Potential Contributions of the Tobacco Nicotine-Derived Nitrosamine Ketone to White Matter Molecular Pathology in Fetal Alcohol Spectrum Disorder

A Rare Case of Cervical Vagal Nerve Schwannoma in a 30-Year-Old Ethiopian Man

Schwannoma is a slowly growing benign tumor that arises from Schwann cells. Schwannomas affect both genders equally. It occurs in any age group, but most cases are seen between the third and fifth decade. About one-fourth to one-third of extracranial schwannomas cases originate in the head and neck region. The vagus nerve, followed by the cervical sympathetic chain, is the leading site of origin in the neck region. The majority of patients with schwannomas are asymptomatic. Patients with vagal nerve schwannomas in the neck primarily present with hoarseness of voice due to paralysis of the vocal cords. Because of their rarity and the lack of a neurologic deficit as a presenting symptom, preoperative consideration of schwannomas is tough, and several differential diagnoses may be entertained.The mainstay of treatment for vagal nerve schwannoma is complete surgical excision. Here we present a rare case of cervical vagal nerve schwannoma in a 30-year-old male farmer from Ethiopia. The patient presented with a gradually increasing neck swelling of 10 years duration. He started to have hoarseness in his voice five months prior to his presentation. On examination, he had a huge anterior neck swelling. He had two FNAC results, which were inconclusive, and a neck CT. With the consideration of multinodular goiter versus spindle cell neoplasm, the neck was explored, and complete excision of the mass was done. The excisional biopsy turned out to be a classical cervical schwannoma. So this report aims to make physicians aware of the rare case of schwannomas, particularly vagal nerve schwannomas. Clinicians should consider schwannomas in the differential diagnosis of a patient presenting with a cervical mass. Furthermore, they need to be well aware of the diagnostic workup, mainly the imaging modalities, which are essential for proper preoperative planning, surgical treatment, and postoperative complications of cervical schwannomas.

Environmental and Nutritional "Stressors" and Oligodendrocyte Dysfunction: Role of Mitochondrial and Endoplasmatic Reticulum Impairment

Oligodendrocytes are myelinating cells of the central nervous system which are generated by progenitor oligodendrocytes as a result of maturation processes. The main function of mature oligodendrocytes is to produce myelin, a lipid-rich multi-lamellar membrane that wraps tightly around neuronal axons, insulating them and facilitating nerve conduction through saltatory propagation. The myelination process requires the consumption a large amount of energy and a high metabolic turnover. Mitochondria are essential organelles which regulate many cellular functions, including energy production through oxidative phosphorylation. Any mitochondrial dysfunction impacts cellular metabolism and negatively affects the health of the organism. If the functioning of the mitochondria is unbalanced, the myelination process is impaired. When myelination has finished, oligodendrocyte will have synthesized about 40% of the total lipids present in the brain. Since lipid synthesis occurs in the cellular endoplasmic reticulum, the dysfunction of this organelle can lead to partial or deficient myelination, triggering numerous neurodegenerative diseases. In this review, the induced malfunction of oligodendrocytes by harmful exogenous stimuli has been outlined. In particular, the effects of alcohol consumption and heavy metal intake are discussed. Furthermore, the response of the oligodendrocyte to excessive mitochondrial oxidative stress and to the altered regulation of the functioning of the endoplasmic reticulum will be explored.

The 20-Year Voyage Aboard the Journal of Alzheimer's Disease: Docking at 'Type 3 Diabetes', Environmental/Exposure Factors, Pathogenic Mechanisms, and Potential Treatments

The Journal of Alzheimer’s Disease (JAD), founded in 1998, played a pivotal role in broadening the field of research on Alzheimer’s disease (AD) by publishing a diverse range of clinical, pathological, molecular, biochemical, epidemiological, experimental, and review articles from its birth. This article recounts my own journey as an author who contributed articles to JAD over the 20 years of the journal’s existence. In retrospect, it seems remarkable that a considerable body of work that originated from our group marks a trail that began with studies of vascular, stress, and mitochondrial factors in AD pathogenesis, exploded into the concept of ‘Type 3 Diabetes’, and continued with the characterization of how environmental, exposure, and lifestyle factors promote neurodegeneration and which therapeutic strategies could reverse the neurodegeneration cascade.

Ethanol-Induced White Matter Atrophy Is Associated with Impaired Expression of Aspartyl-Asparaginyl-β-Hydroxylase (ASPH) and Notch Signaling in an Experimental Rat Model

Alcohol-induced white matter (WM) degeneration is linked to cognitive-motor deficits and impairs insulin/insulin-like growth factor (IGF) and Notch networks regulating oligodendrocyte function. Ethanol downregulates Aspartyl-Asparaginyl-β-Hydroxylase (ASPH) which drives Notch. These experiments determined if alcohol-related WM degeneration was linked to inhibition of ASPH and Notch. Adult Long Evans rats were fed for 3, 6 or 8 weeks with liquid diets containing 26% ethanol (caloric) and in the last two weeks prior to each endpoint they were binged with 2 g/kg ethanol, 3×/week. Controls were studied in parallel. Histological sections of the frontal lobe and cerebellar vermis were used for image analysis. Frontal WM proteins were used for Western blotting and duplex ELISAs. The ethanol exposures caused progressive reductions in frontal and cerebellar WM. Ethanol-mediated frontal WM atrophy was associated with reduced expression of ASPH, Jagged 1, HES-1, and HIF-1α. These findings link ethanol-induced WM atrophy to inhibition of ASPH expression and signaling through Notch networks, including HIF-1α.