Pathogenic Characterization of European Genotype Porcine Reproductive and Respiratory Syndrome Virus Recently Isolated in Mainland China.

BACKGROUND: Porcine reproductive and respiratory syndrome virus (PRRSV) is an important pathogen in pig that causes tremendous economic loss in the global swine industry. PRRSV is divided into the European and North American genotypes, with virulence ranging from apathogenic-moderately virulent to highly pathogenic. The emergence of new highly virulent type 1 strains and coexistence of the two genotypes complicate the differential diagnosis, disease prevention, and control of PRRSV. Although the emergence of a novel type 1 PRRSV strain in mainland China was first confirmed in 2011, there is no information available concerning the pathogenesis of this strain. OBJECTIVES: We sought to determine the pathogenesis of a newly emerged Chinese type 1 PRRSV strain HLJB1. METHODS: Pigs were infected with HLJB1 and characterized using serological and histopathological tests. RESULTS: HLJB1 infection induced transient chemosis, reddened conjunctiva, skin cyanosis, mild transient pyrexia, dyspnea, and tachypnea between 7 and 13 days post-infection. Gross pneumonic lesions were characterized by multifocal, tan-mottled areas. Lymph nodes and spleen were enlarged. Characteristic microscopic lesions consisted of pulmonary consolidation and alveolar septal thickening with red blood cell infiltration, depletion of splenic lymphocytes, and hyperplasia and activation of macrophage. No pigs infected with HLJB1 died during the experiment. CONCLUSION: Our findings indicate that Chinese type I PRRSV strain HLJB1 caused classic PRRSV-specific lesions. As it caused lower viremia in pigs compared with other classic type 1 isolates, HLJB1 is less virulent than other type I strains.

Efficient amplification of NK cells and their anti-tumor cytotoxic activity in vitro / 中国免疫学杂志

Objective:To efficiently amplify NK cells and determine their cytotoxic activity against a variety of tumor cell lines in vitro,thereby providing evidence for potential clinical application.Methods: PBMCs were isolated from adult peripheral blood and co-cultured with K562 cells that were genetically modified to express 4-1BBL,IL-15 and IL-21 on the surface for 15 days to effectively amplify NK cells.The total cell number and Purity of CD3-CD56+ cells were measured.Granzyme B and perforin expression of the amplified NK cells were detected by flow cytometry and real-time PCR.The anti-tumor effect on different cancer cells was evaluated.Results: This method obtained a more than 1.1×1010 CD3-CD56+ NK cells with 95% purity over a 15 day amplification procedure.The expanded NK cells could efficiently release granzyme B and Perforin.The cytotoxicity against different tumor cells was followed the order from strong to weak:gastric,pancreatic,cervical,ovarian and renal cancer cells,with the highest activity against gastric cancer cell line A549 (90% at E∶T=10∶1) (P<0.05).A time-dependent killing effect of activated NK cells on cervical,liver and pancreatic cancer cells was observed.Conclusion: This amplification procedure can consistently generate large amounts of pure NK cells with effective cytotoxic function against a variety of tumor cells.

Status and correlation between fatigue and health locus of control in COPD patients / 现代临床护理

Objective To investigate the status and correlation between fatigue and health locus of control in patients with chronic obstructive pulmonary disease ( COPD ) . Method The multidimensional fatigue symptom inventory-short form and health locus of control questionnaire were used to investigate the fatigue and health locus of control among 150 COPD patients. Results The score on fatigue was 78.82 ± 1.50, in the middle-high level. The two factors scored the higher were physical fatigue and activity. The total score on health locus of control was 61.76 ± 5.02, at a middle-low level. The dimensions of health locus of control, ranked in a descending way in scores, included external control by destiny and authorities and internal control. The scores on external control by destiny and authorities were positively related that of total score on fatigue (P<0.05 for both) and the score of internal control was negatively correlated (P<0.05). Conclusion The fatigue of COPD patients was at high level and the health locus of control was at middle level. In the clinical practice, nurses should pay attention to the enhancement of patients′health locus of control to help them take up health behaviors for the purpose of lowering their fatigue.

Adenovirus induced acute hepatitis in non-human primates after liver-directed gene therapy / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To define the mechanism of acute hepatitis in non-human primates after liver directed gene therapy.</p><p><b>METHODS</b>Differences in immune response exhibited by 8 rhesus monkeys receiving adenovirus (Ad) or lipofectamine-mediated gene transfer by various routes, the time course, and the nature of the specific immune responses to both adenoviral vectors and transgene products were studied using HE staining (H&E) and immunohistochemical staining.</p><p><b>RESULTS</b>The monkeys developed mild to moderate acute hepatitis 1 to 3 weeks after intravenous or intrabiliary injection of first generation replication-defective adenoviruses carrying the Escherichia coli lacZ gene. This was accompanied by adenovirus-mediated T-cell proliferation and neutralizing antibodies to the adenovirus. Increased numbers of CD3(+), CD4(+) and CD8(+) T-lymphocytes were detected in the diseased livers, while B-lymphocytes were absent. Hepatocytes demonstrated increased expression of beta 2-microglobulins (beta 2-MG) and HLA-DR antigens in the plasma membranes. The development of acute hepatitis and the accompanying immune abnormalities were delayed in immunosuppressed monkeys until after the discontinuation of immunosuppressive therapy. The monkeys infused with Ad. CMVluc showed more significant and longer durations of hepatitis than the monkeys infused with adenoviruses carrying the lacZ gene. Lipofectamine-mediated gene transfer was inefficient. There was neither lacZ expression nor significant immune response in the liver of monkeys infused with lipofectamine via the portal vein or the common bile duct.</p><p><b>CONCLUSION</b>Immune response to the hepatocytes in liver directed gene therapy is MHC class I restricted and T-cell mediated. Both adenoviral vectors and foreign genes are related to the liver damage. Mild to moderate hepatic inflammation seen with the E-1 deleted vector is reversible. Immunosuppression regimens may prolong transgene expression and delay the development of acute adenoviral hepatitis.</p>