Persistence of SARS-CoV-2 colonization and high expression of inflammatory factors in cardiac tissue 6 months after COVID-19 recovery: a prospective cohort study.

Background: The presence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in myocardial autopsy tissues has been observed in certain individuals with coronavirus disease 2019 (COVID-19). However, the duration of cardiac involvement remains uncertain among recovered COVID-19 patients. Our study aims to evaluate the long-term persistence of SARS-CoV-2 within cardiac tissue. Methods: We prospectively and consecutively evaluated the patients undergoing mitral valve replacement (MVR) and left atrial (LA) volume reduction surgery from May 25 to June 10, 2023 at our center, who had been approximately 6 months of recovery after Omicron wave. Patients tested positive for SARS-CoV-2 upon admission were excluded. The surgical LA tissue was collected in RNA preservation solution and stored at -80 ℃ immediately. Then SARS-CoV-2, interleukin-6 (IL-6) and interleukin-1ß (IL-1ß) RNA expression in LA tissues were assessed through thrice-repeated reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analyses. Categorical variables were assessed using the Chi-square or Fisher's exact tests, and continuous variables was analyzed using the Mann-Whitney U test. Results: Nine of 41 patients were enrolled, all of whom tested negative for SARS-CoV-2 upon admission (two antigen and PCR tests). In four of nine patients, SARS-CoV-2 RNA was detected in their LA tissue, indicating viral colonization. Among the four positive cases, the IL-6 and IL-1ß relative expression levels in the LA tissue of one patient were increased approximately 55- and 110-fold, respectively, compared to those of SARS-CoV-2 (-) patients. Increased expression of IL-6 and IL-1ß were observed in the myocardium of this patient. Another patient demonstrated a remarkable 7-fold increase in both IL-6 and IL-1ß expression, surpassing that of SARS-CoV-2 (-) patients. Additionally, no other cardiac inflammation-related diseases or conditions were presented in these two patients. The IL-6 and IL-1ß expression levels of the remaining two patients were not significantly different from those of SARS-CoV-2 (-) patients. The relative expression levels of IL-6 and IL-1ß in cardiac tissues of all SARS-CoV-2 (-) patients were relatively low. Interestingly, despite abnormally elevated levels of IL-6 and IL-1ß within their cardiac tissue, two patients did not show a significant increase in serum IL-6 and IL-1ß levels when compared to other patients. Conclusions: Our research suggests that certain COVID-19-recovered patients have persistent colonization of SARS-CoV-2 in their cardiac tissue, accompanied by a local increase in inflammatory factors.

A Gas-Steamed Route to Mesoporous Open Metal-Organic Framework Cages Enhancing Flame Retardancy and Smoke Suppression of Polyurea.

Up to now, metal-organic frameworks (MOFs) with open nanostructures have shown outstanding capabilities in trapping smoke particles compared to the original MOFs. However, only a few MOF-based strategies have been reported to synthesize hierarchical porous cages thus far, which are mainly restricted to environmentally unfriendly wet-chemical liquid methods. Herein, as a proof-of-concept, a gas-steamed metal-organic framework approach was designed to fabricate a series of cheeselike open cages with hierarchical porosity. Briefly, zeolitic imidazolate framework-67 (ZIF-67) and phytic acid were employed as precursor and etchant, respectively. Abandoning the conventional wet-chemical method, the coordination bond of ZIF-67 was cleaved by acidic steam, forming an open framework with a high specific surface area and a hierarchical porous structure. The universality of this method was also confirmed by the selection of different etchants. Impressively, they also show outstanding fume-toxic adsorption capability and labyrinth effects based on abundant and complex porous channels. At only 5 wt % loading, Co3O4@open ZIF-67 cage-2 (Co3O4@OZC-2) imparted polyurea (PUA) composites with a 21.2% limiting oxygen index, and the peak of heat release rate, total heat release, and total smoke production were reduced by around 37.5, 25.5, and 40.4%, respectively, compared to neat PUA. This work will shed light on the advanced structural design of polymer composites with high fire safety, especially smoke suppression performance, so as to obtain more feasible applications.

Novel kokumi peptides from yeast extract and their taste mechanism via an in silico study.

Yeast extract, a widely utilized natural substance in the food industry and biopharmaceutical field, holds significant potential for flavor enhancement. Kokumi peptides within yeast extracts were isolated through ultrafiltration and gel chromatography, followed by identification using liquid chromatography tandem mass spectrometry (LC-MS/MS). Two peptides, IQGFK and EDFFVR, were identified and synthesized using solid-phase methods based on molecular docking outcomes. Sensory evaluations and electronic tongue analyses conducted with chicken broth solutions revealed taste thresholds of 0.12 mmol L-1 for IQGFK and 0.16 mmol L-1 for EDFFVR, respectively, and both peptides exhibited kokumi properties. Additionally, through molecular dynamics simulations, the binding mechanisms between these peptides and the calcium-sensing receptor (CaSR) were explored. The findings indicated stable binding of both peptides to the receptor. IQGFK primarily interacted through electrostatic interactions, with key binding sites including Asp275, Asn102, Pro274, Trp70, Tyr218, and Ser147. EDFFVR mainly engaged via van der Waals energy and polar solvation free energy, with key binding sites being Asp275, Ile416, Pro274, Arg66, Ala298, and Tyr218. This suggests that both peptides can activate the CaSR, thereby inducing kokumi activity. This study provides a theoretical foundation and reference for the screening and identification of kokumi peptides, successfully uncovering two novel kokumi peptides derived from yeast extract.

Exploring novel Kokumi peptides in Agaricus bisporus: selection, identification, and tasting mechanism investigation through sensory evaluation and computer simulation analysis.

Agaricus bisporus contains amino acids associated with thickness and full-mouthfeel, making it a potential candidate for salt substitutes and flavor enhancers in various food applications. Kokumi peptides were isolated from the enzymatic digest of Agaricus bisporus using ultrafiltration nanofiltration, gel chromatographic separation, and RP-HPLC, coupled with sensory evaluation. Subsequently, the peptides, EWVPVTK and EYPPLGR, were selected for solid-phase synthesis based on molecular docking. Sensory analysis, including thresholds, time intensity, and dose-configuration relationships, indicated that EWVPVTK and EYPPLGR exhibited odor thresholds of 0.6021 mmol L-1 and 2.332 mmol L-1 in an aqueous solution. Molecular docking scores correlated with low sensory thresholds, signifying strong taste sensitivities. EWVPVTK, in particular, demonstrated a higher sense of richness at lower concentrations compared to EYPPLGR. Molecular docking and dynamics simulations elucidated that the interactions between Kokumi peptides and the CaSR receptor primarily involved hydrogen bonding, electrostatic interactions, and hydrophobic interactions. Both EWVPVTK and EYPPLGR exhibited stable binding to the CaSR receptor. Active binding sites were identified, with EWVPVTK interacting at Arg 66, Asp 216, Gln 245, and Asn 102, while EYPPLGR engaged with Ser 272, Gln 193, Glu 297, Ala-298, Tyr-2, and Agr-66 in hydrophilic interactions through hydrogen bonds. Notably, these two Kokumi peptides were found to be enriched in umami and sweet amino acids, underscoring their pivotal role in umami perception. This study not only identifies novel Kokumi peptides from Agaricus bisporus but also contributes theoretical foundations and insights for future studies in the realm of Kokumi peptides.

Case report: A toxoplasmic encephalitis in an immunocompromised child detected through metagenomic next-generation sequencing.

There exist numerous pathogens that are capable of causing infections within the central nervous system (CNS); however, conventional detection and analysis methods prove to be challenging. Clinical diagnosis of CNS infections often depends on clinical characteristics, cerebrospinal fluid (CSF) analysis, imaging, and molecular detection assays. Unfortunately, these methods can be both insensitive and time consuming, which can lead to missed diagnoses and catastrophic outcomes, especially in the case of infrequent diseases. Despite the application of appropriate prophylactic regimens and evidence-based antimicrobial agents, CNS infections continue to result in significant morbidity and mortality in hospital settings. Metagenomic next-generation sequencing (mNGS) is a novel tool that enables the identification of thousands of pathogens in a target-independent manner in a single run. The role of this innovative detection method in clinical pathogen diagnostics has matured over time. In this particular research, clinicians employed mNGS to investigate a suspected CNS infection in a child with leukemia, and unexpectedly detected Toxoplasma gondii. Case: A 3-year-old child diagnosed with T-cell lymphoblastic lymphoma was admitted to our hospital due to a 2-day history of fever and headache, along with 1 day of altered consciousness. Upon admission, the patient's Glasgow Coma Scale score was 14. Brain magnetic resonance imaging revealed multiple abnormal signals. Due to the patient's atypical clinical symptoms and laboratory test results, determining the etiology and treatment plan was difficulty.Subsequently, the patient underwent next-generation sequencing examination of cerebrospinal fluid. The following day, the results indicated the presence of Toxoplasma gondii. The patient received treatment with a combination of sulfamethoxazole (SMZ) and azithromycin. After approximately 7 days, the patient's symptoms significantly improved, and they were discharged from the hospital with oral medication to continue at home. A follow-up polymerase chain reaction (PCR) testing after about 6 weeks revealed the absence of Toxoplasma. Conclusion: This case highlights the potential of mNGS as an effective method for detecting toxoplasmic encephalitis (TE). Since mNGS can identify thousands of pathogens in a single run, it may be a promising detection method for investigating the causative pathogens of central nervous system infections with atypical features.

An integrated computational strategy to predict personalized cancer drug combinations by reversing drug resistance signatures.

Drug resistance currently poses the greatest barrier to cancer treatments. To overcome drug resistance, drug combination therapy has been proposed as a promising treatment strategy. Herein, we present Re-Sensitizing Drug Prediction (RSDP), a novel computational strategy, for predicting the personalized cancer drug combination A + B by reversing the resistance signature of drug A. The process integrates multiple biological features using a robust rank aggregation algorithm, including Connectivity Map, synthetic lethality, synthetic rescue, pathway, and drug target. Bioinformatics assessments revealed that RSDP achieved a relatively accurate prediction performance for identifying personalized combinational re-sensitizing drug B against cell line-specific intrinsic resistance, cell line-specific acquired resistance, and patient-specific intrinsic resistance to drug A. In addition, we developed the largest resource of cell line-specific cancer drug resistance signatures, including intrinsic and acquired resistance, as a byproduct of the proposed strategy. The findings indicate that personalized drug resistance signature reversal is a promising strategy for identifying personalized drug combinations, which may guide future clinical decisions regarding personalized medicine.

Comparative evaluation for phytochemical composition and regulation of blood glucose, hepatic oxidative stress and insulin resistance in mice and HepG2 models of four typical Chinese dark teas.

BACKGROUND: Dark tea, comprising one of the six major teas, has many biological activities, which originate from their active substrates, such as polyphenols, polysaccharides, and so on. The hypoglycemic effect is one of its most prominent activities, although less is known about their evaluation and potential role in the hypoglycemic mechanism. RESULTS: In the present study, we separately analyzed the phytochemical composition, glycosidase inhibition and free radical scavenging activities, and hypoglycemic activity in type 2 diabetes mellitus mice, as well as the alleviation of insulin resistance in HepG2 cells of four dark tea aqueous extracts. The results showed that the phytochemical composition of dark tea aqueous extracts was significantly different, and they all had good glycosidase inhibition and free radical scavenging activities, in vivo hypoglycemic activity and alleviation of insulin resistance, and could also activate the phosphatidylinositol 3-kinase-Akt-perixisome proliferation-activated receptor cascade signaling pathway to regulate glucose and lipid metabolism, change the key enzyme activities related to glucose metabolism and antioxidant activity, and reduce oxidative stress and inflammatory factor levels. Among them, Liubao brick tea (LBT) and Pu-erh tea (PET) possessed better glycosidase inhibitory activity, in vivo hypoglycemic activity and improved insulin resistance activity, whereas Qingzhuan brick tea and Fuzhuan brick tea had better free radical scavenging activity, which may be explained by their distinct phytochemical compositions, such as tea proteins, polysaccharides, polyphenols, catechins, and tea pigments and some elements. CONCLUSION: Dark tea is a highly attractive candidate for developing antidiabetic food, LBT and PET may be good natural sources of agricultural products with anti-diabetic effects. © 2021 Society of Chemical Industry.

An Ion-In-Conjugation-Boosted Organic Semiconductor Gas Sensor Operating at High Temperature and Immune to Moisture.

Organic electrical gas sensors have been developed for many decades because of their high sensitivity and selectivity. However, their industrialization is severely hindered by their intrinsic humidity susceptibility and poor recovery. Conventional organic sensory materials can only operate at room temperature owing to their weak intermolecular interactions. Herein, we demonstrate using a croconate polymer (poly-4,4'-biphenylcroconate) that the "ion-in-conjugation" concept enables organic gas sensors to operate at 100 °C and 70 % relative humidity with almost complete recovery. The fabricated sensor had a parts-per-billion (ppb) detection limit for NO2 and showed the highest sensitivity (2526 ppm-1 at 40 ppb) of all reported NO2 chemiresistive sensors. Furthermore, charge transfer increased with temperature. Theoretical calculations and in situ FTIR spectra confirmed the ion-in-conjugation-inspired hydrogen bond as key for excellent sensitivity. A NO2 alarm system was assembled to demonstrate the feasibility of this sensor.

Measurement of Water Velocity in Gas-Water Two-Phase Flow with the Combination of Electromagnetic Flowmeter and Conductance Sensor.

A method to measure the superficial velocity of the water phase in gas-water flow using an electromagnetic flowmeter (EMF) and rotating electric field conductance sensors (REFCSs) is introduced in this paper. An electromagnetic flowmeter instrument factor model is built and the correlation between electromagnetic flowmeter output and gas holdup in different flow patterns are explored through vertical upward gas-water flow dynamic experiments in a pipe with an inner diameter (ID) of 20 mm. Water superficial velocity is predicted based on pattern identification among bubble, churn, and slug flows. The experimental results show that water superficial velocity can be predicted fairly accurately for bubble, churn, and slug flows with a water cut higher than 60% (absolute average percentage deviation and absolute average deviation are 4.1057% and 0.0281 m/s, respectively). The output of the electromagnetic flowmeter is unstable and invalid in slug flows with a water cut below 60% due to the non-conducting gas slug is almost filling the pipe. Therefore, the electromagnetic flowmeter is not preferred to be used in such conditions.

Antioxidant, Antimicrobial and Anti-Inflammatory Activities of Essential Oil Derived from the Wild Rhizome of Atractylodes macrocephala.

The present study investigated the chemical composition, antioxidant, antimicrobial, and anti-inflammatory activities of essential oil (EO) derived from the wild rhizomes of Atractylodes macrocephala Koidz. (AMA) growing in Qimen County (eastern China). GC/MS analysis identified fifteen compounds, representing 92.55 % of AMA EO. The major compounds were atractylone (39.22 %), ß-eudesmol (27.70 %), thymol (5.74 %), hinesol (5.50 %), and 11-isopropylidenetricyclo[4.3.1.1(2,5)]undec-3-en-10-one (4.71 %). Ferricyanide reducing, 1,1-diphenyl-2-picyrlhydrazyl (DPPH) and 3-ethyl-benzothiazoline-6-sulfonic acid (ABTS) scavenging assays revealed that AMA EO exhibited strong antioxidant capacities. Additionally, AMA EO showed inhibitory effects on growth of Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, Staphylococcus aureus, and Bacillus subtilis, with the minimum inhibitory concentrations (MIC) ranging from 0.5 to 2.0 mg/mL. Treatments with AMA EO also significantly inhibited nitric oxide (NO) and prostaglandin E2 (PGE2 ) production in lipopolysaccharide-stimulated RAW264.7 cells, indicating anti-inflammatory activity of AMA EO. Furthermore, treatments with AMA EO decreased the transcriptional levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), which might be the molecular mechanisms underlying its anti-inflammatory effects. Overall, these results provide a theoretical basis for further study and application of AMA EO in food and medicine products.

miR-155 increases stemness and decitabine resistance in triple-negative breast cancer cells by inhibiting TSPAN5.

Effective therapeutic targets for triple-negative breast cancer (TNBC), a special type of breast cancer (BC) with rapid metastasis and poor prognosis, are lacking, especially for patients with chemotherapy resistance. Decitabine (DCA) is a Food and Drug Administration-approved DNA methyltransferase inhibitor that has been proven effective for the treatment of tumors. However, its antitumor effect in cancer cells is limited by multidrug resistance. Cancer stem cells (CSCs), which are thought to act as seeds during tumor formation, regulate tumorigenesis, metastasis, and drug resistance through complex signaling. Our previous study found that miR-155 is upregulated in BC, but whether and how miR-155 regulates DCA resistance is unclear. In this study, we demonstrated that miR-155 was upregulated in CD24- CD44+ BC stem cells (BCSCs). In addition, the overexpression of miR-155 increased the number of CD24- CD44+ CSCs, DCA resistance and tumor clone formation in MDA-231 and BT-549 BC cells, and knockdown of miR-155 inhibited DCA resistance and stemness in BCSCs in vitro. Moreover, miR-155 induced stemness and DCA resistance by inhibiting the direct target gene tetraspanin-5 (TSPAN5). We further confirmed that overexpression of TSPAN5 abrogated the effect of miR-155 in promoting stemness and DCA resistance in BC cells. Our data show that miR-155 increases stemness and DCA resistance in BC cells by targeting TSPAN5. These data provide a therapeutic strategy and mechanistic basis for future possible clinical applications targeting the miR-155/TSPAN5 signaling axis in the treatment of TNBC.

Synthesis of illite/iron nanoparticles and their application as an adsorbent of lead ions.

Illite/iron nanoparticles (I-nZVI) with different iron contents were synthesized using a liquid-phase reduction method to remove Pb(II) from aqueous solution. The adsorbents were characterized by Lorentz transmission electron microscopy (L-TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and the BET-N2 technique. The composite adsorbents and illite removed Pb(II) from aqueous solution to explore the effect of different reaction conditions, including contact time, concentration, pH, and temperature. The results of batch experiments demonstrated that the removal efficiency mainly depends on the amount of nanoscale zerovalent iron. Under different conditions, the order of the removal efficiency was 30% I-nZVI > 20% I-nZVI > 10% I-nZVI > illite. Reactions between Fe(0) and Pb(II) took place on the surface of the absorbents, and the removal of Pb(II) was based on adsorption and reductive reactions. The adsorption of lead ions by I-nZVI and pure illite conformed to the pseudo-second-order reaction kinetic model, and intraparticle diffusion may not play a remarkable role in removing Pb(II). The adsorption of Pb(II) by 30% I-nZVI, 20% I-nZVI, 10% I-nZVI, and illite was more in line with the Langmuir adsorption model. Thermodynamic studies indicated that the Pb(II) removal process is endothermic in nature, which is in agreement with the experimental results. The high removal efficiency helps to achieve the goal of remediation.

The application of p2PSA% and prostate health index in prostate cancer detection: A prospective cohort in a Tertiary Medical Center.

BACKGROUND/PURPOSE: Prostate specific antigen (PSA) with low specificity that causes unnecessary prostate biopsies increases clinical morbidities, psychological stress, and medical expenses. We aimed to test the accuracy and cutoff value of Prostate Health Index (PHI) in men for prostate cancer detection. METHODS: We prospectively enrolled 213 men who underwent prostate biopsy with PSA≦10 ng/ml or abnormal findings on digital rectal examination. Total PSA (tPSA), free PSA (fPSA) and p2PSA levels were measured by serum samples before prostate biopsy. PHI was calculated as (p2PSA/fPSA) × âˆštPSA. Multivariable logistic regression analyses were used to predict the risk of cancer and detect clinically significant prostate cancer. RESULTS: 33 (27.0%) patients were confirmed with the diagnoses of prostate cancer by prostate biopsy. The levels of p2PSA, %p2PSA, and PHI showed statistically significant differences between prostate cancer patients and non-cancer patients. %p2PSA and PHI had the highest area under the receiver operating characteristic curve (AUC) of 0.723 and 0.772 (both p < 0.001), respectively, predicting cancer detection at biopsy than other predictors (tPSA, fPSA, %fPSA, and PSA density (AUC: 0.544, 0.538, 0.593, and 0.664, respectively). In multivariable logistic regression, %p2PSA had a statistical significant odds ratio 8.51 (p = 0.003) and PHI had an odds ratio with marginal significance 4.18 (p = 0.06). CONCLUSION: %p2PSA and PHI increased the diagnostic accuracy with significantly greater sensitivity and specificity than tPSA. We determined an optimal cut-off value of PHI among Taiwanese population. These findings support the usefulness in the decisional process of prostate biopsy.

cAMP Receptor Protein of Salmonella enterica Serovar Typhimurium Modulate Glycolysis in Macrophages to Induce Cell Apoptosis.

We studied the role of glycolysis in the mechanism of cAMP receptor protein-induced macrophage cell death of Salmonella enterica serovar Typhimurium (S. Typhimurium). Cell apoptosis, caspase-3, -8, -9 enzyme activity, and pyruvic acid, lactic acid, ATP, and hexokinase (HK) contents were determined after infection of macrophages with S. Typhimurium SL1344 wild-type and a cAMP receptor protein mutant strain. While cell apoptosis, caspase-3, -8, -9 enzyme activity, lactic acid, hexokinase, and ATP levels significantly changed by infection with crp mutants compared to the wild-type strain (P < 0.05). Our data suggest that the cAMP receptor protein of S. Typhimurium can modulate macrophage death by effecting glycolysis levels. This finding may help to elucidate the mechanisms of S. Typhimurium pathogenesis.

Nanoscale Zero-Valent Iron Decorated on Bentonite/Graphene Oxide for Removal of Copper Ions from Aqueous Solution.

The removal efficiency of Cu(II) in aqueous solution by bentonite, graphene oxide (GO), and nanoscale iron decorated on bentonite (B-nZVI) and nanoscale iron decorated on bentonite/graphene oxide (GO-B-nZVI) was investigated. The results indicated that GO-B-nZVI had the best removal efficiency in different experimental environments (with time, pH, concentration of copper ions, and temperature). For 16 hours, the removal efficiency of copper ions was 82% in GO-B-nZVI, however, it was 71% in B-nZVI, 26% in bentonite, and 18% in GO. Bentonite, GO, B-nZVI, and GO-B-nZVI showed an increased removal efficiency of copper ions with the increase of pH under a certain pH range. The removal efficiency of copper ions by GO-B-nZVI first increased and then fluctuated slightly with the increase of temperature, while B-nZVI and bentonite increased and GO decreased slightly with the increase of temperature. Lorentz-Transmission Electron Microscope (TEM) images showed the nZVI particles of GO-B-nZVI dispersed evenly with diameters ranging from 10 to 86.93 nm. Scanning electron microscope (SEM) images indicated that the nanoscale iron particles were dispersed evenly on bentonite and GO with no obvious agglomeration. The qe,cal (73.37 mg·g-1 and 83.89 mg·g-1) was closer to the experimental value qe,exp according to the pseudo-second-order kinetic model. The qm of B-nZVI and GO-B-nZVI were 130.7 mg·g-1 and 184.5 mg·g-1 according to the Langmuir model.

Function of the parotid gland in juvenile recurrent parotitis: a case series.

Our aim was to find out how the parotid gland functions in 44 patients with juvenile recurrent parotitis, and to assess the value of measuring the serum amylase activity. Clinical and personal details were recorded, and all patients had their serum amylase activity measured together with sialography during the chronic phase. The function of the gland was classified by sialographic images. The chi square test and Spearman's rank correlation coefficient were used in the statistical analyses. There was a significant association between the degree of glandular function and serum amylase activity (p=0.014). The patients with unilateral and bilateral disease differed significantly in their degree of glandular function (p=0.020), those with bilateral disease having poorer function. There were no significant correlations between other clinical variables and glandular function. Serum amylase activity is an important diagnostic variable in juvenile recurrent parotitis, and poor parotid function reflects the severity of the disease.

ATF2 translation is induced under chemotherapeutic drug-mediated cellular stress via an IRES-dependent mechanism in human hepatic cancer Bel7402 cells.

Activating transcription factor (ATF) 2 is a member of the ATF/cyclic AMP-responsive element binding protein family, which exhibits both oncogenic and tumor-suppressor functions. In our preliminary experiments, it was observed that the expression of the ATF2 protein was induced following treatment with adriamycin (ADR) and paclitaxel (PTX), which may be regulated by internal ribosome entry segment (IRES)-mediated translation. By constructing a bicistronic vector containing the ATF2 5'-untranslated region (UTR), it was demonstrated that the ATF2 5'-UTR contains an IRES and maps a 30-nucleotide (nt) sequence (from nt 299 to nt ~269), which was essential for the IRES activity. The ATF2 IRES activity exhibited significant variation in different cell lines. In addition, it was observed that ADR and PTX also induced ATF2 IRES activity in Bel7402 cells. The present study has demonstrated that ATF2 translation is initiated via IRES, which is upregulated by ADR and PTX, thus suggesting that the regulation of the IRES-dependent translation of ATF2 may be involved in effecting the cancer cell response to chemotherapeutic drugs-mediated cellular stress.

The effect of propofol and sevoflurane on antioxidants and proinflammatory cytokines in a porcine ischemia-reperfusion model.

OBJECTIVES: Ischemia-reperfusion (IR) features massive oxidative stress of tissues and cytokine response. Propofol and sevoflurane, both of which are commonly used anesthetics, are thought to have different antioxidant activities. The aim of this study is to delineate the influence of these two drugs on the production of free radicals and proinflammatory cytokines in IR conditions via in vitro and in vivo models. METHODS: An in vitro IR model was performed by incubating porcine cells (including mononuclear cells, and coronary and aortic smooth muscle cells) with either propofol 25 µM or sevoflurane 2% in the hypoxia chamber (1% O2, 37°C) for 1 hour, followed by room temperature air for 2 hours. Reactive oxygen species (ROS) and tumor necrosis factor-α (TNF-α) were also measured via flow cytometry and enzyme-linked immunosorbent assay methods, respectively. Ten pigs were used for the in vivo study. After anesthesia with either propofol (10-15 mg/kg/h) or sevoflurane (2%), internal carotid and femoral arterial catheters were inserted for direct blood pressure monitoring and blood sampling. The IR models were produced via descending thoracic aorta clamping for 1 hour and declamping for 2 hours during the procedure for left ventricular assist device implantation. Blood serum was sampled from upper and lower body vessels for ROS and TNF-α evaluation via thiobarbituric acid reacting substances method and enzyme-linked immunosorbent assay, respectively. RESULTS: The results showed significant reduction of both ROS and TNF-α levels in the propofol group in vitro IR model. However, there was no difference in lipid peroxidation and TNF-α level between propofol and sevoflurane for the in vivo IR model. CONCLUSION: We concluded that propofol, compared with sevoflurane, can significantly inhibit ROS formation on a cell level. In addition, propofol can significantly inhibit TNF-α formation of monocytes and coronary smooth muscle cells but not aortic smooth muscle cells.

Structural Insights into the Distinct Binding Mode of Cyclic Di-AMP with SaCpaA_RCK.

Cyclic di-AMP (c-di-AMP) is a relatively new member of the family of bacterial cyclic dinucleotide second messengers. It has attracted significant attention in recent years because of the abundant roles it plays in a variety of Gram-positive bacteria. The structural features that allow diverse bacterial proteins to bind c-di-AMP are not fully understood. Here we report the biophysical and structural studies of c-di-AMP in complex with a bacterial cation-proton antiporter (CpaA) RCK (regulator of the conductance of K(+)) protein from Staphylococcus aureus (Sa). The crystal structure of the SaCpaA_RCK C-terminal domain (CTD) in complex with c-di-AMP was determined to a resolution of 1.81 Å. This structure revealed two well-liganded water molecules, each interacting with one of the adenine bases by a unique H2Olp-π interaction to stabilize the complex. Sequence blasting using the SaCpaA_RCK primary sequence against the bacterial genome database returned many CpaA analogues, and alignment of these sequences revealed that the active site residues are all well-conserved, indicating a universal c-di-AMP binding mode for CpaA_RCK. A proteoliposome activity assay using the full-length SaCpaA membrane protein indicated that c-di-AMP binding alters its antiporter activity by approximately 40%. A comparison of this structure to all other reported c-di-AMP-receptor complex structures revealed that c-di-AMP binds to receptors in either a "U-shape" or "V-shape" mode. The two adenine rings are stabilized in the inner interaction zone by a variety of CH-π, cation-π, backbone-π, or H2Olp-π interaction, but more commonly in the outer interaction zone by hydrophobic CH-π or π-π interaction. The structures determined to date provide an understanding of the mechanisms by which a single c-di-AMP can interact with a variety of receptor proteins, and how c-di-AMP binds receptor proteins in a special way different from that of c-di-GMP.