PTEN modulates hepatitis B virus-X protein induced survival signaling in Chang liver cells

PTEN gene, a novel tumor suppressor is frequently mutated or deleted in several malignancies including human hepatocellular carcinoma (HCC). We report previously that human hepatitis B virus-X (HBx) protein achieves protection from apoptotic cell death through-PI3K-Akt-Bad signaling that is p53-independent in liver cells (JBC; 276, 16969 (2000)). In this report, we demonstrated the PTEN effect on HBx induced anti-apoptotic signaling in Chang liver cells (CHL). Expression of PTEN in CHL cells downregulate HBx induced PI3K, Akt activities, Akt, Bad phosphorylations, decreased caspase 3 activity and protection from DNA fragmentations. PTEN suppression of CHL cell growth at G1 phase (JBC;278,4057(2003)) in cell cycle analysis, which is overcome by HBx activated Akt/PKB further confirmed that same PI3K/Akt pathway is involved in cell survival and apoptosis by HBx and PTEN. PTEN suppression of HBx-mediated cell survival through PI3K pathway is specific, since PTEN does not suppress the effect of HBx on the protection from Fas-mediated apoptosis. Taken together, these findings demonstrate that PTEN potently modulate HBx-mediated signaling and is a viable target in therapeutic approaches to inhibit the formation of HCC caused by HBV infections.     

Lactobacillus casei suppresses experimental arthritis by down-regulating T helper 1 effector functions

Although the beneficial effects of probiotics on wide variety of diseases have been shown, little is known about how probiotics modulate the immune system. In this study we elucidated the underlying mechanisms how Lactobacillus casei (L. casei) protects against rheumatoid arthritis (RA) progression by investigating the effector functions of CD4(+) T cells. Oral administration of L. casei suppressed collagen-induced arthritis (CIA) and reduced paw swelling, lymphocyte infiltration and destruction of cartilage tissue. L. casei administration reduced type II collagen (CII)-reactive proinflammatory molecules (IL-1beta, IL-2, IL-6, IL-12, IL-17, IFN-gamma, TNF-alpha and Cox-2) by CD4(+) T cells. L. casei administration also reduced translocation of NF-kappaB into nucleus and CII-reactive Th1-type IgG isotypes IgG2a and IgG2b, while up-regulating immunoregulatory IL-10 levels. Our results suggest that oral administration of L. casei suppresses the type II collagen-reactive effector function of Th1-type cellular and humoral immune responses in arthritic inflammation.     

Failure of epidural analgesia converted to epidural anesthesia for cesarean delivery in a patient with bronchial atresia in labor

Bronchial atresia is a rare anomaly characterized generally by obstruction in the bronchial system, mucus accumulation, emphysematous changes and bulla formation in the peripheral lung. Regional anesthesia is the choice for cesarean delivery in a parturient patient with this anomaly. We report a patient with a diagnosis of bronchial atresia in whom the conversion of epidural analgesia to epidural anesthesia for cesarean delivery failed during labor, needing the application of general anesthesia for a successful delivery.     

CXCR3 polymorphism is associated with male gender and pleuritis in patients with systemic lupus erythematosus

Background

Systemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease involving multiple organs. Chemokines and their receptors play an important role in the pathogenesis of SLE. Lymphocytes expressing CXCR3, chemokine receptors of CXCL4, 9, 10, and 11, increase in patients with SLE and animal models, particularly in those with skin manifestations and nephritis. We investigated CXCR3 genetic polymorphisms in patients with SLE and their association with clinical manifestations.

Methods

A total of 346 patients with SLE and 540 healthy controls were investigated for CXCR3 intron 1 polymorphisms rs2280964 and rs34334103 by Taqman analysis.

Results

rs2280964 and rs34334103 were not associated with all patients with SLE, but rs34334103 showed a significant association with male patients with SLE. Among the clinical manifestations, pleuritis was associated with the rs34334103 polymorphism.

Conclusion

The CXCR3 polymorphism rs34334103 was associated with male gender and pleuritis in patients with SLE.     

Cytomegalovirus infection in children who underwent hematopoietic stem cell transplantation at a single center: A retrospective study of the risk factors

Abstract:  CMV infection is one of the major causes of morbidity and mortality after HSCT. The aim of this single center retrospective study was to analyze risk factors for CMV infection in pediatric patients who underwent HSCT. We retrospectively reviewed the medical records of 117 pediatric patients who underwent allogeneic HSCT at Asan Medical Center between December 2000 and January 2007. After HSCT, CMV antigenemia was detected by identifying CMV pp65 early antigen in white blood cells. The incidence of CMV antigenemia was 24% (28/117) at a median of 38 days (range: 19–123 days) after HSCT. In multivariate analysis, CMV antigenemia occurred significantly more often in CMV seropositive recipients, patients who received grafts from alternative donors, T-cell depleted grafts, patients on ATG-containing conditioning regimens, or patients who received steroid for acute GVHD (p < 0.05). CMV antigenemia tend to develop earlier in patients who received ATG-containing conditioning regimens (p = 0.09). A second episode of CMV antigenemia was observed in three out of 28 patients (11%). The incidence of CMV disease was 5.9% (7/117) at a median of 97 days (range: 34–120 days). Manifestation of CMV disease included retinitis in two, pneumonitis in two, hepatitis in one, hepatitis with colitis in one, and gastritis in one. Six of the 12 patients (50%) with HG antigenemia (CMV pp65 antigen positivity ≥40 cells) developed clinical CMV disease, a rate that was significantly higher than seen in patients with LG antigenemia (6.25%; p < 0.01). We recommend that patients with these risk factors should carefully undergo regular evaluations for CMV infection. We also suggest that earlier and more aggressive preemptive treatment and serial follow-up of CMV disease is necessary in patients with HG-antigenemia.     

Impairment of p38 MAPK-mediated cytosolic phospholipase A2 activation in the kidneys is associated with pathogenicity of Candida albicans

In studying the mechanisms underlying the susceptibility of the kidney to candidal infection, we previously reported that the reduced production of cytokines [i.e. tumour necrosis factor-alpha (TNF-alpha)] via platelet-activating factor (PAF)-induced activation of nuclear factor-kappaB (NF-kappaB) renders the organ susceptible to the fungal burden. In this study, we investigated the possibility that pathogenic Candida albicans may evade clearance and perhaps even multiply by inhibiting elements in the signalling pathway that lead to the production of TNF-alpha. The fungal burden of pathogenic C. albicans in the kidneys was 10(4)-10(5)-fold higher than that of a non-pathogenic strain. PAF-induced early activation of NF-kappaB and TNF-alpha mRNA expression were both observed in the kidneys of mice infected with non-pathogenic strains of C. albicans, but not in mice infected with pathogenic strains. Impairment of PAF-mediated early NF-kappaB activation following infection with pathogenic C. albicans was associated with the prevention of activation of the enzyme cytosolic phospholipase A(2) (cPLA(2)) as well as the upstream pathway of cPLA(2), p38 mitogen-activated protein kinase. Collectively, these findings indicate that C. albicans exerts its pathogenicity through impairing the production of anticandidal cytokines by preventing cPLA(2) activity. This novel mechanism provides insight into understanding pathogenic C. albicans and perhaps identifies a target for its treatment.     

Respiratory syncytial virus infections in hospitalized infants: association between viral load, virus subgroup, and disease severity

The relationships between host factors, virus strain, viral load, and illness severity in respiratory syncytial virus (RSV)-induced bronchiolitis are poorly defined. These relationships were evaluated prospectively in 81 previously healthy infants hospitalized with RSV bronchiolitis. Disease severity was determined by the respiratory rate, the duration of hospitalization, and whether patients during their hospitalization required pediatric intensive care unit admission or mechanical ventilation. RSV typing into subgroup A and B was obtained by RT-PCR-hybridization assay. The nasopharyngeal RSV viral loads were measured by real-time quantitative RT-PCR. Disease severity correlated significantly with the presence of risk factor (estimated gestational age < 37 weeks and/or birth weight < 2,500 g) and with chronologic age 相似文献