A patient's infectivity is determined by the presence of the virus in different body fluids, secretions, and excreta. The persistence and clearance of viral RNA from different specimens of patients ...with 2019 novel coronavirus disease (COVID-19) remain unclear. This study analyzed the clearance time and factors influencing 2019 novel coronavirus (2019-nCoV) RNA in different samples from patients with COVID-19, providing further evidence to improve the management of patients during convalescence.
The clinical data and laboratory test results of convalescent patients with COVID-19 who were admitted to from January 20, 2020 to February 10, 2020 were collected retrospectively. The reverse transcription polymerase chain reaction (RT-PCR) results for patients' oropharyngeal swab, stool, urine, and serum samples were collected and analyzed. Convalescent patients refer to recovered non-febrile patients without respiratory symptoms who had two successive (minimum 24 h sampling interval) negative RT-PCR results for viral RNA from oropharyngeal swabs. The effects of cluster of differentiation 4 (CD4)+ T lymphocytes, inflammatory indicators, and glucocorticoid treatment on viral nucleic acid clearance were analyzed.
In the 292 confirmed cases, 66 patients recovered after treatment and were included in our study. In total, 28 (42.4%) women and 38 men (57.6%) with a median age of 44.0 (34.0-62.0) years were analyzed. After in-hospital treatment, patients' inflammatory indicators decreased with improved clinical condition. The median time from the onset of symptoms to first negative RT-PCR results for oropharyngeal swabs in convalescent patients was 9.5 (6.0-11.0) days. By February 10, 2020, 11 convalescent patients (16.7%) still tested positive for viral RNA from stool specimens and the other 55 patients' stool specimens were negative for 2019-nCoV following a median duration of 11.0 (9.0-16.0) days after symptom onset. Among these 55 patients, 43 had a longer duration until stool specimens were negative for viral RNA than for throat swabs, with a median delay of 2.0 (1.0-4.0) days. Results for only four (6.9%) urine samples were positive for viral nucleic acid out of 58 cases; viral RNA was still present in three patients' urine specimens after throat swabs were negative. Using a multiple linear regression model (F = 2.669, P = 0.044, and adjusted R = 0.122), the analysis showed that the CD4+ T lymphocyte count may help predict the duration of viral RNA detection in patients' stools (t = -2.699, P = 0.010). The duration of viral RNA detection from oropharyngeal swabs and fecal samples in the glucocorticoid treatment group was longer than that in the non-glucocorticoid treatment group (15 days vs. 8.0 days, respectively; t = 2.550, P = 0.013) and the duration of viral RNA detection in fecal samples in the glucocorticoid treatment group was longer than that in the non-glucocorticoid treatment group (20 days vs. 11 days, respectively; t = 4.631, P < 0.001). There was no statistically significant difference in inflammatory indicators between patients with positive fecal viral RNA test results and those with negative results (P > 0.05).
In brief, as the clearance of viral RNA in patients' stools was delayed compared to that in oropharyngeal swabs, it is important to identify viral RNA in feces during convalescence. Because of the delayed clearance of viral RNA in the glucocorticoid treatment group, glucocorticoids are not recommended in the treatment of COVID-19, especially for mild disease. The duration of RNA detection may relate to host cell immunity.
Biliproteins have extended the spectral range of fluorescent proteins into the region of maximal transmission of most tissues and are favorable for multiplexing, but their application presents ...considerable challenges. Their fluorescence derives from open-chain tetrapyrrole chromophores which often require the introduction of dedicated reductases and lyases. In addition, their fluorescence yield generally decreases with increasing wavelengths and depends strongly on the state of the binding protein. We report fluorescent biliproteins, termed BDFPs, that are derived from the phycobilisome core subunit, ApcF2: this subunit is induced in the thermophilic cyanobacterium, Chroococcidiopsis thermalis, by far-red light and binds phycocyanobilin non-covalently. The BDFPs obtained by molecular evolution of ApcF2 bind the more readily accessible biliverdin covalently while retaining the red-shifted fluorescence in the near-infrared spectral region (~710nm). They are small monomers (~15kDa) and not only show excellent photostability, but are also thermostable up to 80°C, tolerate acid down to pH2 and high concentrations of denaturants. The result indicates far-red adapting cyanobacteria as a useful source for designing extremely red-shifted fluorescent markers. In vivo performance of BDFPs as biomarkers in conventional and super-resolution microscopy, alone or fused to target proteins, is exemplified in several mammalian cells, including, human cell lines, in the nematode, Caenorhabditis elegans and, at low pH, in Lactobacillus lactis.
•Three near-infrared fluorescent biliproteins (λFmax ~710nm), BDFPs, are reported.•Their labeling is shown in mammalian cells, a nematode and Lactobacillus lactis.•The BDFPs bind biliverdin covalently and show excellent photostability.•The BDFPs are thermostable up to 80°C, tolerate acid down to pH2.•Two BDFPs among them are small monomers (~15kDa).
Plant expansins are proteins involved in cell wall loosening, plant growth, and development, as well as in response to plant diseases and other stresses. In this study, we identified 128 expansin ...coding sequences from the wheat (Triticum aestivum) genome. These sequences belong to 45 homoeologous copies of TaEXPs, including 26 TaEXPAs, 15 TaEXPBs and four TaEXLAs. No TaEXLB was identified. Gene expression and sub-expression profiles revealed that most of the TaEXPs were expressed either only in root tissues or in multiple organs. Real-time qPCR analysis showed that many TaEXPs were differentially expressed in four different tissues of the two wheat cultivars-the cold-sensitive 'Chinese Spring (CS)' and the cold-tolerant 'Dongnongdongmai 1 (D1)' cultivars. Our results suggest that the differential expression of TaEXPs could be related to low-temperature tolerance or sensitivity of different wheat cultivars. Our study expands our knowledge on wheat expansins and sheds new light on the functions of expansins in plant development and stress response.
Paper mill sewage sludge was employed as the raw material for producing activated carbon by physical activation with steam in this study. The important parameters, which greatly affect the ...characteristics of sludge-based activated carbon (SAC), such as the carbonization temperature, carbonization time, activation temperature and activation time, were investigated. In comparison with the carbonized sludge, SAC was applied to remove methylene blue (MB) from aqueous solution in static and dynamic adsorption experiments. The results indicated that the best quality SAC was obtained at a carbonization temperature of 300
°C, carbonization time of 60
min, activation temperature of 850
°C and activation time of 40
min. SAC prepared under the optimum conditions had remarkable adsorptive properties and notable treatment effect for MB. Accordingly, it was concluded that the procedure of physical activation with steam could be an environmentally benign and effective approach for preparation of sludge-based adsorbent.
► The sludge-based activated carbon was prepared by physical activation with steam. ► The optimum preparation conditions were determined. ► The treatment effect of produced adsorbent for methylene blue was notable.
Radiotherapy (RT) is an effective treatment option for cancer patients, which induces the production of reactive oxygen species (ROS) and causes oxidative stress (OS), leading to the death of tumor ...cells. OS not only causes apoptosis, autophagy and ferroptosis, but also affects tumor immune response. The combination of RT and immunotherapy has revolutionized the management of various cancers. In this process, OS caused by ROS plays a critical role. Specifically, RT-induced ROS can promote the release of tumor-associated antigens (TAAs), regulate the infiltration and differentiation of immune cells, manipulate the expression of immune checkpoints, and change the tumor immune microenvironment (TME). In this review, we briefly summarize several ways in which IR induces tumor cell death and discuss the interrelationship between RT-induced OS and antitumor immunity, with a focus on the interaction of ferroptosis with immunogenic death. We also summarize the potential mechanisms by which ROS regulates immune checkpoint expression, immune cells activity, and differentiation. In addition, we conclude the therapeutic opportunity improving radiotherapy in combination with immunotherapy by regulating OS, which may be beneficial for clinical treatment.
This study aimed to develop a novel therapeutic vaccine based on a unique B cell epitope and investigate its therapeutic potential against chronic hepatitis B (CHB) in animal models.
A series of ...peptides and carrier proteins were evaluated in HBV-tolerant mice to obtain an optimised therapeutic molecule. The immunogenicity, therapeutic efficacy and mechanism of the candidate were investigated systematically.
Among the HBsAg-aa119-125-containing peptides evaluated in this study, HBsAg-aa113-135 (SEQ13) exhibited the most striking therapeutic effects. A novel immunoenhanced virus-like particle carrier (CR-T3) derived from the roundleaf bat HBV core antigen (RBHBcAg) was created and used to display SEQ13, forming candidate molecule CR-T3-SEQ13. Multiple copies of SEQ13 displayed on the surface of this particulate antigen promote the induction of a potent anti-HBs antibody response in mice, rabbits and cynomolgus monkeys. Sera and purified polyclonal IgG from the immunised animals neutralised HBV infection in vitro and mediated efficient HBV/hepatitis B virus surface antigen (HBsAg) clearance in the mice. CR-T3-SEQ13-based vaccination induced long-term suppression of HBsAg and HBV DNA in HBV transgenic mice and eradicated the virus completely in hydrodynamic-based HBV carrier mice. The suppressive effects on HBsAg were strongly correlated with the anti-HBs level after vaccination, suggesting that the main mechanism of CR-T3-SEQ13 vaccination therapy was the induction of a SEQ13-specific antibody response that mediated HBV/HBsAg clearance.
The novel particulate protein CR-T3-SEQ13 suppressed HBsAg effectively through induction of a humoural immune response in HBV-tolerant mice. This B cell epitope-based therapeutic vaccine may provide a novel immunotherapeutic agent against chronic HBV infection in humans.
Two new seco‐prezizaane‐type sesquiterpenes, 2β‐hydroxy‐6‐deoxyneoanisatin (1) and 3,4‐anhydro‐2‐oxo‐1α‐hydroxy‐6‐deoxyneoanisatin (2), and two new prenylated C6‐C3 compounds, illilanceofunones A (3) ...and B (4), were obtained from the fruits of Illicium lanceolatum, along with four known prenylated C6‐C3 compounds (5–8). Their structures were proposed through HR‐ESI‐MS, 1H, 13C, and 2D NMR data interpretation. Moreover, the absolute configuration of 1 and 2 were further assigned by single‐crystal X‐ray diffraction analysis and electronic circular dichroism (ECD) calculations, respectively. Illihenryipyranol A (6) exhibited neuroprotective activity against MPP+‐induced PC12 cell damage in a dose‐dependent manner.
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Ferroptosis, a form of cell death driven by iron-dependent lipid peroxidation, has known as one of the most significant pathological processes involved in diabetic kidney disease ...(DKD). Stimulator of interferon genes (STING) has been demonstrated its potential in regulating ferroptosis, but the regulatory role in DKD mice and underlying mechanisms haven’t been illustrated. To elucidate whether and how STING regulates ferroptosis in DKD, we detected the influence of STING on diabetic-related ferroptosis in a diabetic model and in erastin-induced renal tubular epithelial cells (RTECs). Our study demonstrated that STING was abnormally activated and promoted ferroptosis in DKD. STING deficiency alleviated renal pathologic damages and disfunction in diabetic mice via alleviating ferroptosis and reducing oxidative stress. Mechanismly, STING inhibition was shown to improve ferroptosis and reduce oxidative stress in erastin-induced RTECs. The disruption of ferroportin1 (FPN1) on the basis of STING inhibition abolished the improvements in ferroptosis and promoted reactive oxygen species (ROS) generation. Further, STING inhibition alleviated ferroptosis via stabilizing FPN1 protein level by decreasing ubiquitinated FPN1 for proteasomal degradation. In conclusion, STING deficiency protected against diabetic renal injury via alleviating ferroptosis through stabilizing FPN1 and reducing oxidative stress, providing a possible potential approach for the treatment of DKD.
We have determined high-resolution crystal structures of a CDK2/Cyclin A transition state complex bound to ADP, substrate peptide, and MgF3−. Compared to previous structures of active CDK2, the ...catalytic subunit of the kinase adopts a more closed conformation around the active site and now allows observation of a second Mg2+ ion in the active site. Coupled with a strong Mg2+ effect on in vitro kinase activity, the structures suggest that the transient binding of the second Mg2+ ion is necessary to achieve maximum rate enhancement of the chemical reaction, and Mg2+ concentration could represent an important regulator of CDK2 activity in vivo. Molecular dynamics simulations illustrate how the simultaneous binding of substrate peptide, ATP, and two Mg2+ ions is able to induce a more rigid and closed organization of the active site that functions to orient the phosphates, stabilize the buildup of negative charge, and shield the subsequently activated γ-phosphate from solvent.
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► Structure of a CDK2/Cyclin A protein kinase transition state mimic using ADP/MgF3 ► CDK2 protein kinase utilizes two catalytic Mg ions for the phosphoryl-transfer step ► The active site closes and becomes more rigid once all reactants and 2Mg are bound ► The binding of the second catalytic Mg is a transient step during the catalytic cycle
Preferential removal of phosphate from aqueous was conducted by a novel biomass-based nanocomposite (EP-N
+
-Zr) with encapsulated hydrous zirconium oxide, and the biopolymer EP-N
+
-Zr features were ...described. EP-N
+
-Zr exhibited high selective sequestration toward phosphate when humic acid or other competing anions (Cl
−
, SO
4
2−
, NO
3
−
, ClO
4
−
) coexisted at relatively high levels. Such excellent performance of EP-N
+
-Zr was attributed to its specific two site structures; the embedded HZO nanoparticles and quaternary ammonia groups N
+
(CH
2
CH
3
)
3
Cl
−
bonded inside the biomass—
Enteromorpha prolifera
, which facilitated preferable capture towards phosphate through specific affinity and nonspecific preconcentration of phosphate ions on the basis of the ion exchange, respectively. The maximum adsorption capacity of phosphate (20 °C) as calculated by Langmuir model was 88.5 mg(P)/g. Regeneration tests showed that EP-N
+
-Zr could be recycled at least five times without noticeable capacity losses using binary NaOH-NaCl as eluent.
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