Recurrent pyogenic cholangitis (RPC), also known as Hong Kong disease, Oriental cholangitis, and Oriental infestational cholangitis, is a chronic infection characterized by recurrent bouts of bacterial cholangitis with primary hepatolithiasis. It is exclusive to people who live or have lived in southeast Asia. Presentation
Presentation can be atypical and without pain or fever, especially in the elderly. Positive symptoms include biliary colic, acute pancreatitis, obstructive jaundice and less commonly, liver enlargement and abnormal liver function tests. Additional complications in the acute setting include ascending cholangitis, gallbladder empyema, clotting within the hepatic and portal veins, sepsis and death.Chronic biliary obstruction may cause jaundice, itchiness, liver abscesses, and cirrhosis, particularly at the left lobe segment 3, and can eventually lead to intraductal papillary mucinous neoplasm or cholangiocarcinoma. Pathogenesis
With RPC, the gallstones found within the biliary system are made of calcium bilirubinate or pigmented calcium. Calcium bilirubinate stones are prevalent in Asia and very rare in Europe and the United States. They tend to be friable concretions of various shapes and sizes within the biliary tree, and their associated bile is often muddy in consistency and contains numerous fine particles of calcium bilirubinate as well. This differs greatly from cholesterol stones, which are common in Europe and the United States. The formation of calcium bilirubinate stones in RPC has been attributed to a high incidence of infection with Escherichia coli in bile. In humans, the majority of bilirubin is excreted in the bile as bilirubin glucuronide.Hepatolithiasis is associated with Clonorchis sinensis and Ascaris lumbricoides infestation of the liver.
The isomer which is marketed is (−)-(1R,2S)-ephedrine.Ephedrine hydrochloride has a melting point of 187−188 °C.In the outdated D/L system (+)-ephedrine is also referred to as D-ephedrine and (−)-ephedrine as L-ephedrine (in which case, in the Fisher projection, the phenyl ring is drawn at the bottom).Often, the D/L system (with small caps) and the d/l system (with lower-case) are confused. The result is that the levorotary l-ephedrine is wrongly named L-ephedrine and the dextrorotary d-pseudoephedrine (the diastereomer) wrongly D-pseudoephedrine. The IUPAC names of the two enantiomers are (1R,2S)- respectively (1S,2R)-2-methylamino-1-phenylpropan-1-ol. A synonym is erythro-ephedrine. Sources
Agricultural
Ephedrine is obtained from the plant Ephedra sinica and other members of the genus Ephedra, from which the name of the substance is derived. Raw materials for the manufacture of ephedrine and traditional Chinese medicines are produced in China on a large scale. As of 2007, companies produced for export US$13 million worth of ephedrine from 30,000 tons of ephedra annually, or about ten times the amount used in traditional Chinese medicine. Synthetic
Most of the l-ephedrine produced today for official medical use is made synthetically as the extraction and isolation process from E. sinica is tedious and no longer cost effective. Biosynthetic
Ephedrine was long thought to come from modifying the amino acid L-phenylalanine. L-Phenylalanine would be decarboxylated and subsequently attacked with ω-aminoacetophenone. Methylation of this product would then produce ephedrine. This pathway has since been disproven. A new pathway proposed suggests that phenylalanine first forms cinnamoyl-CoA via the enzymes phenylalanine ammonia-lyase and acyl CoA ligase.