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Clinical HIV outcome trajectories associated with a history of child protective service out-of-home care: Longitudinal cohort findings with women living with HIV in Canada. HIV Med 2024. [PMID: 38757480 DOI: 10.1111/hiv.13660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Accepted: 04/29/2024] [Indexed: 05/18/2024]
Abstract
OBJECTIVES Knowledge gaps exist regarding the effects of experiencing child protective services (CPS) out-of-home care (e.g. foster homes) among women with HIV. We examined whether CPS out-of-home care was associated with HIV clinical outcome trajectories among women with HIV in a longitudinal cohort study in Ontario, British Columbia, and Quebec, Canada. METHODS At three timepoints across 5 years (2013-2018), we examined self-reported current antiretroviral therapy (ART) use and viral load (VL) detectability (>50 copies/mL). We used latent class growth analysis (LCGA) to identify trajectories of ART use and VL outcomes across study waves. LCGA identifies subgroups (classes) with similar trajectories within the sample. We assessed whether HIV outcome trajectories could be predicted by CPS history. We then conducted a mediation analysis to test whether a mental health latent construct mediated the association between CPS history and detectable VL. RESULTS Nearly one-fifth (n = 272; 19%) of participants (n = 1422; mean age 42.8 years) reported CPS out-of-home care. Most participants (89%) were in classes that consistently used ART and had an undetectable VL. Individuals with CPS out-of-home care histories were twice as likely to have a consistently detectable VL (β = 0.72, p = 0.02); there were no differences in ART use trajectories. In mediation analyses, we found an indirect path from CPS history to a consistently detectable VL via baseline mental health status (β = 0.02, 95% confidence interval 0.005-0.04, p = 0.02), with a significant odds ratio (1.12, z = 2.43, p = 0.02). CONCLUSION Among women with HIV in Canada, experiencing childhood CPS out-of-home care was associated with a reduced likelihood of achieving viral suppression, via poorer mental health.
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Community partnership to optimize engagement in research: Reflections on the trans women HIV research initiative. Br J Clin Pharmacol 2024. [PMID: 38469905 DOI: 10.1111/bcp.16038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 02/12/2024] [Indexed: 03/13/2024] Open
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Dissemination of the Women-Centred HIV Care Model: A Multimodal Process and Evaluation. J Int Assoc Provid AIDS Care 2024; 23:23259582231226036. [PMID: 38389331 PMCID: PMC10894538 DOI: 10.1177/23259582231226036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 12/15/2023] [Accepted: 12/26/2023] [Indexed: 02/24/2024] Open
Abstract
BACKGROUND Using data from a national cohort study and focus groups, the Women-Centred HIV Care (WCHC) Model was developed to inform care delivery for women living with HIV. METHODS Through an evidence-based, integrated knowledge translation approach, we developed 2 toolkits based on the WCHC Model for service providers and women living with HIV in English and French (Canada's national languages). To disseminate, we distributed printed advertising materials, hosted 3 national webinars and conducted 2 virtual capacity-building training series. RESULTS A total of 315 individuals attended the webinars, and the average WCHC knowledge increased by 29% (SD 4.3%). In total, 131 service providers engaged in 22 virtual capacity-building training sessions with 21 clinical cases discussed. Learners self-reported increased confidence in 15/15 abilities, including the ability to provide WCHC. As of December 2023, the toolkits were downloaded 7766 times. CONCLUSIONS We successfully developed WCHC toolkits and shared them with diverse clinical and community audiences through various dissemination methods.
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HIV prevalence among a retrospective clinical cohort of transgender women in Canada: Results of the Montreal-Toronto Trans study, collected 2018-2019. Int J STD AIDS 2023; 34:1062-1071. [PMID: 37586721 DOI: 10.1177/09564624231185818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/18/2023]
Abstract
BACKGROUND HIV prevalence data among transgender (trans) people are not routinely collected in national estimates, including Canada, contributing to gender-based inequities. We examined HIV prevalence and associated factors among trans women in clinical care in two large Canadian cities. METHODS Retrospective chart data of trans women aged 16+ were collected from six family medicine and/or HIV clinics in Montreal and Toronto, Canada, 2018-2019. Multinomial logistic regression was used to analyze factors associated with documented HIV positive or missing HIV status relative to documented HIV negative status. RESULTS Among 1,059 patients, 7.5% were HIV positive, 54.4% HIV negative, and 38.1% missing HIV data. Findings showed lower odds of being HIV positive for those <30 years or 30-50 years (vs. >50 years); higher odds were seen for those: of Black race/ethnicity (vs. white), landed immigrant or refugee (vs. Canadian citizen), receiving social assistance (vs. not), and whom ever having used recreational drugs. CONCLUSIONS Albeit high, the prevalence of HIV was lower than expected based on global estimates. Missing HIV status data suggest gaps in testing. Findings highlight socioeconomic and clinical realities among trans women in Canada and inform future HIV prevention and support.
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Oestradiol concentrations in trans women with HIV suppressed on unboosted integrase inhibitor regimens versus trans women without HIV taking oral oestradiol: a pilot study. J Antimicrob Chemother 2023; 78:2653-2659. [PMID: 37681452 PMCID: PMC10631824 DOI: 10.1093/jac/dkad270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 08/15/2023] [Indexed: 09/09/2023] Open
Abstract
BACKGROUND Feminizing hormone therapy (FHT) is essential to many trans women. Concern about negative drug interactions between FHT and ART can be an ART adherence barrier among trans women with HIV. OBJECTIVES In this single-centre, parallel group, cross-sectional pilot study, we measured serum oestradiol concentrations in trans women with HIV taking FHT and unboosted integrase strand transfer inhibitor (INSTI)-based ART versus trans women without HIV taking FHT. METHODS We included trans women with and without HIV, aged ≥18 years, taking ≥2 mg/day of oral oestradiol for at least 3 months plus an anti-androgen. Trans women with HIV were on suppressive ART ≥3 months. Serum oestradiol concentrations were measured prior to medication dosing and 2, 4, 6 and 8 h post-dose. Median oestradiol concentrations were compared between groups using Wilcoxon rank-sum tests. RESULTS Participants (n = 8 with HIV, n = 7 without) had a median age of 32 (IQR: 28, 39) years. Among participants, the median oral oestradiol dose was 4 mg (range 2-6 mg). Participants had been taking FHT for a median of 4 years (IQR: 2, 8). Six trans women with HIV were taking bictegravir/emtricitabine/tenofovir alafenamide and two were taking dolutegravir/abacavir/lamivudine. All oestradiol concentrations were not significantly different between groups. Eleven (73%) participants had target oestradiol concentrations in the range 200-735 pmol/L at C4h (75% among women with HIV, 71% among those without HIV). CONCLUSIONS Oestradiol concentrations were not statistically different in trans women with HIV compared with those without HIV, suggesting a low probability of clinically relevant drug-drug interactions between FHT and unboosted INSTI-based ART.
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Feminizing hormone therapy in a Canadian cohort of transgender women with and without HIV. Antivir Ther 2023; 28:13596535231182505. [PMID: 37289725 DOI: 10.1177/13596535231182505] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
BACKGROUND Potential bidirectional drug-drug interactions between feminizing hormone therapy (FHT) and antiretroviral therapy (ART) are of concern for trans women with HIV and their healthcare providers. This study aimed to characterize patterns of FHT and ART among trans women with HIV and to compare serum hormone levels to trans women without HIV. METHODS Charts of trans women were reviewed at seven HIV primary care or endocrinology clinics in Toronto and Montreal from 2018 to 2019. ART regimens, FHT use, serum estradiol, and serum testosterone levels were compared on the basis of HIV status (positive, negative, missing/unknown). RESULTS Of 1495 trans women, there were 86 trans women with HIV, of whom 79 (91.8%) were on ART. ART regimens were most commonly integrase inhibitor-based (67.4%), many boosted with ritonavir or cobicistat (45.3%). Fewer (71.8%) trans women with HIV were prescribed FHT, compared to those without HIV (88.4%) and those with missing/unknown status (90.2%, p < 0.001). Among trans women on FHT with recorded serum estradiol (n = 1153), there was no statistical difference in serum estradiol between those with HIV (median: 203 pmol/L, IQR: 95.5, 417.5) and those with negative (200 mol/L [113, 407]) or missing/unknown HIV status (227 pmol/L [127.5, 384.5) (p = 0.633). Serum testosterone concentrations were also similar between groups. CONCLUSIONS In this cohort, trans women with HIV were prescribed FHT less often than trans women with negative or unknown HIV status. There was no difference in serum estradiol or testosterone levels of trans women on FHT regardless of HIV status, providing reassurance regarding potential drug-drug interactions between FHT and ART.
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The Impact of COVID-19 Vaccinations on Emergency Department Presentations. Emerg Med Australas 2022; 34:913-919. [PMID: 35475322 PMCID: PMC9111314 DOI: 10.1111/1742-6723.14012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 04/07/2022] [Accepted: 04/21/2022] [Indexed: 11/29/2022]
Abstract
Objective The aim of the present study was to describe the burden of patients presenting to the ED with symptoms occurring after receiving a COVID‐19 vaccination. Methods This was a retrospective cohort study performed over a 4‐month period across two EDs. Participants were eligible for inclusion if it was documented in the ED triage record that their ED attendance was associated with the receipt of a COVID‐19 vaccination. Data regarding the type of vaccine (Comirnaty or ChAdOx1) were subsequently extracted from their electronic medical record. Primary outcome was ED length of stay (LOS) and secondary outcomes included requests for imaging and ED disposition destination. Results During the study period of 22 February 2021 to 21 June 2021, 632 patients were identified for inclusion in the present study, of which 543 (85.9%) had received the ChAdOx1 vaccination. The highest proportion of COVID‐19 vaccine‐related attendances occurred in June 2021 and accounted for 21 (8%) of 262 total daily ED attendances. Patients who had an ED presentation related to ChAdOx1 had a longer median ED LOS (253 vs 180 min, P < 0.001) compared to Comirnaty and a higher proportion had haematology tests and imaging requested in the ED. Most patients (n = 588, 88.8%) were discharged home from the ED. Conclusion There was a notable proportion of ED attendances related to recent COVID‐19 vaccination administration, many of which were associated with lengthy ED stays and had multiple investigations. In the majority of cases, the patients were able to be discharged home from the ED.
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Short report: Characterizing HIV care among a clinical sample of transgender women living with HIV. HIV Med 2022; 23:324-330. [PMID: 35193172 DOI: 10.1111/hiv.13261] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 01/15/2022] [Accepted: 01/18/2022] [Indexed: 12/01/2022]
Abstract
INTRODUCTION This study aimed to characterize and identify factors associated with HIV care among transgender (trans) women living with HIV (TWLWH) in two urban centres in Canada. METHODS Retrospective data were collected from clinic charts of TWLWH aged 16 years and older across seven family medicine, endocrinology and/or HIV clinics in Montreal and Toronto, Canada, from 2018 to 2019 (n = 86). We assessed the proportion of individuals being ever engaged in HIV care [defined as having any recorded antiretroviral therapy (ART) regimen and/or viral load], current ART use, and most recent viral load (suppressed [<200 copies/ml] vs. unsuppressed) overall and compared across subgroups using χ2 tests. RESULTS All TWLWH in our sample [100.0%, 95% confidence interval (CI): 95.8-100.0%] were engaged in HIV care; most (93.0%, 95% CI: 85.4-97.4%) were currently using ART and most (93.4%, 95% CI: 85.3-97.8%) with complete data (n = 71/76) were virally suppressed. A higher proportion of trans women of colour (100.0%) reported current ART use compared with white trans women (76.9%, p = 0.017). A higher proportion of those with no documented history of injection drug use (IDU; 96.6%) were virally suppressed compared with those with a history of IDU (66.7%, p = 0.022). Although not statistically significant, 96.2% of those currently reporting feminizing hormone use were virally suppressed, compared with 85.0% of those not reporting use (p = 0.202). CONCLUSIONS Once engaged in HIV care, TWLWH in Canada appear to have excellent ART use and viral suppression. Findings can be leveraged to identify target populations to enhance HIV care and to further explore the relationship between gender-affirming medical care and HIV care.
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Development of the Canadian Women-Centred HIV Care Model Using the Knowledge-to-Action Framework. J Int Assoc Provid AIDS Care 2021; 20:2325958221995612. [PMID: 33845677 PMCID: PMC8047935 DOI: 10.1177/2325958221995612] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 12/21/2020] [Accepted: 01/04/2021] [Indexed: 01/16/2023] Open
Abstract
In Canada, women make up 25% of the prevalent HIV cases and represent an important population of those living with HIV, as a high proportion are racialized and systemically marginalized; furthermore, many have unmet healthcare needs. Using the knowledge-to-action framework as an implementation science methodology, we developed the "Women-Centred HIV Care" (WCHC) Model to address the needs of women living with HIV. The WCHC Model is depicted in the shape of a house with trauma- and violence-aware care as the "foundation". Person-centred care with attention with attention to social determinants of health and family make up the "first" floor. Women's health (including sexual and reproductive health and rights) and mental and addiction health care are integrated with HIV care, forming the "second" floor. Peer support, leadership, and capacity building make up the "roof". To address the priorities of women living with HIV in all their diversity and across their life course, the WCHC Model should be flexible in its delivery (e.g., single provider, interdisciplinary clinic or multiple providers) and implementation settings (e.g., urban, rural).
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Mental health among transgender women living with HIV in Canada: findings from a national community-based research study. AIDS Care 2020; 33:192-200. [PMID: 32172609 DOI: 10.1080/09540121.2020.1737640] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Antiretroviral therapy adherence among transgender (trans) women living with HIV (WLWH) is negatively impacted by depression and post-traumatic stress disorder (PTSD). Yet, little is known about factors associated with depression or PTSD among trans WLWH. Using cross-sectional data from a national community-based study of 1422 WLWH (n = 53 trans women), we characterized the prevalence of depressive and PTSD symptoms among trans WLWH and examined associations between factors (e.g., Trans stigma) and depressive and PTSD symptoms. Nearly half of participants reported clinically significant PTSD (45.3%) and depressive symptoms (45.3%) [mean Post-traumatic Stress Disorder Civilian Checklist Version-C score 13.8 (SD = 5.8); mean Center for Epidemiological Studies - Depression score 9.4 (SD = 8.0)]. Univariate linear regression analyses showed that <95% adherence, higher internalized HIV-related stigma, frequency of past-month hazardous alcohol use, and current injection drug use were significantly associated with both higher PTSD and depressive symptom scores, and higher resilience and social support with lower scores. A history of violence in adulthood was associated with higher depressive symptoms scores, whereas sexual relationship power and less difficulty meeting housing costs were associated with lower scores. Findings suggest a need for multi-level interventions to reduce barriers to mental wellbeing while fostering resilience and social support.
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South Asian immigrant women's suggestions for culturally-tailored HIV education and prevention programs. ETHNICITY & HEALTH 2019; 24:945-959. [PMID: 28922011 DOI: 10.1080/13557858.2017.1378806] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Accepted: 08/29/2017] [Indexed: 06/07/2023]
Abstract
Using a community-based, socialist feminist qualitative study, and an emergent research design, we explored the unique individual experiences of South Asian immigrant women living with HIV in the Greater Toronto Area (GTA) of Ontario, Canada. We assessed both the HIV risk context and the strategies for HIV education and prevention as expressed by study participants. Grounded in Connell's social theory of gender, a thematic analysis of semi-structured interviews with 12 women yielded six themes related to the power and impact of stigmatization, community's denial of HIV, infidelity, manifested in resistance to discussing sex and condom use, non-disclosure, and lack of HIV knowledge. This study validated the legitimacy of listening to the voices of South Asian immigrant women living with HIV, who communicated 20 recommendations for researchers, educators, community organizations, and service providers to culturally-tailor HIV education programs.
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Difference Within and Without: Health Care Providers' Engagement With Disability Arts. QUALITATIVE HEALTH RESEARCH 2019; 29:1287-1298. [PMID: 30451073 DOI: 10.1177/1049732318808252] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Re•Vision, an assemblage of multimedia storytelling and arts-based research projects, works creatively and collaboratively with misrepresented communities to advance social well-being, inclusion, and justice. Drawing from videos created by health care providers in disability artist-led workshops, this article investigates the potential of disability arts to disrupt dominant conceptions of disability and invulnerable embodiments, and proliferate new representations of bodymind difference in health care. In exploring, remembering, and developing ideas related to their experiences with and assumptions about embodied difference, providers describe processes of unsettling the mythical norm of human embodiment common in health discourse/practice, coming to know disability in nonmedical ways, and re/discovering embodied differences and vulnerabilities. We argue that art-making produces instances of critical reflection wherein attitudes can shift, and new affective responses to difference can be made. Through self-reflective engagement with disability arts practices, providers come to recognize assumptions underlying health care practices and the vulnerability of their own embodied lives.
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Healthcare Providers' Experiences as Arts-Based Research Participants: "I Created My Story About Disability and Difference, Now What?". Can J Nurs Res 2019; 51:255-263. [PMID: 30845830 DOI: 10.1177/0844562119835130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Little is known about the experiences of healthcare providers as research participants in qualitative studies employing methods that encourage disclosure of their own disabilities. In this paper, we describe the experiences and implications of creating personal stories of disability and difference for healthcare provider participants in an arts-based study. The study design is a supplementary secondary analysis of a subset of data from a larger study focused on transforming negative concepts of disability and difference entitled, Mobilizing New Meanings of Disability and Difference: Using Arts-Based Approaches to Advance Healthcare Inclusion for Women with Disabilities. This supplementary study explores the experiences and perspectives of 17 healthcare provider participants who completed semi-structured interviews following creation of a multi-media story about their experience of disability or difference. Using creative non-fiction methods, two narrative streams are identified about healthcare provider experiences and the impacts of participating. The first addresses shared positive experiences about the research. The second entails more ambivalent reflections on their involvement as participants. The tension between the two experiences generates considerations to forward a mutually beneficial alliance to disrupt ableist understandings in healthcare and reveals new meanings of disability that are agential and integral to the stories and storytellers themselves.
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Social contexts and HIV vulnerabilities among South Asian women in the greater Toronto area: Examining social norms. Health Care Women Int 2017; 39:129-153. [PMID: 29095127 DOI: 10.1080/07399332.2017.1397157] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
We explored how social norms interact with beliefs and social structures (power relations, emotional relations, and gendered division of labor) to influence the experiences of South Asian women with HIV in Canada. The first author conducted semi-structured interviews, and identified five themes using thematic analysis: connection to community/religious institutions, family honor, and restrained/prohibited discussion of sexuality. These norms reproduce hegemonic masculinity; constrain women's social, relational, and economic power; and elevate HIV vulnerability. We present findings to challenge hegemonic masculinity at the international level, and of developing strategies to address both interfamily gender-based violence and racism faced by the South Asians in Canada.
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Improving patient outcomes in fibrous dysplasia/McCune-Albright syndrome: an international multidisciplinary workshop to inform an international partnership. Arch Osteoporos 2017; 12:21. [PMID: 28243882 PMCID: PMC5653227 DOI: 10.1007/s11657-016-0271-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Accepted: 03/31/2016] [Indexed: 02/03/2023]
Abstract
UNLABELLED To develop consensus on improving the management of patients, we convened an international workshop involving patients, clinicians, and researchers. Key findings included the diagnostic delay and variability in subsequent management with agreement to develop an international natural history study. We now invite other stakeholders to join the partnership. PURPOSE The aim of this study was develop a consensus on how to improve the management of patients with fibrous dysplasia and prioritize areas for research METHODS: An international workshop was held over 3 days involving patients, clinicians, and researchers. Each day had a combination of formal presentations and facilitated discussions that focused on clinical pathways and research. RESULTS The patient workshop day highlighted the variability of patients' experience in getting a diagnosis, the knowledge of general clinical staff, and understanding long-term outcomes. The research workshop prioritized collaborations that improved understanding of the contemporary natural history of fibrous dysplasia/McCune-Albright syndrome (FD/MAS). The clinical workshop outlined the key issues around diagnostics, assessment of severity, treatment and monitoring of patients. CONCLUSIONS In spite of advances in understanding the genetic and molecular underpinnings of fibrous dysplasia/McCune-Albright syndrome, clinical management remains a challenge. From the workshop, a consensus was reached to create an international, multi-stakeholder partnership to advance research and clinical care in FD/MAS. We invite other stakeholders to join the partnership.
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Evaluating the costs of mosquito resistance to malaria parasites. Evolution 2005; 59:2560-72. [PMID: 16526504 PMCID: PMC1602058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Costly resistance mechanisms have been cited as an explanation for the widespread occurrence of parasitic infections, yet few studies have examined these costs in detail. A malaria-mosquito model has been used to test this concept by making a comparison of the fitness of highly susceptible lines of mosquitoes with lines that are resistant to infection. Malaria infection is known to cause a decrease in fecundity and fertility of mosquitoes; resistant mosquitoes were thus predicted to be fitter than susceptible ones. Anopheles gambiae were selected for refractoriness/resistance or for increased susceptibility to infection by Plasmodium yoelii nigeriensis. Additional lines that acted as controls for inbreeding depression were raised in parallel but not exposed to selection pressure. Selections were made in triplicate so that founder effects could be detected. Resistance mechanisms that were selected included melanotic encapsulation of parasites within 24 h postinfection and the complete disappearance of parasites from the gut. Costs of immune surveillance were assessed after an uninfected feed, and costs of immune deployment were assessed after exposure to infection and to infection and additional stresses. Mosquito survivorship was unaffected by either resistance to infection or by an increased burden of infection when compared with low levels of infection. In most cases reproductive fitness was equally affected by refractoriness or by infection. Resistant mosquitoes did not gain a fitness advantage by eliminating the parasites. Costs were consistently associated with larval production and egg hatch rate but rarely attributed to changes in blood feeding and never to changes in mosquito size. No advantages appeared to be gained by the offspring of resistant mosquitoes. Furthermore, we were unable to select for refractoriness in groups of mosquitoes in which 100% or 50% of the population were exposed to infection every generation for 22 generations. Under these selection pressures, no population had become completely refractory and only one became more resistant. Variations in fitness relative to control lines in different groups were attributed to founder effects. Our conclusion from these findings is that refractoriness to malaria is as costly as tolerance of infection.
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Abstract
The peripheral nervous system consists of multiple neural lineages derived from the neural crest (NC). Pax-3 is expressed in the NC and when mutated in the splotch mouse (Sp) results in the loss of derivatives from this precursor cell population. We have investigated the role of Pax-3 in regulating the generation of neurons from NC-derived precursor cells in vitro. Pax-3 mRNA in NC cultures is initially expressed in all NC but is subsequently only retained in neurons, suggesting a role in their generation. To determine whether Pax-3 is involved in neuron development, we first examined the generation of sensory-like neurons in NC cultures from Sp mice. Fivefold less sensory-like neurons were generated in NC cultures from Sp homozygous mice as compared to wild-type littermates. The role of Pax-3 in sensory neuron generation was then directly examined in dorsal root ganglia cultures by down-regulating the expression of Pax-3 protein with antisense oligonucleotides. It was found that antisense oligonucleotides inhibited 80-90% of newly generated sensory neurons; however, there was no significant effect on the survival of sensory neurons or the precursor population. These results suggest that Pax-3 has a role in regulating the differentiation of peripheral neurons.
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MESH Headings
- Animals
- Cell Differentiation
- Cells, Cultured
- DNA-Binding Proteins/genetics
- DNA-Binding Proteins/metabolism
- Embryo, Mammalian
- Ganglia, Spinal/cytology
- Ganglia, Spinal/embryology
- Gene Expression Regulation, Developmental/drug effects
- Genotype
- Mice
- Mice, Inbred CBA
- Mice, Neurologic Mutants
- Neural Crest/cytology
- Neurons/cytology
- Neurons/physiology
- Oligodeoxyribonucleotides, Antisense/pharmacology
- PAX3 Transcription Factor
- Paired Box Transcription Factors
- Polymerase Chain Reaction
- RNA, Messenger/genetics
- Thionucleotides
- Transcription Factors/genetics
- Transcription Factors/metabolism
- Transcription, Genetic/drug effects
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Third-Order Near-Resonance Nonlinearities in Dithiolenes and Rare Earth Metallocenes. ACTA ACUST UNITED AC 1991. [DOI: 10.1021/bk-1991-0455.ch041] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
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Use of neotropical rodents in protein efficiency studies. LABORATORY ANIMAL SCIENCE 1973; 23:499-503. [PMID: 4354701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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