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Endocrinology
Published in Paul Bentley, Ben Lovell, Memorizing Medicine, 2019
Pregnancy: Symptomatic: Allows sparing or avoidance of thiourea, esp. at 3rd trimesterThiourea (low-dose, as Graves goes into partial remission, and risk of causing neonatal hypothyroidism and goitre, with stridor)
New Biological Targets for the Treatment of Leishmaniasis
Published in Venkatesan Jayaprakash, Daniele Castagnolo, Yusuf Özkay, Medicinal Chemistry of Neglected and Tropical Diseases, 2019
Fabrizio Carta, Andrea Angeli, Christian D.-T. Nielsen, Claudiu T. Supuran, Agostino Cilibrizzi
Substitution of the urea function (15a, b) with a thiourea bioisosteric group (15c–e) did not significantly affect the inhibitory potency. Derivatives 15a–e (Figure 15) exhibited micromolar inhibition, showing a pronounced selectivity for LdcCA versus other protozoan CAs. Moreover, compound 15e also displayed excellent LdcCA selectivity over the human isoform hCA II. Thus, the benzoxaborole chemotype offers interesting opportunities for CA targeting in pathogenic protozoans eliciting leishmaniasis, thus warranting further development (Nocentini et al. 2018).
T
Published in Anton Sebastian, A Dictionary of the History of Medicine, 2018
Thyrotoxicosis [Greek: thyreos, shield + toxikon, poison] (Syn: Graves disease, Parry disease) Exophthalmic goiter resulting from thyrotoxicosis was described by Caleb Hillier Parry (1755–1822), a physician from Bath in 1786, who published eight more cases later. Robert James Graves (1796–1853), a Dublin physician, gave an account of three cases in 1835, and Karl Adolph von Basedow (1799–1854) from Merseberg near Leipzig, described four cases in 1840. Albrecht von Graefe (1828–1870), an eye surgeon in Berlin, described the stationary nature of the eyelid (lid lag sign) in thyrotoxicosis, the Graefe sign. Julia and Cosmo Mackenzie of Johns Hopkins Hospital identified the antithyroid properties of thiourea in 1930 while experimenting with products to induce intestinal suppression of bacterial flora. Phenyl thiourea was discovered about the same time by Curt Richter. Effectiveness of thiourea in humans was established around 1940 by Edwin B. Astwood (b 1909) of Boston, who used thiourea and thiouracil as treatment for hyperthyroidism in 1943. Radioiodine was used in the study of thyroid disease by M. P. Kelsey and co-workers in 1949 and introduced as treatment for thyrotoxicosis by G.W. Blomfield and co-workers in 1951.
2-Aminobenzoxazole-appended coumarins as potent and selective inhibitors of tumour-associated carbonic anhydrases
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Alma Fuentes-Aguilar, Penélope Merino-Montiel, Sara Montiel-Smith, Socorro Meza-Reyes, José Luis Vega-Báez, Adrián Puerta, Miguel X. Fernandes, José M. Padrón, Andrea Petreni, Alessio Nocentini, Claudiu T. Supuran, Óscar López, José G. Fernández-Bolaños
TCDI was tentatively used as a green substitute for thiophosgene in the preparation of isothiocyanates. Attempts to isolate the corresponding isothiocyanate upon isothiocyanation reaction of 6a,d gave rather modest yields (roughly 17%, Scheme 3); increase of the reaction times led to decomposition of the isothiocyanate. It was then assumed that reaction of TCDI with coumarin-amino derivatives 6a,d was not complete, and presumably, a thioureido derivative involving the amino-coumarin and one of the imidazole units from TCDI was obtained as the major compound instead of the heterocumulenes 7. Interestingly, the addition of 2-aminophenol to the crude reaction mixture gave the corresponding transient thiourea, as evidenced by TLC. Final in situ iodide-catalyzed oxidative cyclodesulfurization reaction by treatment of thioureas with H2O2 and a catalytic amount of TBAI (Scheme 3) allowed the isolation of benzoxazoles 8a and 8d in a 45% and 34% yield for the one-pot three-step procedure.
Effect of sodium selenite on synaptic plasticity and neurogenesis impaired by hypothyroidism
Published in International Journal of Neuroscience, 2022
Ercan Babur, Özlem Canöz, Burak Tan, Cem Süer, Nurcan Dursun
Ptu is a thiourea derivative drug used in the treatment of hyperthyroidism. Its effect is shown by inhibition of thyroid peroxidase and 5-deiodinase and DIT-MIT binding. In our study, when free T4 levels were compared between groups, a statistically significant decrease was observed in the Ptu group compared to the control group. Se treatment did not affect fT4 thyroid hormone levels although fT3 levels increased by %60 in the Se treated rats. Chaonoine, et al demonstrated after short term thyroidectomy, serum T4 concentrations fell in both the Se-supplemented and Se-deficient rats [29]. Also, altered Se intake had no effect on the fall of serum T3. Esposito and colleagues showed that Se treatment for Hashimoto patients increased fT3 levels while decreasing fT4 levels. This effect of Se supplementation seems to be due to the increase of DIO 1 enzyme activity catalyzing the conversion of T4, T3 rather than the effect of selenium on thyroid hormone synthesis. Type 2 deiodinase enzyme is an important factor in adapting to changes in thyroid hormone levels in the central nervous system. When the thyroid hormone level decreases, such as hypothyroidism, DIO2 enzyme activity increases and attempts to maintenance thyroid hormone levels in the brain cells.
Safety of antithyroid drugs in pregnancy: update and therapy implications
Published in Expert Opinion on Drug Safety, 2020
Thanuya Francis, Niroshan Francis, John H. Lazarus, Onyebuchi E. Okosieme
The thionamide antithyroid drugs are 5–6 ringed sulfur containing thiourea derivatives that inhibit thyroid hormone synthesis by preventing thyroid peroxidize (TPO) catalyzed iodination and coupling of thyroglobulin-linked tyrosine residues [22,23]. The thionamides also have immunosuppressive effects which over time leads to a reduction in TRAb levels but it is unclear whether these immunosuppressive effects are as a result of direct actions on humoral and cellular mechanisms or an indirect effect of hyperthyroidism control [22]. In addition, PTU in large doses blocks peripheral thyroxine (T4) to triiodothyronine (T3) conversion through inhibition of the type 1 deiodinase [22,23]. Lastly, the thionamides may exhibit antioxidant properties but it is also unclear if this action occurs through direct effects or through control of hyperthyroidism.