Nuclei of the human raphe

Along the raphe of the brain stem, a series of small neuronal groups can be observed in the medulla oblongata, the pons and the mesencephalon. The neurons located in and adjacent to the raphe are considered to produce mainly serotonin (5-HT). The groups of nuclei containing 5-HT were first reported in experimental animals in the early 1960s. The presence of such nuclei, however, has not yet been brought to light in the human brainstem except the few atlases, although in several neuroanatomy textbooks, extrapolated data are shown in the form of drawings as if they were the data from the human brain. The aim of this study is to present microscopic photos of such raphe nuclei made from serial sections of the human brainstem, and to clarify the differences between findings in human and textbook drawings from animal data.

Evaluating Japanese patients with the Marfan syndrome using high-throughput microarray-based mutational analysis of fibrillin-1 gene

Marfan syndrome (MS) is an inherited connective tissue disorder, and detailed evaluations of multiple organ systems are required for its diagnosis. Genetic testing of the disease-causing fibrillin-1 gene (FBN1) is also important in this diagnostic scheme. The aim of this study was to define the clinical characteristics of Japanese patients with MS and enable the efficient and accurate diagnosis of MS with mutational analysis using a high-throughput microarray-based resequencing system. Fifty-three Japanese probands were recruited, and their clinical characteristics were evaluated using the Ghent criteria. For mutational analysis, an oligonucleotide microarray was designed to interrogate FBN1, and the entire exon and exon-intron boundaries of FBN1 were sequenced. Clinical evaluation revealed more pulmonary phenotypes and fewer skeletal phenotypes in Japanese patients with MS compared to Caucasians. The microarray-based resequencing system detected 35 kinds of mutations, including 23 new mutations. The mutation detection rate for patients who fulfilled the Ghent criteria reached 71%. Of note, splicing mutations accounted for 19% of all mutations, which is more than previously reported. In conclusion, this comprehensive approach successfully detected clinical phenotypes of Japanese patients with MS and demonstrated the usefulness and feasibility of this microarray-based high-throughput resequencing system for mutational analysis of MS.

[Home medical care center project for an aging society]

We have to create a new paradigm for home medical care system towards a historical increase of elderly population in Japan. Tokyo University and Chiba University have been collaborating to erect a home medical care support center in Kashiwa, Chiba prefecture. We have been constructing a support center as well as a home care doctor system, and also created a teaching course for GPs to learn a home care doctor activity. We have also been constructing a regional network system called IT Net in Chiba, which connects all the entire medical and care staff. We will expand this model in many places and to instruct medical students and residents there in the near future.

Posterior column ataxia with retinitis pigmentosa in a Japanese family with a novel mutation in FLVCR1

Posterior column ataxia with retinitis pigmentosa (PCARP) is an autosomal recessive neurodegenerative disorder characterized by retinitis pigmentosa and sensory ataxia. Previous studies of PCARP in two families showed a linkage to 1q31-q32. However, detailed investigations on the clinical presentations as well as molecular genetics of PCARP have been limited. Here, we describe a Japanese consanguineous family with PCARP. Two affected siblings suffered from childhood-onset retinitis pigmentosa and slowly progressive sensory ataxia. They also showed mild mental retardation, which has not been described in patients with PCARP. Parametric linkage analysis using high-density single nucleotide polymorphism arrays supported a linkage to the same locus. Target capture and high-throughput sequencing technologies revealed a novel homozygous c.1477G>C (G493R) mutation in FLVCR1, which cosegregated with the disease. A recent study has identified three independent mutations in FLVCR1 in the original and other families. Our results further confirmed that PCARP is caused by mutations in FLVCR1.

Itraconazole-induced cholestasis: involvement of the inhibition of bile canalicular phospholipid translocator MDR3/ABCB4

Biliary secretion of bile acids and phospholipids, both of which are essential components of biliary micelles, are mediated by the bile salt export pump (BSEP/ABCB11) and multidrug resistance 3 P-glycoprotein (MDR3/ABCB4), respectively, and their genetic dysfunction leads to the acquisition of severe cholestatic diseases. In the present study, we found two patients with itraconazole (ITZ)-induced cholestatic liver injury with markedly high serum ITZ concentrations. To characterize the effect of ITZ on bile formation in vivo, biliary bile acids and phospholipids were analyzed in ITZ-treated rats, and it was revealed that biliary phospholipids, rather than bile acids, were drastically reduced in the presence of clinically relevant concentrations of ITZ. Moreover, by using MDR3-expressing LLC-PK1 cells, we found that MDR3-mediated efflux of [¹⁴C]phosphatidylcholine was significantly reduced by ITZ. In contrast, BSEP-mediated transport of [³H]taurocholate was not significantly affected by ITZ, which is consistent with our in vivo observations. In conclusion, this study suggests the involvement of the inhibition of MDR3-mediated biliary phospholipids secretion in ITZ-induced cholestasis. Our approach may be useful for analyzing mechanisms of drug-induced cholestasis and evaluating the cholestatic potential of clinically used drugs and drug candidates.

IFNβ-1b may severely exacerbate Japanese optic-spinal MS in neuromyelitis optica spectrum

BACKGROUND

Interferon-β-1b (IFNβ-1b) has been used to prevent exacerbation of relapsing-remitting multiple sclerosis (RRMS) including optic-spinal multiple sclerosis (OSMS) in Japan. We encountered 2 patients with OSMS with unexpectedly severe exacerbation soon after the initiation of IFNβ-1b therapy. The experience urged us to retrospectively review the patients with RRMS who had been treated with IFNβ-1b to identify similar cases.

METHODS

At neurologic departments of 9 hospitals, the medical records of 56 patients with RRMS were reviewed to identify those who showed severe exacerbation soon after the initiation of IFNβ-1b therapy.

RESULTS

Of 56 patients with RRMS, we identified 7 who experienced severe exacerbation (exacerbation with increased scores of Expanded Disability Status Scale ≧7.0) within 90 days of the initiation of IFNβ-1b therapy. In all 7 patients, the exacerbations after the initiation of IFNβ-1b therapy were more severe than those experienced by the individual patients before the use of IFNβ-1b, and seemed to have occurred unexpectedly in a short time after the initiation of INFβ-1b therapy. A retrospective analysis revealed that all 7 patients had antibodies toward aquaporin 4, and the clinical features of all 7 patients after the exacerbation were consistent with those of neuromyelitis optica (NMO) spectrum.

CONCLUSIONS

Our study suggests that IFNβ-1b may trigger severe exacerbation in patients with the NMO spectrum. In INFβ-1b therapy, cases in NMO spectrum should be carefully excluded.

Mechanisms of genomic instabilities underlying two common fragile-site-associated loci, PARK2 and DMD, in germ cell and cancer cell lines

Common fragile sites (CFSs) are specific chromosome regions that exhibit an increased frequency of breaks when cells are exposed to a DNA-replication inhibitor such as aphidicolin. PARK2 and DMD, the causative genes for autosomal-recessive juvenile Parkinsonism and Duchenne and Becker muscular dystrophy, respectively, are two very large genes that are located within aphidicolin-induced CFSs. Gross rearrangements within these two genes are frequently observed as the causative mutations for these diseases, and similar alterations within the large fragile sites that surround these genes are frequently observed in cancer cells. To elucidate the molecular mechanisms underlying this fragility, we performed a custom-designed high-density comparative genomic hybridization analysis to determine the junction sequences of approximately 500 breakpoints in germ cell lines and cancer cell lines involving PARK2 or DMD. The sequence signatures where these breakpoints occur share some similar features both in germ cell lines and in cancer cell lines. Detailed analyses of these structures revealed that microhomologies are predominantly involved in rearrangement processes. Furthermore, breakpoint-clustering regions coincide with the latest-replicating region and with large nuclear-lamina-associated domains and are flanked by the highest-flexibility peaks and R/G band boundaries, suggesting that factors affecting replication timing collectively contribute to the vulnerability for rearrangement in both germ cell and somatic cell lines.

Changes in saliva interleukin-6 levels in patients with oral squamous cell carcinoma

OBJECTIVE

The aim of this study was to elucidate changes in interleukin-6 (IL-6) levels in whole saliva during the treatment of patients with oral squamous cell carcinoma (OSCC).

STUDY DESIGN

Twenty-nine consecutive inpatients with OSCC were enrolled. Stimulated saliva was collected just after hospitalization (period 1), just before main treatment (surgery in 26 cases; period 2), and at the time of discharge (period 3). The mean intervals were 11+/-8 days between periods 1 and 2 and 30+/-18 days between periods 2 and 3. Nineteen age-matched healthy control subjects were also recruited. Interleukin-6 concentrations were measured by a highly sensitive chemiluminescent enzyme immunoassay.

RESULTS

Interleukin-6 was detected in 23 out of 29 samples in the OSCC group in period 1. The concentration of IL-6 was significantly higher in the OSCC group (mean 20.1+/-36.3 pg/mL) than in the control subjects (0.6+/-0.8 pg/mL; P=.003). The mean concentration of IL-6 at period 2 was 43.6+/-95.6 pg/mL, significantly higher than at period 1 (P=.002), and at period 3 was 17.1+/-27.6 pg/mL (P=.52 [compared with period 2]).

CONCLUSIONS

Interleukin-6 was up-regulated in saliva in the OSCC patients. The IL-6 level tended to increase before treatment, and it returned to baseline levels after treatment.

Oral health care reduces the risk of postoperative surgical site infection in inpatients with oral squamous cell carcinoma

PURPOSE

Postoperative wound infection (WI) is a main complication after head and neck surgery. Poor oral health may be a risk factor for WI. We therefore assessed the contribution of oral health care in preventing postoperative WI in patients with oral squamous cell carcinoma (OSCC).

METHODS

A total of 66 consecutive inpatients with OSCC (mean age, 68 years) was divided into two groups that did or did not receive oral health care. There were no significant between group differences in gender, age, or T-, N-, or clinical stage. Patients in the care group were given oral health care plans by doctors of oral medicine, whereas patients in the control group were not. Twenty-three variables were recorded for each patient.

RESULTS

WI was observed in 14/66 patients (21%), three (3/33 = 9%) in the care group and 11 (11/33 = 33%) in the control group (p < 0.025). Univariate statistical analysis showed that 11 factors correlated with WI significantly: T-stage, clinical stage, wearing of dentures, tracheostomy, neck dissection, tissue transplantation, oral health care, preoperative radiation, blood transfusion, operation time, and blood loss. In multiple logistic regression analysis, only two factors were significant independent risk factors for WI: tissue transplantation (p = 0.01; odds ratio, 24.5) and lack of oral health care (p = 0.04; odds ratio, 6.0).

CONCLUSION

Oral health care may reduce the risk of postoperative WI in patients with OSCC.

TRPM7 is not associated with amyotrophic lateral sclerosis-parkinsonism dementia complex in the Kii peninsula of Japan

Amyotrophic lateral sclerosis-parkinsonism dementia complex (ALS/PDC) is a distinct neurodegenerative disorder characterized by ALS pathology with neurofibrillary tangles (NFTs) in the spinal cord and brain. Recent clinical studies have revealed a high incidence and a high familial occurrence of ALS/PDC in both Guam and the Kii peninsula of Japan, suggesting a strong genetic predisposition to this disorder. The T1482I variant (rs8042919) of TRPM7 gene which is suggested to play roles in regulating the cellular homeostasis of Ca(2+), Mg(2+), and trace metals, has recently been reported to be associated with Guamanian patients with ALS/PDC. To investigate whether TRPM7 is associated with Kii ALS/PDC, we conducted parametric linkage analyses of the TRPM7 locus in a large extended family with ALS/PDC. Linkage analysis did not reveal any evidence supporting the linkage to the TRPM7 locus. Resequencing of the entire coding region of TRPM7 did not reveal any pathogenic mutations in an affected individual in this family. The allele frequencies of the T1482I in affected individuals in this family or in those from other families are not significantly different from those in regional controls or those in HapMap-JPT samples. These results indicate that TRPM7 is not associated with ALS/PDC in the Kii peninsula of Japan.

TDP-43 M337V mutation in familial amyotrophic lateral sclerosis in Japan

The clinical features of a Japanese family with autosomal dominant adult-onset amyotrophic lateral sclerosis (ALS) are reported. Weakness initially affected the bulbar musculature, with later involvement of the extremities. Genetic studies failed to detect any mutations of the Cu/Zn superoxide dismutase-1 (SOD1) and Dynactin1 (DCTN1) genes, but revealed a single base pair change from wild-type adenine to guanine at position 1009 in TAR-DNA-binding protein (TDP-43), resulting in a methionine-to-valine substitution at position 337. The immunohistochemical study on autopsied brain of the proband's aunt showed TDP-43-positive cytoplasmic inclusions in the anterior horn cells of the spinal cord and in the hypoglossal nucleus, as well as glial cytoplasmic inclusions in the precentral gyrus, suggesting that a neuroglial proteinopathy was related to TDP-43. In conclusion, a characteristic clinical phenotype of familial ALS with initial bulbar symptoms occurred in this family with TDP-43 M337V substitution, the pathomechanism of which should be elucidated.

A case of atypical amyloid polyneuropathy with predominant upper-limb involvement with the diagnosis unexpectedly found at lung operation

We present a patient of familial amyloid polyneuropathy (FAP) with predominant upper-limb involvement, the pattern of which resembled a mononeuropathy multiplex pattern. Sural nerve biopsy failed to diagnose the disorder, but lung partial resection performed later for other diagnostic purposes suggested FAP. A rare mutation in the transthyretin gene (S50R) was subsequently confirmed. Diagnostic challenges of FAP with atypical clinical presentations, including difficulties in pathological diagnosis, are discussed with a review of the literature.

Mutations for Gaucher disease confer high susceptibility to Parkinson disease

BACKGROUND

Increased frequency of pathogenic variants in GBA, the causative gene for Gaucher disease, has been suggested to be associated with Parkinson disease (PD).

OBJECTIVES

To conduct comprehensive resequencing of GBA to identify all sequence variants and to investigate the association of these variants with PD.

DESIGN

Case-control study.

SETTING

Multicenter university-based study.

PARTICIPANTS

Five hundred thirty-four patients with PD, 34 families in which multiple patients with PD are present, and 544 control subjects.

MAIN OUTCOME MEASURES

Disease status and GBA variations.

RESULTS

Comprehensive resequencing of GBA in 534 patients with PD and 544 controls revealed 27 sequence variants: 11 pathogenic variants associated with Gaucher disease, 11 nonsynonymous variants not associated with Gaucher disease, and 5 synonymous variants. Fifty patients with PD (9.4%) had 1 of the 11 pathogenic variants in the heterozygous state, whereas only 2 controls (0.37%) had such variants (odds ratio, 28.0). Among the pathogenic variants, R120W and L444P/RecNciI were highly prevalent, and each showed a significant association with PD. Furthermore, other rare pathogenic variants were found in 13 patients with PD but not in the controls, further confirming the role of these rare variants in the susceptibility to PD. Patients with PD carrying pathogenic variants were significantly younger than those not carrying them. In addition, concordance of PD states and pathogenic variants was observed in 8 multiplex families with PD.

CONCLUSION

Heterozygous pathogenic variants in GBA confer a high risk for sporadic PD, even for familial clustering, and are associated with significantly earlier age at onset of disease.

A novel ferritin light chain gene mutation in a Japanese family with neuroferritinopathy: description of clinical features and implications for genotype-phenotype correlations

Neuroferritinopathy is a hereditary neurodegenerative disorder caused by mutations in the ferritin light chain gene (FTL1). The cardinal features are progressive movement disturbance, hypoferritinemia, and iron deposition in the brain. To date, five mutations have been described in Caucasian and Japanese families, but the genotype-phenotype correlations remain to be established. We identified a novel FTL1 mutation (exon 4, c.641/642, 4-nucletotide duplication) in a Japanese family and compared the clinical traits with those previously reported. All mutations but one are insertions in exon 4, resulting in frameshifts. Clinical features are similar among patients with the same mutations. Middle-age onset chorea is common in patients with insertions in the 5' portion of exon 4 including our cases, whereas patients with insertions in the 3' portion of exon 4 develop early-onset tremor, suggesting genotype-phenotype correlations. In this family, male predominance and normal serum ferritin levels are characteristic.

[Neurodegenerative disease]

Cloning of responsible genes for hereditary neurological diseases has been one of the most important fields in disease genome research since early days. To date, over two hundred genes for degenerative diseases have been identified. The accomplishment of the Human Genome Project and the development of DNA chip technology enabled man to conduct genome-wide association study(GWAS) of large scale sample sets, opening the way to elucidate genetic factors of sporadic diseases. Several results have been reported, including GWAS for amyotrophic lateral sclerosis and multiple sclerosis. Now new sequencing technology is emerging, which makes personal genome resequencing possible. Deep resequencing or personal genome would change revolutionarily the paradigm of genome research and medicine.

SNP haplotype mapping in a small ALS family

The identification of genes for monogenic disorders has proven to be highly effective for understanding disease mechanisms, pathways and gene function in humans. Nevertheless, while thousands of Mendelian disorders have not yet been mapped there has been a trend away from studying single-gene disorders. In part, this is due to the fact that many of the remaining single-gene families are not large enough to map the disease locus to a single site in the genome. New tools and approaches are needed to allow researchers to effectively tap into this genetic gold-mine. Towards this goal, we have used haploid cell lines to experimentally validate the use of high-density single nucleotide polymorphism (SNP) arrays to define genome-wide haplotypes and candidate regions, using a small amyotrophic lateral sclerosis (ALS) family as a prototype. Specifically, we used haploid-cell lines to determine if high-density SNP arrays accurately predict haplotypes across entire chromosomes and show that haplotype information significantly enhances the genetic information in small families. Panels of haploid-cell lines were generated and a 5 centimorgan (cM) short tandem repeat polymorphism (STRP) genome scan was performed. Experimentally derived haplotypes for entire chromosomes were used to directly identify regions of the genome identical-by-descent in 5 affected individuals. Comparisons between experimentally determined and in silico haplotypes predicted from SNP arrays demonstrate that SNP analysis of diploid DNA accurately predicted chromosomal haplotypes. These methods precisely identified 12 candidate intervals, which are shared by all 5 affected individuals. Our study illustrates how genetic information can be maximized using readily available tools as a first step in mapping single-gene disorders in small families.

Sporadic ataxias in Japan--a population-based epidemiological study

Sporadic spinocerebellar ataxias (SCAs) comprise heterogeneous diseases with poorly understood epidemiologies and etiologies. A population-based epidemiological analysis of sporadic ataxias in the Japanese population was described. The prevalence rate of SCAs in the Japanese population is estimated to be 18.5/100,000. Sporadic SCAs account for 67.2% of total SCAs including hereditary SCAs, with olivopontocerebellar atrophy (OPCA) being the most common form sporadic ataxia (64.7%). The natural history analysis conducted on the basis of International Cooperative Ataxia Rating Scale (ICARS) showed that only 33% of patients with OPCA were able to walk at least with one stick 4-5 years after the onset of OPCA, which is much less than that of patients with cortical cerebellar atrophy (CCA). Similarly, 43% of patients with OPCA were able to stand alone 4-5 years after the onset, while 76% of patients with CCA were able to stand alone at the same disease duration. A population-based epidemiological analysis should provide essential information on the natural history of SCAs.

Morphological evaluation of the human pyramidal tract: tapering of axons

It is generally accepted that nerve fiber conduction velocity is directly proportional to the fiber diameter under the condition, based on a supposition, that the transverse area of axons is normally maintained constant. Using an ideal preparation method for the purpose of axonal discrimination, we examined 43 human spinal cords after making transverse sections at the cervical, thoracic, lumbar and sacral levels and found a tapering of the axons in the lateral pyramidal tract, as the cross-sectional area of the pyramidal axons showed a definite decrease from the cervical to the sacral levels. Our results contradict the supposition that the transverse area of axons is normally maintained constant, which has for a long time been believed to be true without any evidence for it.

Morphometric and functional correlation of human neuronal somata: pyramidal motor, special sensory and general sensory systems

Using an ideal tissue preparation method, we found a definite correlation between various human neuronal somata from the view point of accurate morphometry and functional evaluations. We believe this study may be of value, or even indispensable in the correct understanding of neurological symptomatology and phenomenology.

SNP HiTLink: a high-throughput linkage analysis system employing dense SNP data

BACKGROUND

During this recent decade, microarray-based single nucleotide polymorphism (SNP) data are becoming more widely used as markers for linkage analysis in the identification of loci for disease-associated genes. Although microarray-based SNP analyses have markedly reduced genotyping time and cost compared with microsatellite-based analyses, applying these enormous data to linkage analysis programs is a time-consuming step, thus, necessitating a high-throughput platform.

RESULTS

We have developed SNP HiTLink (SNP High Throughput Linkage analysis system). In this system, SNP chip data of the Affymetrix Mapping 100 k/500 k array set and Genome-Wide Human SNP array 5.0/6.0 can be directly imported and passed to parametric or model-free linkage analysis programs; MLINK, Superlink, Merlin and Allegro. Various marker-selecting functions are implemented to avoid the effect of typing-error data, markers in linkage equilibrium or to select informative data.

CONCLUSION

The results using the 100 k SNP dataset were comparable or even superior to those obtained from analyses using microsatellite markers in terms of LOD scores obtained. General personal computers are sufficient to execute the process, as runtime for whole-genome analysis was less than a few hours. This system can be widely applied to linkage analysis using microarray-based SNP data and with which one can expect high-throughput and reliable linkage analysis.

[Alien hand sign observed at the initial stage of a case of Creutzfeldt-Jakob disease]

A 68-year-old man was admitted to our hospital in the mid-October of 2006 because of a one-month history of peculiar movements of the left hand, which had been preceded by one month by awkward motions in the left leg. Upon neurological examination, spontaneous involuntary movement of the left hand was found. His left hand with his index finger stretched moved toward his right side spontaneously. He could not control his left leg freely. Although he showed mild ataxia in his left hand, there was no weakness, no dystonia, and no apraxia. No sensory abnormality was detected except for mild deep-sensation impairment in his left foot. The results of magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI) were normal; however, single-photon emission computed tomography (SPECT) showed hypoperfusion in the right hemisphere. At the time of admission, although a clinical diagnosis could not be made, we considered that the involuntary movements of his left hand were consistent with alien hand sign (AHS). Two and a half months after its onset, with the development of rapidly progressive dementia and generalized myoclonus, AHS gradually disappeared. Three months after the AHS onset, MRI with DWI showed restricted diffusion within the cortex involving the cingulated gyrus and bilateral temporal lobes, which was more prominent on the right than on the left side. Four months after the AHS onset, 14-3-3 protein level of the cerebrospinal fluid was elevated, and EEG recordings showed diffuse slowing of basic activity with periodic complexes. The patient was clinically diagnosed as having CJD. The patient died of pneumonia four and a half months after the AHS onset. AHS has rarely been reported in patients with CJD. Our case illustrates the importance of considering CJD in the differential diagnosis, if the patient showed AHS, even with normal MRI findings.

Morphometric evaluation of the aging process in various human nerve fibers

We carried out a morphometric comparison of tissue sections from the human spinal cord, medulla oblongata, cranial nerves, autonomic nerves and spinal nerves with the help of a very accurate method that includes two-step fixation, nitrocellulose embedding and discriminative staining. We conducted morphometric evaluations to compare various axonal areas between different individuals using a combination of an image analyzer and a high power microscope. Our study showed a negative correlation between age and axonal area in all nerves except the greater splanchnic nerve. We believe that such data would not have been discovered without the use of our sophisticated electronic equipment together with the special preparation method we employed. Recourse to such methodology will allow more precise study of neurohistology and lead to better understanding of the aging process in human beings.

Development of a high-throughput microarray-based resequencing system for neurological disorders and its application to molecular genetics of amyotrophic lateral sclerosis

BACKGROUND

Comprehensive resequencing of the causative and disease-related genes of neurodegenerative diseases is expected to enable (1) comprehensive mutational analysis of familial cases, (2) identification of sporadic cases with de novo or low-penetrant mutations, (3) identification of rare variants conferring disease susceptibility, and ultimately (4) better understanding of the molecular basis of these diseases.

OBJECTIVE

To develop a microarray-based high-throughput resequencing system for the causative and disease-related genes of amyotrophic lateral sclerosis (ALS) and other neurodegenerative diseases.

DESIGN

Validation of the system was conducted in terms of the signal-to-noise ratio, accuracy, and throughput. Comprehensive gene analysis was applied for patients with ALS. Subjects Ten patients with familial ALS, 35 patients with sporadic ALS, and 238 controls.

RESULTS

The system detected point mutations with 100% accuracy and completed the resequencing of 270 kilobase pairs in 3 working days with greater than 99.9% accuracy of base calls, or the determination of base(s) at each position. Analysis of patients with familial ALS revealed 2 SOD1 mutations. Analysis of the 35 patients with sporadic ALS revealed a previously known SOD1 mutation, S134N, a novel putative pathogenic DCTN1 mutation, R997W, and 9 novel variants including 4 nonsynonymous heterozygous variants consisting of 2 in ALS2, 1 in ANG, and 1 in VEGF that were not found in the controls.

CONCLUSION

The DNA microarray-based resequencing system is a powerful tool for high-throughput comprehensive analysis of causative and disease-related genes. It can be used to detect mutations in familial and sporadic cases and to identify numerous novel variants potentially associated with genetic risks.

Morphological evaluation of the human pyramidal tract: gender and age differences

Using a preparation method composed of secondary chromic acid fixation, nitrocellulose embedding and Luxol fast blue-PAS-hematoxylin stain (a discriminative staining method) for the purpose of axonal discrimination, we examined 43 human spinal cords (31 males and 12 females) at the C5 level to find the differences due to gender and aging in axons of the lateral corticospinal tract. These results can be of great help in understanding the motor functions in relation to gender differences and the aging process.

Lymphomatoid granulomatosis involving central nervous system successfully treated with rituximab alone

OBJECTIVE

To report the successful treatment of a patient with lymphomatoid granulomatosis (LYG), a rare Epstein-Barr virus-positive lymphoproliferative disorder, using rituximab (anti-CD20 monoclonal antibody). The prognosis for LYG has been reported to be poor, and no satisfactory treatment has been established. Because central nervous system (CNS) involvement of LYG has been known to show poor prognosis, the establishment of an effective treatment for CNS LYG with mild adverse effects is desired.

DESIGN

Case report.

SETTING

University hospital.

PATIENT

A 48-year-old Japanese man presenting with slowly progressive spastic paraparesis diagnosed as LYG involving the CNS and lungs.

INTERVENTIONS

The patient was treated with rituximab (375 mg/m2, once weekly for 1 month) alone. Main Outcome Measure Improvement of the lesions on imaging.

RESULTS

The neurological signs resolved and the lesions in the CNS and lungs were mostly diminished after the rituximab monotherapy without any adverse effects. The patient stayed in remission for 18 months.

CONCLUSION

Rituximab monotherapy was effective in treating the patient; hence, rituximab should be considered as the initial treatment against LYG involving the CNS.

Total deletion and a missense mutation of ITPR1 in Japanese SCA15 families

BACKGROUND

Spinocerebellar ataxia type 15 (SCA15) is a progressive neurodegenerative disorder characterized by pure cerebellar ataxia, very slow progression, and distinct cerebellar atrophy. The locus for SCA15 was first mapped to 3p24.2-3pter in an Australian family. We have subsequently mapped two Japanese families presenting with ataxia and postural tremor of the head, arm, or trunk to the SCA15 locus. Recently, partial deletions involving both the type 1 inositol 1,4,5-triphosphate receptor (ITPR1) and sulfatase modifying factor 1 (SUMF1) genes have been identified in Australian and British families with SCA15.

METHODS

We conducted fine haplotype analysis on the region including ITPR1. To identify the deletion, we conducted gene dosage analysis and array-based comparative genomic hybridization (aCGH) analysis. Gene expression analysis was performed using quantitative real-time reverse transcription PCR. Mutational analyses of ITPR1 and SUMF1 were also performed.

RESULTS

We have identified a 414-kb deletion including the entire ITPR1 and exon 1 of SUMF1 in patients in family A. The expression levels of ITPR1 and SUMF1 mRNAs of the patient were half those of the normal control. Furthermore, in family B, we have identified a C-to-T substitution at position 8581 of ITPR1, resulting in the amino acid substitution of leucine for proline at codon 1059, which is highly conserved among species.

CONCLUSIONS

Our results strongly confirm that ITPR1 is the causative gene for SCA15 and suggest that we need to investigate the point mutation in ITPR1 in the patients with autosomal dominant cerebellar ataxia and tremor.

Comparison of preparation methods for the evaluation of nerve axons

We have conducted a study to compare various preparation methods, including a certain number of new methods, to find which ones are best suited to the morphological evaluation of nerve fibers in the pyramidal tract of the human medulla oblongata. Our main concern was to find fixation and staining methods that would minimize errors, especially regarding the tissue shrinkage ratio and the ease of staining. From the two fixation methods we examined, the most satisfactory was the secondary chromic acid fixation (which gave the best overall results when followed by nitrocellulose embedding), as it gives the lowest shrinkage ratio with the narrowest range (10 +/- 0%). Among the ten staining methods we tested, we found that the most suitable for morphological evaluation were the discriminative staining methods (Luxol fast blue-Periodic acid-Schiff-Hematoxylin stain, Masson-Goldner-Goto method and modified Hematoxylin-Eosin stain) and the silver impregnation methods (Luxol fast blue-Silver impregnation and Luxol fast blue-Silver impregnation-Periodic acid-Schiff-Hematoxylin).

Novel SIL1 mutations and exclusion of functional candidate genes in Marinesco-Sjögren syndrome

Marinesco-Sjögren syndrome (MSS) is a rare autosomal recessively inherited neurodegenerative disorder characterized by cerebellar ataxia, cataracts, mental retardation, and progressive myopathy. Recently, mutations in the SIL1 gene, which encodes an endoplasmic reticulum (ER) resident cochaperone, were identified as a major cause of MSS. We here report four novel mutations in SIL1, including the first missense substitution p.Leu457Pro described in MSS. In addition, we excluded three functional candidate genes, HSPA5, HYOU1, and AARS, as causative genes in SIL1 mutation-negative patients. To understand the mechanisms of disturbed SIL1 function, we studied the subcellular localization of the missense mutant Leu457Pro protein in COS-1 cells. Moreover, we studied a mutant protein lacking the putative C-terminal ER retrieval signal. In contrast to the wild-type protein's localization to ER and Golgi apparatus, both mutant proteins formed aggregates within the ER depending on the expression level. These data imply that aggregation of mutant proteins may contribute to MSS pathogenesis. The genetic background of a subgroup of patients with MSS remains uncovered.

[Molecular genetic analysis of amyotrophic lateral sclerosis/parkinsonism-dementia complex (ALS/PDC) in the Kii peninsula]

Recent clinical research have revealed that more than 70% of the patients with ALS/PDC, which is highly prevalent in Hohara area in the Kii peninsula, have family history. 80% of Guamanian patients, who have identical pathological findings to those of ALS/PDC in Kii, are also known to have family history with non-Mendelian trait. These facts suggest strong genetic predisposition to ALS/PDC in both Kii and Guam. However, no genes associated with ALS/PDC have been identified by molecular genetic studies using candidate gene approach. To identify the causative or susceptibility genes for ALS/PDC, we have conducted a genomewide linkage analysis for five families with ALS/PDC in Hohara. The fact that affected individuals were ascertained in successive generations suggest an autosomal dominant (AD) inheritance, while the presence of consanguinity suggests an autosomal recessive (AR) inheritance. Although we can raise possibilities of AD model with incomplete penetrance or AR model with high gene frequency (pseudo-dominant model), the mode of inheritance of ALS/PDC families is complicated and controversial. Therefore, we are also conducting model-free (non-parametric) linkage analysis to identify the disease locus without setting mode of inheritance. More family members and detailed clinical evaluations are required to obtain the convincing evidence of linkage.

Severe hypokinesis caused by paraneoplastic anti-Ma2 encephalitis associated with bilateral intratubular germ-cell neoplasm of the testes

We report a 40-year-old man with severe hypokinesis as paraneoplastic manifestation of a microscopic "carcinoma in situ" of the testis. The young age of the patient, along with progressive neurologic deterioration, detection of anti-Ma2 antibodies, and ultrasound findings of bilateral microcalcifications, led to bilateral orchiectomy, revealing the tumor in both testes. After orchiectomy, neurological symptoms stabilized, but the patient eventually died of systemic complications caused by his severe neurological deficits. Anti-Ma2 paraneoplastic encephalitis should be considered in patients with severe hypokinesis, and intensive investigation and aggressive approach to treatment is encouraged to prevent progression of the neurological deficits.

Multiplex families with multiple system atrophy

BACKGROUND

Multiple system atrophy (MSA) has been considered a sporadic disease, without patterns of inheritance.

OBJECTIVE

To describe the clinical features of 4 multiplex families with MSA, including clinical genetic aspects.

DESIGN

Clinical and genetic study.

SETTING

Four departments of neurology in Japan. Patients Eight patients in 4 families with parkinsonism, cerebellar ataxia, and autonomic failure with age at onset ranging from 58 to 72 years. Two siblings in each family were affected with these conditions.

MAIN OUTCOME MEASURES

Clinical evaluation was performed according to criteria by Gilman et al. Trinucleotide repeat expansion in the responsible genes for the spinocerebellar ataxia (SCA) series and for dentatorubral-pallidoluysian atrophy (DRPLA) was evaluated by polymerase chain reaction. Direct sequence analysis of coding regions in the alpha-synuclein gene was performed.

RESULTS

Consanguineous marriage was observed in 1 of 4 families. Among 8 patients, 1 had definite MSA, 5 had probable MSA, and 2 had possible MSA. The most frequent phenotype was MSA with predominant parkinsonism, observed in 5 patients. Six patients showed pontine atrophy with cross sign or slitlike signal change at the posterolateral putaminal margin or both on brain magnetic resonance imaging. Possibilities of hereditary ataxias, including SCA1 (ataxin 1, ATXN1), SCA2 (ATXN2), Machado-Joseph disease/SCA3 (ATXN1), SCA6 (ATXN1), SCA7 (ATXN7), SCA12 (protein phosphatase 2, regulatory subunit B, beta isoform; PP2R2B), SCA17 (TATA box binding protein, TBP) and DRPLA (atrophin 1; ATN1), were excluded, and no mutations in the alpha-synuclein gene were found.

CONCLUSIONS

Findings in these multiplex families suggest the presence of familial MSA with autosomal recessive inheritance and a genetic predisposition to MSA. Molecular genetic approaches focusing on familial MSA are expected to provide clues to the pathogenesis of MSA.