In a previous study by the authors,positive results from both a case-control study and a cohort study were reported.In the present study a short-term test for the induction of mouse lung tumor by chloroprene was condu...In a previous study by the authors,positive results from both a case-control study and a cohort study were reported.In the present study a short-term test for the induction of mouse lung tumor by chloroprene was conducted to confirm whether chloroprene monomer itself can induce tumors.Kunming albino mice weaned at 2 weeks were subjected to inhaling 0,2.9±0.3, 19.2±1.9,and 189.0±13.3 mg/m^3 chloroprene(GC purity,99.8%)4 h daily(except Sunday) for 7 months.All survivors were killed at the end of the 8th month or when moribund.No lung tumors were found before the 6th month.Thus,survivors at the 6th month were counted as effective animals.Most lung tumors observed were papilloadenomas(50/57),and a few were adenomas(7/57).The tumor incidence in the 2.9 mg/m^3 group was 8.1% in comparison to 1.3% in the control group,with the significance level at P<0.05.The higher the concentration,the higher the incidence.Examination of the multiplicity of tumor induction also demonstrated a dose-response relationship,and the number of tumors per mouse in the 189 mg/m^3 group was significant at P<0.01.1989 Academic Press,Inc.展开更多
It is well known that transit through the epididymis involves an increase in the compaction of sperm chromatin, which acquires fully condensed status at the caput epididymidis. The purpose of this study was to compare...It is well known that transit through the epididymis involves an increase in the compaction of sperm chromatin, which acquires fully condensed status at the caput epididymidis. The purpose of this study was to compare the terminal deoxyribonucleotidyl transferase-mediated dUTP nick end-labelling （TUNEL） assay, the comet assay, the sperm chromatin structure assay （SCSA） and the sperm chromatin dispersion （SCD） test by analysing spermatozoa from the caput and cauda epididymidis in order to demonstrate the ability of each technique to discriminate between different degrees of sperm maturity related to chromatin compaction and DNA fragmentation. Our results suggest that some populations of DNA-fragmented spermatozoa associated with immature sperm can only be identified using the comet assay and the SCSA but not with the SCD test or the TUNEL assay.展开更多
immature male mice were selected in the experiment to assess the effects of Deer semen on the development of testes. 20 mice were fed with 0.05 mL semen·d -1 for 15 days and the rest fed with the same volume...immature male mice were selected in the experiment to assess the effects of Deer semen on the development of testes. 20 mice were fed with 0.05 mL semen·d -1 for 15 days and the rest fed with the same volume of albumeh for the same period as controls. The relative weight of testis to body weight was higher in treated group than that in the control (P<0.05), so was the volume of testis (P<0.05). The density of testis was lower in treated group than in the control (P<0.05). Eighty percent of mice in the treated group showed the appearance of tubule cavity and spermatozoa in the testis, but only about 20% in the control. It was concluded that the Deer semen had improvement effects on the development of testes and sexual maturity of mice.展开更多
文摘In a previous study by the authors,positive results from both a case-control study and a cohort study were reported.In the present study a short-term test for the induction of mouse lung tumor by chloroprene was conducted to confirm whether chloroprene monomer itself can induce tumors.Kunming albino mice weaned at 2 weeks were subjected to inhaling 0,2.9±0.3, 19.2±1.9,and 189.0±13.3 mg/m^3 chloroprene(GC purity,99.8%)4 h daily(except Sunday) for 7 months.All survivors were killed at the end of the 8th month or when moribund.No lung tumors were found before the 6th month.Thus,survivors at the 6th month were counted as effective animals.Most lung tumors observed were papilloadenomas(50/57),and a few were adenomas(7/57).The tumor incidence in the 2.9 mg/m^3 group was 8.1% in comparison to 1.3% in the control group,with the significance level at P<0.05.The higher the concentration,the higher the incidence.Examination of the multiplicity of tumor induction also demonstrated a dose-response relationship,and the number of tumors per mouse in the 189 mg/m^3 group was significant at P<0.01.1989 Academic Press,Inc.
文摘It is well known that transit through the epididymis involves an increase in the compaction of sperm chromatin, which acquires fully condensed status at the caput epididymidis. The purpose of this study was to compare the terminal deoxyribonucleotidyl transferase-mediated dUTP nick end-labelling （TUNEL） assay, the comet assay, the sperm chromatin structure assay （SCSA） and the sperm chromatin dispersion （SCD） test by analysing spermatozoa from the caput and cauda epididymidis in order to demonstrate the ability of each technique to discriminate between different degrees of sperm maturity related to chromatin compaction and DNA fragmentation. Our results suggest that some populations of DNA-fragmented spermatozoa associated with immature sperm can only be identified using the comet assay and the SCSA but not with the SCD test or the TUNEL assay.
文摘immature male mice were selected in the experiment to assess the effects of Deer semen on the development of testes. 20 mice were fed with 0.05 mL semen·d -1 for 15 days and the rest fed with the same volume of albumeh for the same period as controls. The relative weight of testis to body weight was higher in treated group than that in the control (P<0.05), so was the volume of testis (P<0.05). The density of testis was lower in treated group than in the control (P<0.05). Eighty percent of mice in the treated group showed the appearance of tubule cavity and spermatozoa in the testis, but only about 20% in the control. It was concluded that the Deer semen had improvement effects on the development of testes and sexual maturity of mice.
