Thyroid hormone analogues: An update

The development of thyroid hormone (TH) analogues was prompted by the attempt to exploit the effects of TH on lipid metabolism, avoiding cardiac thyrotoxicosis. Analysis of the relative distribution of the α and β subtypes of nuclear TH receptors (TRα and TRβ) showed that TRα and TRβ are responsible for cardiac and metabolic responses, respectively. Therefore, analogues with TRβ selectivity were developed, and four different compounds have been used in clinical trials: GC-1 (sobetirome), KB-2115 (eprotirome), MB07344/VK2809, and MGL-3196 (resmetirom). Each of these compounds was able to reduce low-density lipoprotein cholesterol, but a phase 3 trial with eprotirome was interrupted because of a significant increase in liver enzymes and the contemporary report of cartilage side effects in animals. As a consequence, the other projects were terminated as well. However, in recent years, TRβ agonists have raised new interest for the treatment of nonalcoholic fatty liver disease (NAFLD). After obtaining excellent results in experimental models, clinical trials have been started with MGL-3196 and VK2809, and the initial reports are encouraging. Sobetirome turned out to be effective also in experimental models of demyelinating disease. Aside TRβ agonists, TH analogues include some TH metabolites that are biologically active on their own, and their synthetic analogues. 3,5,3′-triiodothyroacetic acid has already found clinical use in the treatment of some cases of TH resistance due to TRβ mutations, and interesting results have recently been reported in patients with the Allan-Herndon-Dudley syndrome, a rare disease caused by mutations in the TH transporter MCT8. 3,5-diiodothyronine (T2) has been used with success in rat models of dyslipidemia and NAFLD, but the outcome of a clinical trial with a synthetic T2 analogue was disappointing. 3-iodothyronamine (T1AM) is the last entry in the group of active TH metabolites. Promising results have been obtained in animal models of neurological injury induced by β-amyloid or by convulsive agents, but no clinical data are available so far

An update on vitamin d metabolism

Vitamin D is a steroid hormone classically involved in the calcium metabolism and bone homeostasis. Recently, new and interesting aspects of vitamin D metabolism has been elucidated, namely the special role of the skin, the metabolic control of liver hydroxylase CYP2R1, the specificity of 1α-hydroxylase in different tissues and cell types and the genomic, non-genomic and epigenomic effects of vitamin D receptor, which will be addressed in the present review. Moreover, in the last decades, several extraskeletal effects which can be attributed to vitamin D have been shown. These beneficial effects will be here summarized, focusing on the immune system and cardiovascular system

First Record of the Fruit Fly Parasitoid Doryctobracon crawfordi (Viereck) (Hymenoptera: Braconidae) in Brazil.

Doryctobracon crawfordi (Viereck) was recorded in the states of Amapá and Roraima, Brazil. This is also the first time that this parasitoid is associated with Anastrepha atrigona Hendel from Geissospermum argenteum

On the identity of Trichogramma demoraesi Nagaraja (Hymenoptera: Trichogrammatidae), with a checklist and a key to Trichogramma species associated with Erinnyis ello (L.) (Lepidoptera, Sphingidae) in Brazil.

Specimens collected from eggs of the cassava hornworm Erinnyis ello, originally identified as T. demoraesi, were compared with the paratype of this species. Based on morphological analysis, the specimens from E. ello actually belong to Trichogramma marandobai Brun, Moraes and Soares, 1986. Therefore, T. demoraesi is not a parasitoid of the eggs of E. ello, a major pest of cassava. The main features separating the two species, and a checklist and key to the species of Trichogramma associated with E. ello are presented.Autoria: QUERINO [i.e. SILVA], R. B. Q. da. RANYSE BARBOSA QUERINO DA SILV