Bile secretion is dependent on the coordinated functions of a number of hepatobiliary transport systems. Cholestasis may be caused by an impairment of bile secretion, an obstruction of bile flow or a combination of th...Bile secretion is dependent on the coordinated functions of a number of hepatobiliary transport systems. Cholestasis may be caused by an impairment of bile secretion, an obstruction of bile flow or a combination of the two. The common consequence of all forms of cholestasis is retention of bile acids and other potentially toxic compounds in the hepatooltes leading to apoptosis or necrosis of hepatocytes and eventually to chronic cholestatic liver disease. In certain cholestatic disorders there is also leakage of bile acids into the peribiliary space causing portal inflammation and fibrosis. The following pharmacological targets for treatment of intrahepatic cholestasis can be identified: stimulation of orthograde biliary secretion and retrograde secretion of bile acids and other toxic cholephils into the systemic circulation for excretion via the kidneys to reduce their retention in the hepatocytes; stimulation of the metabolism of hydrophobic bile acids and other toxic compounds to more hydrophilic, less toxic metabolites; protection of injured cholangiocytes against toxic effects of bile; inhibition of apoptosis caused by elevated levels of cytotoxic bile acids; inhibition of fibrosis caused by leakage of bile acids into the peribiliary space. The clinical results of ursodeoxcholic acid therapy of primary biliary cirrhosis may be regarded as the first success of this strategy.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
Outstanding progress regarding the pathophysiology of Crohn's disease (CD) has led to the development of innovative therapeutic concepts. Numerous controlled trials have been performed in CD. This review concentra...Outstanding progress regarding the pathophysiology of Crohn's disease (CD) has led to the development of innovative therapeutic concepts. Numerous controlled trials have been performed in CD. This review concentrates on the results of randomized,placebo-controlled trials,and meta-analyses when available,that provide the highest degree of evidence. Current guidelines on the management of CD recommend a step-up approach to treatment involving the addition of more powerful therapies as the severity of disease and refractoriness to therapy increase. The advent of biological drugs has opened new therapeutic horizons for treating CD,modifying the treatment goals. However,the large majority of patients with CD will be managed through conventional therapy,even if they are a prelude to biological therapy.展开更多
文摘Bile secretion is dependent on the coordinated functions of a number of hepatobiliary transport systems. Cholestasis may be caused by an impairment of bile secretion, an obstruction of bile flow or a combination of the two. The common consequence of all forms of cholestasis is retention of bile acids and other potentially toxic compounds in the hepatooltes leading to apoptosis or necrosis of hepatocytes and eventually to chronic cholestatic liver disease. In certain cholestatic disorders there is also leakage of bile acids into the peribiliary space causing portal inflammation and fibrosis. The following pharmacological targets for treatment of intrahepatic cholestasis can be identified: stimulation of orthograde biliary secretion and retrograde secretion of bile acids and other toxic cholephils into the systemic circulation for excretion via the kidneys to reduce their retention in the hepatocytes; stimulation of the metabolism of hydrophobic bile acids and other toxic compounds to more hydrophilic, less toxic metabolites; protection of injured cholangiocytes against toxic effects of bile; inhibition of apoptosis caused by elevated levels of cytotoxic bile acids; inhibition of fibrosis caused by leakage of bile acids into the peribiliary space. The clinical results of ursodeoxcholic acid therapy of primary biliary cirrhosis may be regarded as the first success of this strategy.
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,
文摘Outstanding progress regarding the pathophysiology of Crohn's disease (CD) has led to the development of innovative therapeutic concepts. Numerous controlled trials have been performed in CD. This review concentrates on the results of randomized,placebo-controlled trials,and meta-analyses when available,that provide the highest degree of evidence. Current guidelines on the management of CD recommend a step-up approach to treatment involving the addition of more powerful therapies as the severity of disease and refractoriness to therapy increase. The advent of biological drugs has opened new therapeutic horizons for treating CD,modifying the treatment goals. However,the large majority of patients with CD will be managed through conventional therapy,even if they are a prelude to biological therapy.