54 results on '"Lindsay LL"'
Search Results
2. Advancing health equity for Indigenous peoples in Canada: development of a patient complexity assessment framework.
- Author
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Sehgal A, Henderson R, Murry A, Crowshoe LL, and Barnabe C
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- Humans, Canada, Health Literacy, Health Services, Indigenous organization & administration, Resilience, Psychological, Health Equity, Health Services Accessibility, Indigenous Canadians
- Abstract
Background: Indigenous patients often present with complex health needs in clinical settings due to factors rooted in a legacy of colonization. Healthcare systems and providers are not equipped to identify the underlying causes nor enact solutions for this complexity. This study aimed to develop an Indigenous-centered patient complexity assessment framework for urban Indigenous patients in Canada., Methods: A multi-phased approach was used which was initiated with a review of literature surrounding complexity, followed by interviews with Indigenous patients to embed their lived experiences of complexity, and concluded with a modified e-Delphi consensus building process with a panel of 14 healthcare experts within the field of Indigenous health to identify the domains and concepts contributing to health complexity for inclusion in an Indigenous-centered patient complexity assessment framework. This study details the final phase of the research., Results: A total of 27 concepts spanning 9 domains, including those from biological, social, health literacy, psychological, functioning, healthcare access, adverse life experiences, resilience and culture, and healthcare violence domains were included in the final version of the Indigenous-centered patient complexity assessment framework., Conclusions: The proposed framework outlines critical components that indicate the presence of health complexity among Indigenous patients. The framework serves as a source of reference for healthcare providers to inform their delivery of care with Indigenous patients. This framework will advance scholarship in patient complexity assessment tools through the addition of domains not commonly seen, as well as extending the application of these tools to potentially mitigate racism experienced by underserved populations such as Indigenous peoples., (© 2024. The Author(s).)
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- 2024
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3. Race as a determinant of prenatal depressive symptoms: analysis of data from the 'All Our Families' study.
- Author
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Roy A, Patten S, Thurston W, Beran T, Crowshoe LL, and Tough S
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- Pregnancy, Female, Humans, Ethnicity, Minority Groups, Pregnant Women, Depression epidemiology, Depression, Postpartum
- Abstract
Objectives: Prenatal depression is a serious maternal-child health concern. Risk factors and health consequences appear more prevalent in Indigenous communities and ethnic minority groups; however, research on these populations is limited. We examined the following questions: (A) How do pregnant Indigenous women, ethnic minority women, and White women compare on levels of depressive symptoms and possible clinical depression, and on major risk and protective factors? (B) Is non-dominant (non-White) race associated with higher depressive symptoms and possible clinical depression? (C) What factors mediate and moderate the relationship between race and depression?, Design: Data were from the All Our Families study ( n = 3354 pregnant women from Alberta, Canada). Depressive symptoms were measured with the Edinburgh Postnatal Depression Scale (EPDS). Descriptive statistics and multivariable regression methods were used to assess the hypotheses that Indigenous and ethnic minority women would have significantly higher mean EPDS score estimates and higher proportions scoring above cut-offs for possible clinical depression, relative to White women. The association between race and depressive symptoms was hypothesised to be partially mediated by risk factors of socioeconomics, health background, discrimination, domestic violence, and psychosocial stress. Potential confounders were age, marital status, and parity. Diet and social support were hypothesised as protective buffers between stress and depressive symptoms., Results: A higher proportion of White women were married, had family income over $80,000, were employed, and had adequate social support, relative to other women. They had significantly lower mean depressive symptom score, and a smaller proportion scored above cut-offs for possible clinical depression. The positive association between race and depressive symptoms appeared to be partially mediated by socioeconomic factors and psychosocial stress. Social support appeared to moderate the association between stress and depressive symptoms., Conclusions: Strategies to address socioeconomic status, stress, and social support among racialized minority women may reduce the risk for prenatal depression.
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- 2024
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4. Critically examining health complexity experienced by urban Indigenous peoples in Canada by exploring the factors that allow health complexity to persist: a qualitative study of Indigenous patients in Calgary, Alberta.
- Author
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Sehgal A, Scott S, Murry A, Henderson R, Barnabe C, and Crowshoe LL
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- Humans, Alberta, Canada, Qualitative Research, Violence, Urban Population, Health Services, Indigenous, Indians, North American, Indigenous Peoples, Health Status
- Abstract
Objectives: This study aims to identify and critically examine the components of health complexity, and explore the factors that allow it to exist, among urban Indigenous peoples in Canada., Design: Qualitative exploration with relational conversations., Setting: Calgary, Alberta, Canada., Participants: A total of nine urban Indigenous patients were recruited from a multidisciplinary primary healthcare clinic that serves First Nations, Métis and Inuit peoples. Recruitment and data collection took place between September and November 2021., Results: Thematic analysis revealed three main themes, namely: sources of health complexity, psychological responses to adversity, and resilience, strengths, and protective factors. Key sources of health complexity arose from material resource disparities and adverse interpersonal interactions within the healthcare environment, which manifest into psychological distress while strengths and resilience emerged as protective factors., Conclusion: The healthcare system remains inapt to address complexity among urban Indigenous peoples in Canada. Healthcare violence experienced by Indigenous peoples only further perpetuates health complexity. Future clinical tools to collect information about health complexity among urban Indigenous patients should include questions about the factors defined in this study., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2023
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5. Spread of Makoyoh'sokoi (Wolf Trail): a community led, physical activity-based, holistic wellness program for Indigenous women in Canada.
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Frehlich L, Amson A, Doyle-Baker P, Black T, Boustead D, Cameron E, Crowshoe LL, McBrien K, Ji YJ, McGuire A, Oliver A, Tuttauk L, Zhang J, Checholik C, and Wicklum S
- Subjects
- Female, Humans, Canada, Chronic Disease, Exercise, Health Promotion
- Abstract
Globally, Indigenous populations have been impacted by colonization. Populations who have endured colonization are at higher risk of developing chronic diseases. Canada's Truth and Reconciliation Commission emphasizes reducing barriers to participation in physical activity and recommends the creation of culturally relevant and supportive policies and programing. Physical activity is a cornerstone in health promotion and public health to combat chronic diseases; however, in Canada, Indigenous developed physical activity programing is sparse, and those targeting women are non-existent in some regions. Makoyoh'sokoi (The Wolf Trail Program) is an 18-week long, holistic wellness program that was created by and for Indigenous women. Makoyoh'sokoi was developed by communities following extensive consultation and cultural oversight. Makoyoh'sokoi's core program consists of 12 weeks of weekly physical activity programing and health education, followed by another 6 weeks of weekly health education. Notably, communities have control over the program to modify based on individual needs and challenges. Programs commence and conclude with a ceremony with Elders giving a blessing and opening each other to connection. The goals of Makoyoh'sokoi are to empower women, improve health outcomes, and to implement a sustainable program by training a network of community members in their respective communities to facilitate delivery., (© 2023. BioMed Central Ltd., part of Springer Nature.)
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- 2023
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6. Patient complexity assessment tools containing inquiry domains important for Indigenous patient care: A scoping review.
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Sehgal A, Barnabe C, and Crowshoe LL
- Subjects
- Humans, Patient Care, Population Groups
- Abstract
Patient complexity assessment tools (PCATs) are utilized to collect vital information to effectively deliver care to patients with complexity. Indigenous patients are viewed in the clinical setting as having complex health needs, but there is no existing PCAT developed for use with Indigenous patients, although general population PCATs may contain relevant content. Our objective was to identify PCATs that include the inquiry of domains relevant in the care of Indigenous patients with complexity. A scoping review was performed on articles published between 2016 and 2021 to extend a previous scoping review of PCATs. Data extraction from existing frameworks focused on domains of social realities relevant to the care of Indigenous patients. The search resulted in 1078 articles, 82 underwent full-text review, and 9 new tools were identified. Combined with previously known and identified PCATs, only 6 items from 5 tools tangentially addressed the domains of social realities relevant to Indigenous patients. This scoping review identifies a major gap in the utility and capacity of PCATs to address the realities of Indigenous patients. Future research should focus on developing tools to address the needs of Indigenous patients and improve health outcomes., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2022
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7. Indigenous Mentorship in the Health Sciences: Actions and Approaches of Mentors.
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Murry AT, Barnabe C, Foster S, Taylor AS, Atay EJ, Henderson R, and Crowshoe LL
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- Canada, Faculty, Humans, Program Evaluation methods, Mentoring, Mentors
- Abstract
Phenomenon : Indigenous and non-Indigenous scholars have called for mentorship as a viable approach to supporting the retention and professional development of Indigenous students in the health sciences. In the context of Canadian reconciliation efforts with Indigenous Peoples, we developed an Indigenous mentorship model that details behavioral themes that are distinct or unique from non-Indigenous mentorship. Approach : We used Flanagan's Critical Incidents Technique to derive mentorship behaviors from the literature, and focus groups with Indigenous faculty in the health sciences associated with the AIM-HI network funded by the Canadian Institutes of Health Research. Identified behaviors were analyzed using Lincoln and Guba's Cutting-and-Sorting technique. Findings : Confirming and extending research on mainstream mentorship, we identified behavioral themes for 1) basic mentoring interactions, 2) psychosocial support, 3) professional support, 4) academic support, and 5) job-specific support. Unique behavioral themes for Indigenous mentors included 1) utilizing a mentee-centered approach, 2) advocating on behalf of their mentees and encouraging them to advocate for themselves, 3) imbuing criticality, 4) teaching relationalism, 5) following traditional cultural protocols, and 6) fostering Indigenous identity. Insights : Mentorship involves interactive behaviors that support the academic, occupational, and psychosocial needs of the mentee. Indigenous mentees experience these needs differently than non-Indigenous mentees, as evidenced by mentor behaviors that are unique to Indigenous mentor and mentee dyads. Despite serving similar functions, mentorship varies across cultures in its approach, assumptions, and content. Mentorship programs designed for Indigenous participants should consider how standard models might fail to support their needs.
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- 2022
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8. Indigenous strengths-based approaches to healthcare and health professions education - Recognising the value of Elders' teachings.
- Author
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Kennedy A, Sehgal A, Szabo J, McGowan K, Lindstrom G, Roach P, Crowshoe LL, and Barnabe C
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Background: A strengths-based lens is essential for the pursuit of health equity among Indigenous populations. However, health professionals are often taught and supported in practice via deficit-based approaches that perpetuate inequity for Indigenous peoples. Deficit narratives in healthcare and health education are reproduced through practices and policies that ignore Indigenous strengths, disregard human rights, and reproduce structural inequalities. When strengths are recognised it is possible to build capacities and address challenges, while not losing sight of the structural factors impacting Indigenous peoples' health., Objective: In this paper, we examine Indigenous strengths-based approaches to policy and practice in healthcare and health professions education when delivered alongside teachings shared by Elders from the Cree, Blackfoot and Métis Nations of Alberta, Canada., Method: Literature and Elders' teachings were used to shift strengths-based approaches from Western descriptions of what might be done, to concrete actions aligned with Indigenous ways., Results: Four pointers for future action adopting a strengths-based approach are identified: enacting gifts - focusing on positive attributes; upholding relationality - centring good relationships; honouring legacy - restoring self-determination; and reconciling truth - attending to structural determinants of health., Conclusion: Identified directions and actionable strategies offer a promising means to advance Indigenous health equity through strengths-based actions that change existing narratives and advance health equity., Competing Interests: Declaration of conflicting interests: The author(s) declare no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2022.)
- Published
- 2022
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9. An Update on the Practical Management of a Hexapod System in Lower Limb Orthoplastic Reconstruction for Acute Shortening and Relengthening Procedures.
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Schnack LL, Oexeman S, and Rodriguez-Collazo ER
- Abstract
Background . The use of circular external fixation is a fundamental necessity in the armamentarium of a lower limb orthoplastic reconstructive surgeon. External fixation offers orthoplastic surgeons the ability to address soft tissue and osseous defects simultaneously. Using Ilizarov principles, the reconstructive surgeon must have the ability to address unique scenarios when performing orthoplastic principles. This article offers practical surgical management concepts based on experience using the TL-Hex Orthofix Truelok Hexapod System for acute shortening and relengthening. A soft tissue and osseous defect can be managed through this surgical approach as a limb salvage alternative to amputation. The information provided will lead to improved management strategies and outcomes for the practitioner and patient when presented with soft tissue and osseous defects., (© 2022, HMP Global. All rights reserved. Reproduction in whole or in part prohibited. Content may not be reproduced in any form without written permission. Rights, Permission, Reprint, and Translation information is available at www.hmpglobal.com.)
- Published
- 2022
10. The Indigenous primary health care and policy research network: Guiding innovation within primary health care with Indigenous peoples in Alberta.
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Crowshoe LL, Sehgal A, Montesanti S, Barnabe C, Kennedy A, Murry A, Roach P, Green M, Bablitz C, Tailfeathers E, and Henderson R
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- Alberta, Canada, Health Policy, Humans, Policy, Primary Health Care, Indigenous Peoples, Population Groups
- Abstract
In 2015, the Truth and Reconciliation Commission of Canada released its Final Report with 94 Calls to Action, several of which called upon the health care sector to reform based on the principles of reconciliation. In the province of Alberta, Canada, numerous initiatives have arisen to address the health legacy Calls to Action, yet there is no formal mechanism to connect them all. As such, these initiatives have resulted in limited improvements overall. Recognizing the need for clear leadership, responsibility, and dedicated funding, stakeholders from across Alberta were convened in the Spring of 2019 for two full-day roundtable meetings to provide direction for a proposed Canadian Institutes of Health Research Network Environment for Indigenous Health Research that focused on primary health care and policy research. The findings from these roundtable meetings were synthesized and integrated into the foundational principles of the Indigenous Primary Health Care and Policy Research (IPHCPR) Network. The IPHCPR Network has envisioned a renewed and transformed primary health care system to achieve Indigenous health equity, aligned with principles and health legacy Calls to Action advocated by the Truth and Reconciliation Commission of Canada., Competing Interests: Declaration of Competing Interest The authors report no declarations of interest., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2021
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11. An equity-oriented admissions model for Indigenous student recruitment in an undergraduate medical education program.
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Henderson RI, Walker I, Myhre D, Ward R, and Crowshoe LL
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Background: With the 2015 publication of the Truth and Reconciliation Commission of Canada's calls to action, health professional schools are left grappling with how to increase the recruitment and success of Indigenous learners. Efforts to diversify trainee pools have long looked to quota-based approaches to recruit students from underserved communities, though such approaches pose dilemmas around meaningfully dismantling structural barriers to health professional education. Lessons shared here from developing one multi-layered admissions strategy highlight the importance of equity-rather than equality-in any recruitment for learners from medically underserved communities., Summary: The promotion of fairness in the recruitment of future practitioners is not just a question of equalizing access to, in this case, medical school; it involves recognizing the wider social and structural mechanisms that enable privileged access to the medical profession by members of dominant society. This recognition compels a shift in focus beyond merely giving the disadvantaged increased access to an unfair system, towards building tools to address deeper questions about what is meant by the kind of excellence expected of applicants, how it is to be measured, and to what extent these recruits may contribute to improved care for the communities from which they come., Conclusion: Equity-based approaches to student recruitment move health professional schools beyond the dilemma of recruiting students from marginalized backgrounds who happen to be most similar to the dominant student population. Achieving this requires a complex view of the target population, recognizing that disadvantage is experienced in many diverse ways, that barriers are encountered along a spectrum of access, and that equity may only emerge when a critically, socially conscious approach is embedded throughout institutional practices., Competing Interests: The authors declare no competing interests in sharing the insights in this article or in any other aspect of their work., (© 2021 Henderson, Walker, Myhre, Ward, Crowshoe; licensee Synergies Partners.)
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- 2021
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12. Cadre de soins fondé sur l’éducation pour l’équité: Éliminer les obstacles sociaux des patients autochtones vivant avec le diabète de type 2.
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Crowshoe LL, Henderson R, Jacklin K, Calam B, Walker L, and Green ME
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- 2019
13. Educating for Equity Care Framework: Addressing social barriers of Indigenous patients with type 2 diabetes.
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Crowshoe LL, Henderson R, Jacklin K, Calam B, Walker L, and Green ME
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- Canada, Cultural Competency, Diabetes Mellitus, Type 2 ethnology, Education methods, Female, Humans, Indians, North American psychology, Middle Aged, Diabetes Mellitus, Type 2 therapy, Education standards, Health Services, Indigenous organization & administration, Patient Education as Topic standards
- Abstract
Objective: To present a clinical framework for addressing critical social elements for Indigenous patients with type 2 diabetes., Sources of Information: The Educating for Equity (E4E) Care Framework was developed through a rigorous analysis of qualitative research that included the perspectives of Indigenous patients (n = 32), physicians (n = 28), and Indigenous health curriculum developers (n = 5) across Canada. A national advisory group of Indigenous health experts, educators, leaders, physicians, and community members provided feedback on integrating analysis from primary research into recommendations for physicians. Systematic literature reviews were conducted and a nominal group technique process helped forge research team consensus around the framework's themes and recommendations., Main Message: For Indigenous patients with type 2 diabetes, social factors arising from the legacy of colonization are often barriers to improved diabetes outcomes, while culture is often not recognized as a facilitator in diabetes management. Structural competency in balance with cultural safety should be central to the clinical process when negotiating diabetes management with Indigenous patients. The E4E Care Framework presented in this article provides recommendations to navigate this terrain., Conclusion: A focus on social and cultural elements is fundamental to effective diabetes care among Indigenous patients. The E4E Care Framework is a resource that can help clinicians improve Indigenous patients' capacity for change in a way that acknowledges the social factors that affect the increasing diabetes rates, while using a cultural lens to facilitate improved outcomes., (Copyright© the College of Family Physicians of Canada.)
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- 2019
14. Impacts of Educating for Equity Workshop on Addressing Social Barriers of Type 2 Diabetes With Indigenous Patients.
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Crowshoe LL, Han H, Calam B, Henderson R, Jacklin K, Walker L, and Green ME
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- Adult, Cultural Competency psychology, Diabetes Mellitus, Type 2 complications, Diabetes Mellitus, Type 2 ethnology, Education methods, Female, Humans, Male, Middle Aged, Ontario, Patient Education as Topic standards, Population Groups ethnology, Psychometrics instrumentation, Psychometrics methods, Surveys and Questionnaires, Diabetes Mellitus, Type 2 psychology, Education standards, Patient Education as Topic methods, Population Groups psychology, Social Conditions
- Abstract
Introduction: Health education about Indigenous populations in Canada (First Nations, Inuit, and Métis people) is one approach to enable health services to mitigate health disparities faced by Indigenous peoples related to a history of colonization and ongoing social inequities. This evaluation of a continuing medical education workshop, to enhance family physicians' clinical approach by including social and cultural dimensions within diabetes management, was conducted to determine whether participation in the workshop improved self-reported knowledge, skills, and confidence in working with Indigenous patients with type 2 diabetes., Methods: The workshop, developed from rigorous national research with Indigenous patients, diabetes care physicians, and Indigenous health medical educators, was attended by 32 family physicians serving Indigenous populations on three sites in Northern Ontario. A same-day evaluation survey assessed participants' satisfaction with workshop content and delivery. Preworkshop and postworkshop surveys consisting of 5-point Likert and open-ended questions were administered 1 week before and 3 month after the workshop. Descriptive statistics and t test were performed to analyze Likert scale questions; thematic analysis was used to elicit and cluster themes from open-ended responses., Results: Participants reported high satisfaction with all aspects of the workshop. Reporting improved understanding of socioeconomic (P = .002), psychosocial, and cultural factors (P = .001), participants also described adapting their clinical approach to more actively incorporating social and cultural factors and focusing on patient-centered care., Discussion: The workshop was effective in shifting physician's self-reported knowledge, attitudes, and skills resulting in clinical approach modifications within social, psychosocial, and cultural domains for their Indigenous patients with diabetes.
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- 2018
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15. Babesia conradae infection in coyote hunting dogs infected with multiple blood-borne pathogens.
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Dear JD, Owens SD, Lindsay LL, Biondo AW, Chomel BB, Marcondes M, and Sykes JE
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- Animals, Babesiosis blood, Babesiosis epidemiology, Blood-Borne Pathogens, California epidemiology, Case-Control Studies, Coyotes, Dogs, Polymerase Chain Reaction, Risk Factors, Time Factors, Babesia classification, Babesiosis parasitology, Dog Diseases parasitology
- Abstract
Background: Babesia conradae is an intraerythrocytic piroplasm infecting dogs in the southern United States. Ticks have been suspected, but unproven, as vectors. We identified B. conradae and other blood-borne pathogens in 2 kennels of sighthounds with a history of coyote fighting., Objectives: To examine clinicopathologic abnormalities associated with B. conradae infection, risk factors for infection, and the prevalence of coinfections with other blood-borne pathogens., Animals: Fifty-five Greyhounds and Greyhound mixes METHODS: Blood samples were collected from each dog for CBC, serum biochemistry panel, conventional and real-time PCR assays (Babesia spp., hemoplasmas, Ehrlichia canis, Bartonella spp., Anaplasma spp., and Rickettsia spp.), vector-borne pathogen ELISA, and immunofluorescent serology and culture for Bartonella spp and Francisella tularensis sero-agglutination test. Associations between B. conradae infection and coyote fighting, age and laboratory abnormalities were investigated., Results: Twenty-nine dogs were PCR-positive for B. conradae. Of these, 16 were PCR-positive for other vector-borne organisms including Mycoplasma haemocanis, "Candidatus Mycoplasma haematoparvum," E. canis, and a Hepatozoon felis-like organism. Twelve of the 20 dogs tested for seroreactivity to Bartonella spp. antigens were positive, but none were seropositive for tularemia. Infection with B. conradae was associated with a history of aggressive interactions with coyotes; lower hematocrit, leukocyte count, MCHC, platelet count and serum albumin concentration; and higher MCV, MPV, and serum globulin concentration., Conclusions and Clinical Importance: Babesia conradae infection should be considered in dogs with anemia, leukopenia, thrombocytopenia, hypoalbuminemia and hyperglobulinemia. As with B. gibsoni, aggressive interactions with other canids may play a role in B. conradae transmission., (© 2018 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)
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- 2018
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16. Exploring Canadian Physicians' Experiences With Type 2 Diabetes Care for Adult Indigenous Patients.
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Crowshoe LL, Henderson RI, Green ME, Jacklin KM, Walker LM, and Calam B
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- Canada epidemiology, Culturally Competent Care, Humans, Indians, North American ethnology, Interviews as Topic, Diabetes Mellitus, Type 2 ethnology, Diabetes Mellitus, Type 2 therapy, Health Services, Indigenous, Physicians statistics & numerical data, Quality of Health Care
- Abstract
Objectives: The perspectives of physicians caring for Indigenous patients with diabetes offer important insights into the provision of health-care services. The purpose of this study was to describe Canadian physicians' perspectives on diabetes care of Indigenous patients, a preliminary step in developing a continuing medical education intervention described elsewhere., Methods: Through in-depth semistructured interviews, Canadian family physicians and specialists with sizeable proportions of Indigenous clientele shared their experiences of working with Indigenous patients who have type 2 diabetes. Recruitment involved a purposive and convenience sampling strategy, identifying participants through existing research and the professional relationships of team members in the provinces of British Columbia, Alberta and Ontario. Participants addressed their understanding of factors contributing to the disease, approaches to care and recommendations for medical education. The research team framed a thematic analysis through a collaborative, decolonizing lens., Results: The participants (n=28) included 3 Indigenous physicians, 21 non-Indigenous physicians and 4 non-Indigenous diabetes specialists. They practised in urban, reserve and rural adjacent-to-reserve contexts in 5 Canadian provinces. The physicians constructed a socially framed understanding of the complex contexts influencing Indigenous patients with diabetes in tension with structural barriers to providing diabetes care. As a result, physicians adapted care focusing on social factors and conditions that take into account the multigenerational impacts of colonization and the current social contexts of Indigenous peoples in Canada., Conclusions: Adaptations in diabetes care by physicians grounded in the historical, social and cultural contexts of their Indigenous patients offer opportunities for improving care quality, but policy and health system supports and structural competency are needed., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
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17. Does the Shoe Fit? Considerations for Proper Shoe Fitting.
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Blazer MM, Jamrog LB, and Schnack LL
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- Female, Foot physiology, Humans, Male, Podiatry, Foot anatomy & histology, Orthopedic Nursing, Shoes, Sports
- Abstract
It is important to be properly evaluated for shoes to avoid complications. Ill-fitting shoes can lead to pathologies in different populations. The focus of this article is to review the components and function of a basic athletic-type shoe, general shoe-fitting techniques, and selecting appropriate footwear for various populations including those with diabetes, elderly, and females. Poorly fitting shoes can exacerbate structural foot deformities. Unevenly distributed plantar pressures and wear can lead to ulcerations in diabetic populations. Resources and transportation may impact the elderly population when obtaining new shoes. Esthetics is of superior consideration for females. The Brannock Device measurements are important to ensure a correct fit in guiding shoe selection. The orthopaedic nurse should be able to recognize foot ailments caused by ill-fitting shoe gear. Seeking the advice of a podiatrist should be considered before purchasing shoes.
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- 2018
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18. Microscopic and molecular identification of hemotropic mycoplasmas in South American coatis (Nasua nasua).
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Cubilla MP, Santos LC, de Moraes W, Cubas ZS, Leutenegger CM, Estrada M, Lindsay LL, Trindade ES, Franco CRC, Vieira RFC, Biondo AW, and Sykes JE
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- Animals, Animals, Domestic, Animals, Wild microbiology, Brazil epidemiology, DNA, Bacterial genetics, Female, Male, Microscopy, Microscopy, Confocal, Microscopy, Electron, Scanning methods, Mycoplasma genetics, Mycoplasma ultrastructure, Mycoplasma Infections epidemiology, Mycoplasma Infections microbiology, Mycoplasma Infections transmission, RNA, Ribosomal, 16S genetics, Real-Time Polymerase Chain Reaction, Sequence Analysis, DNA, Mycoplasma isolation & purification, Mycoplasma Infections veterinary, Procyonidae microbiology
- Abstract
Hemoplasmas were detected in two apparently healthy captive South American coatis (Nasua nasua) from southern Brazil during an investigation for vector-borne pathogens. Blood was subjected to packed cell volume (PCV) determination, a commercial real-time PCR panel for the detection of Anaplasma spp., Babesia spp., Bartonella spp., Hepatozoon spp., Leishmania spp., Mycoplasma haemofelis, 'Candidatus Mycoplasma turicensis', 'Candidatus Mycoplasma haemominutum', Neorickettsia risticii, Rickettsia rickettsii and Leptospira spp., and a pan-hemoplasma conventional PCR assay. PCV was normal, but both coatis tested positive for hemoplasmas and negative for all the remaining pathogens tested. Using different techniques for microscopy (light, confocal or SEM), structures compatible with hemoplasmas were identified. Sequencing of the 16S rRNA gene identified an organism resembling Mycoplasma haemofelis and another hemotropic Mycoplasma sp., with a sequence identity of 96.8% to a Mycoplasma sp. previously detected in capybaras., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2017
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19. Occurrence of hemotropic mycoplasmas in non-human primates (Alouatta caraya, Sapajus nigritus and Callithrix jacchus) of southern Brazil.
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Cubilla MP, Santos LC, de Moraes W, Cubas ZS, Leutenegger CM, Estrada M, Vieira RFC, Soares MJ, Lindsay LL, Sykes JE, and Biondo AW
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- Animals, Animals, Wild microbiology, Brazil epidemiology, Coinfection blood, Coinfection microbiology, Erythrocytes microbiology, Monkey Diseases blood, Monkey Diseases microbiology, Mycoplasma genetics, Mycoplasma Infections blood, Mycoplasma Infections epidemiology, Mycoplasma Infections microbiology, Phylogeny, Polymerase Chain Reaction, Sequence Analysis, DNA, Alouatta microbiology, Callithrix microbiology, Cebinae microbiology, Monkey Diseases epidemiology, Mycoplasma isolation & purification, Mycoplasma Infections veterinary
- Abstract
Hemoplasmas, the erythrocyte-associated mycoplasmas, have been detected in several primates, causing mostly subclinical infection. This study aimed to determine the prevalence of hemoplasma infection in captive and free-ranging monkeys from southern Brazil, as well as factors and hematological abnormalities associated with infection. Blood samples from 40 non-human primates (NHP) were tested for hemoplasmas and coinfections. An overall of 10/40 (25.0%) NHP tested positive for hemoplasmas using PCR-based assays, including 9/14 (64.3%) black howler monkeys (Alouatta caraya) and 1/24 (4.2%) black-horned capuchin (Sapajus nigritus). Infection was not statistically associated with anemia, but wild-born monkeys and male black howler monkeys were more likely to be positive when compared with captive-born animals and female black howler monkeys, respectively. The sequences from the black howler monkey hemoplasma were similar (94% identity) to the squirrel monkey hemoplasma ("Candidatus Mycoplasma kahanei") and were phylogenetically located in a different cluster when compared to the human hemoplasma ("Candidatus Mycoplasma haemohominis")., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
- Published
- 2017
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20. Capture and characterization of influenza A virus from primary samples using glycan bead arrays.
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Cohen M, Fisher CJ, Huang ML, Lindsay LL, Plancarte M, Boyce WM, Godula K, and Gagneux P
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- Animals, Dogs, Ducks virology, Influenza A virus metabolism, Madin Darby Canine Kidney Cells, Magnetics, Mucins, Neuraminidase metabolism, Sensitivity and Specificity, Viral Proteins metabolism, Cloaca virology, Influenza A virus isolation & purification, Microspheres, Polysaccharides metabolism
- Abstract
Influenza A viruses (IAVs) utilize sialylated host glycans as ligands for binding and infection. The glycan-binding preference of IAV hemagglutinin (HA) is an important determinant of host specificity. Propagation of IAV in embryonated chicken eggs and cultured mammalian cells yields viruses with amino acid substitutions in the HA that can alter the binding specificity. Therefore, it is important to determine the binding specificity of IAV directly in primary samples since it reflects the actual tropism of virus in nature. We developed a novel platform for analysis of IAV binding specificity in samples that contain very low virus titers. This platform consists of a high-density flexible glycan display on magnetic beads, which promotes multivalent interactions with the viral HA. Glycan-bound virus is detected by quantifying the viral neuraminidase activity via a fluorogenic reporter, 2'-(4-methylumbelliferyl)-α-d-N-acetylneuraminic acid. This method eliminates the need for labeling the virus and significantly enhances the sensitivity of detection., (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Published
- 2016
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21. Mini-med school for Aboriginal youth: experiential science outreach to tackle systemic barriers.
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Henderson RI, Williams K, and Crowshoe LL
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- Adolescent, Education, Medical, Health Services Accessibility, Humans, Medically Underserved Area, Poverty Areas, Social Marginalization, Education, Premedical
- Abstract
Introduction: Addressing systemic barriers experienced by low-income and minority students to accessing medical school, the University of Calgary's Cumming School of Medicine has spearheaded a year-round, mini-med school outreach initiative for Aboriginal students., Method: Junior and senior high school youth generally attend the half-day program in classes or camps of 15-25, breaking into small groups for multisession activities. Undergraduate medical education students mentor the youth in stations offering experiential lessons in physical examination, reading x-rays, and anatomy. All resources from the medical school are offered in-kind, including a pizza lunch at midday, whereas community partners organize transportation for the attendees., Results: Opening the medical school and its resources to the community offers great benefits to resource-constrained schools often limited in terms of science education resources. The model is also an effort to address challenges among the medical professions around attracting and retaining students from underserved populations., Conclusion: The prospect of increasing admission rates and successful completion of medical education among students from marginalized communities poses a real, though difficult-to-measure, possibility of increasing the workforce most likely to return to and work in such challenging contexts. A mini-medical school for Aboriginal youth highlights mutual, long-term benefit for diverse partners, encouraging medical educators and community-based science educators to explore the possibilities for deepening partnerships in their own regions.
- Published
- 2015
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22. Likelihood of coronary angiography among First Nations patients with acute myocardial infarction.
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Bresee LC, Knudtson ML, Zhang J, Crowshoe LL, Ahmed SB, Tonelli M, Ghali WA, Quan H, Manns B, Fabreau G, and Hemmelgarn BR
- Subjects
- Aged, Alberta epidemiology, Female, Follow-Up Studies, Humans, Incidence, Male, Middle Aged, Myocardial Infarction ethnology, Prevalence, Prospective Studies, Risk Factors, Survival Rate trends, Time Factors, Coronary Angiography statistics & numerical data, Indians, North American, Myocardial Infarction diagnostic imaging
- Abstract
Background: Morbidity due to cardiovascular disease is high among First Nations people. The extent to which this may be related to the likelihood of coronary angiography is unclear. We examined the likelihood of coronary angiography after acute myocardial infarction (MI) among First Nations and non-First Nations patients., Methods: Our study included adults with incident acute MI between 1997 and 2008 in Alberta. We determined the likelihood of angiography among First Nations and non-First Nations patients, adjusted for important confounders, using the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) database., Results: Of the 46,764 people with acute MI, 1043 (2.2%) were First Nations. First Nations patients were less likely to receive angiography within 1 day after acute MI (adjusted odds ratio [OR] 0.73, 95% confidence interval [CI] 0.62-0.87). Among First Nations and non-First Nations patients who underwent angiography (64.9%), there was no difference in the likelihood of percutaneous coronary intervention (PCI) (adjusted hazard ratio [HR] 0.92, 95% CI 0.83-1.02) or coronary artery bypass grafting (CABG) (adjusted HR 1.03, 95% CI 0.85-1.25). First Nations people had worse survival if they received medical management alone (adjusted HR 1.38, 95% CI 1.07-1.77) or if they underwent PCI (adjusted HR 1.38, 95% CI 1.06-1.80), whereas survival was similar among First Nations and non-First Nations patients who received CABG., Interpretation: First Nations people were less likely to undergo angiography after acute MI and experienced worse long-term survival compared with non-First Nations people. Efforts to improve access to angiography for First Nations people may improve outcomes., (© 2014 Canadian Medical Association or its licensors.)
- Published
- 2014
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23. Complete genome sequences of the first reported california h16 influenza a viruses.
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Lindsay LL, Plancarte M, Brenn-White M, and Boyce WM
- Abstract
Two reassortant H16 influenza A viruses were isolated from gulls in California. Seven of the eight segments were most closely related to H16 and H13 isolates from eastern North America and Iceland. Of note is a C-terminal truncation of the nonstructural 1 (NS1) protein in one of the isolates that is usually found in swine H1N1 virus.
- Published
- 2014
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24. Evaluation of phenotypic markers in full genome sequences of avian influenza isolates from California.
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Mertens E, Dugan VG, Stockwell TB, Lindsay LL, Plancarte M, and Boyce WM
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- Amino Acid Sequence, Animals, Birds, California, Genetic Markers, Genetic Variation, High-Throughput Nucleotide Sequencing, Influenza A Virus, H1N1 Subtype isolation & purification, Influenza A Virus, H5N1 Subtype isolation & purification, Influenza in Birds transmission, Molecular Sequence Data, Sequence Analysis, RNA, Hemagglutinin Glycoproteins, Influenza Virus genetics, Influenza A Virus, H1N1 Subtype genetics, Influenza A Virus, H5N1 Subtype genetics, Influenza in Birds genetics
- Abstract
We evaluated phenotypic markers in full-genome sequences of avian influenza isolates to identify avian strains with increased potential for transmission and pathogenicity in mammals. Of 149 markers examined, 67 were positive in the consensus sequences from 206 avian isolates. Analysis of deep sequencing data in a subset of 24 isolates revealed that 344 subpopulations occurred at marker positions. Markers in subpopulations were significantly more likely to be negative (258/344) than positive (86/344), but nearly all of the marker-positive subpopulations (78/86) were associated with marker-negative consensus sequences. Our analysis revealed significant variation in important markers among avian isolates, and showed that consensus sequences do not fully convey an isolate's potential for increased transmissibility and pathogenicity in mammals., (Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2013
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25. Avian influenza: mixed infections and missing viruses.
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Lindsay LL, Kelly TR, Plancarte M, Schobel S, Lin X, Dugan VG, Wentworth DE, and Boyce WM
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- Animals, California epidemiology, Chickens, Cloaca virology, Epidemiological Monitoring, Female, Hemagglutinin Glycoproteins, Influenza Virus genetics, Influenza A virus genetics, Male, Molecular Sequence Data, RNA, Viral genetics, Real-Time Polymerase Chain Reaction methods, Sequence Analysis, DNA, Virus Cultivation methods, Anseriformes virology, Coinfection virology, Influenza A virus classification, Influenza A virus isolation & purification, Influenza in Birds virology, Virology methods
- Abstract
A high prevalence and diversity of avian influenza (AI) viruses were detected in a population of wild mallards sampled during summer 2011 in California, providing an opportunity to compare results obtained before and after virus culture. We tested cloacal swab samples prior to culture by matrix real-time PCR, and by amplifying and sequencing a 640bp portion of the hemagglutinin (HA) gene. Each sample was also inoculated into embryonated chicken eggs, and full genome sequences were determined for cultured viruses. While low matrix Ct values were a good predictor of virus isolation from eggs, samples with high or undetectable Ct values also yielded isolates. Furthermore, a single passage in eggs altered the occurrence and detection of viral strains, and mixed infections (different HA subtypes) were detected less frequently after culture. There is no gold standard or perfect reference comparison for surveillance of unknown viruses, and true negatives are difficult to distinguish from false negatives. This study showed that sequencing samples prior to culture increases the detection of mixed infections and enhances the identification of viral strains and sequences that may have changed or even disappeared during culture.
- Published
- 2013
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26. Complete Genome Sequence of a Reassortant H14N2 Avian Influenza Virus from California.
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Boyce WM, Schobel S, Dugan VG, Halpin R, Lin X, Wentworth DE, Lindsay LL, Mertens E, and Plancarte M
- Abstract
We report the complete genome sequence of a reassortant H14N2 avian influenza virus isolated in 2011 from a northern shoveler in California. This introduced Eurasian subtype acquired seven segments from North American viruses and circulated in the Pacific Flyway 1 year after its detection in the Mississippi Flyway.
- Published
- 2013
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27. Hemotropic mycoplasma in a free-ranging black howler monkey (Alouatta caraya) in Brazil.
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Santos LC, Cubilla MP, de Moraes W, Cubas ZS, Oliveira MJ, Estrada M, Leutenegger CM, Sykes JE, Lindsay LL, Marcondes M, Barros Filho IR, and Biondo AW
- Subjects
- Animals, Animals, Wild microbiology, Brazil epidemiology, Female, Monkey Diseases diagnosis, Mycoplasma Infections diagnosis, Mycoplasma Infections epidemiology, Alouatta, Monkey Diseases epidemiology, Mycoplasma Infections veterinary
- Abstract
Hemotropic mycoplasmas are bacteria that infect erythrocytes and cause subclinical infections to life-threatening disease. We describe hemotropic mycoplasma infection in a free-ranging black howler monkey (Alouatta caraya). This is the first molecular detection of a hemotropic mycoplasma in a nonhuman primate from Brazil.
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- 2013
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28. Severe myositis associated with Sarcocystis spp. infection in 2 dogs.
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Sykes JE, Dubey JP, Lindsay LL, Prato P, Lappin MR, Guo LT, Mizisin AP, and Shelton GD
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- Animals, Dog Diseases etiology, Dog Diseases pathology, Dogs, Female, Male, RNA, Ribosomal, 18S genetics, Real-Time Polymerase Chain Reaction veterinary, Sarcocystis genetics, Sarcocystosis complications, Sarcocystosis pathology, Dog Diseases parasitology, RNA, Protozoan genetics, Sarcocystis isolation & purification, Sarcocystosis veterinary
- Abstract
Background: Dogs are definitive hosts for numerous species of the intracellular protozoan parasite Sarcocystis. Reports of sarcocysts in muscles of dogs most often represent incidental findings., Hypothesis/objectives: To report the clinicopathologic, ultrastructural, and molecular findings in 2 dogs with myositis associated with Sarcocystis spp. infection, as well as the response to treatment with antiprotozoal drugs., Animals: Two dogs with severe myositis in association with massive sarcocystosis., Methods: Retrospective case review. Affected dogs were identified by a diagnostic laboratory. Attending clinicians were contacted, and the medical records reviewed. Immunostaining and electron microscopy were performed on muscle biopsies. Biopsies also were subjected to 18S rRNA gene PCR., Results: Both dogs had fever, lymphopenia, thrombocytopenia, and increased serum alanine aminotransferase (ALT) activity when first evaluated. One dog developed hyperbilirubinemia. Subsequently, both dogs had increased serum creatine kinase activity and clinical signs of myositis, with reluctance to move, generalized pain, and muscle wasting. Histopathology of muscle biopsies showed severe inflammatory and necrotizing myopathy with numerous sarcocysts. Ultrastructural studies and 18S rRNA gene sequence results were consistent with infection with a Sarcocystis spp. other than Sarcocystis neurona. Both dogs initially were treated unsuccessfully with clindamycin and anti-inflammatory drugs. One dog died. The other dog subsequently responded to treatment with decoquinate., Conclusions and Clinical Importance: Sarcocystis spp. infection should be included in the differential diagnosis for dogs that develop fever, thrombocytopenia, increased liver enzyme activities, and clinical and biochemical evidence of myositis. Although additional studies are required, decoquinate holds promise as an effective treatment for the disease., (Copyright © 2011 by the American College of Veterinary Internal Medicine.)
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- 2011
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29. The environmental sustainability of dental practice.
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McClea PT, Agnew CM, Jo JJ, and Lindsay LL
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- Composite Resins chemistry, Dental Amalgam chemistry, Dental Materials chemistry, Dental Waste prevention & control, Hazardous Waste prevention & control, Humans, Medical Waste Disposal, New Zealand, Waste Management, Dentists, Environment, Environmental Pollution prevention & control, Professional Practice
- Published
- 2011
30. Relationship between clinical manifestations and pulsed-field gel profiles of Streptococcus canis isolates from dogs and cats.
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Kruger EF, Byrne BA, Pesavento P, Hurley KF, Lindsay LL, and Sykes JE
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- Animals, Cats, Dogs, Electrophoresis, Gel, Pulsed-Field veterinary, Female, Male, Serotyping veterinary, Streptococcal Infections classification, Streptococcal Infections microbiology, Streptococcus classification, Streptococcus isolation & purification, Streptococcus pathogenicity, Cat Diseases microbiology, Dog Diseases microbiology, Streptococcal Infections veterinary, Streptococcus genetics
- Abstract
Little is known regarding the degree of genotypic relatedness between Streptococcus canis isolates from dogs and cats. The purpose of this study was to determine whether correlations existed between the genotypes of canine and feline S. canis isolates as determined using pulsed-field gel electrophoresis (PFGE) and different clinical manifestations of disease. Eighty-two isolates of S. canis were examined that had been collected from dogs and cats presenting to the University of California, Davis Veterinary Medical Teaching Hospital (VMTH) between 1998 and 2005. Associated clinical manifestations included sepsis, otitis, pyometra, skin infections, necrotizing fasciitis, respiratory disease, and urinary tract infections. In addition, 9 feline isolates from a southern California shelter that experienced an outbreak of S. canis infection manifesting as necrotizing fasciitis and death were examined. Bacterial isolates were characterized by PFGE analysis using the restriction enzyme SmaI. The relationships between banding patterns were analyzed using gel analysis software combined with visual interpretation. The feline shelter isolates of S. canis were 99% similar in bacterial PFGE profile. The remainder of samples had less than 80% similarity in PFGE banding patterns. The relatedness of the PFGE profile in the feline shelter isolates suggested a clonal origin. In the isolates from the VMTH population, there was no relationship between specific disease manifestations and PFGE profile. PFGE typing does not appear to be useful for identifying isolates associated with specific disease presentations; however may be more useful to identify outbreaks of S. canis infections or to detect clonal populations in outbreaks., (Copyright © 2010 Elsevier B.V. All rights reserved.)
- Published
- 2010
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31. Human coinfection with Bartonella henselae and two hemotropic mycoplasma variants resembling Mycoplasma ovis.
- Author
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Sykes JE, Lindsay LL, Maggi RG, and Breitschwerdt EB
- Subjects
- Anti-Bacterial Agents therapeutic use, Bacteriological Techniques methods, Cat-Scratch Disease drug therapy, Cat-Scratch Disease microbiology, DNA, Bacterial blood, Humans, Male, Middle Aged, Mycoplasma Infections drug therapy, Mycoplasma Infections microbiology, Polymerase Chain Reaction methods, Texas, Treatment Outcome, Veterinarians, Bartonella henselae isolation & purification, Blood microbiology, Cat-Scratch Disease complications, Cat-Scratch Disease diagnosis, Mycoplasma isolation & purification, Mycoplasma Infections complications, Mycoplasma Infections diagnosis
- Abstract
Two variants of an organism resembling the ovine hemoplasma, Mycoplasma ovis, were detected by PCR in blood samples from a veterinarian in Texas. Coinfection with similar variants has been described in sheep. This represents the first report of human infection with this organism. The veterinarian was coinfected with Bartonella henselae.
- Published
- 2010
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32. Corynebacterium ulcerans bronchopneumonia in a dog.
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Sykes JE, Mapes S, Lindsay LL, Samitz E, and Byrne BA
- Subjects
- Animals, Anti-Bacterial Agents therapeutic use, Antifungal Agents therapeutic use, Corynebacterium Infections microbiology, Dogs, Itraconazole therapeutic use, Male, Pneumonia, Bacterial drug therapy, Pneumonia, Bacterial microbiology, Pulmonary Aspergillosis drug therapy, Pulmonary Aspergillosis microbiology, Pulmonary Aspergillosis veterinary, Corynebacterium classification, Corynebacterium Infections veterinary, Pneumonia, Bacterial veterinary
- Published
- 2010
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33. Use of dried blood smears for detection of feline hemoplasmas using real-time polymerase chain reaction.
- Author
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Sykes JE, Owens SD, Terry JC, Lindsay LL, and Pusterla N
- Subjects
- Animals, Cat Diseases microbiology, Cats, DNA, Bacterial genetics, DNA, Bacterial isolation & purification, Glyceraldehyde-3-Phosphate Dehydrogenases genetics, Mycoplasma enzymology, Mycoplasma isolation & purification, Mycoplasma Infections blood, Mycoplasma Infections genetics, Polymerase Chain Reaction methods, RNA, Bacterial blood, RNA, Bacterial genetics, RNA, Bacterial isolation & purification, RNA, Ribosomal, 18S blood, RNA, Ribosomal, 18S genetics, RNA, Ribosomal, 18S isolation & purification, Sensitivity and Specificity, Cat Diseases blood, DNA, Bacterial blood, Mycoplasma genetics, Mycoplasma Infections veterinary
- Abstract
The objective of the current study was to determine the sensitivity and specificity of real-time polymerase chain reaction (real-time PCR) for feline hemoplasmas when applied to DNA extracted from dried whole-blood smears in comparison to that for DNA extracted from liquid whole blood. Blood samples were collected into ethylenediamine tetra-acetic acid tubes from 305 cats with possible or suspected hemoplasmosis, and dried blood smears from each sample were prepared. DNA was extracted from blood smears and a 160-microl aliquot of each liquid blood sample by using a robotic extractor and was subjected to real-time PCR for feline glyceraldehyde-3-phosphate dehydrogenase (liquid blood), 18S ribosomal RNA (dried blood), and "Candidatus Mycoplasma haemominutum", Mycoplasma haemofelis, and "Candidatus Mycoplasma turicensis" DNA. When using the results for liquid whole blood as the gold standard, the sensitivity of each assay for "Ca. M. haemominutum", M. haemofelis, and "Ca. M. turicensis" was 49 of 66 (74%), 11 of 13 (85%), and 11 of 20 (55%), respectively. The specificity of each assay was 224 of 234 (96%), 287 of 287 (100%), and 280 of 280 (100%), respectively. When possible, liquid blood samples should be submitted for detection of feline hemoplasmas by using real-time PCR. The improved sensitivity of real-time PCR on blood smears for M. haemofelis compared with that of the other hemoplasma species may reflect the higher organism burdens associated with infection with this species.
- Published
- 2008
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34. Prevalences of various hemoplasma species among cats in the United States with possible hemoplasmosis.
- Author
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Sykes JE, Terry JC, Lindsay LL, and Owens SD
- Subjects
- Anemia epidemiology, Anemia microbiology, Animals, Cat Diseases epidemiology, Cats, Cross-Sectional Studies, DNA, Bacterial chemistry, DNA, Bacterial genetics, Female, Male, Mycoplasma isolation & purification, Mycoplasma Infections epidemiology, Mycoplasma Infections microbiology, Polymerase Chain Reaction methods, Polymerase Chain Reaction veterinary, Prevalence, Sex Factors, Species Specificity, United States epidemiology, Anemia veterinary, Cat Diseases microbiology, Mycoplasma classification, Mycoplasma Infections veterinary, Phylogeny
- Abstract
Objective: To determine prevalences of various hemoplasma species among cats in the United States with possible hemoplasmosis and identify risk factors for and clinicopathologic abnormalities associated with infection with each species., Design: Cross-sectional study. Animals-310 cats with cytologic evidence of hemoplasmosis (n = 9) or acute or regenerative anemia (309)., Procedures: Blood samples were tested by means of a broad-spectrum conventional PCR assay for hemoplasma DNA and by means of 3 separate species-specific real-time PCR assays for DNA from "Candidatus Mycoplasma haemominutum" (Mhm), Mycoplasma haemofelis (Mhf), and "Candidatus Mycoplasma turicensis" (Mtc)., Results: Overall prevalences of Mhm, Mhf, and Mtc infection were 23.2% (72/310), 4.8% (15/310), and 6.5% (20/310), respectively. Mixed infections were detected in 20 (6.5%) cats. Cats infected with hemoplasmas were more likely to be male than were uninfected cats. Infection with FeLV or FIV was significantly associated with infection with Mhf. Compared with uninfected cats, cats infected with Mhf had higher reticulocyte counts, nucleated RBC counts, and mean corpuscular volume; cats infected with Mhm had higher mean corpuscular volume; and cats infected with Mtc had higher monocyte counts., Conclusions and Clinical Relevance: Results supported the suggestion that these 3 hemoplasma species commonly occur among cats in the United States and that pathogenicity of the 3 species varies.
- Published
- 2008
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35. In vitro effects of the active metabolite of leflunomide, A77 1726, on feline herpesvirus-1.
- Author
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Williams CR, Sykes JE, Mehl M, MacLeod JS, Lindsay LL, Poland AM, Chen YJ, Kyles AE, Waldman WJ, and Gregory CR
- Subjects
- Aniline Compounds metabolism, Animals, Antiviral Agents metabolism, Apoptosis drug effects, Apoptosis physiology, Cat Diseases drug therapy, Cats, Cell Line, Cell Survival drug effects, Cell Survival physiology, Crotonates, DNA, Viral chemistry, DNA, Viral genetics, Herpesviridae physiology, Herpesviridae Infections virology, Hydroxybutyrates metabolism, Isoxazoles metabolism, Leflunomide, Microscopy, Electron, Transmission veterinary, Mitochondria drug effects, Mitochondria physiology, Nitriles, Polymerase Chain Reaction veterinary, Statistics, Nonparametric, Toluidines, Viral Load veterinary, Virus Replication drug effects, Aniline Compounds pharmacology, Antiviral Agents pharmacology, Cat Diseases virology, Herpesviridae drug effects, Herpesviridae Infections drug therapy, Hydroxybutyrates pharmacology, Isoxazoles pharmacology
- Abstract
Objective: To determine whether the active metabolite of leflunomide, A77 1726 (A77), inhibits replication of feline herpesvirus-1 (FHV-1) in cell culture., Study Population: Crandell Rees feline kidney (CRFK) cell cultures., Procedures: Cell cultures were inoculated with FHV-1 and treated simultaneously with concentrations of A77 ranging from 0 to 200microM. The antiviral effect of A77 was determined by use of conventional plaque reduction assays. The effect of A77 on viral load was determined via real-time PCR analysis, and transmission electron microscopy was used to evaluate the effect of A77 on viral morphology. To determine whether the antiviral effect was attributable to alterations in CRFK cell viability and number, CRFK cells were treated with various concentrations of A77 and stained with Annexin V and propidium iodide to assess apoptosis and a mitochondrial function assay was used to determine cell viability., Results: Concentrations of A77 > or = 20microM were associated with substantial reduction in plaque number and viral load. Concentrations > or = 100microM were associated with complete suppression of plaque formation. At low concentrations of A77, clusters of intracytoplasmic virus particles that appeared to lack tegument and an external membrane were detected. Treatment of uninfected CRFK cell monolayers with A77 was associated with reduction in mitochondrial function with minimal evidence of apoptosis., Conclusions and Clinical Relevance: Leflunomide may be an alternative to current calcineurin-based immunosuppressive protocols used in feline organ transplantation because of its antiherpesviral activity.
- Published
- 2007
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36. Proteolysis of Xenopus laevis egg envelope ZPA triggers envelope hardening.
- Author
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Lindsay LL and Hedrick JL
- Subjects
- Animals, Antibodies chemistry, Blotting, Western, Cloning, Molecular, DNA, Complementary metabolism, Electrophoresis, Polyacrylamide Gel, Enzyme Inhibitors pharmacology, Female, Fertilization, Male, Metalloproteases metabolism, Ovum metabolism, Peptide Hydrolases chemistry, Protease Inhibitors pharmacology, Protein Structure, Tertiary, Proteins chemistry, Spermatozoa metabolism, Temperature, Xenopus laevis, Zona Pellucida metabolism, Zona Pellucida Glycoproteins, Egg Proteins chemistry, Membrane Glycoproteins chemistry, Receptors, Cell Surface chemistry, Zona Pellucida chemistry
- Abstract
The egg envelope of most animal eggs is modified following fertilization, resulting in the prevention of polyspermy and hardening of the egg envelope. In frogs and mammals a prominent feature of envelope modification is N-terminal proteolysis of the envelope glycoprotein ZPA. We have purified the ZPA protease from Xenopus laevis eggs and characterized it as a zinc metalloprotease. Proteolysis of isolated egg envelopes by the isolated protease resulted in envelope hardening. The N-terminal peptide fragment of ZPA remained disulfide bond linked to the ZPA glycoprotein moiety following proteolysis. We propose a mechanism for egg envelope hardening involving ZPA proteolysis by an egg metalloprotease as a triggering event followed by induction of global conformational changes in egg envelope glycoproteins.
- Published
- 2004
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37. Strategy for profiling and structure elucidation of mucin-type oligosaccharides by mass spectrometry.
- Author
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Zhang J, Lindsay LL, Hedrick JL, and Lebrilla CB
- Subjects
- Animals, Carbohydrate Conformation, Chromatography, High Pressure Liquid, Fourier Analysis, Oligosaccharides isolation & purification, Xenopus, Mucins chemistry, Oligosaccharides chemistry, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization methods
- Abstract
A strategy combining accurate mass determination, tandem mass spectrometry, structure homology, and exoglycosidases is described that allows the structural characterization of mucin-type O-linked oligosaccharides. The method is used to profile with quantitation the O-linked oligosaccharide (both neutral and anionic) components of the only diploid Xenopus frog, Xenopus tropicalis. Collision-induced dissociation was used to determine connectivity, to identify previously characterized oligosaccharides, and to determine the presence of structural motifs in unknown oligosaccharides. Exoglycosidase digestion was used to identify the individual residues along with the linkages. The enzymes were also used to cleave larger oligosaccharides to smaller units that are similar to previously elucidated components. By using CID, isomeric structures were compared to determine whether they were identical. In this way, the exoglycosidases were more effectively used, and their use was minimized. A total of 35 oligosaccharides including neutral, sialylated, and sulfated were characterized in this way. The relative abundances of all components were also determined based on HPLC.
- Published
- 2004
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38. Interparental conflict and adolescent adjustment: why does gender moderate early adolescent vulnerability?
- Author
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Davies PT and Lindsay LL
- Subjects
- Adolescent, Adult, Female, Humans, Male, Psychology, Adolescent, Sex Factors, Conflict, Psychological, Family Relations, Marriage psychology, Parents psychology, Social Adjustment
- Abstract
The role of child gender in the relationship between interparental conflict and adolescent psychological symptoms was examined in a sample of 924 children 10 to 15 years old and 172 of their mothers. Interparental conflict was a significantly stronger predictor of adolescent internalizing symptoms for girls than boys across type of informant (i.e., mother or child). In examining why the risk posed by interparental conflict differed by gender, further analyses indicated that girls' tendencies to experience elevated levels of communion partly accounted for their greater vulnerability to interparental conflict.
- Published
- 2004
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39. Cross-fertilization and structural comparison of egg extracellular matrix glycoproteins from Xenopus laevis and Xenopus tropicalis.
- Author
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Lindsay LL, Peavy TR, Lejano RS, and Hedrick JL
- Subjects
- Amino Acid Sequence, Animals, Cloning, Molecular, DNA, Complementary, Extracellular Matrix Proteins genetics, Female, Lectins genetics, Male, Molecular Sequence Data, Ovum metabolism, Spermatozoa physiology, Xenopus laevis metabolism, Extracellular Matrix Proteins metabolism, Fertilization, Glycoproteins metabolism, Ovum physiology, Xenopus metabolism
- Abstract
While the anuran amphibian Xenopus laevis is a widely used vertebrate model system, it is not optimal for genetic manipulations due to its tetraploid genome and long generation time. A current alternative amphibian model system, Xenopus tropicalis, has the advantages of a diploid genome and a much shorter generation time. We undertook a comparative investigation of X. tropicalis egg extracellular matrix glycoproteins in relation to those already characterized in X. laevis. Fertilization methods and isolation of egg extracellular molecules were directly transferable from X. laevis to X. tropicalis. Cross-fertilizations were successful in both directions, indicating similar molecules involved in sperm-egg interactions. Egg envelopes analyzed by SDS-PAGE were found to have almost identical gel patterns, whereas jelly component profiles were similar only for the larger macromolecules (>90 kDa). The cDNA sequences for egg envelope glycoproteins ZPA, ZPB, ZPC, ZPD and ZPAX, and also egg cortical granule lectin involved in the block to polyspermy, were cloned for X. tropicalis and showed a consistent approximately 85% amino acid identity to the X. laevis sequences. Thus, homologous egg extracellular matrix molecules perform the same functions, and the molecular and cellular mechanisms of fertilization in these two species are probably equivalent.
- Published
- 2003
- Full Text
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40. Position of the American Dietetic Association: Addressing world hunger, malnutrition, and food insecurity.
- Author
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Struble MB and Aomari LL
- Subjects
- Agriculture, Child, Child, Preschool, Conservation of Natural Resources, Female, Humans, Infant, Infant, Newborn, International Cooperation, Politics, Poverty, United Nations, Food Supply, Hunger, Nutrition Disorders
- Abstract
It is the position of the American Dietetic Association (ADA) that access to adequate amounts of safe, nutritious, and culturally appropriate food at all times is a fundamental human right. Hunger continues to be a worldwide problem of staggering proportions. The Association supports programs and encourages practices that combat hunger and malnutrition, produce food security, promote self-sufficiency, and are environmentally and economically sustainable. The Association is aware that hunger exists in a world of plenty and that poverty, gender inequity, ethnocentrism, racism, and the lack of political will are key constraints to solving the problems of global hunger and malnutrition. Recognizing that simplistic approaches are inadequate, the ADA identifies sustainable development as the long-term strategy to ending world hunger and achieving food security. Sustainable development requires political, economic, and social changes that include empowering the disenfranchised, widening access to assets and other resources, narrowing the gap between rich and poor, and adjusting consumption patterns so as to foster good stewardship of nature. Additionally, because the health status of future generations is related to the well-being of their mothers, achieving food security will also require increased access for women to education, adequate health care and sanitation, and economic opportunities. This position paper reviews the complex issues of global food insecurity and discusses long-term solutions for achieving world food security. Achieving the end of world hunger has been and is now within our grasp. There is sufficient food to feed everyone, and solutions can be realized now that will benefit all of humanity. As noted in the paper, most people who examine the costs of ending versus not ending world hunger are bewildered by the question of why humanity did not solve the problem a long time ago. The Association supports programs and encourages practices that combat hunger and malnutrition, produce food security, promote self-sufficiency, respect local cultures, and are environmentally and economically sustainable. The ADA recognizes that decisions and actions that dietetics professionals make as practitioners and consumers can help reduce the extent of poverty and hunger both here and abroad. This paper provides information, resources, and strategies to assist dietetics professionals in improving the public's understanding of key issues, becoming advocates of the poor, and influencing the political will to end world hunger.
- Published
- 2003
- Full Text
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41. Identification and characterization of a unique Xenopus laevis egg envelope component, ZPD.
- Author
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Lindsay LL, Yang JC, and Hedrick JL
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, Cloning, Molecular, DNA, Complementary, Egg Proteins genetics, Female, Glycoproteins genetics, Humans, Membrane Proteins, Molecular Sequence Data, Phylogeny, Sequence Alignment, Xenopus laevis, Egg Proteins isolation & purification, Glycoproteins isolation & purification
- Abstract
We report the identification of a previously undetected Xenopus laevis egg envelope component discovered through cloning experiments. A cDNA sequence was found that represented a mature protein of 32 kDa. Peptide antibodies were generated to probe for the protein in egg envelope samples and reactivity was found to a glycoprotein of approximately 80 kDa. When deglycosylated egg envelope samples were probed, a 32 kDa protein was labeled, confirming the size of the translated cDNA sequence. A BLAST analysis showed that it is most closely related (34% amino acid identity) to the ZP domains of mammalian tectorin, uromodulin and ZPA. From a dendrogram of known egg envelope glycoproteins, the new glycoprotein was shown to be unique among egg envelope components and was designated ZPD. A similar glycoprotein was identified by immunocrossreactivity in Xenopus tropicalis and Xenopus borealis egg envelopes.
- Published
- 2002
- Full Text
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42. A hatching enzyme substrate in the Xenopus laevis egg envelope is a high molecular weight ZPA homolog.
- Author
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Lindsay LL, Wallace MA, and Hedrick JL
- Subjects
- Amino Acid Sequence, Animals, Base Sequence, Female, In Situ Hybridization, Molecular Sequence Data, Oocytes chemistry, Ovary cytology, Sequence Alignment, Xenopus laevis, Oocytes cytology, Zona Pellucida chemistry
- Abstract
The Xenopus laevis egg envelope is composed of six or more glycoproteins, three of which have been cloned and identified as the mammalian homologs ZPA (ZP2), ZPB (ZP1) and ZPC (ZP3). The remaining glycoproteins are a triplet of high molecular weight components that are selectively hydrolyzed by the hatching enzyme. We have isolated one of these proteins and cloned its cDNA. The mRNA for the protein was found to be expressed only in early stage oocytes, as are other envelope components. From the deduced amino acid sequence, it was indicated to be a secreted glycoprotein with a characteristic ZP domain in the C-terminal half of the molecule. The N-terminal half was unrelated to any known glycoprotein. Comparative sequence analysis of the ZP domain indicated that it was derived from an ancestor of ZPA and ZPB, with the greatest identity to ZPA. This envelope component has been designated ZPAX.
- Published
- 2001
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43. Ovochymase, a Xenopus laevis egg extracellular protease, is translated as part of an unusual polyprotease.
- Author
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Lindsay LL, Yang JC, and Hedrick JL
- Subjects
- Amino Acid Sequence, Animals, Cloning, Molecular, Endopeptidases analysis, Endopeptidases genetics, Molecular Sequence Data, Endopeptidases chemistry, Ovum enzymology, Protein Biosynthesis, Xenopus laevis metabolism
- Abstract
Ovochymase, an extracellular Xenopus laevis egg serine active-site protease with chymotrypsin-like (Phe-X) substrate specificity, is released during egg activation. Molecular cloning results revealed that ovochymase is translated as part of an unusual polyprotein proenzyme. In addition to the ovochymase protease domain at the C terminus of the deduced amino acid sequence, two unrelated serine protease domains were present, each with apparent trypsin-like (Arg/Lys-X) substrate specificity, and thus, they were designated ovotryptase1 (at the N terminus) and ovotryptase2 (a mid domain). Also, a total of five CUB domains were interspersed between the protease domains. The presence of a hydrophobic signal sequence indicated that the polyprotein was secreted. Immunolocalization and Western blot studies of all three proteases showed that they are all present in the perivitelline space of unactivated eggs, apparently as proenzymes processed away from the original polyprotein. Western blot analysis also showed that the vast majority of the proteases in ovary, eggs, and embryos were present as the proenzyme forms, suggesting that the functions of these proteases depend on very limited levels of activation.
- Published
- 1999
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44. Oviductin, the Xenopus laevis oviductal protease that processes egg envelope glycoprotein gp43, increases sperm binding to envelopes, and is translated as part of an unusual mosaic protein composed of two protease and several CUB domains.
- Author
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Lindsay LL, Wieduwilt MJ, and Hedrick JL
- Subjects
- Amino Acid Sequence, Animals, DNA, Complementary chemistry, DNA, Complementary isolation & purification, Female, Glycoproteins metabolism, Male, Molecular Sequence Data, Protein Biosynthesis, Sequence Analysis, Serine Endopeptidases chemistry, Serine Endopeptidases genetics, Serine Endopeptidases pharmacology, Sperm-Ovum Interactions drug effects, Spermatozoa physiology, Xenopus Proteins, Xenopus laevis
- Abstract
The glycoprotein envelope surrounding the Xenopus laevis egg is converted from an unfertilizable to a fertilizable form during transit through the pars recta portion of the oviduct. Envelope conversion involves the pars recta protease oviductin, which selectively hydrolyzes envelope glycoprotein gp43 to gp41. Oviductin cDNA was cloned, and sequence analysis revealed that the protease is translated as the N terminus of an unusual mosaic protein. In addition to the oviductin protease domain, a protease domain with low identity to oviductin was present, possessing an apparent nonfunctional catalytic site. Three CUB domains were also present, which are related to the mammalian spermadhesin molecules implicated in mediating sperm-envelope interactions. We propose that during post-translational proteolytic processing of the mosaic oviductin glycoprotein, the processed N-terminal protease domain is released coupled to two C-terminal CUB domains and constitutes the enzymatically active protease molecule. In functional studies, isolated coelomic egg envelopes treated with oviductin purified from the oviduct showed a dramatic increase in sperm binding. This observation established that oviductin alone was the oviductal factor responsible for converting the egg envelope to a sperm-penetrable form, via an increase in sperm binding. Trypsin mimicked oviductin's effect on envelope hydrolysis and sperm binding, demonstrating that gp43 processing is the only requirement for envelope conversion.
- Published
- 1999
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45. Characterization of neutral oligosaccharide-alditols from Xenopus laevis egg jelly coats by matrix-assisted laser desorption Fourier transform mass spectrometry.
- Author
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Tseng K, Lindsay LL, Penn S, Hedrick JL, and Lebrilla CB
- Subjects
- Animals, Borohydrides, Carbohydrate Sequence, Cesium, Molecular Sequence Data, Oligosaccharides isolation & purification, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Xenopus laevis, Oligosaccharides chemistry, Ovum chemistry
- Abstract
Neutral oligosaccharides were released by alkaline sodium borohydride reduction of the jelly coating from the South African clawed toad, Xenopus laevis. The oligosaccharides were isolated by HPLC and analyzed by matrix-assisted laser desorption ionization (MALDI)-Fourier transform mass spectrometry (FTMS). The mass spectrometry analysis allowed confirmation of 12 structures first proposed by Strecker et al. using nuclear magnetic resonance. In addition, seven new oligosaccharides with weak abundances were found and characterized by mass spectrometry. A method for discriminating metastable fragments from quasimolecular ions is described. It involves doping the sample with cesium chloride. Cesium-coordinated oligosaccharides do not fragment as readily as those coordinated to sodium. Tandem MS experiments are performed on an unknown oligosaccharide illustrating the potential of MALDI-collision-induced dissociation-FTMS.
- Published
- 1997
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46. Isolation and characterization of ovochymase, a chymotrypsin-like protease released during Xenopus laevis egg activation.
- Author
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Lindsay LL and Hedrick JL
- Subjects
- Amino Acid Sequence, Animals, Electrophoresis, Gel, Two-Dimensional, Endopeptidases chemistry, Endopeptidases genetics, Humans, In Vitro Techniques, Isoenzymes chemistry, Isoenzymes genetics, Isoenzymes isolation & purification, Molecular Sequence Data, Molecular Weight, Sequence Homology, Amino Acid, Vitelline Membrane enzymology, Xenopus laevis, Endopeptidases isolation & purification, Oocytes enzymology
- Abstract
A chymotrypsin-like protease contained in the perivitelline space of unactivated Xenopus eggs is released during egg activation and appears to participate in vitelline envelope conversion. This 30-kDa protease, which we have termed ovochymase, was isolated from the exudate of activated eggs using a soy bean trypsin inhibitor-agarose affinity column. The column eluant contained only two proteins, the 30-kDa ovochymase plus a 78-kDa chymotrypsin-like proteolytic activity. The 78-kDa protease was not usually observed in fresh egg exudate samples and thus was activated during the purification process and may represent the proposed precursor of the 30-kDa protease. The 30- and 78-kDa proteases were separated by gel filtration HPLC or by SDS-PAGE. The N-terminal amino acid sequence of SDS-PAGE-isolated ovochymase was determined to be VVGGQQAAPR. This conserved amino acid sequence, plus active site specific inhibition and substrate specificity studies, places ovochymase in the serine protease I family of enzymes. A two-dimensional protease activity gel revealed that ovochymase is present as several isozymes with a wide range of pI's.
- Published
- 1995
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47. Localization of a chymotrypsin-like protease to the perivitelline space of Xenopus laevis eggs.
- Author
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Lindsay LL, Larabell CA, and Hedrick JL
- Subjects
- Animals, Cell Membrane ultrastructure, Female, Male, Ovum ultrastructure, Vitelline Membrane ultrastructure, Xenopus laevis, Chymotrypsin analysis, Endopeptidases analysis, Ovum enzymology, Sperm-Ovum Interactions, Vitelline Membrane enzymology
- Abstract
A chymotrypsin-like protease is released from Xenopus laevis eggs at activation and is involved in conversion of the vitelline envelope to the fertilization envelope. To localize this enzyme in unactivated and activated eggs, we used the synthetic peptide substrate succinylalanylalanylprolylphenylalanyl-4-methoxy-2-naphthylamide whose product can be visualized using transmission electron microscopy. Protease product was localized within the perivitelline space of unactivated eggs, appearing as strings of beads. No protease activity was detected in activated eggs, which is consistent with the observation that the protease is released from the egg at activation.
- Published
- 1992
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48. Extracellular Mg2+ induces an intracellular Ca2+ wave during oocyte activation in the marine shrimp Sicyonia ingentis.
- Author
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Lindsay LL, Hertzler PL, and Clark WH Jr
- Subjects
- Animals, Decapoda, Female, Fertilization, Calcium metabolism, Magnesium pharmacology, Oocytes metabolism
- Abstract
In contrast to most systems in which oocyte activation is triggered by the fertilizing sperm, Sicyonia ingentis oocytes are activated by seawater Mg2+ during spawning. S. ingentis oocytes were spawned into Mg(2+)-free seawater and microinjected with the fluorescent Ca2+ indicator Fluo-3 to study the effects of added Mg2+ on intracellular Ca2+ levels. The Mg2+ induced a wave of fluorescence across the oocyte that traveled at a speed of 13 +/- 3 microns/sec. Extracellular Ca2+ was not required for induction of the wave. Treatment with Ca2+ ionophore in Mg(2+)-free medium or a localized injection (0.3% oocyte volume) of 3-5 microM Ca2+ also initiated the wave; injection of 250 mM Mg2+ (up to 1.5% oocyte volume) had no effect. Microinjection of 750 microM EGTA (final) suppressed the Mg(2+)-induced wave, while an identical concentration of EDTA had no inhibitory effect. Subsequent to the initial Mg(2+)-induced intracellular Ca2+ increase, a second Ca2+ increase was observed at approximately 15 min postspawning; the timing of this second increase appeared to be independent of when the Mg(2+)-induced wave was initiated, thus an event associated with spawning may be involved. While oocytes in normal seawater were monospermic, those in Mg(2+)-free seawater were polyspermic, suggesting a role for the Mg(2+)-induced Ca2+ wave in regulating sperm entry into the oocyte.
- Published
- 1992
- Full Text
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49. Preloading of micromolar intracellular Ca2+ during capacitation of Sicyonia ingentis sperm, and the role of the pHi decrease during the acrosome reaction.
- Author
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Lindsay LL and Clark WH Jr
- Subjects
- Acrosome physiology, Animals, Calcium Channels metabolism, Decapoda, Female, Hydrogen-Ion Concentration, Male, Acrosome metabolism, Calcium metabolism, Sperm Capacitation
- Abstract
In studying the mechanism controlling the sperm acrosome reaction (AR) in the marine shrimp Sicyonia ingentis, intracellular Ca2+ and pH were measured using the fluorescent indicators Fura-2 and Fluo-3 for Ca2+, and SNARF-1 for pH. Capacitated sperm possessed an apparent resting Ca2+ concentration of 1-2 microM which remained constant upon induction of the AR with egg water. Uncapacitated sperm had extremely low Ca2+ levels and did not respond to egg water. These results suggest that, while in other species the Ca2+ is elevated to micromolar levels during initiation of the AR, S. ingentis sperm are preloaded with Ca2+ during capacitation and the trigger for the AR is downstream of the Ca2+ increase. The notion that Ca2+ influx is not involved at the actual time of the AR in capacitated S. ingentis sperm is supported by the inability of Ca2+ ionophore A23187 to induce the AR and the ineffectiveness of Ca2+ channel antagonists to block egg water-induced AR. Measurements of capacitated sperm pH showed a significant decrease during the first 10-15 min of the AR, which did not correlate temporally to either acrosomal exocytosis (at 5 min post-induction) or filament formation (after 45 min). Inhibition of egg protease activity required for induction of filament formation did not inhibit the pH drop, indicating that intracellular acidification is not the final trigger for filament formation, although it may be required prior to action of the protease.
- Published
- 1992
- Full Text
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50. Protease-Induced Formation of the Sperm Acrosomal Filament.
- Author
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Lindsay LL and Clark WH Jr
- Abstract
Filament extension during the sperm acrosome reaction in Sicyonia ingentis is triggered by an egg trypsin-like protease whose action can be mimicked using trypsin. Using biotinylated trypsin and either a fluorescently-labeled or colloidal gold-labeled antibody to biotin, trypsin binding was localized to the anterior granule of the sperm which is exposed upon acrosomal exocytosis. The binding was to proteinaceous material at the base of the granule juxtaposed to the inner acrosomal membrane. Other labeled proteins also bound in the same pattern but only in the presence of unlabeled trypsin; non-proteolytic proteins did not induce filament formation. Binding of all proteins tested occurred slowly over a period of about 30 min. A minimum of 30 min of trypsin exposure was required in order to trigger filament formation, and increasing trypsin concentration did not reduce this time requirement. These results indicate that the protease slowly uncovers a binding site for itself (or other proteins), and then its proteolytic activity is again required to induce filament formation. The protease kallikrein appeared to be a more potent inducer than trypsin, while thrombin and clostripain had no apparent inducing activity.
- Published
- 1992
- Full Text
- View/download PDF
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