Impaired interferon response in senecavirus A infection and identification of 3Cpro as an antagonist.

Senecavirus A (SVA), a picornavirus, causes vesicular diseases and epidemic transient neonatal losses in swine, resulting in a multifaceted economic impact on the swine industry. SVA counteracts host antiviral response through multiple strategies facilitatng viral infection and transmission. However, the mechanism of how SVA modulates interferon (IFN) response remains elusive. Here, we demonstrate that SVA 3C protease (3Cpro) blocks the transduction of Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway to antagonize type I IFN response. Mechanistically, 3Cpro selectively cleaves and degrades STAT1 and STAT2 while does not target JAK1, JAK2, and IRF9, through its protease activity. Notably, SVA 3Cpro cleaves human and porcine STAT1 on a Leucine (L)-Aspartic acid (D) motif, specifically L693/D694. In the case of STAT2, two cleavage sites were identified: glutamine (Q) 707 was identified in both human and porcine, while the second cleavage pattern differed, with residues 754-757 (Valine-Leucine-Glutamine-Serine motifs) in human STAT2 and Q758 in porcine STAT2. These cleavage patterns by SVA 3Cpro partially differ from previously reported classical motifs recognized by other picornaviral 3Cpro, highlighting the distinct characteristics of SVA 3Cpro. Together, these results reveal a mechanism by which SVA 3Cpro antagonizes IFN-induced antiviral response but also expands our knowledge about the substrate recognition patterns for picornaviral 3Cpro.IMPORTANCESenecavirus A (SVA), the only member in the Senecavirus genus within the Picornaviridae family, causes vesicular diseases in pigs that are clinically indistinguishable from foot-and-mouth disease (FMD), a highly contagious viral disease listed by the World Organization for Animal Health (WOAH). Interferon (IFN)-mediated antiviral response plays a pivotal role in restricting and controlling viral infection. Picornaviruses evolved numerous strategies to antagonize host antiviral response. However, how SVA modulates the JAK-STAT signaling pathway, influencing the type I IFN response, remains elusive. Here, we identify that 3Cpro, a protease of SVA, functions as an antagonist for the IFN response. 3Cpro utilizes its protease activity to cleave STAT1 and STAT2, thereby diminishing the host IFN response to promote SVA infection. Our findings underscore the significance of 3Cpro as a key virulence factor in the antagonism of the type I signaling pathway during SVA infection.

Gut microbiota enhance energy accumulation of black-necked crane to cope with impending migration.

Less is known about the role of gut microbiota in overwintering environmental adaptation in migratory birds. Here, we performed metagenomic sequencing on fresh fecal samples (n = 24) collected during 4 periods of overwintering (Dec: early; Jan: middle I; Feb: middle II; Mar: late) to characterize gut microbial taxonomic and functional characteristics of black-necked crane (Grus nigricollis). The results demonstrated no significant change in microbial diversity among overwintering periods. Analysis of compositions of microbiomes with bias correction (ANCOM-BC) determined 15 Proteobacteria species enriched in late overwintering period. Based on previous reports, these species are associated with degradation of chitin, cellulose, and lipids. Meanwhile, fatty acid degradation and betalain biosynthesis pathways are enriched in late overwintering period. Furthermore, metagenomic binning obtained 91 high-quality bins (completeness >70% and contamination <10%), 5 of which enriched in late overwintering period. Carnobacterium maltaromaticum, unknown Enterobacteriaceae, and Yersinia frederiksenii have genes for chitin and cellulose degradation, acetate, and glutamate production. Unknown Enterobacteriaceae and Y. frederiksenii hold genes for synthesis of 10 essential amino acids required by birds, and the latter has genes for γ-aminobutyrate production. C. maltaromaticum has genes for pyridoxal synthesis. These results implied the gut microbiota is adapted to the host diet and may help black-necked cranes in pre-migratory energy accumulation by degrading the complex polysaccharide in their diet, supplying essential amino acids and vitamin pyridoxal, and producing acetate, glutamate, and γ-aminobutyrate that could stimulate host feeding. Additionally, enriched Proteobacteria also encoded more carbohydrate-active enzymes (CAZymes) and antibiotic resistance genes (ARGs) in late overwintering period. KEY POINTS: • Differences in gut microbiota function during overwintering period of black-necked cranes depend mainly on changes in core microbiota abundance • Gut microbiota of black-necked crane adapted to the diet during overwintering period • Gut microbiota could help black-necked cranes to accumulate more energy in the late overwintering period.

Development and application of a colloidal-gold dual immunochromatography strip for detecting African swine fever virus antibodies.

African swine fever (ASF) is an acute and highly contagious infectious disease caused by the African swine fever virus (ASFV). Currently, there is no vaccine against ASF worldwide, and no effective treatment measures are available. For this reason, developing a simple, rapid, specific, and sensitive serological detection method for ASFV antibodies is crucial for the prevention and control of ASF. In this study, a 1:1 mixture of gold-labeled p30 and p72 probes was used as the gold-labeled antigen. The p30 and p72 proteins and their monoclonal antibodies were coated on a nitrocellulose membrane (NC) as a test (T) line and control (C) line, respectively. A colloidal-gold dual immunochromatography strip (ICS) for ASFV p30 and p72 protein antibodies was established. The results showed that the colloidal-gold dual ICS could specifically detect ASFV antibodies within 5-10 min. There was no cross-reaction after testing healthy pig serum; porcine reproductive and respiratory syndrome virus (PRRSV), foot-and-mouth disease type A virus (FMDV-A), foot-and-mouth disease type O virus (FMDV-O), porcine circovirus type 2 (PCV-2), and classical swine fever virus (CSFV) positive sera. A positive result was obtained only for the positive control P1. The sensitivity of the test strips was 1:256, which was equivalent to that of commercially ELISA kits. Their coincidence rate with the two commercial ASFV ELISA antibodies detection kits was higher than 98%. The test strips were stably stored at 18-25 °C and 4 °C for 4 and 6 months, respectively. The colloidal-gold dual ICS prepared in this study had high sensitivity and specificity and were characterized by rapid detection, simple operation, and easy interpretation of results. Therefore, they are of great significance to diagnose, prevent, and control African swine fever. KEY POINTS: • We establish an antibody detection that is quick and can monitor an ASF infection. • We observe changes in two protein antibodies to dynamically monitor ASF infection. • We use diversified detection on a single test strip to detect both antibodies.

Foot-and-Mouth Disease Virus Capsid Protein VP1 Interacts with Host Ribosomal Protein SA To Maintain Activation of the MAPK Signal Pathway and Promote Virus Replication.

Foot-and-mouth disease virus (FMDV) is the causative agent of foot-and-mouth disease, a highly contagious, economically important viral disease. The structural protein VP1 plays significant roles during FMDV infection. Here, we identified that VP1 interacted with host ribosomal protein SA (RPSA). RPSA is a viral receptor for dengue virus and classical swine fever virus infections. However, the incubation of susceptible cells using the anti-RPSA antibodies did not block the infection of FMDV. Overexpression of porcine RPSA in the insusceptible cells could not trigger FMDV infection, suggesting that RPSA was not responsible for FMDV entry and infection. On the contrary, we found that overexpression of RPSA suppressed FMDV replication, and knockdown of RPSA enhanced FMDV replication. We further determined that FMDV infection activated the mitogen-activated protein kinase (MAPK) pathway and demonstrated that MAPK pathway activation was critically important for FMDV replication. RPSA negatively regulated MAPK pathway activation during FMDV infection and displayed an antiviral function. FMDV VP1 interacted with RPSA to abrogate the RPSA-mediated suppressive role in MAPK pathway activation. Together, our study indicated that MAPK pathway activation was required for FMDV replication and that host RPSA played a negatively regulatory role on MAPK pathway activation to suppress FMDV replication. FMDV VP1 bound to RPSA to promote viral replication by repressing RPSA-mediated function and maintaining the activation of MAPK signal pathway.IMPORTANCE Identification of virus-cell interactions is essential for making strategies to limit virus replication and refine the models of virus replication. This study demonstrated that FMDV utilized the MAPK pathway for viral replication. The host RPSA protein inhibited FMDV replication by suppressing the activation of the MAPK pathway during FMDV infection. FMDV VP1 bound to RPSA to repress the RPSA-mediated regulatory effect on MAPK pathway activation. This study revealed an important implication of the MAPK pathway for FMDV infection and identified a novel mechanism by which FMDV VP1 has evolved to interact with RPSA and maintain the activation of the MAPK pathway, elucidating new information regarding the signal reprogramming of host cells by FMDV.

The Pseudoknot Region of the 5' Untranslated Region Is a Determinant of Viral Tropism and Virulence of Foot-and-Mouth Disease Virus.

Foot-and-mouth disease virus (FMDV) is the causative agent of foot-and-mouth disease. It is characterized by genetic instability and different antigenic properties. The nonstructural protein 3A is a primary determinant of the tropism and virulence of Cathay topotype FMDVs. However, several other determinants are also speculated to be involved in viral tropism and virulence. Deletion of 43 nucleotides (nt) in the pseudoknot (PK) region of the 5' untranslated region (UTR) has been found to coexist with the identified 3A deletion in Cathay topotype FMDV genomes. In this study, we isolated an O/ME-SA/PanAsia lineage FMDV strain, O/GD/CHA/2015, that includes an 86-nt deletion in the PK region and shows a porcinophilic phenotype. To investigate the potential role of the PK region in viral pathogenicity, we generated a recombinant FMDV strain with an incomplete PK region and compared its virulence and pathogenesis to the intact FMDV strain in swine and bovines. Deletion of the 86 nt in the PKs had no major effects on the pathogenicity of the virus in swine but significantly attenuated its ability to infect bovine cells and cattle, indicating that the PK region is a newly discovered determinant of viral tropism and virulence. The role of the 43-nt deletion existing in the Cathay topotype FMDV was also investigated by evaluating the infection properties of genetically engineered viruses. Consistently, the 43-nt deletion in the PK region significantly decreased the pathogenicity of the virus in bovines. Overall, our findings suggest that the PK region deletion occurred naturally in the FMDV genome and that the PK region is highly associated with viral host range and functions as a novel determinant for FMDV pathogenesis.IMPORTANCE This study demonstrates that the deletion in the PK region occurred naturally in the FMDV genome. The isolated O/ME-SA/PanAsia lineage FMDV with an 86-nt deletion in the PK region showed a pig-adapted characteristic that could cause clinical signs in swine but not bovines. Compared to the wild-type FMDV strain, which possesses full infection capacity in both swine and bovines, the recombinant virus with the 86-nt deletion in the PK region is deficient in causing disease in bovines. Deletion of the previously reported 43 nt in the PK region also led to significantly decreased pathogenicity of FMDV in bovines. This study indicates that the PK region is a novel determinant of the tropism and virulence of FMDV.

Cellular DNAJA3, a Novel VP1-Interacting Protein, Inhibits Foot-and-Mouth Disease Virus Replication by Inducing Lysosomal Degradation of VP1 and Attenuating Its Antagonistic Role in the Beta Interferon Signaling Pathway.

DnaJ heat shock protein family (Hsp40) member A3 (DNAJA3) plays an important role in viral infections. However, the role of DNAJA3 in replication of foot-and-mouth-disease virus (FMDV) remains unknown. In this study, DNAJA3, a novel binding partner of VP1, was identified using yeast two-hybrid screening. The DNAJA3-VP1 interaction was further confirmed by coimmunoprecipitation and colocalization in FMDV-infected cells. The J domain of DNAJA3 (amino acids 1 to 168) and the lysine at position 208 (K208) of VP1 were shown to be critical for the DNAJA3-VP1 interaction. Overexpression of DNAJA3 dramatically dampened FMDV replication, whereas loss of function of DNAJA3 elicited opposing effects against FMDV replication. Mechanistical study demonstrated that K208 of VP1 was critical for reducing virus titer caused by DNAJA3 using K208A mutant virus. DNAJA3 induced lysosomal degradation of VP1 by interacting with LC3 to enhance the activation of lysosomal pathway. Meanwhile, we discovered that VP1 suppressed the beta interferon (IFN-ß) signaling pathway by inhibiting the phosphorylation, dimerization, and nuclear translocation of IRF3. This inhibitory effect was considerably boosted in DNAJA3-knockout cells. In contrast, overexpression of DNAJA3 markedly attenuated VP1-mediated suppression on the IFN-ß signaling pathway. Poly(I⋅C)-induced phosphorylation of IRF3 was also decreased in DNAJA3-knockout cells compared to that in the DNAJA3-WT cells. In conclusion, our study described a novel role for DNAJA3 in the host's antiviral response by inducing the lysosomal degradation of VP1 and attenuating the VP1-induced suppressive effect on the IFN-ß signaling pathway.IMPORTANCE This study pioneeringly determined the antiviral role of DNAJA3 in FMDV. DNAJA3 was found to interact with FMDV VP1 and trigger its degradation via the lysosomal pathway. In addition, this study is also the first to clarify the mechanism by which VP1 suppressed IFN-ß signaling pathway by inhibiting the phosphorylation, dimerization, and nuclear translocation of IRF3. Moreover, DNAJA3 significantly abrogated VP1-induced inhibitive effect on the IFN-ß signaling pathway. These data suggested that DNAJA3 plays an important antiviral role against FMDV by both degrading VP1 and restoring of IFN-ß signaling pathway.

Long-Term Efficacy of Deep Brain Stimulation of Bilateral Globus Pallidus Internus in Primary Meige Syndrome.

OBJECTIVE: Deep brain stimulation (DBS) of the internal segment of the globus pallidus (GPi) is an alternative therapy in ameliorating the clinical symptoms of primary Meige syndrome. Nevertheless, proof of its efficacy and safety is insufficient due to several case reports and small-sample clinical studies. This study aims to investigate postoperative long-term efficacy in patients undergoing DBS of the GPi for primary Meige syndrome. METHODS: We performed a retrospective study to assess the efficacy and safety of bilateral GPi stimulation in 40 patients with primary Meige syndrome who responded poorly to medical treatments or botulinum toxin injections. All participants were postoperatively followed up at the outpatient clinic, and their motor functions were assessed using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS). The severity of patients' dystonia was evaluated before surgery and at follow-up neurostimu-lation. RESULTS: The implanted stimulator was turned on 1 month after surgery. All 40 patients received monopolar stimulation using the following parameters: voltage 2.5-3.5 V (average: 2.6 ± 0.8 V), frequency 60-160 Hz (average: 88.0 ± 21.3 Hz), and pulse width 60-185 µS (average: 90.0 ± 21.1 µS). In 28 of 40 patients, the symptoms had signifi-cantly improved within 1 week of stimulation. Most of the patients had been followed up for 6-24 months (average: 15.0 ± 7.8 months). The clinical symptoms of all patients had significantly improved. At 6, 12, and 24 months after surgery, the BFMDRS subscores of eyes, mouth, speech, and swallowing were significantly lower, and subscores of mouth movement showed progressively decreased with prolonged stimulation time. The overall improvement rate was 83%. Five adverse events occurred in the 40 patients; all of these events resolved without permanent sequelae. CONCLUSIONS: Bilateral GPi-DBS demonstrated satisfactory long-term efficacy in the treatment of primary Meige syndrome and could serve as an effective and safe option.

[Analysis of digital gene expression profiles of the cultivated Polygala tenuifolia in different phenological phases].

The content changes of chemical components in different phenological phase of the cultivated Polygala tenuifolia is one of the important factors for determination of the best harvest time in the production practice. In this study, the digital gene expression (DGE) profiles of the cultivated P. tenuifolia were analyzed in different phenological phase (flowering fruit bearing stage, wilting stage, dormancy stage). The differentially expressed genes were found in the biosynthesis of chemical composition in P. tenuifolia, and the representational ones were validated by RT-q PCR. Then, the key enzymes(CYP450s and UGTs) involved in the downstream of the triterpenoid saponins biosynthesis pathway in P. tenuifolia were predicted through the correlation analysis of gene expression. The number of down-regulated genes was more than that of up-regulated in P. tenuifolia from flowering fruit bearing stage to dormancy stage. Six differentially expressed genes (HMGS, PMK, FPPS, SQS, SE, ß-AS) and five (PAL, C4 H, 4CL, CAD, peroxidase) were annotated to the triterpenoid saponins and phenylpropanoid biosynthesis pathway in P. tenuifolia, respectively. Compared to wilting and dormancy stages, the saponins, xanthones, and lignins were largely synthesized at the flowering fruit bearing stage of P. tenuifolia. Furthermore, UGT83A1, CYP716B1, CYP98A3, CYP86B1, and CYP94A1 may be the part of key enzymes in the downstream of the triterpenoid saponins biosynthesis pathway in P. tenuifolia. This study provides evidence to support the correctness of traditional harvest time of P. tenuifolia at the level of transcription, and lays the scientific foundation for gene cloning and functional verification of CYP450 s and UGTs in the downstream of the triterpenoid saponins biosynthesis pathway in P. tenuifolia in the future.

[Effects of different cavosurface margins on color matching of the resin composite].

OBJECTIVE: To evaluate effects of color matching of different cavosurface margins on the resin composites in vitro. METHODS: Twenty extracted human premolars with an A2 shade buccal surface were used in this study. Rectangular shaped cavities (3.0 mm depth, 2.0 mm width, 2.0 mm length) were prepared in the center of the buccal surfaces. The gingival and occlusal cavosurface margins were prepared to be either shoulder or bevel; the other cavosurface margins remained vertical. Ten teeth were filled with Clearfil AP-X (AP), the other ten with Clearfil Majesty (MJ) and light cured. The color difference at the cavosurface margin area was measured using a spectrophotometer (CrystalEye) and evaluated by 3 observers subjectively. The data were statistically analyzed using repeated measures ANOVA and Chi-square test. RESULTS: When measured by CrystalEye, the color difference between the tooth and resin composite was reduced from the center of restoration to the cavosurface margin area. Both objective and subjective evaluations showed that for AP, the color difference at the cavosurface margin area had no statistical difference among 3 types of the margins; for MJ, the color difference at bevel margin area was significantly smaller than that at the vertical margin area. CONCLUSION: The resin composite restorations produced the color matching at marginal area. The color matching of resin composites with higher diffused light transmission property is more susceptible to the type of cavosurface margins. Preparing bevels may reduce the color difference between the restoration and tooth surface.

Analysis of the interferences in quantitation of a site-specifically PEGylated exendin-4 analog by the Bradford method.

Protein modification has been found to affect the estimation of protein concentration in some of the traditional dye-based absorbance measurements. In this work, a distinct reduction in A595 was observed during the quantitation of a PEGylated exendin-4 analogue (Ex4C) by the Bradford method and the PEGylation process was found to interfere with the measurement. Lys(12), Arg(20), and Lys(27) were further proved to be the major amino acids that functioned as dye-binding sites. The shielding effect produced by the large polymer was demonstrated to depend on the length of PEG that was used for modification.

Boosting Upconversion Efficiency in Optically Inert Shelled Structures with Electroactive Membrane through Electron Donation.

This study innovatively addresses challenges in enhancing upconversion efficiency in lanthanide-based nanoparticles (UCNPs) by exploiting Shewanella oneidensis MR-1, a microorganism capable of extracellular electron transfer. Electroactive membranes, rich in c-type cytochromes, are extracted from bacteria and integrated into membrane-integrated liposomes (MILs), encapsulating core-shelled UCNPs with an optically inactive shell, forming UCNP@MIL constructs. The electroactive membrane, tailored to donate electrons through the inert shell, independently boosts upconversion emission under near-infrared excitation (980 or 1550 nm), bypassing ligand-sensitized UCNPs. The optically inactive shell restricts energy migration, emphasizing electroactive membrane electron donation. Density functional theory calculations elucidate efficient electron transfer due to the electroactive membrane hemes' highest occupied molecular orbital being higher than the valence band maximum of the optically inactive shell, crucial for enhancing energy transfer to emitter ions. The introduction of a SiO2 insulator coating diminishes light enhancement, underscoring the importance of unimpeded electron transfer. Luminescence enhancement remains resilient to variations in emitter or sensitizing ions, highlighting the robustness of the electron transfer-induced phenomenon. However, altering the inert shell material diminishes enhancement, emphasizing the role of electron transfer. This methodology holds significant promise for diverse biological applications. UCNP@MIL offers an advantage in cellular uptake, which proves beneficial for cell imaging.

Picornavirus VP3 protein induces autophagy through the TP53-BAD-BAX axis to promote viral replication.

Macroautophagy/autophagy and apoptosis are pivotal interconnected host cell responses to viral infection, including picornaviruses. Here, the VP3 proteins of picornaviruses were determined to trigger autophagy, with the autophagic flux being triggered by the TP53-BAD-BAX axis. Using foot-and-mouth disease virus (FMDV) as a model system, we unraveled a novel mechanism of how picornavirus hijacks autophagy to bolster viral replication and enhance pathogenesis. FMDV infection induced both autophagy and apoptosis in vivo and in vitro. FMDV VP3 protein facilitated the phosphorylation and translocation of TP53 from the nucleus into the mitochondria, resulting in BAD-mediated apoptosis and BECN1-mediated autophagy. The amino acid Gly129 in VP3 is essential for its interaction with TP53, and crucial for induction of autophagy and apoptosis. VP3-induced autophagy and apoptosis are both essential for FMDV replication, while, autophagy plays a more important role in VP3-mediated pathogenesis. Mutation of Gly129 to Ala129 in VP3 abrogated the autophagic regulatory function of VP3, which significantly decreased the viral replication and pathogenesis of FMDV. This suggested that VP3-induced autophagy benefits viral replication and pathogenesis. Importantly, this Gly is conserved and showed a common function in various picornaviruses. This study provides insight for developing broad-spectrum antivirals and genetic engineering attenuated vaccines against picornaviruses.Abbreviations: 3-MA, 3-methyladenine; ATG, autophagy related; BAD, BCL2 associated agonist of cell death; BAK1, BCL2 antagonist/killer 1; BAX, BCL2 associated X, apoptosis regulator; BBC3/PUMA, BCL2 binding component 3; BCL2, BCL2 apoptosis regulator; BID, BH3 interacting domain death agonist; BIP-V5, BAX inhibitor peptide V5; CFLAR/FLIP, CASP8 and FADD like apoptosis regulator; CPE, cytopathic effects; CQ, chloroquine; CV, coxsackievirus; DAPK, death associated protein kinase; DRAM, DNA damage regulated autophagy modulator; EV71, enterovirus 71; FMDV, foot-and-mouth disease virus; HAV, hepatitis A virus; KD, knockdown; MAP1LC3/LC3, microtubule associated protein 1 light chain 3; MOI, multiplicity of infection; MTOR, mechanistic target of rapamycin kinase; PML, promyelocytic leukemia; PV, poliovirus; SVA, Seneca Valley virus; TCID50, 50% tissue culture infectious doses; TOR, target of rapamycin. TP53/p53, tumor protein p53; WCL, whole-cell lysate.

Comparative analysis of cloned cDNAs encoding Chinese yellow cattle and Gansu black swine integrin receptors for foot-and-mouth disease virus.

To analyze foot-and-mouth disease virus tropism and host range with respect to the integrin receptor, we cloned cDNAs encoding the integrin αν, ß1, ß3, ß6 and ß8 subunits from Chinese yellow cattle and Gansu black swine and carried out comparative analysis of their molecular characteristics. The lengths of the mature proteins and the functional domains of the four integrin ß subunits were the same between bovine and swine; however, the number of putative N-linked glycosylation sites and cysteine residues and their arrangement varied. Homology analysis of the nucleotide and amino acid sequences showed that FMDV integrin receptors of Chinese yellow cattle and Gansu black swine are highly conserved. Phylogenetic analysis showed that all FMDV integrin receptor subunits of cattle and swine are clustered into the Artiodactyla group; however, Chinese yellow cattle are phylogenetically closer to sheep than to Gansu black swine. We postulate that the host tropism of FMDV may, in part, be related to the divergence of integrin subunits among different species.

[TG-fTIR study of the thermal-conversion properties of holo-cellulose derived from woody biomass].

Thermal-conversion properties of cellulose, hemi-cellulose and holo-cellulose derived from woody biomass were studied using TG-FTIR, and also compared to those of avicel cellulose and xylan. 3-D diffusion model was applied to calculate the kinetic parameters of thermal-conversion reaction of biomass materials, such as the activation energy, pre-exponential factors, etc, which showed good regression results. With the analysis of three-dimensional IR spectra of gas products, featured peaks of HzO, CO, CO2, CH4, and oxygenates were obviously observed where showing up with the maximum weight-loss rate in DTG curves. The possible forming routes of major gaseous products were analyzed and discussed. The order of releasing amounts for gaseous productions was approximately as CO2 > H2O > CO CH4. Based on the comprehensive understanding and comparative analysis of the whole results, it is concluded that the thermal conversion process of holo-cellulose was the result of interaction between cellulose and hemi-cellulose under the dominant role of cellulose.

[Research of implant accuracy using a digital registration method].

PURPOSE: The aim of this study was to introduce a new method to evaluate the clinical accuracy of implant position. The results were compared to traditional cone beam CT (CBCT) method. METHODS: A total of 36 implants from 24 patients with sufficient bone volume were enrolled into the study. CBCT method and digital registration method were compared to evaluate the accuracy of implant position. The measurement parameters were defined as deviations between ideal and postsurgical implant position at occlusal point(d1), apical point(d2) and axis(α). The deviations between two methods were analyzed with SPSS 19.0 software package. RESULTS: The deviations between ideal and postsurgical implant position using CBCT were (0.88±0.64) mm for occlusal point, (1.07±0.85) mm for apical point and (4.74±2.35)° for angle. In digital registration method, the deviations were (0.86±0.67) mm for occlusal point, (1.12±0.88) mm for apical point and (4.56±2.66)° for angle. No significant difference(P＞0.05) was found between the two methods. CONCLUSIONS: There was no significant difference between the two methods in evaluating the clinical accuracy of implant position. Digital registration method could be accepted in clinical application.

Degradation of Host Proteins and Apoptosis Induced by Foot-and-Mouth Disease Virus 3C Protease.

Foot-and-mouth disease (FMD), induced by the foot-and-mouth disease virus (FMDV), is a highly contagious disease of cloven-hoofed animals. Previous studies have reported that FMDV 3C protease could degrade multiple host proteins; however, the degradation mechanism mediated by FMDV 3C is still unclear. Here, we found that transient expression of FMDV 3C degraded various molecules in NF-κB signaling in a dose-dependent manner, and the proteolytic activity of FMDV 3C is important for inducing degradation. Additionally, 3C-overexpression was associated with the induction of apoptosis. In this study, we showed that an apoptosis inhibitor CrmA abolished the ability of 3C to degrade molecules in NF-κB signaling. Further experiments using specific caspase inhibitors confirmed the irrelevance of caspase3, caspase8, and caspase9 activity for degradation induced by 3C. Altogether, these results suggest that FMDV 3C induces the widespread degradation of host proteins through its proteolytic activity and that the apoptosis pathway might be an important strategy to mediate this process. Further exploration of the relationship between apoptosis and degradation induced by 3C could provide novel insights into the pathogenic mechanisms of FMDV.

The accuracy of healthcare worker versus self collected (2-in-1) Oropharyngeal and Bilateral Mid-Turbinate (OPMT) swabs and saliva samples for SARS-CoV-2.

BACKGROUND: Self-sampling for SARS-CoV-2 would significantly raise testing capacity and reduce healthcare worker (HCW) exposure to infectious droplets personal, and protective equipment (PPE) use. METHODS: We conducted a diagnostic accuracy study where subjects with a confirmed diagnosis of COVID-19 (n = 401) and healthy volunteers (n = 100) were asked to self-swab from their oropharynx and mid-turbinate (OPMT), and self-collect saliva. The results of these samples were compared to an OPMT performed by a HCW in the same patient at the same session. RESULTS: In subjects confirmed to have COVID-19, the sensitivities of the HCW-swab, self-swab, saliva, and combined self-swab plus saliva samples were 82.8%, 75.1%, 74.3% and 86.5% respectively. All samples obtained from healthy volunteers were tested negative. Compared to HCW-swab, the sensitivities of a self-swab sample and saliva sample were inferior by 8.7% (95%CI: 2.4% to 15.0%, p = 0.006) and 9.5% (95%CI: 3.1% to 15.8%, p = 0.003) respectively. The combined detection rate of self-swab and saliva had a sensitivity of 2.7% (95%CI: -2.6% to 8.0%, p = 0.321). The sensitivity of both the self-collection methods are higher when the Ct value of the HCW swab is less than 30. The specificity of both the self-swab and saliva testing was 100% (95% CI 96.4% to 100%). CONCLUSION: Our study provides evidence that sensitivities of self-collected OPMT swab and saliva samples were inferior to a HCW swab, but they could still be useful testing tools in the appropriate clinical settings.

Development of a hamster kidney cell line expressing stably T7 RNA polymerase using retroviral gene transfer technology for efficient rescue of infectious foot-and-mouth disease virus.

Reverse genetics systems, with the ability to manipulate viral genomes at the DNA molecular level, are an important platform for study of the assembly and function of viruses. Genome manipulation, such as gene recombination, mosaicism, and mutation may interfere with replication, assembly and release of viruses. An efficient, convenient and economical method of virus rescue is undoubtedly required for increasing the efficiency of rescuing recombinant viruses. To develop an efficient, helper virus-free viral recovery system (reverse genetics), a retroviral gene transfer technology was used to establish a stable BHK-21 cell line (designated as BHKT7) which expressed constitutively bacteriophage T7 RNA polymerase (T7 RNAP). An improved method for rescue of infectious foot-and-mouth disease virus (FMDV) was then developed. FMDV full-length cDNA under control of a T7 promotor, was transfected into BHKT7 of differing passages. FMDV virus was rescued efficiently from the BHKT7 cells, the passage number not having an effect on the efficiency of recovery. As a result, the cell line was stable even after multiple passages, expressing sufficient T7 RNAP to support ex vivo transcription and efficient rescue. The reverse genetics system described below is efficient, stable, and convenient. The system could provide not only the basis of gene function research into FMDV, but could also be used for reverse genetics research into other positive-strand RNA viruses, without the need for helper viruses.

Quantitative determination of pegylated consensus interferon in rhesus monkey serum using a competitive enzyme-linked immunosorbent assay.

A competitive enzyme-linked immunosorbent assay (ELISA) with generated mouse anti-consensus interferon (CIFN) antibody was developed for quantitative determination of pegylated consensus interferon (PEG-CIFN) in rhesus monkey serum. The operational concentrations of the original assay were determined using the chessboard method. ELISA working range was 10-5000 ng/ml, corresponding to a limit of quantification of 8.4 ng/ml in rhesus monkey serum. In a precision test, intra-assay CV ranged 1.8-9.6% and inter-assay CV ranged 3.5-12.7%. Relative recovery rate of this ELISA assay ranged from 102.65-115.77%, with RSD values ranging from 2.26-5.44%. Three groups of rhesus monkeys received 1250 microg/kg, 300 microg/kg, 150 microg/kg PEG-CIFN by subcutaneous administration, and blood samples were drawn via the femoral vein at the specified time points. PEG-CIFN in rhesus monkey serum was determined using the competitive ELISA, and the results were compared with antiviral activity assay. In conclusion, the competitive ELISA assay we developed has sufficient sensitivity, precision, and accuracy for the analysis of a rhesus monkey serum sample.

Demonstration of three injection methods for the analysis of extrinsic and intrinsic blood supply of the peripheral nerve.

BACKGROUND: The use of free vascularized nerve grafts requires an intimate and accurate knowledge of the blood supply of peripheral nerve. This study was designed to compare the advantages and disadvantages of three methods employed to reveal the blood supply of the peripheral nerve, and to provide morphological basis for vascularized nerve grafts. METHODS: The blood supply of brachial plexus and its main branches (ulnar, median, radial, musculocutaneous and axillary nerve) were observed using three vascular injection techniques: three specimens were injected with red latex through the thoracic aorta; two side specimens were injected with a Chinese ink solution, through the subclavian artery, for diaphanization and histology; one fresh cadaver was injected with the gelatin-lead oxide mixture through the femoral artery for radiography. RESULTS: The blood supply of the brachial plexus and its main branches was well examined using the three different vascular injection techniques. Perfusion with red latex exposed the extrinsic blood supply. Diaphanization and histology showed the intrinsic blood supply, while gelatin-lead oxide injection technique interactively displayed both the intrinsic and extrinsic blood supply to the peripheral nerve. CONCLUSION: The standard method for the study of the extrinsic blood supply to the peripheral nerve is the red latex perfusion; diaphanization and histology are very suitable to study the intrinsic blood supply of the peripheral nerve; while gelatin-lead oxide technique is the standard for visualization of the integral topography of the blood supply of the peripheral nerve.