Kampo medicine and Muro disease (Amyotrophic Lateral Sclerosis and Parkinsonism-Dementia Complex): Postscript and Historical Footnote.

Western Pacific Amyotrophic Lateral Sclerosis and Parkinsonism-dementia Complex (ALS/PDC) is a disappearing neurodegenerative disease in three former high-incidence foci of the U.S. territory of Guam, Papua-Indonesia (New Guinea) and Kii Peninsula, Honshu Island, Japan (Muro disease). We report additional data that associate medicinal use of cycad seed to Muro disease in the southern Kozagawa focus of ALS/PDC. In the other two ALS/PDC-affected populations, cycad seed was used as a traditional topical medicine in New Guinea and Guam and, additionally, for food on Guam.

Association between oxidative stress and microRNA expression pattern of ALS patients in the high-incidence area of the Kii Peninsula.

Amyotrophic lateral sclerosis (ALS) is a progressive degenerative disorder of the upper and lower motor neuron systems. The high incidence of ALS in the southern part of the Kii Peninsula of Japan (K-ALS) was reported in the 1960s, but it has gradually decreased to the worldwide average. Although causes of the high incidence of ALS in this area are unknown, our previous studies suggested that environmental factors, including essential mineral deficiency and increased metal-induced oxidative stress, play a role in its development. Recently, it has been reported that microRNAs (miRNA) contribute to the degeneration of nervous system such as ALS. The aim of this study is to explore specific miRNAs in K-ALS and evaluate relationships between oxidative stress. We comprehensively analyzed serum miRNAs and examined urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), serum Cu/Zn superoxide dismutase (SOD) and serum Nɛ-hexanoyl lysin (HEL) as oxidative stress markers in the patients with K-ALS, sporadic ALS (S-ALS), residents in this area (K-residents) and controls from another area. The expression levels of miR-92a-3p and miR-486-5p in the patients with K-ALS were significantly higher than those in controls. The HEL levels were significantly higher in the patients with K-ALS than in those with S-ALS and controls. The expression levels of miR-92a-3p and miR-486-5p were not correlated with the levels of HEL. A set of high levels of miR-92a-3p, miR-486-5p and serum HEL may be a useful biomarker for K-ALS in the Kii Peninsula. The findings should be further studied by a large number of subjects.

Kampo medicine and Muro disease (Amyotrophic Lateral Sclerosis and Parkinsonism-Dementia Complex).

Western Pacific Amyotrophic Lateral Sclerosis and Parkinsonism-dementia Complex (ALS/PDC) is a disappearing neurodegenerative disease in three former high-incidence foci of Guam-USA, Papua-Indonesia and Kii Peninsula, Honshu Island, Japan. The latter includes two distinct ALS/PDC-affected regions (Hohara and Kozagawa), where the disorder is known as Muro disease. In Hohara, oral exposure to plant (cycad) neurotoxins used in traditional medical practice has been linked previously to Muro disease. We report new observations that link Kampo medicine to Muro disease in the southern Kozagawa focus. Oral exposure to cycad seed toxins is associated with all three foci of Western Pacific ALS/PDC.

Lifestyle Changes and Oxidative Stress in a High-incidence Area of Amyotrophic Lateral Sclerosis in the Southwestern Kii Peninsula, Japan.

Objective Lifestyle changes may play an important role in the incidence reduction and delay of onset age of amyotrophic lateral sclerosis (ALS) in the Koza/Kozagawa/Kushimoto (K) area. The aim of this study was to evaluate recent lifestyle changes in the K area and to investigate the relationships between lifestyle and oxidative stress among the residents. Methods We conducted a medical checkup for elderly residents in the K area and the control area and evaluated the urinary 8-OHdG levels, cognitive function test scores and metal contents in serum and scalp hair, coupled with a lifestyle questionnaire survey between 2010 and 2015. Results Recent lifestyle changes among the K residents, including a decrease in the Japanese pickle consumption, increase in fresh vegetable consumption and decrease in farm work, were evaluated in this study. Low consumption of Japanese pickles, high consumption of fresh vegetables, rare farm work and low levels of 8-OHdG/creatinine were all associated with high scores in the cognitive function tests. Frequent farm work and consumption of Japanese pickles was associated with high contents of transition metals, such as Mn, Al and V, in the scalp hair. Conclusion These lifestyle changes among residents in the K area may be associated with their oxidative stress.

Neutron activation analysis of scalp hair from ALS patients and residents in the Kii Peninsula, Japan.

The aim of this study was to evaluate the accumulation of transition metals in the scalp hair of amyotrophic lateral sclerosis (ALS) patients in the Koza/Kozagawa/Kushimoto (K) area (K-ALS) in the Kii Peninsula, Japan. Metal contents were measured in the unpermed, undyed hair samples of 88 K-residents, 20 controls, 7 K-ALS patients, and 10 sporadic ALS patients using neutron activation analysis at the Research Reactor Institute, Kyoto University. A human hair standard and elemental standards were used as comparative standards. The contents of Zn, Mn, and V were higher, while that of S was lower in K-ALS patients than in the controls. The content of Mn in K-ALS patients negatively correlated with clinical durations. The content of Al was significantly higher in K-residents than in the controls, with 15.9 % of K-residents having high Mn contents over the 75th percentile of the controls. The contents of Zn, Mn, and V were high in the scalp hair of K-ALS patients and correlated with the content of Al. The accumulation of these transition metals may chronically increase metal-induced oxidative stress, which may, in turn, trigger the neuronal degeneration associated with K-ALS.

Environmental characteristics and oxidative stress of inhabitants and patients with amyotrophic lateral sclerosis in a high-incidence area on the Kii Peninsula, Japan.

OBJECTIVE: Although Oshima, in the Kii Peninsula of Japan, is located within a high incidence area of amyotrophic lateral sclerosis (ALS) (Koza/Kozagawa/Kushimoto area, K area), no patients with ALS were detected between 1960 and 1999. However, the incidence recently increased between 2000 and 2009. On Oshima, the source of drinking water was changed from a regional river/wells to the Kozagawa River in the K area in 1975. We speculate that this change in water source may have played a role in the recent increase in the incidence of ALS. The aim of this study is to find contributing factors that may have triggered the locally high incidence of ALS. METHODS: We investigated a possible association between the mineral content of drinking water and serum and oxidative stress markers among patients with ALS in the K area (K-ALS), residents of Oshima and controls. RESULTS: We found that the levels of Ca and Zn in the recent drinking water in Oshima are low and that the serum levels of Ca and Zn in the Oshima residents and patients with K-ALS were significantly lower, while the oxidative stress markers were significantly higher, than those of the controls. The serum Zn and urinary 8-OHdG/creatinine levels explained 60% and 58% of the variations among the three groups, respectively. The serum Zn levels were negatively correlated with the serum Cu levels in the patients with K-ALS, and the serum Cu levels exhibited a tendency to be positively correlated with the 8-OHdG/creatinine levels in both the patients with K-ALS (r: 0.64) and the residents free from K-ALS (r: 0.32, p<0.01). CONCLUSION: Taken together, we suggest that the low levels of Ca and Zn in the drinking water are possibly associated with an imbalance of metal metabolism in Oshima residents and an increase in oxidative stress markers in patients with K-ALS, although the causative relationship is not clear. This is a cross-sectional study, and a prospective study is needed in the future.

Mutational analysis of familial and sporadic amyotrophic lateral sclerosis with OPTN mutations in Japanese population.

Our objective was to elucidate the genetic epidemiology of familial amyotrophic lateral sclerosis (FALS) and sporadic ALS (SALS) with OPTN mutations in the Japanese population. Mutational analysis of OPTN was conducted in 18 FALS pedigrees in whom mutations in other causative genes have been excluded and in 218 SALS patients by direct nucleotide sequence analysis. Novel non-synonymous variants identified in ALS patients were further screened in 271 controls. Results showed that although no mutations were identified in the FALS pedigrees, a novel heterozygous non-synonymous variant c.481G > A (p.V161M) was identified in one SALS patient, who originated from the southernmost part of the Kii Peninsula. The mutation was not present in 271 controls. As the clinical feature, the patient carrying V161M showed predominantly upper motor neuron signs with slow progression. This study suggests that mutations in OPTN are not the main cause of ALS in the Japanese population.

An increase in ALS incidence on the Kii Peninsula, 1960-2009: a possible link to change in drinking water source.

We investigated changes in the incidence of amyotrophic lateral sclerosis (ALS) in the Koza/Kozagawa/Kushimoto area (K. area) in the Kii Peninsula, Japan in 1960-2009. Probable and definite ALS cases diagnosed using El Escorial criteria were collected during a five-decade period: period I-V, 1960-2009. Forty-three ALS patients matched the selection criteria in the overall K. area, including three patients on Oshima, a small island opposite the mainland K. area. The age- and gender-adjusted incidence of ALS in the overall K. area (standardized for the 2005 Japanese population) decreased from 5.47/100,000 (95% CI 1.86-9.08) in period I to 0.61/100,000 (95% CI-0.28-1.50) in period III, and then increased to 4.39/100,000 (95% CI 1.70-7.07) in period V. On Oshima, the age- and gender-adjusted incidence of ALS was 9.45/100,000 (95% CI-7.39-26.29) in period V. The present research indicates an increase of ALS incidence in the K. area, especially on Oshima. A limitation of this study was the small population.

C9ORF72 repeat expansion in amyotrophic lateral sclerosis in the Kii peninsula of Japan.

BACKGROUND: In the Kii peninsula of Japan, high prevalences of amyotrophic lateral sclerosis (ALS) and parkinsonism-dementia complex have been reported. There are 2 major foci with a high prevalence, which include the southernmost region neighboring the Koza River (Kozagawa and Kushimoto towns in Wakayama prefecture) and the Hohara district (Mie prefecture). OBJECTIVE: To delineate the molecular basis of ALS in the Kii peninsula of Japan, we analyzed hexanucleotide repeat expansion in the chromosome 9 open reading frame 72 (C9ORF72) gene, which has recently been identified as a frequent cause of ALS and frontotemporal dementia in the white population. DESIGN: Case series. SETTING: University hospitals. PATIENTS: Twenty-one patients (1 familial patient and 20 sporadic patients) with ALS from Wakayama prefecture, and 16 patients with ALS and 16 patients with parkinsonism-dementia complex originating from Mie prefecture surveyed in 1994 through 2011 were enrolled in the study. In addition, 40 probands with familial ALS and 217 sporadic patients with ALS recruited from other areas of Japan were also enrolled in this study. MAIN OUTCOME MEASURES: After screening by repeat-primed polymerase chain reaction, Southern blot hybridization analysis was performed to confirm the expanded alleles. RESULTS: We identified 3 patients with ALS (20%) with the repeat expansion in 1 of the 2 disease foci. The proportion is significantly higher than those in other regions in Japan. Detailed haplotype analyses revealed an extended shared haplotype in the 3 patients with ALS, suggesting a founder effect. CONCLUSIONS: Our findings indicate that the repeat expansion partly accounts for the high prevalence of ALS in the Kii peninsula.

[Changes in the incidence and clinical features of ALS in the Koza, Kozagawa, and Kushimoto area of the Kii Peninsula--from the 1960s to the 2000s (follow-up study)].

In the 1960's, ALS was highly prevalent in the southern part of the Kii Peninsula, especially in the Koza, Kozagawa, and Kushimoto area (K area). Thereafter, the incidence of ALS was considered to have gradually decreased, and the disease almost disappeared in the 1980's. However, new patients have been continuously identified in this area, and indicating the importance of studying the changes in the incidences of ALS. This study investigated the characteristic clinical features and incidence of ALS in K area during the following periods: period I: between 1967 and 1971, period II: between 1989 and 1999, and period III: between 2000 and 2008. Data on all patients with motor neuron disease were collected for each year within these periods from medical doctors and medical staff of the regional public health center and municipal office. Neurologists on our research team examined and assessed each of these patients on the basis of the El Escorial criteria. Probable and definite ALS patients diagnosed by neurologists using the El Escorial criteria in K area during the research periods were collected. The crude incidence rate of ALS in K area were similar in period I, i.e. 6.0/100,000, and in period III, i.e., 5.7/100,000. The age-, and sex-adjusted incidence (considering the 2000 census) in women in K area during period III, especially in Kozagawa district, was higher than that in periods I and II. The adjusted incidence rate in Kozagawa district was 8.8/100,000, and was higher than that in other areas of the world. The clinical features of patients in this area were quite similar to those of patients with classical ALS. Five patients from 3 families with a family history of ALS and 2 patients without a family history presented with the clinical features of ALS and PDC during these research periods. The mean age at onset for period III was higher than that in period I (p < 0.01). The frequency of ALS patients with upper-extremity onset in period III was lower than that in period I (p = 0.05), whereas the frequency of patients with bulbar-onset has recently increased. Conclusion The result of present study indicate that the recent incidence of ALS in K area is high, the age of onset has recently become higher and the number of bulbar-onset patients has increased. All the abovementioned findings could be attributed to an increase in the senility rate in the population. Between 2000 and 2008, the age-adjusted incidence in ALS for women in K area, especially in the Kozagawa district, was high, indicating an increase in that the incidence of ALS among women in this area after 2000. The factors responsible for the high incidence of ALS in this area remain to be clarified.

Lifestyle factors and risk of amyotrophic lateral sclerosis: a case-control study in Japan.

PURPOSE: We examined the associations between lifestyle factors and the risk of amyotrophic lateral sclerosis (ALS) using a case-control study in Aichi Prefecture, Japan. METHODS: The study comprised 183 ALS patients diagnosed by the El Escorial World Federation of Neurology criteria as well as 366 gender- and age-matched controls randomly selected from the general population with the use of the basic register of residents. Detailed information on lifestyle factors was obtained through a mailed self-administered questionnaire. The strength of association between ALS and a potential risk factor was assessed by calculating odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Vigorous physical activity, self reported stress, a type A behavior pattern, and less frequent intakes of green-yellow vegetables were significantly associated with increased risk of ALS, whereas smoking and drinking habits were not. The greatest effect on risk for ALS was posed by the combination of a type A behavior pattern and less frequent intakes of green-yellow vegetables (adjusted OR, 11.2; 95% CI, 3.8 to 33.0). CONCLUSION: These data suggested that imbalances between excessive productions of oxidants as patient-specific factors and a diminished or missing antioxidant defense system in motor neurons may increase the risk of ALS.

Immunohistochemical expression of IGF-I and GSK in the spinal cord of Kii and Guamanian ALS patients.

Insulin-like growth factor-I (IGF-I) is a potent survival factor for motor neurons in animals, and glycogen synthase kinase-3beta (GSK-3beta) is suspected to play roles in apoptosis and tau phosphorylation. Here we report the immunological expression of IGF-I, GSK-3beta, phosphorylated-GSK-3alpha/beta (p-GSK-3alpha/beta) and phosphorylated-tau in the spinal cord and hippocampus of Kii and Guam amyotrophic lateral sclerosis (ALS) patients. Sixteen ALS patients (10 Japanese sporadic, 3 Kii and 3 Guam ALS) and 14 neurological controls (10 Japanese and 4 Guamanian) were examined. The immunoreactivity for each antibody was rated by the percentages of positive neurons to total anterior horn neurons in each patient and was analyzed statistically. Many normal-looking neurons from Japanese sporadic ALS, Kii ALS and Guam ALS patients, as well as from Japanese and Guam controls, were positive for anti-IGF-I antibody. A positive correlation between IR scores for anti-IGF-I antibody and clinical durations of Japanese sporadic ALS patients was found in this study (P < 0.0001). This suggested that IGF-I might have a protective effect against ALS degeneration. In Japanese sporadic ALS patients, abnormal as well as normal-looking neurons showed significant high IR scores for anti-GSK-3beta antibody than those of controls. Anterior horn neurons from Guam and Kii ALS patients characteristically showed weak staining for anti-GSK-3beta antibody but were markedly positive for anti-pGSK-3alpha/beta antibody compared to those from both Japanese controls and Japanese sporadic ALS patients, and showed the co-localization of IGF-I and p-GSK-3alpha/beta. This suggested that the IGF-I signaling pathway in Guam and Kii ALS patients might function to phosphorylate GSK-3beta to protect neurons from ALS degeneration. Neurofibrillary tangles (NFTs) in the hippocampus and spinal cord from Kii and Guam ALS patients showed the co-localization of PHF-tau and p-GSK-3alpha/beta by a confocal laser scanning technique. The predominant expression of p-GSK-3alpha/beta compared to GSK-3beta in spinal motor neurons and the co-localization of p-GSK-3alpha/beta and PHF-tau in NFT-laden neurons in the hippocampus and spinal cord were characteristic findings of Kii and Guam ALS patients.

Survival rate of patients with amyotrophic lateral sclerosis in Wakayama Prefecture, Japan, 1966 to 2005.

To investigate longitudinal changes in the survival rate of patients with amyotrophic lateral sclerosis in Wakayama Prefecture, Japan, we made a retrospective hospital-based study of 454 patients diagnosed with motor neuron disease (MND) at Wakayama Medical University (WMU) Hospital between 1966 and 2005. Of the 454 patients, 240 who were born and who lived in Wakayama Prefecture were diagnosed with definite or probable ALS during this period, according to the El Escorial criteria. The clinical data of the 240 patients, including sex, birth date, birthplace, address, age at onset, initial symptoms, date when respiratory support was applied (tracheostomy, noninvasive positive pressure ventilation, or mandatory artificial ventilation), and date of death were reviewed retrospectively. The age at onset of patients who developed initial symptoms before 1990 was 53.4+/-10.6 (mean+/-S.D.) and that in 1990 or thereafter was 64.8+/-10.3, respectively, showing a significant difference (p<0.0001). Clinical duration was determined from onset to either date of death or initiation of respiratory support in this study. Survival rate was compared using the Kaplan-Meier method according to age at onset, sex, initial symptoms and year of onset. Mean age at onset shifted towards older age according to a later year of onset, due to the overwhelming senility rate in Wakayama Prefecture. Older onset patients had a significantly poorer survival rate than younger onset patients when it was compared based on 10-year age groups (log rank, p<0.0001). Male patients had a poorer survival rate than female patients (p<0.0001). ALS patients with bulbar palsy onset showed shorter clinical durations than those with lower leg onset (p<0.0071, Breslow-Gehan-Wilcoxon test). Patients over 70 years old more frequently showed bulbar palsy onset compared to those younger than 69 (p=0.003). In a comparison of year of onset before and after 1990, ALS patients after 1990 had characteristics of older age onset and shorter clinical duration, and more frequently showed bulbar palsy onset compared with those before 1990. These findings indicated that younger onset patients with ALS decreased after 1990 in Wakayama Prefecture and this might partly explain the recent decline of ALS incidence in Wakayama Prefecture. The shift of the mean age at onset to older age might be due to exogenous factors, including changes in lifestyle, food, and drinking water in this area. Bulbar palsy onset and age at onset were expected as predictors of the survival rate.

Nutritional status and risk of amyotrophic lateral sclerosis in Japan.

Only a few human studies have reported the relationship between dietary factors and the risk of amyotrophic lateral sclerosis (ALS). We therefore analyzed the relationship between macronutrients (carbohydrate, protein and fat) and the risk of ALS using a case-control study in Japan. The study comprised 153 ALS patients diagnosed by the El Escorial World Federation of Neurology criteria, and 306 gender- and age- matched controls randomly selected from the general population. A self-administered food frequency questionnaire was used to estimate pre-illness intakes of food groups and nutrients. The strength of association between ALS and a potential risk factor was assessed by calculating odds ratios (ORs) and 95% confidence intervals (CIs). A high intake of carbohydrate was significantly associated with an increased risk of ALS (adjusted OR = 2.14, 95% CI 1.05-4.36; the highest versus the lowest tertile). ORs for the second and third tertile of total fat were 0.57 and 0.41 (95% CI 0.21-0.80), respectively. ORs for the highest tertile of intake versus the lowest were 0.41 (95% CI 0.21-0.80) for total fat, 0.30 (95% CI 0.16-0.5) for saturated fatty acids (SFAs), 0.35 (95% CI 0.18-0.69) for monounsaturated fatty acids (MUFAs) and 0.58 (95%CI 0.40-0.96) for polyunsaturated fatty acids (PUFAs). Our findings suggest that high intakes of carbohydrate and low intakes of fat and some kinds of fatty acids may, when combined, increased the risk of ALS.

Expression of insulin-like growth factor-II and leukemia inhibitory factor antibody immunostaining on the ionized calcium-binding adaptor molecule 1-positive microglias in the spinal cord of amyotrophic lateral sclerosis patients.

Amyotrophic lateral sclerosis (ALS) is a progressive degenerative disease involving the upper and lower motor neuron systems. Activated microglia are reported to enhance motor neuron death by secreting neurotoxic cytokines in SOD1-transgenic mice. Recent studies have provided evidence that chronic stimulation leads microglia to acquire an anti-inflammatory phenotype, characterized by activated morphology and induction of neuroprotective and immunoregulatory molecules. However, little information is available on the protective functions of microglia in the ALS spinal cord. To investigate the roles of microglia in ALS, we examined the appearance of ionized calcium-binding adaptor molecule 1-positive (Iba1-positive) microglia as correlated to the disease duration and immunohistochemical expression of neurogrowth factors in the ALS spinal cord. In this study, the number of Ibal-positive rod-like microglia significantly increased in the ALS spinal cord compared to controls. The number of ramified microglia was positively correlated with the number of normal-looking neurons and clinical duration of ALS patients; however, the number of rod-like microglia was not correlated with that of abnormal neurons, nor with the clinical duration of the disease. Some rod-like microglia were positive for anti-insulin-like growth factor-II (IGF II) and anti-leukemia inhibitory factor (LIF) immunostaining. Motor neurons in the ALS spinal cords also showed immunore-activity for IGF-II, LIF and the receptors of IGF-II and LIE Taken together, these findings suggest that at least some microglia might have a protective effect on motor neurons in the ALS spinal cord. Neuroprotective and/or neurotoxic effects of microglia on motor neurons should be further studied.

The role of exogenous risk factors in amyotrophic lateral sclerosis in Wakayama, Japan.

The incidence of ALS in Wakayama Prefecture has been markedly higher than that elsewhere in the world. Recently, however, the incidence has gradually decreased, especially in men, and the age at onset has shifted to the elderly, indicating the possible role of exogenous factors in the development of ALS. To evaluate factors related to the disease, we conducted a retrospective study. This study examined 108 patients with definite ALS diagnosed according to El Escorial criteria and 302 neurological controls (older than 40 years old) consecutively admitted to Wakayama Medical Hospital between 1999 and 2004. Having past history of cervical spondylosis or spinal spondylotic myelopathy (CS/SSM) with/without surgical treatment, cervical MRI findings, history of bone fracture, and occupation at onset were compared between the ALS patients and the neurological controls. Among 108 ALS patients, 45.4% had past history of CS/SSM compared to 19.4% of the neurological controls (p<0.0001, OR: 3.725, 95% CI 2.173-6.387). Among the ALS patients, 13% had had surgical treatment for CS/SSM, which was significantly higher than the 4.3% of the neurological controls (p<0.003, OR: 4.333, 95% CI 1.647-11.401). Cervical MRI findings were classified into four grades according to the severity of canal narrowing and compression of the spinal cord. Regarding cervical MRI findings, the percentage of ALS patients who showed canal narrowing and compression of the spinal cord was significantly higher than that of the controls (ALS: 72.0%, the controls: 29.5%, OR: 4.799, 95% CI 2.65-8.70). Comparison of the occupation at disease onset revealed that primary and secondary industrial occupations significantly increased the risk of ALS (2.69, 95% CI 1.40-5.16, 2.81, 95% CI 1.45-5.46, respectively). Conversely, tertiary industrial occupations significantly decreased the risk of ALS (age- and sex-adjusted OR: 0.54, 95% CI 0.30-0.98). In conclusion, CS/SSM, surgical treatment for CS/SSM and occupation at onset are suspected to be risk factors for developing/triggering or worsening ALS.

[Etiology of Kii ALS/PDC, featuring a mineral hypothesis].

In 1960s, epidemiological surveys in both Kozagawa and Hobara foci revealed the characteristics of Kii ALS as follows: younger age at onset. M/F ratio of 1.5-1.8:1, familial clustering and presence of Alzheimer's neurofibrillary tangles (NFTs). The segregation ratio of six families in Hobara was estimated 0.304 +/- 0.096 ( p +/- 95% confidence level), suggesting a multifactorial inheritance. Kii environmental studies showed that extremely low contents of calcium (Ca) and magnesium (Mg) in the birthplace's rivers of ALS patients inversely and significanthy correlated with high mortality rates, aluminum (Al) contents, and densities of hipocampal NFTs. In experimental animals, a low Ca and Mg, and high Al content diet led to a neuronal loss with axonal swellings and chromatolysis, and positive staining of cortical neurons with anti-PHF antibodies. Recently, a significant loss of dopaminergic neurons was identified exclusively in the substantia nigra in 1-year-old rat fed under a low Mg intake over two generations. Kii people may have a predisposition to develop ALS/PDC precipitated by their environmental status, suggesting gene-environmental interactions.

[Amyotrophic lateral sclerosis associated with extrapyramidal symptoms or signs].

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.

Magnesium deficiency over generations in rats with special references to the pathogenesis of the Parkinsonism-dementia complex and amyotrophic lateral sclerosis of Guam.

Parkinsonism-dementia complex (PDC) and amyotrophic lateral sclerosis (ALS) are fatal neurological diseases. The incidence on Guam was very high between 1950 and 1965 but decreased dramatically after 1965. It is thought that drinking water containing low levels of calcium (Ca) and magnesium (Mg), and high levels of aluminum and of a plant excitatory neurotoxin are involved in the pathogenesis of these diseases. The present experiment was performed in rats that were exposed to low Ca and/or Mg intake over two generations, thus simulating the conditions of human life on Guam, where several generations live continuously in the same environment. Significant loss of dopaminergic neurons was identified exclusively in the substantia nigra in 1-year-old rats that had been exposed continuously to low Mg intake (one-fifth of the normal level) over generations. The present study suggests that low Mg intake over generations may be involved in the pathogenesis of substantia nigra degeneration in humans.

A species-specific difference in the effects of harmaline on the rodent olivocerebellar system.

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.