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Biomedical subjects

K Yoshimura

Publications and source records attributed to K Yoshimura.

At least 91 records · Page 5Linked to original sources
PubMed2000

Molecular cloning of ring finger protein 21 (RNF21)/interferon-responsive finger protein (ifp1), which possesses two RING-B box-coiled coil domains in tandem.

We have cloned the full length of a novel cDNA, named ring finger protein 21 (RNF21), composed of the RING finger-B box-coiled coil (RBCC) domain and the B30.2 domain, which are characteristic of the RBCC-B30.2 family. As a structural feature, the RNF21 cDNA possessed at least three kinds of isoforms, due to alternative splicing, consisting of the long form with the RBCC-RBCC-B30.2 domain, the medium form with the RBCC-B30.2 domain, and the short form with only the RBCC domain. Moreover, respective transcripts corresponding to the three isoforms were detected in various human organs by reverse transcription-PCR and Northern blot analyses. Interestingly, the medium form of the RNF21 mRNA expressed most predominantly was dramatically up-regulated within 8-16 h by interferon stimulation of HeLa cells. These findings suggest that RNF21 is a downstream gene that may mediate interferon's biological action.

Alternative Splicing↗
PubMed2000

MALDI-TOF mass spectrometry of insoluble giant polycyclic aromatic hydrocarbons by a new method of sample preparation

The insolubility of giant polycyclic aromatic hydrocarbons (PAHs) prevents their characterization by conventional analytical methods, which require a solubilization of the analyte. Laser desorption mass spectrometry may be used to analyze insoluble samples but is limited to relatively low molecular weights (approximately 2000), in the case of PAHs. To overcome this limitation, we applied MALDI-TOF mass spectrometry. Since MALDI sample preparation also requires solubility of analyte and matrix molecules, the sample preparation needed modification. The giant PAHs (>2000 Da) were investigated after using a new sample preparation, consisting of mechanically mixing analyte and matrix without any solubilization procedures. This solvent-free process allows insoluble compounds to be characterized. Furthermore, new organic molecules can be used as a matrix. Indeed, 7,7,8,8-tetracyanoquinodimethane, a new matrix with promising properties, has proven to be particularly suitable for the measurement of PAHs. Thanks to the successful characterization with MALDI-TOF mass spectrometry, the chemical design of giant PAHs, which was hindered until now for a lack of analytical methods, can now continue to develop.

Journal Article↗
PubMed2000

Anticachectic effects of Coptidis rhizoma, an anti-inflammatory herb, on esophageal cancer cells that produce interleukin 6.

Herbs as alternative cancer therapies have attracted a great deal of recent attention due to their low toxicity and costs. In this study, the antitumor activity and anticachectic effect of Coptidis rhizoma, an anti-inflammatory herb, were investigated in nude mice carrying a human esophageal cancer cell line YES-2, which constitutively secretes interleukin-6 (IL-6) and induces cachexia when injected into these mice. In this study, in vivo growth of YES-2 cells was not affected by an oral supplement containing the extract powder of C. rhizoma at a final concentration of 1% (CR supplement). However, in comparison with normal diet, CR supplement significantly attenuated weight loss of tumor-bearing mice without a change in food or water intake. Tumor IL-6 levels were significantly lower in mice treated with CR supplement than in control mice (P<0.001). Serum IL-6 was detectable in four (50%) of eight control mice; IL-6 was not detected in mice treated with CR supplement. We also confirmed that berberine (8-32 microM), a major component of C. rhizoma, dose-dependently inhibited secretion of IL-6 by YES-2 cells in vitro. Moreover, reverse transcription-PCR assay showed that treatment of YES-2 cells with berberine (8-32 microM) for 24 h reduced IL-6 mRNA expression. Our results suggest that C. rhizoma may have an anticachectic effect on esophageal cancer and an effect is associated with the ability of berberine to down-regulate tumor IL-6 production.

Administration, Oral↗
PubMed2000

Molecular cloning of testis-abundant finger Protein/Ring finger protein 23 (RNF23), a novel RING-B box-coiled coil-B30.2 protein on the class I region of the human MHC.

We have identified a genomic DNA fragment, using the PCR method with degenerate oligonucleotide primers which contain the conserved sequence of the RING finger domain. Using the DNA fragment as a probe, a novel cDNA was cloned from human and mouse testis. The cDNA had a domain structure of the typical RING-B box-coiled coil (RBCC)-B30.2 domain and therefore was named testis-abundant finger protein (tfp). Indeed, the transcript was highly expressed in the testis, although it was also found ubiquitously in various organs by Northern blot analysis. The tfp gene was mapped at the class I region of the human MHC (major histocompatibility complex), within which some known RBCC-B30.2 proteins such as RFP, RFB30/HERF1, AFP, and HZF had been localized. These findings demonstrate that several RBCC-B30.2 proteins including tfp, which are non-HLA proteins, are clustered within the class I region of the human MHC.

Amino Acid Sequence↗
PubMed2000

cDNA cloning of a novel bHLH-PAS transcription factor superfamily gene, BMAL2: its mRNA expression, subcellular distribution, and chromosomal localization.

We isolated a human cDNA encoding a novel member of the bHLH-PAS transcription factor superfamily, BMAL2, which is highly similar to, but distinct from, BMAL1. The composite cDNA covered a 1720-bp sequence consisting of a putative 1653-bp open reading frame encoding a polypeptide of 551 amino acids. The deduced BMAL2 product contains a bHLH-PAS domain in its N-terminal region and a variable C-terminus. The overall identity of BMAL2 polypeptide to that of human BMAL1 is 49%. RNA analysis revealed that expression of BMAL2 transcripts was restricted to the fetal brain and to the adult liver in human, while human BMAL1 mRNA was expressed in the brain and skeletal muscle. The chromosomal localization of the human BMAL2 gene was determined by fluorescent in situ hybridization to be localized on chromosome 12 at region p12.2-p11.2. These results suggest that BMAL2 may play different roles from BMAL1 in the embryonic brain and in adult mammals.

Adult↗
PubMed2000

Significance of involvement by squamous cell carcinoma of the ducts of esophageal submucosal glands. Analysis of 201 surgically resected superficial squamous cell carcinomas.

BACKGROUND: Ductal involvement (DI) is often observed in superficial squamous cell carcinoma of the esophagus (SSCCE), defined as carcinoma with invasion limited to the submucosa. The purpose of this study was to clarify the clinicopathologic significance of DI in SSCCE. METHODS: Two hundred one surgically resected lesions from 140 patients with SSCCE were examined histopathologically. Clinicopathologic factors, such as macroscopic type, tumor location, maximum tumor size, depth of invasion, lymphatic and blood vessel permeation, lymph node metastasis, and prognosis, were examined to investigate the association between these factors and the presence of DI. RESULTS: Of the 201 SSCCE lesions, 43 (21.3%) had 152 DIs (1-32 DIs per lesion). The DI always remained in situ, and there were no tumors showing submucosal invasion through the DI. As for the relation between clinicopathologic factors and the presence of DI, multivariate analysis showed only maximum tumor size to correlate with the presence of DI (P < 0.0001). There were no significant differences between DI negative and DI positive lesions in tumor location, macroscopic type, lymphatic and blood vessel permeation, lymph node metastasis, or prognosis. In 83 mucosal carcinomas, including in situ carcinomas or carcinomas that invaded no deeper than the lamina muscularis mucosa, no lymph node metastasis was found, and the 5-year survival rate was 100% (unaffected by the presence of DI). Among these 83 lesions, DI was found in 11 (13.8%), of which 6 (7.2%) had DI extending to the submucosal layer. CONCLUSIONS: These results indicate that DI as a pathway of tumor spread to the deeper layer is of little significance in squamous cell carcinoma of the esophagus, and that mucosal carcinomas with DI that extends to the submucosa should not be classified as submucosal carcinoma.

Adult↗
PubMed2000

Evaluation of the New International Union Against Cancer TNM staging for gastric carcinoma.

BACKGROUND: The lymph node (N) classification in the International Union Against Cancer (UICC) TNM staging system for gastric adenocarcinoma has been revised. The new classification is based on the number of positive regional lymph nodes instead of the anatomic location of the regional lymph node metastasis. Both classification systems were compared for prognostic significance. METHODS: A total of 4362 gastric carcinoma patients who underwent resection between 1969 and 1990 were analyzed. RESULTS: Thirteen percent of patients could not be staged according to the new system. Based on the previous classification, 647 patients were classified as pN1 and 711 patients as pN2. When reclassified, 587 patients remained pN1, 54 patients became pN2, and 6 patients became pN3. Of the 711 pN2 patients, 333 became pN1, 267 remained pN2, and 111 patients became pN3. Both lymph node classification methods defined groups with widely differing prognoses. The prognoses of patients classified as new pN2 were more homogeneous than those of the group classified as old pN2. Survival of new pT4/pN1 patients was significantly better than that of other subgroups in Stage IV. Nine potential prognostic factors, including lymph node metastasis, were studied in multivariate analysis. The hazard ratios were 1.38 (1.16-1.64) for pN1 and 2.55 (2.16-3.01) for pN2, based on the old classification. They were 1.51 (1.29-78) for pN1, 3.11 (2.56-3.78) for pN2, and 3.88 (2.98-5.05) for pN3, based on the new classification. CONCLUSIONS: The new N classification is superior as a prognostic factor to the old N classification, although there is inadequacy in stage grouping. [See editorial on pages 1763-5, this issue.]

Humans↗
PubMed2000

Molecular characterization and physiological role of ascorbate peroxidase from halotolerant Chlamydomonas sp. W80 strain.

A cDNA clone encoding an ascorbate peroxidase was isolated from the cDNA library from halotolerant Chlamydomonas W80 by a simple screening method based on the bacterial expression system. The cDNA clone contained an open reading frame encoding a mature protein of 282 amino acids with a calculated molecular mass of 30,031 Da, preceded by the chloroplast transit peptide consisting of 37 amino acids. In fact, ascorbate peroxidase was localized in the chloroplasts of Chlamydomonas W80 cells; the activity was detected in the stromal fraction but not in the thylakoid membrane. The deduced amino acid sequence of the cDNA showed 54 and 49% homology to chloroplastic and cytosolic ascorbate peroxidase isoenzymes of spinach leaves, respectively. The enzyme from Chlamydomonas W80 cells was purified to electrophoretic homogeneity. The molecular properties of the purified enzyme were similar to those of the other algal ascorbate peroxidases rather than those of ascorbate peroxidases from higher plants. The enzyme was relatively stable in ascorbate-depleted medium compared with the chloroplastic ascorbate peroxidase isoenzymes of higher plants. The presence of NaCl (3%) as well as of beta-d-thiogalactopyranoside was needed for the expression of Chlamydomonas W80 ascorbate peroxidase in Escherichia coli.

Amino Acid Sequence↗
PubMed2000

Histopathologic findings predicting lymph node metastasis and prognosis of patients with superficial esophageal carcinoma: analysis of 240 surgically resected tumors.

BACKGROUND: If it were possible to elucidate the histopathologic findings predicting lymph node metastasis and prognosis in superficial squamous cell carcinoma of the esophagus (SSCCE), they could be used as markers to identify patients who do not require additional surgical resection after endoscopic mucosal resection (EMR). METHODS: Two hundred forty surgically resected SSCCEs were examined histopathologically. Histopathologic factors including vertical tumor invasion depth in the submucosal layer (VTIDsm), degree of nuclear atypia (low, one point; high, two points), growth pattern (expansive, one point; infiltrative, two points), and histologic grade (calculated by adding the latter two scores to obtain Grade 1, two points; Grade 2, three points; and Grade 3, four points) were evaluated to investigate the associations among these factors, lymph node metastasis, and prognosis. RESULTS: No lymph node metastasis was found in 54 patients with carcinoma limited to the lamina propria. Their 5-year survival rate was 100%. Multivariate analysis of 186 carcinomas invading beyond the lamina propria showed that lymphatic permeation correlated with lymph node metastasis (P<0.0001) and the presence of lymph node metastasis and a high histologic grade were independent factors indicating a poor prognosis (P = 0.0061 and 0.023, respectively). In 53 patients whose tumors had invaded the lamina muscularis or slightly invaded the submucosa (VTIDsm <500 microm), no lymph node metastasis was found in the lymphatic permeation negative and blood vessel permeation negative patients with VTIDsm values <200 microm and histologic Grades 1 or 2. CONCLUSIONS: Lymphatic permeation is a good predictor of lymph node metastasis in patients with SSCCE. Lymph node metastasis and the histologic grade are independent prognostic factors. Vessel permeation, VTIDsm, and histologic grade were found to be important factors for identifying patients who did not require additional surgical treatment after EMR.

Biomarkers, Tumor↗
PubMed2000

Carbachol-induced [Ca2+]i increase, but not activation of protein kinase C, stimulates exocytosis in rat parotid acini.

1. A column perfusion system was applied to rat parotid acinar cells to clarify the roles of Ca2+ and protein kinase C (PKC) in the mechanisms of carbachol (CCh)-induced amylase secretion. 2. CCh evoked a biphasic response of amylase secretion with an initial rapid and large peak that reached maximum at about 10 s followed by a sustained plateau. The time profile and the dose-response relationship paralleled with those of cytosolic free Ca2+ concentration ([Ca2+]i). 3. The CCh-induced sustained response of amylase secretion maintained by Ca2+ influx into cells was ATP dependent, while the initial peak response regulated by Ca2+ released from InsP3-sensitive stores was relatively ATP independent. 4. Restoration of extracellular Ca2+ during continuous stimulation with CCh in Ca(2+)-free medium evoked a second rapid and large peak of amylase secretion. 5. Phorbol 12,13-dibutyrate (PDBu) potentiated the CCh-induced amylase secretion in both the initial peak and the sustained plateau without enhancing CCh-induced [Ca2+]i changes. 6. PKC inhibitors such as Ro 31-8220 inhibited the potentiating effect of PDBu but only slightly reduced amylase secretion induced by CCh alone. 7. These results suggest that a CCh-induced rise in [Ca2+]i triggers the final fusion and/or exocytosis of amylase secretion. CCh also has some ability to promote ATP-dependent priming of secretory granules that, together with Ca2+ influxed into cells, contributes to the CCh-induced sustained plateau of amylase secretion. PDBu-induced activation of PKC promotes the priming of secretory granules, thereby enhancing the efficacy for Ca2+ to trigger fusion/exocytosis.

Adenosine Triphosphate↗
PubMed2000

Stimulation of NO production and of eNOS phosphorylation in the microcirculation in vivo.

The role of nitric oxide (NO) in microvascular permeability is controversial, in part because the regulation of its endothelial constitutive synthase, eNOS, has been studied in vitro but not in vivo. Our study was designed to detect the morphologic and functional presence of eNOS and to test whether eNOS could be phosphorylated by platelet-activating factor (PAF), an agent that induces hyperpermeability. Immunocytochemistry was applied using human anti-eNOS antibodies in the hamster cheek pouch (hcp). The hcp microvessels demonstrated positive reaction products in the endothelium. The functional presence of eNOS in hcp was investigated by topical application of 10(-7) M PAF to the hcp and by measuring NO production by chemiluminescence. The mean baseline value of NO release was 63.3 +/- 6.9 pmol/ml (mean +/- SE). Application of PAF led to an increase in mean NO release to 120.8 +/- 31.2 pmol/ml (P < 0.05). In another series of experiments, 10(-7) M PAF was applied topically to hcp preincubated with [(32)P]orthophosphoric acid. Immunoprecipitation and Western blots detected (32)P-labeled bands that migrated with the mobility of positive eNOS indicating phosphorylated eNOS protein. The intensity of the radioactive bands was evaluated by computer-assisted image analysis. Comparison of the net band intensities yielded a mean PAF-treated/control ratio of 1.6 +/- 0.1. Our data demonstrate the morphologic and functional presence of eNOS in the microcirculation. The data also provide evidence that the function of microvascular eNOS is subject to regulation by phosphorylation.

Animals↗
PubMed2000

SCID mice show a similar susceptibility to Angiostrongylus cantonensis as do wild-type mice of the C.B-17 strain.

C.B-17-SCID/SCID (SCID) mice infected with Angiostrongylus cantonensis yielded a high percentage of worm recovery and did not show any body weight loss until day 24 postinfection. Unexpectedly, C.B-17-+/+(+/+) mice also produced a similar worm burden containing well-developed worms. This is probably attributable to the observation that +/+ mice failed to induce eosinophilia in cerebrospinal fluid (CSF) despite their production of antigen-specific IgA and IgGI; +/+ mice have defective bone-marrow eosinopoiesis, which in turn results in reduced blood and CSF eosinophilia. Interleukin 5 (IL-5) production in +/+ mice is similar to that in BALB/c and C57BL/6 mice. However, bone-marrow eosinopoiesis in response to IL-5 is markedly suppressed in +/+ mice. This is probably associated with impaired expression of common beta-chain mRNA in bone-marrow cells of +/+ mice, which leads to the failure of bone-marrow eosinopoiesis. Hence, +/+ mice may serve as a useful model for the elucidation of eosinophil production in the mouse and for determination of the relationship between parasite infection and the eosinophil.

Angiostrongylus cantonensis↗
PubMed2000

Development of an optical fiber hydrophone with fiber Bragg grating

A new type of optical fiber hydrophone is constructed with a fiber Bragg grating (FBG) based on the intensity modulation of laser light in an FBG under the influence of sound pressure. The FBG hydrophone shows linearity, with dynamic range about 70 dB. It can measure amplitude and phase of an acoustic field in real time, and operates in a wide range of acoustic frequency, at least from 1 kHz to 3 MHz. No signal distortion is observed in the detected signal. Because of the simplicity in its operating principle and geometry, an FBG hydrophone is expected to be an acoustic sensor of high practicality compared to a conventional optical fiber hydrophone.

Journal Article↗
PubMed2000

Age-related changes in the posterior limb of the internal capsule revealed by magnetic resonance imaging.

In this study, we examined the age-related differences in the corticospinal tract (CST) of the posterior limb (PL) of the internal capsule (IC) by analyzing 53 magnetic resonance (MR) images from 45 subjects. Regions in the posterior part of the PL of the IC were observed as hypointense areas in T1-weighted images of axial sections at 4 years of age. These regions became clear, spotty hyperintense areas in T2-weighted images of subjects older than 9 years. These regions persisted in all cases beyond 9 years of age, level on both T1- and T2-weighted images. The region is consistent with the CST from MR images of coronal and sagittal sections in our study. These results suggest that differences among the region may occur, such as an increase in fiber size and an increase in the thickness of the myelin sheaths, depending on age after the completion of general myelination in the CST.

Adolescent↗
PubMed2000

Preparation and dynamic viscoelasticity characterization of alkali-solubilized collagen from shark skin.

Alkali-solubilized collagens, prepared by alkali-acid extraction and alkali direct extraction (abbreviated AASC and ALSC, respectively), were characterized by dynamic viscoelastic measurement of collagen solution (10 mg/mL). The optimum preparative conditions in terms of yield and polypeptide size are as follows: for the alkali-acid extraction, a pretreatment with 0.5 or 1 M NaOH containing 15% Na(2)SO(4) within 5 days at 20 degrees C followed by the subsequent acid extraction, and for the alkaline direct extraction, a treatment with 0.5 M NaOH containing 10% NaCl at 4 degrees C for 20-30 days. A major portion of the polypeptide sizes of AASC and ALSC is composed of alpha chains (alpha1 and alpha2). Dynamic viscoelasticity of collagen solution was measured as a function of temperature. AASC showed a greater contribution of elastic behavior rather than viscous behavior. On the contrary, ALSC exhibits a stronger viscous behavior than elastic behavior.

Animals↗
PubMed2000

Physical properties of shark gelatin compared with pig gelatin.

Physical properties of shark gelatin were examined during gel formation and postgelation in comparison with pig gelatin. Samples with various concentrations and pH values were evaluated by breaking strength, dynamic viscoelasticity, and dynamic light scattering. Sol-gel and gel-sol transition temperatures for shark gelatin were remarkably lower than those for pig gelatin. Shark gelatin gel shows a narrower pH range to form a stable gel compared with pig gelatin. Melting enthalpy of shark gelatin gel was greater than that of pig gelatin gel, and G' of shark gelatin gel changed more extensively with rising temperature in comparison with pig gelatin gel. It is concluded that shark gelatin has different characteristics from pig gelatin not only for gel characteristics but also for the solution property.

Animals↗
PubMed2000

Expression analysis of ESts derived from the inner bark of Cryptomeria japonica.

To assist genetic research into Cryptomeria japonica, which is one of the most important forest tree species in Japan, expressed sequence tag (EST) analysis was carried out. The cDNA clones were isolated from a library derived from inner bark tissues. Partial sequences were obtained from 2231 clones, representing 1398 unique transcripts. Putative functions were assigned to 1583 clones, which represented 882 unique transcripts, by a Blast algorithm. Homology analysis suggested that ESTs related to cell wall formation represented about 3% of the clones. Transcripts of plant stress response genes were also abundant in the inner bark library, especially genes involved in wounding and drought responses. This indicates that the stress response systems of this tree species are similar to those of other plants, and that these systems are highly conserved among plant species. The remaining 648 clones, which represented 516 unique transcripts, did not show any significant homology to known sequences in the databases searched: these are expected to represent genes specific to Cryptomeria and, possibly, to related species.

Cycadopsida↗