866 research outputs found
Infiltration of T Lymphocytes and Expression of ICAM-1 in the Hippocampus of Patients with Hippocampal Sclerosis
We and others have previously shown that reactive microglia express the major histocompatibility complex (MHC) class I and class II antigens in the hippocampus of patients suffering from epilepsy. Although the MHC glycoproteins serve as restriction elements for T lymphocytes, there is little information available regarding T lymphocytes in hippocampal sclerosis. In the present study, we investigated T lymphocyte infiltration in human hippocampi in four cases of epilepsy with hippocampal sclerosis, as well as in four control cases without neurological disease. No CD8- or CD4-positive T lymphocytes were seen in hippocampi from the control cases. In contrast, CD8- and CD4-positive T lymphocytes had infiltrated into the hippocampi of patients with hippocampal sclerosis. In addition, expression of intercellular adhesion molecule-1 was diffusely upregulated in the hippocampi with hippocampal sclerosis. These results indicate that T lymphocyte infiltration is involved in the pathology of hippocampal sclerosis
Characteristics of patients misdiagnosed with Alzheimer’s disease and their medication use: an analysis of the NACC-UDS database
BACKGROUND: This study compared individuals whose clinical diagnosis of Alzheimer’s disease (AD) matched or did not match neuropathologic results at autopsy on clinical and functional outcomes (cognitive impairment, functional status and neuropsychiatric symptoms). The study also assessed the extent of potentially inappropriate medication use (using potentially unnecessary medications or potentially inappropriate prescribing) among misdiagnosed patients. METHODS: Longitudinal data from the National Alzheimer’s Coordinating Center Uniform Data Set (NACC-UDS, 2005–2010) and corresponding NACC neuropathological data were utilized to compare 88 misdiagnosed and 438 accurately diagnosed patients. RESULTS: Following adjustment of sociodemographic characteristics, the misdiagnosed were found to have less severe cognitive and functional impairment. However, after statistical adjustment for sociodemographics, dementia severity level, time since onset of cognitive decline and probable AD diagnosis at baseline, the groups significantly differed on only one outcome: the misdiagnosed were less likely to be depressed/dysphoric. Among the misdiagnosed, 18.18% were treated with potentially inappropriate medication. An additional analysis noted this rate could be as high as 67.10%. CONCLUSIONS: Findings highlight the importance of making an accurate AD diagnosis to help reduce unnecessary treatment and increase appropriate therapy. Additional research is needed to demonstrate the link between potentially inappropriate treatment and adverse health outcomes in misdiagnosed AD patients
Dopaminergic Retinal Cell Loss and Visual Dysfunction in Parkinson Disease
Objective: Considering the demonstrated implication of the retina in Parkinson disease (PD) pathology and the importance of dopaminergic cells in this tissue, we aimed to analyze the state of the dopaminergic amacrine cells and some of their main postsynaptic neurons in the retina of PD. Methods: Using immunohistochemistry and confocal microscopy, we evaluated morphology, number, and synaptic connections of dopaminergic cells and their postsynaptic cells, AII amacrine and melanopsin‐containing retinal ganglion cells, in control and PD eyes from human donors. Results: In PD, dopaminergic amacrine cell number was reduced between 58% and 26% in different retinal regions, involving a decline in the number of synaptic contacts with AII amacrine cells (by 60%) and melanopsin cells (by 35%). Despite losing their main synaptic input, AII cells were not reduced in number, but they showed cellular alterations compromising their adequate function: (1) a loss of mitochondria inside their lobular appendages, which may indicate an energetic failure; and (2) a loss of connexin 36, suggesting alterations in the AII coupling and in visual signal transmission from the rod pathway. Interpretation: The dopaminergic system impairment and the affection of the rod pathway through the AII cells may explain and be partially responsible for the reduced contrast sensitivity or electroretinographic response described in PD. Also, dopamine reduction and the loss of synaptic contacts with melanopsin cells may contribute to the melanopsin retinal ganglion cell loss previously described and to the disturbances in circadian rhythm and sleep reported in PD patients. These data support the idea that the retina reproduces brain neurodegeneration and is highly involved in PD pathology.This work was supported by the Michael J. Fox Foundation for Parkinson’s Research. I.O.-L. and X.S.-S. acknowledge financial support from the Ministry of Education, Spain (FPU 14/03166; FPU 16/04114). N.C. acknowledges financial support from the Ministry of Economy and Competitiveness, Spain (MINECO-FEDER-BFU2015-67139-R), Carlos III Institute of Health (RETICS-FEDER RD16/0008/0016), Retina Asturias Association, and Generalitat Valenciana-European Regional Development Fund (IDIFEDER/2017/064). The Brain and Body Donation Program has been supported by the NIH National Institute of Neurological Disorders and Stroke (U24 NS072026), the NIH National Institute on Aging (P30 AG19610), the Arizona Department of Health Services, the Arizona Biomedical Research Commission, and the Michael J. Fox Foundation for Parkinson’s Research
Spatial clustering of filarial transmission before and after a Mass Drug Administration in a setting of low infection prevalence
BACKGROUND: In the global program for the elimination of lymphatic filariasis (LF) longitudinal assessment of the prevalence of microfilaremia and antigenemia is recommended to monitor the effect of mass treatment on transmission. Additional monitoring tools such as entomologic and antibody methods may be useful in identifying residual foci of infection. In this study, we characterized serologic markers of infection and exposure spatially both before and after mass treatment, in an area of initial low Wuchereria bancrofti infection prevalence. METHODS: Consenting persons in the sentinel community were tested for circulating microfilaria and antigen (by immunochromatographic test) before and after the 1(st )annual mass drug administration of diethylcarbamazine and albendazole. A cohort of 161 persons provided serum specimens both years that were tested for antifilarial IgG (1 and 4) antibody. Every house was mapped using a differential Global Positioning System; this information was linked to the serologic data. W. bancrofti infection in the mosquito vector was assessed with year-round collection. Multiple linear regression was used to investigate the influence of antigen-positive persons on the antifilarial antibody responses of antigen-negative neighbors. RESULTS: After mass treatment, decreases were observed in the sentinel site in the overall prevalence of antigen (10.4% to 6.3%) and microfilaremia (0.9 to 0.4%). Of the persons in the cohort that provided serum specimens both years, 79% received treatment. Antigen prevalence decreased from 15.0% to 8.7%. Among 126 persons who received treatment, antigen and antifilarial IgG1 prevalence decreased significantly (p = 0.002 and 0.001, respectively). Among 34 persons who did not receive treatment, antifilarial IgG1 prevalence increased significantly (p = 0.003). Average antifilarial IgG1 levels decreased in households with high treatment coverage and increased in households that refused treatment. Each 10-meter increase in distance from the residence of a person who was antigen-positive in 2000 was associated a 4.68 unit decrease in antifilarial IgG1 level in 2001, controlling for other factors (p = 0.04). DISCUSSION: Antifilarial antibody assays can be used as a measure of filarial exposure. Our results suggest that micro-scale spatial heterogeneity exists in LF exposure and infection. Treatment appeared to be associated with reduced exposure at the sub-community level, suggesting the need to achieve high and homogeneous coverage. Public health messages should note the benefits of having one's neighbors receive treatment with antifilarial drugs
Phosphorylated α‐synuclein in the retina is a biomarker of Parkinson's disease pathology severity
Background: PD patients often have visual alterations, for example, loss of visual acuity, contrast sensitivity or motion perception, and diminished electroretinogram responses. PD pathology is mainly characterized by the accumulation of pathological α‐synuclein deposits in the brain, but little is known about how synucleinopathy affects the retina. Objective: To study the correlation between α‐synuclein deposits in the retina and brain of autopsied subjects with PD and incidental Lewy body disease. Methods: We evaluated the presence of phosphorylated α‐synuclein in the retina of autopsied subjects with PD (9 subjects), incidental Lewy body disease (4 subjects), and controls (6 subjects) by immunohistochemistry and compared the retinal synucleinopathy with brain disease severity indicators. Results: Whereas controls did not show any phosphorylated α‐synuclein immunoreactivity in their retina, all PD subjects and 3 of 4 incidental Lewy body disease subjects had phosphorylated α‐synuclein deposits in ganglion cell perikarya, dendrites, and axons, some of them resembling brain Lewy bodies and Lewy neurites. The Lewy‐type synucleinopathy density in the retina significantly correlated with Lewy‐type synucleinopathy density in the brain, with the Unified Parkinson's disease pathology stage and with the motor UPDRS. Conclusion: These data suggest that phosphorylated α‐synuclein accumulates in the retina in parallel with that in the brain, including in early stages preceding development of clinical signs of parkinsonism or dementia. Therefore, the retina may provide an in vivo indicator of brain pathology severity, and its detection could help in the diagnosis and monitoring of disease progression.This work was supported by the Michael J. Fox Foundation for Parkinson's Research. I.O.L. acknowledges financial support from the Ministerio de Educación, Spain (FPU 14/03166). N.C. acknowledges financial support from the Ministerio de Economía y Competitividad, Spain (MINECO‐FEDER‐BFU2015‐67139‐R), Generalitat Valenciana (Prometeo 2016/158), and Instituto Carlos III (ISCIII RETICS‐FEDER RD12/0034/0010). The Brain and Body Donation Program has been supported by the National Institute of Neurological Disorders and Stroke (U24 NS072026), the National Institute on Aging (P30 AG19610), the Arizona Department of Health Services, the Arizona Biomedical Research Commission, and the Michael J. Fox Foundation for Parkinson's Research
The Impact of Aging on Brain Pituitary Adenylate Cyclase Activating Polypeptide Pathology and Cognition in Mice and Rhesus Macaques
Pituitary adenylate cyclase activating polypeptide (PACAP) is associated with Alzheimer\u27s disease (AD), but its age-related effects are unknown. We chose the rhesus macaque due to its closeness to human anatomy and physiology. We examined four variables: aging, cognitive performance, amyloid plaques and PACAP. Delayed nonmatching-to-sample recognition memory scores declined with age and correlated with PACAP levels in the striatum, parietal and temporal lobes. Because amyloid plaques were the only AD pathology in the old rhesus macaque, we further studied human amyloid precursor protein (hAPP) transgenic mice. Aging was associated with decreased performance in the Morris Water Maze (MWM). In wild type (WT) C57BL/6 mice, the performance was decreased at age 24-26 month whereas in hAPP transgenic mice, it was decreased as early as 9-12 month. Neuritic plaques in adult hAPP mice clustered in hippocampus and adjacent cortical regions, but did not propagate further into the frontal cortex. Cerebral PACAP protein levels were reduced in hAPP mice compared to age-matched WT mice, but the genetic predisposition dominated cognitive decline. Taken together, these data suggest an association among PACAP levels, aging, cognitive function and amyloid load in nonhuman primates, with both similarities and differences from human AD brains. Our results suggest caution in choosing animal models and in extrapolating data to human AD studies
Soluble P-tau217 reflects amyloid and tau pathology and mediates the association of amyloid with tau
Alzheimer\u27s disease is characterized by β-amyloid plaques and tau tangles. Plasma levels of phospho-tau217 (P-tau217) accurately differentiate Alzheimer\u27s disease dementia from other dementias, but it is unclear to what degree this reflects β-amyloid plaque accumulation, tau tangle accumulation, or both. In a cohort with post-mortem neuropathological data (N = 88), both plaque and tangle density contributed independently to higher P-tau217, but P-tau217 was not elevated in patients with non-Alzheimer\u27s disease tauopathies (N = 9). Several findings were replicated in a cohort with PET imaging ( BioFINDER-2 , N = 426), where β-amyloid and tau PET were independently associated with P-tau217. P-tau217 concentrations correlated with β-amyloid PET (but not tau PET) in early disease stages and with both β-amyloid and (more strongly) tau PET in late disease stages. Finally, P-tau217 mediated the association between β-amyloid and tau in both cohorts, especially for tau outside of the medial temporal lobe. These findings support the hypothesis that plasma P-tau217 concentration is increased by both β-amyloid plaques and tau tangles and is congruent with the hypothesis that P-tau is involved in β-amyloid-dependent formation of neocortical tau tangles
Reduced clinical and postmortem measures of cardiac pathology in subjects with advanced Alzheimer's Disease
Background. Epidemiological studies indicate a statistical linkage between atherosclerotic vascular disease (ATH) and Alzheimer\u27s disease (AD). Autopsy studies of cardiac disease in AD have been few and inconclusive. In this report, clinical and gross anatomic measures of cardiac disease were compared in deceased human subjects with and without AD. Methods. Clinically documented cardiovascular conditions from AD (n = 35) and elderly non-demented control subjects (n = 22) were obtained by review of medical records. Coronary artery stenosis and other gross anatomical measures, including heart weight, ventricular wall thickness, valvular circumferences, valvular calcifications and myocardial infarct number and volume were determined at autopsy. Results. Compared to non-demented age-similar control subjects, those with AD had significantly fewer total diagnosed clinical conditions (2.91 vs 4.18), decreased coronary artery stenosis (70.8 vs 74.8%), heart weight (402 vs 489 g for males; 319 vs 412 g for females) and valvular circumferences. Carriage of the Apolipoprotein E-ε4 allele did not influence the degree of coronary stenosis. Group differences in heart weight remained significant after adjustment for age, gender, body mass index and apolipoprotein E genotype while differences in coronary artery stenosis were significantly associated with body mass index alone. Conclusions. The results are in agreement with an emerging understanding that, while midlife risk factors for ATH increase the risk for the later development of AD, once dementia begins, both risk factors and manifest disease diminish, possibly due to progressive weight loss with increasing dementia as well as disease involvement of the brain\u27s vasomotor centers. © 2011 Beach et al; licensee BioMed Central Ltd
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