1
|
Wescott EC, Sun X, Gonzalez-Ericsson P, Hanna A, Taylor BC, Sanchez V, Bronzini J, Opalenik SR, Sanders ME, Wulfkuhle J, Gallagher RI, Gomez H, Isaacs C, Bharti V, Wilson JT, Ballinger TJ, Santa-Maria CA, Shah PD, Dees EC, Lehmann BD, Abramson VG, Hirst GL, Brown Swigart L, van ˈt Veer LJ, Esserman LJ, Petricoin EF, Pietenpol JA, Balko JM. Epithelial Expressed B7-H4 Drives Differential Immunotherapy Response in Murine and Human Breast Cancer. Cancer Res Commun 2024; 4:1120-1134. [PMID: 38687247 PMCID: PMC11041871 DOI: 10.1158/2767-9764.crc-23-0468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 01/30/2024] [Accepted: 03/29/2024] [Indexed: 05/02/2024]
Abstract
Combinations of immune checkpoint inhibitors (ICI, including anti-PD-1/PD-L1) and chemotherapy have been FDA approved for metastatic and early-stage triple-negative breast cancer (TNBC), but most patients do not benefit. B7-H4 is a B7 family ligand with proposed immunosuppressive functions being explored as a cancer immunotherapy target and may be associated with anti-PD-L1 resistance. However, little is known about its regulation and effect on immune cell function in breast cancers. We assessed murine and human breast cancer cells to identify regulation mechanisms of B7-H4 in vitro. We used an immunocompetent anti-PD-L1-sensitive orthotopic mammary cancer model and induced ectopic expression of B7-H4. We assessed therapy response and transcriptional changes at baseline and under treatment with anti-PD-L1. We observed B7-H4 was highly associated with epithelial cell status and transcription factors and found to be regulated by PI3K activity. EMT6 tumors with cell-surface B7-H4 expression were more resistant to immunotherapy. In addition, tumor-infiltrating immune cells had reduced immune activation signaling based on transcriptomic analysis. Paradoxically, in human breast cancer, B7-H4 expression was associated with survival benefit for patients with metastatic TNBC treated with carboplatin plus anti-PD-L1 and was associated with no change in response or survival for patients with early breast cancer receiving chemotherapy plus anti-PD-1. While B7-H4 induces tumor resistance to anti-PD-L1 in murine models, there are alternative mechanisms of signaling and function in human cancers. In addition, the strong correlation of B7-H4 to epithelial cell markers suggests a potential regulatory mechanism of B7-H4 independent of PD-L1. SIGNIFICANCE This translational study confirms the association of B7-H4 expression with a cold immune microenvironment in breast cancer and offers preclinical studies demonstrating a potential role for B7-H4 in suppressing response to checkpoint therapy. However, analysis of two clinical trials with checkpoint inhibitors in the early and metastatic settings argue against B7-H4 as being a mechanism of clinical resistance to checkpoints, with clear implications for its candidacy as a therapeutic target.
Collapse
Affiliation(s)
- Elizabeth C. Wescott
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Xiaopeng Sun
- Breast Cancer Research Program, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Paula Gonzalez-Ericsson
- Breast Cancer Research Program, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Ann Hanna
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Brandie C. Taylor
- Breast Cancer Research Program, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Violeta Sanchez
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Juliana Bronzini
- Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee
| | - Susan R. Opalenik
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Melinda E. Sanders
- Breast Cancer Research Program, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Julia Wulfkuhle
- Center for Applied Proteomics and Molecular Medicine, George Mason University, Manassas, Virginia
| | - Rosa I. Gallagher
- Center for Applied Proteomics and Molecular Medicine, George Mason University, Manassas, Virginia
| | - Henry Gomez
- Department of Medical Oncology, Instituto Nacional de Enfermedades Neoplásicas, Lima, Perú
| | - Claudine Isaacs
- Division of Hematology-Oncology, Department of Medicine, Georgetown University, Washington, District of Columbia
| | - Vijaya Bharti
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee
| | - John T. Wilson
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee
| | - Tarah J. Ballinger
- Division of Hematology and Oncology, Indiana University School of Medicine, Indianapolis, Indiana
| | | | - Payal D. Shah
- Abramson Cancer Center, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Elizabeth C. Dees
- Department of Medicine, School of Medicine, University of North Carolina, Chapel Hill, North Carolina
| | - Brian D. Lehmann
- Breast Cancer Research Program, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Vandana G. Abramson
- Breast Cancer Research Program, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Gillian L. Hirst
- Department of Surgery, University of California San Francisco, San Francisco, California
| | - Lamorna Brown Swigart
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, California
| | - Laura J. van ˈt Veer
- Department of Laboratory Medicine, University of California San Francisco, San Francisco, California
| | - Laura J. Esserman
- Department of Surgery, University of California San Francisco, San Francisco, California
| | - Emanuel F. Petricoin
- Center for Applied Proteomics and Molecular Medicine, George Mason University, Manassas, Virginia
| | - Jennifer A. Pietenpol
- Breast Cancer Research Program, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
- Johns Hopkins Sidney Kimmel Comprehensive Cancer Center, Baltimore, Maryland
- Department of Biochemistry, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Justin M. Balko
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee
- Breast Cancer Research Program, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
- Cancer Biology Program, Vanderbilt University, Nashville, Tennessee
| |
Collapse
|
2
|
Taylor BC, Sun X, Gonzalez-Ericsson PI, Sanchez V, Sanders ME, Wescott EC, Opalenik SR, Hanna A, Chou ST, Van Kaer L, Gomez H, Isaacs C, Ballinger TJ, Santa-Maria CA, Shah PD, Dees EC, Lehmann BD, Abramson VG, Pietenpol JA, Balko JM. NKG2A Is a Therapeutic Vulnerability in Immunotherapy Resistant MHC-I Heterogeneous Triple-Negative Breast Cancer. Cancer Discov 2024; 14:290-307. [PMID: 37791898 PMCID: PMC10850946 DOI: 10.1158/2159-8290.cd-23-0519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 08/21/2023] [Accepted: 09/25/2023] [Indexed: 10/05/2023]
Abstract
Despite the success of immune checkpoint inhibition (ICI) in treating cancer, patients with triple-negative breast cancer (TNBC) often develop resistance to therapy, and the underlying mechanisms are unclear. MHC-I expression is essential for antigen presentation and T-cell-directed immunotherapy responses. This study demonstrates that TNBC patients display intratumor heterogeneity in regional MHC-I expression. In murine models, loss of MHC-I negates antitumor immunity and ICI response, whereas intratumor MHC-I heterogeneity leads to increased infiltration of natural killer (NK) cells in an IFNγ-dependent manner. Using spatial technologies, MHC-I heterogeneity is associated with clinical resistance to anti-programmed death (PD) L1 therapy and increased NK:T-cell ratios in human breast tumors. MHC-I heterogeneous tumors require NKG2A to suppress NK-cell function. Combining anti-NKG2A and anti-PD-L1 therapies restores complete response in heterogeneous MHC-I murine models, dependent on the presence of activated, tumor-infiltrating NK and CD8+ T cells. These results suggest that similar strategies may enhance patient benefit in clinical trials. SIGNIFICANCE Clinical resistance to immunotherapy is common in breast cancer, and many patients will likely require combination therapy to maximize immunotherapeutic benefit. This study demonstrates that heterogeneous MHC-I expression drives resistance to anti-PD-L1 therapy and exposes NKG2A on NK cells as a target to overcome resistance. This article is featured in Selected Articles from This Issue, p. 201.
Collapse
Affiliation(s)
| | - Xiaopeng Sun
- Cancer Biology Program, Vanderbilt University, Nashville, Tennessee
| | - Paula I. Gonzalez-Ericsson
- Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
- Breast Cancer Research Program, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Violeta Sanchez
- Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Melinda E. Sanders
- Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
- Breast Cancer Research Program, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Elizabeth C. Wescott
- Department of Pathology, Microbiology, and Immunology, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Susan R. Opalenik
- Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Ann Hanna
- Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Shu-Ting Chou
- Cancer Biology Program, Vanderbilt University, Nashville, Tennessee
| | - Luc Van Kaer
- Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Pathology, Microbiology, and Immunology, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Henry Gomez
- Department of Medical Oncology, Instituto Nacional de Enfermedades Neoplásicas, Lima, Perú
| | - Claudine Isaacs
- Division of Hematology-Oncology, Department of Medicine, Georgetown University, Washington, District of Columbia
| | - Tarah J. Ballinger
- Division of Hematology and Oncology, Indiana University School of Medicine, Indianapolis, Indiana
| | | | - Payal D. Shah
- Abramson Cancer Center, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Elizabeth C. Dees
- Department of Medicine, School of Medicine, University of North Carolina, Chapel Hill, North Carolina
| | - Brian D. Lehmann
- Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
- Breast Cancer Research Program, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Vandana G. Abramson
- Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
- Breast Cancer Research Program, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Jennifer A. Pietenpol
- Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
- Breast Cancer Research Program, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Biochemistry, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Justin M. Balko
- Department of Medicine, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
- Breast Cancer Research Program, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Pathology, Microbiology, and Immunology, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, Tennessee
| |
Collapse
|
3
|
James JL, Taylor BC, Axelrod ML, Sun X, Guerin LN, Gonzalez-Ericsson PI, Wang Y, Sanchez V, Fahey CC, Sanders ME, Xu Y, Hodges E, Johnson DB, Balko JM. Polycomb repressor complex 2 suppresses interferon-responsive MHC-II expression in melanoma cells and is associated with anti-PD-1 resistance. J Immunother Cancer 2023; 11:e007736. [PMID: 38315170 PMCID: PMC10660662 DOI: 10.1136/jitc-2023-007736] [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] [Accepted: 10/17/2023] [Indexed: 02/07/2024] Open
Abstract
BACKGROUND Despite the remarkable success of immunotherapy in treating melanoma, understanding of the underlying mechanisms of resistance remains limited. Emerging evidence suggests that upregulation of tumor-specific major histocompatibility complex-II (tsMHC-II) serves as a predictive marker for the response to anti-programmed death-1 (PD-1)/programmed death ligand 1 (PD-L1) therapy in various cancer types. The genetic and epigenetic pathways modulating tsMHC-II expression remain incompletely characterized. Here, we provide evidence that polycomb repressive complex 2 (PRC2)/EZH2 signaling and resulting H3K27 hypermethylation suppresses tsMHC-II. METHODS RNA sequencing data from tumor biopsies from patients with cutaneous melanoma treated with or without anti-PD-1, targeted inhibition assays, and assays for transposase-accessible chromatin with sequencing were used to observe the relationship between EZH2 inhibition and interferon (IFN)-γ inducibility within the MHC-II pathway. RESULTS We find that increased EZH2 pathway messenger RNA (mRNA) expression correlates with reduced mRNA expression of both presentation and T-cell genes. Notably, targeted inhibition assays revealed that inhibition of EZH2 influences the expression dynamics and inducibility of the MHC-II pathway following IFN-γ stimulation. Additionally, our analysis of patients with metastatic melanoma revealed a significant inverse association between PRC2-related gene expression and response to anti-PD-1 therapy. CONCLUSIONS Collectively, our findings demonstrate that EZH2 inhibition leads to enhanced MHC-II expression potentially resulting from improved chromatin accessibility at CIITA, the master regulator of MHC-II. These insights shed light on the molecular mechanisms involved in tsMHC-II suppression and highlight the potential of targeting EZH2 as a therapeutic strategy to improve immunotherapy efficacy.
Collapse
Affiliation(s)
- Jamaal L James
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Brandie C Taylor
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Margaret L Axelrod
- Department of Medicine, Washington University in St Louis, St Louis, Missouri, USA
| | - Xiaopeng Sun
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Lindsey N Guerin
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA
| | - Paula I Gonzalez-Ericsson
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Breast Cancer Research Program, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Yu Wang
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Violeta Sanchez
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Catherine C Fahey
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Hematology/Oncology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Melinda E Sanders
- Breast Cancer Research Program, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Yaomin Xu
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Emily Hodges
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA
- Genetics Institute, Vanderbilt University, Nashville, Tennessee, USA
| | - Douglas B Johnson
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Justin M Balko
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
- Breast Cancer Research Program, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| |
Collapse
|
4
|
Friedman JK, Taylor BC, Hagel Campbell E, Allen K, Bangerter A, Branson M, Bronfort G, Calvert C, Cross L, Driscoll M, Evans R, Ferguson JE, Haley A, Hennessy S, Meis LA, Burgess DJ. Gender differences in PTSD severity and pain outcomes: baseline results from the LAMP trial. medRxiv 2023:2023.10.13.23296998. [PMID: 37873176 PMCID: PMC10593051 DOI: 10.1101/2023.10.13.23296998] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Background Post-traumatic stress disorder (PTSD) and chronic pain are highly prevalent comorbid conditions. Veterans dually burdened by PTSD and chronic pain experience more severe outcomes compared to either disorder alone. Few studies have enrolled enough women Veterans to test gender differences in pain outcomes [catastrophizing, intensity, interference] by the severity of PTSD. Aim Examine gender differences in the association between PTSD symptoms and pain outcomes among Veterans enrolled in a chronic pain clinical trial. Methods Participants were 421 men and 386 women Veterans with chronic pain who provided complete data on PTSD symptoms and pain outcomes. We used hierarchical linear regression models to examine gender differences in pain outcomes by PTSD symptoms. Results Adjusted multivariable models indicated that PTSD symptoms were associated with higher levels of pain catastrophizing (0.57, 95% CI [0.51, 0.63]), pain intensity (0.30, 95% CI [0.24, 0.37]), and pain interference (0.46, 95% CI [0.39, 0.52]). No evidence suggesting differences in this association were found in either the crude or adjusted models (all interaction p-values<0.05). Conclusion These findings may reflect the underlying mutual maintenance of these conditions whereby the sensation of pain could trigger PTSD symptoms, particularly if the trauma and pain are associated with the same event. Clinical implications and opportunities testing relevant treatments that may benefit both chronic pain and PTSD are discussed.
Collapse
Affiliation(s)
- J K Friedman
- Center for Care Delivery and Outcomes Research, Minneapolis Veterans Affairs Healthcare System (MVAHCS), Minneapolis, MN
- University of Minnesota Medical School, Minneapolis, MN
| | - B C Taylor
- Center for Care Delivery and Outcomes Research, Minneapolis Veterans Affairs Healthcare System (MVAHCS), Minneapolis, MN
- University of Minnesota Medical School, Minneapolis, MN
| | - E Hagel Campbell
- Center for Care Delivery and Outcomes Research, Minneapolis Veterans Affairs Healthcare System (MVAHCS), Minneapolis, MN
| | - K Allen
- Center of Innovation to Accelerate Discovery and Practice Transformation, Durham VAHCS, Durham, NC
- Thurston Arthritis Research Center, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - A Bangerter
- Center for Care Delivery and Outcomes Research, Minneapolis Veterans Affairs Healthcare System (MVAHCS), Minneapolis, MN
| | - M Branson
- Center for Care Delivery and Outcomes Research, Minneapolis Veterans Affairs Healthcare System (MVAHCS), Minneapolis, MN
| | - G Bronfort
- Integrative Health & Wellbeing Research Program, Bakken Center for Spirituality & Healing, University of Minnesota, Minneapolis, MN
- University of Minnesota School of Nursing, Minneapolis, MN
| | - C Calvert
- Center for Care Delivery and Outcomes Research, Minneapolis Veterans Affairs Healthcare System (MVAHCS), Minneapolis, MN
- University of Minnesota Medical School, Minneapolis, MN
| | - Ljs Cross
- Center for Care Delivery and Outcomes Research, Minneapolis Veterans Affairs Healthcare System (MVAHCS), Minneapolis, MN
| | - M Driscoll
- VA Connecticut Healthcare System, West Haven, CT
- Yale School of Medicine, New Haven, CT
| | - R Evans
- Integrative Health & Wellbeing Research Program, Bakken Center for Spirituality & Healing, University of Minnesota, Minneapolis, MN
- University of Minnesota School of Nursing, Minneapolis, MN
| | - J E Ferguson
- University of Minnesota Medical School, Minneapolis, MN
| | - A Haley
- Integrative Health & Wellbeing Research Program, Bakken Center for Spirituality & Healing, University of Minnesota, Minneapolis, MN
- University of Minnesota School of Nursing, Minneapolis, MN
| | - S Hennessy
- Center for Care Delivery and Outcomes Research, Minneapolis Veterans Affairs Healthcare System (MVAHCS), Minneapolis, MN
| | - L A Meis
- Center for Care Delivery and Outcomes Research, Minneapolis Veterans Affairs Healthcare System (MVAHCS), Minneapolis, MN
- University of Minnesota Medical School, Minneapolis, MN
- Women's Health Sciences Division, National Center for PTSD, Boston, MA
| | - D J Burgess
- Center for Care Delivery and Outcomes Research, Minneapolis Veterans Affairs Healthcare System (MVAHCS), Minneapolis, MN
- University of Minnesota Medical School, Minneapolis, MN
| |
Collapse
|
5
|
Hanna A, Sun X, Tran E, Sheng Q, Taylor BC, Opalenik SR, Balko JM. Abstract 4152: Longitudinal local and peripheral immunologic changes associated with PD-L1 response in a murine breast cancer model. Cancer Res 2023. [DOI: 10.1158/1538-7445.am2023-4152] [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] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Abstract
Immune checkpoint inhibitors (ICI) have significantly enhanced patient survival in many cancers but yield limited success in breast cancer. ICIs activate anti-tumor immunity by overriding the inhibition of tumor infiltrating lymphocytes (TILs). Clinical trials in triple negative breast cancer (TNBC) patients, who harbor TILs within tumor stroma, have demonstrated increased survival (IMpassion130) and pathologic complete response (KEYNOTE-522) to ICI leading to FDA-approval of ICI and chemotherapy combinations in metastatic TNBC. However, ICI benefit is heterogeneous among patients. We sought to model ICI response in vivo to evaluate therapeutic resistance and response heterogeneity and to ascertain predictive biomarkers for favorable ICI outcomes. An immunocompetent EMT6 orthotopic mammary tumor model was used to investigate the efficacy of anti-PD-L1. Matched longitudinal samples of the tumor microenvironment (TME) (collected by fine-needle aspiration) and peripheral blood (PBMC) from mice were profiled by bulk RNA and T-cell receptor sequencing.
Anti-PD-L1 robustly suppressed primary tumor growth and extended survival beyond the control group. The addition of chemotherapy demonstrated moderate therapeutic efficacy but failed to enhance ICI benefit. Phenotypic profiling of the TME revealed increased T cells, DCs, and NK cells in anti-PD-L1 only and chemotherapy combination groups. Despite using a genetically identical tumor model and host, PD-L1 blockade induced heterogeneous responses, like clinical outcomes in TNBC patients, ranging from complete response (CR) to intrinsic resistance (IR). The primary TME showed upregulated signatures of cytotoxic T cell response and activation, specifically inflammatory interferon signaling (both prior to and post ICI administration) that corresponded to favorable outcomes to anti-PD-L1 in individual mice. Longitudinal analysis of the peripheral blood identified modest changes among mice at baseline that progressively deviated by response type (IR-vs-CR). Mice harbored enriched myeloid signatures and clonal T cell expansion during therapy corresponding to ICI resistance and response, respectively. Further investigations of matched peripheral blood and the primary TME signatures may identify systemic biomarkers and tumor antigen-specific T cell clones to accurately predict ICI response in patients and uncover mechanisms for sensitizing tumors refractory to ICI.
Thus, we identify an in vivo model that emulates TNBC patient heterogeneous outcomes to ICI combinatorial approaches. We describe host-specific signatures, specifically from myeloid cells, that correlate with differential responses to ICI, which may serve as a basis for peripheral blood tracking of breast cancer patient responses.
Citation Format: Ann Hanna, Xiaopeng Sun, Emily Tran, Quanhu Sheng, Brandie C. Taylor, Susan R. Opalenik, Justin M. Balko. Longitudinal local and peripheral immunologic changes associated with PD-L1 response in a murine breast cancer model. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4152.
Collapse
Affiliation(s)
- Ann Hanna
- 1Vanderbilt University Medical Center, Nashville, TN
| | | | | | - Quanhu Sheng
- 1Vanderbilt University Medical Center, Nashville, TN
| | | | | | | |
Collapse
|
6
|
Taylor BC, Sun X, Balko J, Gonzalez-Ericsson P, Sanders M. Abstract PD2-06: Implications of Heterogeneity in Breast Tumor Cell MHC-I Expression on Immunity and Therapeutic Resistance. Cancer Res 2023. [DOI: 10.1158/1538-7445.sabcs22-pd2-06] [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] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
Abstract
Background Immune checkpoint inhibitors (ICIs) targeting the PD-1/L1 axis are approved in early-stage treatment for triple-negative breast cancer (TNBC), but only a fraction of patients benefit. Tumor expressed antigens bound to major histocompatibility complex-I (MHC-I) are required for CD8-mediated tumoricidal activity, and thus, response to anti-PD-1/L1 targeted ICI. However, many breast tumors downregulate, or heterogeneously express, MHC-I, making them less susceptible to ICIs. Tumor cells downregulating MHC-I may be effectively targeted by natural killer (NK) cells due to ‘missing self’ signals. However, this heterogeneity in MHC-I expression is poorly modeled in most preclinical studies, limiting our understanding of how to overcome ICI resistance in the context of heterogeneous MHC-I expression, as is often observed clinically. Objective We aimed to 1) quantitatively delineate how intratumoral heterogeneity in MHC class I expression affects immune responses and immunotherapy outcomes in mouse models and 2) determine whether targeting inhibitory signals on NK cells can overcome ICI resistance in MHC-I heterogenous TNBC. Methods We performed quantitative immunofluorescence for MHC-I, CD8, CD56, and pan-cytokeratin on breast cancer tumors from diverse subtypes (n=314) to obtain single-cell-resolution MHC-I expression and spatial information of tumor and immune cells. Fluorescence intensity and spatial analysis were processed to output individual tumor/stromal cell MHC-I expression and the composition of the local tumor microenvironment. To determine the functional effect of MHC-I heterogeneity in vivo, we generated a CRISPR-guided B2m knockout (B2m-null) in a murine orthotopic model (EMT6). We then combined MHC-I-proficient and MHC-I-deficient isogenic lines at various ratios to model how populations of MHC-I loss affected the immune microenvironment. We also assessed a second, intrinsically heterogenous (MHC-I expression) TNBC model E0771. To evaluate changes in the microenvironment, we used flow cytometry and an immune NanoString panel to evaluate gene expression patterns in tumor cells and infiltrating immune cells. Results TNBC patients had the highest MHC-I expression level across tumor cells, but also the highest variability and probability of demonstrating bimodal MHC-I expression (consisting of high and low/absent cells within a single tumor). ER+ tumors were unimodally low. Using spatial analysis, we identified that heterogenous MHC-I tumors had significantly higher levels of infiltrating NK cells(Paired T-Test: p=0.03). In murine models, even 10% or less of MHC-I-null (B2m-null) EMT6 cells in the tumor injection resulted in acquisition of ICI resistance. Interestingly, heterogeneity in expression of MHC-I resulted in a substantial infiltration by NKG2A+ NK cells compared to MHC-I high or -low tumors (Student T-Test: p=.002). Activation of these infiltrating NK cells via anti-NKG2A and anti-PD-L1 combination treatment restored complete responses in heterogeneous EMT6 tumors, and significantly extended survival in both E0771 (Mantel-Cox: p< 0.0001) and EMT6 models (Mantel-Cox: < 0.0001). Additionally, anti-NKG2A and anti-PDL1 combination treatment improved complete response in the heterogenous MHC-I EMT6 model to 30% and in the parental EMT-6 tumors to 70%. Conclusion Combined therapy with anti-NKG2A (targeting NK cells) and anti-PD-L1 (targeting CD8+ T cells) can restore immunotherapy responses and overcome resistance due to lack of MHC-I expression in tumor cell subpopulations.
Citation Format: Brandie C. Taylor, Xiaopeng Sun, Justin Balko, Paula Gonzalez-Ericsson, Melinda Sanders. Implications of Heterogeneity in Breast Tumor Cell MHC-I Expression on Immunity and Therapeutic Resistance [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr PD2-06.
Collapse
Affiliation(s)
| | | | - Justin Balko
- 3Vanderbilt University Medical Center, Nashville, Tennessee
| | | | | |
Collapse
|
7
|
Axelrod ML, Meijers WC, Screever EM, Qin J, Carroll MG, Sun X, Tannous E, Zhang Y, Sugiura A, Taylor BC, Hanna A, Zhang S, Amancherla K, Tai W, Wright JJ, Wei SC, Opalenik SR, Toren AL, Rathmell JC, Ferrell PB, Phillips EJ, Mallal S, Johnson DB, Allison JP, Moslehi JJ, Balko JM. T cells specific for α-myosin drive immunotherapy-related myocarditis. Nature 2022; 611:818-826. [PMID: 36385524 PMCID: PMC9930174 DOI: 10.1038/s41586-022-05432-3] [Citation(s) in RCA: 89] [Impact Index Per Article: 44.5] [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] [Received: 01/31/2022] [Accepted: 10/07/2022] [Indexed: 11/17/2022]
Abstract
Immune-related adverse events, particularly severe toxicities such as myocarditis, are major challenges to the utility of immune checkpoint inhibitors (ICIs) in anticancer therapy1. The pathogenesis of ICI-associated myocarditis (ICI-MC) is poorly understood. Pdcd1-/-Ctla4+/- mice recapitulate clinicopathological features of ICI-MC, including myocardial T cell infiltration2. Here, using single-cell RNA and T cell receptor (TCR) sequencing of cardiac immune infiltrates from Pdcd1-/-Ctla4+/- mice, we identify clonal effector CD8+ T cells as the dominant cell population. Treatment with anti-CD8-depleting, but not anti-CD4-depleting, antibodies improved the survival of Pdcd1-/-Ctla4+/- mice. Adoptive transfer of immune cells from mice with myocarditis induced fatal myocarditis in recipients, which required CD8+ T cells. The cardiac-specific protein α-myosin, which is absent from the thymus3,4, was identified as the cognate antigen source for three major histocompatibility complex class I-restricted TCRs derived from mice with fulminant myocarditis. Peripheral blood T cells from three patients with ICI-MC were expanded by α-myosin peptides. Moreover, these α-myosin-expanded T cells shared TCR clonotypes with diseased heart and skeletal muscle, which indicates that α-myosin may be a clinically important autoantigen in ICI-MC. These studies underscore the crucial role for cytotoxic CD8+ T cells, identify a candidate autoantigen in ICI-MC and yield new insights into the pathogenesis of ICI toxicity.
Collapse
Affiliation(s)
- Margaret L Axelrod
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Wouter C Meijers
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Cardiology, University Medical Center Groningen, Groningen, The Netherlands
- Department of Cardiology, Thorax Center, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Elles M Screever
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Cardiology, University Medical Center Groningen, Groningen, The Netherlands
- Department of Cardiology, Thorax Center, Erasmus University Medical Center, Rotterdam, Netherlands
| | - Juan Qin
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Section of Cardio-Oncology and Immunology, Division of Cardiology and the Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA
| | - Mary Grace Carroll
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Xiaopeng Sun
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Elie Tannous
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Yueli Zhang
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Ayaka Sugiura
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Brandie C Taylor
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Ann Hanna
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Shaoyi Zhang
- Section of Cardio-Oncology and Immunology, Division of Cardiology and the Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA
| | - Kaushik Amancherla
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Warren Tai
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Division of Cardiology, University of California, Los Angeles, CA, USA
| | - Jordan J Wright
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Spencer C Wei
- Department of Immunology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Susan R Opalenik
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Abigail L Toren
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jeffrey C Rathmell
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Center for Immunobiology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - P Brent Ferrell
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Elizabeth J Phillips
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Institute for Immunology and Infectious Diseases, Murdoch University, Perth, Australia
- Department of Dermatology, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Simon Mallal
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Institute for Immunology and Infectious Diseases, Murdoch University, Perth, Australia
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Douglas B Johnson
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - James P Allison
- Department of Immunology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
- Parker Institute for Cancer Immunotherapy, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Javid J Moslehi
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
- Section of Cardio-Oncology and Immunology, Division of Cardiology and the Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA.
| | - Justin M Balko
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA.
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.
- Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN, USA.
| |
Collapse
|
8
|
Abstract
Immunotherapy has become a key therapeutic strategy in the treatment of many cancers. As a result, research efforts have been aimed at understanding mechanisms of resistance to immunotherapy and how anti-tumor immune response can be therapeutically enhanced. It has been shown that tumor cell recognition by the immune system plays a key role in effective response to T cell targeting therapies in patients. One mechanism by which tumor cells can avoid immunosurveillance is through the downregulation of Major Histocompatibility Complex I (MHC-I). Downregulation of MHC-I has been described as a mechanism of intrinsic and acquired resistance to immunotherapy in patients with cancer. Depending on the mechanism, the downregulation of MHC-I can sometimes be therapeutically restored to aid in anti-tumor immunity. In this article, we will review current research in MHC-I downregulation and its impact on immunotherapy response in patients, as well as possible strategies for therapeutic upregulation of MHC-I.
Collapse
Affiliation(s)
- Brandie C. Taylor
- Department of Medicine, Cancer Biology, Vanderbilt University, Nashville, TN, United States
| | - Justin M. Balko
- Department of Medicine, Cancer Biology, Vanderbilt University, Nashville, TN, United States
- Department of Medicine, Hematology and Oncology, Vanderbilt University Medical Center, Nashville, TN, United States
- *Correspondence: Justin M. Balko,
| |
Collapse
|
9
|
Ensrud KE, Vo TN, Burghardt AJ, Schousboe JT, Cauley JA, Taylor BC, Hoffman AR, Orwoll ES, Lane NE, Langsetmo L. Weight loss in men in late life and bone strength and microarchitecture: a prospective study. Osteoporos Int 2018; 29:1549-1558. [PMID: 29572622 PMCID: PMC6035779 DOI: 10.1007/s00198-018-4489-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 03/12/2018] [Indexed: 01/22/2023]
Abstract
UNLABELLED Weight loss in men in late life was associated with lower bone strength. In contrast, weight gain was not associated with a commensurate increase in bone strength. Future studies should measure concurrent changes in weight and parameters of bone strength and microarchitecture and evaluate potential causal pathways underlying these associations. INTRODUCTION Our aim was to determine associations of weight loss with bone strength and microarchitecture. METHODS We used data from 1723 community-dwelling men (mean age 84.5 years) who attended the MrOS study Year (Y) 14 exam and had high-resolution peripheral quantitative computed tomography (HR-pQCT) scans at ≥ 1 skeletal sites (distal tibia, distal radius, or diaphyseal tibia). Weight change from Y7 to Y14 exams (mean 7.3 years between exams) was classified as moderate weight loss (loss ≥ 10%), mild weight loss (loss 5 to < 10%), stable weight (< 5% change), or weight gain (gain ≥ 5%). Mean HR-pQCT parameters (95%CI) were calculated by weight change category using linear regression models adjusted for age, race, site, health status, body mass index, limb length, and physical activity. The primary outcome measure was estimated failure load. RESULTS There was a nonlinear association of weight change with failure load at each skeletal site with different associations for weight loss vs. weight gain (p < 0.03). Failure load and total bone mineral density (BMD) at distal sites were lower with greater weight loss with 7.0-7.6% lower failure loads and 4.3-5.8% lower BMDs among men with moderate weight loss compared to those with stable weight (p < 0.01, both comparisons). Cortical, but not trabecular, BMDs at distal sites were lower with greater weight loss. Greater weight loss was associated with lower cortical thickness at all three skeletal sites. CONCLUSION Weight loss in men in late life is associated with lower peripheral bone strength and total BMD with global measures reflecting cortical but not trabecular parameters.
Collapse
Affiliation(s)
- K E Ensrud
- Department of Medicine, University of Minnesota, Minneapolis, MN, USA.
- Division of Epidemiology & Community Health, University of Minnesota, Minneapolis, MN, USA.
- Center for Chronic Disease Outcomes Research, VA Health Care System, One Veterans Drive (111-0), Minneapolis, MN, 55417, USA.
| | - T N Vo
- Division of Epidemiology & Community Health, University of Minnesota, Minneapolis, MN, USA
| | - A J Burghardt
- Department of Radiology & Biomedical Imaging, University of California, San Francisco, CA, USA
| | - J T Schousboe
- HealthPartners Institute, Bloomington, MN, USA
- Division of Health Policy and Management, University of Minnesota, Minneapolis, MN, USA
| | - J A Cauley
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - B C Taylor
- Department of Medicine, University of Minnesota, Minneapolis, MN, USA
- Division of Epidemiology & Community Health, University of Minnesota, Minneapolis, MN, USA
- Center for Chronic Disease Outcomes Research, VA Health Care System, One Veterans Drive (111-0), Minneapolis, MN, 55417, USA
| | - A R Hoffman
- Department of Medicine, Stanford University, Stanford, CA, USA
| | - E S Orwoll
- Bone and Mineral Unit, Oregon Health & Science University, Portland, OR, USA
| | - N E Lane
- Department of Medicine, University of California, Davis, CA, USA
| | - L Langsetmo
- Division of Epidemiology & Community Health, University of Minnesota, Minneapolis, MN, USA
| | | |
Collapse
|
10
|
Schousboe JT, Vo TN, Langsetmo L, Taylor BC, Kats AM, Schwartz AV, Bauer DC, Cauley JA, Ensrud KE. Predictors of change of trabecular bone score (TBS) in older men: results from the Osteoporotic Fractures in Men (MrOS) Study. Osteoporos Int 2018; 29:49-59. [PMID: 29090329 PMCID: PMC5777142 DOI: 10.1007/s00198-017-4273-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2017] [Accepted: 10/12/2017] [Indexed: 02/08/2023]
Abstract
UNLABELLED Among older men, characteristics that predict longitudinal changes in trabecular bone score (TBS) are different from characteristics that predict changes in bone mineral density (BMD). Most notably, weight loss is strongly associated with concomitant loss in BMD but with concomitant increases in TBS, when measured on Hologic densitometers. INTRODUCTION Our objective was to compare and contrast predictors of changes in TBS, total hip BMD, and lumbar spine BMD. METHODS Our study population was 3969 Osteoporotic Fractures in Men (MrOS) cohort participants (mean age 72.8 years) with repeat measures of TBS, lumbar spine and total hip BMD, body mass index (BMI) less than 37 kg/m2, and no use of bisphosphonate or glucocorticoid medications. TBS was scored (Med-Imaps Software version 2.1) and BMD measured on Hologic densitometers. RESULTS One thousand four hundred forty-four men had a TBS decrease > 0.04 units (estimated least significant change for TBS), 795 men had a TBS increase > 0.04 units, and 1730 men had TBS change ≤ 0.04 units over mean follow-up of 4.6 years. Older age was not associated with TBS change, but was associated with greater decline in lumbar spine and total hip BMD. Compared to stable weight, > 10% weight loss was strongly associated with an increase in TBS [effect size = 1.24 (95% CI 1.12, 1.36)] and strongly associated with a decrease in total hip BMD [- 1.16 (95% CI - 1.19, - 1.03)]. Other predictors discordant for longitudinal changes of TBS and BMD included baseline BMI, walk speed, and ACE inhibitor use. CONCLUSIONS Predictors of changes in TBS are different from predictors of changes in lumbar spine and total hip BMD. At least when assessed on Hologic densitometers, weight loss is associated with subsequent declines in spine and total hip BMD but subsequent increase in TBS. Faster walk speed may protect against loss of hip BMD, but is not associated with longitudinal changes of TBS.
Collapse
Affiliation(s)
- J T Schousboe
- Park Nicollet Clinic and HealthPartners Institute, 3800 Park Nicollet Blvd., Minneapolis, MN, 55416, USA.
- Division of Health Policy and Management, University of Minnesota, Minneapolis, MN, USA.
| | - T N Vo
- Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, MN, USA
| | - L Langsetmo
- Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, MN, USA
| | - B C Taylor
- Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, MN, USA
- Center for Chronic Diseases Outcomes Research, VA Health Care System, Minneapolis, MN, USA
- Department of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - A M Kats
- Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, MN, USA
- Center for Chronic Diseases Outcomes Research, VA Health Care System, Minneapolis, MN, USA
- Department of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - A V Schwartz
- Department of Biostatistics and Epidemiology, University of California, San Francisco, CA, USA
| | - D C Bauer
- Department of Biostatistics and Epidemiology, University of California, San Francisco, CA, USA
- Department of Medicine, University of California, San Francisco, CA, USA
| | - J A Cauley
- Department of Epidemiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - K E Ensrud
- Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, MN, USA
- Center for Chronic Diseases Outcomes Research, VA Health Care System, Minneapolis, MN, USA
- Department of Medicine, University of Minnesota, Minneapolis, MN, USA
| | | |
Collapse
|
11
|
Langsetmo L, Shikany JM, Burghardt AJ, Cawthon PM, Orwoll ES, Cauley JA, Taylor BC, Schousboe JT, Bauer DC, Vo TN, Ensrud KE. High dairy protein intake is associated with greater bone strength parameters at the distal radius and tibia in older men: a cross-sectional study. Osteoporos Int 2018; 29:69-77. [PMID: 29063213 PMCID: PMC5772967 DOI: 10.1007/s00198-017-4261-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 10/09/2017] [Indexed: 12/17/2022]
Abstract
UNLABELLED Dairy protein but not plant protein was associated with bone strength of the radius and tibia in older men. These results are consistent with previous results in women and support similar findings related to fracture outcomes. Bone strength differences were largely due to thickness and area of the bone cortex. INTRODUCTION Our objective was to determine the association of protein intake by source (dairy, non-dairy animal, plant) with bone strength and bone microarchitecture among older men. METHODS We used data from 1016 men (mean 84.3 years) who attended the Year 14 exam of the Osteoporotic Fractures in Men (MrOS) study, completed a food frequency questionnaire (500-5000 kcal/day), were not taking androgen or androgen agonists, and had high-resolution peripheral quantitative computed tomography (HR-pQCT) scans of the distal radius and distal or diaphyseal tibia. Protein was expressed as percentage of total energy intake (TEI); mean ± SD for TEI = 1548 ± 607 kcal/day and for total protein = 16.2 ± 2.9%TEI. We used linear regression with standardized HR-pQCT parameters as dependent variables and adjusted for age, limb length, center, education, race/ethnicity, marital status, smoking, alcohol intake, physical activity level, corticosteroids use, supplement use (calcium and vitamin D), and osteoporosis medications. RESULTS Higher dairy protein intake was associated with higher estimated failure load at the distal radius and distal tibia [radius effect size = 0.17 (95% CI 0.07, 0.27), tibia effect size = 0.13 (95% CI 0.03, 0.23)], while higher non-dairy animal protein was associated with higher failure load at only the distal radius. Plant protein intake was not associated with failure load at any site. CONCLUSION The association between protein intake and bone strength varied by source of protein. These results support a link between dairy protein intake and skeletal health, but an intervention study is needed to evaluate causality.
Collapse
Affiliation(s)
- L Langsetmo
- Division of Epidemiology and Community Health, University of Minnesota, 1300 S. 2nd St., Suite 300, Minneapolis, MN, 55454, USA.
| | - J M Shikany
- Division of Preventive Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - A J Burghardt
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA
| | - P M Cawthon
- California Pacific Medical Center Research Institute, San Francisco, CA, USA
- Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA
| | - E S Orwoll
- Bone and Mineral Unit, Oregon Health Sciences University, Portland, OR, USA
| | - J A Cauley
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
| | - B C Taylor
- Division of Epidemiology and Community Health, University of Minnesota, 1300 S. 2nd St., Suite 300, Minneapolis, MN, 55454, USA
- Department of Medicine, University of Minnesota, Minneapolis, MN, USA
- Center for Chronic Disease Outcomes Research, Minneapolis VA Health Care System, Minneapolis, MN, USA
| | - J T Schousboe
- Park Nicollet Clinic and HealthPartners Institute, Bloomington, MN, USA
- Division of Health Policy and Management, University of Minnesota, Minneapolis, MN, USA
| | - D C Bauer
- Departments of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - T N Vo
- Division of Epidemiology and Community Health, University of Minnesota, 1300 S. 2nd St., Suite 300, Minneapolis, MN, 55454, USA
| | - K E Ensrud
- Division of Epidemiology and Community Health, University of Minnesota, 1300 S. 2nd St., Suite 300, Minneapolis, MN, 55454, USA
- Department of Medicine, University of Minnesota, Minneapolis, MN, USA
- Center for Chronic Disease Outcomes Research, Minneapolis VA Health Care System, Minneapolis, MN, USA
| | | |
Collapse
|
12
|
Schousboe JT, Paudel ML, Taylor BC, Kats AM, Virnig BA, Dowd BE, Langsetmo L, Ensrud KE. Pre-fracture individual characteristics associated with high total health care costs after hip fracture. Osteoporos Int 2017; 28:889-899. [PMID: 27743069 PMCID: PMC5332123 DOI: 10.1007/s00198-016-3803-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2016] [Accepted: 10/03/2016] [Indexed: 01/17/2023]
Abstract
UNLABELLED Older women with pre-fracture slow walk speed, high body mass index, and/or a high level of multimorbidity have significantly higher health care costs after hip fracture compared to those without those characteristics. Studies to investigate if targeted health care interventions for these individuals can reduce hip fracture costs are warranted. INTRODUCTION The aim of this study is to estimate the associations of individual pre-fracture characteristics with total health care costs after hip fracture, using Study of Osteoporotic Fractures (SOF) cohort data linked to Medicare claims. METHODS Our study population was 738 women age 70 and older enrolled in Medicare Fee for Service (FFS) who experienced an incident hip fracture between January 1, 1992 and December 31, 2009. We assessed pre-fracture individual characteristics at SOF study visits and estimated costs of hospitalizations, skilled nursing facility and inpatient rehabilitation stays, home health care visits, and outpatient utilization from Medicare FFS claims. We used generalized linear models to estimate the associations of predictor variables with total health care costs (2010 US dollars) after hip fracture. RESULTS Median total health care costs for 1 year after hip fracture were $35,536 (inter-quartile range $24,830 to $50,903). Multivariable-adjusted total health care costs for 1 year after hip fracture were 14 % higher ($5256, 95 % CI $156 to $10,356) in those with walk speed <0.6 m/s compared to ≥1.0 m/s, 25 % higher ($9601, 95 % CI $3314 to $16,069) in those with body mass index ≥30 kg/m2 compared to 20 to 24.9 mg/kg2, and 21 % higher ($7936, 95 % CI $346 to $15,526) for those with seven or more compared to no comorbid medical conditions. CONCLUSIONS Pre-fracture poor mobility, obesity, and multiple comorbidities are associated with higher total health care costs after hip fracture in older women. Studies to investigate if targeted health care interventions for these individuals can reduce the costs of hip fractures are warranted.
Collapse
Affiliation(s)
- J T Schousboe
- Park Nicollet Clinic and HealthPartners Institute, HealthPartners, 3800 Park Nicollet Blvd, Minneapolis, MN, 55416, USA.
- Division of Health Policy and Management, University of Minnesota, Minneapolis, MN, USA.
| | - M L Paudel
- Division of Epidemiology, University of Minnesota, Minneapolis, MN, USA
| | - B C Taylor
- Division of Epidemiology, University of Minnesota, Minneapolis, MN, USA
- Center for Chronic Diseases Outcomes Research, Minneapolis VAMC, Minneapolis, MN, USA
- Department of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - A M Kats
- Division of Epidemiology, University of Minnesota, Minneapolis, MN, USA
| | - B A Virnig
- Division of Health Policy and Management, University of Minnesota, Minneapolis, MN, USA
| | - B E Dowd
- Division of Health Policy and Management, University of Minnesota, Minneapolis, MN, USA
| | - L Langsetmo
- Division of Epidemiology, University of Minnesota, Minneapolis, MN, USA
| | - K E Ensrud
- Division of Epidemiology, University of Minnesota, Minneapolis, MN, USA
- Center for Chronic Diseases Outcomes Research, Minneapolis VAMC, Minneapolis, MN, USA
- Department of Medicine, University of Minnesota, Minneapolis, MN, USA
| |
Collapse
|
13
|
Fink HA, Litwack-Harrison S, Taylor BC, Bauer DC, Orwoll ES, Lee CG, Barrett-Connor E, Schousboe JT, Kado DM, Garimella PS, Ensrud KE. Erratum to: Clinical utility of routine laboratory testing to identify possible secondary causes in older men with osteoporosis: the osteoporotic fractures in men (MrOS) study. Osteoporos Int 2017; 28:419-420. [PMID: 27766366 PMCID: PMC5262150 DOI: 10.1007/s00198-016-3805-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- H A Fink
- Geriatric Research Education & Clinical Center, Minneapolis VA, Health Care System, One Veterans Drive, 11-G, Minneapolis, MN, 55417, USA.
| | - S Litwack-Harrison
- Department of Epidemiology & Statistics, University of California, San Francisco, San Francisco Coordinating Center, Mission Hall: Global Health & Clinical Sciences Building, 550 16th Street, 2nd, floor, Box, San Francisco, CA, #0560, USA
| | - B C Taylor
- Center for Chronic Disease Outcomes Research, Minneapolis VA Health Care System, One Veterans Drive, Mail code 152, Building 9, Minneapolis, MN, 55417, USA
| | - D C Bauer
- Department of Medicine, University of California, San Francisco, 1545 Divisadero St, 3rd Floor, San Francisco, CA, USA
| | - E S Orwoll
- Bone & Mineral Unit, Department of Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, CR113, Portland, OR, 97239, USA
| | - C G Lee
- Portland Veterans Affairs HealthCareSystem, 3710SWUSVeterans Hospital Rd, R&D45, Portland, OR, 97239, USA
| | - E Barrett-Connor
- Department of Family Medicine & Public Health, University of California, San Diego 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - J T Schousboe
- Health Research Center, Park Nicollet Institute for Research and Education, 3800 Park Nicollet Boulevard, Minneapolis, MN, 55416, USA
| | - D M Kado
- Department of Family Medicine & Public Health, University of California, San Diego 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - P S Garimella
- Division of Nephrology, Tufts Medical Center, 800 Washington, Street, Box 391, Boston, MA, 02111, USA
| | - K E Ensrud
- Division of General Internal Medicine, Minneapolis VA Health Care System, One Veterans Drive, 111-0, Minneapolis, MN, 55417, USA
| | | |
Collapse
|
14
|
Fink HA, Litwack-Harrison S, Taylor BC, Bauer DC, Orwoll ES, Lee CG, Barrett-Connor E, Schousboe JT, Kado DM, Garimella PS, Ensrud KE. Clinical utility of routine laboratory testing to identify possible secondary causes in older men with osteoporosis: the Osteoporotic Fractures in Men (MrOS) Study. Osteoporos Int 2016; 27:331-8. [PMID: 26458388 PMCID: PMC4719570 DOI: 10.1007/s00198-015-3356-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 09/29/2015] [Indexed: 11/25/2022]
Abstract
UNLABELLED We investigated the value of routine laboratory testing for identifying underlying causes in older men diagnosed with osteoporosis. Most osteoporotic and nonosteoporotic men had ≥1 laboratory abnormality. Few individual laboratory abnormalities were more common in osteoporotic men. The benefit of routine laboratory testing in older osteoporotic men may be low. INTRODUCTION To evaluate the utility of recommended laboratory testing to identify secondary causes in older men with osteoporosis, we examined prevalence of laboratory abnormalities in older men with and without osteoporosis. METHODS One thousand five hundred seventy-two men aged ≥65 years in the Osteoporotic Fractures in Men study completed bone mineral density (BMD) testing and a battery of laboratory measures, including serum calcium, phosphorus, alkaline phosphatase, parathyroid hormone (PTH), thyroid-stimulating hormone (TSH), 25-OH vitamin D, total testosterone, spot urine calcium/creatinine ratio, spot urine albumin/creatinine ratio, creatinine-derived estimated glomerular filtration rate, 24-h urine calcium, and 24-h urine free cortisol. Using cross-sectional analyses, we calculated prevalence ratios (PRs) and 95 % confidence intervals (CI) for the association of any and specific laboratory abnormalities with osteoporosis and the number of men with osteoporosis needed to test to identify one additional laboratory abnormality compared to testing men without osteoporosis. RESULTS Approximately 60 % of men had ≥1 laboratory abnormality in both men with and without osteoporosis. Among individual tests, only vitamin D insufficiency (PR, 1.13; 95 % CI, 1.05-1.22) and high alkaline phosphatase (PR, 3.05; 95 % CI, 1.52-6.11) were more likely in men with osteoporosis. Hypercortisolism and hyperthyroidism were uncommon and not significantly more frequent in men with osteoporosis. No osteoporotic men had hypercalciuria. CONCLUSIONS Though most of these older men had ≥1 laboratory abnormality, few routinely recommended individual tests were more common in men with osteoporosis than in those without osteoporosis. Possibly excepting vitamin D and alkaline phosphatase, benefit of routine laboratory testing to identify possible secondary causes in older osteoporotic men appears low. Results may not be generalizable to younger men or to older men in whom history and exam findings raise clinical suspicion for a secondary cause of osteoporosis.
Collapse
Affiliation(s)
- H A Fink
- Geriatric Research Education & Clinical Center, Minneapolis VA Health Care System, One Veterans Drive, 11-G, Minneapolis, MN, 55417, USA.
| | - S Litwack-Harrison
- Department of Epidemiology & Statistics, University of California, San Francisco, San Francisco Coordinating Center, Mission Hall: Global Health & Clinical Sciences Building, 550 16th Street, 2nd floor, Box #0560, San Francisco, CA, USA
| | - B C Taylor
- Center for Chronic Disease Outcomes Research, Minneapolis VA Health Care System, One Veterans Drive, Mail code 152, Building 9, Minneapolis, MN, 55417, USA
| | - D C Bauer
- Department of Medicine, University of California, San Francisco, 1545, Divisadero St, 3rd Floor, San Francisco, CA, USA
| | - E S Orwoll
- Bone & Mineral Unit, Department of Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, CR113, Portland, OR, 97239, USA
| | - C G Lee
- Portland Veterans Affairs Health Care System, 3710 SW US Veterans Hospital Rd, R&D45, Portland, OR, 97239, USA
| | - E Barrett-Connor
- Department of Family Medicine & Public Health, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - J T Schousboe
- Health Research Center, Park Nicollet Institute for Research and Education, 3800 Park Nicollet Boulevard, Minneapolis, MN, 55416, USA
| | - D M Kado
- Department of Family Medicine & Public Health, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - P S Garimella
- Division of Nephrology, Tufts Medical Center, 800 Washington Street, Box 391, Boston, MA, 02111, USA
| | - K E Ensrud
- Division of General Internal Medicine, Minneapolis VA Health Care System, One Veterans Drive, 111-0, Minneapolis, MN, 55417, USA
| | | |
Collapse
|
15
|
Lederle FA, Noorbaloochi S, Nugent S, Taylor BC, Grill JP, Kohler TR, Cole L. Multicentre study of abdominal aortic aneurysm measurement and enlargement. Br J Surg 2015; 102:1480-7. [DOI: 10.1002/bjs.9895] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 04/23/2015] [Accepted: 06/10/2015] [Indexed: 11/11/2022]
Abstract
Abstract
Background
No effective treatment is currently available to prevent progression of small and medium-sized abdominal aortic aneurysms (AAAs). Identification of drugs with sufficient promise to justify large expensive randomized trials remains challenging. One potentially useful strategy is to look for associations between commonly used drugs and AAA enlargement in appropriately adjusted observational studies.
Methods
Potential AAA measurements were identified from abdominal imaging reports in the electronic data files of three medical centres from 1995 to 2010. AAA measurements were extracted manually and patients with an aneurysm of 3 cm or larger, who had at least two measurements over an interval of at least 6 months, were identified. Other data were obtained from the electronic data files (demographics, co-morbidities, smoking status, drug use) to conduct a propensity analysis of the associations of drugs and other factors with AAA enlargement.
Results
From 52 962 abdominal imaging studies, 5362 patients with an AAA of 3 cm or more were identified, of whom 2428 had at least two measurements over at least 6 months. Mean AAA follow-up was 3·4 years and the mean AAA enlargement rate was 2·0 mm per year. Propensity analysis demonstrated no significant association of AAA enlargement with statins, beta-blockers, angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers. Diabetes was associated with a reduction in AAA enlargement of 1·2 mm per year (P = 0·008), and chronic obstructive pulmonary disease was associated with increased enlargement (0·5 mm per year; P = 0·050). Moderate AAA measurement variation and substantial terminal digit preference were also observed, but the digit preference became less pronounced after 2000.
Conclusion
This study confirms the negative association of diabetes with AAA progression. There was no evidence that commonly used cardiovascular drugs affect AAA enlargement.
Collapse
Affiliation(s)
- F A Lederle
- Center for Chronic Disease Outcomes Research, Veterans Affairs (VA) Health Care System, Minneapolis, Minnesota, USA
| | - S Noorbaloochi
- Center for Chronic Disease Outcomes Research, Veterans Affairs (VA) Health Care System, Minneapolis, Minnesota, USA
| | - S Nugent
- Center for Chronic Disease Outcomes Research, Veterans Affairs (VA) Health Care System, Minneapolis, Minnesota, USA
| | - B C Taylor
- Center for Chronic Disease Outcomes Research, Veterans Affairs (VA) Health Care System, Minneapolis, Minnesota, USA
| | - J P Grill
- Center for Chronic Disease Outcomes Research, Veterans Affairs (VA) Health Care System, Minneapolis, Minnesota, USA
| | - T R Kohler
- VA Medical Center, Seattle, Washington, USA
| | - L Cole
- VA Medical Center, West Los Angeles, California, USA
| |
Collapse
|
16
|
Fink HA, Kuskowski MA, Cauley JA, Taylor BC, Schousboe JT, Cawthon PM, Ensrud KE. Association of stressful life events with accelerated bone loss in older men: the osteoporotic fractures in men (MrOS) study. Osteoporos Int 2014; 25:2833-9. [PMID: 25169421 PMCID: PMC4331181 DOI: 10.1007/s00198-014-2853-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 08/12/2014] [Indexed: 10/24/2022]
Abstract
UNLABELLED Prior studies suggest an association between stressful life events and fractures that may be mediated by BMD. In the current study, risk of accelerated hip BMD loss was higher in older men with any type of stressful life event and increased with the number of types of stressful life events. INTRODUCTION Prior studies suggest that stressful life events may increase adverse health outcomes, including falls and possibly fractures. The current study builds on these findings and examines whether stressful life events are associated with increased bone loss. METHODS Four thousand three hundred eighty-eight men aged ≥65 years in the Osteoporotic Fractures in Men study completed total hip bone mineral density (BMD) measures at baseline and visit 2, approximately 4.6 years later, and self-reported stressful life events data mid-way between baseline and visit 2, and at visit 2. We used linear regression to model the association of stressful life events with concurrent annualized total hip BMD loss, and log binomial regression or Poisson regression to model risk of concurrent accelerated BMD loss (>1 SD more than mean annualized change). RESULTS Men (75.3 %) reported ≥1 type of stressful life event, including 43.3 % with ≥2 types of stressful life events. Mean annualized BMD loss was -0.36 % (SD 0.88), and 13.9 % of men were categorized with accelerated BMD loss (about 5.7 % or more total loss). Rate of annualized BMD loss increased with the number of types of stressful life events after adjustment for age (p < 0.001), but not after multivariable adjustment (p = 0.07). Multivariable-adjusted risk of accelerated BMD loss increased with the number of types of stressful life events (RR, 1.10 [95 % confidence interval (CI), 1.04-1.16]) per increase of one type of stressful life event). Fracture risk was not significantly different between stressful life event-accelerated bone loss subgroups (p = 0.08). CONCLUSIONS In these older men, stressful life events were associated with a small, dose-related increase in risk of concurrent accelerated hip bone loss. Low frequency of fractures limited assessment of whether rapid bone loss mediates any association of stressful life events with incident fractures. Future studies are needed to confirm these findings and to investigate the mechanism that may underlie this association.
Collapse
Affiliation(s)
- H A Fink
- Geriatric Research Education & Clinical Center, Veterans Affairs Health Center, Minneapolis, MN, USA,
| | | | | | | | | | | | | | | |
Collapse
|
17
|
Schousboe JT, Paudel ML, Taylor BC, Virnig BA, Cauley JA, Curtis JR, Ensrud KE. Magnitude and consequences of misclassification of incident hip fractures in large cohort studies: the Study of Osteoporotic Fractures and Medicare claims data. Osteoporos Int 2013; 24. [PMID: 23208073 PMCID: PMC3738433 DOI: 10.1007/s00198-012-2210-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
UNLABELLED In the Study of Osteoporotic Fractures (SOF), 18.5 % of incident hip fractures identified in Medicare Fee-for-Service claims data were not reported to or confirmed by the cohort. Cognitive impairment was a modest risk factor for false-negative hip fracture ascertainment via self-report. INTRODUCTION Prospective cohort studies of fractures that rely on participant self-report to be the initial signal of an incident fracture could be prone to bias if a significant proportion of fractures are not self-reported. METHODS We used data from the SOF merged with Medicare Fee-for-Service claims data to estimate the proportion of participants who had an incident hip fracture identified in Medicare claims that was either not self-reported or confirmed (by review of radiographic reports) in SOF. RESULTS Between 1/1/1991 and 12/31/2007, 647 SOF participants had a hip fracture identified in Medicare claims, but 120 (18.5 %) were either not reported to or confirmed by the cohort. False-negative hip fracture ascertainment was associated with a reduced modified Mini-Mental State Exam (MMSE) score (odds ratio 1.31 per SD decrease, 95 % C.I. 1.06-1.63). Point estimates of associations of predictors of incident hip fracture were changed minimally when the misclassification of incident hip fracture status was corrected with use of claims data. CONCLUSIONS A substantial minority of incident hip fractures were not reported to or confirmed in the SOF. Cognitive impairment was modestly associated with false-negative hip fracture ascertainment. While there was no evidence to suggest that misclassification of incident hip fracture status resulted in biased associations of potential predictors with hip fracture in this study, false-negative incident fracture ascertainment in smaller cohort studies with limited power may increase the risk of type 2 error (not finding significant associations of predictors with incident fractures).
Collapse
|
18
|
Schousboe JT, Gourlay M, Fink HA, Taylor BC, Orwoll ES, Barrett-Connor E, Melton LJ, Cummings SR, Ensrud KE. Cost-effectiveness of bone densitometry among Caucasian women and men without a prior fracture according to age and body weight. Osteoporos Int 2013; 24:163-77. [PMID: 22349916 PMCID: PMC3739718 DOI: 10.1007/s00198-012-1936-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2011] [Accepted: 01/13/2012] [Indexed: 12/21/2022]
Abstract
UNLABELLED We used a microsimulation model to estimate the threshold body weights at which screening bone densitometry is cost-effective. Among women aged 55-65 years and men aged 55-75 years without a prior fracture, body weight can be used to identify those for whom bone densitometry is cost-effective. INTRODUCTION Bone densitometry may be more cost-effective for those with lower body weight since the prevalence of osteoporosis is higher for those with low body weight. Our purpose was to estimate weight thresholds below which bone densitometry is cost-effective for women and men without a prior clinical fracture at ages 55, 60, 65, 75, and 80 years. METHODS We used a microsimulation model to estimate the costs and health benefits of bone densitometry and 5 years of fracture prevention therapy for those without prior fracture but with femoral neck osteoporosis (T-score ≤ -2.5) and a 10-year hip fracture risk of ≥3%. Threshold pre-test probabilities of low BMD warranting drug therapy at which bone densitometry is cost-effective were calculated. Corresponding body weight thresholds were estimated using data from the Study of Osteoporotic Fractures (SOF), the Osteoporotic Fractures in Men (MrOS) study, and the National Health and Nutrition Examination Survey (NHANES) for 2005-2006. RESULTS Assuming a willingness to pay of $75,000 per quality adjusted life year (QALY) and drug cost of $500/year, body weight thresholds below which bone densitometry is cost-effective for those without a prior fracture were 74, 90, and 100 kg, respectively, for women aged 55, 65, and 80 years; and were 67, 101, and 108 kg, respectively, for men aged 55, 75, and 80 years. CONCLUSIONS For women aged 55-65 years and men aged 55-75 years without a prior fracture, body weight can be used to select those for whom bone densitometry is cost-effective.
Collapse
|
19
|
Slinin Y, Paudel ML, Taylor BC, Fink HA, Ishani A, Canales MT, Yaffe K, Barrett-Connor E, Orwoll ES, Shikany JM, Leblanc ES, Cauley JA, Ensrud KE. 25-Hydroxyvitamin D levels and cognitive performance and decline in elderly men. Neurology 2009; 74:33-41. [PMID: 19940271 DOI: 10.1212/wnl.0b013e3181c7197b] [Citation(s) in RCA: 142] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVE To test the hypothesis that lower 25-hydroxyvitamin D [25(OH)D] levels are associated with a greater likelihood of cognitive impairment and risk of cognitive decline. METHODS We measured 25(OH)D and assessed cognitive function using the Modified Mini-Mental State Examination (3MS) and Trail Making Test Part B (Trails B) in a cohort of 1,604 men enrolled in the Osteoporotic Fractures in Men Study and followed them for an average of 4.6 years for changes in cognitive function. RESULTS In a model adjusted for age, season, and site, men with lower 25(OH)D levels seemed to have a higher odds of cognitive impairment, but the test for trend did not reach significance (impairment by 3MS: odds ratio [OR] 1.84, 95% confidence interval [CI] 0.81-4.19 for quartile [Q] 1; 1.41, 0.61-3.28 for Q2; and 1.18, 0.50-2.81 for Q3, compared with Q4 [referent group; p trend = 0.12]; and impairment by Trails B: OR 1.66, 95% CI 0.98-2.82 for Q1; 0.96, 0.54-1.69 for Q2; and 1.30, 0.76-2.22 for Q3, compared with Q4 [p trend = 0.12]). Adjustment for age and education further attenuated the relationships. There was a trend for an independent association between lower 25(OH)D levels and odds of cognitive decline by 3MS performance (multivariable OR 1.41, 95% CI 0.89-2.23 for Q1; 1.28, 0.84-1.95 for Q2; and 1.06, 0.70-1.62 for Q3, compared with Q4 [p = 0.10]), but no association with cognitive decline by Trails B. CONCLUSION We found little evidence of independent associations between lower 25-hydroxyvitamin D level and baseline global and executive cognitive function or incident cognitive decline.
Collapse
Affiliation(s)
- Y Slinin
- One Veterans Dr. (111J), Minneapolis, MN 55417, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Ishani A, Paudel M, Taylor BC, Barrett-Connor E, Jamal S, Canales M, Steffes M, Fink HA, Orwoll E, Cummings SR, Ensrud KE. Renal function and rate of hip bone loss in older men: the Osteoporotic Fractures in Men Study. Osteoporos Int 2008; 19:1549-56. [PMID: 18392664 DOI: 10.1007/s00198-008-0608-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2007] [Accepted: 01/15/2008] [Indexed: 10/22/2022]
Abstract
UNLABELLED Older men with reduced renal function are at increased risk of hip bone loss. Given the robustness of this association across different measures and a growing body of literature, our findings indicate that clinicians should take into account renal function when evaluating older men for osteoporosis risk and bone loss. Future randomized controlled trials should test whether interventions in this high risk population are effective in preventing bone loss and decreasing fracture incidence. INTRODUCTION Studies examining whether kidney impairment, not requiring dialysis, is associated with osteoporosis have reported conflicting results. METHODS We tested the hypothesis that reduced renal function in older men as manifested by higher concentrations of cystatin C or lower levels of estimated glomerular filtration rate (eGFR) is associated with higher rates of bone loss. We measured serum cystatin C, serum creatinine and total hip bone mineral density (BMD) at baseline in a cohort of 404 older men enrolled in the Osteoporotic Fractures in Men (MrOS) Study and followed them prospectively for an average of 4.4 years for changes in BMD. Associations between renal function and change in hip BMD were examined using linear regression. RESULTS In multivariable analysis, the mean rate of decline in total hip BMD showed an increase in magnitude with higher cystatin C concentration (mean annualized percent change -0.29, -0.34, -0.37 and -0.65% for quartiles 1 to 4; p for trend=0.004). Similarly, adjusted rates of hip bone loss were higher among men with lower eGFR as defined by the modification of diet in renal disease formula (mean annualized percent change -0.58, -0.39, -0.37, and -0.31 for quartiles 1 to 4; p for trend=0.02), but not among men with lower eGFR as defined by the Cockcroft-Gault formula (mean annualized percent change -0.47, -0.44, -0.31 and -0.43 for quartiles 1 to 4; p for trend=0.48). CONCLUSIONS Older men with reduced renal function are at increased risk of hip bone loss. Our findings suggest that health care providers should consider renal function when evaluating older men for risk factors for bone loss and osteoporosis.
Collapse
Affiliation(s)
- A Ishani
- Center for Chronic Disease Outcomes Research, Veterans Affairs Medical Center, Minneapolis, MN, USA.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Fink HA, Kuskowski MA, Taylor BC, Schousboe JT, Orwoll ES, Ensrud KE. Association of Parkinson's disease with accelerated bone loss, fractures and mortality in older men: the Osteoporotic Fractures in Men (MrOS) study. Osteoporos Int 2008; 19:1277-82. [PMID: 18301854 DOI: 10.1007/s00198-008-0584-4] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2007] [Accepted: 11/20/2007] [Indexed: 11/28/2022]
Abstract
UNLABELLED Among community-dwelling older men, compared to those without Parkinson's disease (PD), over approximately 5 years, those with baseline PD had a significantly greater rate of annualized total hip bone loss (-1.1% vs. 0.4%), proportion of incident non-spine fractures (14.9% vs. 7.2%) and mortality (34.8% vs. 9.5%). INTRODUCTION The objective of this study was to examine the association of Parkinson's disease (PD) with bone loss and fractures in older men. METHODS This prospective cohort study analyzed data from 5,937 community dwelling men aged >or=65 years at six clinical centers of the Osteoporotic Fractures in Men (MrOS) Study. At baseline and visit two (mean interval 4.6 +/-0.4 SD years), community-diagnosed PD was ascertained by self-report and hip bone mineral density (BMD) was measured using dual energy x-ray absorptiometry (DXA). Incident fractures were self-reported. Fractures and deaths were centrally adjudicated. RESULTS At baseline, 46 (0.8%) men had PD. Age-adjusted mean annualized total hip bone loss was greater in men with vs. those without PD (-1.08% vs. -0.36%, p < 0.001). 15.2% of men with PD and 7.2% of men without PD experienced an incident non-spine fracture (age-adjusted HR 2.4, 95%CI 1.1-5.0). 34.8% of men with PD and 9.5% of men without PD died during follow-up (age-adjusted HR 3.5, 95%CI 2.2-5.5). Associations of PD with bone loss, fractures and mortality were modestly altered by additional individual adjustment for possible confounders. CONCLUSIONS In community-dwelling older men, PD was associated with increased bone loss, fractures and mortality. In addition to implementing fall prevention measures, clinicians should consider osteoporosis screening in older men with PD.
Collapse
Affiliation(s)
- H A Fink
- Geriatric Research Education and Clinical Center, VA Medical Center, Minneapolis, MN, USA.
| | | | | | | | | | | | | |
Collapse
|
22
|
Moffett SP, Oakley JI, Cauley JA, Lui LY, Ensrud KE, Taylor BC, Hillier TA, Hochberg MC, Li J, Cayabyab S, Lee JM, Peltz G, Cummings SR, Zmuda JM. Osteoprotegerin Lys3Asn polymorphism and the risk of fracture in older women. J Clin Endocrinol Metab 2008; 93:2002-8. [PMID: 18319311 PMCID: PMC2386283 DOI: 10.1210/jc.2007-1019] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Osteoprotegerin (OPG) is a soluble decoy receptor for receptor activator nuclear factor kappa-beta that blocks osteoclastic bone resorption. OBJECTIVE We investigated the association between a Lys3Asn polymorphism in the OPG gene and bone mineral density (BMD), and the risk of fracture in 6695 women aged 65 yr and older participating in the Study of Osteoporotic Fractures. DESIGN BMD was measured using either single-photon absorptiometry (Osteon Osteoanalyzer; Dove Medical Group, Los Angeles, CA) or dual-energy x-ray absorptiometry (Hologic QDR 1000; Hologic, Inc., Bedford, MA). Incident fractures were confirmed by physician adjudication of radiology reports. Genotyping was performed using an immobilized probe-based assay. RESULTS Women who were homozygous for the minor G (Lys) allele had significantly lower BMD at the intertrochanter, distal radius, lumbar spine, and calcaneus than those with the C (Asn) allele. There were 701 incident hip fractures during 13.6-yr follow-up (91,249 person-years), including 362 femoral neck and 333 intertrochanteric hip fractures. Women with the C/C (Asn-Asn) genotype had a 51% higher risk of femoral neck fracture (95% confidence interval, 1.13-2.02) and 26% higher risk of hip fracture (95% confidence interval, 1.02-1.54) than those with the G/G (Lys-Lys) genotype. These associations were independent of BMD. Intertrochanteric fractures were not associated with the Lys3Asn polymorphism. CONCLUSION These results require confirmation but suggest a role for the OPG Lys3Asn polymorphism in the genetic susceptibility to hip fractures among older white women.
Collapse
Affiliation(s)
- S P Moffett
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, 130 DeSoto Street, Pittsburgh, PA 15261, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Rodondi N, Taylor BC, Bauer DC, Lui LY, Vogt MT, Fink HA, Browner WS, Cummings SR, Ensrud KE. Association between aortic calcification and total and cardiovascular mortality in older women. J Intern Med 2007; 261:238-44. [PMID: 17305646 DOI: 10.1111/j.1365-2796.2007.01769.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
OBJECTIVES To determine whether older women with abdominal aortic calcification had a greater cardiovascular and all-cause mortality, as such data are limited in older adults. DESIGN Prospective cohort study with a mean follow-up of 13 years. SETTING Community-based sample with four US clinical centres. SUBJECTS A total of 2056 women aged > or =65 years with abdominal aortic calcification assessed on baseline radiographs. MAIN OUTCOME MEASURE Mortality rate (all, cardiovascular, cancer or other cause) adjudicated from death certificates and hospital records. RESULTS The prevalence of abdominal aortic calcification increased with age, ranging from 60% at age 65-69 years to 96% at 85 years and older. Participants with aortic calcification were more likely to die during follow-up of any cause (47% vs. 27%) or a cardiovascular-specific cause (18% vs. 11%, both P < 0.001) than those without aortic calcification. In age-adjusted analyses, aortic calcification was associated with a greater rate of all-cause and cause-specific mortality (cardiovascular, cancer, and other, all P < or = 0.01). In analyses adjusted for age and cardiovascular risk factors, aortic calcification was associated with an increased rate of all-cause mortality (HR: 1.37, 95% CI: 1.15-1.64), and noncardiovascular noncancer mortality (HR: 1.57, 95% CI: 1.17-2.11). The associations between aortic calcification and cancer mortality (HR: 1.44, 95% CI: 1.00-2.08) or cardiovascular mortality (HR: 1.18, 95% CI: 0.88-1.57) showed a similar pattern without reaching statistical significance, but was slightly stronger for mortality from coronary heart disease (HR: 1.53, 95% CI: 0.91-2.56). CONCLUSIONS Abdominal aortic calcification in older women is associated with increased mortality. Future research should examine potential mechanisms for this association.
Collapse
Affiliation(s)
- N Rodondi
- Cardiovascular Prevention Clinic, University Outpatient Clinic, Department of Community Medicine and Public Health, University of Lausanne, Lausanne, Switzerland.
| | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Ensrud KE, Lewis CE, Lambert LC, Taylor BC, Fink HA, Barrett-Connor E, Cauley JA, Stefanick ML, Orwoll E. Endogenous sex steroids, weight change and rates of hip bone loss in older men: the MrOS study. Osteoporos Int 2006; 17:1329-36. [PMID: 16767524 DOI: 10.1007/s00198-006-0088-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2005] [Accepted: 02/02/2006] [Indexed: 10/24/2022]
Abstract
INTRODUCTION Lower levels of endogenous sex steroids or declines in these hormones may contribute to the increased rates of bone loss observed in older adults experiencing weight loss. We hypothesized that among older men with weight loss, higher rates of bone loss at the hip would be observed in men with lower baseline bioavailable sex steroids or those with greater declines in these hormones. METHODS To test this hypothesis, body weight, hip bone mineral density (BMD) using dual energy x-ray absorptiometry and endogenous sex steroids in paired serum samples by sensitive immunoassays were measured at a baseline and at a second examination that was held an average of 1.8 years later in 1267 older men enrolled in the Osteoporotic Fractures in Men (MrOS) study. RESULTS Men experiencing weight loss had higher rates of hip bone loss than those with stable weight or weight gain within each quartile of baseline sex steroid level [p values for test of trend across weight change categories <0.010 within each quartile of bioavailable estradiol and testosterone and <0.060 within each quartile of sex hormone-binding globulin (SHBG)]. Results were similar when a change in sex steroids was substituted for baseline sex steroids in the analyses. Among men with weight loss, the rate of decline in total hip BMD showed a stepwise increase in magnitude with decreasing baseline bioavailable estradiol (p value for trend <0.040), with increasing baseline SHBG (p value for trend<0.030) and with greater decreases in bioavailable testosterone from baseline (p value for trend <0.001). CONCLUSIONS These findings support the hypothesis that the impact of weight loss in older men on rates of hip bone loss may be increased by the presence of a sex steroid insufficiency.
Collapse
Affiliation(s)
- K E Ensrud
- Department of Medicine 111-0, VA Medical Center, One Veterans Drive, Minneapolis, MN 55417, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Donovan FM, Taylor BC. Enhanced cardiac thermal dilution measurement of cardiac output, volumes, regurgitation, valve effective diameters, ventricular power and efficiency -- Feasibility analysis using digital simulation. Technol Health Care 2002; 9:377-86. [PMID: 11673669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Cardiac output is measured by the thermal dilution method which uses a quadruple lumen catheter, with a thermistor on the tip, through the right atrium, right ventricle and into the pulmonary artery. Cold saline is injected into the right atrium and the resulting pulmonary artery temperature profile is integrated. The same procedure performed with three thermistors and three pressure sensors located on the catheter to measure temperature and pressure in the atrium, ventricle and artery respectively will produce a set of temperature and pressure curves with shapes determined by injectate temperature, injectate volume, heart rate, systolic time interval, body temperature, cardiac output, volumes, flow rates and valve openings. A digital computer program has been developed to optimize the fit of a lumped parameter model to the thermodilution curves in order to determine heart rate, systolic time as a fraction of cardiac cycle, right atrial systolic and diastolic volumes, ventricular systolic and diastolic volumes, cardiac output, inflow valve forward and reverse flow rates and effective diameters, outflow valve forward and reverse flow rates and effective diameters, ventricular power and efficiency. The program has been tested over a range of operating conditions including noise in the temperature and pressure signals, randomly varying heart rate and cardiac cycle. All of the data for the tests were produced by a digital computer simulation of a pulsatile artificial heart. The results of these tests indicate that the enhanced thermal dilution analysis method is feasible.
Collapse
Affiliation(s)
- F M Donovan
- Mechanical Engineering Department, University of South Alabama, EGCB 212, Mobile, AL 36688, USA.
| | | |
Collapse
|
26
|
Donovan FM, Taylor BC. Enhanced cardiac thermal dilution analysis for cardiac output, volumes, stroke volumes, and regurgitation rates--sensitivity analysis using digital simulation. Crit Rev Biomed Eng 2001; 28:69-74. [PMID: 10999367 DOI: 10.1615/critrevbiomedeng.v28.i12.120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Cardiac output is measured by placing a double lumen catheter with a thermistor on the tip through the right ventricle into the pulmonary artery, injecting cold saline into the right atrium, and integrating the resulting pulmonary artery temperature profile. If a similar procedure is performed with thermistors located in the right atrium, right ventricle, and pulmonary artery, the resulting temperature curves are determined by the known or easily measured quantities: injectate temperature, injectate volume, heart rate, systolic time interval, body temperature, and time in the cardiac cycle at which injection begins and the unknown quantities: right atrial, right ventricular, pulmonary artery mean and stroke volumes, inflow and outflow valve regurgitation rates, and cardiac output. A digital computer program using a lumped parameter model has been developed to use these quantities to produce thermal dilution curves and optimize the fit of the model curves to the temperature curves from the thermal dilution measurement to determine the unknown quantities. The program is used to investigate the effects of measuring system time constant, heat transfer, and noise on the accuracy of these measurements. The results indicate that the method is practical.
Collapse
Affiliation(s)
- F M Donovan
- Mechanical Engineering Department, University of South Alabama, Mobile 36688, USA
| | | |
Collapse
|
27
|
McBride JW, Corstvet RE, Taylor BC, Osburn BI. Primary and anamnestic responses of bovine bronchoalveolar and peripheral blood lymphocyte subsets to aerosolized Pasteurella haemolytica A1. Vet Immunol Immunopathol 1999; 67:161-70. [PMID: 10077422 DOI: 10.1016/s0165-2427(98)00218-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Site-specific responses of bronchoalveolar and peripheral blood lymphocyte subsets were compared during primary and anamnestic immune responses against live Pasteurella haemolytica A1 (Ph1). Eight 1-year old calves were sequentially exposed intrabronchially with aerosolized Ph1 on days 0, 14, and 21, and two calves were sham exposed. Bronchoalveolar and peripheral blood lymphocytes were analyzed before each Ph1 exposure, and on days 3 and 7 post exposure using single and two-color flow cytometry to identify CD2+, CD4+, CD8+, CD21+, CD45R+, CD25+ and gammadelta lymphocyte subsets. Significant differences (p < 0.05) in bronchoalveolar and peripheral blood lymphocyte subsets were observed before Ph1 exposure. Subsequent aerosol exposures, resulted in significant (p < 0.05) changes in bronchoalveolar lymphocyte subsets and the CD4:CD8 bronchoalveolar lymphocyte ratio, but concomitant changes were not observed in peripheral blood lymphocytes. Expression of CD2, CD4 and CD8 lymphocyte differentiation antigens was consistently lower and more heterogeneous on bronchoalveolar lymphocytes. Differential analysis of bronchoalveolar leukocytes revealed a significant increase in bronchoalveolar lymphocytes and neutrophils during anamnestic responses.
Collapse
Affiliation(s)
- J W McBride
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis 95616, USA.
| | | | | | | |
Collapse
|
28
|
Abstract
This study evaluates the use of artificial neural networks to estimate stroke volume from pre-processed, thoracic impedance plethysmograph signals from 20 healthy subjects. Standard back-propagation was used to train the networks, with Doppler stroke volume estimates as the desired output. The trained networks were then compared to two classical biophysical approaches. The coefficient of determination (R2 x 100%) between the biophysical approaches and the Doppler was 8.20% and 9.90%, while it was 77.38% between the best neural network and the Doppler. Among these methods, only the neural network residuals had a significant zero mean Gaussian distribution (alpha=0.05). Our results indicate that an invertible relationship may exist between thoracic bioimpedance and stroke volume, and that artificial neural networks may offer a potentially advantageous approach for estimating stroke volume from thoracic electrical impedance, both because of their ease of use and their lack of confounding assumptions.
Collapse
Affiliation(s)
- A P Mulavara
- Department of Biomedical Engineering, The University of Akron, OH 44325-0302, USA
| | | | | | | | | | | |
Collapse
|
29
|
Taylor BC, Keefe RG, Dellinger JD, Nakamura Y, Cullor JS, Stott JL. T cell populations and cytokine expression in milk derived from normal and bacteria-infected bovine mammary glands. Cell Immunol 1997; 182:68-76. [PMID: 9427811 DOI: 10.1006/cimm.1997.1215] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This study investigated the effect of naturally acquired bacterial infection of the bovine mammary gland on subpopulations of T lymphocytes and cytokine expression in milk. Twenty-nine lactating cows with mastitis were compared to 12 normal animals. CD4+ lymphocytes represented a significantly greater percentage of the milk-derived lymphocytes in infected mammary glands compared to normal controls. Cytokine mRNA expression by cells derived from milk was investigated using reverse transcriptase-polymerase chain reaction (RT-PCR). No IL-2 or IL-4 mRNA was detected in any samples, while IFN-gamma mRNA was detected in all milk samples. IL-10 mRNA was detected in cells from the milk of 2 mastitic cows and 1 normal cow, and IL-12 mRNA was detected in 2 cows with mastitis. While TNF-alpha mRNA was not detected in this study, IL-6 mRNA was identified in cells from the milk of all animals, with levels being greater in mastitic animals.
Collapse
Affiliation(s)
- B C Taylor
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis 95616, USA.
| | | | | | | | | | | |
Collapse
|
30
|
McBride JW, Corstvet RE, Dietrich MA, Berry C, Brennan R, Taylor BC, Stott JL, Osburn BI. Memory and CD8+ are the predominant bovine bronchoalveolar lymphocyte phenotypes. Vet Immunol Immunopathol 1997; 58:55-62. [PMID: 9343339 DOI: 10.1016/s0165-2427(96)05777-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [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: 02/05/2023]
Abstract
Bovine lymphocytes obtained by bronchoalveolar lavage (BAL) of healthy calves were simultaneously analyzed and compared to peripheral blood lymphocytes using monoclonal antibodies specific for bovine leukocyte differentiation antigens. Phenotypic differences were observed between bronchoalveolar and peripheral blood T-lymphocyte subpopulations, demonstrating selective lymphocyte migration to the bovine lung. The bronchoalveolar and peripheral blood T-lymphocyte populations, defined by expression of CD2, were similar, but bronchoalveolar T lymphocytes were predominately CD8+ while peripheral blood T cells were predominately CD4+. In addition, memory lymphocytes, characterized by low expression of CD45R and activated lymphocytes (CD25+), were found in significantly higher proportions in the bronchoalveolar compartment. The proportion of gammadelta T lymphocytes was, however, significantly higher in peripheral blood. B cells were observed in similar proportions in the bronchoalveolar compartment and peripheral blood.
Collapse
Affiliation(s)
- J W McBride
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California at Davis, 95616, USA.
| | | | | | | | | | | | | | | |
Collapse
|
31
|
Meyers PJ, Bowman T, Blodgett G, Conboy HS, Gimenez T, Reid MP, Taylor BC, Thayer J, Jöchle W, Trigg TE. Use of the GnRH analogue, deslorelin acetate, in a slow-release implant to accelerate ovulation in oestrous mares. Vet Rec 1997; 140:249-52. [PMID: 9080642 DOI: 10.1136/vr.140.10.249] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [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: 02/04/2023]
Abstract
In two separate controlled clinical trials, the efficacy and safety of 2.2 mg of the GnRH analogue deslorelin, administered subcutaneously as a short-term implant to normally cycling mares in oestrus with a dominant ovarian follicle more than 30 mm in diameter, were evaluated, using a placebo as a negative control. The oestrous cycle of each mare was followed by teasing, palpation per rectum and transrectal ultrasonography. Follicles were monitored every 24 hours by ultrasonography until ovulation occurred. The mares were either mated naturally or inseminated artificially. In trial 1, 174 mares were treated at six locations in Canada, and in trial 2, 98 mares were treated at three locations in the USA. In trial 1, the treatment with deslorelin reduced the mean (sd) time to ovulation from 84.2 (48.4) hours to 50.2 (19.6) hours (P < 0.001) and in trial 2 it reduced it from 88.8 (40.3) hours to 54.1 (26.5) hours (P < 0.001). In trial 1, the percentage of mares ovulating within 48 hours increased from 37.7 per cent in control mares to 86.1 per cent in treated mares (P < 0.001) and in trial 2 the percentage increased from 26.5 to 80.9 per cent (P < 0.001). In trial 2, the duration of oestrus in the deslorelin-treated mares was reduced from 6.1 days to 4.3 days and the number of matings or artificial inseminations was reduced from 2.5 to 1.7 (P < 0.001). In trial 1, days 12 to 20 pregnancy rates for matings at the treatment oestrus were not different for deslorelin-treated (75.6 per cent) and placebo-treated (66.1 per cent) mares. In trial 2, days 12 to 20 pregnancy rates from matings at the treatment oestrus were lower for deslorelin-treated (58.7 per cent) than for placebo-treated (83.3 per cent) mares (P < 0.05), although pregnancy rates were similar for deslorelin-treated (97.1 per cent) and placebo-treated (95.0 per cent) mares after mating at the second oestrus. In both trials, pregnancy losses due to early or late abortions were within the normally expected range and similar for deslorelin-treated (3.6 and 3.7 per cent, respectively) and placebo-treated (13.4 and 7.5 per cent) mares. The treatments did not cause systemic side effects and local reactions at the implantation sites were slight and of short duration.
Collapse
Affiliation(s)
- P J Meyers
- Equine Research Centre, University of Guelph, Ontario, Canada
| | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Barratt-Boyes SM, Rossitto PV, Taylor BC, Ellis JA, MacLachlan NJ. Response of the regional lymph node to bluetongue virus infection in calves. Vet Immunol Immunopathol 1995; 45:73-84. [PMID: 7604539 DOI: 10.1016/0165-2427(94)05331-l] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Bluetongue virus (BTV) infection of cattle is characterized by prolonged cell-associated viremia. In an effort to further evaluate the antiviral response of BTV-infected cattle, the role of the regional lymph node (LN) in the immune response of calves to BTV was characterized. Calves were inoculated with BTV in the skin of the neck in an area drained by the superficial cervical LN. Calves were euthanized at regular intervals after inoculation and both BTV-challenged and contralateral (control) superficial cervical LNs were harvested. In addition, some calves had cannulation of the superficial cervical efferent lymphatics prior to inoculation. Lymphocyte subpopulation analysis was done on LN cell suspensions and lymph cells using a panel of cell-specific monoclonal antibodies. There was a significant increase in the proportion of B cells in the challenged LN after inoculation as compared with the control LN. In addition, BTV-specific antibodies were detected in efferent lymph plasma from the challenged LN in one cannulated calf by 9 days after inoculation (DAI), as determined by competitive enzyme-linked immunosorbent assay, whereas BTV-specific antibodies were not detected in serum from this calf through 12 DAI. Analysis of lymph cells revealed a sustained increase in cell output from the challenged LN due to an increase in lymphoblasts and CD8+ T cells. In contrast, the cell output from the control LN dropped markedly by 8 DAI and there was no significant increase in any specific cell population. Double label analysis characterized lymphoblasts as activated CD8+ cells, as determined by expression of MHC Class II antigens (CD8+ MHC II+). These cells were only transiently present as CD8+ MHC II+ cells were not identified in lymph from the challenged LN at 14 DAI. Few CD8+ MHC II+ cells were identified at any time in lymph from the control LN or in lymph from a mock infected calf. The data indicate that B cell proliferation in the challenged LN and release of activated CD8+ cells from this LN were specific responses to BTV infection. The rapid expansion of activated CD8+ T cells indicates that these cells may limit early viral spread. It is concluded that the regional LN draining inoculated skin is critical to the immune response of calves to BTV infection.
Collapse
Affiliation(s)
- S M Barratt-Boyes
- Department of Veterinary Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis 95616, USA
| | | | | | | | | |
Collapse
|
33
|
Taylor BC, Mattapallil J, Moore PF, Scibienski RJ, Stott JL. Characterization of a novel bovine leukocyte protein involved in cell-cell adhesion. Tissue Antigens 1994; 44:252-60. [PMID: 7532875 DOI: 10.1111/j.1399-0039.1994.tb02391.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Preliminary characterization of an apparently novel bovine leukocyte adhesion protein is described. Two IgG1 monoclonal antibodies, UC-C1 and UC-H5, raised against established cultures of IL-2-dependent bovine peripheral blood lymphocytes (PBL) were found to react with an antigen expressed by the majority of bovine peripheral blood leukocytes. Immunoprecipitation and polyacrylamide gel electrophoresis of the antigen produced a distinct protein band of molecular weight 160,000, and additional diffuse protein bands of approximate molecular weight 180,000, 175,000, and 150,000. Two-color flow cytometric analyses showed that the antigen was expressed at low density on a small proportion of circulating B lymphocytes, but was highly expressed on all circulating T lymphocytes. The majority of monocytes and all granulocytes expressed the antigen at a density lower than that of T lymphocytes. Peripheral blood lymphocytes stimulated with concanavalin A had an approximately 3-fold increased expression of the antigen, which was apparent within 18 h and remained stable in long-term cultures. Expression of the antigen in thymus, analyzed by the immunoperoxidase technique, was predominantly restricted to thymocytes in the immediate subcapsular cortex and medulla; expression in lymph nodes and spleen was predominantly confined to lymphocytes in T-cell areas. Flow-cytometric analysis demonstrated that thymocytes and the majority of peripheral and mesenteric lymph node-derived T cells had relatively low surface density of antigen compared to circulating T cells. Binding of UC-C1 or UC-H5 to the antigen on lymphocytes induced homotypic aggregation. UC-C1 completely blocked binding of FITC-conjugated UC-H5 to blood mononuclear cells, suggesting that the antibodies recognize the same epitope or proximal epitopes.
Collapse
Affiliation(s)
- B C Taylor
- Department of Veterinary Pathology, Microbiology and Immunology, University of California, Davis
| | | | | | | | | |
Collapse
|
34
|
Abstract
The phenotype of bovine milk lymphocytes was investigated and compared to peripheral blood lymphocytes using monoclonal antibodies specific for bovine leukocyte differentiation antigens and flow cytometry. T lymphocytes traffic selectively into bovine milk while B lymphocytes represent a minor population in milk by comparison to peripheral blood. The vast majority of T cells in milk express alpha beta T cell receptors and are predominantly CD8+. T cells in milk express twofold higher levels of CD2 and fivefold lower levels of CD45R, characteristics associated with memory T cells. Grouping of cows by lactational stage and analysis of lymphocyte subpopulation percentages indicated that CD4+ T cells are present in relatively low numbers in milk of cows in the first 50 days of lactation and have a significant tendency to increase in number as lactation progresses.
Collapse
Affiliation(s)
- B C Taylor
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California at Davis 95616-8739
| | | | | | | |
Collapse
|
35
|
Taylor BC, Choi KY, Scibienski RJ, Moore PF, Stott JL. Differential expression of bovine MHC class II antigens identified by monoclonal antibodies. J Leukoc Biol 1993; 53:479-89. [PMID: 7684762 DOI: 10.1002/jlb.53.5.479] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Four monoclonal antibodies (mAbs), UC-A4, UC-D3, UC-H9, and IL-A21, specific for bovine major histocompatibility complex class II proteins are described. Sequential immunoprecipitation experiments using biotin-labeled peripheral blood mononuclear cells suggested, but did not conclusively establish, that each of these antibodies recognized a different epitope. The epitope identified by IL-A21 appeared to be common to all of the class II proteins precipitated by the four mAbs, and UC-D3 and UC-H9 each appeared to react with distinct epitopes on separate subsets of these class II proteins. Monoclonal antibody UC-A4 appeared to identify an epitope on a subset of the class II molecules identified by UC-H9. Differences found in the expression by lymphoid cells of class II proteins identified by the four mAbs were indicative of each mAb recognizing a different epitope. UC-H9 and IL-A21 class II proteins were detected on all surface immunoglobulin (S'Ig) positive cells in peripheral blood, but UC-A4 and UC-D3 class II proteins were not. Expression of UC-A4 class II proteins, detected at low density on a strikingly reduced number of S'Ig+ cells from the blood of some bovine leukosis virus-infected cattle, could be increased by culturing these B cells with lipopolysaccharide. All peripheral blood monocytes expressed UC-H9 and IL-A21 class II proteins, but only a proportion of monocytes expressed detectable UC-A4 and UC-D3 class II proteins. Almost all mitogen-stimulated BoCD4+ and BoCD8+ T cells expressed UC-H9 and IL-A21 class II proteins, whereas fewer stimulated T cells of both subsets expressed UC-A4 and UC-D3 class II proteins. All gamma/delta receptor (gamma/delta R) T cells expressed UC-D3, UC-H9, and IL-A21 class II proteins, but no cells (of gamma/delta R+ or CD4+/CD2+ phenotype) from gamma/delta R+ T cell-enriched cultures expressed UC-A4 class II proteins.
Collapse
Affiliation(s)
- B C Taylor
- Department of Veterinary Microbiology and Immunology, University of California, Davis 95616
| | | | | | | | | |
Collapse
|
36
|
Taylor BC, Stott JL, Scibienski RJ, Redelman D. Development and characterization of a monoclonal antibody specific for the bovine low-affinity interleukin-2 receptor, BoCD25. Immunol Suppl 1992; 77:150-4. [PMID: 1398763 PMCID: PMC1421608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
An IgM monoclonal antibody, UC-2C2 was produced using splenocytes from mice immunized with cultures of interleukin-2 (IL-2)-dependent bovine peripheral blood lymphocytes. UC-2C2 was found to recognize a cell surface antigen of apparent molecular weight 52,000-54,000 present on activated bovine peripheral blood mononuclear leucocytes (PBML) but not on resting PBML or cells of the bovine lymphoblastoid cell line BL3. The 52,000-54,000 MW antigen was expressed early following activation of PBML by mitogens or alloantigens, with the majority of cells positive by 48 h of culture. UC-2C2 was unable to block binding of phycoerythrin (PE)-conjugated human recombinant IL-2 to PHA-stimulated bovine PBML as determined by flow cytometric analysis. However, two-colour analyses indicated that the antigen recognized by UC-2C2 was present on the same cell population that expressed IL-2 receptors. All activated T lymphocytes of BoCD4, BoCD8 and gamma delta receptor positive phenotypes expressed the target antigen of UC-2C2 and IL-2 receptors. Monocytes and B lymphocytes expressed the target antigen of UC-2C2 and IL-2 receptors at a lower density. This differential expression by the various PBML subpopulations parallels that described for expression of the low-affinity IL-2 receptor (CD25) on human leucocyte subpopulations. Based upon the relative molecular weight, time-course of expression and cellular distribution of the antigen identified by UC-2C2, it is inferred that UC-2C2 recognizes an epitope on the bovine homologue of CD25 which is not involved in binding IL-2.
Collapse
Affiliation(s)
- B C Taylor
- Department of Veterinary Microbiology and Immunology, University of California, Davis 95616
| | | | | | | |
Collapse
|
37
|
Abstract
Alterations in peripheral blood lymphocyte subpopulations were examined in bovine leukosis virus (BLV)-infected cattle using antibodies specific for differentiation antigens in conjunction with analytical flow cytometry. Animals considered to be aleukemic and lymphocytotic were included in the study. Significantly fewer numbers of circulating B-lymphocytes (surface Ig-positive) and T-helper lymphocytes (BoCD4-positive) were identified in BLV-infected aleukemic cattle compared to non-infected controls while no significant differences were established for T-cytotoxic/suppressor lymphocytes (BoCD8-positive). In contrast, BLV-infected animals with persistent lymphocytosis had elevated numbers of circulating B-lymphocytes with no significant perturbation in circulating T-lymphocyte subsets identified when compared as a group with the negative control cattle. Application of regression analysis to data from individual lymphocytotic cattle demonstrated a significant correlation between absolute numbers of B- and T-lymphocytes. Increased numbers of B-lymphocytes were correlated with increased numbers of T-helper and T-cytotoxic/suppressor lymphocytes.
Collapse
Affiliation(s)
- B C Taylor
- Department of Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis 95616
| | | | | | | |
Collapse
|
38
|
Abstract
The dynamic characteristics of catheter-transducer systems using rigid tubes with compliance lumped in the transducer and oscillatory flow of fluid in rigid tubes were analyzed. A digital computer model based on one dimensional laminar oscillatory flow was developed and verified by exact solution of the Navier-Stokes Equation. Experimental results indicated that the damping ratio and resistance is much higher at higher frequencies of oscillation than predicted by the one dimensional model. An empirical correction factor was developed and incorporated into the computer model to correct the model to the experimental data. Amplitude of oscillation was found to have no effect on damping ratio so it was concluded that the increased damping ratio and resistance at higher frequencies was not due to turbulence but to two dimensional flow effects. Graphs and equations were developed to calculate damping ratio and undamped natural frequency of a catheter-transducer system from system parameters. Graphs and equations were also developed to calculate resistance and inertance for oscillatory flow in rigid tubes from system parameters and frequency of oscillation.
Collapse
Affiliation(s)
- F M Donovan
- Mechanical Engineering Department, University of South Alabama, Mobile 36688
| | | | | |
Collapse
|
39
|
Culbertson WW, Brod RD, Flynn HW, Taylor BC, Brod BA, Lightman DA, Gordon G. Chickenpox-associated acute retinal necrosis syndrome. Ophthalmology 1991; 98:1641-5; discussion 145-6. [PMID: 1666176 DOI: 10.1016/s0161-6420(91)32061-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [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: 12/28/2022] Open
Abstract
Acute retinal necrosis (ARN) syndrome usually occurs as the result of secondary reactivation of latent, previously acquired, varicella-zoster or herpes simplex virus. The authors report four patients who developed a mild form of ARN within 1 month (5 to 28 days) after the onset of chickenpox. In contrast to typical cases of ARN, these cases were less severe, with retinitis limited to two quadrants or less (three patients), no retinal detachment (four patients), minimal vitreitis (four patients), and no loss of visual acuity (four patients). Thus, ARN may occur during the course of primary varicella-zoster infection.
Collapse
Affiliation(s)
- W W Culbertson
- Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami School of Medicine, FL 33136
| | | | | | | | | | | | | |
Collapse
|
40
|
Taylor BC, Sheffer DB. Understanding techniques for measuring cardiac output. Biomed Instrum Technol 1990; 24:188-97. [PMID: 2188704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In summary, use of thermodilution as a method to measure cardiac output has attained universal appeal in the clinical environment. Other means of detecting cardiac output (impedance-cardiogram and ballistocardiogram, to name two) have been developed and are being used clinically, but the development of the flow-directed thermodilution catheter has profoundly affected the universal acceptance of the thermodilution method. Thermodilution techniques, when performed properly, are capable of obtaining accurate and reproducible results. Medical and nursing personnel who are educated in proper procedures will be able to make educated choices when faced with difficult decisions. It is likely that they will turn to the biomedical or clinical engineering department for help if those personnel are well informed regarding the techniques and procedures.
Collapse
|
41
|
Taylor BC, Ellis DM, Drew JM. Quantification and simulation of fluid-filled catheter/transducer systems. Med Instrum 1986; 20:123-9. [PMID: 3724585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Optimization of fluid-filled catheter/transducer systems for blood pressure measurement requires a prior knowledge of how each component affects overall dynamic response. This paper presents a method to measure resistance, inertance, and compliance of individual components by investigating the causal relationships between added known compliances and resonance. Additionally, a computer simulation that combines individual component values to synthesize practical blood pressure monitoring systems is presented. Complete monitoring systems are modeled through the combination of characterized components such as transducers, monitoring lines, and catheters and used to predict overall system response to any input function.
Collapse
|
42
|
Abstract
Eighteen patients (19 eyes) developed retinal complications following YAG laser capsulotomy. Complications included one retinal flap tear, two macular holes, six eyes with cystoid macular edema, and ten retinal detachments. The retinal complications resulted from opening the capsule and were not a specific complication of the YAG laser.
Collapse
|
43
|
Abstract
Flat anterior chambers were caused by varying mechanisms in 10 of 70 consecutive pseudophakic eyes operated on for retinal detachment. With iris or capsular implant fixation, three of 46 (7%) developed flat anterior chambers, and with anterior chamber lenses, the occurrence was seven of 24 (29%). Events initiating flat chambers included wound leak, pupillary block, and choroidal detachment. In eyes with flat anterior chambers, the retina could not be reattached in one case, extensive peripheral anterior synechia with persistent intraocular pressure elevation occurred in another case, and bullous keratopathy remained in two additional instances. Endothelial cell densities were obtained in eight eyes and were low on an age-related basis.
Collapse
|
44
|
Abstract
Spontaneous vitreous hemorrhage, without trauma, accounted for 317 patients (375 eyes) seen during a four-year period from July 1, 1975, to June 30, 1979. The most common causes were proliferative diabetic retinopathy, 39.2%; retinal tear, 12.1%; posterior vitreous detachment, 12%; vein occlusion, 10.4%; retinal detachment, 6.7%; intraocular lens, 3.2%; proliferative sickle retinopathy, 1.3%; miscellaneous, 7.4%; and unknown, 6.7%. Emphasis is placed on the importance of establishing the specific cause so that specific therapy may be instituted.
Collapse
|
45
|
Abstract
Retrospective and prospective techniques were used to analyze a consecutive series of 406 eyes to identify factors contributing to cystoid macular edema following lens implantation. Vitreous loss and rupture of the posterior capsule were highly significant in the production and persistence of this complication.
Collapse
|
46
|
Harris WS, Taylor BC, Winslow RL. Cystoid macular edema following intraocular lens implantation. Ophthalmic Surg 1977; 8:134-7. [PMID: 904865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
This presentation recounts the original description of CME and the more recent developments associated with intravenous fluorescein angiography in its study and diagnosis. The work of previous authors to show the incidence of CME and its possible prognosis are reviewed. Our findings in a retrospective study agree with the other authors and show that there is no particular increase in CME following intraocular lens implantation regardless of the type of surgical procedure used. It is established that vitreous loss does increase the incidence of CME. A prospective study with routine intravenous fluorescein at six weeks is presented and shows an incidence that is below that found by other authors when it was performed following routine intracapsular cataract extraction.
Collapse
|
47
|
Clark P, Crawford H, Sims JL, Taylor BC, Meyer OO. Memorial resolution on the death of William Shainline Middleton, MD. Wis Med J 1976; 75:28-9. [PMID: 1108458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
48
|
Taylor BC, Davison TW, Sharp WV, Wright J, Rubal B, Malin K. Dynamic fatigue evaluation of artificial hearts by thermal gradient visualization. Trans Am Soc Artif Intern Organs 1973; 19:561-6. [PMID: 4722773 DOI: 10.1097/00002480-197301900-00099] [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] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
|
49
|
Sharp WV, Taylor BC, Wright JI, Nuwayser E, Miller BG, Hampton GR, Wilson CL. Neointimal survival - a function of attachment and thickness. Trans Am Soc Artif Intern Organs 1972; 18:232-8. [PMID: 4279486 DOI: 10.1097/00002480-197201000-00058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
50
|
|