Biomedical subjects

K Shoji

Publications and source records attributed to K Shoji.

At least 37 records · Page 2Linked to original sources

PubMed1999

Structure-activity relationship of polyphenols on inhibition of chemical mediator release from rat peritoneal exudate cells.

The effect of phenolic compounds in foodstuffs on histamine and leukotriene B4 (LTB4) release from rat peritoneal exudate cells and their antioxidative activity were examined to assess their antiallergenic activities. Among them, triphenols such as pyrogallol and gallic acid inhibited histamine release from the cells, but diphenols did not. On the other hand, o- and p-diphenols such as catechol and hydroquinone with strong antioxidative activity inhibited LTB4 release as strongly as pyrogallol, but an m-derivative resorcinol with weak antioxidative activity did not. Though carboxylated compounds and their noncarboxylated counterparts were antioxidative, the former exerted a much weaker inhibitory effect on the LTB4 release than the latter. In flavonols, only myricetin with a triphenolic B ring strongly inhibited histamine release, but all flavonols strongly suppressed LTB4 release irrespective of the number of OH groups in the B ring. Among flavonoids with an o-diphenolic B ring, flavonol and flavone with a C4-carbonyl group strongly inhibited LTB4 release, whereas the activity of anthocyan without C4-carbonyl was much weaker than the above compounds. These results suggest that triphenolic structure is essential for the inhibition of histamine release. On the other hand, antioxidative activity and membrane permeability of phenolic compounds seemed to be essential for the inhibition of LTB4 release. In addition, the C4-carbonyl group seemed to be important for strongly inhibiting LTB4 release.

Animals↗

PubMed1999

The effects of several nucleotides on the molecular state and catalytic activity of Thiobacillus novellus cytochrome c oxidase. ATP affects the oxidase uniquely.

The catalytic activity and molecular aspects of Thiobacillus novellus cytpchrome c oxidase were affected by ATP. The steady-state kinetics in the oxidation of ferrocytochrome c by the oxidase varied with the presence or absence of ATP; the [S]-v curve of the reaction was sigmoid in the absence of ATP whereas it was a Michaelis-Menten-type hyperbola in the presence of 700 microM ATP. The oxidase was a dimer of the minimal structural subunit consisting of one molecule each of two subunits in the presence of Tween 20 and in the absence of ATP. The dimer dissociated into monomers in the presence of 700 microM ATP. The trough at 452 nm seen in the second derivative absorption spectrum of the CO compound of the oxidase in the absence of ATP, a characteristic of the cytochrome a component of cytochrome aa3, dissappeared in the presence of 700 microM ATP. However, ADP, AMP, GTP, CTP and UTP had little affect on both the [S]-v curve and the molecular mass of the oxidase when used in place of ATP.

Adenosine Triphosphate↗

PubMed1999

Anatomic study for posterior medialization thyroplasty.

To attain posterior medialization by thyroplasty type I, we simulated the surgery using 3 cadaveric larynges. Two approaches were applied to adduct the arytenoid cartilage: one involved compression of the vocal process, and the other, compression of the muscular process inward. The inner perichondrium was incised to reach the arytenoid cartilage from the framework. To compress the vocal process, a large silicone plug was required. In this method, there was some difficulty in compressing the vocal process precisely, and there was the risk of postoperative extrusion of the large plug. In contrast, the muscular process was more superficial relative to the framework, and it could be precisely compressed, resulting in sufficient posterior glottal closure. The silicone plug required for this procedure has a shallow depth that may provide the advantage of preventing postoperative extrusion. In conclusion, the compression of the muscular process is preferable for safely achieving posterior glottal closure.

Arytenoid Cartilage↗

PubMed1999

[Three-dimensional reconstruction of functional brain images].

We consider PET (positron emission tomography) measurement with SPM (Statistical Parametric Mapping) analysis to be one of the most useful methods to identify activated areas of the brain involved in language processing. SPM is an effective analytical method that detects markedly activated areas over the whole brain. However, with the conventional presentations of these functional brain images, such as horizontal slices, three directional projection, or brain surface coloring, makes understanding and interpreting the positional relationships among various brain areas difficult. Therefore, we developed three-dimensionally reconstructed images from these functional brain images to improve the interpretation. The subjects were 12 normal volunteers. The following three types of images were constructed: 1) routine images by SPM, 2) three-dimensional static images, and 3) three-dimensional dynamic images, after PET images were analyzed by SPM during daily dialog listening. The creation of images of both the three-dimensional static and dynamic types employed the volume rendering method by VTK (The Visualization Toolkit). Since the functional brain images did not include original brain images, we synthesized SPM and MRI brain images by self-made C++ programs. The three-dimensional dynamic images were made by sequencing static images with available software. Images of both the three-dimensional static and dynamic types were processed by a personal computer system. Our newly created images showed clearer positional relationships among activated brain areas compared to the conventional method. To date, functional brain images have been employed in fields such as neurology or neurosurgery, however, these images may be useful even in the field of otorhinolaryngology, to assess hearing and speech. Exact three-dimensional images based on functional brain images are important for exact and intuitive interpretation, and may lead to new developments in brain science. Currently, the surface model is the most common method of three-dimensional display. However, the volume rendering method may be more effective for imaging regions such as the brain.

Brain↗

PubMed1999

[Airway management in a patient with lower lip squamous cell carcinoma after radical surgical resection].

General anesthesia was scheduled in a patient who had undergone radical surgical resection because of his lower lip squamous cell carcinoma. His oral area had been reconstructed drastically and this pathological change indicated difficulties of mask fitting, mask ventilation and laryngoscopic intubation. Before induction of general anesthesia, we performed fiberbronchoscopic transnasal awake intubation. The patient's condition was stable during both intubation and operation. At the end of anesthesia, the tracheal tube was removed after the patient had become fully awake and had recovered completely from neuromuscular brockade. In conclusion, it is important to evaluate and recognize the difficult airway preoperatively. When this is suspected, awake intubation should be chosen to secure and guarantee the airway.

Anesthesia, General↗

PubMed1998

Cloning of a cDNA encoding an importin-alpha and down-regulation of the gene by light in rice leaves.

The import of nuclear proteins into nuclei begins with recognition of nuclear localization signal-harboring proteins and binding to a nuclear pore targeting complex. A cDNA for an importin-alpha protein, a subunit of the complex, was isolated from rice plants. The amino acid sequence deduced from the nucleotide sequence of the cDNA exhibited a high homology to those of importin-alpha proteins from many organisms such as Arabidopsis thaliana, Saccharomyces cerevisiae, human, mouse, Xenopus laevis and Drosophila melanogaster. Down-regulation of the transcription by light was shown in the leaves of light- and dark-grown seedlings by RNA blot analysis. The down-regulation was specific to leaves, whereas no light effect was observed in root tissues or calli, in which higher levels of the transcript were detected.

Amino Acid Sequence↗

PubMed1998

A novel importin alpha from rice, a component involved in the process of nuclear protein transport.

In eukaryotes, nuclear proteins that are transported into nuclei have nuclear localization signals (NLSs), which are recognized by proteins called importin alpha. We isolated a rice cDNA, #61L, and the corresponding gene that encodes a protein, which shows significant homology to the importin alpha. Although the encoded protein had only 23-27% amino acid identity to the importin alphas from various organisms including plants, the fusion protein with glutathione S-transferase showed a specific binding activity to the NLS of SV40 T-antigen. These results suggest that the rice #61L protein is a novel importin alpha in plants.

Amino Acid Sequence↗

PubMed1998

Isolation and characterization of two importin-beta genes from rice.

The nuclear transport of proteins is mediated by the complex of importin-alpha and importin-beta. We isolated two cDNAs encoding importin-beta from rice. A rice importin-beta was demonstrated to interact with rice GST-importin-alpha fusion proteins. The presence of two importin-beta genes was shown for the first time among a variety of eukaryotes.

Amino Acid Sequence↗

PubMed1997

The role of the temporal coding system in the auditory cortex on speech recognition.

To elucidate the temporal coding system for speech recognition, we synthesized stimulation sounds which do not contain formant information but do contain temporal information by transforming original sound wave to click sequences. Using this stimulation sound, we performed a recognition test and used PET to examine the cortical activities in normal subjects listening to this sound. The results of the recognition test showed a good perception of the sounds made from sequential speech. The PET study demonstrated significant activation of the superior temporal gyri while listening to the stimulation speech sounds. Our results imply that these stimulation sounds were processed semantically in the auditory cortices. The temporal processing system is thought to make an important contribution to speech recognition.

Adult↗

PubMed1997

Cloning of cDNA encoding the rice 22 kDa protein of Photosystem II (PSII-S) and analysis of light-induced expression of the gene.

Cloning of rice cDNA encoding the chlorophyll-binding 22 kDa protein of Photosystem II (PSII-S) and the light-induced expression of the gene are reported. One of the light-responsive cDNA clones, isolated by screening with a light-specific subtracted cDNA probe, was shown to encode PSII-S of rice. Genomic Southern analysis suggested that the PSII-S gene, psbS, is a single-copy gene in rice. A brief exposure to red light induced a severalfold increase in the steady state level of PSII-S transcripts in etiolated seedlings. The red light effect was reversed by far-red light, suggesting involvement of phytochrome in the PSII-S gene regulation. Prolonged exposure (3 h) to blue light, however, revealed a much stronger effect than red light on the accumulation of PSII-S transcripts in the etiolated seedlings. In dark-adapted green plants, prolonged exposure to blue light induced re-accumulation of transcripts encoding PSII-S, whereas red light had little effect.

Amino Acid Sequence↗

PubMed1997

Use of hydroxyapatite for reconstruction after surgical removal of intraosseous hemangioma in the zygomatic bone.

Two rare cases of intraosseous hemangiomas in the zygomatic bone that were repaired after surgical removal of the tumor with hydroxyapatite implants are reported. Case 1 is a 42-year-old woman, and case 2 is a 46-year-old man. They complained of swelling in the right cheek. An intraosseous tumor in the right zygomatic bone was observed in both patients. The tumor was resected, and hydroxyapatite was employed to repair the defect caused by removal. After 4 years since the operation in case 1 and 8 months in case 2, the patients show satisfactory cosmetic appearance. Hydroxyapatite implant was useful for reconstruction of the defect after surgical removal of hemangiomas in the zygomatic bone.

Adult↗

PubMed1997

Effect of tea polyphenols on histamine release from rat basophilic leukemia (RBL-2H3) cells: the structure-inhibitory activity relationship.

We studied the effect of tea polyphenols on histamine release from rat basophilic leukemia (RBL-2H3) cells. Among tea polyphenols, (-)- epigallocatechin gallate (EGCG) most strongly and dose-dependently inhibited histamine release from cells stimulated with a calcium ionophore, A23187. (-)-Epigallocatechin (EGC) and (-)-epicatechin gallate (ECG) with a triphenol residue moderately inhibited histamine release, whereas diphenolic (+)-catechin (C) and (-)-epicatechin (EC) did not. The magnitude of the inhibitory effect was in the order EGCG > ECG > EGC. Among simple polyphenols, the triphenol compounds, pyrogallol (PG) and gallic acid (GA) exerted inhibitory activity, but the diphenols, pyrocatechol, hydroquinone, and resorcinol did not. In addition, the mixture of PG and GA inhibited histamine release as strongly as EGCG with two triphenol residues. Similarly, they inhibited histamine release induced by IgE-antigen complex stimulation more efficiently than that induced by A23187 stimulation. EGCG did not inhibit the increase of intracellular Ca2+ in RBL-2H3 cells stimulated with A23187 or IgE antigen. These results indicate that the triphenol structure plays an important role in the inhibitory activity of tea polyphenols. Their activity seemed to be exerted through the metabolic events occurring after the elevation of intracellular Ca2+ concentration.

Animals↗

PubMed1997

[Radiation therapy for uterine cervix cancer: importance of evaluation of pre-treatment tumor size with MR imaging].

From May 1992 through December 1995, a total of 42 patients with previously untreated squamous cell carcinoma of the uterine cervix were treated by using middle-dose-rate intracavitary therapy, and their previously treated local tumor volume was evaluated with MRI. According to the staging of FIGO, 2 patients were classified as Stage IB, 2 as IIA, 18 as IIB, 1 as IIIA, 14 as IIIB, 2 as IVA and 3 as IVB. Cumulative 3-year survival rates were 89% in Stage IIB and 54% in IIIB. 3-year local control rates were 100% in Stage IIB and 67% in IIIB. On the other hand, the cumulative survival rate for the local control group in all stages was 100% at 2 years and 82% at 3 years. For the pelvic failure group it was 41% at 2 years. All of those in the pelvic failure group had bulky local tumor sizes of more than 60 mm in the previous treatment MRI study. The 3-year cumulative survival rate and local control rate for tumors less than 60 mm were 84% and 100%, but for tumors over 60 mm the respective rates were 45% and 33% (p < 0.01). The a results showed that the group with pretreatment of local tumors over 60 mm on MRI had a poor outcome. We concluded that pretreatment tumor volume is an important factor in prognosis and the evaluation of pretreatment tumor volume by imaging study (MRI) is necessary.

Adult↗

PubMed1996

An iron dioxygenase from Alcaligenes faecalis catalyzing the oxidation of pyruvic oxime to nitrite.

An enzyme which participated in the oxidation of hydroxylamine to nitrite from was partially purified Alcaligenes faecalis, and some of its properties were studied. The enzyme oxidized aerobically pyruvic oxime to nitrite in the presence of hydroxylamine or ascorbate. As molecular oxygen equimolar to nitrite formed was consumed in the enzymatic oxidation of pyruvic oxime to nitrite, the enzyme was thought to be a dioxygenase. It was an iron protein, and a reducing reagent was required to keep the iron in the ferrous state for the action of the enzyme.

Alcaligenes↗

PubMed1996

Inhibitory effect of tea polyphenols on histamine and leukotriene B4 release from rat peritoneal exudate cells.

The effect of tea polyphenols on the release of chemical mediators, histamine and leukotriene B4 (LTB4), from rat peritoneal exudate cells (PEC) was studied. Among polyphenols, (-)-epigallocatechin gallate (EGCG) most strongly inhibited the histamine release from the cells stimulated with a calcium ionophore, A23187 or compound 48/80. Though (+)-catechin (C) and (-)-epicatechin (EC) had no effect, (-)-epigallocatechin (EGC) and (-)-epicatechin gallate (ECG) moderately inhibited the histamine release. Similarly, EGCG, ECG, and EGC inhibited LTB4 release from PEC, whereas C and EC were not effective. The magnitude of the inhibitory effect on the release of these mediators of tea polyphenols was in the order of EGCG > ECG > EGC. These results indicated an important role of the triphenol structure in the inhibitory activity. Therefore, the possible antiallergic effect of tea polyphenols can be expected.

Animals↗

PubMed1996

Radiation therapy for T1,2 glottic carcinoma: impact of overall treatment time on local control.

PURPOSE: Local control probabilities of T1,2 glottic laryngeal cancer were evaluated in relation to dose and fractionation of radiation therapy (RT). MATERIALS AND METHODS: Between 1975 and 1993, 96 T1N0M0 glottic cancers and 32 T2N0M0 glottic cancers were treated with definitive RT. Total RT dose was 60-66 Gy/2 Gy for most of the T1 and T2 tumors, although 10 T2 tumors were treated with hyperfractionation (72-74.4 Gy/1.2 Gy bid). Of the 128 patients, 90 T1 glottic tumors and 30 T2 glottic tumors were followed for > 2 years after treatment. Multivariate analyses using the Cox proportional hazards model and a logistic regression analysis were performed to evaluate the significance of prognostic variables on local control. RESULTS: The 5-year local control probability for T1 tumors was 85%, whereas that for T2 tumors was 71%. Multivariate analyses demonstrated that only overall treatment time (OTT) was a significant variable for local control. Total RT dose, normalized total doses at a fraction size of 2 Gy, and fraction size were not significant. Local control probability of T1 tumors with an OTT of 42-49 days was significantly higher than that of tumors with an OTT of > 49 days (P < 0.02). Only a 1-week interruption of RT, due to holidays, significantly reduced the 5-year local control probability of T1 glottic tumors from 89 to 74% (P < 0.05). CONCLUSIONS: These results indicate that OTT is a significant prognostic factor for local control of T1 glottic tumors.

Adult↗

PubMed1996

Structure and expression of two seed-specific cDNA clones encoding stearoyl-acyl carrier protein desaturase from sesame, Sesamum indicum L.

We have isolated two cDNA clones (CDES01) and 04) encoding stearoyl-acyl carrier protein desaturase (SACPD; EC 1.14.99.6) from immature sesame seeds, and have analyzed accumulation levels of the corresponding mRNAs at different stages and organs in sesame. Clone CDES01 contains an open reading frame coding for a 396-amino acid protein of 45 kDa. CDES04 encodes a partial sequence of 141-amino acids. Deduced amino acid sequences of both clones exhibit a high identity to those of other plant SACPD cDNAs. Northern blots probed with CDES01 and CDES04 indicate that both messages accumulate in a seed-specific manner with a peak at 21 days after anthesis. However, expression patterns also indicate that regulation between CDES01 and CDES04 are slightly different. The CDES01 message accumulates at a low level in young leaves in addition to seeds, whereas accumulation of the RNA transcript corresponding to CDES04 is restricted to seeds. This observation implies the presence of at least two isozymes of SACPD having overlapping but slightly distinct functions in sesame.

Amino Acid Sequence↗

PubMed1996

Salivary duct carcinoma: a clinicopathologic study of three cases with a review of the literature.

Three cases of salivary duct carcinoma are presented. They occurred in a 60 year old man, a 66 year old man and a 57 year old woman. All of the lesions were located in the parotid gland. The tumor size ranged from 3 to 5 cm across the largest diameter. Facial paralysis was observed in two cases. Histologically, intraductal and invasive adenocarcinoma showing papillary, cribriform, and solid patterns with comedolike necrosis was observed. Immunohistochemically, the tumor cells were positive for keratin and epithelial membrane antigen. No myoepithelial cells were demonstrated within the tumor by staining for S-100 protein, alpha-smooth muscle actin or muscle specific actin. Ultrastructurally, intracytoplasmic lumina with microvilli, a moderate number of mitochrondria, lysosomes, and tight junctions were found. Regional lymph node metastasis was observed in one case, and distant metastasis developed in two cases. All of the patients were treated with adjuvant postoperative irradiation. One patient died of disease at 11 months after the initial diagnosis, another was alive with disease at 8 months, and the third patient was alive without disease at 2 years and 3 months. Salivary duct carcinoma should be differentiated from low-grade salivary gland carcinomas using morphologic and clinical criteria because of its poor prognosis even with aggressive therapy.

Adenocarcinoma↗