Background and Objective: Chronic heavy alcohol consumption and daily cigarette smoking are the most prevalent substance use problems in the U.S., including Veterans. Excessive alcohol use causes neurocognitive and be...Background and Objective: Chronic heavy alcohol consumption and daily cigarette smoking are the most prevalent substance use problems in the U.S., including Veterans. Excessive alcohol use causes neurocognitive and behavioral deficits that can be linked to neurodegeneration. Similarly, preclinical and clinical data suggest that smoking also leads to brain atrophy. This study examines the differential and additive effects of alcohol and cigarette smoke (CS) exposures on cognitive-behavioral function. Methods: A 4-way experimental model of chronic alcohol and CS exposures was generated using 4-week-old male and female Long Evans rats that were pair-fed with Lieber-deCarli isocaloric liquid diets containing 0% or 24% ethanol for 9 weeks. Half of the rats in the control and ethanol groups were exposed to CS for 4 hours/day and 4 days/week for 9 weeks. All rats were subjected to Morris Water Maze, Open Field, and Novel Object Recognition testing in the last experimental week. Results: Chronic alcohol exposure impaired spatial learning as shown by significantly increased latency to locate the platform, and it caused anxiety-like behavior marked by the significantly reduced percentage of entries to the center of the arena. Chronic CS exposure impaired recognition memory as suggested by significantly less time spent at the novel object. Combined exposures to alcohol and CS did not show any significant additive or interactive effect on cognitive-behavioral function. Conclusion: Chronic alcohol exposure was the main driver of spatial learning, while the effect of secondhand CS exposure was not robust. Future studies need to mimic direct CS exposure effects in humans.展开更多
The toxicity of benzene was attributed to the formation of free radical. In this study, a method of measuring lipid peroxidation(LPO)in white blood cells(WBC)was reported. After the rats inhaled benzene in different c...The toxicity of benzene was attributed to the formation of free radical. In this study, a method of measuring lipid peroxidation(LPO)in white blood cells(WBC)was reported. After the rats inhaled benzene in different concentrations (6.310\+9, 71.810\+9 and 459.510\+\{-9\} g/L) for 30 days and in concentration of 71.810\+\{-9\} g/L for 10, 20 and 30 days,indicators reflecting toxicity of blood free radicals such as leukocyte LPO, plasma LPO, erythrocyte superoxide dismutase(SOD), erythrocyte glutathione were measured. After 30 day administration, level of leukocyte LPO in all rats of the exposed groups was remarkably higher than that in the control group. Leukopenia occurred only in 71.810\+\{-9\} g/L and 459.510\+\{-9\} g/L groups. The level of leukocyte LPO also increased in 71.810\+\{-9\} g/L group 20 day administration group. Other biochemical indicators had no significant change. It was suggested that the decrease of peripheral leukocytes following benzene exposure might result from, at least in lipid peroxidation, toxic \{effectpart, membrane lipid peroxidation and the determination of leukocyte LPO level is more sensitive than leukocyte count. \;展开更多
Erythropoietin has been shown to exhibit neuroprotective effects in animal models. A neonatal rat model of hypoxic-ischemic white matter damage was established via bilateral carotid artery ligation in 4-day-old Spragu...Erythropoietin has been shown to exhibit neuroprotective effects in animal models. A neonatal rat model of hypoxic-ischemic white matter damage was established via bilateral carotid artery ligation in 4-day-old Sprague-Dawley rats. The rats were subsequently treated with recombinant human erythropoietin to observe pathological changes in the brain and long-term neurobehavioral functions before and after intervention. Results showed that the number of myelin basic protein-positive cells, which reflected myelin/oligodendrocyte damage, significantly increased, although the number of amyloid precursor protein-positive cells, which reflected axonaf injury, significantly decreased in periventricular white matter at 72 hours and 7 days following erythropoietin intervention. The number of glial fibrillary acidic protein-positive cells, indicating astrocytic damage, significantly decreased in periventricular white matter of erythropoietin-treated rats at 48 hours, 72 hours, 7 days and 26 days. Following erythropoietin intervention in the 30-day-old rats, head-turning time in the slope test was shortened and open-field test scores increased. These results suggested that erythropoietJn promoted repair of white matter damage, as well as improved neurobehavioral functions in a rat model of hypoxic-ischemic injury.展开更多
Background & Objective: Chronic excessive alcohol consumption causes white matter degeneration with myelin loss and impaired neuronal conductivity. Subsequent rarefaction of myelin accounts for the sustained defic...Background & Objective: Chronic excessive alcohol consumption causes white matter degeneration with myelin loss and impaired neuronal conductivity. Subsequent rarefaction of myelin accounts for the sustained deficits in cognition, learning, and memory. Correspondingly, chronic heavy or repeated binge alcohol exposures in humans and experimental models alter myelin lipid composition leading to build-up of ceramides which can be neurotoxic and broadly inhibitory to brain functions. Methods: This study examined the effects of chronic + binge alcohol exposures (8 weeks) and intervention with myriocin, a ceramide inhibitor, on neurobehavioral functions (Open Field, Novel Object Recognition, and Morris Water Maze tests) and frontal lobe white matter myelin lipid biochemical pathology in an adult Long-Evans rat model. Results: The ethanol-exposed group had significant deficits in executive functions with increased indices of anxiety and impairments in spatial learning acquisition. Myriocin partially remediated these effects of ethanol while not impacting behavior in the control group. Ethanol-fed rats had significantly smaller brains with broadly reduced expression of sulfatides and reduced expression of two of the three sphingomyelins detected in frontal white matter. Myriocin partially resolved these effects corresponding with improvements in neurobehavioral function. Conclusion: Therapeutic strategies that support cerebral white matter myelin expression of sulfatide and sphingomyelin may help remediate cognitive-behavioral dysfunction following chronic heavy alcohol consumption in humans.展开更多
Niviventer confucianus is a common species of rodent in South China. We designed an experimental protocol to determine the influence of temperature on energy requirement and food assimilation of the N. confucianus . I...Niviventer confucianus is a common species of rodent in South China. We designed an experimental protocol to determine the influence of temperature on energy requirement and food assimilation of the N. confucianus . In our feeding trials, four experimental temperatures were applied: 17℃,22℃,27℃ and 32℃. The energy requirements of N. confucianus under different temperature were:107 43±6 44 KJ/animal/day (17℃),94 76±4 46 KJ/animal/day (22℃),73 96±5 65 KJ/animal/day(27℃),and 62 80±5 15 KJ/animal/day(32℃),respectively. Moreover, the energy intake, digested and assimilated energy of N. confucianus decreased with temperature increase. However, no significant differences on digestibility and assimilation rate of N. confucianus were found among four experimental temperatures. It indicated that, during a range of particular temperatures, N. confucianus might maintain relatively high digestibility by change of digest tract morphology.展开更多
Digested energy, metabolizable energy, digestibility and assimilation rate were quantified at different photoperiods in Niviventer confucianus using the food balance method. Three photoperiods were applied: a short ph...Digested energy, metabolizable energy, digestibility and assimilation rate were quantified at different photoperiods in Niviventer confucianus using the food balance method. Three photoperiods were applied: a short photoperiod (8L∶16D), normal photoperiod(12L∶12D) and a long photoperiod(16L∶8D). The results show that digestibility and assimilation rate were highest in the short photoperiod with values of 83 97%±1 16% and 80 46%±1 34%, and lowest in the normal photoperiod with values of 81 74%±1 76% and 78 45%±1 41%. Moreover, the energy intake, digestibility and assimilated energy of N. confucianus decreased with the amount of daylight. The statistical significance of the results obtained by a one-factor analysis of variance were all less than 0 01 or 0 05 except for digested energy. This indicates that photoperiod is an important environmental factor to affect the energy metabolism of Niviventer confucianus .展开更多
文摘Background and Objective: Chronic heavy alcohol consumption and daily cigarette smoking are the most prevalent substance use problems in the U.S., including Veterans. Excessive alcohol use causes neurocognitive and behavioral deficits that can be linked to neurodegeneration. Similarly, preclinical and clinical data suggest that smoking also leads to brain atrophy. This study examines the differential and additive effects of alcohol and cigarette smoke (CS) exposures on cognitive-behavioral function. Methods: A 4-way experimental model of chronic alcohol and CS exposures was generated using 4-week-old male and female Long Evans rats that were pair-fed with Lieber-deCarli isocaloric liquid diets containing 0% or 24% ethanol for 9 weeks. Half of the rats in the control and ethanol groups were exposed to CS for 4 hours/day and 4 days/week for 9 weeks. All rats were subjected to Morris Water Maze, Open Field, and Novel Object Recognition testing in the last experimental week. Results: Chronic alcohol exposure impaired spatial learning as shown by significantly increased latency to locate the platform, and it caused anxiety-like behavior marked by the significantly reduced percentage of entries to the center of the arena. Chronic CS exposure impaired recognition memory as suggested by significantly less time spent at the novel object. Combined exposures to alcohol and CS did not show any significant additive or interactive effect on cognitive-behavioral function. Conclusion: Chronic alcohol exposure was the main driver of spatial learning, while the effect of secondhand CS exposure was not robust. Future studies need to mimic direct CS exposure effects in humans.
文摘The toxicity of benzene was attributed to the formation of free radical. In this study, a method of measuring lipid peroxidation(LPO)in white blood cells(WBC)was reported. After the rats inhaled benzene in different concentrations (6.310\+9, 71.810\+9 and 459.510\+\{-9\} g/L) for 30 days and in concentration of 71.810\+\{-9\} g/L for 10, 20 and 30 days,indicators reflecting toxicity of blood free radicals such as leukocyte LPO, plasma LPO, erythrocyte superoxide dismutase(SOD), erythrocyte glutathione were measured. After 30 day administration, level of leukocyte LPO in all rats of the exposed groups was remarkably higher than that in the control group. Leukopenia occurred only in 71.810\+\{-9\} g/L and 459.510\+\{-9\} g/L groups. The level of leukocyte LPO also increased in 71.810\+\{-9\} g/L group 20 day administration group. Other biochemical indicators had no significant change. It was suggested that the decrease of peripheral leukocytes following benzene exposure might result from, at least in lipid peroxidation, toxic \{effectpart, membrane lipid peroxidation and the determination of leukocyte LPO level is more sensitive than leukocyte count. \;
基金the Natural Science Foundation of Guangdong Province, No. 5002248Social Development Science and Technology Project in Guangdong Province, No. 2006B36030006
文摘Erythropoietin has been shown to exhibit neuroprotective effects in animal models. A neonatal rat model of hypoxic-ischemic white matter damage was established via bilateral carotid artery ligation in 4-day-old Sprague-Dawley rats. The rats were subsequently treated with recombinant human erythropoietin to observe pathological changes in the brain and long-term neurobehavioral functions before and after intervention. Results showed that the number of myelin basic protein-positive cells, which reflected myelin/oligodendrocyte damage, significantly increased, although the number of amyloid precursor protein-positive cells, which reflected axonaf injury, significantly decreased in periventricular white matter at 72 hours and 7 days following erythropoietin intervention. The number of glial fibrillary acidic protein-positive cells, indicating astrocytic damage, significantly decreased in periventricular white matter of erythropoietin-treated rats at 48 hours, 72 hours, 7 days and 26 days. Following erythropoietin intervention in the 30-day-old rats, head-turning time in the slope test was shortened and open-field test scores increased. These results suggested that erythropoietJn promoted repair of white matter damage, as well as improved neurobehavioral functions in a rat model of hypoxic-ischemic injury.
文摘Background & Objective: Chronic excessive alcohol consumption causes white matter degeneration with myelin loss and impaired neuronal conductivity. Subsequent rarefaction of myelin accounts for the sustained deficits in cognition, learning, and memory. Correspondingly, chronic heavy or repeated binge alcohol exposures in humans and experimental models alter myelin lipid composition leading to build-up of ceramides which can be neurotoxic and broadly inhibitory to brain functions. Methods: This study examined the effects of chronic + binge alcohol exposures (8 weeks) and intervention with myriocin, a ceramide inhibitor, on neurobehavioral functions (Open Field, Novel Object Recognition, and Morris Water Maze tests) and frontal lobe white matter myelin lipid biochemical pathology in an adult Long-Evans rat model. Results: The ethanol-exposed group had significant deficits in executive functions with increased indices of anxiety and impairments in spatial learning acquisition. Myriocin partially remediated these effects of ethanol while not impacting behavior in the control group. Ethanol-fed rats had significantly smaller brains with broadly reduced expression of sulfatides and reduced expression of two of the three sphingomyelins detected in frontal white matter. Myriocin partially resolved these effects corresponding with improvements in neurobehavioral function. Conclusion: Therapeutic strategies that support cerebral white matter myelin expression of sulfatide and sphingomyelin may help remediate cognitive-behavioral dysfunction following chronic heavy alcohol consumption in humans.
文摘Niviventer confucianus is a common species of rodent in South China. We designed an experimental protocol to determine the influence of temperature on energy requirement and food assimilation of the N. confucianus . In our feeding trials, four experimental temperatures were applied: 17℃,22℃,27℃ and 32℃. The energy requirements of N. confucianus under different temperature were:107 43±6 44 KJ/animal/day (17℃),94 76±4 46 KJ/animal/day (22℃),73 96±5 65 KJ/animal/day(27℃),and 62 80±5 15 KJ/animal/day(32℃),respectively. Moreover, the energy intake, digested and assimilated energy of N. confucianus decreased with temperature increase. However, no significant differences on digestibility and assimilation rate of N. confucianus were found among four experimental temperatures. It indicated that, during a range of particular temperatures, N. confucianus might maintain relatively high digestibility by change of digest tract morphology.
文摘Digested energy, metabolizable energy, digestibility and assimilation rate were quantified at different photoperiods in Niviventer confucianus using the food balance method. Three photoperiods were applied: a short photoperiod (8L∶16D), normal photoperiod(12L∶12D) and a long photoperiod(16L∶8D). The results show that digestibility and assimilation rate were highest in the short photoperiod with values of 83 97%±1 16% and 80 46%±1 34%, and lowest in the normal photoperiod with values of 81 74%±1 76% and 78 45%±1 41%. Moreover, the energy intake, digestibility and assimilated energy of N. confucianus decreased with the amount of daylight. The statistical significance of the results obtained by a one-factor analysis of variance were all less than 0 01 or 0 05 except for digested energy. This indicates that photoperiod is an important environmental factor to affect the energy metabolism of Niviventer confucianus .
