PubMed Health⌕ Search

Biomedical subjects

F Qi

Publications and source records attributed to F Qi.

59 records · Page 4Linked to original sources
PubMed1995

Effects of tetrandrine and chlorpromazine on synthesis of collagen and hyaluronic acid in cultured human lung fibroblasts.

AIM: To study the effects of tetrandrine (Tet) and chlorpromazine (Chl) on synthesis of collagen and hyaluronic acid (HA) in cultured human lung fibroblasts (HLF). METHODS: The synthesis of collagen and HA was assessed by measuring the incorporation of [3H]proline and radioimmunoassay. RESULTS: Both Tet (5-80 mumol L-1) and Chl (10-40 mumol L-1) diminished the collagen synthesis in a concentration-dependent manner. The suppression was aggravated at 36-48 h. The HA content in the supernatant of culture also decreased gradually with the increasing dosage of Tet or Chl after 24-h exposure. There was no obvious toxic effect of Tet on HLF cells at 5-20 mumol L-1. CONCLUSION: Tet 5-20 mumol L-1 decreased the production of collagen and HA without obvious toxity on HLF, suggesting that Tet could be a hopeful anti-fibrosis drug.

Alkaloids↗
PubMed1994

Natural recombination in bovine viral diarrhea viruses.

BVDV isolates exist as two biotypes differentiated at the molecular level by production of a p80 polypeptide. Insertions consisting of host cell sequences and/or duplicated and rearranged viral sequences have been observed in the portion of the genome coding for the p80 polypeptide in some, but not all, cytopathic BVDV. The significance of these insertions to biotypic expression has yet to be demonstrated. It has been hypothesized that recombination results in the production of the p80 polypeptide by introduction of a cleavage site into a precursor polypeptide or the introduction of a second copy of the p80 gene. Because inserts have not been identified in all cytopathic BVDV examined, it appears that recombination may not be the only mechanism involved in biotypic determination.

Animals↗
PubMed1993

The nucleotide sequence of the 5'-untranslated region of bovine viral diarrhoea virus: its use as a probe in rapid detection of bovine viral diarrhoea viruses and border disease viruses.

A 289 bp cDNA fragment from the 5'-untranslated region (UTR) of 16 bovine viral diarrhoea virus (BVDV) isolates was amplified by reverse transcription and polymerase chain reaction, and sequenced by dideoxy DNA sequencing. The sequence showed greater than 90% homology between the isolates and BVDV NADL in this region, and greater than 97% homology within a 72 base sub-region (nt 314-386). The 289 bp fragment was then used as a probe for rapid detection of BVDV and border disease virus (BDV) from cell culture samples by dot-blot hybridization. This probe hybridized to 100% of BVDV isolates (n = 78) and 100% of BDV isolates (n = 9), but not to the uninfected BT cells or other bovine infectious agents. A shorter probe from the more conserved sub-region also was tested for hybridization with some of the isolates, and the results were similar to those using the longer probe. These results suggest that the 5'-UTR is highly conserved among BVDV and BDV isolates, and may be used as a potential probe for rapid detection of BVDV and BDV in clinical and cell culture samples from cattle and sheep.

Animals↗
PubMed1992

Analysis of the bovine viral diarrhea virus genome for possible cellular insertions.

Mucosal disease is the most severe disease resulting from bovine viral diarrhea virus (BVDV) infection in cattle. Two biotypes of BVDV may be isolated from animals with mucosal disease: cytopathic (cp) and noncytopathic (ncp). These "pairs" of cp/ncp viruses are often closely related and it has been suggested that the cp virus arises from a ncp virus by insertion of cellular RNA in the p125 region of the BVDV genome. We have used four pairs of cp/ncp BVDV isolated from cattle with mucosal disease, to examine the genomic sequence of the region of the genome coding for the nonstructural protein p125 (processed to p54/p80 in cp viruses) by PCR analysis and sequencing. We did not detect any cellular gene insertions in any of the four ncp viruses; however, we found a large duplication of the p80 gene and a ubiquitin gene insertion in three of the four cp isolates. Our results suggest that cellular RNA insertions in the p125 region may contribute significantly to the cytopathogenicity of BVDV. However, this does not appear to be the only mechanism of cytopathogenicity as we did not detect any insertions or duplications in one of the cp viruses. Comparison of the DNA sequence in the p80 region revealed greater homology within the "pairs" than to NADL, which lend further support to the hypothesis that a cp virus is originated from a ncp virus.

Amino Acid Sequence↗