Parkinson Disease: Ito Y

Ito Y, Akao Y, Shimazawa M, Seki N, Nozawa Y, Hara H. · Department of Biofunctional Molecules, Gifu Pharmaceutical University, Gifu, Japan. · CNS Drug Rev. · Pubmed #17894646 No free full text.

Abstract: Lignin is a durable aromatic network polymer that is second only to cellulose in natural abundance. Lig-8, a lignophenol derivative from bamboo lignin, is a highly potent neuroprotectant. It protects human neuroblastoma cells (SH-SY5Y) from hydrogen peroxide (H2O2)-induced apoptosis by preventing caspase-3 activation via either caspase-8 or caspase-9. It exerts this antiapoptotic effect by protecting mitochondrial membrane permeability from damage by H2O2 or the peripheral benzodiazepine receptor ligand PK11195. Lig-8 has been also shown to scavenge the reactive oxygen or nitrogen species in vitro. Furthermore, lig-8 suppresses apoptosis induced by oxygen-glucose deprivation, tunicamycin (endoplasmic reticulum [ER]-stress inducer), or proteasome inhibitor in pheochromocytoma cells. In addition, in vivo, lig-8 reduced intravitreal N-methyl-D-aspartate-induced retinal damage (decreases in retinal ganglion cells and inner plexiform layer thickness) in mice. Lig-8 prevents neuronal damage partly by inhibiting excessive endoplasmic reticulum stress. In this article, we review the protective effects of lig-8 against apoptosis induced by various stimuli. Apoptosis is an active, energy-dependent process through which living cells initiate their own death. It can be induced by a variety of physiological and pharmacological stimuli. Apoptotic cell death is associated with neurodegenerative disorders such as Alzheimer, Parkinson, or Huntington disease as well as glaucoma. We believe that the elucidation of the mechanism of antiapoptotic action of lig-8 may help in finding new approaches to the treatment of neurodegenerative disorders.

Suzuki M, Hirai T, Ito Y, Sakamoto T, Oka H, Kurita A, Inoue K. · Department of Neurology, The Jikei University School of Medicine, 3 25 8, Nishi-Shinbashi, Minato-ku, Tokyo, 105 8461, Japan. · J Neurol Sci. · Pubmed #17826796 No free full text.

Abstract: We report a case of antecollis, or dropped head with Parkinson's disease (PD) induced by pramipexole, a nonergot dopamine agonist. An 80-year-old woman presented with progressively severe neck flexion, which developed within a few weeks of taking pramipexole at 3 mg/day. She had a disturbed gait and complained of difficulty in daily activity because of restricted visual field and severe stooped posture. Surface EMG showed disproportionate tonus of the neck muscles but needle EMG of the neck muscles was normal. Withdrawal of pramipexole resulted in immediate improvement; the patient could keep the head in natural position and walk normally. Pramipexole-induced antecollis may be serious, but is a reversible dystonia in patients with PD. Clinicians should be aware of such complication.

Suzuki M, Kurita A, Hashimoto M, Fukumitsu N, Abo M, Ito Y, Urashima M, Inoue K. · Department of Neurology, The Jikei University School of Medicine, 3-25-8, Nishi-Shinbashi, Minato-ku, Tokyo 105-8461, Japan. · J Neurol Sci. · Pubmed #16199056 No free full text.

Abstract: BACKGROUND: Iodine-123-labeled metaiodobenzylguanidine (123I-MIBG) myocardial scintigraphy has been used to evaluate cardiac sympathetic denervation in Lewy body disease (LBD) including Parkinson's disease (PD) and dementia with Lewy bodies (DLB). Patients with LBD had marked reductions in cardiac MIBG accumulation, indicative of severe impairment of the cardiac sympathetic nervous systems. However, the differences in scintigraphy between DLB and PD have not been determined. OBJECTIVE: To compare cardiac sympathetic function in early disease stage measured with 123I-MIBG scintigraphy between DLB and PD. METHODS: 123I-MIBG myocardial scintigraphy was performed in 22 patients with early-stage DLB, 41 patients with early idiopathic PD and 15 normal control subjects who were matched for age and disease duration. The heart-to-mediastinum (H/M) ratio was calculated. RESULTS: 123I-MIBG uptake of the myocardium was significantly lower in patients with early DLB than in controls. The mean value of H/M ratio in patients with DLB was significantly lower than those in patients with PD, independent of the Hoehn and Yahr stage. CONCLUSIONS: Our findings suggest that cardiac sympathetic function in DLB is severely impaired even in the early disease stage.

Okada Y, Ito Y, Aida J, Yasuhara M, Ohkawa S, Hirokawa K. · Department of Clinical Pathology, Tokyo Metropolitan Tama Geriatric Hospital, Tokyo, Japan. · Pathol Int. · Pubmed #15363036 No free full text.

Abstract: Lewy bodies (LB) are characteristic pathological findings for idiopathic Parkinson disease, and extracranial organs have also been known to exhibit these structures. Clinically, the possible involvement of LB in cardiac dysfunction has attracted attention based on the findings of studies using [123I] metaiodobenzyl guanidine (MIBG) scintigraphy. The purpose of the present study was to investigate the possible involvement of LB in heart disease. A total of 40 autopsy cases consisting of Lewy body disease and Parkinson syndrome were examined. The former were cases with intracranial LB regardless of clinical symptoms, and the latter were cases with parkinsonism but without intracranial LB. The presence of heart disease or an atrial arrhythmia and the results of an MIBG scintigraphy study were clinically examined. The sinoatrial node was examined microscopically and immunohistochemically. The results showed that heart disease and atrial arrhythmia complications were more frequent in cases with Lewy body disease than in cases with Parkinson syndrome and that LB were frequently found in extracranial organs, especially in the sinoatrial nodal ganglion, in cases with Lewy body disease. In the current report, we hypothesized that neuronal changes involving LB in the sinoatrial nodal ganglion may cause arrhythmia and ischemic heart disease as a result of vasoconstriction.

Ito Y, Fujita M, Shimada S, Watanabe Y, Okada T, Kusuoka H, Tohyama M, Nishimura T. · Division of Tracer Kinetics, Biomedical Research Center, Osaka University Medical School, Japan. · Synapse. · Pubmed #10029235 No free full text.

Abstract: Early diagnosis of Parkinson's disease (PD) is important for the potential application of neuroprotective therapies. The purpose of this study was to assess the detection of the early changes of PD by either imaging the dopamine transporter (DAT) or uptake of L-3,4-dihydroxyphenylalanine (L-DOPA). An early to advanced stage model of PD was induced in rats by stereotaxic injection of 1-10 microg 6-hydroxydopamine (6-OHDA) into the substantia nigra pars compacta. Using adjacent sections of the same animals, the binding of [I-125]beta-CIT, which labels DAT and the uptake of [C-14]L-DOPA, were evaluated 4 weeks after induction of the lesion. Any decrease in dopaminergic neurons was evaluated by in situ hybridization histochemistry (ISH) by detection of DAT mRNA-positive neurons. In addition, the expression levels of DAT, dopa decarboxylase (DDC), and vesicular monoamine transporter (VMAT2) in each neuron were studied with ISH. Our results show a decrease in both [I-125]beta-CIT binding and [C-14]L-DOPA uptake in parallel with a decrease in DA neurons from early to advanced stage models of PD. The decrease in [C-14]L-DOPA uptake was smaller than that in [I-125]beta-CIT binding in the same animal (P < 0.0001). Expression levels of DAT, DDC, and VMAT2 mRNAs were also decreased with the progression of the disease. Although ISH failed to detect the origin of the discrepancy between [I-125]beta-CIT and [C-14]L-DOPA levels, it was concluded that [C-14]L-DOPA levels underestimated the decrease of dopaminergic neurons and that [I-125]beta-CIT levels more precisely reflected the decrease.

Oka H, Yoshioka M, Morita M, Onouchi K, Suzuki M, Ito Y, Hirai T, Mochio S, Inoue K. · Department of Neurology, Jikei University School of Medicine, Tokyo, 105-8461, Japan. · Neurology. · Pubmed #17909159 No free full text.

Abstract: OBJECTIVE: To examine the relation between the results of cardiac (123)I-meta-iodobenzylguanidine (MIBG) scintigraphy and cardiovascular autonomic function in Lewy body disease (LBD). METHODS: The subjects were 66 patients with LBD, 44 of whom had Parkinson disease (PD), 10 PD with dementia (PDD), and 12 dementia with Lewy bodies (DLB); 20 age-matched healthy subjects were studied as controls. Cardiovascular autonomic function was evaluated on the basis of cardiac (123)I-MIBG uptake, cardiovascular autonomic response on the Valsalva maneuver (VM), and systolic blood pressure (SBP) response on head-up tilt table (HUT) testing. RESULTS: Patients with LBD had reduced cardiac (123)I-MIBG uptake, cardiovascular autonomic response on the VM, and SBP response on HUT testing as compared with controls. Cardiac (123)I-MIBG uptake and cardiovascular autonomic function in PDD and DLB were severely impaired as compared with those in PD. Cardiac (123)I-MIBG uptake in LDB was not significantly related to vasomotor sympathetic function, baroreceptor reflex gain, cardiac parasympathetic function, or the changes in SBP on HUT testing. Cardiac (123)I-MIBG uptake was, however, significantly related to the blood pressure overshoot in phase IV of the VM. CONCLUSION: Cardiac (123)I-meta-iodobenzylguanidine uptake clinically reflects cardiac sympathetic dysfunction in Lewy body disease.

Oka H, Yoshioka M, Onouchi K, Morita M, Mochio S, Suzuki M, Hirai T, Ito Y, Inoue K. · Department of Neurology, Jikei University School of Medicine, 3-25-8, Nishi-shinbashi, Minato-ku, Tokyo, Japan. · Brain. · Pubmed #17673498 links to  free full text

Abstract: Clinical symptoms of Parkinson's disease (PD) include not only motor distress but also autonomic dysfunction. Orthostatic hypotension (OH) occurs in one-fifth to one-half of all patients with PD. We examined the relation of this type of hypotension to clinical features and cardiovascular parameters such as cardiac 123I-meta-iodobenzylguanidine (MIBG) uptake, changes on the Valsalva maneuver, and plasma norepinephrine concentrations on head-up tilt-table testing (HUT). We performed HUT in 55 patients with PD and divided them into two groups according to the presence or absence of OH, defined as a drop in systolic blood pressure (SBP mmHg) by 20 mmHg or more on standing. We evaluated cardiac sympathetic function by 123I-MIBG scintigraphy and assessed cardiovascular autonomic function by using the Valsalva maneuver in all subjects. We also performed HUT, 123I-MIBG scintigraphy and assessed cardiovascular autonomic function by using the Valsalva maneuver in 20 controls. The results of HUT showed that 20 patients had OH and 35 did not. The hypotension was associated with gender, older age, longer disease duration, posture and gait instability phenotype, low mini-mental state examination scores and visual hallucinations. Cardiac 123I-MIBG uptakes were lower in patients with OH. SBP fell further during early second phase in patients with OH than in patients without the condition and their increase in SBP during the late second phase and the overshoot of SBP during the fourth phase were lower. The blood pressure recovery time during the fourth phase on the Valsalva maneuver was longer in patients with OH than in those without OH. There was, however, no association between the fall in SBP on HUT and baroreflex sensitivity or the plasma norepinephrine concentrations, adjusted by age, disease duration, disease severity and dopaminergic medication using multiple regression analyses. Patients without OH already had impaired cardiac sympathetic and baroreceptor reflex functions as early abnormalities of cardiovascular autonomic control. Our results suggest that pronounced vasomotor and cardiac sympathetic dysfunction is the primary cause of OH in PD, although baroreceptor reflex failure may also make a minor contribution. It was unclear whether vasomotor and cardiac sympathetic dysfunction in patients with PD was caused primarily by the impairment of preganglionic or postganglionic lesions.