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Acinic cell carcinoma of the parotid gland: A diagnostic dilemma on cytology

Sharma A, Ahuja S, Diwaker P, Wadhwa N, Arora VK

Malays J Pathol, 2019 Aug;41(2):191-194.
PMID: 31427555

INTRODUCTION: Acinic cell carcinoma (ACC) represents 1-6% of parotid gland neoplasms.
CASE REPORT: We report cytomorphological features of two uncommon variants of acinic cell carcinoma. The first case was an eleven-year-old female with a nodular mass in parotid and the FNA smears demonstrated a lymphoepithelial lesion composed of epithelial tumour cells with features of acinar cells in a lymphoid background. The second case was a 62-year-old male with a large parotid mass. The FNA smears revealed presence of extracellular, acellular amyloid-like material with tumour cells arranged in follicles.
DISCUSSION: Awareness of cytomorphological features of these unusual variants of acinic cell carcinoma may help to avoid diagnostic pitfall.

Matched MeSH terms: Amyloidogenic Proteins
Scopolamine, a Toxin-Induced Experimental Model, Used for Research in Alzheimer's Disease

Chen WN, Yeong KY

CNS Neurol Disord Drug Targets, 2020;19(2):85-93.
PMID: 32056532 DOI: 10.2174/1871527319666200214104331

Scopolamine as a drug is often used to treat motion sickness. Derivatives of scopolamine have also found applications as antispasmodic drugs among others. In neuroscience-related research, it is often used to induce cognitive disorders in experimental models as it readily permeates the bloodbrain barrier. In the context of Alzheimer's disease, its effects include causing cholinergic dysfunction and increasing amyloid-β deposition, both of which are hallmarks of the disease. Hence, the application of scopolamine in Alzheimer's disease research is proven pivotal but seldom discussed. In this review, the relationship between scopolamine and Alzheimer's disease will be delineated through an overall effect of scopolamine administration and its specific mechanisms of action, discussing mainly its influences on cholinergic function and amyloid cascade. The validity of scopolamine as a model of cognitive impairment or neurotoxin model will also be discussed in terms of advantages and limitations with future insights.

Matched MeSH terms: Amyloidogenic Proteins
Self-assembling amyloid-like nanostructures from SARS-CoV-2 S1, S2, RBD and N recombinant proteins

Morozova OV, Manuvera VA, Barinov NA, Subcheva EN, Laktyushkin VS, Ivanov DA, et al.

Arch Biochem Biophys, 2024 Feb;752:109843.
PMID: 38072298 DOI: 10.1016/j.abb.2023.109843

Self-assembling nanoparticles (saNP) and nanofibers were found in the recombinant coronavirus SARS-CoV-2 S1, S2, RBD and N proteins purified by affinity chromatography using Ni Sepharose. Scanning electron (SEM), atomic force (AFM) microscopy on mica or graphite surface and in liquid as well as dynamic light scattering (DLS) revealed nanostructures of various sizes. AFM in liquid cell without drying on the surface showed mean height of S1 saNP 80.03 nm, polydispersity index (PDI) 0.006; for S2 saNP mean height 93.32 nm, PDI = 0.008; for N saNP mean height 16.71 nm, PDI = 0.99; for RBD saNP mean height 16.25 nm, PDI = 0.55. Ratios between the height and radius of each saNP in the range 0.1-0.5 suggested solid protein NP but not vesicles with internal empty spaces. The solid but not empty structures of the protein saNP were also confirmed by STEM after treatment of saNP with the standard contrasting agent uranyl acetate. The saNP remained stable after multiple freeze-thaw cycles in water and hyperosmotic solutions for 2 years at -20 °C. Receptor-mediated penetration of the SARS-CoV-2 S1 and RBD saNP in the African green mokey kidney Vero cells with the specific receptors for β-coronavirus reproduction was more efficient compared to unspecific endocytosis into MDCK cells without the specific receptors. Amyloid-like structures were revealed in the SARS-CoV-2 S1, S2, RBD and N saNP by means of their interaction with Thioflavin T and Congo Red dyes. Taken together, spontaneous formation of the amyloid-like self-assembling nanostructures due to the internal affinity of the SARS-CoV-2 virion proteins might induce proteinopathy in patients, including conformational neurodegenerative diseases, change stability of vaccines and diagnostic systems.

Matched MeSH terms: Amyloidogenic Proteins
Single-chain Fv Antibodies for Targeting Neurodegenerative Diseases

Chia KY, Ng KY, Koh RY, Chye SM

CNS Neurol Disord Drug Targets, 2018;17(9):671-679.
PMID: 29546836 DOI: 10.2174/1871527317666180315161626

BACKGROUND & OBJECTIVE: Protein misfolding and aggregation have been considered the common pathological hallmarks for a number of neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD) and Huntington's disease (HD). These abnormal proteins aggregates damage mitochondria and induce oxidative stress, resulting in neuronal cell death. Prolonged neuronal damage activates microglia and astrocytes, development of inflammation reaction and further promotes neurodegeneration. Thus, elimination of abnormal protein aggregates without eliciting any adverse effects are the main treatment strategies. To overcome this, recent studies have deployed single- chain fragment variable antibodies (scFvs) to target the pathological protein aggregates, such as amyloid-beta (Aβ) peptides, α-synuclein (α-syn) and Huntingtin (Htt). To date scFv has been effective at inhibiting abnormal protein aggregates formation in both in vitro and in vivo model system of AD, PD and HD.
CONCLUSION: Currently active research is still ongoing to improve the scFv gene delivery technology, to further enhance brain penetration, intracellular stability, solubility and efficacy of scFv intrabody.

Matched MeSH terms: Amyloidogenic Proteins/immunology
Fulltext Alzheimer's disease-like perturbations in HIV-mediated neuronal dysfunctions: understanding mechanisms and developing therapeutic strategies

Jha NK, Sharma A, Jha SK, Ojha S, Chellappan DK, Gupta G, et al.

Open Biol, 2020 Dec;10(12):200286.
PMID: 33352062 DOI: 10.1098/rsob.200286

Excessive exposure to toxic substances or chemicals in the environment and various pathogens, including viruses and bacteria, is associated with the onset of numerous brain abnormalities. Among them, pathogens, specifically viruses, elicit persistent inflammation that plays a major role in Alzheimer's disease (AD) as well as dementia. AD is the most common brain disorder that affects thought, speech, memory and ability to execute daily routines. It is also manifested by progressive synaptic impairment and neurodegeneration, which eventually leads to dementia following the accumulation of Aβ and hyperphosphorylated Tau. Numerous factors contribute to the pathogenesis of AD, including neuroinflammation associated with pathogens, and specifically viruses. The human immunodeficiency virus (HIV) is often linked with HIV-associated neurocognitive disorders (HAND) following permeation through the blood-brain barrier (BBB) and induction of persistent neuroinflammation. Further, HIV infections also exhibited the ability to modulate numerous AD-associated factors such as BBB regulators, members of stress-related pathways as well as the amyloid and Tau pathways that lead to the formation of amyloid plaques or neurofibrillary tangles accumulation. Studies regarding the role of HIV in HAND and AD are still in infancy, and potential link or mechanism between both is not yet established. Thus, in the present article, we attempt to discuss various molecular mechanisms that contribute to the basic understanding of the role of HIV-associated neuroinflammation in AD and HAND. Further, using numerous growth factors and drugs, we also present possible therapeutic strategies to curb the neuroinflammatory changes and its associated sequels.

Matched MeSH terms: Amyloidogenic Proteins/metabolism