AIM:To study the blood-brain barrier integrity,brain edema, animal behavior and ammonia plasma levels in prehepatic portal hypertensive rats with and without acute liver intoxication. METHODS:Adults male Wistar rats w...AIM:To study the blood-brain barrier integrity,brain edema, animal behavior and ammonia plasma levels in prehepatic portal hypertensive rats with and without acute liver intoxication. METHODS:Adults male Wistar rats were divided into four groups.Group Ⅰ:sham operation;Ⅱ:Prehepatic portal hypertension,produced by partial portal vein ligation;Ⅲ: Acetaminophen intoxication and Ⅳ:Prehepatic portal hypertension plus acetaminophen.Acetaminophen was administered to produce acute hepatic injury.Portal pressure,liver serum enzymes and ammonia plasma levels were determined.Brain cortex water content was registered and trypan blue was utilized to study blood brain barrier integrity.Reflexes and behavioral tests were recorded. RESULTS:Portal hypertension was significantly elevated in groups Ⅱ and Ⅳ.Uver enzymes and ammonia plasma levels were increased in groups Ⅱ,Ⅲ and Ⅳ.Prehepatic portal hypertension (group Ⅱ),acetaminophen intoxication (group Ⅲ) and both (group Ⅳ) had changes in the blood brain-barrier integrity (trypan blue) and hyperammonemia.Cortical edema was present in rats with acute hepatic injury in groups Ⅲ and Ⅳ.Behavioral test (rota rod) was altered in group Ⅳ. CONCLUSION:These results suggest the possibility of another pathway for cortical edema production because blood brain barrier was altered (vasogenic) and hyperammonemia was registered (oltotoxic).Group Ⅳ,with behavioral altered test,can be considered as a model for study at an early stage of portal-systemic encephalopathy.展开更多
AIM： To search for new antiviral agents from traditional Chinese medicine, specifically anti-enterovirosuses agents. METHODS： The aqueous extracts （AE） of more than 100 traditionally used medicinal plants in China...AIM： To search for new antiviral agents from traditional Chinese medicine, specifically anti-enterovirosuses agents. METHODS： The aqueous extracts （AE） of more than 100 traditionally used medicinal plants in China were evaluated for their in vitro anti-Coxsackie virus B3 activities with a MTT-based colorimetric assay. RESULTS： The test for AE of 16 plants exhibited anti- Coxsackie virus B3 activities at different magnitudes of potency. They can inhibit three steps （inactivation, adsorption and replication） during the infection. Among the 16 plants, Sargentodoxa cuneata （Oliv.） Rehd. et Wils., Sophora tonkinensis Gapnep., Paeonia veitchii Lynch, Spatholobus suberectus Dunn. and Cyrtorniurn fortunei J, sm. also have activity against other enterovirus, including Coxsackie virus 135, Polio virus I, Echo virus 9 and Echo virus 29. Cell cytotoxic assay demonstrated that all tested AE had CC50 values higher than their EC50 values. CONCLUSION： The sixteen traditionally used medicinal plants in China possessed antMral activity, and some of them merit further investigations.展开更多
Currently, pharmaceutical preparations are serious contributors to liver disease; hepatotoxicity ranking as the most frequent cause for acute liver failure and post-commercialization regulatory decisions. The diagnosi...Currently, pharmaceutical preparations are serious contributors to liver disease; hepatotoxicity ranking as the most frequent cause for acute liver failure and post-commercialization regulatory decisions. The diagnosis of hepatotoxicity remains a difficult task because of the lack of reliable markers for use in general clinical practice. To incriminate any given drug in an episode of liver dysfunction is a step-by-step process that requires a high degree of suspicion, compatible chronology, awareness of the drug’s hepatotoxic potential, the exclusion of alternative causes of liver damage and the ability to detect the presence of subtle data that favors a toxic etiology. This process is time-consuming and the final result is frequently inaccurate. Diagnostic algorithms may add consistency to the diagnostic process by translating the suspicion into a quantitative score. Such scales are useful since they provide a framework that emphasizes the features that merit attention in cases of suspected hepatic adverse reaction as well. Current efforts in collecting bona fide cases of drug-induced hepatotoxicity will make refinements of existing scales feasible. It is now relatively easy to accommodate relevant data within the scoring system and to delete low-impact items. Efforts should also be directed toward the development of an abridged instrument for use in evaluating suspected drug-induced hepatotoxicity at the very beginning of the diagnosis and treatment process when clinical decisions need to be made. The instrument chosen would enable a confident diagnosis to be made on admission of the patient and treatment to be fine-tuned as further information is collected.展开更多
At the present time, more than one-half of all cancer patients are treated with radiation therapy. Despite a good therapeutic index, radiotherapy can disable normal tissue injury to normal tissues in long-term cancer ...At the present time, more than one-half of all cancer patients are treated with radiation therapy. Despite a good therapeutic index, radiotherapy can disable normal tissue injury to normal tissues in long-term cancer survivors.Thus, an important challenge to modern radiation therapy is to increase the tolerance of normal tissues,展开更多
AIM： To assess the defensive nature of Sargassum polycystum （S. polycystum） （Brown alga） against acetaminophen （AAP）-induced changes in drug metabolizing microsomal enzyme system, tumor necrosis factor （TNF-α...AIM： To assess the defensive nature of Sargassum polycystum （S. polycystum） （Brown alga） against acetaminophen （AAP）-induced changes in drug metabolizing microsomal enzyme system, tumor necrosis factor （TNF-α） and fine structural features of the liver during toxic hepatitis in rats. METHODS： Male albino Wistar strain rats used for the study were randomly categorized into 4 groups. Group Ⅰ consisted of normal control rats fed with standard diet. Group II rats were administered with acetaminophen （800 mg/kg body weight, intraperitoneally）. Group Ⅲ rats were pre-treated with S. polycystum extract alone. Group IV rats were orally pre-treated with S. polycystum extract （200 mg/kg body weight for 21 d） prior to acetaminophen induction （800 mg/kg body weight, intraperitoneally）. Serum separated and liver was excised and microsomal fraction was isolated for assaying cytochrome P450, NADPH Cyt P450 reductase and bs. Serum TNF-α was detected using ELISA. Fine structural features of liver were examined by transmission electron microscopy. RESULTS： Rats intoxicated with acetaminophen showed considerable impairment in the activities of drug metabolizing microsomal enzymes, such as cytochrome P450, NADPH Cyt P450 reductase and bs when compared with the control rats. The rats intoxicated with acetaminophen also significantly triggered serum TNF-a when compared with the control rats. These severe alterations in the drug metabolizing enzymes were appreciably pretreated with S. polycystum. prevented in the rats The rats pretreated withS. polycystum showed considerable inhibition in the elevation of TNF-α compared to the rats intoxicated with acetaminophen. The electron microscopic observation showed considerable loss of structural integrity of the endoplasmic reticulum, lipid infiltration and ballooning of mitochondria in the acetaminophen-intoxicated rats, whereas the rats treated with S. polycystum showed considerable protection against acetaminophen-induced alterations in structural integrity. CONCLUSION： These observations suggest that the animals treated with S. polycystum extract may have the ability to protect the drug metabolizing enzyme system and mitochondrial functional status from free radical attack, thereby showing its defense mechanism in protecting hepatic cells from acetaminophen toxic metabolite N-acetyl-para-benzoquinone-imine （NAPQI）.展开更多
基金Supported by Grant #TB 56 from the University of Buenos Aires,Argentina
文摘AIM:To study the blood-brain barrier integrity,brain edema, animal behavior and ammonia plasma levels in prehepatic portal hypertensive rats with and without acute liver intoxication. METHODS:Adults male Wistar rats were divided into four groups.Group Ⅰ:sham operation;Ⅱ:Prehepatic portal hypertension,produced by partial portal vein ligation;Ⅲ: Acetaminophen intoxication and Ⅳ:Prehepatic portal hypertension plus acetaminophen.Acetaminophen was administered to produce acute hepatic injury.Portal pressure,liver serum enzymes and ammonia plasma levels were determined.Brain cortex water content was registered and trypan blue was utilized to study blood brain barrier integrity.Reflexes and behavioral tests were recorded. RESULTS:Portal hypertension was significantly elevated in groups Ⅱ and Ⅳ.Uver enzymes and ammonia plasma levels were increased in groups Ⅱ,Ⅲ and Ⅳ.Prehepatic portal hypertension (group Ⅱ),acetaminophen intoxication (group Ⅲ) and both (group Ⅳ) had changes in the blood brain-barrier integrity (trypan blue) and hyperammonemia.Cortical edema was present in rats with acute hepatic injury in groups Ⅲ and Ⅳ.Behavioral test (rota rod) was altered in group Ⅳ. CONCLUSION:These results suggest the possibility of another pathway for cortical edema production because blood brain barrier was altered (vasogenic) and hyperammonemia was registered (oltotoxic).Group Ⅳ,with behavioral altered test,can be considered as a model for study at an early stage of portal-systemic encephalopathy.
文摘AIM： To search for new antiviral agents from traditional Chinese medicine, specifically anti-enterovirosuses agents. METHODS： The aqueous extracts （AE） of more than 100 traditionally used medicinal plants in China were evaluated for their in vitro anti-Coxsackie virus B3 activities with a MTT-based colorimetric assay. RESULTS： The test for AE of 16 plants exhibited anti- Coxsackie virus B3 activities at different magnitudes of potency. They can inhibit three steps （inactivation, adsorption and replication） during the infection. Among the 16 plants, Sargentodoxa cuneata （Oliv.） Rehd. et Wils., Sophora tonkinensis Gapnep., Paeonia veitchii Lynch, Spatholobus suberectus Dunn. and Cyrtorniurn fortunei J, sm. also have activity against other enterovirus, including Coxsackie virus 135, Polio virus I, Echo virus 9 and Echo virus 29. Cell cytotoxic assay demonstrated that all tested AE had CC50 values higher than their EC50 values. CONCLUSION： The sixteen traditionally used medicinal plants in China possessed antMral activity, and some of them merit further investigations.
基金Supported partly by research grants from the Agencia Espaoladel Medicamento from the Fondo de Investigación Sanitaria(FIS 04-1688 and FIS 04-1759)
文摘Currently, pharmaceutical preparations are serious contributors to liver disease; hepatotoxicity ranking as the most frequent cause for acute liver failure and post-commercialization regulatory decisions. The diagnosis of hepatotoxicity remains a difficult task because of the lack of reliable markers for use in general clinical practice. To incriminate any given drug in an episode of liver dysfunction is a step-by-step process that requires a high degree of suspicion, compatible chronology, awareness of the drug’s hepatotoxic potential, the exclusion of alternative causes of liver damage and the ability to detect the presence of subtle data that favors a toxic etiology. This process is time-consuming and the final result is frequently inaccurate. Diagnostic algorithms may add consistency to the diagnostic process by translating the suspicion into a quantitative score. Such scales are useful since they provide a framework that emphasizes the features that merit attention in cases of suspected hepatic adverse reaction as well. Current efforts in collecting bona fide cases of drug-induced hepatotoxicity will make refinements of existing scales feasible. It is now relatively easy to accommodate relevant data within the scoring system and to delete low-impact items. Efforts should also be directed toward the development of an abridged instrument for use in evaluating suspected drug-induced hepatotoxicity at the very beginning of the diagnosis and treatment process when clinical decisions need to be made. The instrument chosen would enable a confident diagnosis to be made on admission of the patient and treatment to be fine-tuned as further information is collected.
文摘At the present time, more than one-half of all cancer patients are treated with radiation therapy. Despite a good therapeutic index, radiotherapy can disable normal tissue injury to normal tissues in long-term cancer survivors.Thus, an important challenge to modern radiation therapy is to increase the tolerance of normal tissues,
基金Supported by Council of Scientific and Industrial Research, New Delhi, India
文摘AIM： To assess the defensive nature of Sargassum polycystum （S. polycystum） （Brown alga） against acetaminophen （AAP）-induced changes in drug metabolizing microsomal enzyme system, tumor necrosis factor （TNF-α） and fine structural features of the liver during toxic hepatitis in rats. METHODS： Male albino Wistar strain rats used for the study were randomly categorized into 4 groups. Group Ⅰ consisted of normal control rats fed with standard diet. Group II rats were administered with acetaminophen （800 mg/kg body weight, intraperitoneally）. Group Ⅲ rats were pre-treated with S. polycystum extract alone. Group IV rats were orally pre-treated with S. polycystum extract （200 mg/kg body weight for 21 d） prior to acetaminophen induction （800 mg/kg body weight, intraperitoneally）. Serum separated and liver was excised and microsomal fraction was isolated for assaying cytochrome P450, NADPH Cyt P450 reductase and bs. Serum TNF-α was detected using ELISA. Fine structural features of liver were examined by transmission electron microscopy. RESULTS： Rats intoxicated with acetaminophen showed considerable impairment in the activities of drug metabolizing microsomal enzymes, such as cytochrome P450, NADPH Cyt P450 reductase and bs when compared with the control rats. The rats intoxicated with acetaminophen also significantly triggered serum TNF-a when compared with the control rats. These severe alterations in the drug metabolizing enzymes were appreciably pretreated with S. polycystum. prevented in the rats The rats pretreated withS. polycystum showed considerable inhibition in the elevation of TNF-α compared to the rats intoxicated with acetaminophen. The electron microscopic observation showed considerable loss of structural integrity of the endoplasmic reticulum, lipid infiltration and ballooning of mitochondria in the acetaminophen-intoxicated rats, whereas the rats treated with S. polycystum showed considerable protection against acetaminophen-induced alterations in structural integrity. CONCLUSION： These observations suggest that the animals treated with S. polycystum extract may have the ability to protect the drug metabolizing enzyme system and mitochondrial functional status from free radical attack, thereby showing its defense mechanism in protecting hepatic cells from acetaminophen toxic metabolite N-acetyl-para-benzoquinone-imine （NAPQI）.
