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Halloran B, Zhang M, Mbogori T, Friesen C. Postpartum Depression and Preconception Vitamin Supplementation: An Analysis of the Pregnancy Risk Assessment Monitoring System (PRAMS), 2016-2018. J Acad Nutr Diet 2021. [DOI: 10.1016/j.jand.2021.06.075] [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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Rohse P, Butlewski J, Klein F, Wagner T, Friesen C, Schwarz A, Wiesendanger R, Sengstock K, Becker C. A cavity optomechanical locking scheme based on the optical spring effect. Rev Sci Instrum 2020; 91:103102. [PMID: 33138582 DOI: 10.1063/5.0010255] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 09/12/2020] [Indexed: 06/11/2023]
Abstract
We present a novel locking scheme for active length-stabilization and frequency detuning of a cavity optomechanical device based on the optical spring effect. The error signal is generated by utilizing the position measurement of a thermally driven intra-cavity nanomechanical device and employing its detuning-dependent frequency shift caused by the dispersive coupling to the cavity field. The scheme neither requires external modulation of the laser or the cavity nor does it demand for additional error signal readout, rendering its technical implementation rather simple for a large variety of existing optomechanical devices. Specifically, for large-linewidth microcavities or in situations where other locking schemes appear unfavorable conceptually or are hard to realize technically, the optical spring lock represents a potential alternative for stabilizing the cavity length. We explain the functional principle of the lock and characterize its performance in terms of bandwidth and gain profile.
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Affiliation(s)
- P Rohse
- ZOQ (Zentrum für Optische Quantentechnologien), Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - J Butlewski
- ZOQ (Zentrum für Optische Quantentechnologien), Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - F Klein
- ZOQ (Zentrum für Optische Quantentechnologien), Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - T Wagner
- ZOQ (Zentrum für Optische Quantentechnologien), Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - C Friesen
- INF (Institut für Nanostruktur- und Festkörperphysik), Universität Hamburg, Jungiusstraße 9, 20355 Hamburg, Germany
| | - A Schwarz
- INF (Institut für Nanostruktur- und Festkörperphysik), Universität Hamburg, Jungiusstraße 9, 20355 Hamburg, Germany
| | - R Wiesendanger
- ZOQ (Zentrum für Optische Quantentechnologien), Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - K Sengstock
- ZOQ (Zentrum für Optische Quantentechnologien), Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - C Becker
- ZOQ (Zentrum für Optische Quantentechnologien), Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany
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Hashmi S, Buckley G, Hughbanks L, Flotow A, Friesen C. Comparison of the Rate of Overweight or Obesity among Veterans and Non-Veterans with and without a Known Depressive Disorder: An Examination of the 2018 BRFSS Data. J Acad Nutr Diet 2020. [DOI: 10.1016/j.jand.2020.06.183] [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: 10/23/2022]
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Hayes M, Tunnell C, Arthur T, Friesen C. Practices and Beliefs of Registered Dietitians in Indiana Regarding Ketogenic Diets for the Treatment of Type 2 Diabetes Mellitus. J Acad Nutr Diet 2020. [DOI: 10.1016/j.jand.2020.06.239] [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: 10/23/2022]
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Abstract
SummaryDespite good achievements in prevention and control, cancer is still a leading cause of death worldwide. The development of resistances against conventional treatment modalities is one of the main causes of failure in the treatment of cancer. Radio- and chemotherapies fail frequently due to intrinsic or acquired resistances in apoptotic signalling pathways or alterations in DNA-repair processes.Targeted radiotherapies employing α-particle-emitting radionuclides and Auger-emitting electrons are a promising approach in cancer treatment to break radio- and chemo – resistance by overcoming DNA-repair mechanisms and reversing deficient activation of apoptotic pathways in cancer cells.
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Friesen C, Vukovich R, Yen A, Kistler B, Wilson R. Health and Nutrition-Related Characteristics of Faculty and Staff Who Received Services at the Nutrition Assessment Laboratory: Part of Ball State University's “Working Well” Worksite Wellness Program. J Acad Nutr Diet 2017. [DOI: 10.1016/j.jand.2017.06.020] [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: 11/28/2022]
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Maxwell C, Pike K, Friesen C. Sports Nutrition Knowledge, Perceptions, Resources, and Advice Given by Certified CrossFit Trainers. J Acad Nutr Diet 2017. [DOI: 10.1016/j.jand.2017.06.094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Friesen C, Fetterman M, Barclay J, Burns J. Taking Steps to Healthy Success: What Level of Training and Technical Assistance is Associated with the Greatest Adoption of Nutrition and Physical Activity “Best Practices” in the Child Care Setting? J Acad Nutr Diet 2017. [DOI: 10.1016/j.jand.2017.06.197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Güthle M, Friesen C, Hofheinz R, Muche R, Ettrich T, Perkhofer L, Berger A, Seufferlein T. Eine Phase I/II-Studie zur Therapie mit D,L-Methadon in der Behandlung von Patienten mit histologisch gesicherten chemorefraktären kolorektalen Karzinomen. Z Gastroenterol 2015. [DOI: 10.1055/s-0035-1559240] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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10
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Abstract
Librarian-mediated literature searching is a key service provided at medical libraries. This analysis outlines ten years of data on 19,248 literature searches and describes information on the volume and frequency of search requests, time spent per search, databases used, and professional designations of the patron requestors. Combined with information on best practices for expert searching and evaluations of similar services, these findings were used to form recommendations on the improvement and standardization of a literature search service at a large health library system.
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Affiliation(s)
- Carol Friesen
- a Neil John Maclean Health Sciences Library, University of Manitoba , Winnipeg , Manitoba , Canada
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11
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Rimmer E, Houston BL, Kumar A, Abou-Setta AM, Friesen C, Marshall JC, Rock G, Turgeon AF, Cook DJ, Houston DS, Zarychanski R. The efficacy and safety of plasma exchange in patients with sepsis and septic shock: a systematic review and meta-analysis. Crit Care 2014; 18:699. [PMID: 25527094 PMCID: PMC4318234 DOI: 10.1186/s13054-014-0699-2] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Accepted: 11/27/2014] [Indexed: 01/04/2023]
Abstract
Introduction Sepsis and septic shock are leading causes of intensive care unit (ICU) mortality. They are characterized by excessive inflammation, upregulation of procoagulant proteins and depletion of natural anticoagulants. Plasma exchange has the potential to improve survival in sepsis by removing inflammatory cytokines and restoring deficient plasma proteins. The objective of this study is to evaluate the efficacy and safety of plasma exchange in patients with sepsis. Methods We searched MEDLINE, EMBASE, CENTRAL, Scopus, reference lists of relevant articles, and grey literature for relevant citations. We included randomized controlled trials comparing plasma exchange or plasma filtration with usual care in critically ill patients with sepsis or septic shock. Two reviewers independently identified trials, extracted trial-level data and performed risk of bias assessments using the Cochrane Risk of Bias tool. The primary outcome was all-cause mortality reported at longest follow-up. Meta-analysis was performed using a random-effects model. Results Of 1,957 records identified, we included four unique trials enrolling a total of 194 patients (one enrolling adults only, two enrolling children only, one enrolling adults and children). The mean age of adult patients ranged from 38 to 53 years (n = 128) and the mean age of children ranged from 0.9 to 18 years (n = 66). All trials were at unclear to high risk of bias. The use of plasma exchange was not associated with a significant reduction in all-cause mortality (risk ratio (RR) 0.83, 95% confidence interval (CI) 0.45 to 1.52, I2 60%). In adults, plasma exchange was associated with reduced mortality (RR 0.63, 95% CI 0.42 to 0.96; I2 0%), but was not in children (RR 0.96, 95% CI 0.28 to 3.38; I2 60%). None of the trials reported ICU or hospital lengths of stay. Only one trial reported adverse events associated with plasma exchange including six episodes of hypotension and one allergic reaction to fresh frozen plasma. Conclusions Insufficient evidence exists to recommend plasma exchange as an adjunctive therapy for patients with sepsis or septic shock. Rigorous randomized controlled trials evaluating clinically relevant patient-centered outcomes are required to evaluate the impact of plasma exchange in this condition. Electronic supplementary material The online version of this article (doi:10.1186/s13054-014-0699-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Emily Rimmer
- Department of Internal Medicine, University of Manitoba, GC425-820 Sherbrook Street, HSC, Winnipeg, R3A 1R9, Canada. .,Department of Haematology and Medical Oncology, CancerCare Manitoba, 675 McDermot Ave, Winnipeg, R3E 0V9, Canada.
| | - Brett L Houston
- Faculty of Medicine, University of Manitoba, 250 Brodie Centre, 727 McDermot Ave, Winnipeg, R3E 3P5, Canada.
| | - Anand Kumar
- Department of Internal Medicine, University of Manitoba, GC425-820 Sherbrook Street, HSC, Winnipeg, R3A 1R9, Canada.
| | - Ahmed M Abou-Setta
- George & Fay Yee Center for Healthcare Innovation, University of Manitoba/Winnipeg Regional Health Authority, GE706-820 Sherbrook Street, HSC, Winnipeg, R3A 1R9, Canada.
| | - Carol Friesen
- Neil John Maclean Health Sciences Library, University of Manitoba, Brodie Centre, 727 McDermot Ave, Winnipeg, R3E 3P5, Canada.
| | - John C Marshall
- Section of Critical Care Medicine, St. Michael's Hospital, 30 Bond Street, Toronto, M5B 1W8, Canada.
| | - Gail Rock
- Ottawa Hospital, 501 Smyth Road, Ottawa, K1H 8L6, Canada.
| | - Alexis F Turgeon
- Division of Critical Care Medicine, Department of Anesthesiology and Critical Care Medicine and Population Health and Optimal Health Practices Unit, CHU de Québec Research Center, Université Laval, 1401-18th Street, Québec, G1J 1Z4, Canada.
| | - Deborah J Cook
- Department of Medicine, McMaster University, Hamilton, L8S 4K1, Canada. .,Department of Clinical Epidemiology and Biostatistics, McMaster University, 1280 Main Street, West, Hamilton, Canada.
| | - Donald S Houston
- Department of Internal Medicine, University of Manitoba, GC425-820 Sherbrook Street, HSC, Winnipeg, R3A 1R9, Canada. .,Department of Haematology and Medical Oncology, CancerCare Manitoba, 675 McDermot Ave, Winnipeg, R3E 0V9, Canada.
| | - Ryan Zarychanski
- Department of Internal Medicine, University of Manitoba, GC425-820 Sherbrook Street, HSC, Winnipeg, R3A 1R9, Canada. .,Department of Haematology and Medical Oncology, CancerCare Manitoba, 675 McDermot Ave, Winnipeg, R3E 0V9, Canada. .,George & Fay Yee Center for Healthcare Innovation, University of Manitoba/Winnipeg Regional Health Authority, GE706-820 Sherbrook Street, HSC, Winnipeg, R3A 1R9, Canada.
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12
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Manyanga T, Froese M, Zarychanski R, Abou-Setta A, Friesen C, Tennenhouse M, Shay BL. Pain management with acupuncture in osteoarthritis: a systematic review and meta-analysis. BMC Complement Altern Med 2014; 14:312. [PMID: 25151529 PMCID: PMC4158087 DOI: 10.1186/1472-6882-14-312] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 08/18/2014] [Indexed: 01/22/2023]
Abstract
BACKGROUND The utility of acupuncture in managing osteoarthritis symptoms is uncertain. Trial results are conflicting and previous systematic reviews may have overestimated the benefits of acupuncture. METHODS Two reviewers independently identified randomized controlled trials (up to May 2014) from multiple electronic sources (including PubMed/Medline, EMBASE, and CENTRAL) and reference lists of relevant articles, extracted data and assessed risk of bias (Cochrane's Risk of Bias tool). Pooled data are expressed as mean differences (MD), with 95% confidence intervals (CI) (random-effects model). RESULTS We included 12 trials (1763 participants) comparing acupuncture to sham acupuncture, no treatment or usual care. We adjudicated most trials to be unclear (64%) or high (9%) risk of bias. Acupuncture use was associated with significant reductions in pain intensity (MD -0.29, 95% CI -0.55 to -0.02, I2 0%, 10 trials, 1699 participants), functional mobility (standardized MD -0.34, 95% CI -0.55 to -0.14, I2 70%, 9 trials, 1543 participants), health-related quality of life (standardized MD -0.36, 95% CI -0.58 to -0.14, I2 50%, 3 trials, 958 participants). Subgroup analysis of pain intensity by intervention duration suggested greater pain intensity reduction with intervention periods greater than 4 weeks (MD -0.38, 95% CI -0.69 to -0.06, I2 0%, 6 trials, 1239 participants). CONCLUSIONS The use of acupuncture is associated with significant reductions in pain intensity, improvement in functional mobility and quality of life. While the differences are not as great as shown by other reviews, current evidence supports the use of acupuncture as an alternative for traditional analgesics in patients with osteoarthritis. SYSTEMATIC REVIEW REGISTRATION CRD42013005405.
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Affiliation(s)
- Taru Manyanga
- />Department of Community Health Sciences, University of Manitoba, Winnipeg, Manitoba Canada
- />Surgery Rehabilitation Department, Seven Oaks General Hospital, Winnipeg, Manitoba Canada
| | - Maria Froese
- />Surgery Rehabilitation Department, Seven Oaks General Hospital, Winnipeg, Manitoba Canada
| | - Ryan Zarychanski
- />Department of Internal Medicine, University of Manitoba, Winnipeg, Manitoba Canada
- />George & Fay Yee Center for Healthcare Innovation, University of Manitoba/Winnipeg Regional Health Authority, Winnipeg, Manitoba Canada
| | - Ahmed Abou-Setta
- />George & Fay Yee Center for Healthcare Innovation, University of Manitoba/Winnipeg Regional Health Authority, Winnipeg, Manitoba Canada
| | - Carol Friesen
- />Neil John Maclean Health Sciences Library, University of Manitoba, Winnipeg, Manitoba Canada
| | - Michael Tennenhouse
- />Neil John Maclean Health Sciences Library, University of Manitoba, Winnipeg, Manitoba Canada
| | - Barbara L Shay
- />Department of Physiotherapy, School of Medical Rehabilitation, University of Manitoba, Winnipeg, Manitoba Canada
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Enns JE, Yeganeh A, Zarychanski R, Abou-Setta AM, Friesen C, Zahradka P, Taylor CG. The impact of omega-3 polyunsaturated fatty acid supplementation on the incidence of cardiovascular events and complications in peripheral arterial disease: a systematic review and meta-analysis. BMC Cardiovasc Disord 2014; 14:70. [PMID: 24885361 PMCID: PMC4065588 DOI: 10.1186/1471-2261-14-70] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [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: 03/17/2014] [Accepted: 05/28/2014] [Indexed: 12/25/2022] Open
Abstract
Background Individuals with peripheral arterial disease are at higher risk for cardiovascular events than the general population. While supplementation with omega-3 polyunsaturated fatty acids (PUFA) has been shown to improve vascular function, it remains unclear if supplementation decreases serious clinical outcomes. We conducted a systematic review and meta-analysis to determine whether omega-3 PUFA supplementation reduces the incidence of cardiovascular events and complications in adults with peripheral arterial disease. Methods We searched five electronic databases (MEDLINE, EMBASE, CENTRAL, Scopus and the International Clinical Trials Registry Platform) from inception to 6 December 2013 to identify randomized trials of omega-3 PUFA supplementation (from fish or plant oils) that lasted ≥12 weeks in adults with peripheral arterial disease. No language filters were applied. Data on trial design, population characteristics, and health outcomes were extracted. The primary outcome was major adverse cardiac events; secondary outcomes included myocardial infarction, cardiovascular death, stroke, angina, amputation, revascularization procedures, maximum and pain-free walking distance, adverse effects of the intervention, and quality of life. Trial quality was assessed using the Cochrane Risk of Bias tool. Results Of 741 citations reviewed, we included five trials enrolling 396 individuals. All included trials were of unclear or high risk of bias. There was no evidence of a protective association of omega-3 PUFA supplementation against major adverse cardiac events (pooled risk ratio 0.73, 95% CI 0.22 to 2.41, I2 75%, 2 trials, 288 individuals) or other serious clinical outcomes. Adverse events and compliance were poorly reported. Conclusions Our results showed that insufficient evidence exists to suggest a beneficial effect of omega-3 PUFA supplementation in adults with peripheral arterial disease with regard to cardiovascular events and other serious clinical outcomes.
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Affiliation(s)
| | | | | | | | | | | | - Carla G Taylor
- Department of Physiology, University of Manitoba, Winnipeg, Canada.
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Fernandes N, Driver S, Ellery J, Friesen C. Healthy meals, healthy families: a pilot intervention to improve nutrition knowledge and confidence to prepare healthy meals among low‐income individuals (624.6). FASEB J 2014. [DOI: 10.1096/fasebj.28.1_supplement.624.6] [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: 11/11/2022]
Affiliation(s)
- Nicolle Fernandes
- Family and Consumer Sciences Ball State UniversityMuncieINUnited States
| | - Stacey Driver
- Family and Consumer Sciences Ball State UniversityMuncieINUnited States
| | - Jane Ellery
- Institute for Wellness & Gerontology Ball State UniversityMuncieINUnited States
| | - Carol Friesen
- Family and Consumer Sciences Ball State UniversityMuncieINUnited States
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Fernandes N, Driver S, Murr R, Friesen C. Impact of a point system program in increasing fruit and vegetable consumption among university employees (1021.12). FASEB J 2014. [DOI: 10.1096/fasebj.28.1_supplement.1021.12] [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: 11/11/2022]
Affiliation(s)
- Nicolle Fernandes
- Family and Consumer SciencesBall State UniversityMuncieINUnited States
| | - Stacey Driver
- Family and Consumer SciencesBall State UniversityMuncieINUnited States
| | - Rhonda Murr
- Family and Consumer SciencesBall State UniversityMuncieINUnited States
| | - Carol Friesen
- Family and Consumer SciencesBall State UniversityMuncieINUnited States
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Azad MB, Coneys JG, Kozyrskyj AL, Field CJ, Ramsey CD, Becker AB, Friesen C, Abou-Setta AM, Zarychanski R. Probiotic supplementation during pregnancy or infancy for the prevention of asthma and wheeze: a systematic review and meta-analysis. Allergy Asthma Clin Immunol 2014. [PMCID: PMC4126008 DOI: 10.1186/1710-1492-10-s1-a25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Azad MB, Coneys JG, Kozyrskyj AL, Field CJ, Ramsey CD, Becker AB, Friesen C, Abou-Setta AM, Zarychanski R. Probiotic supplementation during pregnancy or infancy for the prevention of asthma and wheeze: systematic review and meta-analysis. BMJ 2013; 347:f6471. [PMID: 24304677 PMCID: PMC3898421 DOI: 10.1136/bmj.f6471] [Citation(s) in RCA: 137] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
OBJECTIVE To evaluate the association of probiotic supplementation during pregnancy or infancy with childhood asthma and wheeze. DESIGN Systematic review and meta-analysis of randomised controlled trials. DATA SOURCES Medline, Embase, and Central (Cochrane Library) databases from inception to August 2013, plus the World Health Organization's international clinical trials registry platform and relevant conference proceedings for the preceding five years. Included trials and relevant reviews were forward searched in Web of Science. REVIEW METHODS Two reviewers independently identified randomised controlled trials evaluating probiotics administered to mothers during pregnancy or to infants during the first year of life. The primary outcome was doctor diagnosed asthma; secondary outcomes included wheeze and lower respiratory tract infection. RESULTS We identified 20 eligible trials including 4866 children. Trials were heterogeneous in the type and duration of probiotic supplementation, and duration of follow-up. Only five trials conducted follow-up beyond participants' age of 6 years (median 24 months), and none were powered to detect asthma as the primary outcome. The overall rate of doctor diagnosed asthma was 10.7%; overall rates of incident wheeze and lower respiratory tract infection were 33.3% and 13.9%, respectively. Among 3257 infants enrolled in nine trials contributing asthma data, the risk ratio of doctor diagnosed asthma in participants randomised to receive probiotics was 0.99 (95% confidence interval 0.81 to 1.21, I(2)=0%). The risk ratio of incident wheeze was 0.97 (0.87 to 1.09, I(2)=0%, 9 trials, 1949 infants). Among 1364 infants enrolled in six trials, the risk ratio of lower respiratory tract infection after probiotic supplementation was 1.26 (0.99 to 1.61, I(2)=0%). We adjudicated most trials to be of high (ten trials) or unclear (nine trials) risk of bias, mainly due to attrition. CONCLUSIONS We found no evidence to support a protective association between perinatal use of probiotics and doctor diagnosed asthma or childhood wheeze. Randomised controlled trials to date have not yielded sufficient evidence to recommend probiotics for the primary prevention of these disorders. Extended follow-up of existing trials, along with further clinical and basic research, are needed to accurately define the role of probiotics in the prevention of childhood asthma. SYSTEMATIC REVIEW REGISTRATION PROSPERO (CRD42013004385).
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Affiliation(s)
- Meghan B Azad
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada T6G 1C9
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Abstract
Selecting an infant feeding method is one of the most important decisions a mother-to-be makes. Little information is available to characterize women who plan to use both formula and breast milk. In this study, 89 pregnant women indicated their anticipated feeding method and the sources and initiator of infant feeding information. No differences were found in the type of resources used by women who planned to breastfeed, formula feed, or combination feed. Women in the study were four times more likely to initiate a conversation about infant feeding methods with a family member or friend than with a health care provider. Involving these key individuals in perinatal education classes and support programs is a simple, but powerful, strategy that childbirth educators can use to promote breastfeeding.
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Affiliation(s)
- J Chezem
- J o C arol C hezem is an associate professor in the Department of Family and Consumer Sciences at Ball State University in Muncie, Indiana
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Friesen C, Bacher S, Hormann I, Roscher M, Miltner E. Cytotoxic effects of opioids on cancer cell lines. Int J Clin Pharmacol Ther 2011; 49:60-62. [PMID: 21176729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023] Open
Affiliation(s)
- C Friesen
- Institute of Legal Medicine, University of Ulm, Ulm, Germany.
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20
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Friesen C, Hormann I, Roscher M, Bacher S, Miltner E. [Overcoming of radiation resistances]. Nuklearmedizin 2010; 49 Suppl 1:S31-S36. [PMID: 21152691] [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] [Received: 09/14/2010] [Accepted: 09/21/2010] [Indexed: 05/30/2023]
Abstract
Despite good achievements in prevention and control, cancer is still a leading cause of death worldwide. The development of resistances against conventional treatment modalities is one of the main causes of failure in the treatment of cancer. Radio- and chemotherapies fail frequently due to intrinsic or acquired resistances in apoptotic signalling pathways or alterations in DNA-repair processes. Targeted radiotherapies employing α-particle-emitting radionuclides and Auger-emitting electrons are a promising approach in cancer treatment to break radio- and chemoresistance by overcoming DNA-repair mechanisms and reversing deficient activation of apoptotic pathways in cancer cells.
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Affiliation(s)
- C Friesen
- Institut für Rechtsmedizin, Universität Ulm, Prittwitzstr. 6, 89075 Ulm.
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Hartling L, Chari R, Friesen C, Vandermeer B, Lacaze-Masmonteil T. A systematic review of intentional delivery in women with preterm prelabor rupture of membranes. J Matern Fetal Neonatal Med 2009; 19:177-87. [PMID: 16690512 DOI: 10.1080/14767050500451470] [Citation(s) in RCA: 24] [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: 10/24/2022]
Abstract
OBJECTIVE To evaluate the effect of intentional delivery versus expectant management in women with preterm prelabor rupture of membranes (PPROM). METHODS We searched electronic databases and trials registries, contacted experts, and checked reference lists of relevant studies. Studies were included if they were randomized controlled trials comparing intentional delivery versus expectant management after PPROM, the gestational age of participants was between 30 and 36 weeks, and the study reported one of several pre-determined outcomes. RESULTS Four studies were included in the meta-analysis. No difference was found between intentional delivery and expectant management in neonatal intensive care unit (NICU) length of stay (LOS) (weighted mean difference (WMD) -0.81 day, 95% confidence interval (CI) -1.66, 0.04), respiratory distress syndrome (risk difference (RD) -0.01, 95% CI -0.07, 0.06), and confirmed neonatal sepsis (RD -0.01, 95% CI -0.05, 0.04). One study found a significantly lower incidence of suspected neonatal sepsis among the intentional delivery group (RD -0.31, 95% CI -0.50, -0.12; number needed to treat (NNT) 3, 95% CI 2, 8). Maternal LOS was significantly shorter for the intentional delivery group (WMD -1.39 day, 95% CI -2.03, -0.75). There was a significant difference in the incidence of clinical chorioamnionitis favoring intentional delivery (RD -0.16, 95% CI -0.23, -0.10; NNT 6, 95% CI 5, 11). There was no significant difference in the incidence of other maternal outcomes, including cesarean section (RD 0.05, 95% CI -0.01, 0.11). CONCLUSIONS Intentional delivery may be favorable to expectant management for some maternal outcomes (chorioamnionitis and LOS). There is insufficient evidence to suggest that either strategy is beneficial or harmful for the baby. Large multicenter trials with primary neonatal outcomes are required to assess whether intentional delivery is associated with less neonatal morbidity.
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Affiliation(s)
- Lisa Hartling
- Department of Obstetrics and Gynecology, University of Alberta, Edmonton, Canada
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Dowling S, Spooner CH, Liang Y, Dryden DM, Friesen C, Klassen TP, Wright RB. Accuracy of Ottawa Ankle Rules to exclude fractures of the ankle and midfoot in children: a meta-analysis. Acad Emerg Med 2009; 16:277-87. [PMID: 19187397 DOI: 10.1111/j.1553-2712.2008.00333.x] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [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: 12/29/2022]
Abstract
OBJECTIVES The objectives were to conduct a systematic review to determine the diagnostic accuracy of the Ottawa Ankle Rules (OAR) to exclude ankle and midfoot fractures in children and the extent to which x-ray use could be reduced without missing significant fractures. METHODS The authors conducted comprehensive searches of electronic databases and gray literature sources. Independent reviewers applied standard inclusion and exclusion criteria. The criterion standard diagnostic test was an ankle and/or foot x-ray or proxy measure to ensure no missed fractures. Standard 2 x 2 tables were constructed. Sensitivities and specificities were pooled using an approximation of the inverse variance; 95% confidence intervals (95% CIs) were calculated using the exact method. Likelihood ratios (LR +/-) and diagnostic odds ratios were combined under DerSimonian and Laird random effects model. RESULTS A pooled analysis of 12 studies (N = 3,130) identified 671 fractures (prevalence = 21.4%). Ten studies reported Salter-Harris Type I (SH-I) fractures. The pooled sensitivity was 98.5% (95% CI = 97.3 to 99.2), suggesting that the OAR can be used to rule out a fracture. Four of 10 missed fractures were characterized: 1 SH-I, 1 SH-IV, and 2 "insignificant fractures" (either SH-I or avulsion fractures <3 mm). The pooled estimate for rate of x-ray reduction was 24.8% (95% CI = 23.3% to 26.3%; range = 5% to 44%). CONCLUSIONS The OAR appear to be a reliable tool to exclude fractures in children greater than 5 years of age presenting with ankle and midfoot injuries. Employing the OAR would significantly decrease x-ray use with a low likelihood of missing a fracture.
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Affiliation(s)
- Shawn Dowling
- Department of Emergency Medicine, Calgary Health Region, University of Calgary, Calgary, Alberta, Canada.
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Russell K, Dryden DM, Liang Y, Friesen C, O'Gorman K, Durec T, Wild TC, Klassen TP. Risk factors for methamphetamine use in youth: a systematic review. BMC Pediatr 2008; 8:48. [PMID: 18957076 PMCID: PMC2588572 DOI: 10.1186/1471-2431-8-48] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2008] [Accepted: 10/28/2008] [Indexed: 12/02/2022] Open
Abstract
Background Methamphetamine (MA) is a potent stimulant that is readily available. Its effects are similar to cocaine, but the drug has a profile associated with increased acute and chronic toxicities. The objective of this systematic review was to identify and synthesize literature on risk factors that are associated with MA use among youth. More than 40 electronic databases, websites, and key journals/meeting abstracts were searched. We included studies that compared children and adolescents (≤ 18 years) who used MA to those who did not. One reviewer extracted the data and a second checked for completeness and accuracy. For discrete risk factors, odds ratios (OR) were calculated and when appropriate, a pooled OR with 95% confidence intervals (95% CI) was calculated. For continuous risk factors, mean difference and 95% CI were calculated and when appropriate, a weighted mean difference (WMD) and 95% CI was calculated. Results were presented separately by comparison group: low-risk (no previous drug abuse) and high-risk children (reported previous drug abuse or were recruited from a juvenile detention center). Results Twelve studies were included. Among low-risk youth, factors associated with MA use were: history of heroin/opiate use (OR = 29.3; 95% CI: 9.8–87.8), family history of drug use (OR = 4.7; 95% CI: 2.8–7.9), risky sexual behavior (OR = 2.79; 95% CI: 2.25, 3.46) and some psychiatric disorders. History of alcohol use and smoking were also significantly associated with MA use. Among high-risk youth, factors associated with MA use were: family history of crime (OR = 2.0; 95% CI: 1.2–3.3), family history of drug use (OR = 4.7; 95% CI: 2.8–7.9), family history of alcohol abuse (OR = 3.2; 95% CI: 1.8–5.6), and psychiatric treatment (OR = 6.8; 95% CI: 3.6–12.9). Female sex was also significantly associated with MA use. Conclusion Among low-risk youth, a history of engaging in a variety of risky behaviors was significantly associated with MA use. A history of a psychiatric disorder was a risk factor for MA for both low- and high-risk youth. Family environment was also associated with MA use. Many of the included studies were cross-sectional making it difficult to assess causation. Future research should utilize prospective study designs so that temporal relationships between risk factors and MA use can be established.
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Affiliation(s)
- Kelly Russell
- Department of Pediatrics, University of Alberta, Edmonton, Canada.
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Friesen C, Lubatschofski A, Glatting G, Debatin KM, Reske SN. Activation of intrinsic apoptotic pathway by Re-188 irradiation and paclitaxel in coronary artery smooth muscle cells. Q J Nucl Med Mol Imaging 2008; 52:289-95. [PMID: 17380098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
AIM Intravascular brachytherapy efficiently reduces vascular smooth muscle cell (SMC) proliferation, interstitial matrix production, vascular remodeling and restenosis rate after revascularization injury of coronary arteries. In this study we examined the molecular mechanisms of the cytotoxic effect of Re-188-mediated beta-irradiation on a SMC culture model compared to that of paclitaxel. METHODS SMC were irradiated with 1, 3, 10 and 30 Gy with Re-188 or treated with 1, 5, 10 microg/mL paclitaxel. After 24, 48 and 72 h, cell death, apoptosis pathways and cell cycle were examined. RESULTS Irradiation and paclitaxel induced cell cycle arrest in G1. Dose-dependent cell death ranged from 40% at 1 Gy to 80% at 30 Gy irradiation, and induced in 45% of SMC treated with paclitaxel. Irradiation induced increasing rates of necrotic cell death up to 40% at 30 Gy. Activation of caspase-3 was detected, and poly(ADP-ribose)polymerase (PARP), the prototype substrate of caspases, was cleaved upon beta-irradiation. In addition, beta-irradiation-mediated apoptosis activated caspase-9, indicating that mitochondria were involved. Further-more, Bax was upregulated. However, upregulation of death-inducing ligands (DIL) or receptors (DIL-R) was not involved in beta-irradiation-induced apoptosis in SMC. Similar to beta-irradiation, the intrinsic mitochondrial apoptosis pathway was activated by paclitaxel. CONCLUSION These findings demonstrate that beta-irradiation and paclitaxel induced apoptosis and activated apoptosis signaling pathways in SMC at several levels by triggering intrinsic mitochondrial but not external death receptor mediated pathways.
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Affiliation(s)
- C Friesen
- Department of Nuclear Medicine, University of Ulm, Ulm, Germany.
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Buscemi N, Vandermeer B, Friesen C, Bialy L, Tubman M, Ospina M, Klassen TP, Witmans M. The efficacy and safety of drug treatments for chronic insomnia in adults: a meta-analysis of RCTs. J Gen Intern Med 2007; 22:1335-50. [PMID: 17619935 PMCID: PMC2219774 DOI: 10.1007/s11606-007-0251-z] [Citation(s) in RCA: 272] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2006] [Revised: 11/02/2006] [Accepted: 05/09/2007] [Indexed: 02/06/2023]
Abstract
BACKGROUND Hypnotics have a role in the management of acute insomnia; however, the efficacy and safety of pharmacological interventions in the management of chronic insomnia is unclear. OBJECTIVE The objective of this paper is to conduct a systematic review of the efficacy and safety of drug treatments for chronic insomnia in adults. DATA SOURCES Twenty-one electronic databases were searched, up to July 2006. STUDY SELECTION Randomized double-blind, placebo-controlled trials were eligible. Quality was assessed using the Jadad scale. Data were pooled using the random effects model. DATA SYNTHESIS One hundred and five studies were included in the review. Sleep onset latency, as measured by polysomnography, was significantly decreased for benzodiazepines (BDZ), (weighted mean difference: -10.0 minutes; 95% CI: -16.6, -3.4), non-benzodiazepines (non-BDZ) (-12.8 minutes; 95% CI: -16.9, -8.8) and antidepressants (ADP) (-7.0 minutes; 95% CI: -10.7, -3.3). Sleep onset latency assessed by sleep diaries was also improved (BDZ: -19.6 minutes; 95% CI: -23.9, -15.3; non-BDZ: -17.0 minutes; 95% CI: -20.0, -14.0; ADP: -12.2 minutes; 95% CI: -22.3, -2.2). Indirect comparisons between drug categories suggest BDZ and non-BDZ have a similar effect. All drug groups had a statistically significant higher risk of harm compared to placebo (BDZ: risk difference [RD]: 0.15; non-BDZ RD: 0.07; and ADP RD: 0.09), although the most commonly reported adverse events were minor. Indirect comparisons suggest that non-BDZ are safer than BDZ. CONCLUSIONS Benzodiazepines and non-benzodiazepines are effective treatments in the management of chronic insomnia, although they pose a risk of harm. There is also some evidence that antidepressants are effective and that they pose a risk of harm.
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Affiliation(s)
- Nina Buscemi
- University of Alberta/Capital Health Evidence-Based Practice Centre, Department of Pediatrics, University of Alberta, Alberta, Canada
| | - Ben Vandermeer
- University of Alberta/Capital Health Evidence-Based Practice Centre, Department of Pediatrics, University of Alberta, Alberta, Canada
| | - Carol Friesen
- University of Alberta/Capital Health Evidence-Based Practice Centre, Department of Pediatrics, University of Alberta, Alberta, Canada
| | - Liza Bialy
- University of Alberta/Capital Health Evidence-Based Practice Centre, Department of Pediatrics, University of Alberta, Alberta, Canada
- Aberhart Centre One, Room 9428, 11402 University Avenue, Edmonton, AB T6J 2G3 Canada
| | - Michelle Tubman
- University of Alberta/Capital Health Evidence-Based Practice Centre, Department of Pediatrics, University of Alberta, Alberta, Canada
| | - Maria Ospina
- University of Alberta/Capital Health Evidence-Based Practice Centre, Department of Pediatrics, University of Alberta, Alberta, Canada
| | - Terry P. Klassen
- University of Alberta/Capital Health Evidence-Based Practice Centre, Department of Pediatrics, University of Alberta, Alberta, Canada
| | - Manisha Witmans
- Department of Pediatrics, University of Alberta, Alberta, Canada
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McAlister FA, Ezekowitz J, Dryden DM, Hooton N, Vandermeer B, Friesen C, Spooner C, Rowe BH. Cardiac resynchronization therapy and implantable cardiac defibrillators in left ventricular systolic dysfunction. Evid Rep Technol Assess (Full Rep) 2007:1-199. [PMID: 17764218 PMCID: PMC4781294] [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: 05/17/2023]
Abstract
OBJECTIVES To determine the efficacy, effectiveness, and safety of cardiac resynchronization therapy (CRT) and/or implantable cardioverter defibrillators (ICD) in patients with left ventricular systolic dysfunction (LVSD). DATA SOURCES A systematic and comprehensive literature search was conducted to identify randomized controlled trials (RCTs) evaluating efficacy and observational studies evaluating effectiveness or safety of CRT and/or ICD in patients with LVSD. REVIEW METHODS Study selection, quality assessment, and data extraction were completed by several investigators in duplicate and independently. Random-effects models were used for analyses. RESULTS From 11,340 citations, we identified 14 RCTs (4,420 patients) for the CRT efficacy review, 106 studies (9,209 patients) for the CRT effectiveness review, 89 studies (9,677 patients) for the CRT safety review, 12 RCTs (8,516 patients) for the ICD efficacy review, 48 studies (15,097 patients) for the ICD effectiveness review, and 49 studies (12,592 patients) for the ICD safety review-all studies enrolled only patients with LVSD. An additional 12 studies (68,848 patients) were included for an analysis of peri-implant outcomes for all patients with ICD (i.e., not only LVSD patients). All patients in the CRT studies had LVSD (mean LVEF from 21 to 30 percent) and prolonged QRS duration (mean from 155 to 209 msec), and 91 percent had New York Heart Association (NYHA) class III or IV symptoms. In patients with LVSD and heart failure symptoms, CRT improved ejection fraction (weighted mean difference 3.0 percent [95% CI, 0.9 to 5.1]), quality of life (weighted mean reduction in Minnesota Living with Heart Failure Questionnaire 8.0 points [95% CI, 5.6 to 10.4 points]), and function (59 percent of CRT recipients vs. 37 percent of controls improved by at least one NYHA class in the RCTs and between 63 percent and 82 percent of CRT recipients improved by at least one NYHA class in observational studies). The proportion of patients hospitalized for HF was reduced by 37 percent (95% CI, 7 to 57 percent) and all-cause mortality was reduced by 22 percent (95% CI, 9 to 33 percent; NNT=29 over 6 months). Implant success rate was 93 percent, 0.3 percent of patients with LVSD died during implantation. Over a median 11-month followup, 6.6 percent of CRT devices exhibited lead problems and 5 percent malfunctioned. In patients with LVSD, ICD reduced all-cause mortality by 20 percent (95% CI, 10 to 29 percent; NNT=20 over 35 months). ICD implant success rate was 99 percent and peri-implant deaths occurred in 1.2 percent of LVSD patients and 1.3 percent of all implantees. The frequency of post-implantation complications in LVSD patients per 100 patient years included 1.4 (95% CI, 1.2 to 1.6) device malfunctions, 1.5 (95% CI, 1.3 to 1.8) lead problems, 0.6 (95% CI, 0.5 to 0.8) implant site infections, and 19.1 (95% CI, 16.5 to 22.0) inappropriate discharges in RCT participants and 4.7 (95% CI, 4.3 to 5.1) inappropriate discharges in patients enrolled in observational studies. CONCLUSIONS ICD and CRT reduce all-cause mortality in patients with LVSD meeting RCT entry criteria. The incremental benefit of CRT plus ICD over CRT alone in patients with LVSD remains uncertain. None of the trials reported differences in the efficacy of CRT or ICD across patient subgroups, nor did our meta-regression detect any subgroup effects; however, subgroup analyses and meta-regression using aggregate trial data are post-hoc analyses and were underpowered to detect such effects. Examination of individual patient trial data is urgently needed to define which clinical subgroups are most likely to benefit from these devices.
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Klassen TP, Kiddoo D, Lang ME, Friesen C, Russell K, Spooner C, Vandermeer B. The effectiveness of different methods of toilet training for bowel and bladder control. Evid Rep Technol Assess (Full Rep) 2006:1-57. [PMID: 17764212 PMCID: PMC4781561] [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: 05/17/2023]
Abstract
OBJECTIVES The objectives of this report are to determine the following: (1) the effectiveness of the toilet training methods, (2) which factors modify the effectiveness of toilet training, (3) if the toilet training methods are risk factor for adverse outcomes, and (4) the optimal toilet training method for achieving bowel and bladder control among patients with special needs. DATA SOURCES MEDLINE, Ovid MEDLINE In-Process & Other Non-Indexed Citations, Ovid OLDMEDLINE, Cochrane Central Register of Controlled Trials, EMBASE, CINAHL, PsycINFO, ERIC, EBM Reviews, HealthSTAR, AMED, Web of Science, Biological Abstracts, Sociological Abstracts, OCLC ProceedingsFirst, OCLC PapersFirst, Dissertation Abstracts, Index to Theses, National Research Register's Projects Database, and trials registers. REVIEW METHODS Two reviewers assessed the studies for inclusion. Studies were included if they met the following criteria: STUDY DESIGN RCT, CCT, prospective or retrospective cohort, case-control, cross-sectional or case-series; POPULATION infants, toddlers, or children with or without co-morbidities, neuromuscular, cognitive, or behavioral handicaps disabilities; INTERVENTION at least one toilet training method; and OUTCOME bladder and/or bowel control, successes, failures, adverse outcomes. Methodological quality was assessed independently by two reviewers. Data were extracted by one reviewer and a second checked for accuracy and completeness. Due to substantial heterogeneity, meta-analysis was not possible. RESULTS Twenty-six observational studies and eight controlled trials were included. Approximately half of the studies examined healthy children while the remaining studies assessed toilet training of mentally or physically handicapped children. For healthy children, the Azrin and Foxx method performed better than the Spock method, while child-oriented combined with negative term avoidance proved better than without. For mentally handicapped children, individual training was superior to group methods; relaxation techniques proved more efficacious than standard methods; operant conditioning was better than conventional treatment, and the Azrin and Foxx and a behavior modification method fared better than no training. The child-oriented approach was not assessed among mentally handicapped children. For children with Hirschsprung's disease or anal atresia, a multi-disciplinary behavior treatment was more efficacious than no treatment. CONCLUSIONS Both the Azrin and Foxx method and the child-oriented approach resulted in quick, successful toilet training, but there was limited information about the sustainability of the training. The two methods were not directly compared, thus it is difficult to draw definitive conclusions regarding the superiority of one method over the other. In general, both programs may be used to teach toilet training to healthy children. The Azrin and Foxx method and operant conditioning methods were consistently effective for toilet training mentally handicapped children. Programs that were adapted to physically handicapped children also resulted in successful toilet training. A lack of data precluded conclusions regarding the development of adverse outcomes.
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Trimble T, Tang L, Vasiljevic N, Dimitrov N, van Schilfgaarde M, Friesen C, Thompson CV, Seel SC, Floro JA, Sieradzki K. Anion adsorption induced reversal of coherency strain. Phys Rev Lett 2005; 95:166106. [PMID: 16241822 DOI: 10.1103/physrevlett.95.166106] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2005] [Indexed: 05/05/2023]
Abstract
Experimental results are presented for stress evolution, in vacuum and electrolyte, for the first monolayer of Cu on Au(111). In electrolyte the monolayer is pseudomorphic and the stress-thickness change is -0.60 N/m, while conventional epitaxy theory predicts a value of +7.76 N/m. In vacuum, the monolayer is incoherent with the underlying gold. Using a combination of first-principles based calculations and molecular dynamic simulations we analyzed these results and demonstrate that in electrolyte, overlayer coherency is maintained owing to anion adsorption.
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Affiliation(s)
- T Trimble
- Ira A. Fulton School of Engineering, Arizona State University, Tempe, 85287-6106, USA
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Affiliation(s)
- Michelle Tubman
- Alberta Research Centre for Child Health Evidence, Room 9419 4th Floor, Aberhart Centre One, 11402 University Avenue, Edmonton Alberta, Canada T6G 2J3
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Abstract
The authors discuss 3 challenges in conducting and interpreting any systematic review that are particularly relevant for systematic reviews of therapeutic devices or surgical procedures: 1) inclusion or exclusion of grey literature, 2) the role of nonrandomized studies, and 3) issues in applying the results to clinical care that are unique to the surgical and therapeutic device literature. The authors also discuss empirical evidence related to these topics and illustrate how reviewers in the Agency for Healthcare Research and Quality's Evidence-based Practice Center program have dealt with these challenges in developing evidence reports for decision makers and clinicians about therapeutic devices or surgical procedures.
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Affiliation(s)
- Lisa Hartling
- Capital Health Evidence-based Practice Center, University of Alberta, Edmonton, Canada
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Abstract
The use of complementary and alternative medicine (CAM) continues to grow in the United States. The Agency for Healthcare Research and Quality has devoted a substantial proportion of the Evidence-based Practice Center (EPC) program to systematic reviews of CAM. Such syntheses present different challenges from those conducted on western medicine topics, and in many ways are more difficult. We discuss 3 challenges: identifying evidence about CAM, assessing the quality of individual studies, and addressing rare serious adverse events. We use illustrations from EPC evidence reports to show readers approaches to the 3 areas and then present specific recommendations for each issue.
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Affiliation(s)
- Paul G Shekelle
- Southern California Evidence-based Practice Center, RAND Corporation, Santa Monica, California 90401, USA.
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Buscemi N, Vandermeer B, Friesen C, Bialy L, Tubman M, Ospina M, Klassen TP, Witmans M. Manifestations and management of chronic insomnia in adults. Evid Rep Technol Assess (Summ) 2005:1-10. [PMID: 15989374 PMCID: PMC4781279 DOI: 10.1037/e439752005-001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
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Friesen C, Thompson CV. Correlation of stress and atomic-scale surface roughness evolution during intermittent homoepitaxial growth of (111)-oriented Ag and Cu. Phys Rev Lett 2004; 93:056104. [PMID: 15323716 DOI: 10.1103/physrevlett.93.056104] [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] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2003] [Indexed: 05/24/2023]
Abstract
Stress evolution during intermittent homoepitaxial growth of (111)-oriented Cu and Ag thin films has been studied. A tensile stress change is observed when growth is stopped, but the change is reversed when growth is resumed. Reflection high energy electron diffraction analysis of the atomic scale surface roughness during intermittent growth demonstrates a strong correlation between the surface structure and reversible stress evolution. The results are discussed in terms of an evolving surface defect population.
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Affiliation(s)
- C Friesen
- Department of Materials and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Friesen C, Kiess Y, Debatin KM. A critical role of glutathione in determining apoptosis sensitivity and resistance in leukemia cells. Cell Death Differ 2004; 11 Suppl 1:S73-85. [PMID: 15105835 DOI: 10.1038/sj.cdd.4401431] [Citation(s) in RCA: 145] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
In chemosensitive leukemias and solid tumors, anticancer drugs have been shown to induce apoptosis. Deficiencies in the apoptotic pathways may lead to chemoresistance. Here we report that glutathione (GSH) plays a critical role in activation of apoptosis pathways by CD95 (APO-1/Fas) or anticancer drugs. Upon treatment with anticancer drugs or CD95 triggering, CD95-resistant or Bcl-x(L) overexpressing CEM cells were deficient in activation of apoptosis pathways. CD95-resistant and Bcl-x(L) overexpressing CEM cells exhibited higher intracellular GSH levels in comparison to parental cells. Downregulation of GSH by L-buthionine-(S,R)-sulfoxime (BSO), a specific inhibitor of glutathione synthesis, reversed deficiencies in activation of apoptosis pathways by anticancer drugs or CD95. Interestingly, downregulation of GSH by BSO increased CD95 DISC formation in type I cells. In hybrids of CD95-resistant cells with sensitive cells and hybrids of overexpressing Bcl-x(L) cells with sensitive cells, the phenotype of apoptosis resistance was dominant. Also, in these hybrids, downregulation of GSH reversed CD95- and chemoresistance. We conclude that dominant apoptosis resistance depends, at least in part, on intracellular GSH levels, which may affect apoptosis signaling at different compartments, for example, the death receptor or mitochondria.
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Affiliation(s)
- C Friesen
- University Children's Hospital, Prittwitzstr.43, D-89075 Ulm, Germany
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Chezem J, Friesen C, Boettcher J. Breastfeeding knowledge, breastfeeding confidence, and infant feeding plans: effects on actual feeding practices. J Obstet Gynecol Neonatal Nurs 2003; 32:40-7. [PMID: 12570180 DOI: 10.1177/0884217502239799] [Citation(s) in RCA: 149] [Impact Index Per Article: 7.1] [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: 11/16/2022] Open
Abstract
OBJECTIVE To explore relationships among breastfeeding knowledge, breastfeeding confidence, and infant feeding plans and their effects on feeding practices in first-time breastfeeding mothers. DESIGN Prospective descriptive design. SETTING Telephone interviews were conducted prenatally and at 6 weeks, 3 months, and 6 months postpartum. PARTICIPANTS Seventy-four of 83 first-time mothers with prenatal intentions to breastfeed completed all study requirements. The majority were White (95%), between the ages of 21 and 30 years (73%), with a post-high school education (85%), and household incomes of more than 200% of the federal poverty guideline (88%). MAIN OUTCOME MEASURES Breastfeeding knowledge, breastfeeding confidence, planned infant feeding method, planned breastfeeding duration, weeks of daily human milk substitute feeding, breastfeeding duration, achievement of breastfeeding goals. RESULTS Breastfeeding knowledge was strongly correlated with breastfeeding confidence (r = .262; p = .025) and actual lactation duration (r = .455; p = .0001). Compared with women planning to exclusively breastfeed their infants, those planning to combination feed planned shorter breastfeeding duration (p = .022), reported shorter actual duration (p = .004), and were less likely to meet their breastfeeding goal (p = .034). The variables maternal education, breastfeeding knowledge, and weeks of daily human milk substitute feeding were used to develop a prediction equation that correctly categorized 93% of participants who met their breastfeeding goal and 90% of those who did not. CONCLUSIONS Expectations and the actual breastfeeding experience differed among women planning to combination feed and those planning to exclusively breastfeed. Whether a cause or consequence, daily human milk substitute feeding was associated with negative breastfeeding outcomes.
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Affiliation(s)
- JoCarol Chezem
- Department of Family and Consumer Sciences, Ball State University, Muncie, IN 47306-0250, USA.
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Friesen C, Thompson CV. Reversible stress relaxation during precoalescence interruptions of volmer-weber thin film growth. Phys Rev Lett 2002; 89:126103. [PMID: 12225105 DOI: 10.1103/physrevlett.89.126103] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2002] [Indexed: 05/21/2023]
Abstract
From in situ stress measurements, we have observed that a large component of the precoalescence compressive stress that develops during Volmer-Weber growth of polycrystalline Cu films relaxes reversibly. This phenomenon is similar to the reversible stress relaxation previously observed in the postcoalescence regime. We have also observed that less than a tenth of a monolayer of deposition leads to an instantaneous stress of order 1 GPa. The stress changes in both the precoalescence and postcoalescence regimes of growth are explained by changes in the adatom population during and after deposition.
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Affiliation(s)
- C Friesen
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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Abstract
In addition to myelosuppression, anticancer drugs cause rapid and persistent depletion of lymphocytes, possibly by direct apoptosis induction in mature T and B cells. Induction of apoptosis regulators was analyzed in peripheral blood lymphocytes from pediatric patients undergoing first-cycle chemotherapy for solid tumors. In vivo chemotherapy induced a significant increase in lymphocyte apoptosis ex vivo. The activation of initiator caspase-8 and effector caspase-3 and the cleavage of caspase substrates was detected 12 to 48 hours after the onset of therapy. Caspase inhibition by Z-VAD-fmk did not reduce ex vivo lymphocyte apoptosis in all patients, indicating the additional involvement of caspase-independent cell death. No evidence for the involvement of activation-induced cell death was found in the acute phase of lymphocyte depletion as analyzed by activation marker expression and sensitivity for CD95 signaling. Lymphocyte apoptosis in vivo appeared to be predominantly mediated by the mitochondrial pathway because a marked decrease of mitochondrial membrane potential (DeltaPsi(M)) was detected after 24 to 72 hours of treatment, preceded by the increased expression of Bax. Interestingly, despite the use of DNA-damaging agents, p53 remained completely undetectable throughout treatment. In contrast, in vitro treatment with cytarabine and etoposide induced p53 protein, CD95 receptor expression, CD95 sensitivity, and CD95 receptor-ligand interaction in stimulated cycling lymphocytes, but no such induction was seen in resting cells. These data suggest that chemotherapy-induced lymphocyte depletion involves distinct mechanisms of apoptosis induction, such as direct mitochondrial and caspase-dependent pathways in resting cells and p53-dependent pathways in cycling lymphocytes.
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Affiliation(s)
- K Stahnke
- Department of Pediatrics, University Children's Hospital, Ulm, Germany
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Fulda S, Meyer E, Friesen C, Susin SA, Kroemer G, Debatin KM. Cell type specific involvement of death receptor and mitochondrial pathways in drug-induced apoptosis. Oncogene 2001; 20:1063-75. [PMID: 11314043 DOI: 10.1038/sj.onc.1204141] [Citation(s) in RCA: 171] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2000] [Revised: 11/22/2000] [Accepted: 11/29/2000] [Indexed: 12/12/2022]
Abstract
Apoptosis in response to cellular stress such as treatment with cytotoxic drugs is mediated by effector caspases (caspase-3) which can be activated by different initiator pathways. Here, we report on a cell type specific triggering of death receptor and/or mitochondrial pathways upon drug treatment. In type I cells (BJAB), both the receptor and the mitochondrial pathway were activated upon drug treatment, since blockade of either the receptor pathway by overexpression of dominant negative FADD (FADD-DN) or of the mitochondrial pathway by overexpression of Bcl-X(L) only partially inhibited apoptosis. Drug treatment induced formation of a FADD- and caspase-8-containing CD95 death-inducing signaling complex (DISC) in type I cells resulting in activation of caspase-8 as the most apical caspase. In contrast, in type II cells (Jurkat), apoptosis was predominantly controlled by mitochondria, since overexpression of Bcl-2 completely blocked drug-induced apoptosis, while overexpression of FADD-DN had no protective effect. In these cells, caspases including caspase-8 were activated by mitochondria-driven signaling events and no DISC was detected despite expression levels of CD95, FADD and caspase-8 proteins comparable to type I cells. Likewise, drug-induced CD95 aggregation was predominantly found in type I cells. Bid was cleaved prior to mitochondrial alterations in type I cells providing a molecular link between caspase-8 activation and mitochondrial perturbations, whereas in type II cells, Bid was cleaved downstream of mitochondria. Our findings of a cell type specific response to cytotoxic drugs have implications for the identification of molecular parameters for chemosensitivity or resistance in different tumor cells.
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Affiliation(s)
- S Fulda
- University Children's Hospital, Prittwitzstr. 43, D-89075 Ulm, Germany
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Abstract
Cytotoxic drugs commonly used in chemotherapy of leukemia and solid tumors have been shown to primarily act by inducing apoptosis in sensitive target cells. Apoptosis may involve activation of death-inducing ligand/receptor systems such as CD95 (APO-1/Fas). Treatment with anticancer drugs such as doxorubicin, methotrexate, cytarabine, etoposide and cisplatin at therapeutic concentrations leads to induction of CD95-ligand (CD95-L). CD95-L can mediate cell death in an autocrine/paracrine manner by crosslinking CD95 receptor (CD95). Interfering with CD95-ligand/receptor interaction by antagonistic antibodies to the receptor reduces sensitivity to drug-mediated apoptosis in some cell systems. In addition, treatment with cytotoxic drugs may result in upregulation of CD95, thereby increasing the sensitivity to the CD95 death signal. Apoptosis depends on activation of caspases. Deficient activation of the CD95 system was found in drug-resistant cells. In addition, CD95-resistant and doxorubicin-resistant cells displayed cross-resistance for induction of cell death. Thus, intact apoptosis pathways such as the CD95 system may play a role in determining sensitivity or resistance of tumor cells to chemotherapy.
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Affiliation(s)
- C Friesen
- University Children's Hospital, Ulm; and Division of Molecular Oncology, German Cancer Research Center, Heidelberg, Germany
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Friesen C, Fulda S, Debatin KM. Induction of CD95 ligand and apoptosis by doxorubicin is modulated by the redox state in chemosensitive- and drug-resistant tumor cells. Cell Death Differ 1999; 6:471-80. [PMID: 10381639 DOI: 10.1038/sj.cdd.4400512] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [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: 01/06/2023] Open
Abstract
Induction of CD95 ligand (CD95-L) may contribute to drug-induced apoptosis in chemosensitive leukemias and solid tumors. Here we report that induction of CD95-L and apoptosis by doxorubicin in leukemic and neuroblastoma cells is regulated by the redox state and reactive oxygen species (ROS). Preincubation of chemosensitive cells with antioxidants such as N-acetyl-cysteine (NAC) or glutathione (GSH), significantly reduced doxorubicin-induced apoptosis, hyperexpression of ROS, loss of mitochondrial membrane potential (DeltaPsim) and upregulation of CD95-L expression. Doxorubicin-resistant cells exhibited higher levels of GSH in comparison to chemosensitive cells and were deficient in hyperproduction of ROS, loss of DeltaPsim and upregulation of CD95-L in response to cytotoxic drugs. Downregulation of intracellular GSH concentrations reversed deficient drug-induced hyperproduction of ROS and CD95-L upregulation. In addition, overexpression of Bcl-XL in CEM cells blocked doxorubicin-triggered ROS and CD95-L expression. These findings suggest that induction of CD95-L by cytotoxic drugs is modulated by the cellular redox state and mitochondria derived ROS.
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Affiliation(s)
- C Friesen
- University Children's Hospital, Prittwitzstr.43, 89075 Ulm, Germany
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Abstract
Killing of target cells by cytotoxic T cells is mediated by induction of apoptosis requiring functional death pathways. Kill is mediated either by the CD95 or the perforin/granzyme pathway. We found that SH-EP neuroblastoma cells are preferentially killed via CD95, while in the T leukemia cell line CEM CD95 and perforin/granzyme are involved. In both types of cell lines, cells resistant to CD95- and drug-induced apoptosis are crossresistant to cytotoxic T cell kill. Resistant cells show decreased apoptosis and deficient activation of caspases indicated by decreased cleavage of the prototype caspase substrate PARP. Preincubation with the caspase inhibitor zVAD-fmk strongly decreased LAK cell kill in sensitive cells. Although parental CEM cells could be sensitized for LAK kill by preincubation with doxorubicin, resistance could not be reverted in doxorubicin or CD95 resistant CEM cells. These data demonstrate the crossresistance in induction of apoptosis by different cytotoxic regimens in tumor cells and may have implications for the immunotherapy of tumors in which apoptosis resistance was induced by previous chemotherapy.
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Abstract
The CD95 (APO-1/Fas) system plays an important role in lymphocyte homeostasis and contributes to anticancer drug-induced apoptosis in some tumor cells. Most childhood B-lineage ALL cells are constitutively resistant towards CD95-induced death. We report here that chemotherapeutic drugs, such as doxorubicin, cytarabine, methotrexate and 6-mercaptopurine, sensitize CD95-resistant pre-B-ALL cell lines for CD95- and lymphokine-activated killer (LAK)-induced cell death. Enhanced susceptibility in drug-treated cells was found to be associated with increased expression of CD95 mRNA and surface expression of CD95 protein, as well as loss of Bcl-xL protein and disturbance of mitochondrial function. Low level activation of caspases and cleavage of poly(ADP-ribose) polymerase following CD95 triggering was strongly increased in drug pre-treated cells. Furthermore, drug pre-treated cells could be rescued from CD95-mediated apoptosis by blocking the CD95-signaling pathway with a FADD-dominant negative expression construct. Our data suggest that chemotherapeutic drugs may sensitize pre-B ALL cells by at least two mechanisms: (1) by increasing CD95 expression; and (2) by lowering the threshold for apoptotic signals. These findings may explain the effectiveness of low-dose chemotherapy and indicate an active role for key molecules of apoptosis and the immune system during chemotherapy of leukemia.
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Affiliation(s)
- C Posovszky
- Division of Molecular Oncology, German Cancer Research Center, Heidelberg
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Chezem J, Friesen C. Attendance at breast-feeding support meetings: relationship to demographic characteristics and duration of lactation in women planning postpartum employment. J Am Diet Assoc 1999; 99:83-5. [PMID: 9917738 DOI: 10.1016/s0002-8223(99)00022-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Affiliation(s)
- J Chezem
- Department of Family and Consumer Sciences, Ball State University, Muncie, IN 47306, USA
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Chezem J, Friesen C, Montgomery P, Fortman T, Clark H. Lactation duration: influences of human milk replacements and formula samples on women planning postpartum employment. J Obstet Gynecol Neonatal Nurs 1998; 27:646-51. [PMID: 9836159 DOI: 10.1111/j.1552-6909.1998.tb02634.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVE To examine the influences of inhospital administration of breast milk replacements and receipt of formula samples on lactation duration among women planning postpartum employment. DESIGN Prospective design. SETTING Telephone interviews conducted prenatally and at 6 weeks, 3 months, and 6 months post-partum. PARTICIPANTS Sixty-nine participants entered the study; 53 completed all scheduled interviews. MAIN OUTCOME MEASURES Incidence and type of in-hospital human milk replacement, incidence and sources of formula samples, incidence of breastfeeding at 6 weeks postpartum, and duration of lactation. RESULTS During hospitalization, 19% of infants received formula; the incidence of breastfeeding at 6 weeks and duration of breastfeeding were significantly shorter in these infants compared with infants who were not fed formula. Fifty-nine percent of participants received formula samples from the hospital, 30% received samples from a physician's office, and 51% received samples by mail. Receipt of formula samples by mail was associated with reduced incidence of breastfeeding at 6 weeks and shortened duration of lactation. CONCLUSIONS Early formula feeding and receipt of formula samples by mail may be barriers to lactation in women employed outside the home.
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Affiliation(s)
- J Chezem
- Department of Family and Consumer Sciences, Ball State University, Muncie, IN 47306, USA
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Abstract
Recent experimental evidence suggests that apoptosis pathways such as the CD95 system are an important mediator of chemotherapy-induced apoptosis in various tumor cell lines. Therapeutic concentrations of cytotoxic drugs induce CD95 and CD95-L that mediates apoptosis via an autocrine/paracrine loop by crosslinking CD95. Interfering with CD95-L/receptor interaction by antagonistic antibodies to the receptor or by inhibition of CD95-L expression strongly reduces apoptosis. Drug-induced apoptosis critically depends on activation of caspases since apoptosis is almost completely abrogated by the caspase inhibitor zVAD-fmk. The receptor apical caspase FLICE/MACH (caspase-8) and the downstream caspase CPP32 (caspase-3) are cleaved resulting in processing of substrates such as the nuclear enzyme PARP. In addition, the response to cytotoxic drugs is modulated by pro- and antiapoptotic proteins of the Bcl-2 family and p53. Defects in apoptosis pathways, e.g. deficient upregulation of CD95-L, downregulation of CD95 expression or blockade of caspase activation may confer resistance to cytotoxic drug treatment. Thus, chemosensitivity of tumor cells depends on intact apoptosis pathways such as the CD95 system that are activated by chemotherapeutic drugs. These findings may have implications for drug sensitivity and resistance of tumor cells.
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Affiliation(s)
- S Fulda
- University Children's Hospital, Ulm, Germany
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47
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Abstract
We have identified the CD95 system as a key mediator of chemotherapy-induced apoptosis in leukemia and neuroblastoma cells. Here, we report that sensitivity of various solid tumor cell lines for drug-induced cell death corresponds to activation of the CD95 system. Upon drug treatment, strong induction of CD95 ligand (CD95-L) and caspase activity were found in chemosensitive tumor cells (Hodgkin, Ewing's sarcoma, colon carcinoma and small cell lung carcinoma) but not in tumor cells which responded poorly to drug treatment (breast carcinoma and renal cell carcinoma). Blockade of CD95 using F(ab')2 anti-CD95 antibody fragments markedly reduced drug-induced apoptosis, suggesting that drug-triggered apoptosis depended on CD95-L/receptor interaction. Moreover, drug treatment induced CD95 expression, thereby increasing sensitivity for CD95-induced apoptosis. Drug-induced apoptosis critically depended on activation of caspases (ICE/Ced-3-like proteases) since the broad-spectrum inhibitor of caspases zVAD-fmk strongly reduced drug-mediated apoptosis. The prototype substrate of caspases, poly(ADP-ribose) polymerase, was cleaved upon drug treatment, suggesting that CD95-L triggered autocrine/paracrine death via activation of caspases. Our data suggest that chemosensitivity of solid tumor cells depends on intact apoptosis pathways involving activation of the CD95 system and processing of caspases. Our findings may have important implications for new treatment approaches to increase sensitivity and to overcome resistance of solid tumors.
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Affiliation(s)
- S Fulda
- Hematology/Oncology, University Children's Hospital, Ulm, Germany
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48
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Abstract
We have identified the CD95 system as a key mediator of chemotherapy-induced apoptosis in leukemia and neuroblastoma cells. Here, we report that sensitivity of various solid tumor cell lines for drug-induced cell death corresponds to activation of the CD95 system. Upon drug treatment, strong induction of CD95 ligand (CD95-L) and caspase activity were found in chemosensitive tumor cells (Hodgkin, Ewing's sarcoma, colon carcinoma and small cell lung carcinoma) but not in tumor cells which responded poorly to drug treatment (breast carcinoma and renal cell carcinoma). Blockade of CD95 using F(ab')2 anti-CD95 antibody fragments markedly reduced drug-induced apoptosis, suggesting that drug-triggered apoptosis depended on CD95-L/receptor interaction. Moreover, drug treatment induced CD95 expression, thereby increasing sensitivity for CD95-induced apoptosis. Drug-induced apoptosis critically depended on activation of caspases (ICE/Ced-3-like proteases) since the broad-spectrum inhibitor of caspases zVAD-fmk strongly reduced drug-mediated apoptosis. The prototype substrate of caspases, poly(ADP-ribose) polymerase, was cleaved upon drug treatment, suggesting that CD95-L triggered autocrine/paracrine death via activation of caspases. Our data suggest that chemosensitivity of solid tumor cells depends on intact apoptosis pathways involving activation of the CD95 system and processing of caspases. Our findings may have important implications for new treatment approaches to increase sensitivity and to overcome resistance of solid tumors.
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Affiliation(s)
- S Fulda
- Hematology/Oncology, University Children's Hospital, Ulm, Germany
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Abstract
We have identified two cell types, each using almost exclusively one of two different CD95 (APO-1/Fas) signaling pathways. In type I cells, caspase-8 was activated within seconds and caspase-3 within 30 min of receptor engagement, whereas in type II cells cleavage of both caspases was delayed for approximately 60 min. However, both type I and type II cells showed similar kinetics of CD95-mediated apoptosis and loss of mitochondrial transmembrane potential (DeltaPsim). Upon CD95 triggering, all mitochondrial apoptogenic activities were blocked by Bcl-2 or Bcl-xL overexpression in both cell types. However, in type II but not type I cells, overexpression of Bcl-2 or Bcl-xL blocked caspase-8 and caspase-3 activation as well as apoptosis. In type I cells, induction of apoptosis was accompanied by activation of large amounts of caspase-8 by the death-inducing signaling complex (DISC), whereas in type II cells DISC formation was strongly reduced and activation of caspase-8 and caspase-3 occurred following the loss of DeltaPsim. Overexpression of caspase-3 in the caspase-3-negative cell line MCF7-Fas, normally resistant to CD95-mediated apoptosis by overexpression of Bcl-xL, converted these cells into true type I cells in which apoptosis was no longer inhibited by Bcl-xL. In summary, in the presence of caspase-3 the amount of active caspase-8 generated at the DISC determines whether a mitochondria-independent apoptosis pathway is used (type I cells) or not (type II cells).
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Affiliation(s)
- C Scaffidi
- Tumor Immunology Program, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
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Fulda S, Friesen C, Los M, Scaffidi C, Mier W, Benedict M, Nuñez G, Krammer PH, Peter ME, Debatin KM. Betulinic acid triggers CD95 (APO-1/Fas)- and p53-independent apoptosis via activation of caspases in neuroectodermal tumors. Cancer Res 1997; 57:4956-64. [PMID: 9354463] [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: 02/05/2023]
Abstract
Betulinic acid (BA), a melanoma-specific cytotoxic agent, induced apoptosis in neuroectodermal tumors, such as neuroblastoma, medulloblastoma, and Ewing's sarcoma, representing the most common solid tumors of childhood. BA triggered an apoptosis pathway different from the one previously identified for standard chemotherapeutic drugs. BA-induced apoptosis was independent of CD95-ligand/receptor interaction and accumulation of wild-type p53 protein, but it critically depended on activation of caspases (interleukin 1beta-converting enzyme/Ced-3-like proteases). FLICE/MACH (caspase-8), considered to be an upstream protease in the caspase cascade, and the downstream caspase CPP32/YAMA/Apopain (caspase-3) were activated, resulting in cleavage of the prototype substrate of caspases PARP. The broad-spectrum peptide inhibitor benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone, which blocked cleavage of FLICE and PARP, also completely abrogated BA-triggered apoptosis. Cleavage of caspases was preceded by disturbance of mitochondrial membrane potential and by generation of reactive oxygen species. Overexpression of Bcl-2 and Bcl-XL conferred resistance to BA at the level of mitochondrial dysfunction, protease activation, and nuclear fragmentation. This suggested that mitochondrial alterations were involved in BA-induced activation of caspases. Furthermore, Bax and Bcl-xs, two death-promoting proteins of the Bcl-2 family, were up-regulated following BA treatment. Most importantly, neuroblastoma cells resistant to CD95- and doxorubicin-mediated apoptosis were sensitive to treatment with BA, suggesting that BA may bypass some forms of drug resistance. Because BA exhibited significant antitumor activity on patients' derived neuroblastoma cells ex vivo, BA may be a promising new agent for the treatment of neuroectodermal tumors in vivo.
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Affiliation(s)
- S Fulda
- Division of Hematology/Oncology, University Children's Hospital, German Cancer Research Center, Heidelberg
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