Exposure of Escherichia coli to antibiotic-efflux pump inhibitor combinations in a pharmacokinetic model: impact on bacterial clearance and drug resistance

BACKGROUND

Efflux pump inhibitors (EPIs) offer an attractive therapeutic option when combined with existing classes. However, their optimal dosing strategies are unknown.

METHODS

MICs of ciprofloxacin (CIP)+/-chlorpromazine, phenylalanine-arginine β naphthylamide (PAβN) and a developmental molecule MBX-4191 were determined and the pharmacodynamics (PD) was studied in an in vitro model employing Escherichia coli MG1655 and its isogenic MarR mutant (I1147). Exposure ranging experiments were performed initially then fractionation. Changes in bacterial load and population profiles were assessed. Strains recovered after EPI simulations were studied by WGS.

RESULTS

The CIPMICs for E. coli MG1655 and I1147 were 0.08 and 0.03 mg/L. Chlorpromazine at a concentration of 60 mg/L, PAβN concentrations of 30 mg/L and MBX-4191 concentrations of 0.5-1.0 mg/L reduced CIP MICs for I1147 and enhanced bacterial killing. Using CIP at an AUC of 1.2 mg·h/L, chlorpromazine AUC was best related to reduction in bacterial load at 24 h, however, when the time drug concentration was greater than 25 mg/L (T > 25 mg/L) chlorpromazine was also strongly related to the effect. For PaβN with CIP AUC, 0.6 mg·h/L PaβN AUC was best related to a reduction in bacterial load. MBX-4191T > 0.5-0.75 mg·h/L was best related to reduction in bacterial load. Changes in population profiles were not seen in experiments of ciprofloxacin + EPIs. WGS of recovered strains from simulations with all three EPIs showed mutations in gyrA, gyrB or marR.

CONCLUSIONS

AUC was the pharmacodynamic driver for chlorpromazine and PAβN while T > threshold was the driver for MBX-4191 and important in the activity of chlorpromazine and PAβN. Changes in population profiles did not occur with combinations of ciprofloxacin + EPIs, however, mutations in gyrA, gyrB and marR were detected.

Thermal neutron transmutation doping of GaN semiconductors

High quality Ge doping of GaN is demonstrated using primarily thermal neutrons for the first time. In this study, GaN was doped with Ge to concentrations from 10¹⁶ Ge atoms/cm³ to 10¹⁸ Ge atoms/cm³. The doping concentrations were measured using gamma-ray spectroscopy and confirmed using SIMS analysis. The data from SIMS analysis also show consistent Ge doping concentration throughout the depth of the GaN wafers. After irradiation, the GaN was annealed in a nitrogen environment at 950 °C for 30 min. The neutron doping process turns out to produce spatially uniform doping throughout the whole volume of the GaN substrate.

Qualitative Ampule and Multitest for Beta-Lactam Residues in Fluid Milk Products: Collaborative Study

A collaborative study was performed on a rapid Bacillus stearothermophilus agar diffusion ampule method to detect low levels of penicillin G in 7 types of fluid milk products. A multitest technique for processing a large number of samples simultaneously was also studied. Slight modifications were made in the original method to establish more uniformity and to eliminate doubtful responses by specifying a confirmation procedure. Twenty samples spiked with penicillin G (0.000 to 0.008 IU/mL) and tetracycline hydrochloride were frozen and sent to 20 laboratories in the ampule test, and 16 laboratories in the multitest. Each analyst was asked to do a screening run and a confirmation run. Results were reported by color reaction and also as positive or negative for β-lactam inhibitors. The concentrations (penicillin G) where percent positive results equal 100 or not significantly less than 100 (α = 0.05) ranged from 0.005 to 0.007 IU/mi in the ampule test and from 0.004 to 0.007 IU/mL in the multitest. Both techniques have been adopted official first action.

An emerging framework for fully incorporating public involvement (PI) into patient-reported outcome measures (PROMs)

Patient-reported outcome measures (PROMs) are widely used in the United Kingdom (UK) and internationally to report and monitor patients’ subjective assessments of their symptoms and functional status and also their quality of life. Whilst the importance of involving the public in PROM development to increase the quality of the developed PROM has been highlighted this practice is not widespread. There is a lack of guidance on how public involvement (PI) could be embedded in the development of PROMs, where the roles can be more complex than in other types of research. This paper provides a timely review and sets out an emerging framework for fully incorporating PI into PROM development.

GRIPP2 reporting checklists: tools to improve reporting of patient and public involvement in research

BACKGROUND

While the patient and public involvement (PPI) evidence base has expanded over the past decade, the quality of reporting within papers is often inconsistent, limiting our understanding of how it works, in what context, for whom, and why.

OBJECTIVE

To develop international consensus on the key items to report to enhance the quality, transparency, and consistency of the PPI evidence base. To collaboratively involve patients as research partners at all stages in the development of GRIPP2.

METHODS

The EQUATOR method for developing reporting guidelines was used. The original GRIPP (Guidance for Reporting Involvement of Patients and the Public) checklist was revised, based on updated systematic review evidence. A three round Delphi survey was used to develop consensus on items to be included in the guideline. A subsequent face-to-face meeting produced agreement on items not reaching consensus during the Delphi process.

RESULTS

One hundred forty-three participants agreed to participate in round one, with an 86% (123/143) response for round two and a 78% (112/143) response for round three. The Delphi survey identified the need for long form (LF) and short form (SF) versions. GRIPP2-LF includes 34 items on aims, definitions, concepts and theory, methods, stages and nature of involvement, context, capture or measurement of impact, outcomes, economic assessment, and reflections and is suitable for studies where the main focus is PPI. GRIPP2-SF includes five items on aims, methods, results, outcomes, and critical perspective and is suitable for studies where PPI is a secondary focus.

CONCLUSIONS

GRIPP2-LF and GRIPP2-SF represent the first international evidence based, consensus informed guidance for reporting patient and public involvement in research. Both versions of GRIPP2 aim to improve the quality, transparency, and consistency of the international PPI evidence base, to ensure PPI practice is based on the best evidence. In order to encourage its wide dissemination this article is freely accessible on The BMJ and Research Involvement and Engagement journal websites.

GRIPP2 reporting checklists: tools to improve reporting of patient and public involvement in research

Background While the patient and public involvement (PPI) evidence base has expanded over the past decade, the quality of reporting within papers is often inconsistent, limiting our understanding of how it works, in what context, for whom, and why.Objective To develop international consensus on the key items to report to enhance the quality, transparency, and consistency of the PPI evidence base. To collaboratively involve patients as research partners at all stages in the development of GRIPP2.Methods The EQUATOR method for developing reporting guidelines was used. The original GRIPP (Guidance for Reporting Involvement of Patients and the Public) checklist was revised, based on updated systematic review evidence. A three round Delphi survey was used to develop consensus on items to be included in the guideline. A subsequent face-to-face meeting produced agreement on items not reaching consensus during the Delphi process.Results 143 participants agreed to participate in round one, with an 86% (123/143) response for round two and a 78% (112/143) response for round three. The Delphi survey identified the need for long form (LF) and short form (SF) versions. GRIPP2-LF includes 34 items on aims, definitions, concepts and theory, methods, stages and nature of involvement, context, capture or measurement of impact, outcomes, economic assessment, and reflections and is suitable for studies where the main focus is PPI. GRIPP2-SF includes five items on aims, methods, results, outcomes, and critical perspective and is suitable for studies where PPI is a secondary focus.Conclusions GRIPP2-LF and GRIPP2-SF represent the first international evidence based, consensus informed guidance for reporting patient and public involvement in research. Both versions of GRIPP2 aim to improve the quality, transparency, and consistency of the international PPI evidence base, to ensure PPI practice is based on the best evidence. In order to encourage its wide dissemination this article is freely accessible on The BMJ and Research Involvement and Engagement journal websites.

Leaf venation, as a resistor, to optimize a switchable IR absorber

Leaf vascular patterns are the mechanisms and mechanical support for the transportation of fluidics for photosynthesis and leaf development properties. Vascular hierarchical networks in leaves have far-reaching functions in optimal transport efficiency of functional fluidics. Embedding leaf morphogenesis as a resistor network is significant in the optimization of a translucent thermally functional material. This will enable regulation through pressure equalization by diminishing flow pressure variation. This paper investigates nature's vasculature networks that exhibit hierarchical branching scaling applied to microfluidics. To enable optimum potential for pressure drop regulation by algorithm design. This code analysis of circuit conduit optimization for transport fluidic flow resistance is validated against CFD simulation, within a closed loop network. The paper will propose this self-optimization, characterization by resistance seeking targeting to determine a microfluidic network as a resistor. To advance a thermally function material as a switchable IR absorber.

Quantitative neurodegenerative pathology does not explain the degree of hippocampal atrophy on MRI in degenerative dementia

OBJECTIVE

The purpose of this study was to investigate the neuropathological substrates underlying in vivo hippocampal atrophy on magnetic resonance imaging (MRI) in autopsy confirmed neurodegenerative dementia cases.

METHODS

Thirty-one neuropathologically verified cases (23 with Lewy body dementia (LBD) and eight with Alzheimer's disease (AD)) were included who had undergone an MRI scan close to death (mean 1.5 years). Manual volumetric measurements were undertaken for the hippocampus, entorhinal cortex and amygdala on MRI, along with quantitative neuropathological analysis of plaque, tangle and Lewy body pathology in the same regions. The relationship between neuropathology and MRI volumes was assessed using correlations and linear regression.

RESULTS

Hippocampal and amygdala volumes were significantly smaller in cases with AD than with LBD, but there was no difference in entorhinal cortex volume. Analysing all cases together, a significant positive correlation was observed between normalised hippocampal volume and percent area of Lewy bodies in the hippocampus (r=0.449, p=0.017) but not with tangles (r=0.059, p=0.766) or plaques (r=-0.361, p=0.119). There were no other significant correlations between regional MRI volume and measures of neuropathology. Regression analysis showed that overall diagnosis of AD rather than burden of individual pathological changes was the most significant predictor of hippocampal volume loss in autopsy confirmed cases.

CONCLUSION

Our results suggest that (i) hippocampal and amygdala but not entorhinal cortex, volumes differ between AD and LBD and (ii) factors other than current markers of neurodegenerative pathological change are responsible for atrophy of medial temporal lobe structures in AD and LBD.

Health self-advocacy training for persons with intellectual disabilities

BACKGROUND

People with intellectual disabilities (ID) have unequal access to health care. While systemic efforts are addressing health inequalities, there remains a need to demonstrate that persons with ID can increase their health self-advocacy skills.

METHOD

A randomised control design with up to 6-month follow-up was used to evaluate the 3Rs (Rights, Respect and Responsibility) health self-advocacy training program for persons with ID (n = 31). Training involved teaching participants to recognise and redress health rights violations in the context of respect and responsibility. Training materials included PowerPoint slides and interactive video scenarios illustrating health rights, respect and responsibility problem and non-problems. Two-hour training sessions were conducted twice a week in a group format where participants played a game and answered questions.

RESULTS

The health rights training group made significantly more correct responses on post training and follow-up tests than the control group. Training effects generalised to untrained scenarios and in situ health interviews.

CONCLUSIONS

The results of this study suggest that persons with ID can learn complex skills related to health self-advocacy. More research is needed to improve in situ generalisation.

Degenerative Myelopathy in Two Boxer Dogs

Degenerative myelopathy (DM) is a common, slowly progressive, debilitating disease reported in several dog breeds, including the German Shepherd Dog and Pembroke Welsh Corgi. Boxer dogs present occasionally for a thoracolumbar myelopathy for which no cause is identified on MRI or cerebrospinal fluid analysis. Despite a lack of a histologic description of DM in the Boxer in the veterinary literature, such dogs are presumed to have DM. Here we report 2 histologically confirmed cases of DM in the Boxer breed in which histologic studies disclosed marked degenerative changes in the spinal cord that were most prominent in the thoracic and cranial lumbar segments. Lesions consisted of myelin vacuolation and degeneration, myelophagocytosis, reactive astrocytosis, and ellipsoid formation most prominent in the lateral and ventral funiculi. We present a detailed histologic description of DM in the Boxer dog and compare it to DM in other purebred dogs.

Medial temporal lobe atrophy on MRI differentiates Alzheimer's disease from dementia with Lewy bodies and vascular cognitive impairment: a prospective study with pathological verification of diagnosis

The purpose of this study was to determine the diagnostic accuracy of medial temporal lobe atrophy (MTA) on MRI for distinguishing Alzheimer's disease from other dementias in autopsy confirmed cases, and to determine pathological correlates of MTA in Alzheimer's disease, dementia with Lewy bodies (DLB) and vascular cognitive impairment (VCI). We studied 46 individuals who had both antemortem MRI and an autopsy. Subjects were clinicopathologically classified as having Alzheimer's disease (n = 11), DLB (n = 23) or VCI (n = 12). MTA was rated visually using a standardized (Scheltens) scale blind to clinical or autopsy diagnosis. Neuropathological analysis included Braak staging as well as quantitative analysis of plaques, tangles and alpha-synuclein Lewy body-associated pathology in the hippocampus. Correlations between MTA and pathological measures were carried out using Spearman's rho, linear regression to assess the contributions of local pathologic changes to MTA. Receiver operator curve analysis was used to assess the diagnostic specificity of MTA for Alzheimer's disease among individuals with Alzheimer's disease, DLB and VCI. MTA was a highly accurate diagnostic marker for autopsy confirmed Alzheimer's disease (sensitivity of 91% and specificity of 94%) compared with DLB and VCI. Across the entire sample, correlations were observed between MTA and Braak stage (rho = 0.50, P < 0.001), per cent area of plaques in the hippocampus (rho = 0.37, P = 0.014) and per cent area of tangles in the hippocampus (rho = 0.49, P = 0.001). Linear regression showed Braak stage (P = 0.022) to be a significant predictor of MTA but not percent area of plaques (P = 0.375), percent area of tangles (P = 0.330) or percent area of Lewy bodies (P = 0.086). MTA on MRI had robust discriminatory power for distinguishing Alzheimer's disease from DLB and VCI in pathologically confirmed cases. Pathologically, it is more strongly related to tangle rather than plaque or Lewy body pathology in the temporal lobe. It may have utility as a means for stratifying samples in vivo on the basis of putative differences in pathology.

Evaluation of the BD ProbeTec ET system for the direct detection of Mycobacterium tuberculosis from clinical samples

Early detection of disease caused by members of the Mycobacterium tuberculosis complex (MTBC) is essential in controlling transmission of tuberculosis. Clinical evaluation of the BD ProbeTec ET system for the direct detection of MTBC organisms in clinical specimens is carried out by comparing results obtained with conventional liquid culture and reference laboratory identification. In 186 specimens (159 respiratory, 27 non-respiratory), the BD ProbeTec ET assay detected eight out of 11 MTBC culture-positive specimens, with overall sensitivity, specificity, positive predictive value and negative predictive value of 85%, 100%, 100% and 99%, respectively. The data show that the BD ProbeTec ET assay is a highly sensitive and specific technique, and gives an accurate result from a clinical specimen within three to four hours.

White matter lesions in an unselected cohort of the elderly: astrocytic, microglial and oligodendrocyte precursor cell responses

White matter lesions in an unselected cohort of the elderly: astrocytic, microglial and oligodendrocyte precursor cell responsesHyperintense lesions are frequently identified in T2-weighted magnetic resonance images (MRI) in the ageing brain. The pathological correlate and pathogenesis of white matter lesions (WML) remain unclear, and it is uncertain whether pathology and pathogenesis differ in periventricular lesions (PVL) compared with deep subcortical lesions (DSCL). Therefore we characterized astrocytic, microglial and oligodendrocyte responses in PVL and DSCL and compared them with control white matter using immunohistochemistry. Both PVL and DSCL were associated with severe myelin loss and increased microglia (P = 0.069 and P < 0.001), compared with nonlesional aged brain. Clasmatodendritic astroglia, immunoreactive for the serum protein fibrinogen, were present in 67% of PVL examined and 42% of DSCL. Compared with control and DSCL cases, more MAP-2 +13 positive remyelinating oligodendrocytes (P = 0.003 and P = 0.035) and platelet-derived growth factor alpha receptor positive reactive astrocytes (P < 0.001) were present in the perilesional white matter of PVL. In addition to a role for hypoperfusion, our data suggest that dysfunction of the blood-brain barrier may also contribute to the pathogenesis of a proportion of cerebral WML associated with ageing, and that attempts at remyelination are only associated with PVL and not DSCL.

APOE epsilon4 and cognitive decline in older stroke patients with early cognitive impairment

BACKGROUND

Dementia is common post stroke, but the potential role of early cognitive impairment and APOE epsilon4 as risk factors is unclear.

METHOD

Stroke survivors older than 75 years without dementia at 3 months post stroke received a detailed neuropsychological evaluation at 3 and 15 months post stroke, which included the Cambridge Assessment of Mental Disorders in the Elderly (CAMCOG). Early cognitive impairment was diagnosed using the criteria for cognitive impairment/no dementia (vascular CIND). APOE genotype was determined using a standardized method.

RESULTS

One hundred thirty-seven older stroke patients without dementia (mean age 80.6 +/- 4.3, mean CAMCOG score 83.5 +/- 10.4, 68 women) participated in the study, of whom 40 met the criteria for CIND. Stroke patients with one or more APOE epsilon4 alleles were significantly more likely to have CIND (14/40 vs 17/97, odds ratio = 2.5, 95% CI 1.1 to 5.8). Over the 1 year of follow-up, CIND patients with one or more APOE epsilon4 alleles had a mean decline on the total CAMCOG of 2.7 points compared with an improvement of >4 points among patients without APOE epsilon4 (T = 2.9 p = 0.006). CIND patients with an APOE epsilon4 allele also experienced greater decline in memory (T = 2.5, p = 0.015).

CONCLUSION

In older stroke patients with early cognitive impairment, the presence of an APOE epsilon4 allele is associated with greater progression of cognitive decline. This has implications for interventions aimed at the secondary prevention of dementia in stroke patients.

Deep Impact: observations from a worldwide Earth-based campaign

On 4 July 2005, many observatories around the world and in space observed the collision of Deep Impact with comet 9P/Tempel 1 or its aftermath. This was an unprecedented coordinated observational campaign. These data show that (i) there was new material after impact that was compositionally different from that seen before impact; (ii) the ratio of dust mass to gas mass in the ejecta was much larger than before impact; (iii) the new activity did not last more than a few days, and by 9 July the comet's behavior was indistinguishable from its pre-impact behavior; and (iv) there were interesting transient phenomena that may be correlated with cratering physics.

NINDS AIREN neuroimaging criteria do not distinguish stroke patients with and without dementia

OBJECTIVE

To determine the utility of the neuroimaging component within the National Institute of Neurological Disorders and Stroke (NINDS) Association Internationale pour la Recherche et l'Enseignement en Neurosciences (AIREN) criteria for vascular dementia for distinguishing between patients with and without dementia in the context of cerebrovascular disease.

METHOD

One hundred twenty-five poststroke patients age > or =75 (27 with and 98 without poststroke dementia) from representative hospital-based stroke registers in the North East of England were evaluated using a 1.5 T MR scanner. The proportion of patients with and without poststroke dementia meeting the imaging component of the NINDS AIREN criteria was determined, and hippocampal atrophy (measured using the Schelten scale) was compared between the two groups.

RESULTS

There were no significant differences between the patients with and without poststroke dementia on any criteria of the imaging parameters within the NINDS AIREN criteria. In addition, there were no significant differences in the number or size of cortical or subcortical infarcts between the two groups, with 13 patients without dementia having cortical infarcts >50 mm. Patients with dementia had greater hippocampal atrophy (right: Mann-Whitney U test, Z = 2.5, p = 0.01; left: Mann-Whitney U test, Z = 2.5, p = 0.01).

CONCLUSION

The neuroimaging component of the NINDS AIREN criteria does not distinguish between older patients with and without poststroke dementia.

Hippocampal atrophy, whole brain volume, and white matter lesions in older hypertensive subjects

OBJECTIVE

To determine the potential role of whole brain atrophy, hippocampal atrophy, or both, and small vessel disease/white matter lesions as mechanisms underlying the cognitive impairment associated with hypertension.

METHODS

Using MRI scanning the authors determined hippocampal volumes, whole brain volumes, and location and severity of white matter lesions, using Scheltens scale, in 103 hypertensive (166 +/- 8/88 +/- 7 mm Hg, 54 female) and 51 normotensive (132 +/- 12/74 +/- 7 mm Hg, 21 female) subjects age > or = 70 years.

RESULTS

Compared to normotensive subjects, older hypertensive subjects had significantly smaller whole brain volumes (887 +/- 109 vs 930 +/- 97 cm3, p = 0.02) and nonsignificantly reduced hippocampal volumes (5.39 +/- 1.60 vs 5.67 +/- 1.80 cm3, p = 0.33). Hypertensive subjects had an increased burden of periventricular lesions: bands (p = 0.03), frontal caps (p = 0.08), occipital caps (p = 0.07), and total periventricular hyperintensities (p = 0.02). They also had higher scores in subcortical areas: frontal (p = 0.04), temporal (p = 0.03), and deep white matter areas (p = 0.05). A correlation was found between whole brain volumes and systolic blood pressure (r = -0.19, p = 0.02). No correlation was seen between whole brain volumes and white matter lesion burden.

CONCLUSIONS

Moderate hypertension in non-impaired older subjects is associated with smaller whole brain volume and an increased burden of subcortical and periventricular white matter lesions.

The application of serial MRI analysis techniques to the study of cerebral atrophy in late-onset dementia

We have used a serial MR image analysis technique previously developed for studies of cerebral atrophy in early-onset dementia and applied it to a study of late-onset dementia patients with images acquired using a different scanner and scan sequence. Validation and optimisation tests showed that with only small changes to key analysis parameters the technique can successfully be applied to previously untested data with dissimilar image characteristics. The overall accuracy in estimation of cerebral atrophy using the technique was determined to be between 2 and 4 ml (1sigma) depending on the conditions during image acquisition. By comparing the results of alternative registration techniques we demonstrate the potential of using of fully automated 9 DOF image registration as an effective and efficient means of correcting for scanner pixel size variations, even in the presence of significant cerebral atrophy. Applied to the late-onset dementia study, patients were found to have significantly increased mean atrophy rates (p<0.001) compared to controls. In general the analysis technique is shown to be a robust, accurate and transferable tool of potential value for future studies of dementia and related neuro-degenerative disorders.

Comparison of the pathology of cerebral white matter with post-mortem magnetic resonance imaging (MRI) in the elderly brain

White matter lesions (WML) on magnetic resonance imaging (MRI) brain scans are associated with ageing. They are unrelated to specific disorders, and their impact on cognitive and other brain functions is poorly characterized. Pathological studies often omit systematic survey of WML because of the need to study multiple full coronal tissue blocks, and uncertainty over the significance of lesions identified in periventricular and deep subcortical regions. Post-mortem MRI provides a means of mapping WML but the sensitivity and specificity of the method are unresolved. In this study post-mortem MRI of WML in fixed brain slices was compared with pathology in 33 brains donated to the Medical Research Council Cognitive Function and Ageing Study (MRC CFAS). This study shows that MRI detection of WML was less sensitive than pathology: periventricaular lesions (PVL) sensitivity = 95% (87-99%), specificity = 71% (44-90%); deep subcortical lesions (DSCL) sensitivity = 86% (79-93%), specificity = 80% (72-88%). False negative MRI was associated with milder pathology, but lesions detected by myelin attenuation alone showed both microglial and endothelial activation. Therefore post-mortem MRI of formalin-fixed brain slices is a reliable method to obtain systematic data on the severity and distribution of cerebral white matter disease, and appears to detect those WML most likely to have clinical impact.

Visual rating of age-related white matter changes on magnetic resonance imaging: scale comparison, interrater agreement, and correlations with quantitative measurements

BACKGROUND AND PURPOSE

To provide further insight into the MRI assessment of age-related white matter changes (ARWMCs) with visual rating scales, 3 raters with different levels of experience tested the interrater agreement and comparability of 3 widely used rating scales in a cross-sectional and follow-up setting. Furthermore, the correlation between visual ratings and quantitative volumetric measurement was assessed.

METHODS

Three raters from different sites using 3 established rating scales (Manolio, Fazekas and Schmidt, Scheltens) evaluated 74 baseline and follow-up scans from 5 European centers. One investigator also rated baseline scans in a set of 255 participants of the Austrian Stroke Prevention Study (ASPS) and measured the volume of ARWMCs.

RESULTS

The interrater agreement for the baseline investigation was fair to good for all scales (kappa values, 0.59 to 0.78). On the follow-up scans, all 3 raters depicted significant ARWMC progression; however, the direct interrater agreement for this task was poor (kappa, 0.19 to 0.39). Comparison of the interrater reliability between the 3 scales revealed a statistical significant difference between the scale of Manolio and that of Fazekas and Schmidt for the baseline investigation (z value, -2.9676; P=0.003), demonstrating better interrater agreement for the Fazekas and Schmidt scale. The rating results obtained with all 3 scales were highly correlated with each other (Spearman rank correlation, 0.712 to 0.806; P< or =0.01), and there was significant agreement between all 3 visual rating scales and the quantitative volumetric measurement of ARWMC (Kendall W, 0.37, 0.48, and 0.57; P<0.001).

CONCLUSIONS

Our data demonstrate that the 3 rating scales studied reflect the actual volume of ARWMCs well. The 2 scales that provide more detailed information on ARWMCs seemed preferential compared with the 1 that yields more global information. The visual assessment of ARWMC progression remains problematic and may require modifications or extensions of existing rating scales.

Patterns of cerebral atrophy in dementia with Lewy bodies using voxel-based morphometry

Previous cross-sectional MRI studies based on region-of-interest analyses have shown that increased cerebral atrophy is a feature of both Dementia with Lewy bodies (DLB) and Alzheimer's disease (AD). Relative preservation of the hippocampus and temporal lobe structures in DLB compared to AD has been reported in region-of-interest-based studies. Recently, image processing techniques such as voxel-based morphometry (VBM) have been developed to provide an unbiased, visually informative, and comprehensive means of studying patterns of cerebral atrophy. We report the first study to use the voxel-based approach to assess patterns of cerebral atrophy in DLB compared to control subjects and AD. Regional gray matter volume loss was observed bilaterally in the temporal and frontal lobes and insular cortex of patients with DLB compared to control subjects. Comparison of dementia groups showed preservation of the medial temporal lobe, hippocampus, and amygdala in DLB relative to AD. Significant gray matter loss was also observed in the thalamus of AD patients compared to DLB.

Volumetric MRI study of the caudate nucleus in patients with dementia with Lewy bodies, Alzheimer's disease, and vascular dementia

OBJECTIVES

To determine whether parkinsonian symptoms in dementia with Lewy bodies (DLB) are associated with greater atrophy of the caudate nucleus in comparison with patients with Alzheimer's disease (AD) and vascular dementia (VaD).

METHODS

T1weighted MR scans were acquired in elderly patients with DLB, AD, VaD, and healthy controls. Normalised volumetric measurements of the caudate nucleus were obtained and parkinsonian symptoms rated using Hoehn and Yahr staging.

RESULTS

There were no significant differences in the volume of the caudate nucleus between patients with dementia. However, the left caudate volume was significantly reduced in AD and DLB compared with controls. Parkinsonian symptoms did not correlate with caudate nucleus volume.

CONCLUSIONS

Parkinsonian symptoms in DLB may be more closely coupled to neurochemical rather than structural changes in the caudate nucleus, and volumetric MRI analysis of caudate nucleus does not discriminate between patients with DLB, AD, and VaD.

Dementia with Lewy bodies and AD are not associated with occipital lobe atrophy on MRI

Dementia with Lewy bodies (DLB) is associated with occipital changes in blood flow and metabolism, but structural changes in this region have not previously been assessed. The authors performed volumetric MRI measurement of the occipital lobe blind to the diagnosis in 23 subjects with DLB, 25 with AD, and 24 age-matched control subjects. There were no significant differences between groups in occipital lobe volume. The authors conclude gross structural changes in the occipital lobe do not occur in patients with mild to moderate DLB or AD.

Dementia with Lewy bodies: diagnosis and management

OBJECTIVE

To summarize the clinical, pathological, imaging and treatment aspects of dementia with Lewy bodies (DLB).

METHOD

Review of literature (MEDLINE).

RESULTS

DLB is the second most common form of degenerative dementia, accounting for up to 20% of cases in the elderly. It is characterized by fluctuating cognitive impairment, spontaneous parkinsonism and recurrent visual hallucinations. Consensus clinical criteria have been published and have been shown to have high specificity, but they may still lack sensitivity. Pathologically, DLB may be classified as a Lewy body (LB) disorder and/or as an alpha-synucleinopathy. It is probable that a spectrum of LB disorders exists with the clinical features reflecting the distribution and severity of pathology. Although both DLB and Alzheimer's disease (AD) show a reduction in pre-synaptic cholinergic transmission from the basal forebrain, in DLB there are also deficits in cholinergic transmission from brain stem nuclei. Post-synaptic cortical muscarinic receptors are more functionally intact in DLB suggesting potential responsiveness to cholinergic enhancement. Neuroimaging findings indicate a relative preservation of medial temporal lobe structures in DLB but similar distribution of white matter changes on MRI compared with AD. Defects in nigrostriatal dopamine pathways in DLB have been demonstrated with functional neuroimaging using ligands highlighting pre- and post-synaptic dopaminergic systems. Preliminary studies also indicate subtle differences in perfusion patterns on SPECT with a greater degree of occipital hypoperfusion in DLB compared with AD. Accurate diagnosis of DLB is clinically important as the management of psychosis and behavioural disturbances is complicated by sensitivity to neuroleptic medication. There is accumulating evidence to suggest that DLB may be particularly amenable to cholinergic enhancers. The clinical management of DLB is considered using a four step approach: making a diagnosis; identification of problem symptoms; appropriate non-pharmacological interventions; and pharmacological interventions.

CONCLUSIONS

Consensus criteria for probable DLB have high specificity-a positive clinical diagnosis is likely to be correct. Treatment choices must consider effects upon motor, cognitive and psychiatric symptoms. Non-pharmacological management is an essential first step, as is reduction or withdrawal of drugs with potential adverse effects. Neuroleptic sensitivity reactions appear less likely to occur with the newer atypical antipsychotics. Cholinesterase inhibitors have been shown in open-label studies and one placebo RCT to be well tolerated and effective in treating cognitive and psychiatric symptoms in DLB. They may become first-line treatments.

Expression of P-selectin and intercellular adhesion molecule-1 in human brain after focal infarction or cardiac arrest

Data from experimental studies indicate that acute inflammation contributes to ischaemic brain damage. Tethering of neutrophils to brain endothelium is mediated by selectins, and subsequent adhesion and migration by endothelial intercellular adhesion molecule-1 (ICAM-1) and neutrophil CD18. In experimental studies of ischaemia-reperfusion injury, brain damage has been ameliorated by administration of antibodies to these adhesion molecules. We studied the expression of P-selectin and ICAM-1 in sections of brain from patients who had experienced cardiac arrest or focal brain infarction, and who died 3.5 h to 9 days later. Endothelial immunopositivity for both adhesion molecules was maximal at about 2-3 days then declined. Between 1 day and 3 days, P-selectin was also detected on platelets in blood vessels within infarcted tissue. Within infarcts, but not sections of brain from cardiac arrest patients, P-selectin and ICAM-1 were again detectable at 1 week, when hyperplastic endothelial cells were labelled in capillaries in and immediately adjacent to the infarcted tissue. The finding that P-selectin and ICAM-1 are upregulated within focally infarcted brain tissue supports the concept that blocking neutrophil adhesion may be of benefit in treating atherothrombotic strokes in man.

Progressive brain atrophy on serial MRI in dementia with Lewy bodies, AD, and vascular dementia

The authors determined rates of brain atrophy, as assessed by the boundary shift integral on serial MRI, in patients with dementia with Lewy Bodies (DLB, n = 10), AD (n = 9), vascular dementia (VaD, n = 9), and age-matched controls (n = 20). Mean % +/- SD atrophy rates per year were as follows: DLB, 1.4 +/- 1.1; AD, 2.0 +/- 0.9; VaD, 1.9 +/- 1.1; and controls, 0.5 +/- 0.7. Dementia subjects had higher rates than controls (p < 0.001), but there were no significant differences between the three dementia groups. The authors found accelerating atrophy with increasing severity of cognitive impairment, further emphasizing the need for early diagnosis and intervention in dementia.

A comparison of medial and lateral temporal lobe atrophy in dementia with Lewy bodies and Alzheimer's disease: magnetic resonance imaging volumetric study

OBJECTIVES

To compare medial and lateral temporal lobe atrophy on magnetic resonance imaging (MRI) in dementia with Lewy bodies (DLB) and Alzheimer's disease (AD), and to examine the relationship between volumetric indices and cognitive and non-cognitive symptoms.

METHODS

T(1)-weighted 1.0-tesla MRI scans were acquired in elderly subjects with DLB (n = 26; mean age = 75.8 years) and AD (n = 22; 77.3 years) and normal controls (n = 26; 76.2 years). MRI-based volume measurements of the hippocampus, parahippocampus, fusiform gyrus, combined inferior and middle temporal gyri, and superior temporal gyrus were acquired.

RESULTS

Hippocampal and parahippocampal volumes were significantly larger in subjects with DLB compared to AD. Differences in hippocampal volumes between DLB and AD were observed across the entire length, and in all subjects with dementia there was a loss of hippocampal asymmetry compared to normal controls. Atrophy of temporal lobe structures correlated with memory impairment in both groups, and with age in DLB. There was no association between atrophy and psychotic symptoms in either group.

CONCLUSIONS

Subjects with DLB and AD have a different pattern of temporal lobe atrophy with the most striking differences relating to medial rather than lateral temporal lobe structures. These structural differences could explain the relative preservation of memory function in DLB compared to AD.