Characterization of avain metapneumovirus subgroup C isolated from chickens in Beijing, China.

Avian metapneumovirus (aMPV) is an important causative agent that causes acute respiratory disease and egg-dropping in chickens and turkeys. Here, we characterized an aMPV subgroup C (aMPV/C) from 320-day-old broiler breeder chickens with severe respiratory diseases in Beijing, China, as evidenced by RT-PCR typing and confirmation of the nucleoprotein (N) gene sequence. The N gene sequence of the aMPV/C strain (designated BJ17) exhibited no deletions or insertions and possessed 94.6% to 99.6% identity to those of published aMPV/C isolates. The phylogenetic tree of the nucleotide sequences constructed using the neighbor-joining clustering method showed that the BJ17 strain formed one cluster with other aMPV/C viruses and formed one subcluster with published Chinese aMPV/C isolates regardless of Muscovy duck or chicken origins. Comparative analysis of the N proteins showed that a unique amino acid residue D at position 110 might be associated with regional distribution due to its occurrence in all the Chinese aMPV/C isolates only. Strain BJ17 was successfully isolated by cultured Vero cell passage and further inoculated in 3-wk-old specific-pathogen-free chickens for the examination of pathogenicity. Animal experimental results showed that BJ17-inoculated chickens had severe respiratory diseases and inflammatory lesions, as demonstrated by pathological changes and aMPV antigen in the nasal turbinate, tracheae, and lung tissues. These results enrich the available information regarding the epidemiology and pathogenicity of aMPV/C in chickens, which may facilitate the development of effective measures against aMPV/C infection in China.

Application of one-stage hybrid technique in treatment of pernicious placenta previa / 实用医学杂志

Objective To assess the value of one-stage hybrid technique for treatment of pernicious placenta previa. Methods 12 patients with pernicious placenta previa who had received simultaneously Cesarean section and temporary balloon occlusion of abdominal aorta or internal iliac artery in the hybrid operation room were included in this study. 12 patients with pernicious placenta previa who had preserved balloon ducts in internal iliac artery before Cesarean section were chosen as a control group. Balloons were filled to control hemorrhage during the procedure. The hemodynamic parameters including blood pressure and heart rate were monitored during the opera-tion. Surgical duration ,amount of blood loss ,amount of blood transfusion ,volume of infusion ,urine volume during the procedure,postoperative volume of blood loss within 24 hours,uterine hysterectomy rate and neonatal conditions were compared between the two groups. Results During the operation,the blood pressure and heart rate in hybrid group were more stable. The mean surgical duration was(72 ± 8)min,the intraoperative mean amount of blood loss was(620 ± 95)mL,the mean amount of blood transfusion was(550 ± 40)mL,the mean volume of infusion was(1850 ± 160)mL,the mean amount of blood loss in 24 h after the operation was(75 ± 9) mL in the hybrid group,which were significantly lower than those in the control group(P<0.05 for all comparisons). No serious complications occurred in any of the two groups after the operation. There were no significant differences in neonatal conditions between the two groups. Conclusions One-stage hybrid technique has an obvious effect in the control of intraoperative bleeding in patients with pernicious placenta previa. It is worth popularizing in the hospital whose conditions are permitted.

Regulatory role of ASK1 in porcine circovirus type 2-induced apoptosis.

Porcine circovirus type 2 (PCV2), a major causative agent of postweaning multisystemic wasting syndrome which is an emerging and important swine disease, can induce apoptotic responses in vitro and in vivo. However, the molecular mechanism of PCV2-induced apoptosis is not well understood. Apoptosis signal-regulating kinase 1 (ASK1), serves as an upstream enzyme that activates the JNK and p38 MAPK pathways, has been shown to play a target role in the regulation of apoptosis. Here, we showed that PCV2 infection induced ASK1 phosphorylation which preceded activation of JNK1/2 and p38 signaling in the cultured cells, and that the phosphatidylinostol 3-kinase (PI3K)/Akt signaling triggered by PCV2 infection limited the extent of JNK1/2 and p38 activation and thereby apoptotic cell death. Furthermore, inhibition of JNK and p38 activation is associated with PI3K-dependent negative-regulation of ASK1 in the PCV2-infected cells. These results indicate an important regulatory role of ASK1 in PCV2-induced apoptotic responses.

Avian metapneumovirus subgroup C infection in chickens, China.

Avian metapneumovirus causes acute respiratory tract infection and reductions in egg production in various avian species. We isolated and characterized an increasingly prevalent avian metapneumovirus subgroup C strain from meat-type commercial chickens with severe respiratory signs in China. Culling of infected flocks could lead to economic consequences.