Deficiency of mastl, a mitotic regulator, results in cell detachment from developing tissues of zebrafish embryos

To form tissues with unique functions and structures, it is important that the cells that comprise them maintain physical contact. On the other hand, with each mitosis, drastic changes in cell shapes, cell adhesion, and cytoskeletal architecture may cause such contacts to be temporarily weakened, risking improper development and maintenance of tissues. Despite such risks, tissues form properly during normal development. However, it is not well understood whether mitotic abnormalities affect tissue formation. Here, analysis of zebrafish embryos with aberrant mitosis shows that proper progression of mitosis is important to maintain cell contact in developing tissues. By screening mutants with abnormal trunk and tail development, we obtained a mutant with perturbed expression of some tissue-specific genes in embryonic caudal regions. The responsible gene is mastl/gwl, which is involved in progression of mitosis. Analysis focusing on the chordo-neural hinge (CNH), the primordium of axial tissues, shows that cell detachment from the CNH is increased in mastl mutant embryos. Time-lapse imaging reveals that this cell detachment occurs during mitosis. These results suggest that cells are unable to maintain contact due to abnormalities in progression of mitosis in mastl mutants.

Safety and efficacy of nivolumab and standard chemotherapy drug combination in patients with advanced non-small-cell lung cancer: a four arms phase Ib study

In this phase Ib study, four combination therapies of nivolumab 10 mg/kg and standard chemotherapy (cisplatin/gemcitabine, cisplatin/pemetrexed, carboplatin/paclitaxel/bevacizumab, or docetaxel) showed acceptable toxicity profiles in patients with advanced non-small-cell lung cancer. Furthermore, these combination therapies presented encouraging antitumor activities.

Background

The human IgG4 monoclonal antibody nivolumab targets programmed cell death-1 (PD-1) and promotes antitumor response by blocking the interaction of PD-1 with its ligands. This single-center phase Ib study investigated the tolerability, safety, and pharmacokinetics of nivolumab combined with standard chemotherapy in patients with advanced non-small-cell lung cancer (NSCLC).

Patients and methods

Patients who had stage IIIB without indication for definitive radiotherapy, stage IV, or recurrent NSCLC were eligible. Regimens were nivolumab 10 mg/kg + gemcitabine/cisplatin (arm A), pemetrexed/cisplatin (arm B), paclitaxel/carboplatin/bevacizumab (arm C), or docetaxel (arm D). Regimens A, B, and D were repeated every 3 weeks for up to four cycles and regimen C was repeated for up to six cycles; nivolumab alone (arm A), with pemetrexed (arm B), bevacizumab (arm C), or docetaxel (arm D) was continued every 3 weeks as maintenance therapy until disease progression or unacceptable toxicity. Dose-limiting toxicity (DLT) was evaluated during the first treatment cycle.

Results

As of March 2014, six patients were enrolled in each arm. The combination of nivolumab 10 mg/kg and chemotherapy was well tolerated. DLT was observed in only one patient in arm A (alanine aminotransferase increased). Select adverse events (those with a potential immunologic cause) of any grade were observed in six, four, six, and five patients in arms A, B, C, and D, respectively. Three, three, six, and one patient achieved partial response while median progression-free survival was 6.28, 9.63 months, not reached, and 3.15 months in arms A, B, C, and D, respectively.

Conclusions

Combination of nivolumab 10 mg/kg and chemotherapy showed an acceptable toxicity profile and encouraging antitumor activity in patients with advanced NSCLC.

Clinical trials number

Japanese Pharmaceutical Information Center Clinical Trials Information (JapicCTI)-132071.

Durability of Flexible Molded Polyurethane Foams

In recent years, we have developed highly resilient (HR) flexible molded foams with superb durability, resilience and vibration characteristics, and we have reported that these improvements were based on control of cross link degree of polymer, morphology and mobility of hard and soft segments. This paper describes factors that dominantly influence the durability and the mechanism of fatigue by investigation of cross linking by covalent and hydrogen-bonds and the morphology of hard/soft segments. In this study, we use molded foams with different durabilities. These are TDI-based high performance/conventional HR, MDI-based high-performance/conventional HR, and hot molded foams.

On the whole, a small apparent viscosity coefficient, which is calculated from vibration characteristics of the foam, and a higher cross link degree of foam polymer make static and dynamic durability of flexible molded foam better. Mobility of the soft segment, estimated by solid state NMR, also dominates dynamic durability. Accordingly, hydrogen-bonds of the hard segment contribute against creep as a cross link point in static/dynamic durability test, and tight hydrogen-bonds of hot molded foam are durable against rupture or rebonding by water molecules in the wet compression set oven.

The drop in cross link degree of foam polymer was not observed during vibration durability test. Accordingly, the mechanism of fatigue could be the change of state in hydrogen-bonds or tangling of polymer-chains, or relatively macro rupture.

Measurement and comparison of individual external doses of high-school students living in Japan, France, Poland and Belarus-the 'D-shuttle' project

Twelve high schools in Japan (of which six are in Fukushima Prefecture), four in France, eight in Poland and two in Belarus cooperated in the measurement and comparison of individual external doses in 2014. In total 216 high-school students and teachers participated in the study. Each participant wore an electronic personal dosimeter 'D-shuttle' for two weeks, and kept a journal of his/her whereabouts and activities. The distributions of annual external doses estimated for each region overlap with each other, demonstrating that the personal external individual doses in locations where residence is currently allowed in Fukushima Prefecture and in Belarus are well within the range of estimated annual doses due to the terrestrial background radiation level of other regions/countries.

[Diffusion studies of redox-sensitive nitroxyl spin probes through bilayer lipid membranes using 300 MHz electron spin resonance spectrometer]

Electron spin resonance (ESR) studies were carried out for 14N-labeled deuterated 3-methoxy-carbonyl-2,2,5,5-tetramethyl-pyrrolidine-1-oxyl (MC-PROXYL) and 3-carboxy-2,2,5,5-tetramethyl-1-pyrrolidin-1-oxyl (carboxy-PROXYL) in pure water and various concentrations of liposomal solutions by using 300 MHz ESR spectrometer. The ESR parameters such as the line width, hyperfine coupling constant, rotational correlation time, g-factor, partition parameter and permeability were reported for the samples. The line width broadening was observed for MC-PROXYL and carboxy-PROXYL in liposomal solution. The hyperfine coupling constant was observed for both nitroxyl spin probes. The permeable and impermeable nature of nitroxyl spin probes was demonstrated. The rotational correlation time increases with increasing concentration of liposome. The partition parameter increases with increasing concentration of liposome for MC-PROXYL, which indicates that the nitroxyl spin probes diffuse into lipid membrane. The permeability value decreases with increasing concentration of liposome, which reveals an increase in membrane permeability. The peaks corresponding to the lipid phase were observed for MC-PROXYL in liposomal solution, but not resolved for carboxy-PROXYL. These results confirm the permeable and impermeable nature of nitroxyl spin probes.

Neurotransmitters, psychotropic drugs and microglia: clinical implications for psychiatry

Psychiatric disorders have long and dominantly been regarded to be induced by disturbances of neuronal networks including synapses and neurotransmitters. Thus, the effects of psychotropic drugs such as antipsychotics and antidepressants have been understood to modulate synaptic regulation via receptors and transporters of neurotransmitters such as dopamine and serotonin. Recently, microglia, immunological/inflammatory cells in the brain, have been indicated to have positive links to psychiatric disorders. Positron emission tomography (PET) imaging and postmortem studies have revealed microglial activation in the brain of neuropsychiatric disorders such as schizophrenia, depression and autism. Animal models of neuropsychiatric disorders have revealed the underlying microglial pathologies. In addition, various psychotropic drugs have been suggested to have direct effects on microglia. Until now, the relationship between microglia, neurotransmitters and psychiatric disorders has not been well understood. Therefore, in this review, at first, we summarize recent findings of interaction between microglia and neurotransmitters such as dopamine, serotonin, norepinephrine, acetylcholine and glutamate. Next, we introduce up-to-date knowledge of the effects of psychotropic drugs such as antipsychotics, antidepressants and antiepileptics on microglial modulation. Finally, we propose the possibility that modulating microglia may be a key target in the treatment of various psychiatric disorders. Further investigations and clinical trials should be conducted to clarify this perspective, using animal in vivo studies and imaging studies with human subjects.

Anti-Inflammatory properties of antipsychotics via microglia modulations: are antipsychotics a 'fire extinguisher' in the brain of schizophrenia?

Schizophrenia is one of the most severe psychiatric diseases noted for its chronic and often debilitating processes; affecting approximately 1% of the world's population, while its etiology and therapeutic strategies still remain elusive. In the 1950s, the discovery of antipsychotic effects of haloperidol and chlorpromazine shifted the paradigm of schizophrenia. These drugs proved to be antagonists of dopamine D2 receptor (D2R), thus dopamine system dysfunction came to be hypothesized in the pathophysiology of schizophrenia, and D2R antagonism against dopamine neurons has been considered as the primary therapeutic target for schizophrenia. In addition, abnormalities of glutamatergic neurons have been indicated in the pathophysiology of schizophrenia. On the other hand, recent neuroimaging studies have shown that not only dementia but also schizophrenic patients have a significant volume reduction of some specific regions in the brain, which indicates that schizophrenia may involve some neurodegenerative process. Microglia, major sources of various inflammatory cytokines and free radicals such as superoxide and nitric oxide (NO) in the CNS, play a crucial role in a variety of neurodegenerative diseases such as dementia. Recent postmortem and positron emission computed tomography (PET) studies have indicated that activated microglia may be present in schizophrenic patients. Recent in vitro studies have suggested the anti-inflammatory effects of antipsychotics on microglial activation. In this article, we review the anti-inflammatory effects of antipsychotics on microglia, and propose a novel therapeutic hypothesis of schizophrenia from the perspective of microglial modulation.

A novel instrumented multipeg running wheel system, Step-Wheel, for monitoring and controlling complex sequential stepping in mice

Motor control is critical in daily life as well as in artistic and athletic performance and thus is the subject of intense interest in neuroscience. Mouse models of movement disorders have proven valuable for many aspects of investigation, but adequate methods for analyzing complex motor control in mouse models have not been fully established. Here, we report the development of a novel running-wheel system that can be used to evoke simple and complex stepping patterns in mice. The stepping patterns are controlled by spatially organized pegs, which serve as footholds that can be arranged in adjustable, ladder-like configurations. The mice run as they drink water from a spout, providing reward, while the wheel turns at a constant speed. The stepping patterns of the mice can thus be controlled not only spatially, but also temporally. A voltage sensor to detect paw touches is attached to each peg, allowing precise registration of footfalls. We show that this device can be used to analyze patterns of complex motor coordination in mice. We further demonstrate that it is possible to measure patterns of neural activity with chronically implanted tetrodes as the mice engage in vigorous running bouts. We suggest that this instrumented multipeg running wheel (which we name the Step-Wheel System) can serve as an important tool in analyzing motor control and motor learning in mice.

Intrinsic Radiosensitivity and PLD Repair in Osteosarcoma Cell Lines

The response to radiation of seven osteosarcoma cell lines was analysed by in vitro colony-forming assay and compared with that of eight human fibroblast strains. The values of D0, the surviving fraction after 2 Gy (S2Gy), and the mean inactivation dose (D) of osteosarcoma cells in log-phase culture were significantly higher than those of fibroblast strains (p less than 0.01). PLD (potentially lethal damage) repair of osteosarcoma cells evaluated in the plateau phase of growth showed great variation for enhancement of survival, although all of the values were maximized within 12 h after irradiation. In the osteosarcoma, intrinsic radiosensitivity in vitro reflected the clinical response to radiation. However, the capacity for PLD repair might not be a good indicator for predicting the results of radiation therapy.

A kinetic study of enhancing effect by phenolic compounds on the hydroxyl radical generation during ozonation

Ozone decomposition in aqueous solution proceeds through a radical type chain mechanism. These reactions involve the very reactive and catalytic intermediates O2- radical, OH radical, HO2 radical, OH-, H2O2, etc. OH radical is proposed as an important factor in the ozonation of water among them. In the present study, the enhancing effects of several phenolic compounds; phenol, 2-, 3-, 4-monochloro, 2,4-dichloro, 2,4,6-trichlorophenol on OH radical generation were mathematically evaluated using the electron spin resonance (ESR)/spin-trapping technique. OH radical was trapped with a 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a stable adduct, DMPO-OH. The initial velocities of DMPO-OH generation in ozonated water containing phenolic compounds were quantitatively measured using a combined system of ESR spectroscopy with stopped-flow apparatus, which was controlled by homemade software. The initial velocities of DMPO-OH generation increased as a function of the ozone concentration. The relation among ozone concentration, amount of phenolic compounds and the initial velocity (v0) of DMPO-OH generation was mathematically analyzed and the following equation was obtained, v0 (10(-6) M/s) = (A' x [PhOHs (10(-9) M)] + 0.0005) exp (60 x [ozone (10(-9) M)]). The equation fitted very well with the experimental results, and the correlation coefficient was larger than 0.98.

A possible target of antioxidative therapy for diabetic vascular complications-vascular NAD(P)H oxidase

A growing body of evidence has shown that oxidative stress may be involved in the development of vascular complications associated with diabetes. However, the molecular mechanism for increased reactive oxygen species (ROS) production in diabetes remains uncertain. Among various possible mechanisms, attention have increasingly been paid to NAD(P)H oxidase as the most important source of ROS production in vascular cells. High glucose level stimulates ROS production through protein kinase C (PKC)-dependent activation of vascular NAD(P)H oxidase. Furthermore, the expression of NAD(P)H oxidase components is increased in micro- and macrovascular tissues of diabetic animals in association with various functional disorders and histochemical abnormalities. These results suggest that vascular NAD(P)H oxidase-driven ROS production may contribute to the onset or development of diabetic micro- or macrovascular complications. In this point of view, the possible new strategy of antioxidative therapy for diabetic vascular complications is discussed in this review.

Inhibitory effects of D2 agonists by striatal injection on excessive release of dopamine and hyperactivity induced by Bay K 8644 in rats

We investigated by means of behavioral and neurochemical studies the effects of either D(1) or D(2) agonist on excessive dopamine release and hyperactivity induced by the microinjection of Bay K 8644, and an L-type Ca(2+) channel stimulant, into the rat caudate putamen under a novel environmental condition. Hyperactivity (locomotor activity and rearing counts) and significant increases in extracellular dopamine levels induced by Bay K 8644 were concomitantly observed. D(1) agonist, SKF81297, administered into the caudate putamen did not block Bay K 8644-induced hyperactivity measured by monitoring both animal activity and increases in extracellular dopamine levels detected by microdialysis. Pretreatment with the D(2) agonists, bromocriptine, talipexole and pramipexole, into the caudate putamen significantly blocked Bay K 8644-induced hyperactivity for 45 min after Bay K 8644 administration, although the single administration of these agonists significantly potentiated locomotor activity and rearing behavior. Furthermore, these agonists significantly suppressed Bay K 8644-induced extracellular dopamine levels. Our results indicate that these D(2) agonists (1) act on postsynaptic neuronal D(2) receptors under conditions of normal or low dopamine release in the caudate putamen, and (2) act on presynaptic D(2) receptors (autoreceptors) when excessive levels of dopamine are released or hyperdopamine neuronal activity is induced. Consequently, the effect of D(2) agonists in the clinical treatment of Parkinson's disease may be due to stimulation of postsynaptic D(2) receptors rather than presynaptic autoreceptors.

Quantitative determination of OH radical generation and its cytotoxicity induced by TiO(2)-UVA treatment

Titanium dioxide (TiO(2)) has been reported to produce OH radical under ultraviolet-A (UVA) irradiation and to induce cytotoxicity. Various crystal forms and sizes of TiO(2) with UVA irradiation from OH radical generation was analysed spin trapping-X band (electron-spin resonance (ESR) spectroscopy. The amount of OH radical was determined with ESR signal intensity of the adducts in which OH radical was trapped with the spin-trapping reagent dimethyl pyrroline-N-oxide (DMPO). The formation of OH radicals varied in both crystal size and form of TiO(2). Irradiation of the anatase form of TiO(2) produced large numbers of OH radical in TiO(2) and UVA in a dose-dependent manner, but rutil form (90 nm in size) showed less OH radical generation. The crystal size had large influence on OH radical generation, but the optimum size for the OH radical generation was different between both forms. The UVA absorption spectrum of TiO(2) differed in regard to crystal size and form of TiO(2), but no relation was observed between UVA absorbency and OH radical formation. The cytotoxicity of TiO(2)-UVA irradiation was determined against Chinese hamster ovary (CHO) cells and a significant relationship was obtained between the cytotoxicity and the OH generation. Measurement of the amount of OH radical production by UVA irradiation with ESR is needed to clarify the effect of crystal form or sizes of TiO(2) on OH radical production and cytotoxicity.

Toxicity assessment of 255 chemicals to pure cultured nitrifying bacteria using biosensor

The bioassay has been attracting attention as a method of toxicity assessments of micropollutants in the environment. In this study, we report the characteristics (selectivity and sensitivity) of the nitrifying bacteria biosensor for 255 kinds of chemicals as a model of chemical contaminant in the environment and the results of evaluation of mixed samples of several substances. In the nitrifying bacteria respiration inhibition test using the biosensor, 56 chemicals were detected. It was found that this biosensor is especially sensitive to seven chemicals that have a thiocarbonyl functional group (>C=S), such as a thioamide group of thiocarbamate group. These chemicals are considered to specifically inhibit AMO by chelation of copper. The samples consisted of a mixture of seven types of anilines that inhibit respiration in the bacteria, a mixture of five types of chlorophenols, and a mixture of eight types of substances that contain thiocarbonyl groups were examined. All of the mixed samples inhibited the respiration of the nitrifying bacteria more than 10% by the inhibition rate, and observed a synergistic effects of the substances in the samples.

Development of rapid in vitro assay for oxidative liver injury and its application to 230 chemicals

Water environments are thought to be polluted with thousands of synthetic chemicals and biproducts involving persistent organic pollutants and endocrine disrupters, and their human and ecological impacts are causing serious anxiety. Many bioassays have been undertaken to evaluate the hazardous impacts of toxic chemicals dissolved in water. Reactive Oxygen Species (ROS) are well known to be involved in the toxicity of various chemicals. ROS are mostly generated in liver and cause oxidative damage to DNA, lipids and proteins, resulting in the failure of cellular functions. In order to develop an in vitro bioassay system to estimate ROS induced liver toxicity by chemicals, we investigated the lipid peroxidation, liver cell injury, and genotoxicity using the human hepatocellular carcinoma cell line, Hep-G2 (ATCC HB 8065), and applied it to 230 chemicals.

Microdosimetry of epithermal neutron field at the Kyoto University reactor

Microdosimetric spectra were measured in order to gain the microdosimetric parameters of some epithermal neutron fields. Changes in dose mean lineal energy YD as a function of depth of heavy water showed a trend of softening with heavy water of the beam. The neutron absorbed dose was obtained by using the frequency mean lineal energy. Results show good agreement with measurements with the activation method using gold foil. This study demonstrated how microdosimetric parameters change in radiation quality as a function of heavy water depth.

Estrogen-like effect and cytotoxicity of chemical compounds

Luciferase assay, cytotoxicity test and protein quantitative analysis were performed after the exposure of chemical compounds to MVLN cells that are utilized to detect the endocrine disrupting activity. These consequences indicate that the concentration is different between the estrogen receptor mediated proliferation of breast cancer cells and the estrogen receptor mediated transcription by chemical compounds.

8-oxo-dGTPase, which prevents oxidative stress-induced DNA damage, increases in the mitochondria from failing hearts

BACKGROUND

Reactive oxygen species (ROS) can cause an oxidative modification of nucleotides, such as 8-oxo-7,8-dihydrodeoxyguanosine triphosphate (8-oxo-dGTP), which can lead to defects in DNA replication. The misincorporation of 8-oxo-dGTP into DNA is prevented by 8-oxo-dGTPase, which hydrolyzes 8-oxo-dGTP into 8-oxo-dGMP. The changes in this defensive system have not yet been examined in failing hearts, in which the generation of ROS increases.

METHODS AND RESULTS

Myocardial infarction (MI) was created in mice by ligating the left coronary artery. Four weeks later, the left ventricle was dilated and contractility was diminished on echocardiography. The generation of ROS, as measured by electron spin resonance spectroscopy with 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, increased in the noninfarcted left ventricle from MI mice. The formation of thiobarbituric acid-reactive substances also increased in the mitochondria from MI mice. 8-Oxo-dGTPase was detected in the mitochondrial fractions isolated from MI mice using a Western blot analysis with an antibody to its human homologue (hMTH1). Immunohistochemistry showed positive staining for hMTH1 was localized in the cardiac myocytes.

CONCLUSIONS

The level of 8-oxo-dGTPase increased in the mitochondria isolated from post-MI hearts as oxidative stress increased, thus suggesting that a preventive mechanism is activated against ROS-induced DNA damage. As a result, 8-oxo-dGTPase is considered a useful marker of mitochondrial oxidative stress in heart failure.

Increased base change mutations at G:C pairs in Escherichia coli deficient in endonuclease III and VIII

Various types of mutation induced by oxidative DNA damage, induced by hydrogen peroxide and riboflavin photosensitization, were determined in Escherichia coli (E. coli) mutants deficient in endonuclease III (endo III) and endonuclease VIII (endo VIII). The majority of hydrogen peroxide-induced and spontaneous mutations consisted of G:C to A:T and to T:A base changes, shown on the mutation assay system by a reversion at a specific site of the lacZ gene. Base changes were also localized at G:C pairs in the mutation of the supF gene, induced by riboflavin photosensitization, which specifically yields 7,8-dihydro-8-oxoguanine (8-oxoG). G:C to T:A and to C:G transversions dominated in both mutants. These results suggest that endo III and endo VIII are involved in the repair of oxidative lesions of guanine.