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Cureus Mar 2020Carcinoid syndrome (CS) is a paraneoplastic syndrome caused by the release of serotonin and other substances from well-differentiated neuroendocrine tumors (NETs). The... (Review)
Review
Carcinoid syndrome (CS) is a paraneoplastic syndrome caused by the release of serotonin and other substances from well-differentiated neuroendocrine tumors (NETs). The hallmark symptoms of carcinoid syndrome are flushing and diarrhea; atypical signs and symptoms can include wheezing, abdominal pain, valvular heart disease, telangiectasias, pellagra, and the complications of mesenteric fibrosis, including ureteral obstruction, bowel obstruction, and bowel ischemia. These symptoms are mediated by the release of serotonin (5-HT), histamine, kallikrein, prostaglandins, and tachykinins. The diagnosis of CS requires these symptoms and corresponding elevations in lab tests. Treatment options include surgery and medical management with somatostatin analogs.
PubMed: 32257725
DOI: 10.7759/cureus.7186 -
Nutrients Feb 2018The skin is the third most zinc (Zn)-abundant tissue in the body. The skin consists of the epidermis, dermis, and subcutaneous tissue, and each fraction is composed of... (Review)
Review
The skin is the third most zinc (Zn)-abundant tissue in the body. The skin consists of the epidermis, dermis, and subcutaneous tissue, and each fraction is composed of various types of cells. Firstly, we review the physiological functions of Zn and Zn transporters in these cells. Several human disorders accompanied with skin manifestations are caused by mutations or dysregulation in Zn transporters; acrodermatitis enteropathica (Zrt-, Irt-like protein (ZIP)4 in the intestinal epithelium and possibly epidermal basal keratinocytes), the spondylocheiro dysplastic form of Ehlers-Danlos syndrome (ZIP13 in the dermal fibroblasts), transient neonatal Zn deficiency (Zn transporter (ZnT)2 in the secretory vesicles of mammary glands), and epidermodysplasia verruciformis (ZnT1 in the epidermal keratinocytes). Additionally, acquired Zn deficiency is deeply involved in the development of some diseases related to nutritional deficiencies (acquired acrodermatitis enteropathica, necrolytic migratory erythema, pellagra, and biotin deficiency), alopecia, and delayed wound healing. Therefore, it is important to associate the existence of mutations or dysregulation in Zn transporters and Zn deficiency with skin manifestations.
Topics: Carrier Proteins; Cation Transport Proteins; Deficiency Diseases; Fibroblasts; Humans; Keratinocytes; Mutation; Skin; Skin Diseases; Zinc
PubMed: 29439479
DOI: 10.3390/nu10020199 -
Neurotherapeutics : the Journal of the... Jul 2023Niacin (vitamin B3) is an essential nutrient that treats pellagra, and prior to the advent of statins, niacin was commonly used to counter dyslipidemia. Recent evidence... (Review)
Review
Niacin (vitamin B3) is an essential nutrient that treats pellagra, and prior to the advent of statins, niacin was commonly used to counter dyslipidemia. Recent evidence has posited niacin as a promising therapeutic for several neurological disorders. In this review, we discuss the biochemistry of niacin, including its homeostatic roles in NAD supplementation and metabolism. Niacin also has roles outside of metabolism, largely through engaging hydroxycarboxylic acid receptor 2 (Hcar2). These receptor-mediated activities of niacin include regulation of immune responses, phagocytosis of myelin debris after demyelination or of amyloid beta in models of Alzheimer's disease, and cholesterol efflux from cells. We describe the neurological disorders in which niacin has been investigated or has been proposed as a candidate medication. These are multiple sclerosis, Alzheimer's disease, Parkinson's disease, glioblastoma and amyotrophic lateral sclerosis. Finally, we explore the proposed mechanisms through which niacin may ameliorate neuropathology. While several questions remain, the prospect of niacin as a therapeutic to alleviate neurological impairment is promising.
Topics: Humans; Niacin; Amyloid beta-Peptides; Pellagra; Nervous System Diseases; Alzheimer Disease; Neurology
PubMed: 37084148
DOI: 10.1007/s13311-023-01376-2 -
Folia Medica Cracoviensia Sep 2021Pellagra is a rare disease caused by niacin deficiency or a disruption of its metabolism. Its manifestations are dermatitis with pronounced photosensitivity,... (Review)
Review
Pellagra is a rare disease caused by niacin deficiency or a disruption of its metabolism. Its manifestations are dermatitis with pronounced photosensitivity, gastrointestinal symptoms, and neuropsychiatric ailments. Currently pellagra is developed in people who chronically abuse alcohol or are treated with medications from specific pharmacological groups (immunosuppressive and anti-tuberculosis drugs). Although the root cause of the disease was established in the mid-twentieth century, a detailed explanation of the processes leading to the development of symptoms has not yet been proposed. They include complex abnormalities at the molecular, metabolic, and immunological levels. Diagnostics is based primarily on the clinical presentation of the disease, while auxiliary tests play secondary role. The low prevalence of the disease, meaning that physicians are unfamiliar with its recognition, often leads to delays in diagnosis and appropriate treatment. The therapy is causal and based on administering niacinamide. Failure to implement treatment in the early stages of the disease leads to the patient's death. The aim of this literature review is to summarize the current state of knowledge on the pathomechanisms of pellagra, highlighting the clinical implications, and key elements of diagnostic and therapeutic management that are important in the treatment of pellagra patients.
Topics: Humans; Pellagra; Prevalence
PubMed: 34882669
DOI: 10.24425/fmc.2021.138956 -
Journal of Clinical Medicine Jan 2021Inflammatory bowel diseases (IBDs) may be associated with extra-intestinal manifestations. Among these, mucocutaneous manifestations are relatively frequent, often... (Review)
Review
Inflammatory bowel diseases (IBDs) may be associated with extra-intestinal manifestations. Among these, mucocutaneous manifestations are relatively frequent, often difficult to diagnose and treat, and may complicate the course of the underlying disease. In the present review, a summary of the most relevant literature on the dermatologic manifestations occurring in patients with inflammatory bowel diseases has been reviewed. The following dermatological manifestations associated with IBDs have been identified: (i) specific manifestations with the same histological features of the underlying IBD (occurring only in Crohn's disease); (ii) cutaneous disorders associated with IBDs (such as aphthous stomatitis, erythema nodosum, psoriasis, epidermolysis bullosa acquisita); (iii) reactive mucocutaneous manifestations of IBDs (such as pyoderma gangrenosum, Sweet's syndrome, bowel-associated dermatosis-arthritis syndrome, aseptic abscess ulcers, pyodermatitis-pyostomatitis vegetans, etc.); (iv) mucocutaneous conditions secondary to treatment (including injection site reactions, infusion reactions, paradoxical reactions, eczematous and psoriasis-like reactions, cutaneous infections, and cutaneous malignancies); (v) manifestations due to nutritional malabsorption (such as stomatitis, glossitis, angular cheilitis, pellagra, scurvy, purpura, acrodermatitis enteropathica, phrynoderma, seborrheic-type dermatitis, hair and nail abnormalities). An accurate dermatological examination is essential in all IBD patients, especially in candidates to biologic therapies, in whom drug-induced cutaneous reactions may assume marked clinical relevance.
PubMed: 33477990
DOI: 10.3390/jcm10020364 -
Antioxidants (Basel, Switzerland) Aug 2021Vitamin B3 (nicotinic acid, niacin) deficiency causes the systemic disease pellagra, which leads to dermatitis, diarrhea, dementia, and possibly death depending on its... (Review)
Review
Vitamin B3 (nicotinic acid, niacin) deficiency causes the systemic disease pellagra, which leads to dermatitis, diarrhea, dementia, and possibly death depending on its severity and duration. Vitamin B3 is used in the synthesis of the NAD family of coenzymes, contributing to cellular energy metabolism and defense systems. Although nicotinamide (niacinamide) is primarily used as a nutritional supplement for vitamin B3, its pharmaceutical and cosmeceutical uses have been extensively explored. In this review, we discuss the biological activities and cosmeceutical properties of nicotinamide in consideration of its metabolic pathways. Supplementation of nicotinamide restores cellular NAD pool and mitochondrial energetics, attenuates oxidative stress and inflammatory response, enhances extracellular matrix and skin barrier, and inhibits the pigmentation process in the skin. Topical treatment of nicotinamide, alone or in combination with other active ingredients, reduces the progression of skin aging and hyperpigmentation in clinical trials. Topically applied nicotinamide is well tolerated by the skin. Currently, there is no convincing evidence that nicotinamide has specific molecular targets for controlling skin aging and pigmentation. This substance is presumed to contribute to maintaining skin homeostasis by regulating the redox status of cells along with various metabolites produced from it. Thus, it is suggested that nicotinamide will be useful as a cosmeceutical ingredient to attenuate skin aging and hyperpigmentation, especially in the elderly or patients with reduced NAD pool in the skin due to internal or external stressors.
PubMed: 34439563
DOI: 10.3390/antiox10081315