Molecular epidemiology of PRRSV from China's Guangxi Province between 2007 and 2009.

Porcine reproductive and respiratory syndrome (PRRS) is considered to be one of the most important infectious diseases affecting livestock. This study used gene sequence analysis of ORF5 and Nsp2 to determine the molecular epidemiology of PRRSV in different parts of the Guangxi province of China. These genes were selected due to their extensive variation within the genome. Out of 189 samples from animals suspected to have PRRS, 145 were PRRSV RNA positive. ORF5 and Nsp2 gene sequence analysis of 31 of these samples showed that all of the Guangxi isolates were of type 2. A phylogenetic tree analysis based on ORF5 showed that the Guangxi isolates were divided into two groups. Most of these were closely related to highly pathogenic strains, showing a 30 amino acid deletion at positions 481 and 533-561 of Nsp2, but an additional unique isolate (GXNN06) possessed a further four amino acid deletion at positions 485-488 of Nsp2.

In vitro infection with classical swine fever virus inhibits the transcription of immune response genes.

BACKGROUND: Classical swine fever virus (CSFV) can evade the immune response and establish chronic infection under natural and experimental conditions. Some genes related to antigen processing and presentation and to cytokine regulation are known to be involved in this response, but the precise mechanism through which each gene responds to CSFV infection remains unclear. RESULTS: In this study, the amplification standard curve and corresponding linear regression equations for the genes SLA-2, TAP1, SLA-DR, Ii, CD40, CD80, CD86, IFN-α, and IFN-ß were established successfully. Real-time RT-PCR was used to quantify the immune response gene transcription in PK-15 cells post CSFV infection. Results showed that: (1) immune response genes were generally down-regulated as a result of CSFV infection, and (2) the expression of SLA-2, SLA-DR, Ii and CD80 was significantly decreased (p < 0.001). CONCLUSION: We conclude that in vitro infection with CSFV inhibits the transcription of host immune response genes. These findings may facilitate the development of effective strategies for controlling CSF.

Phylogenetic analysis of the E2 gene of classical swine fever virus from the Guangxi Province of southern China.

In this study, suspected classical swine fever (CSF) samples from the Guangxi Province of China were obtained from pigs with acute CSF, aborted fetuses, newborn pigs that died at 1-2 days of age, tonsils of healthy pigs, and leukocytes of immunized sows during 2001-2009. About 92 of 775 samples were found to be positive by RT-PCR, and 41 isolates were obtained. Phylogenetic analysis was performed on the 31 isolates by sequencing the E2 gene, and the isolates were found to cluster into two groups: (1) isolates from aborted fetuses (except GXGZ02), deceased newborn baby pigs, tonsils of healthy pigs, and leukocytes of immunized sows belonged to group 1.1, along with vaccine strain, HCLV, and standard virulent strain, Shimen, of China, and (2) 20 isolates from pigs with acute CSF belonged to group 2.1, 13 of which were clustered into subgroup 2.1b with isolates from other provinces of China, and 7 of which were clustered into subgroup 2.1a with isolates from Italy and Germany.

Endoplasmic reticulum stress caused by left ventricular hypertrophy in rats: effects of telmisartan.

INTRODUCTION: Studies have revealed that excessive endoplasmic reticulum (ER) stress leads to apoptosis. Although cardiomyocytes apoptosis contributes to the transition from left ventricular hypertrophy (LVH) to heart failure, it is unknown whether ER stress participates in the pathologic process. The authors first induced coarctation of the abdominal aorta in rats to induce LVH and then investigated the effect of telmisartan on the resulting ER stress. METHODS: Male Sprague-Dawley rats were randomly divided into 3 groups: sham operation, abdominal aortic coarctation (AAC) and AAC + telmisartan. Telmisartan (5 mg · kg · d) or vehicle was infused into the stomach 1 week after the operation. ER stress signaling pathway molecules and apoptosis were studied in pressure-overloaded hearts 9 weeks after AAC. RESULTS: Telmisartan significantly reduced LVH and interstitial fibrosis and improved left ventricular function compared with AAC alone. Cardiac markers of ER stress such as GRP78, C/EBP homologous protein, caspase-12 and phospho c-Jun NH2-terminal kinase were significantly increased in rats with AAC, and telmisartan significantly blunted these changes. Rats that received both telmisartan and AAC had less apoptosis due to ER stress. CONCLUSIONS: Increased ER stress might be responsible for enhanced cardiomyocyte apoptosis after aortic coarctation. Telmisartan may reduce ER stress and thereby attenuate both apoptosis and cardiac hypertrophy.

[Leaching behavior of heavy metal elements in lead-free solders].

Leaching behavior of heavy metal elements from Sn-3.5 Ag-0.5 Cu, Sn-3.5 Ag, Sn-0.5 Cu lead-free solders and their joints were investigated in typical acid, alkaline and saline corrosion solutions. It is found that for solder alloys, significant leaching of Sn was observed in NaCl saline solution, about two orders of magnitude higher than that in acid and alkaline solution. However, in the case of solder joints, more leaching of Sn was observed in acid solution from Sn-3.5 Ag/Cu and Sn-0.5 Cu/Cu joints, and in NaOH alkaline solution for Sn-3.5 Ag - 0.5 Cu joint.