Dissected tissues of three shellfish species, the Chinese scallop, Chlamys farreri, Manila clam, Ruditapes philippinarurn, and Razor shell, Solen strictu were evaluated for in vitro transformation of paralytic shellfi...Dissected tissues of three shellfish species, the Chinese scallop, Chlamys farreri, Manila clam, Ruditapes philippinarurn, and Razor shell, Solen strictu were evaluated for in vitro transformation of paralytic shellfish poisoning （PSP） toxins. Tissue homogenates were incubated with extraction from toxic algae Alexandriurn rninutura to determine toxin conversion. The effects of heating and addition of a natural reductant （glutathione） on toxin conversion were also assessed. The toxin profile was investigated through high performance liquid chromatography with fluorescence detection （HPLC-FLD）. The evident variations in the toxin content were observed only in Chinese scallop viscera homogenates. The concentration of GTX4 was reduced by 45% （approximately 0.8 μmol/dm^3） and 25% （approximately 1 μmol/dm^3） for GTX1, while GTX2 and GTX3 increased by six times （approximately 1 μmol/dm^3） and 3 times （approximately 0.3μmol/dm^3） respectively. Simultaneously, the total toxicity decreased by 38% during the 48 h incubation period, the final toxicity was 20.4 nmol STXeq/g. Furthermore, heated Chinese scallop viscera homogenates samples were compared with non-heated samples. The concentration of the GTX4 and GTX1 was clearly 28% （approximately 0.53 μmol/dm^3） and 17% （approximately 0.69μmol/dm^3） higher in heated samples, GTX2 and GTX3 were four times （0.66 μmol/dm^3） and two times （0.187 μmol/dm^3） lower respectively. GSH （＋） Chinese scallop viscera homogenates samples were compared with GSH （-） samples, the concentration in the GTX4 and GTX1 was 9% （approximately 0.12 μmol/dm^3） and 11% （approximately 0.36 μmol/dm^3） lower respectively, GTX2 and GTX3 was 17% （approximately 0.14 μmol/dm^3） and 19% （approximately 0.006 μmol/dm^3） higher respectively. In contrast,there was a little change in the concentration of PSP toxins of Manila clam and Razor shell tissue ho- mogenates. These observations on three shellfish tissues confirmed that there were species-specific differences in PSP toxins transformation. PSP toxins transformation was more pronounced in viscera tissue than in muscle tissue. PSP toxins was possibly interfered by some carbamoylase enzyme, and the activity in Chinese scallop viscera tissue is more remarkable than in the other two species.展开更多
A rat liver epithelial cell line designated LW13 was established using a sequential sedimentation method. The cell line retained many normal properties of liver epithelial cells and showed some structural and function...A rat liver epithelial cell line designated LW13 was established using a sequential sedimentation method. The cell line retained many normal properties of liver epithelial cells and showed some structural and functional features resembling those of liver parenchymal cells. LW13 cells became malignant after the introduction of exogenous transforming EJ Ha ras gene. Tumors produced by inoculation of the transformed cells into baby rats .contained areas of poorly differentiated hepatocellular carcinoma. In situ hybridization analysis confirmed the random rather than specific integration of exogenous ras gene into host chromosomes. Furthermore , an at least tenfold increase in the expression of the endogenous c myc gene was detected among transformed cell lines, suggesting the involvement of the c myc proto oncogene in the in vitro transformation of rat liver epithelial cells by EJ Ha ras oncogene.展开更多
For electronic microscopic observation, we found SSV-transformed NIH 3T3 cells were different from non-transformed cells. In SSV-transformed NIH 3T3 cells nuclei cytoplasma ratio was increased and in cytoplasma the ri...For electronic microscopic observation, we found SSV-transformed NIH 3T3 cells were different from non-transformed cells. In SSV-transformed NIH 3T3 cells nuclei cytoplasma ratio was increased and in cytoplasma the ribosomes (polyribosomes were attached to the swollen rough endoplasmic reticulum. It was likely that ribosomes were lined together functionally and structionally to produce specific protein (PDGF-like protein).展开更多
基金The International cooperation programs of the Ministry of Science and Technology of China under contract No.2007DFA30710the Society commonweal programs of the Ministry of Science and Technology of China under contract No.2005DIB2J116
文摘Dissected tissues of three shellfish species, the Chinese scallop, Chlamys farreri, Manila clam, Ruditapes philippinarurn, and Razor shell, Solen strictu were evaluated for in vitro transformation of paralytic shellfish poisoning （PSP） toxins. Tissue homogenates were incubated with extraction from toxic algae Alexandriurn rninutura to determine toxin conversion. The effects of heating and addition of a natural reductant （glutathione） on toxin conversion were also assessed. The toxin profile was investigated through high performance liquid chromatography with fluorescence detection （HPLC-FLD）. The evident variations in the toxin content were observed only in Chinese scallop viscera homogenates. The concentration of GTX4 was reduced by 45% （approximately 0.8 μmol/dm^3） and 25% （approximately 1 μmol/dm^3） for GTX1, while GTX2 and GTX3 increased by six times （approximately 1 μmol/dm^3） and 3 times （approximately 0.3μmol/dm^3） respectively. Simultaneously, the total toxicity decreased by 38% during the 48 h incubation period, the final toxicity was 20.4 nmol STXeq/g. Furthermore, heated Chinese scallop viscera homogenates samples were compared with non-heated samples. The concentration of the GTX4 and GTX1 was clearly 28% （approximately 0.53 μmol/dm^3） and 17% （approximately 0.69μmol/dm^3） higher in heated samples, GTX2 and GTX3 were four times （0.66 μmol/dm^3） and two times （0.187 μmol/dm^3） lower respectively. GSH （＋） Chinese scallop viscera homogenates samples were compared with GSH （-） samples, the concentration in the GTX4 and GTX1 was 9% （approximately 0.12 μmol/dm^3） and 11% （approximately 0.36 μmol/dm^3） lower respectively, GTX2 and GTX3 was 17% （approximately 0.14 μmol/dm^3） and 19% （approximately 0.006 μmol/dm^3） higher respectively. In contrast,there was a little change in the concentration of PSP toxins of Manila clam and Razor shell tissue ho- mogenates. These observations on three shellfish tissues confirmed that there were species-specific differences in PSP toxins transformation. PSP toxins transformation was more pronounced in viscera tissue than in muscle tissue. PSP toxins was possibly interfered by some carbamoylase enzyme, and the activity in Chinese scallop viscera tissue is more remarkable than in the other two species.
文摘A rat liver epithelial cell line designated LW13 was established using a sequential sedimentation method. The cell line retained many normal properties of liver epithelial cells and showed some structural and functional features resembling those of liver parenchymal cells. LW13 cells became malignant after the introduction of exogenous transforming EJ Ha ras gene. Tumors produced by inoculation of the transformed cells into baby rats .contained areas of poorly differentiated hepatocellular carcinoma. In situ hybridization analysis confirmed the random rather than specific integration of exogenous ras gene into host chromosomes. Furthermore , an at least tenfold increase in the expression of the endogenous c myc gene was detected among transformed cell lines, suggesting the involvement of the c myc proto oncogene in the in vitro transformation of rat liver epithelial cells by EJ Ha ras oncogene.
文摘For electronic microscopic observation, we found SSV-transformed NIH 3T3 cells were different from non-transformed cells. In SSV-transformed NIH 3T3 cells nuclei cytoplasma ratio was increased and in cytoplasma the ribosomes (polyribosomes were attached to the swollen rough endoplasmic reticulum. It was likely that ribosomes were lined together functionally and structionally to produce specific protein (PDGF-like protein).
