John Q. Trojanowski

Bio: John Q. Trojanowski is an academic researcher from University of Pennsylvania. The author has contributed to research in topics: Alzheimer's disease & Dementia. The author has an hindex of 226, co-authored 1467 publications receiving 213948 citations. Previous affiliations of John Q. Trojanowski include Vanderbilt University & University of California, San Francisco.

D2-40, a novel monoclonal antibody against the M2A antigen as a marker to distinguish hemangioblastomas from renal cell carcinomas.

Abstract: Hemangioblastomas (HB) are characterized by the presence of vacuolated tumor cells resembling the tumor cells seen in clear cell renal cell carcinomas (CRCC). The distinction between HB and metastatic CRCC in the brain is critical as they have different therapeutic and prognostic ramifications. The issue is further complicated by the possibility of both HB and metastatic CRCC in brains of patients with Von Hippel Lindau (VHL) disease. We studied the expression of a novel monoclonal antibody D2-40, which recognizes an oncofetal antigen (M2A) in HB and CRCC, by immunohistochemistry. The vacuolated tumor cells in all HB were stained positively with D2-40. Nineteen of 23 (83%) HB showed strong, membranous staining in the vacuolated tumor cells, and 4 of 23 (17%) showed weaker staining. No expression was seen in CRCC, either primary in the kidney (0/20), or metastatic CRCC in the brain (0/8). Three of the patients with HB also had VHL disease, and no difference was seen in D2-40 staining of HB in patients with or without VHL disease. Two of these three VHL disease patients had both primary CRCC and HB resected at our institution. In these two patients, strong D2-40 expression was seen in the HB, but no expression was seen in the CRCC, underlying the utility of this marker in distinguishing HB from CRCC in patients with VHL disease in addition to sporadic cases. In summary, the monoclonal antibody D2-40 is a useful marker to distinguish HB from CRCC.

The North American Multiple System Atrophy Study Group.

Abstract: The North American Multiple System Atrophy Study Group involves investigators in 12 US medical centers funded by a grant from the National Institutes of Health. The objectives are to examine the environmental and genetic risk factors for MSA; elucidate pathogenic mechanisms underlying the disorder; and refine evaluations used for assessment. During its first year, the group enrolled 87 patients, implemented four cores, and initiated four scientific projects. Most patients among the 87 had parkinsonian features, which frequently began asymmetrically and remained asymmetrical; one-third responded to levodopa and many developed levodopa complications; almost two-thirds of the patients had cerebellar dysfunction, of these 90% had ataxia; urinary incontinence occurred commonly, and sleep disorders affected most. The investigators studied the effects of oxidative and nitrative stress upon the formation of alpha-synuclein inclusions; generated transgenic models of alpha-synuclein accumulation that recapitulate several behavioral and neuropathological features of MSA; and compared the severity of the autonomic features of MSA, Parkinson's disease and dementia with Lewy bodies.

Attenuated neurodegenerative disease phenotype in tau transgenic mouse lacking neurofilaments.

Abstract: Previous studies have shown that transgenic (Tg) mice overexpressing human tau protein develop filamentous tau aggregates in the CNS The most abundant tau aggregates are found in spinal cord and brainstem in which they colocalize with neurofilaments (NFs) as spheroids in axons To elucidate the role of NF subunit proteins in tau aggregate formation and to test the hypothesis that NFs are pathological chaperones in the formation of intraneuronal tau inclusions, we crossbred previously described tau (T44) Tg mice overexpressing the smallest human tau isoform with knock-out mice devoid of NFL (NFL−/−) or NFH (NFH−/−) Depletion of NF subunit proteins from the T44 mice (ie, T44;NFL−/− and T44;NFH−/−), in particular NFL, resulted in a dramatic decrease in the total number of tau-positive spheroids in spinal cord and brainstem Concomitant with the reduction in spheroid number, the bigenic mice showed delayed accumulation of insoluble tau protein in the CNS, increased viability, reduced weight loss, and improved behavioral phenotype when compared with the single T44 Tg mice These results imply that NFs are pathological chaperones in the development of tau spheroids and suggest a role for NFs in the pathogenesis of neurofibrillary tau lesions in neurodegenerative disorders that contain both NFs and tau proteins

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

The diagnosis of dementia due to Alzheimer’s disease: Recommendations from the National Institute on Aging-Alzheimer’s Association workgroups on diagnostic guidelines for Alzheimer's disease

Abstract: The National Institute on Aging and the Alzheimer's Association charged a workgroup with the task of revising the 1984 criteria for Alzheimer's disease (AD) dementia. The workgroup sought to ensure that the revised criteria would be flexible enough to be used by both general healthcare providers without access to neuropsychological testing, advanced imaging, and cerebrospinal fluid measures, and specialized investigators involved in research or in clinical trial studies who would have these tools available. We present criteria for all-cause dementia and for AD dementia. We retained the general framework of probable AD dementia from the 1984 criteria. On the basis of the past 27 years of experience, we made several changes in the clinical criteria for the diagnosis. We also retained the term possible AD dementia, but redefined it in a manner more focused than before. Biomarker evidence was also integrated into the diagnostic formulations for probable and possible AD dementia for use in research settings. The core clinical criteria for AD dementia will continue to be the cornerstone of the diagnosis in clinical practice, but biomarker evidence is expected to enhance the pathophysiological specificity of the diagnosis of AD dementia. Much work lies ahead for validating the biomarker diagnosis of AD dementia.

The Amyloid Hypothesis of Alzheimer's Disease: Progress and Problems on the Road to Therapeutics

Abstract: It has been more than 10 years since it was first proposed that the neurodegeneration in Alzheimer9s disease (AD) may be caused by deposition of amyloid β-peptide (Aβ) in plaques in brain tissue. According to the amyloid hypothesis, accumulation of Aβ in the brain is the primary influence driving AD pathogenesis. The rest of the disease process, including formation of neurofibrillary tangles containing tau protein, is proposed to result from an imbalance between Aβ production and Aβ clearance.

Free Radicals in the Physiological Control of Cell Function

Abstract: At high concentrations, free radicals and radical-derived, nonradical reactive species are hazardous for living organisms and damage all major cellular constituents. At moderate concentrations, how...