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.

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.

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.

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.

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.

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.

Neuropathology of cognitively normal elderly

Despite general agreement about the boundaries of Alzheimer disease (AD), establishing a maximum limit for Alzheimer-type pathology in cognitively intact individuals might aid in defining more precisely the point at which Alzheimer pathology becomes clinically relevant. In this study, we examined the neuropathological changes in the brains of 39 longitudinally followed. cognitively normal elderly individuals (24 women, 15 men; age range 74-95, median 85 years). Neuropathological changes of the Alzheimer type were quantified by determining neurofibrillary tangle (NFT) staging by the method of Braak and Braak and by quantification of the abundance of diffuse, cored, and neuritic plaque burden using the scheme developed by the Consortium to Establish a Registry for Alzheimer Disease (CERAD). Vascular, Lewy body, and argyrophilic grain pathology were also assessed. We found 34 subjects (87%) with a Braak stage <IV; 32 subjects (82%) with less than moderate numbers of cored plaques and 37 subjects (95%) with less than moderate numbers of tau-positive neuritic plaques. Many subjects had moderate or frequent diffuse plaques (n = 19, 49%). By the National Institute on Aging-Reagan Institute (NIA-RI) criteria, none of our cases met criteria for high "likelihood" of AD. Four met NIA-RI criteria for intermediate "likelihood." Seven cases met CERAD criteria for possible AD. Nineteen met Khachaturian criteria for AD. Only 1 subject had neocortical Lewy bodies. Small, old infarcts were common, but no subjects had more than 2 of these and none had a single large infarction. Thus, the majority of individuals who are cognitively normal near the time of their death have minimal amounts of tau-positive neuritic pathology (Braak stage <IV and neuritic plaques <6 per x100 field in the most affected neocortical region). The few subjects with more severe AD pathology can be expected based on incidence rates of AD in the very elderly.

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.

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.

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.

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.

Use of NHS Direct calls for surveillance of influenza--a second year's experience

A second year's call data to NHS Direct are presented to evaluate their usefulness for influenza surveillance. During the winter of 2000-01, age-group-specific data relating to the 'cold/flu' algorithm were collected from six NHS Direct sites (population coverage: 16 million). The total number of calls was collected from all 23 NHS Direct sites on a daily basis. Despite the winter of 2000-01 having been a season of low activity for influenza in the United Kingdom, NHS Direct data demonstrated a peak in the 'cold/flu' calls as a proportion of the total calls (3.1% [672 'cold/flu' calls] during week 06/01). This coincided with the peak recorded by routine influenza surveillance systems. There was also an earlier peak in the proportion of 'cold/flu' calls (3.3% during weeks 52/00 [789 'cold/flu' calls] and 01/01 [749 'cold/flu' calls]) which may have been due to other respiratory infections, the lack of specificity of the definition of NHS Direct 'cold/flu' calls and an increase in 'out-of-hours' calls to NHS Direct at the time. Despite limitations, the timeliness of NHS Direct data, the total population coverage of the service and the ability to provide local information on 'cold/flu' calls make the call data suitable for further surveillance during the winter of 2001-02. It is hoped that as NHS Direct reaches a 'steady state' in terms of population coverage and uniformity of clinical support systems, it will be possible to begin to construct 'baselines' for the respiratory disease related call data.

The impact of sporadic campylobacter and salmonella infection on health and health related behaviour: a case control study

The aim of the work was to explore the impact on general and psychological health of those with a proven bacterial gastrointestinal infection and to compare this with controls from whom no bacterial pathogen was identified. A case control study was conducted using an interviewer-administered questionnaire. Thirty-nine cases from whose faeces salmonella or campylobacter had been cultured were compared with matched controls. Reported gastrointestinal symptoms, general health and self-reported hygiene practices were compared. At the time of acute illness the General Household Questionnaire suggested similar levels of morbidity, though by follow up the controls were substantially more likely to be distressed. Cases were more likely to have changed their food preparation practices, to avoid certain eating places and to have been given advice about food preparation. In this small study a positive diagnosis of salmonella or campylobacter seems to have had a reassuring effect when compared with those for whom no diagnosis was made.

Antemortem MRI findings correlate with hippocampal neuropathology in typical aging and dementia

OBJECTIVES

To assess the diagnostic specificity of MRI-defined hippocampal atrophy for AD among individuals with a variety of pathologically confirmed conditions associated with dementia as well as changes attributable to typical aging, and to measure correlations among premortem MRI measurements of hippocampal atrophy, mental status examination performance, and the pathologic stage of AD.

METHODS

An unselected series of 67 individuals participating in the Mayo Alzheimer's Disease Research Center/Alzheimer's Disease Patient Registry who had undergone a standardized antemortem MRI study and also postmortem examination were identified. Hippocampal volumes were measured from antemortem MRI. Each postmortem specimen was assigned a pathologic diagnosis and in addition, the severity of AD pathology was staged using the method of Braak and Braak.

RESULTS

Individuals with an isolated pathologic diagnosis of AD, hippocampal sclerosis, frontotemporal degeneration, and neurofibrillary tangle--only degeneration usually had substantial hippocampal atrophy, while those with changes of typical aging did not. Among all 67 subjects, correlations (all p < 0.001) were observed between hippocampal volume and Braak and Braak stage (r = -0.39), between hippocampal volume and Mini-Mental State Examination (MMSE) score (r = 0.60), and between MMSE score and Braak and Braak stage (r = -0.41).

CONCLUSIONS

Hippocampal atrophy, while not specific for AD, was a fairly sensitive marker of the pathologic AD stage (particularly among subjects with isolated AD pathology [r = -0.63, p = 0.001]) and consequent cognitive status.

Impact of infections on primary care--greater than expected

Though infection has declined as a cause of death it consumes a major proportion of primary care resources, and because of antibiotic resistance is increasingly important. We examined the burden of illness attributable to infection in primary care by analysing data from the fourth practice-based national morbidity survey which monitored all consultations by diagnosis in 470,000 persons over a 12 month period from September 1991 to August 1992. Rates of persons consulting, new episodes of illness and consultations were calculated according to the list of infections published by Wilson and Bhopal (W&B list), and as amended by the Communicable Disease Surveillance Centre (CDSC list); selected comparisons were made with national data on hospital derived finished consultant episodes and deaths. Forty-one percent of all registered persons consulted on at least one occasion during the year for infection (estimated by either list). Infections accounted for 40% of all new episodes of illness and 29% of all consultations; respiratory infections accounted for approximately half the infection total. New episode rates were highest in children aged less than 1 year and lowest in males 25-54 years and females 55-64 years. Except in infancy, rates were higher in females. There were 734 episodes of infection annually per 1,000 population reported in general practice compared with 20 per 1,000 finished consultant episodes. The average episode of infection prompted 1.2 general practice consultations. Improved management through more precise diagnosis by near patient tests is desirable, but is unlikely to be obtained cost effectively if consultation numbers or the time spent is substantially increased. These results emphasise the importance of adequate training for general practitioners in the natural history, epidemiology, diagnosis and treatment (pharmacology) of infection.

Prospective analysis of risk factors for nursing home placement of dementia patients

OBJECTIVE

To examine risk factors for nursing home placement in a community-based dementia cohort.

METHODS

Cognitively normal participants and cognitively impaired patients from a large AD Patient Registry were followed from diagnosis to placement, death, or last follow-up. This included over 3,600 person-years of surveillance. The normal group included 473 participants who did not, at any point, meet Diagnostic and Statistical Manual of Mental Disorders, 3rd ed., revised (DSM-III-R) criteria for dementia. The patient group included 512 patients who met DSM-III-R criteria for dementia or criteria for mild cognitive impairment at diagnosis. Demographic, medical, social, cognitive, behavioral, and functional predictors of time to placement were examined using Cox modeling.

RESULTS

In the normal group, only 21 people (4%) required nursing home placement. With subjects, enrollment year, age at initial evaluation, being widowed, and living in a retirement community were associated with time to placement in separate univariate analyses. Of 512 cognitively impaired patients, 203 (39.6%) were placed in nursing homes. Median time from diagnosis to placement was 5.3 years. Within the patient sample, four predictors were determined to be associated with time to nursing home placement. These included gender, enrollment year, functional status, and cognitive score. Interactions were present for functional status with cognitive score and enrollment year.

CONCLUSION

In patients with dementia who are within 5 years of diagnosis, placement rates of approximately 10% per year can be expected. Disease severity indices including degree of cognitive and functional impairment are primary risk factors for placement.

Can calls to NHS Direct be used for syndromic surveillance?

This study assessed whether NHS Direct could be a useful source of surveillance data for communicable diseases, using influenza as a pilot condition. Data on the weekly total number of calls and the number from people reporting influenza-like symptoms to three pilot NHS Direct sites were collected between November 1999 and March 2000. NHS Direct data were compared with routinely available influenza surveillance data. The NHS Direct call rate peaked at 331 per 100,000 population in week 52 of 1999. The percentage of calls for 'influenza-like illness' (one site) peaked at 15% during week 51. Information about weekly call numbers to NHS Direct could be produced in a timely way. It was not clear whether the observed peak in calls reflected a true increase in influenza or whether it was the result of an increase in calls over the Christmas/Millennium holiday period due to more difficulty in accessing other services. The ability to assess the proportion of calls made directly by, or on behalf of, each age group will be of vital importance in interpreting seasonal respiratory disease.

Results of follow-up of human contacts of bovine tuberculosis in cattle during 1993-7 in North Staffordshire

The purpose of the study was to describe the results of follow up of human contacts of bovine tuberculosis. The bovine tuberculosis cases occurred on farms in North Staffordshire between 1993 and 1997. A total of 162 people were identified as having close contact with cattle diagnosed as having bovine tuberculosis, or who had drunk unpasteurized milk from a herd with bovine tuberculosis. A retrospective review of chest clinic notes was performed. One hundred and thirty-eight people attended for follow up, and Heaf test results, necessity for chest X-ray and further clinical follow-up are described. No case of human Mycobacterium bovis infection was identified. It is suggested that follow-up of human contacts is limited to those with close contact with herds who have bovine tuberculosis and cattle with visible pulmonary lesions or evidence of udder infection. Children on the farms with affected cattle should also be offered BCG in advance of the routine school's programme.

T3-activation of the rat growth hormone gene is inhibited by a zinc finger/homeodomain protein

Since the transcription factor Zfhep is expressed in somatotropes and binds the rat growth hormone (rGH) gene T3-response element (TRE), we investigated whether Zfhep regulates the response of this gene to T3. In cotransfection experiments, Zfhep did not regulate the native rGH promoter in the absence of T3. However, Zfhep repressed T3-mediated activation significantly in either GH(3) or JEG-3 cells. Up to 70% repression was mediated through the rGH TRE in a heterologous promoter (thymidine kinase), but was not observed with the idealized DR4 or chicken lysozyme F2 TREs. Zfhep apparently does not repress T3-mediated activation simply by competition for binding to DNA since the C-terminal DNA-binding domain of Zfhep (which is sufficient for DNA-binding) is not sufficient for repression and since cotransfection of excess thyroid hormone receptor (TR) did not prevent repression by Zfhep. These data indicate that the rGH TRE is a composite element that can integrate Zfhep and T3 regulation.

Reduction in mortality from heartwater in cattle, sheep and goats exposed to field challenge using an inactivated vaccine

Inactivated vaccines for heartwater prepared with the commercially acceptable Montanide ISA 50 (ISA 50) adjuvant were field tested in Boer goats in Botswana, Angora goats in South Africa, and Merino sheep in Zambia and Zimbabwe. Two vaccines, one made using the Zimbabwean Mbizi isolate and the other using the respective local field isolate (Sunnyside in Botswana; Bathurst in South Africa; Lutale in Zambia), were tested at each site, except in Zimbabwe where only the Mbizi vaccine was tested. Compared with unvaccinated animals, the Mbizi vaccine significantly protected goats and sheep against field Amblyomma tick challenge in Botswana, Zambia and Zimbabwe (P = 0.018, 0.002 and 0.017, respectively), but failed to protect Angora goats in South Africa. However, in South Africa the vaccine prepared using the local field isolate Bathurst, induced significant protection (P=0.008). The vaccines containing the local isolates at all other sites were less protective than the Mbizi vaccine. The Mbizi inactivated vaccine also significantly protected 17 of 21 cattle (P = 0.05) against heartwater challenge from field ticks in Zimbabwe. Against the same challenge only 7 of 21 unvaccinated control cattle survived. This study demonstrates that heartwater is a major constraint to upgrading livestock in endemic areas, and caused an overall mortality of 77.6% in naive sheep and goats (97 of 125 died) and 67% in cattle (14 of 21 died). In contrast, the vaccine had a protective effect by reducing the overall mortality in sheep and goats to 54.3% (113 of 208 died) and to 19% in cattle (4 of 21 died).

Assessment and management of behavioral disturbances in nursing home patients with dementia

Behavioral disturbances among nursing home patients with dementia are common and substantially affect patients and caregivers. Assessing the environmental, medical, and psychiatric causes of problematic behaviors and implementing a plan of behavioral, medical, and psychiatric management can reduce difficult target behaviors. This article presents a multifaceted approach to assessing patients with dementia who have behavioral problems, reviews medical and pharmacological management of these problems, and presents a multidisciplinary approach to developing treatment plans aimed at reducing such behaviors among nursing home patients with dementia.

Mild cognitive impairment and Alzheimer disease: regional diffusivity of water

PURPOSE

To compare the regional diffusivity of water in the brains of normally aging elderly people and patients with mild cognitive impairment (MCI) or Alzheimer disease.

MATERIALS AND METHODS

Magnetic resonance images were obtained in 21 patients with Alzheimer disease, 19 patients with MCI, and 55 normally aging elderly control subjects without evidence of cognitive impairment. Regions of interest were drawn to compare the apparent diffusion coefficient (ADC) and the anisotropy index (AI) in frontal, parietal, temporal, occipital, anterior, and posterior cingulate white matter (WM), and the thalami and hippocampi.

RESULTS

Hippocampal ADC was higher in MCI and Alzheimer disease patients than in control subjects. ADC of the temporal stem and posterior cingulate, occipital, and parietal WM was higher in Alzheimer disease patients than in control subjects. Except for occipital AI, which was lower in MCI patients than in control subjects, there were no differences in AI among the three groups for any of the regions.

CONCLUSION

Hippocampal ADC was significantly different between control subjects and MCI patients, many of whom likely have preclinical Alzheimer disease. Elevation in hippocampal ADC may reflect early ultrastructural changes in the progression of Alzheimer disease.