Biomedical subjects

G E Smith

Publications and source records attributed to G E Smith.

At least 19 recordsLinked to original sources

PubMed2006

Cognitive impairment in hemodialysis patients is common.

BACKGROUND: Hemodialysis patients are at high risk for cognitive impairment due to their older age and high prevalence of stroke and cardiovascular risk factors. METHODS: Using a cross-sectional design, the authors measured cognitive function in 374 hemodialysis patients aged 55 years and older and an age-matched comparison group in Minneapolis and St. Paul, MN. Cognitive performance was measured in three domains: memory, executive function, and language. Subjects were classified as having no, mild, moderate, or severe cognitive impairment. RESULTS: Of 338 subjects who completed testing in at least two of the three cognitive domains, 13.9% (95% CI 10.4, 18.1) were classified with mild impairment, 36.1% (31.0, 41.5) with moderate impairment, 37.3% (32.1, 42.7) with severe impairment, and 12.7% (9.4, 16.8) with normal cognition. Only 2.9% had a documented history of cognitive impairment. Factors associated with severe cognitive impairment on adjusted logistic regression were stroke (adjusted OR [AOR] 1.95; 95% CI 1.08, 3.49; p < 0.03), equilibrated Kt/V > 1.2 (1.67; 1.01, 2.75; p < 0.05), and education >12 years (0.32; 0.14, 0.72; p < 0.01). The AOR for severe cognitive impairment in a random sample of 101 hemodialysis patients vs an age-matched comparison group was 3.54 (1.28, 9.78; p < 0.02). CONCLUSIONS: Moderate to severe cognitive impairment is common and undiagnosed in hemodialysis patients. Further studies are needed to determine whether dialysis exacerbates the cognitive impairment attributable to underlying disease. Cognitive testing in hemodialysis patients before dialysis initiation and periodically may be warranted.

Age Distribution↗

PubMed2006

Reducing variation in antibacterial prescribing rates for 'cough/cold' and sore throat between 1993 and 2001: regional analyses using the general practice research database.

OBJECTIVE: To use the General Practice Research Database (GPRD) to explore the regional variation in prescribing for single diagnostic episodes of 'cough/cold' and sore throat and how this changed between 1993 and 2001. METHODS: Data from the GPRD was used to conduct a longitudinal survey of morbidity and antibiotic prescribing data. RESULTS: Nationally there has been a substantial reduction in diagnosed episodes per 1000 patient years at risk for both diagnoses: from 104.6 (104.0-105.2) to 86.5 (86.0-86.9) for cough/cold (-17.3%) and from 102.8 (102.2-103.4) to 69.2 (68.8-69.6) for sore throat (-32.6%). In addition to the changes in diagnostic rate there have been reductions in diagnosis-related prescribing: from 41.8% to 34.8% of cough/cold episodes (-7.0%) and from 77.3% to 60.8% of sore throat episodes (-16.4%). These aggregated data conceal wide regional variations. For cough/cold the change in prescribing rate during the study varied from -16.0% to +5.3% and for sore throat from -28.3% to -7.3%. CONCLUSIONS: In addition to a substantial reduction in diagnosis of cough/cold and sore throat, there has been a reduction in diagnosis-related prescribing episodes in almost all regions. Although there continues to be regional variation in diagnosis-related prescribing this has reduced substantially over the 9-year study period.

Anti-Bacterial Agents↗

PubMed2006

Syndromic surveillance use to detect the early effects of heat-waves: an analysis of NHS direct data in England.

OBJECTIVES: To investigate the effects of high ambient temperatures, including the summer 2003 heat-episode, on NHS Direct usage and its suitability as a surveillance tool in heat health warning systems. METHODS: Analyses of data on calls to NHS Direct in English Regions in the period Dec 2001-May 2004. Outcomes were daily rates of all symptomatic calls, and daily proportion of calls for selected causes (fever, vomiting, difficulty breathing, heat/sun-stroke) RESULTS: Total calls were moderately increased as environmental temperature increased; this effect was greatest in calls for young children and for fever. Total calls were moderately elevated during two summer heat episodes in 2003: calls specifically for heat/sun stroke increased acutely in response to these episodes. No association was apparent between environmental temperature and proportion of calls for vomiting and difficulty breathing. CONCLUSIONS: Calls to NHS Direct are sensitive to daily temperatures and extreme weather. NHS Direct is timely and has great potential in health surveillance. Calls for heat- and sun-stroke are now routinely monitored as part of the UK Heat-wave plan

Adolescent↗

PubMed2006

Can syndromic surveillance data detect local outbreaks of communicable disease? A model using a historical cryptosporidiosis outbreak.

A national UK surveillance system currently uses data from a health helpline (NHS Direct) in an attempt to provide early warning of a bio-terrorist attack, or an outbreak caused by a more common infection. To test this syndromic surveillance system we superimposed data from a historical outbreak of cryptosporidiosis onto a statistical model of NHS Direct call data. We modelled whether calls about diarrhoea (a proxy for cryptosporidiosis) exceeded a statistical threshold, thus alerting the surveillance team to the outbreak. On the date that the public health team were first notified of the outbreak our model predicted a 4% chance of detection when we assumed that one-twentieth of cryptosporidiosis cases telephoned the helpline. This rose to a 72% chance when we assumed nine-tenths of cases telephoned. The NHS Direct surveillance system is currently unlikely to detect an event similar to the cryptosporidiosis outbreak used here and may be most suited to detecting more widespread rises in syndromes in the community, as previously demonstrated. However, the expected rise in NHS Direct call rates, should improve early warning of outbreaks using call data.

Communicable Disease Control↗

PubMed2006

Surveillance of sexually transmitted diseases in general practice: a description of trends in the Royal College of General Practitioners Weekly Returns Service between 1994 and 2001.

This paper describes the incidence of sexually transmitted infections (STIs) recorded in the Weekly Returns Service (WRS) between 1994 and 2001. There were approximately 76,500 new diagnoses of STIs (7500 males, 71,000 females) and associated syndromes. Candidiasis was the commonest condition reported in males and females followed by pelvic inflammatory disease. The ratio of males to females was 7.1 for non-specific urethritis, and 9.1 and 2.1 for Reiter's syndrome and pediculosis pubis, respectively. The incidence of anogenital warts and genital herpes changed little over time. New diagnoses of genital herpes were higher in females than in males (ratio 2.8:1), whereas the mean annual incidence of genital warts was similar in males and females. The WRS provides an insight into the burden of STI diagnoses, and diagnoses related to STIs that are managed in general practice, and as such has the potential to make a substantial contribution to STI surveillance in England.

Adolescent↗

PubMed2005

Urinary catheterization in care homes for older people: self-reported questionnaire audit of catheter management by care home staff.

A self-administered questionnaire was used to determine care home staff's reported knowledge of the urinary catheter care standards published by the National Institute for Clinical Excellence (NICE) and the Association of Continence Care, and to see whether this differed in homes with higher catheterization rates. Seven hundred and fifty out of 1438 (52%) nursing and care staff from 37 randomly selected care homes with high, medium and low catheterization rates responded. There was no difference in reported practice in care homes in the three health districts sampled or those with differing catheterization rates. Eighty-three percent of the nursing staff and 40% of the other care staff received formal catheter care training. However, at least 10% of all staff reported not washing their hands before handling a catheter, and delaying emptying a urine bag until it was full, rather than three-quarters full. Only 45% of nursing staff and 40% of other care staff encouraged residents to empty their own catheter bags. Routine use of catheter maintenance solutions or bladder washouts was reported by 50% of all staff. Nursing staff (29%) and other care staff (54%) took urine specimens from the catheter bag tap. Compliance with standards has improved greatly since an audit in 1998. However, some non-compliance remains. There is a need for ongoing local audit and formal training in urinary catheter care, particularly for non-qualified care staff. Education is needed to ensure local implementation of NICE guidance.

Aged↗

PubMed2005

Brain atrophy rates predict subsequent clinical conversion in normal elderly and amnestic MCI.

OBJECTIVE: To test the hypothesis that the atrophy rate measured from serial MRI studies is associated with time to subsequent clinical conversion to a more impaired state in both cognitively healthy elderly subjects and in subjects with amnestic mild cognitive impairment (MCI). METHODS: Ninety-one healthy elderly patients and 72 patients with amnestic MCI who met inclusion criteria were identified from the Mayo Alzheimer's Disease Research Center and Alzheimer's Disease Patient Registry. Atrophy rates of four different brain structures--hippocampus, entorhinal cortex, whole brain, and ventricle--were measured from a pair of MRI studies separated by 1 to 2 years. The time of the second scan marked the beginning of the clinical observation period. RESULTS: During follow-up, 13 healthy patients converted to MCI or Alzheimer disease (AD), whereas 39 MCI subjects converted to AD. Among those healthy at baseline, only larger ventricular annual percent volume change (APC) was associated with a higher risk of conversion (hazard ratio for a 1-SD increase 1.9, p = 0.03). Among MCI subjects, both greater ventricular volume APC (hazard ratio for a 1-SD increase 1.7, p < 0.001) and greater whole brain APC (hazard ratio for a 1-SD increase 1.4, p = 0.007) increased the risk of conversion to AD. Both ventricular APC (hazard ratio for a 1-SD increase 1.59, p = 0.001) and whole brain APC (hazard ratio for a 1-SD increase 1.32, p = 0.009) provided additional predictive information to covariate-adjusted cross-sectional hippocampal volume at baseline about the risk of converting from MCI to AD. DISCUSSION: Higher whole brain and ventricle atrophy rates 1 to 2 years before baseline are associated with an increased hazard of conversion to a more impaired state. Combining a measure of hippocampal volume at baseline with a measure of either whole brain or ventricle atrophy rates from serial MRI scans provides complimentary predictive information about the hazard of subsequent conversion from mild cognitive impairment to Alzheimer disease. However, overlap among those who did vs those who did not convert indicate that these measures are unlikely to provide absolute prognostic information for individual patients.

Age Factors↗

PubMed2005

DWI predicts future progression to Alzheimer disease in amnestic mild cognitive impairment.

The authors assessed whether measures of hippocampal water diffusivity at baseline can predict future progression to Alzheimer disease (AD) in amnestic mild cognitive impairment (aMCI). Higher baseline hippocampal diffusivity was associated with a greater risk of progression to AD in aMCI (p = 0.002). Magnetic resonance diffusion-weighted imaging may help identify patients with aMCI who will progress to AD as well as or better than structural MRI measures of hippocampal atrophy.

Age Factors↗

PubMed2005

Atypical progressive supranuclear palsy underlying progressive apraxia of speech and nonfluent aphasia.

Progressive supranuclear palsy (PSP) is a clinicopathological entity typically presenting as an akinetic rigid syndrome with early falls, axial rigidity, vertical supranuclear gaze palsy and levodopa resistance. Pathological features consist of tau deposition in neuronal and glial cells located mainly in subcortical and brainstem structures. Rare cases with the pathological diagnosis of atypical PSP have been described in which neocortical tau deposition is more widespread than what is usually seen in typical PSP. Progressive nonfluent aphasia (PNFA) is a syndrome characterized by spontaneous nonfluent speech and early preserved comprehension of language. Apraxia of speech (AOS) is a motor speech disorder that may be a feature of PNFA. We report the clinical and pathological findings of four cases that presented with features most consistent with PNFA predominated by AOS. Pathological features in these four cases included the typical features of PSP subcortically and in brainstem structures, but combined with tau-positive neuronal and glial pathology in the neocortex. Comprehensive semiquantitative analyses of tau burden including neurofibrillary tangles and pretangles, coiled bodies, tufted astrocytes and threads were undertaken in the four cases of atypical PSP and compared to 10 cases of typical PSP. Semiquantitative analysis demonstrated that in atypical PSP, the pathology shifts from subcortical grey and brainstem regions, commonly affected in typical PSP, towards neocortical regions. This shift in pathology accounts for the presentation of PNFA and AOS observed in our patients, as well as the lack of classic features of PSP. These cases demonstrate that atypical PSP can present as AOS and PNFA without the classic features of PSP.

Adult↗

PubMed2004

1H MR spectroscopy in common dementias.

OBJECTIVE: To determine the 1H MR spectroscopic (MRS) findings and intergroup differences among common dementias: Alzheimer disease (AD), vascular dementia (VaD), dementia with Lewy bodies (DLB), and frontotemporal lobar degeneration (FTLD). METHODS: The authors consecutively recruited 206 normal elderly subjects and 121 patients with AD, 41 with FTLD, 20 with DLB, and 8 with VaD. The 1H MRS metabolite ratio changes in common dementias were evaluated with respect to normal and also differences among the common dementias. RESULTS: N-acetylaspartate (NAA)/creatine (Cr) was lower than normal in patients with AD, FTLD, and VaD. Myo-inositol (mI)/Cr was higher than normal in patients with AD and FTLD. Choline (Cho)/Cr was higher than normal in patients with AD, FTLD, and DLB. There were no metabolite differences between patients with AD and FTLD or between patients with DLB and VaD. NAA/Cr was lower in patients with AD and FTLD than DLB. MI/Cr was higher in patients with AD and FTLD than VaD. MI/Cr was also higher in patients with FTLD than DLB. CONCLUSIONS: NAA/Cr levels are decreased in dementias that are characterized by neuron loss, such as AD, FTLD, and VaD. MI/Cr levels are elevated in dementias that are pathologically characterized by gliosis, such as AD and FTLD. Cho/Cr levels are elevated in dementias that are characterized by a profound cholinergic deficit, such as AD and DLB.

Acetylcholine↗

PubMed2004

Comparison of different MRI brain atrophy rate measures with clinical disease progression in AD.

OBJECTIVE: To correlate different methods of measuring rates of brain atrophy from serial MRI with corresponding clinical change in normal elderly subjects, patients with mild cognitive impairment (MCI), and patients with probable Alzheimer disease (AD). METHODS: One hundred sixty subjects were recruited from the Mayo Clinic Alzheimer's Disease Research Center and Alzheimer's Disease Patient Registry Studies. At baseline, 55 subjects were cognitively normal, 41 met criteria for MCI, and 64 met criteria for AD. Each subject underwent an MRI examination of the brain at the time of the baseline clinical assessment and then again at the time of a follow-up clinical assessment, 1 to 5 years later. The annualized changes in volume of four structures were measured from the serial MRI studies: hippocampus, entorhinal cortex, whole brain, and ventricle. Rates of change on several cognitive tests/rating scales were also assessed. Subjects who were classified as normal or MCI at baseline could either remain stable or convert to a lower-functioning group. AD subjects were dichotomized into slow vs fast progressors. RESULTS: All four atrophy rates were greater among normal subjects who converted to MCI or AD than among those who remained stable, greater among MCI subjects who converted to AD than among those who remained stable, and greater among fast than slow AD progressors. In general, atrophy on MRI was detected more consistently than decline on specific cognitive tests/rating scales. With one exception, no differences were found among the four MRI rate measures in the strength of the correlation with clinical deterioration at different stages of the disease. CONCLUSIONS: These data support the use of rates of change from serial MRI studies in addition to standard clinical/psychometric measures as surrogate markers of disease progression in AD. Estimated sample sizes required to power a therapeutic trial in MCI were an order of magnitude less for MRI than for change measures based on cognitive tests/rating scales.

Aged↗

PubMed2004

DLB fluctuations: specific features that reliably differentiate DLB from AD and normal aging.

OBJECTIVE: To determine whether certain aspects of fluctuations reliably distinguish dementia with Lewy bodies (DLB) from Alzheimer's disease (AD) and normal aging. METHODS: Participants included 200 community-dwelling cognitively normal elderly persons, 70 DLB patients, and 70 AD patients with collateral informants. A 19-item questionnaire was administered to the informants that queried about symptoms of fluctuations and delirium. RESULTS: Fluctuations occur infrequently in nondemented elderly persons aged 58 to 98 years. In contrast, four characteristics of fluctuations were found to significantly differentiate AD from DLB. These composite features include daytime drowsiness and lethargy, daytime sleep of 2 or more hours, staring into space for long periods, and episodes of disorganized speech. The presence of three or four features of this composite occurred in 63% of DLB patients compared with 12% of AD patients and 0.5% of normal elderly persons. Informant endorsement of three or four of these items yielded a positive predictive value of 83% for the clinical diagnosis of DLB against an alternate diagnosis of AD. Endorsement of fewer than three items had a negative predictive value of 70% for the absence of a clinical diagnosis of DLB in favor of AD. The authors present evidence of test-retest reliability, convergent validity, and empirical verification with a separate cross-validation sample. Fluctuations were not associated with any particular combination of hallucinations, parkinsonism, or REM sleep behavior disorder. CONCLUSIONS: Based on informant report, disturbed arousal and disorganized speech are specific aspects of fluctuations in dementia with Lewy bodies that reliably distinguish dementia with Lewy bodies from Alzheimer's disease and normal aging.

Aged↗

PubMed2004

Effect of destruction of gyrus cinguli in rat brain on the development of tolerance to the analgesic effect of morphine and physical dependence on morphine.

We studied the effect of bilateral laser destruction of rat anterior cingulate gyrus on the analgesic effect of morphine and development of tolerance and physical dependence on morphine. Bilateral laser destruction of the anterior cingulate gyrus did not modulate pain sensitivity, analgesic effect of morphine, and development of morphine tolerance. Destruction of the cingulate gyrus alleviated symptoms of the abstinence syndrome in morphine-dependent animals. We showed that morphine-induced analgesia and morphine tolerance are not associated with activity of the anterior cingulate gyrus. However, this structure plays a key role in the development of physical dependence on morphine and abstinence syndrome.

Analgesia↗

PubMed2004

How representative is the population covered by the RCGP spotter practice scheme? Using Geographical Information Systems to assess.

BACKGROUND: The Royal College of General Practitioners Weekly Returns Service (WRS) is a network of sentinel general practices providing weekly data on illnesses diagnosed in general practice across England and Wales. The WRS contributes to the surveillance of infectious disease, most notably influenza. We use Geographical Information Systems (GIS) techniques to establish whether the practice populations of the current WRS are representative of the general population. METHODS: This study compares the practice population with the general population using the Department of the Environment, Transport and Regions (DETR) Indices of Deprivation 2000 scores for English wards. RESULTS: Comparisons at the national level reveal that the WRS population is less deprived than the general population. At a supra-regional level the WRS practice population shows the same North-South differences as the national population, but the proportions of patients in the more deprived and least deprived wards are more exaggerated in the WRS population. A supplementary analysis reveals that the WRS has no patients in the most deprived wards of London. CONCLUSION: The differences have implications for the future recruitment of practices to the WRS. Previous studies have demonstrated the effect of socio-economic deprivation on GP consultation rates. To ensure that the consultation rates reported by the WRS will better reflect consulting patterns in the general population the WRS will need to recruit practices with patients in the most deprived areas of the South and less deprived areas in the North of England. This study demonstrates the value of GIS in the establishment of surveillance systems.

Communicable Diseases↗

PubMed2003

Comparison of memory fMRI response among normal, MCI, and Alzheimer's patients.

OBJECTIVE: To determine whether an fMRI memory encoding task distinguishes among cognitively normal elderly individuals, patients with mild cognitive impairment (MCI), and patients with early Alzheimer's disease (AD). METHODS: Twenty-nine subjects (11 normal, 9 MCI, 9 AD) were studied with an fMRI memory encoding task. A passive sensory task was also performed to assess potential intergroup differences in fMRI responsiveness. Activation in the medial temporal lobe for the memory task and in the anatomic rolandic area for the sensory task was studied. Intergroup comparisons were performed using receiver operating characteristic (ROC) analyses. The ROC method provides rigorous control of artifactual false-positive "activation." Subjects were tested for recall and recognition of the encoding task stimuli following the fMRI study. RESULTS: Medial temporal lobe activation was greater in normal subjects than MCI and AD patients (p = 0.03 and p = 0.04). There was no difference between AD and MCI patients in fMRI memory performance [corrected]. There was an association between fMRI memory activation (area under the ROC curve) and post-fMRI performance on recognition and free recall. There was no difference among the three groups on the sensory task. CONCLUSIONS: MCI and AD patients had less medial temporal lobe activation on the memory task than the normal subjects but similar activation as normal subjects on the sensory task. These findings suggest decreased medial temporal activation may be a specific marker of limbic dysfunction due to the neurodegenerative changes of AD. In addition, fMRI is sufficiently sensitive to detect changes in the prodromal, MCI, phase of the disease.

Aged↗

PubMed2003

Insulin degrading enzyme (IDE) genetic variants and risk of Alzheimer's disease: evidence of effect modification by apolipoprotein E (APOE).

Insulin degrading enzyme (IDE) is a protease that degrades insulin and the beta-amyloid peptide implicated in Alzheimer's disease (AD). We reexamined data on five previously reported IDE polymorphisms stratifying the analysis by the presence or absence of an apolipoprotein E (APOE) epsilon4 allele. Three IDE variants were associated with AD within epsilon4-negative subjects (genotype exact test P-values < or =0.02). A haplotype containing the minor variant at each of these sites represented an estimated 4.2% of case haplotypes versus 12.3% of control haplotypes among epsilon4-negative subjects. Lack of this minor haplotype may be predictive of AD, potentially explaining some fraction of disease within subjects without the APOE epsilon4 risk allele. Confirmation of this finding with a larger sample of cases and controls is warranted.

Aged↗

PubMed2003

Synucleinopathy pathology and REM sleep behavior disorder plus dementia or parkinsonism.

OBJECTIVE: To determine if synucleinopathy pathology is related to REM sleep behavior disorder (RBD) plus dementia or parkinsonism. METHODS: The clinical and neuropathologic findings were analyzed on all autopsied cases evaluated at Mayo Clinic Rochester from January 1990 to April 2002 who were diagnosed with RBD and a neurodegenerative disorder. Ubiquitin and/or alpha-synuclein immunocytochemistry was used in all cases. The clinical and neuropathologic diagnoses were based on published criteria. RESULTS: Fifteen cases were identified (14 men). All had clear histories of dream enactment behavior, and 10 had RBD confirmed by polysomnography. RBD preceded dementia or parkinsonism in 10 (66.7%) patients by a median of 10 (range 2 to 29) years. The clinical diagnoses included dementia with Lewy bodies (DLB) (n = 6); multiple-system atrophy (MSA) (n = 2); combined DLB, AD, and vascular dementia (n = 1); dementia (n = 1); dementia with parkinsonism (n = 1); PD (n = 1); PD with dementia (n = 1); dementia/parkinsonism/motor neuron disease (n = 1); and AD/Binswanger's disease (n = 1). The neuropathologic diagnoses were Lewy body disease (LBD) in 12 (neocortical in 11 and limbic in 1) and MSA in 3. Three also had argyrophilic grain pathology. In the LBD cases, concomitant AD pathology was present in six (one also with Binswanger's pathology, and one also with multiple subcortical infarcts). CONCLUSION: In the setting of degenerative dementia or parkinsonism, RBD often reflects an underlying synucleinopathy.

Age of Onset↗

PubMed2003

What can analysis of calls to NHS direct tell us about the epidemiology of gastrointestinal infections in the community?

OBJECTIVES: Most gastrointestinal (GI) illness within the UK goes undetected by routine surveillance. A national telephone helpline for health advice (NHS Direct) offers a new source of data on GI infection. We aim to describe NHS Direct calls suggestive of GI infection and the outcome of these calls. METHODS: Details of over 150000 telephone calls were collected from NHS Direct over a 6-month period. Calls about 'diarrhoea', 'vomiting' or 'food poisoning' were defined as GI calls and described according to the age of the patient and call outcome. RESULTS: Gastrointestinal calls accounted for 10.3% of total calls ('diarrhoea'=4.9%, 'vomiting'=5.1%). GI calls as a proportion of total calls were significantly high in children under 1 year (23.5%) and aged 1-4 years (21.5%). Call outcomes which resulted in further NHS care being recommended accounted for 72.3% of total calls and 54.5% of GI calls. CONCLUSIONS: A high proportion of NHS Direct calls were about GI symptoms especially for children under 5 years. When compared with all NHS Direct calls, GI calls were less likely to result in further NHS care being recommended. Analysis of NHS Direct calls provides further insight into GI infection in the community.

Adolescent↗