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S Matsunaga

Publications and source records attributed to S Matsunaga.

At least 19 recordsLinked to original sources
PubMed2006

Nonsense mutation of feline beta-hexosaminidase beta-subunit (HEXB) gene causing Sandhoff disease in a family of Japanese domestic cats.

G(M2) gangliosidoses are inherited metabolic disorders and are caused by severely reduced enzymatic activity of lysosomal beta-hexosaminidase. In the present study, the open reading frame (ORF) of the HEXB gene in a family of Japanese domestic cats with G(M2) gangliosidosis variant 0 (Sandhoff disease) was determined. Two types of abnormal cDNA clones were obtained from the liver of an affected cat tissue. One showed a single nucleotide substitution from C to T at nucleotide position 667 of the HEXB ORF. In the deduced amino acid sequence, the codon of arginine was altered to a stop codon. The genotyping, using PCR-primer introduced restriction analysis confirmed that Sandhoff disease in this family is associated with this nonsense mutation. Discovery of the nonsense mutation will permit the confirmation of the clinical diagnosis of Sandhoff disease in conjugation with the already established enzyme-based test.

Animals↗
PubMed2006

Three-dimensional analysis of pulp chambers in maxillary second deciduous molars.

OBJECTIVE: The purpose of this study was to clarify the positional relationship between the crown contour and the pulp chamber using micro-CT system for restorations of maxillary second deciduous molar. METHODS: Five maxillary second deciduous molar teeth each from the deciduous dentition and the mixed dentition periods were used. The positional relationship between the crown contour and pulp chamber was three-dimensionally observed by micro-CT. In addition, the thickness of the dentin at each of the pulp horns and the volume ratio of the pulp chamber against the whole crown were measured. RESULTS: In relationship to the crown contour and the pulp chamber, the pulp horn of the mesiobuccal cusp showed greatest protrusion and eminent swelling of its mesial wall in both the deciduous dentition and the mixed dentition periods. Furthermore, the pulp chamber was shifted to the mesial side. The volume ratio of the pulp chamber to the whole crown, the ratio in the mixed dentition period showed to be significantly smaller than in the deciduous dentition period. The dentin thickness at the mesiobuccal pulp horn was the thinest. CONCLUSIONS: These results suggest that in preparation of cavities in maxillary second deciduous molars, care is necessary not to expose of the mesiobuccal pulp horn. Especially, the mesial wall of the mesiobuccal pulp horn should be noted.

Child↗
PubMed2006

Trisoxazole macrolides from Hexabranchus nudibranchs and other marine invertebrates.

Trisoxazole macrolides are cytotoxic and antifungal metabolites initially isolated from the egg-ribbons of the Hexabranchus nudibranch and later found in other marine invertebrates. They possess a characteristic macrolide portion, in which three contiguous oxazole units are integrated, and a side-chain with an N-methyl-vinylformamide terminus. The planar structures of the first members of this group, ulapualides and kabiramide C, were determined by interpretation of spectral data in conjunction with chemical degradation. Following these studies, the structures of approximately 35 congeners have been reported, including mycalolides from a marine sponge Mycale sp. The absolute stereochemistry of mycalolides was determined by chemical methods. Trisoxazole macrolides depolymerize F-actin and form a 1:1 complex with G-actin, thereby exhibiting potent toxicity toward eukaryotic cells. X-ray crystallography established the mode of binding of some of the members to G-actin and their absolute stereochemistry.

Actins↗
PubMed2006

Calreticulin as a new histone binding protein in mitotic chromosomes.

Calreticulin (CRT) is a multifunctional Ca(2+)-binding protein that mainly functions in the endoplasmic reticulum as a molecular chaperone for newly synthesized proteins. Recently we reported the protein composition of human metaphase chromosomes (Uchiyama et al., 2004), which included CRT. Here we describe new characteristics of CRT in vitro as well as its localization on the surface of metaphase chromosomes in vivo. CRT was detected in the chromosomal fraction by Western blotting and its binding partners were identified as core and linker histones by ligand overlay assay. Surface plasmon resonance sensor analyses revealed that CRT is bound to chromatin fibers. Moreover, we found that CRT has both supercoiling activity, which assists core histone assembly into chromatin fibers, and binding ability to histone H2A/H2B dimers and histone H3/H4 tetramers. Unlike the chromosome scaffold proteins, indirect immunofluorescent staining revealed that CRT is located on the surface of metaphase chromosomes. These results suggest that CRT plays a role which involves chromatin dynamics on the surface of mitotic chromosomes.

Calreticulin↗
PubMed2005

Delayed segmental motor paralysis following laminoplasty: two case reports.

STUDY DESIGN: Two patients who experienced the onset of segmental motor paralysis several years after laminoplasty are presented. OBJECTIVES: To discuss the mechanism of development of delayed segmental motor paralysis following laminoplasty. SETTING: A department of orthopaedic surgery in Japan. METHODS: One patient experienced motor weakness in his deltoid and biceps muscles on the left side 5 years after laminoplasty. The other patient noticed motor weakness in his deltoid and biceps on the right side 7 years after laminoplasty. CT myelography revealed posterior spur formation and hypertrophic facet joints on the hinged side at the C4-C5 level in both patients. RESULTS: Posterior foraminotomy was performed at the C4-C5 level on the hinged side in both patients. Postoperatively, motor weakness in the deltoid and biceps muscles was improved in both patients. CONCLUSIONS: Although spondylotic changes, including spur formation and disc herniation, have occasionally developed in operated segments after laminoplasty, few patients have required additional surgery for treatment of relapse of neurological deficits. It has been believed that spinal cord is rarely compressed by the spondylotic changes since it shifts posteriorly in the enlarged spinal canal. However, laminoplasty disturbs the facet joints since the medial portion of dorsal cortex and cancellous bone in facet joints is drilled out to make a trough. Facet joints disturbed in this fashion undergo degeneration over time after surgery. Nerve roots may occasionally be compressed by degenerated facet joints and spurs that have developed at the entrance of root canal, resulting in segmental motor paralysis several years after laminoplasty. Careful long-term observation is necessary after this procedure.

Aged↗
PubMed2005

N-acetylcysteine fails to modulate the in vitro function of sarcoplasmic reticulum of diaphragm in the final phase of fatigue.

AIM: In the present study, we tested the hypothesis whether N-acetylcysteine (NAC), a non-specific antioxidant, might influence fatigue by modulating Ca2+-handling capacity by the sarcoplasmic reticulum (SR). METHODS: In the presence (10 mm) or absence of NAC, bundles of rat diaphragm were stimulated with tetanic trains (350 ms, 30-40 Hz) at 1 train every 2 s for 300 s. SR functions, as assessed by SR Ca2+-uptake and release rates and SR Ca2+-ATPase activity, were measured in vitro on muscle homogenates. RESULTS: Following the 300-s stimulation, the force developed by NAC-treated muscles is approximately 1.8-fold higher (P < 0.05) than that of muscles without NAC treatment. Stimulation elicited an 18-30% depression in SR function (P < 0.05). Despite the differing degrees of fatigue between NAC-treated and non-treated muscles, SR functions in these muscles were reduced to similar extents. CONCLUSIONS: These results suggest that modulation of SR function measured in vitro may not be a major contributor to inhibition of diaphragmic fatigue with antioxidant, at least, in the final phase of fatigue where force output is remarkably reduced.

Acetylcysteine↗
PubMed2004

GM2-gangliosidosis variant 0 (Sandhoff-like disease) in a family of Japanese domestic cats.

A five-month-old, female Japanese domestic shorthair cat with proportionate dwarfism developed neurological disorders, including ataxia, decreased postural responses and generalised body and head tremors, at between two and five months of age. Leucocytosis due to lymphocytosis with abnormal cytoplasmic vacuolations was observed. The concentration of G(M2)-ganglioside in its cerebrospinal fluid was markedly higher than in normal cats, and the activities of beta-hexosaminidases A and B in its leucocytes were markedly reduced. On the basis of these biochemical data, the cat was diagnosed antemortem with G(M2)-gangliosidosis variant 0 (Sandhoff-like disease). The neurological signs became more severe and the cat died at 10 months of age. Histopathologically, neurons throughout the central nervous system were distended, and an ultrastructural study revealed membranous cytoplasmic bodies in these distended neurons. The compound which accumulated in the brain was identified as G(M2)-ganglioside, confirming G(M2)-gangliosidosis. A family study revealed that there were probable heterozygous carriers in which the activities of leucocyte beta-hexosaminidases A and B were less than half the normal value. The Sandhoff-like disease observed in this family of Japanese domestic cats is the first occurrence reported in Japan.

Animals↗
PubMed2004

Isolation of an active element from a high-copy-number family of retrotransposons in the sweetpotato genome.

A large number of plant retrotransposons have been characterized, but only three families ( Tnt1, Tto1 and Tos17) have been demonstrated to be transpositionally competent. We have used a novel approach to identify an active member of the Ty1- copia retrotransposon family with estimated 400 copies in the sweetpotato genome. Ty1- copia reverse transcriptase (RTase) sequences from the sweetpotato genome were analyzed, and a group of retrotransposon copies that probably arose by recent transposition events was identified and analyzed further. Transcripts containing long terminal repeats (LTRs) of this group were amplified from callus cDNA by the 3'RACE technique. Patterns of sequence-specific amplification polymorphism (S-SAP) of the LTR sequences in genomic DNA were compared between a normal plant and callus lines derived from it. In this way, a callus-specific S-SAP product was identified, which apparently resulted from the insertion of the retrotransposon detected by 3'RACE during cell culture. We conclude that our approach provides an effective way to identify active elements among the members of high-copy-number retrotransposon families.

Base Sequence↗
PubMed2004

Different time course of changes in sarcoplasmic reticulum and myosin isoforms in rat soleus muscle at early stage of hyperthyroidism.

AIMS AND METHODS: We studied changes in the expression of myosin and sarcoplasmic reticulum (SR) Ca2+-ATPase (SERCA) and in Ca2+ uptake and release rates by the SR in rat slow-twitch soleus muscles treated with thyroid hormone (3,5,3'-triiodo-l-thyronine, T3) for 1, 3, 7 and 21 days. RESULTS: The content of fast SR Ca2+-ATPase isoform SERCA1a protein significantly increased as early as 3 days of T3 treatment, while a rise in fast myosin heavy chain isoforms was found only 21 days after the onset of T3 administration. T3-induced slow-to-fast transitions were much less pronounced in myosin light chain than in myosin heavy chain. Moreover, in vitro measurements of SR Ca2+-handling capacity with indo-1 indicated that increases in uptake rate preceded those of release rate (7 vs. 21 days). CONCLUSION: These data suggest that changes in the myosin and SERCA expressions seem not to occur in a coordinated manner at the early stage of hyperthyroidism and that intervention with T3 may temporarily produce slow-twitch type I fibres which contain, in addition to slow SERCA2a isoform, the appreciable amounts of fast SERCA1a isoform. Moreover, it is speculated that some fibres in the hyperthyroid soleus muscles may temporarily acquire unique contractile properties distinct from normal fast and slow fibres.

Animals↗
PubMed2004

Protein composition of human metaphase chromosomes analyzed by two-dimensional electrophoreses.

A large amount of metaphase chromosomes were isolated from synchronized human cell lines by a polyamine procedure. All the chromosomal proteins extracted by an acetic acid extraction method were fully dissolved into the sample solutions for isoelectric focusing (IEF) or radical free and highly reduced (RFHR) two-dimensional electrophoreses (2-DEs). As a result, well-separated and highly reproducible 2-DE patterns were obtained. This could not be attained by an ordinary acetone precipitation method. The 2-DE patterns visualized using Coomassie Brilliant Blue (CBB) staining indicated that more than one hundred proteins were involved in the isolated metaphase chromosomes, although the most abundant proteins, histones, occupied a greater part of the chromosomal proteins. It was also shown that colcemid treatment for cell cycle synchronization had little effect on the 2-DE pattern compared to that obtained without the treatment. Furthermore, no significant differences were observed in the 2-DE patterns among the chromosomal proteins prepared from two different human cell lines, BALL-1 and K562. However, 2-DE analysis of isolated metaphase chromosomes from HeLa cells apparently showed a smaller number of proteins than the BALL-1 and K562 cell lines at a neutral pI range. The present study paves the way for elucidating protein composition of human metaphase chromosomes.

Cell Line, Tumor↗
PubMed2002

Altered sarcoplasmic reticulum function in rat diaphragm after high-intensity exercise.

The present study examined the effects of acute high-intensity exercise on Ca(2+) uptake and release rates and Ca(2+)-adenosine triphosphatase (ATPase) activity of the sarcoplasmic reticulum (SR) from the costal diaphragm. The rats were run on a treadmill at an estimated requirement of 100% of maximal O2 consumption until fatigued (average time to exhaustion: 4.79 min). Muscle lactate and inorganic phosphate after exercise were increased by 65% (P < 0.05) and 35% (P < 0.05), respectively. With exercise, Ca(2+) uptake and release, which were detected in homogenates using the Ca(2+) fluorescent dye indo-1, were decreased by 24% (P < 0.05) and 22% (P < 0.05), respectively. The reduction in Ca(2+) uptake was paralleled by decreased activity of SR Ca(2+)-ATPase in both the absence and presence of Ca(2+) ionophore. These findings demonstrate that, in the diaphragm as well as in the locomotor muscles that have been explored in previous studies, the attenuations of the SR function is brought about by acute high-intensity exercise. These changes in the SR of the diaphragm may contribute, at least in part, to deteriorations in exercise tolerance and work productivity resulting from repetitive physical activities.

Animals↗
PubMed2002

Pica in mice as a new model for the study of emesis.

In general, rats and mice have not been used in research on emesis because they do not vomit. However, emetogenic stimuli such as anticancer drugs, apomorphine, copper sulfate and rotation induced pica, a behavior characterized by eating nonfood substances such as kaolin, in rats. We also found that cisplatin induced pica in mice, but it was rather difficult to determine the exact kaolin consumption in this species. In this study, we prepared kaolin pellets mixed with carmine, a dye not absorbed in the gastrointestinal tract, and estimated kaolin consumption by determination of carmine excreted in feces. Cisplatin (5 mg/kg) caused a significant increase in kaolin consumption (saline: 0.15 +/- 0.08 g vs. cisplatin: 0.45 +/- 0.16 g) and pretreatment with the 5-HT3 receptor antagonist, ondansetron (2 mg/kg), suppressed the increased consumption (vehicle: 0.33 +/- 0.05 g vs. ondansetron: 0.13 +/- 0.04 g). These findings suggested that the exact kaolin consumption could be quantified by the determination of carmine in feces and that mice could be useful for studying emesis.

Animals↗
PubMed2001

Enantioselective 1,4-addition of unmodified ketone catalyzed by a bimetallic Zn-Zn-linked-BINOL complex.

1,4-Addition (Michael addition) of 2-hydroxy-2'-methoxyacetophenone (2) to various alpha,beta-unsaturated ketones was efficiently promoted by a bimetallic Zn-Zn-linked-BINOL complex 3 with good yield (up to 90%) and excellent enantiomeric excess (up to 99% ee). The resulting 2-hydroxy-1,5-diketones were successfully converted to synthetically more versatile esters and amides. [reaction: see text]

Journal Article↗
PubMed2001

Cancer chemopreventive agents, serratane-type triterpenoids from Picea jezoensis.

Seven serratane-type triterpenoids isolated from the cuticle of Picea jezoensis (Sieb. et Zucc.) Carr. jezoensis (Pinaceae) and the stem bark of Picea jezoensis (Sieb. et Zucc.) Carr. hondoensis (Mayer) Rehder (Pinaceae) were studied their possible inhibitory effects on Epstein-Barr virus early antigen (EBV-EA) activation induced by 12-O-tetradecanoylphorbol-13-acetate (TPA). All compounds showed strong inhibitory effects on the EBV-EA activation, being stronger than that of oleanolic acid, which exerts on cancer preventive activity in animal carcinogenesis models. Among these compounds, 13alpha, 14alpha-epoxy-3beta-methoxyserratan-21beta-ol and 3beta-methoxy-21alpha-hydroxyserrat-14-en-29-al were investigated for the inhibitory effects in a two-stage mouse skin carcinogenesis test on mouse skin using 7,12-dimethylbenz[a]anthracene as initiator and TPA as promoter. 13alpha,14alpha-Epoxy-3beta-methoxyserratan-21beta-ol was found to exhibit the excellent anti-tumor promoting activity in the in vivo carcinogenesis test.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2001

Direct catalytic enantio- and diastereoselective aldol reaction using a Zn-Zn-linked-BINOL complex: a practical synthesis of syn-1,2-diols.

[reaction: see text] The direct catalytic enantio- and diastereoselective aldol reaction with 2-hydroxy-2'-methoxyacetophenone proceeded smoothly using as little as 1 mol % of a dinuclear zinc catalyst, Zn-Zn-linked-BINOL complex 2, to afford alpha,beta-dihydroxy ketones in a highly syn-selective manner (up to syn/anti 97/3) and in excellent yields (up to 95%) and ees (up to 99%). Efficient transformations of the alpha,beta-dihydroxy ketone into an alpha,beta-dihydroxy ester and an alpha,beta-dihydroxy amide via regioselective rearrangements are also described.

Journal Article↗
PubMed2001

Quality of life in elderly patients with ossification of the posterior longitudinal ligament.

STUDY DESIGN: A longitudinal cohort study of 216 elderly patients with ossification of the posterior longitudinal ligament for an average of 13 years was performed. OBJECTIVE: To know the quality of life experienced by patients after treatment. SUMMARY OF BACKGROUND DATA: No report is available on the quality of life experienced by elderly patients with ossification of the posterior longitudinal ligament. Because the life prognosis of patients with this condition is relatively good, the quality of life experienced by elderly patients with this disease is an important subject. METHODS: The study participants were 216 elderly patients with ossification of the posterior longitudinal ligament. Conservative therapy was performed for 126 patients, and surgical therapy for 90 patients. Surgery was basically indicated for patients with myelopathy, who were classified using Nurick's grading system. The cumulative survival rate of these patients and their disabilities in daily living were reviewed. The occurrence of fracture resulting from osteoporosis was surveyed, and the relation of such fractures to bone mineral density was examined. RESULTS: The cumulative survival rate of 70-year-old patients exhibiting Nurick Grade 5 severe myelopathy before treatment was 20%, whereas that of patients without myelopathy or those with Grades 1, 2, 3, or 4 myelopathy before treatment was 80%. Patients who underwent surgical therapy for Grade 3 or 4 myelopathy were statistically more likely to be independent of assistance with activities of daily living than those with similar degrees of myelopathy who underwent conservative therapy. The final quality of life was poor for patients with Grade 5 myelopathy at the first examination, regardless of therapeutic method. The prevalence of complication by fracture in patients with ossification of the posterior longitudinal ligament was 1.4% for men and 8.6% for women. The bone mineral density in these patients without myelopathy was significantly higher than in healthy subjects of the same age. CONCLUSION: The study data suggest that surgical treatment should be chosen for patients exhibiting moderate myelopathy to obtain satisfactory quality of life for them over a long period.

Absorptiometry, Photon↗
PubMed2001

Significance of occipitoaxial angle in subaxial lesion after occipitocervical fusion.

STUDY DESIGN: The significance of occipitoaxial angle in the development of subaxial subluxation after occipitocervical fusion was determined in a minimum 5-year follow-up study performed retrospectively. OBJECTIVE: To clarify the association between the position of the fixed occipital bone and axis and the development of subaxial subluxation. SUMMARY OF BACKGROUND DATA: There have been few reports describing the association between the position of fixation of the occipital bone and axis and subaxial lesion in occipitocervical fusion. MATERIALS AND METHODS: Thirty-eight patients with rheumatoid arthritis who underwent occipitocervical fusion for irreducible atlantoaxial dislocation were reviewed. The angle between the McGregor line and the inferior surface of the axis (O-C2) was measured in healthy volunteers and patients who had undergone occipitocervical fusion. The association between any changes in the alignment of the cervical vertebrae and the development of subaxial subluxation during follow-up periods was studied. RESULTS: The number of the patients in whom postoperative kyphosis and swan neck deformity developed was only five, but in four (80%) of them, retroversion of the occipital bone was used to increase the O-C2 angle. In 14 patients, in whom anteversion of the occipital bone against the axis was excessive, 12 (86%) patients experienced subaxial subluxation after surgery. In the patients in whom fixed O-C2 angles were in normal range, only one patient developed such abnormal changes in the middle and lower cervical vertebrae. CONCLUSION: It is necessary to give attention to the position of the fixed occipital bone and axis during procedures of occipitoaxial fusion for patients with rheumatoid arthritis.

Adult↗