Humans ; Severe Acute Respiratory Syndrome ; diagnosis ; drug therapy ; prevention & control

Technological innovation paves a way for constant advances of medical sciences.Presently great emphasis has been put on creative clinical researches globally.More and more clinical studies by Chinese authors have been published in internationally reputed journals,and they have drawn wide attention.Compare with experimental research,clinical research may yield huge social and/or economic benefits,and may help to solve clinical problems over a relatively short period of time.In a populous country like China,large cohort of patients may mean a conceivable advantage for clinical research,which is of paramount significance in promotion of medical sciences and in improving the health status of the Chinese people.Clinical researchers should therefore be actively involved in this clinical research.Understandably,solutions are urgently needed for some obstacles,such as the low financial input from government and the incompetence in selecting research subjects and in designing study by clinicians.Nevertheless,we believe that,with the substantial support from our government,Chinese clinical research will surely have a bright future.

Following the one in the last,Five spirits should be advocated in scientific research,Prof Zhong's paper in this issue goes further with 5 expectations he has for the young generation of Chinese clinical scientists.The expectations highlight the need for willingness-to-do,ability-to-do,skill-to-do,perseverance-to-do and immunity against frustration for young scientists in clinical research.Among these,the willingness-to-do seems to be the primary motion,ability-to-do,skill-to-do and immunity against frustration are considered crucial aspects,and perseverance-to-do is the basis.His passionate intention was directed to education of readers in review of his strenuous efforts and valuable experiences during decades of scientific research.Hopefully,meeting with Prof Zhong in this journal would bring about implications and enlightenments for your work in clinical science.

Academician Zhong Nanshan advocates to broad scientific and technical workers nationwide five spirits which should be upheld in scientific research:first,scientific and technical workers should love their homeland;second,they should respect and promote science;third,they should advocate innovation;fourth,they should respect and stick to honesty;and fifth,they should advocate the spirit of cooperation.

The new revision of 《Guideline on Diagnosis and Management of Cough(2009)》 is published in China in 2009 following the first revision of 《Guideline on Diagnosis and Management of Cough (draft)》in 2005.The new revision hold prvious stucture basically,more focuses on diagnosis and management of chronic ough,adds new sections including subacute cough,empiric treatment,phlegm-removing drugs,and assessement of cough severity as an appendix.A few news terms have been intrduced to replace older terms,such as upper airway cough syndrome for post nasal drip symdrome,and postinfection cough for cough post influenza.

AIM: To study the expression of matrix metalloproteinase-9 (MMP-9) in human bronchial epithelial cell treated with TNF-?, ConA and mechanical injury. METHODS: RT-PCR and gelatin zymography were performed to observe the dynamic expression of matrix metalloproteinase-9(MMP-9) in human bronchial epithelial cell line H292 at different timepoint(2 h, 6 h,12 h, 24 h) after stimulation with TNF-?, ConA and mechanical injury. RESULTS: Human bronchial epithelial cell H292 expressed and secreted matrix metalloproteinase-9 in the presence of TNF-?, ConA and mechanical injury. On stimulation with mechanical injury alone, MMP-9 was initially expressed at 2 h, peaked at 12 h, and decreased at 24 h. Furthermore, on stimulation with combination of ConA and mechanical injury, the MMP-9 mRNA expression was the highest among in all the groups. Zymography show that the MMP-9 activity appeared just at 24 h timepoint, and was highest at the group of combination of ConA and mechanical injury. CONCLUTION: Human bronchial epithelial cell expressed and secreted MMP-9 when treated with TNF-?, ConA and mechanical injury.

Objective To study the effects of N-acetylcysteine (NAC) on the proliferation, apoptosis and collagen synthesis of human lung fibroblast (HLF). Methods HLF was primarily cultured in complete medium of DMEM/F12. Different concentrations of NAC (5,10,20,40mmol/L) were administrated. Cell proliferations were tested by methylthiazolyltetrazolium (MTT) ,apoptosis and cell cycle were detected with Flow cytometer and mRNA and 40 mmoi/L )after 24 hours,the apoptosis rates were (34.38±5.80)%, (37.72±3.10)%, (44.05± 4.52) % and (59.18±5.24) % ) respectively, significantly higher than that of the controls (3.92±1.24) % pression of type Ⅰ procollagen in HLF was decreased significantly after administration of NAC at 5, 10,20, 40 mmol/L respectively (P < 0.01 ). Conclusion Administration of NAC induces apoptosis and directly inhibites the proliferation and the collagen synthesis of HLF.

AIM: To investigate the level of ET-1 produced by cultured human bronchial epithelial cells (HBECs) under injury and the effects of injured HBECs on ET-1 production in sub-epithelial fibroblasts. The interaction between ET-1 and matrix metalloproteinase-9(MMP-9) was detected in HBECs under damage. The purpose of the study is to evaluate the effect of injured HBECs related to ET-1 release on airway remodeling in asthma. METHODS: ET-1 level was detected in supernatants from cultured HBECs 12 h after being treated with either mechanical scraping or LPS stimulation or mechanical scraping plus LPS, as well as from subepithelial fibroblasts cocultured with mechanical damaged HBECs. It was also measured in the supernatant from HBECs transfected with MMP-9 expression plasmid. MMP-9 activity was assessed in supernatants from HBECs stably transfected with pEGFPc1 -antisense-ET-1 converting enzyme(ECE) RNA. RESULTS: It was found that there was an increase in ET-1 level in supernatants from HBECs either treated with mechanical scraping plus LPS or transiently transfected with MMP-9 plasmid, as well as from sub-epithelial fibroblasts cocultured with mechanical scraping HBECs compared with that in controls. Gelatin zymography showed a obviously attenuated gelatinolytic activity of MMP-9 in conditioned media of HBECs expressing antisense ECE RNA after mechanical damage. CONCLUSIONS: Airway epithelial cells under injury are able to overproduce ET-1 as well as initiate ET-1 release from sub-epithelial fibroblasts, MMP-9 produced by injured bronchial epithelial cells may also increase ET-1 processing leading to ET-1 production further. The interaction between ET-1 and MMP-9, both of which enhanced in damaged HBECs, may play an important role in airway inflammation related to airway remodeling in asthma.

Objective To clone and analyze the cDNA of major allergen Der f 2 of Dermatophagoides farinae in south China. Methods cDNA of Der f 2 was cloned by RT-PCR, screened and their sequences were analyzed. Results cDNAof Der f 2 was cloned. The sequence of the cloned Der f 2 was different with that published (D10448) in GenBank, with 87 additional nucleotides inserted into the 62th nucleotide of the original one. According to the original ORF, the deduced amino acids that were located prior or after the inserted 29 amino acid sequence showed no changes. Conclusion The cDNA of Der f 2 was cloned from Dermatophagoides farinae and its sequence showed significant difference with that reported in the GenBank.