Bacterial antiviral defense pathways encode eukaryotic-like ubiquitination systems.

Ubiquitination and related pathways play crucial roles in protein homeostasis, signaling, and innate immunity1-3. In these pathways, an enzymatic cascade of E1, E2, and E3 proteins conjugates ubiquitin or a ubiquitin-like protein (Ubl) to target-protein lysine residues4. Bacteria encode ancient relatives of E1 and Ubl proteins involved in sulfur metabolism5,6 but these proteins do not mediate Ubl-target conjugation, leaving open the question of whether bacteria can perform ubiquitination-like protein conjugation. Here, we demonstrate that a bacterial antiviral immune system encodes a complete ubiquitination pathway. Two structures of a bacterial E1:E2:Ubl complex reveal striking architectural parallels with canonical eukaryotic ubiquitination machinery. The bacterial E1 encodes an N-terminal inactive adenylation domain (IAD) and a C-terminal active adenylation domain (AAD) with a mobile α-helical insertion containing the catalytic cysteine (CYS domain). One structure reveals a pre-reaction state with the bacterial Ubl C-terminus positioned for adenylation, and the E1 CYS domain poised nearby for thioester formation. A second structure mimics an E1-to-E2 transthioesterification state, with the E1 CYS domain rotated outward and its catalytic cysteine adjacent to the bound E2. We show that a deubiquitinase (DUB) in the same pathway pre-processes the bacterial Ubl, exposing its C-terminal glycine for adenylation. Finally, we show that the bacterial E1 and E2 collaborate to conjugate Ubl to target-protein lysine residues. Together, these data reveal that bacteria possess bona fide ubiquitination systems with strong mechanistic and architectural parallels to canonical eukaryotic ubiquitination pathways, suggesting that these pathways arose first in bacteria.

A nomogram based on clinicopathological and ultrasound characteristics to predict central neck lymph node metastases in papillary thyroid cancer.

Purpose: Papillary thyroid cancer (PTC) has grown rapidly in prevalence over the past few decades, and central neck lymph node metastasis (CNLNM) is associated with poor prognoses. However, whether to carry out preventive central neck lymph node dissection (CNLND) is still controversial. We aimed to construct a prediction model of CNLNM to facilitate making clinical surgical regimens. Methods: A total of 691 patients with PTC between November 2018 and December 2021 were included in our study. Univariate and multivariate analyses were performed on basic information and clinicopathological characteristics, as well as ultrasound characteristics (American College of Radiology (ACR) scores). The prediction model was constructed and performed using a nomogram, and then discriminability, calibrations, and clinical applicability were evaluated. Results: Five variables, namely, male, age >55 years, clinical lymph node positivity, tumor size ≥1 cm, and ACR scores ≥6, were independent predictors of CNLNM in the multivariate analysis, which were eventually included to construct a nomogram model. The area under the curve (AUC) of the model was 0.717, demonstrating great discriminability. A calibration curve was developed to validate the calibration of the present model by bootstrap resampling, which indicated that the predicted and actual values were in good agreement and had no differentiation from the ideal model. The decision curve analysis (DCA) indicated that the prediction model has good clinical applicability. Conclusions: Our non-invasive prediction model combines ACR scores with clinicopathological features presented through nomogram and has shown good performance and application prospects for the prediction of CNLNM in PTCs.

Global trends of researches on radioactive enteritis: A bibliometric and visualization study.

BACKGROUND: Radiation enteritis (RE) caused by radiation therapy, can seriously affect human health. Recently, studies on RE have been growing rapidly, but there are no bibliometric studies on RE. This study aims to explore the development trends and research hotspots of RE. METHODS: Academic papers on the Web of Science were retrieved on the topic of "radioactive enteritis" from the establishment of the database to December 2020. Countries, institutions, and subjects selected in this field were visualized using Citespace, HistCite, and Vosviewer. The annual trends in publications, distribution, co-authorship status, and research hotspots were analyzed. RESULTS: The authors ranked first in terms of publication amount were Delaney, Francois, Milliat, and Vozenin-Brotons. The United States had the highest number of posts, followed by China, France, the United Kingdom, and Spain. CONCLUSION: Future research in the field of RE will focus on double-blind clinical trials of RE, and the related mechanisms, such as oxidative stress and apoptosis.

Treatment of oil-based drilling cuttings using the demulsification separation-Fenton oxidation method.

In this study, demulsification separation-Fenton oxidation technology was employed as a combined technology to treat total petroleum hydrocarbons (TPH) in oil-based drill cuttings (OBDC). Batch experiments were carried out to optimize the technology parameter. Under the optimal condition, 70% and 51% TPH removal rate was obtained for demulsification technology and Fenton oxidation technology, respectively. Eighty-five percent of TPH removal rate was obtained using combination technology of demulsification separation and Fenton oxidation. Multiple characterizations were used to analyze the physical and chemical properties of treated OBDC. The result of XRD pattern indicated the combination technology had no obvious effect for structure phase of OBDC. The results of FTIR, GC-MS, TG-DTG and SEM were used to characterize the treated OBDC. This paper provides an efficient and feasible combined technology for OBDC treatment, which expands a new strategy for the removal of TPH from solid waste.