Brown Pigment Stones Research Articles

Epidemiological study on Korean gallstone disease: a nationwide cooperative study.

To clarify the epidemiological characteristics of gallstone disease in Korea and to evaluate the chronological changes in gallstone disease, the authors performed this first prospective nationwide cooperative study. The subjects were 1263 gallstone patients who were admitted at 19 hospitals in Korea from February to July 1997. Questionnaires were recorded on 1263 patients and gallstones were harvested from 1133 patients. The proportion of patients with gallbladder (GB), common bile duct (CBD), and intrahepatic duct (IHD) stones among total gallstone patients was 64.0%, 21.9%, and 14.1%, respectively. GB stones were categorized as cholesterol (58.1%), black pigment (25.2%), and brown pigment (12.1%) stones. CBD stones were classified as brown pigment (76.1%), cholesterol (18.4%), and black pigment (3.5%) stones. IHD stones were classified as brown pigment (61.4%) and mixed (35.6%) stones. Intrahepatic mixed stones had mean cholesterol and bilirubin contents of 63.4 +/- 20.8% and 23.1 +/- 9.9%, respectively. In contrast, IHD brown pigment stones had mean cholesterol and bilirubin contents of 35.1 +/- 20.5% and 39.6 +/- 17.4%, respectively. Our study showed that the type and composition of gallstones in Korea was somewhat different compared with those in the West. This study also demonstrated that there have been chronological changes in the type and composition of gallstones when compared with previous domestic data. Another nationwide cooperative study may be needed to elucidate and confirm the changing pattern of gallstone disease.

Mucin Content in Gallbladderswith Brown Pigment Stones orCombination Stones with a Brown Periphery

Background/Aims: Gallbladder mucus itself has been recognized to play an important role in gallstone development. Despite the diverse mechanisms of stone induction and the differences in stone composition, there is a quantitative increase in the epithelial mucus production period before stone formation. As brown pigment stones are found frequently in gallstone disease, we conducted a study on gallbladders with brown pigment stones or combination stones with a brown periphery to evaluate the mucin content in the gallbladder epithelium in comparison to gallbladders with cholesterol stones and those without stones. Methods: Gallbladder specimens were fixed in 10% formalin immediately after cholecystectomy and then embedded in paraffin. The specimens were sectioned for periodic acid-Schiff-alcian blue (PAS-AB, pH 2.5) double stain to evaluate the intra-epithelial mucin content. The PAS-AB index was calculated as a proportion of the PAS-AB-positive mucin area to the total epithelial area, using a computerized image analyzer. Results: Evaluation of the PAS-AB index on the lining epithelia of gallbladders showed that it was 32.43 ± 9.96% in gallbladders with brown stones, which is significantly (p < 0.001) higher than in gallbladders with cholesterol stones (15.63 ± 6.75%) and gallbladders without stones (9.55 ± 4.77%). Conclusion: The results show that gallbladders with brown stones contain more abundant mucin than gallbladders with cholesterol stones or those without stones. They also suggest that the gallbladder epithelium per se might play a more important role in stone formation in those with brown stones than in those with cholesterol stones.

Cluster Analysis of Gallstone FT-IR Spectra: Tests on Simulated Mixture Spectra and Comparison between Spectral and Morphological Classification of Human Gallstones

Sixty-four combination spectra of three major gallstone components [i.e., cholesterol, calcium bilirubinate, and calcium carbonate (aragonite)] were simulated in accordance with a “fractal” ternary diagram. Comparison between the original pattern of composition and factorial maps of pretreated spectra makes it possible to show the effects of different normalization procedures (Euclidean norm, spectrum maximum, and area under spectrum set to 1). Cluster analysis of these spectra, depending on different agglomerative links (single linkage, complete linkage, average linkage, and Ward's criterion), was carried out. All the resultant trees yield the same groups, but Ward's criterion best preserves the pattern of the data. More than 100 gallstones from France and Vietnam were classified by using cluster analysis of their FT-IR spectra with Ward's criterion. Seven homogeneous groups of spectra were extracted, which have been significantly correlated to the four morphological types of gallstones: pure cholesterol, mixed cholesterol, brown pigment, and black pigment stones. This analysis also reveals that the morphological groups are not homogeneous in composition, in particular for black pigment stones.

Inhibition of biliary endoprostheses occlusion by ampicillin-sulbactam in an in vitro model

An important first step in stent occlusion is the formation of a bacterial biofilm. This is followed by deposition of granules similar to that found in brown pigment stones. Previous in vitro models for studying occlusion have used synthetic biles without bilirubin or pooled human bile, which is limited in supply. Our aim was to develop a new in vitro model of stent occlusion with porcine gallbladder bile and then, with the model, assess whether ampicillin-sulbactam can prevent biofilm formation and thus occlusion. Sterile porcine gallbladder bile was contaminated with Escherichia coli then divided into eight reservoirs, four of which then received ampicillin-sulbactam. The bile was then circulated through 1OF polyethylene stents. Bile was changed weekly for 8 weeks. In the stents that were untreated, biofilm and sludge were seen in all four, whereas the four ampicillin-sulbactam-treated stents had no biofilm when viewed by electron microscopy. Furthermore, the levels of calcium, cholesterol, and bilirubin in the reservoirs decreased significantly in the untreated bile as compared with the treated bile ( p < 0.05). In this in vitro model, the losses of calcium, cholesterol, and bilirubin are likely caused by deposition of granules into the biofilm matrix. Ampicillin-sulbactam can prevent biofilm formation if used continuously.

Migration of metallic clips used during laparoscopic cholecystectomy and formation of gallstones around them: surgical implications from a prospective study.

Two groups of patients, with laparoscopic cholecystectomy (LC) were prospectively studied. All patients had serial plain abdominal X-ray examinations at various intervals after operation, to record the position of clips placed during LC. Seventy-one patients had less cystic duct (CD) dissection and > or =4 clips placed during the procedure. One hundred and fifteen patients had a larger CD dissection and only 4 clips placed (2 on the cystic artery and 2 on the CD, without additional clips on smaller vessels). In the former group, 7 patients had clip migration within 1 month and 11 within 1 year vs 1 either at 1 month or 1 year in the latter group (p = 0.01 and <0.001, respectively). During the follow-up, a 72-year-old man belonging to the former group had a recurrent common duct brown pigment stone containing a metallic clip 26 months after operation. He was treated successfully by endoscopic sphincterotomy. Factors predisposing to clip migration were short cystic stump, inadvertent clip dislodgment or incorrect placement, cystic duct ischemic necrosis, and local suppurative complications. Data from 29 patients with GS formed around suture material or phytobezoars observed during a prospective study and from the physicochemical and structural analysis of a cumulative series of 64 GS containing foreign bodies are also presented and discussed. It is suggested that metallic clips can migrate from their initial sites at various intervals within the peritoneal cavity or into the common duct and serve as a nidus for GS formation. Metallic clip migration in most cases is due to technical factors and can usually be prevented. However, it is not possible to prevent either clip migration or GS formation in every case, since even well-placed clips can migrate due to suppurative complications or local ischemic damage, and, once that penetration within the bile tract has occurred, GS are usually going to form, irrespective of the nature and the shape of the foreign body.

A spectroscopic study of pigment gallstones in China

Spectroscopic studies of various types of gallstones carried out in China are reviewed. Three basic classes of gallstones are surveyed: cholesterol stones, brown pigment stones, and black pigment stones. The emphasis of this review is on brown gallstones. The primary spectroscopic methods used in the studies surveyed are Fourier transform infrared absorption and Fourier transform Raman scattering. Chemical components studied in gallstones include cholesterol, bile pigments, glycoproteins, proteins, bilirubin metal complexes, and salts of calcium and other metals. Further studies are needed characterize the relationship of these components to more complex features of gallstones. © 1997 John Wiley & Sons, Inc. Biospectroscopy 3: 371–380, 1997

A spectroscopic study of pigment gallstones in China

Spectroscopic studies of various types of gallstones carried out in China are reviewed. Three basic classes of gallstones are surveyed: cholesterol stones, brown pigment stones, and black pigment stones. The emphasis of this review is on brown gallstones. The primary spectroscopic methods used in the studies surveyed are Fourier transform infrared absorption and Fourier transform Raman scattering. Chemical components studied in gallstones include cholesterol, bile pigments, glycoproteins, proteins, bilirubin metal complexes, and salts of calcium and other metals. Further studies are needed characterize the relationship of these components to more complex features of gallstones. © 1997 John Wiley & Sons, Inc. Biospectroscopy 3: 371–380, 1997

The internal biliary fistula--reappraisal of incidence, type, diagnosis and management of 33 consecutive cases.

To reevaluate the current features of spontaneous internal biliary fistulas, we reviewed 1,929 consecutive patients who had been treated for biliary tract diseases during the recent 12-year period. Thirty-three patients had internal biliary fistulas and the incidence was 1.9%. Of 33 patients, 20 were women and 13 were men with the average age 63 years, and their mean duration of illness was 4 years. A total of 37 fistulas were found and the most common type was choledochoduodenal (62%), followed by cholecystoduodenal (19%), cholecystocholedochal (11%) and cholecystocolonic (8%) fistulas. Internal biliary fistulas of thirty-one patients were caused by biliary stones and those of two patients by malignant tumors. All of the 17 bile samples examined were bacteria positive and the majority of calculi were brown pigment stones. All of the choledochoduodenal fistulas were correctly diagnosed by endoscopic retrograde cholangiography. In 14 patients with cholecystoenteric or cholecystocholedochal fistulas, direct evidence of the internal fistula was obtained only in 7 patients (50%) preoperatively. Pneumobilia, a small atrophic gallbladder adherent to the neighboring organs and a history of spontaneous disappearance of jaundice in elderly patients may indicate the presence of a cholecystoentric fistula. Since the preoperative diagnostic rate for internal biliary fistula involving the gallbladder is still low, care is necessary before and at the time of surgery especially during laparoscopic cholecystectomy for elderly patients with cholelithiasis.

Contact solvents for common bile duct stones. Study in an in vitro system

Cholesterol and brown pigment stones found in the common bile duct are often radiolucent and therefore indistinguishable. The purpose of this study was to define contact solvent systems able to dissolve both stone types. The influence of mucolytic agents on in vitro pigment stone dissolution was first determined. It was shown that dithioerythritol induced more rapid dissolution than N-acetylcysteine. Alternating treatment with an aqueous alkaline solvent (pH = 9.5), composed of sodium deoxycholate 50 mM, ethylenediaminetetraacetate 26 mM and dithioerythritol 50 mM, for 45 min, and an organic solvent methyl tert-butyl ether/dimethyl sulfoxide (90/10) for 15 min, was more effective for bilirubin, cholesterol, and fatty acid solubilization (p < 0.01) than using these solvents separately. The dissolution of brown stones was nearly completed within 9 h and that of mixed cholesterol stones was obtained within 3 h. We conclude that the alternating treatment described is very effective for the rapid in vitro dissolution of the two major stone types present in the bile ducts, and deserves further assessment in vivo.

Pathogenesis and Clinical Presentation of Bile Duct Calculi

Clearer understanding of the pathogenesis of bile duct calculi and better recognition of the clinical presentation of various clinical disorders caused by biliary stones are essential for proper diagnosis and treatment. This article reviews the pathogenesis of secondary stones (cholesterol and black pigment stones) and primary stones (brown pigment stones), as well as the main features of biliary calculi (pain, obstruction, and sepsis), followed by discussion of the clinical presentations of bile duct stones with gallbladder in situ and after cholecystectomy, and description of the manifestations of primary bile duct stones, cholangitis, primary sclerosing cholangitis, oriental cholangitis, and gallstone pancreatitis.

Pathogenesis and Clinical Presentation of Bile Duct Calculi.

Clearer understanding of the pathogenesis of bile duct calculi and better recognition of the clinical presentation of various clinical disorders caused by biliary stones are essential for proper diagnosis and treatment. This article reviews the pathogenesis of secondary stones (cholesterol and black pigment stones) and primary stones (brown pigment stones), as well as the main features of biliary calculi (pain, obstruction, and sepsis), followed by discussion of the clinical presentations of bile duct stones with gallbladder in situ and after cholecystectomy, and description of the manifestations of primary bile duct stones, cholangitis, primary sclerosing cholangitis, oriental cholangitis, and gallstone pancreatitis.

Increase of deoxycholate in supersaturated bile of patients with cholesterol gallstone disease and its correlation with de novo syntheses of cholesterol and bile acids in liver, gallbladder emptying, and small intestinal transit

A total of 100 nonobese and normolipidemic subjects (29 control subjects, 49 patients with cholesterol stones [CSs], and 22 patients with brown pigment stones) were studied to elucidate the pathogenetic contributions of deoxycholate (DC) to supersaturated bile formation with special reference to de novo syntheses of cholesterol and bile acids in the liver. A higher proportion of DC was observed in gallbladder bile from patients with CSs (CSs; 21.7 ± 1.4%, mean ± SEM, vs. control subjects; 10.2 ± 0.9%). Cholesterol saturation in bile was elevated parallel to the increase of DC ( r = .48; P = .0002), irrespective of the existence of stones. In a comparison between the 52 subjects with increased DC in bile (>10% of biliary bile acids) and the 20 subjects without the increase (<10%), the molar percentage of cholesterol in bile was significantly higher in the former (9.4 ± 0.5%) than in the latter (6.7 ± 0.4%) ( P < .001). Consistent with the decrease in steady-state level of low-density lipoprotein (LDL) receptor-messenger RNA (mRNA), the catalytic activity and mRNA level of microsomal hepatic 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, the rate-limiting enzyme for de novo cholesterol synthesis, were significantly lower in the former (2.9 ± 0.3 pmol/min/mg protein) than in the latter (5.1 ± 0.6) ( P < .0001). Biliary molar percentage of bile acids was significantly lower in the former (69.8 ± 1.1%) than in the latter (75.2 ± 1.5%) ( P < .01). However, contrary to expectations, the catalytic activity and mRNA level of cholesterol 7a-hydroxylase, the rate-limiting enzyme for bile acid synthesis, were significantly higher in the former (5.8 ± 0.4 pmol/min/mg protein) than in the latter (3.7 ± 0.6) ( P < .01). The magnitude of the impaired gallbladder emptying (control subjects; 78.4 ± 4% vs. CSs; 58 ± 3%; P < .0005) together with the prolonged small intestinal transit (control subjects; 126 ± 9 minutes vs. CSs; 198 ± 9 minutes; P < .01) correlated significantly with the increased percentage of DC in bile. It is concluded that in cholesterol gallstone disease an increase of DC in bile, linked to an impaired gallbladder emptying together with a prolonged small intestinal transit, may play a significant role in downregulating de novo cholesterol synthesis but not bile acid synthesis in the liver. It is further suggested that the formation of supersaturated bile may be attributed to a hypersecretion of cholesterol (derived from an exogeneous source) driven by the flow of DC through the liver, combined with a normosecretion or hyposecretion of bile acids, the pool size of which is reduced because of changes in distribution, e.g., a sequestration into the hypomotile gallbladder and intestine.

Primary dual defect of cholesterol and bile acid metabolism in liver of patients with intrahepatic calculi

Background/Aims Intrahepatic calculi, which are characterized by cholesterol-rich pigment stones, are highly prevalent in East Asia. Their pathogenesis remains unknown. To elucidate the etiological factors underlying the formation of cholesterol-supersaturated bile, which leads to the formation of cholesterol-rich pigment stones, cholesterol and bile acid de novo syntheses in the liver were studied. Methods Liver specimens were assayed for the catalytic activities and steady-state messenger RNA levels of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase and cholesterol 7α-hydroxylase. Results The activity of HMG-CoA reductase, consistent with the messenger RNA level, was significantly higher in 13 patients with intrahepatic brown pigment stones (11.2 ± 1.3 pmol · min −1 · mg protein −1 [mean ± SEM; P < 0.0001] for affected hepatic lobes and 13.4 ± 1.7 [ P < 0.0001] for unaffected ones [ P < 0.0001]) than in 19 control subjects (6.4 ± 0.4) and in 29 patients with gallbladder cholesterol stones (2.1 ± 0.1). On the other hand, the activity of 7α-hydroxylase, consistent with the messenger RNA level, was significantly lower in patients with intrahepatic brown pigment stones (2.8 ± 0.5 pmol · min −1 · mg protein −1 [ P < 0.0001] for affected lobes and 2.6 ± 0.5 [ P < 0.0001] for unaffected ones) than in control subjects (6.0 ± 0.6) and in patients with cholesterol stones (5.1 ± 0.5). Conclusions In intrahepatic calculi, the formation of supersaturated bile and cholesterol-rich pigment stones may be attributed to the primary dual defect of up-regulated cholesterogenesis and down-regulated bile acid synthesis in the liver.

Elevated Anti-Alginate Serum Titers in Patients with Acute Cholangitis and Gallstones Imbedded with Pseudomonas aeruginosa

Electron microscopy and bacteriological culture revealed viable bacteria covered with a glycocalyx (biofilm) in choledochal stones recovered from two patients with acute cholangitis. On the cut surface of the choledochal stones, the cholesterol stone component was surrounded with a layer of brown pigment stone. In each case, bacterial culture of the choledochal stone recovered <i>Pseudomonas aeruginosa.</i> Since alginate is the main component of the glycocalyx produced by <i>P. aeruginosa</i>, serum lgM, IgG and IgA anti-alginate antibodies were measured in each patient. The present study is the first to demonstrate acute and transient IgM seroconversion to alginate in cases of acute cholangitis, in one case, the elevation of anti-alginate IgM preceded the elevation of anti-alginate IgG. The authors propose that the bacterial glycocalyx may play a significant role in acute cholangitis.

Common bile duct stones are mainly brown and associated with duodenal diverticula.

This study investigated the composition of common duct gall stones from 61 patients, aged 49-94. The stones were collected endoscopically with a dormia basket after endoscopic papillotomy. The cholesterol content was measured both by infrared spectroscopy (mean 29%, range 0-99%) and enzymatically (mean 23%, range 0-96%). The results of the two measurements showed good correlation (r2 = 0.92), indicating that cholesterol can be adequately measured enzymatically. Most of the stones were pigment stones. When examined by infrared spectroscopy, 44 stones (72%) contained less than 50% cholesterol (mean 4%, range 0-23%). The bilirubinate content in these stones was 56%, range 12-100%. Forty two of these stones were brown stones, and only two were black stones. Pigment stones were associated with juxtapapillary diverticula (p < 0.01). It was found that brown pigment stones were the commonest symptomatic bile duct calculi in the patients studied, who are representative of a Western population.

The distribution of calcium salt precipitates in the core, periphery and shell of cholesterol, black pigment and brown pigment gallstones

Calcium bilirubinate, palmitate, carbonate and phosphate have been identified in the cores of cholesterol and pigment gallstones, suggesting a role for precipitated calcium salts in the early events of gallstone formation. Previous studies that compared the calcium salt contents of cholesterol and pigment stones required destruction of gallstone structure. We have used scanning electron microscopy with windowless energy-dispersive x-ray microanalysis to determine the prevalence of calcium salts in a series of cholesterol (n = 105), black pigment (n = 35) and brown pigment (n = 6) gallstones obtained from 146 consecutive patients undergoing cholecystectomy. These techniques provide specific identification of cholesterol and individual calcium salts as they occur within the core, periphery and shell of gallstones without destroying stone structure. Calcium precipitates more than 0.5 micron in diameter can be detected in a cholesterol background at a detection limit of 0.01% by weight. Calcium salts were detected in the centers of 88% of cholesterol and 100% of black (p < 0.05 vs. cholesterol) and brown pigment stones. Calcium bilirubinate was identified in the cores of 54% of cholesterol and in all pigment stones (p < 0.001 black pigment vs. cholesterol). Calcium palmitate was detected in all brown pigment stones, in 39% of cholesterol stones (p < 0.001 vs. brown pigment) and in 31% of black stones (p < 0.01 vs. brown pigment). Peripheral calcium salts were detected less in cholesterol (19%) than in black or brown stones (100%, p < 0.05). Fourteen percent of cholesterol and black pigment stones were surrounded by shells containing mostly calcium carbonate.(ABSTRACT TRUNCATED AT 250 WORDS)

The distribution of calcium salt precipitates in the core, periphery and shell of cholesterol, black pigment and brown pigment gallstones

Calcium bilirubinate, palmitate, carbonate and phosphate have been identified in the cores of cholesterol and pigment gallstones, suggesting a role for precipitated calcium salts in the early events of gallstone formation. Previous studies that compared the calcium salt contents of cholesterol and pigment stones required destruction of gallstone structure. We have used scanning electron microscopy with windowless energy-dispersive x-ray microanalysis to determine the prevalence of calcium salts in a series of cholesterol (n=105), black pigment (n=35) and brown pigment (n=6) gallstones obtained from 146 consecutive patients undergoing cholecystectomy. These techniques provide specific identification of cholesterol and individual calcium salts as they occur within the core, periphery and shell of gallstones without destroying stone structure. Calcium precipitates more than 0.5 μm in diameter can be detected in a cholesterol background at a detection limit of 0.01% by weight. Calcium salts were detected in the centers of 88% of cholesterol and 100% of black (p<0.05 vs. cholesterol) and brown pigment stones. Calcium bilirubinate was identified in the cores of 54% of cholesterol and in all pigment stones (p<0.001 black pigment vs. cholesterol). Calcium palmitate was detected in all brown pigment stones, in 39% of cholesterol stones (p<0.001 vs. brown pigment) and in 31% of black stones (p<0.01 vs. brown pigment). Peripheral calcium salts were detected less in cholesterol (19%) than in black or brown stones (100%, p<0.05). Fourteen percent of cholesterol and black pigment stones were surrounded by shells containing mostly calcium carbonate. The range of stone cholesterol contents (0% to 100%) and frequency of calcium salt precipitates suggest that pigment and cholesterol gallstones represent a spectrum of disease differing more in their peripheral compositions than in their central regions. Cholesterol and pigment gallstones may differ more in growth than in the initial events of stone nidation. (HEPATOLOGY 1994;19:1124–1132.)

Chemical dissolution of gallstones in Taiwan: an in vitro study.

To evaluate the potential for the chemical dissolution of gallstones, 480 stones from 214 patients were studied. The stones were obtained via surgery or endoscopically. They were classified into cholesterol-rich mixed stones, brown pigment stones and black stones. The composition of bilirubin and cholesterol was determined by Fourier transformed infrared spectroscopy. Two per cent tetrasodium ethylenediamine acetate (EDTA), dimethylsulfoxide (DMSO) or methyl-tert-butyl-ethylene (MTBE) were used to dissolve the stones. To enhance solubility, surfactant polysorbate-20 was used to mix two of the individual three solvents. Methyl-tert-butyl-ethylene was found to have the best dissolution ability (by dry weight) 94, 13.4 and 20% for mixed, brown and black stones, respectively. Dimethylsulfoxide resulted in 13, 14 and 25% dissolution and EDTA 9.5, 13 and 16.5%. In contrast, pure water dissolved 4, 6 and 10.4% of the stones, respectively. A combination of the dissolution agents did not enhance the dissolution rate. In fact, the combination of solvents unexpectedly reduced the solubility of the stones: EDTA/MTBE was 17.5, 6.7 and 16.0%; DMSO/MTBE 43.2, 21.9 and 18.0%; DMSO/EDTA 9.1, 7.0 and 9.6%. In conclusion, cholesterol-rich mixed stones were able to be dissolved using MTBE but results of contact dissolution for gallstones are still far from satisfactory.

Differences in outer membrane characteristics between gallstone-associated bacteria and normal bacterial flora

Previous studies with scanning electron microscopy (SEM) have suggested that pigment gallstones contain bacteria. We set out to culture these bacteria and to study their membrane characteristics. We studied gallstones from 54 patients (36 men, 18 women; mean age 55·4 years) admitted consecutively to two hospitals for cholecystectomy. SEM detected bacteria in all of 14 brown pigment stones, 2 of 14 black pigment stones, and in the pigmented centres of 9 of 19 mixed cholesterol stones; no bacteria were detected in 14 pure cholesterol stones or within the cholesterol portions of mixed stones. We were able to culture bacteria from all gallstones with bacteria seen on SEM and for which sufficient material was available (n=16). 20 bacterial species were recovered from these stones. Gallstones containing bacteria were associated with clinical sepsis and cholangitis. All bacteria obtained from gallstones agglutinated human O P1 erythrocytes, which reflects the presence of P1-specific fimbriae. 5 strains were positive for Forssman-antigen-specific fimbriae. None showed evidence of mannose-specific fimbriae. All of the organisms bound anti-Gal, a ubiquitous naturally occurring IgG specific for α-galactosyl residues. The presence of P1 fimbriae and α-galactosyi residues and the absence of mannose-specific fimbriae distinguish these organisms from gut flora. We postulate that possession of these unusual properties may enhance the ability of bacteria to colonise the biliary tree and initiate pigment gallstone formation.

Alterations of bile acid composition in gallstones, bile, and liver of patients with hepatolithiasis, and their etiological significance.

A detailed comparison was made of the bile acid composition in gallstones (brown pigment stones) and paired bile and liver from both affected and unaffected lobes by gallstones, which were taken at operation from 16 patients with hepatolithiasis, with the aim of elucidating whether stone formation is derived from possible local disturbances limited to intrahepatic bile ducts. Brown pigment stones in the intrahepatic bile ducts, most of which were accompanied by bile with high cholesterol saturation, had significantly more cholesterol, and less calcium bilirubinate and bile acid than those found in the extrahepatic bile ducts. Intrahepatic gallstones had significantly lower amounts of secondary and unconjugated bile acids, the bile acids modified by bacterial intervention, than extrahepatic stones. Bile specimens from both affected and unaffected lobes showed significantly increased molar percentages of cholesterol and decreased percentages of bile acids than bile from controls. In contrast, liver specimens from both lobes showed significantly higher concentrations of total bile acids. Secondary bile acids were present in a much lower proportion in bile and liver from both lobes than in bile and liver from controls. On the other hand, unconjugated bile acids were present in a much higher proportion in bile and liver from patients and only in negligible amounts in bile from controls. Furthermore, the plasma levels of mevalonate and those of 7 alpha-hydroxy-4-cholestene-3-one were found to be significantly higher and lower in patients than in controls, respectively, indicating that in hepatolithiasis cholesterol synthesis might increase and bile acid synthesis might decrease in the liver. These findings suggested that alterations of bile acid composition in gallstones, bile, and liver of patients with hepatolithiasis may be attributed to not only secondary changes resulting from local disturbances limited to intrahepatic bile ducts but also possible primary alterations of hepatocyte metabolism, such as bile acid conjugation and primary defects in cholesterol and bile acid synthesis.