Risk factors for invasive aspergillosis in living donor liver transplant recipients.

Invasive aspergillosis (IA) is a severe complication of liver transplantation. Risk factors for IA after deceased donor liver transplantation (DDLT) have been presented in several reports, but are not well established for living donor liver transplant recipients. Here, a retrospective case-control study was performed. Five cases with IA were investigated after living donor liver transplantation (LDLT) between January 1999 and December 2002 at Kyoto University Hospital. For comparison, living donor liver transplant recipients without IA were taken as controls. These patients had undergone LDLT 1 month before or after each IA case and had the same survival times as the latter. We evaluated the clinical and laboratory findings for both groups up until their demise. Patients with IA after LDLT had a very poor prognosis. By univariate analysis, risk factors for IA were preoperative intensive care unit stay (P = 0.02) and preoperative steroid administration (P = 0.02). Preoperative steroid administration for fulminant hepatitis possibly predisposed to the development of IA after LDLT.     

Apoptotic signaling pathway activated by Helicobacter pylori infection and increase of apoptosis-inducing activity under serum-starved conditions

The enhanced gastric epithelial cell apoptosis observed during infection with Helicobacter pylori has been suggested to be of significance in the etiology of gastritis, peptic ulcers, and neoplasia. To investigate the cell death signaling induced by H. pylori infection, human gastric epithelial cells were incubated with H. pylori for up to 72 h. H. pylori infection induced the activation of caspase -8, -9, and -3 and the expression of the proapoptotic Bcl-2 family proteins Bad and Bid. The peak of the activity of the caspases occurred at 24 h. At this time, the inhibition of caspase-8 or -9 almost completely suppressed H. pylori-induced apoptosis. Inhibition of caspase-8 suppressed the expression of Bad and Bid and the subsequent activation of caspase-9 and -3. These observations indicate that H. pylori induces apoptosis through a pathway involving the sequential induction of apical caspase-8 activity, the proapoptotic proteins Bad and Bid, caspase-9 activity, and effector caspase-3 activity. Activation of the pathway was independent of CagA or vacuolating toxin. A membrane fraction of H. pylori was sufficient to activate this pathway, and treatment with proteinase K eliminated the activity. Apoptotic activity of the membrane fraction was significantly increased by incubating the bacteria under serum-starved conditions for 24 h. These observations suggest that environmental conditions in the human stomach could induce H. pylori-mediated pathogenesis, leading to a variety of clinical outcomes.     

Clinical heterogeneity of neonatal intrahepatic cholestasis caused by citrin deficiency: case reports from 16 patients

A deficiency of citrin, which is encoded by the SLC25A13 gene, causes both adult-onset type II citrullinemia (CTLN2) and neonatal intrahepatic cholestasis (NICCD). We analyzed 16 patients with NICCD to clarify the clinical features of the disease. Severe intrahepatic cholestasis with fatty liver was the most common symptom, but the accompanying clinical features were variable, namely; suspected cases of neonatal hepatitis or biliary atresia, positive results from newborn screening, tyrosinemia, failure to thrive, hemolytic anemia, bleeding tendencies and ketotic hypoglycemia. Laboratory data showed elevated serum bile acid levels, hypoproteinemia, low levels of vitamin K-dependent coagulation factors, and hypergalactosemia. Hypercitrullinemia was detected in 11 out of 15 patients examined. Most of the patients were given a lactose-free and/or medium chain triglycerides-enriched formula and lipid-soluble vitamins. The prognosis of the 16 patients is going fairy well at present, but we should observe these patients carefully to see if they manifest any symptom of CTLN2 in the future.     

Proteins of newcastle disease virus. a comparison by partial protease digestion among the strains of different pathogenicity

To investigate the relationship between the pathogenicity of Newcastle disease virus and the structure of viral proteins, two typical strains were sampled from each of three groups of different pathogenicities and these six strains were compared for protein structure by sizing peptides generated by partial digestion with Staphylococcus aureus V8 protease and chymotrypsin. These digests yielded closely similar peptide patterns for the internal polypeptides L and NP, whereas those of the glycoproteins HN and F showed apparent variations which appeared to be specific for the individual groups. Although not as significant as in the glycoproteins, group-dependent variations were also detectable with the M protein. These results suggest that the external proteins might undergo considerable changes whereas the internal proteins would be highly stable and that there is a definite correlation between such changes in the external proteins and the pathogenicity of the virus.     

The structural proteins of Newcastle disease virus. I. Identification of a minor internal protein

The nature of the G-loop heterogeneity and of the split end heterogeneity in Mu phage DNA have been studied. The structures of the molecules seen in self-renatured Mu phage DNA samples show that there are two classes of native molecules in which the G sequence occurs either in a direct or in an inverted order. By studying the structure of a single strand of Mu DNA when spread under weakly denaturing conditions, it is shown that the G region is flanked by very short (50 nucleotides or less) inverted repeat sequence. The G loop inversion is attributed to a phage enzyme-directed reciprocal recombination between these inverted repeat sequences. A second slightly larger inverted repeat sequence occurs within the G loop, but this sequence is not active in reciprocal recombination. By studying suitable diheteroduplexes of F-prime factors containing an inverted Mu prophage, with a reference F factor and with Mu phage DNA, it is shown that the highly heterogeneous split ends of Mu phage are lost when Mu becomes a prophage.     

Cross-linking of Newcastle disease virus (NDV) proteins

Summary The proxomity and spatial relationships of the structural proteins of Newcastle disease virus (NDV) were studied by chemical cross-liking with a series of imidoesters. When the virions were reacted by the cross-linker with a distance 6.1 Å or longer between the functional groups and analyzed by polyacrylamide gel electrophoresis, remarkable changes were observed in the migration patterns of the viral proteins. The most striking one was the extensive decrease in the intensity of the M protein band, and although not so strikingly, glycoprotein and nucleocapsid protein bands were reduced significantly. Instead, several protein complexes appeared at and near the top of the gels. The protein complexes formed by a reversible cross-linker, dimethyl-3,3-dithiobispropionimidate (DTBP), were analyzed by two dimensional electrophoresis; the complexes on the first-dimension cylindrical gels were cleaved by reduction with 2-mercaptoethanol and electrophoresed laterally on the second-dimension slab gels. The results indicated that homodimers of glycoprotein, nucleocapsid protein and M protein were generated under the condition of the most gentle cross-linking employed. At the same time, however, trimer and higher homopolymers of M protein were already detectable. Under the more extensive conditions, the bulk of M protein was cross-linked to form a large protein complex with very high molecular weight. Further, small but significant amounts of glycoprotein and nucleocapsid protein were always detected in this complex.These results suggest that M protein may be present in the virion in close enough proximity to interact with each other and may further have some interactions with glycoprotein and nucleocapsid protein. On the basis of these findings possible roles of M protein in virus assembly were discussed.With 6 Figures