Carotid artery disease in post-stroke survivors and effects of enriched environment on stroke pathology in a mouse model of carotid artery stenosis.

AIMS: Carotid artery disease (CAD) is an important risk factor for stroke. We first evaluated CAD and stroke pathology in elderly post-stroke survivors. To simulate CAD, we assessed long-term consequences of bilateral common carotid artery stenosis (BCAS) in mice and exposed them to environmental enrichment (EE). METHODS: Histopathological methods were used to determine degrees of CAD (% area stenosis), brain infarct types, sizes and distribution in post-stroke survivors and BCAS mice. Adult male C57BL/6J mice after BCAS or sham surgery were randomly assigned to standard housing (Std) or limited (3 h) or full-time (Full) exposure to EE per day for 12 weeks. RESULTS: High frequencies of moderate carotid artery stenosis (51-75%) were evident in post-stroke survivors whereas those with severe CAD (>75% stenosis) exhibited greater numbers of cortical rather than subcortical infarcts and, were at higher risk of developing dementia. BCAS in mice reduced cerebral blood flow by 52% (P < 0.01) and thickened carotid artery walls, regardless of EE duration. Remarkably, the total and cortical infarcts declined by >50% in BCAS mice exposed to EE compared with BCAS-Std (P < 0.01). Frontal lobe and cortical strokes were associated with worsening working memory tested in a radial maze paradigm. Proteomic analysis revealed EE, both BCAS-3 h and BCAS-Full attenuated coagulation cascade factors including fibrinogen and von Willebrand factor, markers of blood-brain barrier damage. CONCLUSION: Small cortical and subcortical infarcts were evident in both post-stroke survivors with CAD and BCAS mice. Experimental evidence suggested that moderate exposure to EE is sufficient to reduce subsequent stroke lesions.

Priorities for research in multiple conditions in later life (multi-morbidity): findings from a James Lind Alliance Priority Setting Partnership.

INTRODUCTION: multiple conditions in later life (multi-morbidity) is a major challenge for health and care systems worldwide, is of particular relevance for older people, but has not (until recently) received high priority as a topic for research. We have identified the top 10 research priorities from the perspective of older people, their carers, and health and social care professionals using the methods of a James Lind Alliance Priority Setting Partnership. METHODS: in total, 354 participants (162 older people and carers, 192 health professionals) completed a survey and 15 older people and carers were interviewed to produce 96 'unanswered questions'. These were further refined by survey and interviews to a shortlist of 21 topics, and a mix of people aged 80+ living with three or more conditions, carers and health and social care providers to prioritised the top 10. RESULTS: the key priorities were about the prevention of social isolation, the promotion of independence and physical and emotional well-being. In addition to these broad topics, the process also identified detailed priorities including the role of exercise therapy, the importance of falls (particularly fear of falling), the recognition and management of frailty and Comprehensive Geriatric Assessment. CONCLUSION: these topics provide a unique perspective on research priorities on multiple conditions in later life and complement existing UK and International recommendations about the optimisation of health and social care systems to deliver essential holistic models of care and the prevention and treatment of multiple co-existing conditions.

Neighbourhood deprivation, health inequalities and service access by adults with intellectual disabilities: a cross-sectional study.

BACKGROUND: Adults with intellectual disabilities (IDs) experience health inequalities and are more likely to live in deprived areas. The aim of this study was to determine whether the extent of deprivation of the area a person lives in affects their access to services, hence contributing to health inequalities. METHOD: A cross-sectional study design was used. Interviews were conducted with all adults with IDs within a defined location (n = 1023), and their medical records were reviewed. The extent of area deprivation was defined by postcode, using Carstairs scores. RESULTS: Area deprivation did not influence access to social supports, daytime primary health-care services or hospital admissions, but people in more deprived areas made less use of secondary outpatient health care [first contacts (P = 0.0007); follow-ups (P = 0.0002)], and more use of accident and emergency care (P = 0.02). Women in more deprived areas were more likely to have had a cervical smear; there was little association with other health promotion uptake. Area deprivation was not associated with access to paid employment, daytime occupation, nor respite care. These results were essentially unchanged after adjusting for type of accommodation and level of ability. CONCLUSIONS: Deprivation may not contribute to health inequality in the population with IDs in the same way as in the general population. Focusing health promotion initiatives within areas of greatest deprivation would be predicted to introduce a further access inequality.

Adults with intellectual disabilities: prevalence, incidence and remission of self-injurious behaviour, and related factors.

BACKGROUND: Self-injurious behaviour (SIB) is a serious condition, with implications for the person, their family and financial costs to the state providing care. The previously reported prevalence of SIB has ranged from 1.7% to 41%, or 1.7%-23.7% in community studies. There has been little study of remission rate, and incidence has not previously been reported. SIB has been reported to be individually associated with lower ability, autism and communication impairments, but given the inter-relationships between these three factors, it is not known whether they are independently associated with SIB. This study investigates the point prevalence, incidence and remission rates of SIB among the adult population with intellectual disabilities (ID), and explores which factors are independently associated with SIB. METHOD: A prospective cohort study design was used in a general community setting. The participants were all adults (16 years and over) with ID in a defined geographical area. Individual assessments were conducted with all participants. RESULTS: The point prevalence of SIB (as defined by DC-LD) was 4.9%, the two-year incidence was 0.6%, and two-year remission rate was 38.2%. Independently related to SIB were: lower ability level, not living with a family carer, having attention deficit hyperactivity disorder, visual impairment, and not having Down syndrome. Other factors, including communication impairment, autism, and level of deprivation of the area resided within, were not related. CONCLUSIONS: SIB is not as enduring and persistent as previously thought; a significant proportion gains remission in this time period. This should provide hope for families, paid carers and professionals, and reduce therapeutic nihilism. Our study is a first tentative step towards identifying risk-markers for SIB, and developing aetiological hypotheses for subsequent testing. The extent to which SIB may be a relapsing-remitting (episodic) condition requires further investigation, so does further hypothesis-based investigation of factors that might be predictive of incidence of, and remission from, SIB.

Autonomic dysfunction in dementia.

BACKGROUND: There are no studies of autonomic function comparing Alzheimer's disease (AD), vascular dementia (VAD), dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD). AIMS: To assess cardiovascular autonomic function in 39 patients with AD, 30 with VAD, 30 with DLB, 40 with PDD and 38 elderly controls by Ewing's battery of autonomic function tests and power spectral analysis of heart rate variability. To determine the prevalence of orthostatic hypotension and autonomic neuropathies by Ewing's classification. RESULTS: There were significant differences in severity of cardiovascular autonomic dysfunction between the four types of dementia. PDD and DLB had considerable dysfunction. VAD showed limited evidence of autonomic dysfunction and in AD, apart from orthostatic hypotension, autonomic functions were relatively unimpaired. PDD showed consistent impairment of both parasympathetic and sympathetic function tests in comparison with controls (all p<0.001) and AD (all p<0.03). DLB showed impairment of parasympathetic function (all p<0.05) and one of the sympathetic tests in comparison with controls (orthostasis; p = 0.02). PDD had significantly more impairment than DLB in some autonomic parameters (Valsalva ratio: p = 0.024; response to isometric exercise: p = 0.002). Patients with VAD showed impairment in two parasympathetic tests (orthostasis: p = 0.02; Valsalva ratio: p = 0.08) and one sympathetic test (orthostasis: p = 0.04). These results were in contrast with AD patients who only showed impairment in one sympathetic response (orthostasis: p = 0.004). The prevalence of orthostatic hypotension and autonomic neuropathies was higher in all dementias than in controls (all p<0.05). CONCLUSION: Autonomic dysfunction occurs in all common dementias but is especially prominent in PDD with important treatment implications.

Topological analysis of antigenic determinants on a variant surface glycoprotein of Trypanosoma brucei.

Nine monoclonal antibodies specific for the variant surface glycoprotein (VSG) of Trypanosoma brucei MITat 1.6 have been produced and characterised as part of a coordinated project to define the three dimensional structure and immunological profile of this and other VSG molecules. Competition radioimmunoassays using all combinations of these antibodies identified five distinct antigenic determinants, showing varying degrees of overlap, on the MITat 1.6 VSG molecule. A map has been constructed of the determinants which have been identified. Immunofluorescent staining of living trypanosomes in suspension revealed that only one of the five determinants is exposed on the surface of intact trypanosomes, the other four being accessible to antibody only after the surface coat has been disrupted or released into solution. Immunoblots, to detect binding of the antibodies to MITat 1.6 VSG transferred from sodium dodecyl sulphate gels to nitrocellulose paper, showed binding of all the monoclonal antibodies, except those recognising the surface of the living trypanosome, to VSG in this form. This suggests the surface determinant may be more conformationally iabile than the others identified. The significance of the existence, and apparent predominance of variant specific antigenic determinants which are cryptic in the intact surface coat is discussed.

Mapping of antigenic determinants within peptides of a variant surface glycoprotein of Trypanosoma brucei.

The location of antigenic determinants in the primary amino acid sequence of the variant surface glycoprotein of Trypanosoma brucei MITat 1.6 was investigated using monoclonal antibodies in conjunction with the known cyanogen bromide and tryptic cleavage patterns of this antigen. The cyanogen bromide digestion fragments of the antigen were purified and used to raise polyclonal antisera, which were specific for the appropriate cyanogen bromide fragment and partial digestion products, as well as recognising the intact variant surface glycoprotein. Competition radioimmunoassays were carried out between these antisera and nine monoclonal antibodies specific for MITat 1.6 variant surface glycoprotein, which have previously been characterised and shown to recognise five antigenic determinants of which only one is exposed on the surface of the living trypanosome. The binding of the monoclonal antibodies to the major tryptic peptide of MITat 1.6 variant surface glycoprotein was investigated by immunoblotting and by competition radioimmunoassay, and revealed that the five antigenic determinants recognised by the nine monoclonal antibodies are all located in the N-terminal two thirds of the MITat 1.6 variant surface glycoprotein molecule. Three of the determinants are located in an immunodominant region apparently formed by the folding together of two of the cyanogen bromide peptides. The other two determinants appear to be more conformationally labile; one of these is the determinant which is exposed on the surface of the living trypanosome, which is located in the N-terminal one third of the molecule.

Chemical and biological profiles of sediments as indicators of sources of genotoxic contamination in Hamilton Harbour. Part I: analysis of polycyclic aromatic hydrocarbons and thia-arene compounds.

Bottom sediment and suspended sediment samples from Hamilton Harbour (western Lake Ontario) and from a major tributary were profiled using polycyclic aromatic hydrocarbons (PAH) and thia-arenes as source apportionment tracers. Ratios of selected PAH and ratios of monomethyl and dimethyl/ethyl dibenzothiophenes to the parent dibenzothiophenes were calculated. Thia-arene and PAH profiles of Standard Reference Material SRM 1649 (urban dust/organics), SRM 1650 (diesel), SRM 1597 (coal tar), Hamilton coal tar and a composite Hamilton air particulate sample provided source sample data. The gas chromatography-mass spectrometry (GC-MS) chromatograms of all sample extracts were dominated by homocyclic PAH but interpretation of PAH profiles with respect to source was difficult. In contrast, thia-arene analyses revealed more distinct differences in profiles of samples collected in different areas of the harbour, including the tributary. These results indicated that areas of coal tar-contaminated sediment are potential contributors to the overall contaminant burden of sediments and suspended sediments in Hamilton Harbour. These data also indicated that contaminants related to mobile combustion sources were entering the harbour via a major tributary.

Chemical and biological profiles of sediments as indicators of sources of contamination in Hamilton Harbour. Part II: bioassay-directed fractionation using the Ames Salmonella/microsome assay.

Bottom sediment and suspended sediment samples from Hamilton Harbour (western Lake Ontario) and from a major tributary were profiled using a bioassay-directed fractionation approach. Sample extracts were fractionated using an alumina/Sephadex gel clean-up procedure to afford non-polar aromatic fractions which were characterized using chemical analyses and the Ames/microsome bacterial assay in Salmonella typhimurium strains YG1025 with the addition of oxidative metabolism (S9), and YG1024 without S9. Non-polar aromatic fractions of selected samples were separated by normal phase HPLC into 1-min fractions which were subjected to bioassay analyses. The bioassays using strain YG1025+S9, a TA100-type strain, were performed to assess genotoxicity arising from the presence of polycyclic aromatic hydrocarbons (PAH). Fractions which exhibited mutagenic activity contained PAH with molecular masses of 252, 276 and 278 amu; these fractions contained over 80% of the genotoxicity attributable to PAH. Individual compounds identified using Gas Chromatography-Mass Spectrometry analyses in these active fractions included benzo[a]pyrene, indeno[cd]pyrene and dibenz[a,h]anthracene. The YG1025+S9 mutagenic activity profiles were similar for all samples. Mutagenic activity profiles generated using strain YG1024-S9, a TA98-type strain sensitive to compounds characteristic of mobile source emissions, were very different. The mutagenic activities in strain YG1024-S9 were greatest for harbour-suspended sediment samples collected from sites impacted by a major tributary. Suspended sediments collected near areas known to contain high levels of coal tar-contamination in the bottom sediments contained higher levels of genotoxic PAH than suspended sediments collected from other areas of the harbour.

Motor subtype and cognitive decline in Parkinson's disease, Parkinson's disease with dementia, and dementia with Lewy bodies.

BACKGROUND: A previous cross sectional study found over-representation of a postural instability gait difficulty (PIGD) motor subtype in Parkinson's disease patients with dementia (PDD) and dementia with Lewy bodies (DLB), compared with Parkinson's disease (PD). AIMS: (1) To examine rates of cognitive and motor decline over two years in PD (n=40), PDD (n=42) and DLB (n=41) subjects, compared with age matched controls (n=41), (2) to record whether motor phenotypes of PD, PDD, and DLB subjects changed during the study, (3) to find out if cognitive and motor decline in PD was associated with baseline motor subtype, and (4) to report the incidence of dementia in PD patients in relation to baseline motor subtype. RESULTS: Most of PDD and DLB participants were PIGD subtype at baseline assessment. In the non-demented PD group, tremor dominant (TD) and PIGD subtypes were more evenly represented. Cognitive decline over two years was greater in PDD and DLB groups (mean decline in MMSE -4.5 and -3.9, respectively), compared with PD (-0.2) and controls (-0.3). There was an association between PIGD subtype and increased rate of cognitive decline within the PD group. Of 40 PD patients, 25% of the 16 PIGD subtype developed dementia over two years, compared with none of the 18 TD or six indeterminate phenotype cases (chi2=6.7, Fisher's exact test p<0.05). CONCLUSION: A PIGD motor subtype is associated with a faster rate of cognitive decline in PD and may be considered a risk factor for incident dementia in PD.

Autonomic function assessed by heart rate variability is normal in Alzheimer's disease and vascular dementia.

Heart rate variability (HRV) is a sensitive method for the assessment of autonomic function and requires little cooperation from the subject, making it suitable for use in dementia. Preliminary studies have suggested that HRV may be impaired in Alzheimer's disease (AD). HRV has not been studied in vascular dementia (VAD). We investigate autonomic function in AD and VAD, using power spectral analysis of HRV. One hundred and fourteen participants were evaluated (14 AD, 20 VAD and 80 controls). The resting ECG was recorded for 5 min with participants in the supine position. Power spectral analysis used to obtain spectral bands in the very-low-frequency (<0.04 Hz), low-frequency (0.04-0.15 Hz) and high-frequency (0.15-0.40 Hz) bands and total spectral power (<0.40 Hz) according to international HRV guidelines. There were no differences in HRV in patients with AD or VAD when compared with controls.

A method for the analysis of butyltin chlorides in air by gas chromatography with atomic emission detection.

An initial screening test compared the use of tropolone (2-hydroxy-2,4-6-cycloheptatrienone) in acetic acid with sodium diethyldithiocarbamate (NaDDC) as chelating agents for the extraction of butyltin chlorides from glass fiber filters and XAD-2 resin tube. NaDDC was chosen for subsequent analyses. Mono-, di-, and tributyltin chloride were spiked onto glass fiber filters and XAD-2 resin, extracted in toluene with NaDDC and derivatized with pentylmagnesium bromide. Derivatized butyltin species were determined by gas chromatography with plasma atomic emission detection. Glass fiber filters and XAD-2 resin were found to provide high retention of butyltin compounds during sampling and efficient recovery of butyltin compounds by extraction with NaDDC.

Purification and properties of the membrane form of variant surface glycoproteins (VSGs) from Trypanosoma brucei.

Variant surface glycoproteins (VSG) of Trypanosoma brucei are released in a water soluble form on impairment of membrane integrity. We have previously shown that this release is the result of an enzyme-mediated event which converts the hydrophobic membrane form VSG into the hydrophilic water-soluble form. We now present further details of the methods by which membrane form VSG ( mfVSG ) may be isolated, uncontaminated by water-soluble VSG ( sVSG ). The sensitivity to different metal ions of the enzyme that mediated the conversion event is discussed, and some biochemical characteristics of different mfVSG preparations are presented.

Disposition of 3H-enisoprost, a gastric antisecretory prostaglandin, in healthy humans.

1. After oral administration of 3H-enisoprost (450 micrograms) to five healthy men, as a solution in capsules, peak 3H levels of 5624 +/- 566 pg equiv./ml (mean +/- S.E.M.) were reached within one hour. No unchanged drug was detected in plasma. 2. Enisoprost was rapidly de-esterified to SC-36067 [(+/-)11 alpha, 16 zeta-dihydroxy-16-methyl-9-oxoprost-4Z, 13E-dien-1-oic acid], a pharmacologically active analogue, which reached peak concentrations of 651 +/- 200 pg/ml within 20 min of dosing. SC-36067 was eliminated metabolically, with a half-life of 1.61 h, by a combination of beta-oxidation, omega-oxidation and 9-keto-reduction. 3. After nine days 59.0 +/- 2.98% and 17.4 +/- 1.57% of the dose was excreted in urine and faeces respectively. The majority of this excretion was complete in two days. 4. Five urinary metabolites were identified by GC-MS. These were (+/-)3-[2 beta-(4-hydroxy-4-methyl-1E-octenyl)-3 alpha-hydroxy-5-oxo-1 alpha-cyclopentanyl]propanoic acid (SC-41411; 3.6% dose), (+/-)3-[3 alpha,5-dihydroxy-2 beta-(4-hydroxy-4-methyl-1E-octenyl)-1 alpha-cyclopentanyl]propanoic acid (SC-41411 PGF analogue; 4.8% dose), (+/-)3-[2 beta-(8-carboxy-4-hydroxy- 4-methyl-1E-octenyl)-3 alpha-hydroxy-5-oxo-1 alpha-cyclopentanyl] propanoic acid (SC-41411-16-carboxylic acid; 22% dose), (+/-)3-[2 beta-(8-carboxy-4- hydroxy-4-methyl-1E-octenyl)-3 alpha,5-dihydroxy-1 alpha-cyclopentanyl] propanoic acid (SC-41411 PGF analogue-16-carboxylic acid; 8.5% dose) and its gamma lactone (2.6% dose). 5. These metabolites were also identified chromatographically in plasma, as were SC-36067, (+/-)3-[2 beta-(4-hydroxy-4-methyl-1E-octenyl)-5-oxo-1 alpha- cyclopent-3-enyl]propanoic acid and (+/-)3-[2 beta-(4-hydroxy-4-methyl-1E-octenyl)-5-oxo-cyclopent-1- propanoic acid. 6. Some 5-10% of the dose was excreted in urine as tritiated water, indicating that oxidation of the 11 alpha-hydroxy group in SC-36067 or its metabolites also occurred.

Comparison of antiplatelet activity of microencapsulated aspirin 162.5 Mg (Caspac XL), with enteric coated aspirin 75 mg and 150 mg in patients with atherosclerosis.

AIMS: A new formulation, low dose microencapsulated aspirin, permits slow absorption of aspirin and presystemic acetylation of platelet cyclo-oxygenase within the portal circulation, potentially avoiding deleterious effects on gastric and systemic prostaglandin synthesis. The objective of this study was to determine whether the administration of microencapsulated aspirin was as effective as enteric coated (EC) aspirin as an inhibitor of platelet function in patients with atherosclerosis. METHODS: One hundred and four patients were enrolled and randomised after a run in period of at least 14 days on aspirin EC 75 mg (day 0), to receive either microencapsulated aspirin 162.5 mg (n=34), aspirin EC 150 mg (n=36) or continue on aspirin EC 75 mg (n=34) for 28 days. Serum thromboxane B2 and collagen-induced platelet aggregation and release of 5-hydroxytryptamine (EC50 values) were measured on days 0 and 28. Aggregation/release EC50s were then repeated in the presence of a large dose of aspirin added in vitro to determine the EC50 at the maximum level of platelet inhibition. RESULTS: Median thromboxane B2 levels were low after 14 days run-in therapy with aspirin EC 75 mg, but significant further reductions were seen on day 28 in patients randomised to microencapsulated aspirin 162.5 mg (P=0.0368) and aspirin EC 150 mg (P=0.0004) compared with those remaining on aspirin EC 75 mg. Median EC50 s on day 28 showed small but significant increases from baseline (day 0) in aggregation in patients randomised to microencapsulated aspirin 162.5 mg (0.62-0.85, P=0.0482) and in both aggregation and release in patients randomised to aspirin EC 150 mg (0.95-1.20, P=0.0002, 8.4-11.7, P<0. 0001, respectively) signifying enhanced antiplatelet activity. No changes were seen in patients continuing on aspirin EC 75 mg. Results following addition of high dose aspirin in vitro suggest that mechanisms other than thromboxane synthesis may be operative in the long term effects of microencapsulated aspirin 162.5 mg and aspirin EC 150 mg over aspirin EC 75 mg. CONCLUSIONS: The results show good inhibition of thromboxane B2 synthesis and subsequent platelet activity by all preparations of aspirin, although both microencapsulated aspirin 162.5 mg and aspirin EC 150 mg are slightly more effective than aspirin EC 75 mg. A randomised trial is now required to determine whether microencapsulated aspirin is associated with fewer gastric side-effects.