From safety to frustration: The neural substrates of inhibitory learning in aversive and appetitive conditioning procedures

Inhibitory associative learning counters the effects of excitatory learning, whether appetitively or aversively motivated. Moreover, the affective responses accompanying the inhibitory associations are of opponent valence to the excitatory conditioned responses. Inhibitors for negative aversive outcomes (e.g. shock) signal safety, while inhibitors for appetitive outcomes (e.g. food reward) elicit frustration and/or disappointment. This raises the question as to whether studies using appetitive and aversive conditioning procedures should demonstrate the same neural substrates for inhibitory learning. We review the neural substrates of appetitive and aversive inhibitory learning as measured in different procedural variants and in the context of the underpinning excitatory conditioning on which it depends. The mesocorticolimbic dopamine pathways, retrosplenial cortex and hippocampus are consistently implicated in inhibitory learning. Further neural substrates identified in some procedural variants may be related to the specific motivation of the learning task and modalities of the learning cues. Finally, we consider the translational implications of our understanding of the neural substrates of inhibitory learning, for obesity and addictions as well as for anxiety disorders.

Haem Iron Intake Is Associated with Increased Major Adverse Cardiovascular Events, All-Cause Mortality, Congestive Cardiac Failure, and Coronary Revascularisation in Older Men: The Concord Health and Ageing in Men Project

BACKGROUND

Nutritional intake can influence major adverse cardiovascular events (MACE). Dietary iron is found in two forms: haem-iron (HI) only found in animal sources and non-haem iron (NHI) present mostly in plant sources.

OBJECTIVE

We evaluated the associations between dietary iron intakes with MACE and iron status biomarkers.

DESIGN

Prospective cohort study.

SETTING

The Concord Health and Ageing in Men Project, Sydney, Australia.

PARTICIPANTS

539 community-dwelling older Australian men aged 75 years and older.

METHODS

Men underwent nutritional assessment using a validated diet history questionnaire. Entries were converted to food groups and nutrients. The dietary calculation was used to derive HI and NHI intakes from total iron intakes. Analyses of iron intakes with iron status biomarkers were conducted using linear regression, and with MACE and individual endpoints were conducted using Cox regression. Five-point MACE comprised of all-cause mortality, myocardial infarction (MI), congestive cardiac failure (CCF), coronary revascularisation, and/or ischaemic stroke. Four-point MACE included the four endpoints of MI, CCF, coronary revascularisation, and/or ischaemic stroke, and excluded all-cause mortality.

RESULTS

At a median of 5.3 (4.6 - 6.3) years follow-up, the incidences were: 31.2% (n = 168) five-point MACE, 17.8% (n = 96) four-point MACE excluding all-cause mortality, 20.1% (n = 111) all-cause mortality, 11.3% (n = 61) CCF, and 3.1% (n = 15) coronary revascularisation. In adjusted analyses, higher HI intake (per 1mg increment) was associated with increased five-point MACE (HR: 1.45 [95% CI: 1.16, 1.80, P = .001]), four-point MACE excluding all-cause mortality (HR: 1.64 [95% CI: 1.26, 2.15, P <.001]), all-cause mortality (HR: 1.51 [95% CI: 1.15, 1.99, P = .003]), CCF (HR: 2.08 [95% CI: 1.45, 2.98, P <.001]), and coronary revascularisation (HR: 1.89 [95% CI: 1.15, 3.10, P = .012]). Compared with the bottom tertile of NHI intake, the middle tertile of NHI intake was associated with reduced risk of all-cause mortality (HR: 0.56 [95% CI: 0.33, 0.96, P = .035]). Total iron intake was not associated with MACE and individual endpoints. Dietary iron intakes were not associated with serum iron and haemoglobin.

CONCLUSION

Higher haem iron intake was independently associated with increased risks of five-point MACE, four-point MACE excluding all-cause mortality, all-cause mortality, CCF, and coronary revascularisation in older men over 5 years.

Strain comparisons in inhibitory discrimination learning and novel object recognition procedures

Strain differences in visual abilities and exploratory tendencies can confound rats' performance in cognitive tests of learning and memory. In the present study we compared the performance of albino Wistar and pigmented Lister Hooded rats in appetitive conditioning and recognition memory procedures, specifically within-subjects inhibitory learning (A+ /AX-) and novel object recognition (NOR) variants. The inhibition task included an excitatory training stage and summation and retardation tests. Difference scores were used to help control for individual variation in baseline nosepoke responding. NOR was tested after a 10 min delay, following 24hr delay and using a recency variant. Discrimination ratios were used to control for individual variation in exploratory activity. In the inhibitory learning procedure, Lister Hooded showed more magazine activity prior to stimulus presentations than Wistar rats but this was a transient effect restricted to day 1 of excitatory training. There was no strain difference in associative learning at the excitatory training stage. The Wistars went on to show some performance advantage at the inhibitory discrimination stage and marginally stronger retardation test performance. In the NOR tasks, there was no significant effect of strain on cognitive performance, but the Wistars showed some advantage in the 10 min delay variant, whereas in the 24hr delay and relative recency NOR variants, the Lister Hooded rats showed some advantage. Overall the results of the present study confirm the suitability of Wistar rats for use in associative learning and basic NOR procedures.

Frailty and Cause-Specific Hospitalizations in Community-Dwelling Older Men

OBJECTIVES

The types of medical conditions leading to hospitalization in frail older people have not been investigated. The objectives were to evaluate associations between frailty and (a) risk of all-cause and cause-specific hospitalization, and (b) rate of all-cause and cause-specific hospitalizations.

DESIGN, SETTING AND PARTICIPANTS

Community-dwelling men aged 70+ years in the Concord Health and Ageing in Men Project (CHAMP) were assessed for frailty at baseline (2005-2007, n=1705).

MEASUREMENTS

Frailty was determined by both the Fried frailty phenotype (FP) and the Rockwood frailty index (FI). Non-elective and elective hospitalization data were accessed from the New South Wales (NSW) Admitted Patient Data Collection and mortality from the NSW Deaths Registry for the period 2005-2017. Causes of hospitalization were categorized using ICD-10 classification of principal diagnoses based on organ system involved into 14 major categories.

RESULTS

Nearly 80% of CHAMP men had at least one non-elective hospitalization and 63% had an elective hospitalization over a 9-year follow-up. Men with FP frailty were twice as likely to have a non-elective hospitalization (HR: 1.98, 95%CI: 1.61-2.44) and a greater number of non-elective hospitalizations (IRR: 1.44, 95%CI: 1.22-1.70). Similar relationships were found between FI frailty and non-elective hospitalizations. Men with frailty (either FP or FI) were more likely to have at least one non-elective hospitalization for 13 of the 14 cause-related admissions. In contrast, frailty was only associated with 3 cause-related elective hospitalizations. Men with frailty were also more likely to have an increased number of non-elective hospitalizations for all 14 causes, but only for 6 causes of elective hospitalizations.

CONCLUSIONS

Our findings suggest frailty increases the risk and number of non-elective hospitalizations in older men for a wide range of cause. Strategies on early identification of frailty, followed by appropriate preventative strategies to lower the risk of non-elective hospital admissions are warranted.

Oral health behaviours of older Australian men: the Concord Health and Ageing in Men Project

BACKGROUND

The Concord Health and Ageing in Men Project (CHAMP) is a cohort study of the health of a representative sample of older Australian men. The aim of this paper is to describe the oral health behaviours and dental service use of CHAMP participants and explore associations between oral health behaviours with and general health status.

METHOD

Information collected related to socio-demographics, general health, oral health service-use and oral health behaviours. Key general health conditions were ascertained from the health questionnaire and included physical capacity and cognitive status.

RESULTS

Fifty-seven percent of the men reported visiting a dental provider at least once or more a year and 56.7% did so for a "dental check-up". Of those with some natural teeth, 59.3% claimed to brush their teeth at least twice or more a day. Most men (96%) used a standard fluoride toothpaste. Few participants used dental floss, tooth picks or mouth-rinses to supplement oral hygiene. Cognitive status and self-rated general health were associated with dental visiting patterns and toothbrushing behaviour.

CONCLUSIONS

Most older men in CHAMP perform favourable oral health behaviours. Smoking behaviour is associated with less favourable dental visiting patterns, and cognitive status with toothbrushing behaviour.

Oral health of community-dwelling older Australian men: the Concord Health and Ageing in Men Project (CHAMP)

BACKGROUND

The Concord Health and Ageing in Men Project (CHAMP) is a cohort study of the health of a representative sample of Australian men aged 70 years and older. The aim of this report is to describe the oral health of these men.

METHODS

Oral health was assessed when the men were all aged 78 years or older. Two calibrated examiners conducted a standardized intraoral assessment. Descriptive data were analysed by statistical association tests. Participants were excluded from the collection of some periodontal assessments if they had a medical contraindication.

RESULTS

Dental assessments of 614 participants revealed 90 (14.6%) were edentate. Men had a mean of 13.8 missing teeth and 10.3 filled teeth. Dentate participants had a mean of 1.1 teeth with active coronal decay. Those in the low-income group had a higher rate of decayed teeth and lower rate of filled teeth. Thirty-four participants (5.5%) had one or more dental implants, and 66.3% relied on substitute natural teeth for functional occlusion. Of those with full periodontal assessments; 90.9% had sites with pocket depths of 3 mm or more, 96.6% had sites with CAL of 5 mm or more, and 79.7% had three or more sites with GI scores of 2 or more.

CONCLUSIONS

There was a high prevalence of periodontal diseases and restorative burden of dentitions, which suggests that greater attention needs to be given to prevention and health maintenance in older Australian men.

Vitamin D status among older community dwelling men living in a sunny country and associations with lifestyle factors: the Concord Health and Ageing in Men Project, Sydney, Australia

OBJECTIVES

Inadequate vitamin D status (25-hydroxyvitamin D (25(OH)D) concentrations <50 nmol/L) is an increasingly important public health issue in Australia. The aim of this analysis is to describe 25(OH)D levels in community dwelling men aged ≥70 years in Sydney, Australia, and to determine associations between serum 25(OH)D levels and socioeconomic and lifestyle factors.

DESIGN

A population-based, cross-sectional analysis of the baseline phase of the Concord Health and Ageing in Men Project (CHAMP), a large epidemiological study conducted in Sydney between January 2005 and May 2007.

PARTICIPANTS

1659 non-institutionalised men aged ≥70 years.

METHODS

The cross-sectional analysis of the baseline phase of the Concord Health and Ageing in Men Project (CHAMP), a large epidemiological study conducted in Sydney between January 2005 and May 2007. Participants included 1659 community dwelling men who were interviewed and had clinical assessments. Main outcome measurements included serum 25(OH)D levels measured in blood samples using a radioimmunoassay kit (DiaSorin Inc., Stillwater, MN). Covariates included age, socioeconomic measures, season of blood sample, physical activity, sun exposure, vitamin D supplement use, cigarette smoking status, alcohol consumption, obesity and measures of health.

RESULTS

Prevalence of vitamin D insufficiency was 43.0%; highest in winter (55.5%) and spring (53.9%), and was associated with season (winter and spring), low physical activity, avoidance of sun exposure, current smoking and obesity, even after adjustment for confounding factors.

CONCLUSION

Inadequate vitamin D status is highly prevalent among Australian older men and is associated with specific lifestyle factors. These findings emphasize the need to screen and monitor 25(OH)D levels in this population group, despite living in a sunny country such as Australia.

Predictors of the rate of BMD loss in older men: findings from the CHAMP study

Though bone loss tends to accelerate with age there are modifiable factors that may influence the rate of bone loss even in very old men.

INTRODUCTION

The aim of this 2-year longitudinal study was to examine potential predictors of change in total hip bone mineral density (BMD) in older men.

METHODS

The Concord Health and Ageing in Men Project is a population-based study in Sydney, Australia. For this study, 1,122 men aged 70-97 years had baseline and follow-up measures of total hip BMD measured with dual X-ray absorptiometry. Data about mobility, muscle strength, balance, medication use, cognition, medical history and lifestyle factors were collected using questionnaires and clinical assessments. Serum 25-hydroxyvitamin D [25(OH)D] was also measured. Multivariate linear regression models were used to assess relationships between baseline predictors and change in BMD.

RESULTS

Over a mean of 2.2 years, there was a mean annualised loss of total hip BMD of 0.006 g/cm(2)/year (0.6 %) and hip BMC of 0.14 g/year (0.3 %). Annual BMD loss accelerated with increasing age, from 0.4 % in men aged between 70 and 75 years, to 1.2 % in men aged 85+ years. In multivariate regression models, predictors of faster BMD loss were anti-androgen, thiazolidinedione and loop-diuretic medications, kidney disease, poor dynamic balance, larger hip bone area, older age and lower serum 25(OH)D. Factors associated with attenuated bone loss were walking for exercise and use of beta-blocker medications. Change in BMD was not associated with baseline BMD, smoking, alcohol consumption, BMI, frailty, or osteoarthritis.

CONCLUSION

There was considerable variation in the rate of hip bone loss in older men. Walking, better balance and beta blockers may attenuate the acceleration of BMD loss that occurs with age.

Health and functional status of adults with intellectual disability referred to the specialist health care setting: a five-year experience

Aims and Method. The Developmental Disability Database in the Department of Rehabilitation Medicine at a metropolitan hospital was audited for observations on adults with Intellectual Disability living in the local region (total population 180,000) who were seen in an identified multidisciplinary specialist clinic, during 2006-2010. Results. There were 162 people (representing half the known number of adults with Intellectual Disability living in the region): 77 females, 85 males, age range 16-86 years. The most common complex disabilities referred to the specialists in this clinic were epilepsy (52%), challenging or changing behavior (42%) and movement disorders (34%). Early onset dementia was a feature of the group (7%). The prevalence of prescription of medications for gastro-oesophageal reflux was high (36%) and similar to the numbers of people taking psychotropic medications. The rates of chronic cardiovascular disease (2%), chronic respiratory disease (10%) and generalised arthritis (11%) were low overall, but did rise with increasing age. Conclusions. Complex neurological disabilities are common, and chronic medical illnesses are uncommon in adults with Intellectual Disability referred to specialist clinicians in this region. A combined, coordinated, multidisciplinary clinic model addresses some of the barriers experienced by adults with Intellectual Disability in the secondary health system.

Lifestyle factors, medications, and disease influence bone mineral density in older men: findings from the CHAMP study

Aging alone is not the only factor accounting for poor bone health in older men. There are modifiable factors and lifestyle choices that may influence bone health and result in higher bone density and lower fracture risk even in very old men.

INTRODUCTION

The aim of this cross-sectional analysis was to identify the factors associated with areal bone mineral density (BMD) and their relative contribution in older men.

METHODS

The Concord Health and Ageing in Men Project is a population-based study in Sydney, Australia, involving 1,705 men aged 70-97. Data were collected using questionnaires and clinical assessments. BMD of the hip and spine was measured by dual X-ray absorptiometry.

RESULTS

In multivariate regression models, BMD of the hip was associated with body weight and bone loading physical activities, but not independently with age. The positive relationship between higher BMD and recreational activities is attenuated with age. Factors independently associated with lower BMD at the hip were inability to stand from sitting, a history of kidney stones, thyroxine use, and Asian birth and at the spine, chronic obstructive pulmonary disease, paternal fracture history, and thyroxine use. Higher body weight, participation in dancing, tennis or jogging, quadriceps strength, alcohol consumption, and statin use were associated with higher hip BMD, while older age, osteoarthritis, higher body weight, and aspirin use were associated with higher spinal BMD.

CONCLUSION

Maintaining body weight, physical activity, and strength were positively associated with BMD even in very elderly men. Other parameters were also found to influence BMD, and once these were included in multivariate analysis, age was no longer associated with BMD. This suggests that age-related diseases, lifestyle choices, and medications influence BMD rather than age per se.

Socioeconomic status and bone health in community-dwelling older men: the CHAMP Study

SUMMARY

The association between socioeconomic status (SES) and bone health, specifically in men, is unclear. Based upon data from the large prospective Concord Health in Ageing Men Project (CHAMP) Study of community-dwelling men aged 70 years or over, we found that specific sub-characteristics of SES, namely, marital status, living circumstances, and acculturation, reflected bone health in older Australian men.

INTRODUCTION

Previous studies reported conflicting results regarding the relationship between SES and bone health, specifically in men. The main objective of this study was to investigate associations of SES with bone health in community-dwelling men aged 70 years or over who participated in the baseline phase of the CHAMP Study in Sydney, Australia.

METHODS

The Australian Socioeconomic Index 2006 (AUSEI06) based on the Australian and New Zealand Standard Classification of Occupations was used to determine SES in 1,705 men. Bone mineral density and bone mineral content (BMC) were determined by dual-energy X-ray absorptiometry. Bone-related biochemical and hormonal parameters, including markers of bone turnover, parathyroid hormone, and vitamin D, were measured in all men.

RESULTS

General linear models adjusted for age, weight, height, and bone area revealed no significant differences across crude AUSEI06 score quintiles for BMC at any skeletal site or for any of the bone-related biochemical measures. However, multivariate regression models revealed that in Australian-born men, marital status was a predictor of higher lumbar BMC (β = 0.07, p = 0.002), higher total body BMC (β = 0.05, p = 0.03), and lower urinary NTX-I levels (β=-0.08, p = 0.03), while living alone was associated with lower BMC at the lumbar spine (β=-0.05, p = 0.04) and higher urinary NTX-I levels (β=0.07, p = 0.04). Marital status was also a predictor of higher total body BMC (β = 0.14, p = 0.003) in immigrants from Eastern and South Eastern Europe. However, in immigrants from Southern Europe, living alone and acculturation were predictors of higher femoral neck BMC (β = 0.11, p = 0.03) and lumbar spine BMC (β = 0.10, p = 0.008), respectively.

CONCLUSIONS

Although crude occupation-based SES scores were not significantly associated with bone health in older Australian men, specific sub-characteristics of SES, namely, marital status, living circumstances, and acculturation, were predictors of bone health in both Australia-born men and European immigrants.

Gait slowing as a predictor of incident dementia: 6-year longitudinal data from the Sydney Older Persons Study

Current definitions for the preclinical phase of dementia focus predominantly on cognitive measures, with particular emphasis on memory and the prediction of Alzheimer's disease. Incorporation of non-cognitive, clinical markers into preclinical definitions may improve their predictive power. The Sydney Older Persons Study examined 6-year outcomes of 630 community-dwelling participants aged 75 or over at recruitment. At baseline, participants were defined as demented, cognitively intact or having a syndrome possibly representing the preclinical phase of Alzheimer's disease, vascular dementia, an extrapyramidal dementia or various combinations of the three. Those with cognitive impairment in combination with gait and motor slowing were the most likely to dement over the 6-year period (OR 5.6; 95% CI 2.5-12.6). This group was also the most likely to die (OR 3.3; 95% CI 1.6-6.9). White matter indices on MRI scanning were not consistently correlated with gait abnormalities. Simple measures of gait may provide useful clinical tools, assisting in the prediction of dementia. However, the underlying nature of these deficits is not yet known.

Histocompatibility antigens, aspirin use and cognitive performance in non-demented elderly subjects

HLA genotype and anti-inflammatory drug use have independently been associated with a lower risk of Alzheimer's disease (AD). We recently reported a negative association between aspirin use and AD. To investigate this further, we performed a cross-sectional study to investigate cognitive performance in 151 non-demented individuals in relation to HLA-DRB1 genotype and aspirin use. Aspirin and HLA-DRB1*01 were positive predictors of performance on logical memory (aspirin, p=0.04) and verbal fluency tests (HLA-DRB1*01, p=0.018), respectively. HLA-DRB1*05 had a negative impact on the Boston naming test (p=0.002). Our results suggest that aspirin use and inflammatory genotype may influence cognition in non-demented subjects.

A 6-year study of cognition and spatial function in the demented and non-demented elderly: the Sydney Older Persons Study

BACKGROUND

Spatial function has been suggested to be disproportionately worse in people with dementia with Lewy bodies (DLB) than other dementia groups, and poor performance on the Mini-Mental State Examination pentagon copying (PC) task has been proposed as adequate for assessing this. We aimed to establish the prevalence of poor PC in the non-demented elderly; determine the validity of the use of PC as a spatial function test, and determine if poor PC is more common in DLB than non-DLB dementias.

METHODS

In a population-based sample of 299 participants, 126 were rated as being cognitively normal (clinical rating scale [CDR] = 0), 95 mildly cognitively impaired (CDR = 0.5), and 78 met criteria for dementia, 19 of whom met criteria for probable DLB (pDLB) and 25 with none of the core features of DLB (non-DLB). The accuracy of PC performance was determined across CDR groups, and the relationship of PC to performance on a broad range of cognitive tests was evaluated. The dementia groups were compared cross-sectionally to determine differences in PC and other cognitive test performance, as well as 3 and 6 years earlier to determine cognitive differences at initial stages of cognitive decline.

RESULTS

Poor PC was common in the non-demented elderly (39% CDR = 0; 43% CDR = 0.5). In this non-demented group, PC was selectively related to tests of spatial function. Poor PC was not significantly different in the pDLB and non-DLB groups at any assessment time, however it became more prevalent as dementia severity increased. Memory function and verbal fluency were more impaired in the pDLB group in the early stages of the disorder.

COMMENT

PC appears to be a good measure of spatial function in the elderly. However, in contrast to other findings of poor spatial skills in DLB when dementia is in the mild to moderate stages, poor PC performance has not been shown to be a good early marker of DLB and its clinical correlates are yet to be determined.

Preclinical syndromes predict dementia: the Sydney older persons study

OBJECTIVES

To identify if preclinical syndromes for Alzheimer's disease, vascular dementia, and Parkinson's disease and related dementias exist. Identification of dementia at early or even preclinical stages has important implications for treatment.

METHODS

A community dwelling sample of 647 subjects aged 75 and over at recruitment were followed up for a mean period of 3.19 years (range 2.61 to 4.51 years). Each subject was asked to participate in a medical assessment which included a standardised medical history examining both past and current health and medication usage; a neuropsychological battery (mini mental state examination, Reid memory test, verbal fluency, subsets of the Boston naming test and similarities, clock drawing and copied drawings) and physical examination. Preclinical syndromes for the three predominant dementias (Alzheimer's disease, vascular dementia and Parkinson's disease, and related dementias) and their combinations were defined using cognitive, motor, and vascular features. Their longitudinal outcome as defined by death and dementia incidence was examined.

RESULTS

Preclinical syndromes affected 55.7% (n=299) of subjects. Preclinical syndromes showed a trend for an increased odds of death (odds ratio 1.72, p=0.056) and a significantly increased odds of developing dementia (odds ratio 4.81, p<0.001). Preclinical syndromes were highly sensitive, detecting 52 of 58 (89.7%) incident dementias. Two hundred and sixteen of 268 (80.6%) preclinical subjects did not show dementia over the 3 year period (positive predictive value 19.4%). Subjects defined as having a combination of cognitive, extrapyramidal, and vascular features were at greatest risk of progressing to dementia.

CONCLUSIONS

Preclinical syndromes were sensitive and significant predictors of dementia. In view of their poor positive predictive value, the preclinical syndromes as defined in this study remain a research tool needing both definitional refinement and greater periods of observation. Multiple coexistent preclinical disorders resulted in a greater incidence of dementia, providing evidence for an additive role between multiple disorders.

The incidence of dementia in an Australian community population: the Sydney Older Persons Study

OBJECTIVES

Limited Australian dementia incidence data are available. This study aimed to identify the incidence of dementia and its subtypes in an Australian community dwelling population.

METHOD

A community dwelling sample of 647 subjects aged > or =75 years at recruitment were followed for a mean period of 3.2 years (range 2.6-4.5 years). The incidence of dementia (measured in person years at risk) was identified for different levels of severity of dementia, Alzheimer's disease and vascular dementia.

RESULTS

Incidence figures were slightly higher than those previously reported. The incidence of dementia and of Alzheimer's disease increased with age but was not affected by gender. The incidence of vascular dementia was not affected by age.

CONCLUSION

This study provides the largest body of data on the incidence of dementia in Australia, indicating a slightly higher incidence of dementia than previous reports. Further Australian data are required to confirm these findings.

Anti-inflammatory drugs protect against Alzheimer disease at low doses

CONTEXT

Anti-inflammatory medications have an inverse association with Alzheimer disease (AD).

OBJECTIVES

To examine at what doses this anti-inflammatory drug effect occurs and whether other medications and/or International Classification of Diseases, Ninth Revision, Clinical Modification diagnoses affect the association.

DESIGN

Subjects 75 years and older from a random population sample were classified by consensus using International Classification of Diseases, Ninth Revision, Clinical Modification diagnoses. Drug associations with different types of dementia with and without the International Classification of Diseases, Ninth Revision, Clinical Modification diagnoses as well as dosage data were analyzed.

SETTING

The Centre for Education and Research on Aging, Concord Hospital, Concord, Australia.

PATIENTS

The Sydney Older Persons Study recruited 647 subjects (average age, 81 years). A total of 163 patients were given diagnoses placing them in different dementia categories and were compared with 373 control subjects. Of the patients with dementia, 78 had AD without vascular dementia, 45 had vascular dementia (permissive of other dementia diagnoses), and 40 had other dementia diagnoses (without AD or vascular dementia).

MAIN OUTCOME MEASURES

Fifty drugs or drug groups were subjected to a 2 (drug used vs drug not used) x 4 (dementia and control groups) chi(2) analysis. Drugs with inverse associations were identified and potential confounders (logistic regression) and dosage data (exact small sample 1-tailed tests) analyzed.

RESULTS

As expected, there was an inverse association between nonsteroidal anti-inflammatory drugs and aspirin (and unexpectedly angiotensin-converting enzyme inhibitors) and AD. This association was not observed with vascular dementia or any other diagnoses. Analysis showed no evidence for a dosage effect, ie, responses were equivalent for low and high doses.

CONCLUSIONS

This study does not support a high-dose anti-inflammatory action of nonsteroidal anti-inflammatory drugs or aspirin in AD. Potential mechanisms for the beneficial effects of these medications are discussed.

Motor function and disability in the dementias

Epidemiological and neuropathological series have identified three predominant dementing processes; Alzheimer's disease (AD), vascular dementia (VaD) and dementia associated with Lewy bodies (termed Parkinson's disease dementia (PDD) in this paper). While each has its own distinguishing features and by definition all impact upon day to day functioning, no random community derived sample has examined clinical features as defined by gait and balance abnormalities and compared disability ratings of the three dementias simultaneously. Six hundred and forty-seven community dwelling subjects participated in the Sydney Older Persons Study and of these 537 participated in a medical assessment. Of these 537,482 informants rated disability. Gait and balance abnormalities of the three major dementias were identified and the association of the dementias with disability examined. The three major dementias showed evidence of both slowing and ataxia in gait and balance tests. This was maximal in those with PDD. Similarly, all showed evidence of disability that was maximal in those with PDD. In conclusion, this study has identified that gait abnormalities are present in all three dementias to a varying degree. It is hypothesised that the varying levels of disability observed are a consequence of the varying levels of motor impairment, resulting in greater levels of disability in those with PDD.

A lumped parameter model of left ventricular filling-pressure waveforms

Assessment of left-ventricular function and quantification of valve stenosis are important in clinical practice as well as in physiological research. This paper describes a mathematical model of diastolic ventricular filling and flow across the mitral valve. The model primarily consists of a system of three first-order, non-linear ordinary differential equations. The equations are solved in MATLAB using the ode45 command. The model generates pressure versus time waveforms for the atrium and ventricle, and flow versus time waveforms for mitral valve flow. Comparisons between model outputs and in-vivo data collected in two porcine experiments show excellent agreement.

Alcohol consumption in a community sample of older people

OBJECTIVE

To examine the prevalence and pattern of alcohol use among community-living elderly Australians.

METHODS

A survey was conducted of randomly selected non-institutionalised people aged 75 years and older living in the inner western suburbs of Sydney. Personal interviews by trained interviewers covered background demographic information and self-reported alcohol use.

RESULTS

72% of men and 54% of women drank alcohol. The median usual daily volume of ethanol consumed by drinkers was 10 grams for men and 1.3 grams for women. However 11% of male drinkers and 6% of female drinkers consumed at defined hazardous or harmful levels.

CONCLUSIONS AND IMPLICATIONS

Although a sizeable majority of these older people were either non-drinkers or very light drinkers, a small but important proportion drank in the hazardous to harmful range. Despite increasing evidence of the health benefits of alcohol consumption it remains important to be alert for potentially harmful alcohol use among older people.

How is household vulnerability gendered? Female-headed households in the collectives of Suleimaniyah, Iraqi Kurdistan

This research tries to reach an understanding of the well-being of female-headed household members through a comparison to male-headed household members in the collectives of the Suleimaniyah governorate in Iraqi Kurdistan. Research was undertaken in five collectives in Suleimaniyah during the summer of 1998. The research contributes to the current gender and development debates which are concerned with improving the understanding of the specific gendered forms of disadvantage faced by female-headed households rather than assuming the universal poverty of this group. An understanding of well-being is approached through a broad conceptualisation of vulnerability in preference to a narrow poverty definition. That the findings of this research are complex attests to the multi-dimensional and mutually constitutive gendered experiences of vulnerability. The definitive conclusion to emerge from this research is a refuting of the rhetoric-fuelled stereotype that households headed by women are at a disadvantage in all the dimensions of vulnerability in comparison to households headed by men. The research also establishes the methodological necessity of examining intra-household distributive mechanisms that determine individuals' well-being.

Long-term benzodiazepine use by elderly people living in the community

OBJECTIVE

To investigate the prevalence of long-term benzodiazepine use in an elderly community sample, and factors associated with such use.

METHOD

Data came from the Sydney Older Persons Study, a longitudinal study of people aged 75 or over. There were 337 subjects who were interviewed in 1991-93, and subsequently followed up after three and 4.5 years. At the first interview, subjects were assessed for socio-demographic characteristics, physical and mental health, and use of health services. At the first and subsequent interviews, subjects were asked about use of medications, including benzodiazepines.

RESULTS

There were 16.6% who were using benzodiazepines at the time of all three interviews, while a further 19.6% were using them at one or two interviews. In a multivariate ordered logit regression model, long-term benzodiazepine use was associated with treatment for nervous conditions, restless sleep, being female, being divorced and greater contact with medical services.

CONCLUSIONS

The prevalence of benzodiazepine use in the elderly is high and much of this use is long term. The high prevalence of benzodiazepine use stands in contrast to the findings from national surveys that the elderly living in the community tend to have better mental health than younger age groups.

IMPLICATIONS

Efforts are needed to reduce the number of elderly people becoming long-term users. The use of benzodiazepines in this age group is of particular concern, because they may be a risk factor for falls and for cognitive impairment in the elderly.

Pseudomonas aeruginosa gene products PilT and PilU are required for cytotoxicity in vitro and virulence in a mouse model of acute pneumonia

Type IV pili of the opportunistic pathogen Pseudomonas aeruginosa mediate twitching motility and act as receptors for bacteriophage infection. They are also important bacterial adhesins, and nonpiliated mutants of P. aeruginosa have been shown to cause less epithelial cell damage in vitro and have decreased virulence in animal models. This finding raises the question as to whether the reduction in cytotoxicity and virulence of nonpiliated P. aeruginosa mutants are primarily due to defects in cell adhesion or loss of twitching motility, or both. This work describes the role of PilT and PilU, putative nucleotide-binding proteins involved in pili function, in mediating epithelial cell injury in vitro and virulence in vivo. Mutants of pilT and pilU retain surface pili but have lost twitching motility. In three different epithelial cell lines, pilT or pilU mutants of the strain PAK caused less cytotoxicity than the wild-type strain but more than isogenic, nonpiliated pilA or rpoN mutants. The pilT and pilU mutants also showed reduced association with these same epithelial cell lines compared both to the wild type, and surprisingly, to a pilA mutant. In a mouse model of acute pneumonia, the pilT and pilU mutants showed decreased colonization of the liver but not of the lung relative to the parental strain, though they exhibited no change in the ability to cause mortality. These results demonstrate that pilus function mediated by PilT and PilU is required for in vitro adherence and cytotoxicity toward epithelial cells and is important in virulence in vivo.

Carer distress in the general population: results from the Sydney Older Persons Study

OBJECTIVE

To assess distress in a sample of carers who were selected from a community survey rather than recruited via community-service agencies.

METHODS

A community survey was carried out on 630 people aged 75 or over living in Sydney, Australia. Informants nominated by these elderly people were divided into full carer (n = 21), partial carer (n = 187) and non-carer groups (n = 344). Informants completed the General Health Questionnaire (a continuous measure of psychiatric symptoms), the life satisfaction index (a measure of well-being) and the interpersonal bonding measure (a measure of quality of the relationship with the elderly person). Elderly participants had a medical examination, were assessed for disability and were questioned about use of services.

RESULTS

Elderly people who had a full carer were more disabled and had more medical diagnoses. Full, but not partial, carers reported more psychiatric symptoms and lower life satisfaction. In multivariate analysis, the main determinant of carer distress was a relationship in which the carer felt controlled by the elderly person.

CONCLUSION

When carers are selected from a population-based sample, only those who are full carers are more distressed. However, relationship factors are the most important determinant of distress.

Informant-based staging of dementia using the clinical dementia rating

The staging of dementia is ideally based on both an examination of the patient and a history taken from an informant. However, in some circumstances, only an informant history is possible. The aim of this study was to assess the validity of the Clinical Dementia Rating (CDR) when the rating is based solely on informant data. The CDR was used in a study of 360 persons aged 78 or older who were participants in a community survey, the Sydney Older Persons Study. The CDR was completed in two ways: (1) a social scientist made the ratings based on an informant interview; and (2) a physician made the ratings after an examination of the subject. All CDRs were scored in the conventional way, as well as by the revised method proposed by Gelb and St. Laurent (Alzheimer Dis Assoc Disord 1993;4:202-11). The informant CDR showed moderate agreement with the clinician CDR, showing that it would be a valid substitute in situations in which the subject could not be examined. The revised scoring method was slightly easier to implement than the conventional method.

Impact of chronic systemic and neurological disorders on disability, depression and life satisfaction

OBJECTIVE

To assess the effects of a range of chronic systemic and neurological disorders on three life quality indicators: disability, depressive symptoms and life satisfaction.

METHODS

As part of the Sydney Older Persons Study, a community survey was carried out with 434 non-demented people aged 75 or over living in Sydney, Australia. Subjects were given a medical examination covering the following disorders: heart disease, chronic lung disease, bone and joint disease, stroke, visual loss, peripheral vascular disease, obesity, other systemic diseases, gait ataxia, gait slowing (including Parkinsonism) and cognitive impairement short of dementia. They were also assessed on a clinician-rated disability scale and given self-report depression and life satisfaction scales.

RESULTS

Gait slowing affected all three indicators of life quality. Heart disease and chronic lung disease affected disability and depressive symptoms, but not life satisfaction. These associations were present when the effects of age, sex, education and all other disorders were controlled in multiple regression analyses. However, when disability was also controlled, none of the physical disorders predicted life satisfaction and only heart disease continued to predict depressive symptoms.

CONCLUSION

Of the physical disorders considered in the study, gait slowing, heart disease and chronic lung disease had the greatest impact on life quality. These disorders affect depressive symptoms and life satisfaction largely because they increase disability.

Health habits and risk of cognitive impairment and dementia in old age: a prospective study on the effects of exercise, smoking and alcohol consumption

Previous research has yielded inconsistent results on the effects of exercise, smoking and alcohol use on cognitive impairment and dementia in old age. We analysed data from the Sydney Older Persons Study to see if these health habits were associated with cognitive functioning, dementia or Alzheimer's disease. Health habits were assessed in Wave 1 of the study, when the subjects were aged 75 years or over. Three years later, the subjects were tested for cognitive functioning and clinically examined for dementia and Alzheimer's disease. The analysis was restricted to the 327 subjects examined in Wave 2 who were non-demented in Wave 1. There were few significant associations between health habits and cognitive performance and these were not found consistently across cognitive measures. No associations were found with dementia or Alzheimer's disease. While these health habits do not affect risk for dementia and cognitive impairment in the very elderly, who are at highest risk for these disorders, we cannot discount a role at younger ages.

Automatic determination of patellofemoral kinematic parameters through X-ray image processing

Examination of plain Merchant-view X-rays of the patellofemoral joint is often used to diagnose patellofemoral joint malalignment and to qualify the pathology. As digital image processing becomes more widespread, an image processing algorithm is being developed for medical personnel to easily display, manipulate and analyze digitized plain Merchant-view X-ray films on personal computers. The method provides measurement of the kinematic parameters: sulcus angle (SA), patellofemoral congruence angle (PFC), lateral patellar angle (LPA), patellar rotation angle (PR), and lateral patellar displacement (LPD). Smooth edges of the patella and the femur are obtained by using image enhancement, edge detection and morphological thinning techniques based on the thresholds chosen manually for boundary detection. Six landmarks for determining the kinematic parameters are marked automatically on the edges of patella and femur. Parameter measurements for twelve X-ray films of six patients are calculated for analysis and comparison with hand calculated parameters. The goal is develop an algorithm that can evaluate the geometry of the patellofemoral joint, and is cost effective.

Neurodegenerative and other chronic disorders among people aged 75 years and over in the community

OBJECTIVES

To assess age-related disease patterns in the older population in the community, especially the prevalence of neurodegenerative disorders and their association with systemic and vascular diseases.

DESIGN

Cross-sectional, community-based study.

SETTING

Area served by the Central Sydney Area Health Service, August 1991 to March 1994.

SUBJECTS

647 people aged 75 years or over, living in the community; 537 (83%) underwent medical assessment.

OUTCOME MEASURES

Clinician diagnoses of chronic disease, including neurodegenerative disorders (cognitive and visual impairment, gait ataxia and slowing, dementia and Parkinson's disease); arteriopathy score; age-related trends; and correlations among diagnoses and arteriopathy score.

RESULTS

Subjects had mean age of 81.0 years (range, 75-97). The most common diagnosis was arthritis (women, 73%; men, 68%), while the most common neurodegenerative diagnoses were gait ataxia (women, 57%; men, 42%), visual impairment (women, 40%; men, 45%) and cognitive impairment (women, 39%; men, 36%). Neurodegenerative diagnoses increased significantly in prevalence with increasing age, while most systemic diseases tended to decrease, although not significantly. Dementia was diagnosed in 92 subjects (17%), with Alzheimer's disease being the most common cause, but many having multiple causes. Significant correlations were found between neurodegenerative diagnoses and between the arteriopathy score and stroke, but not neurodegenerative diagnoses.

CONCLUSIONS

The increase in comorbidities in the older population arises from an age-related increase in neurodegenerative disorders. These form a cluster suggesting a common aetiologic process which is not arteriopathic.

Nongenomic effects of progesterone on human intestinal smooth muscle cells

Previous experiments demonstrated that progesterone affects intestinal smooth muscle cells through genomic and nongenomic pathways. We hypothesized that the nongenomic effect was mediated by changes in membrane excitability. We studied the effects of progesterone and other steroid hormones on a human intestinal smooth muscle cell line, using the whole cell patch-clamp technique. Ionic currents were elicited through steps from -70 mV to various test potentials. Progesterone dose-dependently reduced calcium currents. The decrease in inward current was partly due to a shift in the steady-state inactivation to more hyperpolarized potentials. This effect did not involve gene transcription, since it was not blocked by the progesterone antagonist ZK-98-299. The progesterone analogue 5-beta-dihydroprogesterone also decreased calcium currents, whereas its stereoisomer, 5-alpha- dihydroprogesterone, did not affect the properties of voltage-sensitive ion channels. Similarly, estradiol and dexamethasone did not alter inward currents. We conclude that progestins exert their nongenomic effects on intestinal smooth muscle cells by decreasing calcium currents. The change in the calcium signal may contribute to the reduction in muscle contraction observed after progesterone.

Neurological signs, aging, and the neurodegenerative syndromes

OBJECTIVES

To identify the prevalence of neurological signs said to be associated with "normal" aging in subjects 75 years and older. To examine the association of these signs with age, stroke, the neurodegenerative diagnoses (dementia, cognitive impairment, gait ataxia, gait slowing, and parkinsonism), and systemic diseases.

DESIGN

Subjects participated in a standardized clinical history, examination, neurological evaluation, and neuropsychological assessment battery. A linear regression model that allowed the simultaneous consideration of multiple parameters was used to assess the independent contribution of age and disease to the presence of the signs. Correlations between the signs and age in the subgroup free of neurological diagnoses were performed.

SETTING

Community-based study in Sydney, Australia.

PARTICIPANTS

A random sample of 647 community-dwelling subjects older than 75 years.

MAIN OUTCOME MEASURES

Standardized neurological examination in 537 subjects.

RESULTS

With the exception of impaired vibration sense (beta = .009, P < .01), loss of upward gaze (beta = .005, P < .01), and bradykinesia (beta = .005, P < .01), all signs were associated with the neurodegenerative syndromes and stroke. Analysis of the subgroup free of neurological diagnoses confirmed these findings. Apart from impaired vibration sense of the thumbs (r = 0.22, P < .01) and gait instability (r = 0.20, P < .05), no significant associations with age were identified.

CONCLUSION

It is not aging to which many neurological signs should be attributed, but rather to the neurodegenerative syndromes that accompany aging.

Mechanical characteristics and active tension generation in rat intestinal arterioles

The contributions of active and passive wall tension to regulation of arteriolar diameters were determined for large (1A), intermediate (2A), and small (3A) arterioles in the small intestine of the anesthetized rat. Active tension (Ta) contributed greater than 85% of total wall force at rest in 2A and 3A and 75-80% of total force in 1A. Ta was approximately 90% of peak active tension (Ta,peak) for large through small arterioles, even though absolute Ta varied by fourfold. A linear relationship between microvascular pressure and Ta was observed for decreases in pressure in all arterioles. Ta remained nearly constant for pressure increases of 40% in 2A and 3A but was increased in 1A. Because of the plateau of the circumference-Ta relationship near Ta,peak, superfusion of progressively increasing concentrations of norepinephrine or adenosine resulted in maintenance of the close Ta-Ta,peak relationship unless the vessel diameter changed greater than 25%. These results indicate that, while arteriolar diameters vary substantially, near-peak Ta is generated for a variety of physiological conditions.