Fred M. Konikoff

Pregnancy and the biliary tract

Pregnancy induces many physiological changes, some of which may have pathological results. In population studies, gallstones were found in 6.5% to 8.4% of nulliparous women, and in 18.4% to 19.3% of women with two to three or more pregnancies. In women followed throughout pregnancy, neoformation of gallstones was documented in 3% to 8.1% depending on the population. Some 20% to 30% of these gallstones redissolve postpartum. The frequency of biliary colic during pregnancy is controversial, and the recommended therapeutic approach during pregnancy is conservative. When essential, invasive procedures are relatively well tolerated, preferably during the second trimester. Biliary sludge disappears postpartum in the great majority. Gallstones and sludge are most likely caused by biliary stasis, prolonged intestinal transit and increased cholesterol saturation of bile, which were all demonstrated to occur during pregnancy.

Elevated serum iron predicts poor response to interferon treatment in patients with chronic HCV infection

To date, there are no firm clinical, demographic, biochemical, serologic, or histologic features predicting which patients with chronic hepatitis C are more likely to respond to therapy with interferon-α. Serum iron, total iron-binding capacity, transferrin saturation, and ferritin were measured in the fasting state. The amount of stainable iron in liver biopsy specimens was evaluated histochemically as well. All patients received subcutaneous recombinant human IFN-α2a three million units thrice weekly by self-administration. Eleven of 13 (84%) responders had low to normal serum iron levels as compared to one of 26 (4%) nonresponders (P<0.001). The serum transferrin was similar in both groups, but iron saturation was significantly lower in responders (30±10%) than in nonresponders (53±12%) (P<0.001). Serum ferritin and hepatic iron content were higher in nonresponders (NS). It is suggested that increased serum iron and transferrin saturation blunt the action of interferon, as they have opposite effects on the immune system. Iron overload can thus lead to a poor response to interferon. It remains to be seen whether reducing iron overload will improve the response to interferon therapy.

Direct visualization of lipid aggregates in native human bile by light- and cryo-transmission electron-microscopy

The evolution of microstructures present in human gallbladder and hepatic bile was observed simultaneously by video‐enhanced light microscopy (VELM) and transmission electron microscopy of vitrified specimens (cryo‐TEM), as a function of time after withdrawal from patients. Fresh centrifuged gallbladder bile samples contained small (6 nm) spherical micelles in coexistence with vesicles (40 nm). Out of the seven bile samples investigated four contained, in addition, two types of elongated aggregates that have not been previously described. Uncentrifuged gallbladder bile also contained a mixture of ribbon‐ and plate‐like crystals seen by VELM, but not by cryo‐TEM. In aged (3–6‐week‐old) gallbladder bile samples VELM also revealed spiral and helical crystal structures. No such crystals were present in hepatic bile samples, although microcrystals, not observable by VELM were seen by cryo‐TEM in addition to micelles and vesicles. The similarity of these observations to those observed in bile models lends strong support for the validity of the model systems. Furthermore, the presence of microcrystals in hepatic bile samples, apparently devoid of crystals by light microscopy, indicates that under certain conditions the common criterion of ‘nueleation time’ (NT), based on light microscopy, does not represent the real time of nucleation. In the human bile samples investigated in this study the dissociation between NT and the time of observation of microcrystals was seen in hepatic but not in gallbladder bile samples. Hence, crystal growth may be rate limiting only in dilute biles.

Cannabis for Inflammatory Bowel Disease

The marijuana plant Cannabis sativa has been used for centuries as a treatment for a variety of ailments. It contains over 60 different cannabinoid compounds. Studies have revealed that the endocannabinoid system is involved in almost all major immune events. Cannabinoids may, therefore, be beneficial in inflammatory disorders. In murine colitis, cannabinoids decrease histologic and microscopic inflammation. In humans, cannabis has been used to treat a plethora of gastrointestinal problems, including anorexia, emesis, abdominal pain, diarrhea, and diabetic gastroparesis. Despite anecdotal reports on medical cannabis in inflammatory bowel disease (IBD), there are few controlled studies. In an observational study in 30 patients with Crohns disease (CD), we found that medical cannabis was associated with improvement in disease activity and reduction in the use of other medications. In a more recent placebo-controlled study in 21 chronic CD patients, we showed a decrease in the CD activity index >100 in 10 of 11 subjects on cannabis compared to 4 of 10 on placebo. Complete remission was achieved in 5 of 11 subjects in the cannabis group and 1 of 10 in the placebo group. Yet, in an additional study, low-dose cannabidiol did not have an effect on CD activity. In summary, evidence is gathering that manipulating the endocannabinoid system can have beneficial effects in IBD, but further research is required to declare cannabinoids a medicine. We need to establish the specific cannabinoids, as well as appropriate medical conditions, optimal dose, and mode of administration, to maximize the beneficial effects while avoiding any potential harmful effects of cannabinoid use.

Diagnostic yield of routine push enteroscopy with a graded-stiffness enteroscope without overtube

BACKGROUNDnPush enteroscopy has become a standard procedure for evaluation of small intestinal disorders. Its diagnostic yield and acceptability, however, has been hampered by the use of an overtube, which is both inconvenient and potentially hazardous. This study assessed the clinical value of enteroscopy with a graded-stiffness videoenteroscope without an overtube.nnnMETHODSnA total of 121 consecutive patients (mean age 59 years, range 12-89 years) underwent diagnostic enteroscopy. All procedures (n = 126) were performed with a push-type graded-stiffness videoenteroscope without an overtube. Indications were the following: unexplained iron deficiency anemia (45%), GI bleeding (29%), abdominal pain (6%), malabsorption (5.5%), imaging abnormality (5.5%), diarrhea (4%), intestinal obstruction (3%), and vomiting (2%).nnnRESULTSnThe mean depth of instrument insertion distal to the pylorus was 121 cm. A diagnosis was made in 40% of all procedures. The findings included ulcerations or erosions in 43%, angioectasia in 35%, inflammation in 14%, tumors in 6%, and varices in 2%. In all cases of a positive enteroscopic diagnosis, therapeutic maneuvers were performed, and no patient needed a further diagnostic procedure. Patient comfort was good. No complications were observed.nnnCONCLUSIONSnRoutine enteroscopy with a graded-stiffness enteroscope without an overtube is safe and comfortable for the patient and the endoscopist, and has a clinical efficacy comparable with that reported for enteroscopy with use of an overtube. A prospective, randomized study is warranted to assess the exact role of this form of enteroscopy in patient care.

Treatment of preestablished diet-induced fatty liver by oral fatty acid-bile acid conjugates in rodents

Background Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in industrialized countries. It has no accepted medical therapy. Fatty acid–bile acid conjugates (FABACs) were proven to prevent diet-induced NAFLD in rodents. Aim This study was undertaken to test whether oral FABACs are also effective in reducing liver fat in preestablished diet-induced NAFLD. Methods NAFLD was induced in mice and rats by a high-fat diet and maintained by various proportions thereof. The FABACs used were conjugates of cholic acid with either arachidic or stearic acids. Results FABAC therapy reduced liver fat in all four series of experiments. The rapidity of the effect was inversely proportional to the concentration of fat in the maintenance diet. In mice on a 25% maintenance diet FABACs decreased total liver lipids by about 30% in 4 weeks (P<0.03). Diglycerides (P<0.003) and triglycerides (P<0.01) were the main neutral liver lipids that decreased during FABAC therapy. Both FABACs tested reduced liver fat in NAFLD at doses of 25 and 150u2009mg/kg/day. High-fat diet increased, whereas FABAC therapy decreased plasma 16u2009:u20091/(16u2009:u20090+16u2009:u20091) fatty acid ratio – a marker of stearoyl CoA desaturase activity. In HepG2 cells FABACs decreased de-novo fatty acid synthesis dose dependently. Conclusion Oral FABAC therapy decreased liver fat in preestablished NAFLD in mice and rats. Inhibition of stearoyl CoA desaturase activity and fatty acid synthesis are mechanisms that may contribute to this decrease. FABACs may be potential therapeutic agents for human NAFLD.

IMAGING SUPRAMOLECULAR AGGREGATES IN BILE MODELS AND HUMAN BILE

Investigation of cholesterol crystallization is essential for the understanding of gallstone formation. Previous work has revealed a variety of aggregates of different sizes and shapes prior to the appearance of “classical” plate—like cholesterol monohydrate crystals both in native biles and model systems. In this article, we review existing data based on various microscopic techniques and present data on microstructural pathways leading to cholesterol crystal formation in two different bile models and in native bile.

Arachidyl amido cholanoic acid (Aramchol) is a cholesterol solubilizer and prevents the formation of cholesterol gallstones in inbred mice.

We have recently synthesized fatty acid bile acid conjugates (FABAC) that were able to reduce and retard cholesterol crystallization in model and human biles. When given orally, they prevented the formation of cholesterol crystals in the bile of hamsters. The aim of the present study was to determine whether the FABAC are cholesterol solubilizers, whether they can dissolve pre-existing crystals, whether they can prevent the formation of cholesterol gallstones, and to investigate the optimal type of bond between the fatty acid and bile acid. The presence of cholesterol crystals was determined by light microscopy, and the total crystal mass of precipitated crystals was measured by chemical means. Inbred (C57J/L) mice on a lithogenic diet were used to evaluate cholesterol crystal formation, dissolution, and gallstone formation in vivo. Arachidyl amido cholanoic acid (Aramchol) was the FABAC used in the present experiments. At equimolar amounts, the cholesterol-solubilizing capacity of Aramchol was higher than that of taurocholate and similar to that of phosphatidylcholine. The addition of Aramchol dissolved approximately 50% of preexisting crystals in model bile solutions. The same phenomenon was demonstrated in human bile ex vivo, with a dose-response effect. All inbred mice developed cholesterol crystals in bile after 10–14 d on the lithogenic diet. Thereafter, supplementation of the diet with Aramchol progressively reduced the proportion of mice with crystals to 25% after 28 d. On the lithogenic diet, 100% of inbred mice developed cholesterol gallstones in the gallbladder by day 21. None of the mice whose diet was supplemented with 0.5 mg or 1.0 mg of Aramchol/d developed stones or crystals. FABAC are a new class of molecules that are cholesterol solubilizers and which are able to dissolve cholesterol crystals in bile. Upon oral administration, they dissolve pre-existing cholesterol crystals and prevent the formation of gallstones in gallstone-susceptible mice.

Effects of Fatty Acid Bile Acid Conjugates (FABACs) on Biliary Lithogenesis: Potential Consequences for Non-Surgical Treatment of Gallstones

Fatty acid bile acid conjugates (FABACs) are novel synthetic lipid molecules, which were designed for the treatment of cholesterol gallstones. The rationale was to combine a cholesterol solubilizing moiety (a saturated fatty acid) with a bile acid (cholic acid) as a vehicle to enable secretion into bile and entry into the enterohepatic circulation. An amide bond was used to provide stability against intestinal degradation. Initial in vitro studies showed that FABACs are indeed cholesterol solubilizers, able to prevent biliary cholesterol crystallization. Arachidyl-amido-cholanoic acid (Aramchol) was found to be the most potent FABAC in these studies. Animal studies revealed that Aramchol was absorbed after oral administration and could prevent cholesterol crystallization as well as dissolve preformed crystals in rodents fed a lithogenic diet. In gallstone susceptible mice, Aramchol prevented gallstone formation and dissolved gallstones. FABACs were found to be metabolically active substances, also able to decrease blood cholesterol, atherosclerotic plaques and fat accumulation in the liver in several animal species. The underlying mechanisms of action are under active investigation, and several effects, e.g. on cholesterol and bile salt metabolizing enzymes as well as cholesterol efflux from cells have been discovered. These findings are, however, only the beginning of our understanding of the metabolic actions as well as the potential of use of FABACs as therapeutic agents.

Apolipoprotein-e genotype and the risk of developing cholelithiasis following bariatric surgery: a clue to prevention of routine prophylactic cholecystectomy

Background: Obesity and especially rapid weight loss following bariatric surgery are known risk factors for cholelithiasis. Since the risk may be high, prophylactic cholecystectomy has been advocated. Apolipoprotein (Apo) E, an important carrier protein in cholesterol metabolism and trafficking, is believed to play a role in gallstone pathogenesis. In particular, the Apo E4 allele has been suggested to be associated with cholesterol cholelithiasis. The aim of this study was to assess the incidence of postoperative cholelithiasis in our patient population and to determine a possible correlation with the Apo-E genotype. Methods: 134 morbidly obese patients undergoing gastric restrictive surgery [laparoscopic assisted gastric banding (LAGB) or silastic ring vertical gastroplasty (SRVG)] had abdominal ultrasound before and 6 to 12 months after operation, to determine the presence of gallstones. None of the patients enrolled in the study had gallstones before surgery.They did not have a prophylactic cholecystectomy or receive bile salt treatment. Apo-E genotypes were determined by Polymerase Chain Reaction restriction enzyme analysis. Results: 10 patients (7.5%) developed postoperative cholelithiasis. The incidence of cholelithiasis in each ApoE genotype was: E2/E3 - 1/20 (5%), E3/E3 - 3/91 (3%), E3/E4 - 6/21 (29%), and E4/E4 - 0/2. ApoE allele frequencies in the study population were identical to those of a healthy control population. The mean BMI dropped from 43.6 to 29.4 kg/m2. Conclusions: The occurrence of postoperative gallstones was low in our population. However, in subjects with the Apo-E3/E4 genotype, the incidence is of practical significance. These data suggest that Apo-E genotyping may be useful in selecting patients for gallstone prevention (surgical or medical) when undergoing bariatric surgery.Further testing in larger patient populations may be able to give more definite guidelines in the future.