylvania, Philadelphia 19104-4268, USA
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17
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Meier F, Satyamoorthy K, Nesbit M, Hsu MY, Schittek B, Garbe C, Herlyn M. Molecular events in melanoma development and progression. Front Biosci 1998; 3:D1005-10. [PMID: 9740553 DOI: 10.2741/a341] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Based on clinical and histopathological features, five steps of melanoma progression have been proposed: common acquired and congenital nevi with structurally normal melanocytes, dysplastic nevus with structural and architectural atypia, early radial growth phase (RGP) primary melanoma, advanced vertical growth phase primary melanoma (VGP) with competence for metastasis, and metastatic melanoma. Despite a wealth of research resources (tissues, cell lines, and antibodies), the genetic alterations responsible for the development and stepwise progression of melanoma are still unclear. Cytogenetic analyses have failed to identify consistent gene deletions, mutations, translocations, or amplifications in sporadic cases. However, in vitro characterization of melanoma cells has revealed fundamental differences from normal melanocytes. Earlier work using monoclonal antibodies has defined a variety of melanoma-associated antigens that mediate cell-cell or cell-substratum adhesion, growth regulation, proteolysis, and modulation of immune responses. Functional studies of these individual candidate molecules will lead to a better understanding of the pathogenesis of melanoma and of potential targets for rational therapy.
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Affiliation(s)
- F Meier
- The Wistar Institute, 3601 Spruce Street, Philadelphia, PA 19104, USA
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18
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Shih LM, Hsu MY, Palazzo JP, Herlyn M. The cell-cell adhesion receptor Mel-CAM acts as a tumor suppressor in breast carcinoma. Am J Pathol 1997; 151:745-51. [PMID: 9284823 PMCID: PMC1857834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Mel-CAM (MUC18 or CD146) is a cell adhesion molecule sharing sequence homology with members of the immunoglobulin gene superfamily. Mel-CAM was originally described as a marker associated with invasion and metastasis in melanoma. We determined here the distribution and biological significance of Mel-CAM in normal, benign proliferative, and neoplastic breast ductal epithelium. Using a Mel-CAM-specific monoclonal antibody, we, immunohistochemically demonstrate Mel-CAM expression in 14 of 14 (100%) normal breast epithelia and benign proliferative ductal epithelial lesions, whereas Mel-CAM expression can only be focally detected in 12 of 72 (17%) breast carcinomas. Solid-phase cell adhesion assay revealed that breast carcinoma cells in culture express the ligand for Mel-CAM. Transfection of Mel-CAM cDNA into breast carcinoma cells induces a more cohesive cell growth pattern and establishes smaller tumors in immunocompromised mice than mock transfectants. In conclusion, Mel-CAM is distributed throughout normal and benign proliferative mammary ductal epithelium, but it is frequently lost in carcinomas; it functions as a heterophilic cell-cell adhesion molecule in breast epithelium, and loss of Mel-CAM expression in breast carcinoma may be an important step for tumor progression.
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Affiliation(s)
- L M Shih
- Wistar Institute, Philadelphia, PA 19104-4268, USA
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19
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Shih IM, Speicher D, Hsu MY, Levine E, Herlyn M. Melanoma cell-cell interactions are mediated through heterophilic Mel-CAM/ligand adhesion. Cancer Res 1997; 57:3835-40. [PMID: 9288796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Mel-cell adhesion molecule (CAM), also known as MUC18 and CD146, is a novel member of the immunoglobulin supergene family. Mel-CAM was first identified as an integral membrane glycoprotein in human melanoma and is also abundantly expressed by endothelial cells of various origins. In a previous study (I. M. Shih et al., Cancer Res., 54: 2514-2520, 1994), we showed that Mel-CAM is a cell-cell adhesion molecule with a possible role in melanoma invasion and metastasis. Here, we define the molecular mechanism responsible for cell-cell adhesion of Mel-CAM and demonstrate its role in melanoma-endothelial cell interactions. Most of human melanoma cells, including Mel-CAM-negative SBcl-2 cells, adhered to nitrocellulose-immobilized Mel-CAM produced by baculovirus recombinants. This adhesion can be blocked by full-length Mel-CAM or polyclonal antiserum against Mel-CAM. Adhesion is not affected by the presence of EDTA, truncated Mel-CAM extracellular domain, or heparan sulfate proteoglycan. In cell aggregation assays, Mel-CAM-negative SBcl-2 cells cluster with U937TM cells (U937 transfected with Mel-CAM cDNA) but not with control nontransfectants, suggesting that SBcl-2 cells express the ligand for Mel-CAM. SBcl-2 cells also form heterotypic aggregates with Mel-CAM-positive human endothelial cells but not with Mel-CAM-negative but ligand-positive smooth muscle cells. Taken together, our results show that Mel-CAM mediates cell-cell adhesion through heterophilic adhesion to an as yet unidentified ligand present on melanoma but not on endothelial cells. Thus, melanoma-endothelial interactions during metastasis may occur through this novel mechanism.
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Affiliation(s)
- I M Shih
- The Wistar Institute, Philadelphia, Pennsylvania 19104, USA
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20
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Hsu MY, Wheelock MJ, Johnson KR, Herlyn M. Shifts in cadherin profiles between human normal melanocytes and melanomas. J Investig Dermatol Symp Proc 1996; 1:188-94. [PMID: 9627715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Direct contacts between keratinocytes and melanocytes play an important role in conserving the characteristic phenotype and biologic behavior of melanocytic cells. Although the mechanisms involved remain unclear, given the role of adhesion molecules in controlling cellular interactions, disturbances in normal keratinocyte-melanocyte adhesion mediated by cadherin may contribute to malignant transformation by releasing melanocytes from a variety of contact-mediated regulatory controls. To determine the potential clinical relevance of cadherin profiles in melanomas and to study their possible involvement in the phenotypic plasticity of melanocytic cells, we used immunostaining, biochemical, and co-culture techniques. Double immunofluorescence demonstrated expression of cadherins and their associating proteins, alpha- and beta-catenin, in melanocytes in situ. Melanomas were heterogeneous when evaluated immunohistochemically, with positive rates of four of 14, eight of 12, and 12 of 16 to anti-E-, anti-P-, and anti-N-cadherin monoclonal antibodies, respectively. Flow cytometry indicated abundant expression of E-cadherin but marginal P- and N-cadherin in cultured melanocytes. In contrast, only one (WM1232) of 16 melanoma cell lines tested was positive for E-cadherin, none was positive for P-cadherin, and all but one were positive for N-cadherin. Western blot confirmed E-cadherin expression in melanocytic cells. Immunoprecipitation further revealed complexes of E-cadherin with catenins in WM1232 melanoma cells. Co-culture studies indicated that only melanoma cells expressing E-cadherin (WM1232) were susceptible to keratinocyte-mediated control of the expression of the melanoma cell adhesion molecule, Mel-CAM. The results suggest downregulation of E-cadherin but upregulation of N-cadherin in melanoma cells. Such a shift in cadherin profiles may endow melanocytic cells with new adhesive properties and altered spatial relations that favor uncontrolled proliferation, migration, and invasion.
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Affiliation(s)
- M Y Hsu
- Wistar Institute, Philadelphia, Pennsylvania 19104-4268, USA
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21
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Abstract
Two recA genes, recA1 and recA2, in Myxococcus xanthus were cloned by using the recA gene of Escherichia coli, and their DNA sequences were determined. On the basis of deduced amino acid sequences, RecA1 and RecA2 have 67.0% identity to each other and 60.5 and 60.9% identities to E. coli RecA, respectively. Expression of recA2 was detected in both vegetative and developmental cells by Northern blot (RNA) analysis, and a threefold induction was observed when cells were treated with nalidixic acid. Repeated attempts to isolate a recA2 disruption mutant have failed, while a recA1 disruption mutant was readily isolated. Both the recA1 and recA2 genes expressed in E. coli complement the UV sensitivity of an E. coli recA strain.
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Affiliation(s)
- N Norioka
- Department of Biochemistry, Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA
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22
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Shih IM, Elder DE, Hsu MY, Herlyn M. Regulation of Mel-CAM/MUC18 expression on melanocytes of different stages of tumor progression by normal keratinocytes. Am J Pathol 1994; 145:837-45. [PMID: 7943174 PMCID: PMC1887332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The cell-cell adhesion receptor, Mel-CAM/MUC18, is highly expressed on metastatic melanoma cells and is also detectable on primary melanomas but not on normal melanocytes. Previous studies have shown that increased Mel-CAM/MUC18 expression correlates with tumor thickness and metastatic potential. We show here that normal melanocytes and nevus cells in culture express Mel-CAM/MUC18, but expression is down-regulated when cells are co-cultured with keratinocytes. Such keratinocyte-mediated regulation of Mel-CAM/MUC18 expression on melanocytes, nevus cells, and early melanomas can also be demonstrated in situ in patients' specimens. On the other hand, melanoma cells from primary and metastatic lesions constitutively express Mel-CAM/MUC18, and keratinocytes have no modulatory effect. These results suggest that contact between keratinocytes and human melanocytic cells modulates Mel-CAM/MUC18 expression, raising the possibility that escape from keratinocyte control during melanoma development leads to expression of antigens that contribute to the malignant phenotype.
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Affiliation(s)
- I M Shih
- Wistar Institute, Philadelphia, PA 19104-4268
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23
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Shimamoto T, Hsu MY, Inouye S, Inouye M. Reverse transcriptases from bacterial retrons require specific secondary structures at the 5'-end of the template for the cDNA priming reaction. J Biol Chem 1993; 268:2684-92. [PMID: 7679101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Multicopy single-stranded DNA (msDNA) is a peculiar molecule consisting of a single-stranded DNA that is branched out from an internal G residue of an RNA molecule (msdRNA) via a 2',5'-phosphodiester linkage. The genetic unit required for msDNA synthesis is designated "retron" and consists of msr (a gene for msdRNA), msd (a gene for msDNA), and a gene for reverse transcriptase (RT) in a single operon. To date, four different msDNAs have been isolated from Escherichia coli. They do not share any primary sequences in either RNA or DNA. To elucidate the specificity of bacterial RT for msDNA synthesis, the msr-msd region from retron-Ec67 was introduced into E. coli cells producing RT-Ec73, or the msr-msd region from retron-Ec73 into E. coli cells producing RT-Ec67. In both cases, msDNA was not synthesized. However, when the msdRNA coding regions (msr) for retron-Ec67 and -Ec73 were mutually exchanged and the chimeric genes were introduced into E. coli cells producing either RT-Ec67 or RT-Ec73, it was thus found that msDNA was produced only when msr and RT were from the same retron. Requirement of the msr region for msDNA synthesis by RT was further investigated by mutations in the msr region for retron-Ec67. These analyses revealed that there is a strict requirement for specific primary sequences as well as the secondary structure in msdRNA. This finding is discussed in relationship to the mechanism of the priming reaction of cDNA synthesis by eukaryotic retroviral RTs using tRNAs.
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Affiliation(s)
- T Shimamoto
- Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Rutgers, Piscataway 08854
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24
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Hsu MY, Eagle SG, Inouye M, Inouye S. Cell-free synthesis of the branched RNA-linked msDNA from retron-Ec67 of Escherichia coli. J Biol Chem 1992; 267:13823-9. [PMID: 1378431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
msDNA-Ec67 is produced in a clinical strain of Escherichia coli and composed of a 67-base single-stranded DNA, which is linked to the 2'-OH group of the 15th rG residue of a 58-base RNA molecule by a 2',5'-phosphodiester linkage (Lampson, B. C., Sun, J., Hsu, M.-Y., Vallejo-Ramirez, J., Inouye, S., and Inouye, M. (1989) Science 243, 1033-1038). The production of msDNA-Ec67 is dependent upon retron-Ec67, which consists of the msr-msd region and the gene for reverse transcriptase (RT). These two elements were separately cloned into plasmids; p67-BHO.6 contained the msr-msd region and pRT-67 contained the RT gene under the lpp-lac promoter-operator. msDNA-Ec67 was produced only when cells were transformed with both plasmids. In addition, msDNA-Ec67 was synthesized in a cell-free system using total RNA prepared from cells harboring plasmid p67-BHO.6 and purified Ec67-RT. Using this cell-free system, the priming reaction, during initiation of DNA synthesis, was demonstrated to be a specific template-directed event; only dTTP was incorporated into a 132-base precursor RNA yielding a 133-base compound. This specific dT addition could be altered to dA or dC by simply substituting the 118th A residue of the putative msr-msd transcript with a T or G residue. The priming reaction was blocked when A was substituted for G at the 15th residue of the precursor RNA transcript, which corresponds to the branched rG residue in msDNA. DNA chain elongation could be terminated by adding ddNTP in the cell-free system, forming a sequence ladder. The DNA sequence determined from this ladder completely agreed with the msDNA sequence. The RT extension reaction was completely blocked when the RNA preparation was treated with RNase A but not when the preparation was treated with DNase. This clearly demonstrates that RNA but not DNA is responsible for the msDNA production. A part of the fully extended cell-free product contained a 13-base RNA strand resistant to RNase A, which is consistent with the previously proposed model. In this model, the 5'-end sequence of the msr-msd transcript (a2; bases 1-13) forms a duplex with the 3'-end sequence (a1) of the same transcript, thus serving as a primer, as well as a template for msDNA synthesis by RT. Our results are inconsistent with a model recently proposed by Lease and Yee (Lease, R. A., and Yee, T. (1991) J. Biol. Chem. 266, 14497-14503).
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MESH Headings
- Base Sequence
- Cell-Free System
- DNA, Bacterial/genetics
- DNA, Single-Stranded/biosynthesis
- DNA, Single-Stranded/genetics
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Genes, Bacterial
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Nucleic Acid Conformation
- Oligodeoxyribonucleotides
- Operon
- Plasmids
- Promoter Regions, Genetic
- RNA, Bacterial/biosynthesis
- RNA, Bacterial/genetics
- RNA, Bacterial/isolation & purification
- Restriction Mapping
- Transcription, Genetic
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Affiliation(s)
- M Y Hsu
- Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway 08854
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25
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Hsu MY, Xu C, Inouye M, Inouye S. Similarity between the Myxococcus xanthus and Stigmatella aurantiaca reverse transcriptase genes associated with multicopy, single-stranded DNA. J Bacteriol 1992; 174:2384-7. [PMID: 1372604 PMCID: PMC205862 DOI: 10.1128/jb.174.7.2384-2387.1992] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To determine the evolutional relationship of bacterial retroelements of Myxococcus xanthus and Stigmatella aurantiaca, the nucleotide sequence of 3,060 bases encompassing msr, msd, and the upstream region of msd (downstream of msr) of S. aurantiaca DW4 was determined and compared with the same region from M. xanthus. An open reading frame was found 92 bases upstream of msd which encoded a polypeptide of 480 amino acid residues having 73% identity with the reverse transcriptase of M. xanthus. Together with high homologies in msr (86%) and msd (81%) regions, the present data indicate that the reverse transcriptase genes as well as the retrons of M. xanthus (retron-Mx162) and S. aurantiaca (retron-Sa163) were derived from a common progenitor retron which possibly before the two myxobacterial species diverged.
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Affiliation(s)
- M Y Hsu
- Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Rutgers, Piscataway 08854
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26
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Hsu MY, Inouye M, Inouye S. Retron for the 67-base multicopy single-stranded DNA from Escherichia coli: a potential transposable element encoding both reverse transcriptase and Dam methylase functions. Proc Natl Acad Sci U S A 1990; 87:9454-8. [PMID: 1701261 PMCID: PMC55184 DOI: 10.1073/pnas.87.23.9454] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The region (retron-Ec67) required for the biosynthesis of a branched-RNA-linked multicopy single-stranded DNA (msDNA-Ec67) from a clinical isolate of Escherichia coli was mapped at a position equivalent to 19 min on the K-12 chromosome. The element containing the retron consisted of a unique 34-kilobase sequence that was flanked by direct repeats of a 26-base-pair sequence found in the K-12 chromosomal DNA. This suggests that the 34-kilobase element was probably integrated into the E. coli genome by a mechanism related to transposition or phage integration. In the 34-kilobase sequence an open reading frame of 285 residues was found, which displays 44% sequence identity with the E. coli Dam methylase. Interestingly, there are three GATC sequences, the site of Dam methylation, in the promoter region of the gene for reverse transcriptase.
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Affiliation(s)
- M Y Hsu
- Department of Biochemistry, Robert Wood Johnson Medical School, Rutgers, University of Medicine and Dentistry of New Jersey, Piscataway 08854
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27
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Hata R, Bessem C, Bringas P, Hsu MY, Slavkin HC. Epidermal growth factor regulates gene expression of both epithelial and mesenchymal cells in mouse molar tooth organs in culture. Cell Biol Int Rep 1990; 14:509-19. [PMID: 2369760 DOI: 10.1016/0309-1651(90)91178-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Epidermal growth factor and cis-hydroxyproline specifically inhibited synthesis of type 1 collagen, a major gene product of the differentiated dental mesenchymal cells (odontoblasts). In tandem, synthesis of enamel proteins, specific gene products of differentiated dental epithelial cells (ameloblasts), was also inhibited. Under these culture conditions, total protein synthesis in tooth organs was not inhibited but rather increased. Inhibition curves of the gene products specific for epithelial and mesenchymal phenotypes were quite similar, indicating coordinate and intimately associated regulation of gene expression under conditions that perturb cytodifferentiation.
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Affiliation(s)
- R Hata
- Department of Tissue Physiology, Tokyo Medical and Dental University, Japan
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28
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Shapshak P, Sun NC, Resnick L, Hsu MY, Tourtellotte WW, Schmid P, Conrad A, Fiala M, Imagawa DT. The detection of HIV by in situ hybridization. Mod Pathol 1990; 3:146-53. [PMID: 2183211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A simplified method of in situ hybridization is described for the detection of HIV targets. This standardized method can be applied to sections of formalin-fixed paraffin-embedded tissues, cell blocks, and smears of cultured cells using 3H- or 35S-labeled DNA and 35S-labeled RNA probes. In order to use elevated stringencies in the hybridization and wash steps, tissue sections and cells are covalently bonded to silanated glass slides without their subsequent loss from the slides. Routine hematoxylin and eosin or Romanovsky's stains enable the identification of the cells detected by in situ hybridization. HIV-infected neuroblastoma and lymphoid cell lines, lymph nodes, bone marrow, kidney, as well as brain tissue from patients with acquired immunodeficiency syndrome (AIDS) and AIDS-related complex are used to demonstrate the generality of the procedure. The standardized method described widens the ease and applicability of in situ hybridization in the investigation of pathologic tissues with the use of diverse specimens and probes.
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Affiliation(s)
- P Shapshak
- Pearlman Research Center, Mount Sinai Medical Center, Miami Beach, Florida
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29
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Sun NC, Shapshak P, Lachant NA, Hsu MY, Sieger L, Schmid P, Beall G, Imagawa DT. Bone marrow examination in patients with AIDS and AIDS-related complex (ARC). Morphologic and in situ hybridization studies. Am J Clin Pathol 1989; 92:589-94. [PMID: 2816812 DOI: 10.1093/ajcp/92.5.589] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Bone marrow examinations were performed on 20 patients with acquired immune deficiency syndrome (AIDS) and 39 with AIDS-related complex (ARC). Fever of unknown origin and thrombocytopenia were common in ARC, but anemia and leukopenia were most frequent in AIDS. Changes in stromal cells and perivascular cuffing of plasma cells were found significantly more often in patients with AIDS than in those with ARC. Malignancies were common in both groups. Human immunodeficiency virus (HIV) nucleic acids were detected with the use of a 3H-labeled cDNA probe with an in situ hybridization method in 11 bone marrow samples (three ARC and eight AIDS). Most commonly positive cells were mononucleated, resembling lymphocytes and histiocytes. Endothelial cells, interdigitating reticulum cells, nucleated red blood cells, and immature myeloid cells also had positive results in some instances. The number of HIV-positive cells was not related to the size of the bone biopsies or the clinical diagnoses. The authors postulate that changes in the peripheral blood and bone marrow of these patients may be related to latent persistent infection with HIV.
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Affiliation(s)
- N C Sun
- Department of Pathology, Harbor-UCLA Medical Center, Torrance, California 90509
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30
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Hsu MY, Inouye S, Inouye M. Structural requirements of the RNA precursor for the biosynthesis of the branched RNA-linked multicopy single-stranded DNA of Myxococcus xanthus. J Biol Chem 1989; 264:6214-9. [PMID: 2467910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
A precursor RNA molecule (pre-msdRNA) of approximately 375 bases is considered to form a stable secondary structure which serves as a primer as well as a template to synthesize the branched RNA-linked multicopy single-stranded DNA (msDNA) of Myxococcus xanthus. When 3-base mismatches were introduced into the stem structure immediately upstream of the branched rG residue to which msDNA is linked by a 2',5'-phosphodiester linkage, the production of msDNA was almost completely blocked. However, if additional 3-base substitutions were made on the other strand to resume the complementary base pairing, msDNA production was restored, being consistent with the proposed model of msDNA synthesis. We also found that the branched rG residue of pre-msdRNA could not be replaced with either rC or rA, while the 5' end (dC) of msDNA which is linked to the branched rG could be substituted with a dG residue. Together with several other mutations, the structural requirements of pre-msdRNA are discussed with respect to the mechanism of msDNA biosynthesis.
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Affiliation(s)
- M Y Hsu
- Department of Biochemistry, Robert Wood Johnson Medical School at Rutgers, University of Medicine and Dentistry of New Jersey, Piscataway 08854
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31
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Hsu MY, Inouye S, Inouye M. Structural Requirements of the RNA Precursor for the Biosynthesis of the Branched RNA-linked Multicopy Single-stranded DNA of Myxococcus xanthus. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)83336-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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32
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Chin CJ, Leung W, Chen YP, Hsu MY, Lin FJ. [Clinical evaluation of aggressive nutritional care to head and neck cancer patients during radiation therapy]. Changgeng Yi Xue Za Zhi 1989; 12:37-44. [PMID: 2505913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Anorexia, dysphagia, and dysgeusia are the most prevalent symptoms in head and neck cancer patients during radiation therapy. The patients, who were in poor general condition, suffered marked loss of body weight and consequently were unable to tolerate further anti-cancer treatments. Aggressive nutritional support to the head and neck cancer patients was started in April, 1986 to improve the general condition of these patients in our hospital. The physiological condition of 152 patients who underwent nutritional support were evaluated as a study group (Group I) between August 1986 and May 1987. Group II, 165 patients without nutritional care were evaluated as a control group between August 1985 and May 1986. In Group I, oral supplementary diets or enteral feedings were provided as nutritional support to all of the anorectic patients. Anthropometric measurement and laboratory data were collected in both groups at the several time points. An average of 1.1 kilogram (Kg) and 3.5Kg body weight loss was observed in Group I and Group II, respectively (P less than 0.005). In patients diagnosed with nasopharyngeal carcinoma, the average duration of radiation treatment was 11 days shorter in Group I than that in Group II (42 vs 53 days). In conclusion, aggressive nutritional care performed by a group of clinical staff, which included doctors (radiation oncologist), dietitians and oncologic nurses, was sufficient to improve the general condition of the head and neck cancer patients during radiation therapy and to therefore increase the recovery rate of these patients after radiation treatments.(ABSTRACT TRUNCATED AT 250 WORDS)
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33
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Lampson BC, Sun J, Hsu MY, Vallejo-Ramirez J, Inouye S, Inouye M. Reverse transcriptase in a clinical strain of Escherichia coli: production of branched RNA-linked msDNA. Science 1989; 243:1033-8. [PMID: 2466332 DOI: 10.1126/science.2466332] [Citation(s) in RCA: 92] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Branched RNA-linked multicopy single-stranded DNA (msDNA) originally detected in myxobacteria has now been found in a clinical isolate of Escherichia coli. Although lacking homology in the primary structure, the E. coli msDNA is similar in secondary structure to the myxobacterial msDNA's, including the 2',5'-phosphodiester linkage between RNA and DNA. A chromosomal DNA fragment responsible for the production of msDNA was cloned in an E. coli K12 strain; its DNA sequence revealed an open reading frame (ORF) of 586 amino acid residues. The ORF shows sequence similarity with retroviral reverse transcriptases and ribonuclease H. Disruption of the ORF blocked msDNA production, indicating that this gene is essential for msDNA synthesis.
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MESH Headings
- Amino Acid Sequence
- Base Sequence
- Cloning, Molecular
- DNA Probes
- DNA Restriction Enzymes
- DNA, Bacterial/genetics
- DNA, Single-Stranded/analysis
- DNA, Single-Stranded/biosynthesis
- DNA, Single-Stranded/genetics
- Endoribonucleases/genetics
- Escherichia coli/enzymology
- Escherichia coli/genetics
- Genes, Bacterial
- HIV/enzymology
- HIV/genetics
- Human T-lymphotropic virus 1/enzymology
- Human T-lymphotropic virus 1/genetics
- Molecular Sequence Data
- Myxococcales/genetics
- Nucleic Acid Hybridization
- RNA, Bacterial/analysis
- RNA, Bacterial/biosynthesis
- RNA, Bacterial/genetics
- RNA-Directed DNA Polymerase/genetics
- Retroviridae/enzymology
- Retroviridae/genetics
- Ribonuclease H
- Sequence Homology, Nucleic Acid
- Transformation, Bacterial
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Affiliation(s)
- B C Lampson
- Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway 08854
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Abstract
Myxobacteria have been shown to produce a peculiar RNA-DNA complex called msDNA, in which a single-stranded DNA is branched out from a RNA molecule (msdRNA) by a 2',5' phosphodiester linkage. It has been predicted that reverse transcriptase is required for msDNA biosynthesis. We identified a gene for reverse transcriptase in M. xanthus in the region that has been demonstrated to code for a cis- or transacting element for msDNA synthesis. This gene is located immediately downstream of the msdRNA coding region, and codes for a polypeptide of 485 amino acid residues. The polypeptide shows sequence similarity with retroviral reverse transcriptases. This fact, together with the mode of msDNA synthesis, suggests a possible relationship between retroviruses and the msDNA system. The analysis of the gene and the distribution of the msDNA system in independent isolates of M. xanthus indicate that the element is as old as other essential genes in M. xanthus and that it was not recently acquired into the genome.
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Affiliation(s)
- S Inouye
- Department of Biochemistry, Robert Wood Johnson Medical School at Rutgers University of Medicine and Dentistry of New Jersey, Piscataway 08854
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Slavkin HC, Bringas P, Bessem C, Santos V, Nakamura M, Hsu MY, Snead ML, Zeichner-David M, Fincham AG. Hertwig's epithelial root sheath differentiation and initial cementum and bone formation during long-term organ culture of mouse mandibular first molars using serumless, chemically-defined medium. J Periodontal Res 1989; 24:28-40. [PMID: 2524567 DOI: 10.1111/j.1600-0765.1989.tb00854.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Studies were designed to test the hypothesis that Hertwig's epithelial root sheath (HERS) synthesizes and secretes enamel-related proteins that participate in the process of acellular cementum formation. Our experimental strategy was to examine sequential root development of the mouse mandibular first molar in vivo and in long-term organ culture in vitro using serumless, chemically-defined medium. Using anti-amelogenin, anti-enamelin and anti-peptide antibodies, enamel-related antigens were localized within intermediate cementum during HERS differentiation and root formation in vivo. Cap stage molars maintained for periods of up to 31 days in organ culture expressed morphogenesis and cytodifferentiation as identified by tooth crown and initial root, cementum and bone formation. Metabolically-labeled HERS products were analyzed by immunodetection using enamel-related antibodies and one- and two-dimensional SDS gel electrophoresis. A 72 kDa and 26 kDa polypeptide were identified in forming mouse cementum. Both of these root putative cementum proteins yield similar (identical) amino acid compositions; however, both proteins differed from the compositions of either mouse crown enamelin or amelogenin proteins. This approach provides a new and novel in vitro model towards understanding HERS differentiation and functions related to root and bone formation. The data support the hypothesis that HERS cells synthesize polypeptides related to but also different from canonical crown enamel proteins.
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Abstract
We have previously reported that the expression of the wheat Cab-1 gene is subject to phytochrome regulation and a 1.8-kb 5' upstream sequence of this gene is sufficient for the regulated expression. To delineate sequences for the phytochrome response we analyzed a series of 5' deletion mutants as well as chimeric gene constructs comprising different sequences of the Cab-1 upstream region in transgenic tobacco seedlings. We found that a deletion mutant containing a 357-bp 5' upstream sequence still exhibits maximal levels of phytochrome-regulated expression. A 268-bp enhancer-like element, located between -89 and -357, is responsible for the phytochrome response of the Cab-1 gene; sequences upstream from -357 to -843 and downstream from -124 to +1100 are probably not involved. Finally, we show that the Cab-1 mRNA stability is not regulated by phytochrome.
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Affiliation(s)
- F Nagy
- Laboratory of Plant Molecular Biology, Rockefeller University, New York, NY 10021-6399
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Hsu MY, Davis C, Jaskoll TF, Zeineh RA, Unakar NJ, Bekhor I. Crystallin mRNA product levels in lens undergoing reversal and inhibition of galactose cataracts. Invest Ophthalmol Vis Sci 1987; 28:1413-21. [PMID: 3610556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
In our previous work, two-dimensional gel electrophoretic analysis of the translational products from mRNA of lens from rats maintained on 50% galactose up to 45 days has suggested that synthesis of mRNA was not arrested by the disease process, but it decreased significantly relative to the control. The loss in mRNA number was due mainly to loss in cell population. Specifically, the gamma-crystallin mRNA product decreased to very low levels at onset of the disease. However, this mRNA was resynthesized in the surviving cells as the cataracts matured. Therefore, it became of interest to explore whether reversal or inhibition of cataracts would lead to some measurable changes in mRNA population in the experimental lens. The results show that the percentage (relative to the total mRNA population) of the in vitro [35S]-labeled translational products from alpha-, beta- and gamma-crystallin mRNAs combined, remained unchanged irrespective of the state of the lens. The severity of the cataracts was examined by indirect immunofluorescence with polyclonal MP26 antibody. Reversal of cataracts led to partial recovery of normal fiber cell morphology. Treatment with sorbinil in combination with galactose led to inhibition of cataracts with indication of appearance of vacuoles at longer periods of exposure to the drug. The translational products profile reflected the expected variation in non-crystallin and crystallin mRNA synthesis. It is concluded that there appears to be a combined fixed level of synthesis for the crystallins, such that inhibition in synthesis of gamma-crystallin mRNAs appears to lead to an increase in synthesis of alpha-crystallin mRNAs, while synthesis of beta-crystallin mRNAs showed insignificant fluctuation. A similar conclusion may also be drawn relative to the combined synthesis for the non-crystallin mRNAs.
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Cross JH, Hsu MY. Development of Brugia malayi in Mongolian gerbils previously exposed to Wuchereria bancrofti. Southeast Asian J Trop Med Public Health 1987; 18:183-5. [PMID: 3313736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Twelve Mongolian gerbils, Meriones unguiculatus, were infected with 100 third-stage larvae of Wuchereria bancrofti. One month later these animals, along with 4 control animals, were given 100 third-stage larvae of Brugia malayi. Eleven of the 12 experimental animals and the 4 controls survived, and 8 of the experimental animals and all of the controls demonstrated microfilaremia after 3 months. The animals were killed at 6-months post-infection and examined for parasites. One W. bancrofti larva was found in one of the experimental animals, and 15% of the B. malayi given were recovered as adults from the testes, viscera, and carcass. Thirty-eight percent of the worms given to the controls were recovered from the testes, viscera, and pelt. The worms from the experimental animals also appeared to be smaller. This study suggests that gerbils are able to develop partial resistance to Brugia malayi following a previous infection with Wuchereria bancrofti.
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Affiliation(s)
- J H Cross
- U.S. Naval Medical Research Unit No. 2, Manila, Philippines
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Hsu MY, Jaskoll TF, Unakar NJ, Bekhor I. Survival of fiber cells and fiber-cell messenger RNA in lens of rats maintained on a 50% galactose diet for 45 days. Exp Eye Res 1987; 44:577-86. [PMID: 3297752 DOI: 10.1016/s0014-4835(87)80165-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Previous work from this laboratory has shown that in cataractous lens from rats fed a 50% galactose diet up to 32 days, synthesis of crystallin mRNAs was reduced while synthesis of mRNAs for the non-crystallin proteins appeared to be maintained at equivalent or higher levels than found in the controls. In this study, we find that the population of mRNA from the 45-day cataractous lens included all of the crystallin mRNAs and substantial amounts of mRNAs for the non-crystallin proteins, in particular those proteins of molecular weights ranging from 45,000 to 92,000, and pIs from 5.5 to 7.0. At the 45-day cataractous stage, the observed mRNA products totaled between 100 and 120, while for the control they numbered between 40 and 50. In addition, hybrid-select measurements with a lambda gt11 MP26 clone established that MP26 mRNA persisted in the fiber cells of 11-, 20-, 32- and 45-day galactosemic lens. The data, therefore, suggest that continuous exposure of the lens to galactose apparently leads to significant fluctuations in mRNA synthesis and survival. Indirect immunofluorescence (with a monospecific polyclonal rabbit anti-MP26 antibody) and light-microscopy studies demonstrated that although the cortical fiber cells were swollen and structurally disoriented, they retained their nuclei, while the enucleated fiber cells were absent. The microscopy data also suggest that differentiation of the epithelial cells to fiber cells continued in the cataractous lens. Fiber-cell migration was backward as compared with the control, and the surviving cells were localized within the cortex and appeared to be surrounded by damaged cells or cell debris. It is suggested that persistent fiber-cell survival, and continued synthesis of various classes of mRNA by the nucleated cells in the cataractous lens could explain why reversal of cataracts results in recovery in both cell morphology and transparency in the non-nuclear portion of the lens.
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Abstract
We have monitored changes in the chlorophyll a/b-binding protein (Cab) mRNA levels in etiolated wheat leaves exposed to light of different wavelengths by Northern blot hybridizations and 5' S1 nuclease protection assays. Accumulation of the Cab mRNA and the specific Cab-1 transcript is regulated by phytochrome. Transcript levels are elevated by red light and the red enhancement can be partially reversed by far-red light. Moreover, far-red light alone can elicit a small increase in the transcript levels. These characteristic features of the wheat Cab-1 phytochrome response can be recapitulated in etiolated seedlings of transgenic tobacco containing the Cab-1 gene. Analyses of a chimeric construct revealed that a 1.8-kb 5'-flanking fragment (-1816 to +31) of the Cab-1 gene can confer phytochrome response as well as leaf-specific expression on a heterologous coding sequence.
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Affiliation(s)
- F Nagy
- Rockefeller University, Laboratory of Plant Molecular Biology, 1230 York Avenue, New York, NY 1021-6399, USA
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41
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Cross JH, Hsu MY, Lu SK. Hybridization between Brugia malayi and Brugia pahangi from south Kalimantan, Indonesia. Southeast Asian J Trop Med Public Health 1984; 15:190-3. [PMID: 6505786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Hybridization experiments were carried out between sub-periodic Brugia malayi and B. pahangi recovered from cats originating from the same area in South Kalimantan (Borneo), Indonesia. Five to six week-old immature males and females of both species from Mongolian gerbil (Meriones unguiculatus) intraperitoneal infections were inoculated into the peritoneal cavity of other gerbils. Mating occurred between the species and microfilariae developed into infective third-stage larvae in mosquitoes. Larvae from the mosquitoes developed into adults in the peritoneal cavity of gerbils but microfilariae were not produced since the males were sterile. Back-crossing between hybrids and males and females of the parental species were also done and female hybrids produced microfilariae when crossed with parental males but females from the parental species did not produce microfilariae when mated with the hybrid males. This confirmed that the males were sterile but the females were not. If these species are hybridized in nature and humans are exposed to hybrid third-stage larvae, could this lead to occult filarial infection? These results confirmed previous hybridization experiments of these species orginating from other geographic areas.
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Cross JH, Hsu MY, Hung CK. Studies on trypanosomes in the Taiwan monkey. Southeast Asian J Trop Med Public Health 1983; 14:536-42. [PMID: 6673131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Fifty-three or 9% of 594 Taiwan monkeys, Macaca cyclopis, were found infected with a Trypanosome species. The parasites were recovered from monkey blood in diaphasic blood-agar culture medium with a Locke's solution overlay. Trypanosomes were found on only a few thick blood smears and no dividing or multiplying forms were found. Some of the organisms had a free-flagellum (4.7 microns), an undulating membrane and both ends of the body were pointed. The total length averaged 41.7 microns; nucleus was slightly anteriorly located. Blood from culture positive monkey would not infect monkeys or other animals, but cultured parasites readily infected monkeys and one mouse, and one rat treated with cortisone. Triatoma rubrofasciata and Triatoma protracta fed upon culture-positive monkeys did not become infected but one of the former became infected after membrane feeding upon cultured parasites mixed with monkey blood. Studies were also done on the development of Trypanosome conorhini in monkeys and other animals. The parasite was recovered from the hind-and mid-gut of naturally infected Taiwan Triatoma rubrofasciata (109 of 117). Some bugs also had salivary gland infections. Most laboratory animals (rats, mice, Mongolian gerbils, guinea pigs, rabbits) developed infections detected by blood-smear and culture. The parasite was serially passaged through monkeys and bugs monthly for one year but there was no change in the development pattern. Only trypmastigotes were present in blood smears; no dividing forms were found. Triatoma rubrofasciata and Triatoma protracta readily developed gut infections when fed upon monkeys, but only a few Rhodnius prolixus became infected.(ABSTRACT TRUNCATED AT 250 WORDS)
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Cross JH, Partono F, Hsu MY, Ash LR, Oemijati S. Further studies on the development of Wuchereria bancrofti in laboratory animals. Southeast Asian J Trop Med Public Health 1981; 12:114-22. [PMID: 7020095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
In an attempt to obtain a small animal laboratory model for Wuchereria bancrofti Mongolian gerbils and hamsters were infected with third-stage larvae of strains of the parasite from Indonesia and China. Gerbils were necropsied at 7 to 591 days and larvae recovered up to 219 days. The third molt occurred on or before 10 days and worms found after 14 days were in the fourth stage. More worms were recovered early in the infection (7 to 30 days) than in older infections. The worms were usually recovered from the testes, pelt and carcass and heart and lungs. An adult male worm was recovered on one occasion from the lung of a gerbil at 92 days. The parasite was also found to develop in hamsters with results similar to those in gerbils. Gerbils and hamsters were given antithymocyte sera before and after infection and more worms were recovered and the worms larger in size in some treated animals. Continued studies with geographic strains of W. bancrofti in various animals should be encouraged in order to find a small laboratory animal model for the parasite.
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44
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Abstract
Abstract
We describe here a simple, rapid chromatographic procedure for quantitatively separating serum creatine kinase isoenzymes (EC 2.7.3.2), with diethylaminoethyl (DEAE)-Sepharose CL-6B as the anion-exchanger. We established the column bed height and the elution parameters by use of a simplex procedure. DEAE-Sepharose CL-6B equilibrated in tris(hydroxymethyl)aminomethane (50 mmol/L, pH 7.5, and containing 30 mmol of NaCl per liter) is packed into a miniature polystyrene column with bed dimensions of 0.7 x 1.5 cm. The DEAE-Sepharose column system was evaluated and compared with a DEAE-Sephadex A-50 column system. The results indicate that the Sepharose column yields MM, MB, and BB isoenzymes uniquely, without cross contamination. Coefficients of variation (CV’s) for 10 replicate column assays were 2.8, 5.9, and 15.2% for 569 U of MM per liter, 82.3 U of MB per liter, and 9.0 U of BB per liter, respectively. The serum sample was enriched with baboon heart extract. Day-to-day reproducibility for a serum control assayed on 10 days yielded CV’s of 4.6, 9.9, and 40.3% for 391, 45.3 and 1.9 U of isoenzymes MM, MB, and BB per liter, respectively. A reference interval for each isoenzymes was derived from data on 81 men and 63 women.
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Bondar RJ, Shevchik DG, Hsu MY, Kohler MM. Improved separation of creatine kinase isoenzymes by use of DEAE-Sepharose Cl-6B. Clin Chem 1980; 26:618-24. [PMID: 7261307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
We describe here a simple, rapid chromatographic procedure for quantitatively separating serum creatine kinase isoenzymes (EC 2.7.3.2), with diethylaminoethyl (DEAE)-Sepharose CL-6B as the anion-exchanger. We established the column bed height and the elution parameters by use of a simplex procedure. DEAE-Sepharose CL-6B equilibrated in tris(hydroxymethyl)aminomethane (50 mmol/L, pH 7.5, and containing 30 mmol of NaCl per liter) is packed into a miniature polystyrene column with bed dimensions of 0.7 x 1.5 cm. The DEAE-Sepharose column system was evaluated and compared with a DEAE-Sephadex A-50 column system. The results indicate that the Sepharose column yields MM, MB, and BB isoenzymes uniquely, without cross contamination. Coefficients of variation (CV's) for 10 replicate column assays were 2.8, 5.9, and 15.2% for 569 U of MM per liter, 82.3 U of MB per liter, and 9.0 U of BB per liter, respectively. The serum sample was enriched with baboon heart extract. Day-to-day reproducibility for a serum control assayed on 10 days yielded CV's of 4.6, 9.9, and 40.3% for 391, 45.3 and 1.9 U of isoenzymes MM, MB, and BB per liter, respectively. A reference interval for each isoenzymes was derived from data on 81 men and 63 women.
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Bondar RJ, Shevchik DG, Hsu MY, Kohler MM. Improved separation of creatine kinase isoenzymes by use of DEAE-Sepharose Cl-6B. Clin Chem 1980. [DOI: 10.1093/clinchem/26.5.0618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
We describe here a simple, rapid chromatographic procedure for quantitatively separating serum creatine kinase isoenzymes (EC 2.7.3.2), with diethylaminoethyl (DEAE)-Sepharose CL-6B as the anion-exchanger. We established the column bed height and the elution parameters by use of a simplex procedure. DEAE-Sepharose CL-6B equilibrated in tris(hydroxymethyl)aminomethane (50 mmol/L, pH 7.5, and containing 30 mmol of NaCl per liter) is packed into a miniature polystyrene column with bed dimensions of 0.7 x 1.5 cm. The DEAE-Sepharose column system was evaluated and compared with a DEAE-Sephadex A-50 column system. The results indicate that the Sepharose column yields MM, MB, and BB isoenzymes uniquely, without cross contamination. Coefficients of variation (CV’s) for 10 replicate column assays were 2.8, 5.9, and 15.2% for 569 U of MM per liter, 82.3 U of MB per liter, and 9.0 U of BB per liter, respectively. The serum sample was enriched with baboon heart extract. Day-to-day reproducibility for a serum control assayed on 10 days yielded CV’s of 4.6, 9.9, and 40.3% for 391, 45.3 and 1.9 U of isoenzymes MM, MB, and BB per liter, respectively. A reference interval for each isoenzymes was derived from data on 81 men and 63 women.
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Abstract
Brugia malayi and B. Pahangi microfilariae from gerbil intraperitoneal infections were inoculated into the thorax of male and female Toxorhynchites amboinesis and developed into third-stage larvae as early as 11 days. In a comparative study with Aedes togoi fed on microfilaremic gerbils, third-stage larvae were found at 10 days. Some third-stage larvae of B. malayi inoculated into gerbils developed to advanced stages. Third-stage larvae of Wuchereria bancrofti were recovered in low numbers from Tx. amboinesis and Tx. aurifluus inoculated with microfilariae recovered from human blood by membrane filtration. Development of all filarial species was similar in both male and female mosquitoes. Toxorhynchites species are plant feeders and therefore reduce the hazards of laboratory transmission of pathogenic agents. Because of their large size, manipulations with this mosquito species are easy and the size allows for a larger inoculum to be used. This group of mosquitoes should develop into useful laboratory vectors for the transmission of arthropod-borne diseases.
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Hsu MY, Kohler MM, Barolia L, Bondar RJ. Separation of five isoenzymes of serum lactate dehydrogenase by discontinuous gradient elution from a miniature ion-exchange column. Clin Chem 1979; 25:1453-8. [PMID: 455684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We describe a simple, fast chromatographic technique for quantitatively separating the five isoenzymes of lactate dehydrogenase (LD; EC 1.1.1.27) in serum. A 250-microL serum sample is applied to a 6.0 x 0.7 cm column of QAE-Sephadex A-50 and eluted stepwise with five different buffers. The isoenzyme fractions, assayed by the method of Wroblewski and LaDue [Proc. Soc. Exp. Biol, Med. 90, 210 (1955)], are stable at room temperature for 24 h. For all five isoenzymes the average within-day coefficient of variation is 4.3%; the day-to-day CV for 20 days is 6.3%. Of some common potentially interfering substances tested, only sodium fluoride (238 mmol/L) was found to do so, by slowing the elution from the column and making the fractions turbid. The expected range in international (IUB) united and percent for each isoenzyme was determined from data on 73 men and 70 women. From these data we calculate, by a percentile estimate of a nongaussian distribution, a normal range of LD-1/LD-2 ratio of 0.55--0.87 for men and 0.52--0.91 for women. The LD isoenzyme patterns in both normal and above-normal samples of 147 sera, as evaluated by the present column method and by electrophoresis, correlated well.
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Hsu MY, Kohler MM, Barolia L, Bondar RJ. Separation of five isoenzymes of serum lactate dehydrogenase by discontinuous gradient elution from a miniature ion-exchange column. Clin Chem 1979. [DOI: 10.1093/clinchem/25.8.1453] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
We describe a simple, fast chromatographic technique for quantitatively separating the five isoenzymes of lactate dehydrogenase (LD; EC 1.1.1.27) in serum. A 250-microL serum sample is applied to a 6.0 x 0.7 cm column of QAE-Sephadex A-50 and eluted stepwise with five different buffers. The isoenzyme fractions, assayed by the method of Wroblewski and LaDue [Proc. Soc. Exp. Biol, Med. 90, 210 (1955)], are stable at room temperature for 24 h. For all five isoenzymes the average within-day coefficient of variation is 4.3%; the day-to-day CV for 20 days is 6.3%. Of some common potentially interfering substances tested, only sodium fluoride (238 mmol/L) was found to do so, by slowing the elution from the column and making the fractions turbid. The expected range in international (IUB) united and percent for each isoenzyme was determined from data on 73 men and 70 women. From these data we calculate, by a percentile estimate of a nongaussian distribution, a normal range of LD-1/LD-2 ratio of 0.55--0.87 for men and 0.52--0.91 for women. The LD isoenzyme patterns in both normal and above-normal samples of 147 sera, as evaluated by the present column method and by electrophoresis, correlated well.
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50
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Abstract
Infective larvae of Wuchereria bancrofti from laboratory-raised Culex pipiens fatigans and Aedes togoi mosquitoes fed on human volunteers in Jakarta, Indonesia (J strain) and Kinmen Island, China (K strain) were introduced into Taiwan monkeys (Macaca cyclopis) by subcutaneous inoculation, by foot puncture, or by permitting infected mosquitoes to feed weekly on the monkeys. Some animals were splenectomized and others were treated with varying regimens of immunosuppressants. Necropsy was done on monkeys that died or were killed and the entire bodies were examined for worms. A total of 78 monkeys (43 males and 35 females) were exposed to infection and parasites were found in 29% of the females and 63% of males. In infections of 38 days or less worms were recovered from the testes of males and the pelt, carcass and lymph nodes of both sexes, but after 42 days of infection most worms were in the testes of males, and a few were recovered from lymph nodes and carcasses of females. Worms recovered at 8-11 days were third-stage, those found between 14 and 38 days fourth-stage, and ones found between 42 and 103 days were young adults. After 148 days most were adults and microfilariae were seen in the uteri of female worms at 160 days and later. The parasites continued to grow in size with time. Microfilariae were detected in the blood of nine monkeys between 8 and 18 months and the patent period varied from 5-21 months. Microfilarial densities were low and erratic, and periodicity could not be determined. The effectiveness of methods of administering infections and the value of various treatment regimens seem uncertain; monkey antilymphocytic sera, however, appeared to have some influence. Parasites were found in 36% of the Taiwan monkeys given the J strain and 54% of those given the K strain. A limited number of M. mulatta (3), M.irus (fascicularis) (3) and Aotus trivirgatus (4) were also given infective larvae and adult W. bancrofti were recovered from the testes of one male M. mulatta and one male M. irus; uterine microfilariae were found in one female worm from the latter monkey. A. trivirgatus were negative. Low numbers of infective larvae recovered from mosquitoes fed on patent monkeys were introduced intermittently into seven clean monkeys and one became microfilaremic between 11 and 17 months postinoculation.
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