RESUMO
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.
RESUMO
Objective To explore the clinical effect of patients of oral and maxillofacial space infection treated with improved closed negative pressure drainage combined with hyperbaric oxygen, and the possibility of using this method to decrease the hospital expenses. Methods 156 patients with oral and maxillofacial space infection were divided into control group, closed negative pressure drainage group and improved closed negative pressure drainage combined with hyperbaric oxygen group by random number table. 52 patients in each group. The granulation tissue growth time, the healing of wound, clinical effect of the 8thday, hospitalization days, wound healing time, antibiotic cost, average cost in hospital were recorded after treatment. Results The average wound healing time of patients in improved closed negative pressure drainage combined with hyperbaric oxygen group was(6.06 ± 0.23)days, while the granulation tissue growth time was(16.13 ± 2.89)days, both of them were much shorter than the control group[(15.46 ± 4.68)days and(28.60 ± 3.50)days respectively],as well as the closed negative pressure drainage group [(7.43 ± 0.75) days and (22.67 ± 4.34) days respectively], and the differences were statistically significant which the F values equaled to 6.213 and 8.451, P values all less than 0.05. The total healing rate of patients in closed negative pressure drainage group and improved closed negative pressure drainage combined with hyperbaric oxygen group were both 100.00%(52/52), the difference was statistically significant compared with control group (χ2=6.89, P<0.05). The average hospitalization days of the patients in the closed negative pressure drainage group and improved closed negative pressure drainage combined with hyperbaric oxygen group were (8.20 ± 1.49) days and (7.45 ± 0.42)days, the antibiotic cost were(5 068.34 ± 1 074.68)RMB and (5 001.00 ± 456.00) RMB, the average total cost were (9 457.43 ± 647.23)RMB and (9 249.00 ± 367.00)RMB, all these indexes were much lower that which in control group[(18.40 ± 5.89)days,(21 000.43 ± 2 036.48) RMB and (31 000.66 ± 2 711.36) RMB], and the differences were statistically significant, F values equaled to 15.221, 29.434 and 81.220 each, P values were all less than 0.01. Conclusions Improved closed negative pressure drainage combined with hyperbaric oxygen method could improve the clinical effect of patients with oral and maxillofacial space infection, speed up the granulation tissue, shorten the in-hospital time as well as reduce the medical cost.
