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Fulltext The pattern of amyloid deposition in the lung

Looi LM

Malays J Pathol, 1999 Jun;21(1):29-35.
PMID: 10879276

A review of routine histopathological samples and autopsies examined at the Department of Pathology, University of Malaya revealed 15 cases of amyloidosis of the lung. Two were localized depositions limited to the lung while in the remainder, lung involvement was part of the picture of systemic amyloidosis. Both cases of localized amyloidosis presented with symptomatic lung/bronchial masses and a clinical diagnosis of tumour. Histology revealed "amyloidomas" associated with heavy plasma cell and lymphocytic infiltration and the presence of multinucleated giant cells. In both cases, the amyloid deposits were immunopositive for lambda light chains and negative for kappa chains and AA protein. One was a known systemic lupus erythematosus patient with polyclonal hypergammaglobulinaemia. The other patient was found to have plasma cell dyscrasia with monoclonal IgG lambda gammopathy. Both patients did not develop systemic amyloidosis. In contrast, lung involvement in systemic AA amyloidosis was not obvious clinically or macroscopically but was histologically evident in 75% of cases subjected to autopsy. Amyloid was detected mainly in the walls of arterioles and small vessels, and along the alveolar septa. It was less frequently detected in the pleura, along the basement membrane of the bronchial epithelium and around bronchial glands. In one case of systemic AL amyloidosis associated with multiple myeloma, an "amyloidoma" occurred in the subpleural region reminiscent of localized amyloidosis. These cases pose questions on (1) whether localized "tumour-like" amyloidosis is a forme fruste of systemic AL amyloidosis and (2) the differing pattern of tissue deposition of different chemical types of amyloid fibrils, with the suggestion that light chain amyloid has a greater tendency to nodular deposition than AA amyloid.

Matched MeSH terms: Amyloid/metabolism*
Insights into the Pathophysiology of Alzheimer's Disease and Potential Therapeutic Targets: A Current Perspective

Rajah Kumaran K, Yunusa S, Perimal E, Wahab H, Müller CP, Hassan Z

J Alzheimers Dis, 2023;91(2):507-530.
PMID: 36502321 DOI: 10.3233/JAD-220666

The aging population increases steadily because of a healthy lifestyle and medical advancements in healthcare. However, Alzheimer's disease (AD) is becoming more common and problematic among older adults. AD-related cases show an increasing trend annually, and the younger age population may also be at risk of developing this disorder. AD constitutes a primary form of dementia, an irreversible and progressive brain disorder that steadily damages cognitive functions and the ability to perform daily tasks. Later in life, AD leads to death as a result of the degeneration of specific brain areas. Currently, the cause of AD is poorly understood, and there is no safe and effective therapeutic agent to cure or slow down its progression. The condition is entirely preventable, and no study has yet demonstrated encouraging findings in terms of treatment. Identifying this disease's pathophysiology can help researchers develop safe and efficient therapeutic strategies to treat this ailment. This review outlines and discusses the pathophysiology that resulted in the development of AD including amyloid-β plaques, tau neurofibrillary tangles, neuroinflammation, oxidative stress, cholinergic dysfunction, glutamate excitotoxicity, and changes in neurotrophins level may sound better based on the literature search from Scopus, PubMed, ScienceDirect, and Google Scholar. Potential therapeutic strategies are discussed to provide more insights into AD mechanisms by developing some possible pharmacological agents for its treatment.

Matched MeSH terms: Plaque, Amyloid/metabolism
Intratumour amyloidosis in Malaysians: an immunohistochemical study

Looi LM

Ann Acad Med Singap, 1986 Jan;15(1):52-6.
PMID: 3010797

Congo red screening of tumour material examined at the Department of Pathology, University of Malaya revealed intratumour deposits of amyloid in 12% of nasopharyngeal carcinomas, 66% of basal cell carcinomas, 100% of medullary carcinomas of the thyroid, 56% of islet cell tumours of the pancreas, 1 out of 16 carcinoids and 1 out of 100 thyroid adenomas. All the deposits were permanganate resistant and did not contain AA protein, indicating that what was encountered was not secondary amyloid. The deposits showed variable staining for immunoglobulin light chains and amyloid P component with a standard peroxidase antiperoxidase method. The possibility that intratumour amyloid has a neoplastic origin is discussed.

Matched MeSH terms: Amyloid/metabolism
Fulltext Fluorine-19 Magnetic Resonance Imaging for Detection of Amyloid β Oligomers Using a Keto Form of Curcumin Derivative in a Mouse Model of Alzheimer's Disease

Yanagisawa D, Ibrahim NF, Taguchi H, Morikawa S, Tomiyama T, Tooyama I

Molecules, 2021 Mar 04;26(5).
PMID: 33806326 DOI: 10.3390/molecules26051362

Recent evidence suggests that the formation of soluble amyloid β (Aβ) aggregates with high toxicity, such as oligomers and protofibrils, is a key event that causes Alzheimer's disease (AD). However, understanding the pathophysiological role of such soluble Aβ aggregates in the brain in vivo could be difficult due to the lack of a clinically available method to detect, visualize, and quantify soluble Aβ aggregates in the brain. We had synthesized a novel fluorinated curcumin derivative with a fixed keto form, named as Shiga-Y51, which exhibited high selectivity to Aβ oligomers in vitro. In this study, we investigated the in vivo detection of Aβ oligomers by fluorine-19 (19F) magnetic resonance imaging (MRI) using Shiga-Y51 in an APP/PS1 double transgenic mouse model of AD. Significantly high levels of 19F signals were detected in the upper forebrain region of APP/PS1 mice compared with wild-type mice. Moreover, the highest levels of Aβ oligomers were detected in the upper forebrain region of APP/PS1 mice in enzyme-linked immunosorbent assay. These findings suggested that 19F-MRI using Shiga-Y51 detected Aβ oligomers in the in vivo brain. Therefore, 19F-MRI using Shiga-Y51 with a 7 T MR scanner could be a powerful tool for imaging Aβ oligomers in the brain.

Matched MeSH terms: Plaque, Amyloid/metabolism
Danshen (Salvia miltiorrhiza) water extract shows potential neuroprotective effects in Caenorhabditis elegans

Yuen CW, Murugaiyah V, Najimudin N, Azzam G

J Ethnopharmacol, 2021 Feb 10;266:113418.
PMID: 32991971 DOI: 10.1016/j.jep.2020.113418

ETHNOPHARMACOLOGICAL RELEVANCE: Danshen, is a traditional Chinese medicine obtained from the dried root and rhizome of Salvia miltiorrhiza Bunge. It is known to be used for neurological disorder including for Alzheimer's disease (AD). This study uncovers the effect of Danshen water extract on the Alzheimer's disease model of C.elegans.
MATERIAL AND METHODS: The composition of Danshen water extract was determined using (High Performance Liquid Chromatography (HPLC). Then Thioflavin T assay was used to determined if Danshen water extract could prevent the aggregation of amyloid-β peptide (Aβ). Alzheimer's disease C.elegans model was used to determine the effect of Danshen water extract. Finally, the reactive oxygen species (ROS) was determined using the 2,7-dichlorofuorescein diacetate method.
RESULTS: In this study, we found that standardized Danshen water extract that contains danshensu (1.26%), salvianolic acid A (0.35%) and salvianolic acid B (2.21%) are able to bind directly to Aβ and prevents it from aggregating. The IC50 for the inhibition of Aβ aggregation by Danshen water extract was 0.5 mg/ml. In the AD model of C.elegans, Danshen water extract managed to alleviates the paralysis phenotype. Furthermore, the administration of Danshen water extract displayed antioxidant properties toward the Aβ-induced oxidative stress.
CONCLUSIONS: AD is a widespread neurodegenerative disease attributed to the accumulation of extracellular plaques comprising Aβ. Danshen water extract could significantly reduce the progress of paralysis in the AD model of C. elegans, showing promising results with its antioxidant properties. It can be concluded that Danshen water extract could potentially serve as a therapeutic for AD.

Matched MeSH terms: Plaque, Amyloid/metabolism
Tocotrienol-Rich Fraction Modulates Amyloid Pathology and Improves Cognitive Function in AβPP/PS1 Mice

Ibrahim NF, Yanagisawa D, Durani LW, Hamezah HS, Damanhuri HA, Wan Ngah WZ, et al.

J Alzheimers Dis, 2017;55(2):597-612.
PMID: 27716672

Alzheimer's disease (AD) is the most common cause of dementia. The cardinal neuropathological characteristic of AD is the accumulation of amyloid-β (Aβ) into extracellular plaques that ultimately disrupt neuronal function and lead to neurodegeneration. One possible therapeutic strategy therefore is to prevent Aβ aggregation. Previous studies have suggested that vitamin E analogs slow AD progression in humans. In the present study, we investigated the effects of the tocotrienol-rich fraction (TRF), a mixture of vitamin E analogs from palm oil, on amyloid pathology in vitro and in vivo. TRF treatment dose-dependently inhibited the formation of Aβ fibrils and Aβ oligomers in vitro. Moreover, daily TRF supplementation to AβPPswe/PS1dE9 double transgenic mice for 10 months attenuated Aβ immunoreactive depositions and thioflavin-S-positive fibrillar type plaques in the brain, and eventually improved cognitive function in the novel object recognition test compared with control AβPPswe/PS1dE9 mice. The present result indicates that TRF reduced amyloid pathology and improved cognitive functions, and suggests that TRF is a potential therapeutic agent for AD.

Matched MeSH terms: Amyloid/metabolism