Endoscopic retrograde cholangiopancreatography (ERCP) outcomes can improve after further training for an individual already experienced in ERCP.

This study was carried out to assess the impact of therapeutic endoscopy training on the endoscopic retrograde cholangiopancreatography (ERCP) practice of a physician who was practicing ERCP for many years in a community setting in the United States. A retrospective chart review of 390 ERCPs performed by the physician was accomplished; 176 and 214 ERCPs were performed before and after undergoing therapeutic endoscopy training respectively. Rates of common bile duct cannulation; postprocedure pancreatitis; use of common bile duct and pancreatic stents, as well as frequency of biliary and pancreatic sphincterotomies were assessed. The rate of common bile duct cannulation increased from 87% to 96% (P=0.008), while post-ERCP pancreatitis decreased from 8% to 3% (P=0.056), demonstrating that further guided experience in ERCP improved technical competency and decreased complications of ERCP for a physician already performing ERCPs independently in the USA.

Specific immunotherapy of experimental myasthenia gravis in vitro and in vivo: the Guided Missile strategy.

Current immunotherapy of myasthenia gravis (MG) is often effective, but entails risks of infection and neoplasia. The "Guided Missile" strategy described here is designed to target and eliminate the individual's unique AChR-specific T cell repertoire, without otherwise interfering with the immune system. We genetically engineered dendritic cells to present AChR epitopes and simultaneously express Fas ligand in an ongoing EAMG model. In both in vitro and in vivo experiments, these engineered cells specifically killed AChR-responsive T cells without otherwise damaging the immune system. AChR antibodies were markedly reduced in the treated mice. Translation of this method to treat human MG is possible.

Cerebral thromboembolism: value of susceptibility-weighted imaging in the initial diagnosis of acute infarction.

Susceptibility-weighted imaging (SWI) is commonly used to diagnose cerebral hemorrhage, calcification, and other T2* lesions. Its role in the detection of cerebral thromboemboli has been suggested for emboli of the anterior division of the middle cerebral artery (MCA). The purpose of our study was to determine SWI's accuracy and sensitivity in detection of all sites of cerebral thromboemboli, not just MCA emboli. Two neuroradiologists retrospectively reviewed consecutive MRI brain examinations with SWI for cerebral thromboemboli in 100 patients with clinical suspicion for stroke determined by the NIH Stroke Scale (NIHSS) score. FLAIR, MRA, CT, and catheter angiography were reviewed for thromboemboli in the same patients. Thromboembolic sites included: the internal carotid artery (ICA) terminus, anterior MCA, posterior MCA, any other cerebral artery, or if not present. The exclusion criteria included: no magnetic resonance angiogram (MRA) or catheter angiogram for comparison, lack of restricted diffusion, lacunar infarcts, and the presence of massive hemorrhage. The accuracy, sensitivity, and specificity of each imaging modality were determined. Twenty-four patients were excluded based on the aforementioned criteria. Cerebral thromboemboli were identified in 35 of the remaining 76 patients. Of the 35 patients with thromboemboli, 30 were identified on SWI. FLAIR detected 22/35 emboli, MRA 30/33, CT 18/35, and catheter angiography 12/12. The accuracies for SWI, FLAIR, and CT were 97%, 84%, and 74%, respectively. The sensitivities for SWI, FLAIR, and CT were 85%, 61%, and 52%, respectively. The specificities for SWI, FLAIR, and CT were 100%, 98%, and 93%, respectively. There is an adjunctive role of SWI to identify cerebral thromboemboli in patients with acute infarction. SWI is superior to FLAIR and CT, and complementary to MRA and catheter angiography in emboli detection. This study supports SWI detection of MCA emboli, but also emphasizes its utility in emboli detection of other arteries based on a high accuracy and sensitivity.

Granzyme B: evidence for a role in the origin of myasthenia gravis.

PURPOSE OF RESEARCH: Although the pathogenesis of myasthenia gravis (MG) as an antibody mediated disorder of acetylcholine receptors (AChRs) at neuromuscular junctions is well understood, the origin of the autoimmune response is unclear. The thymus is intimately involved in initiation of the autoimmune response; the antigen, AChR, is present in the thymus, but how the autoimmune response is triggered is not known. Granzyme B (GrB), a proteolytic enzyme present in cytolytic T cells and natural killer (NK) cells, selectively cleaves many potential autoantigens (but few non-autoantigens), generating novel fragments that trigger autoreactive responses. This protease has been strongly implicated in the pathogenesis of several autoimmune diseases including lupus, rheumatoid arthritis, dermatomyositis, and others. In the studies described in this manuscript, we examined the ability of GrB to cleave the AChR subunits, and performed biochemical, immunohistochemical and molecular studies on thymus glands from myasthenic patients and controls to assess GrB expression. MAIN RESULTS: GrB efficiently and specifically cleaves subunits of AChR, especially the epsilon subunit. GrB is present in thymus glands from myasthenia patients, but is absent in control thymuses. CONCLUSIONS: Our results provide evidence supporting a potential role for GrB in the process of initiation of MG, and are consistent with the concept of an immunodominant epsilon epitope.

Novel VCP mutations in inclusion body myopathy associated with Paget disease of bone and frontotemporal dementia.

Inclusion body myopathy associated with Paget disease of bone and frontotemporal dementia (IBMPFD, OMIM 167320) has recently been attributed to eight missense mutations in valosin-containing protein (VCP). We report novel VCP mutations N387H and L198W in six individuals from two families who presented with proximal muscle weakness at a mean age of diagnosis of 40 years, most losing the ability to walk within a few years of onset. Electromyographic studies in four individuals were suggestive of 'myopathic' changes, and neuropathic pattern was identified in one individual in family 1. Muscle biopsy in four individuals showed myopathic changes characterized by variable fiber size, two individuals showing rimmed vacuoles and IBM-type cytoplasmic inclusions in muscle fibers, and electron microscopy in one individual revealing abundant intranuclear inclusions. Frontotemporal dementia associated with characteristic behavioral changes including short-term memory loss, language difficulty, and antisocial behavior was observed in three individuals at a mean age of 47 years. Detailed brain pathology in one individual showed cortical degenerative changes, most severe in the temporal lobe and hippocampus. Abundant ubiquitin-positive tau-, alpha-synuclein-, polyglutamine repeat-negative neuronal intranuclear inclusions and only rare intracytoplasmic VCP positive inclusions were seen. These new mutations may cause structural changes in VCP and provide some insight into the functional effects of pathogenic mutations.

Specific immunotherapy of experimental myasthenia by genetically engineered APCs: the "guided missile" strategy.

Although treatment of MG with general immunosuppressive agents is often effective, it has important drawbacks, including suppression of the immune system as a whole, with the risks of infection and neoplasia, and numerous other adverse side effects. Ideally, treatment of MG should eliminate the specific pathogenic autoimmune response to AChR, without otherwise suppressing the immune system or producing other adverse side effects. Although antibodies to AChR are directly responsible for the loss of AChRs at neuromuscular junctions in MG, the AChR antibody response is T cell-dependent, and immunotherapy directed at T cells can abrogate the autoantibody response, with resulting benefit. As in other autoimmune diseases, the T cell response in MG is highly heterogeneous. The design of specific immunotherapy must take this heterogeneity into account and target the entire repertoire of AChR-specific T cells. We describe our investigation of a novel strategy for specific immunotherapy of MG, involving gene transfer to convert antigen-presenting cells (APCs) to "guided missiles" that target AChR-specific T cells, and that induce apoptosis and elimination of those T cells. This strategy uses the ability of APCs from a given individual to present the entire spectrum of AChR epitopes unique for that individual, and thereby to target the entire repertoire of antigen-specific T cells of the same individual. Using viral vectors, we have genetically engineered the APCs to process and present the most important domain of the AChR molecule, and to express a "warhead" of Fas ligand (FasL) to eliminate the activated AChR-specific T cells with which they interact. Our results show that the APCs express the appropriate gene products, and effectively and specifically eliminate AChR-specific T cells by the Fas/FasL pathway, while sparing T cells of other specificities.

Ataxia associated with Hashimoto's disease: progressive non-familial adult onset cerebellar degeneration with autoimmune thyroiditis.

UNLABELLED: Acquired cerebellar ataxia has been described with hypothyroidism, and is typically reversible by thyroid hormone replacement therapy. The cerebellar dysfunction has been attributed to metabolic and physiological effects of the endocrine disorder. In a few patients, however, ataxia has persisted despite thyroid replacement therapy. Other mechanisms may be involved in ataxia associated with thyroid disorders. OBJECTIVE: To document progressive non-familial adult onset cerebellar degeneration (PNACD) occurring in six patients with raised antithyroid antibodies (Hashimoto's/autoimmune thyroiditis), and other autoimmune manifestations, in the absence of hypothyroidism; and to document the independence of the cerebellar disorder from the endocrine dysfunction. METHODS: A case study of six patients with PNACD reviewing the clinical course and relation to endocrine and autoimmune status. RESULTS: All six patients were euthyroid when they developed their symptoms; had raised antithyroid antibodies consistent with Hashimoto's autoimmune thyroiditis; and had strong personal or family histories of organ specific autoimmune diatheses. Brain MRI disclosed atrophy of the cerebellar vermis in four patients and olivopontocerebellar atrophy in two. Other possible causes of cerebellar degeneration were excluded. De novo treatment (two patients) or continued treatment (three patients) with L-thyroxine did not modify the progression of the ataxia. CONCLUSIONS: Cerebellar degeneration in these patients with raised antithyroid antibodies may be immune mediated. The presence of antithyroid antibodies may signal or cause the autoimmune process producing cerebellar degeneration. "Hashimoto's associated ataxia" seems to represent a recognisable and not uncommon condition; a trial of immunomodulating therapy should be considered in these patients.

Psychological features in persons at risk for familial Alzheimer's disease.

Persons at risk for inherited neurodegenerative diseases may experience symptoms of anxiety and depression because of concern over the possibility of developing the disease in the future. The purpose of this study was to assess psychological and emotional symptoms in persons at the age of risk for developing early-onset familial Alzheimer's disease (FAD). Their responses on a psychiatric rating scale (SCL-90-R) were compared with four groups: patients with mild FAD; head injury patients; patients with clinically diagnosed depression; and healthy control subjects. Mean scores of the at-risk FAD group were not statistically different than those of the controls. In contrast, the head injury and depressed groups had significantly elevated scores across the clinical scales. These results suggest that depression and anxiety are not prominent features in persons at genetic risk for early-onset familial Alzheimer's disease. Similar results have been found in studies of persons at risk for developing Huntington's disease, another autosomal dominant neurodegenerative disease.

Specific immunotherapy of experimental myasthenia gravis in vitro: the "guided missile" strategy.

We describe a strategy for specific immunotherapy of myasthenia gravis (MG) based on genetic engineering of antigen presenting cells (APCs) to present the autoantigen acetylcholine receptor (AChR) and express the "warhead" Fas ligand (FasL). For transduction of APCs we prepared recombinant attenuated vaccinia virus vectors carrying the following three gene constructs: (i) AChR fused to LAMP1 to present AChR and target AChR-specific T cells; (ii) FasL to eliminate the targeted T cells; and (iii) truncated FADD to protect APCs from self-destruction by FasL. The engineered APCs effectively expressed the genes of interest and killed AChR-specific T cells in culture by the Fas/FasL pathway. T cells specific for an unrelated antigen were spared. Our in vitro demonstration that engineered APCs target and kill antigen-specific T cells represents a promising novel strategy for specific immunotherapy of MG and other autoimmune diseases.

Postmenopausal estrogen replacement therapy and the risk of Alzheimer disease.

BACKGROUND: Previous studies have examined the relation between postmenopausal estrogen replacement therapy (ERT) and the risk of Alzheimer disease (AD). The findings have been inconsistent, since some studies have been interpreted as showing a protective effect while others have reported no effect. OBJECTIVE: To determine whether exposure to ERT is associated with a reduced risk of AD. DESIGN: Population-based nested case-control study. SETTING: The United Kingdom-based General Practice Research Database. PATIENTS: The base cohort consisted of women who were recipients of ERT (n = 112 481) and a similar cohort of women who did not use estrogens (n = 108 925). The 2 cohorts were restricted to women born on or before January 1, 1950. From the 2 cohorts, we identified and verified 59 newly diagnosed cases of AD and 221 matched control subjects. MAIN OUTCOME MEASURE: Prior and current use of ERT in cases compared with controls. RESULTS: Among the 59 newly diagnosed cases of AD, 15 (25%) were current estrogen users, while among the controls, 53 (24%) were current users. The adjusted odds ratio comparing all current estrogen recipients with nonrecipients was 1.18 (95% confidence interval, 0.59-2.37). In estrogen users who took the drug for 5 years or longer compared with nonusers, the odds ratio was 1.05 (95% confidence interval, 0.32-3.44). Odds ratios were similar for estrogen recipients who received estrogens alone and recipients who received combined estrogen-progestin treatment. CONCLUSION: The use of ERT in women after the onset of menopause was not associated with a reduced risk of developing AD.

Specific immunotherapy by genetically engineered APCs: the "guided missile" strategy.

We tested the hypothesis that APCs genetically engineered to present an Ag and to express Fas ligand (FasL) simultaneously can target and eliminate Ag-specific T cells. Transgenic T cells specific for influenza hemagglutinin (HA) were used as targets. We prepared recombinant vaccinia virus vectors (VVV) to transfer the gene constructs individually or simultaneously into APCs. We prevented unwanted viral replication by attenuating the VVVs with psoralen-UV light treatment. For presentation of the HA Ag, APCs were transduced with cDNA for HA flanked by sequences of the lysosome-associated membrane protein that direct efficient processing and presentation of the Ag by APCs. As a "warhead" for the APCs, we transduced them with the gene for FasL, which induces apoptosis of Fas-expressing activated T cells. To protect the transduced APCs from self-destruction by FasL, we transferred cDNA for a truncated form of Fas-associated death domain, which inhibits Fas-mediated cell death. Our results show that the engineered APCs effectively expressed the genes of interest. APCs transduced with VVV carrying all three gene constructs specifically killed HA-transgenic T cells in culture. Coculture with T cells specific for an unrelated Ag (OVA) had no significant effect. Our in vitro findings show that APCs can be genetically engineered to target and kill Ag-specific T cells and represent a promising novel strategy for the specific treatment of autoimmune diseases.

Mycophenolate mofetil: a safe and promising immunosuppressant in neuromuscular diseases.

The authors report the use mycophenolate mofetil (MM) in the treatment of neuromuscular diseases. Thirty-eight patients (32 with MG, three with inflammatory myopathy, and three with chronic acquired demyelinating neuropathy) were treated with MM for an average duration of 12 months. All patients tolerated MM without major side effects. Twenty-four patients improved either in their functional status or in their ability to reduce corticosteroid dose. Mean time to improvement was 5 months.

Neointimal thickening after stent delivery of paclitaxel: change in composition and arrest of growth over six months.

OBJECTIVES: The purpose of this study was to determine long-term effects of stent-based paclitaxel delivery on amount, rate and composition of neointimal thickening after stent implantation. BACKGROUND: Paclitaxel prevents vascular smooth muscle cell proliferation and migration in vitro and in vivo. These actions, coupled with low solubility, make it a viable candidate for modulating vascular responses to injury and prolonged effects after local delivery. We asked whether local delivery of paclitaxel for a period of weeks from a stent coated with a bioerodible polymer could produce a sustained reduction in neointimal hyperplasia for up to six months after stenting. METHODS: Stainless steel stents were implanted in the iliac arteries of rabbits after endothelial denudation. Stents were uncoated or coated with a thin layer of poly(lactide-co-sigma-caprolactone) copolymer alone or containing paclitaxel, 200 microg. RESULTS: Paclitaxel release in vitro followed first-order kinetics for two months. Tissue responses were examined 7, 28, 56 or 180 days after implantation. Paclitaxel reduced intimal and medial cell proliferation three-fold seven days after stenting and virtually eliminated later intimal thickening. Six months after stenting, long after drug release and polymer degradation were likely complete, neointimal area was two-fold lower in paclitaxel-releasing stents. Tissue responses in paclitaxel-treated vessels included incomplete healing, few smooth muscle cells, late persistence of macrophages and dense fibrin with little collagen. CONCLUSIONS: Poly(lactide-co-sigma-caprolactone) copolymer-coated stents permit sustained paclitaxel delivery in a manner that virtually abolishes neointimal hyperplasia for months after stent implantation, long after likely completion of drug delivery and polymer degradation.

Statins and the risk of dementia.

BACKGROUND: Dementia affects an estimated 10% of the population older than 65 years. Because vascular and lipid-related mechanisms are thought to have a role in the pathogenesis of Alzheimer's disease and vascular dementia, we did an epidemiological study of the potential effect of HMGCoA (3 hydroxy-3methylglutaryl-coenzyme A) reductase inhibitors (statins) and other lipid-lowering agents on dementia. METHODS: We used a nested case-control design with information derived from 368 practices which contribute to the UK-based General Practice Research Database. The base study population included three groups of patients age 50 years and older: all individuals who had received lipid-lowering agents (LLAs); all individuals with a clinical diagnosis of untreated hyperlipidaemia; and a randomly selected group of other individuals. From this base population, all cases with a computer-recorded clinical diagnosis of dementia were identified. Each case was matched with up to four controls derived from the base population on age, sex, practice, and index date of case. FINDINGS: The study encompassed 284 cases with dementia and 1080 controls. Among controls 13% had untreated hyperlipidaemia, 11% were prescribed statins, 7% other LLAs, and 69% had no hyperlipidaemia or LLA exposure. The relative risk estimates of dementia adjusted for age, sex, history of coronary-artery disease, hypertension, coronary-bypass surgery and cerebral ischaemia, smoking and body mass index for individuals with untreated hyperlipidaemia (odds ratio 0.72 [95% CI 0.45-1.14]), or treated with nonstatin LLAs (0.96 [0.47-1.97], was close to 1.0 and not significant compared with people who had no diagnosis of hyperlipidaemia or exposure to other lipid-lowering drugs. The adjusted relative risk for those prescribed statins was 0.29 (0.13-0.63; p=0.002). INTERPRETATION: Individuals of 50 years and older who were prescribed statins had a substantially lowered risk of developing dementia, independent of the presence or absence of untreated hyperlipidaemia, or exposure to nonstatin LLAs. The available data do not distinguish between Alzheimer's disease and other forms of dementia.

Inhibition of cyclooxygenase-2 protects motor neurons in an organotypic model of amyotrophic lateral sclerosis.

The pathogenesis of motor neuron loss in amyotrophic lateral sclerosis (ALS) is thought to involve both glutamate-mediated excitotoxicity and oxidative damage due to the accumulation of free radicals and other toxic molecules. Cyclooxygenase-2 (COX-2) may play a key role in these processes by producing prostaglandins, which trigger astrocytic glutamate release, and by inducing free radical formation. We tested the effects of COX-2 inhibition in an organotypic spinal cord culture model of ALS. The COX-2 inhibitor (SC236) provided significant protection against loss of spinal motor neurons in this system, suggesting that it may be useful in the treatment of ALS.

Familial Alzheimer's disease: site of mutation influences clinical phenotype.

Alzheimer's disease (AD) is caused by multiple genetic and/or environmental etiologies. Because differences in the genetically determined pathogenesis may cause differences in the phenotype, we examined age at onset and age at death in 90 subjects with dominantly inherited AD due to different mutations (amyloid precursor protein, presenilin-1, and presenilin-2 genes). We found that among patients with dominantly inherited AD, genetic factors influence both age at onset and age at death.

Targeting antigen-specific T cells by genetically engineered antigen presenting cells. A strategy for specific immunotherapy of autoimmune disease.

We describe a strategy for specific immunotherapy of autoimmune disease based on targeting the antigen-specific T cells in an experimental model of myasthenia gravis. To address the problem of heterogeneity of the T cell repertoire, we have genetically engineered antigen presenting cells (APCs) to process and present epitopes of the autoantigen, acetylcholine receptor (AChR), to the entire spectrum of AChR-specific syngeneic T cells. APCs derived from BALB/c mice were stably transfected with cDNA for the key immunogenic domain of the AChR alpha-subunit, flanked by sequences of the lysosome-associated membrane protein (LAMP) that direct APCs to process and present the antigen via the MHC Class II pathway. Transfected APCs strongly stimulated AChR-specific T cells from BALB/c mice. Fas ligand, or antibody to Fas, abrogated the T cell response, by inducing apoptosis of the APC-stimulated T cells. The new results of this investigation are (1) that autoreactive T cells can be effectively targeted by autologous APCs that are engineered to present the relevant autoantigen, and (2) that these specifically targeted and activated T cells can be profoundly inhibited by agents that trigger the Fas-mediated apoptosis pathway. The present findings suggest that engineering APCs for simultaneous presentation of the autoantigen and delivery of FasL will provide a powerful strategy for the elimination of autoreactive T cells.