The early diagnosis of lung carcinoma with normal plain CT scan / 复旦学报（医学版）

Objective To explore the diagnosis for early stage lung cancer with "normal" plain CT scan in order to draw the concern of physician to these patients. Methods We reviewed and analyzed 3 cases of central bronchogenic carcinoma with normal plain CT scan at first visit who were confirmed through fiber bronchoscope examination and PET/CT scan later. Then we compared the values of some diagnostic methods for early-stage central bronchogenic carcinoma. Results Three patients were all males with long smoking history. They came to hospital for cough and bloody sputum. All their plain CT scan showed "no abnormal findings", but their symptom continued. Later, the fiber bronchoscope examination and PET/CT scan strongly suggested that they were suffered from central bronchogenic carcinoma, and then the pathological findings and sputum cytology confirmed the diagnosis. Two patients received lobectomy, and the other one was suggested to accept radiotherapy because of his poor lung function. Conclusions The positive rate of plain CT scan for early-stage central bronchogenic carcinoma is relatively low. Thus, some of these patients lost the chance of surgery and combined therapy. So physicians should pay more attention to these patients with symptoms of persistent bloody sputum or obstructive pneumonia, even if the plain CT scan is negative at first visit. Using PET/CT and fiber bronchoscope examination, physicians can confirm the diagnosis of central bronchogenic carcinoma. So these two methods are important in the diagnosis for early-stage central bronchogenic carcinoma without any abnormal plain CT scan findings.

Prokaryotic expression of recombinant Streptococcus suis IgG binding protein and its binding activity with IgG / 生物工程学报

Streptococcus suis (S. suis) IgG-binding protein (SPG) was present in all S. suis strains examined. It showed binding activities with IgG from various host species. Little was known about the biological role of this protein, but it was commonly believed that it acted as virulence factor. In this study, the genes encoding SPG were amplified respectively from the total DNA of the S. suis serotype 1/2, 1, 2 and 9 with PCR and expressed in Escherichia coli BL21 by plasmid pET28a as vector. The recombinant proteins were first purified with affinity chromatography (Ni-NTA), and further purified by sephadexG-200 gel chromatography. The recombinant SPG proteins were identified to have binding activities with IgG of different host species, and for human and porcine IgG they showed better binding activities. But the SPG from different serotypes of S. suis showed no great differences in their binding activities with IgG from the same host species.

The rescue of H1N1 subtype swine influenza virus / 生物工程学报

The swine influenza virus (SIV) strain A/Swine/TianJin/01/2004(H1N1) (A/S/TJ/04) was rescued successfully by an eight-plasmid rescue system. The cDNAs of SIV 8 gene segments were synthesized by RT-PCR and cloned into the RNA polymerase I/II bidirection expression vector PHW2000 independently, resulting in 8 recombinant plasmids. The 8 recombinant plasmids were cotransfected into COS-1 cell, 30 h later TPCK-trypsin was added to 0.5 microg/mL. The COS-1 cell and supernatant were harvested 48 h after cotransfection and were inoculated into the allantoic cavity of 9-day-old specific-pathogen free (SPF) chicken eggs. The allantoic fluid of dead eggs was harvested and passaged 3 generations in SPF chicken eggs to get infective virus. The successful rescue of A/S/TJ/04 SIV was identified by hemagglutination assay, hemagglutination inhibition assay, sequence analysis and electron microscope observation. The successful rescue of SIV built a platform for the research of the relationship between genome structure and function of SIV, the mechanisms of trans-species transmission of influenza virus and for the generation of new SIV as vaccine.