Causes of infectious mononucleosis-like syndrome in adult patients.
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Biomedical subjects
Publications and source records attributed to Naomi Matsumoto.
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Two AAA peroxins, Pex1p and Pex6p, are encoded by PEX1 and PEX6, the causal genes for peroxisome biogenesis disorders of complementation group 1 (CG1) and CG4, respectively. PEX26 responsible for peroxisome biogenesis disorders of CG8 encodes Pex26p, the recruiter of Pex1p.Pex6p complexes to peroxisomes. We herein assigned the binding regions between human Pex1p and Pex6p and elucidated pivotal roles of the AAA cassettes, called D1 and D2 domains, in Pex1p-Pex6p interaction and peroxisome biogenesis. ATP binding in both AAA cassettes but not ATP hydrolysis in D2 of both Pex1p and Pex6p was prerequisite for Pex1p-Pex6p interaction and their peroxisomal localization. The AAA cassettes, D1 and D2, were essential for peroxisome-restoring activity of Pex1p and Pex6p. In HEK293 cells, endogenous Pex1p was partly localized likely as a homo-oligomer in the cytoplasm, while Pex6p and Pex26p were predominantly localized on peroxisomes. Interaction of Pex1p with Pex6p conferred a conformational change and dissociation of the Pex1p oligomer. These results suggested that Pex1p possesses two distinct oligomeric forms, a homo-oligomer in the cytosol and a hetero-oligomer on peroxisome membranes, possibly playing distinct functions in peroxisome biogenesis.
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OBJECTIVE: To estimate the rate that subjects with Mild Memory Impairment /Not Dementia (MMI/ND) shifted to dementia in a population-based cohort and to establish simple diagnostic methods for identification of high-risk persons for dementia. METHODS: Subjects in a community-based elderly cohort of MMI/ND were followed longitudinally. Subjects were selected from the participants in the first Nakayama study. MMI/ND was defined as memory deficit with objective memory assessment, without dementia, impairment of general cognitive function, or disability in activities of daily living. The conversion rate was calculated using the person-year method. RESULTS: At baseline, the sample consisted of 104 subjects (59 female; 45 male) selected from 1,162 community dwellers aged over 65 year. During the five-year follow-up, 14 subjects died, 13 moved to other communities, and six refused to participate further. Eleven (10.6%) subjects were diagnosed with Alzheimer's disease (AD), five (4.8%) were diagnosed with vascular dementia (VaD), and six (5.8%) were diagnosed with dementia of other etiology. The annual conversion rate that MMI/ND shifted to AD is calculated on 8.5% per 100 person-year, and shifted to dementia on 16.1% per 100 person-year in this survey. CONCLUSIONS: The rate at which subjects with MMI/ND whose conditions shifted to dementia was the same as the rate that subjects with mild cognitive impairment (MCI) shifted to dementia in a previous report. It would be useful to identify groups of high-risk individuals for dementia by simple diagnostic methods.
OBJECTIVE: Neuropsychiatric disturbances are common and burdensome symptoms of dementia. Assessment and measurement of neuropsychiatric disturbances are indispensable to the management of patients with dementia. Neuropsychiatric Inventory (NPI) is a comprehensive assessment tool that evaluates psychiatric symptoms in dementia. We translated the NPI-Caregiver Distress Scale part of NPI (NPI-D) and NPI-Brief Questionnaire Form (NPI-Q) into Japanese and examined their validity and reliability. SUBJECTS AND METHODS: The subjects were 152 demented patients and the caregivers who lived with them. These patients consisted of 76 women and 76 men; their mean age was 73.9 +/- 7.8 (S.D.; range: 49 to 93) years. Their caregivers consisted of 46 men and 106 women; their mean age was 65.0 +/- 11.4 (S.D.; range: 35 to 90) years. The Mini-Mental State Examination (MMSE) was conducted with all patients and NPI-Q, NPI, NPI-D, and the Zarit caregiver burden interview (ZBI) were conducted with all caregivers. We examined validity of NPI-D by comparing its score with the MMSE and ZBI scores, and the validity of NPI-Q by comparing its score with the NPI and NPI-D scores. In order to evaluate test-retest reliability, NPI-D was re-adopted to 30 randomly selected caregivers by a different examiner one month later and NPI-Q was re-executed by 27 randomly selected caregivers one day later. RESULTS: Total NPI-D score was significantly correlated with ZBI (rs = 0.59, p < 0.01). Test-retest reliability of NPI-D was adequate (ri = 0.47, p < 0.01). Total NPI-Q severity score and distress score were strongly correlated with NPI (r = 0.77, p < 0.01) and NPI-D (r = 0.80, p < 0.01) scores, respectively. Test-retest reliability of the scores of NPI-Q was acceptably high (the severity score; ri = 0.81, p < 0.01, the distress score; ri = 0.80, p < 0.01). CONCLUSION: The Japanese version of NPI-D and NPI-Q demonstrated sufficient validity and reliability as well as the original version of them. These are useful tools for evaluating psychiatric symptoms in demented patients and their caregivers' distress attributable to these symptoms.
We examined alteration of regional cerebral blood flow (rCBF) in a case of Alzheimer's disease (AD) patient with musical hallucination. To detect regions related to musical hallucination, single-photon emission computed tomography (SPECT) imaging of the patient and nine sex, age, and cognitive function-matched AD patients without delusions and hallucinations were compared using statistical parametric mapping 99 (SPM99). In comparison with controls, the patient had increased rCBF in left temporal regions and left angular gyrus. This profile could be relevant to the neuroanatomical basis of musical hallucinations.
Peroxisome biogenesis disorders (PBDs) are fatal autosomal recessive diseases and are caused by impaired peroxisome biogenesis. PBDs are genetically heterogeneous and classified into 13 complementation groups (CGs). CG8 is one of the most common groups and has three clinical phenotypes, including Zellweger syndrome (ZS), neonatal adrenoleukodystrophy, and infantile Refsum disease (IRD). We recently isolated PEX26 as the pathogenic gene for PBD of CG8. Pex26p functions in recruiting to peroxisomes the complexes of the AAA ATPase peroxins, Pex1p and Pex6p. In the present work, we identified four distinct mutations in PEX26 from five patients of CG8 PBD including 2 with ZS and 3 with IRD, in addition to 7 mutant alleles in 8 patients in the first report describing the pathogenic PEX26 gene for CG8 PBD. Phenotype-genotype analyses revealed that temperature-sensitive (ts) peroxisome assembly gave rise to a milder IRD in contrast to the non-ts phenotype of the cells from ZS patients. Furthermore, we present several lines of evidence that show that the instability, insufficient binding to Pex1p x Pex6p complexes, or mislocalization of patient-derived Pex26p mutants is most likely responsible for the CG8 PBDs.
The human disorders of peroxisome biogenesis (PBDs) are subdivided into 12 complementation groups (CGs). CG8 is one of the more common of these and is associated with varying phenotypes, ranging from the most severe, Zellweger syndrome (ZS), to the milder neonatal adrenoleukodystrophy (NALD) and infantile Refsum disease (IRD). PEX26, encoding the 305-amino-acid membrane peroxin, has been shown to be deficient in CG8. We studied the PEX26 genotype in fibroblasts of eight CG8 patients--four with the ZS phenotype, two with NALD, and two with IRD. Catalase was mostly cytosolic in all these cell lines, but import of the proteins that contained PTS1, the SKL peroxisome targeting sequence, was normal. Expression of PEX26 reestablished peroxisomes in all eight cell lines, confirming that PEX26 defects are pathogenic in CG8 patients. When cells were cultured at 30 degrees C, catalase import was restored in the cell lines from patients with the NALD and IRD phenotypes, but to a much lesser extent in those with the ZS phenotype, indicating that temperature sensitivity varied inversely with the severity of the clinical phenotype. Several types of mutations were identified, including homozygous G89R mutations in two patients with ZS. Expression of these PEX26 mutations in pex26 Chinese hamster ovary cells resulted in cell phenotypes similar to those in the human cell lines. These findings confirm that the degree of temperature sensitivity in pex26 cell lines is predictive of the clinical phenotype in patients with PEX26 deficiency.
Peroxisomes are ubiquitous organelles with a single membrane that contain over 50 different enzymes that catalyse various metabolic pathways, including beta-oxidation and lipid synthesis. Peroxisome biogenesis disorders (PBDs), such as Zellweger syndrome and neonatal adrenoleukodystrophy, are fatal genetic diseases that are autosomal recessive. Among the PBDs of the 12 complementation groups (CGs), 11 associated PEX genes have been isolated. Accordingly, only the PBD pathogenic gene for CG8 (also called CG-A) remains unidentified. Here we have isolated human PEX26 encoding a type II peroxisomal membrane protein of relative molecular mass 34,000 (M(r) 34K) by using ZP167 cells, a Chinese hamster ovary (CHO) mutant cell line. Expression of PEX26 restores peroxisomal protein import in the fibroblasts of an individual with PBD of CG8. This individual possesses a homozygous, inactivating pathogenic point mutation, Arg98Trp, in Pex26. Pex6 and Pex1 of the AAA ATPase family co-immunoprecipitate with Pex26. Epitope-tagged Pex6 and Pex1 are discernible as puncta in normal CHO-K1 cells, but not in PEX26-defective cells. PEX26 expression in ZP167 cells re-establishes colocalization of Pex6 and Pex1 with Pex26, in a Pex6-dependent manner. Thus, Pex26 recruits Pex6-Pex1 complexes to peroxisomes.
Epoxy resins are widely used in adhesives, coatings, materials for molds and composites, and encapsulation. Acid anhydrides such as methyltetrahydrophthalic anhydride are being used as curing agents for epoxy resins. The anhydride hardeners are well-known industrial inhalant allergens, inducing predominantly type I allergies. In the electronic components industry, these substances have been consumed in large quantities. Therefore, safe use in the industry demands control of the levels of exposure causing allergic diseases in the workshop. We conducted a prospective survey of two electronics plants to clarify how to control the atmospheric level of the anhydrides in the work environment. Measurements of the levels of the anhydrides in air started according to the Working Environment Measurement Standards (Ministry of Labour Notification No. 46, 1976) in April 2000, along with improvements in the work environment. A value of 40 micrograms/m3 was adopted as the administrative control level to judge the propriety of the working environment control. A total of 2 unit work areas in both plants belonged to Control Class III. The exposure originated from manual loading, casting, uncured hot resins, and leaks in an impregnating-machine or curing ovens. In order to achieve the working environment control, complete enclosure of the source, installation of local exhaust ventilation, and improvement or maintenance of the local exhaust ventilation system were performed on the basis of the results of the working environment measurement, with the result that the work environment was improved (Control Class I). It became evident that these measures were effective just like other noxious substances.
In an electronics plant, a new one-component naphthalene type epoxy resin was used as an adhesive for reinforcing a circuit board. The resinous part of the adhesive consisted of diglycidyl ether of bisphenol A (DGEBA) and 1,6-bis(2,3-epoxypropoxy)naphthalene type epoxy resins. The hardener was methylhexahydrophthalic anhydride (MHHPA). Of 54 workers, 15 (27.8%) were diagnosed to have work-related dermatitis but were not patch tested. Therefore, it was impossible to determine the specific agent responsible for the worker's symptoms or to distinguish between allergic and irritant contact dermatitis. They worked without protective gloves until they started to develop skin symptoms. The hands were the commonly affected region (13 out of 15 cases). The latent period of dermatitis was very short (mean 2.2 weeks). Of these, 10 cases (66.7%) received medication for dermatitis, and 9 cases (60%) were transferred to other work. The work-related skin symptoms were closely related to the specific tasks, i.e., filling dispensers with the adhesive and manual application of the adhesive to a portion of a circuit board using a dispenser. For occupational hygiene reasons, contact with epoxy resins should be minimized by taking all possible measures into use, including protective gloves. Further studies are required to clarify the allergenicity of 1,6-bis(2,3-epoxypropoxy)naphthalene, since very little is known about the mechanism through which it leads to the symptoms of dermatitis.
We assessed the surgical indication in obstructive sleep apnea syndrome (OSAS) by comparing cephalometry between a responder group of uvulopalatopharyngoplasty (UPPP) and a nonresponder group. Cephalometric studies were conducted on 43 patients--42 men and one women--who required UPPP and underwent both pre- and postoperative polysomnography, and on 50 non-OSAS patients who formed the control group. Angles and distances were measured based on the Downs-Northwestern method as detailed in the reference cited. The comparison between the OSAS and control groups indicated anterior displacement of the maxilla, and anteroposterior discrepancies of the maxilla and the mandible in OSAS. Significant differences were seen in distance measurements for all values other than the distance from the sella to the nasion. We then compared the 3 groups--responders, nonresponders, and controls. From differences in the Y-axis angle, the Gonial angle, the ANB angle, the distance from the gonion to the menton, and the maximum thickness of the soft palate between responder and control groups, we concluded that the efficacy of UPPP is higher in OSAS patients who have several factors such as micrognathia, anteroposterior discrepancy in the maxillary and mandibular bases, and thick soft palate. We concluded that routinely conducting that cephalometric analysis would be useful for deciding on adopting UPPP.