Porcine reproductive and respiratory syndrome virus (PRRSV) has been recognized as one of the most important pathogens of pigs throughout the world. In 2006, more than 10 provinces of China have experienced an epizootic outbreak of pig diseases characterized by high fever, reddened skin and high morbidity and mortality. From June 2006 to April 2007, we have investigated some clinical samples in Hubei province by RT-PCR and cloned several major genes, N, GP5 and NSP2 gene, shown in this study. Phylogenetic analysis of these genes revealed that the highly pathogenic PRRSV variant, ZB, was responsible for 2006 emergent outbreak of pig disease in Hubei province similar with those variants isolated from other provinces in China in 2006, and belongs to the NA-type PRRSV. In the PRRSV variants, the N and GP5 shear about 90% identity with prototypic ATCC VR-2332 and some typical NA-type Chinese isolates, except the 2850bp NSP2 gene (only shares 65% identity with ATCC VR-2332). But they all shear more than and 97% identity with other highly pathogenetic Chinese PRRSV strains. Additionally, there are extensive amino acid (aa) mutations in the GP5 protein and 2 deletions in the Nsp2 protein when compared with the previous isolates. Most of the variants found in 2006 epizootic outbreak of pig diseases in China were the farthest variants from the typical NA-type PRRSV in phylogenetic distance, and these diversities may be responsible for the differences in the pathogenicity observed between these variants and original Chinese PRRSV strains.

Objective: To investigate the effect of recombinant human keratinocyte growth factor 2 (rhKGF-2) on lung tissue of rabbits with severe smoke inhalation injury. Methods: A total of 120 New Zealand rabbits were divided into 5 groups by random number table after being inflicted with severe smoke inhalation injury, with 24 rats in each group. Rabbits in the simple injury group inhaled air, while rabbits in the injury+phosphate buffer solution (PBS) group inhaled 5 mL PBS once daily for 7 d. Rabbits in injury+1 mg/kg rhKGF-2 group, injury+2 mg/kg rhKGF-2 group, and injury+5 mg/kg rhKGF-2 group received aerosol inhalation of 1 mg/kg, 2 mg/kg, and 5 mg/kg rhKGF-2 (all dissolved in 5 mL PBS) once daily for 7 d, respectively. On treatment day 1, 3, 5, and 7, blood samples were taken from the ear central artery of 6 rabbits in each group. After the blood was taken, the rabbits were sacrificed, and the tracheal carina tissue and lung were collected. Blood pH value, arterial oxygen partial pressure (PaO₂), arterial blood carbon dioxide pressure (PaCO₂), and bicarbonate ion were detected by handheld blood analyzer. The expressions of pulmonary surfactant-associated protein A (SP-A) and vascular endothelial growth factor (VEGF) in lung tissue were detected by Western blotting. Pathomorphology of lung tissue and trachea was observed by hematoxylin-eosin staining. Data were processed with analysis of variance of two-way factorial design and Tukey test. Results: (1) Compared with those in simple injury group, the blood pH values of rabbits in the latter groups on treatment day 1-7 had no obvious change (P>0.05). The PaO₂ of rabbits in injury+2 mg/kg rhKGF-2 group on treatment day 5 and 7 were (75.0±2.4) and (71.0±4.5) mmHg (1 mmHg=0.133 kPa), respectively, which were significantly higher than (62.0±6.8) and (63.0±3.0) mmHg in simple injury group (q=4.265, 8.202, P<0.05 or P<0.01). The PaO₂ of rabbits in injury+5 mg/kg rhKGF-2 group on treatment day 7 was (82.0±4.9) mmHg, which was significantly higher than that in simple injury group (q=6.234, P<0.01). Compared with that in simple injury group, the PaCO₂ of rabbits in injury+2 mg/kg rhKGF-2 group on treatment day 3 was significantly decreased (q=4.876, P<0.01) and significantly increased on treatment day 5 (q=5.562, P<0.01); the PaCO₂ of rabbits in injury+5 mg/kg rhKGF-2 group was significantly increased on treatment day 5 and 7 (q=5.013, 4.601, P<0.05 or P<0.01). Compared with that in simple injury group, the serum bicarbonate ion of rabbits in injury+1 mg/kg rhKGF-2 group on treatment day 7 was significantly increased (q=5.142, P<0.01); the serum bicarbonate ion of rabbits in injury+2 mg/kg rhKGF-2 group on treatment day 5 and 7 were significantly increased (q=4.830, 6.934, P<0.01); the serum bicarbonate ion of rabbits in injury+5 mg/kg rhKGF-2 group on treatment day 5 were significantly increased (q=3.973, P<0.05). (2) The expressions of SP-A in lung tissue of rabbits in simple injury group and injury+PBS group in each treatment time point were close (P>0.05). The expressions of SP-A in lung tissue of rabbits in injury+2 mg/kg rhKGF-2 group and injury+5 mg/kg rhKGF-2 group on treatment day 3 were 0.091±0.007 and 0.101±0.009, respectively, significantly higher than 0.069±0.009 in simple injury group (q=10.800, 13.580, P<0.01). The expressions of SP-A in lung tissue of rabbits in injury+1 mg/kg rhKGF-2 group, injury+2 mg/kg rhKGF-2 group, and injury+5 mg/kg rhKGF-2 group on treatment day 5 and 7 were 0.127±0.008, 0.132±0.006, 0.194±0.006, 0.152±0.017, 0.166±0.004, 0.240±0.008, significantly higher than 0.092±0.003 and 0.108±0.005 in simple injury group (q=6.789, 12.340, 17.900, 9.875, 31.480, 40.740, P<0.01). (3) On treatment day 1 and 5, there was no significant difference in the expression of VEGF in lung tissue of rabbits among the 5 groups (P>0.05). Compared with those in simple injury group, the expressions of VEGF in lung tissue of rabbits in injury+2 mg/kg rhKGF-2 group on treatment day 3 and 7 were significantly increased (q=4.243, 8.000, P<0.05 or P<0.01), and the expression of VEGF in lung tissue of rabbits in injury+5 mg/kg rhKGF-2 group on treatment day 7 was significantly increased (q=20.720, P<0.01). (4) On treatment day 1, the injury of rabbits in each group was similar, with a large number of neutrophils infiltrated and abscess formed in the alveolar and interstitial tissue, thickened alveolar septum, some collapsed alveolar and atelectasis; large area of tracheal mucosa was degenerated and necrotic, with a large amount of inflammatory exudates blocking in the cavity. On treatment day 3, the inflammation of lung tissue and trachea in each group were improved, but the inflammation in simple injury group and injury+PBS group was also serious. On treatment day 5, the inflammation in lung tissue and trachea of rabbits in injury+2 mg/kg rhKGF-2 group and injury+5 mg/kg rhKGF-2 group were improved much obviously than those in the other groups. On treatment day 7, the inflammation in lung tissue of rabbits in injury+5 mg/kg rhKGF-2 group alleviated obviously than those in the other groups, most alveoli had no obvious exudative fluid, the alveolar cavity was intact and clear, the local alveolar dilated like a cyst, and the alveolar septum thinning; the improvement of inflammation of trachea was more obvious than the other groups, the tracheal mucosa tended to be more complete, and few neutrophils were infiltrated in the endotracheal cavity. Conclusions Atomization inhalation of rhKGF-2 can improve the PaO₂ level of rabbits with severe smoke inhalation injury, reduce airway inflammation, increase the expression of SP-A and VEGF in lung tissue, thus promoting the repair of lung tissue.

Objective To investigate the characteristics of clinical cellular immunity and its relationship with prognosis in elderly patients with severe infection caused by Omicron variant.Methods The clinical data of 53 patients with Omicron variant infection admitted to the geriatric Intensive Care Unit of the First Affiliated Hospital of Kunming Medical University from December 2022 to February 2023 were retrospectively analyzed.The patients were divided into 22 survival cases and 31 death cases for comparison between the two groups.Logistic analysis is adopted to define the omicron variants of elderly severe infections prognostic factors and construct the ROC curve.Results Mu-ltivariate logistic analysis revealed that the independent risk factors were elevated IL-6(P = 0.043)and decreased absolute T lymphocyte count(P = 0.011).AUC value of ROC of IL-6,absolute T lymphocyte count and IL-6 combined with absolute T lymphocyte count was 0.818,0.796 and 0.887.Conclusion Elevated IL-6 and decreased absolute T lymphocyte count are independent risk factors for elderly severe patients with Omicron variant infections.

Objective To explore the public's cognition and attitude towards general medicine,general practitioners,and pre-hospital first-aid knowledge in Ludian County,Yunnan Province,to find out the training and learning methods that are more acceptable to the public for this kind of related knowledge,and to propose targeted solutions.Methods A complete random sampling survey was conducted among the nucleic acid collection office at the gate of the vegetable market from October 15,2022,to December 30,2022,and the outpatient clinic of Wenping Street Health Center from January 1,2023,to February 28,2023,by using electronic questionnaire and paper questionnaire.Results Nearly 50%of the people in Ludian County of Yunnan Province lack the knowledge of general medicine and pre-hospital emergency care,especially the knowledge of electrical defibrillation.People with higher education and the medical profession have a higher understanding of general medicine,and people with a higher understanding of general medicine are more willing to participate in pre-hospital emergency care.The average Ridit value is:very familiar with general medicine(0.774)>Knowledge of some general practices(0.565)>Never heard of general practice(0.400).The higher education level and the more comprehensive understanding of general medicine had a positive impact on participation in pre-hospital emergency care,with B values of 0.624 and 0.619,OR 95%CI of 1.867(1.544～2.257)and 1.857(1.298～2.657),respectively.Taking medical staff as a reference,the B value of medical students was = 0.942,P = 0.234,the difference was not significant,and the B value of non-medical professional population was all less than 0,the effect is negative.In addition,most people have a positive attitude towards learning pre-hospital first aid,and more than 70%of people are willing to learn and train related knowledge of pre-hospital first aid.Conclusions People in urban areas of Ludian County,Yunnan Province have poor understanding of general practice,low recognition of general practitioners,low demand for general practitioners,and lack of awareness of the importance of pre-hospital emergency treatment.Because of the cognitive differences among different groups,it is necessary to conduct specific training for different groups.