Immunohistochemical characteristics of ganglionated plexuses in the human gallbladder

Indirect triple immunolabelling techniques were used to identify the presence of choline acetyl-transferase (ChAT), neuronal nitric oxide synthase (nNOS), Dopamine beta-hydroxylase (DβH), neuromedin U-8 (NMU-8), and neuropeptide Y (NPY) in the ganglionated plexuses of the human gallbladder. Of all the intrinsic cholinergic neurons examined, NMU-8-immunoreactive (-IR) neurons appeared to be the most populous, followed closely by neurons containing NPY-IR. nNOS-IR neurons were often observed to coexist with ChAT, NMU, and NPY. Occasionally, these nNOS positive neurons were seen triple labeled with ChAT, NMU-8, and NPY. Results also indicate that not all nNOS and NMU-8-IR coexistent neurons express NPY immunoposi-tivity. Our findings suggest that these intrinsic neurons may be categorized into a distinct population of neurons that express both inhibitory and excita-tory capabilities.Intrinsic cholinergic neurons that were ChAT-IR displayed a spectrum of immunopositivity. Interestingly, a small subpopulation of these neurons ap-peared to be extremely weak ChAT-IR or simply ChAT-immunonegative. These occasionally obser-ved ChAT-immunonegative neurons at times ex-pressed single immunopositivity for NMU-8 or nNOS, while more frequently, these ChAT-immunonegative neurons were found to be single immunopositive, or at times, double immunopositi-ve for NMU-8-, NPY-, or nNOS-IR.Dopamine beta-hydroxylase (DβH) antibodies were used to confirm the lack of intrinsic sympat-hetic innervation in the human gallbladder. As suspected, in all the sections examined, DβH-IR neu-rons were not detected. The only indication of DβH immunopositivity was noted among delicate fibers surrounding the neurons and blood vessels within the organ

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Expression of group XIIA phospholipase A2 in human digestive organs.

Cellular distribution of group XIIA phospholipase A2 (GXIIA PLA2) was studied in human digestive organs by immunohistochemistry. GXIIA PLA2 protein was detected in epithelial cells of normal gastrointestinal tract, gallbladder and pancreatic acinar cells. The GXIIA PLA2 protein was evenly distributed in the cytoplasm in contrast to secretory granular distribution of GIB PLA2 and GIIA PLA2 in pancreatic acinar cells and small intestinal Paneth cells respectively. Epithelial cells of intestinal glands in Crohn's disease and ulcerative colitis expressed abundant GXIIA PLA2 , whereas inflammatory cells were devoid of the enzyme protein. Tumour cells in colonic adenomas and carcinomas and pancreatic ductogenic carcinomas expressed GXIIA PLA2 protein at varying intensity levels. The putative functions of GXIIA PLA2 remain to be investigated and its role in healthy and diseased digestive organs can only be speculated on at present.

Postprandial response and tissue distribution of the bile acid synthesis-related genes, cyp7a1, cyp8b1 and shp, in rainbow trout Oncorhynchus mykiss.

In mammals, cholesterol 7α-hydroxylase (CYP7A1) and sterol 12α-hydroxylase (CYP8B1) are rate-limiting enzymes in bile acid synthesis. In addition, a small heterodimer partner (SHP) is also known to inhibit bile acid synthesis via the suppression of CYP7A1 and CYP8B1 expression. However, little information is currently available regarding primary structure of the genes involved in bile acid synthesis in fish. We therefore cloned cyp7a1, cyp8b1 and shp genes from rainbow trout and obtained cDNAs encoding two isoforms each of Cyp7a1 (-1 and -2), Cyp8b1 (-1 and -2) and Shp (-1 and -2). Both cyp7a1-1 and -2 encoded proteins of 512 amino acids. Trout cyp7a1-1 was expressed not only primarily in the kidney, pyloric caecum and mid-gut, but also weakly in the liver, eye, gill and ovary. cyp7a1-2 was highly expressed in the liver, pyloric caecum and mid-gut. cyp8b1-1 and -2, which encoded proteins of 512 and 509 amino acids, respectively, were principally expressed in the liver. Both shp-1 and -2, which encoded proteins of 288 and 290 amino acids, respectively, were strongly expressed in the liver, but shp-2 was also highly expressed in the gallbladder and digestive tract. The temporal changes in the expression of cyp7a1-1/-2, cyp8b1-1/-2 and shp-1/-2 in the liver were assessed after consumption of a single meal. Expression of cyp7a1-1/-2 and cyp8b1-1/-2 increased within 3h post feeding (hpf) when the stomach was still approximately 84% full and the gallbladder was almost completely empty. Although the expression of shp-1 did not change after feeding, the expression pattern of shp-2 was inversely related to the expression patterns of cyp7a1-1/-2 and cyp8b1-1/-2. Specifically, shp-2 expression decreased until 3 hpf before returning to initial levels at 24 hpf. These findings suggest that Cyp7a1s/8b1s and Shp-2 function antagonistically in bile acid synthesis in rainbow trout.

Agenesia de vesícula biliar: una causa inusual de hipertransaminasemia / Absence of the gallbladder: an unusual cause of hypertransaminasemia

La agenesia de vesícula biliar es una entidad poco frecuente, y su presentación con algún síntoma asociado es más infrecuente aún. La mayoría de casos se detectan de forma accidental en el curso de una exploración quirúrgica ante un cuadro sugestivo de litiasis biliar. Se presenta el caso de una niña de 4 años de edad con elevaciones transitorias y recurrentes de enzimas hepáticas, en quien sólo se encontró, tras un estudio exhaustivo, una agenesia de vesícula biliar como posible causa de esta alteración. Es un cuadro que hay que tener en cuenta para evitar procedimientos invasivos en estos pacientes(AU)

Abscence of the gallbladder is a very rare malformation and its symptomatic presentation is even more unusual. Most of the cases reported were discovered while a surgical exploration of the abdomen was performed in patients with biliary symptoms. It is reported a rare paediatric case. The patient was 4 years old and presented recurrent and transient elevation of liver transaminases. After a complete study only absence of the gallbladder was found as cause. Awareness of this entity by clinicians and surgeons is important because invasive diagnostic procedures can be avoided(AU)

The liver function test enzymes and glucose level are positively correlated in gallbladder cancer: a cancer registry data analysis from north central India.

AIM OF STUDY: To investigate the trend of expression of liver function test enzymes and other biochemical changes during gallbladder carcinogenesis. MATERIALS AND METHODS: Eight hundred and seventy-eight gallbladder disease patients were selected to study the liver function test enzymes and routine blood biochemical changes in the last five years (2004-08). Statistical analysis was performed using Graph Pad prism 5.02 software. RESULTS: The liver function test enzymes showed significant correlations among themselves, and with glucose in gallbladder cancer and gallstone disease patients (N = 878). Out of 878 gallbladder cases, 46 (5.24%) showed significantly higher glucose level of 216.66 mg/dL (P < 0.0001). All the three pathological conditions of gallbladder, gallbladder cancer with stones (GBCS), gallbladder cancer without stones (GBC) and calculus cholecystitis (CC), showed highly significant positive correlation (Pearson) between Serum Glutamic Oxaloactetic Transaminase (SGOT) and Serum Glutamic Pyruvic Transaminase (SGPT) [P < 0.0001, (GBCS); P < 0.0001, (GBC), and P < 0.0001, (CC)]. SGOT and SGPT also showed positive correlation with higher glucose level independently, in both GBCS and CC (P < 0.0001 and P < 0.0001), respectively. CONCLUSION: Simultaneous elevation of glucose and liver function test enzymes in GBC makes the diagnosis complex. Any patient of gallbladder diseases with higher level of glucose may have the possibility of developing gallbladder cancer.

Alpha-methylacyl coenzyme A racemase overexpression in gallbladder carcinoma confers an independent prognostic indicator.

AIMS: Increased ß-oxidation of branched-chain fatty acids provides an additional metabolic advantage for cancer cells thereby enhancing tumour development and progression. Alpha-methylacyl coenzyme A racemase (AMACR) is an enzyme essential for the catabolism of branched-chain fatty acids that allows their subsequent ß-oxidation and thus plays an important role in generating biological energy. However, the expression of AMACR has never been systemically investigated in gallbladder carcinoma. This study evaluated the expression status, associations with clinicopathological variables and prognostic implications of AMACR in a well-defined cohort of gallbladder carcinoma and confirmed their expression status in gallbladder carcinoma cells. METHODS: AMACR immunostaining was assessable in 89 cases on tissue microarrays of gallbladder carcinoma, and it was correlated with clinicopathological factors and patient survival. In three gallbladder carcinoma cell lines and one non-tumorigenic cholangiocyte, AMACR mRNA expression was measured by real-time reverse transcription PCR and the endogenous expression of AMACR protein was analysed by western blotting. RESULTS: AMACR overexpression was significantly associated with an advanced primary tumour status (p=0.027) and American Joint Committee on Cancer stage (p=0.027), an increased histological grade (p=0.002) and vascular invasion (p=0.017). Importantly, AMACR overexpression independently predicted worse disease-specific survival (p=0.0452, RR 1.887). Expression levels of AMACR mRNA and total protein in various cells were comparable. The abundance of AMACR expression increased in tumour cells and was even higher in the metastatic cell line. CONCLUSIONS: In primary gallbladder carcinoma, AMACR overexpression was correlated with important prognosticators and independently portended worse outcomes, highlighting the potential prognostic and therapeutic utility of AMACR in gallbladder carcinoma.

Dynamics of BNF-induced in vivo ethoxyresorufin-O-deethylase (EROD) activity during embryonic development of medaka (Oryzias latipes).

This study aimed to characterize quantitatively the temporal basal and induced ethoxyresorufin-O-deethylase (EROD) activity as indicator of cytochrome P4501A (CYP1A) function during embryonic development of medaka (Oryzias latipes). For this purpose, non-invasive methods over fluorescence images of the whole embryo (non-organ-specific [NOS] EROD activity) or specifically of the gallbladder (organ-specific [OS] EROD activity) were used. To induce this EROD activity, embryos were continuously exposed to ß-naphthoflavone (BNF; 0.005, 0.05, 0.5, 5 µg/L). Analytical chemistry suggested no signs of BNF dissipation. Mean fluorescence intensity values for EROD induction increased with BNF concentration throughout embryonic development. Significant increments in the NOS activity were seen from exposures to ≥ 0.5 µg BNF/L as early as 2 days post-fertilization (dpf), and in the OS EROD activity as soon as the gallbladder was conspicuous (i.e. 4 dpf). Morphometric in vivo analysis of the gallbladder during embryonic development did not indicate significant dilation after BNF treatment suggesting normal hepatic bile formation. The conditions optimized in this study using intact embryos should allow the quantitation of EROD activity induced by specific chemicals, mixtures and environmental samples in terms of BNF-equivalents, offering a proper estimation of their potency. These results demonstrate the utility of medaka in a fish embryo test for a non-invasive CYP1A analysis expressed as EROD activity, fitting in the three R principles for the minimization of animal use in ecotoxicology evaluations and that are among the objectives of the European Community regulation for the Registration, Evaluation, Authorization and Restriction of Chemical substances (REACH).

Reflujo pancreáticobiliar en pacientes con colelitiasis y sin colelitiasis: estudio comparativo / Pancreaticobiliary reflux in patients with cholelithiasis and without cholelithiasis: a comparative study

Background. Pancreaticobiliary reflux is a pathologic phenomenon occurring in patients with gallstones. However, the occurrence of pancreaticobiliary reflux has not been studied in patients without gallstones. The objective of this study was to measure the bile levels of amylase and lipase in patients without gallstones submitted to cholecystectomy as part of another surgical procedure, and to compare these values with patients submitted to cholecystectomy for gallstone disease. Patients and Methods. A prospective observational comparative study was designed. A sample of 136 consecutive patients was included. Amylase and lipase levels were measured in bile. Normal serum amylase levels at our institution are 28-100 U/L and for lipase are 13-60 U/L. There are no established normal levels for pancreatic enzymes in bile. However, we considered elevated the bile amylase and lipase levels whenever they were higher than normal plasma levels. Results. One-hundred three patients (76 percent) had gallstones and 33 (24 percent) liad healthy gallbladders without gallstones. According to normal plasma levels for amylase and lipase, these enzymes in bile were elevated in 83.5 percent patients with gallstones, compared to elevated levels of amylase in 6 percent patients and lipase in 3 percent patients without gallstones. Conclusions. Pancreaticobiliary reflux is a common phenomenon in patients with gallstones and occurs sporadically in patients without gallstones.

Introducción. El reflujo pancreáticobiliar es un fenómeno patológico que ocurre en pacientes con colelitiasis. La ocurrencia de este fenómeno no ha sido estudiada en pacientes sin colelitiasis. El presente estudio tiene por objetivo medir los niveles de amilasa y lipasa en la bilis de pacientes sin colelitiasis, colecistectomizados como parte de otro procedimiento quirúrgico y comparar estos valores con pacientes colecistectomizados por colelitiasis. Pacientes y Métodos. Se diseñó un estudio observacional y comparativo. Una muestra de 136 pacientes consecutivos fue incluida. Se midieron los niveles de amilasa y lipasa en la bilis. En nuestra institución los valores normales para amilasa son 28-100 U/L y para lipasa 13-60 U/L. No se han establecido valores normales de enzimas pancreáticas en la bilis. Para efectos del presente estudio, se consideró como elevados los niveles biliares de amilasa y lipasa cuando fueron mayores a los valores plasmáticos normales. Resultados. 103 pacientes (76 por ciento) tenían colelitiasis y 33 (24 por ciento) tenían vesículas normales sin cálculos. De acuerdo a los valores plasmáticos normales de amilasa y lipasa, estas enzimas se encontraron elevadas en 83,5 por ciento de los pacientes con colelitiasis comparados con valores elevados de amilasa en 6 por ciento en pacientes sin colelitiasis y de lipasa en 3 por ciento de estos pacientes. Conclusiones. El reflujo pancreaticobiliar es un fenómeno común en pacientes con colelitiasis y ocurre esporádicamente en pacientes sin colelitiasis.

Lack of adiponectin promotes formation of cholesterol gallstones in mice.

Plasma adiponectin levels are reduced in obese people, and hypoadiponectinemia is recently reported to associate with cholesterol gallstone formation in human. The aim of this study was to examine the role of adiponectin in gallstone formation using adiponectin knockout mice. We analyzed male knockout and C57BL6J mice fed normal or lithogenic diet for 6 weeks. On lithogenic diet, the prevalence rate of gallstone was significantly greater in knockout mice than C57BL6J mice. The molar percentages of beta and omega-muricholic acid were significantly higher and hepatic sterol 12 alpha-hydroxylase expression (cyp8b1) was significantly lower in knockout mice than C57BL6J mice fed normal diet. The bile apolipoprotein A-I protein levels were decreased in knockout mice. Histological examination showed gallbladder wall thickening and accumulation of glycoprotein in the gallbladder of knockout mice. Gallbladder phospholipase A2-IVA expression was significantly higher in knockout mice than in C57BL6J mice fed lithogenic diet. Our results indicate that lack of adiponectin promotes gallstone formation in mice.

Interstitial cells of Cajal are present in human extrahepatic bile ducts.

BACKGROUND AND AIMS: Interstitial cells of Cajal (ICC) are distributed with smooth muscle throughout the gastrointestinal tract and are involved in regulating motility. ICC were recently discovered in the wall of the human gallbladder. This study sought to determine whether ICC are present in human bile ducts. METHODS: Biliary tract samples were obtained from several sources: surgical specimens (n = 16, 11 women, mean age 61 years); archival post-mortem specimen (n = 1, 86 years, man); and cadavers (n = 2, 68 and 80 years, men). Paraffin-embedded sections (3 microm) from the gallbladder (fundus, body and neck) and both extrahepatic and intrahepatic bile ducts were investigated. A double immunofluorescence protocol using polyclonal and monoclonal c-kit antibodies and mast cell tryptase was used to distinguish c-kit-positive cells with typical ICC morphology from c-kit-positive mast cells. Small bowel samples were used as positive controls. ICC in the gallbladder were confirmed by ultrastructural study. RESULTS: c-kit-positive cells with characteristic ICC morphology were identified in the subepithelial and muscular layers of the gallbladder and extrahepatic bile ducts. They were most prominent within the muscle layer of the extrahepatic bile ducts where they were organized into loosely arranged laminae running parallel to circular smooth muscle fibers. ICC were not found in intrahepatic bile ducts. CONCLUSION: This study demonstrates for the first time that ICC are present in human extrahepatic bile ducts where they are more densely aggregated than in the gallbladder. This cellular network is likely to be involved in biliary tract motility and its related disorders.

Developmental changes in Ca2+ homeostasis and contractility in gallbladder smooth muscle.

Relatively little is known about the contribution of Ca(2+)-dependent and -independent mechanisms in the contractility of neonatal gastrointestinal smooth muscle. We therefore studied Ca(2+) homeostasis and Ca(2+) sensitization mechanisms in 10-day-old and adult guinea pig gallbladder smooth muscle to elucidate developmental changes in these processes. Gallbladder contractility was evaluated by isometrical tension recordings from strips, intracellular Ca(2+) concentration was estimated by epifluorescence microscopy of fura-2-loaded isolated cells, and protein expression and phosphorylation were assessed by Western blot analysis. The neonatal gallbladder contracted significantly less to CCK than adult tissue, but this correlated with an increased Ca(2+) mobilization, suggesting immaturity of Ca(2+) sensitization mechanisms. The enhanced Ca(2+) release in the newborn gallbladder was the result of the increase in the size of the releasable Ca(2+) pool. Moreover, in neonatal smooth muscle cells, neither the plasma membrane Ca(2+) pump nor the Na(+)/Ca(2+) exchanger collaborate in the extrusion of Ca(2+). In contrast, in these cells, there is an increase in phospholamban phosphorylation, which could drive to an overactivity of the sarco(endo)plasmic reticulum Ca(2+)-ATPase pump. The reduced Ca(2+) sensitivity in neonatal tissues was demonstrated by the lack of effect to Y-27362, an inhibitor of Rho kinase (ROCK), and GF-109203X, an inhibitor of PKC, on agonist-induced contraction. In addition, the neonatal gallbladder showed lower levels of RhoA, ROCK, PKC, and two effectors [C-kinase-dependent inhibitor of 17 kDa (CPI-17) and myosin phosphatase targetting 1 (MYPT1)] as well as an absence of CPI-17 and MYPT1 phosphorylation in response to agonists. In conclusion, our results indicate that the main mechanisms involved in smooth muscle contractility are under developmental regulation.

Helicobacter pylori damages human gallbladder epithelial cells in vitro.

AIM: To study the mechanism by which Helicobacter pylori (H pylori) damages human gallbladder epithelial cells (HGBEC). METHODS: H pylori isolated from gallbladder were cultured in a liquid medium. Different concentration supernatants and sonicated extracts of H pylori cells were then added to HGBEC in a primary culture. The morphological changes in HGBEC as well as changes in the levels of alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and glutamyltransferase (GGT) were measured. RESULTS: According to the culture curve of HGBEC, it was convenient to study the changes in HGBEC by adding H pylori sonicated extracts and H pylori culture supernatants. Both H pylori sonicated extracts and H pylori culture supernatants had a significant influence on HGBEC morphology, i.e. HGBEC grew more slowly, their viability decreased and their detachment increased. Furthermore, HGBEC ruptured and died. The levels of ALP (33.84+/-6.00 vs 27.01+/-4.67, P<0.05), LDH (168.37+/-20.84 vs 55.51+/-17.17, P<0.01) and GGT (42.01+/-6.18 vs 25.34+/-4.33, P<0.01) significantly increased in the HGBEC culture supernatant in a time- and concentration-dependent. The damage to HGBEC in H pylori culture liquid was more significant than that in H pylori sonicated extracts. CONCLUSION: H pylori induces no obvious damage to HGBEC.

Emodin increases Ca(2+) influx through L-type Ca(2+) channel in guinea pig gallbladder smooth muscle.

Emodin is known to be used in the treatment of cholesterol stones and cholecystitis. This study sought to investigate the effects of emodin on the contraction of gallbladder smooth muscle (GBSM), intracellular Ca(2+) concentration and L-type calcium current in GBSM cells. Gallbladder muscle strips were obtained from adult guinea pigs and the resting tension was recorded. Gallbladder smooth muscle cells were isolated by enzymatic digestion. Cells were loaded with fluo-3/AM and [Ca(2+)](i) was determined by a laser confocal microscope. Calcium current was recorded by the whole-cell patch clamp method. Emodin increased the resting tension of GBSM strips in a dose-dependent manner. Emodin elevated [Ca(2+)](i) in GBSM cells, and this effect was attenuated by pretreatment with nifedipine. In addition, Emodin increased L-type calcium current at concentrations of 1 to 30 microM (at +10 mV, 10 microM, 45.1+/-5.2% compared to control, EC(50) =3.11 microM). In the presence of protein kinase C (PKC) inhibitor, Staurosporine, emodin did not significantly affect the calcium current. However, phorbol 12, 13-dibutyrate mimicked emodin in enhancement of the calcium current. These results suggest that emodin promotes gallbladder contraction by increasing Ca(2+) influx through L-type calcium channel via PKC pathway.

Inhibitory effects of genistein and resveratrol on guinea pig gallbladder contractility in vitro.

AIM: To observe and compare the effects of phytoestrogen genistein, resveratrol and 17beta-estradiol on the tonic contraction and the phasic contraction of isolated gallbladder muscle strips and to study the underlying mechanisms. METHODS: Isolated strips of gallbladder muscle from guinea pigs were suspended in organ baths containing Kreb's solution, and the contractilities of strips were measured before and after incubation with genistein, resveratrol and 17beta-estradiol respectively. RESULTS: Similar to 17beta-estradiol, genistein and resveratrol could dose-dependently inhibit the phasic contractile activities, they decreased the mean contractile amplitude and the contractile frequencies of gallbladder muscle strips, and also produced a marked reduction in resting tone. The blocker of estrogen receptor ICI 182780 failed to alter the inhibitory effects induced by genistein and resveratrol, but potassium bisperoxo (1, 10 phenanthroline) oxovanadate bpV (phen), a potent protein tyrosine phosphatase inhibitor, markedly attenuated the inhibitory effects induced by genistein and resveratrol. In calcium-free Kreb's solution containing 0.01 mmol/L egtazic acid (EGTA), genistein and resveratrol inhibited the first phasic contraction induced by acetylcholine (ACh), but did not affect the second contraction induced by CaCl(2). In addition, genistein, resveratrol and 17beta-estradiol also could reduce the contractile responses of ACh and KCl, and shift their cumulative concentration-response curves rightward. CONCLUSION: Phytoestrogen genistein and resveratrol can directly inhibit the contractile activity of isolated gallbladder muscle both at rest and in response to stimulation. The mechanisms responsible for the inhibitory effects probably due mainly to inhibition of tyrosine kinase, Ca(2+) influx through potential-dependent calcium channels (PDCs) and Ca(2+) release from sarcoplasmic reticulum (SR), but were not related to the estrogen receptors.

Expression of matrix metalloproteinases in gallbladder carcinoma and their significance in carcinogenesis.

The correlation between matrix metalloproteinase (MMP)-2, MMP-9, and MMP-14 expression on the prognostic parameters of gallbladder carcinoma (GBC) and their role in carcinogenesis were evaluated. Carcinomas of the gallbladder (n=20) and chronic cholecystitis (n=10) were studied for the expression of MMP-2, MMP-9, and MMP-14 by immunohistochemistry. In all of the cases, metaplastic and dysplastic epithelial alterations, and (in GBC histologic type, grade of differentiation, level of infiltration, perineural and angiolymphatic invasion, liver invasion, and lymph node involvement were noted. MMP-2, MMP-9, MMP-14 were expressed in tumor epithelium in 9 (45%), 20 (100%), and 20 (100%) of the cases, respectively. MMP stromal expression including muscle layer, vascular endothelium, fibroblasts, and lymphoid cells were detected in all cases. MMP-2 was not expressed in normal, metaplastic, and dysplastic epithelia. In contrast, MMP-9 and MMP-14 immunoreactivities were present in antral-type metaplastic areas as moderate (grade 2) and strong in dysplastic epithelia (grade 3). Only in mucinous-type GBC was the expression of the MMPs lower than in the other types. No significant correlation was detected with the grade of differentiation, level of infiltration, perineural and angiolymphatic invasion, liver invasion, or lymph node involvement. These data suggest that MMP-9 and MMP-14 overexpression may have an important role in tumorigenesis. MMP-2, MMP-9, and MMP-14 were expressed in GBC epithelium but also the expression in the stromal component may be essential for the malignant potential of GBC.

Inflammatory cytokines promote inducible nitric oxide synthase-mediated DNA damage in hamster gallbladder epithelial cells.

AIM: To investigate the link between chronic biliary inflammation and carcinogenesis using hamster gallbladder epithelial cells. METHODS: Gallbladder epithelial cells were isolated from hamsters and cultured with a mixture of inflammatory cytokines including interleukin-1beta, interferon-gamma, and tumor necrosis factor-alpha. Inducible nitric oxide synthase (iNOS) expression, nitric oxide (NO) generation, and DNA damage were evaluated. RESULTS: NO generation was increased significantly following cytokine stimulation, and suppressed by an iNOS inhibitor. iNOS mRNA expression was demonstrated in the gallbladder epithelial cells during exposure to inflammatory cytokines. Furthermore, NO-dependent DNA damage, estimated by the comet assay, was significantly increased by cytokines, and decreased to control levels by an iNOS inhibitor. CONCLUSION: Cytokine stimulation induced iNOS expression and NO generation in normal hamster gallbladder epithelial cells, which was sufficient to cause DNA damage. These results indicate that NO-mediated genotoxicity induced by inflammatory cytokines through activation of iNOS may be involved in the process of biliary carcinogenesis in response to chronic inflammation of the biliary tree.

Expression of orotate phosphoribosyltransferase (OPRT) in hepatobiliary and pancreatic carcinoma.

The purpose of this study was to clarify the role of orotate phosphoribosyltransferase (OPRT) in the progression of hepatobiliary and pancreatic carcinomas. Representative sections from 8 surgically resected pancreatic carcinomas, 5 gallbladder carcinomas and 19 hepatocellular carcinomas (HCCs) were examined microscopically. Sites of pancreatic intraepithelial neoplasia (PanIN) were counted, and histologic subtypes of invasive ductal carcinoma of the pancreas (IDC) were determined. Gallbladder carcinomas and HCCs were examined histologically, and the subtypes and spread patterns were assessed. Expression of OPRT was examined immunohistochemically. A total of 75 PanINs were identified. Expression of OPRT increased as lesions progressed from early to high-grade PanINs (PanIN-1A and -1B versus PanIN-2 and -3, p=0.0004). Three (37.5%) of the 8 pancreatic IDCs were positive for OPRT. In the remaining 5 cases, OPRT was expressed only in the neoplastic ducts adjacent to PanIN-3s. In gallbladder carcinomas, mucosal neoplastic epithelium showed dense cytoplasmic expression in 4 of the 5 cases, but expression was absent in the deeply invasive lesions. Among HCCs, 15 of the 19 cases were negative for OPRT in the central area of the tumor, but 8 of the 19 cases expressed OPRT in vascularly invasive lesions. Our data suggest that OPRT is involved in early events of pancreatic and gallbladder carcinogenesis and invasion of HCC.

Mucolytic activity of bacterial and human chitinases.

Several pulmonary pathologies, like cystic fibrosis (CF), are characterized by hypersecretion and stasis of tenacious mucus. Bacterial glycosidases are known to degrade mucins but their use as mucolytic agents is questionable. The observation that bacterial chitinases degrade mucins and the recent discovery of human chitinases, which have been proposed to be involved in the genesis of asthma, prompted us to evaluate the mucolytic properties of human derived chitinases. The effect of these human chitinases, and bacterial chitinases (positive control), on the viscoelasticity of CF sputa and on the electrophoretic mobility of human mucins was tested. Commercial bacterial chitinase drastically degraded CF sputum, while human derived chitinases did not. Accordingly, the commercial bacterial chitinase was found to degrade mucins, whereas recombinant human chitinases did not. A thorough analysis of the commercial chitinase elucidated that contaminating proteases and also nucleases assisted in the mucolytic effect. Indeed, recombinant bacterial chitinases very slightly reduced the viscoelasticity of CF sputum, but they caused a significant degradation of the CF sputum when they were combined with proteases. In conclusion, this work shows that recombinant human and recombinant bacterial chitinases have no or very low mucolytic activities, respectively. The observed mucolytic properties of commercial bacterial chitinase are due to a synergistic effect between chitinolytic and proteolytic enzymes at one hand and at the other hand also due to the presence of contaminating nucleases.

Changes in cholecystokinin and peptide Y gene expression with feeding in yellowtail (Seriola quinqueradiata): relation to pancreatic exocrine regulation.

In fish, the regulation of digestive enzyme secretion by hormonal control such as cholecystokinin (CCK) and neuropeptide Y (NPY)-related peptide is not well understood. To investigate the roles of fish CCK and peptide Y (PY) in digestive enzyme secretion, mRNA levels of CCK and PY, pyloric caeca enzyme activities and mRNA levels of pancreatic digestive enzymes (lipase, trypsin and amylase) were measured at pre- and post-prandial stages in yellowtail. Pyloric caeca were sampled at 0, 0.5, 1.5, 3, 6, 12, 24 and 48 h after feeding. The mRNA levels of trypsin and amylase increased after feeding, suggesting that transcription was induced by feed ingestion. Digestive enzyme activities decreased in exocrine pancreas after feeding, suggesting the stored enzyme was secreted from pancreas post-prandially. mRNA levels for CCK displayed a time-dependent increase, peaking between 1.5 and 3 h after-feeding followed by a rapid decrease 3 to 6 h after feeding. The mRNA expression pattern of PY was inverse to the pattern of CCK, decreasing until 1.5 h after feeding and then rising to initial levels by 12 h after feeding. These results suggest that CCK and PY work antagonistically in the exocrine pancreas of yellowtail.