Peripheral quantitative computed tomography-derived muscle density and peripheral magnetic resonance imaging-derived muscle adiposity: precision and associations with fragility fractures in women.

PURPOSE: To determine the degree to which muscle density and fractures are explained by inter and intramuscular fat (IMF). METHODS: Women ⋝50 years of age (Hamilton, ON, Canada) had peripheral magnetic resonance imaging and peripheral quantitative computed tomography scans at 66% of the tibial length. Muscle on computed tomography images was segmented from subcutaneous fat and bone using fixed thresholds, computing muscle density. IMF was segmented from muscle within magnetic resonance images using a region-growing algorithm, computing IMF volume. Fracture history over the last 14 years was obtained. Odds ratios for fractures were determined for muscle density, adjusting for IMF volume, total hip BMD, age and body mass index. RESULTS: Women with a history of fractures were older (N=32, age:75.6±8.3 years) than those without (N=39, age: 67.0±5.2 years) (<0.01). IMF volume explained 49.3% of variance in muscle density (p<0.001). Odds for fractures were associated with lower muscle density even after adjusting for IMF volume but were attenuated after adjusting for age. CONCLUSIONS: Muscle adiposity represents only 50% of the muscle density measurement. Properties of muscle beyond its adiposity may be related to fractures, but larger and prospective studies are needed to confirm these associations.

A Frailty Index predicts 10-year fracture risk in adults age 25 years and older: results from the Canadian Multicentre Osteoporosis Study (CaMos).

UNLABELLED: We created a 30-item Frailty Index in the Canadian Multicentre Osteoporosis Study. A Frailty Index is a sensitive measure that can quantify fracture risk according to degree of frailty. Our results indicated that at any age, frailty was an important independent risk factor for fracture over 10 years. INTRODUCTION: In later life, frailty has been linked to fractures. It is likely that the antecedents of fracture are seen across the life course, in ways not entirely captured by traditional osteoporosis risk factors. Using data collected from the prospective, population-based Canadian Multicentre Osteoporosis Study (CaMos), we created the 30-item CaMos Frailty Index and examined whether it was associated with incident fractures over 10 years. METHODS: All CaMos participants aged 25 years and older (n = 9,423) were included in the analysis. To examine the relationship between baseline Frailty Index scores and incident fractures, a competing risk proportional sub-distribution hazards model was used with death considered a competing risk. Analyses were adjusted for age, sex, body mass index, education level, femoral neck T-score, and antiresorptive therapy. RESULTS: At baseline, the mean age was 62.1 years [standard deviation (SD) 13.4], and 69.4 % were women. The mean Frailty Index score was 0.13 (SD 0.11), ranging from 0 to 0.66. For every 0.10 increase in Frailty Index scores (approximately one SD), the hazard ratio was 1.25 (p < 0.001) for all fractures, 1.18 (p = 0.043) for hip fractures, and 1.30 (p ≤ 0.001) for clinical vertebral fractures. CONCLUSION: The CaMos Frailty Index quantified fracture risk according to degree of frailty. Irrespective of age and bone mineral density, the Frailty Index was associated with hip, vertebral, and all-type clinical fractures. Predicting late onset illnesses may have to consider overall health status and not just traditional risk factors.

Antidepressant use and 10-year incident fracture risk: the population-based Canadian Multicentre Osteoporosis Study (CaMoS).

UNLABELLED: We used data from a large, prospective Canadian cohort to assess the association between selective serotonin reuptake inhibitors (SSRIs) and serotonin and noradrenaline reuptake inhibitors (SNRIs) and fracture. We found an increased risk of fractures in individuals who used SSRI or SNRI, even after controlling for multiple risk factors. INTRODUCTION: Previous studies have suggested an association between SSRIs and increasing risk of fragility fractures. However, the majority of these studies were not long-term analyses or were performed using administrative data and, thus, could not fully control for potential confounders. We sought to determine whether the use of SSRIs and SNRIs is associated with increased risk of fragility fracture, in adults aged 50 + . METHODS: We used data from the Canadian Multicentre Osteoporosis Study (CaMos), a prospective randomly selected population-based community cohort; our analyses focused on subjects aged 50+. Time to event methodology was used to assess the association between SSRI/SNRI use, modeled time-dependently, and fragility fracture. RESULTS: Among 6,645 subjects, 192 (2.9%) were using SSRIs or/and SNRIs at baseline. During the 10-year study period, 978 (14.7%) participants experienced at least one fragility fracture. In our main analysis, SSRI/SNRI use was associated with increased risk of fragility fracture (hazard ratio (HR), 1.88; 95% confidence intervals (CI), 1.48-2.39). After controlling for multiple risk factors, including Charlson score, previous falls, and bone mineral density hip and lumbar bone density, the adjusted HR for current SSRI/SNRI use remained elevated (HR, 1.68; 95% CI, 1.32-2.14). CONCLUSIONS: Our results lend additional support to an association between SSRI/SNRI use and fragility fractures. Given the high prevalence of antidepressants use, and the impact of fractures on health, our findings may have a significant clinical impact.

Non-hip, non-spine fractures drive healthcare utilization following a fracture: the Global Longitudinal Study of Osteoporosis in Women (GLOW).

UNLABELLED: We evaluated healthcare utilization associated with treating fracture types in >51,000 women aged ≥55 years. Over the course of 1 year, there were five times more non-hip, non-spine fractures than hip or spine fractures, resulting in twice as many days of hospitalization and rehabilitation/nursing home care for non-hip, non-spine fractures. INTRODUCTION: The purpose of this study is to evaluate medical healthcare utilization associated with treating several types of fractures in women ≥55 years from various geographic regions. METHODS: Information from the Global Longitudinal Study of Osteoporosis in Women (GLOW) was collected via self-administered patient questionnaires at baseline and year 1 (n = 51,491). Self-reported clinically recognized low-trauma fractures at year 1 were classified as incident spine, hip, wrist/hand, arm/shoulder, pelvis, rib, leg, and other fractures. Healthcare utilization data were self-reported and included whether the fracture was treated at a doctor's office/clinic or at a hospital. Patients were asked if they had undergone surgery or been treated at a rehabilitation center or nursing home. RESULTS: During 1-year follow-up, there were 195 spine, 134 hip, and 1,654 non-hip, non-spine fractures. Clinical vertebral fractures resulted in 617 days of hospitalization and 512 days of rehabilitation/nursing home care; hip fractures accounted for 1,306 days of hospitalization and 1,650 days of rehabilitation/nursing home care. Non-hip, non-spine fractures resulted in 3,805 days in hospital and 5,186 days of rehabilitation/nursing home care. CONCLUSIONS: While hip and vertebral fractures are well recognized for their associated increase in health resource utilization, non-hip, non-spine fractures, by virtue of their 5-fold greater number, require significantly more healthcare resources.

Fragility fractures and the osteoporosis care gap in women: the Canadian Multicentre Osteoporosis Study.

UNLABELLED: Canadian women over 50 years old were studied over a 10-year period to see if those who sustained a fracture (caused by minimal trauma) were receiving the recommended osteoporosis therapy. We found that approximately half of these women were not being treated, indicating a significant care gap in osteoporosis treatment. INTRODUCTION: Prevalent fragility fracture strongly predicts future fracture. Previous studies have indicated that women with fragility fractures are not receiving the indicated treatment. We aimed to describe post fracture care in Canadian women using a large, population-based prospective cohort that began in 1995-1997. METHODS: We followed 5,566 women over 50 years of age from across Canada over a period of 10 years in the Canadian Multicentre Osteoporosis Study. Information on medication use and incident clinical fragility fractures was obtained during a yearly questionnaire or interview and fractures were confirmed by radiographic/medical reports. RESULTS: Over the 10-year study period, 42-56% of women with yearly incident clinical fragility fractures were not treated with an osteoporosis medication. During year 1 of the study, 22% of the women who had experienced a fragility fracture were on treatment with a bisphosphonate and 26% were on hormone therapy (HT). We were not able to differentiate HT use for menopause symptoms vs osteoporosis. Use of bisphosphonate therapy increased over time; odds ratio (OR) for use at year 10 compared to use at year 1 was 3.65 (95% confidence interval (CI) 1.83-7.26). In contrast, HT use declined, with an OR of 0.07 (95%CI 0.02-0.24) at year 10 compared to year 1 of the study. CONCLUSION: In a large population-based cohort study, we found a therapeutic care gap in women with osteoporosis and fragility fractures. Although bisphosphonate therapy usage improved over time, a substantial gap remains.

The Tough Guy prehospital experience: patterns of injury at a major UK endurance event.

BACKGROUND: Data from mass gathering events help when planning allocation of resources and in setting standards of care. There is currently a lack of data from the UK. AIM: To determine the frequency of injuries and hospital transfer rates at a large outdoor endurance event. METHODS: 251 patient attendances from four consecutive events over 2 years (two summers two winters; 2006-2007) were analysed. RESULTS: 1%-2% of contenders required medical help. Hypothermia (n = 84), soft tissue problems (n = 71) and musculoskeletal problems (n = 51) were the most common conditions encountered. 4% of patients required immediate transfer to the hospital. The medical team was able to prevent 31 hospital transfers, which represents a reduction of 78%. 13% of cases specifically required a doctor who was able to prevent more immediate hospital transfers than other care givers. The majority of injuries were classified as minor (n = 228), with the remaining as intermediate (n = 23); there were no life-threatening injuries or deaths. No patient required intravenous fluid. Overall, in winter, more patients were treated when compared with summer (157 vs 94). There were significantly more retirements in winter (69 vs 22, p<0.001), although hospital transfer rates were similar. CONCLUSIONS: Medical teams should plan for casualty rates of 1%-2% of competitors and hospital transfer rates of approximately 5% of patients treated. Outdoor events in winter create more casualties than in summer and require greater resources. Trauma and exposure injuries are common; critical illness is uncommon. An adequately equipped and skilled medical team reduces hospital admissions.

The impact of incident fractures on health-related quality of life: 5 years of data from the Canadian Multicentre Osteoporosis Study.

UNLABELLED: Using prospective data from the Canadian Multicentre Osteoporosis Study (CaMos), we compared health utilities index (HUI) scores after 5 years of follow-up among participants (50 years and older) with and without incident clinical fractures. Incident fractures had a negative impact on HUI scores over time. INTRODUCTION: This study examined change in health-related quality of life (HRQL) in those with and without incident clinical fractures as measured by the HUI. METHODS: The study cohort was 4,820 women and 1,783 men (50 years and older) from the CaMos. The HUI was administered at baseline and year 5. Participants were sub-divided into incident fracture groups (hip, rib, spine, forearm, pelvis, other) and were compared with those without these fractures. The effects of both time and fracture type on HUI scores were examined in multivariable regression analyses. RESULTS: Men and women with hip fractures, compared to those without, had lower HUI measures that ranged from -0.05 to -0.25. Both women and men with spine fractures had significant deficits on the pain attributes (-0.07 to -0.12). In women, self-care (-0.06), mobility and ambulation (-0.05) were also negatively impacted. Women with rib fractures had deficits similar to women with spine fractures, and these effects persisted over time. In men, rib fractures did not significantly affect HUI scores. Pelvic and forearm fractures did not substantially influence HUI scores. CONCLUSION: The HUI was a sensitive measure of HRQL change over time. These results will inform economic analyses evaluating osteoporosis therapies.

The osteoporosis care gap in men with fragility fractures: the Canadian Multicentre Osteoporosis Study.

UNLABELLED: We examined osteoporosis diagnosis/treatment in 2,187 community dwelling men age 50+. After five years in the study, 90% of men with fragility fractures remained undiagnosed and untreated for osteoporosis. The need to treat fragility fractures is well established in guidelines, and these numbers represent an important care gap. INTRODUCTION: Whether physicians in the community are recognizing and appropriately treating osteoporosis and fragility fractures in men remains unknown. We examined the rate of diagnosis and treatment in community dwelling men participating in the Canadian Multicentre Osteoporosis Study (CaMos). METHODS: Between February 1996 and September 2002, 2,187 participants were recruited from nine sites across Canada and prospectively followed. Information on osteoporosis diagnosis, fractures, medications were collected annually by a detailed questionnaire. DXA examination of lumbar spine (L1-4) and hip were conducted at baseline and year five. RESULTS: Diagnosis and treatment in men with clinical fragility fractures was low: at baseline and year five only 2.3% and 10.3% of men with a clinical fracture reported an osteoporosis diagnosis, respectively. At year five, 90% of men with a clinical fragility fracture were untreated. Hip fractures were the most commonly treated (37.5% by year five). A diagnosis of osteoporosis resulted in greater treatment: 67% of participants with diagnosed osteoporosis were treated with a bisphosphonate and 87% were taking calcium and/or vitamin D (year five). CONCLUSIONS: In this population-based study, both a diagnostic and therapeutic gap existed between knowledge and practice related to fragility fractures and osteoporosis in men aged >or=50 years.

Health-related quality of life measurements in elderly Canadians with osteoporosis compared to other chronic medical conditions: a population-based study from the Canadian Multicentre Osteoporosis Study (CaMos).

The objective of this research was to determine the relative decrement in health-related quality of life, as measured by the health utilities index mark 3 (HUI3), in osteoporosis compared to other chronic medical conditions. The impact of chronic medical conditions other than osteoporosis on HUI3 measurements had been previously established in the 1996/1997 Canadian National Population Health Survey (NPHS). The Canadian Multicentre Osteoporosis Study (CaMos) is a national population-based study in which regional participants were randomly recruited, regardless of presence of osteoporosis. We analyzed data from participants aged > or = 65 years who completed a baseline HUI3 questionnaire and provided information on their medical history (n=3,750). We determined the age- and gender-adjusted mean decrement in HUI3 for several chronic medical conditions, including osteoporosis. The mean changes in HUI3 adjusted for age and gender (with 95% confidence intervals) were as follows: arthritis -0.10 (-0.11, -0.09), chronic obstructive pulmonary disease (COPD) -0.07 (-0.09, -0.05), diabetes mellitus -0.05 (-0.08, -0.03), heart disease -0.06 (-0.08, -0.04), hypertension -0.02 (-0.03, -0.01), and osteoporosis -0.08 (-0.11, -0.06), respectively (model r2=0.17; P<0.0001). These findings were comparable to those observed in the NPHS, with the exception of osteoporosis, which had not been previously studied in this fashion. The decrement in HUI3 score seen in participants with osteoporosis was comparable to that observed in other chronic medical conditions, such as arthritis, COPD, diabetes mellitus or heart disease.

The association between osteoporotic fractures and health-related quality of life as measured by the Health Utilities Index in the Canadian Multicentre Osteoporosis Study (CaMos).

Osteoporotic fractures can be a major cause of morbidity. It is important to determine the impact of fractures on health-related quality of life (HRQL). A total of 3,394 women and 1,122 men 50 years of age and older, who were recruited for the Canadian Multicentre Osteoporosis Study (CaMos), participated in this cross-sectional study. Minimal trauma fractures of the hip, pelvis, spine, lower body (included upper and lower leg, knee, ankle, and foot), upper body (included arm, elbow, sternum, shoulder, and clavicle), wrist and hand (included forearm, hand, and finger), and ribs were studied. Participants with subclinical vertebral deformities were also examined. The Health Utilities Index Mark II and III Systems were used to assess HRQL. Past osteoporotic fractures varied in prevalence from 1.2% (pelvis) to 27.8% (lower body) in women and 0.3% (pelvis) to 29.3% (wrist) in men. Multivariate linear regression analyses [parameter estimates and corresponding 95% confidence intervals (CI)] indicated that minimal trauma fractures were negatively associated with HRQL and that this relationship depends on fracture type and gender. The multi-attribute scores for the Mark II system were negatively related to hip (-0.05; 95% CI: -0.09, -0.01), lower body (-0.02; 95% CI: -0.03, -0.000), and subclinical vertebral fractures (-0.02; 95% CI: -0.03, -0.00) for women. The multi-attribute scores for the Mark III system were negatively related to hip (-0.09; 95% CI: -0.14, -0.03) and rib fractures (-0.06; 95% CI: -0.11, -0.00) for women, and rib fractures (-0.06; 95% CI: -0.12, -0.00) for men. In conclusion, this study demonstrates a negative association between osteoporotic fractures and quality of life in both women and men.

Associations among disease conditions, bone mineral density, and prevalent vertebral deformities in men and women 50 years of age and older: cross-sectional results from the Canadian Multicentre Osteoporosis Study.

This cross-sectional cohort study of 5566 women and 2187 men 50 years of age and older in the population-based Canadian Multicentre Osteoporosis Study was conducted to determine whether reported past diseases are associated with bone mineral density or prevalent vertebral deformities. We examined 12 self-reported disease conditions including diabetes mellitus (types 1 or 2), nephrolithiasis, hypertension, heart attack, rheumatoid arthritis, thyroid disease, breast cancer, inflammatory bowel disease, neuromuscular disease, Paget's disease, and chronic obstructive pulmonary disease. Multivariate linear and logistic regression analyses were performed to determine whether there were associations among these disease conditions and bone mineral density of the lumbar spine, femoral neck, and trochanter, as well as prevalent vertebral deformities. Bone mineral density measurements were higher in women and men with type 2 diabetes compared with those without after appropriate adjustments. The differences were most notable at the lumbar spine (+0.053 g/cm2), femoral neck (+0.028 g/cm2), and trochanter (+0.025 g/cm2) in women, and at the femoral neck (+0.025 g/cm2) in men. Hypertension was also associated with higher bone mineral density measurements for both women and men. The differences were most pronounced at the lumbar spine (+0.022 g/cm2) and femoral neck (+0.007 g/cm2) in women and at the lumbar spine (+0.028 g/cm2) in men. Although results were statistically inconclusive, men reporting versus not reporting past nephrolithiasis appeared to have clinically relevant lower bone mineral density values. Bone mineral density differences were -0.022, -0.015, and -0.016 g/cm2 at the lumbar spine, femoral neck, and trochanter, respectively. Disease conditions were not strongly associated with vertebral deformities. In summary, these cross-sectional population-based data show that type 2 diabetes and hypertension are associated with higher bone mineral density in women and men, and nephrolithiasis may be associated with lower bone mineral density in men. The importance of these associations for osteoporosis case finding and management require further and prospective studies.

An electrophysiological characterisation of long-term potentiation in cultured dissociated hippocampal neurones.

Long-term potentiation (LTP) of synaptic transmission is under intense investigation. It is believed that the mechanisms involved in its induction and expression are critically involved in synaptic processes that are important for learning and memory and other physiological functions. A reliable means of inducing LTP in dissociated cultured neurones would facilitate investigations into the molecular basis of LTP but has been hard to achieve. Here we report a mechanism for inducing LTP in postnatal dissociated hippocampal neurones using transient depolarisation. This form of LTP is prevented by NMDA receptor antagonists and by chelating Ca2+ in the postsynaptic neurone. It is manifest primarily as an increase in the frequency of mEPSCs.

Transient synaptic activation of NMDA receptors leads to the insertion of native AMPA receptors at hippocampal neuronal plasma membranes.

The molecular mechanisms underlying long-term potentiation (LTP) of excitatory synaptic transmission in the hippocampus are not well understood. Transient depolarisation of cultured postnatal hippocampal neurones (3x1 s exposure to 90 mM K+) induces a form of LTP that is manifest primarily as an increase in mEPSC frequency. Site-directed antibodies that recognise an extracellular region of all AMPA receptor (AMPAR) subunits (GluR1-4) were used for the immunolabelling of living neurones. These antibodies were raised in two species to enable sequential immunofluorescent labelling of individual living neurones before and after the induction of LTP. High K+ treatment resulted in the appearance of new AMPAR clusters at sites on the neuronal surface that previously lacked detectable AMPARs. The appearance of new AMPAR clusters was NMDA receptor (NMDAR)-dependent since it was antagonised by the application of NMDAR antagonists. Our data indicate that the transient synaptic activation of NMDARs can lead to the insertion of native AMPARs at sites on the neuronal membrane that initially lacks AMPARs.

GABA(B) receptors couple directly to the transcription factor ATF4.

The inhibitory neurotransmitter gamma-aminobutyric acid (GABA), acts at ionotropic (GABA(A) and GABA(C)) and metabotropic (GABA(B)) receptors. Functional GABA(B) receptors are heterodimers of GABA(B(1)) and GABA(B(2)) subunits. Here we show a robust, direct, and specific interaction between the coiled-coil domain present in the C-terminus of the GABA(B(1)) subunit and the transcription factor ATF4 (also known as CREB2). ATF4 and GABA(B(2)) binding to the GABA(B(1)) subunit were mutually exclusive. In rat hippocampal neurons native GABA(B(1)) showed surprisingly little similarity to GABA(B(2)) in its subcellular distribution. GABA(B(1)) and ATF4, however, were highly colocalized throughout the cell and displayed a punctate distribution within the dendrites. Activation of GABA(B) receptors in hippocampal neurons caused a dramatic translocation of ATF4 out of the nucleus into the cytoplasm. These data suggest a novel neuronal signaling pathway that could regulate the functional expression of GABA(B) receptors and/or modulate gene transcription.

The influence of osteoporotic fractures on health-related quality of life in community-dwelling men and women across Canada.

Health-related quality of life (HRQL) was examined in relation to prevalent fractures in 4816 community-dwelling Canadian men and women 50 years and older participating in the Canadian Multicentre Osteoporosis Study (CaMos). Fractures were of three categories: clinically recognized main fractures, subclinical vertebral fractures and fractures at other sites. Main fractures were divided and analyzed at the hip, spine, wrist/forearm, pelvis and rib sites. Baseline assessments of anthropometric data, medical history, therapeutic drug use, spinal radiographs and prevalent fractures were obtained from all participants. The SF-36 instrument was used as a tool to measure HRQL. A total of 652 (13.5%) main fractures were reported. Results indicated that hip, spine, wrist/forearm, pelvis and rib fractures had occurred in 78 (1.6%), 40 (0.8%), 390 (8.1%), 19 (0.4%) and 125 (2.6%) individuals, respectively (subjects may have had more than one main fracture). Subjects who had experienced a main prevalent fracture had lower HRQL scores compared with non-fractured participants. The largest differences were observed in the physical functioning (-4.0; 95% confidence intervals (CI): -6.0, -2.0) and role-physical functioning domains (-5.8; 95% CI: -9.5, -2.2). In women, the physical functioning domain was most influenced by hip (-14.9%; 95% CI: -20.9, -9.0) and pelvis (-18.1; 95% CI: -27.6, -8.6) fractures. In men, the role-physical domain was most affected by hip fractures (-35.7; 95% CI: -60.4, -11.1). Subjects who experienced subclinical vertebral fractures had lower HRQL scores than those without prevalent fractures. In conclusion, HRQL was lower in the physical functioning domain in women and the role-physical domain in men who sustained main fractures at the hip. Subclinical vertebral fractures exerted a moderate effect on HRQL.

Developmental changes in synaptic AMPA and NMDA receptor distribution and AMPA receptor subunit composition in living hippocampal neurons.

AMPA and NMDA receptors mediate most excitatory synaptic transmission in the CNS. We have developed antibodies that recognize all AMPA or all NMDA receptor variants on the surface of living neurons. AMPA receptor variants were identified with a polyclonal antibody recognizing the conserved extracellular loop region of all four AMPA receptor subunits (GluR1-4, both flip and flop), whereas NMDA receptors were immunolabeled with a polyclonal antibody that binds to an extracellular N-terminal epitope of the NR1 subunit, common to all splice variants. In non-fixed brain sections these antibodies gave labeling patterns similar to autoradiographic distributions with particularly high levels in the hippocampus. Using these antibodies, in conjunction with GluR2-specific and synaptophysin antibodies, we have directly localized and quantified surface-expressed native AMPA and NMDA receptors on cultured living hippocampal neurons during development. Using a quantitative cell ELISA, a dramatic increase was observed in the surface expression of AMPA receptors, but not NMDA receptors, between 3 and 10 d in culture. Immunocytochemical analysis of hippocampal neurons between 3 and 20 d in vitro shows no change in the proportion of synapses expressing NMDA receptors (approximately 60%) but a dramatic increase (approximately 50%) in the proportion of them that also express AMPA receptors. Furthermore, over this period the proportion of AMPA receptor-positive synapses expressing the GluR2 subunit increased from approximately 67 to approximately 96%. These changes will dramatically alter the functional properties of hippocampal synapses.

Surface expression of AMPA receptors in hippocampal neurons is regulated by an NSF-dependent mechanism.

Here, we show that disruption of N-ethylmaleimide-sensitive fusion protein- (NSF-) GluR2 interaction by infusion into cultured hippocampal neurons of a blocking peptide (pep2m) caused a rapid decrease in the frequency but no change in the amplitude of AMPA receptor-mediated miniature excitatory postsynaptic currents (mEPSCs). N-methyl-D-aspartate (NMDA) receptor-mediated mEPSCs were not changed. Viral expression of pep2m reduced the surface expression of alpha-amino-3-hydroxy-5-methyl-isoxazolepropionate (AMPA) receptors, whereas NMDA receptor surface expression in the same living cells was unchanged. In permeabilized neurons, the total amount of GluR2 immunoreactivity was unchanged, and a punctate distribution of GluR2 was observed throughout the dendritic tree. These data suggest that the NSF-GluR2 interaction is required for the surface expression of GluR2-containing AMPA receptors and that disruption of the interaction leads to the functional elimination of AMPA receptors at synapses.

Screening seniors for risk of functional decline: results of a survey in family practice.

OBJECTIVE: To measure functional status, determine risk of functional decline and assess consistency between responses and standardized instruments. DESIGN: A mailed survey which measured functional impairment, recent hospitalization and bereavement. A positive response on at least one of these factors indicated that the individual was "at risk" for functional decline. A random sample (n = 73) of "at risk" subjects (specifically, family practice patients aged 70 and older) were assessed by a nurse. RESULTS: The response rate was 89% (369/415), 59% of seniors were female and the mean age was 77.1 (SD = 5.5) years. Self-reported risk, based on activities of daily living (ADLs), was associated with impairment in at least one basic ADL (p < 0.0005) using a standardized instrument. The positive predictive value of the survey for ADL impairment was 65%. CONCLUSION: Response to a mailed survey was high and self-reported ADL risks were consistent with findings from standardized assessment tools.

Chlamydial cervicitis: testing the practice guidelines for presumptive diagnosis.

OBJECTIVE: To test the recommendation from the Canadian guidelines for sexually transmitted diseases (STDs) that mucopurulent endocervical discharge and 10 or more polymorphonuclear leukocytes (PMNs) per high-power field of a Gram-stained endocervical smear or, when Gram staining is not possible, the presence of endocervical discharge and one of edema, erythema or induced mucosal bleeding of the cervix can be considered diagnostic for chlamydial cervicitis. METHODS: A total of 596 consecutive women attending 2 family planning clinics for routine care underwent vaginal speculum examination and were tested for Chlamydia trachomatis and Neisseria gonorrhoeae. PMN counts from Gram-stained endocervical smears and the presence or absence of putative indicators of chlamydial infection were recorded. RESULTS: The prevalence of chlamydial cervicitis was 6.2% (37/596), and no women tested positive for N. gonorrhoeae. Presumptive diagnosis of chlamydial cervicitis based on the guidelines criteria of mucopurulent endocervical discharge and 10 or more PMN per high-power microscopic field had a sensitivity and specificity of 18.9% and 97.0% respectively, a positive predictive value of 29.2% and a positive likelihood ratio (LR) of 6.2 (p = 0.003). Presumptive diagnosis based on endocervical discharge with edema, erythema or induced mucosal bleeding of the cervix had a sensitivity and specificity of 43.2% and 80.0% respectively, a positive predictive value of 12.5% and a positive LR of 2.2 (p = 0.002). In the presence of bacterial vaginosis or vaginitis, the LR for the criteria of mucopurulent endocervical discharge and 10 or more PMN per high-power field was 5.4 (p = 0.04), whereas the LR was 4.3 (p = 0.10) if bacterial vaginosis and vaginitis were absent. CONCLUSIONS: In this setting, the practice of making a presumptive diagnosis of chlamydial cervicitis on the basis of the criteria given in the Canadian STD guidelines was not supported.