Pathogenesis of calcium bilirubinate gallstone: role of E. coli, beta-glucuronidase and coagulation by inorganic ions, polyelectrolytes and agitation

Cholelithiasis in Taiwan. Gallstone characteristics, surgical incidence, bile lipid composition, and role of beta-glucuronidase

The nature and occurrence of gallstones in Taiwan and their etiologic factors might not be the same as in Western countries and warranted a systematic investigation. Gallbladder biles and gallstones were obtained at surgery from 100 and 74 patients, respectively. Common duct bile and stones were either drained through an indwelling common duct T-tube or aspirated through a nasobiliary catheter in 108 patients. Gallstones were analyzed for bilirubin, cholesterol, bile acid, calcium, and residue, and biles for bile acid, cholesterol, phospholipid, bilirubin, and beta-glucuronidase. There were four major kinds of gallstones in Taiwan: cholesterol/mixed stones, high-residue black formed pigment stones, low-residue brown formed pigment stones, and muddy pigment stones. The surgical incidence of all types of stones increased steadily during the past four decades. During the past 15 years the relative frequencies for mixed, formed pigment, and muddy pigment stones had been roughly 40, 40, and 20%, respectively, with a further increase in the mixed stones and a decrease in the muddy pigment stones in recent years. Improvement of nutritional status and living standards might contribute to such changes. Cholesterol content in the common duct and gallbladder biles was higher in the mixed stone group than in other groups. Bacterial beta-glucuronidase activity was detected in 53% of patients with muddy pigment stones. Endogenous beta-glucuronidase activity and concentration were also highest in this group, intermediate in the formed pigment and mixed stone group, and lowest in the control. We concluded that hypercholesterobilia was responsible for increasing incidence of mixed stones during the past two decades, while both bacterial and human beta-glucuronidase might contribute to pigment cholelithiasis.

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 7 alpha-hydroxylase.

RESULTS

The activity of HMG-CoA reductase, consistent with the messenger RNA level, was significantly higher in 13 patients with intrahepatic grown 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 7 alpha-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.

Molecular genetic evidence of bacterial colonization of cholesterol gallstones

BACKGROUND/AIMS

Cholesterol gallstone formation is believed to be unrelated to the presence of bacteria because attempts to culture potentially causative bacteria from surgically removed cholesterol stones have failed. However, the formation of gallbladder gallstones takes years. Embedded bacteria may be damaged or killed. The aim of this study was to search for bacterial DNA sequences in cholesterol stones with negative bacterial culture.

METHODS

Bacterial gene fragments were amplified in vitro from DNA extracted from cholesterol gallbladder stones. Comparative 16S ribosomal RNA sequence analysis was used for identification.

RESULTS

Gallstones with cholesterol content between 70% to 90% harbored bacterial DNA (16 of 17 patients). No bacterial DNA was found in the gallstones with cholesterol content of > 90% (3 patients). Three bacterial groups typical for gallstone colonization were identified. Propionibacteria-related DNA was found in the stones of 9 patients (45%). Enterobacterial type sequences were obtained in 5 patients (25%). A more heterogenous sequence collection was retrieved from 7 patients (35%) and could be assigned to the major bacterial line of gram-positive bacteria with a low DNA guanine and cytosine content.

CONCLUSIONS

Most cholesterol gallstones harbor bacterial DNA. It is important to determine the actual role of these microorganisms in gallstone formation.

Omitting side-holes in biliary stents does not improve drainage of the obstructed biliary system: a prospective randomized trial

Sludge, which occludes biliary stents, forms mainly around the side-holes of such stents. It has been reported that omitting the side-holes results in less sludge formation and theoretically improves drainage. To compare the clinical efficacy of biliary stents with and without side-holes, we randomized patients with malignant or benign strictures to receive 10FG polyethylene stents either with side-holes (SH) or without side-holes (NSH). The patients were seen at 4, 12, 20, and 28 weeks after stenting for symptom evaluation and serum liver enzyme and bilirubin assays. The stents were replaced only when clinical symptoms of cholangitis developed. Each group included 35 patients. The mean age of patients in the SH group was 68 years, and the ratio of men to women was 1:1.3. In the NSH group, the mean age of patients was 67 years, and the ratio of men to women was 1:1.4. Eight patients with SH stents and eight with NSH stents died before the stents were removed; two NSH stents migrated into the duodenum. During a mean follow-up period of 8.1 weeks (range, 1.1 to 28 weeks for the SH group and 0.6 to 28 weeks for the NSH group), 18 stents were found to be occluded in the SH group and 17 in the NSH group. The median time before total occlusion was 7.8 weeks (range, 2.6 to 28) for SH stents and 7.9 weeks (range, 0.6 to 28) for NSH stents (p > 0.1, NS). The occluded stents removed from these patients were freeze-dried and weighed to quantitate the sludge blocking the stent lumen.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term observations on morphological changes of choledochal epithelium after choledochoenterostomy in rats

Morphological changes of the common bile duct were observed macroscopically and microscopically 20 months after choledochojejunostomy and choledochocolonostomy in rats. The common bile ducts were remarkably dilated in all rats of both experimental models. Choledochal stones consisting of fatty acid calcium and calcium bilirubinate were seen in two of six rats with choledochojejunostomy and two of five rats with choledochocolonostomy. The main pathological change observed in both the groups was remarkable hyperplasia of the choledochal epithelium. Only one rat with choledochojejunostomy revealed normal epithelium with choledochal stone formation. Intestinal metaplasia was seen in two rats with choledochojejunostomy and all with choledochocolonostomy. Squamous pseudostratification of the epithelium indicating atypism was observed in two rats with choledochojejunostomy. Sialomucin producing cells and sulfomucin producing cells were seen in the hyperplastic portion of the epithelium. No malignant alteration of the epithelium was detected. These findings indicate that long-lasting exposure to digestive enzymes and bacteria causes epithelial hyperplasia and further exposure to digestive enzymes plays a major role in appearance of the epithelial atypism. Carcinogenesis of the choledochal epithelium under such an environment will need much more time to be established.

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 alpha-galactosyl residues. The presence of P1 fimbriae and alpha-galactosyl 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.

Total protein in common duct bile measured by acetonitrile precipitation and a micro bicinchoninic acid (BCA) method

Bile protein assays are complicated due to interference by other bile substances. In the present study we describe a microtiter plate method for the purification and quantification of bile proteins. The method is based on addition of acetonitrile in three steps to reconstituted freeze-dried bile, followed by ethanol washing of the precipitated proteins. Finally, protein in the precipitate is quantitated by two-point colour development using micro BCA reagents. Overall recoveries of protein in reconstituted bile spiked with exogenous protein (Seronorm) ranged from 91.0% (coefficient of variation; CV = 7.0%) to 97.1% (CV = 2.4%) by recoveries of 125I-Fibrinogen and 125I-Albumin. Bile pigments were largely removed during precipitation and washing, as verified by high pressure liquid chromatography (HPLC). Preferably the samples should be freeze-dried initially, as this lowered the blank readings. Two-point colour development with the BCA reagents were identical for standards assayed directly and standards added to protein depleted bile, and processed through all steps. Hence, no interference by either residual bile constituents nor the reagents upon the BCA protein assay could be detected. Standard curves ranged from 0.05 to 5.0 gl-1 (r > 0.98). Within day reproducibility (n = 15) was 7.8% (CV) and day to day (n = 10) was 12.1% (CV). Mean protein concentration in common duct bile from 30 patients was 1.20 gl-1 (range 0.34-3.87 gl-1). The method appears suitable for assay of bile protein, requires only limited sample volumes and allows processing of many samples within a short time.

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.

Worm extraction and biliary drainage in hepatobiliary and pancreatic ascariasis

From December 1989 to March 1992, 50 (32%) of 156 patients with hepatobiliary and pancreatic ascariasis underwent various endoscopic interventional procedures. Endoscopic intervention was performed when patients did not respond to energetic symptomatic treatment within the first few days of hospitalization (n = 45) or when worms had not moved out of the ducts into the duodenum at 3 weeks (n = 5). Worm extraction was successful in all 18 patients from the ampullary orifice and in 34 (89.5%) of 38 patients from the bile or pancreatic duct. In five patients with pyogenic cholangitis, endoscopic nasobiliary drainage was performed to decompress the bile ducts. After worm extraction/nasobiliary drainage, 41 (91%) of the 45 patients with biliary disease (n = 42) or acute pancreatitis (n = 3) had rapid relief of symptoms. Three patients developed complications related to endoscopy, including cholangitis (n = 2) and hypotension (n = 1).

Serial cholangiographic appearances in recurrent pyogenic cholangitis

From December 1982 to December 1991, cholangiograms were obtained in 227 patients with recurrent pyogenic cholangitis. Cholangiographic abnormalities included biliary dilation, calculi, sludge, excessive branching, and arrowhead formation of intrahepatic ducts and biliary strictures. In 21 patients, previous evidence of biliary ascariasis was seen. Repeat cholangiograms were performed in 55 patients in a follow-up period of 18.0 +/- 1 months. Of these patients, 12 treated conservatively continued to get recurrent cholangitis and revealed worsening abnormalities on repeat cholangiograms. Another 25 patients had successful endoscopic sphincterotomy and extraction of biliary calculi. These patients remained free of symptoms on follow-up, with significant resolution of abnormalities on repeat cholangiograms. The remaining 18 patients with failed surgical or endoscopic interventions continued to get recurrent episodes of cholangitis and worsening of abnormalities on repeat cholangiograms. This retrospective study indicates that the natural course of recurrent pyogenic cholangitis is a progressive, destructive cholangiopathy. Ascaris lumbricoides invasion of the biliary tree is an initiating event in a sub-group of patients.

Treatment of choledocholithiasis in patients with liver cirrhosis. Surgical treatment or endoscopic sphincterotomy?

OBJECTIVE

The clinical features of choledocholithiasis were analyzed in cirrhotic patients. The outcomes of surgical treatment and endoscopic sphincterotomy (EST) in this situation were compared and the risk factors predictive of an increased mortality rate were identified.

SUMMARY BACKGROUND DATA

In cirrhotic patients, high risk for gallbladder stones in cholecystectomy has been established. Common bile duct stones can often exacerbate liver dysfunction and might be more difficult to treat.

METHODS

Among 16 cirrhotic patients with choledocholithiasis, 9 underwent choledocholithotomy and T-tube placement (surgery group) and 7 underwent EST (EST group). Pretreatment clinical data were comparable between groups.

RESULTS

Among 16 patients, 15 had biliary tract symptoms and 7 had cholangitis. The surgery group had excessive intraoperative hemorrhage (1576 mL) and a high morbidity rate (66.7%). The mortality rate was 44.4%: 0% in Child A or B classification patients and 80% in Child C patients. The common causes of death were liver failure, postoperative hemorrhage, and sepsis. The EST group had no complications related to procedures, but there was one death (14.3%) due to preexisting liver failure. Hepatic dysfunction, coagulopathy, and cholangitis were factors predictive of an increased mortality rate.

CONCLUSIONS

Choledocholithiasis in cirrhotic patients should be treated by EST after liver function and general condition are improved by medical management, except in emergency cases.

Expression of alpha-amylase isoenzymes and trypsin by the proliferating epithelium of large intrahepatic bile ducts and intrahepatic peribiliary glands in hepatolithiasis

The expression of alpha-amylase isoenzymes (pancreatic and salivary) and trypsin by the epithelium of large intrahepatic bile ducts and peribiliary glands was examined immunohistochemically in hepatolithiasis (n = 22), extrahepatic biliary obstruction (n = 20) and normal liver (n = 22). Hepatolithiasis was associated with marked proliferation of bile duct cells and peribiliary glands. Expression of pancreatic and salivary amylase was observed in the proliferating bile duct cells and peribiliary glands of all livers, and trypsin was found in 68% of the livers. In extrahepatic biliary obstruction, proliferation of the biliary epithelium was less marked, but expression of amylase isoenzymes was observed in all livers and trypsin was found in 50%. All normal livers showed expression of amylase isoenzymes in large intrahepatic bile ducts, septal bile ducts and peribiliary glands, and trypsin was found in 73%. The density of enzyme-containing acini was highest in hepatolithiasis, intermediate in extrahepatic biliary obstruction and lowest in normal liver. These results show that the proliferating biliary epithelium in hepatolithiasis contains amylase isoenzymes and trypsin and that biliary epithelium retains the ability to produce these enzymes after proliferation, suggesting that a large amount of amylase isoenzyme and trypsin may be secreted into the bile ducts in hepatolithiasis. These enzymes may play an important role in the pathophysiology of hepatolithiasis.

Histological evaluation of the intrahepatic biliary tree in intrahepatic cholesterol stones, including immunohistochemical staining against apolipoprotein A-1

Apolipoprotein A-1 is known to be one of inhibiting factors of cholesterol nucleation in bile, and decreased activity of apolipoprotein A-1 is considered to predispose cholesterol-supersaturated bile to formation of cholesterol crystals. To study the pathogenesis of the intrahepatic formation of cholesterol stones, we examined surgically resected liver specimens from six patients with intrahepatic cholesterol stones and compared the characteristic histopathological features with those of intrahepatic calcium bilirubinate stones, using morphological examination and immunohistochemical staining against apolipoprotein A-1. Morphologically, in all six patients with cholesterol stones the severity of chronic proliferative cholangitis with proliferation of the mucus-producing glandular elements in the walls of the large bile duct or periductal tissues was less extensive than that seen with calcium bilirubinate stones, and cholesterol crystals had formed in the septal and interlobular bile ducts. Immunohistochemically, unlike the normal liver and calcium bilirubinate stone-containing lobes, the hepatocytes and the epithelial lining of the bile ducts and peribiliary glands of the cholesterol stone-containing lobes did not react completely (some of the epithelial cells reacted only faintly) with apolipoprotein A-1 antibody. These findings suggest that an abundance of mucous substance and bacterial infection of the biliary tree may not be necessary for the formation of cholesterol stones, compared with findings in cases of calcium bilirubinate stones. We suggest that cholesterol crystals may be produced in the septal and interlobular bile ducts in the microenvironment of cholesterol-supersaturated bile and decreased activity of apolipoprotein A-1.

Bacterial biofilm, brown pigment stone and blockage of biliary stents

Bacterial pathogens gain access into the biliary system by descending via the portal venous circulation or ascending through the sphincter of Oddi in duodenal-biliary reflux. Bacteria thrive as glycocalyx-enclosed microcolonies, coalescing to form an adherent biofilm. The establishment of biofilm is a key event in the formation of biliary sludge and pigment gallstones, and the blockage of biliary stents. The biofilm mode of growth is very effective because it provides bacteria with a measure of protection from antibacterial agents and phagocytic leucocytes. Calcification of the matrix confers further protection for the micro-organisms living inside the biofilm. To date, attempts to prevent blockage of biliary stent have employed physical methods by using large self-expandable stents and stents without side hole. Incorporation of antibiotics within stents has not been successful presumably because bacteria once living in their biofilm are quite resistant to antimicrobial agents. Even the most toxic bile salts have no effect on the biofilm bacteria. Yet, hydrophobic bile salts reduce bacterial adhesion on biomaterial, suggesting that incorporation of such bile salts might prevent the formation of bacterial biofilm.

Quantification of lipopolysaccharides in human bile with or without gram-negative bacteria

Lipopolysaccharide (LPS) was assayed in 78 samples of human common-duct bile, obtained at endoscopic retrograde cholangiography. The LPS was assayed by a chromogenic limulus amebocyte lysate (LAL) test, after dilution of bile samples in heparinized plasma and inactivation of inhibitors. The assay was not influenced by other biliary constituents, as demonstrated by the recovery of standards. Bile pigments did not influence the results. The LAL test was positive in 60 of the samples, 59 of which had a positive culture for gram-negative bacteria or Candida sp. The levels of LPS were significantly correlated to the total number of bacteria (n = 16, R = 0.55, p less than 0.05). The median LPS level was 35,250 ng/l and showed a very large variation (140 ng/l to 27.8 mg/l). In four of the samples gram-negative bacteria were present, but no LPS could be detected. The study demonstrates the presence of LPS in great quantities in human bile and supports the feasibility of using the LAL test on bile samples. The presence of LPS (within the detection limit) appears to be associated with local microbial colonization.

Lactoferrin and lysozyme in the intrahepatic bile duct of normal livers and hepatolithiasis. An immunohistochemical study

Lactoferrin and lysozyme have bactericidal activities and are responsible for mucosal defense against local bacterial infections. To assess the local defense mechanisms in the intrahepatic biliary tree, we studied the distribution of lactoferrin and lysozyme immunohistochemically in 14 normal autopsy livers and in 29 surgically resected and two autopsy livers of hepatolithiasis. In the latter, bacterial infection was constantly found. Lactoferrin and lysozyme were detected in low doses and in specific areas in the intramural and extramural glands of certain normal livers. In contrast, in hepatolithiasis, the incidence of lactoferrin- and lysozyme-positive cases significantly increased both in the intramural glands (94% and 77% of 31 cases, respectively) and in the extramural glands (72% and 48% of 29 cases, respectively) (p less than 0.01) in the stone-containing bile ducts. These glands proliferated considerably in the stone-containing bile ducts and were stained more widely and intensely than in normal livers. These data suggest that these proliferated peribiliary glands in the stone-containing bile ducts produce and secrete significant amounts of lactoferrin and lysozyme. Increased production and secretion of lactoferrin and lysozyme suggests activated local defense mechanisms against bacterial infection in the stone-containing bile ducts, and may be beneficial for inhibition of the growth of calculi and prevention of the suppurative inflammation.

Complications of hepatolithiasis

Hepatolithiasis or intrahepatic stone is associated with a variety of complications of which biliary sepsis is one. Left untreated, infection results in formation of micro-abscesses, portal thrombophlebitis and fistulation into adjacent structures. With repeated infection, biliary strictures and severe destruction of liver parenchyma occur. Biliary cirrhosis, portal hypertension and bleeding varices are the terminal manifestations. Early recognition and proper treatment are essential for the prevention of severe complications and functional deterioration.

Pathogenesis of hepatic atrophy in canine model of hepatolithiasis

The pathogenesis of the hepatic atrophy that accompanies hepatolithiasis was investigated pathomorphologically using a canine model. Two groups were evaluated: infected and noninfected. In the infected group, inflammation in Glisson's capsule caused by cholangitis involved the portal vein at the region of the large bile duct. At this region, the periportal fibrosis ratio was significantly greater in the infected group than in the noninfected group both at 1 and 3 months. At the regions of the septal and interlobular bile ducts, the caliber ratio of the portal vein in the two experimental groups was less than in the normal liver both at 1 and 3 months. At both regions, the caliber ratio of the portal vein in the infected group was less than in the noninfected group at 3 months. The rate of atrophy was significantly greater in the infected group than in the noninfected group at 3 months. These results suggest that disturbance of the portal venous blood flow attributed to cholangitis of the large bile ducts is one of the most important factors leading to hepatic atrophy in hepatolithiasis.

Experimental clogging of biliary endoprostheses. Role of bacteria, endoprosthesis material, and design

The major problem facing patients treated with biliary endoprostheses is their frequent clogging, necessitating their exchange. Clogged endoprostheses contain mainly bacteria embedded in an amorphous proteinaceous material with the occasional presence of food fibres. We studied this problem in an in vitro model, evaluating the role of bacteria, endoprosthesis design, and material in sludge formation. We found endoprostheses perfused with artificially contaminated bile to contain significantly more sludge than those perfused with sterile bile (p less than 0.05). The amount of sludge varied with the bacterial species used. Endoprostheses perfused with bacteria producing beta-glucuronidase were not associated with a particularly large amount of sludge. Endoprostheses with side holes contained significantly more sludge than those without (p less than 0.05). Furthermore, endoprostheses made of material with a low friction coefficient, such as Teflon, contained significantly less sludge than endoprostheses made of materials with a higher friction coefficient, such as polyethylene and polyurethane (p less than 0.05). These results emphasize the role of bacteria in endoprostheses clogging and clearly demonstrate the harmful effect that side holes have on endoprosthesis function.

Physicochemical and bacteriological analysis of the contents of occluded biliary endoprostheses

The deposits obstructing 12 biliary endoprostheses were examined by scanning electron microscopy and analyzed quantitatively by Fourier transform infrared spectroscopy. Calcium palmitate and bilirubinate associated with proteins were found in all the deposits. Apart from the small amount of cholesterol, this composition closely resembled that of brown pigment gallstones and suggested an infectious cause. Facultative aero-anaerobic organisms were found on bacteriological investigation. beta-Glucuronidase activity was only detected in one sample, suggesting that the calcium bilirubinate may have been formed through tissue glucuronidases. In our study, deposit formation was thought to have been caused by the action of bacterial phospholipases (although not measured) rather than beta-glucuronidases.

Mucosal dysplasia of the liver and the intraductal variant of peripheral cholangiocarcinoma in hepatolithiasis

Four cases are reported of the intraductal variant of peripheral cholangiocarcinoma among surgical specimens from 32 cases of hepatolithiasis. The cancers arose from the periphery of the stone-containing bile duct and spread chiefly along the luminal surface. Microscopically, these tumors showed papillary proliferation and therefore were diagnosed as the intraductal spreading type of peripheral cholangiocarcinoma. Mucosal dysplasia also was noticed in the vicinity of the tumors. In six other cases, mucosal dysplasia was observed in the periphery of the stone. Immunohistochemically, anti-CA 19-9 staining was observed diffusely in the cytoplasm of dysplastic lesions and carcinomas. Anti-carcinoembryonic antigen staining was restricted to the luminal surface and/or the supranuclear region of the cytoplasm in carcinomas. It was not identified in dysplastic cells. These results suggest that the mucosal dysplasia occasionally observed near stones is a precursor of the intraductal spreading type of peripheral cholangiocarcinoma in the presence of hepatolithiasis. The authors hypothesize that the lining epithelium of the large bile duct, when persistently exposed to biochemically altered bile, may undergo a carcinomatous transformation through a stage of mucosal dysplasia.

Mucosal dysplasia of the liver and the intraductal variant of peripheral cholangiocarcinoma in hepatolithiasis

Four cases are reported of the intraductal variant of peripheral cholangiocarcinoma among surgical specimens from 32 cases of hepatolithiasis. The cancers arose from the periphery of the stone-containing bile duct and spread chiefly along the luminal surface. Microscopically, these tumors showed papillary proliferation and therefore were diagnosed as the intraductal spreading type of peripheral cholangiocarcinoma. Mucosal dysplasia also was noticed in the vicinity of the tumors. In six other cases, mucosal dysplasia was observed in the periphery of the stone. Immunohistochemically, anti-CA 19-9 staining was observed diffusely in the cytoplasm of dysplastic lesions and carcinomas. Anti-carcinoembryonic antigen staining was restricted to the luminal surface and/or the supranuclear region of the cytoplasm in carcinomas. It was not identified in dysplastic cells. These results suggest that the mucosal dysplasia occasionally observed near stones is a precursor of the intraductal spreading type of peripheral cholangiocarcinoma in the presence of hepatolithiasis. The authors hypothesize that the lining epithelium of the large bile duct, when persistently exposed to biochemically altered bile, may undergo a carcinomatous transformation through a stage of mucosal dysplasia.

The bacteriology of cholelithiasis--China versus Japan

Cholelithiasis differs considerably from area to area in the world. Calcium bilirubinate stones or brown pigment stones are said to predominate in the Orient, however, this situation may differ within the Orient. In order to compare cases in China and Japan, 102 consecutive cases of cholelithiasis operated on in Shenyang, China were analyzed for the composition of gallstones and bacterial species isolated from bile in relation to the location and composition of gallstones. In Shenyang, calcium bilirubinate stones predominated, occurring in 49.0 per cent of the cholelithiasis cases. This was much higher than in Japan, which had 17.5 per cent. The incidence of bacteria was also very high, ranging from 20 to 96 per cent, with an average of 66.7 per cent depending on the kind of gallstone present. Bacterial species possessing beta-glucuronidase activity were present in nearly all the cases of calcium bilirubinate stones (92.0 per cent). The incidence of bacteria with beta-glucuronidase activity especially of E. coli was much higher than in Japan (50.8 per cent versus 21.8 per cent) in concordance with the higher incidence of calcium bilirubinate stones in China (49.0 versus 17.5 per cent).

Clogging of biliary endoprostheses. A morphologic and bacteriologic study

The main problem encountered with the use of biliary endoprostheses is their tendency to clog, which necessitates their exchange. We studied this problem by performing light and electron microscopy and bacterial cultures on both unused and clinically used endoprostheses. These examinations showed several basic defects in their manufacture, such as irregular inner surfaces and badly constructed side holes. The deposit that ultimately led to their occlusion was found mainly to be concentrated around the side holes. Minimizing the amount of material, bacteria, and plant fibres adhering to the endoprosthesis is the desired goal and may be achieved by improving their manufacture and design.

Significance of different conjugate forms of bilirubin in the formation of pigment gallstones

The aim of the present study was to analyse bile samples from cases with gallstones by high performance liquid chromatography according to the type of stones present, with special reference to the glucoside and xyloside conjugates of bilirubin, and to investigate their deconjugation. The composition of bilirubin conjugates in bile was similar between cholesterol and black pigment stones except that the total bilirubin concentration was about 5 times higher in black pigment stone cases with haemolysis. Unconjugated bilirubin was higher in brown pigment stone cases than in cholesterol stone cases, although total bilirubin concentration was lower in the former. In addition, in brown pigment stone cases, bile contained statistically less bilirubin diglucuronide and more bilirubin diglucoside and monoglucoside than in bile with cholesterol stones (P less than 0.05). Glucoside and xyloside conjugates are also major components, regardless of the types of gallstones present, accounting for as much as 18 to 25%. Incubation experiment revealed that bilirubin diglucuronide was more readily deconjugated than bilirubin diglucoside or bilirubin monoglucoside monoxyloside. Therefore, glucuronide conjugates were likely to be the main source of unconjugated bilirubin in the formation of pigment gallstones.

Adenomatous hyperplasia of the bile duct epithelium of the canine liver, caused by bacterial infection

Morphologic changes of the intrahepatic bile ducts after induction of bile stasis and bacterial infection of the biliary tract in two lobes of the liver in mongrel dogs were studied to examine the pathophysiology of hepatolithiasis. Three groups of dogs were prepared by cannulation of the bile duct branch draining the left lateral lobes of the liver and were treated as follows: in group 1 the cannula was clamped after injection of 10(7) Escherichia coli (aerobic bacteria) and 10(7) Bacteroides fragilis (anaerobic bacteria) organisms; in group 2 the cannula was clamped after injection of E. coli only; and in group 3 the cannula was clamped without injection of bacteria. Three months later the livers of killed dogs were examined. In group 1 epithelial adenomatous hyperplasia was noted in association with chronic cholangitis characterized by moderate to severe periductal fibrosis with a large number of inflammatory cells. In group 2 periductal fibrosis was severe, but epithelial hyperplasia was found to a much lesser degree than in group 1. In group 3 no periductal fibrosis or epithelial adenomatous hyperplasia was demonstrated. These findings suggest that adenomatous hyperplasia of the bile duct epithelium may be caused by bacterial infection of the biliary tract in combination with bile stasis.

Microanalysis of bile acid composition in intrahepatic calculi and its etiological significance

Brown pigment stones in the intrahepatic bile ducts were compared with those found in the extrahepatic bile ducts with special reference to the bile acids modified by bacterial intervention, that is, unconjugated, glucuronidated, secondary, and ketonic bile acid fractions. The former showed significantly lower amounts of total bile acids (P less than 0.01) and lower proportions of unconjugated bile acid fraction (P less than 0.01), secondary bile acid fraction (P less than 0.05), and ketonic bile acid fraction (P less than 0.05) to total bile acids than the latter. The discriminant analysis using these bile acid parameters led to complete separation between intrahepatic and extrahepatic stones in the case of brown pigment stones. In contrast, cholesterol stones in the intrahepatic bile ducts showed the bile acid composition close to those found in the extrahepatic ducts and gallbladder. The above data show that the bacterial infection plays a less important role in the formation and ensuing growth of most intrahepatic brown pigment stones than in extrahepatic stones, and that factors other than or in addition to bacterial infection are involved.

Biliary sludge and microcalculi in intrahepatic bile ducts. Morphologic and X-ray microanalytical observations in 18 among 1,179 consecutively autopsied livers

To clarify the morphology and pathogenesis of intrahepatic calculi in the incipient stage, we examined biliary sludge and microcalculi in intrahepatic bile ducts by morphologic and X-ray microanalytical methods in 18 (1.5%) among 1,179 autopsied livers. The hepatobiliary conditions of these 18 livers were intra- and extrahepatic biliary obstruction in 14 cases, hepatic fibrosis in three cases, and cirrhosis with hepatocellular carcinoma in the remaining one. Grossly, brown-pigmented microcalculi were observed floating in biliary sludge. Microscopically, the biliary sludge was composed of mucin, fibrinous materials, desquamated epithelial cells and a few bilirubin granules. The microcalculi were embedded in the sludge and consisted of mucin and precipitates of bilirubin with a granular, lamellar or amorphous appearance. Bacterial colonies were recognized in both the sludge and microcalculi in all but three cases. Intrahepatic bile ducts harboring sludge and microcalculi showed a minimal to moderate degree of glandular proliferation with mucin production. X-ray microanalysis disclosed that the sludge contained little calcium ion, whereas microcalculi were calcium-rich. These findings suggest that biliary obstruction, bacterial infection and mucin hypersecretion play an important role in the formation of intrahepatic biliary sludge and microcalculi, and that sludge is causally related to the formation of intrahepatic microcalculi. Intrahepatic microcalculi and biliary sludge may represent a pathogenetic sequence in the early stage of calcium bilirubinate hepatolithiasis.

Total biliary protein, mucus glycoproteins, cyclic-AMP, and apolipoproteins in the gallbladder bile of patients with cholesterol stones and stone-free controls

The concentrations of total protein, mucus glycoprotein, cyclic-AMP, and apolipoproteins A-I, A-II, and B were determined in the gallbladder bile of patients with cholesterol gallbladder stones and in stone-free controls. The total protein content was significantly increased in gallstone patients (2.03 +/- 0.6 versus 1.31 +/- 0.67 mg/ml; p less than 0.05), as was the mucus glycoprotein concentration (380 +/- 88.5 versus 128 +/- 57.2 micrograms/ml; p less than 0.05). The cyclic-AMP concentration in the gallbladder fluid was increased up to 91 +/- 20 pmol/100 microliters in the gallstone subjects, as compared with 46 +/- 26 pmol/100 microliters (p less than 0.01) in stone-free controls. Cyclic-AMP concentrations correlated positively with the glycoprotein content of the bile in cholesterol gallstone patients (r = 0.66; p less than 0.05). The apolipoprotein concentrations were determined by the radial immundiffusion technique. The corresponding values for patients with stones and controls were 7.5 +/- 0.8 versus 3.0 +/- 0.8 for Apo A-I (p less than 0.025), 10.4 +/- 0.6 versus 6.3 +/- 1.3 for Apo A-II (p less than 0.02), and 1.9 +/- 0.5 versus 1.6 +/- 0.2 mg/dl for Apo B (NS), respectively. Biliary proteins probably play an important role in the nucleation process during the pathogenesis of cholesterol gallbladder stones.

The role of bacteria in pigment gallstone disease

One hundred ten of nine hundred sixty consecutive patients who underwent surgery for gallstones (GS) had pigment stones (PS) (11.45%). Fifty brown PSs contained calcium bilirubinate, small amounts of cholesterol, and always calcium palmitate, were usually found in the common duct (96%), and were almost always associated with bile infection (98%) and diffuse erosion of the biliary mucosa. Fifty-one black PSs contained bilirubin polymers, calcium carbonate, and/or phosphate, seldom cholesterol, and never evident amounts of calcium palmitate, were mostly found in the gallbladder, and were associated with hemolysis or liver damage and with hyperplastic cholecystosis. Bile infection was found in 19.6% of cases, but bacteria were never found in the center of black PSs by scanning electron microscopy. Nine additional patients (8.2% of PSs, 0.9% of GSs) had concomitant black and brown PSs that were mostly found in the common duct and were always associated with bile infection. It is suggested that, even if PSs with concomitant black and brown material can be found, black and brown PSs greatly differ not only in pathogenesis but also in clinical behavior and treatment. In particular bacterial infection is important only in the pathogenesis of brown PSs while it plays no role in the initial formation of cholesterol, mixed or black GSs.

Bile flow analysis by hepatobiliary scintigraphy in the terminal bile duct in patients with congenital malformations of the pancreatico-biliary ductal system

The authors employed hepatobiliary scintigraphy (HBS), to study a dynamic state of bile stasis in the common bile duct and bile flow through the papilla of Vater in patients with congenital malformations of the pancreatico-biliary ductal system, such as congenital cystic dilatation of the common bile duct (CCDB) and anomalous arrangement of the pancreatico-biliary ductal system (AAPB). The HBS data were evaluated by a cholestatic index (CI), as an indicator of bile stasis in the common bile duct, and passage time (PT), as an indicator of bile flow through the papilla of Vater. CI was significantly higher in CCDB (3.67 +/- 0.92), in AAPB (2.87 +/- 0.28) and in both CCDB and AAPB with symptoms (2.86 +/- 0.59), compared with patients without CCDB or AAPB (0.96 +/- 0.41). PT was prolonged only in patients with AAPB with/without CCDB (greater than 30 minutes) compared to patients without AAPB (less than 12 minutes). This result suggested that bile stasis in the common bile duct was caused by a pooling of bile in the dilated common bile duct in CCDB, and by a disturbance of bile flow through the papilla of Vater in AAPB.

Recurrent pyogenic cholangitis: current management

Successful treatment of recurrent pyogenic cholangitis depends on the ability to delineate the pathology of the entire biliary system and to eradicate all stones, strictures, and destroyed liver segments. Recent advances in imaging techniques and stone fragmentation technology have been applied successfully in the management of this condition. Apart from direct cholangiography and ultrasonography, valuable information can be obtained from computed tomography which is particularly helpful in patients with recurrent disease after previous biliary surgery. Application of electrohydraulic lithotripsy in this disease solves the problem of difficult stone retrieval due to large size, impaction behind relative strictures and inside angulated segmental bile ducts. Together with construction of a hepaticocutaneous jejunostomy serving as a permanent access to the bile duct, it is anticipated that the incidence of recurrence and reoperation in the future can be reduced.

Intrahepatic cholesterol stones: a rationale for dissolution therapy

A case of primary cholesterol hepatolithiasis is reported. Stone composition was documented by infrared spectroscopy, and the presence of cholesterol saturated bile was demonstrated using standard biochemical techniques. The patient was treated with operative stone extraction, choledochoscopy, biliary enteric anastomosis, and oral dissolution therapy. The administration of oral dissolution agents has altered the composition of the patient's bile and may prevent further stone formation. We advocate the use of both stone and biliary biochemical analysis for patients with primary hepatolithiasis to facilitate optimal therapy.

Pathogenesis of gallstones

The many developments in nonoperative methods for the treatment of gallstone disease underscore the importance of understanding the pathogenesis of these stones. Elucidation of the factors responsible for nucleation of crystals and the mechanism by which it occurs would appear to be the challenge if we are to define the cascade of events that results in gallstone formation.

The significance of gallstones in children with sickle cell anemia

Infection is the most common cause of high morbidity, hospitalization, and mortality in children with sickle cell anemia. In this study of pediatric sickle cell anemia patients, aged 1 to 19, we explore the hypothesis that gallstones (usually pigment stones) create a nidus of infection, predisposing the affected patients to high morbidity. Our study involved 86 children with sickle cell anemia at the Howard University Center for Sickle Cell Disease, who had been followed at the clinic for a total of 602 patient years. Review of their records revealed that patients with gallstones had a mean number of 10.24 hospitalizations and 25.35 ambulatory visits; those without gallstones had a mean number of only 4.26 hospitalizations and 13.41 ambulatory visits. In children with sickle cell anemia and gallstones, elective cholecystectomy (or, in the future, cholelithotripsy) could reduce the high morbidity caused by infection.

Hepatobiliary and pancreatic ascariasis in India

500 patients with hepatobiliary and pancreatic disease due to Ascaris lumbricoides infection were studied. 274 patients had duodenal ascariasis, 171 biliary ascariasis, 40 hepatic ascariasis, 8 gall bladder ascariasis, and 7 pancreatic ascariasis. Five clinical presentations were recognised: acute cholecystitis (64 patients), acute cholangitis (121), biliary colic (280), acute pancreatitis (31), and hepatic abscess (4). Ascarides in the duodenum (which were seen to invade only the ampullary orifice) induced either severe biliary colic or episodes of acute pancreatitis. 27 patients had pyogenic cholangitis and were managed by surgical (2) or endoscopic (25) biliary decompression and drainage. Removal of worms from the ampullary orifice and their extraction by mouth led to rapid relief of biliary colic (214 patients) and acute pancreatitis (16). 4 patients died (acute pancreatitis 2, pyogenic cholangitis 1, hepatic abscess 1). In 12 patients worms persisted in the biliary tree at 3 weeks; dead worms were removed from the biliary tree by surgery (5 patients) or with an endoscopic basket (7). Worms moved out of the ductal system in 211 patients. During a mean follow-up of 48 months (SD 14), 76 patients had worm re-invasion of the biliary tree due to ascaris re-infection. Intrahepatic duct and bile duct calculi developed in 7 patients in whom dead worms formed the nidus of stones.

Differences in gallstone structure in primary common bile duct lithiasis and gallbladder lithiasis

Some differences between gallbladder lithiasis and primary common bile duct lithiasis are described. Microbiological cultures and biochemical analyses were carried out on the bile of two groups of patients: 27 suffering from gallbladder and 5 from primary common duct lithiasis. The microstructure and composition of gallstones were also examined by polarized light microscopy and X-ray diffraction. Women predominated in gallbladder lithiasis but not in primary common duct lithiasis group (P less than 0.05) and body weight was higher in the former group (P less than 0.02). Primary common duct lithiasis patients had a higher, although not significant, incidence of duodenal diverticulosis (P = 0.15), and a higher incidence of E. coli-positive cultures in bile (P less than 0.001). No significant difference in the biochemical composition of the bile was found between the groups. Brown pigment stones predominated in primary common duct lithiasis, while cholesterol stones did in gallbladder and secondary common duct lithiasis (P less than 0.0001). Stones formed in the gallbladder generally show linear, radial growths of cholesterol crystals, while those from the common duct present a polystratified, concentric deposition of microgranules composed mainly of pigmentary salts. These differences should be taken into account as additional criteria in the differential diagnosis between primary and secondary common duct lithiasis, as the classical criteria for diagnosing of the former greatly underestimate its actual incidence. The distinction between primary and secondary common duct lithiasis is of practical significance, since each entity requires different treatment.

The pathophysiological characteristics of bile from patients with gallstones: the role of prostaglandins and mucin in gallstone formation

Bile was obtained from 82 patients with various biliary tract diseases and concentrations of prostagloandins, leukotriens, mucin, and a number of lithogenic components were measured in order to evaluate the role of these substances in the pathogenesis of gallstone formation. The characteristics of bile in cases of cholesterol gallstones included high concentrations of prostaglandins and hexosamine and a high cholesterol saturation index. Prostaglandin E2 and prostaglandin F2 alpha concentrations in bile were correlated with hexosamine concentration, and prostaglandins and hexosamine were found to be actively synthesized and secreted in the gallbladder. Prostaglandins E2 and F2 alpha may therefore stimulate mucin secretion in the gallbladder with supersaturated bile. The characteristics of bile in cases of calcium bilirubinate gallstones included a high detection rate for bacteria, high beta-glucuronidase activity, a high percentage of unconjugated bilirubin, a low cholesterol saturation index and high concentrations of prostaglandins and hexosamine. Moreover, the synthesis and secretion of prostaglandins in the biliary tract were accelerated in cases of infected bile. Thus, hypersecretion of mucin, stimulated by prostaglandins, my participate in the onset and development of biliary tract infection or in the formation of calcium bilirubinate gallstones. Regarding the role of prostaglandins and mucin, the hypotheses for gallstone formation previously reported by many authors are supported by the clinical data obtained in the current study.

Dissolution of human brown pigment biliary stones

The chemical dissolution of human brown pigment stones was studied using various monophasic multicomponent solvents. Among the nine solutions tested for stone powder dissolution capacity, the two most active were retained for further analysis. The solvent containing 26 mM ethylenediaminetetraacetate, 40 mM sodium deoxycholate, 10 mM monoolein and 30% dimethylsulfoxide was efficient for calcium and bilirubin solubilization. The other solvent containing dimethylsulfoxide/methyl tert-butyl ether (70:30) had a high capacity for dissolution of cholesterol and bilirubin. From in vitro stone dissolution experiments, we found that alternating treatment every 2 h with these two mixtures was more effective than using these solvents separately. Within 24 h, 90% of cholesterol, 80% of bilirubin, and 70% of calcium were dissolved. In vivo, we studied the dissolution of human stones surgically implanted in the gallbladder of 6 rabbits. Alternating perfusions with the solvents selected led to complete disappearance of stones within 16 h in 5 out of 6 cases. The residual histological toxicity in the gallbladder wall, 15 days after perfusion, was low and blood parameters did not differ from the normal values.

High-performance liquid chromatography of bilirubin conjugates in bile: effect of beta-glucuronidase on the bile pigments

A simple, specific, and technically easy high-performance liquid chromatography (HPLC) method for the separation and quantification of unconjugated bilirubin, bilirubin monoglucoside-monoglucuronide, bilirubin diglucuronide, and bilirubin monoglucuronide has been developed. The method was used to determine the bilirubin compounds of bile obtained endoscopically from the common bile duct in 43 patients with gallstone disease and in 6 subjects without gallstones or liver disease. The bile samples were also assessed for the presence of beta-glucuronidase-producing bacteria. The amount of unconjugated bilirubin was significantly higher (p less than 0.01) in bile containing bacteria producing beta-glucuronidase than in bile without such bacterial strains. In six 'normal' bile samples the following quantities of bilirubin conjugates and unconjugated bilirubin were found (median and range): bilirubin monoglucoside-monoglucuronide (mixed conjugate), 61 (27-80) mumol/l; bilirubin diglucuronide, 632 (512-861) mumol/l; bilirubin monoglucuronide, 113 (70-175) mumol/l; and unconjugated bilirubin, 3 (1-7) mumol/l. These results are in good agreement with those obtained with other HPLC methods. The concentrations of unconjugated bilirubin were lower than those found when using conventional diazo methods and thin-layer chromatography. HPLC proved to be a useful tool in gallstone pathogenesis studies. Our results support bacterial glucuronidase as a possible pathogenic factor in pigment gallstone disease.

Bacteria and gallstone nucleation

This preliminary study reports for the first time that there might be a possible association between bacteria and the aetiology of some cholesterol calculi. The gall-bladder biles from 225 cholecystectomy patients underwent bacteriological and microscopic study. Cholesterol calculi from 13 patients (10.2%) were observed to be associated with gall-bladder bile profusely infected with at least one bacterial species that was shown to possess beta-glucuronidase activity, an enzyme that is thought to promote calcium bilirubinate precipitation in bile. Concomitantly, the associated gall-bladder bile was 'high' in calcium bilirubinate precipitation and the precipitate was also detected in the centre of the gallstones. Moreover, in approximately half of these patients (six of 13), the cholesterol gallstones' nuclear areas also contained calcium palmitate, which is also thought to be due to bacterial activity. The results also support the hypothesis that bacteria with active beta-glucuronidase (for example, Escherichia coli) can significantly influence the aetiology of brown pigment gallstones. In contrast, bacteria were observed to have no role in black pigment gallstone formation, as their associated gall-bladder biles were always observed to be sterile.