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Hair Analysis for Detection of Drugs of Abuse
Published in Steven H. Y. Wong, Iraving Sunshine, Handbook of Analytical Therapeutic Drug Monitoring and Toxicology, 2017
Thomas Cairns, Donald J. Kippenberger, AnnMarie Gordon
The exploration of daughter ions for quantitative purposes was first investigated in the case of ethyl carbamate in wines and spirits at the parts per billion level.30 With the availability of a stable isotopically labeled ethyl carbamate reference standard, both confirmation and quantification were accomplished using methane CI/MS/MS. These authors demonstrated that reliable quantitative data at low levels could be generated by isotope dilution techniques involving ratio measurements between daughter ions belonging to the sample and reference standard.
Mechanisms of chemically induced respiratory toxicities
Published in Philippe Camus, Edward C Rosenow, Drug-induced and Iatrogenic Respiratory Disease, 2010
Here, vinyl carbamate is used as a model compound to investigate the specific events that take place in the interval between exposure and the development of lung tumours. Vinyl carbamate is a metabolite of ethyl carbamate (urethane), a chemical formed during fermentation, and that is found in alcoholic beverages and fermented food products.93 Ethyl carbamate was used as a co-solvent for analgesic and sedative drugs in Japan between 1950 and 1975.94 This period represented 25 years during which millions of humans were administered ‘the largest doses of a pure carcinogen that is on record’.95 It has been estimated that the total dose of ethyl carbamate administered to a 60 kg patient was about 0.6 to 3.0 g. Ethyl carbamate has also been used as an antineoplastic agent for the treatment of chronic leukemia and multiple myeloma.96 Today, human exposures occur inadvertently via the consumption of fermented food products and alcoholic beverages as well as tobacco use. A question has been raised regarding the potential carcinogenic risk associated with long-term or perhaps a lifetime exposure to low levels of the carbamate compounds. In this regard, regulatory agencies in Canada and the United States have set limits on the concentrations of ethyl carbamate in wines and distilled spirits.
Anesthesia of Laboratory Rats
Published in Yanlin Wang-Fischer, Manual of Stroke Models in Rats, 2008
Yanlin Wang-Fischer, Lee Koetzner
Urethane (ethyl carbamate) has been popularized for producing long-lasting anesthesia in the rat with minimal cardiovascular and respiratory system depression and good muscle relaxation. Unfortunately, it is a carcinogen34 and should be used only when no suitable alternative is available. If urethane is used, it should be prepared and administered under controlled conditions. Urethane is a high-grade irritant and can cause peritonitis and so should not be used for recovery procedures. Only one study of the neuroprotective effects of urethane has been reported.35 Yokoyama et al. (1997) studied the influence of urethane on bladder hyperactivity induced by middle cerebral artery occlusion in the rat. They found that urethane and MK-801 similarly inhibited the development of stroke-induced bladder hyperactivity and hypothesized that the most likely mechanism was blockade of glutamatergic transmission in the brain.
Assessment of DNA damage in somatic and germ cells of animals living with increased radiation background and their offspring
Published in International Journal of Radiation Biology, 2023
Oksana Raskosha, Lyudmila Bashlykova, Natalia Starobor
The chronic exposure of biological objects to low doses of ionizing radiation is characterized by the appearance of latent damage that may not be detected for a long time, therefore, additional provocative actions are used to detect them. In this study we used urethane (ethyl carbamate; CAS no. 51-79-6, Sigma-Aldrich, USA) which is a carcinogen promoter and was shown to be efficient in transgenerational carcinogenic studies (Salmon and Zeise 1991; European Commission 2012). One part of the voles caught at the experimental and control sites, as well as their offspring (F1–F3), received a single intraperitoneal injection of a 10% urethane, 0.9% NaCl solution in an amount of 1 mg of urethane per 1 g of specimen’s body weight; the second part of voles received an equivalent amount of 0.9% NaCl solution. 48 hours after the injection, the animals were removed from the experiment by decapitation.
Conjugates of TAT and folate with DOX-loaded chitosan micelles offer effective intracellular delivery ability
Published in Pharmaceutical Development and Technology, 2019
Shengyu Zhang, Yanjun Liu, Ye Gan, Nanqing Qiu, Yueqing Gu, Hongyan Zhu
To confirm the in vivo tumor targeting of folate/TAT-PEG-OC, mice-bearing tumor were randomly divided into three groups (5 in each group) including the treated group and two control groups. Before the in vivo imaging experiments, mice were fixed and anesthetized with ethyl carbamate at a dose of 1 mg/mL. The two control groups A and B were administrated with 0.2 ml PEG-OC/ICG-Der-01 and folate-PEG-OC/ICG-Der-01 through the tail vein, respectively. The treated group C was injected with 0.2 ml folate/TAT-PEG-OC/ICG-Der-01. The equivalent dose of ICG-Der-01 was 8 µg in each group. In vivo imaging was performed with an IVIS Lumina IIimaging system (Caliper Life Sciences, USA) and a series of NIR fluorescence images (610 nm excitation, 700 nm emission) were obtained after administration.
A novel vehicle for local protein delivery to the inner ear: injectable and biodegradable thermosensitive hydrogel loaded with PLGA nanoparticles
Published in Drug Development and Industrial Pharmacy, 2018
Juan Dai, Wei Long, Zhongping Liang, Lu Wen, Fan Yang, Gang Chen
One hundred and forty-four animals were randomly assigned to four groups. As the prepared IFN solution or lyophilized IFN NPs powder was diluted after CS and β-GP solutions were mixed, and IFN concentration was not directly proportional to dilution volume, it was very difficult to control equivalent IFN concentration in different preparations. The IFN concentrations of each group were as follows: 1.60 µg/mL for the IFN solution group, 1.00 µg/mL for the IFN CS/β-GP group, 1.63 µg/mL for the IFN NPs group and 1.21 µg/mL for the IFN NPs-CS/GP group. Animals in each group were anesthetized with ethyl carbamate (1.0 g/kg) before administration. The sample (0.1 ml) was injected to unilateral tympanic cavity of the guinea pig in each group and equivalent normal saline (NS) served as blank control. Under deep anesthesia with ethyl carbamate (3.0 g/kg), approximately 5 µL of PL was collected at 0.5, 1, 2, 4, 8, 12, 24, 36, 48, 72 and 96 h post administration with a microsyringe through RWM. The collected PL of each animal was individually determined by ELISA kits after being appropriately diluted with PBS. And at the preliminary study, the recovery rate of IFN in the collected PL was examined. Accordingly, recovery rates of high, middle, low concentration of IFN in PL were varied between 92% and 110%, suggesting that this method could meet the measuring requirement of in vivo samples.