Biomedical subjects

Atsushi Mori

Publications and source records attributed to Atsushi Mori.

17 recordsLinked to original sources

PubMed2006

Monte Carlo simulation of crystal-fluid coexistence states in the hard-sphere system under gravity with stepwise control.

Monte Carlo (MC) simulations were performed for hard spheres (with diameter sigma and mass m) placed between well-separated upper and lower hard walls. A periodic boundary condition was imposed in the horizontal direction. The system was exposed to the gravitational field with the acceleration due to gravity g. After preparing a melt as the initial state, g was increased stepwise up to mgsigma/k(B)T(identical with g(*))=1.5 or 2.0 with an increment Deltag(*) = 0.1; k(B)T is the temperature multiplied by Boltzmann's constant. We maintained g(*) at each value for 2.0 x 10(5) MC cycles. The transition of the system into a metastable state such as a polycrystalline state due to trapping phenomena was successfully avoided. A monotonic increase and subsequent saturation were observed for the development of the crystalline region formed at the bottom of the system. The development of this region accompanied a shrinkage of the defective (or less ordered) crystalline region that was formed between the bottom region and the fluid phase. As the development of the bottom region almost saturated, the defective region grew upward again.

Journal Article↗

PubMed2006

Age-related severity of dopaminergic neurodegeneration to MPTP neurotoxicity causes motor dysfunction in C57BL/6 mice.

This study investigated the influence of advancing age on dopaminergic neuronal degeneration induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) intoxication from the perspective concerning the relationship between dopaminergic function and behavioral features. Young (10 weeks) and older (14-15 months) C57BL/6 mice were treated with one to four injections of MPTP (20 mg/kg at 2h intervals). Although young mice showed no mortality in either MPTP treatment, older mice exhibited mortality from only two injections of MPTP during the experimental period. An extensive dopaminergic cell loss was found in both the striatum and substantia nigra of older mice given one and two injections of MPTP with marked decrease in striatal dopamine (DA) levels, but not young mice. We also found a behavioral change in the tail suspension test associated with the extent of decrease in striatal DA levels in MPTP-treated older mice, but not in young mice. These results clearly present age-related vulnerability to MPTP neurotoxicity in C57BL/6 mice and strongly support our previous report showing that there is a critical threshold level of the decrement in striatal DA contents causing motor dysfunction in this mouse model of Parkinson's disease.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed2006

Cystic clear cell tumor of borderline malignancy of the ovary lacking fibromatous components: report of two cases and a possible new histological subtype.

BACKGROUND: All of the ovarian borderline clear cell tumors ever reported had, without exception, an adenofibromatous pattern. CASE: We report two cases of borderline cystic clear cell tumor of the ovary without apparent invasive lesions or adenofibromatous components. CONCLUSION: This is the first report of cystic clear cell tumors of borderline malignancy, indicating a possible new histological subtype.

Adenocarcinoma, Clear Cell↗

PubMed2006

H MRS identifies lactate rise in the striatum of MPTP-treated C57BL/6 mice.

Mitochondrial dysfunction has been implicated in the death of nigrostriatal dopaminergic neurons in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated experimental models of Parkinson's disease (PD). Here we utilized proton magnetic resonance spectroscopy ((1)H MRS) to identify changes in energy metabolism in the striatum of MPTP-treated C57BL/6 mice. Remarkable increases in lactate/creatine (Lac/Cr) ratio were observed at 2 h and then quickly returned to about the basal level by 7 h after injection of MPTP. Neurochemical and Western blot analyses revealed that dopamine contents and protein levels of tyrosine hydroxylase and dopamine transporter in the striatum were profoundly decreased at 3 days after MPTP treatment. Pretreatment with deprenyl, a monoamine oxidase B inhibitor, or GBR-12909, a dopamine uptake inhibitor, almost completely attenuated both the increases in striatal Lac/Cr ratio and the subsequent loss of dopaminergic nerve terminals in MPTP-treated mice. The present study indicates that (1)H MRS is a sensitive measure of biochemical alterations of the brain in a mouse model of PD, and further shows that the increases in striatal Lac/Cr ratio induced by MPTP may be associated with mitochondrial energy crisis, followed by dopaminergic neurotoxicity.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed2006

Omission of mediastinal lymph node dissection in lung cancer: its techniques and diagnostic procedures.

To reduce or omit a mediastinal lymph node dissection in the patients with clinical stage I non-small cell lung cancer (NSCLC), several authors examined the prevalence of metastatic sites of lymph nodes. Because lymphatic drainage usually heads for the upper mediastinum in upper lobe cancer and for the lower mediastinum in lower lobe cancer, upper and lower mediastinal lymph node dissection could be reduced in lung cancers of lower lobe and upper lobe. By using sentinel node (SN) navigation surgery, it is possible to omit mediastinal lymph node dissection. Radiological findings are also useful to determine reduction of mediastinal lymph node dissection. In clinical stage Ia adenocarcinomas that show ground glass opacity (GGO) findings on computed tomography (CT) or negative for fluorodeoxyglucose accumulation on positron emission tomography (PET), mediastinal lymph node dissection can be omitted, because these types of adenocarcinomas rarely metastasize to the lymph nodes. By using these procedures, mediastinal lymph node dissection can be reduced or omitted with little risk of local recurrence.

Carcinoma, Non-Small-Cell Lung↗

PubMed2005

Neural mechanisms underlying motor dysfunction as detected by the tail suspension test in MPTP-treated C57BL/6 mice.

Contradictory data on behavioral changes in MPTP-treated C57BL/6 mice have been reported, even though the toxin-treated mice have been widely used for non-clinical studies as an in vivo model of Parkinson's disease (PD). We found that the duration of immobility in the tail suspension test (TST) was significantly increased in MPTP-treated C57BL/6 mice as compared with control mice without a significant change in the locomotor activity (LA). Dopamine (DA) contents and protein levels of tyrosine hydroxylase and dopamine transporter in the striatum were profoundly decreased in the toxin-treated mice. These behavioral and neurobiochemical changes were almost completely inhibited by a pretreatment with deprenyl, a monoamine oxidase-B inhibitor. The stimulation of dopaminergic neurotransmission induced by L-dopa or a dopamine D2 receptor agonist ameliorated the increase in immobility time. Threshold level of striatal DA that produced the increase in immobility time in MPTP-treated mice was estimated to be between 11 and 27% of control level. We concluded that the increase in immobility time in the TST was induced by the nigrostriatal dopaminergic degeneration and was thought to be a consequence of motor dysfunction in this mouse model of PD.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed2005

Differential effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine in the olfactory bulb and the striatum in mice.

The present study was undertaken to examine whether 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) causes damage of dopaminergic glomerular cells of the olfactory bulb (OB) in C57BL/6 mice. At 3 days after MPTP treatment, dopamine level in the striatum and the OB decreased to 13% and 84% of the control mice, respectively. While a small reduction of tyrosine hydroxylase protein level was observed in the OB of MPTP-treated mice, dopamine transporter (DAT) was undetectable at the protein level in this region. These results indicate that the DAT protein level could account for resistance of the OB to the Parkinsonism-inducing toxin.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed2004

Analyses of the partition coefficient, log P, using ab initio MO parameter and accessible surface area of solute molecules.

To analyze the log P(sol/w) values (sol: n-octanol or chloroform, w: water) in the framework of the molecular orbital (MO) procedure, we selected solute descriptors such as the solvation energy difference between aqueous and organic solvent phases and the "surface" area of solute molecules to which water molecules are accessible. The solvation energy of solute molecules in their minimum free-energy conformation was calculated using the ab initio self-consistent reaction field-MO method with the conductor-like screening model. The experimentally measured log P(sol/w) value of various solutes except for those of amphiprotics was shown to be analyzable reasonably well by the MO model with additional descriptors for the hydrogen-bonding patterns in the solute-solvent interactions.

1-Octanol↗

PubMed2004

Anterior cruciate ligament injuries among wakeboarders: a case report.

No previous cases of anterior cruciate ligament (ACL) injuries sustained during wake-boarding have been reported. We report on a case involving an ACL injury sustained during wakeboarding. A 27-year-old man sustained an injury while attempting a wakeboarding maneuver(a heel-side back roll, consisting of a jump and simultaneous roll toward the heel side). He failed to complete his roll before landing, striking the water with his right shoulder foremost, then plunging underwater. When his wakeboard struck the water, his left knee was sprained by the rotational force exerted by the board. The patient was diagnosed with an isolated ACL injury and underwent arthroscopic ACL reconstructive surgery. The board used in wakeboarding is wider and subject to greater water resistance than that used in water skiing. The feet of the wakeboarder are firmly attached by binding boots to a board, laterally with respect to the direction of motion, impeding easy separation of the board from the feet in the event of a fall. Thus, wakeboarding conditions would appear to put wakeboarders at particular risk for ACL injuries. These conditions need be assessed from a medical perspective in order to devise ways to minimize the risk of such injuries.

Adult↗

PubMed2003

1-methyl-4-phenylpyridinium (MPP+) decreases mitochondrial oxidation-reduction (REDOX) activity and membrane potential (Deltapsi(m)) in rat striatum.

Mitochondrial dysfunction has long been implicated in the death of nigrostriatal dopaminergic neurons in Parkinson's disease (PD) and its experimental models. Here we further analyzed changes in the mitochondrial oxidation-reduction (REDOX) activity and membrane potential (Deltapsi(m)) of striatal synaptosomes after the infusion of 1-methyl-4-phenylpyridinium (MPP+) into rat striatum. MPP+ (40 nmol) treatment produced decreases in mitochondrial REDOX activity and Deltapsi(m) at 18 h, as measured by fluorometric analysis with both Alamar blue and JC-1 (5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolyl-carbocyanine iodide) dyes. At this time point, tyrosine hydroxylase (TH) and dopamine transporter (DAT) protein levels were not altered, but both decreased at 7 days after MPP+ (40 nmol) infusion. Both measures of mitochondrial dysfunction induced by MPP+ (40 nmol) at 18 h were attenuated, at least in part, by pretreatment with a selective dopamine uptake inhibitor GBR-12909 (1-(2-(bis(4-fluorophenyl)methoxy)ethyl)-4-(3-phenylpropyl) piperazine). In addition, GBR-12909 partially attenuated MPP+ (40 nmol)-caused a loss of striatal nerve terminal as indicated by decreases in TH and DAT immunoreactivities as well as dopamine and its metabolites levels. The present study indicates that decreases in mitochondrial REDOX activity and Deltapsi(m) may play a role in MPP+ -induced dopaminergic neurotoxicity, and further provides that improvement of mitochondrial dysfunction may be a better way to slow progressive dopaminergic neurodegeneration commonly associated with PD.

1-Methyl-4-phenylpyridinium↗

PubMed2003

The effect of pulmonary rehabilitation in patients with post-tuberculosis lung disorder.

STUDY OBJECTIVES: Although the benefit of pulmonary rehabilitation (PR) has been demonstrated for patients with COPD, the benefit for patients with non-COPD lung disorders is still unclear. In the present study, we compared the effect of PR on patients with post-tuberculosis (TBC) lung disorders and patients with COPD. DESIGN: We performed a prospective nonrandomized open trial over a 9-week period. PATIENTS AND METHODS: Thirty-two patients with post-TBC lung disorders (thoracoplasty, 25 patients; mean [+/- SD] age, 71 +/- 5 years; FEV(1), 0.84 +/- 0.29 L) and 32 age-matched and FEV(1)-matched COPD patients were enrolled in the study. First, we compared the exercise tolerance between groups using a 6-min walking test. Next, we trained the patients using a 9-week outpatient PR program. We assessed improvement using clinical dyspnea ratings, a daily activity score, and the results of a 6-min walking test. RESULTS: When age and FEV(1) were matched, the distance covered during the 6-min walking test did not differ between the groups. After rehabilitation, significant improvement was observed in both the post-TBC group and the COPD group in terms of Medical Research Council dyspnea grade, transition dyspnea index, activity score, and 6-min walking distance (42 m [p < 0.01] vs 47 m [p < 0.01], respectively). The magnitudes of the improvement in these parameters were comparable between the groups. CONCLUSIONS: PR is as beneficial in post-TBC lung disorder patients as in COPD patients if the severity of the disability is similar.

Aged↗

PubMed2003

[The effects of pulmonary rehabilitation in elderly patients].

Pulmonary rehabilitation is one of the most important treatment modalities for patients with chronic lung disease. To determine the effects of an outpatient pulmonary rehabilitation program for the older members (aged 77 +/- 3 years; seniors) of an elderly patient group with chronic lung disease, we prospectively compared the degrees of improvement of lung function, dyspnea, daily activities and exercise tolerance (6-minute walking distance) after a 9-week rehabilitation program in 27 seniors with chronic lung disease (COPD 18, post-tuberculosis lung disorders 8, lung fibrosis 1; %FEV1 50.9 +/- 17.1%) with that in disease- and %FEV1-matched younger members (aged 70 +/- 2 years; juniors; %FEV1 49.3 +/- 16.1%) of the elderly patient group. All patients performed supervised weekly outpatient exercise and education activities for 9 weeks and a home exercise regimen. Assessments were made before and after the program. Twenty-three of the seniors and 25 of the juniors completed the program. There was no significant difference in the withdrawal rates between these groups. Although lung function and blood gas data had not changed significantly after rehabilitation, the clinical symptoms and the 6-minute walking exercise improved significantly in both groups (Baseline Dyspnea Index focal score: +1.3 +/- 0.9 in the seniors and +0.6 +/- 0.9 in the juniors: 6-minute walking distance: +/- 52 m and +/- 62 m, respectively) and the improvement of the Baseline Dyspnea Index focal score was significantly greater in the seniors than in the juniors. We observed the patients after they had followed the program for 2,000 days and found that the continuation ratio of rehabilitation in the seniors was far inferior to that in the juniors (continuation ratios for 1.2 and 3 years in the seniors were 50.5, 18.0 and 0%, respectively, and in the juniors, 79.5, 66.2 and 61.5%). We concluded that, although the senior elderly patients could benefit from the pulmonary rehabilitation program, it is difficult to maintain this benefit for many years.

Activities of Daily Living↗

PubMed2002

The effects of age and sex on chondroitin sulfates in normal synovial fluid.

OBJECTIVE: To examine how age and sex influence chondroitin sulfates (CS) in normal synovial fluid, we measured the concentrations of chondroitin 6-sulfate (C6S), chondroitin 4-sulfate (C4S), and hyaluronic acid (HA) in healthy subjects of different ages. METHODS: Synovial fluid samples were obtained from 82 healthy volunteers, ages 20-79 years. RESULTS: The concentrations of CS and HA and the C6S:C4S ratio varied with age. Their values were highest between 20 and 30 years of age, and thereafter they showed a tendency to decrease. Statistically, the C6S concentration and the C6S:C4S ratio at ages 60-70 years were significantly lower than those at 20-30 years of age. There was also a clear between-sex difference, in which the CS concentrations and the C6S:C4S ratio in women were significantly lower than those in men (P = 0.0003 for C6S, P = 0.02 for C4S, P = 0.002 for C6S:C4S ratio). In sharp contrast, little between-sex difference was found in the HA concentration. In multiple regression analysis, age correlated strongly with the C6S concentration and the C6S:C4S ratio (r = -0.521 and r = -0.617, respectively), weakly with the C4S concentration (r = -0.202), and moderately with the HA concentration (r = -0.483). Sex showed a weak correlation with the concentrations of C6S and C4S and the C6S:C4S ratio (r = 0.307, r = 0.225, and r = 0.237, respectively), and little correlation was seen between sex and the HA concentration. CONCLUSION: The CS concentrations and the sulfation patterns in normal synovial fluid vary with age and sex, and these physiologic variations need to be taken into account when using synovial fluid CS as markers for arthritic conditions.

Adult↗

PubMed2002

Alteration of methamphetamine-induced striatal dopamine release in mint-1 knockout mice.

Mint-1, which is also called as X11 or mammalian Lin10, protein has been implicated in the synaptic vesicle exocytosis and the targeting and localization of synaptic membrane proteins. Here, we established mint-1 gene knockout (mint-1 KO) mice and investigated vesicular and transporter-mediated dopamine (DA) release evoked by high K(+) and methamphetamine (METH), respectively. Compared with wild-type control, high K(+)-evoked striatal DA release was attenuated, but not significantly, in the KO mice as measured by microdialysis method. The METH-induced DA release was significantly attenuated in the KO mice. In addition, METH-induced stereotypy was also significantly attenuated in the KO mice. Mint-1 KO mice showed more sensitive and prominent behavioral response to an approaching object as compared with wild-type mice. These results suggest that mint-1 protein is involved in transporter-mediated DA release induced by METH.

Adaptor Proteins, Signal Transducing↗

PubMed2002

Intracerebral adenosine infusion improves neurological outcome after transient focal ischemia in rats.

Second Institute of New Drug Research, Otsuka Pharmaceutical Co., Ltd., Tokushima, Japan In order to elucidate the role of adenosine in brain ischemia, the possible protective effects of adenosine on ischemic brain injury were investigated in a rat model of brain ischemia both in vitro and in vivo. Exogenous adenosine dose-dependently rescued cortical neuronal cells from injury after glucose deprivation in vitro. Adenosine (1 mM) also significantly reduced hypoglycemia/hypoxia-induced glutamate release from the hippocampal slice. In a rat model of transient middle cerebral artery occlusion (MCAO), extracellular adenosine concentration was increased immediately after occlusion, and then returned to the baseline by 30 min after reperfusion. Adenosine infusion through a microdialysis probe into the ipsilateral striatum (1 mM adenosine, 2 microl min(-1), total 4.5 h from the occlusion to 3 h after reperfusion) showed a significant improvement in the neurological outcome, and about 25% reduction of infarct volume, although the effect did not reach statistical significance, compared with the vehicle-treated group at 20 h after 90 min of MCAO. These results demonstrated the neuroprotective effect of adenosine against ischemic brain injury both in vitro and in vivo, suggesting the possible therapeutic application of adenosine regulating agents, which inhibit adenosine uptake or metabolism to enhance or maintain extracellular endogenous adenosine levels, for stroke treatment.

Adenosine↗

PubMed2002

Prediction of the 1-octanol/H2O partition coefficient, log P, by ab initio MO calculations: hydrogen-bonding effect of organic solutes on log P.

To predict the 1-octanol/H2O partition coefficient, log P, based on molecular structures, we calculated the solvent accessible surface area and the solvation energy difference of 166 organic molecules between 1-octanol and water environments with the ab initio molecular orbital self-consistent reaction field method, and then analyzed the relationships among the measured log P values with these two structural quantities by multiple linear-regression analyses. Physicochemically meaningful correlations were obtained, suggesting that non-hydrogen bonding and hydrogen-acceptor molecules behave similarly to each other in partitioning, but that hydrogen-donor molecules behave differently from the former molecules. The results provide a new computational approach for predicting log P.

Journal Article↗

PubMed1996

A Stereochemical Study of the Isomerization of Cyclopropyl Ethers to Allyl Ethers Catalyzed with Zinc Iodide.

Optically active 1-alkoxybicyclo[4.1.0]heptane was converted using zinc iodide as a catalyst to 2-alkoxymethylidenecyclohexane without loss of optical purity. The mechanism of the isomerization was studied using a stereochemical analysis of the product and deuterium labeling experiments. The results indicated that the isomerization takes place through a stepwise mechanism that involves an attack of zinc iodide on the cyclopropane ring to cause ring opening, followed by an intramolecular 1,2-hydride shift with liberation of the zinc iodide.

Journal Article↗