Public experiences and perspectives of primary care in Canada: results from a cross-sectional survey

BACKGROUND

Through medicare, residents in Canada are entitled to medically necessary physician services without paying out of pocket, but still many people struggle to access primary care. We conducted a survey to explore people's experience with and priorities for primary care.

METHODS

We conducted an online, bilingual survey of adults in Canada in fall 2022. We distributed an anonymous link through diverse channels and a closed link to 122 053 people via a national public opinion firm. We weighted completed responses to mirror Canada's population and adjusted for sociodemographic characteristics using regression models.

RESULTS

We analyzed 9279 completed surveys (5.9% response rate via closed link). More than one-fifth of respondents (21.8%) reported having no primary care clinician, and among those who did, 34.5% reported getting a same or next-day appointment for urgent issues. Of respondents, 89.4% expressed comfort seeing another team member if their doctor recommended it, but only 35.9%, 9.5%, and 12.4% reported that their practice had a nurse, social worker, or pharmacist, respectively. The primary care attribute that mattered most was having a clinician who "knows me as a person and considers all the factors that affect my health." After we adjusted for respondent characteristics, people in Quebec, the Atlantic region, and British Columbia had lower odds of reporting a primary care clinician than people in Ontario (adjusted odds ratio 0.30, 0.33, and 0.39, respectively; p < 0.001). We also observed large provincial variations in timely access, interprofessional care, and walk-in clinic use.

INTERPRETATION

More than 1 in 5 respondents did not have access to primary care, with large variation by province. Reforms should strive to expand access to relationship-based, longitudinal care in a team setting.

Virtual interprofessional (VIP) education, a family medicine-occupational therapy-physiotherapy collaborative experience: the perspectives of patients, learners and providers on the opportunities and challenges

This study examined the experiences of patients, Occupational Therapy (OT), Physiotherapy (PT) and Medicine learners, Providers, and Faculty, in implementing a Virtual Interprofessional (VIP) education initiative in two academic Family Medicine (FM) collaborative clinics. A qualitative descriptive study drew on a strength-based approach as part of the evaluation of the interfaculty VIP initiative. Participants involved in VIP care were conveniently sampled. Interviews were conducted with four patients, and focus groups were held with a total of 16 providers, preceptors and learners in OT, PT and FM. Data were analyzed using content analysis and managed using NVivo12. Four main categories emerged: 1) Challenges in implementing VIP care in FM; 2) Operational challenges, 3) Facilitators of VIP care in FM; and 4) Experiential learning outcomes and benefits of VIP care. This innovation supported knowledge and insights on interprofessional competencies acquired during practice, provided inclusive and comprehensive access to care for patients, and identified opportunities to enhance medical, OT and PT education in VIP care in FM. A collaborative approach with faculty from different disciplines (FM, School of Health Professions: OT and PT) can provide ongoing opportunities for VIP care for patients, and foster IP learning and acquisition of competencies for FM, OT and PT learners and providers.

COVID-19 - an opportunity to improve access to primary care through organizational innovations? A qualitative multiple case study in Quebec and Nova Scotia (Canada)

Background

COVID-19 catalyzed a rapid and substantial reorganization of primary care, accelerating the spread of existing strategies and fostering a proliferation of innovations. Access to primary care is an essential component of a healthcare system, particularly during a pandemic. We describe organizational innovations aiming to improve access to primary care and related contextual changes during the first 18 months of the COVID-19 pandemic in two Canadian provinces, Quebec and Nova Scotia.

Methods

We conducted a multiple case study based on 63 semi-structured interviews (n = 33 in Quebec, n = 30 in Nova Scotia) conducted between October 2020 and May 2021 and 71 documents from both jurisdictions. We recruited a diverse range of provincial and regional stakeholders (e.g., policy-makers, decision-makers, family physicians, nurses) involved in reorganizing primary care during the COVID-19 pandemic using purposeful sampling (e.g., based on role, region). Interviews were transcribed verbatim and thematic analysis was conducted in NVivo12. Emerging results were discussed by team members to identify salient themes and organized into logic models.

Results

We identified and analyzed six organizational innovations. Four of these – centralized public online booking systems, centralized access centers for unattached patients, interim primary care clinics for unattached patients, and a community connector to health and social services for older adults – pre-dated COVID-19 but were accelerated by the pandemic context. The remaining two innovations were created to specifically address pandemic-related needs: COVID-19 hotlines and COVID-dedicated primary healthcare clinics.

Innovation spread and proliferation was influenced by several factors, such as a strengthened sense of community amongst providers, decreased patient demand at the beginning of the first wave, renewed policy and provider interest in population-wide access (versus attachment of patients only), suspended performance targets (e.g., continuity ≥80%) in Quebec, modality of care delivery, modified fee codes, and greater regional flexibility to implement tailored innovations.

Conclusion

COVID-19 accelerated the uptake and creation of organizational innovations to potentially improve access to primary healthcare, removing, at least temporarily, certain longstanding barriers. Many stakeholders believed this reorganization would have positive impacts on access to primary care after the pandemic. Further studies should analyze the effectiveness and sustainability of innovations adapted, developed, and implemented during the COVID-19 pandemic.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-022-08140-w.

"At the mercy of some of the regulations": the impact of the residency match and return of service requirement on the early-career decisions of international medical graduates in Canada

BACKGROUND

Return-of-service (ROS) agreements require international medical graduates (IMGs) who accept medical residency positions in Canada to practice in specified geographic areas following completion of training. However, few studies have examined how ROS agreements influence career decisions. We examined IMG resident and early-career family physicians' perceptions of the residency matching process, ROS requirements, and how these factors shaped their early career decisions.

METHODS

As part of a larger project, we conducted semi-structured qualitative interviews with early-career family physicians and family medicine residents in British Columbia, Ontario and Nova Scotia. We asked participants about their actual or intended practice characteristics (e.g., payment model, practice location) and factors shaping actual or intended practice (e.g., personal/professional influences, training experiences, policy environments). Interviews were transcribed verbatim and a thematic analysis approach was employed to identify recurring patterns and themes.

RESULTS

For this study, we examined interview data from nine residents and 15 early-career physicians with ROS agreements. We identified three themes: IMGs strategically chose family medicine to increase the likelihood of obtaining a residency position; ROS agreements limited career choices; and ROS agreements delayed preferred practice choice (e.g., scope of practice and location) of an IMGs' early-career practice.

CONCLUSIONS

The obligatory nature of ROS agreements influences IMG early-career choices, as they necessitate strategically tailoring practice intentions towards available residency positions. Existing analyses of IMGs' early-career practice choices neglect to distinguish between ROS and practice choices made independently of ROS requirements. Further research is needed to understand how ROS influences longer term practice patterns of IMGs in Canada.

Using mobile technology in assessment of entrustable professional activities in undergraduate medical education

BACKGROUND

The adoption of competency-based medical education requires objective assessments of a learner's capability to carry out clinical tasks within workplace-based learning settings. This study involved an evaluation of the use of mobile technology to record entrustable professional activity assessments in an undergraduate clerkship curriculum.

APPROACH

A paper-based form was adapted to a mobile platform called eClinic Card. Students documented workplace-based assessments throughout core clerkship and preceptors confirmed accuracy via mobile phones. Assessment scores for the 2017-2018 academic year were collated and analyzed for all core rotations, and preceptors and students were surveyed regarding the mobile assessment experience.

EVALUATION

The mobile system enabled 80 students and 624 preceptors to document 6850 assessment submissions across 47 clinical sites over a 48-week core clerkship curriculum. Students' scores demonstrated progressive improvement across all entrustable professional activities with stage-appropriate levels of independence reported by end of core clerkship. Preceptors and students were satisfied with ease of use and dependability of the mobile assessment platform; however, students felt quality of formative coaching feedback could be improved.

REFLECTION

Our preliminary evaluation suggests the use of mobile technology to assess entrustable professional activity achievement across a core clerkship curriculum is a feasible and acceptable modality for workplace-based assessment. The use of mobile technology supported a programmatic assessment approach. However, meaningful coaching feedback, as well as faculty development and support, emerged as key factors influencing successful adoption and usage of entrustable professional activities within an undergraduate medical curriculum.

Primary care of adults with severe and profound intellectual and developmental disabilities: Family physicians' perspectives on patient-physician relationships

OBJECTIVE

To explore family physicians' perspectives on the development of the patient-physician relationship with adult patients living with severe or profound intellectual and developmental disabilities (IDD).

DESIGN

Constructivist grounded theory.

SETTING

St John's, NL, and across Canada.

PARTICIPANTS

Fifteen family physicians currently caring for patients with severe or profound IDD.

METHODS

Data were collected via in-depth, semistructured interviews conducted in-person or by telephone. Interviews were audiorecorded and transcribed verbatim. Field notes were documented immediately by the interviewer and discussed with the research team. Memos in the form of reflective notes served as additional sources of data.

MAIN FINDINGS

From the perspective of family physicians, the core process in the development of the patient-physician relationship was acceptance. This acceptance was bidirectional. With respect to family physicians accepting patients, family physicians had to accept that their patients with severe and profound IDD were as equally deserving of their respect as any other patient-as unique individuals with their own goals and potential. With respect to patients accepting their family physicians, family physicians had to seek out signs of acceptance from their patients to fully appreciate and develop a trusting relationship. This bidirectional process of acceptance required family physicians to adapt the way they practised (eg, by spending more time with the patient and finding alternate forms of communication). It also required family physicians to define their role (eg, building trust and being an advocate) in a relationship that had the patient as the primary focus but simultaneously acknowledged the important involvement of the caregiver.

CONCLUSION

For family physicians, the process of acceptance seems to underpin the development of the patient-physician relationship with adult patients with severe or profound IDD. Findings highlight the need for family physicians to adapt the way they deliver care to these patients and define their role in these complex relationships. Ultimately, this study highlights family physicians' acceptance of their patients' humanity regardless of the nature of the relationship that was created between them.

Evaluation of the Characteristics of a Workplace Assessment Form to Assess Entrustable Professional Activities (EPAs) in an Undergraduate Surgery Core Clerkship

OBJECTIVE

Entrustable Professional Activities (EPAs) are explicit, directly observable tasks requiring the demonstration of specific knowledge, skills, and behaviors that learners are expected to perform without direct supervision once they have gained sufficient competence. Undergraduate level implementation of EPAs is relatively new. We examined the characteristics of a workplace assessment form (clinic card) as part of a formative programmatic assessment process of EPAs for a core undergraduate surgery rotation.

DESIGN

A clinic card was introduced to assess progression towards EPA achievement in the clerkship curriculum phase. Students completing their core eight (8) week clerkship surgery rotation submitted at least 1 clinic card per week. We compiled assessment scores for the 2015 to 2016 academic year, in which EPAs were introduced, and analyzed relationships between scores and time, EPA, training site, and assessor role. We surveyed preceptors and students, and conducted a focus group with clinical discipline coordinators of all core rotations.

SETTING

This study took place at the Faculty of Medicine, Memorial University in St. John's, Newfoundland, Canada.

PARTICIPANTS

Third year medical students (n = 79) who completed their core eight (8) week surgery clerkship rotation during the 2015 to 2016 academic year, preceptors, and clinical discipline coordinators participated in this study.

RESULTS

EPAs reflecting tasks commonly performed by students were more likely to be assessed. EPAs frequently observed during preceptor-student encounters had higher entrustment ratings. Most EPAs showed increased entrustment scores over time and no significant differences in ratings between teaching sites nor preceptors and residents. Survey and focus group feedback suggest clinic cards fostered direct observation by preceptors and promoted constructive feedback on clinical tasks. A binary rating scale (entrustable/pre-entrustable) was not educationally beneficial.

CONCLUSIONS

The findings support the feasibility, utility, catalytic and educational benefits of clinic cards in assessing EPAs in a core surgery rotation in undergraduate medical education.

Patient-centred primary care of adults with severe and profound intellectual and developmental disabilities: Patient-caregiver-physician relationship

OBJECTIVE

To explore the process of the development of the patient-physician relationship in adult patients with severe or profound intellectual and developmental disabilities (IDD), from the perspective of the patients' caregivers.

DESIGN

Constructivist grounded theory.

SETTING

St John's, NL.

PARTICIPANTS

Thirteen primary caregivers (5 males, 8 females) of 1 or more adults with severe or profound IDD.

METHODS

Data were collected via in-depth, semistructured interviews conducted in person or by telephone. Interviews were audiorecorded and transcribed verbatim. Field notes were documented immediately by the interviewer and discussed with the research team. Memos in the form of reflective notes served as additional sources of data.

MAIN FINDINGS

From the perspective of the caregivers, the core process in the development of the patient-physician relationship was protection. This process began as a result of the caregiver's recognition of the patient's vulnerability and moved through a number of stages before resulting in the development of a dynamic triangular interaction between the patient, caregiver, and family physician. First, the caregiver provides extreme nurturing to the patient, which results in the development of a strong bond between them. The patient and caregiver approached the family physician together as one unit, and then decided together on whether or not to open the patient-caregiver bond to the physician. The resultant dynamic triangular interaction formed the starting point from which 1 of 4 different relationship-development trajectories began. Which trajectory was taken and, therefore, the character of the relationships that developed was determined by how the caregiver and patient experienced their interaction with the family physician.

CONCLUSION

Findings highlight the process of protection and the centrality of the patient-caregiver bond within the development of a triadic relationship involving the patient with IDD, the caregiver, and the family physician. How a physician approaches this bond can influence the trajectory of the resulting relationship.

Soins primaires aux adultes ayant des déficiences intellectuelles et développementales

Objectif

Mettre à jour les Lignes directrices consensuelles canadiennes 2011 en matière de soins primaires aux adultes ayant une déficience développementale.

Méthodes

Des médecins de famille et d’autres professionnels de la santé expérimentés dans les soins aux personnes ayant des DID ont examiné et synthétisé les récentes connaissances empiriques, d’écosystèmes, expertes et expérientielles. Un système a été conçu pour catégoriser la qualité des recommandations.

Recommandations

Les adultes ayant des DID sont un groupe hétérogène de patients qui présentent des affections médicales et des facteurs qui influent sur leur santé, qui diffèrent de ceux qui touchent les autres membres de la communauté de par leur nature, leurs manifestations, leur gravité ou leur complexité. Ces personnes nécessitent une approche de soins et des interventions adaptées à leurs besoins. Les présentes lignes directrices offrent des conseils en matière de normes de soins. Nous avons incorporé des références à des outils cliniques et à d’autres ressources pratiques. Les approches de soins décrites ici s’appliquent aussi à d’autres groupes de patients ayant un déficit cognitif ou de la communication, ou d’autres déficits des fonctions adaptatives.

Conclusion

À titre de fournisseurs de soins de première ligne, les médecins de famille jouent un rôle vital de promotion de la santé et de bien-être auprès des adultes ayant des DID. Ces lignes directrices peuvent les aider à prendre des décisions avec les patients et les aidants naturels.

Primary care of adults with intellectual and developmental disabilities: 2018 Canadian consensus guidelines

OBJECTIVE

To update the 2011 Canadian guidelines for primary care of adults with intellectual and developmental disabilities (IDD).

METHODS

Family physicians and other health professionals experienced in the care of people with IDD reviewed and synthesized recent empirical, ecosystem, expert, and experiential knowledge. A system was developed to grade the strength of recommendations.

RECOMMENDATIONS

Adults with IDD are a heterogeneous group of patients and have health conditions and factors affecting their health that can vary in kind, manifestation, severity, or complexity from those of others in the community. They require approaches to care and interventions that are adapted to their needs. These guidelines provide advice regarding standards of care. References to clinical tools and other practical resources are incorporated. The approaches to care that are outlined here can be applied to other groups of patients that have impairments in cognitive, communicative, or other adaptive functioning.

CONCLUSION

As primary care providers, family physicians play a vital role in promoting the health and well-being of adults with IDD. These guidelines can aid their decision making with patients and caregivers.

Does rural generalist focused medical school and family medicine training make a difference? Memorial University of Newfoundland outcomes

INTRODUCTION

Rural recruitment and retention of physicians is a global issue. The Faculty of Medicine at Memorial University of Newfoundland, Canada, was established as a rural-focused medical school with a social accountability mandate that aimed to meet the healthcare needs of a sparse population distributed over a large landmass as well as the needs of other rural and remote areas of Canada. This study aimed to assess whether Memorial medical degree (MD) and postgraduate (PG) programs were effective at producing physicians for their province and rural physicians for Canada compared with other Canadian medical schools.

METHODS

This retrospective cohort study included medical school graduates who completed their PG training between 2004 and 2013 in Canada. Practice locations of study subjects were georeferenced and assigned to three geographic classes: Large Urban; Small City/Town; and Rural. Analyses were performed at two levels. (1) Provincial level analysis compared Memorial PG graduates practicing where they received their MD and/or PG training with other medical schools who are the only medical school in their province (n=4). (2) National-level analysis compared Memorial PG graduates practicing in rural Canada with all other Canadian medical schools (n=16). Descriptive and bivariate analyses were performed.

RESULTS

Overall, 18 766 physicians practicing in Canada completed Canadian PG training (2004-2013), and of those, 8091 (43%) completed Family Medicine (FM) training. Of all physicians completing Canadian PG training, 1254 (7%) physicians were practicing rurally and of those, 1076 were family physicians. There were 379 Memorial PG graduates and of those, 208 (55%) completed FM training and 72 (19%) were practicing rurally, and of those practicing rurally, 56 were family physicians. At the national level, the percentage of all Memorial PG graduates (19.0%) and FM PG graduates (26.9%) practicing rurally was significantly better than the national average for PG (6.4%, p<0.000) and FM (12.9%, p<0.000). Among 391 physicians practicing in Newfoundland and Labrador (NL), 257 (65.7%) were Memorial PG graduates and 247 (63.2%) were Memorial MD graduates. Of the 163 FM graduates, 148 (90.8%) were Memorial FM graduates and 118 (72.4%) were Memorial MD graduates. Of the 68 in rural practice, 51 (75.0%) were Memorial PG graduates and 31 (45.6%) were Memorial MD graduates. Of the 41 FM graduates in rural practice, 39 (95.1%) were Memorial FM graduates and 22 (53.7%) were Memorial MD graduates. Two-sample proportion tests demonstrated Memorial University provided a larger proportion of its provincial physician resource supply than the other four single provincial medical schools, by medical school MD for FM (72.4% vs 44.3%, p<0.000) and for overall (63.2% vs 43.5% p<0.000), and by medical school PG for FM (90.8 % vs 72.0%, p<0.000).

CONCLUSION

This study found Memorial University graduates were more likely to establish practice in rural areas compared with the national average for most program types as well as more likely to establish practice in NL compared with other single medical schools' graduates in their provinces. This study highlights the impact a comprehensive rural-focused social accountability approach can have at supplying the needs of a population both at the regional and rural national levels.

From pipelines to pathways: the Memorial experience in educating doctors for rural generalist practice

CONTEXT

This report describes the community context, concept and mission of The Faculty of Medicine at Memorial University of Newfoundland (Memorial), Canada, and its 'pathways to rural practice' approach, which includes influences at the pre-medical school, medical school experience, postgraduate residency training, and physician practice levels. Memorial's pathways to practice helped Memorial to fulfill its social accountability mandate to populate the province with highly skilled rural generalist practitioners. Programs/interventions/initiatives: The 'pathways to rural practice' include initiatives in four stages: (1) before admission to medical school; (2) during undergraduate medical training (medical degree (MD) program); (3) during postgraduate vocational residency training; and (4) after postgraduate vocational residency training. Memorial's Learners & Locations (L&L) database tracks students through these stages. The Aboriginal initiative - the MedQuest program and the admissions process that considers geographic or minority representation in terms of those selecting candidates and the candidates themselves - occurs before the student is admitted. Once a student starts Memorial's MD program, the student has ample opportunities to have rural-based experiences through pre-clerkship and clerkship, of which some take place exclusively outside of St. John's tertiary hospitals. Memorial's postgraduate (PG) Family Medicine (FM) residency (vocational) training program allows for deeper community integration and longer periods of training within the same community, which increases the likelihood of a physician choosing rural family medicine. After postgraduate training, rural physicians were given many opportunities for professional development as well as faculty development opportunities. Each of the programs and initiatives were assessed through geospatial rurality analysis of administrative data collected upon entry into and during the MD program and PG training (L&L). Among Memorial MD-graduating classes of 2011-2020, 56% spent the majority of their lives before their 18th birthday in a rural location and 44% in an urban location. As of September 2016, 23 Memorial MD students self-identified as Aboriginal, of which 2 (9%) were from an urban location and 20 (91%) were from rural locations. For Year 3 Family Medicine, graduating classes 2011 to 2019, 89% of placement weeks took place in rural communities and 8% took place in rural towns. For Memorial MD graduating classes 2011-2013 who completed Memorial Family Medicine vocational training residencies, (N=49), 100% completed some rural training. For these 49 residents (vocational trainees), the average amount of time spent in rural areas was 52 weeks out of a total average FM training time of 95 weeks. For Family Medicine residencies from July 2011 to October 2016, 29% of all placement weeks took place in rural communities and 21% of all placement weeks took place in rural towns. For 2016-2017 first-year residents, 53% of the first year training is completed in rural locations, reflecting an even greater rural experiential learning focus.

LESSONS LEARNED

Memorial's pathways approach has allowed for the comprehensive training of rural generalists for Newfoundland and Labrador and the rest of Canada and may be applicable to other settings. More challenges remain, requiring ongoing collaboration with governments, medical associations, health authorities, communities, and their physicians to help achieve reliable and feasible healthcare delivery for those living in rural and remote areas.

Periostin facilitates eosinophil tissue infiltration in allergic lung and esophageal responses

Periostin is an extracellular matrix protein that has been primarily studied in the context of the heart, where it has been shown to promote cardiac repair and remodeling. In this study, we focused on the role of periostin in an allergic eosinophilic inflammatory disease (eosinophilic esophagitis (EE)) known to involve extensive tissue remodeling. Periostin was indeed markedly overexpressed (35-fold) in the esophagus of EE patients, particularly in the papillae, compared with control individuals. Periostin expression was downstream from transforming growth factor-beta and interleukin-13, as these cytokines were elevated in EE esophageal samples and markedly induced periostin production by primary esophageal fibroblasts (107- and 295-fold, respectively, at 10 ng ml(-1)). A functional role for periostin in eliciting esophageal eosinophilia was demonstrated, as periostin-null mice had a specific defect in allergen-induced eosinophil recruitment to the lungs and esophagus (66 and 72% decrease, respectively). Mechanistic analyses revealed that periostin increased (5.8-fold) eosinophil adhesion to fibronectin. As such, these findings extend the involvement of periostin to esophagitis and uncover a novel role for periostin in directly regulating leukocyte (eosinophil) accumulation in T helper type 2-associated mucosal inflammation in both mice and humans.

Electronic fingerprinting of the dead

To date, a number of methods exist for the capture of fingerprints from cadavers that can then be used in isolation as a primary method for the identification of the dead. We report the use of a handheld, mobile wireless unit used in conjunction with a personal digital assistant (PDA) device for the capture of fingerprints from the dead. We also consider a handheld single-digit fingerprint scanner that utilises a USB laptop connection for the electronic capture of cadaveric fingerprints. Both are single-operator units that, if ridge detail is preserved, can collect a 10-set of finger pad prints in approximately 45 and 90 s, respectively. We present our observations on the restrictions as to when such devices can be used with cadavers. We do, however, illustrate that the images are of sufficient quality to allow positive identification from finger pad prints of the dead. With the development of mobile, handheld, biometric, PDA-based units for the police, we hypothesize that, under certain circumstances, devices such as these could be used for the accelerated acquisition of fingerprint identification data with the potential for rapid near-patient identification in the future.

Spinal hemiepiphysiodesis correlates with physeal histomorphometric gradients

Compression of a growth plate is known to correlate with changes to growth plate structure. The purpose of this study was to determine if the height of the physeal hypertrophic zones and chondrocyte size were directly related to the distance from a spine implant. The implant was designed with the goal of slowing spine growth asymmetrically. For stapled vertebrae, hypertrophic zone height, cell height and cell width were decreased across the coronal plane of the growth plate, with the lowest values under the staple, 8 weeks postoperatively.

Glycation of rat sciatic nerve tubulin in experimental diabetes mellitus

Diabetic neuropathy is associated with some early defects of axonal transport in experimental animals. Axonal transport is dependent on intact microtubules, and unsubstituted lysine residues of tubulin are essential for microtubule polymerization. As lysine residues are the major target for the non-enzymatic attachment of glucose, the effect of diabetes on the extent of glycation of tubulin was investigated. There was a more than four-fold increase in the extent of glycation of tubulin in the sciatic nerve of rats with streptozotocin-induced diabetes of 2 weeks duration compared with control rats. In contrast, no such increase in glycation was observed in brain microtubule protein from diabetic rats at that stage of diabetes. Incubation of brain microtubule protein with glucose prior to in vitro polymerization showed that the early stages of glycation were not associated with inhibition of microtubule assembly. The observed glycation of peripheral nerve tubulin in early experimental diabetes may nevertheless contribute to axonal transport abnormalities through an as yet undetermined impairment of microtubule function.

Electrolysis-induced myocardial dysfunction. A novel method for the study of free radical mediated tissue injury

Oxygen-derived free radicals and other oxidizing species are thought to be involved in inflammation and ischemic tissue injuries. Recently, oxygen-derived free radicals also have been implicated in tissue injury of the myocardium subjected to ischemia/reperfusion. The purpose of this investigation was to determine if electrolysis of a physiological buffer would serve as a source of free radicals, and if these radicals would lead to alterations in myocardial function. Isolated Langendorff-perfused rabbit hearts perfused with buffer subjected to a 20 mA D.C. current for 2 min demonstrated significant increases in coronary perfusion pressure (37 +/- 6 mmHg), left ventricular end diastolic pressure (41 +/- 7 mmHg), and loss in left ventricular developed pressure (35 +/- 5%). The free radical scavengers, superoxide dismutase and a combination of tryptophan plus glycine, were effective in protecting the hearts from the effects of electrolysis. The presence of free radicals was semiquantitated with a radical-luminol chemiluminescent assay. In this assay a variety of radical scavengers and antioxidants were effective (i.e., dimethyl sulfoxide, nitro blue tetrazolium, ascorbate, superoxide dismutase, 1, 3-diphenylisobenzofuran, and glycine, catalase), whereas mannitol and tryptophan were not effective. The data indicate that electrolysis of a physiological buffer produces a milieu containing several reactive oxygen species or free radicals that have the potential to produce alterations in a biological system. This method has the advantage over existing protocols for the generation of radicals in that it is a blood-free and an enzyme-free system.

Effect of nivazol on ACTH secretion by human pituitary corticotrophic tumours in cell culture

The effects of nivazol, a novel steroid which lacks glucocorticoid activity, on ACTH secretion by cell cultures of human pituitary corticotrophic tumours has been investigated. Nivazol (0.002-20 mumol/l) inhibited ACTH secretion by 50-80%, after 4 and 24 h of incubation. (Trilostane (0.3-30 mumol/l) did not affect basal or stimulated ACTH secretion.) The potency of nivazol was comparable with that of hydrocortisone, and less than dexamethasone. The stimulatory effects of oCRF and AVP were reduced or completely blocked by nivazol in a similar manner to that previously described for hydrocortisone. It is concluded that nivazol may be of benefit in the direct treatment of Cushing's disease, particularly since it lacks glucocorticoid activity.