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Biomedical subjects

M Matsui

Publications and source records attributed to M Matsui.

At least 55 records · Page 3Linked to original sources
PubMed2001

Systematic status of Hynobius tokyoensis (Amphibia: Urodela) from Aichi Prefecture, Japan: a biochemical survey.

Taxonomic status of a salamander now identified as Hynobius tokyoensis from Aichi Prefecture, Japan, was assessed by allozymic comparisons with its relatives. All three populations of H. tokyoensis from Aichi formed a monophyletic group with populations of H. nebulosus; this group is substantially diverged from a conspecific population from Kanagawa that formed another group with H. lichenatus. In the former group, the population of H. nebulosus from near the type locality was more divergent from the other conspecific populations than were three populations of H. tokyoensis from Aichi. It is quite clear that the salamander from Aichi now identified as H. tokyoensis is genetically much closer to H. nebulosus than to H. tokyoensis from Kanagawa, which is closest geographically to its type locality. This result conforms well to reported results of morphological and genetic studies, and the salamander from Aichi, now called H. tokyoensis, should be identified as H. nebulosus, which is sufficiently diverged from H. tokyoensis to be considered a distinct species.

Algorithms↗
PubMed2001

New chimpanzee MHC class I alleles cloned by polymerase chain reaction.

We describe polymerase chain reaction (PCR) cloning of full-length Patr-A, -B and -Cw locus alleles from a chimpanzee using one sense/antisense primer pair. Of the six alleles cloned here, two have not previously been described. Comparison of nucleotide sequences between the two novel Patr alleles and various HLA alleles suggests that the new Patr-A allele belongs to the A1/A3/A11 family, whereas the new Patr-Cw allele is not closely related to any known HLA-Cw allele.

Alleles↗
PubMed2001

Arabidopsis transcriptional regulation by light stress via hydrogen peroxide-dependent and -independent pathways.

BACKGROUND: High (intense) light stress causes the formation of oxygen radicals in chloroplasts and has the potential to damage them. However, plants are able to respond to this stress and protect the chloroplasts by various means, including transcriptional regulation in the nucleus. Although the corresponding signalling pathway is largely unknown, the high light response in the expression of the Arabidopsis APX2 gene is reported to be mediated by hydrogen peroxide. RESULTS: We characterized light stress signalling by analysing expression profiles of another high light-inducible gene of Arabidopsis, ELIP2, with the aid of an ELIP2 promoter-luciferase gene fusion. The established ELIP2:LUC transgenic Arabidopsis showed activation by high light, but not by hydrogen peroxide. On the other hand, the native ELIP2 gene as well as the APX2 gene was activated by the hydrogen peroxide. The activation of ELIP2:LUC by intense light was not inhibited by K252a but by okadaic acid. CONCLUSION: The light stress signalling from the chloroplast to the nucleus is revealed to be mediated through at least two pathways: both hydrogen peroxide-dependent and -independent. The latter pathway is thought to be mediated by the protein phosphatase 2A/1 activity that is suppressed by okadaic acid.

Arabidopsis↗
PubMed2001

DFL1, an auxin-responsive GH3 gene homologue, negatively regulates shoot cell elongation and lateral root formation, and positively regulates the light response of hypocotyl length.

A novel dominant mutant designated 'dwarf in light 1' (dfl1-D) was isolated from screening around 1200 Arabidopsis activation-tagged lines. dfl1-D has a shorter hypocotyl under blue, red and far-red light, but not in darkness. Inhibition of cell elongation in shoots caused an exaggerated dwarf phenotype in the adult plant. The lateral root growth of dfl1-D was inhibited without any reduction of primary root length. The genomic DNA adjacent to the right border of T-DNA was cloned by plasmid rescue. The rescued genomic DNA contained a gene encoding a GH3 homologue. The transcript was highly accumulated in the dfl1-D. The dfl1-D phenotype was confirmed by over-expression of the gene in the wild-type plant. The dfl1-D showed resistance to exogenous auxin treatment. Moreover, over-expression of antisense DFL1 resulted in larger shoots and an increase in the number of lateral roots. These results indicate that the gene product of DFL1 is involved in auxin signal transduction, and inhibits shoot and hypocotyl cell elongation and lateral root cell differentiation in light.

Amino Acid Sequence↗
PubMed2001

Autoimmune hepatitis with membranous glomerulonephritis.

We report on a case of autoimmune hepatitis (AIH) associated with membranous glomerulonephritis. A 61-year-old woman was admitted because of peripheral edema, proteinuria and abnormal liver function test findings. A diagnosis of AIH was made on the basis of an elevation of aminotransferase and serum IgG levels, the presence of positive antinuclear antibody and the characteristic histological features of chronic active hepatitis. Histological examination of a renal biopsy specimen disclosed membranous glomerulonephritis with granular deposits of IgG, IgM, C3 and C1q along the capillary walls. This condition is rare in AIH and should be carefully distinguished from systemic lupus erythematosus.

Female↗
PubMed2001

Sylvian fissure and medial temporal lobe structures in patients with schizophrenia: a magnetic resonance imaging study.

Volumes of the medial temporal lobe structures (i.e. the amygdala, hippocampus, and parahippocampal gyrus), Sylvian fissure, and inferior horn of the lateral ventricle relative to the cerebral hemisphere were measured in 24 patients with schizophrenia and 23 normal controls using magnetic resonance imaging. The patients had significantly larger Sylvian fissures and inferior horns bilaterally than the controls. In the patients the right Sylvian fissure size showed a significant positive correlation with the duration of illness. Moreover, earlier onset of illness was significantly correlated with decreased volume of the left medial temporal lobe structures. These results replicate previous finding of inferior horn enlargement and suggest the significance of the Sylvian fissure and the medial temporal lobe structures in pathophysiology of schizophrenia.

Adolescent↗
PubMed2001

Bizarre parosteal osteochondromatous proliferation (Nora's lesion) of the foot.

A 22-year-old man presented with a growing lump on the fifth metatarsal of the right foot. Radiographically, the lesion was a calcified mass stuck on to the bone. The T2-weighted magnetic resonance images showed heterogeneity in intensity. A tumor was suspected and an excisional biopsy was done. The lesion was composed of a cartilaginous cap and bone tissue. Histological examination revealed characteristic features of bizarre parosteal osteochondromatous proliferation (BPOP), such as hypercellularity, a blue tinctorial quality in the osteocartilaginous interfaces, and a scattering of binucleated or bizarre enlarged chondrocytes. Immunohistochemically, basic fibroblast growth factor was expressed in nearly all chondrocytes within the cartilaginous cap, while vascular endothelial growth factor was expressed only in enlarged chondrocytes near the osteocartilaginous interfaces. Reverse transcription-polymerase chain reaction detected chondromodulin-I transcripts in the tissue of the cartilaginous cap. These findings indicate that the processes occurring in BPOP are similar to those occurring in endochondral ossification in the growth plate, and they support the concept that BPOP is a reparative process. BPOP is a rare tumorous lesion of the bone and is occasionally confused with other benign or malignant conditions. Thus, it is important to consider the clinical, radiographical and the gross histological features of the lesion when making a diagnosis.

Adult↗
PubMed2001

Cutaneous photoprotection from ultraviolet injury by green tea polyphenols.

BACKGROUND: In animal models, extracts from green tea have been shown to be remarkably effective at reducing the severity of adverse human health effects of overexposure to ultraviolet (UV) radiation. Although sunscreens and other photoprotective measures have traditionally been used for this purpose, there is a need for additional measures and natural products are increasingly being explored for that purpose. OBJECTIVE: Our purpose was to evaluate the effect of polyphenols from green tea on parameters associated with acute UV injury. METHODS: Areas of skin of normal volunteers were treated with an extract of green tea or one of its constituents. Thirty minutes later, the treated sites were exposed to a 2 minimal erythema dose solar simulated radiation. UV-treated skin was examined clinically for UV-induced erythema, histologically for the presence of sunburn cells or Langerhans cell distributions, or biochemically for UV-induced DNA damage. RESULTS: Application of green tea extracts resulted in a dose-dependent inhibition of the erythema response evoked by UV radiation. The (-)-epigallocatechin-3-gallate (EGCG) and (-)-epicatechin-3-gallate (ECG) polyphenolic fractions were most efficient at inhibiting erythema, whereas (-)-epigallocatechin (EGC) and (-)-epicatechin (EC) had little effect. On histologic examination, skin treated with green tea extracts reduced the number of sunburn cells and protected epidermal Langerhans cells from UV damage. Green tea extracts also reduced the DNA damage that formed after UV radiation. CONCLUSION: Polyphenolic extracts of green tea are effective chemopreventive agents for many of the adverse effects of sunlight on human health and may thus serve as natural alternatives for photoprotection.

Administration, Topical↗
PubMed2001

Tumoral calcinosis in both index fingers: a case report.

Tumoral calcinosis is an uncommon disease of unknown aetiology that usually involves the periarticular tissues of large joints. We report a rare case in which it presented in both index fingers in a 5-year-old boy. The tumours were resected and he made an uncomplicated recovery except for mild tapering deformity on the left. There has been no sign of recurrence a year later.

Calcinosis↗
PubMed2001

Age-related volumetric changes of brain gray and white matter in healthy infants and children.

To date there is little information about brain development during infancy and childhood, although several quantitative studies have shown volume changes in adult brains. We performed three-dimensional magnetic resonance imaging (3D-MRI) in 28 healthy children aged 1 month to 10 years. We examined the volumes of whole brain and frontal and temporal lobes with an advanced method for segmenting images into gray matter (GM), white matter (WM) and cerebrospinal fluid (CSF) compartments. Growth spurts of whole brain and frontal and temporal lobes could be seen during the first 2 years after birth. During this period the frontal lobes grew more rapidly than the temporal lobes, the right--left asymmetry was more noticeable in the temporal lobes than in the frontal lobes and the increase in GM was larger than that in WM in the temporal lobes. Subsequently, WM volume increased at a higher rate than GM volume throughout childhood. Quantitative information on normal brain development may play a pivotal role in clarifying brain neurodevelopmental abnormalities.

Age Factors↗
PubMed2001

Overexpression of the heterotrimeric G-protein alpha-subunit enhances phytochrome-mediated inhibition of hypocotyl elongation in Arabidopsis.

Plant heterotrimeric G-proteins have been implicated in a number of signaling processes. However, most of these studies are based on biochemical or pharmacological approaches. To examine the role of heterotrimeric G-proteins in plant development, we generated transgenic Arabidopsis expressing the Galpha subunit of the heterotrimeric G-protein under the control of a glucocorticoid-inducible promoter. With the conditional overexpression of either the wild type or a constitutively active version of Arabidopsis Galpha, transgenic seedlings exhibited a hypersensitive response to light. This enhanced light sensitivity was more exaggerated in a relatively lower intensity of light and was observed in white light as well as far-red, red, and blue light conditions. The enhanced responses in far-red and red light required functional phytochrome A and phytochrome B, respectively. Furthermore, the response to far-red light depended on functional FHY1 but not on FIN219 and FHY3. This dependence on FHY1 indicates that the Arabidopsis Galpha protein may act only on a discrete branch of the phytochrome A signaling pathway. Thus, our results support the involvement of a heterotrimeric G-protein in the light regulation of Arabidopsis seedling development.

Arabidopsis↗
PubMed2001

Cip4, a new COP1 target, is a nucleus-localized positive regulator of Arabidopsis photomorphogenesis.

Arabidopsis COP1 acts within the nucleus to repress photomorphogenesis, and its nuclear abundance is negatively regulated by light. Here, we report the identification of a COP1-interactive partner, CIP4. CIP4 is a nuclear protein and a potent transcription coactivator. Conditional suppression of CIP4 expression resulted in an elongated hypocotyl and reduced chlorophyll content in the light, indicating that CIP4 is required for the promotion of photomorphogenesis. Furthermore, CIP4 was revealed to act downstream of multiple photoreceptors as well as COP1 in mediating light control of development. CIP4 expression is light inducible and regulated by COP1. However, CIP4 does not play a role in mediating the light induction of anthocyanin accumulation. Together with our previous studies of CIP7 and HY5, our data suggest that COP1 interacts directly with and regulates multiple physiological targets, which in turn regulate distinct sets of light-regulated responses.

Amino Acid Sequence↗
PubMed2001

Enhancement of cognitive performance in schizophrenia by addition of tandospirone to neuroleptic treatment.

OBJECTIVE: The goal of this study was to evaluate the effects of the addition of tandospirone, a serotonin-1A (5-HT(1A)) agonist, to ongoing treatment with typical antipsychotic drugs, on two cognitive domains that are relevant to functional outcome in patients with schizophrenia. METHOD: Twenty-six patients with schizophrenia who were receiving stable doses of typical antipsychotics were randomly assigned to adjunctive treatment with 30 mg/day of tandospirone or placebo for 6 weeks. Executive function and verbal memory as well as psychopathology were assessed at baseline and after 6 weeks. RESULTS: Both cognitive measures improved significantly in the patients who received tandospirone; subjects who did not receive tandospirone showed no change. There was no significant change in psychopathology ratings in either group. CONCLUSIONS: The results suggest the usefulness of 5-HT(1A) agonists for enhancing some types of cognitive performance and possibly social and work function in patients with schizophrenia.

Antipsychotic Agents↗
PubMed2001

[Mercury concentration of fish in Tokyo Bay and the surrounding sea area].

Total mercury in the muscles of three fish species was analyzed in fish caught in Tokyo Bay and the surrounding sea areas, Sagami Bay and Choshi. Tokyo Bay is a semi-closed sea area surrounded by Tokyo, Kanagawa and Chiba prefectures. Sagami Bay and Choshi are open to the Pacific Ocean. A total of 412 fish consisting of northern whiting (Sillago japonica), flatfish (Limanda yokohamae) and sardine (Sardinops melanosticta) were caught in these areas over a 6 months period from November 1998 to April 1999. Total mercury concentration ranged from 0.008-0.092 microgram/g (wet wt.) in northern whiting, 0.006-0.065 microgram/g in flatfish and 0.001-0.045 microgram/g in sardine. All concentrations were below the restriction limit of fish mercury in Japan, 0.4 microgram/g of total mercury concentration. A significant correlation was found between mercury concentrations and body length or body weight in northern whiting and flatfish, irrespective of the sea area. A correlation was also found between mercury concentration in fish and their feeding habits: among the 3 species caught in the same area, crustacean feeding northern whiting had the highest, polychaete feeding flatfish moderate, and plankton feeding sardine had the lowest mercury concentration. In a comparison of mercury concentration in the same species caught in different sea areas, a higher concentration was noted in fish caught in the semi-closed sea area of Tokyo Bay, than in fish caught in the open sea areas of Sagami Bay and Choshi. This difference was most marked in fish caught at the bottom of Tokyo Bay and we considered that the mercury concentration of seawater and sediment in these areas was the cause of mercury accumulation in fish. These findings suggest that improved water quality control and environmental monitoring is necessary in semi-closed sea areas such as Tokyo Bay.

Animals↗
PubMed2001

Long-term prognosis after recovery from myocardial infarction: a community-based survey in Yamagata, Japan.

OBJECTIVE: To assess the long-term prognosis after recovery from acute myocardial infarction (AMI) in the general population in Japan. PATIENTS AND METHODS: Among the 575,000 inhabitants of the Yamagata metropolitan area, a total of 117 patients suffered from first their AMI from April to December 1993. Thirteen patients (11%) died within four weeks after the onset. Of the remaining 104 patients, 101 (mean age, 69+/-12 years) were followed for an average of 65+/-5 months. RESULTS: Twenty-seven of the 101 patients (27%) died during the follow-up period. Compared with survivors, the patients who died were significantly older at the onset of AMI (74+/-12 vs. 67+/-12 years, p<0.01). More diabetic patients than non-diabetic patients died (42 vs. 21%, p<0.05) because of the higher frequency of non-cardiac deaths (29 vs. 11%, p<0.05). The total number of deaths of cardiac origin, including sudden deaths, was 11 (40%) and was lower than the number of definite non-cardiac deaths (n=15). The time from the onset of AMI to death was significantly shorter in cases of cardiac death than in cases of non-cardiac death (median, 16 vs. 45 months, p<0.01). Among non-cardiac deaths, deaths due to lung cancer and cerebral infarction were notable in men (standardized mortality ratio 278) and women (571), respectively. CONCLUSION: Non-cardiac death during long-term follow-up after AMI was more frequent than death of cardiac origin. Thus, preventive measures, including early treatment of complicating diseases, must be implemented to improve the long-term prognosis of patients with myocardial infarction.

Age Factors↗
PubMed2000

Neuregulin is associated with nerve regeneration in axonal neuropathies.

Neuregulins (NRG), the only trophic factors known to support Schwann cell survival, have a potential for use in treatment of patients with chronic neuropathies. Expression of one NRG isoform, NRG-beta1, was increased in axons in the early phase of axonal degeneration in nerve biopsy specimens from patients with neuropathy. Regenerating nerve fibers contained abundant NRG-beta1 in axons, but nerves from patients with chronic axonal neuropathy showed less. NRG-beta1 may act as an axonally derived signal having a trophic effect on denervated Schwann cells, facilitating their supportive role in axonal regeneration.

Axons↗