Dominant-Negative Rho, Rac, and Cdc42 Facilitate the Invasion Process of Vibrio parahaemolyticus into Caco-2 Cells

To clarify the invasive process of Vibrio parahaemolyticus, an invasion assay was performed using cells expressing dominant negative small GTPases of the Rho family. This assay showed that the dominant negative host phenotype facilitates bacterial invasion, suggesting that the mechanism of V. parahaemolyticus invasion differs from that reported for other invasive bacteria.     

Increased circulating levels of soluble Fas ligand are correlated with disease activity in patients with fibrosing lung diseases

OBJECTIVE: The Fas-Fas ligand (FasL) pathway is one of the important apoptosis-signalling molecule systems. We previously determined that this pathway may be involved in the pathogenesis of fibrosing lung diseases. In the present study, we evaluated the clinical significance of the levels of soluble forms of Fas (sFas) and FasL (sFasL) in serum from patients with fibrosing lung diseases. METHODOLOGY: We measured sFas, sFasL, KL-6 (a measure of alveolar type II cell damage), surfactant protein D (SP-D), and surfactant protein A (SP-A) levels in serum from 35 patients with idiopathic pulmonary fibrosis (IPF), 17 patients with interstitial pneumonia associated with collagen vascular diseases (CVD-IP), and 13 normal healthy controls using enzyme-linked immunosorbent assays (ELISA). RESULTS: The serum levels of sFasL were significantly increased in patients with active IPF and CVD-IP, compared with those with inactive disease and controls. There was no significant difference in sFasL levels between patients with inactive disease and controls. Serum sFasL levels were significantly correlated with lactate dehydrogenase and KL-6 levels in IPF. The decrease in sFasL levels following corticosteroid therapy was not correlated with the clinical course of IPF. There was no significant difference in serum sFas levels between IPF or CVD-IP patients and controls. CONCLUSIONS: Although further studies need to be performed on a large number of patients with histologically proven IPF or CVD-IP, it would seem that serum sFasL levels may reflect the activity of IPF and CVD-IP.     

Prognostic factors and risk classifications for patients with metastatic renal cell carcinoma

The introduction of molecular‐targeted therapy has made dramatical changes to treatment for metastatic renal cell carcinoma. Currently, there are four vascular endothelial growth factor receptor‐tyrosine kinase inhibitors and two mammalian target of rapamycin inhibitors in Japan. For the appropriate clinical use of these molecular‐targeted drugs, the identification of prognostic and/or predictive factors in patients who received these drugs is required. Although molecular biological and genetic factors that determine the prognosis of patients with metastatic renal cell carcinoma have been reported, most of these factors are problematic in that the number of patients analyzed was small. In contrast, clinicopathological prognostic factors, including the practice of cytoreductive nephrectomy, pathological findings, metastatic sites and metastasectomy, and abnormal inflammatory response, have been identified by analyzing a relatively large number of patients. Several prognostic classification models that were developed by combining these clinicopathological factors are widely used in not only clinical trials, but also routine clinical practice. However, the quality of these prognostic models is considered to be insufficient regarding prognostic prediction of metastatic renal cell carcinoma patients and, thus, requires further improvements. Recently, basic and clinical studies have been extensively carried out for the identification of promising informative markers and for understanding molecular mechanisms of resistance to molecular‐targeted drugs in metastatic renal cell carcinoma patients. The present review considers ongoing translational research efforts on clinicopathological, molecular biological, and genetic prognostic and/or predictive factors for metastatic renal cell carcinoma patients in the era of molecular‐targeted therapy, and discusses the clinical implications of these findings.     

Reduction of Tubular Flow Rate as a Mechanism of Oliguria in the Early Phase of Endotoxemia Revealed by Intravital Imaging

Urine output is widely used as a criterion for the diagnosis of AKI. Although several potential mechanisms of septic AKI have been identified, regulation of urine flow after glomerular filtration has not been evaluated. This study evaluated changes in urine flow in mice with septic AKI. The intratubular urine flow rate was monitored in real time by intravital imaging using two-photon laser microscopy. The tubular flow rate, as measured by freely filtered dye (FITC-inulin or Lucifer yellow), time-dependently declined after LPS injection. At 2 hours, the tubular flow rate was slower in mice injected with LPS than in mice injected with saline, whereas BP and GFR were similar in the two groups. Importantly, fluorophore-conjugated LPS selectively accumulated in the proximal tubules that showed reduced tubular flow at 2 hours and luminal obstruction with cell swelling at 24 hours. Delipidation of LPS or deletion of Toll-like receptor 4 in mice abolished these effects, whereas neutralization of TNF-α had little effect on LPS-induced tubular flow retention. Rapid intravenous fluid resuscitation within 6 hours improved the tubular flow rate only when accompanied by the dilation of obstructed proximal tubules with accumulated LPS. These findings suggest that LPS reduces the intratubular urine flow rate during early phases of endotoxemia through a Toll-like receptor 4–dependent mechanism, and that the efficacy of fluid resuscitation may depend on the response of tubules with LPS accumulation.     

Is Memorial Sloan-Kettering Cancer Center risk classification appropriate for Japanese patients with metastatic renal cell carcinoma in the cytokine era?

ObjectivesWe investigated the prognosis of Japanese patients with metastatic renal cell carcinoma (RCC), and analyzed the validity of Memorial Sloan-Kettering Cancer Center (MSKCC) risk classification.Materials and methodsThe endpoint of the present study was overall survival. Relationships between overall survival and potential prognostic factors were assessed using the Cox proportional hazard model with a step-wise procedure. Prognostic assessment was also performed according to the MSKCC risk classification. The predictive accuracy of the MSKCC risk classification was measured employing the concordance index.ResultsThe median survival for all patients was 22 months (95% CI, 19–28 months). The eight factors were identified as independent prognostic factor; time from initial diagnosis to metastasis, low hemoglobin (Hb), lactate dehydrogenase (LDH), corrected serum calcium (cCa), C-reactive protein (CRP), and the presence or absence of liver metastasis, bone metastasis, and lymph node metastasis. When the MSKCC risk classification was applied to patients, the median overall survival was not reached and 26 and 10 months in the patients classified as favorable, intermediate, and poor risk, respectively. The c-index was 0.73.ConclusionsThe prognosis of Japanese metastatic renal cell carcinoma patients may be better than that of previous studies from North America or Europe. Although there are some differences in the rate of patients in the risk groups and survival time by risk group between these patients, the MSKCC risk classification may be applicable for Japanese patients with metastatic renal cell carcinoma.