RESUMO
This guideline provides evidence-based key recommendations for the prevention, diagnosis and therapy of gallstones and upgrades the 2007 version. The guideline was developed by an interdisciplinary team of gastroenterologists and surgeons, and patient support groups under the auspice of the German Society for Gastroenterology and Metabolic Diseases and the German Society for General Surgery and Surgery of the Alimentary Tract. The guideline used structural S3 consensus-based methodology and includes statements on clinical practice, medical education, prevention, quality assurance, outcome analysis, and integration of outpatient and inpatient care for patients with gallstone diseases.
Assuntos
Cálculos Biliares , Consenso , Cálculos Biliares/diagnóstico , Cálculos Biliares/prevenção & controle , Cálculos Biliares/terapia , Alemanha , Humanos , Sistema de RegistrosRESUMO
The solution behavior of bilirubin ditaurate (BDT), the first naturally occurring conjugated bile pigment to be physically and chemically characterized, was assessed in aqueous solution and in monomeric and micellar solutions of common taurine-conjugated bile salts (BS). Analytical ultracentrifugation revealed that BDT self-associates in monomer-dimer equilibria between 1 and 500 µM, forming limiting tetramers at low millimolar concentrations. Self-association was enthalpically driven with ΔG values of ≈5 kcal/mol, suggesting strong hydrophobic interactions. Added NaCl and decreases in temperature shifted the oligomerization to lower BDT concentrations. On the basis of circular dichroism spectra and the limiting size of the self-aggregates, we infer that the tetramers are composed of 2P(+) and 2M(-) enantiomeric BDT pairs in "ridge-tile" conformations interacting in a "double-bookend" structure. With added monomeric BS, blue shifts in the UV-vis spectra and tight isosbestic points revealed that BDT/BS heterodimers form, followed by BDT "decorating" BS micelles mostly via hydrophilic interactions. Conformational enantiomerism, fluorescence intensities, and anisotropy, as well as resistance of the hybrid particles to disaggregation in 6 M urea, suggested that two or three hydrogen-bonding sites bound BDT monomers to the hydroxyl groups of BS, possibly via pyrrole-π-orbital-OH interactions. BDT stabilized these interactions by enveloping the BS in its "ridge-tile" pincers with variable strain that maximized van der Waals interactions. Possibly because the BDT molecule becomes highly strained with BS subtending a 7ß-hydroxyl group, BDT became totally resistant to oxidation in air. This work predicts that, because of BS dissolution of the BDT self-aggregates, BS/bilirubin hybrid particles, which are stabilized hydrophilically, are likely to be the dominant mode of transport for all conjugated bilirubins in bile.
Assuntos
Ácidos e Sais Biliares/química , Bilirrubina/análogos & derivados , Micelas , Taurina/análogos & derivados , Bilirrubina/química , Dimerização , Interações Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Estereoisomerismo , Taurina/química , Água/químicaRESUMO
Recently [Neubrand, M. W., et al. (2015) Biochemistry 54, 1542-1557], we determined a concentration-dependent monomer-dimer-tetramer equilibrium in aqueous bilirubin ditaurate (BDT) solutions and explored the nature of high-affinity binding of BDT monomers with monomers and micelles of the common taurine-conjugated bile salts (BS). We now investigate, employing complementary physicochemical methods, including fluorescence emission spectrophotometry and quasi-elastic light scattering spectroscopy, the influence of phosphatidylcholine (PC), the predominant phospholipid of bile and calcium, the major divalent biliary cation, on these self-interactions and heterointeractions. We have used short-chain, lyso and long-chain PC species as models and contrasted our results with those of parallel studies employing unconjugated bilirubin (UCB) as the fully charged dianion. Both bile pigments interacted with the zwitterionic headgroup of short-chain lecithins, forming water-soluble (BDT) and insoluble ion-pair complexes (UCB), respectively. Upon micelle formation, BDT monomers apparently remained at the headgroup mantle of short-chain PCs, but the ion pairs with UCB became internalized within the micelle's hydrophobic core. BDT interacted with the headgroups of unilamellar egg yolk (EY) PC vesicles; however, with the simultaneous addition of CaCl2, a reversible aggregation took place, but not vesicle fusion. With mixed EYPC/BS micelles, BDT became bound to the hydrophilic surface (as with simple BS micelles), and in turn, both BDT and BS bound calcium, but not other divalent cations. The calcium complexation of BDT and BS was enhanced strongly with increases in micellar EYPC, suggesting calcium-mediated cross-bridging of hydrophilic headgroups at the micelle's surface. Therefore, the physicochemical binding of BDT to BS in an artificial bile medium is influenced not only by BS species and concentration but also by long-chain PCs and calcium ions that exert a specific rather than a counterion effect. This work should serve as a physicochemical template for studies with other conjugated bilirubins, including bilirubin diglucuronoside (BDG), the principal bilirubin conjugate (cBR) in human bile.
Assuntos
Ácidos e Sais Biliares/química , Bilirrubina/análogos & derivados , Cloreto de Cálcio/química , Micelas , Fosfatidilcolinas/química , Taurina/análogos & derivados , Anisotropia , Bilirrubina/química , Bilirrubina/metabolismo , Biopolímeros , Dimerização , Modelos Moleculares , Espalhamento de Radiação , Soluções , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Relação Estrutura-Atividade , Taurina/química , Taurina/metabolismo , Lipossomas UnilamelaresRESUMO
BACKGROUND/AIMS: Increased viscosity and supersaturation of cholesterol in gallbladder bile, as well as an impaired motility of the gallbladder, are considered to be important factors in the pathogenesis of cholesterol gallstones. However, the relation of these parameters has not yet been determined. MATERIAL AND METHODS: Bile viscosity (mPa s) was measured by rotation viscosimetry and the composition of gallbladder bile was determined using standard methodology. Gallbladder motility was calculated as ejection fraction in percent of total volume 45 min after a test meal using ultrasonography in patients with gallstones prior to elective cholecystectomy. RESULTS: The study included 35 patients with cholesterol gallstones. Viscosity of gallbladder bile ranged between 0.9 and 12.5 mPa s (median 2.2 mPa s) and an ejection fraction of the gallbladder of 55.4 +/- 18.3% (mean +/- SD) was determined. No significant correlation (r = 0.19, p < 0.2) between the 2 parameters could be calculated. Analysis of the composition of gallbladder bile revealed a positive correlation of all components to biliary viscosity but not to the motility of the gallbladder, with the exceptions of a negative correlation (r = 0.39, p < 0.02) between mucin concentration and the ejection fraction at 45 min after the test meal. CONCLUSIONS: The motility of the gallbladder appears to be unrelated to the viscosity of gallbladder bile or gallbladder bile composition. The negative correlation between the ejection fraction of the gallbladder and mucin concentration of gallbladder bile suggests that chronic inflammation of the gallbladder wall is associated with both an impaired motility of the gallbladder and increased mucin release into gallbladder bile.
Assuntos
Bile/fisiologia , Esvaziamento da Vesícula Biliar/fisiologia , Cálculos Biliares/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Bile/química , Colecistectomia Laparoscópica , Colesterol/análise , Feminino , Cálculos Biliares/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , ViscosidadeRESUMO
BACKGROUND: The combination of photodynamic therapy and biliary drainage by plastic endoprosthesis insertion has produced promising results in the treatment of nonresectable hilar cholangiocarcinoma. The feasibility and efficacy of intraductal photodynamic therapy with subsequent biliary drainage by self-expandable metal stent insertion were evaluated in a prospective phase II study. METHODS: Twenty-four patients were treated with photodynamic therapy after sensitization with porfimer sodium. A plastic endoprosthesis was inserted immediately thereafter and replaced by a metal stent 4 weeks later. A retrospectively analyzed group of 20 patients treated only with biliary drainage served as a historical control group. RESULTS: In 19 of the 24 patients, insertion of a metal stent was technically feasible. The 30-day and 60-day mortality rates were 0%. A significant decrease in serum bilirubin was noted in all patients and quality of life remained stable throughout follow-up. Mean and median survival were, respectively, 15.9(3.1) and 9.9: 95% CI [6.4, 13.4] months after photodynamic therapy. In the control group, mean and median survival were, respectively, 12.5(3.4) and 5.6: 95% CI [3.7, 7.6] months, which was not statistically significantly different from the photodynamic therapy group. CONCLUSIONS: Photodynamic therapy with consecutive biliary drainage by insertion of a self-expandable metal stent is feasible. With respect to the small benefit in overall survival, randomized controlled trials are warranted.