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Biomedical subjects

H Honda

Publications and source records attributed to H Honda.

At least 55 records · Page 3Linked to original sources
PubMed2001

Toxic shock-like syndrome with flu-like prodrome: a possible role of 'enhancing tissue focus' for streptococcal toxic shock.

We describe three patients with invasive group A streptococcal infection, admitted during the 3 months between November 1996 and February 1997. All patients were previously healthy Japanese women who developed a profound shock, with a rapidly fatal outcome, after experiencing flu-like symptoms. All cases conformed to the case definition of toxic shock-like syndrome (TSLS).Currently, the pathogenic mechanism of TSLS remains unclear. Known microbial virulence factors can not sufficiently explain the occurrence of TSLS, and it has been generally considered that host factors may be contributory. On pathological examination, each patient had one organ or tissue that was most severely involved: Case 1 a non-penetrating trauma; Case 2 a pregnant uterus; and Case 3 a pulmonary lesion reminiscent of lymphocytic interstitial pneumonia. On the basis of clinicopathological features of these cases, we propose that the coexistence of 'enhancing tissue focus' may be one of host factors for the progression of TSLS in patients infected with non-invasive GAS.

Adult↗
PubMed2001

Detection of human gastric cancer in resected specimens using a novel infrared fluorescent anti-human carcinoembryonic antigen antibody with an infrared fluorescence endoscope in vitro.

BACKGROUND AND STUDY AIMS: An indocyanine green derivative (ICG-sulfo-OSu) that can be used as an infrared fluorescent labeling substance suitable for detecting microlesions with an infrared fluorescence endoscope has been developed. The aims of the present study were to develop an infrared fluorescence endoscope and to demonstrate its usefulness in detecting cancerous tissue using an antibody coupled with ICG-sulfo-OSu. MATERIALS AND METHODS: ICG-sulfo-OSu-labeled mouse anti-human carcinoembryonic antigen (CEA) antibody and an infrared fluorescence endoscope were used in this study. Biopsy specimens of gastric cancer were stained with anti-CEA antibody using the avidin-biotinylated peroxidase complex method. The positive specimens used for the infrared imaging analysis were freshly resected stomachs from three patients. RESULTS: Treatment of freshly resected stomach specimens with ICG-sulfo-OSu-labeled-anti-CEA antibody complex resulted in positive staining of the tumor sites on infrared fluorescence endoscopy, and the infrared fluorescent images correlated well with the tumor sites. CONCLUSIONS: An anti-CEA antibody with affinity for cancerous lesions and labeled with ICG-sulfo-OSu can therefore be imaged using this infrared fluorescence endoscope. Specific antibodies tagged with ICG-sulfo-OSu can label cancer cells and can generate a strong enough fluorescent signal to detect small cancers when examined with an infrared fluorescence endoscope.

Adenocarcinoma↗
PubMed2001

Visual mislocalisation induced by translational and radial background motion.

Three experiments were conducted to explore how translational and radial background motion affected visual localisation. In experiment 1, subjects were asked to indicate the apparent position of a small spot of light flashing against a background of vertical stripes, at a varying point in time before and after rapid translational motion of the background to the left or right. When the spot was flashed before the background motion, subjects mislocalised it toward the central fixation point. An interesting finding was that this mislocalisation occurred in most cases when the background moved in the direction opposite to the visual half-field in which the spot was flashed. That is to say, a spot flashed on the right side of the fixation point was mislocalised when its background moved to the left, and not when it moved to the right; and the converse was also true. In experiment 2, concentric circles were used as the background, and moved in a contracting or expanding direction. The results indicated that mislocalisation toward the central fixation point occurred when a spot was flashed before contracting motion of the background. The same mislocalisation was observed for the spot flashed in the lower visual field, but not when it was flashed in the upper visual field (experiment 3). It is concluded that the mislocalisation is a visual illusion induced by a transient background motion toward the central fixation point.

Analysis of Variance↗
PubMed2001

High frequency of XY disomy in spermatozoa of severe oligozoospermic men.

Frequencies of disomy and diploidy in spermatozoa for chromosomes X, Y and 18 were compared among severe oligozoospermic men (<5x10(6) spermatozoa/ml), oligozoospermic men (5-20x10(6) spermatozoa/ml), and normospermic men using three-colour fluorescence in-situ hybridization (FISH). Semen samples were collected from 10 severe oligozoospermic men aged 26-49 years, 10 oligozoospermic men aged 27-48 years and seven normospermic men aged 25-31 years. Karyotypes in lymphocytes obtained from peripheral blood were all 46,XY. In severe oligozoospermic men, analysis of 200 interphases per individual using FISH showed XY constitutions for sex chromosomes in all cells. A minimum of 10 000 sperm nuclei per individual for each chromosome was evaluated in severe oligozoospermic men and oligozoospermic men, and a minimum of 6000 sperm nuclei per individual in normospermic men. In total, 245 707 sperm nuclei were evaluated. The hybridization efficiency was 99.8%. The severe oligozoospermic men showed significantly higher frequencies of XY disomy (0.41%) and diploidy (0.49%) compared with oligozoospermic men (0.16%, P < 0.01; 0.22%, P < 0.05) and normospermic men (0.18%, P < 0.05; 0.21%, P < 0.05) (Mann-Whitney U-test). The data suggest that when severe oligozoospermic men undergo intracytoplasmic sperm injection, there can be an increase in the rate of conceptuses with 47,XXY chromosomes.

Adult↗
PubMed2001

Possible horizontal transfer of a transposable element from host to parasitoid.

Full-length mariner-like elements (MLEs) were identified from both a parasitoid wasp, Ascogaster reticulatus, and its moth host, Adoxophyes honmai. MLEs were detected in two related Tortricid moths, but not in another Ascogaster species. The MLEs of A. reticulatus and A. honmai were 97.6% identical in DNA sequence. This high similarity suggests a recent horizontal transfer, probably from the moth host to the wasp parasitoid, facilitated by the intimacy of the host-parasitoid relationship.

Amino Acid Sequence↗
PubMed2001

Targeting hyperthermia for renal cell carcinoma using human MN antigen-specific magnetoliposomes.

Magnetoliposomes (MLs) conjugated with an antibody fragment to give specificity to a tumor were applied to hyperthermia for cancer. The Fab' fragment of the G250 antibody, which binds to MN antigen on many types of human renal cell carcinoma, was cross-linked to N-(6-maleimidocaproyloxy)-dipalmitoyl phosphatidylethanolamine (EMC-DPPE) in liposomal membrane. The targetability of the G250-Fab' fragment-conjugating MLs (G250-FMLs) was investigated using the mouse renal cell carcinoma (mRCC) and MN antigen-presenting cell, MN-mRCC. The amount of G250-FMLs uptake reached 67 pg / cell against MN-mRCC cells in an in vitro experiment using plastic dishes and this value was about 6 times higher than that in the case of MLs. In an in vivo experiment using MN-mRCC-harboring mice, 1.5 mg of the FMLs per carcinoma tissue accumulated (tumor weight was 0.19 g), which corresponded to approximately 50% of the total injection. This value was 27 times higher than that of the MLs. After injection of the FMLs, mice were exposed to intracellular hyperthermia using alternating magnetic field irradiation. The temperature of tumor tissue increased to 43 degrees C and the growth of the carcinoma was strongly arrested for at least 2 weeks. These results indicate the G250-FMLs could target renal cell carcinoma cells in vitro and in vivo, and are efficiently applicable to the hyperthermic treatment of carcinoma.

Animals↗
PubMed2001

Unusual hemodynamics and pseudolesions of the noncirrhotic liver at CT.

Recognition of pseudolesions of the liver at computed tomography (CT) is important because of their close resemblance to primary liver cancers or metastases. Two types of pseudolesion in the noncirrhotic liver include that due to transient extrinsic compression, typically caused by ribs or the diaphragm, and that due to a "third inflow" of blood from other than the usual hepatic arterial and portal venous sources: the cholecystic, parabiliary, or epigastric-paraumbilical venous system. Although the location of both types of pseudolesion are characteristic, their appearances at CT during arterial portography and CT during selective angiography vary from nonenhanced low-attenuation areas to well-enhanced high-attenuation areas, depending on the amount and timing of the inflow and presence or absence of focal metabolic alteration of the hepatocytes. Radiologists need to understand the underlying mechanism of these pseudolesions to better recognize the wide range of their appearances at CT.

Angiography↗
PubMed2001

Short term hypercholesterolemia alters N(G)-nitro-L-arginine- and indomethacin-resistant endothelium-dependent relaxation by acetylcholine in rabbit renal artery.

The tension of isolated rings was measured isometrically to compare the N(G)-nitro-L-arginine- and indomethacin-resistant relaxation by acetylcholine (ACh) in the renal artery from normal rabbits and short term hypercholesterolemia rabbits (0.5% cholesterol chow for 5 weeks). ACh-induced relaxation in the renal artery precontracted with phenylephrine was not influenced by cholesterol-enriched chow. However, in comparison with artery from normal rabbits, the N(G)-nitro-L-arginine- and indomethacin-resistant endothelium-dependent relaxation by ACh was significantly enhanced by the chow. The resistant part of ACh-induced relaxation was significantly inhibited when the artery was treated with tetraethylammonium or SKF 525a. Results suggest that short term hypercholesterolemia modulates endothelium-derived hyperpolarizing factor-mediated relaxation in rabbit renal artery.

Acetylcholine↗
PubMed2001

Effects of phytoestrogens on acetylcholine- and isoprenaline-induced vasodilation in rat aorta.

The influence of the phytoestrogen, isoflavones, on vasodilating responses of the thoracic aorta precontracted with norepinephrine, together with the stimulatory effect on uterine weight (uterotrophic effect), was investigated in ovariectomized rats. In comparison with intact rats, acetylcholine (ACh)-induced vasodilation showed a tendency to be decreased by ovariectomy. On the other hand, isoprenaline (ISO)-induced vasodilation was significantly increased by ovariectomy. Estrogen replacement (17beta-estradiol dipropionate, 300 microg/kg per week, for 1 month) completely restored the impaired ACh- and ISO-induced vasodilation caused by ovariectomy. Dietary isoflavone aglycones (containing 52% genistein, 42% daidzein and 6% glycitein) of 157 mg/kg per day (not 67 mg/kg per day) for 1 month, in addition to the effects of estrogen replacement, completely restored the impaired vasodilation caused by ovariectomy. However, the uterotrophic effect of dietary isoflavones of 157 mg/kg per day was incomplete as compared with that by estrogen replacement. These results indicate that phytoestrogen, isoflavones, certainly possess estrogenic actions on the vasodilating responses caused by ACh and ISO, as well as a weaker uterotrophic effect.

Acetylcholine↗
PubMed2001

Lipase production in two-step fed-batch culture of organic solvent-tolerant Pseudomonas aeruginosa LST-03.

Efficient lipase production by two-step fed-batch culture of an organic solvent-tolerant bacterium, Pseudomonas aeruginosa LST-03, was investigated. When FB synthetic medium was used in flask culture, no lipase activity was detected, whereas lipase was produced at 2.3 I.U./ml in C2 complex medium. However, lipase production was induced in FB medium when a fatty acid was added to the culture broth in the stationary phase. Among fatty acids tested, long chain saturated fatty acids, such as C18 (stearic acid) and C20 (arachidic acid), were found to function as effective inducers for the production of lipase, giving an activity level almost the same as that obtained in C2 medium in flask culture. Two-step lipase production, comprised of a growth phase in fed-batch mode and a production phase in which lipase was induced by the addition of 5% (v/v) stearic acid, was carried out in a jar-fermentor. In the growth phase, the maximum cell concentration at 16 h was only 20 in terms of the optical density at 660 nm (OD660), and a low level of lipase production (8 I.U./ml) was obtained after 167 h. This was considered to be due to the exhaustion of several medium components brought about by the use of an unsuitable medium or feeding solution. After analyzing the contents of the compounds in the culture broth by inductively coupled plasma spectrometry for metal ions and HPLC for anions, a modified FB medium was designed. When this modified FB medium was used in two-step fed-batch culture, the maximum cell concentration reached an OD660 of 55 (30.2 g-dry cells/l) at 16.5 h, and lipase was produced at 96 I.U./ml after 35 h, which is approximately 40 times higher than the production level obtained in flask culture using C2 medium.

Journal Article↗
PubMed2001

Enhanced and prolonged production of plantlets regenerated from carrot callus in a viscous additive-supplemented medium.

To reduce the hydrodynamic stress in plant cell culture and enhance the production of regenerated plantlets, a liquid medium containing a viscous additive was newly designed and plantlet production from embryogenic carrot callus cultivated in the medium was examined. Na-alginate or carboxymethyl cellulose (CMC) was used as the viscous additive. The viscosity of the medium increased with increasing additive content and the number of regenerated plantlets also increased. When carrot calli were cultivated in the medium containing 0.4% CMC, designated as N medium (viscosity, 3 mPa.s), the maximum enhancement of plantlet regeneration, approximately 2.5 times higher than that in the control medium, was obtained. Enlargement of callus size observed in N medium is considered to be the main reason for the enhanced plantlet regeneration. Regeneration enhancement was sufficiently induced after calli were cultivated once in N medium, but this regeneration ability rapidly disappeared after once cultivation in the conventional medium. In repeated batch culture using N medium, plantlet production continued at a high level for 18 batches (250 d) with no significant decrease, while in the control culture without CMC the number of plantlets produced dropped to almost zero by the sixth batch (84 d).

Journal Article↗
PubMed2001

Enhanced regeneration of rice (Oryza sativa L.) embryogenic callus by light irradiation in growth phase.

The effect of light irradiation on the growth and regeneration of embryogenic rice calli was investigated. Rice calli grew slightly better in the light than in the dark during the growth stage. When calli subcultured under light irradiation were transferred into a liquid regeneration culture system, the number of plantlets with shoots regenerated from calli subcultured in the light was higher than in the case of those subcultured in the dark, whereas there was no obvious difference between the light and dark subcultures when a solid medium was used for the regeneration. The number of regenerated plantlets increased with increasing light intensity up to 2000 lx, but remained the same when the light intensity was raised further. The maximum number of regenerated plantlets was obtained under a photoperiod of 16 h/d. About 8800 plantlets per liter-medium were regenerated from light-cultured calli, which is 1.5 times more than the number regenerated from calli grown in the conventional dark culture.

Journal Article↗
PubMed2001

In situ regeneration of rice (Oryza sativa L.) callus immobilized in polyurethane foam.

An in situ regeneration system for rice calli comprised of a callus growth stage and two regeneration stages was developed. After the first stage of regeneration, the medium is changed and the calli are immobilized in polyurethane foam supports, in each of which 3-5 regenerated plantlets develop from the immobilized calli during the second stage. While no significant change in callus size was observed during the first stage of regeneration, in the second stage callus enlargement and shoot regeneration predominated. In the light of these findings, calli were immobilized in the second stage after medium exchange. The use of 10-mm support cubes with an average pore size of 3.6 mm resulted in the most efficient immobilization and in situ regeneration. Medium exchange after 15 d gave the largest number of support cubes with shoots. When rice calli were cultivated in support cubes placed in 60 ml second-stage medium in a 500-ml flask, the immobilization ratio was 83%, and 82% of the support cubes contained 3-5 regenerated plantlets after 25 d. The shoot lengths of the regenerated plantlets obtained from the in situ regeneration culture were longer than those from a suspension culture. When support cubes with 3-5 regenerated plantlets were transferred from the flask to 1 4 MS solid medium supplemented with 10 g/l sorbitol and 5 g/l sucrose, the regenerated plantlets developed quickly into plants with a length above 10 cm after 10 d.

Journal Article↗
PubMed2001

Fuzzy neural network-based prediction of the motif for MHC class II binding peptides.

Characterizing the interaction between major histocompatibility complex (MHC) molecules and antigenic peptides is critical for understanding immunity and developing immunotherapies for autoimmune diseases and cancer. To identify the peptide binding motif and predict peptides that bind to the human MHC classII molecule HLA-DR4(*0401), we applied a fuzzy neural network (FNN) capable of extracting the relationship between input and output. Analysis of the peptide binding motif revealed that the hydrophilicity of the position 1 residue located on the N-terminal side of the nonamer (9mer) was the most important variable and that the van der Waals volume and hydrophilicity of the position 6 residue and the hydrophilicity of the position 7 residue were also important variables. The estimation accuracy (A(ROC) value) was high and the binding motif extracted from the FNN agreed with that derived experimentally. This study demonstrates that FNN modeling allows candidate antigenic peptides to be selected without the need for further experiments.

Journal Article↗
PubMed2001

Radiation-inducible TNF-alpha gene expression under stress-inducible promoter gadd 153 for cancer therapy.

We demonstrated the effectiveness of radiation-inducible expression of the TNF-alpha gene for cancer therapy in vitro. The TNF-alpha gene under the control of the stress-inducible promoter, gadd 153, was introduced into the human glioma cell line, U251-SP. Without cobalt-60 gamma irradiation, no cytotoxicity against the transfected cells was observed. When the transfected cells were irradiated with 10 or 20 gray (Gy), the gadd 153 promoter was highly induced and the expression level of TNF-alpha increased. Five days after the irradiation, the TNF-alpha productions of each cell irradiated with 10 and 20 Gy were 30 and 100 times higher than the basal level, respectively. The cytotoxicities against the transfected cells 5 d after irradiation with 10 and 20 Gy were 79% or 91%, respectively, which are much higher than those against the nontransfected cells that were irradiated at the same dose (43% and 78%, respectively). These results demonstrate that the gadd 153-TNF-alpha system may be an effective tool for radiosurgery of malignant brain tumors.

Journal Article↗
PubMed2001

Cardiac twitch properties simulated by three-states model.

We examined whether the three states model can explain the systolic and relaxation properties of cardiac muscle to clarify what factors affect these properties. Changing the values of the parameters describing the calcium transient and calcium sensitivity, we estimated the effects of these parameters on the systolic and relaxation properties of twitch contraction. The simulations showed the following four features: 1) An increase in the maximum calcium concentration and calcium sensitivity, and a prolongation of the calcium transient led to an increase in peak tension associated with an increase in the time to peak tension. 2) An increase in myosin ATPase activity led to an increase in peak tension associated with a decrease in the time to peak tension. 3) An increase of peak tension was accompanied by a prolongation of the late systolic period. 4) The constant of the late tension relaxation from 25% to 10% of the peak tension was altered when the crossbridge cycling rate, the resting calcium concentration or the late decline of the calcium transient was changed. The simulation were not contradictory to the experimental results and showed that three state muscle model can provide qualitative descriptions on the systolic and relaxation characteristics of cardiac muscle.

Biomechanical Phenomena↗
PubMed2001

Estrogen therapy in a male patient with chronic hepatitis C and irradiation-induced testicular dysfunction.

We report an 18-year-old male patient who developed chronic hepatitis C after blood transfusion and had testicular dysfunction after irradiation for a testicular relapse of childhood acute lymphocytic leukemia after cessation of maintenance therapy, and the initiation of testosterone replacement therapy at puberty. Concomitant administration of estradiol resulted in a reduction in serum alanine aminotransferase and ferritin levels and hepatic iron concentration and staining after 2 years of estrogen therapy, although interferon therapy was withdrawn because of adverse effects. This observation suggests that endogenous estradiol may play a beneficial role in male patients with chronic hepatitis C.

Adolescent↗