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Wu JE, Dong Y, Liu SY, Peng J, Gao Q, Bian L, Yang Y. [Factors influencing the interpretation of immunohistochemical results in breast cancer with low expression of estrogen receptor]. Zhonghua Bing Li Xue Za Zhi 2024; 53:83-85. [PMID: 38178754 DOI: 10.3760/cma.j.cn112151-20230730-00040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Affiliation(s)
- J E Wu
- Department of Pathology, the First Affiliated Hospital of Kunming Medical University, Kunming 650032, China
| | - Y Dong
- Department of Breast Surgery, the First Affiliated Hospital of Kunming Medical University, Kunming 650032, China
| | - S Y Liu
- Department of Pathology, the First Affiliated Hospital of Kunming Medical University, Kunming 650032, China
| | - J Peng
- Department of Pathology, the First Affiliated Hospital of Kunming Medical University, Kunming 650032, China
| | - Q Gao
- Department of Radiology, the First Affiliated Hospital of Kunming Medical University, Kunming 650032, China
| | - L Bian
- Department of Pathology, the First Affiliated Hospital of Kunming Medical University, Kunming 650032, China
| | - Y Yang
- Department of Pathology, the First Affiliated Hospital of Kunming Medical University, Kunming 650032, China
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2
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Ng TM, Ang LW, Heng ST, Kwa ALH, Wu JE, Seah XFV, Lee SY, Seah J, Choo R, Lim PL, Thoon KC, Chlebicki MP, Somani J, Lee TH, Lye DC. Antibiotic utilisation and resistance over the first decade of nationally funded antimicrobial stewardship programmes in Singapore acute-care hospitals. Antimicrob Resist Infect Control 2023; 12:82. [PMID: 37612738 PMCID: PMC10464409 DOI: 10.1186/s13756-023-01289-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 08/14/2023] [Indexed: 08/25/2023] Open
Abstract
OBJECTIVE The aim of this study was to describe the time series of broad-spectrum antibiotic utilisation and incidence of antibiotic-resistant organisms during the implementation of antimicrobial stewardship programmes (ASP) in Singapore. METHODS An observational study was conducted using data from 2011 to 2020 in seven acute-care public hospitals. We applied joinpoint regressions to investigate changes in antibiotic utilisation rate and incidence density of antibiotic-resistant organisms. RESULTS Across the seven hospitals, quarterly broad-spectrum antibiotic utilisation rate remained stable. Half-yearly incidence density of antibiotic-resistant organisms with two joinpoints at first half (H1) of 2012 and second half (H2) of 2014 decreased significantly in the second and third period with a half-yearly percentage change (HPC) of -2.9% and - 0.5%, respectively. Across the five hospitals with complete data, half-yearly broad-spectrum antibiotic utilisation rate with one joinpoint decreased significantly from H1 of 2011 to H2 of 2018 (HPC - 4.0%) and H2 of 2018 to H2 2020 (HPC - 0.5%). Incidence density of antibiotic-resistant organisms decreased significantly in the two joinpoint periods from H1 of 2012 to H2 of 2014 (HPC - 2.7%) and H2 of 2014 to H2 of 2020 (HPC - 1.0%). Ceftriaxone with one joinpoint decreased significantly from H1 of 2011 to H1 of 2014 (HPC - 6.0%) and H1 of 2014 to H2 of 2020 (HPC - 1.8%) and ceftriaxone-resistant E. coli and K. pneumoniae decreased significantly in later periods, from H2 of 2016 to H2 of 2020 (HPC - 2.5%) and H1 of 2012 to H2 of 2015 (HPC - 4.6%) respectively. Anti-pseudomonal antibiotics with one joinpoint decreased significantly from H1 of 2011 to H2 of 2014 (HPC - 4.5%) and H2 of 2014 to H2 of 2020 (HPC - 0.8%) and that of quinolones with one joinpoint at H1 of 2015 decreased significantly in the first period. C. difficile with one joinpoint increased significantly from H1 of 2011 to H1 of 2015 (HPC 3.9%) and decreased significantly from H1 of 2015 to H2 of 2020 (HPC - 4.9%). CONCLUSIONS In the five hospitals with complete data, decrease in broad-spectrum antibiotic utilisation rate was followed by decrease in incidence density of antibiotic-resistant organisms. ASP should continue to be nationally funded as a key measure to combat antimicrobial resistance in acute care hospitals.
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Affiliation(s)
- Tat Ming Ng
- Tan Tock Seng Hospital, Singapore, Singapore.
| | - Li Wei Ang
- National Centre for Infectious Diseases, Singapore, Singapore
- Ministry of Health, Singapore, Singapore
| | | | - Andrea Lay-Hoon Kwa
- Singapore General Hospital, Singapore, Singapore
- Duke- National University of Singapore Medical School, Singapore, Singapore
| | - Jia En Wu
- National University Hospital, Singapore, Singapore
| | | | | | | | - Robin Choo
- Ng Teng Fong General Hospital, Singapore, Singapore
| | - Poh Lian Lim
- Tan Tock Seng Hospital, Singapore, Singapore
- National Centre for Infectious Diseases, Singapore, Singapore
- Ministry of Health, Singapore, Singapore
| | - Koh Cheng Thoon
- KK Women's and Children's Hospital, Singapore, Singapore
- Duke- National University of Singapore Medical School, Singapore, Singapore
- Lee Kong Chian School of Medicine, Singapore, Singapore
| | | | - Jyoti Somani
- National University Hospital, Singapore, Singapore
- Yong Loo Lin School of Medicine, Singapore, Singapore
| | - Tau Hong Lee
- Tan Tock Seng Hospital, Singapore, Singapore
- National Centre for Infectious Diseases, Singapore, Singapore
| | - David C Lye
- Tan Tock Seng Hospital, Singapore, Singapore
- National Centre for Infectious Diseases, Singapore, Singapore
- Yong Loo Lin School of Medicine, Singapore, Singapore
- Lee Kong Chian School of Medicine, Singapore, Singapore
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3
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Liu K, Stahl WK, Riebman JB, Speakman B, Wu JE, Elayi CS, Deering TF, Catanzaro JN. A new window on subcutaneous ICD system performance: Z-lead impedance change over time in devices with and without extracellular matrix envelope use. Eur Heart J 2022. [DOI: 10.1093/eurheartj/ehac544.720] [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: 11/13/2022] Open
Abstract
Abstract
Background
Device impedance for subcutaneous ICDs (S-ICDs) may rise over time reflecting changes in tissue electrical conduction due to fibrosis from the natural foreign body response, increasing the risk of defibrillation failure. A biologic envelope optimized for S-ICDs may mitigate fibrosis and encourages angiogenesis around the device possibly decreasing impedance rise over time. The S-ICD system performs routine low-voltage Z-lead (LVZ) impedance testing (impedance between shocking coil and can) that may provide insight into the impedance changes on device functionality and efficacy over time.
Purpose
Explore early and late impedance changes over time in S-ICDs implanted with and without envelopes using periodic LVZ measurements.
Methods
30 patients received S-ICDs (15 with envelope) between 1/2017 and 3/2021, after excluding those with device complications, uncontrolled comorbidities, or recent cardiac surgery. Impedance data was recorded at initial implantation. LVZ impedance data was extracted from the wireless remote monitoring system, trended over 0–4 years post implant, and analyzed blinded to patient information.
Results
24 patients (12 envelope) had evaluable implant and chronic data sets. Baseline clinical characteristics were similar between groups. Impedance in general was higher in the envelope group at initial implantation (LVZ mean 89 Ω vs 74 Ω) and throughout the first year. Comparing envelope to no envelope, the initial average shock impedance was 87.3±30.50 vs 66.7±10.40, followed by an average low-V impedance drop of 29 Ω vs 17 Ω during the first month, with a recovery to 109 Ω vs 91 Ω at 30 months post implant. After 30 months, impedance trends demonstrated a modest linear increase up to 48 months in the no envelope group in comparison with a modest decrease in the envelope group (sample sizes too small to determine significance) (Figure 1).
Conclusion
The results demonstrate periodic LVZ testing in the S-ICD monitoring system can reliably trend changes in system impedance over time. Impedance measurements within the first 6–7 months (and most markedly within the first 3 months) appear to be transiently lower than the values seen after this timepoint suggesting that early impedance measurements may not predict steady-state impedance. Further studies are needed to explore the impact of envelope use and the S-ICD impedance changes beyond 30 months.
Funding Acknowledgement
Type of funding sources: None.
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Affiliation(s)
- K Liu
- Shands Jacksonville Medical Center, Inc. , Jacksonville , United States of America
| | - W K Stahl
- Boston Scientific , St. Paul , United States of America
| | - J B Riebman
- Aziyo Biologics , Silver Spring , United States of America
| | - B Speakman
- Boston Scientific , St. Paul , United States of America
| | - J E Wu
- Shands Jacksonville Medical Center, Inc. , Jacksonville , United States of America
| | - C S Elayi
- Saint joseph hospital , Lexington , United States of America
| | - T F Deering
- Piedmont Heart Institute , Atlanta , United States of America
| | - J N Catanzaro
- Shands Jacksonville Medical Center, Inc. , Jacksonville , United States of America
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Chen HH, Chung GWT, Wu JE, Foo GTT, Somani J. Antibiotic stewardship algorithm to rationalise antibiotic use among hospitalised COVID-19 patients. Ann Acad Med Singap 2021; 50:366-368. [PMID: 33990830 DOI: 10.47102/annals-acadmedsg.2020493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Affiliation(s)
- Hui Hiong Chen
- Division of Infectious Diseases, Department of Medicine, National University Hospital, Singapore
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5
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Ho V, Tay F, Wu JE, Lum L, Tambyah P. The Case for Intermittent Carbapenem Dosing in Stable Haemodialysis Patients. Antibiotics (Basel) 2020; 9:antibiotics9110815. [PMID: 33207584 PMCID: PMC7696023 DOI: 10.3390/antibiotics9110815] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 10/27/2020] [Accepted: 11/11/2020] [Indexed: 11/25/2022] Open
Abstract
Purpose: Antimicrobial resistant infections are common in patients on haemodialysis, often needing long courses of carbapenems. This results in a longer hospital stay and risk of iatrogenic complications. However, carbapenems can be given intermittently to allow for earlier discharge. We aim to describe the clinical outcomes of intermittent versus daily meropenem in stable, intermittently haemodialysed patients. Methods: In total, 103 records were examined retrospectively. Data collected include demographics, clinical interventions and outcomes such as hospital length of stay (LOS), 30-day readmission rates and adverse events. Findings: Mean age 61.6 ± 14.2 years, 57.3% male. Most common bacteria cultured were Klebsiella pneumoniae (16.5%). The most common indication was pneumonia (27.2%). Mean duration of therapy on meropenem was 12.4 ± 14.4 days; eight patients needed more than 30 days of meropenem. In total, 55.3% did not have intervention for source control; 86.4% received daily dosing of meropenem; 7.8% patients received intermittent dosing of meropenem only, and 5.8 patients received both types of dosing regimens. LOS of the index admission was shorter for the intermittent arm (15.5 ± 7.6 days versus daily: 30.2 ± 24.5 days), though 30-day readmission was higher (50% versus daily: 38.2%). Implications: We recommend further rigorous randomised controlled trials to investigate the clinical utility of intermittent meropenem dosing in patients on stable haemodialysis.
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Affiliation(s)
- Vanda Ho
- Department of Medicine, National University Hospital, National University Health System, Singapore 119228, Singapore; (L.L.); (P.T.)
- Correspondence: ; Tel.: +65-6779-5555
| | - Felecia Tay
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077, Singapore;
| | - Jia En Wu
- Department of Pharmacy, National University Health System, Singapore 119228, Singapore;
| | - Lionel Lum
- Department of Medicine, National University Hospital, National University Health System, Singapore 119228, Singapore; (L.L.); (P.T.)
| | - Paul Tambyah
- Department of Medicine, National University Hospital, National University Health System, Singapore 119228, Singapore; (L.L.); (P.T.)
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077, Singapore;
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6
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Woo ZF, Chung WT, Wu JE, Chen HH. An evaluation of the intravenous to oral antimicrobial conversion program in the inpatient setting. J Pharm Pract Res 2018. [DOI: 10.1002/jppr.1413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Wei Teng Chung
- Department of Pharmacy National University Hospital Singapore
| | - Jia En Wu
- Department of Pharmacy National University Hospital Singapore
| | - Hui Hiong Chen
- Department of Pharmacy National University Hospital Singapore
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7
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Yeo CL, Wu JE, Chung GWT, Chan DSG, Chen HH, Hsu LY. Antimicrobial stewardship auditing of patients reviewed by infectious diseases physicians in a tertiary university hospital. Antimicrob Resist Infect Control 2013; 2:29. [PMID: 24176042 PMCID: PMC4175095 DOI: 10.1186/2047-2994-2-29] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 10/08/2013] [Indexed: 11/10/2022] Open
Abstract
Background The optimal way for antimicrobial stewardship programs (ASPs) to interact with existing infectious disease physician (IDP) services within the same institution is unknown. In our institution, IDPs and our prospective audit and feedback ASP operate independently, with occasionally differing recommendations offered for the same inpatient. We performed a retrospective audit on inpatients that had been reviewed by both IDPs and ASP within a 7-day period, focusing on cases where different therapy-modifying recommendations had been offered. We analyzed the outcomes in inpatients where the ASP recommendations were accepted and compared these with the inpatients where the IDP recommendations were accepted instead. Outcomes assessed were 30-day mortality post-ASP review, unplanned re-admission within 30 days post-discharge from hospital, and clinical deterioration at 7 days post-ASP review. Findings There were 143 (18.9%) patients where differing recommendations had been offered, with primary physicians accepting 69.9% of ASP recommendations. No significant differences in terms of demographics, clinical characteristics, 30-day mortality, and re-admission rates were observed, although clinical deterioration rates were lower in patients where the ASP recommendation was accepted (8.0% vs. 27.9%; p = 0.002). On multivariate analysis, hematology-oncology inpatients were associated with unplanned readmission. Increasing age and hematology-oncology inpatients were associated with clinical deterioration 7 days post-recommendation, whereas acceptance of ASP recommendations was protective. No characteristic was independently associated with 30-day mortality. Conclusion In conclusion, independent reviews by both IDPs and ASPs can be compatible within large tertiary hospitals, providing primary physicians even in situations of conflicting recommendations viable alternative antimicrobial prescribing advice.
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Affiliation(s)
| | | | | | | | | | - Li Yang Hsu
- Department of Medicine, National University Health System, NUHS Tower Block Level 10, 1E Kent Ridge Road, Singapore 119228, Singapore.
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8
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Chung GW, Wu JE, Yeo CL, Chan D, Hsu LY. Antimicrobial stewardship: a review of prospective audit and feedback systems and an objective evaluation of outcomes. Virulence 2013; 4:151-7. [PMID: 23302793 PMCID: PMC3654615 DOI: 10.4161/viru.21626] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Antimicrobial stewardship is an emerging field currently defined by a series of strategies and interventions aimed toward improving appropriate prescription of antibiotics in humans in all healthcare settings. The ultimate goal is the preservation of current and future antibiotics against the threat of antimicrobial resistance, although improving patient safety and reducing healthcare costs are important concurrent aims. Prospective audit and feedback interventions are probably the most widely practiced of all antimicrobial stewardship strategies. Although labor-intensive, they are more easily accepted by physicians compared with formulary restriction and preauthorization strategies and have a higher potential for educational opportunities. Objective evaluation of antimicrobial stewardship is critical for determining the success of such programs. Nonetheless, there is controversy over which outcomes to measure and there is a pressing need for novel study designs that can objectively assess antimicrobial stewardship interventions despite the limitations inherent in the structure of most such programs.
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Affiliation(s)
- Gladys W Chung
- Department of Pharmacy, National University Health System, Singapore
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9
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Yeo CL, Wu JE, Chung GWT, Chan DSG, Fisher D, Hsu LY. Specialist trainees on rotation cannot replace dedicated consultant clinicians for antimicrobial stewardship of specialty disciplines. Antimicrob Resist Infect Control 2012; 1:36. [PMID: 23157732 PMCID: PMC3546899 DOI: 10.1186/2047-2994-1-36] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 11/16/2012] [Indexed: 11/29/2022] Open
Abstract
Our prospective-audit-and-feedback antimicrobial stewardship (AS) program for hematology and oncology inpatients was switched from one led by dedicated clinicians to a rotating team of infectious diseases trainees in order to provide learning opportunities and attempt a “de-escalation” of specialist input towards a more protocol-driven implementation. However, process indicators including the number of recommendations and recommendation acceptance rates fell significantly during the year, with accompanying increases in broad-spectrum antibiotic prescription. The trends were reversed only upon reverting to the original setup. Dedicated clinicians play a crucial role in AS programs involving immunocompromised patients. Structured training and adequate succession/contingency planning is critical for sustainability.
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Affiliation(s)
- Chay Leng Yeo
- Department of Medicine, National University Health System, NUHS Tower Block Level 10, 1E Kent Ridge Road, Singapore, 119228, Singapore.
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10
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Zutter MM, Santoro SA, Wu JE, Wakatsuki T, Dickeson SK, Elson EL. Collagen receptor control of epithelial morphogenesis and cell cycle progression. Am J Pathol 1999; 155:927-40. [PMID: 10487850 PMCID: PMC1866884 DOI: 10.1016/s0002-9440(10)65192-9] [Citation(s) in RCA: 42] [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: 11/23/2022]
Abstract
To define the unique contributions of the alpha subunit cytoplasmic tails of the alpha(1)beta(1) and alpha(2)beta(1) integrin to epithelial differentiation and branching morphogenesis, a variant NMuMG cell line lacking alpha(1)beta(1) and alpha(2)beta(1) integrin expression was stably transfected with the full-length alpha(2) integrin subunit cDNA (X2C2), chimeric cDNA consisting of the extracellular and transmembrane domains of the alpha(2) subunit and the cytoplasmic domain of the alpha(1) subunit (X2C1), or alpha(2) cDNA truncated after the GFFKR sequence (X2C0). The X2C2 and X2C1 transfectants effectively adhered, spread, and formed focal adhesion complexes on type I collagen matrices. The X2C0 transfectants were less adherent to low concentrations of type I collagen, spread less well, and formed poorly defined focal adhesion complexes in comparison to the X2C2 and X2C1 transfectants. The X2C2 and X2C1 transfectants but not the X2C0 transfectants proliferated on collagen substrates. Only the X2C2 transfectants developed elongate branches and tubules in three-dimensional collagen gels and migrated on type I collagen. These findings suggest a unique role for the alpha(2) integrin cytoplasmic domain in postligand binding events and cooperative interactions with growth factors that mediate epithelial differentiation and branching morphogenesis. Either intact alpha(1) or alpha(2) integrin subunit cytoplasmic domain can promote cell cycle progression.
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Affiliation(s)
- M M Zutter
- Department of Pathology, Washington University School of Medicine, St. Louis, Missouri, USA
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11
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Abstract
Epithelial branching morphogenesis is a process by which a continuous epithelium, embedded in mesenchyme, forms tubules that extend and branch into the surrounding mesenchyme. The morphogenetic process is responsible for the architecture of many organs including the lung. Proper expression and function of extracellular matrix (ECM) molecules, such as collagens and laminins, are necessary for branching to occur normally. However, little is known about the role of epithelial cell surface molecules that mediate epithelial-matrix interactions during this process. We have studied the expression patterns of cell surface collagen and laminin integrin receptor alpha subunits, alpha 1, alpha 2, alpha 3, and alpha 6, in relation to that of collagen and laminin during lung branching morphogenesis. The alpha 1 integrin subunit was present on endothelia and smooth muscles around airways and large blood vessels. The mesenchyme expressed high levels of alpha 2 and alpha 6 but not alpha 3, whereas the epithelium expressed all three integrin subunits. In contrast to the widespread epithelial expression of alpha 3 and alpha 6, the epithelial expression of alpha 2 was restricted to branch tips. By performing in situ hybridization and immunofluorescence on serial sections, we found that alpha 2 protein expression on the epithelium correlated spatially and temporally with high level expression of collagen IV and laminin-1 mRNAs, suggesting that the alpha 2-expressing epithelial cells were in the process of producing and assembling their collagen and laminin matrices. While the expression of alpha 3 and alpha 6 on all lung epithelia suggests that these integrins may be important to lung epithelial development, the unique expression pattern of the alpha 2 subunit suggests that the alpha 2 beta 1 integrin may be important at branch tips either in the process of collagen/laminin synthesis and assembly or extension of the epithelial tubules into the mesenchyme.
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Affiliation(s)
- J E Wu
- Department of Pathology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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12
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Keely PJ, Wu JE, Santoro SA. The spatial and temporal expression of the alpha 2 beta 1 integrin and its ligands, collagen I, collagen IV, and laminin, suggest important roles in mouse mammary morphogenesis. Differentiation 1995; 59:1-13. [PMID: 7589890 DOI: 10.1046/j.1432-0436.1995.5910001.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.1] [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: 01/26/2023]
Abstract
To begin to determine the role of the alpha 2 beta 1 integrin and its ligands, collagen I, collagen IV, and laminin, in mammary epithelial differentiation in vivo, we determined the expression of these molecules by in situ hybridization and immunofluorescence in the developing mouse mammary gland. Expression of collagen I, collagen IV, and laminin mRNAs in the mammary gland during puberty corresponded to the period of greatest growth of the gland, 4-7 weeks postnatally. Collagen I expression preceded collagen IV expression, both of which preceded laminin expression, suggesting an important temporal sequence of extracellular matrix (ECM) production. When growth of the epithelium ceased in the adult virgin gland, expression of all three mRNAs became undetectable. Following the onset of pregnancy these molecules were re-expressed with the same chronology observed during puberty. Collagen I, collagen IV, and laminin were expressed by stromal cells immediately surrounding the developing ductal epithelium. Surprisingly, we found no expression of ECM components in the epithelial cells, suggesting the mammary epithelium does not synthesize its own basement membrane. The distribution of collagen I was consistent with a role in duct formation, since collagen I was strikingly abundant around larger mammary ducts, but was sparse around growing endbuds or alveoli. Conversely, there was abundant laminin near growing endbuds and around alveoli, and less around large ducts, suggesting its role is different than collagen I. The alpha 2 beta 1 integrin was present on the basal, lateral, and apical surfaces of the mammary epithelium throughout postnatal development and pregnancy. The alpha 2 beta 1 integrin expression was strongest at midpregnancy, suggesting a role for alpha 2 beta 1 integrin in the alveolar formation that occurs at this time. The alpha 2 beta 1 integrin expression decreased dramatically in the lactating gland. Our results suggest that alpha 2 beta 1 integrin interactions with its temporally and spatially regulated ligands, collagen I, collagen IV, and laminin, could play an important role in mammary morphogenesis in vivo.
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Affiliation(s)
- P J Keely
- Department of Pathology, Washington University School of Medicine, St. Louis, MO 63110-1093, USA
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13
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Abstract
The extracellular matrix plays important roles in embryogenesis. The integrin family of adhesion receptors may mediate critical cellular interactions with the extracellular matrix during development. In this study, we elucidated the developmental spatial and temporal expression pattern of the alpha 2 beta 1 integrin heterodimer, a cell surface receptor for collagens and laminin. We generated reagents for studying the alpha 2 beta 1 integrin and examined the developmental expression of the integrin in postimplantation mice. A partial length murine alpha 2 cDNA was isolated and the protein encoding region was found to be 82% homologous to that of the human alpha 2 cDNA. A synthetic peptide corresponding to the carboxy-terminus of murine alpha 2 was used to generate alpha 2-specific antiserum. The antiserum and riboprobes derived from both the alpha 2 cDNA and the previously characterized murine beta 1 subunit cDNA were used to determine the spatiotemporal expression of the alpha 2 subunit by immunocytochemistry and of the alpha 2 and beta 1 mRNAs by in situ hybridization. Both approaches gave concordant results. Expression of the alpha 2 integrin subunit was observed in both the maternal and embryonic components of the placenta, namely the perivascular and basal zone decidual cells and decidual cells and spongiotrophoblasts at the maternal/embryonic junction. Expression was also observed in cells actively producing and remodeling the extracellular matrix in the maternal uterus and in the developing gut, lens, cartilage, bone, and tooth of the embryo. Generally, expression of the alpha 2 integrin subunit was found in cells entering their later stages of differentiation such as in chondrocytes as they became hypertrophic, ameloblasts and odontoblasts as they became columnar and began to secrete the matrix of the tooth, endothelial cells after they formed tubules, in the lens just prior to and during lens fiber production, and in the collecting ducts of the kidney only after full gestation. Throughout embryogenesis, beta 1 mRNA was widely distributed and present in cell types expressing alpha 2 mRNA and protein. The developmental expression pattern of the alpha 2 beta 1 integrin suggests roles for the integrin in placental development and matrix assembly and remodeling.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigens, CD/biosynthesis
- Antigens, CD/genetics
- Antigens, CD/physiology
- Base Sequence
- Cell Adhesion
- Cell Differentiation
- Cell Line
- DNA, Complementary/genetics
- Embryonic and Fetal Development/genetics
- Embryonic and Fetal Development/physiology
- Extracellular Matrix/physiology
- Female
- Fetal Proteins/biosynthesis
- Fetal Proteins/genetics
- Fetal Proteins/physiology
- Fluorescent Antibody Technique
- Gene Expression Regulation
- Humans
- In Situ Hybridization
- Integrin beta1
- Integrins/biosynthesis
- Integrins/genetics
- Integrins/physiology
- Mice/embryology
- Molecular Sequence Data
- Organ Specificity
- Peptide Fragments/immunology
- Pregnancy Proteins/biosynthesis
- Pregnancy Proteins/genetics
- Pregnancy Proteins/physiology
- RNA Probes
- RNA, Messenger/analysis
- Receptors, Collagen
- Receptors, Laminin/biosynthesis
- Receptors, Laminin/genetics
- Receptors, Laminin/physiology
- Sequence Alignment
- Sequence Homology, Amino Acid
- Uterus/metabolism
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Affiliation(s)
- J E Wu
- Department of Pathology, Washington University School of Medicine, St. Louis, Missouri 63110
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14
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Affiliation(s)
- S A Santoro
- Department of Pathology, Washington University School of Medicine, St. Louis, Missouri 63110, USA
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15
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Sheppard AM, Wu JE, Staubli U, Perlmutter LS. Changes in calpain and brain spectrin immunoreactivity accompany sprouting in the deafferented hippocampus. Synapse 1993; 15:239-42. [PMID: 8278900 DOI: 10.1002/syn.890150309] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- A M Sheppard
- Pulmonary and Critical Care Division, Washington University Medical School, St. Louis, Missouri 63110
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