ABSTRACT
As cyanobacteria with nitrogen-fixing ability, diazotrophic cyanobacteria can adapt to all kinds of habitat and produce many primary and secondary metabolic materials with unique chemical structures, diverse properties, and biological activities. As a nutritional supplement, diazotrophic cyanobacterium such as Nostoc has a long edible history in indigenous populations in China. In recent years, research results have shown that the bioactive substances produced by nitrogen-fixing cyanobacteria are promising candidates for the prevention and control of some human diseases, and the mechanisms of nitrogen-fixing cyanobacteria to achieve health and disease prevention are gradually revealed. This paper reviewed the progress in research and its mechanism of nitrogen-fixing cyanobacteria in anti-oxidation, scavenging free radicals, antibiosis, antivirus, antitumor, antiinflammation, and anticoagulation in the past five years (2013-2017) at home and abroad. Moreover, the existing problems and the development directions in future were also discussed. We expect that it can provide reference for the further development of the related field in China.
ABSTRACT
<p><b>OBJECTIVE</b>To characterize the hepatitis A virus (HAV) wild type strains circulating in Hebei Shijiazhuang of China during 2005-2007, to provide the bases for further investigation of the sources of HAV infection.</p><p><b>METHODS</b>The VP1/P2A junction regions were detected by RT-PCR from HAV IgM positives serum samples during 2005 and 2007, the 34 RT-PCR positive samples were sequenced and subjected to phylogenetic analysis by Neighbor Joining (NJ) method.</p><p><b>RESULTS</b>All the detected HAV strains were identified as sub-genotype I A, the homology of nucleotide sequence in the VP1-2A imation region ranged from 95%-100%, the amino acid sequences of HAV strains almost had no difference.</p><p><b>CONCLUSION</b>There are different HAV strains existing in Hebei Shijiazhuang of China, same HAV strain may exist in different areas; or in one area, identical or different HAV strains may be detected. This work provides the bases for further investigation of the sources of HAV infection and also for effectively control measures to prevent the spread of the disease.</p>