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M Sugiyama

Publications and source records attributed to M Sugiyama.

At least 19 recordsLinked to original sources
PubMed2001

A novel non-viral gene transfer system, polycation liposomes.

To develop a novel non-viral gene transfer system, liposome was modified with cetylated polyethylenimine (PEI). This polycation liposome (PCL) showed remarkable transfection efficiency to COS-1 cells in vitro, in comparison with conventional cationic liposome preparations. Cytotoxicity against COS-1 cells and hemolytic activity of PCL or PCL-DNA complex were quite low in comparison with conventional cationic liposomes. Most conventional cationic liposomes require phosphatidylethanolamine or cholesterol as a component, though PCL did not. Egg yolk phosphatidylcholine- and dipalmitoylphosphatidylcholine-based PCL were as effective as dioleoylphosphatidylethanolamine-based PCL for gene transfer. Furthermore, the transfection efficacy of PCL was enhanced, instead of being diminished, in the presence of serum. Effective gene transfer was observed in all eight malignant and two normal line cells tested as well as in COS-1 cells. The effect of the molecular weight of PEI on PCL-mediated gene transfer was examined, and observed that PEIs with a molecular weight (Mr. Wt.) of 600 and 1800 Da were quite effective but PEI of 25,000 was far less effective. Effectiveness of gene transfer by using PCL was also observed in vivo: GFP and Luciferase genes were effectively expressed in mouse. We also discussed the mechanism of gene transfer by PCL. Taken together, PCL represents a new system useful for transfection and gene therapy.

Animals↗
PubMed2001

Possible contribution of CD44 variant 6 and nuclear beta-catenin expression to the formation of budding tumor cells in patients with T1 colorectal carcinoma.

BACKGROUND: In an earlier study, the authors demonstrated that tumor budding was useful for predicting lymph node metastasis in patients with early invasive (T1) colorectal carcinoma. This study was undertaken to clarify the associations between tumor budding, E-cadherin-catenin complex, and CD44 variant 6 abnormalities. METHODS: In 51 T1 colorectal carcinomas, tumor budding (the number of dedifferentiation units at the invasive margin) on hematoxylin and eosin-stained slides was counted under light microscopy. Immunostaining for E-cadherin, alpha-catenin, beta-catenin, and CD44 variant 6 was performed on formalin fixed, paraffin embedded sections. The associations between locoregional failure (lymph node metastasis or local recurrence) and tumor budding and clinicopathologic parameters and immunoreactivity were examined statistically. RESULTS: In univariate analysis, tumor budding and nuclear beta-catenin expression were associated significantly with locoregional failure (P = 0.004, 0.01). Multivariate analysis showed that tumor budding alone was associated significantly with locoregional failure (P = 0.02), and the association between nuclear beta-catenin expression and locoregional failure was marginally significant (P = 0.07). Analysis of variance showed that lymphatic invasion alone was associated significantly with tumor budding (P = 0.02), and there was a significant interaction effect for tumor budding between CD44 variant 6 expression and nuclear beta-catenin expression (P = 0.01). There was a significant correlation between expression patterns of these two molecules and locoregional failure (P = 0.01). CONCLUSIONS: The current results suggest that the up-regulation of CD44 variant 6 through nuclear beta-catenin activation may contribute to the formation of tumor budding, and immunostaining of these two adhesion molecules may be useful in identifying those at high-risk for locoregional failure among patients with T1 colorectal carcinoma.

Adult↗
PubMed2001

Heterogeneous transforming growth factor (TGF)-beta unresponsiveness and loss of TGF-beta receptor type II expression caused by histone deacetylation in lung cancer cell lines.

Transforming growth factor (TGF)-beta strongly inhibits epithelial cell proliferation. Alterations of TGF-beta signaling are thought to play a role in tumorigenesis. We show in the present study that most lung cancer cell lines have lost the growth-inhibitory response to TGF-beta signal, and that those with TGF-beta unresponsiveness can be divided into two major groups, TGF-beta type II receptor (TGFbetaRII)(+)/Smad7(+) and TGFbetaRII(-)/Smad7(-), suggesting the heterogeneous mechanisms underlying the TGF-beta responsiveness. The mechanism of the loss of TGFbetaRII expression of the latter group was further studied, identifying aberrant DNA methylation of the promoter region in a limited fraction of cell lines. Interestingly, we found that the alteration of chromatin structure because of histone deacetylation may also be involved, showing a good correlation with loss of TGFbetaRII expression. This notion was supported by the findings of a restriction enzyme accessibility assay, of a chromatin immunoprecipitation assay with anti-acetyl histone antibodies, and of an in vivo induction of TGFbetaRII expression by histone deacetylase inhibitors including trichostatin A (TSA) and sodium butyrate. In vitro induction of TGFbetaRII promoter reporter activity by TSA was also detected and found to require the CCAAT box within the -127/-75 region. A positive regulatory mechanism for TGFbetaRII expression in a TGF-beta-expressing cell line was also investigated, and a TPA-responsive element (TRE)-like motif, TRE2, was detected in addition to the previously reported TRE-like motif Y element in the positive regulatory region. Alterations in two discrete proteins interacting with these two TRE-like motifs were also suspected of being involved in the loss of TGFbetaRII expression. This is the first study to demonstrate that, in addition to the TSA-responsive region and TRE2 motif in the TGFbetaRII promoter, the alteration of histone deacetylation may be involved in the loss of TGFbetaRII expression in lung cancer cell lines.

Acylation↗
PubMed2001

Avian-to-mammal transmission of an avian rotavirus: analysis of its pathogenicity in a heterologous mouse model.

It has been suggested that group A avian rotaviruses can be transmitted to mammals, but there is no direct evidence that such viruses induce disease in mammals. Suckling mice were orally inoculated with two avian rotaviruses. A pigeon rotavirus, PO-13, was found to induce diarrhea, but a turkey rotavirus, Ty-3, did not. The diarrhea induced by PO-13 was dependent on the age of the mouse. In histopathological examinations, antigens of PO-13 were sporadically detected in absorptive cells in the ileum, and lesions were observed as ballooning degenerations of absorptive cells in a region from the duodenum to the ileum. However, the rotavirus antigen was not detected in the majority of these degenerative cells. These results indicated that PO-13 could infect and induce diarrhea in suckling mice. This is the first evidence of an avian rotavirus being experimentally transmissible to a mammal.

Animals↗
PubMed2001

Matrilysin (MMP-7) as a significant determinant of malignant potential of early invasive colorectal carcinomas.

Matrix metalloproteinases play a crucial role in tumour invasion and metastasis. Matrilysin (MMP-7) has been shown to correlate with nodal or distant metastasis in colorectal carcinomas; however, its implication in early invasive colorectal carcinomas has not been determined. This study was undertaken to clarify the association of matrilysin expression with clinicopathologic parameters in early invasive colorectal carcinomas. 38 early invasive colorectal carcinomas treated by local excision or radical surgery were examined. Tumour budding was evaluated as the number of dedifferentiation units along the entire invasive margin. Matrilysin protein levels were determined using immunohistochemical study. Univariate analysis showed that matrilysin expression alone was significantly associated with distant metastasis (P = 0.0339), and both tumour budding and matrilysin expression were significantly associated with adverse outcome (P = 0.0005, 0.0341). Histological differentiation, vessel invasion, and depth of invasion were not significantly associated with either distant metastasis or adverse outcome. Multivariate analysis confirmed that tumour budding and matrilysin expression were independently associated with adverse outcome, although the significance of matrilysin expression was marginal (P = 0.0488). Tumour budding at the invasive margin and matrilysin expression are more useful in identifying high-risk groups for adverse outcome in patients with early invasive colorectal carcinomas.

Aged↗
PubMed2001

Detection of dichromate (VI)-induced DNA strand breaks and formation of paramagnetic chromium in multiple mouse organs.

DNA single-strand breaks (and/or alkali-labile sites) induced by Cr(VI) were evaluated with the alkaline single cell gel electrophoresis (SCG) (Comet) assay in five organs (liver, kidney, spleen, lung, and brain) of male mice dosed with K(2)Cr(2)O(7) (20 mg Cr/kg) by a single ip injection in vivo, and the formation of paramagnetic Cr(V) in these organs was investigated by electron spin resonance (ESR) spectrometry. Furthermore, the in vivo effects of deferoxamine (DFO), an iron chelator, and dimethylthiourea (DMTU), a hydroxyl radical scavenger, on the formation of Cr(V) and DNA strand breaks induced by the metal in the liver and kidney were examined. SCG assay detected DNA strand breaks were detected in the liver and kidney at 15 min and showed that they were being repaired at 3 h after Cr(VI) injection. The ESR spectra of paramagnetic Cr(V) were also observed in the liver and kidney for 15 min to 24 h after Cr(VI) injection. In contrast, there were no significant levels of DNA strand breaks and Cr(V) in the spleen, lung, or brain. The pretreatment of mice with DFO reduced the formation of Cr(VI)-induced DNA strand breaks and Cr(V) complexes as well as the total contents of Cr in the liver and kidney at 15 min after the metal injection. In the case of the pretreatment with DMTU, DNA strand breaks induced by Cr(VI) were suppressed in the liver and kidney at 15 min, without any influence on the levels of Cr(V) complexes and total Cr contents in the organs. The in vitro study showed that DFO decreased the levels of Cr(V)-GSH complexes and Cr(V)-mediated hydroxyl radicals, while DMTU reduced only the levels of Cr(V)-mediated hydroxyl radicals without affecting the formation of Cr(V)-GSH complexes. These results demonstrated that the SCG assay may be useful for detecting DNA strand breaks and/or alkali-labile sites caused by Cr(VI) in vivo. The results also indicated that the in vivo formation of hydroxyl radicals during the reduction of Cr(VI) may play an important role in the induction of the DNA strand breaks caused by this metal and implied that the levels of Cr(V) inside the cells may not always be related to the induction of DNA strand breaks.

Animals↗
PubMed2001

Electrocardiographic criteria for predicting total occlusion of the proximal left anterior descending coronary artery in anterior wall acute myocardial infarction.

BACKGROUND: Patients with occlusion of the left anterior descending coronary artery (LAD) proximal to both the first septal branch and the first diagonal branch may benefit most from early reperfusion therapy due to extensive area at risk. HYPOTHESIS: The aim of the study was to examine whether 12-lead electrocardiograms (ECGs) in the acute phase of acute myocardial infarction (AMI) could identify total occlusion of the LAD proximal to both the first septal and the first diagonal branch. METHODS: A 12-lead electrocardiogram was recorded on admission in 128 patients with anterior AMI within 12 h from symptom onset. Patients were divided into three groups according to the culprit lesion: 33 patients had total occlusion of the LAD proximal to both the first septal perforator and the first diagonal branch (Group P), in 51 it was proximal to either the first septal perforator or the first diagonal branch (Group D-a), and in 44 it was distal to both the first septal perforator and the first diagonal branch (Group D-b). RESULTS: Sensitivity and specificity of a greater degree of ST-segment depression in lead III than that of ST-segment elevation in lead aVL were 85 and 95%, respectively, which was better than the results derived by all other ECG criteria (p< 0.001). CONCLUSIONS: We conclude that a greater degree of ST-segment depression in lead III than that of ST-segment elevation in lead aVL is a useful predictor of proximal LAD occlusion in patients with anterior AMI.

Adult↗
PubMed2001

Implications of the absence of ST-segment elevation in lead V4R in patients who have inferior wall acute myocardial infarction with right ventricular involvement.

BACKGROUND: ST-segment elevation of > or = 1.0 mm in lead V4R has been shown to be a reliable marker of right ventricular involvement (RVI), a strong predictor of a poor outcome in patients with inferior acute myocardial infarction (IMI). However, patients with no ST-segment elevation in lead V4R despite the presence of RVI have received little attention. HYPOTHESIS: The study was undertaken to study the clinical features of patients with no ST-segment elevation in lead V4R despite the presence of RVI, which means false negative, as such patients have received little attention in the past. METHODS: We studied 62 patients with a first IMI, who had total occlusion of the right coronary artery (RCA) proximal to the first right ventricular branch and successful reperfusion within 6 h from symptom onset, to examine the implications of the absence of ST-segment elevation in lead V4R despite the presence of RVI. RESULTS: A standard 12-lead electrocardiogram (ECG) and right precordial ECG (lead V4R) were recorded on admission, and three posterior chest ECGs (leads V7 to V9) were additionally recorded in 34 patients. Patients were classified according to the absence (Group 1, n = 18) or presence (Group 2, n = 44) of ST-segment elevation of > or = 1.0 mm in lead V4R on admission. Patients in Group 1 had a greater ST-segment elevation in leads V7 to V9 (2.9+/-2.4 vs. 1.4+/-3.0 mm. p < 0.05), a higher frequency of a dominant RCA (defined as the distribution score > or = 0.7) (72 vs. 11%, p < 0.001), and a higher peak creatine kinase level (3760+/-1548 vs. 2809+/-1824 mU/ml, p < 0.05) than those in Group 2. CONCLUSIONS: In patients with IMI caused by the occlusion of the RCA proximal to the first right ventricular branch, no ST-segment elevation in lead V4R can occur because of concomitant posterior involvement. In such patients, the incidence of RVI may be underestimated on the basis of ST-segment elevation in lead V4R.

Aged↗
PubMed2001

Groin hernias in adults: value of color Doppler sonography in their classification.

PURPOSE: We assessed the abilities of color Doppler and power Doppler sonography to distinguish among types of groin hernias by demonstrating the inferior epigastric artery (IEA) and its relationship with the hernia sac. METHODS: Nineteen consecutive patients (14 men and 5 women), clinically diagnosed as having groin hernias and scheduled to undergo herniorrhaphy, were prospectively enrolled in this study. Ultrasound examinations were performed preoperatively with a 6-12-MHz linear-array transducer. The IEA was identified, if possible, and its relationship to the hernia sac assessed. The sonographic diagnoses were compared with the operative findings. RESULTS: There were 15 indirect inguinal hernias, 4 direct inguinal hernias, and 1 femoral hernia; 1 patient had bilateral inguinal hernias (indirect and direct). In 18 (90%) of 20 hernia cases, the trunk segment of the IEA could be visualized. In 11 (55%) of 20 hernia cases, the origin segment of the IEA could be visualized and its relationship with the hernia sac assessed. In 9 (82%) of the 11 hernia cases, hernia types were correctly diagnosed by sonography. The overall accuracy of sonography for diagnosing the type of hernia was 45% (9 of 20 hernias). CONCLUSIONS: Color Doppler sonography can accurately differentiate types of groin hernias if the origin segment of the IEA and the hernia sac can be visualized simultaneously. However, color Doppler sonography sometimes failed to visualize this segment.

Adult↗
PubMed2001

Involvement of local intercellular communication in the differentiation of zinnia mesophyll cells into tracheary elements.

The transdifferentiation of isolated mesophyll cells of zinnia (Zinnia elegans L.) into tracheary elements (TEs) has been well studied as a model of plant cell differentiation. In order to investigate intercellular communication in this phenomenon, two types of culture method were developed, in which mesophyll cells were embedded in a thin sheet of agarose gel and cultured on solid medium, or embedded in microbeads of agarose gel and cultured in liquid medium. A statistical analysis of the two-dimensional distribution of TEs in the thin-sheet cultures demonstrated their aggregation. In the microbead cultures, the frequency of TE differentiation was shown to depend on the local cell density (the cell density in each microbead): TE differentiation required local cell densities of more than 10(5) cells ml(-1). These results suggest that TE differentiation involves cell-cell communication mediated by a locally acting diffusible factor. This presumptive factor was characterized by applying a modified version of the sheet culture, which used two sheets of different cell densities, a low-density sheet and a high-density sheet. Differentiation of TEs in the former could be induced only by bringing it into contact with the latter. Insertion of a 25-kDa-cutoff membrane between the high-density and low-density sheets severely suppressed such induction of TEs in the low-density sheet while a 300-kDa-cutoff membrane suppressed induction only slightly. Insertion of agarose sheets containing immobilized pronase E or trypsin also interfered with the induction of TEs in the low-density sheets. Thus, a proteinaceous macromolecule of 25-300 kDa in molecular weight was assumed to mediate the local intercellular communication required for TE differentiation. This substance was designated "xylogen" with reference to its xylogenic activity. The time of requirement for xylogen during TE differentiation was assessed by experiments in which cells in the low-density sheet were separated from xylogen produced in the high-density sheet at various times by insertion of a 25-kDa-cutoff membrane between the two sheets, and was estimated to be from the 36th hour to the 60th hour of culture (12-36 h before visible thickening of secondary cell walls of TEs).

Asteraceae↗
PubMed2001

The indication of local excision for T2 rectal carcinomas.

BACKGROUND: Several researchers reported that local excision with or without postoperative chemo-radiation therapy is an alternative approach for sphincter preservation in patients with locally invasive rectal carcinoma. However, indications and long-term results have not yet been determined. METHODS: Seventy-two patients with T2 colorectal carcinomas underwent bowel resection with regional lymph node dissection. The associations between lymph node metastasis (LNM) and clinicopathologic factors were examined with special reference to the presence or absence of moderate to severe degree of focal dedifferentiation or mucinous component at the invasive margin (unfavorable histology). RESULTS: Multivariate logistic regression analysis revealed that both sex and unfavorable histology were significantly associated with LNM (P = 0.0102, 0.0226, respectively). However, the associations between LNM and lymphatic invasion or tumor location were not statistically significant (P = 0.0947, 0.1738). CONCLUSIONS: When locally resected T2 rectal carcinoma specimens have unfavorable histology at the invasive margin, additional bowel resection with lymph node dissection should be recommended.

Colorectal Neoplasms↗
PubMed2001

Prognostic significance of carcinoembryonic antigen levels in peritoneal washes in patients with gastric cancer.

BACKGROUND: Peritoneal metastasis is the most frequent cause of death in patients with gastric cancer. Detection of free cancer cells in the peritoneal cavity at the time of surgery, therefore, is considered to be of great value in predicting the peritoneal recurrence and accordingly in the prognosis in patients with gastric cancer. This study examined the clinical significance of intraoperative determination of carcinoembryonic antigen (CEA) levels in peritoneal washes (pCEA) in patients with gastric cancer. METHODS: CEA levels in peritoneal washes were correlated retrospectively with several clinicopathologic factors including clinical outcome in 56 patients with resectable gastric cancer. RESULTS: Among several clinicopathologic factors, the depth of tumor invasion significantly and independently correlated with pCEA levels as revealed by multivariate stepwise logistic regression analysis. A significant difference in overall survival rates was observed between pCEA-positive and pCEA-negative groups: 5-year survival rates were 95.7% in pCEA-negative and 20% in pCEA-positive patients (P <0.0001). Multivariate analysis indicated that pCEA level is a statistically significant independent prognostic factor for the survival of patients with gastric cancer, and is an important factor for predicting peritoneal recurrence. CONCLUSIONS: pCEA could be a potential predictor of a poor prognosis as well as peritoneal recurrence in patients with gastric cancer. We believe that this information could contribute to determining the optimal intraoperative and postoperative therapeutic plan including adjuvant chemotherapy of gastric cancer.

Adult↗
PubMed2001

Pancreatic transection using ultrasonic dissector in pancreatoduodenectomy.

BACKGROUND: Pancreatoenterostomic leakage after pancreatoduodenectomy may be caused partly by pancreatic juice leakage from transected branch pancreatic ducts on the pancreatic cut surface that do not drain into the main pancreatic duct after pancreatectomy. METHODS: We devised a new technique of pancreatic transection using an ultrasonic dissector followed by duct-to-mucosa pancreatojejunostomy, in order to prevent pancreatoenterostomic leakage after pancreatoduodenectomy in patients with a soft pancreas and a small main pancreatic duct. During pancreatic transection, branch pancreatic ducts and blood vessels are adequately skeletonized and securely ligated. The pancreatic duct is anastomosed to the full thickness of the jejunum with four to six interrupted sutures. RESULTS: Ten patients with a nondilated pancreatic duct (2 to 3 mm) underwent pancreatoduodenectomy by the present method. During pancreatic transection, 24 to 35 ducts including the pancreatic ducts and blood vessels were skeletonized and ligated. Postoperatively, no patients developed pancreatojejunostomic leakage. The present method may prevent pancreatoenterostomic leakage after pancreatoduodenectomy.

Anastomosis, Surgical↗
PubMed2001

Biomechanical behaviour of bovine temporomandibular articular discs with age.

The purpose was to evaluate age-associated changes in the creep and restoration properties of bovine temporomandibular joint (TMJ) discs under and after sustained tensile stress. Forty discs were obtained from 7- and 10-year-old cattle, referred to as the adult and mature adult groups, respectively. Tension of 1.0 MPa was applied and sustained for 20 min to specimens from ten right discs and of 1.5 MPa to specimens from ten left discs. After the period of tension for the study of creep, the specimens were removed from the tension devices and their restoration observed for 20 min. For comparative purposes the relevant results for a young adult group were recruited from data on 3-year-old bovine TMJ discs reported in a previous study on viscoelastic properties. In all the specimens the time-dependent creep curves showed a marked change in strain during the initial 5 s, but the elastic moduli at the onset of stress were significantly larger in the mature adult group than in the other groups. After 20-min creep, the strains were decreased in relation to the age of the specimen and were significantly smaller in the mature adult than in the young adult. With regard to regional differences, the medial specimens exhibited significantly smaller strains than the central ones in all three age groups. Furthermore, the residual strains after 20-min restoration also decreased slightly with age. It is concluded that the bovine TMJ disc becomes stiff and acquires the capacity to recover from continuous deformation during growth and maturation. These findings suggest that the TMJ disc can modify its viscoelasticity in order to withstand extrinsic functional stresses.

Aging↗
PubMed2001

Single vaginal ectopic ureter and renal hypoplasia associated with urogenital sinus and abdominal muscular hypoplasia-a novel subtype of prune-belly syndrome in a female child?

We report a rare case that can be classified as prune-belly syndrome in a female. This patient came to our attention during the 19th week of gestation when massive ascites was found by ultrasound and the mother was transferred to our hospital. After birth, it was demonstrated that the infant had complicated anomalies, including abdominal muscular hypoplasia, urogenital sinus, a single, right-sided vaginal ectopic ureter, and hypoplasia of the right kidney. A sibling had a right hypoplastic kidney and right vesicoureteral reflux. Considering the combination of anomalies and the family history of urinary tract disease, her anomalies could be attributed to a genetic mutation.

Choristoma↗
PubMed2001

Complete nucleotide sequence of a group A avian rotavirus genome and a comparison with its counterparts of mammalian rotaviruses.

The nucleotide sequences encoding four structural proteins (VP1-4) and six nonstructural proteins (NSP1-6) of avian rotavirus PO-13 were determined. Based on the results of earlier sequencing studies [Ito et al., 1995, Sequence analysis of cDNA for the VP6 protein of group A avian rota viruses. Arch. Vriol. 140, 605-612; Rohwedder et al., 1997, Chicken rotavirus Ch-1 shows a second type of avian VP6 gene, Virus Genes 15, 65-71; Rohwedder et al., 1997, Bovine rotavirus 993/83 shows a third subtype of avian VP7 protein, Virus Genes 14, 147-151], determination of PO-13 genome sequence has been completed. The PO-13 genome is 18845 nucleotides in length. It is 290 nucleotides longer than the genome of SA11. The amino acid sequence homology between PO-13 and mammalian rotaviruses ranged from 76-77% (VP1) to 16-18% (NSP1). The features of gene and amino acid sequence were compared with those of the corresponding protein of mammalian rotaviruses. Based on results of the phylogenetic analyses of NSP1, we speculate that an ancestral rotavirus could have separated into groups A, B and C rotaviruses at an early evolutionary stage and that group A rotavirus separated into mammalian and avian rotaviruses with host evolution.

Amino Acid Sequence↗
PubMed2001

Properties of incremental projection learning.

We proposed a method of incremental projection learning which provides exactly the same generalization capability as that obtained by batch projection learning in the previous paper. However, properties of the method have not yet been investigated. In this paper, we analyze its properties from the following aspects: First, it is shown that some of the training data which is regarded as redundant in most incremental learning methods have potential effectiveness, i.e. they will contribute to better generalization capability in the future learning process. Based on this fact, an improved criterion for redundancy of additional training data is derived. Second, the relationship between prior and posterior learning results is investigated where effective training data is classified into two categories from the viewpoint of improving generalization capability. Finally, a simpler representation of incremental projection learning under certain conditions is given. The size of memory required for storing prior results in the representation is fixed and independent of the total number of training data.

Learning↗