Structuring alginate/dopamine powder into macroscopic aerogel microsphere for exceptional removal of tetracycline from water: Performance and mechanisms.

Aerogel was selected as one of IUPAC Top Ten Emerging Technologies in Chemistry in 2022, and has attracted tremendous concerns of scientists in removal of emerging contaminants. In this work a novel Fe3+ cross-linked alginate aerogel (SA/DA-Fe3+) with multiple sorption sites were facilely fabricated and applied for highly efficient removal of tetracycline (TC) from water. Results showed that Fe3+ and DA cooperatively improve adsorption of TC and TC was efficiently removed over a broad pH range of 4-8. The kinetics process can be better described by a chemisorption controlled pseudo-second-order kinetics model and Langmuir isotherm equation with characteristics of monolayer coverage. The fitted qmax value of TC at ambient temperature was 804.6 mg g-1 higher than those of other reported adsorbents. Multiple interactions including π-π EDA, complexation, hydrogen bonding, electrostatic attraction, etc. were involved in adsorption process. Moreover, SA/DA-Fe3+ aerogel exhibited satisfactory stability, reusability, and recyclability for consecutive applications. Most importantly, after consecutively running for >1000 h with dynamic sorption capacity over 500 mg g-1, the packed-column was still not saturated, manifesting its great potentials for treating actual wastewaters. Thus, above superiorities make SA/DA-Fe3+ a promising candidate adsorbent for treating TC-containing wastewater.

Corrosion-Resistance Mechanism of TC4 Titanium Alloy under Different Stress-Loading Conditions.

Titanium alloys have now become the first choice of tubing material used in the harsh oil- and gas-exploitation environment, while the interaction of force and medium is a serious threat to the safety and reliability of titanium alloy in service. In this paper, different stresses were applied to TC4 titanium alloy by four-point bending stress fixture, and the corrosion behavior of TC4 titanium alloy was studied by high-temperature and high-pressure simulation experiments and electrochemical techniques, and the microscopic morphologies and chemical composition of the surface film layer on the specimen were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), to reveal the corrosion-resistance mechanism of TC4 titanium alloy under different stress-loading conditions. The results showed that the pits appeared on the specimens loaded with elastic stress, but the degree of pitting corrosion was still lighter, and the surface film layer showed n-type semiconductor properties with cation selective permeability. While the pits on the specimens loaded with plastic stress were deeper and wider in size, and the semiconductor type of the surface film layer changed to p-type, it was easier for anions such as Cl- and CO32- to adsorb on, destroy, and pass through the protective film and then to contact with the matrix, resulting in a decrease in corrosion resistance of TC4 titanium alloy.

Phytolith Assemblages as a Promising Tool for Quantitative Canopy Coverage Reconstruction in Subtropical Forests, China.

This study investigates the reliability of phytolith assemblage analysis for characterizing subtropical vegetation and explores the potential for using these modern phytolith-vegetation relationships for paleoenvironmental interpretation in southeastern China. The samples were collected from five common subtropical vegetation communities in the Daiyun Mountains, southeastern China, with the above-ground vegetation recorded at each plot. Constrained ordination analysis was used to determine the most important factor governing the variations in phytolith assemblages that could be quantitatively reconstructed with weighted averaging partial least squares regression (WAPLS). The relationship between modern phytolith assemblages and the parent vegetation, as well as production, dispersal, and taphonomic processes, was discussed. Results demonstrated that the main subtropical biomes in southeastern China could be well distinguished by soil phytolith assemblages. In particular, the overall amount of tree coverage was well represented by topsoil phytolith assemblages. Grass silica short cell phytoliths (GSSCP) tended to occur in higher proportions in open habitats (shrub-meadow) at higher elevations, whereas non-grass phytolith morphotypes attained higher frequencies under mixed and broadleaf forests at lower elevations. Human-induced deforestation might increase the frequency of GSSCP within the bulk phytolith assemblage. Our results constitute the primary phytolith reference data for the subtropical zone in southeastern Asia where vegetation change during the Holocene period, particularly forest shifts, anthropogenic deforestation, and early agriculture are poorly documented.

Monitoring the effect of microbial culture on cleaning and sanitizing of the external ventilator circuit.

This research aimed to investigate the microbial spectrum of microorganisms that cause ventilator-associated pneumonia (VAP) among ICU patients in the selected hospital, antimicrobial susceptibility, genetic diversity of common isolates, and the monitoring effect of microbial culture on cleaning and sanitizing of external ventilator circuits in order to reduce the occurrence of hospital infections. For this purpose, endotracheal aspirate (ETA) specimens were sampled from ICU patients with clinically suspected VAP in the hospital between August 2020 and August 2021 and then investigated for microbiological content. This was followed by Kirby-Bauer testing for determining drug sensitivity and ERIC-PCR for genotyping. Afterward, microbial culture was performed on cleaned, sanitized and dried ventilator external ventilator pipelines and those stored aseptically for 4 weeks to evaluate the cleaning and disinfection effect and measure the bacterial content. Results showed that in the 64 confirmed VAP cases, Klebsiella was the most frequently isolated organism, followed by P. aeruginosa and Acinetobacter baumannii, while Candida is the most widely isolated fungus. The antimicrobial susceptibility spectrum revealed that 40% of the isolates were multidrug-resistant (MDR). ERIC-PCR showed no genetic relationship between pneumococcal isolates. Through microbial culture, no pathogenic bacteria were detected among cleaned and sanitized ventilator external ventilator pipelines and those stored aseptically for 4 weeks, indicating a 100% pass rate. It was concluded that ventilators in intensive care units (ICU) are susceptible to contamination, exposing patients to bacterial contamination and other comorbidities. Gram-negative bacteria are the main pathogens of VAP, which are mostly multidrug-resistant. Clinical care measures for ventilators should be strengthened to reduce the incidence of ventilator microbial contamination and to improve accurate clinical diagnosis and correct antimicrobial therapy.

Promising Enzymes for Inhibitors Development Against COVID-19.

After the emergence of COVID-19 in 2019, it has now become a pandemic. COVID-19 has brought painful disasters to people all over the world. It not only threatens lives and health but also induces economic crises. At present, promising methods to eradicate COVID-19 mainly include drugs and vaccines. Enzyme inhibitors have always been a reliable strategy for the treatment of related diseases. Scientists worldwide have worked together to study COVID-19, obtained the structure of key SARS-CoV-2 associated enzymes, and reported the research of inhibitors of these enzymes. This article summarizes COVID-19-related enzyme inhibitors' recent development, mainly including 3CLpro, PLpro, TMPRSS2, and RdRp inhibitors, hoping to provide valuable weapons in the ensuing battle against COVID-19.

Diagnostic application of exome sequencing in Chinese children with suspected inherited kidney diseases.

Background: Inherited kidney diseases (IKDs) are a group of kidney diseases characterized by abnormal kidney structure or function caused by genetic factors, but they are not easily diagnosed in childhood due to either nonspecific symptoms and signs or clinically silent symptoms in the early stages until the progressive stages, even end-stages. Early diagnosis of IKDs is very urgent for timely treatment and improving outcomes of patients. So far, the etiological diagnosis has been accelerated with the advance of clinical genetic technology, particularly the advent of next-generation sequencing (NGS) that is not only a powerful tool for prompt and accurate diagnosis of IKDs but also gives therapy guidance to decrease the risk of unnecessary and harmful interventions. Methods: The patients presenting with urinalysis abnormalities or structural abnormalities from 149 Chinese families were enrolled in this study. The clinical features of the patients were collected, and the potentially causative gene variants were detected using exome sequencing. The clinical diagnostic utility of the genetic testing was assessed after more detailed clinical data were analyzed. Result: In total, 55 patients identified having causative variants by exome sequencing were genetically diagnosed, encompassing 16 (29.1%) autosomal dominant IKDs, 16 (29.1%) autosomal recessive IKDs, and 23 (41.8%) X-linked IKDs, with 25 unreported and 45 reported variants. The diagnostic yield was 36.9%. The utility of the exome sequencing was accessed, 12 patients (21.8%) were confirmed to have suspected IKDs, 26 patients (47.3%) discerned the specific sub-types of clinical category, and 17 patients (30.9%) with unknown etiology or lack of typical manifestations were reclassified. Conclusion: Our study supported that genetic testing plays a crucial role in the early diagnosis for children with IKDs, which affected follow-up treatment and prognostic assessment in clinical practice. Moreover, the variant spectrum associated with IKDs was expanded.

Anthropogenic impact on the organic carbon sources, transport and distribution in a subtropical semi-enclosed bay.

Suspended particulate organic carbon (POC) and sedimentary total organic carbon (TOC) in coastal areas play critical roles in the global carbon cycle, yet sources and dynamics of coastal POC and TOC have been affected by various anthropogenic activities such as aquaculture, sewage discharge, dam construction and land reclamation. To better understand the anthropogenic impacts on coastal organic carbon, this study was carried out in a representative semi-enclosed bay, Dongshan Bay, Southeast China. Through analyses of stable isotopic compositions of both POC (δ13CPOC and δ15NPN) and TOC (δ13CTOC and δ15NTN), the ratio of total organic carbon vs. total nitrogen (C/N), grain size, Chl-a concentrations and hydrological parameters, our study led to the following main findings: 1) During flood season, the distribution of δ13CPOC, δ13CTOC, δ15NPN and δ15NTN values within the bay did not follow the conventional land-sea transition pattern. This distribution pattern indicated more terrestrial organic matter input seaward, which contrasts with the conventional organic matter distribution along the estuarine gradient. 2) Using the organic δ13C, δ15N and C/N signatures of different endmembers, we found that the sources of organic matter deposited in the bay were strongly related to anthropogenic activities, including municipal wastewater discharge, aquaculture, land reclamation and sluice-dyke construction. Furthermore, 3) by applying the Grain Size Trend Analysis Model and the previously-estimated residual current directions, we suggested that human activities have not only altered the sources of organic matter to the semi-enclosed bays, but also significantly modified their transportation and deposition patterns, and might influence the ultimate fate of organic matter into and out of Dongshan Bay. The conclusions of this study should be applicable to similar coastal bays around the world.

Effects of different ozone treatments on the storage quality and stability of fresh peeled garlic.

In order to understand their impacts on the preservation of fresh garlic, varying concentrations of ozone gas and different storage temperatures were tested for this experiment. The results demonstrated that freshly peeled garlic was best preserved by an ozone concentration of 5 ppm and storage at 4 °C compared to other treatment groups. With these optimized conditions, after 25 days of storage, the weight of garlic decreased by only 1.89% and, under the same storage conditions, the water loss rate was only 65.17% that of the control group, with a decay rate of only 12.50%. The rate of decay in the blank control group was three times that of this group. The germination rate was also low: only 30.26%, which was 57.69% that of the blank control group. The hardness was measured at 7.48 kg cm-2, 19.79% higher than that of the blank group. The content of soluble solids was 9.15 g 100 mL-1, which was 10.27% higher than that of the blank group, again proving that the above storage parameters were effective. At the same time, the titratable acid (TA) in the garlic was 15.48%, which was 1.17 times that of the blank group and corresponds to the vitamin C content. Also, the content of diallyl trisulfide only decreased by 3.98% and was 11.2% higher (P < 0.01) than that of the blank group. Finally, the validity of this optimal result was also confirmed by sensory evaluation. These results, for garlic, support the application of ozone as a safe, non-thermal preservation technique benefiting both producers and consumers.

Genetic Diversity, Community Assembly, and Shaping Factors of Benthic Microbial Eukaryotes in Dongshan Bay, Southeast China.

Microbial eukaryotes are pivotal components of marine ecosystems. However, compared with the pelagic environments, the diversity distribution and the driving mechanisms of microbial eukaryotes in the marine sediments have rarely been explored. In this study, sediment cores were collected along a transect from inner to outer Dongshan Bay, Southeast China. By combining high throughput sequencing of small-subunit (SSU) rRNA gene with measurements on multiple environmental variables, the genetic diversity, community structure and assembly processes, and environmental shaping factors were investigated. Alveolata (mainly Ciliophora and Dinophyceae), Rhizaria (mainly Cercozoa), and Stramenopiles (mainly Bacillariophyta) were the most dominant groups in terms of both relative sequence abundance and operational taxonomic unit (OTU) richness. Grain size composition of the sediment was the primary factor determining the alpha diversity of microbial eukaryotes followed by sediment depth and heavy metal, including chromium (Cr), zinc (Zn), and plumbum (Pb). Geographic distance and water depth surpassed other environmental factors to be the primary factors shaping the microbial eukaryotic communities. Dispersal limitation was the primary driver of the microbial eukaryotic communities, followed by drift and homogeneous selection. Overall, our study shed new light on the spatial distribution patterns and controlling factors of benthic microbial eukaryotes in a subtropical bay which is subjected to increasing anthropogenic pressure.

An easy synthesis of nitrogen and phosphorus co-doped carbon dots as a probe for chloramphenicol.

Heteroatom doping in carbon dots (CDs) was found to be an efficient way to regulate the structure of electronic energy levels and enhance the fluorescence characteristics of CDs. Nevertheless, most reported fabrication processes of heteroatom-doped CDs are rigorous and complex. Herein, a facile and novel strategy was developed to rapidly prepare nitrogen and phosphorus co-doped CDs (N,P-CDs) using acetic acid as the carbon source, and arginine, 1,2-ethylenediamine (EDA) and diphosphorus pentoxide as the dopants, respectively. The optical, morphological and structural characterizations of the synthesized N,P-CDs were investigated via UV and photoluminescence spectroscopy, X-ray photoelectron spectroscopy, TEM, and FT-IR spectroscopy. The N,P-CDs display outstanding fluorescence stability under high ionic strength (1.6 M KCl), and long time UV irradiation, indicating that they can be used as favorable candidates for fluorescent probes. The fluorescence of N,P-CDs was selectively quenched by chloramphenicol (CAP) with a short response time. The linear range of the response to CAP was from 0.8 to 70 µM with a limit of detection of 0.36 µM (S/N = 3). Notably, the fabricated N,P-CDs were employed for the highly selective and sensitive detection of CAP in milk samples, indicating their potential applications in biologically related areas.

Honokiol alleviates acetaminophen-induced hepatotoxicity via decreasing generation of acetaminophen-protein adducts in liver.

AIM: Acetaminophen (APAP) overdose is the most frequent cause of drug-induced liver damage. Magnolia officinalis is a traditional hepatoprotective Chinese medicine and Honokiol (HO) is the major active constituent. The present study was to investigate the effect of HO on APAP-induced hepatotoxicity and related mechanisms. MAIN METHODS: Four groups of mice were subjected to treatment as vehicle, APAP, APAP + HO and APAP + HO + NRF2 inhibitor. The morphological and biochemical assessments were used to evaluate the hepatoprotective effects. The extent of APAP-protein adducts was determined through evaluate the hepatic content 3­(cystein­S­yl)acetaminophen (APAP-Cys), the hydrolysis products of APAP-protein adducts. The activities of CYP2E1, CYP1A2 and CYP3A4 were evaluated by cocktail incubation, and the protein expression levels of NRF2, GCLC, GCLM, GS and GST were evaluated by western blot analysis. KEY FINDINGS: Morphological and biochemical assessments clearly demonstrated that HO could alleviate APAP-induced liver damage. The hepatoprotective effect of HO was positively associated with the reduction of APAP-protein adducts. Further investigation suggested that HO induced inhibition of CYP 2E1 and CYP2A1 as well as upregulation of GSH co-contributed to the reduction of APAP-protein adducts. Furthermore, HO induced activations of NRF2 and its target enzymes, such as GCLC, GCLM and GST, gave rise to the upregulation of GSH. SIGNIFICANCE: Our results suggested that HO could alleviate APAP-induced liver damage through reducing the generation of APAP-protein adducts, which might be mediated by inhibiting the activity of CYP 2E1 and CYP2A1 as well as enhancing the generation of GSH via NRF2 pathway.

[Niemann-Pick disease type C caused by NPC1 mutation in a case].

OBJECTIVE: To delineate the clinical and genetic features of a Chinese boy suspected for Niemann-Pick disease type C. METHODS: The patient underwent clinical examination and was subjected to next generation sequencing. Suspected mutations were validated by Sanger sequencing. Potential impact of the novel mutation was predicted by SIFT, PolyPhen-2 and MutationTaster software. RESULTS: The child has featured hepatosplenomegaly, increased direct bilirubin, jaundiced skin and liver damage. DNA sequencing showed that he has carried compound heterozygous mutations of NPC1 gene, namely c.2728GG (p.P90R), which were inherited from his mother and father, respectively. The c.2728G>A (p.G910S) mutation was previously reported, while the c.269C>G (p.P90R) was a novel mutation. CONCLUSION: The child has suffered from Niemann-Pick disease type C due to mutations of NPC1 gene. Above finding has enriched the spectrum of NPC1 mutations and provided a basis for genetic counseling and prenatal diagnosis.

Influence of Nutritional Status on the Absorption of Polyphyllin I, an Anticancer Candidate from Paris polyphylla in Rats.

BACKGROUND AND OBJECTIVES: Protein-calorie malnutrition (PCM) is one of the most suffered complications in cancer patients. Polyphyllin I (PPI), a saponin isolated from rhizome of Paris polyphylla, is a potential candidate in cancer therapy. In this study, the influence of nutritional status on the absorption of PPI in rats was explored after oral administration. METHODS: PCM rats, namely mal-nourished (MN) rats, were induced from well-nourished (WN) rats by caloric restriction protocol. Intestinal absorption of PPI in WN and MN rats was evaluated by pharmacokinetic and intestinal perfusion methods. The potential mechanisms between two groups were investigated on the basis of intestinal permeability, intestinal efflux and PPI's depletions in vivo. The intestinal permeability was analyzed by determining the concentration of paracellular marker transport in serum and the expression of junction proteins in intestine. The intestinal efflux was evaluated through comparing the protein level of P-glycoprotein (P-gp) in intestine, and the depletions of PPI and/or generation of its metabolites in liver and intestines were analyzed by liquid chromatography triple quadrupole mass spectrometry (LC-MS/MS) method. RESULTS: Compared to WN rats, the oral systemic exposure of PPI was significantly increased in MN rats, evidenced by significant enhancement of maximum plasma concentration (Cmax) and area under the plasma concentration-time curve (AUC0-60h) by more than 2.51- and 3.71-folds as well as terminal elimination half-life (t1/2) prolonged from to 7.3 to 14.1 h. Further studies revealed that the potential mechanism might be associated with combined contribution of improved intestinal absorption and depressed deglycosylation of PPI in MN rats. Furthermore, enhanced intestinal absorption of PPI was benefited from increased intestinal permeability and decreased intestinal efflux in MN rats. Meanwhile, the former manifested as increased transport of paracellular marker and decreased junction proteins levels, while the later evidenced by reduced P-gp expression. CONCLUSIONS: The oral exposure of PPI was enhanced in MN rats, which suggested that nutritional status alters the absorption of PPI, and thus the dosage of PPI should be modified during the treatment of cancer patient with PCM.

[Influence of Ureaplasma Urealyticum Infection on Testicular Tissue Structure and Secretion Function in Rats].

OBJECTIVE: To study the influences of ureaplasma urealitycum (UU) infection on testicular tissue structure and secretion function in rats. METHODS: Forty clean grade male SD rats were randomly divided into the experiment group A (at 7 d after surgery), experiment group B (at 14 d after surgery), control group C (at 7 d after surgery) and control group D (at 14 d after surgery). There were 10 rats in each group. The experimental groups were injected with 0.6 mL UU4 through bladder. In the same way, the control groups were injected with the same volume of UU liquid medium. At day 7 and 14 after injection, the structures of testis of all rats were observed by light microscopy and spermatogenic cells by transmission electron microscopy. The content of testosterone in plasma and testicular fluid were detected by chemiluminescence method. RESULTS: The changes of inflammatory pathology (including the layer and amount of spermatogenic cell decreasing, inflammatory cell infiltrating and mature sperms decreasing) in the testis of group A and group B were found by light microscopy, and the inflammatory changes in group B were lighter than those in group A. The structures of testicular tissue in group C and group D were normal. The apoptosis performances of germ cell (including the cell membrane corrugated, nuclear chromatin concentration and nuclear rupture) in the testis of group A and group B were found by transmission electron microscopy, and the changes in group B were lighter than those in group A. The structures of germ cell in group C and group D were normal. The levels of plasma testosterone in group A and group B were significantly lower than that in group C and group D (P<0.01), the difference between group A and group B was not statistically significant. The testosterone level in testis interstitial fluid in group A was significantly lower than that in other groups (P<0.01), the differences between other groups were not statistical significant. CONCLUSIONS: The testicular tissue of UU infected rats can have various pathological damage and functional changes, further confirming that UU infection can cause male infertility. The pathological damage and functional changes of the testicular tissue of rats after UU infection can be gradually restored with the extension of the duration of the disease.

Staphylococcal enterotoxin B administration during pregnancy imprints the increased CD4:CD8 T-cell ratio in the peripheral blood from neonatal to adult offspring rats.

Our previous study demonstrated that Staphylococcal enterotoxin B (SEB) administration during pregnancy could alter the percentage of T cells subpopulation in the thymus of the neonatal rats; however, little is known about the effect of maternal SEB administration during pregnancy on T cells subpopulation in the peripheral blood of the offspring rats. In the present study, pregnant rats at gestational day 16 were intravenously injected with 15 µg SEB. The present study found that prenatal exposure to SEB significantly decreased the percentages of CD8 T cells in the peripheral blood of both neonatal rats on the fifth day after delivery and the adult offspring rats. Furthermore, it significantly increased the percentage of CD4 T cells as well as the ratios of CD4 to CD8 T cells in both neonatal and adult offspring rats. Prenatal exposure to SEB significantly decreased the expression levels of IL-4 and IFN-γ in the plasma of neonatal and adult offspring rats. Furthermore, SEB restimulation significantly increased the percentage of CD8 T cells and significantly decreased the percentage of CD4 T cells. These data suggest the prenatal exposure to SEB can imprint the increased CD4:CD8 T cell ratio in the peripheral blood from the neonate to adulthood through the decreased CD8 T cells and the increased CD4 T cells, and altered the response characteristics of CD4 and CD8 T cells to secondary SEB administration in the peripheral blood of the adult offspring rats.

Decreased Vß8.2 T-cells in neonatal rats exposed prenatally to Staphylococcal enterotoxin B are further deleted by restimulation in an in vitro cultured thymus.

Staphylococcal enterotoxin B (SEB) administration during adulthood can cause the anergy or deletion of variable portion of the ? chain (V?)?expressing T cells. However, the effect of maternal SEB administration during pregnancy on the thymocytes of neonatal rats remains to be elucidated. In the present study, pregnant rats at gestational day 16 were intravenously injected with 15 µg SEB. The present study revealed that prenatal exposure of SEB significantly increased the proportion of cluster of differentiation (CD)4?single positive (SP) T cells and decreased the proportions of CD8?SP, CD4+ V?8.2+ and CD8+ V?8.2+ T cells in the thymus of neonatal rats between day 0 and 5 after delivery. In an in vitro cultured thymus, SEB restimulation significantly increased the proportion of double positive cells and decreased the proportions of CD4?SP, CD8?SP, CD4+ V?8.2+ and CD8+ V?8.2+ T cells. Furthermore, the decreased V?8.2+ T?cells in neonatal rats exposed prenatally to SEB were further deleted by SEB restimulation in an in vitro cultured thymus. These data suggested the special response pattern of the remaining SEB?specific T cells to SEB restimulation in neonatal rats exposed prenatally to SEB.

Development of recombinant antigen array for simultaneous detection of viral antibodies.

Protein microarrays have been developed to study antibody reactivity against a large number of antigens, demonstrating extensive perspective for clinical application. We developed a viral antigen array by spotting four recombinant antigens and synthetic peptide, including glycoprotein G of herpes simplex virus (HSV) type 1 and 2, phosphoprotein 150 of cytomegalovirus (CMV), Rubella virus (RV) core plus glycoprotein E1 and E2 as well as a E1 peptide with the optimal concentrations on activated glass slides to simultaneously detect IgG and IgM against HSV1, HSV2, CMV and RV in clinical specimens of sera and cerebrospinal fluids (CSFs). The positive reference sera were initially used to measure the sensitivity and specificity of the array with the optimal conditions. Then clinical specimens of 144 sera and 93 CSFs were tested for IgG and IgM antibodies directed against HSV1, HSV2, CMV and RV by the antigen array. Specificity of the antigen array for viral antibodies detection was satisfying compared to commercial ELISA kits but sensitivity of the array varied relying on quality and antigenic epitopes of the spotting antigens. In short, the recombinant antigen array has potential to simultaneous detect multiple viral antibodies using minute amount (3 µl) of samples, which holds the particularly advantage to detect viral antibodies in clinical CSFs being suspicious of neonatal meningitis and encephalitis.

Suppression of apoptosis by pseudorabies virus Us3 protein kinase through the activation of PI3-K/Akt and NF-κB pathways.

The pseudorabies virus (PRV) is a major viral disease that causes huge economic loss in the pig industry globally. Most viruses have been found to generate anti-apoptotic factors that facilitate cell survival in the early stages of infection. This study aimed to investigate the anti-apoptotic effects of PRV and study the underlying mechanisms in the early stage of infection. We investigated and compared whether the two PRV Us3 isoforms, Us3a and Us3b, could block apoptosis induced by virus infection, and further identified molecules involved in the signaling pathways. Our results demonstrated that PRV elicits 3-phosphoinositide dependent protein kinase-1/phosphatidylinositide 3-kinases/Akt (PDK-1/PI3-K/Akt)- and nuclear factor-κB (NF-κB)-dependent signaling in the early stage of infection. Inhibition of the PI3-K/Akt or NF-κB pathway enhanced cell death but no effect was observed on virus replication or PRV gene expression. Transiently-expressed GFP- or His-tagged PRV Us3a and Us3b cDNA protect cells against PRV-, avian reovirus- or bovine ephemeral fever virus-induced apoptosis in the cell lines. Us3a and Us3b transient over-expression upregulated several anti-apopototic signaling events, and the anti-apoptosis activity of Us3a is greater than that of Us3b. Kinase activity-deficient point or double point mutated Us3a lost the kinase activity of Us3a, which showed that kinase activity is required for the anti-apoptosis effect of Us3. Akt and NF-κB activation still occurred in UV-inactivated PRV- and cycloheximide-treated cells. In vivo study showed that PRV-infected trigeminal ganglion increases the expression of anti-apoptosis signaling molecules, including Akt, PDK-1 and IκBα, which is a similar result to that seen in the in vitro experiments. Our study suggests that signaling mechanisms may play important roles in PRV pathogenesis.

Staphylococcal enterotoxin B and α­toxin induce the apoptosis of ECV304 cells via similar mechanisms.

Staphylococcal enterotoxin B (SEB) and α­toxin produced by Staphylococcus aureus (S. aureus) are important in the pathogenesis of diseases. In the present study, we investigated the effects of SEB and α­toxin on ECV304 cells. It was identified that both SEB and α­toxin were capable of inducing the apoptosis of ECV304 cells in a dose­ and time­dependent manner. In addition, SEB and α­toxin were able to induce the expression of TNF­α and the activation of caspase­3 and ­8 in the ECV304 cells. The inhibition of TNF­α (with its neutralizing antibody) and caspase­3 and ­8 [with the corresponding inhibitory peptides; z-N-acetyl-Asp-Glu-Val-Asp-aminomethyl-coumarin (DEVD)-fluoromethyl ketone (FMK) for inhibition of caspase­3 and z-N-acetyl-Ile-Glu-Thr-Asp (IETD)-FMK) for inhibition of caspase­8] significantly decreased the rates of cell apoptosis induced by SEB and α­toxin, but was not able to completely block the induced cell apoptosis. These data suggest that SEB and α­toxin induce ECV304 cell apoptosis via a similar mechanism, which is partially mediated by the extrinsic death pathway involving TNF­α and caspase­8. These results provide insights into the synergistic pathogenicity of SEB and α­toxin during S. aureus infection.

Role of α-toxin-induced apoptosis of umbilical vein endothelial cells in vertical infection of Staphylococcus aureus L-form.

OBJECTIVE: To investigate α-toxin-induced apoptosis of umbilical vein endothelial cells and explore its role in vertical infection of Staphylococcus aureus L-form. METHODS: HUV-EC-C cells exposed to different concentrations (0, 10, 30, 90, and 270 ng/ml) of α-toxin for different time lengths (0, 2, 4, 6, and 8 h) were examined for apoptosis using flow cytometry with Annexin V-PI staining. The levels of tumor necrosis factor-α (TNF-α) and the activities of, caspase-3 and caspase-8 in the cell culture were detected by ELISA and colorimetric method, respectively. α-Toxin-induced cell apoptosis was also analyzed in HUV-EC-C cells treated with a neutralizing antibody of TNF-α or with the inhibitory peptides of caspase-3 (zDEVD-FMK) and caspase-8 (zIETD-fmk). RESULTS: α-Toxin induced apoptosis of HUV-EC-C cells in a dose- and time-dependent manner and caused significantly enhanced expression of TNF-α and the activation of both caspase-3 and caspase-8. Inhibition of TNF-α with its neutralizing antibody and the inhibitory peptides of caspase-3 or -8 all significantly decreased α-toxin-induced cell apoptosis, and the caspase-3 inhibitor completely blocked α-toxin-induced cell apoptosis. CONCLUSION: α-Toxin-induced apoptosis is partially mediated by the extrinsic cell death pathway of TNF-α and caspase-8 and plays an important role in the vertical infection of S. aureus L-form to affect fetal growth and development.