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Bernhard W, Barreto K, Toledo D, El-Sayed A, Jett KA, Casaco A, Fonge H, Geyer CR. Evaluation of nimotuzumab Fab 2 as an optical imaging agent in EGFR positive cancers. Sci Rep 2023; 13:10990. [PMID: 37419997 PMCID: PMC10328982 DOI: 10.1038/s41598-023-37873-9] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 06/28/2023] [Indexed: 07/09/2023] Open
Abstract
Molecular-targeted imaging probes can be used with a variety of imaging modalities to detect diseased tissues and guide their removal. EGFR is a useful biomarker for a variety of cancers, because it is expressed at high levels relative to normal tissues. Previously, we showed the anti-EGFR antibody nimotuzumab can be used as a positron emission tomography and fluorescent imaging probe for EGFR positive cancers in mice. These imaging probes are currently in clinical trials for PET imaging and image-guided surgery, respectively. One issue with using antibody probes for imaging is their long circulation time and slow tissue penetration, which requires patients to wait a few days after injection before imaging or surgery, multiple visits and longer radiation exposure. Here, we generated a Fab2 fragment of nimotuzumab, by pepsin digestion and labeled it with IRDye800CW to evaluate its optical imaging properties. The Fab2 had faster tumor accumulation and clearance in mice relative to the nimotuzumab IgG. The fluorescent signal peaked at 2 h post injection and remained high until 6 h post injection. The properties of the Fab2 allow a higher signal to background to be obtained in a shorter time frame, reducing the wait time for imaging after probe infusion.
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Affiliation(s)
- Wendy Bernhard
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada
| | - Kris Barreto
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada
| | | | - Ayman El-Sayed
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada
| | - Kimberly A Jett
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada
| | | | - Humphrey Fonge
- Department of Medical Imaging, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada
| | - C Ronald Geyer
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada.
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2
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Goncin U, Bernhard W, Curiel L, Geyer CR, Machtaler S. Rapid Copper-free Click Conjugation to Lipid-Shelled Microbubbles for Ultrasound Molecular Imaging of Murine Bowel Inflammation. Bioconjug Chem 2022; 33:848-857. [DOI: 10.1021/acs.bioconjchem.2c00104] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Una Goncin
- Department of Medical Imaging, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Wendy Bernhard
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Laura Curiel
- Department of Electrical and Software Engineering, Schulich School of Engineering, University of Calgary, Calgary, Alberta T2N 4V8, Canada
| | - C. Ronald Geyer
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Steven Machtaler
- Department of Medical Imaging, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
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3
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Bernhard W, Barreto K, El-Sayed A, Gonzalez C, Viswas RS, Toledo D, Casaco A, DeCoteau J, Fonge H, Geyer CR. Pre-clinical study of IRDye800CW-nimotuzumab formulation, stability, pharmacokinetics, and safety. BMC Cancer 2021; 21:270. [PMID: 33711962 PMCID: PMC7953729 DOI: 10.1186/s12885-021-08003-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [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] [Received: 09/29/2020] [Accepted: 03/02/2021] [Indexed: 12/23/2022] Open
Abstract
Background Epidermal growth factor receptor (EGFR) is a target for cancer therapy as it is overexpressed in a wide variety of cancers. Therapeutic antibodies that bind EGFR are being evaluated in clinical trials as imaging agents for positron emission tomography and image-guided surgery. However, some of these antibodies have safety concerns such as infusion reactions, limiting their use in imaging applications. Nimotuzumab is a therapeutic monoclonal antibody that is specific for EGFR and has been used as a therapy in a number of countries. Methods Formulation of IRDye800CW-nimotuzumab for a clinical trial application was prepared. The physical, chemical, and pharmaceutical properties were tested to develop the specifications to determine stability of the product. The acute and delayed toxicities were tested and IRDye800CW-nimotuzumab was determined to be non-toxic. Non-compartmental pharmacokinetics analysis was used to determine the half-life of IRDye800CW-nimotuzumab. Results IRDye800CW-nimotuzumab was determined to be non-toxic from the acute and delayed toxicity study. The half-life of IRDye800CW-nimotuzumab was determined to be 38 ± 1.5 h. A bi-exponential analysis was also used which gave a t1/2 alpha of 1.5 h and t1/2 beta of 40.8 h. Conclusions Here, we show preclinical studies demonstrating that nimotuzumab conjugated to IRDye800CW is safe and does not exhibit toxicities commonly associated with EGFR targeting antibodies. Supplementary Information The online version contains supplementary material available at 10.1186/s12885-021-08003-3.
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Affiliation(s)
- Wendy Bernhard
- Department of Pathology and Laboratory Medicine, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Kris Barreto
- Department of Pathology and Laboratory Medicine, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Ayman El-Sayed
- Department of Pathology and Laboratory Medicine, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Carolina Gonzalez
- Department of Pathology and Laboratory Medicine, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Raja Solomon Viswas
- Department of Medical Imaging, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | | | | | - John DeCoteau
- Department of Pathology and Laboratory Medicine, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada
| | - Humphrey Fonge
- Department of Medical Imaging, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada. .,Department of Medical Imaging, Royal University Hospital, Saskatoon, SK, Canada.
| | - Clarence Ronald Geyer
- Department of Pathology and Laboratory Medicine, College of Medicine, University of Saskatchewan, Saskatoon, SK, Canada.
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4
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Solomon VR, Alizadeh E, Bernhard W, Makhlouf A, Hartimath SV, Hill W, El-Sayed A, Barreto K, Geyer CR, Fonge H. Development and preclinical evaluation of cixutumumab drug conjugates in a model of insulin growth factor receptor I (IGF-1R) positive cancer. Sci Rep 2020; 10:18549. [PMID: 33122707 PMCID: PMC7596529 DOI: 10.1038/s41598-020-75279-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 09/29/2020] [Indexed: 12/25/2022] Open
Abstract
Overexpression of insulin growth factor receptor type 1 (IGF-1R) is observed in many cancers. Antibody drug conjugates (ADCs) with PEGylated maytansine (PEG6-DM1) show promise in vitro. We developed PEG6-DM1 ADCs with low and high drug to antibody ratios (DAR) using an anti-IGF-1R antibody cixutumumab (IMC-A12). Conjugates with low (cixutumumab-PEG6-DM1-Low) and high (cixutumumab-PEG6-DM1-High) DAR as 3.4 and 7.2, respectively, were generated. QC was performed by UV spectrophotometry, HPLC, bioanalyzer, and biolayer-interferometry. We compared the in vitro binding and internalization rates of the ADCs in IGF-1R-positive MCF-7/Her18 cells. We radiolabeled the ADCs with 111In and used microSPECT/CT imaging and ex vivo biodistribution to understand their in vivo behavior in MCF-7/Her18 xenograft mice. The therapeutic potential of the ADC was studied in vitro and in mouse xenograft. Internalization rates of all ADCs was high and increased over 48 h and EC50 was in the low nanomolar range. MicroSPECT/CT imaging and ex vivo biodistribution showed significantly lower tumor uptake of 111In-cixutumumab-PEG6-DM1-High compared to 111In-cixutumumab-PEG6-DM1-Low and 111In-cixutumumab. Cixutumumab-PEG6-DM1-Low significantly prolonged the survival of mice bearing MCF-7/Her18 xenograft compared with cixutumumab, cixutumumab-PEG6-DM1-High, or the PBS control group. Cixutumumab-PEG6-DM1-Low ADC was more effective. The study highlights the potential utility of cixutumumab-ADCs as theranostics against IGF-1R positive cancers.
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Affiliation(s)
- Viswas Raja Solomon
- Department of Medical Imaging, RUH Saskatoon, University of Saskatchewan, College of Medicine, 103 Hospital Dr., Saskatoon, SK, S7N 0W8, Canada
| | - Elahe Alizadeh
- Department of Medical Imaging, RUH Saskatoon, University of Saskatchewan, College of Medicine, 103 Hospital Dr., Saskatoon, SK, S7N 0W8, Canada
| | - Wendy Bernhard
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada
| | - Amal Makhlouf
- Department of Medical Imaging, RUH Saskatoon, University of Saskatchewan, College of Medicine, 103 Hospital Dr., Saskatoon, SK, S7N 0W8, Canada.,Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Cairo University, Kasr El-Aini, Cairo, 12411, Egypt
| | - Siddesh V Hartimath
- Department of Medical Imaging, RUH Saskatoon, University of Saskatchewan, College of Medicine, 103 Hospital Dr., Saskatoon, SK, S7N 0W8, Canada
| | - Wayne Hill
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada
| | - Ayman El-Sayed
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada
| | - Kris Barreto
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada
| | - Clarence Ronald Geyer
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada
| | - Humphrey Fonge
- Department of Medical Imaging, RUH Saskatoon, University of Saskatchewan, College of Medicine, 103 Hospital Dr., Saskatoon, SK, S7N 0W8, Canada. .,Department of Medical Imaging, Royal University Hospital Saskatoon, Saskatoon, SK, Canada.
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5
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Böckmann KA, von Stumpff A, Bernhard W, Shunova A, Minarski M, Frische B, Warmann S, Schleicher E, Poets CF, Franz AR. Fatty acid composition of adipose tissue at term indicates deficiency of arachidonic and docosahexaenoic acid and excessive linoleic acid supply in preterm infants. Eur J Nutr 2020; 60:861-872. [PMID: 32476053 PMCID: PMC7900037 DOI: 10.1007/s00394-020-02293-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 05/21/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND Arachidonic (ARA) and docosahexaenoic acid (DHA) are constitutive to membrane phospholipids, and essential for brain and overall development. ARA/DHA pools in term infants (TI) are built during the third trimester, stored as adipose tissue triglycerides and predominantly distributed via plasma phosphatidylcholine (PC). In preterm infants (PTI), placental ARA/DHA supply is replaced by linoleic-acid (LA)-enriched nutrition. This study aimed to investigate the impact of PTI nutrition, compared to placental supply, on fatty acid composition in adipose tissue and blood. METHODS Prospective observational study (4/2017-3/2019) in 12 PTI and 3 PTI with enterostomy (PTI/E) (gestational age (GA) < 32 weeks) with surgical intervention at term (± 6 weeks) and 14 TI (GA ≥ 34 weeks, surgical intervention < 2 weeks postnatally). PTI/E were analyzed descriptively only. PC and triglyceride fatty acids were analyzed with tandem mass spectrometry and gas chromatography, respectively. Results were compared between TI and PTI with Wilcoxon Test and shown as median [25th percentile-75th percentile] mol%. RESULTS PTI had less ARA in adipose tissue TG (0.77[0.67-0.87]% vs. 1.04[0.95-1.14]%, p = 0.0003) and plasma PC (20.7[18.7-22.8]% vs. 28.3[22.7-33.5]%, p = 0.011) than TI. PTI also had less DHA in adipose tissue TG (0.6[0.4-0.8]% vs. 1.1[0.8-1.4]%, p = 0.006) and plasma PC (6.4[5.6-7.1]% vs. 8.4[7.8-13.1]%, p = 0.002). LA was increased in PTI's adipose tissue TG (10.0[8.8-12.3]% vs. 3.0[2.5-3.6]%, p < 0.0001) and plasma PC (48.4[44.6-49.6]% vs. 30.6[24.9-35.6]%, p = 0.0002). Similar differences were observed in erythrocyte PC. CONCLUSION In PTI, LA is increased and ARA/DHA decreased in adipose tissue, plasma and erythrocyte lipids as proxies for other tissues, likely caused by PTI nutrition. This may contribute to impaired PTI development.
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Affiliation(s)
- K A Böckmann
- Department of Neonatology, Faculty of Medicine, Eberhard-Karls-University, Calwer Straße 7, 72076, Tübingen, Germany.
| | - A von Stumpff
- Department of Neonatology, Faculty of Medicine, Eberhard-Karls-University, Calwer Straße 7, 72076, Tübingen, Germany
| | - W Bernhard
- Department of Neonatology, Faculty of Medicine, Eberhard-Karls-University, Calwer Straße 7, 72076, Tübingen, Germany
| | - A Shunova
- Department of Neonatology, Faculty of Medicine, Eberhard-Karls-University, Calwer Straße 7, 72076, Tübingen, Germany
| | - M Minarski
- Department of Neonatology, Faculty of Medicine, Eberhard-Karls-University, Calwer Straße 7, 72076, Tübingen, Germany
| | - B Frische
- Department of Neonatology, Faculty of Medicine, Eberhard-Karls-University, Calwer Straße 7, 72076, Tübingen, Germany
| | - S Warmann
- Department of Pediatric Surgery and Child Urology, Faculty of Medicine, Eberhard-Karls-University, Tübingen, Germany
| | - E Schleicher
- Department of Internal Medicine IV, Faculty of Medicine, Eberhard-Karls-University, Tübingen, Germany
| | - C F Poets
- Department of Neonatology, Faculty of Medicine, Eberhard-Karls-University, Calwer Straße 7, 72076, Tübingen, Germany
| | - A R Franz
- Department of Neonatology, Faculty of Medicine, Eberhard-Karls-University, Calwer Straße 7, 72076, Tübingen, Germany
- Center for Pediatric Clinical Studies, Faculty of Medicine, Eberhard-Karls-University, Tübingen, Germany
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6
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Solomon VR, Alizadeh E, Bernhard W, Hartimath SV, Hill W, Chekol R, Barreto KM, Geyer CR, Fonge H. 111In- and 225Ac-Labeled Cixutumumab for Imaging and α-Particle Radiotherapy of IGF-1R Positive Triple-Negative Breast Cancer. Mol Pharm 2019; 16:4807-4816. [DOI: 10.1021/acs.molpharmaceut.9b00542] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
| | | | | | | | | | | | | | | | - Humphrey Fonge
- Department of Medical Imaging, Royal University Hospital Saskatoon, Saskatoon, SK S7N 0W8, Canada
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7
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Hartimath SV, El-Sayed A, Makhlouf A, Bernhard W, Gonzalez C, Hill W, Parada AC, Barreto K, Geyer CR, Fonge H. Therapeutic potential of nimotuzumab PEGylated-maytansine antibody drug conjugates against EGFR positive xenograft. Oncotarget 2019; 10:1031-1044. [PMID: 30800216 PMCID: PMC6383682 DOI: 10.18632/oncotarget.26613] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [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] [Received: 09/07/2018] [Accepted: 12/20/2018] [Indexed: 12/26/2022] Open
Abstract
Nimotuzumab is a humanized anti-epidermal growth factor receptor I (EGFR) monoclonal antibody. We have developed antibody drug conjugates (ADCs) with nimotuzumab conjugated to PEGylated-maytansine (PEG6-DM1). We generated conjugates with low (nimotuzumab-PEG6-DM1-Low: DAR = 3.5) and high (nimotuzumab-PEG6-DM1-High: DAR = 7.3) drug to antibody ratios (DAR). Quality control was performed using UV spectrophotometry, size exclusion HPLC, bioanalyzer, biolayer interferometry (BLI), and flow cytometry in EGFR-positive DLD-1, MDA-MB-468 (high density EGFR), and HT-29 (very low EGFR density) cells. Control antibody drug conjugates were developed using a human anti-maltose binding protein (MBP) antibody. BLI showed that the binding of nimotuzumab-PEG6-DM1-Low and nimotuzumab-PEG6-DM1-High was slightly but significantly affected by conjugation of the drug (nimotuzumab KD 0.89 ± 0.02 nM < nimotuzumab-PEG6-DM1-Low KD 1.94 ± 0.02 nM < nimotuzumab-PEG6-DM1-High KD 3.75 ± 0.03 nM). In vitro cytotoxicity was determined following incubation of cells with the immunoconjugates and IC50 values were determined. Nimotuzumab-PEG6-DM1-Low and nimotuzumab-PEG6-DM1-High were used to treat EGFR positive KRAS mutant DLD-1 colorectal cancer xenograft. DLD-1 cells were transduced with a red fluorescent protein (iRFP702) to allow the use of near infrared imaging (NIR) for tumor response monitoring. In vitro potency correlated with the number of drugs on antibody, with nimotuzumab-PEG6-DM1-High showing higher activity than nimotuzumab-PEG6-DM1-Low. Three doses (15 mg/kg) of the ADCs prolonged the survival of DLD-1-iRFP-702 tumor bearing mice as monitored by NIR. Nimotuzumab-PEG6-DM1-Low resulted in 4/6 complete cure while nimotuzumab-PEG6-DM1-High resulted in 2/5 complete cure. The novel ADCs were very effective in a colorectal cancer model in vivo.
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Affiliation(s)
- Siddesh V Hartimath
- Department of Medical Imaging, College of Medicine, University of Saskatchewan, Saskatoon SK, S7N 0W8, Canada.,Saskatchewan Centre for Cyclotron Sciences (SCCS), the Fedoruk Centre, Saskatoon SK, S7N 5C4, Canada
| | - Ayman El-Sayed
- Department of Pathology and Laboratory Medicine, College of Medicine, University of Saskatchewan, Saskatoon SK, S7N 5E5, Canada
| | - Amal Makhlouf
- Department of Medical Imaging, College of Medicine, University of Saskatchewan, Saskatoon SK, S7N 0W8, Canada.,Saskatchewan Centre for Cyclotron Sciences (SCCS), the Fedoruk Centre, Saskatoon SK, S7N 5C4, Canada.,Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Cairo University, Kasr El-Aini, 12411, Cairo, Egypt
| | - Wendy Bernhard
- Department of Pathology and Laboratory Medicine, College of Medicine, University of Saskatchewan, Saskatoon SK, S7N 5E5, Canada
| | - Carolina Gonzalez
- Department of Pathology and Laboratory Medicine, College of Medicine, University of Saskatchewan, Saskatoon SK, S7N 5E5, Canada
| | - Wayne Hill
- Department of Pathology and Laboratory Medicine, College of Medicine, University of Saskatchewan, Saskatoon SK, S7N 5E5, Canada
| | | | - Kris Barreto
- Department of Pathology and Laboratory Medicine, College of Medicine, University of Saskatchewan, Saskatoon SK, S7N 5E5, Canada
| | - Clarence Ronald Geyer
- Department of Pathology and Laboratory Medicine, College of Medicine, University of Saskatchewan, Saskatoon SK, S7N 5E5, Canada
| | - Humphrey Fonge
- Department of Medical Imaging, College of Medicine, University of Saskatchewan, Saskatoon SK, S7N 0W8, Canada.,Saskatchewan Centre for Cyclotron Sciences (SCCS), the Fedoruk Centre, Saskatoon SK, S7N 5C4, Canada.,Department of Medical Imaging, Royal University Hospital Saskatoon, Saskatoon SK, S7N 0W8, Canada
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8
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Bernhard W, El-Sayed A, Barreto K, Gonzalez C, Fonge H, Geyer CR. Near infrared imaging of epidermal growth factor receptor positive xenografts in mice with domain I/II specific antibody fragments. Theranostics 2019; 9:974-985. [PMID: 30867810 PMCID: PMC6401412 DOI: 10.7150/thno.30835] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Accepted: 12/31/2018] [Indexed: 12/03/2022] Open
Abstract
Epidermal growth factor receptor (EGFR) is a transmembrane cell surface receptor that is frequently overexpressed and/or mutated in many cancers. Therapies targeting EGFR have poor outcomes due to the lack of reliable diagnostic tests to monitor EGFR. Current in vitro EGFR diagnostic methods are invasive, requiring biopsies, which limits tumor sampling and availability. EGFR molecular imaging provides non-invasive whole-body images capable of detecting primary tumors and metastases, which can be used to diagnose and monitor response to therapy. Methods: We evaluated properties of two anti-EGFR fragments, 8708 and 8709, as molecular-targeted imaging probes. 8708 and 8709 are anti-EGFR antigen binding fragments (Fabs) that recognize domain I/II of EGFR, which is distinct from epitopes recognized by current anti-EGFR therapeutic antibodies. We used complementarity determining region sequences from 8708 and 8709 Fabs to generate an anti-EGFR IgG and (scFv)2 and scFv-Fc antibody fragments. We expressed, purified, and labeled the IgG and fragments with IRDye800CW and used them to image EGFR-positive and -negative xenografts in CD-1 nude mice. 8709 scFv-Fc was also tested for competitive binding with the therapeutic anti-EGFR antibody nimotuzumab and for quantifying ratios of EGFR and EGFRvIII deletion mutant. Results: IRDye800CW-labeled 8708 (scFv)2 and 8709 scFv-Fc imaging probes showed high levels of accumulation and good retention in EGFR-positive xenografts, with peak accumulation occurring at 24 and 48 hours post injection, respectively. IRDye680RD-labeled 8709 scFv-Fc did not compete with IRDye800CW-labeled nimotuzumab for EGFR binding as assayed by flow cytometry using an EGFR-positive cell line. IRDye680RD-labeled 8709 scFv-Fc and IRDye800CW-labeled nimotuzumab used in combination were able to determine the ratio of cells expressing EGFR and a deletion mutant EGFRvIII. Conclusion: IRDye800CW-labeled 8708 (scFv)2 and 8709 scFv-Fc had desirable binding affinities, clearance times, and tumor accumulation to be used for imaging in combination with current EGFR targeted therapies. This study highlights the potential for using 8708 (scFv)2 and 8709 scFv-Fc as EGFR diagnostic and therapy monitoring tools.
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Affiliation(s)
- Wendy Bernhard
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon SK, Canada
| | - Ayman El-Sayed
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon SK, Canada
| | - Kris Barreto
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon SK, Canada
| | - Carolina Gonzalez
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon SK, Canada
| | - Humphrey Fonge
- Department of Medical Imaging, University of Saskatchewan, College of Medicine, Saskatoon SK, Canada
- Saskatchewan Centre for Cyclotron Sciences (SCCS), the Fedoruk Centre, Saskatoon SK, Canada
- Department of Medical Imaging, Royal University Hospital Saskatoon, Saskatoon SK, Canada
| | - Clarence Ronald Geyer
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon SK, Canada
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9
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Hashemi P, Barreto K, Bernhard W, Lomness A, Honson N, Pfeifer TA, Harrigan PR, Sadowski I. Compounds producing an effective combinatorial regimen for disruption of HIV-1 latency. EMBO Mol Med 2019; 10:160-174. [PMID: 29246970 PMCID: PMC5838563 DOI: 10.15252/emmm.201708193] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [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: 01/01/2023] Open
Abstract
Highly active antiretroviral therapy (HAART) has improved the outlook for the HIV epidemic, but does not provide a cure. The proposed “shock‐and‐kill” strategy is directed at inducing latent HIV reservoirs, which may then be purged via boosted immune response or targeting infected cells. We describe five novel compounds that are capable of reversing HIV latency without affecting the general T‐cell activation state. The new compounds exhibit synergy for reactivation of latent provirus with other latency‐reversing agents (LRAs), in particular ingenol‐3‐angelate/PEP005. One compound, designated PH02, was efficient at reactivating viral transcription in several cell lines bearing reporter HIV‐1 at different integration sites. Furthermore, it was capable of reversing latency in resting CD4+ T lymphocytes from latently infected aviremic patient cells on HAART, while producing minimal cellular toxicity. The combination of PH02 and PEP005 produces a strong synergistic effect for reactivation, as demonstrated through a quantitative viral outgrowth assay (qVOA), on CD4+ T lymphocytes from HIV‐1‐infected individuals. We propose that the PH02/PEP005 combination may represent an effective novel treatment for abrogating persistent HIV‐1 infection.
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Affiliation(s)
- Pargol Hashemi
- Biochemistry and Molecular Biology, Molecular Epigenetics, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Kris Barreto
- Biochemistry and Molecular Biology, Molecular Epigenetics, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Wendy Bernhard
- Biochemistry and Molecular Biology, Molecular Epigenetics, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Adam Lomness
- Biochemistry and Molecular Biology, Molecular Epigenetics, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
| | - Nicolette Honson
- The Centre for Drug Research and Development, Vancouver, BC, Canada
| | - Tom A Pfeifer
- The Centre for Drug Research and Development, Vancouver, BC, Canada
| | - P Richard Harrigan
- BC Centre for Excellence in HIV/AIDS, St. Paul's Hospital, Vancouver, BC, Canada
| | - Ivan Sadowski
- Biochemistry and Molecular Biology, Molecular Epigenetics, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
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10
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Hartimath SV, Alizadeh E, Solomon VR, Chekol R, Bernhard W, Hill W, Parada AC, Barreto K, Geyer CR, Fonge H. Preclinical Evaluation of 111In-Labeled PEGylated Maytansine Nimotuzumab Drug Conjugates in EGFR-Positive Cancer Models. J Nucl Med 2019; 60:1103-1110. [PMID: 30655327 DOI: 10.2967/jnumed.118.220095] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [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: 09/05/2018] [Accepted: 12/10/2018] [Indexed: 12/12/2022] Open
Abstract
Epidermal growth factor receptor I (EGFR) is overexpressed in most cancers of epithelial origin. Antibody drug conjugates (ADCs) with PEGylated-maytansine (PEG-DM1) show promise in vitro and in vivo. However, in vivo biodistribution data for ADCs with PEG-DM1 have not been reported. Development of methods to understand the real-time in vivo behavior of these ADCs is needed to move these compounds to the clinic. Methods: Here we have used noninvasive small-animal SPECT/CT imaging and ex vivo biodistribution to understand the in vivo behavior of PEG6-DM1 ADCs. We developed nimotuzumab ADCs conjugated to PEG6-DM1. We generated immunoconjugates with low (nimotuzumab-PEG6-DM1-Low) and high (nimotuzumab-PEG6-DM1-High) drug-to-antibody ratios. The drug-to-antibody of nimotuzumab-PEG6-DM1-Low and nimotuzumab-PEG6-DM1-High was 3.5 and 7.3, respectively. Quality control was performed using ultraviolet spectrophotometry, size-exclusion high-performance liquid chromatography, bioanalyzer, biolayer interferometry, and flow cytometry in EGFR-positive DLD-1 cells. These immunoconjugates were conjugated with DOTA and radiolabeled with 111In. The in vitro binding and internalization rates of 111In-nimotuzumab, 111In-nimotuzumab-PEG6-DM1-Low, and 111In-nimotuzumab-PEG6-DM1-High were characterized. Furthermore, the pharmacokinetics, biodistribution, and imaging characteristics were evaluated in normal and DLD-1 tumor-bearing mice. Results: Flow cytometry and biolayer interferometry showed a trend toward decreasing EGFR affinity with increasing number of PEG6-DM1 on the antibody. Despite the lower overall cellular binding of the PEG6-DM1 radioimmunoconjugates, internalization was higher for PEG6-DM1 ADCs than for the non-PEGylated ADC in the following order: 111In-nimotuzumab-PEG6-DM1-High > 111In-nimotuzumab-PEG6-DM1-Low > 111In-nimotuzumab. Nuclear uptake of 111In-nimotuzumab-PEG6-DM1-High was 4.4-fold higher than 111In-nimotuzumab. Pharmacokinetics and biodistribution showed that 111In-nimotuzumab-PEG6-DM1-High had the slowest blood and whole-body clearance rate. Uptake in DLD-1 tumors of 111In-nimotuzumab was similar to 111In-nimotuzumab-PEG6-DM1-Low but was significantly higher than for 111In-nimotuzumab-PEG6-DM1-High. Tumor-to-background ratios for 111In-nimotuzumab and 111In-nimotuzumab-PEG6-DM1-Low were higher than for 111In-nimotuzumab-PEG6-DM1-High. Conclusion: The results show that conjugation of multiple PEG6-DM1 reduces the affinity for EGFR in vitro. However, the reduced affinity is counteracted by the high internalization rate of constructs with PEG6-DM1 ADCs in vitro. The decreased affinity resulted in low tumor uptake of 111In-nimotuzumab-PEG6-DM1-High, with a slow overall whole-body clearance rate. These data provide insights for evaluating the pharmacokinetics and normal -tissue toxicity and in determining dosing rate of PEGylated ADCs.
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Affiliation(s)
- Siddesh V Hartimath
- Department of Medical Imaging, University of Saskatchewan, College of Medicine, Saskatoon SK, Canada
| | - Elahe Alizadeh
- Department of Medical Imaging, University of Saskatchewan, College of Medicine, Saskatoon SK, Canada
| | - Viswas Raja Solomon
- Department of Medical Imaging, University of Saskatchewan, College of Medicine, Saskatoon SK, Canada
| | - Rufael Chekol
- Department of Medical Imaging, University of Saskatchewan, College of Medicine, Saskatoon SK, Canada
| | - Wendy Bernhard
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon SK, Canada
| | - Wayne Hill
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon SK, Canada
| | | | - Kris Barreto
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon SK, Canada
| | - Clarence Ronald Geyer
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon SK, Canada
| | - Humphrey Fonge
- Department of Medical Imaging, University of Saskatchewan, College of Medicine, Saskatoon SK, Canada .,Department of Medical Imaging, Royal University Hospital (RUH), Saskatoon SK, Canada
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El-Sayed A, Bernhard W, Barreto K, Gonzalez C, Hill W, Pastushok L, Fonge H, Geyer CR. Evaluation of antibody fragment properties for near-infrared fluorescence imaging of HER3-positive cancer xenografts. Am J Cancer Res 2018; 8:4856-4869. [PMID: 30279742 PMCID: PMC6160764 DOI: 10.7150/thno.24252] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 07/10/2018] [Indexed: 11/24/2022] Open
Abstract
In vivo imaging is influenced by the half-life, tissue penetration, biodistribution, and affinity of the imaging probe. Immunoglobulin G (IgG) is composed of discrete domains with known functions, providing a template for engineering antibody fragments with desired imaging properties. Here, we engineered antibody-based imaging probes, consisting of different combinations of antibody domains, labeled them with the near-infrared fluorescent dye IRDye800CW, and evaluated their in vivo imaging properties. Antibody-based imaging probes were based on an anti-HER3 antigen binding fragment (Fab) isolated using phage display. Methods: We constructed six anti-HER3 antibody-based imaging probes: a single chain variable fragment (scFv), Fab, diabody, scFv-CH3, scFv-Fc, and IgG. IRDye800CW-labeled, antibody-based probes were injected into nude mice bearing FaDu xenografts and their distribution to the xenograft, liver, and kidneys was evaluated. Results: These imaging probes bound to recombinant HER3 and to the HER3-positive cell line, FaDu. Small antibody fragments with molecular weight <60 kDa (scFv, diabody, and Fab) accumulated rapidly in the xenograft (maximum accumulation between 2-4 h post injection (hpi)) and cleared primarily through the kidneys. scFv-CH3 (80 kDa) had fast clearance and peaked in the xenograft between 2-3 hpi and cleared from xenograft in a rate comparable to Fab and diabody. IgG and scFv-Fc persisted in the xenografts for up to 72 hpi and distributed mainly to the xenograft and liver. The highest xenograft fluorescence signals were observed with IgG and scFv-Fc imaging probes and persisted for 2-3 days. Conclusion: These results highlight the utility of using antibody fragments to optimize clearance, tumor labeling, and biodistribution properties for developing anti-HER3 probes for image-guided surgery or PET imaging.
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Solomon VR, Gonzalez C, Alizadeh E, Bernhard W, Hartimath SV, Barreto K, Geyer CR, Fonge H. 99mTc(CO) 3+ labeled domain I/II-specific anti-EGFR (scFv) 2 antibody fragment for imaging EGFR expression. Eur J Med Chem 2018; 157:437-446. [PMID: 30103192 DOI: 10.1016/j.ejmech.2018.08.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [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: 06/02/2018] [Revised: 07/31/2018] [Accepted: 08/04/2018] [Indexed: 12/17/2022]
Abstract
Bifunctional chelators (BFCs) are covalently linked to biologically active targeting molecules and radiolabeled with radiometals. Technetium-99 m (99mTc) is the most widely used isotope in nuclear medicine because of its excellent physical properties. The objective of this study was to synthesize and characterize a novel BFC that allows for the labeling of antibodies and antibody fragments using the 99mTc(CO)3+ core which forms a very stable complex with 99mTc in the +1 oxidation sate. This study reports the synthesis of a BFC 1-pyrrolidinyl-2,5-dione-11-(bis((1-(carboxymethyl)-1H-imidazol-2-yl)methyl)amino)undecanoic acid (SAAC-CIM NHS ester), and the in vitro and in vivo evaluation of 99mTc(CO)3-SAAC-CIM-DLO6-(scFv)2 (99mTc(CO)3-DLO6-(scFv)2), a domain I/II-specific anti-epidermal growth factor receptor I (anti-EGFR) antibody fragment. The chelator allowed radiolabeling the (scFv)2 antibody fragment in very mild conditions with no significant decrease in binding to EGFR. Radiochemical yields of >50% (radiochemical purity > 95%) of the resulting anti-EGFR (scFv)2 immunoconjugate 99mTc(CO)3-DLO6-(scFv)2 was obtained. The radioimmunoconjugate was stable in histidine challenge experiments with less than 20% transchelation at 24 h after challenge in the presence of a 1500-fold excess of histidine. In vivo biodistribution of 99mTc(CO)3-DLO6-(scFv)2 indicates that the tracer was mainly cleared via renal excretion and to a lesser extent via the hepatobiliary pathway. The microSPECT imaging studies performed in mice confirmed the in vitro affinity results. The 99mTc(CO)3-DLO6-(scFv)2 shows some promising properties and warrants further investigation for imaging EGFR.
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Affiliation(s)
- Viswas Raja Solomon
- Department of Medical Imaging, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada; Saskatchewan Centre for Cyclotron Sciences (SCCS), The Fedoruk Centre, Saskatoon, SK, Canada
| | - Carolina Gonzalez
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada
| | - Elahe Alizadeh
- Department of Medical Imaging, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada; Saskatchewan Centre for Cyclotron Sciences (SCCS), The Fedoruk Centre, Saskatoon, SK, Canada
| | - Wendy Bernhard
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada
| | - Siddesh V Hartimath
- Department of Medical Imaging, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada; Saskatchewan Centre for Cyclotron Sciences (SCCS), The Fedoruk Centre, Saskatoon, SK, Canada
| | - Kris Barreto
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada
| | - Clarence Ronald Geyer
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada.
| | - Humphrey Fonge
- Department of Medical Imaging, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada; Saskatchewan Centre for Cyclotron Sciences (SCCS), The Fedoruk Centre, Saskatoon, SK, Canada; Department of Medical Imaging, Royal University Hospital Saskatoon, Saskatoon, SK, Canada.
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Chekol R, Solomon VR, Alizadeh E, Bernhard W, Fisher D, Hill W, Barreto K, DeCoteau JF, Parada AC, Geyer CR, Fonge H. 89Zr-nimotuzumab for immunoPET imaging of epidermal growth factor receptor I. Oncotarget 2018; 9:17117-17132. [PMID: 29682209 PMCID: PMC5908310 DOI: 10.18632/oncotarget.24965] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [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] [Received: 01/08/2018] [Accepted: 02/26/2018] [Indexed: 11/25/2022] Open
Abstract
Rationale Epidermal growth factor receptor (EGFR) upregulation is associated with enhanced proliferation and drug resistance in a number of cancers. Nimotuzumab is a humanized monoclonal antibody with high affinity for EGFR. The objective of this study was to determine if 89Zr-DFO-nimotuzumab could be suitable for human use as a PET probe for quantifying EGFR in vivo. Methods To evaluate the pharmacokinetics, biodistribution, microPET imaging, radiation dosimetry, and normal tissue toxicity in tumor and non-tumor bearing mice of 89Zr-desferoxamine-nimotuzumab (89Zr-DFO-nimotuzumab) of a product prepared under GMP conditions. Nimotuzumab was conjugated to DFO and radiolabeled with 89Zr. 89Zr-DFO-nimotuzumab was characterized by in vitro gel-electrophoresis, biolayer interferometry (BLI) and flow cytometry. 89Zr-DFO-nimotuzumab was evaluated in vivo by microPET and ex vivo by biodistribution in healthy and EGFR-positive tumor bearing mice. Results Flow cytometry with A431 cells showed no significant difference in the dissociation constant of nimotuzumab (13 ± 2 nM) compared with DFO-nimotuzumab (17 ± 4 nM). PET imaging in mice xenografts showed persistently high tumor uptake with the highest uptake obtained in DLD-1 xenograft (18.3 %IA/cc) at 168 hp.i. The projected human effective dose was low and was 0.184 mSv/MBq (0.679 rem/mCi) in females and 0.205 mSv/MBq (0.757 rem/mCi) in males. There was no apparent normal tissue toxicity as shown by cell blood counts and blood biochemistry analyses at 168-fold and 25-fold excess of the projected human radioactive and mass dose of the agent. Conclusion 89Zr-DFO-nimotuzumab had low organ absorbed dose and effective dose that makes it suitable for potential human use.
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Affiliation(s)
- Rufael Chekol
- Department of Medical Imaging, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada.,Saskatchewan Centre for Cyclotron Sciences (SCCS), The Fedoruk Centre, Saskatoon, SK, Canada
| | - Viswas Raja Solomon
- Department of Medical Imaging, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada.,Saskatchewan Centre for Cyclotron Sciences (SCCS), The Fedoruk Centre, Saskatoon, SK, Canada
| | - Elahe Alizadeh
- Department of Medical Imaging, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada.,Saskatchewan Centre for Cyclotron Sciences (SCCS), The Fedoruk Centre, Saskatoon, SK, Canada
| | - Wendy Bernhard
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada
| | - Darrell Fisher
- Versant Medical Physics and Radiation Safety, Boston, MA, USA
| | - Wayne Hill
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada
| | - Kris Barreto
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada
| | - John Francis DeCoteau
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada
| | | | - Clarence Ronald Geyer
- Department of Pathology and Laboratory Medicine, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada
| | - Humphrey Fonge
- Department of Medical Imaging, University of Saskatchewan, College of Medicine, Saskatoon, SK, Canada.,Saskatchewan Centre for Cyclotron Sciences (SCCS), The Fedoruk Centre, Saskatoon, SK, Canada.,Department of Medical Imaging, Royal University Hospital Saskatoon, Saskatoon, SK, Canada
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Bernhard W, El-Sayed A, Barreto K, Gonzalez C, Hill W, Parada AC, Fonge H, Geyer CR. Near infrared fluorescence imaging of EGFR expression in vivo using IRDye800CW-nimotuzumab. Oncotarget 2017; 9:6213-6227. [PMID: 29464066 PMCID: PMC5814206 DOI: 10.18632/oncotarget.23557] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [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] [Received: 08/25/2017] [Accepted: 10/27/2017] [Indexed: 01/24/2023] Open
Abstract
Nimotuzumab is a humanized anti-epidermal growth factor receptor (EGFR) monoclonal antibody that is approved in many countries for the treatment of EGFR-positive cancers. Near infrared (NIR) fluorescent dye-labeled antibodies represent an attractive class of image-guided surgical probes because of their high specificity, tumor uptake, and low dissociation from tumor cells that express the antigen. In this study, we developed a NIR fluorescent dye-labeled nimotuzumab immunoconjugate, IRDye800CW-nimotuzumab, and evaluated in vitro binding with EGFR-positive cells, in vivo tumor uptake by NIR fluorescent imaging, and ex vivo biodistribution. There was no difference in binding between nimotuzumab and IRDye800CW-nimotuzumab to EGFR-positive cells. In mice bearing EGFR-positive xenografts, IRDye800CW-nimotuzumab uptake peaked at 4 days post injection and slowly decreased thereafter with high levels of accumulation still observed at 28 days post injection. In EGFR-positive xenografts, IRDye800CW-nimotuzumab showed more than 2-fold higher uptake in tumors compared to IRDye800CW-cetuximab. In addition, liver uptake of IRDye800CW-nimotuzumab was two-fold lower than cetuximab. The lower liver uptake of IRDye800CW-nimotuzumab could have implications on the selected dose for clinical trials of the immunoconjugate. In summary, this study shows that nimotuzumab is a good candidate for NIR fluorescent imaging and image-guided surgery.
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Affiliation(s)
- Wendy Bernhard
- Department of Pathology, University of Saskatchewan, Saskatoon, Canada
| | - Ayman El-Sayed
- Department of Pathology, University of Saskatchewan, Saskatoon, Canada
| | - Kris Barreto
- Department of Pathology, University of Saskatchewan, Saskatoon, Canada
| | - Carolina Gonzalez
- Department of Pathology, University of Saskatchewan, Saskatoon, Canada
| | - Wayne Hill
- Department of Pathology, University of Saskatchewan, Saskatoon, Canada
| | | | - Humphrey Fonge
- Department of Medical Imaging, University of Saskatchewan, Saskatoon, Canada.,Department of Medical Imaging, Royal University Hospital, Saskatoon, Canada.,Saskatchewan Centre for Cyclotron Sciences (SCCS), Fedoruk Centre, Saskatoon, Canada
| | - C Ronald Geyer
- Department of Pathology, University of Saskatchewan, Saskatoon, Canada
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Bernhard W, Lange R, Riethmüller J. 169 Improved lung function and hepatosteatosis after oral choline substitution in CF patients. J Cyst Fibros 2016. [DOI: 10.1016/s1569-1993(16)30407-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Weber D, Stuetz W, Bernhard W, Franz A, Raith M, Grune T, Breusing N. Oxidative stress markers and micronutrients in maternal and cord blood in relation to neonatal outcome. Eur J Clin Nutr 2013; 68:215-22. [PMID: 24327121 DOI: 10.1038/ejcn.2013.263] [Citation(s) in RCA: 82] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 10/21/2013] [Accepted: 10/22/2013] [Indexed: 01/26/2023]
Abstract
BACKGROUND/OBJECTIVES Oxidative stress and micronutrient deficiencies have been related to lower birth weight (BW), small for gestational age (SGA) offspring and preterm delivery. SUBJECTS/METHODS The relation between neonatal outcome (BW, head circumference, SGA, preterm delivery) with markers of oxidative stress and micronutrients in maternal and cord blood was to be examined. Oxidative stress markers (protein carbonyls (PrCarb), 3-nitrotyrosine (3NT), malondialdehyde (MDA)), total protein concentration and lipid-soluble micronutrients (carotenoids, retinol, tocopherols) were measured in 200 newborns (11% preterms, 13% SGA) and 151 mothers. Associations between target parameters in cord plasma and maternal serum with BW, head circumference and risk of being SGA or preterm were explored. RESULTS Maternal protein concentration, PrCarb, MDA and all lipid-soluble micronutrients were significantly higher compared with newborns, except for 3NT, which was significantly elevated in newborns. Newborn parameters correlated positively with those of mothers. Preterms had lower proteins and retinol but higher PrCarb than terms. Maternal PrCarb and retinol were inversely associated with BW and head circumference. Mothers with PrCarb, MDA and retinol in the highest quintile had a 3.3-fold (0.9; 12.1), 2.1-fold (0.7; 6.4) and 3.3-fold (1.2; 9.4) risk, respectively, for delivering an SGA newborn, whereas the lowest quintile of retinol in cord blood was associated with an increased risk for preterm delivery. CONCLUSIONS Oxidative stress (elevated PrCarb) was associated with lower BW/head circumference and SGA. Inadequate hemodilution may explain the inverse relation of maternal retinol with BW and head circumference, and the association between highest maternal retinol and risk for SGA.
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Affiliation(s)
- D Weber
- Department of Nutritional Toxicology, Institute of Nutrition, Friedrich-Schiller-University of Jena, Jena, Germany
| | - W Stuetz
- Department of Nutritional Toxicology, Institute of Nutrition, Friedrich-Schiller-University of Jena, Jena, Germany
| | - W Bernhard
- Department of Neonatology, Faculty of Medicine, Eberhard-Karls-University of Tuebingen, Tuebingen, Germany
| | - A Franz
- Department of Neonatology, Faculty of Medicine, Eberhard-Karls-University of Tuebingen, Tuebingen, Germany
| | - M Raith
- Department of Neonatology, Faculty of Medicine, Eberhard-Karls-University of Tuebingen, Tuebingen, Germany
| | - T Grune
- Department of Nutritional Toxicology, Institute of Nutrition, Friedrich-Schiller-University of Jena, Jena, Germany
| | - N Breusing
- Department of Applied Nutritional Science/Dietetics, Institute of Nutritional Medicine, University of Hohenheim, Stuttgart, Germany
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Bernhard W, Barreto K, Raithatha S, Sadowski I. An upstream YY1 binding site on the HIV-1 LTR contributes to latent infection. PLoS One 2013; 8:e77052. [PMID: 24116200 PMCID: PMC3792934 DOI: 10.1371/journal.pone.0077052] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 08/28/2013] [Indexed: 02/03/2023] Open
Abstract
During HIV-1 infection a population of latently infected cells is established. This population is the major obstacle preventing total eradication of the virus from AIDS patients. HIV-1 latency is thought to arise by various mechanisms including repressive chromatin modifications. Transcription factors such as YY1 have been shown to facilitate repressive chromatin modifications by the recruitment of histone deacetylases. In this study, we identified a novel binding site for YY1 on the HIV-1 LTR, 120 nucleotides upstream of the transcription start site. We show that YY1 can bind to this site in vitro and in vivo and that binding to the LTR is dissociated upon T cell activation. Overexpression of YY1 causes an increase in the proportion of cells that produce latent infections. These observations, in combination with previous results, demonstrate that YY1 plays a prominent role in controlling the establishment and maintenance of latent HIV-1 provirus in unstimulated cells.
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Affiliation(s)
- Wendy Bernhard
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kris Barreto
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Sheetal Raithatha
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Ivan Sadowski
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
- * E-mail:
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Weber D, Stuetz W, Bernhard W, Franz A, Raith M, Grune T, Breusing N. 5-Methyltetrahydrofolate and thiamine diphosphate in cord-blood erythrocytes of preterm versus term newborns. Eur J Clin Nutr 2013; 67:1029-35. [PMID: 24002042 DOI: 10.1038/ejcn.2013.158] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 07/01/2013] [Accepted: 07/31/2013] [Indexed: 11/09/2022]
Abstract
BACKGROUND/OBJECTIVES A low folate or low thiamine status may be associated with the risk of preterm delivery, small for gestational age (SGA) offspring and adverse pregnancy outcomes. SUBJECTS/METHODS 5-Methyltetrahydrofolate (5MTHF) and thiamine diphosphate (TDP) were measured directly in cord-blood erythrocytes (CBEs) of early preterm (n=26; <32 weeks gestational age; including 50% multiple births), late preterm (n=38; 32 to <37 weeks; including 24% multiple births) and term newborns (n=60, 37-42 weeks) via high-performance liquid chromatography and fluorescence detection. Associations between 5MTHF and TDP with gestational age, newborn anthropometrics (birth weight, newborn's length and head circumference) and risk of being SGA were explored. RESULTS Group comparison as well as multivariate linear regression analysis of cord-blood vitamins revealed that 5MTHF was significantly lower in late preterms compared with terms but did not differ between singletons and multiples. TDP tended to be higher in preterms than in terms and lower in multiples than in singletons in both early and late preterms. Multivariate analysis on birth outcomes showed that 5MTHF was significantly positively associated with gestational age, birth weight and newborn's length. 5MTHF, increasing gestational age and parity were associated with a significantly reduced risk for being SGA, while TDP, multiple births and gender were not associated with the risk for being SGA. CONCLUSIONS Higher CBE concentrations of 5MTHF were associated with improved birth outcomes. Lower TDP concentrations were observed in multiple births. Future studies evaluating cord-blood vitamin concentrations and their associations with birth outcomes should additionally include dietary intakes and maternal blood concentrations at different stages of pregnancy.
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Affiliation(s)
- D Weber
- Department of Nutritional Toxicology, Institute of Nutrition, Friedrich-Schiller-University of Jena, Jena, Germany
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Sadowski I, Breitkreutz BJ, Stark C, Su TC, Dahabieh M, Raithatha S, Bernhard W, Oughtred R, Dolinski K, Barreto K, Tyers M. The PhosphoGRID Saccharomyces cerevisiae protein phosphorylation site database: version 2.0 update. Database (Oxford) 2013; 2013:bat026. [PMID: 23674503 PMCID: PMC3653121 DOI: 10.1093/database/bat026] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
PhosphoGRID is an online database that curates and houses experimentally verified in vivo phosphorylation sites in the Saccharomyces cerevisiae proteome (www.phosphogrid.org). Phosphosites are annotated with specific protein kinases and/or phosphatases, along with the condition(s) under which the phosphorylation occurs and/or the effects on protein function. We report here an updated data set, including nine additional high-throughput (HTP) mass spectrometry studies. The version 2.0 data set contains information on 20 177 unique phosphorylated residues, representing a 4-fold increase from version 1.0, and includes 1614 unique phosphosites derived from focused low-throughput (LTP) studies. The overlap between HTP and LTP studies represents only ∼3% of the total unique sites, but importantly 45% of sites from LTP studies with defined function were discovered in at least two independent HTP studies. The majority of new phosphosites in this update occur on previously documented proteins, suggesting that coverage of phosphoproteins in the yeast proteome is approaching saturation. We will continue to update the PhosphoGRID data set, with the expectation that the integration of information from LTP and HTP studies will enable the development of predictive models of phosphorylation-based signaling networks. Database URL:http://www.phosphogrid.org/
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Affiliation(s)
- Ivan Sadowski
- Department of Biochemistry and Molecular Biology, Molecular Epigenetics, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, British Columbia, Canada V6T 1Z3.
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Maas C, Mitt S, Full A, Arand J, Bernhard W, Poets CF, Franz AR. A historic cohort study on accelerated advancement of enteral feeding volumes in very premature infants. Neonatology 2013; 103:67-73. [PMID: 23095283 DOI: 10.1159/000342223] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [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] [Received: 03/15/2012] [Accepted: 07/23/2012] [Indexed: 01/24/2023]
Abstract
BACKGROUND The optimal rate of enteral feeding (EF) advancement in very low birth weight infants is under debate. OBJECTIVES To evaluate the effects of accelerated EF advancement on the time to full enteral feeds, on early postnatal growth as well as on the frequency of necrotizing enterocolitis (NEC) and focal intestinal perforation (FIP) in very premature infants. METHODS In a retrospective single-center historic cohort study, infants with a gestational age <32 weeks at birth and birth weight <1,500 g, born between January 1, 2006, and December 31, 2007 (n = 136), were compared with infants born between January 1, 2010, and December 31, 2010 (n = 88). In 2006/2007, enteral feeds were initiated on day 1 with 10-15 ml/kg/day and advanced by 15-20 ml/kg/day. In 2010, enteral feeds were initiated with 20 ml/kg/day on day 1 and advanced by 25-30 ml/kg/day. Full enteral feeds were defined as ≥ 140 ml/kg/day. Data are presented as median (P25-P75). RESULTS The time to establish full enteral feeds was shorter in 2010: 8 (7-11) days in 2006/2007 versus 6 (5-9) days in 2010. The incidences of NEC and FIP were 2.7 and 4.1% in 2006/2007 and 3.3 and 2.2% in 2010, respectively. Weight gain was not affected by the rate of EF advancement. Higher parenteral protein intake during week 1 in 2006/2007 was associated with better head circumference growth. CONCLUSIONS The new approach was associated with a significantly shorter period to establish full enteral feeds. No difference in the incidence of FIP or NEC was observed; however, the study was underpowered to detect small but possibly important differences.
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Affiliation(s)
- C Maas
- Department of Neonatology, University Children's Hospital Tübingen, Tübingen, Germany
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Maas C, Wiechers C, Bernhard W, Poets CF, Franz AR. No evidence from controlled trials to support the hypothesis that slow feeding advancement in preterm infants reduces the risk of necrotizing enterocolitis. Reply to the letter to the editor by S. Meyer and M. Butte: feeding regimens and necrotising enterocolitis [neonatology 2013;103:233-234]. Neonatology 2013; 104:123. [PMID: 23859949 DOI: 10.1159/000351982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 05/02/2013] [Indexed: 11/19/2022]
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Koslowski R, Bernhard W. Expression von Enzymen des Lipidmetabolismus in der postnatalen Rattenlunge – Effekte von Keratinocyten-Wachstumsfaktor und Glucocorticoiden. Pneumologie 2011. [DOI: 10.1055/s-0031-1296120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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Bernhard W, Gille C, Schleicher E, Stichtenoth G, Perez-Gil J, Griese M, Pynn CJ, Poets CF. Regulation und potentielle Bedeutung lipidomischer Surfactantveränderungen bei Mensch und Versuchstier. Pneumologie 2011. [DOI: 10.1055/s-0031-1296096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
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Bernhard W, Barreto K, Saunders A, Dahabieh MS, Johnson P, Sadowski I. The Suv39H1 methyltransferase inhibitor chaetocin causes induction of integrated HIV-1 without producing a T cell response. FEBS Lett 2011; 585:3549-54. [PMID: 22020221 DOI: 10.1016/j.febslet.2011.10.018] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Revised: 10/05/2011] [Accepted: 10/07/2011] [Indexed: 12/18/2022]
Abstract
Latent HIV-1 (human immunodeficiency virus-1) provirus is unaffected by current AIDS (acquired immunodeficiency syndrome) therapies. We show here that chaetocin, an SUV39H1 histone methyltransferase inhibitor, causes 25-fold induction of latent HIV-1 expression, while producing minimal toxicity and without causing T cell activation. Induction is associated with loss of histone H3 lysine 9 (H3K9) trimethylation at the long terminal repeat (LTR) promoter, and a corresponding increase in H3K9 acetylation. The effect of chaetocin is amplified synergistically in combination with histone deacetylase (HDAC) inhibitors. These results indicate that chaetocin may provide a therapy to purge cells of latent HIV-1, possibly in combination with other chromatin remodeling drugs.
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Affiliation(s)
- Wendy Bernhard
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
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Caspar T, Lin TP, Monroe J, Bernhard W, Spilatro S, Preiss J, Somerville C. Altered regulation of beta-amylase activity in mutants of Arabidopsis with lesions in starch metabolism. Proc Natl Acad Sci U S A 2010; 86:5830-3. [PMID: 16594057 PMCID: PMC297724 DOI: 10.1073/pnas.86.15.5830] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Three classes of mutants of Arabidopsis thaliana (L.) Heynhold with alterations in starch metabolism were found to have higher levels of leaf amylase activity than the wild type when grown in a 12-hr photoperiod. This effect was dependent upon the developmental stage of the plants and was largely suppressed during growth in continuous light. The various amylolytic activities in crude extracts were separated by electrophoresis in nondenaturing polyacrylamide gels and visualized by activity staining. The increased amylase activity in the mutants was due to an up to 40-fold increase in the activity of an extrachloroplast beta-amylase (EC 3.2.1.2). These observations indicate the existence of a regulatory mechanism that controls the amount of beta-amylase activity in response to fluctuations in photosynthetic carbohydrate metabolism. It is paradoxical that beta-amylase appears to be a highly regulated enzyme, but as yet no physiologically relevant function can be assigned to this enzyme due to the absence of starch in the cytoplasmic compartment of leaf cells.
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Affiliation(s)
- T Caspar
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, MI 48824
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Full A, Franz A, Arand J, Poets CF, Bernhard W. Tatsächliche Zufuhr von Cholin und Folsäure bei Frühgeborenen mit <1000g Geburtsgewicht oder <28 SSW Gestationsalter. Klin Padiatr 2010. [DOI: 10.1055/s-0030-1261570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Bernhard W, Koslowski R, Poets CF. Expression von Surfactantproteinen und Enzymen der Surfactantlipidsynthese – Rekombinanter Keratinozytenwachstumsfaktor als Alternative zu Glucocorticoiden. Klin Padiatr 2010. [DOI: 10.1055/s-0030-1261410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Luce S, Rau G, Koster G, Peter CS, Postle AD, Bernhard W. Developmental physiology of human surfactant phosphatidylcholine – Intrauterine changes relative to prenatal glucocorticoids (PNG), respiratory distress (RDS) and bronchopulmonary dysplasia (BPD). Z Geburtshilfe Neonatol 2009. [DOI: 10.1055/s-0029-1222842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Bernhard W, Gesche J, Franz A, Poets CF. Ist die postnatale Versorgung mit Cholin und Methylgruppendonatoren bei Frühgeborenen (FG) ausreichend? – Berechnungen anhand von Literaturdaten und klinischen Ernährungsempfehlungen. Z Geburtshilfe Neonatol 2009. [DOI: 10.1055/s-0029-1222817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Gille C, Basile D, Gebhard C, Spring B, Poets C, Bernhard W, Orlikowsky T. Wirkung von Surfactant und Phosphatidylcholin-Komponenten auf die Expression von Rezeptoren auf T-Zellen. Z Geburtshilfe Neonatol 2006. [DOI: 10.1055/s-2006-946065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Bernhard W, Dombrowsky H, Tschernig T, Vieten G, Rau GA, Ohler F, Acevedo C, Behrens C, von der Hardt H, Poets C. Funktionelle und molekulare Surfactantveränderungen bei Hyperoxie. Z Geburtshilfe Neonatol 2006. [DOI: 10.1055/s-2006-946068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Bernhard W, Dombrowsky H, Tschernig T, Vieten G, Rau GA, Ohler F, Acevedo C, Behrens C, von der Hardt H, Poets C. Funktionelle und molekulare Surfactantveränderungen bei Hyperoxie. Z Geburtshilfe Neonatol 2006. [DOI: 10.1055/s-2006-943153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Gille C, Basile D, Gebhard C, Spring B, Poets C, Bernhard W, Orlikowsky T. Wirkung von Surfactant und Phosphatidylcholin-Komponenten auf die Expression von Rezeptoren auf T-Zellen. Z Geburtshilfe Neonatol 2006. [DOI: 10.1055/s-2006-943150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Gesche J, Poets CF, Bernhard W. Rekombinater humaner Keratinozytenwachstumsfaktor: Perspektive für die Lungenreifung. Z Geburtshilfe Neonatol 2005. [DOI: 10.1055/s-2005-871362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Gille C, Spring B, Bernhard W, Poets CF, Dehio C, Orlikowsky T. Einfluss von Lipid-Extrakt-Surfactant und Einzelkomponenten auf die Phagozytosefähigkeit von Makrophagen. Z Geburtshilfe Neonatol 2005. [DOI: 10.1055/s-2005-871520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Pynn C, Henderson NG, Koster G, Postle AD, Jaworski A, Bernhard W. Differenzielle Synthese von Plasma-Phospholipiden via Cholineinbau und N-Methylierung beim Menschen in vivo. Z Geburtshilfe Neonatol 2005. [DOI: 10.1055/s-2005-871348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Bernhard W, Gille C, Acevedo C, Rau G, Orlikowsky T, Poets CF. Die Bedeutung des molekularen Designs von Surfactant für die alveoläre Funktion. Pneumologie 2005. [DOI: 10.1055/s-2005-862717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Bernhard W, Gesche J, Koslowski R, Spring B, Poets C. KGF erhöht den alveolären Surfactant-Pool vor und während der Alveolarisierung der Rattenlunge. Pneumologie 2005. [DOI: 10.1055/s-2005-862732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Gille C, Spring B, Gerber C, Bernhard W, Orlikowsky T, Poets CF. Porcine Surfactants verändern Phänotyp und Funktion von Blutmonozyten und Neutrophilen Granulozyten. Z Geburtshilfe Neonatol 2004. [DOI: 10.1055/s-2004-829308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Larbig M, Jansen S, Dorsch M, Bernhard W, Bellmann B, Dorin JR, Porteous DJ, Von Der Hardt H, Steinmetz I, Hedrich HJ, Tuemmler B, Tschernig T. Residual cftr expression varies with age in cftr(tm1Hgu) cystic fibrosis mice: impact on morphology and physiology. Pathobiology 2003; 70:89-97. [PMID: 12476034 DOI: 10.1159/000067308] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [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: 11/19/2022] Open
Abstract
Mouse models for cystic fibrosis (CF) mimic intestinal manifestations of the human disease, but the lung disease phenotypes are lacking in most strains. In this work, the issue was addressed whether aging of the respiratory tract leads to lung pathophysiology in the exon 10 insertional mutant cftr(tm1Hgu) mouse. Weight gain, body weight and life-span of cftr(tm1Hgu) mice were significantly reduced compared with control mice. cftr(tm1Hgu) mice expressed 20, 21 or 37% (median) of wild-type cystic fibrosis conductance transmembrane regulator (cftr) mRNA transcript in lungs, intestine and kidney. Wild-type cftr mRNA in renal and respiratory epithelia varied with age from levels similar to Ztm:MF1 controls at the age of 2 and 4 months to levels seen in patients with CFTR splice mutations beyond the age of 6 months. The morphology of the bronchi and more distal airways was apparently normal in cftr(tm1Hgu) mice during their first year of life. The alveolar surfactant phospholipid pool was increased in cftr(tm1Hgu) mice by 1.5- to 2-fold compared with Ztm:MF1 controls. Alveolar clearance of gamma-labelled scandium oxide - the first report of lung clearance measurement in living mice - was reduced in cftr(tm1Hgu) mice compared with littermate controls. Although no progressive lung pathology was seen in the cftr expression of cftr(tm1Hgu) mice, surfactant phospholipid homeostasis, and alveolar and mucociliary clearance were abnormal. Therefore, the described model is useful for studying the initial CF lung pathophysiology.
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Affiliation(s)
- M Larbig
- Fraunhofer Institute Toxicology and Aerosol Research, Medical School of Hannover, Hannover, Germany
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Abstract
Time-of-flight mass spectrometry (TOF-MS) offers new perspectives for forensic toxicology. Qualitative and quantitative analyses of a mixture of three selected benzodiazepines (diazepam, nordazepam and bromazepam) were used to compare gas chromatography (GC-TOF-MS, quadrupole GC-MS, GC-ECD) and liquid chromatography (HPLC-DAD) data. Method validation parameters like LOD, LOQ, S/N-ratios reflect the capabilities of GC-TOF-MS. Five-point calibrations for bromazepam in human peripheral blood (50, 100, 160, 200, 300 ng/ml) using medazepam as internal standard (1000 ng/ml) were performed. The calibrations using GC-TOF-MS (using the fragments of m/z 236 and 288), GC-ECD (dual system) and HPLC-DAD (at 235 nm) all showed correlation coefficients close or superior to 0.99. Quadrupole GC-MS data was not used in the comparison of extracted samples due to the low sensitivity in the full scan mode. Two analyses of real cases concerning bromazepam are presented. In the first case, the presence or absence of bromazepam could not be established with both HPLC-DAD and GC-ECD due to background signals. The extracted ion chromatograms and spectrum traces after the analysis with the GC-TOF-MS could clearly excluded the presence of bromazepam. The second case illustrates the quantitation of bromazepam, where both HPLC-DAD and GC-ECD were unable to give satisfactory results, again due to interfering background signals. The analyses performed on the GC-TOF-MS-system demonstrated high sensitivity and also high selectivity due to the high quality of mass spectra obtained. The advantages of GC-TOF-MS make it a promising analytical technique for forensic toxicology.
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Affiliation(s)
- B Aebi
- Forensic Chemistry and Toxicology, Institute of Legal Medicine, University of Berne, Bühlstrasse 20, CH-3012 Berne, Switzerland.
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Bernhard W, Hoffmann S, Dombrowsky H, Rau GA, Kamlage A, Kappler M, Haitsma JJ, Freihorst J, von der Hardt H, Poets CF. Phosphatidylcholine molecular species in lung surfactant: composition in relation to respiratory rate and lung development. Am J Respir Cell Mol Biol 2001; 25:725-31. [PMID: 11726398 DOI: 10.1165/ajrcmb.25.6.4616] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.3] [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: 11/24/2022] Open
Abstract
Surfactant reduces surface tension at the air-liquid interface of lung alveoli. While dipalmitoylphosphatidylcholine (PC16:0/ 16:0) is its main component, proteins and other phospholipids contribute to the dynamic properties and homeostasis of alveolar surfactant. Among these components are significant amounts of palmitoylmyristoylphosphatidylcholine (PC16:0/ 14:0) and palmitoylpalmitoleoylphosphatidylcholine (PC16:0/ 16:1), whereas in surfactant from the rigid tubular bird lung, PC16:0/14:0 is absent and PC16:0/16:1 strongly diminished. We therefore hypothesized that the concentrations of PC16:0/14:0 and PC16:0/16:1 in surfactants correlate with differences in the respiratory physiology of mammalian species. In surfactants from newborn and adult mice, rats, and pigs, molar fractions of PC16:0/14:0 and PC16:0/16:1 correlated with respiratory rate. Labeling experiments with [methyl-(3)H]choline in mice and perfused rat lungs demonstrated identical alveolar proportions of total and newly synthesized PC16:0/14:0, PC16:0/16:1, and PC16:0/16:0, which were much higher than those of other phosphatidylcholine species. In surfactant from human term and preterm neonates, fractional concentrations not only of PC16:0/16:0 but also of PC16:0/14:0 and PC16:0/ 16:1 increased with maturation. Our data emphasize that PC16:0/14:0 and PC16:0/16:1 may be important surfactant components in alveolar lungs, and that their concentrations are adapted to respiratory physiology.
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Affiliation(s)
- W Bernhard
- Department of Pediatric Pulmonology, Hannover Medical School, Hannover, Germany.
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Bernhard W, Gebert A, Vieten G, Rau GA, Hohlfeld JM, Postle AD, Freihorst J. Pulmonary surfactant in birds: coping with surface tension in a tubular lung. Am J Physiol Regul Integr Comp Physiol 2001; 281:R327-37. [PMID: 11404309 DOI: 10.1152/ajpregu.2001.281.1.r327] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [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: 11/22/2022]
Abstract
As birds have tubular lungs that do not contain alveoli, avian surfactant predominantly functions to maintain airflow in tubes rather than to prevent alveolar collapse. Consequently, we have evaluated structural, biochemical, and functional parameters of avian surfactant as a model for airway surfactant in the mammalian lung. Surfactant was isolated from duck, chicken, and pig lung lavage fluid by differential centrifugation. Electron microscopy revealed a uniform surfactant layer within the air capillaries of the bird lungs, and there was no tubular myelin in purified avian surfactants. Phosphatidylcholine molecular species of the various surfactants were measured by HPLC. Compared with pig surfactant, both bird surfactants were enriched in dipalmitoylphosphatidylcholine, the principle surface tension-lowering agent in surfactant, and depleted in palmitoylmyristoylphosphatidylcholine, the other disaturated phosphatidylcholine of mammalian surfactant. Surfactant protein (SP)-A was determined by immunoblot analysis, and SP-B and SP-C were determined by gel-filtration HPLC. Neither SP-A nor SP-C was detectable in either bird surfactant, but both preparations of surfactant contained SP-B. Surface tension function was determined using both the pulsating bubble surfactometer (PBS) and capillary surfactometer (CS). Under dynamic cycling conditions, where pig surfactant readily reached minimal surface tension values below 5 mN/m, neither avian surfactant reached values below 15 mN/m within 10 pulsations. However, maximal surface tension of avian surfactant was lower than that of porcine surfactant, and all surfactants were equally efficient in the CS. We conclude that a surfactant composed primarily of dipalmitoylphosphatidylcholine and SP-B is adequate to maintain patency of the air capillaries of the bird lung.
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Affiliation(s)
- W Bernhard
- Departments of Pediatric Pulmonology and Neonatology, Hannover Medical School, 30625 Hannover, Germany.
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Bernhard W, Bertling A, Dombrowsky H, Vieten G, Rau G, von der Hardt H, Freihorst J. Metabolism of surfactant phosphatidylcholine molecular species in cftr(tm1HGU/tm1HGU) mice compared to MF-1 mice. Exp Lung Res 2001; 27:349-66. [PMID: 11400861 DOI: 10.1080/019021401750193610] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [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: 10/16/2022]
Abstract
In cftr(tmIHGU/m1HGU) mice, an animal model designed to study pathophysiologic alterations due to the CFTR defect found in cysticfibrosis, surfactant phospholipids of bronchoalveolar lavage fluid (BALF) are increased. To study the metabolical basis of such increases, we intraperitoneally injected cft(tm1HGU/tm1HGU) mice [methyl-3H]choline and measured [methyl-3H]choline incorporation into phosphatidylcholine (PC) molecular species of lung tissue and BALF after 1.5 to 24 hours. MF1 and MF1 x cftr(tm1HGU/tm1HGU) hybrid mice served as controls. In tissue [methyl-3H]choline incorporation into total PC was constant for 24 hours and identical in control and cftr(tmIHGU/m1HGU) mice. However, from 7.5 to 24 hours there was a shift of [methyl-3H]choline incorporation from palmitoyloleoyl-PC and palmitoyllinoleoyl-PC towards PC species enriched in surfactant, dipalmitoyl-PC, palmitoylmyristoyl-PC, and palmitoylpalmitoleoyl-PC. The relative and absolute 3H-labels of PC species were identical for cftr(tmIHGU/m1HGU) compared to control mice. In BALF [methyl-3H]choline of total PC increased from 1.5 to 24 hours (R2 > .98), mainly due to [methyl-3H]choline-labelled dipalmitoyl-PC, in all experimental groups. In BALF from cftr(tmIHGU/m1HGU) mice, the [methyl-3H]choline label of total PC and individual PC species was significantly increased over control values after 24 hours, but not after 1.5 to 6 hours. Numbers and composition of BALF cells were not different between controls and cftr(tmIHGU/m1HGU) mice. We, conclude that increased alveolar phospholipid in cftr(tmIHGU/m1HGU) mice is likely due to decreased reuptake of surfactant.
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Affiliation(s)
- W Bernhard
- Department of Pediatric Pulmonology and Neonatology, Hannover Medical School, Federal Republic of Germany. Bernhard.Wolfgang@.mh-hannover.de
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Bernhard W, Postle AD, Rau GA, Freihorst J. Pulmonary and gastric surfactants. A comparison of the effect of surface requirements on function and phospholipid composition. Comp Biochem Physiol A Mol Integr Physiol 2001; 129:173-82. [PMID: 11369542 DOI: 10.1016/s1095-6433(01)00314-2] [Citation(s) in RCA: 23] [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] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Surfactant is present in the alveoli and conductive airways of mammalian lungs. The presence of surface active agents was, moreover, demonstrated for avian tubular lungs and for the stomach and intestine. As the surface characteristics of these organs differ from each other, their surfactants possess distinct biochemical and functional characteristics. In the stomach so-called 'gastric surfactant' forms a hydrophobic barrier to protect the mucosa against acid back-diffusion. For this purpose gastric mucosal cells secrete unsaturated phosphatidylcholines (PC), but no dipalmitoyl-PC (PC16:0/16:0). By contrast, surfactant from conductive airways, lung alveoli and tubular avian lungs contain PC16:0/16:0 as their main component in similar concentrations. Hence, there is no biochemical relation between gastric and pulmonary surfactant. Alveolar surfactant, being designed for preventing alveolar collapse under the highly dynamic conditions of an oscillating alveolus, easily reaches values of <5 mN/m upon cyclic compression. Surfactants from tubular air-exposed structures, however, like the conductive airways of mammalian lungs and the exclusively tubular avian lung, display inferior compressibility as they only reach minimal surface tension values of approximately 20 mN/m. Hence, the highly dynamic properties of alveolar surfactant do not apply for surfactants designed for air-liquid interfaces of tubular lung structures.
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Affiliation(s)
- W Bernhard
- Departments of Pediatric Pulmonology and Neonatology, Hannover Medical School, 30623, Hannover, Germany.
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Bernhard W, Mottaghian J, Gebert A, Rau GA, von Der HARDT H, Poets CF. Commercial versus native surfactants. Surface activity, molecular components, and the effect of calcium. Am J Respir Crit Care Med 2000; 162:1524-33. [PMID: 11029372 DOI: 10.1164/ajrccm.162.4.9908104] [Citation(s) in RCA: 161] [Impact Index Per Article: 6.7] [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: 11/16/2022] Open
Abstract
Despite their broad clinical use, there is no standardized comparative study on the functional, biochemical, and morphologic differences of the various commercial surfactants in relation to native surfactant. We investigated these parameters in Alveofact, Curosurf, Exosurf, and Survanta, and compared them with native bovine (NBS) and porcine (NPS) surfactant. For Curosurf and Alveofact the concentrations necessary for minimal surface tensions < 5 mN/m were six to 12 times higher (1.5 and 3 mg/ml, respectively) than with NPS and NBS. Exosurf and Survanta only reached 22 and 8 mN/m, respectively. Increasing calcium to nonphysiologic concentrations artificially improved the function of Alveofact and Curosurf, but it had little effect on Exosurf and Survanta. Impaired surface activity of commercial versus native surfactants corresponded with their lack in surfactant protein SP-A and decreased SP-B/C. The higher surface activity of Curosurf compared with Alveofact corresponded with its higher concentration of dipalmitoylphosphatidylcholine (DPPC). Despite their enrichment in DPPC Survanta and Exosurf exhibited poor surface activity because of low or absent SP-B/C. Ultrastructurally, Curosurf and Alveofact consisted mainly of lamellar and vesicular structures, which were also present in NPS and NBS. Exosurf contained crystalline structures only, whereas the DPPC-enriched Survanta contained separate lamellar/vesicular and crystalline structures. We conclude that in vitro surface activity of commercial surfactants is impaired compared with native surfactants at physiologic calcium concentrations. In the presence of SP-B/C, surface activity corresponds to the concentration of DPPC. Our data underscore the importance of a standardized protocol at physiologic calcium concentrations for the in vitro assessment of commercial surfactants.
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Affiliation(s)
- W Bernhard
- Departments of Pediatric Pulmonology and Neonatology and Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
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Bernhard W, Rau G, Gebert A, Hohlfeld J, Postle A, Freihorst J. Surfactant in the tubular bird lung in comparison to the alveolar mammalian lung — similarities and dissimilarities. Comp Biochem Physiol B Biochem Mol Biol 2000. [DOI: 10.1016/s0305-0491(00)80021-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Ledochowski M, Bernhard W, Fuchs D. Homocysteine and heart disease in Indian Asians. Lancet 2000; 355:2249; author reply 2250. [PMID: 10881913 DOI: 10.1016/s0140-6736(05)72744-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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