Care and services partnership in Quebec birthing centres: myth or reality?

CONTEXT: Working with women to best meet their needs has always been central to midwifery in Quebec, Canada. The creation of birthing centres at the end of the 1990s consolidated this desire to prioritize women's involvement in perinatal care and was intended to encourage the establishment of a care and services partnership between care providers and users. The aim of this pilot study is to evaluate the perceptions of clients, midwives and birth assistants of the way in which women are involved in partnership working in Quebec birthing centres. METHODS: A single qualitative case and pilot study was conducted with midwives (n = 5), birth assistants (n = 4), a manager (n = 1), clients (n = 5) and members of the users' committee (n = 2) at a birthing centre in Quebec, Canada in July and August 2023. The partnership was evaluated using the dimensions of a validated CADICEE questionnaire. RESULTS: The women and professionals stressed that the relationship was established in a climate of trust. The caregivers also attached importance to autonomy, information sharing and decision-making, adaptation to context, empathy and recognition of the couple's expertise. The women confirmed that they establish a relationship of trust with the professionals when the latter show empathy and that they adapt the follow-up to their knowledge and life context. Key factors in establishing this kind of care relationship are the time given, a de-medicalized environment, the comprehensive care received, and professionals who are well-informed about the partnership. In addition, the birthing centre has a users' committee that can put forward ideas but has no decision-making powers. CONCLUSIONS: Both the women and the professionals at the birthing centre appear to be working in partnership. However, at the organizational level, the women are not involved in decision-making. A study of all birthing centres in Quebec would provide a more comprehensive picture of the situation.

Integrating accompanying patients into clinical oncology teams: limiting and facilitating factors.

OBJECTIVES: Since 2018, four establishments in Quebec have been instrumental in implementing the PAROLE-Onco program, which introduced accompanying patients (APs) into healthcare teams to improve cancer patients' experience. APs are patient advisors who have acquired specific experiential knowledge related to living with cancer, using services, and interacting with healthcare professionals. They are therefore in a unique and reliable position to be able to provide emotional, informational, cognitive and navigational support to patients who are dealing with cancer. We aimed to explore APs' perspectives regarding the limiting and facilitating factors in terms of how they are integrated into the clinical oncology teams. METHODS: A qualitative study based on semi-structured interviews and focus groups was conducted with 20 APs at the beginning of their intervention (T1) and, two years later, during a second data collection (T2). Limiting and facilitating factors of APs' integration into clinical teams were analyzed in terms of governance, culture, resources and tools. RESULTS: The limited factors raised by APs to be integrated into clinical teams include the following: confusion about the specific roles played by APs, lifting the egos of certain professionals who feel they are already doing what APs typically do, lack of identification of patient needs, absence of APs in project governance organizational boundaries, and team members' availability. Various communication challenges were also raised, resulting in the program being inadequately promoted among patients. Also mentioned as limiting factors were the lack of time, space and compensation. Creating opportunities for team members to meet with APs, building trust and teaching team members how APs' activities complement theirs were enhancing factors. Other facilitators include APs being involved in decision-making committees, being leaders in promoting the PAROLE-Onco program to patients and clinical team members and creating opportunities to communicate with team members to help enhance their work and provide feedback to improve patient services. Awareness of APs' added value for the team and patients is also a key facilitator. Regarding tools, offering accompanying services by telephone allows both patients and APs to benefit from the flexibility they need. CONCLUSION: Over time, APs were able to identify optimal factors for successful implementation. Recommendations include APs and professionals working in co-construction on organization, leadership, resources and status factors. This could help catalyze a change in culture within health establishments and allow people dealing with cancer to benefit from the experiential knowledge of other patients within their clinical team.

An exploratory cross-sectional study of the effects of ongoing relationships with accompanying patients on cancer care experience, self-efficacy, and psychological distress.

BACKGROUND: Centre hospitalier de l'Université de Montréal in Canada introduced accompanying patients (APs) into the breast cancer care trajectory. APs are patients who have been treated for breast cancer and have been integrated into the clinical team to expand the services offered to people affected by cancer. This study describes the profiles of the people who received the support and explores whether one-offs vs ongoing encounters with APs influence their experience of care, on self-efficacy in coping with cancer, and on their level of psychological distress. METHODS: An exploratory cross-sectional study was carried out among patients to compare patients who had one encounter with an AP (G1) with those who had had several encounters (G2). Five questionnaires were administered on socio-demographic characteristics, care pathway, evaluation of the support experience, self-efficacy in coping with cancer, and level of psychological distress. Logbooks, completed by the APs, determined the number of encounters. Linear regression models were used to evaluate the associations between the number of encounters, patient characteristics, care pathway, number of topics discussed, self-efficacy measures in coping with cancer, and level of psychological distress. RESULTS: Between April 2020 and December 2021, 60% of 535 patients who were offered support from an AP accepted. Of these, one hundred and twenty-four patients participated in the study. The study aimed to recruit a minimum of 70 patients with the expectation of obtaining at least 50 participants, assuming a response rate of 70%. There were no differences between G1 and G2 in terms of sociodemographic data and care pathways. Statistical differences were found between G1 and G2 for impacts on and the return to daily life (p = 0.000), the return to the work and impacts on professional life (p = 0.044), announcement of a diagnosis to family and friends (p = 0.033), and strategies for living with treatment under the best conditions (p = 0.000). Significant differences were found on the topics of cancer (p = 0.000), genetic testing (p = 0.023), therapeutic options (p = 0.000), fatigue following treatment (p = 0.005), pain and discomfort after treatment or surgery (p = 0.000), potential emotions and their management (p = 0.000) and the decision-making processes (p = 0.011). A significant relationship was found between the two groups for patients' ability to cope with cancer (p = 0.038), and their level of psychological distress at different stages of the care pathway (p = 0.024). CONCLUSIONS: This study shows differences between one-time and ongoing support for cancer patients. It highlights the potential for APs to help patients develop self-efficacy and cope with the challenges of cancer treatment.

Accompanying patients in clinical oncology teams: Reported activities and perceived effects.

INTRODUCTION: Since 2018, four establishments in Quebec, Canada, have decided to implement the PAROLE-Onco programme, which introduced accompanying patients (APs) in healthcare teams to improve the experience of cancer patients. APs are patient advisors who have had a cancer treatment experience and who conduct consultations to complement the service offered by providing emotional, informational and educational support to patients undergoing treatments (e.g., radiotherapy, chemotherapy, surgery), mostly for breast cancer. We aimed to explore the evolution of APs' perspectives regarding their activities within the clinical oncology teams as well as the perceived effects of their intervention with patients, the clinical team and themselves. METHODS: A qualitative study based on semistructured interviews and focus groups was conducted with APs at the beginning of their intervention (T1) and 2 years afterwards (T2). The themes discussed were APs' activities and the perceived effects of their interventions on themselves, on the patients and on the clinical team. RESULTS: In total, 20 APs were interviewed. In T2, APs' activities shifted from listening and sharing experiences to empowering patients by helping them become partners in their care and felt generally more integrated into the clinical team. APs help patients feel understood and supported, alleviate stress and become partners in the care they receive. They also alleviate the clinical team's workload by offering a complementary service through emotional support, which, according to them, helps patients feel calmer and more prepared for their appointments with healthcare professionals. They communicate additional information about their patients' health journey, which makes the appointment more efficient for healthcare professionals. When APs accompany patients, they feel as if they can make a difference in patients' lives. Their activities are perceived by some as an opportunity to give back but also as a way of giving meaning to their own experience, in turn serving as a learning experience. CONCLUSION: By mobilizing their experiential knowledge, APs provide emotional, informational, cognitive and navigational support, which allows patients to be more empowered in their care and which complements professionals' scientific knowledge, thereby helping to refine their sensitivity to the patients' experiences. PATIENT OR PUBLIC CONTRIBUTION: Two patient-researchers have contributed to the study design, the conduct of the study, the data analysis and interpretation, as well as in the preparation and writing of this manuscript.

Patient engagement in care: A scoping review of recently validated tools assessing patients' and healthcare professionals' preferences and experience.

BACKGROUND: Patient engagement in care is a priority and a key component of clinical practice. Different approaches to care have been introduced to foster patient engagement. There is a lack of a recent review on tools for assessing the main concepts and dimensions related to patient engagement in care. OBJECTIVE: Our scoping review sought to map and summarize recently validated tools for assessing various concepts and dimensions of patient engagement in care. SEARCH STRATEGY: A scoping review of recent peer-reviewed articles describing tools that assess preferences in and experience with patient engagement in care was conducted in four databases (Ovid Medline, Ovid EMBASE, Cochrane Database of Systematic Reviews, CINAHL-EBSCO). We adopted a broad definition based on the main concepts of patient engagement in care: patient-centredness, empowerment, shared decision-making and partnership in care. MAIN RESULTS: Of 2161 articles found, 16, each describing a different tool, were included and analysed. Shared decision-making and patient-centredness are the two main concepts evaluated, often simultaneously in most of the tools. Only four scales measure patient-centredness, empowerment and shared decision-making at the same time, but no tool measures the core dimensions of partnership in care. Most of the tools did not include patients in their development or validation or just consulted them during the validation phase. DISCUSSION AND CONCLUSION: There is no tool coconstructed with patients from development to validation, which can be used to assess the main concepts and dimensions of patient engagement in care at the same time. PATIENT AND PUBLIC CONTRIBUTION: This manuscript was prepared with a patient expert who is one of the authors. Vincent Dumez, who is a patient expert and codirector of the Center of Excellence on Partnership with Patients and the Public, has contributed to the preparation of the manuscript.

Assessing and promoting partnership between patients and health-care professionals: Co-construction of the CADICEE tool for patients and their relatives.

CONTEXT: Partnership between patients and health-care professionals (HCPs) is a concept that needs a valid, practical measure to facilitate its use by patients and HCPs. OBJECTIVE: To co-construct a tool for measuring the degree of partnership between patients and HCPs. DESIGN: The CADICEE tool was developed in four steps: (1) generate key dimensions of patient partnership in clinical care; (2) co-construct the tool; (3) assess face and content validity from patients' and HCPs' viewpoints; and (4) assess the usability of the tool and explore its measurement performance. RESULTS: The CADICEE tool comprises 24 items under 7 dimensions: 1) relationship of Confidence or trust between the patient and the HCPs; 2) patient Autonomy; 3) patient participation in Decisions related to care; 4) shared Information on patient health status or care; 5) patient personal Context; 6) Empathy; and 7) recognition of Expertise. Assessment of the tool's usability and measurement performance showed, in a convenience sample of 246 patients and relatives, high face validity, acceptability and relevance for both patients and HCPs, as well as good construct validity. CONCLUSIONS: The CADICEE tool is developed in co-construction with patients to evaluate the degree of partnership in care desired by patients in their relationship with HCPs. The tool can be used in various clinical contexts and in different health-care settings. PATIENT OR PUBLIC CONTRIBUTION: Patients were involved in determining the importance of constructing this questionnaire. They co-constructed it, pre-tested it and were part of the entire questionnaire development process. Three patients participated in the writing of the article.

Measurements of Arsenic in the Urine and Nails of Individuals Exposed to Low Concentrations of Arsenic in Drinking Water From Private Wells in a Rural Region of Québec, Canada.

Chronic exposure to inorganic arsenic leads to an increased risk of cancer. A biological measurement was conducted in 153 private well owners and their families consuming water contaminated by inorganic arsenic at concentrations that straddle 10 µg/L. The relationship between the external dose indicators (concentration of inorganic arsenic in wells and daily well water inorganic arsenic intake) and the internal doses (urinary arsenic--sum of As(III), DMA, and MMA, adjusted for creatinine--and total arsenic in toenails) was evaluated using multiple linear regressions, controlling for age, gender, dietary sources of arsenic, and number of cigarettes smoked. It showed that urinary arsenic was associated with concentration of inorganic arsenic in wells (p < .001) and daily well water inorganic arsenic intake (p < .001) in adults, and with daily well water inorganic arsenic intake (p = .017) and rice consumption (p = .022) in children (n = 43). The authors' study reinforces the drinking-water quality guidelines for inorganic arsenic.

Telehealth-Delivered Program and Accompanying Patients to Enhance the Clinical Condition of Patients Throughout a Liver Transplant: Protocol for a Mixed Methods Study.

BACKGROUND: Liver transplantation (LT) is indicated in patients with severe acute or chronic liver failure for which no other therapy is available. With the increasing number of LTs in recent years, liver centers worldwide must manage their patients according to their clinical situation and the expected waiting time for transplantation. The LT clinic at the Centre hospitalier de l'Université de Montréal (CHUM) is developing a new health care model across the entire continuum of pre-, peri-, and posttransplant care that features patient monitoring by an interdisciplinary team, including an accompanying patient; a digital platform to host a clinical plan; a learning program; and data collection from connected objects. OBJECTIVE: This study aims to (1) evaluate the outcomes following the implementation of a patient platform with connected devices and an accompanying patient, (2) identify implementation barriers and facilitators, (3) describe service outcomes in terms of health outcomes and the rates and nature of contact with the accompanying patient, (4) describe patient outcomes, and (5) assess the intervention's cost-effectiveness. METHODS: Six types of participants will be included in the study: (1) patients who received transplants and reached 1 year after transplantation before September 2023 (historical cohort or control group), (2) patients who will receive an LT between December 2023 and November 2024 (prospective cohort/intervention group), (3) relatives of those patients, (4) accompanying patients who have received an LT and are interested in supporting patients who will receive an LT, (5) health care professionals, and (6) decision makers. To describe the study sample and collect data to achieve all the objectives, a series of validated questionnaires, accompanying patient logbooks, transcripts of interviews and focus groups, and clinical indicators will be collected throughout the study. RESULTS: In total, 5 (steering, education, clinical-technological, nurse prescription, and accompanying patient) working committees have been established for the study. Recruitment of patients is expected to start in November 2023. All questionnaires and technological platforms have been prepared, and the clinicians, stakeholders, and accompanying patient personnel have been recruited. CONCLUSIONS: The implementation of this model in the trajectory of LT recipients at the CHUM may allow for better monitoring and health of patients undergoing transplantation, ultimately reducing the average length of hospital stay and promoting better use of medical resources. In the event of positive results, this model could be transposed to all transplant units at the CHUM and across Quebec (potentially affecting 888 patients per year) but could also be applied more widely to the monitoring of patients with other chronic diseases. The lessons learned from this project will be shared with decision makers and will serve as a model for other initiatives involving accompanying patients, connected objects, or digital platforms. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/54440.

Reducing social isolation during the COVID-19 pandemic: Assessing the contribution of courtesy phone calls by volunteers.

CONTEXT: During the COVID-19 pandemic, restrictions were imposed on visits in hospitals in the province of Quebec, Canada in an effort to reduce the risk of viral exposure by minimizing face-to-face contact in order to protect patients, visitors and staff. These measures led to social isolation for patients. In order to reduce this isolation, CHUM (the Centre hospitalier de l'Université de Montréal, a teaching hospital) shifted from in-person visits to courtesy telephone calls delivered by volunteers from CHUM's Volunteers, Recreation and Leisure Department. OBJECTIVES: To study: (1) the contribution made by these calls to reducing isolation and their limitations, (2) how the calls can be improved, and (3) whether they should be maintained, based on the views of patients and volunteers. METHODOLOGY: This study examined two populations. The first one consisted of 189 adult patients hospitalized at CHUM who received a courtesy phone call from a volunteer and the second one consisted of the 25 CHUM volunteers who made these calls. Quantitative data were collected from patients and volunteers through questionnaires and a Smartsheet. The patient questionnaire evaluated isolation, the courtesy phone calls, the relationship of trust with the volunteer and sociodemographic questions. The volunteer questionnaire evaluated the appropriateness of the technology for the intervention, the support and training received, the impacts of the courtesy phone call on both the patients and the volunteers, an experience report and sociodemographic information. In addition, a focus group was held with 7 volunteers. Then the verbatim were transcribed and analyzed using QDA miner software. RESULTS: From April 27, 2020 to September 5, 2020 more than 11,800 calls were made, mainly concerning hospitalization conditions or home follow-ups (n = 83), and relationships with relatives, friends, and family (n = 79). For 73.6% of hospitalized patients, the courtesy calls from volunteers were a good response to their needs, and 72% of volunteers agreed. 64.5% of patients felt less isolated and 40% of volunteers felt useful. CONCLUSION: Our data suggest that patients felt less isolated during their hospitalization because of the courtesy calls made by the volunteers, that smartphones could also be used for video calls and, finally, that maintaining this type of service seems as relevant after as during a pandemic to provide social interactions to people isolated for medical reasons.

Healthcare Professional Perspectives on the Use of Remote Patient-Monitoring Platforms during the COVID-19 Pandemic: A Cross-Sectional Study.

The COVID-19 pandemic created an urgent need to act to reduce the spread of the virus and alleviate congestion in healthcare services, protect health professionals, and help them maintain satisfactory quality and safety of care. Remote monitoring platforms (RPM) emerged as potential solutions. In this study, we evaluate, from health professionals' perspectives, the capacity and contribution of two different digital platforms to maintain quality, safety, and patient engagement in care. A cross-sectional study was conducted using a survey in which a total of 491 health professionals participated. The results show that, in general, user perceptions of the quality and safety of care provided through the platforms were positive. The ease of access to health professionals' services in general and shorter waiting times for patients were the two main features that were highly appreciated by most participants. However, some problems were encountered during the use of these two platforms, such as a lack of training and/or direct support for users. To improve the two platforms and maximize their use, the areas for improvement and the issues identified should be addressed as part of a collaborative process involving health professionals and patients as well as health system leaders, decision-makers, and digital platform providers.

Repeated measures of validated and novel biomarkers of exposure to polycyclic aromatic hydrocarbons in individuals living near an aluminum plant in Quebec, Canada.

A longitudinal biomonitoring study was conducted to assess exposure to polycyclic aromatic hydrocarbons (PAH) in non-occupationally exposed nonsmoking adults living in the vicinity of an aluminum plant. Metabolites of several PAH (pyrene, naphthalene, chrysene, fluoranthene, benz[a]anthracene) were measured in the urine of the participants, including 1-hydroxypyrene (1-OHP) as a validated biomarker and pyrene diones as novel biomarkers. In total, 73 individuals living about 1 km away from the plant (taken as the exposed group) were compared repeatedly with 71 individuals living at least 11 km from the smelter (used as the control group). Complete first morning voids were collected twice, at a 2-wk interval, in the fall of 2005 and twice weekly for 2 consecutive weeks in the spring of 2006. Urinary biomarker concentrations were then measured by an ultra-performance liquid chromatography (UPLC) method with time-of-flight mass spectrometry detection (MS-TOF) (UPLC-MS-TOF). For most sampling days, individuals living near the plant showed significantly higher excretion values of both 1-OHP and pyrene diones (mean ratio up to 2- and 2.4-fold, respectively) than individuals living further from the plant. In the group living near the plant, geometric mean concentrations of 1-OHP varied from 0.047 to 0.058 micromol/mol creatinine, depending on the sampling day, as compared to 0.025 to 0.04 micromol/mol creatinine in the reference group. Corresponding mean values for pyrene diones were 0.017-0.056 micromol/mol creatinine and 0.014-0.039 micromol/mol creatinine, respectively. Urinary 1- and 2-naphthols were also measured as a reference and showed no significant differences between the two groups for most sampling days; metabolite concentrations of the other monitored PAH (chrysene, fluoranthene, benz[a]anthracene) were mostly below the analytical limit of detection of 0.005 to 0.01 microg/L, depending on the metabolite, with a detection rate varying from 0 to at most 21%. Individuals living near the aluminum plant thus appeared to be repeatedly exposed to higher pyrene levels than the control group, on the basis of both 1-OHP and pyrene dione excretions. However, 1-OHP concentrations observed in this first group were similar to those of other reference populations of nonsmokers studied in the past. Uptake of the other PAH associated with plant emissions was too small to significantly increase the excretion of their metabolites.

Biomarkers of cadmium, lead and mercury exposure in relation with early biomarkers of renal dysfunction and diabetes: Results from a pilot study among aging Canadians.

Cadmium (Cd), lead (Pb) and mercury (Hg) are known nephrotoxicants that have been associated with the risk of developing type-2 diabetes (T2D). The aim of this pilot study was to explore relations between biomarkers of Cd, Pb and Hg exposure, early urinary biomarkers of renal dysfunction (kidney-injured molecule-1 (KIM-1), N-acetylglucosaminidase and retinol-binding protein (RBP)) and plasma biomarkers deemed predictive of the risk of developing T2D (adiponectin, leptin, branched-chain and aromatic amino acids), among 70 participants (age range: (46-87 yrs)) from the Canadian Longitudinal Study on Aging (CLSA) with normal glycemic control (glycated haemoglobin ≤ 6.5%) in all but four of them. Significant (p < 0.05) Spearman correlation coefficients were obtained between: plasma adiponectin and RBP (r = 0.42), urinary Cd (r = 0.32), blood Cd (r = 0.36); KIM-1 and CdU (r = 0.33) as well as HgU (r = 0.37); RBP and isoleucine (r = -0.28), leucine (r = -0.33), tyrosine (r = -0.3) and valine (r = -0.44); CdU and isoleucine and valine (r = -0.27 for both). Multiple linear regression analyses showed that some T2D-related biomarkers are confounders of associations between RBP and Hg or Cd biomarkers. Path analyses support a mediating effect of adiponectin on the relation between urinary Cd and RBP. Concluding, this pilot study originally investigated a comprehensive set of biomarkers on complex interactions between toxic metal exposure, renal function and T2D in a group of aging Canadians. Its findings warrant further investigation of longitudinal data in a greater number of participants.

WITHDRAWN: Corrigendum to "Biomarkers of cadmium, lead and mercury exposure in relation with early biomarkers of renal dysfunction and diabetes: Results from a pilot study among aging Canadian" [Toxicol. Lett. 312 (2019) 148-156].

The Publisher regrets that this article is an accidental duplication of an article that has already been published, https://doi.org/10.1016/j.toxlet.2019.05.020. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

Human health risk assessment on the consumption of fruits and vegetables containing residual pesticides: A cancer and non-cancer risk/benefit perspective.

Pesticide residues in food is a public health concern. This study aimed to evaluate health risk and benefit associated with chronic consumption of fruits and vegetables (F&V) containing residual pesticides in the province of Quebec, Canada. Based on a representative sample of Quebecers (n=4727, aged 1-79) enrolled in the Canadian nutrition survey, population's mean chronic dietary exposure through consumption of F&V was evaluated for 169 different pesticide active ingredients (PAI), including 135 for which toxicological reference values (TRV) were available in the literature. Total lifetime cancer risk was estimated to be 3.3×10-4 considering the 28 substances for which an oral slope factor was also available. Non-cancer risk quotients greater than 1 were obtained at the 95th percentile of children's exposure for 10 of the 135 PAIs, and considering the most severe pesticide-specific TRV. Dithiocarbamates and imazalil are the authorized PAI that contribute the most to cancer and non cancer risk; they are therefore identified as "priority" PAI. For each estimated case of cancer triggered by PAI exposure, at least 88 cases were deemed prevented by the consumed F&V, based on the population's etiological fraction of the cancer risk that F&V prevent. Concluding, chronic health risks investigated are low and health benefits of F&V consumption by far outweigh the PAI-related risk. However, risk estimates are not negligeable and uncertainties remain. Thus, reducing PAI exposure through F&V consumption with a particular focus on "priority" PAI mentionned above, while maintaining an abundant and varied F&V diet, is desirable.

Alzheimer type II astrocytic changes following sub-acute exposure to manganese and its prevention by antioxidant treatment.

Exposure to manganese in an industrial or clinical setting can lead to manganism, a neurological disorder with similarities to Parkinson's disease. Although the pathogenetic basis of this disorder is unclear, studies indicate this metal is highly accumulated in astrocytes, suggesting an involvement of these glial cells. To investigate this issue, we have used a recently characterized, sub-acute model of manganese neurotoxicity. Treatment of rats with manganese (II) chloride (50 mg/kg body weight, i.p.) once daily for 1 or 4 days led to increases in manganese levels of up to 232, 523, and 427% in the cerebral cortex, globus pallidus, and cerebellum, respectively, by instrumental neutron activation analysis. These changes were accompanied by development of pathological changes in glial morphology identified as Alzheimer type II astrocytosis in both cortical and sub-cortical structures. Co-treatment with either the antioxidant N-acetylcysteine or the manganese chelator 1,2-cyclohexylenedinitrilotetraacetic acid completely blocked this pathology, indicating the cellular transformation may be mediated by oxidative stress associated with the presence of this metal. These findings represent, to our knowledge, the first report of early induction of this pathological hallmark of manganese neurotoxicity, an event previously considered a consequence of chronic exposure to manganese in primates and in human cases of manganism. Our results also indicate that use of this rodent model may provide a novel opportunity to examine the nature and role of the Alzheimer type II astrocyte in the pathophysiology of this disorder as well as in other disease processes in which cerebral accumulation of manganese occurs.

Upregulation of 'peripheral-type' benzodiazepine receptors in the globus pallidus in a sub-acute rat model of manganese neurotoxicity.

Manganese neurotoxicity (MN) is a neurological disorder characterized by selective neuronal loss in the globus pallidus together with characteristic morphological changes known as Alzheimer type II astrocytosis. In order to understand the underlying mechanisms responsible for these processes, we studied early effects of this metal in a sub-acute rat model. Levels of manganese in the globus pallidus were increased by 81% after 1 day of treatment and elevated by 551% compared to controls after 4 days. In addition, manganese treatment led to a 60% increase in ptbr expression, and a 105% increase in levels of its product, the isoquinoline-carboxamide binding protein, a major constituent of the 'peripheral-type' benzodiazepine receptor (PTBR) that is localized to astrocytes, in this brain region after 4 days. These results indicate that PTBRs, and possibly neurosteroids, are an early response to manganese exposure and may play a major role in the pathophysiology of MN.

Manganese distribution in the brain and neurobehavioral changes following inhalation exposure of rats to three chemical forms of manganese.

The central nervous system is an important target for manganese (Mn) intoxication in humans; it may cause neurological symptoms similar to Parkinson's disease. Manganese compounds emitted from the tailpipe of vehicles using methylcyclopentadienyl manganese tricarbonyl (MMT) are primarily Mn phosphate, Mn sulfate, and Mn phosphate/sulfate mixture. The purpose of this study is to compare the patterns of Mn distribution in various brain regions (olfactory bulb, frontal parietal cortex, globus pallidus, striatum and cerebellum) and other tissues (lung, liver, kidney, testis) and the neurobehavioral damage following inhalation exposure of rats to three Mn species. Rats (n=15 rats per Mn species) were exposed 6 h per day, 5 days per week for 13 consecutive weeks to metallic Mn, Mn phosphate or Mn phosphate/sulfate mixture at about 3000 microgm(-3) and compared to controls. At the end of the exposure period, spontaneous motor activity was measured for 36 h using a computerized autotrack system. Mn in tissues was determined by instrumental neutron activation analysis (INAA). The Mn concentrations in the brain were significantly higher in rats exposed to Mn phosphate and Mn phosphate/sulfate mixture than in control rats or rats exposed to metallic Mn. Exposure to Mn phosphate/sulfate mixture caused a decrease in the total ambulatory count related to locomotor activity. Our results confirm that Mn species and solubility have an influence on the brain distribution of Mn in rats.

Human exposure to respirable manganese in outdoor and indoor air in urban and rural areas.

Methylcyclopentadienyl manganese tricarbonyl (MMT), is an additive in gasoline, and its combustion leads to the emission of Mn particles, which increase atmospheric metal concentrations. The objective of this study was to determine the level of outdoor and indoor respirable Mn (MnR) in Montreal, Canada, where MMT has been used since 1976. Ten women were involved in this study: five living in an urban area, near an expressway with high traffic density, and five residing in a rural area characterized by low traffic density. Outdoor and indoor air samples were collected each week (5 in total) during 3 consecutive days; blood samples were collected at the end of the air sampling period. The average concentration of outdoor MnR in the urban area was 0.025 microg/m3, which is significantly different from the average of 0.005 microg/m3 found in the rural area. The average indoor MnR concentration was also significantly different from teh average MnR indoor concentrations within both areas. The mean blood Mn concentrations were not significantly different between the urban area (0.017 microg/m3) and the rural area (0.007 microg/m3). The average outdoor MnR concentrations within both areas. The mean blood Mn concentrations were not significantly different between the two groups. Data suggest that a high outdoor atmospheric MnR leads to a high indoor MnR, but not to an increase in blood Mn levels.

Manganese neurotoxicity: behavioral, pathological, and biochemical effects following various routes of exposure.

The human central nervous system is an important target for manganese intoxication, which causes neurological symptoms similar to those of Parkinson's disease. With the increasing use of methylcyclopentadienyl manganese tricarbonyl (MMT) as an octane-improving additive to unleaded gasoline, the prospect of worldwide manganese exposure is once again attracting attention as increases in environmental manganese concentrations have been recorded relative to traffic density. One crucial question is whether a small increase of manganese contamination resulting from the widespread use of MMT could have neurotoxic effects. In this review we concentrate on central nervous system abnormalities and neurobehavioral disturbances. Most experimental animal studies on manganese neurotoxicity have been conducted in nonhuman primates and rodents. Most studies performed in rodents used oral manganese administration and did not assess bioaccumulation or central nervous system changes. The major effect found was transient modification of spontaneous motor activity. Very few inhalation toxicological studies were carried out. As manganese intoxication in humans usually occurs via inhalation, more studies are required using the respiratory route of administration. Given the proven neurotoxic effects of manganese and the prospect of worldwide MMT usage, this metal should be considered a new environmental pollutant having potentially widespread public health consequences.

Total suspended particulate manganese in ambient air in Montreal 1981-2000.

Our research group previously established the time variation of atmospheric Mn in Montreal for the period 1981-1992. The results indicated stable Mn concentrations between 1981 and 1990 followed by a decrease of almost 50% attributed to the closing of a ferromanganese plant located approximately 25 km from Montreal. The aim of this study is to assess the atmospheric concentrations of Mn in Montreal between 1993 and 2000, to compare these data to those for the period 1981-1992, and to evaluate the presence of any trend. Three sampling stations belonging to the Montreal Urban Community (MUC) air quality surveillance network were selected. Filters from 1993 to 2000 were obtained from the MUC archives. The first sample of each month was selected and chemical analysis was performed by neutron activation analysis. The mean annual atmospheric Mn concentrations in Montreal from 1993 to 2000 were found to be very stable. The mean Mn concentration calculated for this time period was 0.01 microg/m(3) for station 99 (characterized by a low traffic density), which was significantly different (P<0.05) from the mean of 0.03 microg/m(3) for stations 13 and 68 which had higher traffic densities. Even though Mn represented a small percentage of the TSP (varying between 0.02% and 0.14%), the comparison between Mn and TSP is interesting since the stable temporal profile of Mn since 1993 contrasts with the continuously decreasing atmospheric TSP concentrations. This observation suggests that the combustion of MMT used in gasoline could be contributing to maintaining stable atmospheric Mn levels.