Mitochondrial DNA variants as genetic risk factors for Parkinson disease.

BACKGROUND AND PURPOSE: Investigation of the relationship between mitochondrial DNA (mtDNA) variants and Parkinson disease (PD) remains an issue awaiting more supportive evidence. Moreover, an affirming cellular model study is also lacking. METHODS: The index mtDNA variants and their defining mitochondrial haplogroup were determined in 725 PD patients and 744 non-PD controls. Full-length mtDNA sequences were also conducted in 110 cases harboring various haplogroups. Cybrid cellular models, composed by fusion of mitochondria-depleted rho-zero cells and donor mitochondria, were used for a rotenone-induced PD simulation study. RESULTS: Multivariate logistic regression analysis revealed that subjects harboring the mitochondrial haplogroup B5 have resistance against PD (odds ratio 0.50, 95% confidence interval 0.32-0.78; P = 0.002). Furthermore, a composite mtDNA variant group consisting of A10398G and G8584A at the coding region was found to have resistance against PD (odds ratio 0.50, 95% confidence interval 0.33-0.78; P = 0.001). In cellular studies, B4 and B5 cybrids were selected according to their higher resistance to rotenone, in comparison with cybrids harboring other haplogroups. The B5 cybrid, containing G8584A/A10398G variants, showed more resistance to rotenone than the B4 cybrid not harboring these variants. This is supported by findings of low reactive oxygen species generation and a low apoptosis rate in the B5 cybrid, whereas a higher expression of autophagy was observed in the B4 cybrid particularly under medium dosage and longer treatment time with rotenone. CONCLUSIONS: Our studies, offering positive results from clinical investigations and cybrid experiments, provide data supporting the role of variant mtDNA in the risk of PD.

Potent antitumor activity of Oct4 and hypoxia dual-regulated oncolytic adenovirus against bladder cancer.

Most solid tumors undergo hypoxia, leading to rapid cell division, metastasis and expansion of a cell population with hallmarks of cancer stem cells (CSCs). Tumor-selective replication of oncolytic adenoviruses may be hindered by oxygen deprivation in tumors. It is desirable to develop a potent oncolytic adenovirus, retaining its antitumor activity even in a hypoxic environment. We have previously generated an Oct4-dependent oncolytic adenovirus, namely Ad9OC, driven by nine copies of the Oct4 response element (ORE) for specifically killing Oct4-overexpressing bladder tumors. Here, we developed a novel Oct4 and hypoxia dual-regulated oncolytic adenovirus, designated AdLCY, driven by both hypoxia response element (HRE) and ORE. We showed that hypoxia-inducible factor (HIF)-2α and Oct4 were frequently overexpressed in hypoxic bladder cancer cells, and HIF-2α was involved in HRE-dependent and Oct4 transactivation. AdLCY exhibited higher cytolytic activities than Ad9OC against hypoxic bladder cancer cells, while sparing normal cells. AdLCY exerted potent antitumor effects in mice bearing human bladder tumor xenografts and syngeneic bladder tumors. It could target hypoxic CD44- and CD133-positive bladder tumor cells. Therefore, AdLCY may have therapeutic potential for targeting hypoxic bladder tumors and CSCs. As Oct4 is expressed in various cancers, AdLCY may be further explored as a broad-spectrum anticancer agent.

Generating allergen-specific human IgEs for immunoassays by employing human ε gene knockin mice.

BACKGROUND: Antigen-specific human IgEs are important reagents in immunoassays to quantify antigen-specific IgEs in allergic patients, but they are not easy to prepare. METHODS: We constructed a knockin homozygous mouse strain, referred to as HεκKI strain, whose gene segment encoding γ1 constant region has been replaced by that encoding human ε constant region and gene segment encoding κ constant region replaced by that encoding human κ constant region. The mice were tested for their ability to produce antigen-specific chimeric human IgE (with mouse variable regions) upon the immunization with ovalbumin and papain. Subsequently, the spleen cells from the immunized mice were used as the source of B cells for the preparation of hybridomas, which secreted monoclonal human IgE antibodies specific for the antigens. RESULTS: The HεκKI mice expressed human IgE (ε, κ) in serum at levels 10- to 30-fold higher than those of mouse IgE. Upon immunization with an antigen, the mice yielded splenic B cells for preparing hybridomas that secrete chimeric human IgE specific for the antigen. Purified IgEs from those hybridomas could activate a basophilic cell line to undergo degranulation upon the stimulation with their respective antigens. CONCLUSIONS: We have developed a human ε gene and κ gene knockin mouse strain, which is useful for producing various antigen-specific chimeric human IgEs for potential use as standards in immunoassays.

Clinical and genetic analysis of Taiwanese patients with hereditary spastic paraplegia type 5.

BACKGROUND AND PURPOSE: Spastic paraplegia type 5 (SPG5) is an autosomal recessive (AR) hereditary spastic paraplegia (HSP) associated with pure or complicated phenotypes. This study aimed to screen SPG5 in Taiwanese HSP patients. METHODS: Sequencing of the SPG5 gene, CYP7B1, was performed in a cohort of 25 ethnic Han Taiwanese patients with AR or sporadic HSP. Clinical information and magnetic resonance imaging (MRI) were analyzed in confirmed SPG5 patients. RESULTS: One (33%) AR kindred and four (18%) sporadic cases had CYP7B1 mutations. All of the SPG5 cases carried the mutation c.334 C>T (R112X). Haplotype analysis suggested a 'founder effect' in ethnic Hans for this mutation. The phenotype was either pure or complicated by cerebellar ataxia. For the primary HSP phenotype, there were profound dorsal column sensory deficits in all patients. Spine MRI showed thoraco-lumbar cord atrophy in some patients. CONCLUSIONS: Spastic paraplegia type 5 is a common cause of AR and sporadic HSPs that has a higher frequency in Taiwanese than in other ethnic groups. It is associated with a CYP7B1 founder mutation and its phenotype is characterized by pronounced dorsal column sensory loss, with cerebellar ataxia in some patients.

Clinical characteristics of essential tremor in Taiwan: an exploratory-comparative study.

BACKGROUND: There are few large-scale clinical analyses of essential tremor (ET) in Asia. We studied the detailed clinical profile with emphasizing the age of onset, tremor location, specific tremor patterns, and rate of progression (ROP) to delineate the characteristics of Taiwanese ET patients and found the difference between the Taiwanese and the Caucasians ET patients. METHODS: All ET patients fulfilled the Movement Disorders Society diagnosis criteria were investigated with a standardized assessment protocol, which including clinical evaluation, uniform severity scoring, self-reported questionnaires, accelerometry, surface electromyography, and videotaped tremor examination. RESULTS: Of 219 patients recruited from July 2008 to October 2009, 153 completed the study protocol. Their mean age was 58.9 years and 47% were women, and 33.3% had family history (FH). There was bimodal distribution in age of tremor onset in patients without but not in those with FH. Head tremor (HT) was present in 48 of 153 (31%) patients. Patients with HT showed slower tremor frequency and less ROP than those without HT. Sixty-seven (44%) patients presented with intention tremor (IT). Male gender and voice tremor were predictive factors of IT occurrence. CONCLUSIONS: Comparing with the Caucasians, Taiwanese ET patients have different patterns of onset-age distribution and lack of female predominance in ET with HT. However, patients with IT and without HT also progressed more rapid as found in the Caucasian.

Contribution of glucocerebrosidase mutation in a large cohort of sporadic Parkinson's disease in Taiwan.

BACKGROUND AND PURPOSE: The association between glucocerebrosidase (GBA) mutations and Parkinson's disease (PD) is attracting increased attention worldwide. In patients of Chinese ethnicity, other than the common L444P mutation, a few mutations have been reported. However, the contribution of GBA to PD can be answered only by a thorough investigation of its mutations in a unique large population. METHODS: We enrolled 1747 participants: 967 PD patients and 780 healthy individuals. We screened entire GBA coding regions and exon-intron boundaries in 30 randomly chosen PD patients, followed by testing five variants (L444P, D409H, R120W, L174P, and Q497R) in all participants. The G2385R and R1628P in LRRK2 had been previously studied in almost all participants. RESULTS: In total, 36 patients (3.72%) carried a heterozygous mutant GBA allele (27 L444P, 7 RecNciI, and 2 D409H). Only two controls (0.26%) carried heterozygous GBA mutation (1 L444P and 1 RecNciI). In PD group, the mean age at onset in carriers was younger than in non-carriers. The difference in percentage of mutation frequencies between patients and controls was highly significant for the L444P mutation (P < 0.0001). One L444P carrier was also associated with LRRK2 G2385R variant, but no atypical Parkinsonism was observed. CONCLUSIONS: The present study ascertains that L444P mutation in GBA gene may contribute to an earlier onset of development of PD in Han/Chinese population. Following LRRK2 variants, GBA is the second most frequent mutations indicated for sporadic PD development in the Han/Chinese population. These GBA carriers are associated with an earlier onset of Parkinsonism.

A longitudinal study of Taiwanese sialidosis type 1: an insight into the concept of cherry-red spot myoclonus syndrome.

BACKGROUND AND PURPOSE: Sialidosis type 1 (ST-1) is a neurodegenerative disorder with limited long-term follow-up report. This study is to document the chronological profile of ST-1. METHODS: We perform serial analysis of 17 Taiwanese patients with ST-1 focusing on evolution of clinical features, electrophysiological findings, genetic studies, and neuroimage examinations. RESULTS: All patients had a mutation at 554A-->G in exon 3 of the NEU1 gene causing Ser182Gly substitution. Fifteen patients were homozygous. Two patients were heterozygous with novel mutations, 956C-->T causing Ala319Val in one and 163C-->T causing Gln55stop codon in the other. The neuraminidase activity was markedly decreased in all 11 available patients. Only three patients (17.6%) manifested the macular cherry-red spot. The majority of patients (82.3%) developed full-blown manifestation of myoclonus, ataxia, and seizures within 5 years. Abnormal somatosensory evoked potentials with giant cortical waves were found in all patients. Prolonged P100 peak latency of the visual evoked potentials (VEPs) were found in 16 patients (94.1%) in the early stage even without visual symptoms. CONCLUSION: ST-1 in Taiwanese population illustrates distinct characteristics of phenotype with infrequent cherry-red spot. We suggest to screen the NEU1 mutations in patients presenting action myoclonus with abnormal VEPs, even without macular cherry-red spots.

The natural history of neurological manganism over 18 years.

We investigated the clinical features and progression of four patients with chronic manganese intoxication, 18 years after cessation of exposure. Because the results were to be compared with previous observations, we employed the same scoring system. The clinical manifestations were foot dystonia, wide based gait, rigidity, and difficulty in walking backwards. Resting tremor was rarely seen, but tongue tremor was found in 2 patients. The asymmetry initially present in 2 patients persisted 18 years later. Measurements had previously revealed rapid progression in the initial 10 years. We found a plateau over the following decade.

UV light induced photodegradation of malachite green on TiO2 nanoparticles.

The photodegradation of malachite green (MG), a cationic triphenylmethane dye, is examined both under different pH values and amounts of TiO(2). After 15W UV-365nm irradiation for 4h, ca. 99.9% of MG was degraded with addition of 0.5gL(-1) TiO(2) to solutions containing 50mgL(-1) of the MG dye. The HPLC-PDA-ESI-MS technique was used to obtain a better understanding on the mechanistic details of this TiO(2)-assisted photodegradation of the MG dye with UV irradiation. Five intermediates of the process were separated, identified, and characterized for the first time. The results indicated that the N-de-methylation degradation of MG dye took place in a stepwise manner to yield mono-, di-, tri-, and tetra-N-de-methylated MG species generated during the processes. Under acidic conditions, the results indicated that the photodegradation mechanism is favorable to cleavage of the whole conjugated chromophore structure of the MG dye. Under basic conditions, the results showed that the photodegradation mechanism is favorable to a formation of a series of N-de-methylated intermediates of the MG dye.

Genetic and DAT imaging studies of familial parkinsonism in a Taiwanese cohort.

We here summarize the results of genetic investigations on a series of 82 parkinsonian patients from 60 families in Taiwan. We found 13 parkin patients in 7 families (12%), 2 PINK1 sibs from 1 family, and 1 LRRK2 patient from 1 family with I2012T mutation. We also identified SCA2 in 8 patients from 5 families (8%) and SCA3 in 3 patients from 1 family, all presenting with parkinsonian phenotype. In the available patients with parkin, PINK1, SCA2 and SCA3, the dopamine transporter (DAT) scan revealed that the reduction of uptake was primarily observed in the bilateral putamen, basically sharing a similar pattern with that in idiopathic Parkinson's disease. We concluded that the genetic causes contributed to about 25% of our series of familial parkinsonism. The parkin mutations and SCA2 were the most frequent genetic causes in our series with Chinese ethnicity. The results of DAT scan indicated that bilateral putamen was essentially involved in various genetically-caused familial parkinsonism.

Progressive myoclonic ataxia (the Ramsay Hunt syndrome).

It has been suggested from studies of patients with progressive myoclonus epilepsy that the term Ramsay Hunt syndrome should be abandoned, as its use has led to nosologic confusion, and because, in the light of modern diagnostic techniques, the majority of cases can be allocated to specific disease categories, chiefly, Unverricht-Lundborg disease (Baltic myoclonus) and mitochondrial encephalomyopathy. Review of 30 cases of this syndrome, defined as progressive ataxia and myoclonus and infrequent seizures in the absence of dementia, showed that a clinical or biochemically supported diagnosis could not be made in 43%. This low diagnostic yield probably reflects differences in ascertainment of patients; those described here were referred with a syndrome of progressive myoclonic ataxia (the Ramsay Hunt syndrome) rather than progressive myoclonus epilepsy. These two syndromes share common causes, but a smaller proportion of patients with progressive myoclonic ataxia can currently be diagnosed precisely during life.

Chronic manganese intoxication.

We report six cases of chronic manganese intoxication in workers at a ferromanganese factory in Taiwan. Diagnosis was confirmed by assessing increased manganese concentrations in the blood, scalp, and pubic hair. In addition, increased manganese levels in the environmental air were established. The patients showed a bradykinetic-rigid syndrome indistinguishable from Parkinson's disease that responded to treatment with levodopa.

Manganism and idiopathic parkinsonism: similarities and differences.

From the comparison we have made between PD and manganism, we draw the following conclusions: 1. There are similarities between PD and manganism, notably the presence of (a) generalized bradykinesia and (b) widespread rigidity. 2. There are also dissimilarities between PD and manganism, notably the following in manganism: (a) less-frequent resting tremor, (b) more frequent dystonia, (c) a particular propensity to fall backward, (d) failure to achieve a sustained therapeutic response to levodopa, and (e) failure to detect a reduction in fluorodopa uptake by PET. Further studies are likely to yield more discriminants between PD and manganism. For example, PET with raclopride may be useful in early cases of manganism, and MRI may be helpful in patients with advanced manganism.

Levodopa failure in chronic manganism.

We report a placebo-controlled study of levodopa in four patients with extrapyramidal deficits caused by chronic manganese intoxication. Their parkinsonism and dystonia had progressed slowly over a period of 5 years after they left the site of exposure. Initially the patients appeared to respond to levodopa in open observations, but this apparent benefit was not sustained. This short-term, double-blind study indicates that their parkinsonism and dystonia failed to respond to levodopa.

Long-term progression in chronic manganism: ten years of follow-up.

We studied the long-term clinical course of five patients with chronic manganese intoxication. The mean scores of the King's College Hospital Rating Scale for Parkinson's disease increased from 15.0 +/- 4.2 in 1987 to 28.3 +/- 6.70 in 1991 and then to 38.1 +/- 12.9 in 1995. The deterioration was most prominent in gait, rigidity, speed of foot tapping, and writing. Tissue concentrations of manganese in blood, urine, scalp hair, and pubic hair returned to normal. Follow-up MRIs did not show paramagnetic high-signal intensity on T1-weighted images. The data indicate that clinical progression in patients with manganese parkinsonism continues even 10 years after cessation of exposure.

Progression after chronic manganese exposure.

We report a longitudinal follow-up study on six patients with chronic manganese-induced parkinsonism following cessation of manganese exposure. Compared with the 1987 study, their parkinsonian symptoms showed a slow progression, particularly in gait disturbances such as freezing during turning and walking backward with retropulsion. The mean disability scores on the King's College Hospital Rating Scale were 15.0 +/- 4.2 in 1987 and 28.3 +/- 6.7 in 1991 (p = 0.003, paired t test). Review of the video records also confirmed a worsening of parkinsonism, especially in difficulty turning. Three of six patients receiving levodopa treatment had an initial improvement. The response decreased after 2 to 3 years. During the therapy, they did not develop on-off fluctuation or dyskinesia. We conclude that patients with manganese-induced parkinsonism may develop increasing neurologic dysfunction long after cessation of exposure and that their responses to levodopa are different from those of patients with Parkinson's disease.

Presynaptic and postsynaptic striatal dopaminergic function in patients with manganese intoxication: a positron emission tomography study.

We performed PET on four patients with chronic industrial Mn intoxication; presynaptic and postsynaptic dopaminergic function were measured with [18F]6-fluoro-L-dopa (6FD) and [11C]raclopride (RAC). All patients had a rigid-akinetic syndrome; they had no sustained benefit from L-dopa. Influx constants (Ki) of 6FD were normal in the caudate and putamen. RAC binding was mildly reduced in the caudate and normal in the putamen. We conclude that nigrostriatal dopaminergic dysfunction is not responsible for the parkinsonism caused by chronic Mn intoxication. The pathology is likely to be downstream of the dopaminergic projection.

Differential diagnosis of Parkinson's disease and vascular parkinsonism by (99m)Tc-TRODAT-1.

UNLABELLED: The aim of this study was to use brain SPECT to differentiate vascular parkinsonism (VP) from Parkinson's disease. METHODS: Fourteen VP patients (age range, 59-87 y; mean age, 70 +/- 7.5 y), 30 Parkinson's disease patients (age range, 54-84 y; mean age, 65 +/- 8.8 y), and 26 healthy (control) individuals (age range, 50-85 y; mean age, 60 +/- 9 y) were examined. A 925-MBq (25 mCi) dose of (99m)Tc-TRODAT-1 was injected intravenously, and brain SPECT images were acquired 4 h after injection. The ratio of specific to nonspecific striatal (99m)Tc-TRODAT-1 binding was measured and compared. RESULTS: After a region-of-interest analysis of the images from VP patients, Parkinson's disease patients, and healthy volunteers was performed to obtain ratios of putamen to occipital and striatal to occipital binding as a measurement of specific binding to the dopamine transporters in these regions of the brain, where dopamine neurons are concentrated, the specific binding in the 14 VP patients was slightly lower than but not statistically different from that of the healthy individuals in both putamen and caudate areas. A significant decrease in uptake of (99m)Tc-TRODAT-1 in the striatum (P<0.01) was found in Parkinson's disease patients. Reduction of the uptake was more pronounced in the contralateral putamen of Parkinson's disease patients than that of VP patients (P<0.001). A significant bilateral striatal asymmetry was also observed in Parkinson's disease patients but not in VP patients (P< 0.01). CONCLUSION: Our findings clearly show that, for VP patients, (99m)Tc-TRODAT-1 SPECT is a reliable method to differentiate VP from Parkinson's disease. Further studies, including those to differentiate Parkinson's disease from arteriosclerotic parkinsonism and patients with both VP and Parkinson's disease, are needed to help rule out the possibility of Parkinson's disease as early as possible.

Decreased dopamine transporter binding in Machado-Joseph disease.

UNLABELLED: The aim of this study was to use 99mTc-TRODAT-1 brain SPECT for investigation of the binding of dopamine transporter (DAT) in the nigrostriatal dopaminergic pathway of symptomatic Machado-Joseph disease (MJD) and to compare the results with the abnormal cytidylate, adenylate, and guanylate (CAG) expansion in the MJD1 gene and other clinical factors. METHODS: Ten symptomatic MJD patients (8 women, 2 men; age range, 20-71 y; mean age +/- SD, 36.4 +/- 10.6 y; mean duration of illness, 9.8 +/- 5.4 y) and 21 healthy volunteers (age range, 24-71 y; mean age, 47.6 +/- 20.1 y) were examined. Brain SPECT images were acquired 4 h after injection. The ratio of specific to nonspecific nigrostriatal 99mTc-TRODAT-1 binding was measured and compared with the clinical symptoms, duration of illness, and size of abnormal expanded CAG repeats. RESULTS: All nigrostriatal 99mTc-TRODAT-1 ratios were significantly lower in MJD patients than in healthy volunteers (P < 0.05). Discriminant function analysis of all MJD patients showed that the decreased binding of 99mTc-TRODAT-1 in the putamen was not significantly different from that in the caudate nucleus. Eight of 10 MJD patients had significantly decreased 99mTc-TRODAT-1 uptake. Of these 8, 2 had extrapyramidal signs and 6 had no obvious extrapyramidal signs. The other 2 patients, who had normal 99mTc-TRODAT-1 uptake, had no obvious extrapyramidal signs. CONCLUSION: Our findings indicate that 99mTc-TRODAT-1 brain SPECT is an appropriate method for evaluating damage to the nigrostriatal DAT in symptomatic MJD patients with and without extrapyramidal signs. The decreased binding of 99mTc-TRODAT-1 in the nigrostriatal dopaminergic pathway in symptomatic MJD patients correlates with the phenotype of extrapyramidal signs but not with the abnormal CAG repeat length, age at disease onset, or disease duration.

Emotional symptoms are secondary to the voice disorder in patients with spasmodic dysphonia.

The aims of this study were to evaluate the emotional status and life quality of the patients with spasmodic dysphonia (SD) before and after botulinum toxin treatment, and to ascertain whether SD is a somatoform disorder. Ten patients with spasmodic dysphonia were injected unilaterally into the vocal cord with botulinum toxin. Before botulinum toxin treatment, two clinician's rating scales--Hamilton Depression Rating Scale (HDRS) and Hamilton Anxiety Rating Scale (HARS), and three self-rating psychometrics--Zung's Self-Rating Depression Scale (SDS), Life Quality Scale (GHQ/QL-12), and Symptom Distress Checklist (SCL-90) were applied. Self-rating scales were also administered in 20 matched normal controls. The patients were reevaluated 1 month after botulinum toxin treatment. The Clinical Global Impression Scale (CGI) was also rated by the patients themselves and a speech pathologist. The mean scores of SD patients were significantly higher than that of controls in SDS, and subscales of somatization, obsessive-compulsive symptoms, depression, anxiety, and psychoticism in SCL-90. The mean score of GHQ/QL-12 was significantly higher in the control group. The scores of HDRS, SDS, GHQ/QL-12 and subscales of somatization, depression, and anxiety in SCL-90 showed significant improvement after botulinum treatment. In CGI, seven patients were rated as improved by patients themselves and the speech pathologist. The patients with SD had more anxiety, depression and somatization symptoms, and poor life quality than normal controls. Their emotional status and life quality improved after botulinum toxin treatment. The results suggest that the emotional symptoms of patients with SD are mainly secondary to voice disorder.