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Biomedical subjects

T Yamano

Publications and source records attributed to T Yamano.

At least 19 recordsLinked to original sources
PubMed2006

Cutaneous infiltration with Waldenström macroglobulinemia.

A 59-year-old Japanese man was diagnosed as Waldenström macroglobulinema. With impaired general performance and a 2-year history of pruritic eruptions that were initially confined to the forearms, but later involved the face, limbs, and trunk. A skin biopsy that was performed on the forehead showed infiltration with abnormal cells of the dermis around the central vessels. PCR analysis of the skin biopsy showed immunoglobulin heavy chain rearrangement. As the rearrangement band occurred at the same site as that of the bone marrow aspiration, skin infiltration with abnormal cells was proven.

Asian People↗
PubMed2005

Radiation protection system at the RIKEN RI beam factory.

The RIKEN RI (radioactive isotope) Beam Factory is scheduled to commence operations in 2006, and its maximum energy will be 400 MeV u(-1) for ions lighter than Ar and 350 MeV u(-1) for uranium. The beam intensity will be 1 pmicroA (6 x 10(12) particles s(-1)) for any element at the goal. For the hands-on-maintenance and the rational shield thickness of the building, the beam loss must be controlled with several kinds of monitors. Three types of radiation monitors will be installed. The first one consists of a neutron dose equivalent monitor and an ionisation chamber, which are commercially available area monitors. The second one is a conventional hand-held dose equivalent monitor wherein the logarithmic signal is read by a programmable logic controller based on the radiation safety interlock system (HIS). The third one is a simple plastic scintillator called a beam loss monitor. All the monitors have threshold levels for alarm and beam stop, and HIS reads all these signals.

Equipment Design↗
PubMed2003

Successful treatment with micafungin of invasive pulmonary aspergillosis in acute myeloid leukemia, with renal failure due to amphotericin B therapy.

Invasive aspergillosis is an important factor in the morbidity and mortality of patients suffering from hematologic disorders treated with chemotherapy. Treatment with amphotericin B is often limited because of toxicity, particularly nephrotoxicity. We describe a case of invasive pulmonary Aspergillus fumigatus infection in acute myeloid leukemia with renal failure due to amphotericin B therapy, which responded to treatment with a new antifungal agent, micafungin. Micafungin appears to be an effective and safe therapy for Aspergillus infections with renal failure due to amphotericin B.

Amphotericin B↗
PubMed2003

Attenuation of ganglioside GM1 accumulation in the brain of GM1 gangliosidosis mice by neonatal intravenous gene transfer.

A single intravenous injection with 4 x 10(7) PFU of recombinant adenovirus encoding mouse beta-galactosidase cDNA to newborn mice provided widespread increases of beta-galactosidase activity, and attenuated the development of the disease including the brain at least for 60 days. The beta-galactosidase activity showed 2-4 times as high a normal activity in the liver and lung, and 50 times in the heart. In the brain, while the activity was only 10-20% of normal, the efficacy of the treatment was distinct. At the 30th day after the injection, significant attenuation of ganglioside GM1 accumulation in the cerebrum was shown in three out of seven mice. At the 60th day after the injection, the amount of ganglioside GM1 was above the normal range in all treated mice, which was speculated to be the result of reaccumulation. However, the values were still definitely lower in most of the treated mice than those in untreated mice. In the histopathological study, X-gal-positive cells, which showed the expression of exogenous beta-galactosidase gene, were observed in the brain. It is noteworthy that neonatal administration via blood vessels provided access to the central nervous system because of the incompletely formed blood-brain barrier.

Adenoviridae↗
PubMed2001

Effect of L-carnosine on the hyperglycemia caused by intracranial injection of 2-deoxy-D-glucose in rats.

Effects of a chicken essence and one of its components, L-carnosine, on the hyperglycemia caused by intracranial injection of 2-deoxy-D-glucose (2DG-hyperglycemia) in unanesthetized rats were examined. The chicken essence inhibited the 2DG-hyperglycemia. Central or peripheral administration of specific doses of L-carnosine reduced the 2DG-hyperglycemia. L-carnosine inhibited neural activities of sympathetic efferent nerves innervating the adrenal gland and liver and facilitated the activity of vagal celiac nerve innervating the pancreas in urethane anesthetized rats. Specific doses of histamine also suppressed the 2DG-hyperglycemia, and thioperamide eliminated the inhibiting actions of both histamine and L-carnosine on the 2DG-hyperglycemia. Considering mammalian muscles contain L-carnosine, these facts suggest a possibility that L-carnosine might be an endogenous control factor of the blood glucose level through autonomic nerves via H3-receptor.

Adrenal Glands↗
PubMed2001

Immunoproteasome assembly and antigen presentation in mice lacking both PA28alpha and PA28beta.

Two members of the proteasome activator, PA28alpha and PA28beta, form a heteropolymer that binds to both ends of the 20S proteasome. Evidence in vitro indicates that this interferon-gamma (IFN-gamma)-inducible heteropolymer is involved in the processing of intracellular antigens, but its functions in vivo remain elusive. To investigate the role of PA28alpha/beta in vivo, we generated mice deficient in both PA28alpha and PA28beta genes. The ATP-dependent proteolytic activities were decreased in PA28alpha(-/-)/beta(-/-) cells, suggesting that 'hybrid proteasomes' are involved in protein degradation. Treatment of PA28alpha(-/-)/beta(-/-) cells with IFN-gamma resulted in sufficient induction of the 'immunoproteasome'. Moreover, splenocytes from PA28alpha(-/-)/beta(-/-) mice displayed no apparent defects in processing of ovalbumin. These results are in marked contrast to the previous finding that immunoproteasome assembly and immune responses were impaired in PA28beta(-/-) mice. PA28alpha(-/-)/beta(-/-) mice also showed apparently normal immune responses against infection with influenza A virus. However, they almost completely lost the ability to process a melanoma antigen TRP2-derived peptide. Hence, PA28alpha/beta is not a prerequisite for antigen presentation in general, but plays an essential role for the processing of certain antigens.

Adenosine Triphosphate↗
PubMed2001

Effects of maternal age on teratogenicity of di-n-butyltin diacetate in rats.

The present study was designed to assess changes in the teratogenic potency of di-n-butyltin diacetate (DBTA) with increasing maternal age in rats. Pregnant Wistar rats of 3, 7.5 or 12 months were treated orally with DBTA at 0, 7.5, 10, 15 or 22 mg/kg on day 8 of gestation. Cesarean sections were performed on day 20 of gestation. Maternal age had greater impact on litter size in the 7.5- and 12-month dams than the 3-month dams. The death of most of the fetuses of the 12-month dams made it difficult to evaluate the teratogenic potency of DBTA. In 3-month groups, fetuses with external malformation, such as cleft mandible, cleft lower lip, ankyloglossia and/or schistoglossia, which are malformations typical of DBTA, were observed at 15 and 22 mg/kg, while similar malformations were observed in 7.5-month groups at doses of 10 mg/kg and above. At 15 and 22 mg/kg, the incidences of these malformations in 7.5-month groups were similar to these from 3-month groups. In our previous studies, however, single DBTA-treatment at 10 mg/kg on day 8 of gestation has not produced such malformations from 3-month dams. The results suggest that the teratogenic potency of DBTA in 7.5-month dams may be greater than in 3-month dams.

Abnormalities, Drug-Induced↗
PubMed2001

Detection of peritoneal micrometastases of gastric carcinoma with green fluorescent protein and carcinoembryonic antigen promoter.

The aim of this study was to specifically visualize micrometastases in the peritoneal cavity, which cannot be detected by conventional methods, by using enhanced Green Fluorescent Protein (EGFP) containing carcinoembryonic antigen (CEA) promoter in an upstream position. In in vitro experiments, two cell lines from human gastric cancer, MKN45 and MKN1, and a cell line from human fibrosarcoma, HT1080, were transduced with pCEA-EGFP, which contains the CEA promoter region. MKN45 and MKN1, which expressed CEA mRNA, showed positive fluorescence after transduction of pCEA-EGFP, whereas HT1080 did not. In in vivo experiments, 7 days after 10(7) MKN45 had been injected into the peritoneal cavity of BALB/c nude mice, pCEA-EGFP was transduced in the peritoneal cavity using a fusogenic liposome with the envelope protein of Hemagglutinating Virus of Japan on the surface. On the peritoneum of the abdominal wall, fluorescent nodules were detected by fluorescence stereomicroscopy. These nodules had a minimal size of approximately 0.15 mm and could not be detected by conventional stereomicroscopy or macroscopy. They were histologically confirmed to be cancer cells by H&E staining. The results suggest that visualization of peritoneal micrometastasis of gastric cancer using CEA promoter and EGFP can offer a new strategy for diagnosis of micrometastasis.

Animals↗
PubMed2001

Information theory based on nonadditive information content.

We generalize Shannon's information theory in a nonadditive way by focusing on the source coding theorem. The nonadditive information content we adopted is consistent with the concept of the form invariance structure of the nonextensive entropy. Some general properties of the nonadditive information entropy are studied, in addition, the relation between the nonadditivity q and the codeword length is pointed out.

Journal Article↗
PubMed2001

A genetic factor for age-related cataract: identification and characterization of a novel galactokinase variant, "Osaka," in Asians.

Galactokinase (GALK) deficiency is an autosomal recessive disorder characterized by hypergalactosemia and cataract formation. Through mass screening of newborn infants, we identified a novel and prevalent GALK variant (designated here as the "Osaka" variant) associated with an A198V mutation in three infants with mild GALK deficiency. GALK activity and the amount of immunoreactive protein in the mutant were both 20% of normal construct in expression analysis. The K(m) values for galactose and ATP-Mg(2+) in erythrocytes with homozygous A198V were similar to those of the healthy adult control subjects. A population study for A198V revealed prevalences of 4.1% in Japanese and 2.8% in Koreans, lower incidence in Taiwanese and Chinese, no incidence in blacks and whites from the United States, and a significantly high frequency (7.8%; P < .023) in Japanese individuals with bilateral cataract. This variant probably originated in Japanese and Korean ancestors and is one of the genetic factors that causes cataract in elderly individuals.

Adult↗
PubMed2001

Usefulness of repeated direct intratumoral gene transfer using hemagglutinating virus of Japan-liposome method for cytosine deaminase suicide gene therapy.

To investigate the feasibility of repeated gene transfection in suicide gene therapy against human solid tumors by a combination of 5- fluorocytosine (5-FC) and its converting enzyme, cytosine deaminase (CD), we repeatedly transfected the yeast CD gene into the human pancreatic cancer cell line BXPC3 using the hemagglutinating virus of Japan-liposome in a new gene transfer method. The in vivo growth of the s.c. transplanted BXPC3 tumor in nude mice given CD-gene transfection was significantly suppressed by i.p. injection of 5-FC when compared with tumors treated with the control vector. Furthermore, the tumor transfected with the CD gene during a 7-day interval was suppressed much more than that of a single transfection. These results suggest that repeated transfection of the suicide gene together with the combination of 5-FC and the yeast CD gene using the hemagglutinating virus of Japan-liposome gene transfer method may be useful for the treatment of human solid tumors, including pancreatic cancer.

Animals↗
PubMed2001

Brain magnetic resonance imaging in 23 patients with mucopolysaccharidoses and the effect of bone marrow transplantation.

A longitudinal study of cranial magnetic resonance imaging (MRI) was carried out in 23 patients with mucopolysaccharidoses (MPS); 1 each of types IH, VI, and VII; 2 of type IS; 10 of type II; and 4 each of types IIIB and IVA. Six types of distinct abnormalities were 1) cribriform changes or spotty changes in the corpus callosum, basal ganglia, and white matter; 2) high-intensity signal in the white matter on T2-weighted image; 3) ventriculomegaly; 4) diffuse cerebral cortical atrophy; 5) spinal cord compression; and 6) megacisterna magna. The cribriform changes that corresponded to dilated perivascular spaces were found in the patients with MPS IS, II, and VI. The patchy and diffuse intensity changes were found in the patient with MPS II and IIIB, respectively. MPS IH and the severe type of MPS II showed marked ventriculomegaly. Marked cerebral atrophy was observed in all MPS IIIB patients and in the severe type of MPS II patients. Spinal cord compression was a feature usually observed in MPS IH, IVA, VI, and VII. Megacisterna magna was frequent in the patients with MPS II (6/10). In two of five patients, the therapeutic effect of bone marrow transplantation (BMT) was remarkable. Both the cribriform changes and the intensity change of the white matter in a MPS VI patient disappeared eight years after the BMT. Slight improvement of cribriform change was noted in one patient with MPS II three years after the BMT. MRS was not sufficient to estimate the accumulation of glycosaminoglycans but was useful for evaluating neuronal damages.

Adolescent↗
PubMed2001

Connatal tuberculosis in an extremely low birth weight infant: case report and management of exposure to tuberculosis in a neonatal intensive care unit.

UNLABELLED: A case of connatal tuberculosis in an extremely low birth weight infant is reported. The patient was a female with a birth weight of 973 g born in the 27th week of pregnancy. She developed respiratory distress and signs of infection immediately after birth, which did not respond to mechanical ventilation, antibiotics, and corticosteroid therapy. Connatal tuberculosis was confirmed at 48 days of age by isolation of Mycobacterium tuberculosis from the infant's tracheal aspirate and the mother's menstrual discharge. The infant died of respiratory failure at 90 days of age. Mantoux tuberculin skin tests (TST) were performed on 99 infants, 144 medical staff members, and two family members. TST conversion occurred in three medical staff members, and preventive therapy with isoniazid was initiated. Eight exposed infants had normal chest X-rays and negative gastric aspirates for acid-fast bacilli and all received preventive isoniazid therapy. No case of tuberculosis developed during the 2-year follow-up period. CONCLUSION: Connatal tuberculosis should be considered in neonatal respiratory infection resistant to antibiotics. Prevention of transmission of tuberculosis on the neonatal intensive care unit by chemoprophylaxis is important.

Antitubercular Agents↗
PubMed2001

Measurement of bone mineral density of lumbar spine and whole body in low-birth-weight infants: comparison of two methods.

In the present study, we compared lumbar spinal and whole-body bone mineral density (BMD) measurements to determine which is more suitable for evaluating the bone mineral status of low-birth-weight (LBW) infants. Lumbar spinal and whole-body BMD were assessed simultaneously in a prospective series including 152 Japanese LBW infants (birth weight 453-2400 g, gestational age 24-38 weeks) from the age of 40 weeks post-conception to 2 years of age. Lumbar spinal BMD at 40 weeks post-conception was significantly correlated with birth weight (r = 0.74; P < 0.0001), but wholebody BMD was not correlated with birth weight. No correlation was found between lumbar spinal and whole-body BMD at 40 weeks post-conception. However, after 40 weeks post-conception, a significant correlation was found between lumbar spinal and whole-body BMD (r = 0.65; P < 0.0001). For infants with a body weight of 4 kg or less at the time of measurement, no correlation was found between lumbar spinal and whole-body BMD. However, for infants with a body weight above 4 kg, a significant correlation was found between lumbar spinal and whole-body BMD (r = 0.65; P < 0.0001). Thus, lumbar spinal BMD is more suitable than whole-body BMD for evaluation of the bone mineral status of LBW in early infancy. Therefore, lumbar spinal BMD should be used for serial evaluation of changes in the bone mineral status of LBW infants.

Absorptiometry, Photon↗
PubMed2001

Peptide-specific cytotoxicity of T lymphocytes against glutamic acid decarboxylase and insulin in type 1 diabetes mellitus.

Cytotoxic T lymphocytes (CTL) against pancreatic beta-cells probably play a major role in the etiology of type 1 diabetes mellitus (DM). CTLs recognize a complex formed between MHC class I and antigenic peptides fragments derived from intracellular processing of proteins. However, the exogenous peptides, which show strong affinities to MHC class I, can be presented. In this study, we focused on the cytotoxic activity of peripheral lymphocytes in patients with type 1 DM against the peptides of glutamic acid decarboxylase (GAD) and insulin, which can bind MHC class 1 A24. Lymphocytes were isolated from peripheral blood of 12 type 1 DM patients and eight healthy control subjects. The effector cells were cultured with peptides, IL-2 and IL-7, restimulated weekly by autologous antigen presenting cells, which were cultured with IL-4 and GM-CSF. On day 21, CTL activities of cultured effector cells were tested against autologous EB-blast cells as target cells pulsed with the stimulating peptides using 51Cr release assay. The results showed that cytotoxicity against insulin peptide binding to MHC class I A24 was observed in lymphocytes of four out of ten patients with type 1 DM. The mean cytotoxicity was 46.0% of the maximum release. The antibody against HLA-class I inhibited this effect. Cytotoxicity against GAD peptide which bind MHC class I A24 was not observed in seven patients. None of healthy controls showed cytotoxicity against GAD or insulin peptides was observed. This is the first report describing the cytotoxic activity of CD8+ T lymphocytes against insulin in type 1 DM.

Adolescent↗
PubMed2001

Magnetoencephalography in the detection of focal lesions in West syndrome.

BACKGROUND: According to the international classification of epilepsy syndromes, West syndrome (WS) is a form of generalized epilepsy. However, it is known that localized lesions can induce WS and that patients with WS often subsequently develop focal seizures. We evaluated such patients using magnetoencephalography (MEG). METHOD: Fourteen patients of 3 months to 6 years of age who had or who had previously had WS were examined. MEGs were recorded using a laying-type whole-cortex MEG system with a 160-channel first-order gradiometer. Twelve-channel electroencephalography (EEG) and one-channel electrocardiography (ECG) were simultaneously recorded. Equivalent current dipoles were estimated at the point of spikes on the EEG. RESULTS: Patients were classified by magnetic resonance imaging (MRI) findings into a focal lesion group (group F, n=7) and a non-focal lesion group (group N, n=7). The dipoles estimated from the MEG were classified into three groups: W, with the dipoles distributed over a wide brain area (n=7); WC, dipoles distributed over a wide area along with a dense dipole distribution in a specific cortical area (n=3); and C, closed dipole distribution in a unilateral cerebral focal area (n=4). Patients were also classified by the stage of the disease during which the MEG was recorded, and by the type of seizure they experienced. Those with hypsarrhythmia examined early in the disease all had pattern W regardless of their lesion group, whereas those examined later exhibited more diverse dipole patterns that corresponded to seizure type. CONCLUSIONS: Dipoles were distributed widely over bilateral cerebral cortex when patients had infantile spasms with hypsarrhythmia whether or not they had focal lesions. The dipole distribution pattern in MEG changed according to changes in seizure type.

Child↗