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1.
Ann Oncol ; 27(12): 2242-2250, 2016 12.
Article in English | MEDLINE | ID: mdl-27765756

ABSTRACT

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.


Subject(s)
Antibodies, Monoclonal/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Carcinoma, Non-Small-Cell Lung/drug therapy , Neoplasm Recurrence, Local/drug therapy , Adult , Aged , Antibodies, Monoclonal/adverse effects , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Bevacizumab , Carboplatin/administration & dosage , Carcinoma, Non-Small-Cell Lung/pathology , Carcinoma, Non-Small-Cell Lung/radiotherapy , Cisplatin/administration & dosage , Deoxycytidine/administration & dosage , Deoxycytidine/analogs & derivatives , Disease-Free Survival , Docetaxel , Female , Humans , Male , Middle Aged , Neoplasm Recurrence, Local/pathology , Neoplasm Recurrence, Local/radiotherapy , Neoplasm Staging , Nivolumab , Paclitaxel/administration & dosage , Pemetrexed/administration & dosage , Taxoids/administration & dosage , Gemcitabine
2.
Biofizika ; 60(1): 88-94, 2015.
Article in Russian | MEDLINE | ID: mdl-25868345

ABSTRACT

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.


Subject(s)
Lipid Bilayers/chemistry , Nitrogen Oxides/chemistry , Spin Labels , Electron Spin Resonance Spectroscopy/methods , Permeability
3.
Eur J Neurol ; 20(1): 205-7, 2013 Jan.
Article in English | MEDLINE | ID: mdl-22469332

ABSTRACT

BACKGROUND AND PURPOSE: The purpose of the present study was to investigate the prevalence and clinical characteristics of taste disorders in patients with myasthenia gravis (MG). METHODS: We studied 371 Japanese patients with MG (127 men and 244 women; mean age, 56.6±16.9years) consecutively evaluated between May and September 2010 in six neurological centers comprising the East Japan MG Study Group. Ninety-three patients (25%) had thymoma. We interviewed all patients to determine whether they had taste disorders during the clinical course of MG and then further evaluated the patients with MG, who reported having taste disorders, using a questionnaire. RESULTS: Taste disorders were observed in 16 (4.3%) of the 371 patients with MG. We concluded that taste disorders in 2.4% of patients with MG excluding other factors were associated with MG itself. All patients had thymoma with seropositivity for anti-acetylcholine receptor antibodies. Thymoma tended to be advanced, and four patients with Masaoka stage IVa required radiation therapy or chemotherapy. Five patients noticed taste disorders 2-3 months before the onset of MG. Sweet taste loss was more common than salty, bitter, and sour taste loss. CONCLUSIONS: This was the first systematic survey of taste disorders in patients with MG by a multicenter study. Taste disorders were more common in the present sample of patients with MG than in the general population.


Subject(s)
Cooperative Behavior , Myasthenia Gravis/complications , Myasthenia Gravis/epidemiology , Taste Disorders/complications , Taste Disorders/epidemiology , Adult , Aged , Female , Humans , Japan/epidemiology , Male , Middle Aged , Prevalence
4.
Curr Med Chem ; 20(3): 331-44, 2013.
Article in English | MEDLINE | ID: mdl-23157624

ABSTRACT

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.


Subject(s)
Mental Disorders/drug therapy , Microglia/drug effects , Neurotransmitter Agents/pharmacology , Psychiatry , Psychotropic Drugs/pharmacology , Animals , Humans , Microglia/metabolism , Neurotransmitter Agents/chemistry , Psychotropic Drugs/chemistry
5.
Mini Rev Med Chem ; 11(7): 565-74, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21699487

ABSTRACT

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.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Antipsychotic Agents/therapeutic use , Brain/drug effects , Microglia/drug effects , Schizophrenia/drug therapy , Anti-Inflammatory Agents/pharmacology , Antipsychotic Agents/pharmacology , Brain/metabolism , Brain/pathology , Cytokines/metabolism , Humans , Microglia/cytology , Microglia/metabolism , Receptors, Dopamine D2/metabolism , Schizophrenia/metabolism , Schizophrenia/pathology
6.
Radiat Res ; 170(1): 101-17, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18582156

ABSTRACT

Epidemiological data on the health effects of A-bomb radiation in Hiroshima and Nagasaki provide the framework for setting limits for radiation risk and radiological protection. However, uncertainty remains in the equivalent dose, because it is generally believed that direct derivation of the relative biological effectiveness (RBE) of neutrons from the epidemiological data on the survivors is difficult. To solve this problem, an alternative approach has been taken. The RBE of polyenergetic neutrons was determined for chromosome aberration formation in human lymphocytes irradiated in vitro, compared with published data for tumor induction in experimental animals, and validated using epidemiological data from A-bomb survivors. The RBE of fission neutrons was dependent on dose but was independent of the energy spectrum. The same RBE regimen was observed for lymphocyte chromosome aberrations and tumors in mice and rats. Used as a weighting factor for A-bomb survivors, this RBE system was superior in eliminating the city difference in chromosome aberration frequencies and cancer mortality. The revision of the equivalent dose of A-bomb radiation using DS02 weighted by this RBE system reduces the cancer risk by a factor of 0.7 compared with the current estimates using DS86, with neutrons weighted by a constant RBE of 10.


Subject(s)
Neutrons , Nuclear Weapons , Animals , Chromosome Aberrations/radiation effects , Dose-Response Relationship, Radiation , Female , Humans , Japan , Lymphocytes/metabolism , Lymphocytes/radiation effects , Male , Mice , Neoplasms/mortality , Rats , Relative Biological Effectiveness , Risk Assessment , Survivors
7.
Water Sci Technol ; 50(8): 97-102, 2004.
Article in English | MEDLINE | ID: mdl-15566192

ABSTRACT

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.


Subject(s)
Hydroxyl Radical/analysis , Hydroxyl Radical/chemistry , Ozone/chemistry , Phenols/chemistry , Water Purification/methods , Chlorophenols/chemistry , Electron Spin Resonance Spectroscopy , Evaluation Studies as Topic , Kinetics
8.
Curr Med Chem ; 10(17): 1759-64, 2003 Sep.
Article in English | MEDLINE | ID: mdl-12871120

ABSTRACT

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.


Subject(s)
Antioxidants/therapeutic use , Diabetic Angiopathies/drug therapy , NADPH Oxidases/antagonists & inhibitors , Animals , Antioxidants/metabolism , Diabetic Angiopathies/enzymology , Endothelium, Vascular/drug effects , Endothelium, Vascular/enzymology , Enzyme Activation/drug effects , Enzyme Inhibitors/therapeutic use , Glucose/pharmacology , Humans , NADPH Oxidases/metabolism , Protein Kinase C/antagonists & inhibitors , Protein Kinase C/pharmacology , Reactive Oxygen Species/metabolism
9.
Neuroscience ; 118(4): 1091-8, 2003.
Article in English | MEDLINE | ID: mdl-12732253

ABSTRACT

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.


Subject(s)
3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/pharmacology , Calcium Channel Agonists/pharmacology , Dopamine Agonists/pharmacology , Dopamine/metabolism , Hyperkinesis/metabolism , Neostriatum/drug effects , Receptors, Dopamine D2/agonists , 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester/antagonists & inhibitors , Animals , Behavior, Animal/drug effects , Dopamine Antagonists/pharmacology , Extracellular Space/drug effects , Extracellular Space/metabolism , Hyperkinesis/chemically induced , Male , Microdialysis/methods , Motor Activity/drug effects , Neostriatum/anatomy & histology , Neostriatum/metabolism , Rats , Rats, Wistar , Receptors, Dopamine D2/metabolism
10.
Toxicol In Vitro ; 16(5): 629-35, 2002 Oct.
Article in English | MEDLINE | ID: mdl-12206830

ABSTRACT

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.


Subject(s)
CHO Cells/drug effects , Hydroxyl Radical , Photosensitizing Agents/toxicity , Titanium/toxicity , Animals , CHO Cells/metabolism , CHO Cells/radiation effects , Cell Survival/drug effects , Cell Survival/radiation effects , Cricetinae , Crystallization , Dose-Response Relationship, Drug , Dose-Response Relationship, Radiation , Electron Spin Resonance Spectroscopy , Hydroxyl Radical/metabolism , Photosensitizing Agents/radiation effects , Spin Trapping , Titanium/radiation effects , Ultraviolet Rays
11.
Radiat Prot Dosimetry ; 99(1-4): 383-5, 2002.
Article in English | MEDLINE | ID: mdl-12194334

ABSTRACT

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.


Subject(s)
Linear Energy Transfer , Neutrons , Radiometry/methods , Deuterium Oxide , Japan , Sensitivity and Specificity , Thermodynamics , Universities
12.
Water Sci Technol ; 46(11-12): 331-5, 2002.
Article in English | MEDLINE | ID: mdl-12523774

ABSTRACT

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.


Subject(s)
Nitrosomonas , Water Pollutants, Chemical/toxicity , Aniline Compounds/toxicity , Biological Assay , Chlorophenols/toxicity , Nitrosomonas/physiology , Toxicity Tests
13.
Water Sci Technol ; 46(11-12): 337-41, 2002.
Article in English | MEDLINE | ID: mdl-12523775

ABSTRACT

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.


Subject(s)
Lipid Peroxidation , Liver/pathology , Oxidative Stress , Reactive Oxygen Species , Water Pollutants, Chemical/toxicity , Biological Assay/methods , Carcinoma, Hepatocellular/pathology , DNA Damage , Humans , Liver Neoplasms/pathology , Tumor Cells, Cultured
14.
Water Sci Technol ; 46(11-12): 363-6, 2002.
Article in English | MEDLINE | ID: mdl-12523779

ABSTRACT

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.


Subject(s)
Genes, Reporter , Luciferases/pharmacology , Receptors, Estrogen/drug effects , Water Pollutants, Chemical/toxicity , Biological Assay/methods , Breast Neoplasms/pathology , Endocrine System/drug effects , Humans , Luciferases/biosynthesis , Receptors, Estrogen/physiology , Toxicity Tests/methods , Transcriptional Activation , Tumor Cells, Cultured
15.
Circulation ; 104(24): 2883-5, 2001 Dec 11.
Article in English | MEDLINE | ID: mdl-11739300

ABSTRACT

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.


Subject(s)
DNA Damage , DNA Repair Enzymes , Mitochondria, Heart/metabolism , Myocardial Infarction/metabolism , Oxidative Stress/physiology , Phosphoric Monoester Hydrolases/metabolism , Animals , Blotting, Western , Echocardiography , Heart Ventricles/pathology , Heart Ventricles/physiopathology , Hemodynamics , Humans , Jurkat Cells , Lung/growth & development , Male , Mice , Organ Size , Reactive Oxygen Species/metabolism , Thiobarbituric Acid Reactive Substances/metabolism
17.
Circulation ; 104(2): 134-6, 2001 Jul 10.
Article in English | MEDLINE | ID: mdl-11447074

ABSTRACT

BACKGROUND: The generation of reactive oxygen species (ROS) is enhanced in the failing myocardium. We hypothesized that ROS were also increased in the limb skeletal muscles in heart failure. Methods and Results-- Myocardial infarction (MI) was created in mice by ligating the left coronary artery. After 4 weeks, the left ventricle was dilated and contractility was diminished by echocardiography. Left ventricular end-diastolic pressure was elevated after MI in association with an increase in lung weight/body weight and the presence of pleural effusion. The generation of ROS in the limb muscles, including the soleus and gastrocnemius muscles, which were excised after MI, was measured by electron spin resonance spectroscopy with 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl (hydroxy-TEMPO). Overall, generation was increased, but it was attenuated in the presence of dimethylthiourea or 4,5-dihydroxy-1,2-benzenedisulfonic disodium salt in the reaction mixture, indicating increased generation of hydroxyl radicals originating from superoxide anion. Thiobarbituric acid-reactive substance formation was also increased in muscles after MI. Mitochondrial complex I and III activities were both decreased after MI, which may have caused the functional uncoupling of the respiratory chain and ROS production. Antioxidant enzyme activities, including superoxide dismutase, catalase, and glutathione peroxidase, were comparable between groups. CONCLUSIONS: Skeletal muscle in post-MI heart failure expressed an increased amount of ROS in association with ROS-mediated lipid peroxidation. This supports the hypothesis that oxidative stress may cause (at least in part) skeletal muscle dysfunction in heart failure.


Subject(s)
Disease Models, Animal , Heart Failure/metabolism , Muscle, Skeletal/metabolism , Myocardial Infarction/metabolism , Reactive Oxygen Species/metabolism , Animals , Catalase/metabolism , Echocardiography , Electrocardiography , Electron Spin Resonance Spectroscopy , Exercise Tolerance , Glutathione Peroxidase/metabolism , Heart Failure/etiology , Hemodynamics , Lipid Peroxidation , Male , Mice , Myocardial Infarction/complications , Organ Size , Spin Labels , Superoxide Dismutase/metabolism , Thiobarbituric Acid Reactive Substances/metabolism , Ventricular Dysfunction, Left/diagnosis , Ventricular Dysfunction, Left/etiology
18.
J Neurochem ; 77(6): 1425-32, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11413227

ABSTRACT

In the present study, we investigated whether or not the amyloid-beta protein (Abeta) peptide itself spontaneously generates free radicals using electron spin resonance (ESR) spectroscopy while also monitoring the aggregational state of Abeta and Abeta-induced cytotoxicity. The present results demonstrated a four-line spectrum in the presence of both Abeta40 and Abeta42 with Ntert-butyl-alpha-phenylnitrone (PBN), but not in the presence of PBN alone in phosphate-buffered saline (PBS). The fact that the four-line spectrum obtained for the Abeta/PBN in PBS was completely abolished in the presence of the iron-chelating agent Desferal demonstrated the observed four-line spectrum to be iron-dependent. The present study also revealed that either Abeta40 or Abeta42 with PBN in phosphate buffer (PB) did not produce any definite four-line spectrum. Both a thioflavine-T (Th-T) fluorometric assay and circular dichroism (CD) spectroscopy showed the amyloid fibril formation of Abeta in PBS to be much higher than that of Abeta in PB. Moreover, Abeta-induced cytotoxicity assays showed Abeta incubated in PBS to be more cytotoxic than that incubated in PB. These results thus suggest that Abeta-associated free radical generation is strongly influenced by the aggregational state of the peptides.


Subject(s)
Alzheimer Disease/metabolism , Amyloid beta-Peptides/metabolism , Free Radicals/metabolism , Amyloid beta-Peptides/toxicity , Animals , Benzothiazoles , Cell Survival/drug effects , Circular Dichroism , Electron Spin Resonance Spectroscopy , Fluorescent Dyes , Free Radicals/analysis , Humans , PC12 Cells , Rats , Thiazoles
19.
J Cardiovasc Pharmacol ; 37(6): 725-33, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11392469

ABSTRACT

Dahl salt-sensitive (DS) rats fed high-salt diet exert compensated left ventricular (LV) hypertrophy and eventually develop heart failure. Oxidative stress has been shown to be involved in myocardial remodeling and failure and thus might play an important role in this transition from hypertrophy to failure. We measured the amount of reactive oxygen species (ROS) in the myocardium from DS rats by using electron spin resonance spectroscopy with 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl (hydroxy-TEMPO) and also examined the effects of chronic angiotensin-converting enzyme (ACE) inhibition on the transition. We divided DS rats (5 weeks old, 150-200 g) into three groups: low-salt (0.3% NaCl) diet for 10 weeks (LS group), high-salt (8% NaCl) diet for 10 weeks (HS-10+V group), and high-salt diet and cilazapril (10 mg/kg body weight per day) started after 5 weeks of high-salt diet and maintained for 5 weeks (HS-10+Cil group). Systolic blood pressure (mm Hg) was significantly elevated in the HS-10+V (229+/-5) and HS-10+Cil (209+/-5) groups compared with the LS group (141+/-2). The amount of myocardial ROS was not changed after 5 weeks of high-salt diet, but significantly increased in HS-10+V rats compared with LS rats, and was abolished in the HS-10+Cil group. HS-10+V rats exerted the clinical signs of heart failure, including increased lung weight and pleural effusion, associated with LV hypertrophy and LV cavity dilatation. In the HS-10+Cil group, signs of heart failure were significantly attenuated despite only a modest reduction in systolic blood pressure (-20 mm Hg). The progression of LV failure after hypertrophy in high-salt-loaded DS hypertensive rats was associated with increased myocardial ROS, and ACE inhibitor could prevent this transition from compensated hypertrophy to failure.


Subject(s)
Angiotensin-Converting Enzyme Inhibitors/pharmacology , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Heart Failure/drug therapy , Oxidative Stress/drug effects , Reactive Oxygen Species/metabolism , Ventricular Dysfunction, Left/physiopathology , Animals , Blood Pressure/drug effects , Blood Pressure/physiology , Cilazapril/pharmacology , Cilazapril/therapeutic use , Electron Spin Resonance Spectroscopy/methods , Heart Failure/metabolism , Hypertrophy, Left Ventricular/drug therapy , Hypertrophy, Left Ventricular/metabolism , Male , Oxidative Stress/physiology , Piperidines/metabolism , Rats , Rats, Inbred Dahl , Sodium Chloride, Dietary/administration & dosage , Survival Rate , Ventricular Dysfunction, Left/metabolism
20.
Neurosci Lett ; 304(1-2): 65-8, 2001 May 18.
Article in English | MEDLINE | ID: mdl-11335056

ABSTRACT

In the present study, we investigated whether or not the Abeta peptide itself spontaneously generates free radicals using electron spin resonance (ESR) spectroscopy while also observing the Abeta fibril formation by negative stain electron microscopy. The present results demonstrated a four-line spectrum in the presence of Abeta(1-40) with N-tert-butyl-alpha-phenylnitrone (PBN) but not in the presence of PBN alone in phosphate-buffered saline. Negative stain electron microscopy has shown that Abeta peptides after 96 h of incubation showed more amyloid-like fibrils than those after 72 h of incubation while the four-line spectrum obtained by ESR spectroscopy attained a maximum intensity after 72 h of incubation and thereafter its intensity immediately decreased during the 4-day incubation period. These results were also supported by a thioflavine-T (Th-T) fluorometric assay. In conclusion, the present results suggest that Abeta-associated free radical generation is correlated with Abeta fibril formation while its generation is only observed transiently during the process of Abeta fibril formation.


Subject(s)
Amyloid beta-Peptides/metabolism , Peptide Fragments/metabolism , Amyloid beta-Peptides/ultrastructure , Benzothiazoles , Electron Spin Resonance Spectroscopy/methods , Fluorescent Dyes , Fluorometry/methods , Free Radicals/metabolism , Microscopy, Electron/methods , Negative Staining/methods , Peptide Fragments/ultrastructure , Thiazoles
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