Mild cognitive impairment--beyond controversies, towards a consensus: report of the International Working Group on Mild Cognitive Impairment

The First Key Symposium was held in Stockholm, Sweden, 2-5 September 2003. The aim of the symposium was to integrate clinical and epidemiological perspectives on the topic of Mild Cognitive Impairment (MCI). A multidisciplinary, international group of experts discussed the current status and future directions of MCI, with regard to clinical presentation, cognitive and functional assessment, and the role of neuroimaging, biomarkers and genetics. Agreement on new perspectives, as well as recommendations for management and future research were discussed by the international working group. The specific recommendations for the general MCI criteria include the following: (i) the person is neither normal nor demented; (ii) there is evidence of cognitive deterioration shown by either objectively measured decline over time and/or subjective report of decline by self and/or informant in conjunction with objective cognitive deficits; and (iii) activities of daily living are preserved and complex instrumental functions are either intact or minimally impaired.

Preclinical trials in autosomal dominant AD: implementation of the DIAN-TU trial

The Dominantly Inherited Alzheimer's Network Trials Unit (DIAN-TU) was formed to direct the design and management of interventional therapeutic trials of international DIAN and autosomal dominant Alzheimer's disease (ADAD) participants. The goal of the DIAN-TU is to implement safe trials that have the highest likelihood of success while advancing scientific understanding of these diseases and clinical effects of proposed therapies. The DIAN-TU has launched a trial design that leverages the existing infrastructure of the ongoing DIAN observational study, takes advantage of a variety of drug targets, incorporates the latest results of biomarker and cognitive data collected during the observational study, and implements biomarkers measuring Alzheimer's disease (AD) biological processes to improve the efficiency of trial design. The DIAN-TU trial design is unique due to the sophisticated design of multiple drugs, multiple pharmaceutical partners, academics servings as sponsor, geographic distribution of a rare population and intensive safety and biomarker assessments. The implementation of the operational aspects such as home health research delivery, safety magnetic resonance imagings (MRIs) at remote locations, monitoring clinical and cognitive measures, and regulatory management involving multiple pharmaceutical sponsors of the complex DIAN-TU trial are described.

Aspartate mutations in presenilin and gamma-secretase inhibitors both impair notch1 proteolysis and nuclear translocation with relative preservation of notch1 signaling

It has been hypothesized that a presenilin 1 (PS1)-related enzymatic activity is responsible for proteolytic cleavage of the C-terminal intracellular protein of Notch1, in addition to its role in beta-amyloid protein (Abeta) formation from the amyloid precursor protein (APP). We developed an assay to monitor ligand-induced Notch1 proteolysis and nuclear translocation in individual cells : Treatment of full-length Notch1-enhanced green fluorescent protein-transfected Chinese hamster ovary (CHO) cells with a soluble preclustered form of the physiologic ligand Delta leads to rapid accumulation of the C terminus of Notch1 in the nucleus and to transcriptional activation of a C-promoter binding factor 1 (CBF1) reporter construct. Nuclear translocation was blocked by cotransfection with Notch's physiologic inhibitor Numb. Using this assay, we now confirm and extend the observation that PS1 is involved in Notch1 nuclear translocation and signaling in mammalian cells. We demonstrate that the D257A and the D385A PS1 mutations, which had been shown previously to block APP gamma-secretase activity, also prevent Notch1 cleavage and translocation to the nucleus but do not alter Notch1 trafficking to the cell surface. We also show that two APP gamma-secretase inhibitors block Notch1 nuclear translocation with an IC(50) similar to that reported for APP gamma-secretase. Notch1 signaling, assessed by measuring the activity of CBF1, a downstream transcription factor, was impaired but not abolished by the PS1 aspartate mutations or gamma-secretase inhibitors. Our results support the hypotheses that (a) PS1-dependent APP gamma-secretase-like enzymatic activity is critical for both APP and Notch processing and (b) the Notch1 signaling pathway remains partially activated even when Notch1 proteolytic processing and nuclear translocation are markedly inhibited. The latter is an important finding from the perspective of therapeutic treatment of Alzheimer's disease by targeting gamma-secretase processing of APP to reduce Abeta production.

Long-term results of a hydroxyapatite-coated femoral component in total hip replacement: a 15- to 21-year follow-up study

Between 1986 and 1991 we implanted 331 consecutive Furlong hydroxyapatite-coated femoral components of a total hip replacement in 291 patients. A cemented acetabular prosthesis was used in 217 hips and a hydroxyapatite-coated component in 114. We describe the long-term clinical and radiological survival of the femoral component at a mean follow-up of 17.5 years (15 to 21). Only two patients (0.68%) were lost to follow-up. With revision of the femoral component for any reason as the endpoint, the survival at a mean of 17 years was 97.4% (95% confidence interval 94.1 to 99.5), and with revision for aseptic loosening as the endpoint it was 100%. The survival at a maximum of 21 years with revision of the femoral component for any reason as the endpoint was 97.4% (95% confidence interval 81.0 or 99.5). These results compare favourably with the best long-term results of cemented or uncemented femoral components used in total hip replacement.

Notch1 and amyloid precursor protein are competitive substrates for presenilin1-dependent gamma-secretase cleavage

Proteolytic processing of the amyloid precursor protein (APP) by beta- and gamma-secretases results in the production of a highly amyloidogenic Abeta peptide, which deposits in the brains of Alzheimer's disease patients. Similar gamma-secretase processing occurs in another transmembrane protein, Notch1, releasing a potent signaling molecule, the Notch C-terminal domain. It has been shown that both events are dependent on a presenilin-dependent protease. We now test the hypothesis that activated Notch1 and APP are competitive substrates for the same proteolytic activity in neurons. Treatment of neurons with the native Notch ligand, Delta, induces endogenous Notch1 intramembraneous cleavage and diminishes Abeta production in a dose-dependent manner. Complementary experiments showed that the converse was also true. Overexpressing human APP (APP(695Sw)) in neurons leads to a decrease in endogenous Notch1 signal transduction, as assessed by a CBF1 luciferase transcription assay, by Notch C-terminal domain nuclear translocation in vitro and by analysis of Notch C-terminal domain generation and Notch1 staining in vivo. In summary, two complementary approaches suggest that APP and Notch1 are physiologically relevant competitive substrates for gamma-secretase activity.

MR imaging features of amyloid-related imaging abnormalities

BACKGROUND AND PURPOSE

AD is one of the few leading causes of death without a disease-modifying drug; however, hopeful agents are in various phases of development. MR imaging abnormalities, collectively referred to as amyloid-related imaging abnormalities, have been reported for several agents that target cerebral Aβ burden. ARIA includes ARIA-E, parenchymal or sulcal hyperintensities on FLAIR indicative of parenchymal edema or sulcal effusions, and ARIA-H, hypointense regions on gradient recalled-echo/T2* indicative of hemosiderin deposition. This report describes imaging characteristics of ARIA-E and ARIA-H identified during studies of bapineuzumab, a humanized monoclonal antibody against Aβ.

MATERIALS AND METHODS

Two neuroradiologists with knowledge of imaging changes reflective of ARIA reviewed MR imaging scans from 210 bapineuzumab-treated patients derived from 3 phase 2 studies. Each central reader interpreted the studies independently, and discrepancies were resolved by consensus. The inter-reader κ was 0.76, with 94% agreement between neuroradiologists regarding the presence or absence of ARIA-E in individual patients.

RESULTS

Thirty-six patients were identified with incident ARIA-E (17.1%, 36/210) and 26 with incident ARIA-H (12.4%, 26/210); of those with incident ARIA-H, 24 had incident microhemorrhages and 2 had incident large superficial hemosiderin deposits.

CONCLUSIONS

In 49% of cases of ARIA-E, there was the associated appearance of ARIA-H. In treated patients without ARIA-E, the risk for incident blood products was 4%. This association between ARIA-E and ARIA-H may suggest a common pathophysiologic mechanism. Familiarity with ARIA should permit radiologists and clinicians to recognize and communicate ARIA findings more reliably for optimal patient management.

A computational model of neurodegeneration in Alzheimer's disease

Disruption of mental functions in Alzheimer's disease (AD) and related disorders is accompanied by selective degeneration of brain regions. These regions comprise large-scale ensembles of cells organized into systems for mental functioning, however the relationship between clinical symptoms of dementia, patterns of neurodegeneration, and functional systems is not clear. Here we present a model of the association between dementia symptoms and degenerative brain anatomy using F18-fluorodeoxyglucose PET and dimensionality reduction techniques in two cohorts of patients with AD. This reflected a simple information processing-based functional description of macroscale brain anatomy which we link to AD physiology, functional networks, and mental abilities. We further apply the model to normal aging and seven degenerative diseases of mental functions. We propose a global information processing model for mental functions that links neuroanatomy, cognitive neuroscience and clinical neurology.

Familial frontotemporal dementia associated with a novel presenilin-1 mutation

We report a kindred with three cases of dementia. The proband presented with forgetfulness and personality changes at age 56, followed shortly thereafter by behavioral dyscontrol, hyperphagia, hypersexuality, delusions, illusions, disinhibition and double incontinence. Neuroimaging studies were consistent with frontotemporal dementia (FTD). In one allele, an arginine insertion at codon 352 in the presenilin 1 (PSEN1) gene was identified; no mutation was identified in the amyloid precursor protein or tau genes. We conclude that the clinical features of the Kluver-Bucy syndrome and FTD can be associated with PSEN1 mutations. Furthermore, presenilin analyses may be helpful to characterize kindreds with familial dementing illnesses regardless of the phenotype, particularly if no tau mutation is present.

The use of ceramic-on-ceramic bearings in isolated revision of the acetabular component

The practice of removing a well-fixed cementless femoral component is associated with high morbidity. Ceramic bearing couples are low wearing and their use minimises the risk of subsequent further revision due to the production of wear debris. A total of 165 revision hip replacements were performed, in which a polyethylene-lined acetabular component was revised to a new acetabular component with a ceramic liner, while retaining the well-fixed femoral component. A titanium sleeve was placed over the used femoral trunnion, to which a ceramic head was added. There were 100 alumina and 65 Delta bearing couples inserted. The mean Harris hip score improved significantly from 71.3 (9.0 to 100.0) pre-operatively to 91.0 (41.0 to 100.0) at a mean follow up of 4.8 years (2.1 to 12.5) (p < 0.001). No patients reported squeaking of the hip. There were two fractures of the ceramic head, both in alumina bearings. No liners were seen to fracture. No fractures were observed in components made of Delta ceramic. At 8.3 years post-operatively the survival with any cause of failure as the endpoint was 96.6% (95% confidence interval (CI) 85.7 to 99.3) for the acetabular component and 94.0% (95% CI 82.1 to 98.4) for the femoral component. The technique of revising the acetabular component in the presence of a well-fixed femoral component with a ceramic head placed on a titanium sleeve over the used trunnion is a useful adjunct in revision hip practice. The use of Delta ceramic is recommended.

Tattoo pigment in an axillary lymph node simulating metastatic malignant melanoma

We report a case of axillary lymphadenopathy thirty years after a decorative tattoo clinically mimicking metastatic melanoma. The importance of relying on histological confirmation of metastatic disease before altering extent of surgery is discussed. The importance of recording presence of decorative tattoos is stressed.

Mild cognitive impairment--beyond controversies, towards a consensus: report of the International Working Group on Mild Cognitive Impairment

The First Key Symposium was held in Stockholm, Sweden, 2-5 September 2003. The aim of the symposium was to integrate clinical and epidemiological perspectives on the topic of Mild Cognitive Impairment (MCI). A multidisciplinary, international group of experts discussed the current status and future directions of MCI, with regard to clinical presentation, cognitive and functional assessment, and the role of neuroimaging, biomarkers and genetics. Agreement on new perspectives, as well as recommendations for management and future research were discussed by the international working group. The specific recommendations for the general MCI criteria include the following: (i) the person is neither normal nor demented; (ii) there is evidence of cognitive deterioration shown by either objectively measured decline over time and/or subjective report of decline by self and/or informant in conjunction with objective cognitive deficits; and (iii) activities of daily living are preserved and complex instrumental functions are either intact or minimally impaired.

Rapid Notch1 nuclear translocation after ligand binding depends on presenilin-associated gamma-secretase activity

Recent data suggest an intimate relationship between the familial Alzheimer disease gene presenilin 1 (PS1) and proteolytic processing of both the amyloid precursor protein (APP) and the important cell signaling molecule, Notch1. We now show, using mammalian cells transfected with full-length Notch1, that the C terminal domain of Notch1 rapidly translocates to the nucleus upon stimulation with the physiologic ligand Delta and initiates a CBF1-dependent signal transduction cascade. Using this assay, we demonstrate that the same aspartate mutations in PS1 that block APP processing also prevent Notch1 cleavage and translocation to the nucleus. Moreover, we show that two APP gamma-secretase inhibitors also diminish Notch1 nuclear translocation in a dose-dependent fashion. However, Notch1 signaling, assessed by measuring the activity of CBF1, a downstream gene, was reduced but not completely abolished in the presence of either aspartate mutations or gamma-secretase inhibitors. Our results support the hypothesis that similar PS1-related enzymatic activity is necessary for both APP and Notch1 processing, yet suggest that Notch signaling may remain relatively preserved with moderate levels of gamma-secretase inhibition.

Effect of PS1 deficiency and an APP gamma-secretase inhibitor on Notch1 signaling in primary mammalian neurons

Presenilin1 (PS1) has been implicated in normal Notch1 processing and signaling in several experimental systems. In the present study, the relationship between PS1 and Notch1 in mammalian neurons is studied by analyzing Notch1 cleavage and C-terminal nuclear translocation as well as Notch1 signaling via the transactivation of a CBF1-luciferase reporter construct. We show that full-length Notch1 [N1(FL)] transfected into wild type (WT) primary neurons is cleaved in the presence of its biological ligand Delta (Dl) and translocated to the nucleus within 1--3 min of ligand addition. PS1 deficient neurons show normal Notch1 insertion into the cellular membrane, yet lack Notch1 activation resulting in markedly inhibited nuclear translocation of the C-terminal Notch fragment (NICD). PS1 deficient neurons also have impaired Notch1 signaling which can be restored fully or partially to levels seen in WT littermates by transfection with WT or familial Alzheimer's disease-associated M146L mutant PS1, respectively. We also show that pharmacological inhibition of PS1-associated gamma-secretase activity parallels the effects of genetic PS1 deficiency in these assays. These results support the hypothesis that PS1 deficiency blocks neuronal Notch1 processing and signaling.

Something's missing here: a look at the quality of rheumatology referral letters

A convincing body of evidence points to an early window of opportunity for the treatment of rheumatoid arthritis. However, data indicate that in many cases, this window of opportunity is missed. Once a patient does present to their primary care provider, important additional delays in rheumatology assessment can occur. To report the results of our study assessing referral letters to rheumatologists, we examined referral letters received over a one-year period by one full-time rheumatologist practicing at a tertiary-care center. We found only a small percentage of referral letters made mention of the pattern of joint involvement. Just 17% of consults indicated symptom duration. Only 2% mentioned any circadian rhythm of symptoms (such as morning stiffness), and only 6% provided information about functional status. Almost two-thirds (62%) of consults specified only 'joint pain' in the referral letter. We provide objective evidence that referral letters sent to rheumatologists are often lacking in key elements of the medical history. This lack of information means that appropriate triage of referrals by rheumatologists is very difficult. As a response to this, we have developed, with family physicians and rheumatologists, a standardized referral template which is being pilot-tested. Our ultimate goal is to improve wait times for patients with urgent conditions such as inflammatory arthritis.

Pulmonary hypertension, systemic lupus erythematosus, and the contraceptive pill

Pulmonary hypertension in systemic lupus erythematosus (SLE) in the absence of chronic parenchymal lung disease or pulmonary emboli is rare. We report such a case with an acute and rapidly progressive onset of symptoms in a patient who had started taking the contraceptive pill eight months previously.

The modified tibial tubercle osteotomy for anterior knee pain due to chondromalacia patellae in adults: A five-year prospective study

OBJECTIVES

To assess the effectiveness of a modified tibial tubercle osteotomy as a treatment for arthroscopically diagnosed chondromalacia patellae.

METHODS

A total of 47 consecutive patients (51 knees) with arthroscopically proven chondromalacia, who had failed conservative management, underwent a modified Fulkerson tibial tubercle osteotomy. The mean age was 34.4 years (19.6 to 52.2). Pre-operatively, none of the patients exhibited signs of patellar maltracking or instability in association with their anterior knee pain. The minimum follow-up for the study was five years (mean 72.6 months (62 to 118)), with only one patient lost to follow-up.

RESULTS

A total of 50 knees were reviewed. At final follow-up, the Kujala knee score improved from 39.2 (12 to 63) pre-operatively to 57.7 (16 to 89) post-operatively (p < 0.001). The visual analogue pain score improved from 7.8 (4 to 10) pre-operatively to 5.0 (0 to 10) post-operatively. Overall patient satisfaction with good or excellent results was 72%. Patients with the lowest pre-operative Kujala score benefitted the most. Older patients benefited less than younger ones. The outcome was independent of the grade of chondromalacia. Six patients required screw removal. There were no major complications.

CONCLUSIONS

We conclude that this modification of the Fulkerson procedure is a safe and useful operation to treat anterior knee pain in well aligned patellofemoral joints due to chondromalacia patellae in adults, when conservative measures have failed.

Tapinarof for psoriasis and atopic dermatitis: 15 years of clinical research

Tapinarof is a topical, aryl-hydrocarbon receptor agonist that has recently received FDA-approval for the treatment of psoriasis. This novel therapeutic has also been shown to be effective for atopic dermatitis and is currently in phase 3 for this indication. Beyond good efficacy and fast onset of action in patients with psoriasis, the clinical response to tapinarof is notable for durable remission or near remission, maintained for an average of 130 days beyond treatment discontinuation in patients with psoriasis in phase 3 studies. Tapinarof is usually well tolerated but can induce a follicular inflammatory reaction and dermatitis in some patients. This narrative review covers the historical development of this molecule, safety and efficacy data from clinical trials conducted with various topical formulations, and practical considerations derived from our 15 years of clinical trial experience with the drug.

Effective palliative care for minority ethnic groups: the role of a liaison worker

As the issue of equality of access to health-care services becomes more important, there is increasing concern that specialist palliative care services in the UK are under-used by minority ethnic groups (Haroon-Iqbal et al, 1995; Karim et al, 2000). Research into the provision of such services for black and minority ethnic communities identified a number of factors that contribute to a perceived low take-up of services (Hill and Penso, 1995). A strategy to promote ethnic and racial sensitivity in palliative care service delivery, and policies to improve access to, and take-up of, services was recommended. This article presents the important elements relating to equal access to specialist palliative care and the provision of culturally sensitive services, and examines the role of the Macmillan Ethnic Minorities Liaison Officer in the Bradford community palliative care team.

An external automatic device to detect ventricular fibrillation

An analysis of a micro-processor-based system to detect cardiac arrest rhythms was made in a series of 84 cardiac arrests in 78 patients. The ECG was sensed using 2 external ECG/defibrillator pads applied to the chest wall. In 5 arrests, the initial rhythm was continuous electrical pacing in addition to the cardiac arrest and these were not included in the analysis. Of the remaining 79 arrests there were 15 in which the initial rhythm was ventricular fibrillation and 14 were correctly detected by the system (sensitivity 93%). In the remaining 64 arrests the initial rhythm was not ventricular fibrillation and 62 were correctly identified (specificity 97%). A high specificity is required in any device employing automatic detection of ventricular fibrillation. Continuous electrocardiographic recordings of the cardiac arrests were analysed every 8 to 18 s: of 223 sections showing ventricular fibrillation, 165 were correctly determined by the system, i.e. sensitivity 74%, where the rhythm was not ventricular fibrillation, of the 5002 sections 4953 were correctly detected by the system, i.e. specificity 99%. The percentage accuracy of detection of ventricular fibrillation varied from 25-100% (mean 81%) and for detection of non-ventricular fibrillation from 57-100% (mean 99%) in every 8 to 18 s section of ECG tracing per cardiac arrest episode. Thus the automatic detection of cardiac arrest rhythms is feasible with a high degree of accuracy.

Left atrial rhabdomyosarcoma and the use of digital gated computed tomography in its diagnosis

A case of left atrial rhabdomyosarcoma presenting in a patient with known mitral stenosis is described. Computed tomography of the left atrium, gated to the electrocardiogram cycle, was used to visualise the site and extension of the tumour.