Mercury-induced autoimmunity: Drifting from micro to macro concerns on autoimmune disorders.

Mercury (Hg) is widely recognized as a neurotoxic metal, besides it can also act as a proinflammatory agent and immunostimulant, depending on individual exposure and susceptibility. Mercury exposure may arise from internal body pathways, such as via dental amalgams, preservatives in drugs and vaccines, and seafood consumption, or even from external pathways, i.e., occupational exposure, environmental pollution, and handling of metallic items and cosmetics containing Hg. In susceptible individuals, chronic low Hg exposure may trigger local and systemic inflammation, even exacerbating the already existing autoimmune response in patients with autoimmunity. Mercury exposure can trigger dysfunction of the autoimmune responses and aggravate immunotoxic effects associated with elevated serum autoantibodies titers. The purpose of the present review is to provide a critical overview of the many issues associated with Hg exposure and autoimmunity. In addition, the paper focuses on individual susceptibility and other health effects of Hg.

Delayed-type hypersensitivity to metals in connective tissue diseases and fibromyalgia.

Rheumatic diseases include a group of autoimmune disorders with environmental and genetic etiology that are characterized as a subgroup of connective tissue diseases (CTD). Rheumatoid arthritis (RA) often involves the small joints of the hands in a symmetrical fashion that can lead to loss of joint function, and RA, as well as Sjögren's syndrome (SS) and other rheumatic diseases, are often accompanied by sensitivity to metals. Numerous investigations on metal sensitivity were evaluated in this review. A detailed metal exposure history was collected by different evaluation of studies. In all subjects, the main source of metal exposure was nickel, mercury, gold, palladium, titanium, and chromium. All of SLE (systemic lupus erythematosus), RA and SS patients appeared to have an increased frequency of metal delayed-type hypersensitivity (DTH) (Type IV allergy). As dental restorative materials release minor amounts of their metals (including mercury, gold, and nickel), many adults are commonly exposed to these metal ions by vapor or corrosion into saliva. Metal-related DTH in these patients will induce an inflammatory response. Such inflammations are important factors in CTD progress. It is hypothesized that metal-specific T cell reactivity can act as an etiological agent in the propagation and chronification of rheumatic inflammation. The key responses of metal delayed-type hypersensitivity in autoimmunity are precipitating as an appealing challenge for further investigations.

The toxicology of mercury: Current research and emerging trends.

Mercury (Hg) is a persistent bio-accumulative toxic metal with unique physicochemical properties of public health concern since their natural and anthropogenic diffusions still induce high risk to human and environmental health. The goal of this review was to analyze scientific literature evaluating the role of global concerns over Hg exposure due to human exposure to ingestion of contaminated seafood (methyl-Hg) as well as elemental Hg levels of dental amalgam fillings (metallic Hg), vaccines (ethyl-Hg) and contaminated water and air (Hg chloride). Mercury has been recognized as a neurotoxicant as well as immunotoxic and designated by the World Health Organization as one of the ten most dangerous chemicals to public health. It has been shown that the half-life of inorganic Hg in human brains is several years to several decades. Mercury occurs in the environment under different chemical forms as elemental Hg (metallic), inorganic and organic Hg. Despite the raising understanding of the Hg toxicokinetics, there is still fully justified to further explore the emerging theories about its bioavailability and adverse effects in humans. In this review, we describe current research and emerging trends in Hg toxicity with the purpose of providing up-to-date information for a better understanding of the kinetics of this metal, presenting comprehensive knowledge on published data analyzing its metabolism, interaction with other metals, distribution, internal doses and targets, and reservoir organs.

Hallmarks of Periodontitis.

Periodontitis is a complex polymicrobial disease of the oral cavity that affects tooth-supporting tissues. It is caused by multiple factors, such as pathogenic bacteria, genetic predisposition, and host immune response factors. The pathogenesis of periodontal disease involves the complex interrelations among bacterial toxins, several populations of cells, and host cell-secreted inflammatory mediators. Generally, periodontitis is characterized by the formation of intricate and varied biofilms of microbes on the tooth surface, commonly known as dental plaque. Activation of defense cells is characterized by releasing inflammatory mediators, such as proteases, acidic metabolites, cytokines, interleukins, and chemokines, which destroy tissue and ultimately cause bone resorption. The individual periodontal condition has a significant impact on systemic homeostasis, and its disruption can cause the development of some metabolic disorders. This review article summarizes the latest studies on the pathogenesis of periodontitis and describes the role of inflammatory mediators and genetic polymorphism in individuals, as well as relationships with some metabolic conditions. The information is collected from PubMed, Scopus, ScienceDirect, SpringerLink, and clinicaltrials.gov.

A review on natural teeth whitening.

BACKGROUND: Discoloration of teeth occurs for various reasons. Common ingredients like substances from tea and coffee, as well as antibiotics like tetracycline, or food dyes, can percolate into the teeth, and, as such, these stains may persist in the porous structure of the enamel. Smoking is also contributory to dental discoloration, with toxins of tobacco smoke accumulating in a similar way. With aging, teeth tend to be discolored with accumulation of various stains in addition to the enamel gradually eroding to expose the yellow dentin. HIGHLIGHT: This review focused on the effect of several natural ingredients with teeth-whitening properties and their daily clinical application. Metabolic dental bleaching mechanisms, as well as tooth discoloration and decay, were also reviewed. The current scientific literature (mostly from 2000 to 2020) was consolidated from manuscripts retrieved from Scopus, PubMed, ResearchGate, and Google Scholar. CONCLUSION: Natural teeth whitening effectively lightens the natural color of teeth without eroding dental surfaces. On the other hand, commercially available whiteners containing hydrogen peroxide and carbamide peroxide, in high concentrations, can lead to deproteinization and demineralization of teeth through oxidation processes. If used extensively, these compounds may cause a number of adverse effects. Alternative natural teeth-whiteners include ingredients like lemons, strawberries, oranges, papaya, and other fruits. Such natural ingredients offer a milder and safer way of whitening teeth than whiteners containing hydrogen peroxide or carbamide peroxide.

The role of sugar-rich diet and salivary proteins in dental plaque formation and oral health.

BACKGROUND: Dental plaque is a complex colorless film of bacteria that develops on the surfaces of teeth. Different mechanisms of microbial adhesion to tooth surfaces exist. Both non-specific and specific types of adherence have been anticipated. HIGHLIGHT: The present review evaluated the effect of sugar-rich diet and salivary proteins on oral hygiene and dental plaque development. CONCLUSION: The oral microbiota is essential for maintaining and reestablishing a healthy oral cavity. Different types of sugars have different effects on the inhibition and formation of dental plaque. The peptides, proteins, and amino acids secreted by parotid glands in the oral cavity facilitate neutralizing the acidity in dental plaque and preventing dental caries. A properly balanced diet is crucial for both a healthy oral cavity and the oral microbiome.

Neurotoxic effects of mercury exposure in dental personnel.

Numerous studies have reported neurobehavioural effects in dental personnel occupationally exposed to chronic low levels of mercury (Hg). Hg exposure from dental work may also induce various chronic conditions such as elevation of amyloid protein expression, deterioration of microtubules and increase or inhibition of transmitter release at motor nerve terminal endings. Therefore, clinical studies of Hg toxicity in dentistry may provide new knowledge about disturbed metal homeostasis in neurodegenerative diseases such as Alzheimer's disease, multiple sclerosis and mood disorders. The purpose of this MiniReview is to evaluate the evidence of possible relevance between Hg exposure in dentistry and idiopathic disturbances in motor functions, cognitive skills and affective reactions, as well as dose-response relationships.

Lineage and phylogenetic analysis of HPV-16, -18 in saliva of HNSCC patients

Aim: Head and Neck Squamous Cell Carcinoma (HNSCC) is a global health problem whose incidence varies by geographic region and race according to risk factors. Human papillomavirus (HPV) infection is a significant risk factor for HNSCC. HPV-16 and HPV-18 are two forms of HPV that are carcinogenic. HNSCCs that are HPV positive have a better prognosis rather than HPV negative. The purpose of this research was to characterize HPV-16, -18 variations in the saliva of HNSCC patients by examining the genetic diversity of HPV-16, -18 utilizing the full E6, E7, and L1 genes. Methods:The case-control research included 15 patients with HNSCC and 15 healthy volunteers. Unstimulated entire saliva samples were obtained from the case and control groups by spitting method. Genomic DNA was isolated from all saliva samples. A PCR reaction was used to determine the presence of HPV in saliva. HPV-positive samples were genotyped and data were analyzed. We conducted a variant study on the HPV-16, -18 E6, and E7 genes. Results: Three patients with HNSCC were HPV-positive for two HPV genotypes out of 30 people diagnosed with HPV-DNA. HPV-16 and -18 were the most common genotypes. The HPV-16, -18 E6, and E7 genes were sequenced and compared to the HPV-16, -18 (E6, E7) prototype sequence. In all, HPV-16 lineages A1 and HPV-18 lineages A3 were discovered. Conclusion: Regarding the variation of HPV found in Iranian HNSCC patients, the need for further studies in HPV genotyping was seen. Sequencing HPV genes in HNSCC may help answer questions about HPV genotyping in the Iranian population. HPV genotype analysis aids in the development of vaccinations against HNSCC, halting disease progression and preventing HPV-associated HNSCC