Infection by gram-negative organisms via the biliary route results in greater mortality than portal venous infection

Cholangitis requires bile duct obstruction and infection. Patients with cholangitis are often more affected than those with infections that reach the liver through the portal vein. We will attempt to study the influences of (i) route of entry and (ii) presence of bile duct obstruction on hepatic infection. C57BL/6 mice received injections of Escherichia coli or lipopolysaccharide into the obstructed bile duct or portal vein and were monitored for survival. Livers were assayed for bacteria, and cytokine mRNA was measured. In order to examine the effect of biliary obstruction on hepatic infection, animals were subjected to bile duct ligation 1 day prior to portal vein injection and were monitored for survival. The 50% lethal dose (LD(50)) for E. coli injected into the bile duct was 50 CFU/animal; the LD(50) for E. coli injected into the portal vein was 5 x 10(7) CFU/animal. Initial hepatic delivery of bacteria was equivalent 1 h after injection into the bile duct or portal vein. However, by 24 h, a significantly greater amount of bacteria was recovered from the livers of the bile duct-injected group. Interleukin 10 (IL-10) and IL-1RA mRNA was expressed at greater levels in the bile duct-injected group. Prior bile duct ligation followed by portal vein injection resulted in a higher incidence of death than when sham operation was performed prior to portal vein injection. Our data suggest that the increased mortality from cholangitis, compared with that from other hepatic infections, is related to the different route of delivery of pathogen and the maladaptive response (possibly involving IL-10 and IL-1RA) to biliary obstruction itself.     

A longitudinal study of histologic and immunohistologic changes in an experimental model of sclerosing cholangitis*

Summary A longitudinal study of intra and extrahepatic bile duct injuries was performed in an animal model of secondary sclerosing cholangitis induced by formalin injection into the common bile duct. Lymphocytic infiltration inside and around the bile ducts occurred seven days after injection. The disease later evolved to a fibrous cholangitis of the small bile ducts. Septal intrahepatic and extrahepatic bile duct involvement became evident three months after formalin injection. The ductular proliferation led to a progressive biliary cirrhosis with portal to portal fibrous septa. After formalin injection, bile duct cells expressed the Ia antigen in the cytoplasm and/or on the membrane of bile duct cells. The intensity of staining did not correlate with the duration or severity of the disease. Lymphocytes infiltrating into and around the bile duct were mainly T-cells. This study suggests that a local cell-mediated immune response to the injection of a toxic agent induces pathological features similar to those of sclerosing cholangitis in man.This study was supported in part by a grant from the Research Council of the Faculté de Médecine, Université de Paris-Sud, and the Faculté de Médecine, Paris VI     

Surgical anatomy of the vasculobiliary apparatus at the hepatic hilum as applied to liver transplantations and major liver resections

Introduction

To evaluate the hepatic arterial, bile duct and portal venous anatomy as applicable to major liver resections.

THE TERMINAL DISTRIBUTION OF THE HEPATIC ARTERY AND ITS RELATIONSHIP TO THE DEVELOPMENT OF FOCAL LIVER NECROSIS FOLLOWING INTERRUPTION OF THE PORTAL BLOOD SUPPLY

The terminal distribution of the hepatic artery of the human liver was examined by arterial injection of india ink and serial sectioning. The branches of the hepatic artery form capillary networks around the bile duct in the portal tract, from which the capillaries (terminal venous branch) arise and connect with sinusoids at the most peripheral zone of the liver lobules. Evidence of direct anastomosis between the hepatic artery and portal vein inside the portal tract or presence of "innere Pfortaderwurzeln" as well as the intralobular arteriole was not demonstrated.
The authors also studied the hepatic changes caused by interruption of the portal blood supply to the liver lobule. It was demonstrated that the portal tract and its components as well as several layers of liver parenchymal tissue around the portal tract are nourished from blood via the peribiliary capillary plexus and thus remains unaffected by portal obstruction, while other parts of the liver lobule will undergo coagulation necrosis.
Based on the present investigation, the authors believe that the hepatic artery plays the main role in the nourishment of the bile duct while it has little to do with that of the liver lobule, except for the most peripheral layers of the liver lobules adjacent to the portal areas.     

Atrophy and ductopenia of the right hepatic lobe in a patient with choledocholithiasis

An extremely rare case of atrophy and extensive ductopenia of the right hepatic lobe is presented. The surgically resected atrophic right lobe (100 g) did not show cholestasis or cirrhosis. The right hepatic bile duct revealed sclerosis with luminal obliteration and marked diminution of its branches. The extrahepatic bile duct contained a single cholesterol stone. The right portal vein branches showed luminal narrowing. Disturbance of biliary drainage following sclerosing cholangitis and impediment of portal venous flow in the right hepatic lobe were considered responsible for atrophy of the lobe. Although choledocholithiasis presumably played an important part in the pathogenesis of the sclerosing cholangitis and ductopenia, the reason for selective involvement of the right biliary tree remains nuclear.     

ATROPHY AND DUCTOPENIA OF THE RIGHT HEPATIC LOBE IN A PATIENT WITH GHOLEDOCHOLITHIASIS

An extremely rare case of atrophy and extensive ductopenia of the right hepatic lobe is presented. The surgically resected atrophic right lobe (100 g) did not show cholestasls or cirrhosis. The right hepatic bile duct revealed sclerosis with luminal obliteration and marked diminution of its branches. The extrahepatic bile duct contained a single cholesterol stone. The right portal vein branches showed luminal narrowing. Disturbance of biliary drainage following sclerosing cholangitis and impediment of portal venous flow in the right hepatic lobe were considered responsible for atrophy of the lobe. Although choledocholithiasis presumably played an important part in the pathogenesis of the sclerosing cholangitis and ductopenia, the reason for selective involvement of the right biliary tree remains nuclear.     

Clinicomicrobiological analysis of patients with cholangitis

Acute cholangitis is inflammation of biliary ductal system from infection with an associated biliary obstruction. This retrospective study was done to determine the factors responsible for cholangitis and the microbiological profile of the bile in patients with cholangitis. In the study involving 348 patients, 36.4% had associated malignancy. A total of 54% of the bile samples were positive for aerobic culture. Nearly 66-73% of the Escherichia coli and Klebsiella isolates were Extended spectrum beta lactamases (ESBL) producers. Two isolates of Candida spps were also obtained. Polymicrobial infection was seen in 31.5% of the culture positive cases. Ideal antibiotics in case of cholangitis would be those which are excreted in the bile such as third-generation cephalosporins, ureidopenicillins, carbapenems and fluoroquinolones to combat resistance and polymicrobial aetiology. Anti-fungal drugs may also be necessary if the patient is not responding to biliary decompression and antibacterial agents to prevent fungaemia.     

Experimental Mycoplasma pulmonis Infection in Pathogen-Free Mice: Models for Studying Mycoplasmosis of the Respiratory Tract

Mice of a Swiss substrain, reared under rigid pathogen-free (PF) conditions, were inoculated intranasally with broth cultures of Mycoplasma pulmonis ranging in dose from 10¹ to 9 × 10⁹ colony forming units (CFU). A highly reproducible disease resulted with an LD₅₀ of 1.3 × 10⁸ CFU and a PD₅₀ (dose producing pneumonia in 50% of mice) of 3.4 × 10⁵ CFU. The inoculating dose of M pulmonis was found to be the critical determinant of the severity, duration and pathologic character of the respiratory disease produced. PF mice given 10⁴ CFU or less developed a transient illness characterized by low frequencies of rhinitis, otitis media, laryngotracheitis and focal pneumonia. This was proposed as a low dose model. Doses of 10⁵ to 10⁹ CFU resulted in high frequencies of rhinitis, otitis media, laryngotracheitis and pneumonia. Within the first 10 days the pneumonia often was fatal, being characterized by an outpouring of neutrophils and edema fluid into alveolar spaces, pulmonary congestion and hemorrhage and, occasionally, pleuritis. This high dose—acute disease model was shown to be the result of seeding alveoli with large numbers of organisms at the time of intranasal inoculation. In animals surviving doses of 10⁵ to 10⁹ CFU beyond approximately 10 days postinoculation, the larger concentration of organisms was present in bronchi and bronchioles, giving rise to a third model, the high dose—chronic disease model. The predominant lesions were chronic suppurative bronchitis and bronchiolitis, marked peribronchial lymphoid cuffing, variable numbers of neutrophils and macrophages in alveoli, and complications such as bronchiectasis and pulmonary abscesses. Identical lesions were observed in axenic mice infected with M pulmonis. The infection in PF mice is considered a highly useful experimental system, both for comparative study of respiratory mycoplasmosis and for investigations directed toward understanding and eliminating the natural disease this agent causes in conventional mice and rats.     

Enhanced Toxicity for Mice of Combinations of Antibiotics with Escherichia coli Cells or Salmonella typhosa Endotoxin

Enhanced lethality for BALB/c mice has been observed after the administration of Salmonella typhosa endotoxin with either actinomycin D, cycloheximide, or nogalamycin. The dose of actinomycin D required to kill half of the mice (LD₅₀) was 0.8 mg/kg in normal animals, 0.35 mg/kg in mice administered 0.08 mg of endotoxin per kg, and 0.28 mg/kg in mice administered 0.2 mg of endotoxin per kg. The LD₅₀ of endotoxin in normal mice was 12 mg/kg and in mice given 0.4 mg of actinomycin D per kg was 0.067 mg/kg. The LD₅₀ of actinomycin D in mice administered 1.8 × 10⁸ live Escherichia coli cells per kg or 1.8 × 10⁹ heat-killed E. coli cells per kg was reduced to 0.4 mg/kg. The LD₅₀ of cycloheximide was 181 mg/kg in normal animals and 28 mg/kg in mice administered 4 mg of endotoxin per kg. The LD₅₀ of endotoxin in mice given 120 mg of cycloheximide per kg was 0.02 mg/kg. Enhanced lethality due to various combinations of cycloheximide and endotoxin was abolished by pretreatment of mice with endotoxin. The LD₅₀ of nogalamycin was 21 mg/kg in normal mice and 13 mg/kg in mice receiving 1 mg of endotoxin per kg.     

肝内胆管的应用解剖与肝内胆管结石手术入路的研究

目的 探讨肝内叶、段胆管的解剖结构及肝内胆管结石的手术入路。方法 通过研究12例成人肝脏标本的肝内胆管与血管的位置、毗邻关系,设计出经肝的脏面显露左右肝管,经肝的膈面显露肝内叶、段胆管相对合的手术入路,并结合治疗56例复杂性肝内胆管结石患者。结果 左右肝管均位于肝脏脏面门静脉左右干的前上缘;左内叶、右前叶胆管位于相应门静脉的前内侧。右后叶胆管位于门静脉右前支或右前叶下段支脏面测侧者占66.7％(8/12);位于门静脉右后支脏面深侧或后上缘者占83.3％(10/12)。左外叶胆管位于门静脉矢状部脏面深侧者占91.7％(11/12)。选择经肝的脏面显露左右肝管,经肝的膈面显露肝内叶、段胆管相结合的手术入路,治疗复杂性肝内胆管结石患者56例,临床疗效满意。结论 选择经肝的脏面与膈面相结合的手术方式,较易取出结石。     

Distinct from its canonical effects,deletion of IL-12p40 induces cholangitis and fibrosis in interleukin-2Rα−/− mice

The IL-12 family modulates T cell mediated autoimmune diseases and GWAS in PBC have suggested a critical role of IL-12 and its subunits in modulating portal inflammation. We have taken advantage of an aggressive model of portal inflammation and colitis in IL-2Rα^−/− mice to study the specific role of IL-12 and, in particular, the immunobiology of p40^−/−IL-2Rα^−/− mice. Colonies of IL-2Rα^+/−, IL-2Rα^−/− and p40^−/−IL-2Rα^−/− mice were studied for the natural history of immunopathology in liver and colon using histology and immunohistochemistry. Further, to focus on mechanisms, liver, spleen and mesenteric lymph node flow cytometry was employed to identify specific phenotypes; cytokine analysis on inflammatory cell populations was compared between groups. Finally, Real-Time PCR was used to focus on the genes involved in hepatic fibrosis. Surprisingly, p40^−/−IL-2Rα^−/− mice manifest more severe portal inflammation and bile duct damage, including signs of portal hypertension and liver fibrosis, but a significant reduction in colitis. Indeed, p40^−/−IL-2Rα^−/− mice reveal a profound hepatic CD8⁺ T cell infiltrate, whose major component are effector memory cells as well as enhanced hepatic Th1 but reduced Th17 responses. These observations were confirmed by Real-Time PCR analysis of fibrosis-related genes in the liver. Distinct from its canonical effects, IL-12p40 plays a critical role in autoimmune cholangitis, including hepatic fibrosis. These data take on striking significance for any proposed human trials that modulate the IL-12p40 pathway in human PBC.     

Structural aspects of the liver in patients with biliary disease and portal hypertension.

Structural changes were examined in liver tissue from 28 patients with chronic bile duct obstruction in whom portal hypertension was diagnosed. Extrahepatic portal occlusion was found in three patients and cirrhosis of the liver in two. In the remaining 23 patients diffuse hepatocyte hyperplasia and portal fibrosis were observed, but a normal spatial relation between portal tracts and hepatic venous radicles was, for the most part, retained. Liver tissue was also examined from a group of 76 patients with chronic bile duct obstruction in whom there was no indication of portal hypertension but some evidence of hepatocyte hyperplasia and fibrosis. Both these features were much less extensive than the changes seen in the group of patients ostensibly suffering from portal hypertension. The findings suggest that the combination of portal hypertension and chronic bile duct obstruction may not imply the unremitting, progressive, and irreversible changes that accompany cirrhosis because the normal vascular relations are retained. In the light of increasing experimental and clinical evidence of the resorption of collagen and the remodelling of hepatic plates it seems that the structural abnormalities in duct obstruction may substantially regress.     

Role of class II P fimbriae and cytokine response in the pathogenesis of Escherichia coli kidney infection in diabetic mice

Background

The role of class II P fimbriae (P fimbriae II) in diabetic kidney infections is uncertain, although some genetic and epidemiological studies suggest a lower prevalence of P fimbriae II genes in Escherichia coli strains isolated from diabetic patients with complicated kidney infections.

Preferential differentiation of the bile ducts along the portal vein in the development of mouse liver

Summary The development of bile ducts in the mouse liver was studied histochemically, with special reference to their preferential differentiation around the portal vein. Both portal vein and hepatic vein shared a common origin, the omphalomesenteric vein. In the early development of the liver, haematopoietic cells were predominant around both veins. With the progressive development of intrahepatic bile ducts, the following three steps were observed: cluster formation of type I hepatocytes around the portal vein, formation of primitive bile duct structures and basal lamina, then formation of ducts surrounded by connective tissue structures composed of type I and type III collagens and lectin-binding sites, which were predominant around the portal vein compared to the hepatic vein. These results suggest that the deposition of abundant connective tissue structures around the portal vein is a prerequisite for the cell differentiation and basal lamina formation in the bile duct precursors. A possible mechanism of the aggregation of type I hepatocytes around the portein vein is also discussed.     

Successful immunotherapy of autoimmune cholangitis by adoptive transfer of forkhead box protein 3+ regulatory T cells

Treatment of primary biliary cirrhosis (PBC) has lagged behind that of other autoimmune diseases. In this study we have addressed the potential utility of immunotherapy using regulatory T cells (T_reg) to treat murine autoimmune cholangitis. In particular, we have taken advantage of our ability to produce portal inflammation and bile duct cell loss by transfer of CD8⁺ T cells from the dominant negative form of transforming growth factor beta receptor type II (dnTGF-βRII) mice to recombination-activating gene (Rag)1^–/– recipients. We then used this robust established adoptive transfer system and co-transferred CD8⁺ T cells from dnTGF-βRII mice with either C57BL/6 or dnTGF-βRII forkhead box protein 3 (FoxP3⁺) T cells. Recipient mice were monitored for histology, including portal inflammation and intralobular biliary cell damage, and also included a study of the phenotypical changes in recipient lymphoid populations and local and systemic cytokine production. Importantly, we report herein that adoptive transfer of T_reg from C57BL/6 but not dnTGF-βRII mice significantly reduced the pathology of autoimmune cholangitis, including decreased portal inflammation and bile duct damage as well as down-regulation of the secondary inflammatory response. Further, to define the mechanism of action that explains the differential ability of C57BL/6 T_reg versus dnTGF-βRII T_reg on the ability to down-regulate autoimmune cholangitis, we noted significant differential expression of glycoprotein A repetitions predominant (GARP), CD73, CD101 and CD103 and a functionally significant increase in interleukin (IL)-10 in T_reg from C57BL/6 compared to dnTGF-βRII mice. Our data reflect the therapeutic potential of wild-type CD4⁺ FoxP3⁺ T_reg in reducing the excessive T cell responses of autoimmune cholangitis, which has significance for the potential immunotherapy of PBC.     

Dose Response of Listeria monocytogenes Invasion,Fetal Morbidity,and Fetal Mortality after Oral Challenge in Pregnant and Nonpregnant Mongolian Gerbils

Listeria monocytogenes is a food-borne pathogen that can result in adverse pregnancy outcomes, such as stillbirth or premature delivery. The Mongolian gerbil was recently proposed as the most appropriate small-animal model of listeriosis due to its susceptibility to the same invasion pathways as humans. The objectives of this study were to investigate invasion and adverse pregnancy outcomes in gerbils orally exposed to L. monocytogenes, to compare the dose-response data to those of other animal models, and to investigate differences in the responses of pregnant versus nonpregnant gerbils. Gerbils were orally exposed to 0 (control), 10³, 10⁵, 10⁷, or 10⁹ CFU L. monocytogenes in whipping cream. L. monocytogenes was recovered in a dose-dependent manner from fecal samples, adult organs, and pregnancy-associated tissues. Dams exposed to 10⁹ CFU had more invaded organs and higher concentrations of L. monocytogenes in almost all organs than nonpregnant animals, though no differences in fecal shedding were seen between the two groups. Adverse pregnancy outcomes occurred only in the dams treated with 10⁹ CFU. A 50% infectivity dose (ID₅₀) of 2.60 × 10⁶ CFU for fetuses was calculated by fitting the data to a logistic model. Our results suggest that the 50% lethal dose (LD₅₀) falls within the range of 5 × 10⁶ to 5 × 10⁸ CFU. This range includes the guinea pig and nonhuman primate LD₅₀s, but the observation that L. monocytogenes-induced stillbirths can be seen in guinea pigs and primates exposed to lower doses than those at which stillbirths were seen in gerbils indicates that gerbils are not more sensitive to L. monocytogenes invasion.     

The spectrum of bile duct lesions in end-stage primary sclerosing cholangitis

Tissue from 15 livers with primary sclerosing cholangitis, obtained at transplantation, was examined histologically with respect to: small and medium sized bile duct lesions; large bile duct lesions; fibrosis/cirrhosis; and parenchymal changes. Lesions affecting small and medium-sized bile ducts were quantified by determining the percentage of 20 portal tracts involved. The two characteristic bile duct lesions of primary sclerosing cholangitis, periductal fibrosis and fibro-obliterative scars, were largely confined to medium-sized portal areas. Although present in each case, the number of such lesions varied considerably. Loss of bile ducts was the most conspicuous feature in small portal tracts, where the diagnostic duct lesions of primary sclerosing cholangitis were rarely observed. Inflammation, ulceration and cholangiectases of large intrahepatic ducts were common, and appear to be useful additional diagnostic features.     

Portal biliopathy treated with endoscopic biliary stenting

Portal biliopathy is defined as abnormalities in the extra- and intrahepatic ducts and gallbladder of patients with portal hypertension. This condition is associated with extrahepatic venous obstruction and dilatation of the venous plexus of the common bile duct, resulting in mural irregularities and compression of the biliary tree. Most patients with portal biliopathy remain asymptomatic, but approximately 10% of them advance to symptomatic abdominal pain, jaundice, and fever. Magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography are currently used as diagnostic tools because they are noninvasive and can be used to assess the regularity, length, and degree of bile duct narrowing. Management of portal biliopathy is aimed at biliary decompression and reducing the portal pressure. Portal biliopathy has rarely been reported in Korea. We present a symptomatic case of portal biliopathy that was complicated by cholangitis and successfully treated with biliary endoscopic procedures.     

Immunity to Salmonella gallinarum during ontogeny of the chicken: I. Onset of resistance to infection; the minor role of opsonins

The onset of resistance to infection with virulent and avirulent strains of Salmonella gallinarum has been studied in chickens during the first 5 weeks of development. Resistance and susceptibility were measured by the decline or increase, respectively, of bacterial populations in the liver and spleen, as well as by the LD₅₀. There was a dramatic increase in resistance to the avirulent strain from 1 to 5 days after hatching, but the virulent strain remained more lethal until 5 weeks of age. Virulence was associated with bacterial growth. In susceptible hosts, the incremental bacterial growth during the first 4 days after injection was inversely proportional to the LD₅₀. Natural opsonins did not appear to contribute, in more than a minor way, to resistance to infection. There was no difference in rates of clearance of either strain from the circulation during the first week, yet resistance to the avirulent strain became fully established during this period. Conversely, 5-week-old chickens, which are highly resistant to both strains, cleared the avirulent strain much more rapidly than the virulent strain. Possible reasons for different rates of clearance of various forms of bacteria are discussed. No opsonizing antibody could be detected 7 days after injection of S. gallinarum into one or 5-week-old chickens.