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Biomedical subjects

M Ito

Publications and source records attributed to M Ito.

At least 271 records · Page 15Linked to original sources
PubMed2001

Osteoporosis in the Japanese population.

The characteristic of osteoporosis in the Japanese population is different from that in the Caucasian population. The different incidence of vertebral and hip fracture may be related to both genetic and lifestyle factors. In the aspect of genetics, approximately 77% of the Japanese have the bb genotype of the vitamin D receptor gene, which is considered to be associated with higher bone mass and lower bone turnover than the Bb genotype. The incidence of vertebral fracture is significantly lower in the younger birth cohorts in both genders. However, the total number of hip fractures rapidly grows as the elderly population increases in Japan. It may be explained by some epidemiological studies that the traditional Japanese lifestyle may prevent hip fractures in the Japanese elderly. The knowledge of the differences of osteoporosis between Caucasian and Japanese people must contribute to the prevention of osteoporosis and its complications.

Accidental Falls↗
PubMed2001

Gender-specific occurrence of West syndrome in patients with pyruvate dehydrogenase complex deficiency.

Pyruvate dehydrogenase complex (PDHC) deficiency, a major cause of congenital lactic acidemia in children, usually is complicated by seizures, and, in some patients, West syndrome has occurred. We diagnosed 60 patients with PDHC deficiency, including equal numbers of affected males and females. We studied the clinical features in 10 patients with West syndrome caused by PDHC deficiency, and examined the relation to the mutation of the E(1)alpha subunit, representing the great majority of PDHC deficiencies. Among 30 boys and 30 girls with PDHC deficiency,1 boy and 9 girls had West syndrome, even though overall West syndrome shows a slight male preponderance. Therefore, West syndrome associated with PDHC deficiency occurred in 9 of 30 female patients (33%), but in only 1 of 30 male patients (3%). The frequency of West syndrome in patients with PDHC deficiency was significantly higher in females than in males(p<0.05). Lactate concentrations in blood and CSF should be measured in female patients with West syndrome as a screening test for PDHC deficiency, because of gender-specific occurrence of West syndrome caused by PDHC deficiency.

Acidosis, Lactic↗
PubMed2001

Clinical comparisons between two subsets of gastric antral vascular ectasia.

BACKGROUND: The lesions of gastric antral vascular ectasia take two endoscopic forms, diffuse red spots and red stripes. In addition, they are often associated with cirrhosis. The main aim of the present retrospective study was to determine whether differences in endoscopic appearance and presence or absence of cirrhosis have relationships to clinical features and course. METHODS: Gastric antral vascular ectasia in 30 patients was classified into 2 endoscopic subtypes, punctate type (21 patients) and striped type (8 patients); only 1 patient could not be categorized to either type. The 30 patients were divided into groups based on the presence (25) or absence (5) of cirrhosis. RESULTS: All patients with punctate-type vascular ectasias had cirrhosis, whereas only 38% of patients with the striped type had cirrhosis. All patients without cirrhosis had the striped pattern. For patients with the 2 endoscopic types as well as those with and without cirrhosis, the outcomes of endoscopic treatment were similar. CONCLUSIONS: The findings of the present study suggest that cirrhosis is strongly associated with the development of punctate-type vascular ectasias. The endoscopic appearance of vascular ectasias and the presence or absence of cirrhosis did not determine outcome of patients.

Aged↗
PubMed2001

Inhibition by combined therapy with ticlopidine and aspirin of enhanced platelet aggregation during physical exercise in patients with coronary artery disease.

BACKGROUND: Strenuous exercise can be a major trigger for coronary thrombosis and it enhances platelet aggregation. METHODS: We evaluated the effect of antiplatelet therapy on shear stress-induced platelet aggregation (SIPA), in addition to agonist-induced aggregation, before and immediately after ergometer exercise in patients with stable coronary artery diseases (CAD). Forty-eight patients with stable CAD were randomly distributed into 3 groups: no antiplatelet drug (patient control, n = 16), aspirin (ASA) monotherapy (n = 16), and combined therapy with ticlopidine (TIC) and ASA (n = 16). RESULTS: There were significant increases in not only adenosine phosphate (ADP)- and collagen-induced platelet aggregation but also in SIPA during exercise by the patient control group. ASA monotherapy did not attenuate the enhanced ADP-induced aggregation nor SIPA. Combined ASA + TIC therapy significantly inhibited SIPA as well as ADP-induced aggregation both before and after exercise. Significant increases in levels of plasma von Willebrand factor (vWF) occurred during exercise, and these antiplatelet therapies had no apparent effect on increased vWF levels during exercise. Exercise induced a significant increase in the plasma thrombin-antithrombin III complex level with no significant changes in the level of plasmin-plasmin inhibitor complex level in all 3 groups. CONCLUSIONS: Combined therapy with ASA + TIC effectively inhibited increased platelet aggregability in response to acute exercise, with no effects on coagulant or fibrinolytic potentials in patients with CAD. The data suggest that TIC combined with ASA may be superior to ASA alone in preventing acute coronary events during exercise in patients with coronary atherosclerotic disease.

Adenine Nucleotides↗
PubMed2001

Expression of tyrosine kinase receptors Tie-1 and Tie-2 in giant cell tumor of the tendon sheath: a possible role in synovial proliferation.

We have recently demonstrated that Tie-1 and Tie-2 are expressed in synovial cells from rheumatoid arthritis (RA). To elucidate the possible involvement of Tie receptors in synovial proliferation, we analyzed their expression by immunostaining in five cases of giant cell tumor of tendon sheath (GCTTS), which represents a proliferating lesion of synovial cells. Strong immunoreactivity for both Tie-1 and Tie-2, regardless of the individual patient's profile, was observed in all cases of GCTTS. Six sets of double immunohistochemical stainings for Tie-1/Tie-2 and fibronectin, CD68, or CD34 were carried out to determine the phenotype of Tie-1 and Tie-2-positive tumor components. In these studies, both Tie-1 and Tie-2 immunoreactivity were widely observed in the fibronectin-positive fibroblastic and the CD68-positive histiocytic mononuclear cells, as well as in the osteoclast-like giant cells. In tumor vasculature, Tie receptors were expressed in the CD34-positive endothelial cells possessing proliferating cell nuclear antigen (PCNA) immunoreactivity. We also evaluated the correlation of Tie-1/Tie-2 expression and proliferating cells in GCTTS by using double staining of Tie-1/Tie-2 together with PCNA. Overexpression of PCNA immunoreactivity was frequently found in Tie receptors-positive cells with no obvious differences in the expression pattern of Tie-1 and Tie-2. These findings suggest the possible involvement of Tie receptors in the pathogenesis of GCTTS other than solely via their involvement in angiogenesis and subsequent vascularization. It was demonstrated that Tie-2 immunoreactivity was restricted to the fibroblastic, but not histiocytic, phenotype in RA synovium, suggesting different regulatory control of Tie-2 expression in GCTTS and RA synovium. Overexpression of Tie receptors in GCTTS may imply a biological role for these receptors in synovial proliferation.

Adult↗
PubMed2001

Involvement of c-Jun NH2-terminal kinase-1 in heat-induced apoptotic cell death of human monoblastic leukaemia U937 cells.

PURPOSE: To determine the involvement of c-Jun NH(2)-terminal kinase-1 (JNK1) and possibly of HSP27 in heat-induced apoptosis of human monoblastic leukaemia U937 cells. MATERIALS AND METHODS: Dominant negative JNK1 (APF), in which the phosphorylation sites Thr-Pro-Tyr were changed to Ala-Pro-Phe, was overexpressed in U937 cells. Cell viability and DNA fragmentation were analysed by the erythrosin-B dye exclusion test and by agarose gel electrophoresis, respectively. Expression of activated caspase-9, phosphorylated JNK1, JNK2, p38 and HSP27 was examined by Western blotting. JNK1 kinase assay was also performed using c-Jun as a substrate. RESULTS: Loss of viability, activated cleavage form of caspase-9 and DNA fragmentation were rapid in U937 cells after 44 degrees C hyperthermia, while overexpression of dominant negative JNK1 interfered with phosphorylation or activation of JNK1 without affecting that of JNK2 or p38/SAPK, and apparently delayed or reduced cleavage and activation of caspase-9, DNA fragmentation and cell death. Heat-induced phosphorylation of HSP27, observed in parental U937 cells, was suppressed and only slightly detectable in jnk1 mutant cells. CONCLUSIONS: Prolonged phosphorylation or activation of JNK1 was considered important for heat-induced apoptosis and JNK1 may control the process possibly through phosphorylation of HSP27 and caspase-9 activation in U937 cells.

Apoptosis↗
PubMed2001

Sporothrix schenckii thermo-intolerant mutants losing fatal visceral infectivity but retaining high cutaneous infectivity.

Four mutants of the Sporothrix schenckii lung isolate IFM 41598 were isolated by their inability to form colonies on a Sabouraud glucose agar plate incubated at 37 degrees C for 4 days. In contrast to the parent IFM 41598, these thermo-intolerant mutants were all defective in producing fatal visceral infections in mice, even though they retained infectivity in footpad tissues with a small fungal inoculum (approximately equals 10 cfu).

Animals↗
PubMed2001

Use of alternative therapies in older outpatients in the United States and Japan: prevalence, reporting patterns, and perceived effectiveness.

BACKGROUND: The purpose of this study was to determine the prevalence, patterns of reporting, and perceived effectiveness of alternative medical therapies (ATs) among older white American, African American, and Japanese outpatients. METHODS: This study used a questionnaire to interview participants (N = 593; age, >59 y), who were outpatients of geriatric outpatient clinics in Saint Louis, Missouri, and Tokyo, Japan (white Americans, n = 180; African Americans, n = 106; and Japanese, n = 307). RESULTS: Use of >1 AT was greatest among older Japanese (74.3%), followed by white Americans (61.1%) and African Americans (47.2%; p <.001). The most common ATs used among the Japanese (and significantly more than the white and African American groups) were lifestyle diet, herbal therapy, massage, acupressure, and acupuncture. The white and African American groups were more frequent users of relaxation techniques and spiritual healing compared with the Japanese group. Contrary to prior studies of the general population, the use of >1 AT did not correlate with any sociodemographic variables. Reported use of ATs to doctors was low but similar in all three groups (white Americans = 48%, African Americans = 42%, and Japanese = 46%). Perceived effectiveness was high but similar in all three groups (white Americans = 85%, African Americans = 92%, and Japanese = 84%). Although chronic conditions were common reasons for use of ATs, nonmedical reasons (e.g., general health or religious reasons) were also common. CONCLUSIONS: Use of ATs was greater in Japan than in the United States, but for both countries, use by older persons was greater than previous reports of the general population. Because sociodemographic variables do not predict use, and reported use to doctors is low and perceived effectiveness is high, increased awareness and understanding about ATs by health care professionals seems imperative.

Age Distribution↗
PubMed2001

Influence of thoracic radiotherapy on exhaled nitric oxide levels in patients with lung cancer.

BACKGROUND: To determine the physiological role of exhaled nitric oxide (NO) in patients with lung cancer. METHODS: We investigated changes in exhaled NO levels in 29 patients undergoing thoracic radiation therapy with or without chemotherapy. The exhaled NO level was assessed using a chemiluminescence analyzer. RESULTS: The level of exhaled NO was higher in patients with lung cancer before treatment than in controls. With radiotherapy, the exhaled NO level decreased for patients undergoing 40 Gy irradiation and post-radiotherapy. However, five patients showed elevated levels of exhaled NO three times or more than that before radiotherapy. Three of these patients showed signs of radiation pneumonitis. However, none of the other patients showed signs of radiation pneumonitis (p = 0.002). CONCLUSION: Radiation therapy can lower exhaled levels of NO and the levels of exhaled NO may be a useful index for the early prediction of radiation pneumonitis.

Aged↗
PubMed2001

Potential environmental and host participants in the early white matter lesion of adreno-leukodystrophy: morphologic evidence for CD8 cytotoxic T cells, cytolysis of oligodendrocytes, and CD1-mediated lipid antigen presentation.

The 2 most common forms of X-linked adreno-leukodystrophy (ALD) are the juvenile or childhood cerebral form with inflammatory demyelination and the adult adrenomyeloneuropathy (AMN) involving spinal cord tracts without significant inflammation. Modifier genes or environmental factors may contribute to the phenotypic variability. We performed immunohistochemical, an in situ polymerase chain reaction, and TUNEL analyses to identify several viruses, lymphocyte subpopulations, apoptotic cells, and effector molecules, focusing on morphologically normal white matter, dysmyelinative and acute demyelinative lesions. No distinguishing viral antigens were detected. Most lymphocytes were CD8 cytotoxic T cells (CTLs) with the alpha/beta TCR, and they infiltrated morphologically unaffected white matter. Only a few oligodendrocytes were immunoreactive for caspase-3. MHC class II- and TGF-beta-positive microglia were present. CD44, which can mediate MHC-unrestricted target cell death, was seen on many lymphocytes and white matter elements. CD1 molecules, which play major roles in MHC-unrestricted lipid antigen presentation, were noted. Our data indicate that unconventional CD8 CTLs are operative in the early stages of dysmyelination/demyelination and that cytolysis of oligodendrocytes, rather than apoptosis, appears to be the major mode of oligodendrocytic death. The presentation of lipid antigens may be a key pathogenetic element in ALD and AMN-ALD.

Adrenoleukodystrophy↗
PubMed2001

The dorsal root ganglia in adrenomyeloneuropathy: neuronal atrophy and abnormal mitochondria.

Adrenomyeloneuropathy (AMN), a disease of spinal cord, brain, adrenal, and testis, mostly affects men with spastic paraparesis or ataxia beginning in their second or third decade. The spinal cord displays bilateral, usually symmetrical, long tract degeneration particularly of the gracile tract in a "dying-back" pattern. The available data strongly indicate that the fundamental lesion in AMN is an axonopathy or neuronopathy. We compared lumbar dorsal root ganglia (DRG) from 3 AMN patients to 6 age-matched controls histologically, morphometrically, immunohistochemically, and ultrastructurally. There was no apparent neuronal loss, necrosis or apoptosis, nor obvious atrophy; nodules of Nageotte were sparse in both groups. The morphometric studies, however, did reveal neuronal atrophy with a decrease in the number of large neurons and a corresponding increase in neurons less than 2,000 microm2, especially in the 1,500-1,999 microm2 range. No consistent immunohistochemical differences were observed, and no specific cell type appeared to be lost. Many mitochondria in the AMN neurons demonstrated lipidic inclusions; this raises the possibility that, in addition to the well-known peroxisomal defect, impaired mitochondrial function may lead to a failure of ATP-dependent axoplasmic transport in AMN spinal tracts with consequent "dying-back" axonal degeneration. The observation that the DRG parent neurons of the degenerate gracile tracts in AMN undergo atrophy and do not display appreciable evidence of cell death, even at autopsy, provides a wide window of opportunity for the development of therapeutic strategies to combat or prevent this myeloneuropathy.

Adrenoleukodystrophy↗
PubMed2001

Transglycosylation and reverse hydrolysis reactions of endoglycoceramidase from the jellyfish, Cyanea nozakii.

Endoglycoceramidase (EGCase: EC 3.2.1.123) is an enzyme capable of cleaving the glycosidic linkage between oligosaccharides and ceramides in various glycosphingolipids. We report here transglycosylation and reverse hydrolysis reactions of EGCase from the jellyfish Cynaea nozakii. Various alkyl-GM1 oligosaccharides (alkyl-II(3)NeuAcGgOse4) were synthesized when GM1 ganglioside was treated with the EGCase in the presence of 1-alkanols. Among various 1-alkanols tested, methanol was found to be the most preferential acceptor, followed by 1-hexanol and 1-pentanol. GM1 was the best donor, followed by GD1b and GT1b, when methanol was used as an acceptor. However, neither globoside nor glucosylceramide was utilized by the enzyme as a donor substrate. The enzyme transferred oligosaccharides from various glycosphingolipids to NBD-ceramide, a fluorescent ceramide, producing NBD-labeled glycosphingolipids. In addition to the transglycosylation reaction, the enzyme catalyzed the reverse hydrolysis reaction; lactose was condensed to ceramide to generate lactosylceramide in the presence of the enzyme. These results indicate that the jellyfish enzyme will facilitate the synthesis of various neoglycoconjugates and glycosphingolipids.

Alcohols↗
PubMed2001

Isolation and RNA gel blot analysis of genes that could serve as potential molecular markers for leaf senescence in Arabidopsis thaliana.

Nine cDNAs, representing genes in which the transcripts accumulated in senescent leaves of Arabidopsis thaliana, were isolated by differential display reverse transcription polymerase chain reaction (DDRT-PCR) and the genes were designated yellow-leaf-specific gene 1 to 9 (YLS1-YLS9). Sequence analysis revealed that none of the YLS genes, except YLS6, had been reported as senescence-up-regulated genes. RNA gel blot analysis revealed that the transcripts of YLS3 accumulated at the highest level at an early senescence stage, whereas the transcripts from the other YLS genes reached their maximum levels in late senescence stages. Transcripts of YLS genes showed various accumulation patterns under natural senescence, and under artificial senescence induced by darkness, ethylene or ABA. These expression characteristics of YLS genes will be useful as potential molecular markers, which will enhance our understanding of natural and artificial senescence processes.

Abscisic Acid↗
PubMed2001

Phosphorylation of a bifunctional enzyme, 6-phosphofructo-2-kinase/fructose-2,6-bisphosphate 2-phosphatase, is regulated physiologically and developmentally in rosette leaves of Arabidopsis thaliana.

The phosphorylation status of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphate 2-phosphatase (EC 2.7.1.105/ EC 3.1.3.46) in rosette leaves of Arabidopsis was examined. Immunoblotting with specific antisera detected 96-kDa and 92-kDa bands in the crude protein extracts from rosette leaves of Arabidopsis. Incubation of protein samples with alkaline phosphatase before SDS-PAGE reduced the 96-kDa band with concomitant increase of the 92-kDa band, suggesting that the former is a phosphorylated form of the latter. In accordance with this result, 96-kDa and 92-kDa bands were immuno-precipitated from the crude protein extracts from [(32)P]orthophosphate-labeled rosettes of Arabidopsis; and, the former was heavily labeled, the latter faintly labeled. Analysis of phospho-amino acid residues derived from the [(32)P]-labeled 96-kDa band revealed that the phosphorylation occurred on serine and threonine residues, excluding the possibility that the phosphorylated band represent a phospho-histidine intermediate that is known to form in the phosphatase reaction. The relative level of the 96-kDa band over the 92-kDa band in whole rosette extracts changed diurnally and was highest at the beginning of nighttime. Furthermore, the 96-kDa band was highly enriched in the extracts of very young rosette leaves, suggesting that the phosphorylation status of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphate 2-phosphatase is regulated physiologically and developmentally in Arabidopsis.

Arabidopsis↗
PubMed2001

Cloned mice from fetal fibroblast cells arrested at metaphase by a serial nuclear transfer.

Cloning using G(0)-arrested somatic cells has led to the suggestion that this stage of the cell cycle is necessary for the success of cloning. In this study we report that cloned mice can be generated from fetal fibroblasts arrested at metaphase of the cell cycle. The procedure involves fusing a metaphase-arrested fetal fibroblast to an enucleated oocyte. After parthenogenetic activation a polar body and single diploid pronucleus were formed. Some of these were allowed to develop to the blastocyst stage, while others were enucleated and the nucleus was transferred to an enucleated fertilized 1-cell embryo. After the single transfer technique, 2 out of 164 developed to late stages of gestation were dead with gross abnormalities. However, after the serial nuclear transfer, 5 out of 272 embryos were recovered live at Day 19.5, and 2 of these went on to develop into apparently normal adults. All of the cloned embryos showed severe placental hypertrophy and defective differentiation of placental tissues. This study illustrates that reprogramming can occur after nuclear transfer at metaphase of the cell cycle.

Animals↗
PubMed2001

Atrichia with papular lesions: electron microscopic observations of cystic lesions.

Atrichia with papular lesions is a rare inherited skin disorder characterized by congenital atrichia with numerous papules. We describe a 27-year-old woman with atrichia, who had numerous papules on her scalp, nape, and axillae. Histologically, many keratinous cysts were seen in the middermis of a skin specimen from the nape. Electron microscopy showed that the developing keratinocytes in the walls of some cysts were rich in glycogen granules and had epidermoid keratinization with formation of keratohyaline granules and that laminated bodies were formed before keratinization. Langerhans cells were often seen in the walls of the cysts. In addition, a broad glassy vitreous layer surrounded the cyst wall. From these findings, it was suggested that the cystic lesions might have originated from immature or incomplete hair follicles. In particular, the structure of the cyst wall corresponded well to infundibular and/or isthmal portions of the outer root sheath of the hair follicle.

Adult↗