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Biomedical subjects

H Kitano

Publications and source records attributed to H Kitano.

At least 55 records · Page 3Linked to original sources
PubMed2000

Endoscopic surgery for a parathyroid functioning adenoma resection with the neck region-lifting method.

Recently, endoscopic surgery has been applied to cervical exploration. We have developed new techniques for endoscopic neck surgery. We reported on a 53-year-old Japanese man with functioning parathyroid adenoma resected by endoscopic surgery with a neck region-lifting method. A 10-mm midline trocar for the endoscope and two 5-mm lateral trocars were inserted from the anterior chest wall to avoid neck scars. There were no intraoperative complications. The incisions were completely covered by the patient's undergarments.

Adenoma↗
PubMed2000

Specific accumulation of polysaccharide-linked hydroxycinnamoyl esters in the cell walls of irregularly shaped and collapsed internode parenchyma cells of the dwarf rice mutant Fukei 71.

We examined a novel rice mutant, Fukei 71 (Oryza sativa L.), for alterations in the levels of hydroxycinnamoyl esters that are linked to cell wall polysaccharides and lignin units. In this mutant, a recessive mutation at a single locus caused the collapse of parenchyma cells in the internodes. Light microscopy revealed that the abnormal walls of internode parenchyma cells of Fukei 71 were stained by the Mäule reaction, which is specific for syringyl units in phenolic compounds. These walls were not stained by Wiesner's reagent (phloroglucinol-HCl), which reacts cinnamaldehyde in lignin. Levels of p-coumaric acid (PCA) and ferulic acid (FA) were apparently elevated in the abnormal tissue of the mutant. Western blotting analysis with antibodies specific for phenylalanine ammonia-lyase (PAL) revealed higher levels of PAL in the abnormal parenchyma tissue of Fukei 71 than in the parenchyma tissue of the parent cultivar Fujiminori. These results and the observation that PAL was produced at a greatly elevated level indicated that the phenylpropanoid pathway that leads to the biosynthesis of polysaccharide-linked FA and PCA was abnormally activated in the irregularly shaped and collapsed internode parenchyma cells, in which the biosynthesis of lignin is normally repressed.

Cell Wall↗
PubMed2000

Changes in mint1, a novel synaptic protein, after transient global ischemia in mouse hippocampus.

Mints (munc18-interacting proteins) are novel multimodular adapter proteins in membrane transport and organization. Mint1, a neuronal isoform, is involved in synaptic vesicle exocytosis. Its potential effects on development of ischemic damage to neurons have not yet been evaluated. The authors examined changes in mint1 and other synaptic proteins by immunohistochemistry after transient global ischemia in mouse hippocampus. In sham-ischemic mice, immunoreactivity for mint1 was rich in fibers projecting from the entorhinal cortex to the hippocampus and in the mossy fibers linking the granule cells of the dentate gyrus to CA3 pyramidal neurons. Munc18-1, a binding partner of mint1, was distributed uniformly throughout the hippocampus, and synaptophysin 2, a synaptic vesicle protein, was localized mainly in mossy fibers. After transient global ischemia, mint1 immunoreactivity in mossy fibers was dramatically decreased at 1 day of reperfusion but actually showed enhancement at 3 days. However, munc18-1 and synaptophysin 2 were substantially expressed in the same region throughout the reperfusion period. These findings suggest that mint1 participates in neuronal transmission along the excitatory pathway linking the entorhinal cortex to CA3 in the hippocampus. Because mint1 was transiently decreased in the mossy fiber projection after ischemia, functional impairment of neuronal transmission in the projection from the dentate gyrus to CA3 pyramidal neurons might be involved in delayed neuronal death.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Characterization of XET-related genes of rice.

To elucidate the mechanism of internodal elongation in rice (Oryza sativa L.), we analyzed genes encoding xyloglucan endotransglycosylase (XET), a cell wall-loosening enzyme essential for cell elongation. Four rice XET-related (XTR) genes, OsXTR1, OsXTR2, OsXTR3, and OsXTR4, were isolated and their expression patterns in rice plants determined. The expression of the four XTR genes showed different patterns of organ specificity and responses to several plant hormones. OsXTR1 and OsXTR3 were up-regulated by gibberellin and brassinosteroids, whereas OsXTR2 and OsXTR4 showed no clear response to these hormones. Expression of the four XTR genes was also investigated in elongating internodes at different developmental stages. OsXTR1 and OsXTR3 were preferentially expressed in the elongating zone of internodes, while OsXTR2 and OsXTR4 were expressed in nodes and in the divisional and elongating zones of internodes. In three genetic mutants with abnormal heights, the expression of OsXTR1 and OsXTR3 correlated with the height of the mutants, whereas no such correlation was observed for OsXTR2 and OsXTR4. Based on these observations, we discuss the roles that OsXTR1 and OsXTR3 may play in internodal elongation in rice.

Amino Acid Sequence↗
PubMed2000

Shoot organization genes regulate shoot apical meristem organization and the pattern of leaf primordium initiation in rice.

The mechanism regulating the pattern of leaf initiation was analyzed by using shoot organization (sho) mutants derived from three loci (SHO1, SHO2, and SHO3). In the early vegetative phase, sho mutants show an increased rate of leaf production with random phyllotaxy. The resulting leaves are malformed, threadlike, or short and narrow. Their shoot apical meristems are relatively low and wide, that is, flat shaped, although their shape and size are highly variable among plants of the same genotype. Statistical analysis reveals that the shape of the shoot meristem rather than its size is closely correlated with the variations of plastochron and phyllotaxy. Rapid and random leaf production in sho mutants is correlated with the frequent and disorganized cell divisions in the shoot meristem and with a reduction of expression domain of a rice homeobox gene, OSH1. These changes in the organization and behavior of the shoot apical meristems suggest that sho mutants have fewer indeterminate cells and more determinate cells than wild type, with many cells acting as leaf founder cells. Thus, the SHO genes have an important role in maintaining the proper organization of the shoot apical meristem, which is essential for the normal initiation pattern of leaf primordia.

Cell Division↗
PubMed2000

Loss of function of a rice brassinosteroid insensitive1 homolog prevents internode elongation and bending of the lamina joint.

Brassinosteroids (BRs) are plant growth-promoting natural products required for plant growth and development. Physiological studies have demonstrated that exogenous BR, alone or in combination with auxin, enhance bending of the lamina joint of rice. However, little is known about the function of endogenous BR in rice or other grass species. We report here the phenotypical and molecular characterization of a rice dwarf mutant, d61, that is less sensitive to BR compared to the wild type. We cloned a rice gene, OsBRI1, with extensive sequence similarity to that of the Arabidopsis BRI gene, which encodes a putative BR receptor kinase. Linkage analysis showed that the OsBRI1 gene is closely linked to the d61 locus. Single nucleotide substitutions found at different sites of the d61 alleles would give rise to amino acid changes in the corresponding polypeptides. Furthermore, introduction of the entire OsBRI1 coding region, including the 5' and 3' flanking sequences, into d61 plants complemented the mutation to display the wild-type phenotype. Transgenic plants carrying the antisense strand of the OsBRI1 transcript showed similar or even more severe phenotypes than those of the d61 mutants. Our results show that OsBRI1 functions in various growth and developmental processes in rice, including (1) internode elongation, by inducing the formation of the intercalary meristem and the longitudinal elongation of internode cells; (2) bending of the lamina joint; and (3) skotomorphogenesis.

Amino Acid Sequence↗
PubMed2000

Construction of a generalized simulator for multi-cellular organisms and its application to SMAD signal transduction.

In this paper, we report development of a generalized simulation system based on ordinary differential equations for multi-cellular organisms, and results of the analysis on a Smad signal transduction cascade. The simulator implements intra-cellular and extra-cellular molecular processes, such as protein diffusion, ligand-receptor reaction, biochemical reaction, and gene expression. It simulates the spatio-temporal patterning in various biological phenomena for the single and multi-cellular organisms. In order to demonstrate the usefulness of the simulator, we constructed a model of Drosophila's Smad signal transduction, which includes protein diffusion, biochemical reaction and gene expression. The results suggest that the presence of negative feedback mechanism in the Smad pathway functions to improve the frequency response of the cascade against changes in the signaling.

Animals↗
PubMed2000

[Auditory cortical response to monaural stimulation as detected by functional magnetic resonance imaging].

In order to confirm the crossed-innervation between auditory cortex and the ear that receives monosyllabic sound, the auditory cortical response to monaural monosyllabic stimulation as detected by functional magnetic resonance imaging (fMRI) was investigated in six normal hearing subjects. Stimulus amplitude averaged 95 dBSPL at the distal end of the audio system. A series of 440 echo planar images was acquired during the acoustic stimulation within the four OFF-ON cycle paradigm. Five image series with 10 slices were collected within each OFF or On period. Each scanning session began with four baseline images before the OFF-ON paradigm. Monosyllabic sounds were presented monaurally during the ON period at a rate of one monosyllable/sec. Functional MRI data were analyzed with SPM99b software (Statistical Parametric Mapping). The background scanner noise averaged 97dBSPL. The selicon ear plug and headphone as acoustic shields attenuated the noise as much as 17 dB. A broad and intense auditory cortical response was observed bilaterally in response to monaural monosyllable stimulation. Sound presentation to the right ear was followed by a larger response in the left auditory cortex than in the right, and left ear stimulation evoked a larger response in the right auditory cortex than in the left. This pattern was consistent in all subjects examined. The primary auditory cortex responded to monosyllabic words presented to the contralateral ear. The results confirmed the crossed-innervation between the auditory cortex and ear for listening to monosyllables. Functional MRI is a useful tool for investigating auditory cortex function, if the scanner noise is adequated controlled.

Acoustic Stimulation↗
PubMed2000

Plasma endotoxin and serum cytokine levels in patients with alcoholic hepatitis: relation to severity of liver disturbance.

BACKGROUND: Endotoxin plays an important role in the initiation and aggravation of alcoholic liver disease. In this study, we evaluated plasma endotoxin levels and serum concentrations of cytokines and lipopolysaccharide binding protein (LBP) during the acute and recovery phase of patients with alcoholic hepatitis; we also explored the prognostic factors associated with a fatal outcome. METHODS: Fourteen patients, consisting of eight patients with alcoholic hepatitis (AH), five cirrhotics with superimposed AH (LC+AH), and one patient with severe alcoholic hepatitis (SAH), were studied. Among these, two with LC+AH died of hepatic failure. RESULTS: Plasma endotoxin levels in the acute phase were higher in patients with AH (184.4 +/- 159.4 pg/ml) and LC+AH (206.9 +/- 174.9 pg/ml) than in healthy subjects (10.4 +/- 5.5 pg/ml, p < 0.001). In particular, in one patient with SAH and one of two nonsurvivors, plasma endotoxin levels were markedly high relative to the other cases. In most survivors, plasma endotoxin levels decreased in the recovery phase, whereas they further increased at the terminal stage in one of two nonsurvivors. Serum interleukin (IL)-6 and IL-8 levels in the acute phase were significantly higher in patients with AH and LC+AH as compared with healthy subjects. These levels were especially high in nonsurvivors and in one patient with SAH. IL-10 increased in two nonsurvivors, one patient with SAH, and one with LC+AH. In the recovery phase, these cytokine levels in survivors tended to decrease, but in nonsurvivors, IL-6 remained high, and IL-8 and IL-10 further increased. Tumor necrosis factor-alpha levels were below the detection limit throughout the course in all patients. Serum lipopolysaccharide binding protein (LBP) generally was elevated in the acute phase and decreased in the recovery phase in all survivors, but in one of the nonsurvivors, LBP was elevated markedly at the terminal stage. In the acute phase, plasma endotoxin levels were correlated positively with white blood cell counts, neutrophil counts, and serum IL-8. IL-8 was correlated positively with neutrophil counts and negatively with serum cholinesterase, hepaplastin test, and serum albumin levels. IL-6 was correlated positively with white blood cell and neutrophil counts, C-reactive protein, and serum total bilirubin and negatively with hepaplastin test and serum total protein levels. Serum LBP was correlated positively with white blood cell and neutrophil counts. CONCLUSIONS: Endotoxemia and related elevation of IL-8 may play an important role in the activation and migration of neutrophils in patients with alcoholic hepatitis. Marked elevation of inflammatory cytokines, IL-6 and IL-8, are related to severity and poor prognosis of alcoholic hepatitis. Serum LBP may serve as an index of inflammatory reaction in alcoholics.

Acute-Phase Proteins↗
PubMed2000

[A case of effective bisphosphonate therapy of sequential pamidronate and incadronate for bone metastases from breast cancer].

A 55-year-old woman complained of neck pain ten years after undergoing surgery. She was diagnosed as having bone metastases and treated using pamidronate therapy with doxifluridine, tamoxifen and fadrozole, which was assessed as effective. She complained of neck pain 32 months after pamidronate infusion. CT revealed that the sclerosis had continued but new lytic lesions were detected in the cervical vertebra. Thus, we attempted incadronate and medroxyprogesterone acetate (MPA) administration. After 2 months, incadronate therapy with MPA relieved her neck pain. CT revealed lytic lesions of cervical vertebra showing sclerosis 3 months after this treatment and the sclerosis has continued. Bisphosphonate therapy of sequential pamidronate and incadronate with MPA administration is a useful treatment for bone metastasis from breast cancer.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

[A case of effective chemotherapy using CAF followed by docetaxel for advanced breast cancer].

A huge mass measuring 13 x 12 cm and wide cutaneous edema were detected in the right breast of a 51-year-old woman. Under a diagnosis of locally advanced breast cancer (T4bN2M1, stage IV) with liver metastases, we attempted sequential neoadjuvant chemotherapy. After three courses of CAF therapy (cyclophosphamide, doxorubicin (DXR), 5-FU), the primary tumor was decreased by 56% and the liver metastases had disappeared. A minor pathologic response was observed. Subsequently, three courses of docetaxel (TXT) administration were carried out. The primary tumor was then decreased by 75% and the axillary metastases had disappeared. Histopathological examination showed gross viable tumor cells in the residual tumor and positive axillary lymph nodes. The only toxic effect was nausea (grade 1) and no major adverse effects were observed. Neoadjuvant chemotherapy with sequential DXR followed by TXT is a useful treatment for locally advanced breast cancer.

Antineoplastic Agents, Phytogenic↗
PubMed2000

[Two bedridden patients with bone metastases from breast cancer effectively treated with pamidronate therapy].

Case 1: A 43-year-old woman underwent mastectomy because of locally advanced breast cancer with multiple bone metastases. She was treated with CMF therapy but developed a compression fracture of a thoracic vertebra after 10 months and received pamidronate therapy. Pamidronate administration relived her back pain after 2 months and she was able to walk again after 3 months. However, she developed a resistance to the treatment, and then refused another treatment. She was found to have hypercalcemia 6 months later and received pamidronate again, but died 9 months after the treatment. Case 2: A 52-year-old woman underwent mastectomy because of breast cancer (T2) and was diagnosed as having multiple bone metastases 24 months after the operation. She could not turn over in bed due to progressing bone pain and received pamidronate therapy with CMF therapy at home 23 months after the diagnosis. After 2 months, pamidronate administration relieved her bone pain and she was free of pain after 4 months. After 5 months, X-rays revealed that lytic lesions showed sclerosis, and the pamidronate therapy was assessed as producing a PR. Pamidronate therapy improved her quality of life and activities of daily living, and she continues to receive it this time as an outpatient. Pamidronate therapy is promising as an effective treatment for bedridden patients with bone metastasis from breast cancer.

Adult↗
PubMed2000

A gene network inference method from continuous-value gene expression data of wild-type and mutants.

In this paper we introduce a new inference method of a gene regulatory network from steady-state gene expression data. Our method determines a regulatory structure consistent with an observed set of steady-state expression profiles, each generated from wild-type and single deletion mutant of the target network. Our method derives the regulatory relationships in the network using a graph theoretic approach. The advantage of our method is to be able to deal with continuous values of steady-state data, while most of the methods proposed in past use a Boolean network model with binary data. Performance of our method is evaluated on simulated networks with varying the size of networks, indegree of each gene, and the data characteristics (continuous-value/binary), and is compared with that of predictor method proposed by Ideker et al. As a result, we show the superiority of using continuous values to binary values, and the performance of our method is much better than that of the predictor method.

Animals↗
PubMed1999

Suppression of the heterotrimeric G protein causes abnormal morphology, including dwarfism, in rice.

Transgenic rice containing an antisense cDNA for the alpha subunit of rice heterotrimeric G protein produced little or no mRNA for the subunit and exhibited abnormal morphology, including dwarf traits and the setting of small seeds. In normal rice, the mRNA for the alpha subunit was abundant in the internodes and florets, the tissues closely related to abnormality in the dwarf transformants. The position of the alpha-subunit gene was mapped on rice chromosome 5 by mapping with the restriction fragment length polymorphism. The position was closely linked to the locus of a rice dwarf mutant, Daikoku dwarf (d-1), which is known to exhibit abnormal phenotypes similar to those of the transformants that suppressed the endogenous mRNA for the alpha subunit by antisense technology. Analysis of the cDNAs for the alpha subunits of five alleles of Daikoku dwarf (d-1), ID-1, DK22, DKT-1, DKT-2, and CM1361-1, showed that these dwarf mutants had mutated in the coding region of the alpha-subunit gene. These results show that the G protein functions in the formation of normal internodes and seeds in rice.

Base Sequence↗
PubMed1999

Regulation of inner ear fluid in the rat by vasopressin.

The anti-diuretic hormone vasopressin has been shown to be important in regulating inner ear fluid. The diuretic hormone, CNP, and its receptor, ANP-B receptor, may also function in the regulation of inner ear fluid. To determine whether vasopressin directly affects the fluid level, we infused this hormone to rat and assay of V2-AVP receptor mRNA by semiquantitative RT-PCR demonstrated a significantly lower level of this transcript in vasopressin-infused animals than in saline-infused animals. The levels of CNP and ANP-B receptors mRNA, however, were the same in both groups of rats. Results suggest that high plasma levels of vasopressin may be a principal causal factor of endolymphatic hydrops in Meniere's disease, perhaps by down-regulating the number of vasopressin receptors.

Animals↗
PubMed1999

Temperature-Responsiveness of A-B-A Block Telomers at Solid-Liquid Interfaces.

Macroinitiators were prepared by coupling disuccinimidyl ester of 4,4'-azobis(cyanovaleric acid) with poly(N-isopropylacrylamide) (PIPA), which had an amino group at its end. Styrene was telomerized with the initiators in THF. When the styrene content in the A-B-A block telomer obtained (PIPA-b-PSt-b-PIPA) was high, the telomer formed an irreversible aggregation resulting in microspheres, whereas the telomer with a much shorter styrene block could be dispersed monomolecularly. The telomers dispersed in water were aggregated by raising the temperature above 32 degrees C due to a coil-globule transition of PIPA moieties. The PIPA-b-PSt-b-PIPA could be strongly adsorbed to polystyrene (PSt) solid surfaces to form a layer, and the PSt blocks might lay on the PSt surface and the PIPA blocks might direct to the solution phase. The contact angle of air bubbles on the surface of telomer-coated PSt in the air-in-water system was dependent on temperature; that is, with the increase in temperature the contact angle of air bubbles largely decreased and leveled off above the coil-globule transition temperature (Tc). Correspondingly, the amount of protein Concanavalin A adsorbed to the telomer layer deposited on the PSt surface increased gradually with an increase in temperature and leveled off above the Tc. These phenomena were attributed to the changes in hydrophobicity of the telomer layer below and above the Tc. The usefulness of macroinitiators in preparing various kinds of block telomers which have responsiveness to external stimuli was strongly suggested. Copyright 1999 Academic Press.

Journal Article↗