dMicrobiologists have been using agar growth medium for over 120 years. It revolutionized microbiology in the 1890s when microbiologists were seeking effective methods to isolate microorganisms, which led to the successful cultivation of microorganisms as single clones. But there has been a disparity between total cell counts and cultivable cell counts on plates, often referred to as the "great plate count anomaly," that has long been a phenomenon that still remains unsolved. Here, we report that a common practice microbiologists have employed to prepare agar medium has a hidden pitfall: when phosphate was autoclaved together with agar to prepare solid growth media (PT medium), total colony counts were remarkably lower than those grown on agar plates in which phosphate and agar were separately autoclaved and mixed right before solidification (PS medium). We used a pure culture of Gemmatimonas aurantiaca T-27 T and three representative sources of environmental samples, soil, sediment, and water, as inocula and compared colony counts between PT and PS agar plates. There were higher numbers of CFU on PS medium than on PT medium using G. aurantiaca or any of the environmental samples. Chemical analysis of PT agar plates suggested that hydrogen peroxide was contributing to growth inhibition. Comparison of 454 pyrosequences of the environmental samples to the isolates revealed that taxa grown on PS medium were more reflective of the original community structure than those grown on PT medium. Moreover, more hitherto-uncultivated microbes grew on PS than on PT medium.

The programmed cell death 4 (PDCD4) gene was originally identified as a tumor-related gene in humans and acts as a tumor-suppressor in mouse epidermal carcinoma cells. However, its function and regulatory mechanisms of expression in human cancer remain to be elucidated. We therefore investigated the expression of PDCD4 in human hepatocellular carcinoma (HCC) and the role of PDCD4 in human HCC cells. Downregulation of PDCD4 protein was observed in all HCC tissues tested compared with corresponding noncancerous liver, as revealed by Western blotting or immunohistochemical staining. Human HCC cell line, Huh7, transfected with PDCD4 cDNA showed nuclear fragmentation and DNA laddering characteristic of apoptotic cells associated with mitochondrial changes and caspase activation. Transforming growth factor-b1 (TGF-b1) treatment of Huh7 cells resulted in increased PDCD4 expression and occurrence of apoptosis, also concomitant with mitochondrial events and caspase activation. Transfection of Smad7, a known antagonist to TGF-b1 signaling, protected cells from TGF-b1-mediated apoptosis and suppressed TGF-b1-induced PDCD4 expression. Moreover, antisense PDCD4 transfectants were resistant to apoptosis induced by TGF-b1. In conclusion, these data suggest that PDCD4 is a proapoptotic molecule involved in TGF-b1-induced apoptosis in human HCC cells, and a possible tumor suppressor in hepatocarcinogenesis.

Coal-bed methane is one of the largest unconventional natural gas resources. Although microbial activity may greatly contribute to coal-bed methane formation, it is unclear whether the complex aromatic organic compounds present in coal can be used for methanogenesis. We show that deep subsurface-derived Methermicoccus methanogens can produce methane from more than 30 types of methoxylated aromatic compounds (MACs) as well as from coals containing MACs. In contrast to known methanogenesis pathways involving one- and two-carbon compounds, this "methoxydotrophic" mode of methanogenesis couples O-demethylation, CO reduction, and possibly acetyl-coenzyme A metabolism. Because MACs derived from lignin may occur widely in subsurface sediments, methoxydotrophic methanogenesis would play an important role in the formation of natural gas not limited to coal-bed methane and in the global carbon cycle.

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BACKGROUNDThe high recurrence rate of hepatocellular carcinoma (HCC) determines the long‐term prognosis for patients with HCC. In the current study, the authors tested the effects of menatetrenone, a vitamin K2 analog, on recurrent HCC and survival after curative treatment.METHODSSixty‐one patients who were diagnosed as free of HCC after surgical resection or percutaneous local ablation were assigned randomly assigned to either a menatetrenone group (n = 32 patients) or a control group (n = 29 patients). Patients in the menatetrenone group received a daily oral dose of 45 mg of menatetrenone. Disease recurrence and survival rates were analyzed in patients with HCC.RESULTSThe cumulative recurrence rates in the menatetrenone group were 12.5% at 12 months, 39.0% at 24 months, and 64.3% at 36 months; and the corresponding recurrence rates in the control group were 55.2%, 83.2%, and 91.6%, respectively (P = 0.0002). Similar results were obtained even for patients who had low baseline levels of serum des‐γ‐carboxy‐prothrombin. Univariate and multivariate Cox proportional hazard analyses showed that the administration of menatetrenone was the only factor related to the recurrence rate of HCC. The cumulative survival rates for the patients who received menatetrenone were 100% at 12 months, 96.6% at 24 months, and 87.0% at 36 months; and the corresponding survival rates for patients in the control group were 96.4%, 80.9%, and 64.0%, respectively (P = 0.051).CONCLUSIONSThe current study findings suggested that menatetrenone may have a suppressive effect on recurrence of HCC and a beneficial effect on survival, although a larger, placebo‐controlled trial will be required to prove these effects. Cancer 2006. © 2006 American Cancer Society.

Hepatocellular carcinoma (HCC) is characterized by frequent recurrence, even after curative treatment. Vitamin K2, which has been reported to reduce HCC development, may be effective in preventing HCC recurrence. Patients who underwent curative ablation or resection of HCC were randomly assigned to receive placebo, 45 mg/day, or 90 mg/day vitamin K2 in double-blind fashion. HCC recurrence was surveyed every 12 weeks with dynamic computed tomography/magnetic resonance imaging, with HCC-specific tumor markers monitored every 4 weeks. The primary aim was to confirm the superiority of active drug to placebo concerning disease-free survival (DFS), and the secondary aim was to evaluate dose-response relationship. Disease occurrence and death from any cause were treated as events. Hazard ratios (HRs) for disease occurrence and death were calculated using a Cox proportional hazards model. Enrollment was commenced in March 2004. DFS was assessed in 548 patients, including 181 in the placebo group, 182 in the 45-mg/ day group, and 185 in the 90-mg/day group. Disease occurrence or death was diagnosed in 58, 52, and 76 patients in the respective groups. The second interim analysis indicated that vitamin K2 did not prevent disease occurrence or death, with an HR of 1.150 (95% confidence interval: 0.843-1.570, one-sided; P 5 0.811) between the placebo and combined active-drug groups, and the study was discontinued in March 2007. Conclusion: Efficacy of vitamin K2 in suppressing HCC recurrence was not confirmed in this doubleblind, randomized, placebo-controlled study. (HEPATOLOGY 2011;54:532-540)

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AIM: Primary biliary cirrhosis (PBC) is a chronic, cholestatic disease of autoimmune etiology, the histology of which shows a destruction of the intrahepatic bile duct and portal inflammation. Ursodeoxycholic acid (UDCA) is now used as a first-line drug for asymptomatic PBC (aPBC) because it is reported that UDCA decreases mortality and prolongs the time of liver transplantation. However, only 20-30% of patients respond fully to UDCA. Recently, lipoproteinlowering agents have been found to be effective for PBC. The aim of this study was to examine the safety and efficacy of fenofibrate, a member of the fibrate class of hypolipidemic and anti-inflammatory agent via peroxysome proliferatoryactivated receptor α, in patients with aPBC. METHODS:Fenofibrate was administered for twelve weeks in nine patients with aPBC who failed to respond to UDCA. UDCA was used along with fenofibrate during the study. The data from aPBC patients were analyzed to assess the biochemical effect of fenofibrate during the study. RESULTS:The serum levels of alkaline phosphatase (ALP) (285±114.8 IU/L) and immunoglobulin M (IgM) (255.8±85.9 mg/dl) significantly decreased to 186.9±76.2 IU/L and 192.9±67.5 mg/dL respectively, after fenofibrate treatment in patients with aPBC (P<0.05). Moreover, the titer of antimitochondrial antibody (AMA) also decreased in 4 of 9 patients with aPBC. No adverse reactions were observed in any patients.