We applied a new teaching mode,combining problem-based learning (PBL) with extended teaching in clinical internship and case discussion,in order to adapt to the new situation in infectious diseases.The teaching efficacy was evaluated by questionnaire and classroom effect.The results showed that the new mode cultivated the students' self-learning ability and broadened their professional perspective.

ABSTRACT:In this study ,we elucidated the predictors of progression to liver failure during severe acute exacerbation .We analyzed 69 consecutive patients with severe acute exacerbation of chronic hepatitis B for clinical outcome and factors that influ‐enced the development of liver failure ,including viral genotype ,PC (G1896A) and BCP (A1762T/G1764A) mutants .Thirty‐three (47 .8% ) severe acute exacerbation patients progressed to liver failure .Multivariate analysis identified serum bilirubin (TB>256 μmol/dL ,P=0 .008) and prothrombin activity (PTA<40% ,P<0 .001) as significant determinants of progression to liver failure .HBeAg negativity (P=0 .065) and PC mutant (P=0 .090) were associated with the progression to hepatic de‐compensation .Serum total bilirubin ,prothrombin activities ,HBeAg status and PC mutant were predictors of clinical outcome in patients with severe acute exacerbation of chronic hepatitis B .

Objective To explore the etiologies of fever of unknown origin(FUO)and methods for confirming di-agnosis in patients at a hospital,and provide reference for clinical diagnosis and treatment of FUO.Methods Pa-tients with FUO admitted to a hospital between January 2008 and July 2014 were performed clinical diagnosis with methods of serology,bacteriology,molecular biology,bone marrow aspiration,tissue biopsy,and diagnostic thera-py,the etiologies and final diagnosis of 224 patients were analyzed retrospectively.Results Of 224 FUO cases,189 (84.38%)eventually got confirmed diagnosis,35 (15.62%)were not confirmed.The percentage of infectious dis-eases,connective tissue diseases,malignant tumor,and other diseases were 50.45%,18.75%,9.82%,and 5.36%respectively.Among infectious diseases,the major pathogens were bacteria,followed by virus.The major connec-tive tissue diseases were systemic lupus erythematosus and polyarteritis nodosa;the main malignant tumor was he-matological tumor,lymphoma was the main form.Among 189 patients with confirmed diagnosis,30.16% and 24.34% were performed pathogenic and pathologic detection respectively,and 20.11% were performed the other (compre-hensive)methods.Conclusion Infectious diseases,connective tissue diseases,and tumor are major etiologies of FUO.

Objective:To investigate the clinical characteristics and prognosis of the patients with nocardiosis.Methods:From January 2013 to July 2019, 44 patients with nocardiosis in Department of Infectious Diseases, Huashan Hospital, Fudan University in Shanghai were enrolled, and their clinical data were retrospectively analyzed, including baseline characteristics, clinical manifestations, underlying diseases history of glucocorticoid therapy, laboratory data (blood routine examination, procalcitonin, C-reactive protein, lymphocytes subsets, etc.), imaging changes, bacterial strain identification, treatment regimens and outcomes. According to the locations of infection, patients were divided into pulmonary nocardiosis, extrapulmonary single-organ nocardiosis and disseminated nocardiosis. The Mann-Whitney U test was used for comparison between two groups, and the Kruskal-Wallis H test was used for comparison among multiple groups. Results:Among the 44 cases of nocardiosis, 14 cases were pulmonary nocardiosis, 17 cases were extrapulmonary single-organ nocardiosis (including nine cases with central nervous system infection, six cases with skin and soft tissue infection, one case with abdominal abscess and one case with urinary tract infection) and 13 cases were disseminated nocardiosis (including four cases with bloodstream infection, six cases with central nervous system and lung or skin and soft tissue infection, three cases of lung and skin and soft tissue infection). Thirty-four cases had underlying diseases, and 27 cases received glucocorticoid or immunosuppressant treatment. The main symptom of 11 patients in pulmonary nocardiosis group was productive cough, while that of the patients in other two groups was fever. Nocardia species were mainly Nocardia brasiliensis, Nocardia nova and Nocardia farcinicaia. The white blood cell counts and neutrophils proportion were normal or slightly increased in 42 cases, and the platelets were normal or slightly decreased in 41 cases. Erythrocyte sedimentation rate increased in 19 cases, procalcitonin increased in 21 cases, C-reactive protein increased in 34 cases, and ferritin increased in 18 cases. A total of 34 patients were tested for lymphocyte subsets, of which 15 had CD4 + T lymphocytes decreased, 14 had CD8 + T lymphocytes increased, seven had B lymphocytes increased, seven had B lymphocytes decreased, and eight had natural killer cells decreased. The hemoglobin of patients with pulmonary nocardiosis was higher than that of patients with extrapulmonary infection, and the difference was statistically significant ( U=0.095, P=0.025). The imaging manifestations were mainly abscess and inflammatory exudation. Forty cases were cured or improved, one case was still on treatment, and three cases died. Conclusions:The clinical manifestations of nocardiosis involving various organs are non-specific. Standardized treatment could reduce the mortality of nocardiosis.

OBJECTIVETo study the HBsAg transient expression in HepG2 or COS-7 cells with eukaryotic expression plasmids inserting HBsAg gene (pCI-S and pcDNA3.1-S) and the efficacy of naked DNA immunization in mice.

METHODSFirstly, the recombinant plasmids of pCI-S and pcDNA3.1-S were constructed by the cloning technique and the accuracy of these constructs was confirmed by restriction enzyme digestion and DNA sequencing. Secondly, plasmids of pCI-S and pcDNA3.1-S were transferred into HepG2 and COS-7 cells, respectively by means of cationic liposome. HBsAg transient expression was assayed by ELISA in cell culture supernatants and cell lysates. Thirdly, plasmids were injected into quadriceps muscles of BALB/C mice and serum samples were obtained from individual immunized or control mice 4 weeks after injection and boost injection, respectively. Anti-HBs were assayed in mice sera by ELISA. HBsAg-specific CTL responses of spleen cells from immunized mice were tested by the LDH method.

RESULTSPlasmids of pCI-S and pcDNA3.1-S allowed HBsAg transient expression in cell culture supernatants and cell lysates of HepG2 or COS-7 cells. Intramuscular immunization of BALB/C mice with plasmids of pCI-S or pcDNA3.1-S elicited the antibody and cytotoxic T lymphocyte responses to HBsAg.

CONCLUSIONSThe vectors used in this study are effective to induce prime antibody and HBsAg-specific-cytotoxic T lymphocyte responses to HBsAg in mice after intramuscular immunization.

Animals ; COS Cells ; Cloning, Molecular ; DNA, Viral ; genetics ; Eukaryotic Cells ; metabolism ; Female ; Gene Expression ; Hepatitis B ; immunology ; prevention & control ; Hepatitis B Surface Antigens ; genetics ; immunology ; Hepatitis, Viral, Animal ; immunology ; prevention & control ; Humans ; Immunization ; Mice ; Mice, Inbred BALB C ; Plasmids ; genetics ; T-Lymphocytes, Cytotoxic ; immunology ; Transfection ; Tumor Cells, Cultured ; Vaccines, DNA ; genetics ; immunology ; Viral Vaccines ; genetics ; immunology

Severe acute respiratory syndrome coronavirus（SARS-CoV-2）is highly infectious and people are generally susceptible to it. In this article,we reviewed current research into the epidemiological characteristics of coronavirus disease 2019（COVID-19）,introduced China's effective prevention and control experience,preliminarily summarized the phased Results of China's fight against the COVID-19,and reviewed the early measures taken by Singapore,Japan,Italy,Iran and South Korea. We recommended China’s prevention and control measures in response to COVID-19 to the world;appealed to pay attention to non-drug interventions,to strengthen the cooperation and sharing of COVID-19 epidemic data and research,to improve the global ability in respond to public health emergencies,and to reduce the impact of COVID-2019 on the sustainable development of economy and society.