Search PubMed⌕ Search

Biomedical subjects

Masaya Oda

Publications and source records attributed to Masaya Oda.

At least 19 recordsLinked to original sources
PubMed2006

Heterogeneous factors in dementia with Parkinson's disease: IMP-SPECT study.

BACKGROUND: Nature of the dementing process in Parkinson's disease, and particularly its relationship with Alzheimer's disease, diffuse Lewy body disease or frontal dementia remains controversial. OBJECTIVE: We hypothesize that origins of dementia in Parkinson's disease are heterogeneous, so we compared cortical regional cerebral blood flow (rCBF) between Parkinson's disease patients with and without dementia. PATIENTS: Forty consecutive patients with Hoehn-Yahr stage III or IV Parkinson's disease were used (13 patients had dementia (PDD group), and 27 patients had no dementia (PDND group)). RESULTS: There were significant rCBF reductions in the left parietal association cortex and left frontal association cortex in PDD. Multiple logistic regression analysis demonstrated that only rCBF of the left frontal association cortex was significant. PDD patients were divided into three groups according to rCBF patterns: frontal hypoperfusion group, Alzheimer's disease-like group, and diffuse Lewy body disease-like group. CONCLUSIONS: Controversial study results involving PDD patients may be mainly due to heterogeneity in dementing processes in Parkinson's disease.

Aged↗
PubMed2006

Disruptions of the fornix fiber in Parkinsonian patients with excessive daytime sleepiness.

BACKGROUND: Although excessive daytime sleepiness (EDS) in Parkinson's disease (PD) has received a great deal of attention, the underlying pathological mechanism of its development and the relative contributions of brain function to this process are poorly understood. OBJECTIVE: To compare the fractional anisotropy (FA) values of PD patients with EDS and those without EDS, and to investigate the mechanism of EDS in this disease. METHODS: Eleven patients with PD with EDS, 26 patients with PD without EDS and 10 controls participated in this study. Patients with an ESS (Epworth Sleepiness Scale) score >or=10 were defined as having EDS. The FA values of 5 regions of interest (ROI) including the fornix were compared between the three groups. RESULTS: There were significant reductions in FA values of the fornix fiber in patients with EDS. ESS scores had significant correlation with FA values of the fornix. CONCLUSIONS: Our study is the first to find the fornix fiber degeneration in PD patients with EDS. These results indicate that fornix dysfunction may have some correlations with EDS in PD.

Aged↗
PubMed2006

Wisconsin Card Sorting Test and brain perfusion imaging in Parkinson's disease.

BACKGROUND: Few imaging studies investigated frontal dysfunctions in Parkinson's disease. OBJECTIVES: We investigated relationships between Wisconsin Card Sorting Test (WCST) and brain perfusion in patients with non-demented Parkinson's disease. METHODS: Patients were divided into two groups according to WCST score: (1) CA (number of category achieved) or=3. We performed three-dimensional stereotactic surface projection and volume of interest analysis using (123)I-IMP scintigraphy. RESULTS: Hypoperfusions of the bilateral posterior cingulate, rostrodorsal prefrontal, and left frontopolar cortices were shown in CA<or=2 group, with the left cingulate and right rostrodorsal prefrontal cortices showing prominent hypoperfusion. CA and PE (perseverative errors) scores significantly correlated with perfusion of the left posterior cingulate cortex. PE score also correlated with perfusion of the right rostrodorsal prefrontal cortex. CONCLUSION: Data indicated participations of various regions in task achievement. Careful interpretation of WCST scores is required.

Aged↗
PubMed2006

Does cardiac metaiodobenzylguanidine (MIBG) uptake in Parkinson's disease correlate with major autonomic symptoms?

OBJECTIVES: To compare MIBG (metaiodobenzylguanidine) uptake between Parkinson's disease patients with and without autonomic symptoms to investigate meanings of MIBG scintigraphy and correlations between autonomic symptoms and MIBG uptake. METHODS: Forty consecutive patients with Hoehn-Yahr III or IV Parkinson's disease and 12 controls were enrolled. We compared cardiac MIBG uptake between patients with and without orthostatic hypotension. Similar comparisons were performed for constipation and bladder dysfunction. RESULTS: MIBG uptake did not significantly correlate with age, disease duration, Hoehn-Yahr stage, Unified Parkinson's Disease Rating Scale (UPDRS) motor score or levodopa equivalent daily doses. There were no significant correlations between orthostatic hypotension/constipation and cardiac MIBG uptake. Only bladder symptoms significantly correlated with MIBG uptake. CONCLUSION: Meanings of MIBG uptake abnormalities in Parkinson's disease and relationship between MIBG uptake and clinical parameters remain to be resolved in future studies.

3-Iodobenzylguanidine↗
PubMed2006

Minor depression and brain perfusion images in Parkinson's disease.

Depression is common in individuals with Parkinson's disease. However, the pathophysiology of depression in Parkinson's disease remains obscure. Here we compared brain perfusion images of Parkinson's disease patients with and without depression to investigate correlations between depression and brain perfusion images in Parkinson's disease. We divided 40 consecutive patients with Parkinson's disease into two groups: patients with minor depression (n = 22) and patients without depression (n = 18). We then compared brain perfusion images between the two groups. As a result, hypoperfusion of the left superior and inferior frontal gyrus was demonstrated in depressed patients. These results were partially in agreement with previous studies on de novo and parkinsonian major depression. We could not conclude on whether pathophysiological mechanisms differed between de novo depression and depression with Parkinson's disease, and between major and minor depressions.

Aged↗
PubMed2006

Hypoperfusion of the visual pathway in parkinsonian patients with visual hallucinations.

Little is known about the developing mechanisms of visual hallucinations in Parkinson's disease. This study aimed to investigate perfusion changes in parkinsonian patients with visual hallucinations using n-isopropyl-p-[123I]iodoamphetamine ([123I]IMP) single photon emission computed tomography imaging. A total of 70 consecutive patients, including 31 patients with visual hallucinations, and 39 patients without hallucinations, participated in this study. Patients with severe cognitive impairment (Mini-Mental State Examination score < 20), nonvisual hallucinations, or confusion were excluded. We compared brain perfusion changes between the two groups. We found that hallucinatory patients had significant perfusion reductions in the bilateral inferior parietal lobule, inferior temporal gyrus, precuneus gyrus, and occipital cortex compared to nonhallucinatory patients. These results suggested that hypoperfusion of the visual pathway was closely related to visual hallucinations in Parkinson's disease.

Aged↗
PubMed2006

Hypoperfusion of the auditory and prefrontal cortices in Parkinsonian patients with verbal hallucinations.

We examined patients with and without auditory hallucinations, using n-isopropyl-p-[123I]iodoamphetamine single photon emission computed tomographic imaging. We assessed verbal hallucinations in the present study: patients with nonverbal auditory hallucinations were excluded. A total of 11 patients with verbal and visual hallucinations and 17 patients with visual hallucinations only were enrolled. Patients with both verbal and visual hallucinations revealed significant hypoperfusion in the bilateral prefrontal cortex and right superior temporal gyrus compared to patients with visual hallucinations only. There were no significant hyperperfusion in patients with verbal plus visual hallucinations. These results may support the release hallucination theory in verbal hallucinations of Parkinson's disease, although another explanations may be more appropriate and further studies are required.

Aged↗
PubMed2006

Excessive daytime sleepiness in Parkinson disease: a SPECT study.

STUDY OBJECTIVES: The underlying pathologic mechanism of excessive daytime sleepiness (EDS) in Parkinson disease and the relative contributions of brain function to this process are poorly understood. We compared brain perfusion images between patients with Parkinson disease and EDS and those without EDS using n-isopropyl-p-1231 iodoamphetamine single photon emission computed tomography. DESIGN: Clinical study. SETTING: Sumitomo Hospital. PATIENTS: Thirteen patients with Parkinson disease with EDS (EDS group) and 27 patients with Parkinson disease without EDS (no-EDS group) were studied. Whether or not each case had EDS was determined according to the response to the Epworth Sleepiness Scale: patients with an Epworth Sleepiness Scale score > or = 10 were included in the EDS group, and patients with an Epworth Sleepiness Scale score < or = 9 were included in the no-EDS group. MEASUREMENTS AND RESULTS: There were significant hypoperfusions in the left parietal and temporal association cortex in the EDS group. In the multivariable logistic regression model, attention and decreased regional cerebral blood flow of the left parietal association cortex and right caudate and increased regional cerebral blood flow of the right thalamus were the independent and significant factors. CONCLUSIONS: The cortical hypofunction relative to hyperfunction of the brain stem may relate to EDS in Parkinson disease. This is the first imaging study about EDS in Parkinson disease, and further studies are required.

Aged↗
PubMed2006

HTLV-I-associated peripheral neuropathy with smoldering-type adult T-cell leukemia.

BACKGROUND: Peripheral neuropathy with adult T-cell leukemia/lymphoma (ATLL) has seldom been reported. REVIEW SUMMARY: A 69-year-old woman with smoldering-type ATLL presented with pain and muscle weakness of the bilateral upper and lower limbs and gait disturbance. Anti-human T lymphotropic virus type I antibody was positive in the serum but negative in the cerebrospinal fluid. Magnetic resonance imaging (MRI) showed no abnormal signals in the spinal cord or brain. Nerve conduction studies disclosed severe peripheral neuropathy. Sural nerve biopsy disclosed both axonal degeneration and demyelinated fibers, and marked perivascular inflammatory infiltrates mainly consisting of T lymphocytes without malignant changes were seen. Steroid therapy was markedly effective, and the patient became able to walk without assistance. CONCLUSIONS: This is the first reported case of ATLL and peripheral neuropathy in which a nerve biopsy was performed. In our patient, the marked perivascular inflammatory infiltrates mainly consisting of T lymphocytes suggested either immune-mediated vasculitis or tumor invasion. Further studies are needed.

Aged↗
PubMed2006

The endothelin-1 receptor-mediated pathway is not involved in the endothelin-1-induced defenestration of liver sinusoidal endothelial cells.

BACKGROUND/AIMS: We previously reported that endothelin (ET)-1 may be involved in the contraction of hepatic sinusoidal endothelial fenestrae (SEF). Rho has emerged as an important regulator of the actin cytoskeleton and consequently cell morphology. To clarify the role of ET receptors [endothelin A receptor (ETAR) and endothelin B receptor (ETBR)] in ET-1-induced defenestration, we studied the size of hepatic SEF under various experimental conditions. METHODS: Liver sinusoidal endothelial cells (LSECs) isolated from rat livers by collagenase perfusion were cultured and divided into four groups: control, ET-1 (10(-6) -10(-10) M)-treated, ET-1+selective ETAR antagonist (BQ610)-treated and ET-1+ETBR antagonist (BQ788)-treated groups. SEF morphology was observed by scanning electron microscopy. Protein expressions of ETAR and ETBR, Rho A and phosphorylated myosin light-chain kinase were analyzed by Western blotting. F-actin stress fiber formation was observed by confocal microscopy. Active Rho was measured by Ren's modification. Intracellular free Ca2+ concentration ([Ca2+]i) was measured by fluorescence digital imaging using fura-2 AM by Aqua cosmos. RESULTS: ET-1 induced a reduction in the number and size of SEF. ETAR antagonist pretreatment inhibited defenestration induced by low ET-1 concentrations (10(-8) -10(-10) M), whereas ETBR antagonist pretreatment did not block defenestration at low to high ET-1 concentrations (10(-6) -10(-10) M). F-actin stress fibers, Rho A levels and phosphorylated myosin light-chain kinase levels remained the same in various treatments. Active Rho was not detected in control and various treatments. ET-1 did not increase [Ca2+]i. Western blot showed prominent ETBR but scarce ETAR protein expression in LSECs. CONCLUSIONS: The present findings demonstrated that ETBR- and ETAR-induced contractile mechanisms are not involved in ET-1-induced defenestration, and that Rho is also not activated. Therefore, ET-1 induces hepatic defenestration by mechanisms other than receptor-mediated contraction.

Actins↗
PubMed2006

Frontal assessment battery and brain perfusion image in Parkinson's disease.

The objective was to compare brain perfusion image using 3-dimensional stereotactic surface projection analysis of N-isopropyl-p-123I iodoamphetamine single photon emission computed tomography between Parkinson's disease patients with a high frontal assessment battery score and those with a low frontal assessment battery score. Thirty nondemented patients with Parkinson's disease were studied. Patients were divided into 2 groups: a high-scoring group whose frontal assessment battery score was 12 or more and a low-scoring group whose frontal assessment battery score was 11 or less. The high-scoring group included 21 patients, and the low-scoring group included 9 patients. They underwent N-isopropyl-p-123I iodoamphetamine single photon emission computed tomography, and we analyzed the data by the 3-dimensional stereotactic surface projection method. Results showed that left inferior parietal lobule and left supramarginal gyrus perfusion of the low-scoring group were significantly decreased compared with the high-scoring group. It is concluded that patients with Parkinson's disease may have frontal lobe dysfunction, but the decreased frontal assessment battery score may be caused not by progressed frontal lobe dysfunction but by parietal lobe dysfunction added to their preexisting frontal lobe impairment.

Aged↗
PubMed2006

Impaired visual acuity as a risk factor for visual hallucinations in Parkinson's disease.

Pathophysiology of hallucinations in Parkinson's disease is poorly understood. This study investigated relationships between visual hallucinations and visual acuity. Twenty-six consecutive patients with Parkinson's disease participated in this study. Patients were divided into two groups: patients with visual hallucinations (VH group) and those without visual hallucinations (no-VH group). Unaided and corrected eyesight was evaluated in all patients, and if frequent use of prescription glasses or contact lenses was involved, eyesight using these lenses was also measured as the patient's own best eyesight. If a patient did not use prescription glasses or contact lenses, the patient's own best eyesight was defined as the unaided eyesight. Multivariate regression analysis demonstrated that agonist use and best eyesight were different after the backward elimination method. Visual hallucinations were closely related not to uncorrected eyesight or unaided eyesight but to the patient's best eyesight. It is suggested that impaired visual acuity is a risk factor for visual hallucinations.

Aged↗
PubMed2006

Encephalopathy and severe neuropathy due to probable systemic vasculitis as an initial manifestation of mixed connective tissue disease.

We described a 69-year-old woman with neurological manifestations due to mixed connective tissue disease (MCTD). The patient demonstrated subacute cognitive decline, seizure and gait disturbance with no connective tissue manifestation. She had been diagnosed with dementia at another hospital, later in our hospital, serological examinations disclosed high titers of anti-RNP antibody. Cognitive dysfunction in this patient was dramatically ameliorated by steroid therapy. Three months later, she developed edema of the hands, synovitis and acrosclerosis. The patient was finally diagnosed as having MCTD. We emphasized MCTD as a rare cause of "treatable dementia".

Aged↗
PubMed2006

Regulatory mechanisms of hepatic microcirculatory hemodynamics: hepatic arterial system.

This article reviews authors' recent studies on hepatic microcirculation with special reference to hepatic arterial system. It is concluded that: (1) Hepatic arterial blood pours into the hepatic sinusoid indirectly via the anastomosis between the terminal hepatic arteriole (THAo) and the portal venule (PVn), and directly through the THAo or the capillaries derived from the arterial capillary network around the bile duct in the portal tract; (2) The steep blood pressure gradient between the THAo and the sinusoid is considered to be maintained not only by the relaxation and contraction of the "precapillary sphincter" at the end of the THAo, but also by the coordinated dilatation and contraction of two types of sinusoidal endothelial fenestrae (SEF) particularly around the portal tract (zone 1); (3) In the regulation of hepatic sinusoidal microcirculation, the hepatic arterial system may supplementarily provides a driving force to the sinusoidal blood flow for keeping it smooth and constant. The main regulators of the sinusoidal blood flow would be present in the portal venous system. The hepatic artery is essential for supplying oxygen to the sinusoidal blood as well as to the bile ducts, portal venules and nerves in the portal tract.

Arterioles↗
PubMed2006

Attenuating effect of Myakuryu on mesenteric microcirculatory disorders induced by ischemia and reperfusion.

Myakuryu (MR) is a newly developed herbal medicine composing Crataegue oinnatifida bge (COB), Panax notoginseng (PN) and Ginkyo biloba (GB). To examine the effectiveness of MR, we investigated its effects on rat mesenteric microcirculatory injury induced by ischemia/reperfusion (I/R). The mesenteric microcirculation of ileocecal portion of a male Wistar rat was observed through an inverted-type intravital microscope assisted with a charge-coupled devise (CCD) camera. Mesenteric I/R was conducted by a ligation of the mesenteric artery and vein (10 min) and subsequent release of the occlusion. We measured venular diameter, the number of adherent leukocytes, dihydrorhodamine 123 (DHR) fluorescence as an indicator of oxidative stress and mast cell degranulation, with or without MR extract (0.4 g/kg b.w.) via an orogastric tube 1 hr before I/R. The diameters of the observed mesenteric venules were not changed after the mesenteric I/R. MR had no effect on venular diameter. The leukocytes adhering to the post-capillary venular walls started just after reperfusion, and increased thereafter. The increased number of adherent leukocytes was significantly reduced by treatment with MR. DHR fluorescence ratio was significantly increased along the venular wall. MR attenuated the increased oxidation. The mesenteric I/R induced mast cell degranulation. The increase in mast cell degranulation was inhibited by MR. In conclusion, oral administration of MR attenuates I/R-induced microvascular damages in rat mesentery. MR has a therapeutic potential for prevention of I/R-related microvascular injury.

Animals↗
PubMed2006

Increased microvascular permeability in early stage of dextran sulfate sodium-induced colitis: its interaction with lansoprazole binding sites.

To clarify the microvascular changes and the effector sites of lansoprazole during the formation of colitis, the dextran sulfate sodium (DSS)-induced colitis was induced by the oral administration for 3 and 7 days. The alteration of the microvascular permeability was estimated by the intraaortic infusion of FITC-dextran. The effector sites of 3H-lansoprazole were examined by the intraaortic infusion of the radiolabelled compound and the autoradiographic procedure of water-soluble compounds. As a result, marked increase of the microvascular permeability was detected three days after DSS treatment near the inflammatory cells in the tip portion of the colonic mucosa. 3H-lansoprazole in the control rat colon was localized in the goblet cells, while in DSS-treated rats, 3H-lansoprazole was accumulated in the cytoplasm of the mesenchymal cells, and most of them coincided with polymorphonuclear leucocytes and macrophages.

2-Pyridinylmethylsulfinylbenzimidazoles↗