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Πέμπτη 22 Δεκεμβρίου 2022

mTOR Signaling Regulates Zika Virus Replication Bidirectionally through Autophagy and Protein Translation

alexandrossfakianakis shared this article with you from Inoreader

Abstract

Zika virus (ZIKV) reemerged in 2016 and attracted much more attention worldwide. To date, the limited knowledge of ZIKV interactions with host cells in the early stages of infection impedes the prevention of viral epidemics and the treatment of ZIKV disease. The Mammalian target of rapamycin (mTOR) signaling pathway plays an essential role in the regulation of autophagy and protein synthesis during multiple viral infections. This study aimed to investigate the functional role of mTOR signaling in ZIKV replication in human umbilical vein endothelial cells (HUVECs). Immunoblotting demonstrated that ZIKV infection inhibited mTORC1 signaling, enhancing autophagy but obstructing protein translation. Drugs or siRNA for interfering with mTOR signaling molecules were utilized to demonstrate that AKT/TSC2/mTORC1 signaling was involved in ZIKV infection and that autophagy promoted ZIKV production, but viral protein expression was regulated by mTORC1 signaling. Moreover, confocal microscopy indicated a robust correlation between autophagy and viral RNA transcription. This study clarifies the dual functions of mTOR signaling during ZIKV infection and provides theoretical support for developing potential anti-ZIKV drugs based on mTOR signaling molecules and deeper insights to better understand the mechanism between ZIKV and host cells.

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Omicron infection increases IgG binding to spike protein of predecessor variants

alexandrossfakianakis shared this article with you from Inoreader

Abstract

Background

SARS-CoV-2 transmission in India in 2020-2022 was driven predominantly by Wild (Wuhan-Hu-1and D614G), Delta, and Omicron variants. The aim of this study was to examine the effect of infections on the humoral immune response and cross-reactivity to spike proteins of Wuhan-Hu-1, Delta, C.1.2., and Omicron.

Objectives

Residual archival sera (N=81) received between January 2020 and March 2022 were included. Infection status was inferred by a positive SARS-CoV-2 RT-PCR and/or serology (anti-N and anti-S antibodies) and sequencing of contemporaneous samples (N=18) to infer lineage. We estimated the levels and cross-reactivity of infection-induced sera including Wild, Delta, Omicron as well as vaccine breakthrough infections (Delta and Omicron).

Results

We found ~2-fold increase in spike-specific IgG antibody binding in post-Omicron infection compared to the pre-Omicron period, whilst the change in pre- and post-Delta infections were similar. Further investigation of Omicron-specific humoral responses revealed primary Omicron infection as an inducer of cross-reactive antibodies against predecessor variants, in spite of weaker degree of humoral response compared to Wuhan-Hu-1 and Delta infection. Intriguingly, Omicron vaccine-breakthrough infections when compared with primary infections, exhibited increased humoral responses against RBD (7.7-fold) and Trimeric S (Trimeric form of spike protein) (34.6-fold) in addition to increased binding of IgGs towards previously circulating variants (4.2 - 6.5-fold). Despite Delta breakthrough infections showing a higher level of humoral response against RBD (2.9-fold) and Trimeric S (5.7-fold) compared to primary Delta sera, a demonstrably reduced binding (36-49%) was observed to Omicron spike protein.

Conclusions

Omicron vaccine breakthrough infection results in increased intensity of humoral response and wider breadth of IgG binding to spike proteins of antigenically-distinct, predecessor variants.

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Caring for a child with retinoblastoma: Experience of Ethiopian parents

alexandrossfakianakis shared this article with you from Inoreader

Abstract

Objective

This study explored the lived experience of parents of children with retinoblastoma.

Design and method

A phenomenological qualitative study design was used, and a purposive sampling technique to recruit parents of children with retinoblastoma. Semi-structured interviews were conducted to document the lived experience of participants, who were asked to narrate their experiences caring for a child with retinoblastoma, thinking back to the day they learned about their child's condition, as well as their thoughts about the future. The interviews were conducted in Amharic and Oromo language, and audio recordings were transcribed and translated to English. Data were analyzed using thematic analysis.

Results

Thirteen parents (seven mothers, six fathers) participated in the study. Collectively, the children of the participants represented all the stages of the retinoblastoma journey (i.e., diagnosis, treatment, remission, and recurrence). Five major themes emerged from the thematic data analysis: (a) reactions when learning the child's condition; (b) receiving health care; (c) costs of caregiving; (d) support; and (e) uncertainties.

Conclusion

The lived experiences of parents of children with retinoblastoma revealed a significant mental health and psychosocial burden. The sources of mental distress were found to be complex and varied. Holistic care for retinoblastoma should include programs that address the biopsychosocial needs of caregivers.

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Ninety‐day mortality following transoral robotic surgery or radiation at Commission on Cancer‐accredited facilities

alexandrossfakianakis shared this article with you from Inoreader

Abstract

Background

Postoperative mortality for oropharynx squamous cell carcinoma (OPSCC) with transoral robotic surgery (TORS) varies from 0.2% to 6.5% on trials; the real-world rate is unknown.

Methods

NCDB study from 2010 to 2017 for patients with cT1-2N0-2M0 OPSCC with Charleson–Deyo score 0–1. Ninety-day mortality assessed from start and end of treatment at Commission on Cancer-accredited facilities.

Results

3639 patients were treated with TORS and 1937 with radiotherapy. TORS cohort had more women and higher income, was younger, more often treated at academic centers, and more likely to have private insurance (all p < 0.05). Ninety-day mortality was 1.3% with TORS and 0.7% or 1.4% from start or end of radiotherapy, respectively. From end of therapy, there was no significant difference on MVA between treatment modality.

Conclusions

There is minimal difference between 90-day mortality in patients treated with TORS or radiotherapy for early-stage OPSCC. While overall rates are low, for patients with expectation of cure, work is needed to identify optimal treatment.

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