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Brevetoxin
Published in Dongyou Liu, Handbook of Foodborne Diseases, 2018
Chemical detection. Prior to chemical detection, BTX are extracted using various techniques. While BTX produced by algae are lipophilic, their shellfish metabolites are hydrophilic, and metabolites from aerosols also polar. Therefore, extraction of BTX in seawater involves trapping toxins on hydrophobic solid-phase extraction sorbents and eluting with methanol. Marine aerosols are collected with glass fiber filters in air sampling devices, and BTX are then extracted from filters using acetone. Extraction of BTX from shellfish can be done with di-ethyl ether, acetone, or methanol, the latter of which appears more suitable for extraction of polar metabolites. Chemical detection of BTX is achieved through conventional chromatography (high-performance liquid chromatography and diode array UV detection) or more recently liquid chromatography-mass spectrometry (LC-MS) (including LC with electrospray MS and LC with tandem MS [LC-MS/MS]). Although conventional chromatography demonstrates some degree of specificity, it suffers from a lack of standards and equipment as well as data for determination of low numbers of toxins. LC-MS has high specificity and sensitivity but requires expensive instrumentation and suitable standards.
Non-Surgical Rejuvenation of the Ageing Face
Published in John C Watkinson, Raymond W Clarke, Terry M Jones, Vinidh Paleri, Nicholas White, Tim Woolford, Head & Neck Surgery Plastic Surgery, 2018
Lydia Badia, Peter Andrews, Sajjad Rajpar
On the European market, three different branches of BTX-A are officially registered: Botox®/Vistabel® (Allergan), Dysport® (Ipsen)/Azzalure® (Galderma) and Xeomin®/Bocouture® (Merz). The units are not directly comparable. The products have different amounts of complexing proteins or are free of complexing proteins (i.e. Xeomin®/Bocouture®). The diffusion of the different drugs seems to be dependent on concentration. BTX-A has an excellent safety profile and has been used extensively for facial rejuvenation with a focus on hyperkinetic wrinkles and to improve facial wound healing after surgery.
New Trends in Anti-Aging Skin Care
Published in Andreia Ascenso, Sandra Simões, Helena Ribeiro, Carrier-Mediated Dermal Delivery, 2017
Botulinum toxin (BTX) is a neurotoxin produced by different strains of Clostridium botulinum. There are seven subtypes, neurotoxins A-G, from which only A, B, and F subtypes are available for clinical use, the A subtype being the most potent. Although BTX can slow down the skin aging process, it cannot discontinue this process. The BTX mechanism of action consists of blocking the presynaptic release of acetylcholine resulting in temporary chemical denervation at the neuromuscular junction and leading to striated muscular flaccid paralysis. This process occurs through different steps as follows: (a) The neurotoxin binds to a specific receptor on the presynaptic cholinergic neuron; (b) the toxin/receptor complex suffers internalization through endocytosis into nerve terminals, and (c) the formed vesicle is lysed, preventing the acetylcholine release from inside the cell. A significant wrinkle reduction will be obtained through this transitory and reversible paralysis state. Although BTX effects are temporary and localized, repeated injections may lead to a long-term effect. Nevertheless, the side effects are related with BTX’s mechanism of action. Therefore, BTX is not indicated under conditions that may be exacerbated by the toxin (e.g., pre-existing neuromuscular disorders, psychiatric disorders, local infection, etc.). Complications are mild and may include pain, edema, erythema, ecchymosis, headache, and short- term hypoesthesia [43,44,50,51].
A systematic review on biomonitoring of individuals living near or working at solid waste incinerator plants
Published in Critical Reviews in Toxicology, 2019
Laura Campo, Petra Bechtold, Lucia Borsari, Silvia Fustinoni
Benzene, toluene, ethylbenzene, and xylenes (BTEX), are monocyclic aromatic hydrocarbons, belonging to the wide class of volatile organic compounds (VOCs). Once adsorbed into the body, they are extensively metabolized to polar compounds excreted in urine, therefore biomonitoring of BTEX is mostly performed by measuring urinary metabolites, and specifically t,t-muconic acid (t,t-MA) and S-phenylmercapturic acid (SPMA) for benzene, o-cresol for toluene, and methylhyppuric acids for xylenes (ACGIH 2017). Tiny amount of BTEX can also be measured as unmetabolized chemicals in blood and urine (Fustinoni et al. 2005, 2010). BTEX are neurotoxic, moreover, benzene is also classified as a known carcinogen to human, being able to cause acute myeloid leukemia (IARC 2012). The exposure to BTEX in association to SWI was studied in a limited number of population studies (Staessen et al. 2001; Schroijen et al. 2008; Ranzi et al. 2013), and in some occupational studies (Angerer et al. 1992; Wrbitzky et al. 1996).
Occupational health risk assessment of volatile organic compounds emitted from the coke production unit of a steel plant
Published in International Journal of Occupational Safety and Ergonomics, 2020
Fateme Dehghani, Fariborz Omidi, Omidreza Heravizadeh, Saied Barati Chamgordani, Vahid Gharibi, Akbar Sotoudeh Manesh
In summary, the BTEX concentrations were measured in five sections. The benzene levels in the energy and biochemistry section and also in the benzol refinement section were found to be higher than OELs (0.5 mg/L). Furthermore, non-cancer and cancer risks of 30-year periods of occupational exposure to benzene in all of the studied sections as well as the non-cancer risk for toluene in the benzol refinement section were higher than the recommended levels. In conclusion, the current engineering and administrative control measures are not sufficient and should be improved for efficient control of occupational exposures.
Insights into the potential mechanism underlying liver dysfunction in male albino rat exposed to gasoline fumes
Published in Egyptian Journal of Basic and Applied Sciences, 2021
Folarin Owagboriaye, Sulaimon Aina, Rasheed Oladunjoye, Titilola Salisu, Adedamola Adenekan, Gabriel Dedeke
Of all the possible routes and pathways (including dermal contact, sniffing) through which an individual can be exposed to gasoline fumes, occupational inhalation exposure during automobile refueling at the filling station, refining process and bulk transfer serve as the principal exposure routes of gasoline fumes to humans [3]. Exposure to BTEX has been shown to increase workers’ likelihood of increased petroleum product-related health risks [4,5]. The normal physiologic and immune responses have been reported to be modulated by BTEX components [6], and exposure may lead to hepatic dysfunction [7,8].