Pathogenesis of pigment stones and medical treatment

New Evidences of Key Factors Involved in "Silent Stones" Etiopathogenesis and Trace Elements: Microscopic, Spectroscopic, and Biochemical Approach

The knowledge of the key factors involved in etiopathogenesis of the gallstone disease requires chemical, structural, and elemental composition analysis. The application of different complementary analytical techniques, both microscopic and spectroscopic, are aimed to provide a more comprehensive determination of the gallbladder calculi ultrastructure and trace element identification. High sensitivity techniques such as electron microscopy (SEM), Fourier transform infrared (FTIR), electron paramagnetic resonance (EPR) spectroscopy, and X-ray diffraction (XRD) along with biochemical analysis are used in a new attempt to investigate various factors which play a regulatory role in the pathogenesis of gallstones. The microstructure of different types of gallbladder stones has specific characteristics which are related to the elemental composition. The binding of metal ions with bile salts and bilirubin plays important roles in gallstone formation as revealed by FTIR spectrum of calcium bilirubinate complex in pigment gallstones. The EPR results demonstrated the generation of bilirubin free radicals and variation of its electronic structure and conjugation system in the skeleton of bilirubin molecule during complex formation. EPR spectra of pigment gallstones demonstrate the coexistence of four paramagnetic centers including stable bilirubin free radical, Mn2+, Cu2+, and Fe3+ with distinct magnetic parameters and well-resolved hyperfine structure in the case of Mn2+ ions. The result confirms a macromolecular network structure with proteins and the formation of bilirubin-coordinated polymer. Bilirubin and bilirubinate free radical complexes may play an important role in pigment gallstone formation.

TRACE ELEMENT ANALYSIS OF SOUTH INDIAN GALLSTONES BY PIXE

Particle Induced X-ray Emission (PIXE) was used to analyse the elemental concentration of gallstones collected from different parts of south India. Cholesterol gallstones are predominant in north India, whereas pigment gallstones are predominant in south India. The black pigment gallstones are common in hemolytic anemia or in presence of infected bile. PIXE has revealed the elemental profile in each sample. The experimental subjects of the different groups displayed significant variation in their levels of certain trace elements such as copper, zinc, and iron. The concentration of copper was found to be predominant in pigment gallstones investigated in the present study.

Composition of common bile duct stones in Chinese patients during and after endoscopic sphincterotomy

AIM: Endoscopic sphincterotomy (ES) is a well-established therapeutic modality for the removal of common bile duct (CBD) stones. After ES there are still around 10% of patients that experience recurrent CBD stones. The aim of this study is to investigate the composition of CBD stones before and after ES and its clinical significance in Chinese patients.

METHODS: From January 1996 to December 2003, 735 patients with CBD stones received ES at Kaohsiung Veterans General Hospital and stone specimens from 266 patients were sent for analysis. Seventy-five patients had recurrent CBD stones and stone specimens from 44 patients were sent for analysis. The composition of the stones was analyzed by infrared (IR) spectrometry and they were classified as cholesterol or bilirubinate stones according to the predominant composition. Clinical data were analyzed.

RESULTS: In the initial 266 stone samples, 217 (82%) were bilirubinate stones, 42 (16%) were cholesterol stones, 3 were calcium carbonate stones, 4 were mixed cholesterol and bilirubinate stones. Patients with bilirubinate stones were significantly older than patients with cholesterol stones (66 ± 13 years vs 56 ± 17 years, P = 0.001). In the 44 recurrent stone samples, 38 (86%) were bilirubinate stones, 3 (7%) were cholesterol stones, and 3 were mixed cholesterol and bilirubinate stones. In 27 patients, both initial and recurrent stone specimens can be obtained, 23 patients had bilirubinate stones initially and 2 became cholesterol stones in the recurrent attack. In the four patients with initial cholesterol stones, three patients had bilirubinate stones and one patient had a cholesterol stone in the recurrent attack.

CONCLUSION: Bilirubinate stone is the predominant composition of initial or recurrent CBD stone in Chinese patients. The composition of CBD stones may be different from initial stones after ES.

Bacterial DNA in mixed cholesterol gallstones

OBJECTIVE

Numerous investigators have proposed a role for bacteria in biliary lithogenesis. We hypothesized that bacterial DNA is present in gallstones, and that categorical differences exist between gallstone type and the frequency of bacterial sequences.

METHODS

Polymerase chain reaction (PCR) was used to amplify bacterial 16S rRNA and uidA (encoding Escherichia coli [E. coli] beta-glucuronidase) genes in different types of gallstones. PCR products were sequenced.

RESULTS

Bacterial 16S rRNA and uidA DNA sequences in E. coli were detected in all brown pigment, common bile duct, and mixed cholesterol gallstones (n = 14). In contrast, only one (14%) of seven pure cholesterol gallstones yielded a PCR product. Most (88%) mixed cholesterol gallstones yielded PCR amplification products from their central, as well as their outer, portions. Sequenced products possessed 88-98% identity to 16S rRNA genes of E. coli and Pseudomonas species.

CONCLUSIONS

Bacterial DNA sequences are usually present in mixed cholesterol (to 95% cholesterol content), brown pigment, and common bile duct, but rarely in pure cholesterol gallstones. The presence of bacterial beta-glucuronidase is also suggested. The role of bacteria and their products in the formation of mixed cholesterol gallstones, which comprise the majority of cholesterol gallstones, warrants further study.

Biliary tract disease in children

This article discusses congenital and acquired disorders of the bile ducts and gallbladder in infants and children. Problems, such as extrahepatic biliary atresia, that are unique to infants are covered as well as distinctive aspects of hepatobiliary disease in older children. Biliary tract disease in the fetus and neonate presents an important challenge in that not only is hepatic structure and function disturbed but also the process of normal development may be retarded or altered by the disease process.