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Singh MK, Borson S, Lei V, Molloy R, Weng B, Sutjita M. Rare cases of Talaromyces pneumonia in individuals with underlying cancer and no travel to endemic areas. IDCases 2023; 33:e01831. [PMID: 37484827 PMCID: PMC10362278 DOI: 10.1016/j.idcr.2023.e01831] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/26/2023] [Accepted: 06/26/2023] [Indexed: 07/25/2023] Open
Abstract
Introduction Talaromyces marneffei causes a systemic fungal infection, referred to as talaromycosis, in immunocompromised individuals. Talaromycosis is an AIDS (acquired immunodeficiency syndrome) defining illness for patients living in the Southeast Asian region. Here we present two rarely reported cases of pulmonary talaromycosis in Southern California in patients with active cancer, negative HIV status, and no prior travel history to endemic regions. Case description Case 1: A 76-year-old male with a past medical history of emphysema and latent tuberculosis status post rifampin treatment, presented with a necrotic lung mass. He was diagnosed with squamous cell lung carcinoma and bronchoalveolar lavage cultures grew Talaromyces marneffei. He had no animal exposure or prior travel history to Asia. Due to a transfusion reaction to liposomal amphotericin (the mainstay of treatment), he required a transition to posaconazole. He was HIV-negative and expired due to underlying cancer and infection complications.Case2: A 63-year-old male with a past medical history of tuberculosis, diabetes, and cavitary pneumonia with bronchoscopy positive for Talaromyces presented with worsening back pain and was found to have multiple sites of poorly differentiated adenocarcinoma likely originating from gastric adenocarcinoma. He was HIV-negative and expired due to complications from underlying cancer and infection. Conclusion We demonstrate that patients with pulmonary Talaromyces are becoming more prominent outside of endemic areas even in the setting of no prior travel. In addition, since patients with this infection are severely immunosuppressed, they require extensive workup for other comorbidities such as possible underlying cancer or tuberculosis.
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Affiliation(s)
- Manpreet K. Singh
- School of Medicine, University of California, Riverside, Riverside, CA, USA
| | - Sheldon Borson
- School of Medicine, University of California, Riverside, Riverside, CA, USA
| | - Victor Lei
- Department of Family Medicine, Riverside University Health System Medical Center, Moreno Valley, CA, USA
| | - Rhett Molloy
- Department of Internal Medicine, Riverside University Health System Medical Center, Moreno Valley, CA, USA
| | - Bruce Weng
- Department of Internal Medicine, Riverside University Health System Medical Center, Moreno Valley, CA, USA
| | - Made Sutjita
- Department of Internal Medicine, Riverside University Health System Medical Center, Moreno Valley, CA, USA
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2
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Kirchner S, Lei V, Shannon J, Corcoran D, Hughes D, Waters D, Dzirasa K, Coers J, MacLeod A, Zhang J. 558 An aging-susceptible circadian rhythm controls cutaneous antiviral immunity. J Invest Dermatol 2022. [DOI: 10.1016/j.jid.2022.05.568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Lei V, Ferguson M, Geiger R, Williams S, Liu L, Buxton JA. Factors associated with take-home naloxone kit usage in British Columbia: an analysis of administrative data. Subst Abuse Treat Prev Policy 2022; 17:25. [PMID: 35361228 PMCID: PMC8968772 DOI: 10.1186/s13011-022-00452-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/01/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The British Columbia (BC) Take-Home Naloxone (THN) program provides naloxone to people at risk of experiencing or witnessing an opioid overdose for use in reversing suspected overdose events. This study seeks to examine trends and correlates of individuals obtaining a THN kit in BC between 2017 and 2020. METHODS Records of THN kits distributed between 2017 and 2020 were the primary source of data for this analysis. Frequency tables were used to describe characteristics of people obtaining kits from THN sites. Correlates of individuals obtaining a THN kit to replace a previous kit reported as used to reverse an overdose were assessed with multivariate logistic regression. RESULTS Between January 1, 2017, and December 31, 2020, 240,606 THN kits were reported distributed by registered sites to members of the public, with 90,011 records indicating that a kit was obtained to replace a previous kit that had been used to reverse an overdose. There was a significant trend in increasing kits reported used by year (p < 0.01). The kit recipient's risk of overdose was a significant predictor of having reported using a THN kit, and the strength of the association was dependent on gender (Male: Adjusted odds ratio (AOR) 5.37 [95% confidence interval (CI) 5.08 - 5.67]; Female: AOR 8.35 [95% CI 7.90 - 8.82]; Trans and gender expansive: AOR 3.68 [95% CI 2.82 - 4.79]). CONCLUSIONS Between 2017 and 2020, THN kits were used to reverse tens of thousands of overdose events in BC, with people at risk of overdose (i.e. people who use drugs [PWUD]) having greater odds of using a kit to reverse an overdose than those not at risk. Thus, PWUD are responsible for reversing the vast majority of overdoses. THN kits are being distributed to the people who use them most. However, additional strategies in conjunction with community-based naloxone distribution programs are needed to address the rising number of illicit drug toxicity deaths.
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Affiliation(s)
- Victor Lei
- School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada
| | - Max Ferguson
- BC Centre for Disease Control, Vancouver, BC, Canada
| | - Rachael Geiger
- School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada
| | | | - Lisa Liu
- BC Centre for Disease Control, Vancouver, BC, Canada
| | - Jane A Buxton
- School of Population and Public Health, University of British Columbia, Vancouver, BC, Canada. .,BC Centre for Disease Control, Vancouver, BC, Canada.
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Leatherdale A, Stukas S, Lei V, West HE, Campbell CJ, Hoiland RL, Cooper J, Wellington CL, Sekhon MS, Pryzdial ELG, Conway EM. Persistently elevated complement alternative pathway biomarkers in COVID-19 correlate with hypoxemia and predict in-hospital mortality. Med Microbiol Immunol 2022; 211:37-48. [PMID: 35034207 PMCID: PMC8761108 DOI: 10.1007/s00430-021-00725-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 11/29/2021] [Indexed: 01/05/2023]
Abstract
Mechanisms underlying the SARS-CoV-2-triggered hyperacute thrombo-inflammatory response that causes multi-organ damage in coronavirus disease 2019 (COVID-19) are poorly understood. Several lines of evidence implicate overactivation of complement. To delineate the involvement of complement in COVID-19, we prospectively studied 25 ICU-hospitalized patients for up to 21 days. Complement biomarkers in patient sera and healthy controls were quantified by enzyme-linked immunosorbent assays. Correlations with respiratory function and mortality were analyzed. Activation of complement via the classical/lectin pathways was variably increased. Strikingly, all patients had increased activation of the alternative pathway (AP) with elevated levels of activation fragments, Ba and Bb. This was associated with a reduction of the AP negative regulator, factor (F) H. Correspondingly, terminal pathway biomarkers of complement activation, C5a and sC5b-9, were significantly elevated in all COVID-19 patient sera. C5a and AP constituents Ba and Bb, were significantly associated with hypoxemia. Ba and FD at the time of ICU admission were strong independent predictors of mortality in the following 30 days. Levels of all complement activation markers were sustained throughout the patients’ ICU stays, contrasting with the varying serum levels of IL-6, C-reactive protein, and ferritin. Severely ill COVID-19 patients have increased and persistent activation of complement, mediated strongly via the AP. Complement activation biomarkers may be valuable measures of severity of lung disease and the risk of mortality. Large-scale studies will reveal the relevance of these findings to thrombo-inflammation in acute and post-acute COVID-19.
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Affiliation(s)
- Alexander Leatherdale
- Centre for Blood Research, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
- Division of Hematology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Sophie Stukas
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
- Djavad Mowafaghian Centre for Brain Health, School of Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada
| | - Victor Lei
- Centre for Blood Research, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
- Division of Hematology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Henry E West
- Centre for Blood Research, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
| | | | - Ryan L Hoiland
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, Canada
- Centre for Heart, Lung, and Vascular Health, School of Health and Exercise Sciences, University of British Columbia Okanagan, Vancouver, BC, Canada
| | - Jennifer Cooper
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
- Djavad Mowafaghian Centre for Brain Health, School of Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada
| | - Cheryl L Wellington
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
- Djavad Mowafaghian Centre for Brain Health, School of Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada
| | - Mypinder S Sekhon
- Division of Critical Care Medicine, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Edward L G Pryzdial
- Centre for Blood Research, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada
- Canadian Blood Services, Centre for Innovation, University of British Columbia, Vancouver, BC, Canada
| | - Edward M Conway
- Centre for Blood Research, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada.
- Division of Hematology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada.
- Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada.
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Navathe A, Liao J, Delgado K, Yan S, Isenberg W, Landa H, Bond B, Rareshide C, Small D, Pepe R, Refai F, Lei V, Volpp K, Patel M. Effect of Peer Comparison Feedback, Individual Audit Feedback or Both to Clinicians on Opioid Prescribing in Acute Care Settings: A Cluster Randomized Clinical Trial. Health Serv Res 2021. [DOI: 10.1111/1475-6773.13775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Affiliation(s)
- Amol Navathe
- Leonard Davis Institute of Health Economics University of Pennsylvania Philadelphia Pennsylvania USA
| | - Joshua Liao
- Department of Medicine University of Washington Seattle WA USA
| | - Kit Delgado
- University of Pennsylvania Philadelphia Pennsylvania USA
| | - Sherry Yan
- Sutter Health Walnut Creek California USA
| | | | | | | | | | - Dylan Small
- The Wharton School University of Pennsylvania Philadelphia Pennsylvania USA
| | - Rebecca Pepe
- University of Pennsylvania Philadelphia Pennsylvania USA
| | | | - Victor Lei
- Department of Medical Ethics and Health Policy University of Pennsylvania Philadelphia Pennsylvania USA
| | - Kevin Volpp
- Department of MediPerelman School of Medicine and the Wharton School University of Pennsylvania Philadelphia Pennsylvania USA
| | - Mitesh Patel
- University of Pennsylvania Philadelphia Pennsylvania USA
- Crescenz VA Medical Center Philadelphia Pennsylvania USA
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Kapopara PR, Safikhan NS, Huang JL, Meixner SC, Gonzalez K, Loghmani H, Ruf W, Mast AE, Lei V, Pryzdial EL, Conway EM. CD248 enhances tissue factor procoagulant function, promoting arterial and venous thrombosis in mouse models. J Thromb Haemost 2021; 19:1932-1947. [PMID: 33830628 PMCID: PMC8571649 DOI: 10.1111/jth.15338] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 03/16/2021] [Accepted: 04/02/2021] [Indexed: 11/30/2022]
Abstract
BACKGROUND CD248 is a pro-inflammatory, transmembrane glycoprotein expressed by vascular smooth muscle cells (VSMC), monocytes/macrophages, and other cells of mesenchymal origin. Its distribution and properties are reminiscent of those of the initiator of coagulation, tissue factor (TF). OBJECTIVE We examined whether CD248 also participates in thrombosis. METHODS We evaluated the role of CD248 in coagulation using mouse models of vascular injury, and by assessing its functional interaction with the TF-factor VIIa (FVIIa)-factor X (FX) complex. RESULTS The time to ferric chloride-induced occlusion of the carotid artery in CD248 knockout (KO) mice was significantly longer than in wild-type (WT) mice. In an inferior vena cava (IVC) stenosis model of thrombosis, lack of CD248 conferred relative resistance to thrombus formation compared to WT mice. Levels of circulating cells and coagulation factors, prothrombin time, activated partial thromboplastin time, and tail bleeding times were similar in both groups. Proximity ligation assays revealed that TF and CD248 are <40 nm apart, suggesting a potential functional relationship. Expression of CD248 by murine and human VSMCs, and by a monocytic cell line, significantly augmented TF-FVIIa-mediated activation of FX, which was not due to differential expression or encryption of TF, altered exposure of phosphatidylserine or differences in tissue factor pathway inhibitor expression. Rather, conformation-specific antibodies showed that CD248 induces allosteric changes in the TF-FVIIa-FX complex that facilitates FX activation by TF-FVIIa. CONCLUSION CD248 is a newly uncovered protein partner and potential therapeutic target in the TF-FVIIa-FX macromolecular complex that modulates coagulation.
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Affiliation(s)
- Piyushkumar R. Kapopara
- Centre for Blood Research, Life Sciences Institute, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Nooshin S. Safikhan
- Centre for Blood Research, Life Sciences Institute, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Jenny L. Huang
- Centre for Blood Research, Life Sciences Institute, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Scott C. Meixner
- Centre for Blood Research, Life Sciences Institute, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, Canadian Blood Services, Centre for Innovation, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kevin Gonzalez
- Centre for Blood Research, Life Sciences Institute, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, Canadian Blood Services, Centre for Innovation, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Houra Loghmani
- Centre for Blood Research, Life Sciences Institute, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Wolfram Ruf
- Department of Immunology and Microbiology, Scripps Research, La Jolla, California, USA
- Center for Thrombosis and Hemostasis, Johannes Gutenberg University Medical Center, Mainz, Germany
| | - Alan E. Mast
- Blood Research Institute, Versiti, Milwaukee, Wisconsin, USA
| | - Victor Lei
- Centre for Blood Research, Life Sciences Institute, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Edward L.G. Pryzdial
- Centre for Blood Research, Life Sciences Institute, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, Canadian Blood Services, Centre for Innovation, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Edward M. Conway
- Centre for Blood Research, Life Sciences Institute, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
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Caves E, Lei V, Horsley V. 097 Adipose triglyceride lipase dependent adipocyte lipolysis inhibits dermal fibrosis. J Invest Dermatol 2021. [DOI: 10.1016/j.jid.2021.02.115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Lei V, Kwock J, Kirchner S, Ling X, MacLeod A. 341 Age and circadian regulation of cutaneous innate antimicrobial immunity. J Invest Dermatol 2020. [DOI: 10.1016/j.jid.2020.03.348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Kirchner S, Lei V, Coates M, Handfield C, Corcoran D, Ling X, Shannon J, Coutinho Goulart Borges Mariottoni PR, Hughes D, Waters D, Dzirasa K, MacLeod A. 814 Circadian factors BMAL1 and CLOCK control transcriptional innate antiviral immunity programs in response to skin wounding. J Invest Dermatol 2020. [DOI: 10.1016/j.jid.2020.03.829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Louie PK, Varthi AG, Narain AS, Lei V, Bohl DD, Shifflett GD, Phillips FM. Stand-alone lateral lumbar interbody fusion for the treatment of symptomatic adjacent segment degeneration following previous lumbar fusion. Spine J 2018; 18:2025-2032. [PMID: 29679730 DOI: 10.1016/j.spinee.2018.04.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 03/16/2018] [Accepted: 04/09/2018] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Revision posterior decompression and fusion surgery for patients with symptomatic adjacent segment degeneration (ASD) is associated with significant morbidity and is technically challenging. The use of a stand-alone lateral lumbar interbody fusion (LLIF) in patients with symptomatic ASD may prevent many of the complications associated with revision posterior surgery. PURPOSE The objective of this study was to assess the clinical and radiographic outcomes of patients who underwent stand-alone LLIF for symptomatic ASD. STUDY DESIGN This is a retrospective case series. PATIENT SAMPLE We retrospectively reviewed patients with a prior posterior instrumented fusion who underwent a subsequent stand-alone LLIF for ASD by a single surgeon. All patients had at least 18 months of follow-up. Patients were diagnosed with symptomatic ASD if they had a previous lumbar fusion with the subsequent development of back pain, neurogenic claudication, or lower extremity radiculopathy in the setting of imaging, which demonstrated stenosis, spondylolisthesis, kyphosis, or scoliosis at the adjacent level. OUTCOME MEASURES Patient-reported outcomes were obtained at preoperative and final follow-up visits using the Oswestry Disability Index [ODI], visual analog scale (VAS)-back, and VAS-leg. Radiographic parameters were measured, including segmental and overall lordoses, pelvic incidence-lumbar lordosis mismatch, coronal alignment, and intervertebral disc height. METHODS Clinical and radiographic outcomes were compared between preoperative and final follow-up using paired t tests. RESULTS Twenty-five patients met inclusion criteria. The mean age was 62.0±11.3 years. The average follow-up was 34.8±22.4 months. Fifteen (60%) underwent stand-alone LLIF surgery for radicular leg pain, 7 (28%) for symptoms of claudication, and 25 (100.0%) for severe back pain. Oswestry Disability Index scores significantly improved from preoperative values (46.6±16.4) to final follow-up (30.4±16.8, p=.002). Visual analog scale-back (preop 8.4±1.0, postop 3.2±1.9; p<.001), and VAS-leg (preop 3.6±3.4, postop 1.9±2.6; p<.001) scores significantly improved following surgery. Segmental and regional lordoses, as well as intervertebral disc height, significantly improved (p<.001) and remained stable (p=.004) by the surgery. Pelvic incidence-lumbar lordosis mismatch significantly improved at the first postoperative visit (p=.029) and was largely maintained at the most recent follow-up (p=.45). Six patients suffered from new-onset thigh weakness following LLIF surgery, but all showed complete resolution within 6 weeks. Three patients required subsequent additional surgeries, all of which were revised to include posterior instrumentation. CONCLUSIONS Stand-alone LLIF is a safe and effective approach with low morbidity and acceptable complication rates for patients with symptomatic ASD following a previous lumbar fusion.
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Affiliation(s)
- Philip K Louie
- Department of Orthopaedic Surgery, Rush University Medical Center, 1611 W Harrison St, Suite 300, Chicago, IL, 60612, USA
| | - Arya G Varthi
- Orthopaedics and Rehabilitation, Yale University School of Medicine, 47 College St, New Haven, CT, 06520-8071, USA
| | - Ankur S Narain
- Department of Orthopaedic Surgery, Rush University Medical Center, 1611 W Harrison St, Suite 300, Chicago, IL, 60612, USA
| | - Victor Lei
- Department of Orthopaedic Surgery, Rush University Medical Center, 1611 W Harrison St, Suite 300, Chicago, IL, 60612, USA
| | - Daniel D Bohl
- Department of Orthopaedic Surgery, Rush University Medical Center, 1611 W Harrison St, Suite 300, Chicago, IL, 60612, USA
| | - Grant D Shifflett
- DISC Sports & Spine Center, Newport Beach, 13160 Mindanao Way, Suite 300, Marina del Rey, CA, 90292, USA
| | - Frank M Phillips
- Department of Orthopaedic Surgery, Rush University Medical Center, 1611 W Harrison St, Suite 300, Chicago, IL, 60612, USA.
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Abstract
INTRODUCTION The antiphospholipid syndrome (APS) is marked by autoantibodies that recognize anionic phospholipids in a cofactor-dependent manner. A role for complement has been implicated in the pathophysiology, however, elevations of complement activation markers have not been consistently demonstrated in clinical studies. We therefore designed a proof-of-principle study to determine whether complement activation might be detectable in APS by first exposing plasmas to phospholipid vesicles. METHODS We examined complement activation markers in patients with APS, non-APS thrombosis, systemic lupus erythematosus, cancer, patients with antiphospholipid antibodies without thrombosis (APL) and healthy controls. Direct measurements of plasma C5a and sC5b-9 levels were compared to levels that were generated in normal serum by phospholipid vesicles that had been pre-incubated with the same plasmas. We then determined the effects of the C5 inhibitor, eculizumab, examined the complement pathways involved, and determined whether the effects could be reproduced with purified IgGs and β2-glycoprotein I (β2GPI). RESULTS Plasma levels of C5a and sC5b-9 were higher, but not significantly increased in APS patients compared to healthy controls. In contrast, phospholipid vesicles pre-incubated with APS plasmas generated significantly higher levels than healthy controls and the other groups, except for APL patients. Complement activation was abrogated by addition of eculizumab. The results with substrate sera indicated that the alternative and classical/lectin pathways were involved. The results were reproducible with purified IgGs and β2GPI. CONCLUSION This proof-of-principle study confirms a role for complement in APS and opens the possibility of monitoring complement activation by including phospholipid vesicles in assay systems.
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Affiliation(s)
- Jacob H Rand
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065, United States
| | - Xiao-Xuan Wu
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, NY 10065, United States
| | - Lucia R Wolgast
- Department of Pathology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY 10461, United States
| | - Victor Lei
- Centre for Blood Research, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Edward M Conway
- Centre for Blood Research, Department of Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
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Topaz M, Radhakrishnan K, Blackley S, Lei V, Lai K, Zhou L. Studying Associations Between Heart Failure Self-Management and Rehospitalizations Using Natural Language Processing. West J Nurs Res 2016; 39:147-165. [PMID: 27628125 DOI: 10.1177/0193945916668493] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
This study developed an innovative natural language processing algorithm to automatically identify heart failure (HF) patients with ineffective self-management status (in the domains of diet, physical activity, medication adherence, and adherence to clinician appointments) from narrative discharge summary notes. We also analyzed the association between self-management status and preventable 30-day hospital readmissions. Our natural language system achieved relatively high accuracy ( F-measure = 86.3%; precision = 95%; recall = 79.2%) on a testing sample of 300 notes annotated by two human reviewers. In a sample of 8,901 HF patients admitted to our healthcare system, 14.4% ( n = 1,282) had documentation of ineffective HF self-management. Adjusted regression analyses indicated that presence of any skill-related self-management deficit (odds ratio [OR] = 1.3, 95% confidence interval [CI] = [1.1, 1.6]) and non-specific ineffective self-management (OR = 1.5, 95% CI = [1.2, 2]) was significantly associated with readmissions. We have demonstrated the feasibility of identifying ineffective HF self-management from electronic discharge summaries with natural language processing.
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Affiliation(s)
- Maxim Topaz
- 1 Harvard Medical School, Boston, MA, USA.,2 Brigham Women's Health Hospital, Boston, MA, USA
| | | | | | - Victor Lei
- 2 Brigham Women's Health Hospital, Boston, MA, USA
| | | | - Li Zhou
- 1 Harvard Medical School, Boston, MA, USA.,2 Brigham Women's Health Hospital, Boston, MA, USA.,4 Partners Healthcare Inc, Boston, MA, USA
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Foley JH, Walton BL, Aleman MM, O'Byrne AM, Lei V, Harrasser M, Foley KA, Wolberg AS, Conway EM. Complement Activation in Arterial and Venous Thrombosis is Mediated by Plasmin. EBioMedicine 2016; 5:175-82. [PMID: 27077125 PMCID: PMC4816834 DOI: 10.1016/j.ebiom.2016.02.011] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 02/04/2016] [Accepted: 02/05/2016] [Indexed: 12/20/2022] Open
Abstract
Thrombus formation leading to vaso-occlusive events is a major cause of death, and involves complex interactions between coagulation, fibrinolytic and innate immune systems. Leukocyte recruitment is a key step, mediated partly by chemotactic complement activation factors C3a and C5a. However, mechanisms mediating C3a/C5a generation during thrombosis have not been studied. In a murine venous thrombosis model, levels of thrombin–antithrombin complexes poorly correlated with C3a and C5a, excluding a central role for thrombin in C3a/C5a production. However, clot weight strongly correlated with C5a, suggesting processes triggered during thrombosis promote C5a generation. Since thrombosis elicits fibrinolysis, we hypothesized that plasmin activates C5 during thrombosis. In vitro, the catalytic efficiency of plasmin-mediated C5a generation greatly exceeded that of thrombin or factor Xa, but was similar to the recognized complement C5 convertases. Plasmin-activated C5 yielded a functional membrane attack complex (MAC). In an arterial thrombosis model, plasminogen activator administration increased C5a levels. Overall, these findings suggest plasmin bridges thrombosis and the immune response by liberating C5a and inducing MAC assembly. These new insights may lead to the development of strategies to limit thrombus formation and/or enhance resolution. Thrombin is not a major direct contributor to C5a generation during venous thrombosis in mice. Plasmin, a protease generated in response to thrombin generation and fibrin deposition, efficiently cleaves C5 to C5a. In an arterial thrombosis model, administration of a plasminogen activator augments C5a plasma levels. Plasmin participates in immunothrombosis, liberating chemotactic C5a and inducing assembly of the procoagulant C5b-9.
Venous and arterial thrombosis are major causes of death and morbidity. Leukocytes are early and active participants in thrombus formation, recruited partly by complement factor C5a. We examined how C5a is generated in the setting of thrombosis. In venous thrombosis in mice, we show that thrombin, a key clot-promoting enzyme, is not a major contributor to C5a generation. Rather, plasmin, a fibrinolytic enzyme formed in response to thrombin generation and clot formation, efficiently generates C5a. The findings were validated in an arterial thrombosis model in mice. These insights may be valuable in developing therapeutic strategies to limit thrombus formation.
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Key Words
- Complement
- FDP, fibrin degradation product
- FeCl3, ferric chloride
- Fibrinolysis
- IL-8, interleukin-8
- IVC, inferior vena cava
- Leukocytes
- MAC, membrane attack complex
- MCP1-1, monocyte chemoattracant protein-1
- NETs, neutrophil extracellular traps
- PAR1, protease activated receptor 1
- PPACK, Phe-Pro-Arg-chloromethylketone
- R751, arginine 751
- TAT, thrombin antithrombin
- Thrombin
- Thrombosis
- VFKck, Val-Phe-Lys-chloromethylketone
- VWF, von Willebrand factor
- tPA, tissue-type plasminogen activator
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Affiliation(s)
- Jonathan H. Foley
- Centre for Blood Research, Department of Medicine, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, LSC4306, Vancouver V6T 1Z3, Canada
- Department of Haematology, UCL Cancer Institute, University College London, London, United Kingdom
- Katharine Dormandy Haemophilia Centre and Thrombosis Unit, Royal Free NHS Trust, London, United Kingdom
| | - Bethany L. Walton
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, 819 Brinkhous-Bullitt Building, CB# 7525, Chapel Hill, NC 27599-7525, USA
| | - Maria M. Aleman
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, 819 Brinkhous-Bullitt Building, CB# 7525, Chapel Hill, NC 27599-7525, USA
| | - Alice M. O'Byrne
- Centre for Blood Research, Department of Medicine, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, LSC4306, Vancouver V6T 1Z3, Canada
| | - Victor Lei
- Centre for Blood Research, Department of Medicine, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, LSC4306, Vancouver V6T 1Z3, Canada
| | - Micaela Harrasser
- Department of Haematology, UCL Cancer Institute, University College London, London, United Kingdom
| | - Kimberley A. Foley
- Cancer Care and Epidemiology, Queen's Cancer Research Institute, Queen's University, Kingston, Canada
| | - Alisa S. Wolberg
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, 819 Brinkhous-Bullitt Building, CB# 7525, Chapel Hill, NC 27599-7525, USA
| | - Edward M. Conway
- Centre for Blood Research, Department of Medicine, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, LSC4306, Vancouver V6T 1Z3, Canada
- Corresponding author at: Centre for Blood Research, 4306-2350 Health Sciences Mall, University of British Columbia, Vancouver, BC V6T 1Z3, Canada.Centre for Blood Research4306-2350 Health Sciences MallUniversity of British ColumbiaVancouverBCV6T 1Z3Canada
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14
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Topaz M, Radhakrishnan K, Lei V, Zhou L. Mining Clinicians' Electronic Documentation to Identify Heart Failure Patients with Ineffective Self-Management: A Pilot Text-Mining Study. Stud Health Technol Inform 2016; 225:856-857. [PMID: 27332377] [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: 06/06/2023]
Abstract
Effective self-management can decrease up to 50% of heart failure hospitalizations. Unfortunately, self-management by patients with heart failure remains poor. This pilot study aimed to explore the use of text-mining to identify heart failure patients with ineffective self-management. We first built a comprehensive self-management vocabulary based on the literature and clinical notes review. We then randomly selected 545 heart failure patients treated within Partners Healthcare hospitals (Boston, MA, USA) and conducted a regular expression search with the compiled vocabulary within 43,107 interdisciplinary clinical notes of these patients. We found that 38.2% (n = 208) patients had documentation of ineffective heart failure self-management in the domains of poor diet adherence (28.4%), missed medical encounters (26.4%) poor medication adherence (20.2%) and non-specified self-management issues (e.g., "compliance issues", 34.6%). We showed the feasibility of using text-mining to identify patients with ineffective self-management. More natural language processing algorithms are needed to help busy clinicians identify these patients.
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Affiliation(s)
| | | | - Victor Lei
- Brigham Women's Health Hospital, Boston, MA, USA
| | - Li Zhou
- Harvard Medical School, Boston, MA, USA
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15
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Foley JH, Peterson EA, Lei V, Wan LW, Krisinger MJ, Conway EM. Interplay between fibrinolysis and complement: plasmin cleavage of iC3b modulates immune responses. J Thromb Haemost 2015; 13:610-8. [PMID: 25556624 DOI: 10.1111/jth.12837] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 12/18/2014] [Indexed: 02/06/2023]
Abstract
BACKGROUND The plasmin(ogen) and complement systems are simultaneously activated at sites of tissue injury, participating in hemostasis, wound healing, inflammation and immune surveillance. In particular, the C3 proteolytic fragment, iC3b, and its degradation product C3dg, which is generated by cleavage by factor I (FI) and the cofactor complement receptor CR1, are important in bridging innate and adaptive immunity. Via a thioester (TE) bond, iC3b and C3dg covalently tag pathogens, modulating phagocytosis and adaptive immune responses. OBJECTIVE To examine plasmin-mediated proteolysis of iC3b, and to evaluate the functional consequences, comparing the effects with products generated by FI/CR1 cleavage of iC3b. METHODS Dose-dependent and time-dependent plasmin-mediated cleavage of iC3b were characterized by analytical gel electrophoresis. The properties of the resultant TE bond-containing fragments on phagocytosis and induction of pro-inflammatory cytokines were measured in cell culture systems. RESULTS At low concentrations, plasmin effectively cleaves iC3b, but at numerous previously undescribed sites, giving rise to novel C3c-like and C3dg-like moieties, the latter of which retain the TE bond. When attached to zymosan or erythrocytes and exposed to THP-1 macrophages, the C3dg-like proteins behave almost identically to the bona fide C3dg, yielding less phagocytosis as compared with the opsonin iC3b, and more macrophage secretion of the pro-inflammatory cytokine, IL-12. CONCLUSION Plasmin cleavage of iC3b provides a complement regulatory pathway that is as efficient as FI/CR1 but does not require a cellular cofactor.
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Affiliation(s)
- J H Foley
- Centre for Blood Research, Life Sciences Institute, University of British Columbia, Vancouver, BC, Canada; Division of Hematology, Department of Medicine, University of British Columbia, Vancouver, BC, Canada
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16
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Suresh Babu S, Valdez Y, Xu A, O'Byrne AM, Calvo F, Lei V, Conway EM. TGFβ-mediated suppression of CD248 in non-cancer cells via canonical Smad-dependent signaling pathways is uncoupled in cancer cells. BMC Cancer 2014; 14:113. [PMID: 24555435 PMCID: PMC3974058 DOI: 10.1186/1471-2407-14-113] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 02/17/2014] [Indexed: 12/04/2022] Open
Abstract
Background CD248 is a cell surface glycoprotein, highly expressed by stromal cells and fibroblasts of tumors and inflammatory lesions, but virtually undetectable in healthy adult tissues. CD248 promotes tumorigenesis, while lack of CD248 in mice confers resistance to tumor growth. Mechanisms by which CD248 is downregulated are poorly understood, hindering the development of anti-cancer therapies. Methods We sought to characterize the molecular mechanisms by which CD248 is downregulated by surveying its expression in different cells in response to cytokines and growth factors. Results Only transforming growth factor (TGFβ) suppressed CD248 protein and mRNA levels in cultured fibroblasts and vascular smooth muscle cells in a concentration- and time-dependent manner. TGFβ transcriptionally downregulated CD248 by signaling through canonical Smad2/3-dependent pathways, but not via mitogen activated protein kinases p38 or ERK1/2. Notably, cancer associated fibroblasts (CAF) and cancer cells were resistant to TGFβ mediated suppression of CD248. Conclusions The findings indicate that decoupling of CD248 regulation by TGFβ may contribute to its tumor-promoting properties, and underline the importance of exploring the TGFβ-CD248 signaling pathway as a potential therapeutic target for early prevention of cancer and proliferative disorders.
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Affiliation(s)
| | | | | | | | | | | | - Edward M Conway
- Centre for Blood Research, Department of Medicine, University of British Columbia, 4306-2350 Health Sciences Mall, V6T 1Z3, BC Vancouver, Canada.
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17
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Glekas GD, Mulhern BJ, Kroc A, Duelfer KA, Lei V, Rao CV, Ordal GW. The Bacillus subtilis chemoreceptor McpC senses multiple ligands using two discrete mechanisms. J Biol Chem 2012; 287:39412-8. [PMID: 23038252 DOI: 10.1074/jbc.m112.413518] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bacillus subtilis can perform chemotaxis toward all 20 L-amino acids normally found in proteins. Loss of a single chemoreceptor, McpC, was previously found to reduce chemotaxis to 19 of these amino acids. In this study, we investigated the amino acid-sensing mechanism of McpC. We show that McpC alone can support chemotaxis to 17 of these amino acids to varying degrees. Eleven amino acids were found to directly bind the amino-terminal sensing domain of McpC in vitro. Sequence analysis indicates that the McpC sensing domain exhibits a dual Per-Arnt-Sim (PAS) domain structure. Using this structure as a guide, we were able to isolate mutants that suggest that four amino acids (arginine, glutamine, lysine, and methionine) are sensed by an indirect mechanism. We identified four candidate binding lipoproteins associated with amino acid transporters that may function in indirect sensing: ArtP, GlnH, MetQ, and YckB. ArtP was found to bind arginine and lysine; GlnH, glutamine; MetQ, methionine; and YckB, tryptophan. In addition, we found that ArtP, MetQ, and YckB bind the sensing domain of McpC, suggesting that the three participate in the indirect sensing of arginine, lysine, methionine, and possibly tryptophan as well. Taken together, these results further our understanding of amino acid chemotaxis in B. subtilis and gain insight into how a single chemoreceptor is able to sense many amino acids.
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Affiliation(s)
- George D Glekas
- Department of Biochemistry, University of Illinois, Urbana, Illinois 61801, USA
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18
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Freeman SA, Lei V, Dang-Lawson M, Mizuno K, Roskelley CD, Gold MR. Cofilin-Mediated F-Actin Severing Is Regulated by the Rap GTPase and Controls the Cytoskeletal Dynamics That Drive Lymphocyte Spreading and BCR Microcluster Formation. J I 2011; 187:5887-900. [DOI: 10.4049/jimmunol.1102233] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Sawadogo-Lingani H, Lei V, Diawara B, Nielsen DS, Møller PL, Traoré AS, Jakobsen M. The biodiversity of predominant lactic acid bacteria in dolo and pito wort for the production of sorghum beer. J Appl Microbiol 2008; 103:765-77. [PMID: 17897178 DOI: 10.1111/j.1365-2672.2007.03306.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIM To quantify and identify the predominant lactic acid bacteria (LAB) in dolo and pito wort processing, and to examine their biodiversity at strain level. MATERIALS AND RESULTS The processing of dolo and pito wort was studied at four production sites in Burkina Faso and Ghana. The succession of dominant micro-organisms, pH and titratable acidity were determined from sorghum malt through mashing and acidification to final wort. In the sorghum malt and during mashing, the LAB counts were 5.7-7.5 log CFU g(-1). Similar levels of yeasts and gram-negative, catalase-positive bacteria were observed. These levels decreased to 3.7-4.5 log CFU g(-1) and<or=2-3 log CFU g(-1), respectively, at the end of mashing, including a mild heat treatment. During acidification at ambient temperature (30-33 degrees C) lasting for 12-16 h, LAB counts increased to 8.8-9.9 log CFU g(-1), pH decreased from 5.55+/-0.12 to 3.72+/-0.24, and the titratable acidity calculated as lactic acid, increased from 0.13% to 0.61%. The gram-negative, catalase-positive bacteria and yeasts observed in the malt and during mashing were no longer detected. A total of 556 strains of LAB were isolated and purified. The LAB isolates were characterized and identified by a polyphasic approach based on phenotypic and genotypic methods, such as carbohydrate fermentation patterns using API 50 CHL, intergenic transcribed spacers-polymerase chain reaction/restriction fragment length polymorphism (ITS-PCR/RFLP), pulsed-field gel electrophoresis (PFGE) and 16S rRNA gene sequencing. Lactobacillus fermentum was identified as the dominant LAB species in the malt during mashing and during acidification. The other species observed during acidification were Lactobacillus delbrueckii ssp. delbrueckii, Lact. delbrueckii ssp. bulgaricus and Pediococcus acidilactici. These bacteria comprised a minor fraction of the bacterial population and no distinct microbial succession was observed for the LAB. At species level, the LAB profiles were similar for the four production sites; however, a pronounced diversity was observed at strain level. For one site, which had implemented a cleaning procedure between batches only, Lact. fermentum was found. CONCLUSION Lact. fermentum was found to be the dominant LAB species throughout the entire process to final dolo and pito wort, including the acidification. Lact. delbrueckii ssp. delbrueckii, Lact. delbrueckii ssp. bulgaricus and P. acidilactici occurred in low numbers. At strain level, a high diversity based on PFGE-RFLP was observed for Lact. fermentum within and between sites. SIGNIFICANCE AND IMPACT OF THE STUDY This study for the first time gives details of the involvement of LAB in the production of dolo and pito wort, for West African traditional sorghum beer production. One species, Lact. fermentum was predominant throughout the process, and seems to harbour potential starter cultures to be selected according to technological characteristics determined at strain level.
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Affiliation(s)
- H Sawadogo-Lingani
- Département Technologie Alimentaire/IRSAT/CNRST, 03 BP 7047, Ouagadougou, Burkina Faso.
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Lin KBL, Freeman SA, Zabetian S, Brugger H, Weber M, Lei V, Dang-Lawson M, Tse KWK, Santamaria R, Batista FD, Gold MR. The rap GTPases regulate B cell morphology, immune-synapse formation, and signaling by particulate B cell receptor ligands. Immunity 2008; 28:75-87. [PMID: 18191594 DOI: 10.1016/j.immuni.2007.11.019] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2007] [Revised: 10/19/2007] [Accepted: 11/19/2007] [Indexed: 01/17/2023]
Abstract
B lymphocytes spread and extend membrane processes when searching for antigens and form immune synapses upon contacting cells that display antigens on their surface. Although these dynamic morphological changes facilitate B cell activation, the signaling pathways underlying these processes are not fully understood. We found that activation of the Rap GTPases was essential for these changes in B cell morphology. Rap activation was important for B cell receptor (BCR)- and lymphocyte-function-associated antigen-1 (LFA-1)-induced spreading, for BCR-induced immune-synapse formation, and for particulate BCR ligands to induce localized F-actin assembly and membrane-process extension. Rap activation and F-actin assembly were also required for optimal BCR signaling in response to particulate antigens but not soluble antigens. Thus by controlling B cell morphology and cytoskeletal organization, Rap might play a key role in the activation of B cells by particulate and cell-associated antigens.
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Affiliation(s)
- Kevin B L Lin
- Department of Microbiology and Immunology, I3 and CELL Research Groups, Life Sciences Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
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21
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Mak A, Rahmanian R, Lei V, Lawrence D, Krajden M, Brunham RC, Skowronski D, Li Y, Booth T, Goh SH, Petric M. Longitudinal analysis of genotype distribution of influenza A virus from 2003 to 2005. J Clin Microbiol 2006; 44:3583-8. [PMID: 17021086 PMCID: PMC1594783 DOI: 10.1128/jcm.02601-05] [Citation(s) in RCA: 7] [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: 11/20/2022] Open
Abstract
Influenza A viruses cause yearly epidemics, in part, due to their ability to overcome immunity from previous infections through acquisition of mutations. Amino acid sequences encoded by genes 4 (HA), 6 (NA), 7 (M), and 8 (NS) from 77 H3N2 influenza A isolates, collected between November 2003 and March 2005, were analyzed to determine the extent to which the viruses mutated within epidemic periods and between the epidemics. Nucleotide and amino acid sequences were stable throughout the epidemics but experienced substantial changes between epidemics. Major changes occurred in the HA gene in 5 to 7 amino acids and the NA gene in 11 to 13 amino acids and changes of 5 amino acids occurred in the M and NS genes. In the HA gene, changes occurred in sites known to be epitopes that determine the hemagglutination inhibition reactivity, and these were shown to be associated with a change of strain from A/Fujian/411/2002-like to A/California/7/2004-like viruses. Our findings indicate that genotype determination promises to be a rapid approach for detecting new strains of influenza A viruses in a population.
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Affiliation(s)
- Annie Mak
- BC Centre for Disease Control, 655 W12th Ave., Vancouver, BC V5Z 4R4, Canada.
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Lei V, Jakobsen M. Microbiological characterization and probiotic potential of koko and koko sour water, African spontaneously fermented millet porridge and drink. J Appl Microbiol 2004; 96:384-97. [PMID: 14723700 DOI: 10.1046/j.1365-2672.2004.02162.x] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS To identify and examine the diversity of predominant lactic acid bacteria (LAB) in koko and koko sour water (KSW) from different Ghanaian production sites with regard to pattern of fermentation (API 50 CHL), genotype, antimicrobial activity, and resistance to low pH and bile salts. METHODS AND RESULTS In total 215 LAB were isolated from koko and KSW. The isolates were identified using intergenic transcribed spacers (ITS)-PCR restriction fragment length polymorphism (RFLP), API 50 CHL, restriction enzyme analysis with pulsed-field gel electrophoresis (REA-PFGE) and sequencing of the 16S rRNA gene. The dominating micro-organisms in koko was found to be Weisella confusa and Lactobacillus fermentum, followed by Lact. salivarius and Pediococcus spp. Chemometric data analysis were used to link the LAB species to the different production stages and production sites. At intra-species level the isolates were found to have a great diversity. The isolates were investigated for antimicrobial activity using agar diffusion assays, and acid and bile tolerance. Most isolates showed low levels of antimicrobial activity towards the indicator strain Listeria innocua, but not towards the bacteriocin-sensitive Lact. sakei. Growth of all LAB isolates was unaffected by the presence of 0.3% (v/v) oxgall bile. The isolates were able to survive, but were not able to grow in growth medium adjusted to pH 2.5. CONCLUSIONS The dominating LAB of koko and KSW were W. confusa and Lact. fermentum showing a pronounced taxonomic biodiversity at sub-species level between stages within the production as well as between production sites. Other species observed in KSW were Lact. salivarius, Ped. pentosaceus, Ped. acidilactici and Lact. paraplantarum. They occurred in levels of 108 CFU ml-1 in fresh KSW and showed uniform antimicrobial activity, and acid and bile tolerance. SIGNIFICANCE AND IMPACT OF THE STUDY The present study gives a detailed picture of the taxonomy and diversity of LAB in an African-fermented millet product that may have potential as a probiotic product for the local population. The chemometric tools Principal Component Analysis and anova Partial Least Squares Regression were proven to be useful in the analysis of microbial groupings and associations with specific sites and stages in the production of koko and KSW.
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Affiliation(s)
- V Lei
- Department of Dairy and Food Science, The Royal Veterinary and Agricultural University, Food Microbiology, Rolighedsvej, Frederiksberg C, Denmark.
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Lei V, Amoa-Awua WK, Brimer L. Degradation of cyanogenic glycosides by Lactobacillus plantarum strains from spontaneous cassava fermentation and other microorganisms. Int J Food Microbiol 1999; 53:169-84. [PMID: 10634708 DOI: 10.1016/s0168-1605(99)00156-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [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: 10/18/2022]
Abstract
Strains of Lactobacillus plantarum, Leuconostoc mesenteroides, Candida tropicalis and Penicillium sclerotiorum were screened for 19 enzymatic activities using the commercial kit API zym (Bio Mérieux). This activity was compared to the ability of degrading the toxic cyanogenic glycosides amygdalin, linamarin, and linseed cyanogens (a mixture of linustatin and neolinustatin). Good correlation between the beta-glucosidase activity found in the API zym screening and the ability to degrade the cyanogenic glycosides was found for the first three species mentioned. P. sclerotiorum strains exhibited very high activity in the API zym test (substrate: 6-Br-2-naphthyl-beta-D-glucopyranoside), but proved unable to degrade any of the cyanogenic substrates. Among the seven strains of L. plantarum tested, a great variation was seen in the beta-glucosidase activity as well as in the ability to degrade the cyanogens. This was also the case for the strains of C. tropicalis. However, all the glucosidase positive strains of these species were also able to degrade all of the cyanogens tested and at approximately the same rate. A co-culture of the most active strain of L. plantarum and C. tropicalis seemed to degrade linamarin faster than the mono cultures. L. plantarum LPI (originally isolated from fermented cassava) was investigated in further detail. The hydrolytic activity of this strain was intracellular or cell bound, and beta-bis-glycosides such as amygdalin were hydrolysed by a two-stage sequential mechanism as follows: (1) amygdalin to prunasin and (2) prunasin to cyanohydrin. Finally, inoculation of extracted linseed meal (containing linustatin and neolinustatin) with L. plantarum LPI resulted in hydrolysis of the glycosides.
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Affiliation(s)
- V Lei
- Department of Dairy and Food Science, Royal Veterinary and Agricultural University, Frederiksberg C, Copenhagen, Denmark
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