Pathology international
-
Pathology international · Apr 2017
ReviewPlaque formation and the intraneuronal accumulation of β-amyloid in Alzheimer's disease.
Amyloid plaques and neurofibrillary tangles (NFTs) in the brain are the neuropathological hallmarks of Alzheimer's disease (AD). Amyloid plaques are composed of β-amyloid peptides (Aβ), while NFTs contain hyperphosphorylated tau proteins. Patients with familial AD who have mutations in the amyloid precursor protein (APP) gene have either increased production of Aβ or generate more aggregation-prone forms of Aβ. ⋯ Aβ as extracellular aggregates and amyloid plaques are thought to be toxic to the surrounding neurons. The intraneuronal accumulation of Aβ has more recently been demonstrated and is reported to be involved in synaptic dysfunction, cognitive impairment, and the formation of amyloid plaques in AD. We herein provide an overview of the process of the intraneuronal accumulation of Aβ and plaque formation, and discuss its implications for the pathology, early diagnosis, and therapy of AD.
-
Pathology international · May 2015
Case ReportsCD44-expressing undifferentiated carcinoma with rhabdoid features of the pancreas: molecular analysis of aggressive invasion and metastasis.
Carcinoma with rhabdoid features is a rare malignant tumor with a poor prognosis whose molecular mechanism for aggressive behavior is unclear. We describe an undifferentiated pancreatic carcinoma with rhabdoid features that demonstrated extensive invasion and metastasis. Examination of a 63-year-old man with back pain disclosed a retroperitoneal tumor with multiple metastases. ⋯ Immunohistochemistry showed that tumor cells expressed cytokeratin and vimentin, and electron microscopy confirmed a perinuclear mass of intermediate fibrils and lipid droplets, which indicated an undifferentiated carcinoma with rhabdoid features. Tumor tissue contained hyaluronan; tumor cells strongly expressed CD44, matrix metalloproteinase-9, hypoxia-inducible factor-1α, hyaluronan synthase 2, and acyl-CoA:cholesterol acyltransferase 1 and had a high Ki-67(+) ratio. Since hyaluronan is a ligand for CD44, formation of CD44-hyaluronan complex on the cell surface activates CD44 and this activation may explain why the tumor manifested aggressive invasion and metastasis throughout the clinical course.
-
Pathology international · May 2014
Case ReportsCommunity-acquired lobar pneumonia caused by Pseudomonas aeruginosa infection in Japan: a case report with histological and immunohistochemical examination.
Pseudomonas aeruginosa is a common pathogen in nosocomial and/or healthcare-associated pneumonia, but is rare in community-acquired pneumonia. A 50-year-old previously healthy woman was taken to the emergency department because of rapidly progressing dyspnea. Chest radiograph showed consolidation of the entire right upper lobe, a finding suggestive of lobar pneumonia. ⋯ Autopsy revealed that the alveoli throughout the upper right lobe were filled with dense inflammatory cells mainly consisting of macrophages and neutrophils. Immunoreactive bacilli by using an anti-P. aeruginosa antibody were localized within macrophages accumulated in the alveoli as well in the vessel walls. Lobar pneumonia composed of dense neutrophils and bacteria-laden macrophages with total lung congestion and edema may be characteristic for community-acquired P. aeruginosa pneumonia in a healthy adult.