Inflammatory responses in SARS-CoV-2 associated Multisystem Inflammatory Syndrome and Kawasaki Disease in children: An observational study.

Multisystem Inflammatory Syndrome in Children (MIS-C) is a severe inflammatory disease in children related to SARS-CoV-2 with multisystem involvement including marked cardiac dysfunction and clinical symptoms that can resemble Kawasaki Disease (KD). We hypothesized that MIS-C and KD might have commonalities as well as unique inflammatory responses and studied these responses in both diseases. In total, fourteen children with MIS-C (n=8) and KD (n=6) were included in the period of March-June 2020. Clinical and routine blood parameters, cardiac follow-up, SARS-CoV-2-specific antibodies and CD4+ T-cell responses, and cytokine-profiles were determined in both groups. In contrast to KD patients, all MIS-C patients had positive Spike protein-specific CD3+CD4+ T-cell responses. MIS-C and KD patients displayed marked hyper-inflammation with high expression of serum cytokines, including the drug-targetable interleukin (IL)-6 and IFN-γ associated chemokines CXCL9, 10 and 11, which decreased at follow-up. No statistical differences were observed between groups. Clinical outcomes were all favourable without cardiac sequelae at 6 months follow-up. In conclusion, MIS-C and KD-patients both displayed cytokine-associated hyper-inflammation with several high levels of drug-targetable cytokines.

[Diagnostic image (397). A neonate with an abnormal position of the right arm]. / Diagnose in beeld (397). Een neonaat met een bijzondere stand van het rechter armpje.

A term girl was born by breech delivery. At physical examination the right elbow joint was swollen and extremely flexible, due to a luxation of the radius head.

Sequence and expression of amphioxus alkali myosin light chain (AmphiMLC-alk) throughout development: implications for vertebrate myogenesis.

The lower chordate amphioxus, widely considered the closest living invertebrate relative of the vertebrates, is a key organism for understanding the relationship between gene duplications and evolution of the complex vertebrate body plan. In tetrapod vertebrates, the alkali myosin light chain genes (MLC-alk), which code for proteins associated with the globular head of the myosin heavy chain, constitute a large family with stage-, tissue-, and fiber-type-specific expression of different isoforms thought to have arisen by duplication of a single ancestral gene. In protostome invertebrates, e.g., arthropods, molluscs, and nematodes, only one MLC-alk gene has been found, but the number of such genes in deuterostome invertebrates and lower vertebrates is unknown. The present report, describing the sequence and expression throughout development of the amphioxus gene for alkali myosin light chain (AmphiMLC-alk), thus fills a major gap in understanding the relation between gene duplication and increasing diversity of muscle-cell types. A full-length clone (1 kb) of AmphiMLC-alk was isolated from a larval amphioxus cDNA library. It coded for a 149-amino-acid protein most closely related to the vertebrate embryonic form of MLC-alk. Southern blot analysis revealed only one copy of AmphiMLC-alk and suggested that it is the only MLC-alk gene in amphioxus. Northern blot analysis indicated that this gene produces only one transcript, which is expressed at all stages of development and in adults. In situ hybridizations showed expression initially in the myotomes of somites 2-5 of neurula embryos and soon thereafter in the myotomes of somite 1 and of newly forming somites progressively added posteriorly. Myotomal expression continues throughout larval development and into the adult stage as the myotomal cells differentiate into striated, mononucleate muscle cells--unlike vertebrate striated muscle cells, those of amphioxus never become multinucleate. In late larvae and adults myotomal expression of AmphiMLC-alk is localized along the medial edge of the myotome and at the ends of the cells. This is the first demonstration of intracellular localization of MLC transcripts in muscle cells of any animal. Expression of AmphiMLC-alk was also detected in smooth muscles as well as in striated muscles not derived from the myotome. These expression data are consistent with the Southern blot analysis in suggesting that there is only one MLC-alk gene in amphioxus. Thus, duplication of an ancestral vertebrate MLC-alk gene probably occurred after the vertebrate and amphioxus lineages split.(ABSTRACT TRUNCATED AT 400 WORDS)