Drug discarding: a problematic therapeutic event in Parkinson's disease.
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Biomedical subjects
Publications and source records attributed to Tomoyoshi Kondo.
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We conducted a multicenter randomized, placebo-controlled double-blind parallel-group study in Japanese Parkinson's disease (PD) patients with wearing-off motor fluctuations to determine the clinical efficacy and safety of entacapone as an adjunct to concomitant treatment with levodopa and a dopa decarboxylase inhibitor (DCI). We randomized 341 patients to receive entacapone 100 or 200 mg or placebo per dose of levodopa/DCI for 8 weeks. The primary efficacy variable was on time change while awake, determined by patients' diaries. Mean baseline on time in each group was approximately 8 hours. Mean on time change at final assessment was 1.4 hours each for entacapone 100-mg and 200-mg groups and by 0.5 hours for the placebo group (P < 0.05). The two entacapone doses were equally efficacious. Adverse events occurred in 79 patients (69.9%) in placebo, 82 (72.6%) in 100 mg, and 98 (86.0%) in 200 mg. The most common adverse event with entacapone was an increase in dyskinesias. The overall safety profile was satisfactory in both entacapone groups. In conclusion, both entacapone 100 and 200 mg were equally effective in increasing on time of PD patients with wearing-off fluctuations, although the safety and tolerability profile appeared more favorable for the 100-mg dose.
We and other workers found markedly increased levels of proinflammatory cytokines and apoptosis-related proteins in parkinsonian brain. Although the pathogenesis of Parkinson's disease (PD) remains enigmatic, apoptosis might be involved in the degeneration of dopaminergic neurons in PD. To investigate the possible presence of other inflammatory cytokines and/or apoptosis-related protein, the levels of p53 protein, interferon-gamma, and NF-kappaB were measured for the first time in the brain (substantia nigra, caudate nucleus, putamen, cerebellum, and frontal cortex) from control and parkinsonian patients by a highly sensitive sandwich enzyme-linked immunosorbent assay. The p53 protein level in the caudate nucleus was significantly higher in parkinsonian patients than in controls (P<0.05), whereas this protein in the substantia nigra, putamen, and cerebral cortex showed no significant difference between parkinsonian and control subjects. The interferon-gamma level was significantly higher in the nigrostriatal dopaminergic regions (substantia nigra, caudate nucleus, and putamen) in parkinsonian patients than in the controls (P<0.05), but was not significantly different in the cerebellum or frontal cortex between the two groups. In accordance with previous immunohistochemical analysis, the NF-kappaB level in the nigrostriatal dopaminergic regions was significantly higher in parkinsonian patients than in the controls (P<0.05). These data suggest that the significant increase in the levels of p53 protein, interferon-gamma, and NF-kappaB reflect apoptosis and the inflammatory state in the parkinsonian brain and that their elevation is involved in the degeneration of the nigrostriatal dopaminergic neurons.
Selegiline is used an adjunct to L-DOPA therapy. We investigated extracellular striatal dopamine (DA) level in awake rats treated with L-DOPA and/or selegiline using a microdialysis method. Rats given 10 mg/kg, i.p. per day selegiline for 7 days were administered with a single dose of 100 mg/kg, i.p. L-DOPA 0 (3 h), 1, 3, 7, 14, 21, or 28 days after the last selegiline treatment. Carbidopa was administered 0.5 h before L-DOPA administration. The significant increase in basal DA level before L-DOPA treatment persisted until 1 day after the last selegiline treatment, and the significant decrease in basal DOPAC level persisted for more than 28 days. Thus, selegiline affected DA catabolism for more than 28 days. Total monoamine oxidase (MAO) and MAO-B activities at day 0 decreased by 22% and 5.7%, respectively. The significant enhancement of L-DOPA-induced increase in DA level was observed until 3 days after the last selegiline treatment. Next, the effects of reducing L-DOPA dose by 25% were examined 3 h after the last selegiline treatment. A dose-dependent decrease in DA level was observed, indicating that DA level in selegiline-treated rats can be controlled by L-DOPA dose.
The neuropathological hallmark of idiopathic Parkinson's disease (PD) is dopaminergic neuron degeneration in the substantia nigra. However, it has been suggested that the neurodegenerative process initially may occur in the dorsal motor nucleus of the vagus (DMV). This implies that unidentified environmental toxins or neurotropic pathogens that is capable of passing the mucosal barrier of the gastrointestinal tract might affect the enteric nerve endings of the vagal neurons, possibly resulting in retrograde degeneration of the DMV. The present study aimed to evaluate the effects of proteasome inhibition of the intragastric nerve terminals of the DMV in rats. Following multiple injections of PSI, a selective proteasome inhibitor, or vehicle into the ventral wall of the stomach, the medulla oblongata was studied immunohistologically. In the DMV neurons of rats treated with PSI but not vehicle, alpha-synuclein-immunopositive intracytoplasmic inclusions and activated microglia were observed, predominantly in the left DMV. However, there was no significant loss of neurons. These results suggest that intragastric proteasome inhibition has a retrograde effect on DMV neurons but is insufficient to induce cell death, suggesting no causal linkage between inclusion body formation with proteasome inhibition and neuron death in the DMV. This might also implicate that Lewy body formation in the DMV in PD is possibly related to peroral invasion of environmental toxins that inhibit ubiquitin-proteasome system function.
The rodent model of harmaline-induced tremor has been widely used for experimental analysis of tremor. Activation of the olivocerebellar system plays a key role in tremor-generating mechanisms. One undetermined problem is whether there are species-specific differences in effects of harmaline. The present study investigated effects of harmaline on olivocerebellar systems of mice and rats. Systemic administration of harmaline, but not vehicle, produced generalized, high-frequency tremors in both types of rodents. Immunohistochemical studies revealed significant degeneration of Purkinje cells that was associated with activated microgliosis in the cerebellar cortex, following administration of harmaline in rats but not in mice. However, in mice but not rats, microgliosis was induced following administration of harmaline in the inferior olivary nucleus (ION), particularly in its caudal and medial subdivisions. Numbers of neurons in the mouse ION did not decrease, suggesting the possibility that microgliosis in ION might not be a simple neurotoxic effect. Presumably, differences in sensitivity of Purkinje cells between rats and mice may be related to differences in functional alterations in their respective olivocerebellar systems induced by harmaline. Recognition of these species-specific differences in the response of the olivocerebellar system to harmaline is an important consideration for experimental analysis of the rodent model of tremors.
The objective of this study was to investigate the effect of psychological adjustment to Parkinson's disease (PD) on the health-related quality of life (HRQL) in patients with this condition. One hundred eighty-three patients (77 male, 106 female; mean age, 65.8 years) were evaluated using the Parkinson's Disease Questionnaire (PDQ-39) and the Japanese version of the Nottingham Adjustment Scale (NAS-J). Multiple regression analysis was performed using age and sex as the explanatory variables. Comparisons were made of changes in R2 when severity and psychological adjustment subscales were added. In addition, comparisons were made of HRQL scores between groups with different levels of psychological adjustment. R2 was higher when psychological adjustment was included in comparison with severity in the some subscales (emotional well-being, stigma, social support, cognition, communication, and bodily discomfort). HRQL was significantly lower in the low-adjustment group compared with other groups. Psychological adjustment had a greater effect than severity of disease on several subscales in the HRQL of patients with PD. This finding suggests that, in addition to any suppression of the progression of symptoms, psychological intervention may also be effective in enhancing the HRQL of patients with PD.
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The "Parkinson's disease (PD) therapeutic guideline 2002 (PGL)" was published by Societas Neurologica Japonica in Japan. The guideline, which is based on evidence-based medicine (EBM), is a good reference for making medical decisions. Although physicians recognize the usefulness of the guideline, it is unclear whether PD patients know of the its existence. We performed a survey of 42 PD patients to evaluate their thoughts on the guideline. Sixty-seven percent of the patients had no knowledge of the existence of the PGL. However, after informing them of the existence of the PGL, 93% of the patients welcomed its publication. Forty-three percent of the patients wanted to read the PGL, although they expressed reservation that the PGL might be difficult to understand. Ninety-five percent of the patients answered that they would read the PGL if an easy-to read explanation manual were provided. However, none of the patients wanted an excessively strict obedience to the PGL. Eighty-three percent of the patients wanted a flexible application of the PGL to their own therapy. The PGL seems to have been accepted by the patients. A plain-language explanation manual of the PGL for PD patients, if published, would be helpful to the patients' understanding of PD therapy and to building cooperation between patients and physicians.
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This investigation was conducted to clarify the frequency and characteristics of ALS associated with extrapyramidal symptoms or signs in Wakayama prefecture. The questionnaires to survey ALS cases were mailed to all medical centers in Wakayama prefecture. A total of 252 cases were found to have motor neuron diseases. Among them, 204 cases fulfilled probable or definite according to El Escorial Criteria. In 10 of them, extrapyramidal signs were identified as follows: rigidity 50%, tremor 40% and akinesia 10%. Family history of ALS in these cases (20%) is higher than expected in usual ALS, and all of them are negative for SOD-1 mutation. Dementia and autonomic nervous symptoms were observed in several cases. Incidence of extrapyramidal signs in ALS resulted in 4.8%. The incidence of extrapyramidal signs is more frequent than expected by chance, suggesting that the degeneration of basal ganglia and/or substantia nigra may not be so rare in ALS.
Recent studies have suggested that defects in the ubiquitin-proteasome system (UPS) contribute to the etiopathogenetic mechanisms underlying dopaminergic neuronal degeneration in Parkinson's disease. The present study aims to study the effects of proteasome inhibition in the nerve terminals of nigrostriatal dopaminergic neurons in the substantia nigra pars compacta (SNpc). Following a unilaterally intrastriatal injection of lactacystin, a selective proteasome inhibitor, dopaminergic neurons in the ipsilateral SNpc progressively degenerated with alpha-synuclein-immunopositive intracytoplasmic inclusions. When lactacystin was administered at a high concentration, the striatum was simultaneously involved, and alpha-synuclein-immunopositive extracytoplasmic granules appeared extensively within the SN pars reticulata (SNpr). In addition, during the retrograde neuron degeneration in SN, the level of heme oxygenase-1 immunopositivity, an oxidative stress marker, was markedly increased in SNpc neurons. These results reveal that intrastriatal proteasome inhibition sufficiently induces retrograde dopaminergic neuronal degeneration with abundant accumulation of alpha-synuclein in the SN.
There are many reports indicating the existence of free radical adducts in the Parkinson's disease (PD) brain. However, levodopa may have two aspects in its characteristics, one is that levodopa is a source of free radicals in the pathogenesis of PD, and the other is that it is the precursor of the most efficient transmitter in dopaminergic neurons from the viewpoint of therapy. Dopamine (DA) supplemented by levodopa acts as a neural transmitter and as a dopaminergic receptor-mediated trophic agent. From studies using rodent models of parkinsonism, physical exercise potentially induces neurotrophins in the brain and protects or enhances the regeneration of nigrostriatal neurons. In our preliminary experiment, the potential effects of physical exercise on motor and psychological symptoms were observed, suggesting that physical exercise may, to a certain extent, modulate pathological conditions in the brain. On the basis of the above we conclude that DA supplementation in PD potentially increases the levels of neurotrophins in a dopaminergic receptor-mediated manner, and secondarily enhances mobility (physical exercise). In general, levodopa demand increases with disease progression, and physical therapy is more important in advanced stages. To obtain good outcomes of physical exercise, it is essential to maintain a good medical control, particularly at the advanced stages of PD. From these results, it can be speculated that levodopa exerts some neuroprotective effects as long as the dose is not excessively high.
We performed a pilot, crossover trial of zonisamide (ZNS) on essential tremor patients. Patients were randomly selected to start either ZNS or arotinolol treatment for 2 weeks. After a washout period, the patients were switched to an alternative drug. The assessment of tremor was carried out using the Fahn-Tolosa-Marin's clinical rating scale for tremor at baseline and 2 weeks after administration of each drug. There was a significant improvement after ZNS and arotinolol administration compared with the baseline. There was no significant difference in the antitremor effect between ZNS and arotinolol; however, ZNS was more effective for tremors of cranial nerve areas. Although the number of enrolled patients was limited in the present study, this open-label pilot study suggests that ZNS may have a therapeutic potential for essential tremor. A controlled trial of this drug in the future would be valuable.
We report a 32-year-old male patient with early-onset Parkinson's disease who exhibited abnormally increased writing activity. The patient displayed a disabling and pronounced increased writing activity, filling up to 10 pages or more per day in a notebook, and spending more than 12 h writing. In general, there was not much meaning in most of the writing, though there was a particular preference in tabulating the names of various sport and TV personalities. The writing activity gradually diminished following treatment with quetiapine hydrochloride, an anti-psychotic agent, at 25 mg/day. Although the pathophysiological mechanism underlying the increased writing is unclear, we believe it should be regarded as a form of punding or stereotyped behavior that has been suggested to be associated with dopaminergic therapy in Parkinson's disease.
In the 1960s, the incidence of amyotrophic lateral sclerosis (ALS) in the Kozagawa and Koza areas in Wakayama prefecture was much higher than that in other areas of the world. However, between 1980 and 1993, a gradual decrease in the incidence of the disease in these areas was reported. To ascertain whether the decreased incidence has persisted, we conducted a retrospective epidemiological study, and determined the average annual incidence of ALS in Wakayama prefecture from 1998 to 2002. The number of ALS cases encountered during the period was 134 (male 79, female 55). The crude average annual incidence in Wakayama prefecture in total was 2.50 (male 3.08, female 1.99) per 100,000. In the Kozagawa and Koza areas in Wakayama prefecture, where the senility rate rapidly increased in recent years, the average annual incidence of ALS in the present research was 10.56 (male 14.14, female 7.66). When the crude rate was standardized for both age and sex to the Japanese population in 1990, the expected value was 5.24 (male 7.34, female 3.18), which was lower than that of our previous survey. The prevalence in Wakayama prefecture at 31 December 2002 was 11.31 (male 14.40, female 8.53). In Kozagawa and Koza areas, the crude prevalence was 52.81 (male 70.70, female 38.28). These results indicated that the incidence of ALS in Wakayama prefecture, especially for females, steadily decreased compared to that in previous reports. However, a high incidence of ALS persisted among males in Wakayama prefecture, especially in the Kozagawa and Koza areas. Some environmental factors and gender specificity may be related to the decreased incidence of ALS in focus areas.
We investigated the FKBP12 and ryanodine receptor (RyR) immunoreactivity (IR) in the spinal cords of neurological controls and patients with motor neuron disease (MND). In the neurological controls, the cytoplasm of the spinal anterior horn neurons was stained with anti-FKBP12 antibodies and anti-RyR (type 1 and type 2) antibodies. In the MND cases, the residual neurons in the anterior horn of the spinal cord showed IR for RyR (type 1 and 2) antibodies, while weak IR for anti-FKBP12 antibodies was comparable to that of controls. The numbers of neurons recognized with the anti-FKBP 12 or anti-RyR (type 1 and 2) antibodies were counted in the anterior horn of spinal cords from the MND cases and neurological controls. Frequency of neurons stained with anti-FKBP 12 antibody was significantly decreased in the MND cases compared to that in controls (48.7+/-23.2%, 71.0+/-18.5%, respectively, mean+/-SD, p<0.0005). In the MND cases, numbers of normal-appearing, chromatolytic neurons showing IR to anti-FKBP12 (N19) antibody were significantly decreased compared to those in the controls. Immunoreactivities to anti-RyR antibodies (type 1and 2) in MND cases were present and there was no difference compared to those of the controls. Neurons in the spinal cord anterior horn of Kii-ALS cases with prolonged clinical duration were immunostained with both anti-FKBP12 and anti-RyR (type 1 and 2) antibodies similar to that in the controls. The anterior horn neurons of MND cases of short clinical duration showed absent IR to FKBP 12 antibody but present IR to RyR (type 1 and 2) antibodies. The present result suggests that FKBP12 IR was decreased in the MND cases with short clinical duration. RyR (type 1 and 2) is a major component of the intracellular calcium channel, which mediates calcium-induced calcium release. FKBP12, which is an endogenous ligand for RyR, stabilizes the calcium channels preventing calcium leakage in the absence of receptor activation. Imbalance between FKBP12 and RyR IR may play an important role in degeneration due to MND. Further study of the correlation between RyR and FKBP12 should contribute to clarifying the mechanisms of neurodegeneration in MND, including calcium-induced neuronal loss.
Nuclear localization of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is implicated in the process of apoptosis. To study the function of GAPDH, we expressed GAPDH C-terminally fused with or without nuclear localization signal (NLS) in SH-SY5Y and NB41A3 cells using a retrovirus expression system. GAPDH carrying NLS (GAPDH-NLS) was expressed mainly in the nucleus. However, expression of GAPDH-NLS did not cause any difference in cell survival rate as compared to that of the vector alone or GAPDH without NLS. Treatment with 1-Methyl-4-phenyl-pyridium iodide (MPP+) caused no difference in the cell survival rate or in the pattern or extent of apoptosis among the three transductants. In the cells expressing GAPDH without NLS, MPP+ did not cause visible translocation of GAPDH into nucleus before the onset of apoptosis. Since GAPDH is known to comprise a CRM1-mediated nuclear export signal, we blocked the nuclear export of GAPDH by treatment with leptomycin B, an inhibitor of CRM1-mediated nuclear export. The treatment did not cause any difference in apoptosis among the three transductants. An additional treatment with MPP+ induced no apoptotic difference in these cells. Thus, we have concluded that a simple nuclear localization of GAPDH does not induce apoptosis, and that MPP+-induced apoptosis is not caused by nuclear translocation of GAPDH.