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Y Dobashi

Publications and source records attributed to Y Dobashi.

At least 19 recordsLinked to original sources
PubMed2006

Differential expression and pathological significance of autocrine motility factor/glucose-6-phosphate isomerase expression in human lung carcinomas.

To clarify the involvement of autocrine motility factor (AMF) in the phenotype and biological profiles of human lung carcinomas, we analysed protein and mRNA expression in a total of 180 cases. Immunohistochemistry revealed positive staining in 67.2%, with the highest frequency in squamous cell carcinoma (SCC; 90.8%) and the lowest in small cell carcinoma (SmCC; 27.8%). In SCC, the staining frequency and intensity correlated with the degree of morphological differentiation. Generally, the expression levels in immunoblotting analysis corresponded well with immunohistochemical positivity. However, there was less agreement between protein and mRNA levels: in SmCC and large cell carcinomas (LCCs), mRNA showed higher, but protein showed lower expression. Among non-small cell lung carcinomas (NSCLCs), AMF protein levels correlated inversely with tumour size, but tumours exhibiting lymph node metastasis showed higher mRNA expression. In cultured lung carcinoma cells which comprised all histological subtypes, AMF was detected in the lysates of all ten cell lines. Secreted AMF protein was detected in the conditioned media from six cell lines, most of which were SmCC or LCC. Thus, a particular subset of lung carcinomas secrete AMF, which may promote cell motility via autocrine stimulation through its cognate receptor and cause the biological aggressiveness seen in SmCC and LCC. Moreover, treatment by proteasome inhibitors resulted in increased cellular AMF in five cell lines, suggesting that intracellular AMF levels are regulated by both secretion and proteasome-dependent degradation. In conclusion, AMF was detected in a major proportion of lung carcinomas, and may play a part not only in proliferation and/or progression of the tumours, but also, possibly, in the differentiation of SCC. Furthermore, higher mRNA expression may be related to the high metastatic potential of NSCLC and increased protein secretion, leading to a more aggressive phenotype, such as the invasiveness of SmCC and LCC.

Adenocarcinoma↗
PubMed2005

[Chondrosarcoma of the chest wall].

We report 2 patients with chondrosarcoma of the chest wall. They were a 67-year-old woman (case 1) with an anterior chest wall tumor and a 68-year-old woman (case 2) with a painful rib tumor. Their computed tomography (CT) both revealed calcified tumors. Case 1 underwent a wide resection by partial sternectomy, with free surgical margins. Case 2 underwent tumor resection with the posterior part of the 3rd rib, with positive surgical margin in the vertebral site, and received adjuvant radiotherapy. Both patients were pathologically diagnosed as having grade II chondrosarcoma. In their postoperative courses, they are free from recurrence. Wide resection is likely to be the key to successful management of chest wall chondrosarcoma.

Aged↗
PubMed2004

[Prognosis of resected stage I bronchioloalveolar carcinoma of the lung].

In this retrospective study, we investigated the prognosis of 25 patients with resected bronchioloalveolar carcinoma (BAC) of 3.0 cm or less in diameter. We assigned a diagnosis of BAC for non-invasive tumors as defined by the World Health Organization (WHO) classification. The patients ranged in age from 47 to 78 years with an average of 64.0 years. Eighteen patients (72%) were male and 7 patients (28%) were female. All the patients underwent complete resection. As the mode of surgical resection, at least lobectomy was performed in 84%. Sections of the resected tumor were stained by HE and Elastica, and then examined by light microscopy. The tumors ranged in size from 0.5 to 3.0 cm with an average of 1.9 cm. Neither pleural involvement nor vascular permeation was seen in BACs. There was also no lymph node involvement for BACs. The 5-year disease-free survival rate of all 25 patients with BAC was 100%. The unequivocally recognizing invasive features by morphology is important for a prospect of the prognosis of resected BACs.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMed2003

Neck and abdominal muscle activity during a sniff.

Measurement of sniff nasal inspiratory pressure (SNIP) is now used widely as a simple, non-invasive assessment of global respiratory muscle strength, even though the technique evolved originally from measurements of trans-diaphragmatic pressure (Pdi) that reflect the status of the diaphragm. The relative participation of major respiratory muscles, apart from the diaphragm, in the generation of SNIP is not known. Therefore, we examined the activity during a sniff of both neck and abdominal "accessory" muscles. In seven young adults we implanted fine wire EMG electrodes under direct vision with high-resolution ultrasound into scalene, sternocleidomastoid, trapezius, and transversus abdominis. SNIP was measured during sniffs that were short and sharp, from low to maximal intensity, in both standing and supine postures. Mean maximum SNIP was -105.6cmH2O (SD 32.9) in supine and -94.5cmH2O (26.6) in the standing posture, (difference NS). In every subject, scalene activity appeared even at the lowest SNIP, and increased linearly with increasing SNIP. Sternomastoid activity appeared at higher SNIP levels in three of seven subjects. By contrast, trapezius activity was never present at low SNIP, and appeared in only 2 subjects at maximum SNIP. Sniff abdominal expiratory activity was inconsistent with no activity of transversus in four of seven subjects even at greatest SNIP. Thus, we observed differential activation among these non-diaphragm respiratory muscles during SNIP; while some accessory muscles were very active, others were unlikely to contribute to generation of SNIP. Clinically, this indicates SNIP will be impacted unequally by loss of function of specific respiratory muscles.

Abdominal Muscles↗
PubMed2001

Overexpression of cdk4/cyclin D1 induces apoptosis in PC12 cells in the presence of trophic support.

The induction of apoptosis by cell cycle regulator molecules under conditions optimal for exponential growth was examined in rat pheochromocytoma PC12 cells by overexpression of cyclins and cyclin-dependent kinases (cdks). By flow cytometry and by immunofluorescence, only cells overexpressing cdk4 or cyclin D1 underwent apoptosis, which was not associated with G1-arrest. Cdk4 kinase activity was significantly higher in cdk4-, or cyclin D1-expressing cells. Furthermore, induction of apoptosis by cdk4 was abrogated by co-transfection of p16(INK4), or dominant negative cdk4. These results suggest that upregulation of cdk4 kinase activity is a primary and critical mediator of apoptosis in PC12 cells under physiological conditions.

Animals↗
PubMed2001

CDK-inhibitors-associated kinase activity: a possible determinant of malignant potential in smooth muscle tumors of the external soft tissue.

There has been accumulating histological observation of leiomyoma and leiomyosarcoma of the external soft tissue regarding their differential diagnosis. The definitive diagnostic tools have not been established, however, nor have the pathological mechanisms of cell proliferation in these tumors been clarified. Herein, expression of the cyclin-dependent kinase inhibitors (CKIs), p21, p27 and p57 and their associated kinase activities were examined in 61 cases of soft tissue smooth muscle tumors. Immunohistochemical staining showed that all 3 inhibitor proteins were expressed in all cases of leiomyoma and leiomyosarcoma, but that the mean values of their labeling indices (LIs) were higher in the cases of leiomyosarcoma. In addition, the LIs of p21 and p27 were inversely correlated in total cases. Immunoblotting revealed that these proteins are expressed at higher levels in tumors, in particular, in leiomyosarcoma. When CKIs were immunoprecipitated from tissue extracts, cyclin/cdk protein complexes associated with, at least, 1 CKI were detectable only in tumor tissues. Furthermore, cdk2 or cdk4 kinase activity manifested by these cyclin/cdk/CKI complexes (CKI-associated kinase activity) was detectable exclusively from leiomyosarcoma, but not from leiomyoma. Among the cases of leiomyosarcoma, cdk2 activity was generally found associated either with p21 or p27, but not both. Statistical analysis indicated that p21- and p27 LIs are predictive of positive or negative clinical outcome, respectively. In conclusion, the participation of CKIs in active cyclin/cdk complexes in a reciprocal and redundant manner and subsequent CKI- associated kinase activity are the characteristic profiles of malignant phenotype in these tumors. Moreover, immunohistochemical detection of CKIs may provide a useful tool for evaluating patients' prognosis.

Cell Cycle Proteins↗
PubMed2001

Study on the role of G1 cyclins in Epstein-Barr virus-associated human lymphomas maintained in severe combined immune deficiency (SCID) mice.

Five Epstein-Barr virus (EBV)-positive human lymphoma cell lines maintained in severe combined immune deficiency (SCID) mice were used to investigate the role of G1 cyclins in EBV-induced lymphomagenesis. All the primary tumors had been negative for EBV but became positive after establishment in SCID mice, with monoclonal immunoglobulin gene rearrangement and EBV monoclonality. To compare the expression status of G1 cyclins, these EBV-associated lymphoma lines (6 EBV[-] human SCID mouse lymphoma lines, 13 human B cell lymphomas and 8 samples of human tonsil tissue) were examined by reverse transcription-polymerase chain reaction-Southern blotting, Western blotting and immunohistochemistry. mRNA expression of cyclin D1 (CCND1), cyclin D2 (CCND2), cyclin E (CCNE), cyclin-dependent kinase 2 (CDK2) and 4 (CDK4) was found in all 3 types of lymphomas. Western blotting demonstrated identical results. Immunohistochemistry revealed CCND1 to be negative in all lymphomas. CCND2 was positive and restricted to the nuclei in all EBV(+) SCID mouse lymphoma lines, whereas it was limited to the cytoplasm in half of the EBV(-) counterparts. CCNE was positive in the nuclei in all EBV(+) but negative in all EBV(-) SCID mouse lymphoma lines. Immunoprecipitation of EBV(+) and (-) SCID mouse lymphomas for CCND1, CCND2 and CCNE vs. p21, PCNA and CDK2 or CDK4 demonstrated that, in EBV(+) SCID lines, CCND2/CDK4 complexes were present without binding to p21, suggesting independence from p21 regulation. In EBV(-) SCID mouse lymphomas, half of the cases showed complex formation of CCND2/CDK4 without binding of p21. In contrast, CCND1/CDK4 and CCNE/CDK2 were under regulation of p21 in both EBV(+) and (-) lymphomas. These results suggest that differential expression of CCNDs, CCNE and CDKs, as well as variation in their subcellular localization and association with CDK-inhibitor protein, could explain differences in cell proliferation between EBV(+) and EBV(-) lymphomas.

Animals↗
PubMed2001

Hyalinizing spindle cell tumor with giant rosettes: report of a case showing remarkable myofibroblastic differentiation.

We examined the proliferative activity and the differentiation line of tumor cells in a case of "hyalinizing spindle cell tumor with giant rosettes" (HSCGR). A 6 cm tumor within the right deltoid muscle of a 58-year-old female was found by physical and radiographical examinations. A biopsy revealed the histological features of a spindle cell tumor with rosette-like structures. Wide excision was done under the diagnosis of HSCGR. The tumor presented as a gray-whitish, solid mass with focal pseudocystic degeneration. Immunohistochemically, the tumor cells were diffusely positive for vimentin and were also focally positive for S-100, but negative for desmin and alpha-smooth muscle actin. The cells stained positively for Ki-67 with even distribution, there being a correlation with the cellularity of the areas, with a labeling index ranging from 0.3 to 0.5%. In addition, flow cytometry revealed an almost normal diploid DNA pattern and 5.8% S-phase fraction, indicating low proliferative activity. Ultrastructurally, many tumor cells displayed discontinuous basal lamina, pinocytotic vesicles, dilated rough endoplasmic reticulum, and microfilaments with focal dense bodies. The main component of the rosette was collagenous fibrils with normal diameter and normal periodic banding. We interpreted this case of HSCGR as a low grade fibrosarcoma with remarkable differentiation of myofibroblastic lineage, and with focally accumulated, morphologically normal collagenous fibrils.

Cell Differentiation↗
PubMed2000

APC protein is required for initiation of neuronal differentiation in rat pheochromocytoma PC12 cells.

The adenomatous polyposis (APC) gene product is highly expressed in the central nervous system. To elucidate the contribution of the APC protein to neuronal differentiation, we used an inducible antisense mRNA vector to suppress APC protein expression and examined neuronal differentiation of PC12 cells induced by nerve growth factor (NGF). When antisense mRNA was induced, APC protein expression was suppressed to 20% of the noninduced level. In those cells, neurite extension induced by NGF and expression of microtubule-associated protein 2 (MAP2) was completely inhibited. However, once cells had differentiated, antisense APC mRNA expression and subsequent suppression of APC protein expression had no effect on either cell morphology or MAP2 protein expression. These results suggest that the wild type APC is critically involved only in the initiation of neuronal differentiation, but not in the maintenance of the differentiated phenotype, or that the neuronal phenotype could be maintained at lower level of APC protein.

Adenomatous Polyposis Coli Protein↗
PubMed2000

Simultaneous suppression of cdc2 and cdk2 activities induces neuronal differentiation of PC12 cells.

The involvement of cdc2 and cdk2 during neuronal differentiation in rat pheochromocytoma PC12 cells was examined. When PC12 cells were cultured with nerve growth factor (NGF), expression of cdc2 decreased significantly after day 5, while expression of cdk2 decreased gradually after day 7. Cells overexpressing cdc2 or cdk2 were resistant to NGF-induced differentiation and growth suppression, and maintained high cdc2 or cdk2 kinase activity, respectively, during NGF treatment. In contrast, the NGF-treated parental cells showed a marked decline in these kinase activities after day 3. When PC12 cells were treated with specific inhibitors of cdc2/cdk2 (butyrolactone-I, olomoucin), they showed marked neurite extension and up-regulation of microtubule-associated protein 2 expression. In addition, treatment with mixtures of antisense oligonucleotides for cdc2 and cdk2 resulted in down-regulation of both cdc2 and cdk2 kinase activities as well as significant neurite outgrowth and up-regulation of microtubule-associated protein 2 expression. However, neurite outgrowth was not observed in cells treated with either single antisense oligonucleotide, or antisense cdc2 + cdk4 or cdk2 + cdk4 oligonucleotide mixtures. These results suggest that simultaneous down-regulation of cdc2 and cdk2 activity is sufficient and necessary for neuronal differentiation in PC12 cells.

Animals↗
PubMed2000

Involvement of cyclins in cell proliferation and their clinical implications in soft tissue smooth muscle tumors.

Expression of cyclins A and E and cyclin-dependent kinase 2 (cdk2) was examined immunohistochemically in 55 cases of soft tissue smooth muscle tumors, including vascular leiomyoma, and compared to expression of Ki-67 and proliferating cell nuclear antigen. Cyclin A was expressed in 70% of the leiomyoma cases, but with much lower labeling indexes than in leiomyosarcoma. Cyclin E was expressed exclusively in leiomyosarcoma. Although the differences of cyclin A- and cyclin E-labeling indexes between leiomyoma and leiomyosarcoma were statistically significant, no significant differences were found in the other markers. Furthermore, cyclin A- and/or E-positivity predicted a poor prognosis in recurrence- or metastasis-free survivals and overall survival. Immunoblotting revealed that cyclins A and E were expressed, in complex with cdk2, exclusively in tumors. In addition, not only leiomyosarcoma, but also leiomyoma specimens that exhibited negligible levels of complex expression, manifested detectable cdk2 activity. These results suggest 1) up-regulation of active cyclin A/cdk2 expression and associated kinase activity is critical for unrestrained cell proliferation; 2) cyclin E/cdk2 complexes may play a crucial role in leiomyosarcoma; 3) immunohistochemical detection of cyclins can be a more reliable tool for differential diagnosis between leiomyoma versus leiomyosarcoma than that of Ki-67 or proliferating cell nuclear antigen, and be a possible prognostic indicator.

Adult↗
PubMed2000

Alpha-anomer-selective glucosylation of menthol with high yield through a crystal accumulation reaction using lyophilized cells of Xanthomonas campestris WU-9701.

L-Menthyl alpha-D-glucopyranoside (alpha-MenG) is a desirable derivative of L-menthol with useful properties for the production of new flavors and novel food additives. Bacteria were screened for alpha-anomer-selective glucosylation activity toward l-menthol, resulting in the isolation of two strains, Xanthomonas campestris WU-9701 and Stenotrophomonas maltophilia WU-9702, from independent soil samples. Since the safety of X. campestris for use in the food industry is well established, WU-9701 was selected as the more suitable strain for further study. When 50 mg X. campestris WU-9701 lyophilized cells as a biocatalyst were incubated with 1.0 M maltose and 100 mg L-menthol in 10 ml of 10 mM H3BO3NaOHKCl buffer (pH 8.0) at 40 degrees C, alpha-MenG was accumulated, mainly in a crystalline form, through the anomer-selective synthesis reaction without any by-product formation. Under the optimal conditions, 202 mg alpha-MenG was obtained over 48 h with a highest conversion yield of 99.1% based on the supplied L-menthol. Crude alpha-MenG formed through this "crystal accumulation reaction" was easily collected from the reaction mixture by separation on filter paper. Plank-like crystals of purified alpha-MenG were subsequently obtained by recrystallization in ethyl acetate solution.

Journal Article↗
PubMed2000

[Nocturnal oxygen desaturation during home oxygen therapy in patients with chronic respiratory disease].

We investigated nocturnal oxygen desaturation (NOD) in 36 patients with stable chronic respiratory disease who were receiving home oxygen, therapy (HOT). Study data included medical history, chest roentgenograms, measurement of daytime arterial blood gases while awake, and spirometry. Each subject underwent full overnight oximetry monitoring. Three patients were excluded from further investigation because of periodic desaturation suggestive of sleep apnea. The remaining 33 subjects were divided into two groups: 21 patients with sequelae of pulmonary tuberculosis (TB-sequela) and 12 patients with chronic obstructive pulmonary disease (COPD). The COPD group was divided into two subgroups according to the Burrows classification (Am Rev Resp Dis. 90: 14-27, 1964): 5 patients with type A (Type A) and 7 patients with type B (Type B) COPD. The percentages of total sleep time with SaO2 < or = 85% (DST 85) and SaO2 < or = 90% (DST 90) were calculated for each subject. NOD was defined as DST 85 > or = 1%. Arterial oxygen partial pressure (PaO2) while awake was > or = 60 Torr in all subjects. No difference was observed in mean awake PaO2 values between the TB-sequela and COPD groups. NOD was detected in 8 TB-sequela patients but in none of the COPD patients. Mean DST 85 and DST 90 values were significantly (p < 0.05) higher for the TB-sequela group than for the COPD group. Of 15 TB-sequela patients who were able to complete spirometry tests, 6 had NOD. All 6 of these patients had hypercapnia while awake (PaCO2 > or = 50 Torr) and reduced vital capacity (< or = 50% predicted). No difference was observed in mean DST 90 or DST 85 values between the TypeA and TypeB COPD subgroups. We conclude that NOD is common in patients with chronic stable respiratory disease treated with HOT despite daytime euoxia. TB-sequela patients with hypercapnia and restrictive ventilatory impairment are at high risk for NOD.

Aged↗
PubMed2000

[Postural effects on electromyographic activity of the transversus abdominis muscle].

During breathing at rest in humans, electromyographic activity of the expiratory muscles (EMGem), tidal volume (VT), and minute ventilation (V(I)) are higher when standing than when supine. EMGem is known to correlate with VT and V(I). It is not known whether increased EMGem when standing results directly from the change in posture or indirectly from postural changes in ventilatory pattern. Moving average electromyographic activity of the transversus abdominis (EMGta) was recorded using a pair of fine wire electrodes during carbon dioxide (CO2) rebreathing both while standing and while supine. At matched end-tidal CO2 (ETCO2), VT, or V(I) values, EMGta was significantly higher when standing than when supine. Postural differences in EMGta had no correlation with increasing ETCO2, VT, or V(I) during CO2 rebreathing. These results suggested that both the direct effect of the postural change and an indirect effect through changes in ventilatory pattern contribute to the increased EMGem observed when standing compared to that when supine.

Abdominal Muscles↗
PubMed1999

A novel apoptotic cascade mediated by CDK4 in rat pheochromocytoma PC12 cells.

Apoptosis induced by serum withdrawal in pheochromocytoma PC12 cells is promoted by overexpression of cyclin-dependent kinase 4 (CDK4). We compared CDK4-promoted apoptosis with that induced by serum withdrawal alone in PC12 cells. Protein synthesis inhibitors did not prevent apoptosis in parental cells, but prevented the promotion of apoptosis by CDK4 overexpression. Nerve growth factor, basic-fibroblast growth factor, and Bcl-2 proteins protected both parental and CDK4-overexpressing cells from apoptosis. However, insulin-like growth factor-I and Bcl-X(L) protein only partially inhibited apoptosis in the CDK4-overexpressing cells. Bcl-2 or Bcl-X(L) had no significant effect on CDK4 kinase activity in both cell lines. These results suggest a novel CDK4-mediated apoptotic cascade which is normally restrained, but which is activated by CDK4 overexpression. This apoptotic cascade should eventually converge with the cascade induced by serum withdrawal in normal PC12 cells. We discuss the interactions among these apoptotic cascades and the points where anti-apoptotic agents act.

Animals↗
PubMed1999

Tumor extension and cell proliferation in adenocarcinomas of the lung.

To elucidate the mechanism of tumor extension in human pulmonary adenocarcinoma, we immunohistochemically investigated the expression of cell cycle regulator proteins in 54 small adenocarcinomas less than 3 cm in diameter. The Ki-67-labeling index was significantly higher in the periphery of the tumor nodule than in the center. This proliferative potential correlated well with coexpression of cdk2 and cyclin A. p27, one of the cdk inhibitors, was highly expressed in normal bronchial epithelial cells. Peripherally located tumor cells expressed p27 at an intermediate level, but at a higher frequency and level than those in the center. Expression of p21 was also predominant in the periphery. Furthermore, the expression patterns of p21 and p27 were reciprocal. In vitro kinase assays further demonstrated higher cdk2 kinase activity in the periphery. These results suggest that: (i) within an emerging extension made up of peripherally located tumor cells, their high proliferative potential gradually wanes as their relative topographical position becomes more central in the expanding tumor; (ii) peripherally located tumor cells maintain their proliferative potential by higher cyclin A-cdk2 complex activity; and (iii) intermediate expression of p21/p27 in the peripherally located cells promotes higher cyclin A-cdk2 kinase activity, whereas high p21/p27 expression in nonneoplastic cells inhibits kinase activity.

Adenocarcinoma↗