PURPOSE: Survival after liver transplantation (LT) has improved over the years, but infection is still a major complication. We aimed to identify the characteristics of bacterial infections in pediatric LT recipients. METHODS: This study is a retrospective review of 189 consecutive children undergoing LT between 2000 and 2015 at a single center. In this study, the incidence of infection was determined for the following periods: within 1 month, between 1–5 months, and between 6–12 months. Patients who underwent liver transplants more than once or multiple organ transplants were excluded. RESULTS: All patients had received postoperative antibiotic for 3 days. Only the maintenance immunosuppression with oral tacrolimus and steroids were performed. As a result, 132 bacterial infections developed in 87 (46.0%) patients (0.70 events per person-year). Bacterial infections occurred most frequently within the first month (n=84, 63.6%) after LT. In the pathogens, Staphylococcus aureus (15.2%), Enterococcus species (15.2%), and Klebsiella species (13.6%) were most common. Regarding the organ infected, bloodstream was most common (n=39, 29.5%), followed by peritoneum (n=28, 21.2%), urinary tract (n=25, 18.9%), and lungs (n=20, 15.2%). We changed prophylactic antibiotics from ampicillin-sulbactam to piperacillin-tazobactam at 2011, October, there were no significant effects in the prevalence of antibiotics resistant bacterial infections. The 1-year mortality was 9.0% (n=17), in which 41.2% (n=7) was attributable to bacterial infection; septicemia (n=4), pneumonia (n=2), and peritonitis (n=1). CONCLUSIONS: The incidence and type of bacterial infectious complications after LT in pediatric patients were similar to those of previous studies. Bacterial complications affecting mortality occur within 6 months after transplantation, so proper prophylaxis and treatment in this period may improve the prognosis of LT.
Anti-Bacterial Agents ; Bacterial Infections ; Child ; Enterococcus ; Humans ; Immunosuppression ; Incidence ; Klebsiella ; Korea ; Liver Transplantation ; Liver ; Lung ; Mortality ; Peritoneum ; Peritonitis ; Pneumonia ; Prevalence ; Prognosis ; Retrospective Studies ; Sepsis ; Staphylococcus aureus ; Steroids ; Tacrolimus ; Transplants ; Urinary Tract

Rhomboid family member 2 gene (Rhbdf2) is an inactive homologue lacking essential catalytic residues of rhomboid intramembrane serine proteases. The protein is necessary for maturation of tumor necrosis factor-alpha (TNF-α) converting enzyme, which is the molecule responsible for the release of TNF-α. In this study, Rhbdf2 knockout (KO) mice were produced by CRISPR/CAS9. To see the effects of the failure of TNF-α release induced by Rhbdf2 gene KO, collagen-induced arthritis (CIA), which is the representative TNF-α related disease, was induced in the Rhbdf2 mutant mouse using chicken collagen type II. The severity of the CIA was measured by traditional clinical scores and histopathological analysis of hind limb joints. A rota-rod test and grip strength test were employed to evaluate the severity of CIA based on losses of physical functions. The results indicated that Rhbdf2 mutant mice showed clear alleviation of the clinical severity of CIA as demonstrated by the significantly lower severity indexes. Moreover, a grip strength test was shown to be useful for the evaluation of physical functional losses by CIA. Overall, the results showed that the Rhbdf2 gene has a significant effect on the induction of CIA, which is related to TNF-α.
Animals ; Arthritis, Experimental* ; Chickens ; Collagen Type II ; Extremities ; Hand Strength ; Humans ; Joints ; Mice ; Mice, Knockout* ; Serine Proteases ; Tumor Necrosis Factor-alpha

In Drosophila, rhomboid proteases are active cardinal regulators of epidermal growth factor receptor (EGFR) signaling pathway. iRhom1 and iRhom2, which are inactive homologs of rhomboid intramembrane serine proteases, are lacking essential catalytic residues. These are necessary for maturation and trafficking of tumor necrosis factor-alpha (TNF-α) converting enzyme (TACE) from endoplasmic reticulum (ER) to plasma membrane through Golgi, and associated with the fates of various ligands for EGFR. Recent studies have clarified that the activation or downregulation of EGFR signaling pathways by alteration of iRhoms are connected to several human diseases including tylosis with esophageal cancer (TOC) which is the autosomal dominant syndrom, breast cancer, and Alzheimer's disease. Thus, this review focuses on our understanding of iRhoms and the involved mechanisms in the cellular processes.
Alzheimer Disease ; Breast Neoplasms ; Cell Membrane ; Down-Regulation ; Drosophila ; Endoplasmic Reticulum ; Esophageal Neoplasms ; Humans ; Keratoderma, Palmoplantar, Diffuse ; Ligands ; Peptide Hydrolases ; Receptor, Epidermal Growth Factor ; Serine Proteases ; Tumor Necrosis Factor-alpha

The leptin receptor-deficient db/db mouse is a rodent model of type 2 diabetes and obesity. Diabetes in db/db mice shows an age-dependent progression, with early insulin resistance followed by an insulin secretory defect resulting in profound hyperglycemia. However, there is insufficient data on agedependent changes of energy metabolism in db/db mice. We demonstrated an age-dependent decrease in the respiratory exchange ratio (RER), calculated by a ratio of VO2/VCO2, in db/db mice. The RER determined by indirect calorimetry, was 1.03 in db/db mice under 6 weeks of age, which were similar to those in heterozygote (db/+) and wild-type (+/+) mice. However, RER decreased from approximately 0.9 to 0.8 by 10 weeks of age and subsequently returned to approximately 0.9 at 22 weeks of age. The changes in RER were concurrent with the alterations in body weight and blood glucose level. However, other metabolic indicators such as glucose tolerance, changes in body fat mass, and urinary glucose levels, did not change with age. The results suggested that the energy source utilized in db/db mice changed with the age-related progression of diabetes.
Adipose Tissue ; Animals ; Blood Glucose ; Body Weight ; Calorimetry, Indirect ; Energy Metabolism ; Glucose ; Heterozygote ; Hyperglycemia ; Insulin ; Insulin Resistance ; Leptin ; Mice* ; Obesity ; Rodentia

A novel Helicobacter species was identified from the gastrointestinal tract of the Korean striped field mouse (Apodemus agrarius). Biochemical testing, ultrastructure characterization, and 16S rRNA gene sequence analysis suggested that this bacterium represents a distinct taxon. The bacterium was positive for urease activity, susceptible to cephalothin and nalidixic acid, and weakly positive for oxidase and catalase activity. Electron microscopy revealed that the bacterium has spirally curved rod morphology with singular bipolar nonsheathed flagella. Genotypically, the isolated bacterial strains (YMRC 000215, YMRC 000216, and YMRC 000419) were most closely related to a reference strain of Helicobacter mesocricetorum (97.25%, 97.32%, and 97.03% 16S rRNA sequence similarities, respectively). The 16S rRNA sequences of these strains were deposited into GenBank under accession numbers AF284754, AY009129, and AY009130, respectively. We propose the name Helicobacter apodemus for this novel species.
Animals ; Catalase ; Cephalothin ; Databases, Nucleic Acid ; Flagella ; Gastrointestinal Tract* ; Genes, rRNA ; Helicobacter* ; Korea* ; Mice* ; Microscopy, Electron ; Murinae* ; Nalidixic Acid ; Oxidoreductases ; Sequence Analysis ; Urease

N-ethyl-N-nitrosourea (ENU) is a potent mutagen in a mouse model by inducing point mutation in a random manner and, in particular, causing heritable base substitutions in spermatogonia. In this study, systematic development of phenotype-driven mutant mice with large scale was carried out by using ENU. Nine-week-old male mice of C57BL/6J received intraperitoneal injection at three times with 100 mg/kg of ENU at weekly intervals for three weeks. After injections with ENU, the changes of body weight, fatality, recovery of fertile period, and breeding record were measured in these mice. Body weight lost as a result of ENU treatments was reversed after the last ENU injection. Live fertile male mice recovered from infertility from 104 to 165 days after ENU treatments were mated with C57BL/6J female mice for generation of G1 offspring. An average birth rate was 5.9 mice from 1 pair of paternal and maternal mice. All of 231 G1 offspring mice were analyzed by modified-SHIRPA with standard procedure at nine weeks of age. Among G1 mice, 166 mice were identified as mutagenic phenotypes in 20 test items. The changes in mutagenic phenotypes after ENU treatments, for instance, pattern in the region with a different color, touch escape, changes in head morphology, pupil, and teeth, and negative geotaxis etc., were found in these mice. Taken together, these results indicate that ENU may be a trans-generational mutagen in C57BL/6J mice.
Animals ; Birth Rate ; Body Weight ; Breeding* ; Ethylnitrosourea* ; Female ; Fertile Period* ; Head ; Humans ; Infertility ; Injections, Intraperitoneal ; Male ; Mice* ; Phenotype ; Point Mutation ; Pupil ; Spermatogonia ; Tooth ; United Nations

Vitamin D3 up-regulated protein 1 (VDUP1) is a potent growth suppressor that inhibits tumor cell proliferation and cell cycle progression when overexpressed. In a previous study, we showed that VDUP1 knockout (KO) mice exhibited accelerated liver regeneration because such animals could effectively control the expression of cell cycle regulators that drive the G1-to-S phase progression. In the present study, we further investigated the role played by VDUP1 in initial priming of liver regeneration. To accomplish this, VDUP1 KO and wild-type (WT) mice were subjected to 70% partial hepatectomy (PH) and sacrificed at different times after surgery. The hepatic levels of TNF-alpha and IL-6 increased after PH, but there were no significant differences between VDUP1 KO and WT mice. Nuclear factor-kappaB (NF-kappaB), c-Jun-N-terminal kinase (JNK), and signal transducer and activator of transcription 3 (STAT-3) were activated much earlier and to a greater extent in VDUP1 KO mice after PH. A single injection of TNF-alpha or IL-6 caused rapid activation of JNK and STAT-3 expression in both mice, but the responses were stronger and more sustained in VDUP1 KO mice. In conclusion, our findings provide evidence that VDUP1 plays a role in initiation of liver regeneration.
Animals ; Blotting, Western ; Carrier Proteins/*genetics/metabolism ; Cell Proliferation ; *Gene Expression Regulation ; Hepatectomy ; Hepatocytes/*cytology/physiology ; JNK Mitogen-Activated Protein Kinases/genetics/metabolism ; Liver/*physiology ; Male ; Mice, Knockout ; NF-kappa B/genetics/metabolism ; Polymerase Chain Reaction ; *Regeneration ; STAT3 Transcription Factor/genetics/metabolism ; Thioredoxins/*genetics/metabolism

Embryonic stem cells (ESCs) are an emerging source for cell-based therapies aimed at repairing damaged organ tissues; however, the efficiency of directed differentiation is low and refinement of differentiation protocols is hampered by incomplete understanding of the mechanisms involved in this process. To find new compounds which can improve the efficiency of directed differentiation of ESCs to cardiomyocytes, we screened several thousand chemical compounds and identified a promising group. All of the compounds found have a common structure of 1H-pyrrole,2,2'-(phenylmethylene)bis. Here we report the potential mechanism of action for 31002 which showed the strongest activity among the compounds selected. In the presence of 31002, 15 times more cardiomyocytes differentiated from ESCs, i.e., 3.5% to 52% of total differentiated cells. Moreover, the cardiomyocytes showed functional characteristics including rhythmic beating and marker gene expression. 31002 inhibited the down-regulation of genes related to the three germ layers in the late stage of ESCs differentiation, implying that 31002 supports a continuous fate commitment of undifferentiated ESCs to the cardiac lineage by prolonging the three germ layer stages. Therefore, compounds in this group, including 31002, might be useful as directed cardiomyogenic differentiation-inducers to produce cells for use in cell therapy aimed at restoring damaged heart tissue.
Down-Regulation ; Embryonic Stem Cells ; Gene Expression ; Germ Layers ; Heart ; Myocytes, Cardiac ; Tissue Therapy

In order to assess the microbiological contamination of laboratory mice and rats in Korea over the 2-year period from 2007 to 2008, we monitored animals housed in mouse and rat facilities equipped with barrier systems. In a barrier animal facility in Korea, the most important viruses in the identified pathogen were the mouse hepatitis virus (MHV) and Pasteurella (Pa.) pneumotropica, and Staphylococcus aureus was identified as the most common bacterial pathogen in Korea. The most commonly detected parasite in the identified pathogen was Trichomonas spp. in the mouse facilities and Entamoeba spp. in the rat facilities. In many cases, these pathogen-contaminated animals were genetically modified animals obtained from the university. Currently, consistent with the increased transfer of genetically modified animals between domestic and foreign animal facilities, the Pa. pneumotropica and parasites infection rates were shown to have increased as compared to those of the 2004-2006 period. Indeed, the MHV infection rate has been maintained at almost 20% in Korean animal facilities over the past 10 years. These results showed that effective quarantine programs for contaminated genetically engineered mutant mice and the monitoring of regular or irregular MHV monitoring in animal colonies should help to reduce pathogen contamination in Korean animal facilities.
Animals ; Animals, Genetically Modified ; Entamoeba ; Korea ; Mice ; Murine hepatitis virus ; Parasites ; Pasteurella ; Quarantine ; Rats ; Sendai virus ; Staphylococcus aureus ; Trichomonas

In order to assess the microbiological contamination of laboratory mice and rats in Korea over the 2-year period from 2007 to 2008, we monitored animals housed in mouse and rat facilities equipped with barrier systems. In a barrier animal facility in Korea, the most important viruses in the identified pathogen were the mouse hepatitis virus (MHV) and Pasteurella (Pa.) pneumotropica, and Staphylococcus aureus was identified as the most common bacterial pathogen in Korea. The most commonly detected parasite in the identified pathogen was Trichomonas spp. in the mouse facilities and Entamoeba spp. in the rat facilities. In many cases, these pathogen-contaminated animals were genetically modified animals obtained from the university. Currently, consistent with the increased transfer of genetically modified animals between domestic and foreign animal facilities, the Pa. pneumotropica and parasites infection rates were shown to have increased as compared to those of the 2004-2006 period. Indeed, the MHV infection rate has been maintained at almost 20% in Korean animal facilities over the past 10 years. These results showed that effective quarantine programs for contaminated genetically engineered mutant mice and the monitoring of regular or irregular MHV monitoring in animal colonies should help to reduce pathogen contamination in Korean animal facilities.
Animals ; Animals, Genetically Modified ; Entamoeba ; Korea ; Mice ; Murine hepatitis virus ; Parasites ; Pasteurella ; Quarantine ; Rats ; Sendai virus ; Staphylococcus aureus ; Trichomonas