RESUMO
Infantile myofibromatosis is a rare myofibroblastic proliferative disorder characterized by firm, skin-colored to red-purple cutaneous and subcutaneous nodules; these are the most prevalent fibrous tumors observed in infancy. A premature male infant presented at birth with multiple subcutaneous firm skin-colored nodules measuring about 1-2cm each. Full body MRI and excisional biopsy of the right chest nodule confirmed the diagnosis. We review the case of infantile myofibromatosis and discuss its highly heterogeneous presentation and clinical course, as well as histopathology, genetic testing, and approaches to management.
Assuntos
Miofibromatose/congênito , Neoplasias de Cabeça e Pescoço/congênito , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Masculino , Miofibromatose/genética , Miofibromatose/patologia , Fotografação , Couro CabeludoRESUMO
UNLABELLED: Paramyxoviridae consist of a large family of enveloped, negative-sense, nonsegmented single-stranded RNA viruses that account for a significant number of human and animal diseases. The fusion process for nearly all paramyxoviruses involves the mixing of the host cell plasma membrane and the virus envelope in a pH-independent fashion. Fusion is orchestrated via the concerted action of two surface glycoproteins: an attachment protein called hemagglutinin-neuraminidase (HN [also called H or G depending on virus type and substrate]), which acts as a receptor binding protein, and a fusion (F) protein, which undergoes a major irreversible refolding process to merge the two membranes. Recent biochemical evidence suggests that receptor binding by HN is dispensable for cell-cell fusion. However, factors that influence the stability and/or conformation of the HN 4-helix bundle (4HB) stalk have not been studied. Here, we used oxidative cross-linking as well as functional assays to investigate the role of the structurally unresolved membrane-proximal stalk region (MPSR) (residues 37 to 58) of HN in the context of headless and full-length HN membrane fusion promotion. Our data suggest that the receptor binding head serves to stabilize the stalk to regulate fusion. Moreover, we found that the MPSR of HN modulates receptor binding and neuraminidase activity without a corresponding regulation of F triggering. IMPORTANCE: Paramyxoviruses require two viral membrane glycoproteins, the attachment protein variously called HN, H, or G and the fusion protein (F), to couple host receptor recognition to virus-cell fusion. The HN protein has a globular head that is attached to a membrane-anchored flexible stalk of â¼80 residues and has three activities: receptor binding, neuraminidase, and fusion activation. In this report, we have identified the functional significance of the membrane-proximal stalk region (MPSR) (HN, residues 37 to 56) of the paramyxovirus parainfluenza virus (PIV5), a region of the HN stalk that has not had its structure determined by X-ray crystallography. Our data suggest that the MPSR influences receptor binding and neuraminidase activity via an indirect mechanism. Moreover, the receptor binding head group stabilizes the 4HB stalk as part of the general mechanism to fine-tune F-activation.
Assuntos
Avulavirus/enzimologia , Avulavirus/fisiologia , Proteína HN/metabolismo , Ácidos Neuramínicos/metabolismo , Ligação Viral , Internalização do Vírus , Animais , Avulavirus/genética , Linhagem Celular , Análise Mutacional de DNA , Proteína HN/genética , Humanos , MutagêneseRESUMO
UNLABELLED: The Paramyxoviridae comprise a large family of enveloped, negative-sense, single-stranded RNA viruses with significant economic and public health implications. For nearly all paramyxoviruses, infection is initiated by fusion of the viral and host cell plasma membranes in a pH-independent fashion. Fusion is orchestrated by the receptor binding protein hemagglutinin-neuraminidase (HN; also called H or G depending on the virus type) protein and a fusion (F) protein, the latter undergoing a major refolding process to merge the two membranes. Mechanistic details regarding the coupling of receptor binding to F activation are not fully understood. Here, we have identified the flexible loop region connecting the bulky enzymatically active head and the four-helix bundle stalk to be essential for fusion promotion. Proline substitution in this region of HN of parainfluenza virus 5 (PIV5) and Newcastle disease virus HN abolishes cell-cell fusion, whereas HN retains receptor binding and neuraminidase activity. By using reverse genetics, we engineered recombinant PIV5-EGFP viruses with mutations in the head-stalk linker region of HN. Mutations in this region abolished virus recovery and infectivity. In sum, our data suggest that the loop region acts as a "hinge" around which the bulky head of HN swings to-and-fro to facilitate timely HN-mediate F-triggering, a notion consistent with the stalk-mediated activation model of paramyxovirus fusion. IMPORTANCE: Paramyxovirus fusion with the host cell plasma membrane is essential for virus infection. Membrane fusion is orchestrated via interaction of the receptor binding protein (HN, H, or G) with the viral fusion glycoprotein (F). Two distinct models have been suggested to describe the mechanism of fusion: these include "the clamp" and the "provocateur" model of activation. By using biochemical and reverse genetics tools, we have obtained strong evidence in favor of the HN stalk-mediated activation of paramyxovirus fusion. Specifically, our data strongly support the notion that the short linker between the head and stalk plays a role in "conformational switching" of the head group to facilitate F-HN interaction and triggering.
Assuntos
Proteína HN/metabolismo , Vírus da Doença de Newcastle/fisiologia , Vírus da Parainfluenza 5/fisiologia , Ligação Viral , Internalização do Vírus , Animais , Linhagem Celular , Análise Mutacional de DNA , Proteína HN/genética , Humanos , Mutagênese Sítio-Dirigida , Vírus da Doença de Newcastle/genética , Vírus da Parainfluenza 5/genéticaRESUMO
This study underscores the persistent underrepresentation of women in academic dermatology leadership positions by examining the gender composition of editorial boards across top dermatology journals, emphasizing the urgent need for proactive strategies to promote diversity, equity, and inclusion.
Assuntos
Dermatologia , Publicações Periódicas como Assunto , Humanos , Estudos Transversais , Publicações Periódicas como Assunto/estatística & dados numéricos , Feminino , Masculino , Médicas/estatística & dados numéricos , Liderança , Políticas Editoriais , Equidade de GêneroRESUMO
We determined which educational and/or psychological interventions were most effective in atopic dermatitis (AD). A systematic review of published studies evaluated the effectiveness of educational and/or psychological interventions in MEDLINE, Embase, SCOPUS, LILACS, Cochrane, China National Knowledge Infrastructure, Taiwan Electronic Periodical Services, and CiNii. Two reviewers conducted title/abstract, full-text review, and data extraction. Twenty-four prospective studies were included, including 20 randomized controlled trials. Educational (4/7 studies) and combined educational and psychological (5/6 studies) interventions reduced AD severity; psychological (10/11 studies) interventions showed the greatest benefit. The most commonly studied psychological intervention was habit reversal training (8/11 studies), which was most frequently incorporated in studies that reduced AD severity (8/10 studies). The most commonly studied educational interventions were education on AD triggers (7/7 studies) and skin care (7/7 studies); they were incorporated in all studies that reduced AD severity. Different psychological and/or educational interventions successfully reduced AD severity, especially habit reversal training.