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Biomedical subjects

H Honda

Publications and source records attributed to H Honda.

At least 127 records · Page 7Linked to original sources
PubMed1999

Expression of E2A-HLF chimeric protein induced T-cell apoptosis, B-cell maturation arrest, and development of acute lymphoblastic leukemia.

The E2A-HLF fusion gene, generated by t(17;19)(q22;p13) in acute lymphoblastic leukemia (ALL), encodes a chimeric transcription factor in which the trans-activating domains of E2A are fused to the DNA-binding and dimerization domains of hepatic leukemic factor (HLF). To investigate its biological role, we generated transgenic mice expressing E2A-HLF using Ig enhancer and promoter, which direct transgene expression in cells committed to the lymphoid lineage. The transgenic mice exhibited abnormal development in the thymus and spleen and were susceptible to infection. The thymus contained small numbers of thymocytes, and TUNEL staining showed that higher population of thymocytes were undergoing apoptosis. The spleen exhibited a marked reduction in splenic lymphocytes and the flow cytometric analyses and the in vitro colony formation assays showed that the B-cell maturation was blocked at a very early developmental stage. These findings indicated that the expression of E2A-HLF induced T-cell apoptosis and B-cell maturation arrest in vivo and that the susceptibility of the transgenic mice to infection was due to immunodeficiency. Moreover, several transgenic mice developed acute leukemia, classified as T-ALL based on the surface marker analysis and DNA rearrangements, suggesting that an additional event is required for malignant transformation of lymphoid cells expressing E2A-HLF. Our findings provide insight into the biological function of E2A-HLF in lymphoid development and also its role in leukemogenesis.

Adenovirus E2 Proteins↗
PubMed1999

TT virus in bone marrow transplant recipients.

TT virus (TTV) is a newly discovered transfusion-transmissible DNA virus, which may cause posttransfusion hepatitis. The virus was detected in 12% of Japanese blood donors. The aim of the study is to investigate the prevalence and clinical influence of TTV in bone marrow transplant (BMT) recipients. Sera from 25 BMT recipients obtained 6 to 12 weeks after the transplant were examined for TTV-DNA by the seminested polymerase chain reaction. Serial samples were additionally analyzed in patients with TTV-DNA. Fifteen of 25 recipients (60%) were positive for TTV-DNA after transplant, whereas it was detected in only two of 20 BMT donors (10%). In patients positive for TTV-DNA before BMT, the amount of TTV-DNA decreased to an undetectable level during the myelosuppressed period after BMT. We also found that there was a novel group of TTV, G3, classified by the nucleotide sequences. The median peak alanine aminotransferase (ALT) levels were 135.0 IU/L and 116.5 IU/L (normal range, 4 to 36 IU/L) in TTV-positive and TTV-negative recipients, respectively. In one of the seven TTV-positive patients who developed hepatic injury (ALT > 150 IU/L), a serial change in the serum TTV titer showed a good correlation with the ALT level. We concluded that (1) the prevalence of TTV is high in BMT recipients, (2) TTV might be replicated mainly in hematopoietic cells, (3) transfusion-transmitted TTV may cause persistent infection, (4) a novel genetic group of TTV, G3, was discovered, and (5) TTV does not seem to frequently cause hepatic injury, although one patient was strongly suggested to have TTV-induced hepatitis.

Adolescent↗
PubMed1999

Chimeric DNA-RNA hammerhead ribozyme to proliferating cell nuclear antigen reduces stent-induced stenosis in a porcine coronary model.

BACKGROUND: Stent-induced coronary restenosis is a major clinical and public health problem. Proliferating cell nuclear antigen (PCNA) is an important regulator of cell division, and blocking of its expression after angioplasty may limit intimal proliferation. METHODS AND RESULTS: We cloned the porcine PCNA gene and constructed a chimeric hammerhead ribozyme to a segment of the gene with human homology. In vitro studies with both cultured porcine and human vascular smooth muscle cells demonstrated uptake of ribozyme within the nucleus and significant inhibition of cellular proliferation. The ribozyme was then delivered locally into pig coronaries in a stent model. At 30 days, histomorphometric analysis showed neointimal thickness of 0.51+/-0.20 mm in the ribozyme group versus 0.71+/-0.27 and 0.66+/-0.25 mm in stent controls and scrambled ribozyme control, respectively (P=0.002, P=0.03). Quantitative angiographic analysis showed late loss of 1.4+/-0.5 mm for ribozyme versus 1.9+/-0.4 and 2.0+/-0.4 mm for the controls (P=0.05 and P=0. 02). CONCLUSIONS: Chimeric hammerhead ribozyme to PCNA inhibits smooth muscle cell proliferation in vitro and reduces both histomorphometric and angiographic restenosis in the porcine coronary stent model when delivered locally.

Animals↗
PubMed1999

Elongation of oligopeptides in a simulated submarine hydrothermal system.

Oligomerization of a peptide was attempted in a flow reactor that simulated a submarine hydrothermal system. When fluid containing glycine repeatedly circulated through the hot and cold regions in the reactor, oligopeptides were made from glycine. When divalent ions (such as copper ions) were added under acidic conditions, oligoglycine was elongated up to hexaglycine. This observation suggests that prebiotic monomers could have oligomerized in the vicinity of submarine hydrothermal vents on primitive Earth.

Chromatography, High Pressure Liquid↗
PubMed1999

MR detection of cytoplasmic fat in clear cell renal cell carcinoma utilizing chemical shift gradient-echo imaging.

We attempted to determine whether cytoplasmic fat in clear cell renal cell carcinoma (RCC) can be identified by chemical shift gradient-echo magnetic resonance imaging (CSI). CSI was performed for 22 clear cell RCCs and 30 other renal tumors (including 16 non-clear cell RCCs), all of which were surgically proven. Signal reduction in out-of-phase images of these tumors was retrospectively evaluated and compared. The signal loss ratio (SLR) was defined and calculated. Fat staining of specimens from 16 tumors was performed and correlated with SLR. SLR was significantly higher in clear cell RCCs than in non-clear cell RCCs (P < 0.001). There was a significant correlation between degree of fat staining positivity of the specimens and SLR (P < 0.01). When signal reduction in out-of-phase images suggested the diagnosis of clear cell RCC, correct diagnosis of this entity was made in resected renal tumors with sensitivity, specificity, and accuracy of 82%, 90%, and 87%, respectively. CSI can demonstrate cytoplasmic fat in clear cell RCCs, which helps to differentiate this entity from other RCCs.

Adenocarcinoma, Clear Cell↗
PubMed1999

Analysis of segregation and aneuploidy in two reciprocal translocation carriers, t(3;9)(q26.2;q32) and t(3;9)(p25;q32), by triple-color fluorescence in situ hybridization.

Meiotic segregation patterns of chromosomes 3 and 9 were analyzed in sperm of two translocation carriers (t(3;9)(q26.2;q32) and t(3;9)(p25;q32)) by triple-color fluorescent in situ hybridization (FISH) with a telomeric DNA probe in addition to two centromeric probes. The frequencies of each sperm product resulting from alternate or adjacent I, adjacent II and 3:1 segregation in a t(3;9)(q26.2;q32) translocation carrier were 88.35%, 5.44% and 5.94%, respectively. On the other hand, the frequencies of each sperm product in a t(3;9)(p25;q32) translocation carrier were 89.23%, 6.02% and 4.48%, respectively. Of all the sperm products, the frequency of normal or chromosomally balanced sperm in a t(3;9)(q26.2;q32) and a t(3;9)(p25;q32) were 52.49% and 47.25%, respectively. The frequencies of each sperm product resulting from various segregations were different between both carriers and significantly deviated from the expected frequencies. Additional dual-color and triple-color FISH were performed to analyze aneuploidy rates for chromosomes 12, 17, 18, X and Y in order to detect any interchromosomal effect; no evidence of an interchromosomal effect was found.

Abortion, Habitual↗
PubMed1999

Modification of saccade-contingent visual mislocalization by the presence of a visual frame of reference.

The effect of three kinds of background visual field on saccade-contingent mislocalization was compared so as to explore the critical factor responsible for visual stability during saccadic eye movements. A large mislocalization observed in the dark (DARK condition) was substantially decreased when a faint frame pattern was projected against the dark background (FRAME condition) as well as when the background screen being illuminated (LIGHT condition). Large mislocalization in the DARK condition occurred both when targets were presented just before the beginning of a saccade and when they were presented at the end of the saccade, irrespective of the position at which the target was presented. In contrast, in the FRAME and LIGHT conditions, mislocalization appeared to depend on target position. Mislocalization of targets presented immediately before the saccade onset diminished when they were presented near the saccade goal, whereas mislocalization of targets presented at the end of the saccade diminished when they were presented near the original fixation point. It was concluded from these results that the subject made use of the frame and the illuminated background as a visual cue for exocentric localization of the target, and that a saccade-contingent shift of visual attention was involved in producing the selective diminution of mislocalization observed in FRAME and LIGHT conditions.

Fixation, Ocular↗
PubMed1999

Epidermal remodelling in psoriasis (III): a hexagonally-arranged cylindrical papilla model reveals the nature of psoriatic architecture.

A geometric model of hyperproliferative psoriatic epidermis that is remarkably similar to psoriatic skin in vivo has been proposed. This model is based on hexagonally-arranged cylindrical dermal papillae, and it is constructed under the assumption that the total number of viable epidermal cells is proportional to the number of cells within proliferative compartment. Quantitative analyses indicate that at least two distinct conditions are consistent with this assumption, corresponding to psoriasis with and without a granular layer. Psoriasis without a granular layer (G-minus psoriasis) represents an expanding state, and psoriasis with a granular layer (G-plus psoriasis) represents a stationary and/or regressing state. There is also another relationship between G-minus and G-plus psoriasis, that they are exchangeable with each other during the disease evolution. For example, consistent with the regressing nature of G-plus psoriasis, G-minus psoriasis is exchangeable with G-plus psoriasis with less papillary height until the papilla has a certain height (360 microm). On the other hand, G-minus psoriasis with the papillae of more than the critical height is exchangeable with G-plus psoriasis with more papillary height, which ultimately results in a papillomatous architecture. G-minus psoriasis with the critical papillary height (360 microm) is exchangeable with G-plus psoriasis with the same papillary height. Collectively, the model reveals a self-organizing mechanism for the characteristically-or-dered psoriatic architecture, one that is under dynamic control of epidermal remodelling.

Epidermis↗
PubMed1999

Application of an artificial neural network and genetic algorithm for determination of process orbits in the koji making process.

In order to estimate alpha-amylase, glucoamylase, acid proteinase, and acid carboxypeptidase activities in koji from the process variables and initial conditions of the koji making process, artificial neural network (ANN) models (ANN-10, -11, -15, and -21) were constructed with 10, 11, 15, and 21 input variables, respectively. These models could estimate the enzyme activities with high accuracy. Temperature and humidity orbits were then acquired by a genetic algorithm searching in the reverse direction using ANN-10, -11, -15, and -21 (GA-10, -11, -15, and -21). The orbits acquired by GA-15 and -11 were almost identical to the actual orbits, but those acquired by GA-21 and -10 were different. Enzyme activities acquired by GA-15 had 1.3% errors compared with the target values, while those acquired by GA-11 had 9.7% errors. GA-15 was, therefore, selected as the most suitable algorithm and was used to determine temperature and humidity orbits for target enzyme activities. Test koji making was then carried out according to the orbits acquired. As a result, the enzyme activities of the koji produced were almost the same as the target values.

Journal Article↗
PubMed1999

Development of a bioreactor suitable for embryogenic rice callus culture.

Embryogenic rice calli induced from mature rice (Oryza sativa L., Sasanishiki) were cultured in a jarfermentor with disk turbine impellers, an air-lift reactor, and a turbine-blade reactor (TBR(R)), and the effects of agitation were investigated. In all cases, the growth inhibition was observed, though a slightly improved regeneration frequency was obtained in the TBR. To overcome the growth inhibition, small cubes of polyurethane foam were used as immobilization supports in the TBR culture. Supports accumulated around the cylindrical stainless-steel mesh in the reactor and rice calli were observed growing in them. Polyurethane foam with an average pore size of 1.3 mm gave the maximum ratio of immobilized cells during 1-week culture. When 5- or 10-mm cubes were used, supports were observed floating on the medium surface, but 3-mm cube supports accumulated uniformly around the stainless-steel mesh and were found to be suitable for the immobilized culture of rice calli. Three-millimeter cube supports corresponding to 5% by volume were added to 600 ml medium in the TBR and the effects of the agitation speed on the cell growth and regeneration frequency were investigated. At all the agitation speeds examined, no significant decrease in either the cell growth or the regeneration frequency occurred. From these results, it was concluded that the TBR is a suitable reactor for the propagation of embryogenic rice calli and that immobilization supports with 1.3 mm of average pore size are effective in preventing hydrodynamic stress as well as in supplying nutrients to the immobilized calli.

Journal Article↗
PubMed1999

Selection of embryogenic sugarcane callus by image analysis.

In the cultivation of plant calli on solid media, two kinds of calli such as compact and friable calli, which are a bright yellow and a whitish clump, respectively, are often obtained. Distinction of these calli is of much importance in the regeneration step. The image analysis system associated with a Charge Coupled Device (CCD) camera and microscopy were used to distinguish sugarcane calli. The original images from compact and friable calli were input to a computer via an image analysis board. At first, the brightnesses of trichromatic colors, red (R), green (G) and blue (B), of each pixels were extracted and the average brightness value for each color was calculated. From these values of the trichromatic colors, compact and friable calli could not be clearly distinguished. Next, the brightness of yellow, Br(Y), and white, Br(W), were defined using Br(R), Br(G) and Br(B), and the difference between Br(Y) and Br(W), Br(Y-W), which can be used to express the yellowish grade, was calculated. When Br(Y-W) was determined from all pixels of the original images of both calli, the compact calli were found to be clearly distinguished from the friable calli by the frequency distributions of Br(Y-W). Average brightness center value, Av(C(Y-W)), was calculated from the frequency distributions. It was found that the calli with less than 10 units of Av(C(Y-W)) was never regenerated and a proportional relationship between Av(C(Y-W)) and the regeneration frequency of the callus line was obtained.

Journal Article↗
PubMed1999

Construction of COD simulation model for activated sludge process by fuzzy neural network.

Fuzzy neural network (FNN) was applied to construct a simulation model for estimating the effluent chemical oxygen demand (COD) value of an activated sludge process in a "U" plant, in which most of process variables were measured once an hour. The constructed FNN model could simulate periodic changes in COD with high accuracy. Comparing the simulation result obtained using the FNN model with that obtained using the multiple regression analysis (MRA) model, it was found that the FNN model had 3.7 times higher accuracy than the MRA model. The FNN models corresponding to each of the four seasons were also constructed. Analyzing the fuzzy rules acquired from the FNN models after learning, the operational characteristic of this plant could be elucidated. Construction of the simulation model for another plant "A", in which process variables were measured once a day, was also carried out. This FNN model also had a relatively high accuracy.

Journal Article↗
PubMed1999

Release of embryogenic carrot cells with high regeneration potency from immobilized alginate beads.

For the mass-production of regenerated carrot plantlets, embryogenic carrot callus immobilized in calcium alginate gel beads was cultivated in a growth medium and the regeneration frequency of cells released from alginate gel beads was compared with that in a suspension culture. Cells released in the immobilized culture were regenerated at a frequency which was about 1.5 times higher than that obtained in the suspension culture. When CaCl2 was added to the growth medium at 5 mM, repeated batch culture for plantlet production continued for 245 d with no significant decrease in the productivity (1.6 x 10(5) plantlets/l-medium/d).

Journal Article↗
PubMed1999

Autocatalytic synthesis of oligoglycine in a simulated submarine hydrothermal system.

A flow reactor simulating a submarine hydrothermal system was constructed for examining the likelihood of oligopeptide synthesis from amino acids alone without recourse to any of condensing agents, templates or metallic ions. We demonstrated that when the initial reactant is glycine, the flow reactor can synthesize both di- and tri-glycine. The initial buildup of the yields of both the oligopeptides was found to be exponential with the elapse of time. The oligopeptide synthesis from glycine in the flow reactor could be autocatalytic.

Catalysis↗
PubMed1999

Anisatin modulation of the gamma-aminobutyric acid receptor-channel in rat dorsal root ganglion neurons.

1. Anisatin, a toxic, insecticidally active component of Sikimi plant, is known to act on the GABA system. In order to elucidate the mechanism of anisatin interaction with the GABA system, whole-cell and single-channel patch clamp experiments were performed with rat dorsal root ganglion neurons in primary culture. 2. Repeated co-applications of GABA and anisatin suppressed GABA-induced whole-cell currents with an EC50 of 1.10 microM. No recovery of currents was observed after washout with anisatin-free solution. 3. However, pre-application of anisatin through the bath had no effect on GABA-induced currents. The decay phase of currents was accelerated by anisatin. These results indicate that anisatin suppression of GABA-induced currents requires opening of the channels and is use-dependent. 4. Anisatin suppression of GABA-induced currents was not voltage dependent. 5. Picrotoxinin attenuated anisatin suppression of GABA-induced currents. [3H]-EBOB binding to rat brain membranes was competitively inhibited by anisatin. These data indicated that anisatin bound to the picrotoxinin site. 6. At the single-channel level, anisatin did not alter the open time but prolonged the closed time. The burst duration was reduced and channel openings per burst were decreased indicating that anisatin decreased the probability of openings.

Affinity Labels↗
PubMed1999

Aspergillus tracheobronchitis after allogeneic bone marrow transplantation.

We describe a patient who developed Aspergillus tracheobronchitis after BMT. She complained of progressive dyspnea on day +165 and her respiratory function deteriorated rapidly. Although neither early chest X-rays nor CT scans were negative, bronchoscopy revealed formation of a pseudomembrane around the bronchial walls. Based upon pathological and microbiological examinations, she was diagnosed as having invasive Aspergillus tracheobronchitis. Retrospectively analyzed, the Aspergillus circulating antigen detection tests became positive before clinical symptoms developed, and may be beneficial for early diagnosis of Aspergillus tracheobronchitis. This form of aspergillosis should be regarded as one of the serious complications after BMT.

Adult↗
PubMed1999

Frequent breathing-related electroencephalogram arousals in four patients with mild obstructive sleep apneas.

We report cases of four patients with mild obstructive sleep apnea syndrome (OSAS) with frequent breathing-related electroencephalogram (EEG) arousals which led to excessive daytime sleepiness. In spite of a relatively low apnea hypopnea index (AHI), sleep was disrupted by frequent EEG arousals associated with respiratory effort as observed in upper airway resistance syndrome. The effects of sleep stage and sleep position on EEG arousals were also investigated. We consider that AHI alone is not a sufficient index to assess severity of OSAS, and it is very important to examine microarousals by the alteration of esophageal pressure in addition to the effect of sleep position.

Adult↗