Vol. 2 Issue 3
On the cover: Official Journal of the Mexican Association of Hepatology
The small intestine is a unique organ providing dietary and reabsorbed biliary cholesterol to the body. However, the molecular mechanisms whereby cholesterol is absorbed have not yet been fully understood. Recent research suggests that the newly identified ATP-binding cassette (ABC) transporters ABCG5 and ABCG8 are apical cholesterol export pumps that promote partial efflux of cholesterol and nearly complete efflux of plant sterols from enterocytes into the intestinal lumen after their absorption. This provides an explanation why cholesterol absorption is a selective process in that plant sterols and other non-cholesterol sterols are absorbed poorly or not at all. Furthermore, a putative cholesterol import protein has been proposed, but remains uncharacterized. The identification of such a gene should yield new insights into the mechanisms that potentially regulate the influx of cholesterol across the apical brush border membrane of the enterocyte. Combination therapy using a novel and potent cholesterol absorption inhibitor (ezetimibe) and an HMG-CoA reductase inhibitor (statins) offers an efficacious new approach to the prevention and treatment of hypercholesterolemia.
Hepatic encephalopathy (HE) is a complication that presents in as many as 28% of patients with cirrhosis, and reported up to ten years after the diagnosis of cirrhosis. Commonly, it is observed in patients with severe hepatic failure and is characterized by neuropsychiatric manifestations that can range in severity from a mild alteration in mental state to a coma; additionally, some neuromuscular symptoms can be observed. This complication of either acute or chronic hepatic disease is the result of a diminished hepatic reservoir and inability to detoxify some toxins that originate in the bowel. Today, the role of astrocytes, specifically the Alzheimer type II cells, is known to be very important in the pathogenesis of the hepatic encephalopathy, and will be reviewed later. In conclusion, the objectives of this review are: • To understand the pathogenesis of hepatic encephalopathy • To recognize the precipitating factors, as well as preventive measures for the development of the hepatic encephalopathy • To describe the new classification of hepatic encephalopathy and its clinical implications • To recognize the clinical manifestations and stages of the disease • To understand the main diagnostic tests used to detect the hepatic encephalopathy • To describe the main therapeutic treatments of hepatic encephalopathy. presents in as many as 28% of patients with cirrhosis, and reported up to ten years after the diagnosis of cirrhosis. Commonly, it is observed in patients with severe hepatic failure and is characterized by neuropsychiatric manifestations that can range in severity from a mild alteration in mental state to a coma; additionally, some neuromuscular symptoms can be observed. This complication of either acute or chronic hepatic disease is the result of a diminished hepatic reservoir and inability to detoxify some toxins that originate in the bowel. Today, the role of astrocytes, specifically the Alzheimer type II cells, is known to be very important in the pathogenesis of the hepatic encephalopathy, and will be reviewed later.
Background/Aims: Orthotopic liver transplantation is being used with more frequency as the treatment for Wilson´s disease. The experience at the Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran with orthotopic liver transplantation for Wilson´s disease is reported. We perform an extensive literature review for this treatment modality. Methods: Between january 2000 and june 2003, 23 orthotopic liver transplants were performed at our institution, 2 of them for Wilson´s disease. Both the patients presented with chronic advanced liver disease and one presented neurologic dysfunction. Results: Both the patients were trasplanted without any major complication and are alive 43 and 22 months after the transplant respectively. To our knowledge 370 liver transplants have been reported in the international literature since 1994 for the treatment of Wilson´s disease. Conclusions: Currently, orthotopic liver transplantation should be considered as a major option for the treatment of chronic liver disease in patients with Wilson´s disease. Although it is well known that the transplant only partially corrects the defective metabolism in patients with Wilson´s disease, it does convert the copper kinetics of a homozygous to that of a heterozigote, thus, providing an effective phenotypic cure.
Treatment with polyethylene glycol-modified interferon alfa-2a (peginterferon) alone produces significantly higher sustained antiviral responses than treatment with interferon alfa-2a alone in patients with chronic hepatitis C virus (HCV) infection. We compared the efficacy and safety of peginterferon alfa-2a plus ribavirin, interferon alfa-2b plus ribavirin, and peginterferon alfa-2a alone in the initial treatment of chronic hepatitis C. Thirty-two patients were randomly assigned to treatment, and received at least one dose of medication consisting of 180 μg of peginterferon alfa- 2a once weekly plus daily ribavirin (1,000 or 1,200 mg, depending on body weight) (n = 14), weekly peginterferon alfa-2a plus daily placebo (n = 6), or three million units of interferon alfa-2b thrice weekly plus daily ribavirin for 48 weeks (n = 12). More patients who received peginterferon alfa-2a plus ribavirin had a sustained virologic response (defined as the absence of detectable HCV RNA 24 weeks after cessation of therapy) than patients who received interferon alfa-2b plus ribavirin (7/14 vs. 4/12) or peginterferon alfa-2a plus placebo (0/6). The overall safety profiles of the three treatment regimens were similar. In conclusion, for patients with chronic hepatitis C, once-weekly peginterferon alfa-2a plus ribavirin was tolerated as well as interferon alfa-2b plus ribavirin and produced significant improvements in the rate of sustained viral reduction compared with interferon alfa-2b plus ribavirin or peginterferon alfa-2a alone.
We present the case of a 88 years old male, with a history of melena, demonstrated by repeated endoscopys to be secondary to hemobilia, and after endoscopic retrograde cholangiopancreatography we could demonstrate the presence of bleeding intraductal choledocus polyps with histopathological report of intraepitelial adenoma. Hemobilia is a rare cause of upper gastrointestinal hemorrhage with an increasing incidence because of the widespread use of invasive hepatobiliary procedures and improved recognition. In the majority of cases the cause is iatrogenic. The classical presentation of hemobilia is with biliary colic, jaundice, hematemesis, and melena. The diagnosis and evaluation of hemobilia is facilitated by the use of sonography, computed tomography and endoscopic retrograde cholangiopancreatography. Persistent bleeding sometimes requires urgent therapeutic intervention, such as angiography or surgery.