The interaction of Cu2 + ions and NaDC micelles

By mixing an aqueous solution of CuCl2 with an NaDC aqueous solution of various concentration and initial molar ratio, seven coordinated samples with distinct appearances and characters were obtained. Their structures and components were investigated by FT-IR spectroscopy, EXAFS (the extended X-ray absorption fine structure), thermal analysis, X-ray diffraction, laser light scattering, TEM (transmission electron micrograph), element analysis and ICP (inductively coupled plasma) analysis. The following conclusions were given: (1) The complexes of Cu2+-NaDC with distinct appearances and properties were synthesized. (2) After Cu(DC)2 dissolved in NaDC aqueous solution, larger micelles (30-90 nm diameter) formed in the supernate, it is a mixed micelle with Cu(DC)2 and NaDC. So these micelles are a new kind of micelle containing two kinds of metal ions. This is a new result using metal ions as bridges to form micelle. (3) According to the different concentration of Cu2+ to NaDC, the complexes formed as gel or poly-crystals. Both the composition of gel complexes and the coordination structure of carboxyl groups with metal ions varied with the initial molar ratio of Cu2+ to Na+. The gel complexes exhibits the non-stoichiometric character. (4) These results are in agreement with physiological condition. All the different states such as gel, precipitate, micelles of various structures are present in bile of gallbladder. We can suggest an ideal model of the interaction between Cu2+ and bile salts in vivo.

Efficacy of a motilin receptor agonist (ABT-229) for the treatment of gastro-oesophageal reflux disease

BACKGROUND

ABT-229 is a potent motilin agonist without significant antibiotic activity. It has been shown to improve gastric emptying in humans and to increase lower oesophageal sphincter pressure in cats.

AIM

To assess the efficacy of four different doses of ABT-229 (1.25 mg, 2.5 mg, 5 mg, 10 mg b.d.) compared to placebo in the treatment of gastro-oesophageal reflux disease, and to determine its safety in patients with gastro-oesophageal reflux disease.

METHODS

In a double-blind, multicentre study, 324 patients with heartburn were randomized to receive four different doses of ABT-229 or placebo for 8 weeks. The efficacy was evaluated by Patient Symptom Questionnaire, daily diary, endoscopy and global evaluation of efficacy.

RESULTS

There were no statistically significant improvement scores for any of the ABT-229 treatment groups vs. the placebo group in any of the efficacy parameters. Reflux symptom scores were significantly worse after treatment in the dyspeptic group. ABT-229 appeared to be well tolerated and safe in total daily doses up to 20 mg.

CONCLUSION

ABT-229 appears to have limited, if any, clinical utility in the treatment of gastro-oesophageal reflux disease.

Cesium cholate: determination of X-ray crystal structure indicates participation of the ring hydroxyl groups in metal binding

The crystal structure of cesium cholate, C(24)H(36)(OH)(3) COOCs has been determined with three-dimensional X-ray diffractometer data. It crystallized in the monoclinic space group P2(1) with unit-cell dimensions a = 11.543(5) A, b = 8.614(3) A, and c = 12.662(5) A, beta(deg) = 107.95(2), V = 1197.7 A(3) and Z = 2. The atomic parameters were refined to a final r = 0.0269 and R(omega) = 0.0280 for 2342 observed reflections. Each Cs(+) is coordinated to 7 oxygen atoms from 5 different cholate anions with Cs-O distances ranging from 2.957(4) A to 3.678(5) A. In this crystal, 5 cholates are coordinated with 1 Cs(+), and 5 Cs(+) are coordinated with 1 cholate anion. Carboxyl and all the 3 ring hydroxyl groups of cholate anion participate in binding to Cs(+) simultaneously, and there is no water molecule coordinated with the Cs(+). The pattern of successive rows arranged with polar (p) and non-polar (n) faces in apposition leads to the formation of a sandwich sheet structure with polar and non-polar channels. The Cs ions lie within the polar interior of the sandwich. The H-bond network is reorganized in forming cesium cholate from cholic acid. All the oxygen atoms in cholate anion are involved in H-bonding reciprocally or with water molecules to form an extensive 3-dimensional network of H-bonds. Compared with cholic acid and other similar type of steroids, the coordination structure and H-bonding of Cs cholate crystal are distinct.

Distinguishing malignant from normal oral tissues using FTIR fiber-optic techniques

Oral tissue samples were studied using mid-IR fiber-optic attenuated total reflectance spectroscopy and other spectral techniques. The 1745 cm(-1) band, which is assigned to the ester group (C==O) vibration of triglycerides, is a reliable marker that is present in normal tissues but absent or a weak band in malignant oral tissues. Other bands such as C--H stretching bands and the amide bands are also helpful in distinguishing malignant tissues from normal tissues. Subtraction spectra confirmed the above conclusion. In addition, Raman spectroscopic measurements were in agreement with the results observed from FTIR spectra.

Gallstones

At the turn of the millennium, significant advances continue to be made into the epidemiology and pathophysiology of gallstone disease. The NHANES III study, the largest American population-based study of gallstone disease, estimated that more than 20 million Americans have undergone gallbladder surgery or currently have gallstones. Insulin resistance may be an independent risk factor for gallstone disease.Cholecystokinin receptors may be responsible for the altered motility of the gallbladder smooth muscle, and mucin may play an underestimated role as a pronucleating factor. For the first time, researchers have been able to directly observe cholesterol crystallization in human bile. Improved understanding of the multiple factors involved in the pathogenesis of gallstone disease should lead to new therapeutic and preventive strategies.

Acetaminophen hepatoxicity

To determine the influence of psychosocial factors in accidental and deliberate acetaminophen overdose, we reviewed the charts of 207 overdose patients, and 48 met our criteria for acetaminophen toxicity. Two patients died. A psychiatric history was present in 75%, and 25% had a previous or subsequent suicide attempt. A substance abuse history was elicited from 46% and 36% of adolescent teenagers had a teen pregnancy. The mean time to starting N-acetylcysteine was 18.5 hr. Delayed N-acetylcysteine administration led to higher transaminase levels. Alcohol abuse was associated with a longer hospital stay. Mean AST was 8,860 IU/liter in the accidental and 3,013 IU/liter in the suicide groups. We concluded that management of acetaminophen toxicity can be optimized by early identification, obtaining a complete drug screen, starting N-acetylcysteine early or whenever toxic acetaminophen levels or elevated transaminases are identified, and referring patients with acetaminophen toxicity to a liver center.

Inhibitors present in blood do not inhibit PCR from buccal cell preparations: case report

BACKGROUND

Hemochromatosis is a common disease that is characterized by high ferritin levels and/or high iron saturation and mutations in two alleles.

MATERIAL AND METHODS

Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) is often performed on DNA extracted from blood since blood yields high concentrations of DNA. However, inhibitors can cause PCR failure in DNA extracted from blood thus preventing a molecular diagnosis.

RESULTS

This report describes a case where multiple blood draws resulted in unamplifiable DNA. Subsequently, a buccal cell sample was collected and extracted. DNA extracted from the buccal cells yielded amplifiable DNA in contrast to DNA extracted from the patient's blood. In addition, the patient was identified as having a homozygous mutation for one allele of the hemochromatosis gene.

CONCLUSION

These results suggests that a buccal cell DNA extraction may be useful in cases where blood samples contain inhibitory substances for PCR.

Gallstones

This review summarizes the main advances made in the epidemiology, pathogenesis, and medical treatment of gallstone disease in the past year. Whether rapid weight reduction can precipitate gallstone formation is still debated. Phospholipase A(2)-II seems to play an interesting role in the pathogenesis of multiple cholesterol stone formation, and ursodeoxycholic acid may partially halt the formation of multiple cholesterol stones by mediating an anti-inflammatory effect on the gallbladder. Bacterial infections may contribute to gallstone formation, perhaps through secretion of biofilm. The combination of ursodeoxycholic acid and simvastatin for the resolution and prevention of gallstones is promising, but larger studies are needed.

[Molfig, a software for displaying the structure and vibration of molecule]

A Molfig software has been developed for displaying the structure and vibrational mode of molecule in our lab. Various functions and a friendly interface are equipped in the software. The testing results showed that the software may enhance our understanding of the relationship between the vibrational behavior and the structure of molecules.

Gallstone formation and gallbladder bile composition after colectomy in dogs

A high prevalence of gallstones has been described in patients following colectomy. The aim of this study was to examine whether lithogenicity is attributed to colectomy. In the present study, changes in gallbladder bile composition and the mechanism of gallstone formation after colectomy were examined in dogs. Ten mongrel dogs underwent restorative proctocolectomy. Seven dogs which received sham operations served as controls. Over a 12-week postoperative period, samples of gallbladder bile, formed gallstones and serum were collected and analyzed. In 7 of the 10 (70%) colectomized dogs, gallstones were found in the gallbladder, while the control dogs had no stones. Macroscopically the gallstones were similar to black pigment stones observed in humans. Chemical analysis and Fourier transform-infrared spectroscopy examination revealed that the stones were composed mainly of sodium bilirubinate and proteins, with minor amounts of calcium salts and cholesterol. Significant increases in biliary pH and concentrations of ionized calcium and unconjugated bilirubin were observed in the gallbladder bile of the colectomy group compared with that of the control group. The total bile acid and total bilirubin concentrations were significantly decreased in the colectomy group. Cholesterol crystal nucleation did not occur. The inhibitory effect of gallbladder bile on calcium carbonate precipitation in an in vitro assay system was preserved even after colectomy. In conclusion, proctocolectomy increases the concentration of unconjugated bilirubin in gallbladder bile and induces pigment gallstones which are composed mainly of sodium bilirubinate and proteins since calcium ions and cholesterol are stabilized in dogs.

Influence of phospholipid on bile salt binding to calcium hydroxyapatite and on the poisoning of nascent hydroxyapatite crystals

Glycine-conjugated, dihydroxy bile salts inhibit calcium hydroxyapatite (HAP) formation by binding to and poisoning nascent crystal embryos. Their taurine-conjugated counterparts bind less well to hydroxyapatite and do not inhibit its formation; but more hydrophobic, synthetic analogs of the taurine conjugated bile salts are inhibitors of hydroxyapatite formation. Because hydrophobicity is an important determinant of the ability of bile salts to inhibit hydroxyapatite crystal growth, experiments were performed to study the effect of the physiologically important mixed micelles of bile salt and phospholipid. Taurodeoxycholate/phosphatidylcholine (10:1) mixed micelles bound to HAP at lower total lipid concentrations than did pure taurodeoxycholate. At low total lipid concentrations, phosphatidylcholine (PC) binding appeared to predominate, suggesting that PC had a higher affinity than did taurodeoxycholate (TDC) for the HAP surface. Although glycodeoxycholate (3 mM) significantly (> 95%) inhibited hydroxyapatite precipitation, higher concentrations of taurodeoxycholate, either alone or mixed with phosphatidylcholine, did not affect hydroxyapatite formation. These results suggest that biliary phospholipids do not modulate the ability of bile salts to inhibit hydroxyapatite crystal growth.

Risk factors for gallbladder cancer. An international collaborative case-control study

BACKGROUND

Gallbladder cancer has an unusual geographic and demographic distribution, suggesting many possible etiologies.

METHODS

A case-control study was undertaken at four hospitals in La Paz, Bolivia, and at one hospital in Mexico City, Mexico. Eighty-four patients with newly diagnosed, histologically confirmed gallbladder cancer were compared with 126 control subjects without stones and with 264 control subjects with cholelithiasis or choledocholithiasis without cancer. All study subjects underwent abdominal surgery. Study subjects were interviewed regarding demographic characteristics, medical history, family history, diet, and exposure to agents presumed to be risk factors for biliary cancer.

RESULTS

Virtually all subjects in Mexico were judged to be mestizos (i.e., persons of mixed ancestry) In contrast, race was a very strong risk factor for gallbladder cancer in Bolivia. Relative to mestizos who spoke neither language, the odds ratio (95% confidence interval [CI]) for cases versus control subjects without stones for those who spoke Aymara well was 15.9 (CI, 1.9-179), whereas it was 1.4 (CI, 0.2-8.2) for those who spoke Quechua well. An increased risk was also noted for elevated maximum body mass index (P = 0.03), family history of gallstones (odds ratio [OR] = 3.6 [CI, 1.3-11.4]), and physician-diagnosed typhoid (OR = 12.7 [CI, 1.5-598]). An increased risk was also seen with elevated maximum body mass index; compared with those with a body mass index less than 24 kg/m2, those with an index of 24-25 kg/m2, 26-28 kg/m2, and greater than 28 kg/m2 had odds ratios of 1.6 (CI, 0.4-7.6), 1.3 (CI, 0.3-5.6), and 2.6 (CI, 0.5-18.6), respectively (asymptotic test for trend, P = 0.03). Finally, a number of associations were noted with certain dietary and cooking habits.

CONCLUSIONS

Patients with gallbladder cancer differed from control subjects in race, body mass, physician-diagnosed typhoid, and certain dietary patterns. These findings may provide useful clues to the pathogenesis of gallbladder cancer, but given the number of analyses performed, additional cases need to be studied.

Biochemical epidemiology of gallbladder cancer

To evaluate the a priori hypotheses that an increased level of glyco and tauro lithocholic acid, perhaps because of a decreased capacity for hepatic sulfation, contributed to the biochemical epidemiology of gallbladder cancer, a case-control study was undertaken at four hospitals in La Paz, Bolivia, and at one hospital in Mexico City, Mexico. Eighty-four cases with newly diagnosed histologically confirmed gallbladder cancer were compared with 264 controls with cholelithiasis or choledocholithiasis in the absence of cancer and with 126 controls with normal biliary tracts. All study subjects were undergoing abdominal surgery. Interview data were collected for all study subjects, as well as blood, bile, and gallstone specimens when feasible. Sera were analyzed for carcinoembryonic antigen, cholesterol concentration, and total bile acids. Bile specimens were analyzed for carcinoembryonic antigen; and for concentration of bile salts; cholesterol; phospholipids; and the glycine and taurine conjugates of cholic, ursodeoxycholic, chenodeoxycholic, deoxycholic, and lithocholates; sulfoglycolithocholate; and sulfotaurolithocholate. Gallstone specimens were analyzed for the percentage of cholesterol content, the percentage of calcium bilirubinate content, and the percentage of calcium carbonate content. Serum bile acids were increased in cases versus the two control groups (median 11.7 nmol/mL vs. 9.3 nmol/mL for stone controls and 8.2 nmol/L for nonstone controls, P < or = .02 for each pairwise comparison). Biliary bile acids were markedly decreased in the cases (median 3.98 micromol/mL vs. 33.09 micromol/mL, and 154.0 micromol/L, respectively, P < or = .0001 for each comparison), even after excluding those with a serum bilirubin higher than 2.0 mg/dL. Bile cholesterol was lower for the cases as well (median 1.70 micromol/mL vs. 4.90 micromol/mL, and 16.81 micromol/ mL, respectively, P < or = .02), as was the concentration of bile phospholipids (median 2.97 micromol/mL vs. 6.26 micromol/mL, and 52.69 micromol/mL, P = .1 and .0004, respectively). Contrary to our a priori hypothesis, there was no difference between the cases and either control group in their bile concentrations of lithocholate, the proportion of bile acids which were sulfated, or the concentration of nonsulfated lithocholate. However, the cases had a higher concentration of ursodeoxycholate (UDC) (P < .004 for both control groups), especially glycoursodeoxycholate (P < .001 for both control groups). A previously published suggestion that gallstone size differed between cases and controls was not confirmed. In conclusion, cases with gallbladder cancer differed from controls with stones and from controls with normal biliary tracts in their serum and bile biochemistries. These findings may be a reflection of the disease process, or may provide useful clues to its pathogenesis.

Risk factors for gallbladder cancer. An international collaborative case-control study

BACKGROUND

Gallbladder cancer has an unusual geographic and demographic distribution, suggesting many possible etiologies.

METHODS

A case-control study was undertaken at four hospitals in La Paz, Bolivia, and at one hospital in Mexico City, Mexico. Eighty-four patients with newly diagnosed, histologically confirmed gallbladder cancer were compared with 126 control subjects without stones and with 264 control subjects with cholelithiasis or choledocholithiasis without cancer. All study subjects underwent abdominal surgery. Study subjects were interviewed regarding demographic characteristics, medical history, family history, diet, and exposure to agents presumed to be risk factors for biliary cancer.

RESULTS

Virtually all subjects in Mexico were judged to be mestizos (i.e., persons of mixed ancestry) In contrast, race was a very strong risk factor for gallbladder cancer in Bolivia. Relative to mestizos who spoke neither language, the odds ratio (95% confidence interval [CI]) for cases versus control subjects without stones for those who spoke Aymara well was 15.9 (CI, 1.9-179), whereas it was 1.4 (CI, 0.2-8.2) for those who spoke Quechua well. An increased risk was also noted for elevated maximum body mass index (P = 0.03), family history of gallstones (odds ratio [OR] = 3.6 [CI, 1.3-11.4]), and physician-diagnosed typhoid (OR = 12.7 [CI, 1.5-598]). An increased risk was also seen with elevated maximum body mass index; compared with those with a body mass index less than 24 kg/m2, those with an index of 24-25 kg/m2, 26-28 kg/m2, and greater than 28 kg/m2 had odds ratios of 1.6 (CI, 0.4-7.6), 1.3 (CI, 0.3-5.6), and 2.6 (CI, 0.5-18.6), respectively (asymptotic test for trend, P = 0.03). Finally, a number of associations were noted with certain dietary and cooking habits.

CONCLUSIONS

Patients with gallbladder cancer differed from control subjects in race, body mass, physician-diagnosed typhoid, and certain dietary patterns. These findings may provide useful clues to the pathogenesis of gallbladder cancer, but given the number of analyses performed, additional cases need to be studied.

Calcium carbonate in cholesterol gallstones: polymorphism, distribution, and hypotheses about pathogenesis

This study of sets of cholesterol gallstones collected consecutively from 222 patients in La Paz, Bolivia, and Mexico City, Mexico, has developed a reliable infrared (IR) spectroscopic method for the detection of calcium carbonate in cholesterol gallstones and provided the basis for simultaneous identification of each of its three polymorphs: calcite, vaterite, and aragonite. The peaks in the 854 to 876 cm-1 region demonstrated 98% sensitivity and specificity for carbonate detection. As little as 3% carbonate by weight could be detected using these peaks. The overall incidence of carbonate was 19% in these populations containing a high proportion of Amerinds. Infrared microspectroscopy of 10 to 50 microns particles, dissected from stones, allowed a ring-by-ring examination of 11 carbonate-containing stones. It was determined that different carbonate polymorphs, when present in the same gallstone, almost always occurred in separate rings. In approximately half of the gallstones, different polymorphs were present in successive layers in the same stone, indicating that conditions governing stone growth changed cyclically. Carbonates were usually precipitated in peripheral layers rather than in the center, supporting the theory that formation of calcium carbonates may be related to episodes of intermittent obstruction of the cystic duct, as opposed to being a major factor in stone nidation.

Interaction of human gallbladder mucin with calcium hydroxyapatite: binding studies and the effect on hydroxyapatite formation

Calcium hydroxyapatite (HAP) crystals formed in vitro in the presence of polymeric human gallbladder mucin (1.0 mg/mL) were smaller (0.75 +/- 0.39 microns) than control crystals (7.86 +/- 2.76 microns), but the mucin did not affect the kinetics of crystal formation or alter the amount of mineral phase present at equilibrium. In contrast, glycopeptide subunits produced by proteolysis of the native mucin had no effect on HAP crystal size. Both native mucin and glycopeptides bound to mature HAP crystals, but the glycopeptides were much more readily displaced by phosphate ions. Therefore, in experiments where HAP was being formed, the phosphate ions inhibited the interaction of glycopeptides with the nascent HAP. These results indicate that gallbladder mucin may modulate HAP formation in vivo, and that this ability may be altered during pathological states, such as neutrophil infiltration or bacterial colonization, that may cause the release of proteinases capable of digesting mucin.

Inhibition of calcium hydroxyapatite formation by polyamines

The lithogenic potential of bile depends not only on supersaturation of solutes but also on the presence of pro- and anti-nucleating factors. For example, glycine-conjugated dihydroxy bile salt dimers are potent inhibitors of calcium hydroxyapatite precipitation that function by "poisoning" the nascent crystal. Although most inhibitors of apatite formation are anions, theoretically polycations should also be effective, and because significant concentrations of polyamines are present in bile, we have investigated the ability of these molecules to inhibit apatite formation. In vitro, each polyamine (2-10 mmol/l) was able to inhibit apatite formation, and the inhibiting power was correlated with ionic charge. Thus putrescine (2+) was the weakest inhibitor and spermine (4+) was the strongest. Mixtures of polyamines were less effective than were the individual polyamines, except at higher concentrations. Although polyamines were effective over short periods of time (270 min), over longer times (3 days) spermine was unable to prevent apatite formation. Using infrared spectroscopy, we found no evidence for interaction between phosphate ions and spermine in solution. Taken together, these results suggest that polyamines are modest inhibitors of apatite formation that likely function by retarding the dissolution of the intermediate amorphous calcium phosphate phase.

Clostridium difficile diarrhea in patients with AIDS versus non-AIDS controls. Methods of treatment and clinical response to treatment

We reviewed the hospital charts of 17 patients with AIDS and Clostridium difficile diarrhea to determine antibiotic use before C. difficile infection, methods of treatment for C. difficile diarrhea, and response of diarrhea to treatment. Left shift and total white blood cell count before and after treatment for C. difficile were also determined. Non-HIV-infected patients with C. difficile diarrhea served as controls. In the patients with AIDS, resolution of diarrhea was noted in 15 (88%) patients. In 25 (76%) control patients, diarrhea resolved with treatment. The patients with AIDS also had a significant decrease (p < 0.05) in left shift in white blood cell count with treatment; the controls did not. Our study therefore suggests that C. difficile diarrhea is at least as likely to resolve with antibiotic therapy in patients with AIDS as it is in those with the non-AIDS-related disorder. We also found that patients with AIDS and C. difficile diarrhea are more likely than patients without AIDS to have a decreased left shift in white blood cell count after antibiotic therapy.

Differences in antigen expression between neoplastic and nonneoplastic gallbladder epithelium. An immunohistochemical study

Immunoreactivity for a panel of 15 monoclonal antibodies (MAbs), which are known to react with different gastrointestinal tumor antigens, was assessed in formalin-fixed paraffin-embedded sections that were prepared from cholecystectomy specimens obtained from Mexican patients. Each case was classified histologically into one of the following groups: (1) invasive adenocarcinoma (N = 21), (2) high-grade dysplasia (carcinoma in situ) (N = 2), (3) low-grade dysplasia (N = 4), hyperplasia (4) (N = 15), and (5) chronic cholecystitis (N = 10). Significant differences (P < 0.05) were identified among the five histopathologic groups in the proportion of epithelial cells demonstrating immunoreactivity with MAbs to Lewisb; Lewis(a); sialylated Lewis(a); sialylated Lewis(a) and Lewis(a); Y antigen; H antigen; X antigen; X-like antigen; 200-kDa protein of CEA; 180-, 160-, 50-, 40-kDa proteins of CEA; 30- to 37-kDa protein; and an undefined antigen identified by MAb 99-57, with invasive carcinoma more frequently being positive as compared to nonneoplastic (hyperplasia, chronic cholecystitis) epithelium. Significant differences were also observed among the five histopathologic groups (P < or = 0.0005) in the proportion of epithelial cells demonstrating immunoreactivity with MAbs to Y antigen and the 20- to 50-kDa glycoprotein. However, with these two antibodies immunoreactivity was more frequently found in nonneoplastic epithelium rather than in invasive carcinomas. No significant differences in immunoreactivity were detected among the different histologic groups with MAb to blood group B antigen, types 1 and 2. This study demonstrates that cellular antigens are both developed and lost during the process of neoplastic transformation in the gallbladder.(ABSTRACT TRUNCATED AT 250 WORDS)

Primary malignant fibrous histiocytoma of the liver MRI findings

Primary malignant fibrous histiocytoma (MFH) is an unusual tumor which involves the deep fascia or skeletal muscles of the extremities or retroperitoneum. It rarely arises in the liver and, to our knowledge, the MRI appearance of primary MFH of the liver has never been reported. We present a patient with primary MFH of the liver and discuss the findings on MRI, CT, and angiography.

Interaction of bile salts with calcium hydroxyapatite: inhibitors of apatite formation exhibit high-affinity premicellar binding

Of the major human bile salts, only the glycine-conjugated dihydroxy species prevent the transformation of amorphous calcium phosphate to calcium hydroxyapatite, a component of gallstones; we have proposed that this inhibition occurs by competition between the bile salt and HPO4(2-) anions for binding site on the apatite crystal embryo. Now we show that the binding affinity of bile salts to fully mature hydroxyapatite has the following order: glycine-conjugated dihydroxy salts > taurine-conjugated dihydroxy salts > glycocholate approximately taurocholate. Glycine-conjugated dihydroxy bile salts bound with high affinity as "premicellar" aggregates, but the remaining species appeared to bind as a wider range of aggregate sizes. Glycochenodeoxycholate binding was decreased as the pH increased from 6.6 to 9.8 and the apatite surface charge reversed from net positive to net negative. Binding was competitively inhibited by HPO4(2-), but not by H2PO4-. Ca2+ promoted the binding of glycochenodeoxycholate, taurochenodeoxycholate and glycocholate, and for the latter two bile salts the increase was associated with enhanced "premicellar" binding. The binding of taurocholate was not influenced by Ca2+. When either glycocholate or taurocholate was mixed with glycochenodeoxycholate, mixed aggregates were formed that had a lower affinity for apatite than had pure glycochenodeoxycholate aggregates. Because only glycine-conjugated dihydroxy bile salts inhibit apatite formation, these results suggest that inhibition depends on high-affinity "premicellar" bile salt-apatite binding.

Glycochenodeoxycholic acid inhibits calcium phosphate precipitation in vitro by preventing the transformation of amorphous calcium phosphate to calcium hydroxyapatite

Calcium hydroxyapatite can be a significant component of black pigment gallstones. Diverse molecules that bind calcium phosphate inhibit hydroxyapatite precipitation. Because glycine-conjugated bile acids, but not their taurine counterparts, bind calcium phosphate, we studied whether glycochenodeoxycholic acid inhibits calcium hydroxyapatite formation. Glycochenodeoxycholic acid (2 mM) totally inhibited transformation of amorphous calcium phosphate microprecipitates to macroscopic crystalline calcium hydroxyapatite. This inhibition was not mediated by decreased Ca2+ activity. Taurocholic acid (2-12 mM) did not affect hydroxyapatite formation, but antagonized glycochenodeoxycholic acid. Both amorphous and crystalline precipitates contained a surface fraction relatively rich in phosphate. The surface phosphate content was diminish by increasing glycochenodeoxycholic acid concentrations, and this relationship was interpreted as competition between bile acid and HPO4(-4) for binding sites on the calcium phosphate surface. A phosphate-rich crystal surface was associated with rapid transition from amorphous to crystalline states. These results indicate that glycochenodeoxycholic acid prevents transformation of amorphous calcium phosphate to crystalline hydroxyapatite by competitively inhibiting the accumulation of phosphate on the crystal embryo surface.

Gallstone fragmentation during biliary lithotripsy: effect of stone composition and structure

In vitro lithotripsy with the Siemens Lithostar was conducted on 36 radiolucent or minimally calcified gallstones housed in an anthropomorphic phantom. The ease and pattern of fragmentation were correlated with global composition for the entire stone, regional or microcomposition (determined by Fourier-transform infrared spectroscopy), and microstructure (determined by scanning electron microscopy). Stones made up of more than 62% cholesterol required 50% more shock waves to pulverize all fragments to 0.3 cm or less than did stones of less than 62% cholesterol (p less than .01). An inverse relationship was found between the number of shock waves needed for fragmentation and the cholesterol content (r = .77). Although a broad range of fragmentation responses occurred, little variation was seen in the ease of fragmentation within stone families. The majority of stones fractured along radially oriented cholesterol plates, but one third of stones treated showed initial chipping or flaking at the periphery before radial fracture. This type of peripheral erosion most often occurred in stones with peripheral pigment rims. These stones required more shock waves and lagged in pulverization compared with more homogeneous cholesterol stones. The efficiency of fragmentation during biliary lithotripsy correlates with the stones' global cholesterol content. A stone's architecture, as reflected by its regional composition and microstructure, partially predicts the mechanism of fragmentation. These in vitro data may be useful in further refining criteria for selecting patients and understanding the fragmentation process.

Gallstone composition in relation to buoyancy at oral cholecystography

Although it is recognized that some gallstones float at oral cholecystography, the reasons for this are not known. To determine how stone type and composition are related to stone buoyancy, the authors analyzed gallstones from 90 patients in the National Cooperative Gallstone Study. Seventeen patients had floating and 73 had nonfloating radiolucent stones at oral cholecystography. Stone analysis showed that all 17 floating stones were cholesterol stones; 64 of the nonfloating stones were cholesterol stones, while nine were pigment stones. The cholesterol contents of floating and nonfloating cholesterol stones were similar, 90.4% +/- 1.7 and 87.0% +/- 1.2 of stone weight, respectively. The calcium salt content of the nonfloating cholesterol stones was 3.2% +/- 0.6, while that of the floating cholesterol stones was only 1.1% +/- 0.4 (P = .02). The results indicate that floating gallstones are cholesterol stones with a significantly lower calcium salt content than that of nonfloating cholesterol stones.

Protective action of luminal bile salts in necrotizing acute pancreatitis in mice

Bile salts in the intestinal lumen act to inhibit the release of cholecystokinin (CCK). Recent studies have shown that CCK may play a permissive role in the development of acute pancreatitis. In this study, the amount of luminal bile salts in female Swiss Webster mice was either decreased by feeding 4% (wt/wt) cholestyramine or increased by feeding 0.5% sodium taurocholate for 1 wk. Plasma levels of CCK were stimulated by cholestyramine and inhibited by taurocholate. Then, acute pancreatitis was induced either by caerulein injections, or by feeding a choline-deficient, ethionine-supplemented (CDE) diet. Feeding of cholestyramine significantly decreased survival from 25% to 0% in the CDE pancreatitis, and increased the magnitude of elevation of serum amylase levels and the extent of pancreatic necrosis in both models of pancreatitis; CCK-receptor blockade with CR-1409 completely abolished the adverse effects of cholestyramine. In contrast, feeding of taurocholate significantly increased survival to 100% and decreased the elevation of serum amylase and pancreatic necrosis; CCK-8 antagonized these actions of taurocholate. Luminal bile salts appear to provide a physiologic protection against necrotizing pancreatitis, at least in part, both by inhibiting the release of CCK and by promoting resistance of the pancreas to CCK excessive stimulation in vivo.

Current therapy of chronic liver disease

The study of chronic liver disease has been hampered by insufficient information relative to the pathogenesis of the many forms of hepatitis. Consequently, well-designed treatment strategies are frequently lacking. Wilson's disease is characterised by excessive copper accumulation in the liver and other organs. While d-penicillamine is clearly effective, many patients may not tolerate its many adverse effects. Trientine, oral zinc and unithiol have all shown promise as therapeutic alternatives. Autoimmune chronic active hepatitis responds well to prednisone and azathioprine. Cyclosporin has also produced clinical improvement in several case reports but no comparison has yet been made with the current standard therapy. Recombinant interferon-alpha (IFN alpha) has demonstrated the ability to inhibit hepatitis B viral replication, and the combination of oral corticosteroids followed by IFN alpha is more effective than either agent alone in eliminating viral replication in patients with chronic active hepatitis B. Currently, primary sclerosing cholangitis (PSC) has no standard medical management, but corticosteroids and methotrexate may each have a future role in its treatment. Drug treatment for primary biliary cirrhosis (PBC) has been disappointing, and early reports of success with d-penicillamine were not confirmed in large well-controlled trials. While some reports of improvement with several agents have been described, larger studies are still needed. Alcoholic liver disease continues to be associated with significant morbidity and mortality and numerous investigators have researched several different medical avenues of treatment. Success reported with androgens and the antithyroid agent propylthiouracil in alcoholic liver disease will need confirmation by other research before these agents can be recommended for routine use. Finally, colchicine may prove to be effective in slowing the rate of fibrosis in cirrhosis, but this has yet to be conclusively proven.

Serum CEA and CA 19-9: potential future diagnostic or screening tests for gallbladder cancer?

The poor prognosis of gallbladder cancer and the presence of high-risk populations make the identification of a screening test for this disease very desirable. As part of an ongoing case-control study of gallbladder cancer being conducted in Mexico City, Mexico, and in La Paz, Bolivia, blood specimens were sought from all patients with cancer of the gallbladder and on controls of similar age and sex undergoing upper abdominal surgery. Each sample was analyzed for carcino-embryonic antigen (CEA) and CA 19-9. Using the specimens from Bolivia, a serum CEA cutoff of 4.0 ng/ml yielded a sensitivity of 50.0% and a specificity of 92.7%, while a serum CA 19-9 cutoff of 20.0 units/ml yielded a sensitivity of 79.4% and a specificity of 79.2%. Using ROC curve analysis, the latter was a much better test than the former (p less than 0.05). Using the tests in series or in parallel did not substantively improve the results. The specimens from Mexico were used for validation purposes, and yielded very similar results. In conclusion, serum CA 19-9 and CEA are fairly good tests for discriminating patients with gallbladder cancer from patients with gallstones and no cancer, the former being a better test than the latter. These tests may be useful in identifying disease recurrences. In addition, if a sufficiently high-risk population could be identified, this could potentially become a useful screening test for this serious disease, allowing early intervention. However, additional data are needed prior to recommending this clinically.

The "buried bumper syndrome": a complication of percutaneous endoscopic gastrostomy

Percutaneous endoscopic gastrostomy is used for long-term nutritional support and can be performed with relatively few complications. We describe a patient in whom the internal bumper eroded into the stomach wall and was completely covered by gastric epithelium 11 months after gastrostomy tube placement. The gastrostomy tube itself was patent, and the end still protruded into the lumen of the stomach so that tube feeding was not impaired. Endoscopy, in combination with passage of Savary dilators over a guidewire, was safely used to remove the gastrostomy tube and buried bumper. We recommend this approach in patients with the "buried bumper" syndrome to prevent continued tube migration into the gastric and abdominal walls.

Gallbladder mucin and cholesterol and pigment gallstone formation in hamsters

We measured gallbladder mucin production by hamsters fed diets lithogenic for either cholesterol or pigment gallstones. In hamsters on the cholesterol stone diet, gallbladder production of 3H-glucosamine-labeled mucin was elevated two- and seven-fold after 1 and 3 weeks, respectively. After 1 week cholesterol crystals were seen in a mucus gel on the gallbladder surface. In hamsters on the pigment stone diet, gallbladder mucin production was significantly elevated after 1 and 3 weeks. The first precipitation of pigment crystals was in mucus in bile or on the gallbladder surface. Black pigment stones grew by agglomeration of pigment crystals enmeshed in mucus. In conclusion, gallbladder mucin production is increased before cholesterol or pigment stone formation, and the earliest deposition of crystals is in mucus in bile or on the gallbladder surface.

Quantitative infrared spectroscopy of common bile duct gallstones

The aim of this study was to determine the composition of gallstones from the common bile duct of patients from the United States and the relationship of stone type to the time interval after cholecystectomy. We analyzed 56 sets of common bile duct gallstones collected over a 10-yr period using infrared and atomic absorption spectroscopy and chemical methods. Twenty-four sets (43%) of stones were cholesterol stones containing 85.3% cholesterol, 3.2% pigment, 0.6% phosphate, and 1.3% total calcium. Ten sets (18%) were black pigment stones containing 36.5% pigment, 11.4% cholesterol, 7.6% carbonate, 3.0% phosphate, and 6.2% total calcium. Twenty-two sets (39%) were brown pigment stones containing 52.7% pigment, 16.5% calcium palmitate, 10.1% cholesterol, 0.4% phosphate, and 3.4% total calcium. Most of the 26 stones found at the same time as or within several months after cholecystectomy were either cholesterol (69%) or black pigment (19%). In contrast, the majority (59%) of the 22 common duct stones that were diagnosed greater than or equal to 21 mo after cholecystectomy were brown pigment stones. In conclusion, brown pigment stones are a distinct type of pigment stone characterized by their content of substantial amounts of calcium palmitate. They comprise a significant proportion of common duct stones in this series of United States patients, particularly of those found greater than or equal to 21 mo after cholecystectomy.

Hepatocanalicular injury associated with vitamin A derivative etretinate. An idiosyncratic hypersensitivity reaction

A patient with pustular psoriasis developed jaundice, peripheral blood eosinophilia, and biochemical evidence of hepatocanalicular dysfunction four weeks after the initiation of etretinate therapy. A liver biopsy specimen showed bile duct damage, a periportal inflammatory infiltrate composed of neutrophils, eosinophils and lymphocytes, canalicular cholestasis, and focal hepatocyte necrosis. Clinical exclusion of other possible etiologic factors coupled with near resolution of the biochemical abnormalities within six weeks after complete discontinuation of the drug indicates that etretinate may induce an idiosyncratic hypersensitivity reaction. This is the first report to document etretinate associated bile duct injury.

Primary sclerosing cholangitis and pregnancy

Primary sclerosing cholangitis is a chronic, fibrosing, inflammatory disorder of unknown etiology affecting the biliary tree. We describe a case of a pregnancy complicated by this condition. Remarkably, maternal cholestasis improved with advancing gestation. Despite a marked elevation of bile acid levels in cord blood, the patient was delivered of a healthy term infant. The principles of management and potential effects of primary sclerosing cholangitis on pregnancy care are discussed.

An animal model of pigment cholelithiasis

Pigment stones of high calcium content were induced in male hamsters of the Harlan Sprague-Dawley strain fed a nutritionally adequate semipurified diet for a period of 14 weeks. The diet contained moderate amounts of cholesterol (0.30 percent) and ethinyl estradiol (15 micrograms/day per animal). At sacrifice, the incidence of pigment stones was 50 percent. When stones were present, they were in the form of numerous black amorphous rods about 0.1 to 0.4 mm in length. Infrared analysis of the dried stones indicated the following composition: calcium phosphate 26.7 percent, calcium bilirubinate 12.8 percent, cholesterol 15.1 percent, and protein 45.4 percent. Pigment stones were associated with an elevated biliary total calcium level (probably induced by the dietary cholesterol) and a paradoxic decrease in the biliary total bilirubin level. The lithogenic diet produced marked elevations in liver and plasma cholesterol levels and cholesterol saturation of bile, but no cholesterol crystals or stones were observed. The accumulation of elevated levels of cholesterol in the livers of the experimental animals produced mild to moderate hepatotoxicity. The precise mechanism of the dietary induction of pigment stones in this hamster model remains to be elucidated.