BACKGROUND Depletion of replication factors often causes cell death in cancer cells. Depletion of Cdc7, a kinase essential for initiation of DNA replication, induces cancer cell death regardless of its p53 status, but the precise pathways of cell death induction have not been characterized. METHODOLOGY/PRINCIPAL FINDINGS We have used the recently-developed cell cycle indicator, Fucci, to precisely characterize the cell death process induced by Cdc7 depletion. We have also generated and utilized similar fluorescent cell cycle indicators using fusion with other cell cycle regulators to analyze modes of cell death in live cells in both p53-positive and -negative backgrounds. We show that distinct cell-cycle responses are induced in p53-positive and -negative cells by Cdc7 depletion. p53-negative cells predominantly arrest temporally in G2-phase, accumulating CyclinB1 and other mitotic regulators. Prolonged arrest at G2-phase and abrupt entry into aberrant M-phase in the presence of accumulated CyclinB1 are followed by cell death at the post-mitotic state. Abrogation of cytoplasmic CyclinB1 accumulation partially decreases cell death. The ATR-MK2 pathway is responsible for sequestration of CyclinB1 with 14-3-3σ protein. In contrast, p53-positive cancer cells do not accumulate CyclinB1, but appear to die mostly through entry into aberrant S-phase after Cdc7 depletion. The combination of Cdc7 inhibition with known anti-cancer agents significantly stimulates cell death effects in cancer cells in a genotype-dependent manner, providing a strategic basis for future combination therapies. CONCLUSIONS Our results show that the use of Fucci, and similar fluorescent cell cycle indicators, offers a convenient assay system with which to identify cell cycle events associated with cancer cell death. They also indicate genotype-specific cell death modes induced by deficient initiation of DNA replication in cancer cells and its potential exploitation for development of efficient cancer therapies.

Fatigue is a common complaint in modern society. As photosensitivity is associated with fatigue, this study aimed to clarify the relationship between neural response to visual stimuli and fatigue using a 160-channel whole-head-type magnetoencephalographic system. Twelve healthy male volunteers were enrolled. Participants were randomly assigned to two groups in a single-blinded, crossover fashion to perform acute fatigue-inducing mental task sessions, i.e., 0-back or 2-back test for 30min. Visual evoked magnetic field (VEF) intensities were evaluated by standardized low-resolution brain electromagnetic tomography modified for a quantifiable method. VEF consisted of two phases, and although acute fatigue did not alter the VEF intensities and the intensities before the acute fatigue-inducing mental task sessions were not correlated with the Chalder's Fatigue Scale scores in either of the two phases, the intensities after the 0-back test trials for 30min in Phase 1 and those after the 2-back test trials in Phase 2 were significantly correlated with the fatigue scale scores. The daily level of fatigue was related to VEF intensity after the acute mental fatigue loads. Our findings provide new perspectives to evaluate our daily level of fatigue as well as to clarify the neural mechanisms underlying it.

No heavy-atom effect: Highly fluorescent, sulfur- or selenium-containing compounds were synthesized by intramolecular [4+2]-cycloadditions between 9-anthryl or 1-naphthyl and alkynyl moieties. Their fluorescence is based on 1-chalcogeno-1,3-butadiene-conjugated system in a rigid skeleton. Some of them are also highly fluorescent in the solid state. The monoxide of Mbb-S is more fluorescent in the solid state (Φ(F)=0.6) than in solution (Φ(F)<0.02).

The neural substrates of the fatigue sensation have not been totally identified. Several lines of evidence demonstrate that seeing emotional changes in others activates brain regions involved in experiencing similar emotions. We hypothesized that there exists a mirror system regarding the fatigue sensation and that brain regions associated with the fatigue sensation may be activated by viewing other individuals expressing fatigue. In this study, we attempted to identify the neural substrates activated by viewing other fatigued individuals using magnetoencephalography (MEG). Twelve healthy participants were enrolled in our study after providing written informed consent. During MEG recordings, they viewed a set of pictures projected on a screen. The pictures, which were presented in a randomized order, were of a person with a fatigued or neutral facial expression. When participants viewed pictures of people with fatigued expressions, we were able to estimate equivalent current dipoles (ECDs) in the posterior cingulate cortex (PCC) in 9 of 12 participants approximately 300ms after the onset of each picture presentation. When they viewed pictures of people with neutral expressions, we were not able to estimate corresponding ECDs for any participant. The PCC is the brain region activated by viewing others expressing fatigue, suggesting existence of the shared neural substrates of felt and observed fatigue.

Objective: We have previously reported the clinical efficacy of water-in-oil-in-water (W/O/W) emulsions, particularly for non-selective transcatheter arterial infusion (TAI) therapy. W/O/W emulsions limit damage to normal hepatic parenchyma, because of their minimal embolic effect on peripheral arteries and slow release of anticancer agent. The purpose of this study was to evaluate the safety and effectiveness of ultraselective TAI (UTI) of a W/O/W emulsion for hepatocellular carcinoma (HCC).Methods: 11 patients with Stage I-III small HCCs (<5 cm) underwent UTI with a W/O/W emulsion at our institute. Response was assessed using the Response Evaluation Criteria in Solid Tumors. Disease-free survival time was estimated using the Kaplan-Meier method.Results: All 10 patients, excluding a patient who underwent a hepatectomy after UTI, achieved complete response. The 6, 12 and 30 month cumulative disease-free survival rates for the 10 patients were 100%, 90% and 60%, respectively. The patient who underwent hepatectomy after UTI developed complete necrosis of the HCC and peritumoral non-tumorous liver parenchyma.Conclusion: UTI therapy using a W/O/W emulsion for patients with small HCCs results in a good local response.

The purpose of this study was to establish a method for imaging the process of gastrointestinal (GI) absorption and subsequent biodistribution in the human body after oral drug administration, using positron emission tomography (PET) with 2-[(18)F]fluoro-2-deoxy-D-glucose ([(18)F]FDG). First, we developed a method to deliver the radiotracer safely into the stomach using soft gelatin capsules to avoid any significant exposure to the pharyngoesophageal region. Second, we performed pharmacokinetic (PK) analyses on time-radioactivity profiles in GI tissues and blood to calculate the gastric emptying and intestinal elimination rate constants and to estimate the fluid volume in the lumen of the small intestine from PET image analysis. This is the first study involving oral administration of a PET probe in humans, and the results demonstrate the high potential of PET technology to investigate the GI absorption and PK profiles of drugs in humans.

N-linked glycans harbored on glycoproteins profoundly affect the character of proteins by altering their structure or capacity to bind to other molecules. Specific knowledge of the role of N-glycans in these changes is limited due to difficulties in identifying precise carbohydrate structures on a given glycoprotein, which arises from the large amounts of glycoprotein required for N-glycan structural determination. Here, we refined a simple method to purify and detect trace amounts of N-glycans. During the N-glycan purification step, most contaminants were removed by two kinds of columns: a graphite carbon column and a cellulose column. N-Glycans were identified with a three-dimensional high-performance liquid chromatography (HPLC) system. Using our method, a global analysis of N-glycans from human muscle biopsy samples and mouse brain sections was possible. By combining sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with our method, we refined analytical procedures for N-glycans from SDS-PAGE gels using hydrazinolysis to achieve a high N-glycan recovery rate. N-Glycans on as little as 1mg of the target protein transferrin or immunoglobulin G (IgG) were easily detected. These methods allowed us to efficiently determine glycoprotein N-glycans at picomole (pmol) levels.

Myelination is the culmination of a complex process in which oligodendrocyte (OL) progenitors transition through defined stages in a well-coordinated differentiation program. The signaling mechanisms that regulate this progression are poorly understood. Here we investigate the role of extracellular signal-regulated-kinase-1,-2 (Erk1/2) and the mammalian target of rapamycin (mTOR), downstream effectors of the Ras/Raf/Mek/Erk and PI3K/Akt/mTOR pathways, at specific stages of OL development in vitro. Using a panel of developmental stage-specific antigenic markers and pharmacological inhibitors, we provide evidence that Erk1/2 signaling regulates transition of early progenitors to the late progenitor stage and, as a consequence, to the immature OL stage, but not the transition of immature OL to the mature OL stage. In contrast, mTOR signaling is not required for early progenitor transition to late progenitor stage. Surprisingly, it is also not required for the transition of late progenitors to terminally differentiated immature OLs, as has been reported previously, but is required for the next sequential transition of immature OLs to the mature OL stage. Furthermore, mTOR signaling regulates OL cytoskeletal organization and major myelin protein expression. These in vitro findings correlate with our in vivo data showing that inhibition of mTOR by rapamycin injection attenuated the onset of myelination in the early postnatal brain. Thus, these studies demonstrate that Erk1/2 and mTOR signaling sequentially regulates distinct stages of OL progenitor differentiation and suggest that cells in the OL-lineage require distinct signaling mechanisms to transition through specific stages of their development. © 2011 Wiley Periodicals, Inc.

trans-Cyclooctanediyl-bridged [OSSO]-type ligand 4 reacts with TiCl(4)(thf)(2) in toluene to produce the corresponding titanium(IV) dichloro complexes as an inseparable mixture of cis-α isomer 6a and cis-β isomer 6b in a ratio of 2:1, whereas treatment of dilithio salt of 4 with TiCl(3)(thf)(3) in Et(2)O afforded chloride-bridged dimeric titanium(III) complex 8, which indicated the antiferromagnetic character in a nonpolar solvent solution. Di(isopropoxy) titanium(IV) complex 10 having a C(2)-symmetric cis-α configuration was synthesized by the reaction of 4 with Ti(O(i)Pr)(4) in toluene as yellow crystals. Moreover, the reaction of 4 with Ti(NEt(2))(4) in toluene resulted in the unexpected formation of [OSSO]-type bis(phenolato)-bridged dinuclear diamido titanium(IV) complex 11, which adopted a distorted tetrahedral geometry on the titanium center. These titanium complexes were characterized on the basis of their NMR spectroscopic data, and the molecular structures of complexes 8, 10, and 11 were established by single crystal X-ray diffraction. The titanium(IV) and (III) complexes 6 and 8 upon activation with a cocatalyst in toluene polymerized 1-hexene isospecifically to produce poly(1-hexene) having high molecular weight (M(w)= 22,000-52,000 g mol(-1)) and relatively narrow polydispersity (M(w)/M(n)= 1.7-1.8), albeit with low activity [0.27-1.0 g mmol(cat)(-1) h(-1)].

To investigate arenavirus in Zambia, we characterized virus from the kidneys of 5 arenavirus RNA-positive rodents (Mastomys natalensis) among 263 captured. Full-genome sequences of the viruses suggested that they were new strains similar to Lassa virus-related arenaviruses. Analyzing samples from additional rodents and other species can elucidate epizootiologic aspects of arenaviruses.