Nonintubated spontaneous ventilation versus intubated mechanical ventilation anesthesia for video-assisted thoracic surgery in terms of perioperative complications and practitioners' workload assessments: a pilot randomized control study.

BACKGROUND: The use of nonintubated video-assisted thoracoscopic surgery (NI-VATS) has been increasingly reported to yield favourable outcomes. However, this technology has not been routinely used because its advantages and safety have not been fully confirmed. The aim of this study was to assess the safety and feasibility of nonintubated spontaneous ventilation (NI-SV) anesthesia compared to intubated mechanical ventilation (I-MV) anesthesia in VATS by evaluating of perioperative complications and practitioners' workloads. METHODS: Patients who underwent uniportal VATS were randomly assigned at a 1:1 ratio to receive NI-SV or I-MV anesthesia. The primary outcome was the occurrence of intraoperative airway intervention events, including transient MV, conversion to intubation and repositioning of the double-lumen tube. The secondary outcomes included perioperative complications and modified National Aeronautics and Space Administration Task Load Index (NASA-TLX) scores from anesthesiologists and surgeons. RESULTS: Thirty-five patients in each group were enrolled in the intention-to-treat analysis. The incidence of intraoperative airway intervention events was greater in the NI-SV group than in the I-MV group (12 [34.3%] vs. 3 [8.6%]; OR = 0.180; 95% CI = 0.045-0.710; p = 0.009). No significant difference was found in the postoperative pulmonary complications between the groups (p > 0.05). The median of the anesthesiologists' overall NASA-TLX score was 37.5 (29-52) when administering the NI-SV, which was greater than the 25 (19-34.5) when the I-MV was administered (p < 0.001). The surgeons' overall NASA-TLX score was comparable between the two ventilation strategies (28 [21-38.5] vs. 27 [20.5-38.5], p = 0.814). CONCLUSION: The NI-SV anesthesia was feasible for VATS in the selected patients, with a greater incidence of intraoperative airway intervention events than I-MV anesthesia, and with more surgical effort required by anesthesiologists. TRIAL REGISTRATION: Chinese Clinical Trial Registry, ChiCTR2200055427. https://www.chictr.org.cn/showproj.html?proj=147872 was registered on January 09, 2022.

Phosphoprotein Contributes to the Thermostability of Newcastle Disease Virus.

Newcastle disease (ND), caused by Newcastle disease virus (NDV), is highly contagious and represents a major threat to the poultry industry. The thermostable vaccines are not insensitive to heat and ease of storage and transportation, but the mechanism of NDV thermostability remains unknown. The phosphoprotein (P), fusion protein (F), hemagglutinin-neuraminidase protein (HN), and large polymerase protein (L) are associated with NDV virulence. The association between F, HN, or L and viral thermostability has been, respectively, studied in different reports. However, the effects of P on NDV thermostability have not been demonstrated. Here, we utilized an existing reverse genetics system in our laboratory, to generate chimeric viruses by exchanging the P protein between the thermostable NDV4-C strain and the thermolabile LaSota strain. Chimeric viruses were found to possess similar growth properties, passage stability, and virulence, as compared to those of these parental strains. Interestingly, the thermostability of the chimera with P derived from the thermolabile LaSota strain was reduced compared to that of the parental virus, and P of the thermostable NDV4-C strain enhanced chimeric virus thermostability. Our data demonstrate that P is an important factor for the thermostability of NDV and provides information regarding the molecular mechanism of NDV thermostability; moreover, these results suggest a theoretical basis for using the NDV4-C strain as a thermostable vaccine.

Effects of dexmedetomidine hydrochloride on hemodynamics, postoperative analgesia and cognition in cesarean section.

The present study aims to investigate the effects of dexmedetomidine hydrochloride (Dex) on hemodynamics, postoperative analgesia and cognition in cesarean section. One hundred and two pregnant women who underwent cesarean section were selected from August 2016 to July 2017 in People's Hospital of Zhangqiu District and randomly divided into control group and observation group. Control group was anesthetized with bupivacaine hydrochloride, and morphine + ropivacaine hydrochloride were given postoperatively. Observation group received intraoperative anesthesia with bupivacaine hydrochloride and Dex, and Dex + ropivacaine hydrochloride were given for postoperative analgesia. Hemodynamic factors were compared between the two groups. Postoperative Ramsay sedation score, the incidence of adverse reactions and the incidence of transient neurological syndrome (TNS) were compared between the two groups. Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) scoring were performed to evaluate the cognitive function of the two groups. The mean arterial pressure (MAP) and visual analogue scale (VAS) scores of the observation group after anesthesia were significantly lower than those of control group (P<0.05). The Ramsay sedation score of the observation group was significantly better than that of control group at different time-points after surgery (P<0.05). Incidence of postoperative agitation in observation group was significantly lower than that in control group (P<0.05). Incidence of TNS in observation group was significantly lower than that in control group during 1 week after surgery (P<0.05). MoCA and MMSE scores of the observation group were better than that of control group at 1 day after operation (P<0.05). The use of Dex anesthesia in cesarean section can achieve more stable hemodynamic conditions during perioperative period and more obvious analgesic effect after operation. It also reduced the incidence of postoperative TNS and cognitive dysfunction, and had important clinical significance.

Genetic, antigenic, and pathogenic characteristics of avian infectious bronchitis viruses genotypically related to 793/B in China.

In this study, 20 infectious bronchitis virus (IBV) strains, which were genotypically related to 793/B, as assessed by an S1 gene comparison and a complete genomic sequence analysis, were isolated and identified from 2009 to 2014 in China. Phylogenetic analysis, network tree, similarity plot analysis, Recombination Detection Program 4(RDP4) and sequence comparison revealed that 12 of the 20 isolates were likely the reisolated vaccine virus. One isolate, ck/CH/LSD/110857, was shown to have originated from recombination events between H120- and 4/91-like vaccine strains that did not result in changes of antigenicity and pathogenicity. The remaining seven IBV isolates were shown to have originated from recombination events between a 4/91-like vaccine strain and a GX-LY9-like virus, which were responsible for the emergence of a novel serotype. A vaccination-challenge test found that vaccination with the 4/91 vaccine strain did not provide protection against challenge with the recombinant viruses. In addition, the results showed that the recombination events between the vaccine and field strains resulted in altered genetics, serotype, antigenicity, and pathogenicity compared with those of their deduced parental viruses. The results are important not only because this virus is of economic importance to poultry industry, but also because it is important for elucidating the origin and evolution of other coronaviruses.

Genetic, antigenic, and pathogenic characteristics of Newcastle disease viruses isolated from geese in China.

Four Newcastle disease virus (NDV) strains were isolated from domestic, commercial geese that showed clinical signs that were believed to be the result of NDV infections. The genetic, antigenic, and pathogenic characteristics of the 4 NDVs were compared with those of NDV strains that were isolated from chickens. The complete genomes of 2 of the NDV strains contained 15,186 nucleotides (nt); the other 2 contained 15,192 nt, and exhibited the typical genomic organization of genotype II NDV and molecular characteristics of VIId NDVs. Phylogenetic analysis confirmed that the genotype II and VIId NDVs that were isolated from geese belonged to the same clusters as the corresponding genotypes of the chicken isolates. A serologic assay demonstrated that the antigenic relatedness among the NDVs was associated with their genotypes, rather than their hosts, and that amino acid substitutions in the F and/or HN proteins may contribute to the antigenic differences among these NDV genotypes. Geese infected with genotype VIId NDVs that were isolated from geese and chickens showed similar pathologic characteristics. NDVs that were isolated from geese did not differ in genetic, serologic, and pathogenic characteristics from those isolated from chickens, indicating that these NDVs were derived from chicken NDVs. Given the significance of geese in NDV epidemiology, effective biosecurity measures should be adopted to prevent the interspecies transmission of NDVs.

Serotype, antigenicity, and pathogenicity of a naturally recombinant TW I genotype infectious bronchitis coronavirus in China.

Since 2009, strains of the naturally recombinant TW I genotype of infectious bronchitis virus (IBV) have caused considerable damage to the Chinese poultry industry. To better understand the antigenicity and pathogenesis of this genotype, the characteristics of the ck/CH/LDL/140520 strain were compared to those of four commercial IB vaccine strains that are used commonly in China, as well as four attenuated viruses that represent two types of IBV strains, which are believed to have originated in China and are the predominant IBV types circulating in chicken flocks in China and many other parts of the world. The results showed that all eight strains were genetically and serotypically different from the strain ck/CH/LDL/140520. Furthermore, neither the vaccine strains nor the attenuated viruses could provide complete respiratory protection of chickens against a challenge with the ck/CH/LDL/140520 strain, indicating that it is necessary to develop new live vaccines or to evaluate the use of established vaccines in combination to control naturally recombinant TW I-type IBV strains in the future. Our results showed that strain ck/CH/LDL/140520 is very pathogenic, and that it is able to cause cystic oviducts in a high percentage of birds, as well as mortality due to nephritis and respiratory distress with complete tracheal ciliostasis, especially in chickens infected at 1day of age.

Isoflurane Preconditioning Induces Neuroprotection by Up-Regulation of TREK1 in a Rat Model of Spinal Cord Ischemic Injury.

This study aimed to explore the neuroprotection and mechanism of isoflurane on rats with spinal cord ischemic injury. Total 40 adult male Sprague-Dawley rats were divided into the four groups (n=10). Group A was sham-operation group; group B was ischemia group; group C was isoflurane preconditioning group; group D was isoflurane preconditioning followed by ischemia treatment group. Then the expressions of TWIK-related K⁺ channel 1 (TREK1) in the four groups were detected by immunofluorescent assay, real time-polymerase chain reactions (RT-PCR) and western blot. The primary neurons of rats were isolated and cultured under normal and hypoxic conditions. Besides, the neurons under two conditions were transfected with green fluorescent protein (GFP)-TREK1 and lentivirual to overexpress and silence TREK1. Additionally, the neurons were treated with isoflurane or not. Then caspase-3 activity and cell cycle of neurons under normal and hypoxic conditions were detected. Furthermore, nicotinamide adenine dinucleotide hydrate (NADH) was detected using NAD+/NADH quantification colorimetric kit. Results showed that the mRNA and protein expressions of TREK1 increased significantly in group C and D. In neurons, when TREK1 silenced, isoflurane treatment improved the caspase-3 activity. In hypoxic condition, the caspase-3 activity and sub-G1 cell percentage significantly increased, however, when TREK1 overexpressed the caspase-3 activity and sub-G1 cell percentage decreased significantly. Furthermore, both isoflurane treatment and overexpression of TREK1 significantly decreased NADH. In conclusion, isoflurane-induced neuroprotection in spinal cord ischemic injury may be associated with the up-regulation of TREK1.

Thoracic Paravertebral Block versus Epidural Anesthesia Combined with Moderate Sedation for Percutaneous Nephrolithotomy.

OBJECTIVE: To investigate the feasibility of thoracic paravertebral block (TPVB) for percutaneous nephrolithotomy (PCNL) in comparison with epidural anesthesia (EA) combined with moderate sedation. SUBJECTS AND METHODS: One hundred American Society of Anesthesiologists (ASA) I-II adult patients scheduled for first-stage unilateral PCNL were randomly assigned to receive either TPVB or EA. All patients were given standard sedation and analgesia with propofol and sufentanil. Patient characteristics, surgical outcomes, anesthetic outcomes, and time to first use of a patient-controlled intravenous analgesic (PCIA) device and postoperative consumption of sufentanil in the first 24 h were recorded. Intergroup differences of the parameters were analyzed using an independent t test, Mann-Whitney test, and χ2 test as appropriate. RESULTS: Patients who received TPVB consumed more propofol during ureteroscopy (56.2 ± 28.4 vs. 42.9 ± 27.5 mg, p < 0.05) and more sufentanil during ureteroscopy (9.7 ± 4.8 vs. 3.9 ± 2.7 µg, p < 0.05) and during PCNL (7.0 ± 4.3 vs. 1.9 ± 1.8 µg, p < 0.05) than those who received EA. The volume fluids infused in patients who received TPVB was less than in those who received EA (854 ± 362 vs. 1,320 ± 468 ml, p < 0.05). Time to first PCIA use, postoperative 24-hour consumption of sufentanil, and other parameters were comparable between groups. CONCLUSIONS: In this study, TPVB was as effective and safe as EA in providing intraoperative anesthesia and postoperative analgesia for PCNL, although more sedatives and analgesics were used during PCNL in patients who received TPVB.

Sex determination by SRY PCR and sequencing of Tasmanian devil facial tumour cell lines reveals non-allograft transmission.

Devil facial tumour disease (DFTD) is an infectious tumour disease and was hypothesised to be transmitted by allograft during biting based on two cytogenetic findings of DFTD tumours in 2006. It was then believed that DFTD tumours were originally from a female devil. In this study the devil sex-determining region Y (SRY) gene was PCR amplified and sequenced, and six pairs of devil SRY PCR primers were used for detection of devil SRY gene fragments in purified DFTD tumour cell lines. Using three pairs of devil SRY PCR primers, devil SRY gene sequence was detected by PCR and sequencing in genomic DNA of DFTD tumour cell lines from six male devils, but not from six female devils. Four out of six DFTD tumour cell lines from male devils contained nucleotides 288-482 of the devil SRY gene, and another two DFTD tumour cell lines contained nucleotides 381-577 and 493-708 of the gene, respectively. These results indicate that the different portions of the SRY gene in the DFTD tumours of the male devils were originally from the male hosts, rejecting the currently believed DFTD allograft transmission theory. The reasons why DFTD transmission was incorrectly defined as allograft are discussed.

Recombinant duck enteritis viruses expressing major structural proteins of the infectious bronchitis virus provide protection against infectious bronchitis in chickens.

To design an alternative vaccine for control of infectious bronchitis in chickens, three recombinant duck enteritis viruses (rDEVs) expressing the N, S, or S1 protein of infectious bronchitis virus (IBV) were constructed using conventional homologous recombination methods, and were designated as rDEV-N, rDEV-S, and rDEV-S1, respectively. Chickens were divided into five vaccinated groups, which were each immunized with one of the rDEVs, covalent vaccination with rDEV-N & rDEV-S, or covalent vaccination with rDEV-N & rDEV-S1, and a control group. An antibody response against IBV was detectable and the ratio of CD4(+)/CD8(+) T-lymphocytes decreased at 7 days post-vaccination in each vaccinated group, suggesting that humoral and cellular responses were elicited in each group as early as 7 days post-immunization. After challenge with a homologous virulent IBV strain at 21 days post-immunization, vaccinated groups showed significant differences in the percentage of birds with clinical signs, as compared to the control group (p < 0.01), as the two covalent-vaccination groups and the rDEV-S group provided better protection than the rDEV-N- or rDEV-S1-vaccinated group. There was less viral shedding in the rDEV-N & rDEV-S- (2/10) and rDEV-N & rDEV-S1- (2/10) vaccinated groups than the other three vaccinated groups. Based on the clinical signs, viral shedding, and mortality rates, rDEV-N & rDEV-S1 covalent vaccination conferred better protection than use of any of the single rDEVs.

Emergence of novel nephropathogenic infectious bronchitis viruses currently circulating in Chinese chicken flocks.

The emergence of novel infectious bronchitis viruses (IBVs) has been reported worldwide. Between 2011 and 2014, eight IBV isolates were identified from disease outbreaks in northeast China. In the current study we analysed the S1 gene of these eight IBV isolates in addition to the complete genome of five of them. We confirmed that these isolates emerged through the recombination of LX4 and Taiwan group 1 (TW1) viruses at two switch sites, one was in the Nsp 16 region and the other in the spike protein gene. The S1 gene in these viruses exhibited high nucleotide similarity with TW1-like viruses; the TW1 genotype was found to be present in southern China from 2009. Pathogenicity experiments in chickens using three of the eight virus isolates revealed that they were nephropathogenic and had similar pathogenicity to the parental viruses. The results of our study demonstrate that recombination, coupled with mutations, is responsible for the emergence of novel IBVs.

Altered pathogenicity of a tl/CH/LDT3/03 genotype infectious bronchitis coronavirus due to natural recombination in the 5'- 17kb region of the genome.

An infectious bronchitis coronavirus, designated as ck/CH/LGX/130530, was isolated from an IBV strain H120-vaccinated chicken in this study. Analysis of the S1 gene showed that isolate ck/CH/LGX/130530 was a tl/CH/LDT3/03-like virus, with a nucleotide sequence similarity of 99%. However, a complete genomic sequence analysis showed that ck/CH/LGX/130530 was more closely related to a Massachusetts type strain (95% similarity to strain H120) than to the tl/CH/LDT3/03 strain (86%), suggesting that recombination might have occurred during the origin of the virus. A SimPlot analysis of the complete genomic sequence confirmed this hypothesis, and it showed that isolate ck/CH/LGX/130530 emerged from a recombination event between parental IBV H120 strain and pathogenic tl/CH/LDT3/03-like virus. The results obtained from the pairwise comparison and nucleotide similarity showed that the recombination breakpoint was located in the nsp14 gene at nucleotides 17055-17083. In line with the high S1 gene sequence similarity, the ck/CH/LGX/130530 isolate was serotypically close to that of the tl/CH/LDT3/03 strain (73% antigenic relatedness). Furthermore, vaccination with the LDT3-A vaccine, which was derived from the tl/CH/LDT3/03 strain by serial passaging in chicken eggs, provided good protection against challenge with the tl/CH/LDT3/03 strain, in contrast to the poor protection offered with the H120 vaccine. Interestingly, isolate ck/CH/LGX/130530 exhibited low pathogenicity toward specific-pathogen-free chickens compared with the nephropathogenic tl/CH/LDT3/03 strain, which was likely due to natural recombination in the 5' 17-kb region of the genome. Our results also indicate that the replicase gene of IBV isolate ck/CH/LGX/130530 is associated with viral pathogenicity.

Comparative Evaluation of Remifentanil and Dexmedetomidine in General Anesthesia for Cesarean Delivery.

BACKGROUND Use of remifentanil and dexmedetomidine in general anesthesia for cesarean section have been described. This study was designed to evaluate the effects of remifentanil and dexmedetomidine on maternal hemodynamics and bispectral index, and neonatal outcomes in elective caesarean delivery. MATERIAL AND METHODS Forty-four women undergoing elective cesarean delivery with ASA I or II and term or near-term singleton pregnancies were randomly assigned to receive remifentanil at a loading dose of 2 µg/kg over 10 min followed by a continuous infusion of 2 µg/kg/h until about 6 min before fetal delivery (Group REM), or dexmedetomidine at a loading dose of 0.4 µg/kg over 10 min followed by a continuous infusion of 0.4 µg/kg/h until about 6 min before fetal delivery (Group DEX). Maternal hemodynamics and BIS values were recorded. Neonatal effects were assessed using Apgar scores and umbilical cord blood gas analysis. RESULTS Mean arterial pressure (MAP) increased after intubation in both groups, and the change magnitude of the MAP was higher in Group DEX (P<0.05). Patients in Group DEX had a lower BIS value at recovery and consumed less propofol during surgery (P<0.05). The incidences of neonatal resuscitation at 1 min were 81.8% in Group REM and 54.5% in Group DEX (P=0.052). There was no significant difference in either group in Apgar scores at 1 and 5 min and umbilical cord blood gas values. CONCLUSIONS Both remifentanil and dexmedetomidine are effective to blunt hemodynamic responses to intubation and also seem safe for neonates at the administrated doses, but remifentanil still has the potential to cause neonatal transient respiratory depression.

Dexmedetomidine-midazolam versus Sufentanil-midazolam for Awake Fiberoptic Nasotracheal Intubation: A Randomized Double-blind Study.

BACKGROUND: Awake fiberoptic intubation (AFOI) is usually performed in the management of the predicted difficult airway. The aim of this study was to evaluate the feasibility of dexmedetomidine with midazolam (DM) and sufentanil with midazolam (SM) for sedation for awake fiberoptic nasotracheal intubation. METHODS: Fifty patients with limited mouth opening scheduled for AFOI were randomly assigned to two groups (n = 25 per group) by a computer-generated randomization schedule. All subjects received midazolam 0.02 mg/kg as premedication and airway topical anesthesia with a modified "spray-as-you-go" technique. Group DM received dexmedetomidine at a loading dose of 0.5 µg/kg over 10 min followed by a continuous infusion of 0.25 µg·kg-1·h-1, whereas Group SM received sufentanil at a loading dose of 0.2 µg/kg over 10 min followed by a continuous infusion of 0.1 µg·kg-1·h-1. As necessary, since the end of the administration of the loading dose of the study drug, an additional dose of midazolam 0.5 mg at 2-min intervals was given to achieve a modified Observers' Assessment of Alertness/Sedation of 2-3. The quality of intubation conditions and adverse events were observed. RESULTS: The scores of ease of the AFOI procedure, patient's reaction during AFOI, coughing severity, tolerance after intubation, recall of the procedure and discomfort during the procedure were comparable in both groups (z = 0.572, 0.664, 1.297, 0.467, 0.895, and 0.188, respectively, P > 0.05). Hypoxic episodes similarly occurred in the two groups, but the first partial pressure of end-tidal CO2after intubation was higher in Group SM than that in Group DM (45.2 ± 4.2 mmHg vs. 42.2 ± 4.3 mmHg, t = 2.495, P < 0.05). CONCLUSIONS: Both dexmedetomidine and sufentanil are effective as an adjuvant for AFOI under airway topical anesthesia combined with midazolam sedation, but respiratory depression is still a potential risk in the sufentanil regimen.

Molecular and antigenic characteristics of Massachusetts genotype infectious bronchitis coronavirus in China.

In this study, 418 IBVs were isolated in samples from 1717 chicken flocks. Twenty-nine of the isolates were classified as the Massachusetts genotype. These 29 isolates, as well as two previously isolated Massachusetts genotype IBV strains, were studied further. Of the 31 strains, 24 were H120-like and two were M41-like isolates as determined by complete genomic sequence analysis, indicating that most of the IBV isolates were likely the reisolated vaccine virus. The remaining five IBV isolates, ck/CH/LHB/111172, ck/CH/LSD/111219, ck/CH/LHB/130598, ck/CH/LDL/110931, and ck/CH/LHB/130573, were shown to have originated from natural recombination events between an H120-like vaccine strain and other types of viruses. The virus cross-neutralization test found that the antigenicity of ck/CH/LHB/111172, ck/CH/LSD/111219, and ck/CH/LHB/130598 was similar to that of H120. Vaccination with the H120 vaccine offered complete protection against challenge with these isolates. However, isolates ck/CH/LDL/110931 and ck/CH/LHB/130573 were serotypically different from their parental viruses and from other serotypes in this study. Furthermore, vaccination with the H120 vaccine did not provide protection against challenge with these two isolates. The results of this study demonstrated that recombination is the mechanism that is responsible for the emergence of new serotype strains, and it has the ability to alter virus serotypes. Therefore, IBV surveillance of chicken flocks vaccinated with IBV live vaccines, as well as the consideration of new strategies to effectively control IBV infection using inactivated or/and genetically engineered vaccines, is of great importance.

Serotype shift of a 793/B genotype infectious bronchitis coronavirus by natural recombination.

An infectious bronchitis coronavirus, designated as ck/CH/LHLJ/140906, was isolated from an infectious bronchitis virus (IBV) strain H120-vaccinated chicken flock, which presented with a suspected infectious bronchitis virus (IBV) infection. A phylogenetic analysis based on the S1 gene clustered ck/CH/LHLJ/140906 with the 793/B group; however, a pairwise comparison showed that the 5' terminal of the S1 gene (containing hypervariable regions I and II) had high sequence identity with the H120 strain, while the 3' terminal sequence was very similar to that of IBV 4/91 strain. A SimPlot analysis of the complete genomic sequence, which was confirmed by a phylogenetic analysis and nucleotide similarities using the corresponding gene fragments, suggested that isolate ck/CH/LHLJ/140906 emerged from multiple recombination events between parental IBV strains 4/91 and H120. Although the isolate ck/CH/LHLJ/140906 had slightly higher S1 amino acid sequence identity to strain 4/91 (88.2%) than to strain H120 (86%), the serotype of the virus was more closely related to that of the H120 strain (32% antigenic relatedness) than to the 4/91 strain (15% antigenic relatedness). Whereas, vaccination of specific pathogen-free chickens with the 4/91 vaccine provided better protection against challenge with ck/CH/LHLJ/140906 than did vaccination with the H120 strain according to the result of virus re-isolation. As the spike protein, especially in the hypervariable regions of the S1 domain, of IBVs contains viral neutralizing epitopes, the results of this study showed that recombination of the S1 domain resulted in the emergence of a new serotype.

Molecular and antigenic characteristics of Newcastle disease virus isolates from domestic ducks in China.

Newcastle disease (ND) is one of the most devastating diseases to the poultry industry. The causative agents of ND are virulent strains of Newcastle disease virus (NDV), which are members of the genus Avulavirus within the family Paramyxoviridae. Waterfowl, such as ducks and geese, are generally considered potential reservoirs of NDV and may show few or no clinical signs when infected with viruses that are obviously virulent in chickens. However, ND outbreaks in domestic waterfowl have been frequently reported in many countries in the past decade. In this study, 18 NDV strains isolated from domestic ducks in southern and eastern China, between 2005 and 2013, were genetically and phylogenetically characterized. The complete genomes of these strains were sequenced, and they exhibited genome sizes of 15,186 nucleotides (nt), 15,192 nt, and 15,198 nt, which follow the "rule of six" that is required for the replication of NDV strains. Based on the cleavage site of the F protein and pathogenicity tests in chickens, 17 of our NDV isolates were categorized as lentogenic viruses, and one was characterized as a velogenic virus. Phylogenetic analysis based on the partial sequences of the F gene and the complete genome sequences showed that there are at least four genotypes of NDV circulating in domestic ducks; GD1, AH224, and AH209 belong to genotypes VIId, Ib, and II of class II NDVs, respectively, and the remaining 15 isolates belong to genotype 1b of class I NDVs. Cross-reactive hemagglutination inhibition tests demonstrated that the antigenic relatedness between NDV strains may be associated with their genotypes, rather than their hosts. These results suggest that though those NDV isolates were from duck, they still don't form a phylogenetic group because they came from the same species; however, they may play an important role in promoting the evolution of NDVs.

Genomic characteristics and changes of avian infectious bronchitis virus strain CK/CH/LDL/97I after serial passages in chicken embryos.

BACKGROUND: We previously attenuated the infectious bronchitis virus (IBV) strain CK/CH/LDL/97I and found that it can convey protection against the homologous pathogenic virus. OBJECTIVE: To compare the full-length genome sequences of the Chinese IBV strain CK/CH/LDL/97I and its embryo-passaged, attenuated level to identify sequence substitutions responsible for the attenuation and define markers of attenuation. METHODS: The full-length genomes of CK/CH/LDL/97I P5 and P115 were amplified and sequenced. The sequences were assembled and compared using the MEGALIGN program (DNAStar) and a phylogenetic tree was constructed using MEGA4 software. RESULTS: The CK/CH/LDL/97I virus population contained subpopulations with a mixture of genetic mutants. Changes were observed in nsp4, nsp9, nsp11/12, nsp14, nsp15, nsp16, and ORF3a, but these did not result in amino acid substitutions or did not show functional variations. Amino acid substitutions occurred in the remaining genes between P5 and P115; most were found in the S region, and some of the nucleotide mutations resulted in amino acid substitutions. Among the 9 nsps in the ORF1 region, nsp3 contained the most nucleotide substitutions. CONCLUSIONS: Sequence variations in different genes, especially the S gene and nsp3, in the genomes of CK/CH/LDL/97I viruses might contribute to differences in viral replication, pathogenicity, antigenicity, immunogenicity, and tissue tropism.

Infection of equine monocyte-derived macrophages with an attenuated equine infectious anemia virus (EIAV) strain induces a strong resistance to the infection by a virulent EIAV strain.

The Chinese attenuated equine infectious anemia virus (EIAV) vaccine has successfully protected millions of equine animals from EIA disease in China. Given that the induction of immune protection results from the interactions between viruses and hosts, a better understanding of the characteristics of vaccine strain infection and host responses would be useful for elucidating the mechanism of the induction of immune protection by the Chinese attenuated EIAV strain. In this study, we demonstrate in equine monocyte-derived macrophages (eMDM) that EIAVFDDV13, a Chinese attenuated EIAV strain, induced a strong resistance to subsequent infection by a pathogenic strain, EIAVUK3. Further experiments indicate that the expression of the soluble EIAV receptor sELR1, Toll-like receptor 3 (TLR3) and interferon ß (IFNß) was up-regulated in eMDM infected with EIAVFDDV13 compared with eMDM infected with EIAVUK3. Stimulating eMDM with poly I:C resulted in similar resistance to EIAV infection as induced by EIAVFDDV13 and was correlated with enhanced TLR3, sELR1 and IFNß expression. The knock down of TLR3 mRNA significantly impaired poly I:C-stimulated resistance to EIAV, greatly reducing the expression of sELR1 and IFNß and lowered the level of infection resistance induced by EIAVFDDV13. These results indicate that the induction of restraining infection by EIAVFDDV13 in macrophages is partially mediated through the up-regulated expression of the soluble viral receptor and IFNß, and that the TLR3 pathway activation plays an important role in the development of an EIAV-resistant intracellular environment.