Systemic disruption of the homeostasis of transfer RNA isopentenyltransferase causes growth and development abnormalities in Bombyx mori

Isopentenylation at A37 (i⁶A37) of some transfer RNAs (tRNAs) plays a vital role in regulating the efficiency and fidelity of protein synthesis. However, whether insects, which are well known for their highly efficient protein synthesis machinery, employ this regulatory mechanism remains uninvestigated. In the current study, a candidate tRNA isopentenyltransferase (IPT) gene with three alternative splicing isoforms (BmIPT1–BmIPT3) was identified in Bombyx mori (silkworm). Only BmIPT1 could complement a yeast mutant lacking tRNA IPT. Phylogenetic analysis showed that silkworm tRNA IPT is conserved in the Lepidoptera. BmIPT was expressed in all B. mori tissues and organs that were investigated, but was expressed at a significantly higher level in silk glands of the fourth instar compared to the first day of the fifth instar. Interestingly, BmIPT was expressed at a significantly higher level in the domesticated silkworm, B. mori, than in wild Bombyx mandarina in multiple tissues and organs. Knock‐down of BmIPT by RNA interference caused severe abnormalities in silk spinning and metamorphosis. Constitutive overexpression of BmIPT1 using a cytoplasmic actin 4 promoter in B. mori raised its messenger RNA level more than sixfold compared with nontransgenic insects and led to significant decreases in the body weight and cocoon shell ratio. Together, these results confirm the first functional tRNA IPT in insects and show that a suitable expression level of tRNA IPT is vital for silk spinning, normal growth, and metamorphosis. Thus, i⁶A modification at position A37 in tRNA probably plays an important role in B. mori protein synthesis.     

Buscando o motivo da instabilidade hemodinâmica: relato de caso sobre o papel do ultrassom intraoperatório

Background and objectives

A prompt and effective management of trauma patient is necessary. The aim of this case report is to highlight the importance of intraoperative echocardiography as a useful tool in patients suffering from refractory hemodynamic instability no otherwise explained.

A minimally invasive tool to study immune response and skin barrier in children with atopic dermatitis

Atopic dermatitis (AD, atopic eczema) is a very common skin condition affecting 10-20% of children. It affects children of all skin colours and seems to occur more often in Asian children and children with dark skin types. However, most research is performed on children with light skin types. This study, performed in Amsterdam, the Netherlands, aimed to investigate differences between AD in children with dark and light skin types. To study this, the investigators took tape strips from 53 AD children aged 0-12 years and 50 healthy children as control (comparison). Tape stripping is a painless procedure which is ideal to perform in children, in which a small round sticker is attached to the skin. When removing this special sticker, a thin layer of skin cells remains attached to the sticker, allowing the investigators to study several aspects of skin inflammation and skin barrier. The authors found that AD skin from children with light and dark skin have similar levels and types of skin inflammation. However, they found differences in skin barrier markers between these two groups. In light skinned children, markers of good skin barrier were lower in AD skin when compared to healthy children's skin, while in dark AD skin these skin barrier markers were not significantly different from healthy dark skin. This study showed that dark-skinned and light-skinned AD children are similar when it concerns skin inflammation, but in light skinned AD children the skin barrier dysfunction may play an additional role in the development of AD. This suggests that AD in light and dark skin has different mechanisms of development.     

Predictive factors of positive online patient ratings of spine surgeons

BACKGROUND

Online physician rating websites are increasingly used by patients to evaluate their doctors. The purpose of this investigation was to evaluate factors associated with better spine surgeon ratings.