Age-related changes in centripetal ciliary body movement relative to centripetal lens movement in monkeys

The goal was to determine the age-related changes in accommodative movements of the lens and ciliary body in rhesus monkeys. Varying levels of accommodation were stimulated via the Edinger-Westphal (E-W) nucleus in 26 rhesus monkeys, aged 6–27 years, and the refractive changes were measured by coincidence refractometry. Centripetal ciliary process (CP) and lens movements were measured by computerized image analysis of goniovideographic images. Ultrasound biomicroscopy (UBM) at 50 MHz was used to visualize and measure accommodative forward movements of the ciliary body in relation to age, accommodative amplitude, and centripetal CP and lens movements. At ～3 diopters of accommodation, the amount of centripetal lens movement required did not significantly change with age (p = 0.10; n = 18 monkeys); however, the amount of centripetal CP movement required significantly increased with age (p = 0.01; n = 18 monkeys), while the amount of forward ciliary body movement significantly decreased with age (p = 0.007; n = 11 monkeys). In the middle-aged animals (12–16.5 years), a greater amount of centripetal CP movement was required to induce a given level of lens movement and thereby a given level of accommodation (p = 0.01), compared to the young animals (6–10 yrs). Collectively, the data suggests that, with age, the accommodative system may be attempting to compensate for the loss of forward ciliary body movement by increasing the amount of centripetal CP movement. This, in turn, would allow enough zonular relaxation to achieve the magnitude of centripetal lens movement necessary for a given amplitude of accommodation.     

Prevalence of autoimmune diseases in islet transplant candidates with severe hypoglycaemia and glycaemic lability: previously undiagnosed coeliac and autoimmune thyroid disease is identified by screening.

AIMS: Autoimmune diseases such as Addison's or coeliac disease can contribute to hypoglycaemia or malabsorption and are more common in Type 1 diabetes (T1DM). This brief report describes the prevalence of known and newly detected autoimmune disease in clinical islet transplant candidates with longstanding T1DM and severe hypoglycaemia and/or glycaemic lability who are routinely screened for coexisting autoimmune disease. METHODS: One hundred and twenty-four C-peptide negative T1DM subjects [77 (62%) female, mean age 44 +/- 9 years, diabetes duration 28 +/- 11 years, body mass index 24.9 +/- 3.5 kg/m(2)] with indications for clinical islet transplantation at the University of Alberta were screened for autoimmune disease by history and measurement of anti-transglutaminase antibodies (positive > 10 U/ml), 09.00 h cortisol (followed by adrenocorticotrophic hormone-stimulation if < 495 nmol/l) and thyroid-stimulating hormone to determine the prevalence of coeliac disease, Addison's disease and autoimmune thyroid disease, respectively. RESULTS: Forty per cent of subjects had one or more coexisting autoimmune disease. The prevalence of autoimmune disease was 35%, coeliac disease 8% and Addison's disease 1.6%. In 11 individuals (9%), one or more autoimmune disease were newly detected (seven coeliac disease and five thyroid disease). Seven of 10 cases of coeliac disease were newly detected. A gluten-free diet in individuals with newly diagnosed coeliac disease reduced gastrointestinal symptoms, but indications for clinical islet cell transplantation persisted. CONCLUSIONS: Coexisting autoimmune disease is common in candidates for clinical islet cell transplantation. Screening in this group identified a substantial number of previously unrecognized cases. Clinicians should consider the presence of autoimmune disease even in the absence of classical symptoms.     

Teaching ethics to paediatrics residents: the centrality of the therapeutic alliance

Context Previous research on ethical issues encountered by medical professionals in training and practice have presented the thematic content of the cases they encounter rather than the activities in which clinicians engage and in which they most often encounter ethical issues. We conducted a direct observation study of paediatrics residents and their preceptors seeing patients in an out‐patient general paediatrics clinic. Our objectives were to describe the everyday ethics‐related issues paediatrics residents encounter as they interact with patients. Our ultimate goal is to use this knowledge to enhance current efforts to teach ethics to paediatrics residents. Methods The study team directly observed paediatrics residents discussing patients with their faculty preceptors (19 half‐day sessions, 76 hours) in an out‐patient general paediatrics clinic located in an urban academic medical centre. Each interaction between resident and preceptor about a single patient was considered a case for further analysis. Results A total of 247 cases were recorded. Forty‐one of the cases were coded as having ethics‐related content. A constant comparative method of qualitative data analysis revealed that residents were most likely to encounter ethical issues when engaged in the following activities: (i) maintaining a therapeutic alliance with the caregiver (e.g. the parent); (ii) prioritising patient or family needs; (iii) adjusting to the power embodied by the role of doctors, and (iv) distinguishing suboptimal care from abuse or neglect. In addition, our findings indicate that it is through their efforts to maintain the therapeutic alliance with the caregivers of their patients that residents engage in and integrate three processes: developing their medical knowledge; adhering to professional norms, and balancing the power inherent in the doctor’s role with their responsibility to serve the patient’s interests. Conclusions Medical faculty tasked with teaching ethics to paediatrics residents can utilise the results of this project to better target and enhance their ethics education efforts directed at residents in the out‐patient setting. Future research could further examine and test these findings in other clinical settings (e.g. adult general medicine).     

Distribution of metabotropic glutamate receptor mGluR5 immunoreactivity in rat brain

The receptor mGluR5 is a metabotropic glutamate receptor with messenger RNA abundantly present throughout cortex, hippocampus, and caudate/putamen that is also coupled to phosphatidyl inositide hydrolysis and calcium mobilization. In this study, the distribution of mGluR5 was examined in rat brain by immunocytochemistry. The antibody utilized is highly specific and does not cross react with the most closely related other metabotropic glutamate receptor, as determined by Western blot analysis of nonneuronal cells transfected with metabotropic receptor coding sequences. The receptor mGluR5 is widely expressed with the highest density in olfactory bulb, caudate/putamen, lateral septum, cortex, and hippocampus, as confirmed with both immunocytochemistry and Western blot analysis. Electron microscopic studies in hippocampus and cortex indicate that the labeling is mostly on membranes of dendritic spines and shafts. Light and electron microscopic evidence indicates that some mGluR5 immunoreactivity is located in presynaptic axon terminals, suggesting that mGluR5 may function as a presynaptic receptor.     

Sensorineural hearing loss in patients with typical retinitis pigmentosa

We performed detailed audiologic testing in 45 patients with retinitis pigmentosa and 45 age- and sex-matched controls. Ten (22%) of the retinitis pigmentosa patients had a sensorineural hearing loss that varied from mild to severe. None of the control subjects had a hearing loss. Audiograms measured over a ten- to 30-year period were available for four patients with retinitis pigmentosa and each showed progressive hearing loss. The results indicate the important role of audiologic evaluation in treating patients with retinitis pigmentosa.     

Organic brain damage and occupational solvent exposure.

Three hundred and nine men with organic dementia, cerebral atrophy, or psycho-organic syndrome admitted for five nights or more to one of 18 Quebec hospitals were individually matched with patients admitted (1) with some other psychiatric diagnosis and (2) to a general hospital. Lifetime occupational histories were obtained by telephone. Occupational exposure to solvents was assessed blind to type of case by (1) individual ratings and (2) a job exposure matrix; men who worked in moderate or high solvent concentrations for at least 10 years were considered exposed. With the psychiatric referent series, an odds ratio of 1.4 (90% CI 1.0-2.0) was calculated by individual exposure ratings and 1.4 (90% CI 0.9-2.2) by job matrix. Increased risk was mainly in those with organic dementia or cerebral atrophy and an alcohol related diagnosis. The same pattern of risk was found against the general hospital referents. Adjustment for possible confounders did not alter the risk estimates appreciably. Also, lifetime job histories, compared in selected case-referent pairs, gave similar evidence of increased risk (odds ratio 2.3; 90% CI 1.0-5.5). It is concluded that the combined effect of occupational solvent exposure and alcohol intake is probably an important cause of organic brain damage.