PubMed Health⌕ Search

Biomedical subjects

M Iwanami

Publications and source records attributed to M Iwanami.

At least 19 recordsLinked to original sources
PubMed1999

Structural and functional analysis of the LaMDR1 multidrug resistance gene in Leishmania amazonensis.

We determined primary sequences of the LaMDR1 gene in Leishmania amazonensis, a protozoan parasite that causes cutaneous leishmaniasis. The longest open reading frame encodes 1341 amino acids for a protein consisting of two similar halves, each containing six putative transmembrane domains and one ATP-binding domain. The protein has no potential N-glycosylation sites at the extracellular region. The LaMDR1 protein was 91 and 78% identical to the closely related ldmdr1 in L. donovani and lemdr1 in L. enriettii, respectively, revealing less conservation in the C-terminal than in the N-terminal transmembrane domains. Transfection of LaMDR1 conferred a multidrug resistance phenotype to wild-type promastigotes, which exhibited a significant level of resistance to vinblastine, doxorubicin, and actinomycin D, but not to puromycin and colchicine. This drug specificity of LaMDR1 was overlapping with but distinct from that of ldmdr1, suggesting functional diversity of MDR1 proteins among different Leishmania species.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1993

Speech and velopharyngeal function following maxillary advancement in patients with cleft lip and palate.

The influence of maxillary advancement by osteotomy on speech was examined in 10 patients with cleft palates (6 males, 4 females). Ages at the time of surgery ranged from 16 to 26 years (mean, 19.5 yr). LeFort I and II osteotomies were performed in 9 patients and 1 patient, respectively. Preoperatively and postoperatively, hypernasality, nasal emission on pressure consonants, and articulation disturbances were evaluated perceptually, and velopharyngeal function was evaluated by lateral cephalographic and nasopharyngoscopic studies. Hypernasality, which had been judged preoperatively to be absent or slight in 1 patient each, remained unchanged after surgery, whereas the remaining 8 patients showed increased hypernasality after surgery. Nasal emission showed a similar tendency. Articulation errors were not improved postoperatively. Lateral cephalograms recorded from the patients with increased hypernasality showed increases in the shortest palatopharyngeal length and in the soft-palate-length--to--pharyngeal-depth ratio. Also, deterioration in velopharyngeal closure was noted postoperatively compared with preoperatively by nasopharyngoscopy in the majority of patients with increased hypernasality.

Adolescent↗
PubMed1990

Enhancement of interferon-gamma-induced differentiation of human monoblastic leukemia U-937 cells by cAMP-inducing agents.

The effects of combinations of interferons (IFNs) and cAMP-inducing agents on the induction of differentiation of human monocytic leukemia U-937 cells were examined. IFN-gamma induced nitro blue tetrazolium (NBT) reducing activity of U-937 cells in a dose-dependent manner, while cAMP-inducing agents such as cholera toxin, prostaglandin E1, forskolin, and isoproterenol only marginally induced NBT reducing activity. However, they all synergistically increased IFN-gamma induction of NBT reducing activity. Cholera toxin was the most potent of the cAMP-inducing agents. Combination effects of IFN-gamma and cholera toxin on other differentiation-associated markers of alpha-naphthyl acetate esterase activity, morphological maturation, Fc receptors, and surface phenotype were also observed. IFN-alpha and -beta, either alone or in combination with cAMP-inducing agents, did not induce NBT reducing activity. IFN-gamma and cholera toxin also synergistically induced differentiation-associated markers in another human monocytic leukemia cell line, THP-1, and a human myeloblastic leukemia cell line, ML-1. These results suggest that cAMP/A-kinase may be an important but insufficient signal for the maturation process of myelogenous leukemia cells.

Alprostadil↗
PubMed1990

Combination effects of interferon-gamma and cholera toxin on induction of differentiation of an insensitive U-937 clone.

We examined the combination effect of interferon-gamma (IFN-gamma) and cholera toxin and the role of cAMP in the induction of differentiation of a differentiation-insensitive U-937 clone, in which the reactivity to differentiation-inducers was decreased. IFN-gamma (100 units/ml) or cholera toxin (10(-9) M) alone only marginally induced various differentiation-associated characteristics such as NBT-reducing activity, phagocytic activity, a-naphthyl acetate esterase activity and surface markers. However, when combined with each other, they significantly induced these markers. Other cAMP-inducing agents such as prostaglandin E2, forskolin, epinephrine and isoproterenol did not induce NBT-reducing activity, either alone or in combination with IFN-gamma. However, all these cAMP-inducing agents significantly increased intracellular cAMP levels. Tumor necrosis factor, interleukin 6 or granulocyte/macrophage colony-stimulating factor alone did not induce NBT-reducing activity, but they could induce activity when combined with cholera toxin. These results suggest that enhancement of induction of differentiation by cholera toxin in combination with IFN-gamma or other cytokines may not be merely due to increased cAMP levels. There seems to be a transduction signal other than cAMP coupling with cholera toxin to stimulate induction of differentiation of an insensitive U-937 clone.

Cell Differentiation↗
PubMed1989

Novel antitumor antibiotic phospholine. 2. Structure determination.

Phospholine, an antitumor antibiotic, has the molecular formula of C25H40NO8P and possesses a delta-lactone and a phosphoric acid ester as functional groups. Its structure was determined based on interpretation of fast atom bombardment MS, 1H NMR, 13C NMR, 1H-1H correlation spectroscopy (COSY), 13C-1H COSY, heteronuclear multiple bond correlation spectroscopy, elemental analysis and chemical modifications.

Antibiotics, Antineoplastic↗
PubMed1987

Okilactomycin, a novel antibiotic produced by a Streptomyces species. I. Taxonomy, fermentation, isolation and characterization.

Okilactomycin, a novel antibiotic, was isolated from the culture filtrate of a strain of actinomycetes. The producing organism, strain YP-02908L, was identified as Streptomyces griseoflavus subsp. zamamiensis subsp. nov. The antibiotic was extracted with ethyl acetate and purified by silica gel column chromatography. It was obtained as colorless prisms from a dichloromethane solution. It exhibited weak antimicrobial activity against Ehrlich ascites carcinoma in vivo. The apparent molecular formula of okilactomycin was determined as C24H32O6. It is a new member of the lactone group antibiotics.

Animals↗
PubMed1984

Blepharoplasty in Japan.

About 90% of blepharoplasties performed in Japan include the double eyelid procedure. The reasons for the popularity of this procedure relate to changing concepts of beauty among the Japanese people. Facial anatomy contributes to the appearance of sleepiness and lethargy in the flat, monotone Japanese face. The narrower eye opening does not allow for the maximum viewing of the cornea. The shortened lateral canthus presents a facial balance that is not considered as attractive as one with an extended lateral canthus. The double eyelid procedure corrects these features, producing a face that is considered more beautiful.

Adult↗