Biomedical subjects

N Morishita

Publications and source records attributed to N Morishita.

At least 19 recordsLinked to original sources

PubMed2006

Identification of the carbon antisite-vacancy pair in 4H-SiC.

The metastability of vacancies was theoretically predicted for several compound semiconductors alongside their transformation into the antisite-vacancy pair counterpart; however, no experiment to date has unambiguously confirmed the existence of antisite-vacancy pairs. Using electron paramagnetic resonance and first principles calculations we identify the S15 center as the carbon antisite-vacancy pair in the negative charge state (C(Si)V-(C)) in 4H-SiC. We suggest that this defect is a strong carrier-compensating center in n-type or high-purity semi-insulating SiC.

Journal Article↗

PubMed2006

Divacancy in 4H-SiC.

Electron paramagnetic resonance and ab initio supercell calculations suggest that the P6/P7 centers, which were previously assigned to the photoexcited triplet states of the carbon vacancy-antisite pairs in the double positive charge state, are related to the triplet ground states of the neutral divacancy. The spin density is found to be located mainly on three nearest C neighbors of the silicon vacancy, whereas it is negligible on the nearest Si neighbors of the carbon vacancy.

Journal Article↗

PubMed2006

Molecular analysis of malassezia microflora from patients with pityriasis versicolor.

BACKGROUND: Pityriasis versicolor (PV) is a superficial infection of the stratum corneum caused by Malassezia species. Eleven species have been identified within this genus, namely M. globosa, M. restricta, M. sympodialis, M. furfur, M. obtusa, M. slooffiae, M. pachydermatis, M. dermatis, M. japonica, M. yamatoensis, M. nana. M. furfur has long been identified as the causative fungus of PV. However, recent studies using the culture and isolation identified by morphological and physiological characteristics suggest that M. globosa is the causative agent of PV. OBJECTIVES: The aim of this study was to examine the distribution of PV microorganisms with a molecular-based non-culture method. PATIENTS: The subjects were 49 patients with PV (32 males, 17 females; 16-83 years old) who visited our outpatient clinic. METHODS: Samples were taken from lesions for direct microscopy with methylene blue and detected Malassezia species without M. pachydermatis and M. nana using a non-culture-based method consisting of nested PCR with specific primers. RESULTS: The most frequently isolated species were M. globosa and M. restricta (both 93.9%). Only M. globosa was detected from the lesion in which the mycelial form alone was observed microscopically, but M. restricta was not. CONCLUSIONS: Our results suggest that M. globosa is the causative agent of PV.

Adolescent↗

PubMed2006

Microreview of Pityriasis versicolor and Malassezia species.

Recently 11 Malassezia species were isolated. Attention has focused on the relationship between Malassezia species and Malassezia-related disease. The causal fungus of Pityriasis versicolor is M. globosa. The conditions of mycelial form induction are not clear for M. globosa.

Antifungal Agents↗

PubMed2001

[A case of lymphocutaneous sporotrichosis].

We report a case of lymphocutaneous sporotrichosis in a 69-year old man who had nodular-ulcerated lesions on the right hand and forearm. Small nodules remained on the right hand after 8 weeks of 0.5 g daily treatment with potassium iodide. Alternatively, terbinafine therapy (125 mg/day) resulted in healing with atrophic scars after 9 weeks without side effects. We reviewed 67 patients of cutaneous sporotrichosis in Japan from 1993 to 1999. Those cure rates (and mean durations of treatments in parentheses) are 90.9% (8.1 weeks) with potassium iodide, 86.6% (12.6 weeks) with itraconazole (100 mg/day) and 71.4% (12.8 weeks) with terbinafine (125 mg/day) treatments, respectively. These results lead us to consider a daily dose of 250 mg as more appropriate for terbinafine.

Aged↗

PubMed2000

[Dermatophytosis of the external auditory meatus].

Dermatophytosis of the external auditory meatus is believed to be a fairly rare disease. In the past three and a half years we have had seven cases of dermatophytosis in the external auditory meatus. All cases except one were associated with tinea of other lesions. Case 1: A 44-year-old man had tinea of the auricle, tinea pedis and tinea unguium. Case 2: A 14-year-old boy, the son of case 1 had no tinea elsewhere on his body, including the auricle. He scratched the auditory meatus with an earpick which his father had used. Case 3: A 62-year-old man had tinea of the auricle, tinea pedis and tinea unguium. Case 4: A 50-year-old man had tinea of the auricle, tinea pedis and tinea unguium. Case 5: A 36-year-old man had tinea of the auricle, tinea pedis, tinea unguium and tinea cruris. Case 6: A 30-year-old woman had tinea of the auricle. Case 7: A 68-year-old man had tinea of the auricle, tinea pedis, tinea unguium and tinea manuum. Endoscopic examination (except for cases 4 and 7) revealed dry cerumen from cartilaginous to bony region of the external auditory meatus. Direct examination using KOH method of the cerumen in all cases demonstrated numerous fungal elements. Fungal cultures identified Trichophyton rubrum except for cases 3 and 6. All cases were successfully treated with oral itraconazole or terbinafine. We suggest that tinea of the external auditory meatus is frequently associated with that of the auricle.

Adolescent↗

PubMed2000

Characterization of an extracellular keratinase from Microsporum canis.

Extracellular keratinase (Ekase) 48-, 34- and 31.5-kDa polypeptides, which were isolated from Microsporum canis and examined by immunoblotting reacted with a monoclonal antibody against Ekase of M. canis. We analyzed the amino acid and determined the first 17 amino acid NH2-terminal sequences of the 48-, 34- and 31.5-kDa polypeptides. These polypeptides had a high aspartic acid, glycine and alanine content, respectively. The first 17 amino acid residues of the 34-kDa polypeptide were homologous to those of thermomycolin. This indicated that the 34-kDa polypeptide of Ekase is homologous to the thermomycolin produced by Malbranchea pulchella. Furthermore, Ekase was very heat-stable in the presence of 50 mM CaCl2 at 55 degrees C, since 50% of the initial activity remained. In contrast, no activity was detected after heating in the absence of CaCl2. These results indicate a close relationship between dermatophytes and M. pulchella.

Amino Acid Sequence↗

PubMed1997

Dual infection of rabbits with human T cell lymphotropic virus types I and II.

Attempts were made to generate a rabbit model of dual infection with human T lymphotropic virus (HTLV) types I and II. Four groups (A, B, C, and D) of three rabbits each were used. Group A was inoculated with the RW-1 cell line coinfected with HTLV-I and HTLV-II and group B was transfused from a dually infected rabbit. Polymerase chain reaction (PCR) using primers specific for the pol region of each virus detected both HTLV-I and HTLV-II in all group A and two group B rabbits, but HTLV-II only in the remaining group B rabbit. Groups C and D already infected with HTLV-I and HTLV-II, respectively, were inoculated with an HTLV-II- or HTLV-I-producing cell line. One group C rabbit became PCR-positive for both viruses but the other five resisted superinfection with the respective viruses. During prolonged observation, three of the six dually infected rabbits converted to single (HTLV-I or HTLV-II) infection. The in vivo dual infection was confirmed by in vitro establishment of a lymphoid cell line coinfected with HTLV-I and HTLV-II. It was also possible to establish coinfected lymphoid cell lines from HTLV-I-infected rabbits by coculture with lethally irradiated HTLV-II-producing cells and vice versa. The mechanism of viral elimination in dually infected rabbits, as well as that of protective immunity against superinfection, remains to be elucidated.

Animals↗

PubMed1997

Recovery of iodine-123 metaiodobenzylguanidine uptake associated with left ventricular functional recovery in a patient with dilated cardiomyopathy. Endomyocardial histological findings before and after the improvement of uptake.

A 58-year-old man with idiopathic dilated cardiomyopathy was treated with incremental administration of a beta-blocker (metoprolol) and an angiotensin converting enzyme inhibitor (enarapril). The left ventricular end-diastolic dimension and ejection fraction improved in 8 months from 83.3 mm and 17.3% to 46 mm and 69%, respectively. The washout ratio and heart-to-mediastinum ratio depicted on the delayed image for iodine-123 metaiodobenzylguanidine 123I-MIBG) uptake improved from 61.7% and 1.34 to 23.1% and 1.85, respectively, in association with improvement of left ventricular indices. Successive endomyocardial biopsy specimens disclosed reduction of the degrees of vacuolation, staining irregularity, and deformity of myocyte cytoplasm and nucleus compared to the findings before therapy. In this patient with dilated cardiomyopathy 123I-MIBG scintigraphy was useful for the evaluation of the effects of therapy. We conclude that it may be informative in the estimation of the histopathological abnormalities of the myocardium.

3-Iodobenzylguanidine↗

PubMed1996

Biphenotypic leukemia with a new translocation, t(2;6)(q31;q23).

A t(2;6)(q31;q23) was found in a patient with acute biphenotypic leukemia. This cytogenetic change has not been reported previously in acute lymphocytic leukemia (ALL) or biphenotypic leukemia, although deletion of 6q has been frequently found in ALL.

Cell Lineage↗

PubMed1996

Sequential changes in laminin and type IV collagen in the infarct zone--immunohistochemical study in rat myocardial infarction.

BACKGROUND: The healing process, which affects ventricular remodeling, is an important factor in the prognosis of myocardial infarction. We hypothesized that laminin and type IV collagen contribute to extracellular matrix assembly in healing after myocardial infarction. We examined sequential changes in these two components after experimental myocardial infarction in rats. MATERIALS AND METHODS: Hearts were excised from 1 day to 10 weeks after permanent left coronary ligation in rats. Immunohistochemical staining with a polyclonal antibody to laminin and type IV collagen was performed by the avidin-biotin-peroxidase method. RESULTS: Laminin: On day 3, laminin initially appeared in a wavy fashion in the granulation tissue of the infarct peripheral zone and was not restricted to the cell membrane; the staining distribution in the peripheral zone then gradually increased, reaching a maximum on days 7-11. The distribution progressed from the peripheral zone to the outer lesion of the central zone of the infarct for 1-2 days, and reached the center point after 2 weeks. The extent of the staining distribution gradually decreased after reaching this maximum, but the staining did not completely disappear. Type IV Collagen: Changes in type IV collagen were essentially the same as those in laminin. A wavy staining pattern of type IV collagen appeared in the infarct peripheral zone from day 3, reached its maximum extent on days 7-11, and decreased gradually thereafter. The distribution progressed from the peripheral zone to the outer lesion of the central zone for 1-2 days, reaching the center point after 2 weeks. CONCLUSIONS: Laminin and type IV collagen contribute to extracellular matrix formation in the infarct zone relatively early after myocardial infarction.

Animals↗

PubMed1995

Vaccination of rabbits with recombinant vaccinia virus carrying the envelope gene of human T-cell lymphotropic virus type I.

Two groups of 3 rabbits each were immunized with either recombinant vaccinia virus, WR-SFB5env, carrying the human T-cell lymphotropic virus type I (HTLV-I) env gene at the site of the hemagglutinin gene of the WR strain, or control vaccinia virus, HA-WR, lacking the functional hemagglutinin gene. All 6 rabbits responded with anti-vaccinia virus antibodies. WR-SFB5env elicited anti-HTLV-I env antibodies but no vesicular stomatitis virus (HTLV-I) pseudotype neutralizing antibodies in all 3 rabbits. After 10 weeks, the animals were challenged by transfusion of blood from an HTLV-I-infected rabbit. Two of the 3 vaccinated rabbits and all 3 control rabbits became infected with HTLV-I, as indicated by seroconversion and detection of HTLV-I proviral sequences by polymerase chain reaction. The rabbit that had been protected from initial challenge became infected with HTLV-I upon rechallenge 12 weeks after the first challenge. In view of the proven prophylactic effect of passive immunization against HTLV-I, our vaccine trial failed because WR-SFB5env was incapable of inducing neutralizing antibodies against HTLV-I in the immunized animals. It remains to be studied whether cell-mediated immunity such as antibody-dependent cellular cytotoxicity was involved in the temporary protection of I vaccinated rabbit.

Animals↗

PubMed1995

Establishment of novel lymphoid cell lines dually infected with human T cell lymphotropic viruses types I and II.

With the goal of establishing an in vitro system of dual infection with human T cell lymphotropic viruses (HTLV) types I and II, rabbit lymphocytes were cocultured with a mixture of lethally irradiated HTLV-I-producing Ra-1 and HTLV-II-producing RII cell lines. This gave rise to a lymphoid cell line, RW-1, that was dually infected with HTLV-I and -II as detected by immunofluorescence staining, electron microscopy, and polymerase chain reaction using primers specific for the pol and env regions of each virus and by Southern blot hybridization. Two clonal cell lines derived from RW-1 were also coinfected with the viruses, indicating that dual infection had occurred at the single cell level. The coinfection could be readily propagated to fresh lymphocytes by coculture with RW-1. In contrast, attempts to superinfect HTLV-I-infected lymphoid cell lines with HTLV-II and vice versa were consistently unsuccessful, suggesting receptor interference between HTLV-I and -II.

Animals↗

PubMed1995

Autologous pericardial patch repair for postinfarction ventricular septal perforation.

Surgical therapy for ventricular septal perforation associated with acute myocardial infarction is thought to reduce ventricular chamber volume and distort the ventricle due to excision of the myocardium. A 69-year old man underwent elective surgery that used an autologous pericardial patch without excising the myocardium. Intraventricular repair using the autologous pericardial patch enabled preservation of ventricular geometry and chamber volume and did not result in a depression of cardiac function. Moreover, it has been reported that this surgical procedure protects against suture bleeding and decreases the amount of foreign material required, thus possibly reducing the risk of infectious complications.

Aged↗

PubMed1995

Establishment and characterization of an immature human megakaryoblastic cell line, MEG-A2.

We have established a novel human megakaryoblastic cell line, designated as MEG-A2, from a patient with megakaryoblastic crisis of Philadelphia (Ph) chromosome positive chronic myelogenous leukemia. MEG-A2 cells showed positive phenotypes for periodic acid Schiff and alpha-naphthylbutyrate esterase reactions, but were negative for myeloperoxidase and naphthol ASD chloroacetate esterase reactions. Flow cytometric analyses of cell surface markers revealed that MEG-A2 cells had a low level of GP IIb/IIIa expression as well as apparent expressions of CD4, CD7, CD13, CD33 and CD34 antigens, but no expression of GP Ib nor glycophorin A. Stimulation with phorbol 12-myristate 13-acetate (PMA) dramatically increased the expression of megakaryocyte-related markers such as HPL-3, J15, Pit-1, Y2/51 and AN51 in MEG-A2 cells. The PMA-stimulation also induced expression of platelet peroxidase (PPO) in MEG-A2 cells on electromicroscopic observation. Proliferative responses to granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3) or erythropoietin were observed, and the expression of GP IIb/IIIa was increased by stimulation with GM-CSF, IL-3, erythropoietin and interleukin-6 (IL-6). Protein S mRNA expression was seen in cultured cells on Northern blot analysis. Expression of platelet factor 4 mRNA was induced in PMA-stimulated cells, and a marked accumulation of protein was observed in the culture medium. In conclusion, a new cell line, MEG-A2, belongs to the relatively immature megakaryocytic lineage and has markedly increased megakaryocytic characteristics with PMA stimulation.

Adult↗

PubMed1994

Purification and characterization of a rhamnogalacturonase with protopectinase activity from Trametes sanguinea.

In a culture filtrate of Trametes sanguinea IFO 6490, we found a protopectin-solubilizing enzyme, protopectinase-T, that did not degrade polygalacturonic acid. The enzyme was purified to homogeneity with hydrophobic, cation-exchange, anion-exchange, and size-exclusion chromatographies. It had an apparent molecular mass of 55 kDa by SDS/PAGE and 39 kDa by size-exclusion chromatography on Superose 12. The isoelectric point was at pH 8.1. Protopectinase-T was stable from pH 3.0 to 6.0 and at temperatures up to 50 degrees C. The optimum pH for enzyme activity was 4.0 at 37 degrees C, and the optimum temperature was 50 degrees C at pH 5.0. Protopectinase-T catalyzed the release of highly polymerized pectin from lemon peel protopectin.

Chromatography, Gel↗

PubMed1994

Phase I study of E1077, a novel parenteral cephem antibiotic.

The safety and pharmacokinetics of E1077, a new injectable cephem antibiotic, were evaluated in healthy male adult volunteers. In the single-dose studies, 100, 250, 500, 1,000, and 2,000 mg of E1077 were administered by intravenous infusion at a constant rate for 60 minutes, then 1,000 mg of the drug by intravenous infusion at a constant rate for 5 minutes. The Cmax were 6.4, 15.7 +/- 12.0, 34.7 +/- 4.6, 63.2 +/- 4.6, 142.7 +/- 5.6, and 131.6 +/- 36.0 (means +/- SD) micrograms/mL, respectively, and the Cmax and AUC increased linearly with the dose. Plasma concentration-time curves were well described by a two-compartment open model. The plasma elimination half life of the drug was 1.88 +/- 0.15 hours. The mean urinary recovery within the first 24 hours was 94.1 +/- 5.1% of the dose. In the multiple-dose study, 2,000 mg of E1077 was intravenously administered at a constant rate over 60 minutes every 12 hours for 4.5 days (a total of nine times). The Cmax after the first and ninth doses were 134.0 +/- 17.4 and 135.5 +/- 15.5 micrograms/mL, respectively, and trough levels in day 1 and day 5 (at 12 hours after the first and ninth administration, respectively) were 2.2 +/- 0.8 and 1.9 +/- 0.4 micrograms/mL, respectively. No accumulation of the drug in plasma was observed. There were no significant differences in plasma levels or in the urinary recoveries between the single- and multiple-dose regimens.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1994

Immunoglobulin prophylaxis against human T cell lymphotropic virus type II in rabbits.

Hyperimmune globulins, I-IgG and II-IgG, prepared from healthy persons seropositive for human T cell lymphotropic virus (HTLV) types I and II, respectively, were tested for their prophylactic effect against HTLV-II infection in rabbits. Three groups (A, B, and C) of 3 female rabbits each were used. Group A rabbits were inoculated intravenously with HTLV-II-carrying rabbit lymphoid cell line RII. Group B and C rabbits were immunized, respectively, with II-IgG and I-IgG and challenged with RII cells 24 h later. All group A and C rabbits seroconverted for HTLV-II after 2 weeks, but all group B rabbits were protected from HTLV-II infection. Gene amplification by polymerase chain reaction revealed the presence of HTLV-II provirus sequences in all group A and C rabbits but in none of the group B rabbits. These findings indicate that passive immunization with II-IgG is effective in preventing HTLV-II infection and that there is no cross-neutralization between HTLV-I and -II.

Animals↗