Chronic low-level lead (Pb) exposure in children is known to cause a deficit in learning and memory. In vitro studies have demonstrated that Pb altered protein kinase C (PKC) activityt Especially, hippocampal PKC has ...Chronic low-level lead (Pb) exposure in children is known to cause a deficit in learning and memory. In vitro studies have demonstrated that Pb altered protein kinase C (PKC) activityt Especially, hippocampal PKC has been correlated with performance in several learning tasks. The effects of Pb exposure on hippocampal PKC were investigated during development at various postnatal ages: postnatal day (PN) 7, 14, 28, and 56. Two-tenth % Pb acetate was administered to pregnant and lactating dams and then administered to weanling rats in drinking water. PKC activity was measured in both membrane and cytosolic fractions from the hippocampi of the controls and Pb-exposed animals. Pb-induced increase in PKC activity in the cytosolic fraction was obsereved in the PN56 rats. In contrast, PKC activity was decreased by Pb at PN7 in the membrane fraction. Furthermore, a significant decrease in the ratio of membrane to cytosolic PKC activity which is representative of PKC distribution was observed in the PN28 and PN56 Pb-exposed rats relative to the same-age controls. This study indicates that chronic Pb exposure during development influences hippocampal PKC activity and distribution. These changes may be involved in the subclinical neurotoxicity of chronic Pb exposure in young children.展开更多
The toxicokinetics, tissue distribution, and anticholinesteruse (antiChE ) activity of diazinon were investigated in the rat. Plasma concentrations most adequately fitted a two-compartment open model after iv adminis...The toxicokinetics, tissue distribution, and anticholinesteruse (antiChE ) activity of diazinon were investigated in the rat. Plasma concentrations most adequately fitted a two-compartment open model after iv administration of 10 mg/kg and a one-compartment model after oral administration of 80 mg/kg. Diazinon elimination half-life following iv and oral dosing was 4.70 and 2.86 h, respectively. The oral bioavailabllity was found to be low (35.5%). Hepatic extraction ratios after iv administration of 5 or 10 mg展开更多
Potential link between preeclampsia（PE）and posterior cortical atrophy（PCA）：PCA is a neurodegenerative disorder affecting the parietal,occipital,and occipital-temporal brain regions,often manifesting as a decline ...Potential link between preeclampsia（PE）and posterior cortical atrophy（PCA）：PCA is a neurodegenerative disorder affecting the parietal,occipital,and occipital-temporal brain regions,often manifesting as a decline in visual processing and perception skills in affected individuals.展开更多
The effects of selenium (Na_2SeO_3) on aflatoxin B_1 (AFB_1)-induced hepatic neoplasia were studied in the rat. Putative preneoplastic foci and nodules composed of basophilic, eosinophilic, and clear cells developed e...The effects of selenium (Na_2SeO_3) on aflatoxin B_1 (AFB_1)-induced hepatic neoplasia were studied in the rat. Putative preneoplastic foci and nodules composed of basophilic, eosinophilic, and clear cells developed early. Basophilic foci were seen first; in the later stages basophilic and eosinophilic nodules predominated. At each stage the AFB_1 + Se groups showed fewer and smaller foci and nodules than the AFB_1 -Se group. The number of foci in the AFB_1 + 3 ppm Se group and their mean area were smaller than those in the 6 ppm Se + AFB_1 group. At the end of the experiment hepatocellular carcinoma (HCC) was found in 11/18 rats (61%) of the AFB_1-Se group. HCC was not found in either of the groups given AFB_1 +Se. We conclude that Se had an inhibitory effect on the initiation and promotion stages of AFB_1-induced preneoplastic foci and nodules. Se also prevented progression of these nodules to HCC even after cessation of AFB_1 administration. The inhibitory effect of Se at 3 ppm was greater than at 6 ppm. The 6 ppm Se group also showed evidence of toxicity. 1990 Academic Press.Inc.展开更多
1.Once upon a time, the cat and the ratare good friends. One day they hear God willchoose twelve animals to represent the yearin which a person is born. 从前,猫和老鼠是好朋友。有一天,他们听说上天要选十二种动物来代表...1.Once upon a time, the cat and the ratare good friends. One day they hear God willchoose twelve animals to represent the yearin which a person is born. 从前,猫和老鼠是好朋友。有一天,他们听说上天要选十二种动物来代表人出生时的属相。展开更多
This paper introduces a software specially in calculating the contribution rate of machanization in agriculture by usng economy math method,computer technology and Visual Basic 6.0 version.The software package has fri...This paper introduces a software specially in calculating the contribution rate of machanization in agriculture by usng economy math method,computer technology and Visual Basic 6.0 version.The software package has friendly interface,simple operating way and accurate,feasible calculating method.It greatly changes the condition in the past which had considerable lots of data and miscellaneous and trivial methods,which were even hard to seek answer.So it has very high practicl value.展开更多
Objective To investigate the influence of different diets on serum protein expression levels of 4-hydroxynonenal(4-HNE),thioredoxin(Trx),thioredoxin reductase(TrxR)and the sctivities of Trx and TrxR,and to explore the...Objective To investigate the influence of different diets on serum protein expression levels of 4-hydroxynonenal(4-HNE),thioredoxin(Trx),thioredoxin reductase(TrxR)and the sctivities of Trx and TrxR,and to explore the effect of damage to the lung tissue and the underlying mechanisms of different body mass index caused by different diets in the rat models.Methods展开更多
文摘Chronic low-level lead (Pb) exposure in children is known to cause a deficit in learning and memory. In vitro studies have demonstrated that Pb altered protein kinase C (PKC) activityt Especially, hippocampal PKC has been correlated with performance in several learning tasks. The effects of Pb exposure on hippocampal PKC were investigated during development at various postnatal ages: postnatal day (PN) 7, 14, 28, and 56. Two-tenth % Pb acetate was administered to pregnant and lactating dams and then administered to weanling rats in drinking water. PKC activity was measured in both membrane and cytosolic fractions from the hippocampi of the controls and Pb-exposed animals. Pb-induced increase in PKC activity in the cytosolic fraction was obsereved in the PN56 rats. In contrast, PKC activity was decreased by Pb at PN7 in the membrane fraction. Furthermore, a significant decrease in the ratio of membrane to cytosolic PKC activity which is representative of PKC distribution was observed in the PN28 and PN56 Pb-exposed rats relative to the same-age controls. This study indicates that chronic Pb exposure during development influences hippocampal PKC activity and distribution. These changes may be involved in the subclinical neurotoxicity of chronic Pb exposure in young children.
文摘The toxicokinetics, tissue distribution, and anticholinesteruse (antiChE ) activity of diazinon were investigated in the rat. Plasma concentrations most adequately fitted a two-compartment open model after iv administration of 10 mg/kg and a one-compartment model after oral administration of 80 mg/kg. Diazinon elimination half-life following iv and oral dosing was 4.70 and 2.86 h, respectively. The oral bioavailabllity was found to be low (35.5%). Hepatic extraction ratios after iv administration of 5 or 10 mg
基金supported in part by the National Institutes of Health funding,No.4R00HL129192(to JPW)
文摘Potential link between preeclampsia（PE）and posterior cortical atrophy（PCA）：PCA is a neurodegenerative disorder affecting the parietal,occipital,and occipital-temporal brain regions,often manifesting as a decline in visual processing and perception skills in affected individuals.
文摘The effects of selenium (Na_2SeO_3) on aflatoxin B_1 (AFB_1)-induced hepatic neoplasia were studied in the rat. Putative preneoplastic foci and nodules composed of basophilic, eosinophilic, and clear cells developed early. Basophilic foci were seen first; in the later stages basophilic and eosinophilic nodules predominated. At each stage the AFB_1 + Se groups showed fewer and smaller foci and nodules than the AFB_1 -Se group. The number of foci in the AFB_1 + 3 ppm Se group and their mean area were smaller than those in the 6 ppm Se + AFB_1 group. At the end of the experiment hepatocellular carcinoma (HCC) was found in 11/18 rats (61%) of the AFB_1-Se group. HCC was not found in either of the groups given AFB_1 +Se. We conclude that Se had an inhibitory effect on the initiation and promotion stages of AFB_1-induced preneoplastic foci and nodules. Se also prevented progression of these nodules to HCC even after cessation of AFB_1 administration. The inhibitory effect of Se at 3 ppm was greater than at 6 ppm. The 6 ppm Se group also showed evidence of toxicity. 1990 Academic Press.Inc.
文摘1.Once upon a time, the cat and the ratare good friends. One day they hear God willchoose twelve animals to represent the yearin which a person is born. 从前,猫和老鼠是好朋友。有一天,他们听说上天要选十二种动物来代表人出生时的属相。
文摘This paper introduces a software specially in calculating the contribution rate of machanization in agriculture by usng economy math method,computer technology and Visual Basic 6.0 version.The software package has friendly interface,simple operating way and accurate,feasible calculating method.It greatly changes the condition in the past which had considerable lots of data and miscellaneous and trivial methods,which were even hard to seek answer.So it has very high practicl value.
文摘Objective To investigate the influence of different diets on serum protein expression levels of 4-hydroxynonenal(4-HNE),thioredoxin(Trx),thioredoxin reductase(TrxR)and the sctivities of Trx and TrxR,and to explore the effect of damage to the lung tissue and the underlying mechanisms of different body mass index caused by different diets in the rat models.Methods
