Doxycycline Induces Mitophagy and Suppresses Production of Interferon-ß in IPEC-J2 Cells.

Previous reports have demonstrated that the second-generation tetracycline derivative doxycycline (DOX) interrupts mitochondrial proteostasis and physiology, inhibits proliferation of many cell types, and induces apoptosis. However, the effects of DOX, which is widely used in porcine husbandry by feed, on the porcine intestinal epithelium are unclear. In this study, we demonstrated that DOX damaged mitochondrial morphology and induced the co-localization of mitochondria with autophagosomes, suggesting that DOX induces mitophagy in IPEC-J2 cells. We also found evidence that DOX increased intracellular levels of reactive oxygen species (ROS) or mitochondrial-specific ROS in a dose dependent manner. Moreover, 50 µg/ml DOX significantly decreased production of interferon-ß and facilitated replication of transmissible gastroenteritis coronavirus in IPEC-J2 cells. These results demonstrated that DOX induced mitophagy and ROS production, which damaged the intestinal epithelium. As DOX is used extensively in pig husbandry, uncontrolled application poses a significant threat of viral infection, so stricter policies on its usage should be required.

Complete genomic sequence of the coronavirus transmissible gastroenteritis virus SHXB isolated in China.

A strain of transmissible gastroenteritis virus (TGEV), SHXB, was isolated in Shanghai, China. The complete genome of strain SHXB was sequenced, and its sequence was compared those of other TGEV strains in the GenBank database. The comparison showed that there were no insertions or deletions in the 5' and 3'- non-translated regions, in the nonstructural genes ORF1, ORF3, and ORF7, or in the genes encoding the structural proteins envelope (E), membrane (M) and nucleoprotein (N). A phenomenon in common with other strains was that nucleotide (nt) 655 of the spike (S) gene was G, and a common change in nt 1753 of the S gene was a T-to-G mutation that caused a serine-to-alanine mutation at amino acid 585, which is in the region of the main major antigenic sites A and B of the TGEV S protein. A 6-nt deletion was also found at nt 1123-1128 in all Purdue strains except the strain Virulent Purdue. Phylogenetic analysis showed that TGEV SHXB was closely related to the Purdue strains and shared a common ancestor with the Miller strains as well as strain PRCV-ISU-1.

Co-administration of inactivated avian influenza virus with CpG or rIL-2 strongly enhances the local immune response after intranasal immunization in chicken.

Intranasal delivery of vaccines is the most effective means of inducing effective immunity in the upper respiratory tract as well as other mucosal lymphoid tissues. To evaluate the effects of the H5N2 inactivated virus with adjuvant, 120 one-day-old chicks were intranasal immunized with the H5N2 inactivated virus respectively mixed with adjuvant CpG or recombinant IL-2 (rIL-2). The local immunocompetent cells on the respiratory tract were detected. The results showed that the number of intraepithelial lymphocytes (IELs), CD3(+) T lymphocytes and mast cells in respiratory tract increased significantly respectively and the number of IgA and IgG secreting cells increased significantly after immunization. However, there was no significant change in the immunocompetent cells of the animals administrated H5N2 inactivated virus alone compared to the control group. Our results indicated that intranasal administration of H5N2 inactivated virus with adjuvant CpG or rIL-2 could be beneficial to the local immune response in the respiratory tract.

Biphasic effects of propofol on the percentage of alpha2-band power of quantitative pharmaco-electroencephalography of rabbits / 中国组织工程研究

BACKGROUND: Quantitative pharmaco-electroencephalography (QPEEG) can reflect cerebral cortical function, which can be certainly affected by general anesthetics. Anesthesia depth has good correlation with the anesthetic dosage, so if we can find out the areas of brain and band of QPEEG which is relative to the anesthetic dosage, the band may be taken as the index to reflect the depth of anesthesia. OBJECTIVE: To observe the effects of propofol on the alpha2-band (α2- band) of QPEEG in rabbits. DESIGN: A randomized control animal experiment. SETTING: Jiangsu Provincial Key Laboratory of Anesthesiology, Xuzhou Medical College. MATERIALS: The experiment was carried out in the animal laboratory of Xuzhou Medical College from October 2004 to August 2005. Thirtysix healthy adult rabbits were randomly divided into propofol 2.5, 5 and 10 mg/kg groups with 12 rabbits in each, including 6 were used to observe the change of percentage of each band power of QPEEG, and the other 6 were used to observe the latency and duration for the disappearance of righting reflex in the rabbits. METHODS: The experiment was performed between 14:00-17:00 every day. Rabbits in the three groups were treated with intravenous injection of propofol of 2.5, 5 and 10 mg/kg respectively within 30 seconds. ① The conscious rabbits were fixed onto the platform in a prone osition, and the QPEEG was recorded with the method of power spectrum analysis before administration and at 20, 30, 40, 50, 60, 70, 80, 90, 100 and 110 s and 2, 5, 10, 15, 20 and 30 minutes after administration respectively. The sampling time for each time point was 5 s. ② The latency and duration for the disappearance of righting reflex in the rabbits were recorded. RESULTS: ll the 36 rabbits were involved in the analysis of esults. ① After the intravenous injection of propofol, the righting reflexes all disappeared within 1 minute. The greater the dosage, the shorter the latency and the longer the duration r=0.79, P ＜ 0.01). ② Compared with before administration, propofol of 2.5 mg/kg had no obvious influence on the percentage of α2-band power (P ＞ 0.05); The percentages of α2-band power in the brain areas were increased after administration in the propofol 5 mg/kg group (P ＜ 0.05); Except that there were no significant differences in the left and right parietal regions between the propofol 10 mg/kg group and the propofol 5 mg/kg group, the percentages of α2-band power in the other brain areas in the propofol 10 mg/kg group were decreased as compared with those before administration and those in the other two groups (P ＜ 0.05), and the changes above were more obvious in the frontal and temporal regions.CONCLUSION: The influence of propofol on the percentage of α2-band power of QPEEG is biphasic, it is suggested that α2-band would be an index to reflect the anesthesia depth of propofol.

Distributive Properties and Susceptibility of Clinical Candida spp Isolates to Antifungal Agents / 中华医院感染学杂志

OBJECTIVE To study the distributive properties and susceptibility of yeasts to six antifungal agents. METHODS To analyze the distributive properties of 264 clinical Candida spp isolates and study the susceptibility to amphotericin B,nystatin,fluconazole,ketoconazole,miconazole and clotrimazole.The susceptibility of yeasts was tested according to the National Committee for Clinical Laboratory Standards guideline(NCCLS M27-A2). RESULTS Strains of Candida albicans were the most frequent organism isolated accounted for 62.5% of all the isolates.C.tropicalis,C.glabrata,and C.parapsilosis accounted for 20.8%,12.5%,and 1.9%,the others accounted for only 2.3%.The main infected organs were lungs,urinary tract,and digestive tract;the susceptibility tests showed strains of Candida spp to nystatin,amphotericin B,and fluconazole were more active than to the other antifungal agents.The resistance to triazole antifugal agents could be shown. CONCLUSIONS We should strengthen the diagnosis of Candida spp and strengthen the surveillance on susceptibility of clinical isolates Candida spp so as to help the doctors choose the antifungal agents reasonably.

Study on Biological Effects of Songzike Acidic Polysaccharide / 中草药

The biological effects of Songzike acidic polysaccharide (ST90) were studied in vivo and vitro. It was found that ST90 had distinct antineoplastic, antibacterial and antiviral effects.I markedly inhibits proliferation of S180 solid tumor in mice and reduces the mortality of mice infected by Salmonella typhimurium, and shows a protective effect on FL cells infected with adva、adv7, vsv and CB4.