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Biomedical subjects

K Homma

Publications and source records attributed to K Homma.

At least 73 records · Page 4Linked to original sources
PubMed1997

Novel benzoxazole 2,4-thiazolidinediones as potent hypoglycemic agents. Synthesis and structure-activity relationships.

A new series of benzoxazole 2,4-thiazolidinediones was synthesized and evaluated for hypoglycemic activity in genetically obese and diabetic yellow KK mice. 2-Arylmethyl- and 2-(heteroarylmethyl)benzoxazole derivatives showed far more potent activity than known 2,4-thiazolidinedione derivatives such as ciglitazone, troglitazone and pioglitazone. A facile synthesis of benzoxazole 2,4-thiazolidinediones was also established using aminophenol 2,4-thiazolidinedione (11) as a key intermediate. Details of synthesis and structure-activity relationships for this series are described.

Animals↗
PubMed1997

[Clinical efficacy of silver sulfadiazine (AgSD: Geben cream) for ulcerative skin lesions infected with MRSA].

The clinical efficacy was evaluated on 1% silver sulfadiazine (AgSD) cream (Geben cream) for the treatment of ulcerative skin lesions infected with MRSA (methicillin-resistant Staphylococcus aureus). 1% AgSD cream was applied once a day to cutaneous ulcers such as burns or decubitus or various other ulcers, infected with MRSA, in 13 patients. MRSA was eradicated in 45.5% of 11 evaluable patients. The clinical efficacy rate of 1% AgSD cream was 72.7% in this series of treatment. No side effects were noted in any of the patients, either locally or systemically. The results of the present study have indicated that 1% AgSD cream is useful for cutaneous ulcers such as burns or decubitus, infected with MRSA.

Administration, Topical↗
PubMed1997

[Helical CT of the breast: detection of intraductal spread and multicentricity of breast cancer].

PURPOSE: This study was performed to evaluate the clinical utility of postcontrast helical CT (HCT) scan for the detection of intraductal spread (DS) and multicentricity of breast cancer. MATERIALS AND METHODS: DS and multicentricity in 84 patients with invasive ductal carcinoma were evaluated by preoperative postcontrast HCT. The HCT protocol of 3-mm section width and 3 mm/sec table speed was used with the patients in a supine position. Scanning started 70sec after beginning the intravenous injection of 90 ml (27 gI) of contrast material at the rate of 1.5 ml/sec. The three-dimensional images were displayed. RESULTS: Eighty-four of 84 main tumors (100%) were shown as enhanced masses by postcontrast HCT. The sensitivity and specificity of HCT for the detection of DS and multicentricity were 60.0% (18/30) and 88.9% (48/54), and 88.9% (16/18) and 90.9% (60/66), respectively. When DS and multicentric lesions were combined, the sensitivity and the specificity were 76.3% (29/38) and 89.1% (41/46), respectively. CONCLUSION: HCT of the breast is effective in detecting DS and multicentric lesions of breast cancer and might be useful in helping surgeons to successfully perform breast-conserving surgery.

Adult↗
PubMed1996

Identification of substrate proteins for cathepsin L that are selectively hydrolyzed during the differentiation of imaginal discs of Sarcophaga peregrina.

Previously, we showed that cathepsin L is essential for the differentiation of imaginal discs of the flesh fly [Homma, K. & Natori, S. (1994) J. Biol. Chem. 269, 15258-15264]. We have now identified imaginal disc proteins that are susceptible to digestion by cathepsin L and showed that they are selectively hydrolyzed during imaginal disc differentiation. Two of these proteins, with molecular masses of 210 and 200 kDa, were further characterized. Immunofluorescence studies suggested that they were intrinsic components of the basement membranes of various tissues. They were selectively hydrolyzed at the elongation stage of imaginal leg disc differentiation. Western blotting of embryos at various developmental stages showed that these proteins were only detected at the end of embryogenesis.

Animals↗
PubMed1996

Purification, characterization, and cDNA cloning of a novel growth factor from the conditioned medium of NIH-Sape-4, an embryonic cell line of Sarcophaga peregrina (flesh fly).

A growth factor from the conditioned medium of NIH-Sape-4, an embryonic cell line of the flesh fly, was purified to homogeneity. This growth factor, termed IDGF, stimulated the proliferation of NIH-Sape-4 cells in an autocrine manner; it was a homodimer of a protein with a molecular mass of 52 kDa, and its specific activity was comparable with those of mammalian growth factors. Immunoblotting experiments revealed that unfertilized mature eggs of the flesh fly contained this growth factor, a certain level of which was maintained throughout embryonic development. Analysis of cDNA for this growth factor showed that this factor is a novel protein consisting of 553 amino acid residues. No significant sequence similarity was found between this factor and other proteins except atrial gland granule-specific antigen of Aplysia californica.

Amino Acid Sequence↗
PubMed1996

Chromosome spreading techniques for primary gastrointestinal tumors.

The requirement for well spread out chromosomes for the cytogenetic analysis of primary gastrointestinal tumors led us to develop new techniques. These techniques involved two main procedures: (1) preliminary incubation with culture medium in the presence of collagenase, Dispase, and colcemid, for 3 h, and (2) treatment with an extremely hypotonic solution (0.044M KCl) for 30 min. The techniques were applied to 11 gastrointestinal malignancies (including 1 early gastric cancer and 1 metastatic liver lesion of colon cancer) and significant increases (P < 0.01) in the number of metaphases of analyzable karyotypes were obtained, compared with a previous method in which the standard hypotonic molarity of KCL (0.075 M) was employed. The mean value for metaphase numbers of the analyzable karyotypes was 37.0 +/- 3.7% in the 5 gastric cancers and 44.7 +/- 4.8% in the 5 colon cancers and 1 metastatic lesion. These values were three times and more than twice, respectively, the values obtained by the previous method. A fluorescence in situ hybridization (FISH) study was carried out on one cologenic tumor, the alpha-satellite centromere-specific probe 17 being used. Deletion of the long arm of chromosome 17 was demonstrated. The method proposed here could yield a sufficient number of metaphases without the use of tissue culture that might cause alteration of karyotype. It can be employed with small biopsy specimens and in studies utilizing the FISH technique.

Aged↗
PubMed1995

Development of near-field optic/atomic force microscope for biological materials in aqueous solutions.

This paper reports improvements of optical fiber cantilevers and the scanning near-field optical microscopy imaging of biological materials in liquid. In our scanning near-field optical/atomic-force microscope (SNOAM), the scanning of an optical fiber cantilever over the specimen was controlled by dynamic mode AFM to reduce damage to the probe and soft specimens. The typical resonant frequency of the optical fiber cantilever was 19.5 kHz, while it was 23.0 kHz in air. The Q-factor of the cantilever depended on the vibration amplitude and was typically 260-600 in air and 40-240 in water. The relationship between the vibration amplitude and the average sample-probe separation indicated that the cantilever worked in the non-contact mode in water, while it worked in the cyclic-contact mode in air. Cultured cells in aqueous solutions were visualized by the SNOAM, indicating that the SNOAM is suitable to observe soft specimens.

Animals↗
PubMed1995

Fascia-vascularized vs. muscle-vascularized prefabricated flaps using tissue expanders: an experimental study in a rat model.

The aim of this study was to compare the applicability and viability of a fascia-vascularized pedicle (FVP) with those of a muscle-vascularized pedicle (MVP) in the prefabrication of a secondary vascularized pedicle flap using a tissue expander. Experiments were carried out in 32 male Wistar rats. The animals were divided into two groups--Group 1 (n = 10), using a skeletonized pedicle of the right saphenous artery, vein, and nerve with a segment of 8 x 10 mm fascia on its distal end (FVP group); and Group 2 (n = 10), using a 3-mm perivascular cuff of muscle with a segment of 8 x 10 mm fascia and gracilis muscle on its distal end (MVP group). The experiments demonstrated that there was a larger area of flap survival in the expanded muscle-vascularized pedicle flaps (96.6 +/- 3.6 percent) than that found in the expanded fascia-vascularized pedicle flaps (83.0 +/- 14.4 percent) in this rat model (p < 0.005). The microangiography of the flaps showed increased vascularity of the muscle cuff at the end of the vascular pedicle in Group 2.

Angiography↗
PubMed1995

[Nasal smear cytology in bronchial asthma: correlation of appearance and numbers of nasal smear mast cells, eosinophils or basophils and serum IgE antibodies to house dust mite in patients with bronchial asthma].

Nasal smear cytology was studied in pediatric patients with bronchial asthma with special reference with IgE RAST to house dust mite, Dermatophagoides pteronyssinus (Dp). Results obtained were as follows: (1) Numbers of eosinophils on the nasal smear correlated well with Dp RAST score, (2) mast cells were detected before Dp RAST becoming positive and appearance of eosinophils, (3) basophils appeared after detection of eosinophils and only in patients with nasal smear eosinophils. These results suggest that mast cells are the early marker for allergic inflammation and basophils and eosinophils appear in association with overt sensitization with house dust mite in house dust mite-sensitized asthmatic patients.

Adolescent↗
PubMed1994

Purification, characterization, and cDNA cloning of procathepsin L from the culture medium of NIH-Sape-4, an embryonic cell line of Sarcophaga peregrina (flesh fly), and its involvement in the differentiation of imaginal discs.

A cysteine proteinase that preferentially hydrolyzes carbobenzyloxy-Phe-Arg-MCA (MCA, methylcoumaryl-7-amide) was purified from the culture medium of NIH-Sape-4 cells. The molecular mass of this enzyme was easily changed from 50 to 35 kDa, without appreciable loss of enzyme activity. From the analysis of its cDNA, this enzyme was concluded to be a procathepsin L of Sarcophaga. Only procathepsin L was found in the medium, while the mature 35-kDa cathepsin L was found exclusively in the cells, indicating that the cells have a mechanism to secrete procathepsin L selectively. An antibody against procathepsin L was found to inhibit the differentiation of imaginal discs cultured in vitro in the presence of 20-hydroxyecdysone. In fact imaginal discs were shown to secrete procathepsin L into the culture medium. These results suggest that procathepsin L is an essential proteinase for differentiation of imaginal discs. Northern blotting analysis revealed that unfertilized eggs contain a significant amount of mRNA for the procathepsin L as a maternal mRNA.

Amino Acid Sequence↗
PubMed1994

A prolyl endopeptidase of Sarcophaga peregrina (flesh fly): its purification and suggestion for its participation in the differentiation of the imaginal discs.

A prolyl endopeptidase that hydrolyses Suc-Gly-Pro-MCA (Suc, succinyl; MCA, methyl-coumaryl-7-amide) was purified to near homogeneity from NIH-Sape-4 cells derived from the flesh fly (Sarcophaga peregrina). The molecular mass of the purified enzyme was 84 kDa, and its activity was inhibited almost completely by 1 mM diisopropyl fluorophosphate (DFP). Immunoblotting and DFP-labeling experiments revealed that the leg imaginal discs of Sarcophaga contained this enzyme as a major serine proteinase. This prolyl endopeptidase is suggested to be involved in the differentiation of imaginal discs, because 2 mM DFP and 0.1 mM N-benzyloxycarbonyl-thioprolyl-thioprolynal-dimethylaceta l (ZTTA), a specific inhibitor for prolyl endopeptidase, inhibited differentiation of the imaginal discs from the eversion to the elongation stage.

Amino Acid Sequence↗
PubMed1994

[Generation of fiber aerosol by ultrasonic nebulizer].

In this study, our point of view is to generate monodisperse fiber aerosols stably from liquid suspension by using an ultrasonic nebulizer. To fulfill this purpose, we set standard operating conditions in advance by measuring relative humidity of the air flowed from the apparatus, and then generated three kinds of fiber aerosols (potassium titanate whisker, amosite, chrysotile) to investigate this method. The results which were obtained are as follows. 1) Nebulizing method is useful for generating fiber aerosols stably. The longest term obtained in stable generation was as much as 6 hours, and the count median length (CML) of the fibers were 1-2 micrometer. 2) The aerosol concentration ranged from 0.2 to 3.4 mg/m3, and the flow rate of carrier air was found most effective to control aerosol concentration and length. 3) To shift the concentration of liquid suspension was not always effective to shift the aerosol concentration, and too much concentrated suspension tended to cause fiber co-aggregation. 4) Primary fiber sample should be fine to generate fiber aerosol stably, because large-sized fibers will disturb the aerosol generation.

Aerosols↗
PubMed1993

Pharmacokinetics of meropenem in experimentally burned rats.

The pharmacokinetics of meropenem were investigated to examine its penetration into the skin of third degree burned rats. The rats were divided into two groups. One group acted as the control, and the other group had third degree burns induced by immersing their backs into 80 degrees C water for 20 seconds. The rats in each group were given 20 mg/kg of body weight of meropenem intravenously by one bolus injection seven days after burn inducement or depilation. In the non-burned control group, the maximum concentrations of meropenem in the serum and skin of 6.03 micrograms/ml and 0.12 microgram/g were respectively obtained 15 minutes after the injection and decreased very rapidly thereafter. In the burned rats, the maximum concentrations of meropenem in the serum, skin (eschar), and exudate fluid of 7.07 micrograms/ml, 1.44 micrograms/g and 5.99 micrograms/ml were respectively obtained 15 minutes after the injection and decreased very slowly. The penetration of meropenem into the burned skin was higher than that into the normal skin. These results suggest that meropenem is a very useful antibiotic in the treatment of burn infection.

Animals↗
PubMed1993

Primary correction of the unilateral cleft lip nose.

The details of surgical techniques for primary correction of the unilateral cleft lip nose and their results for 45 cases are reported. The technique employed an infracartilaginous incision on the affected side, thus allowing direct suturing of the alar cartilage onto the lateral cartilage. For the post-operative evaluation, the nasal form in both frontal and bottom views was scored for five items. In overall evaluation, the grades of "Good," "Fair," and "Poor" were derived from the total scores of five items. In the postoperative results (range of follow-up: 24 months to 84 months), 24 cases were rated "Good" (53.3%), 13 cases "Fair" (28.9%), and 8 cases "Poor" (17.8%). Thirty cases appear not to need secondary correction (66.6%). The technique is useful because the alar cartilages and lateral cartilages can be accurately sutured, and relatively stable results can be obtained.

Cleft Lip↗
PubMed1993

Prefabricated flaps using tissue expanders: an experimental study in rats.

The aim of this study was to determine if muscle vascularized pedicle flaps (MVP flaps) elevated in expanded tissue on the rat would survive to the same or greater area than flaps elevated in nonexpanded tissue. The animals were divided into three groups: group I (n = 10), with a tissue expander; group II (n = 10), with a tissue expander but not expanded; and group III (n = 10), with a thin silicone sheet (Biobrane). The mean surviving area of group I (96.6 +/- 3.6 percent) was statistically higher than that of group II (73.2 +/- 24.7 percent) (p < 0.05) and group III (59.5 +/- 25.1 percent) (p < 0.005). These experiments demonstrate that there is a larger area of flap survival in expanded muscle vascularized pedicle flaps than that found in nonexpanded flaps in rats. The mechanism of increased vascularity associated with tissue expansion is still unclear, but microangiography of flaps showed increased vascularity of the pedicle itself, especially in group I.

Angiography↗