Biomedical subjects

S Tsutsumi

Publications and source records attributed to S Tsutsumi.

At least 37 records · Page 2Linked to original sources

PubMed2001

Propofol activates vanilloid receptor channels expressed in human embryonic kidney 293 cells.

Propofol (2,6-diisopropylphenol) is an intravenous anesthetic agent structurally unrelated to any other intravenous anesthetics. We examined the effect of propofol on a rat vanilloid receptor that was expressed in the human embryonic kidney (HEK) 293 cells by using calcium imaging method. Propofol caused a concentration-dependent increase in [Ca(2+)](i) in the HEK293 cells with the receptor. These responses were inhibited by removing extracellular calcium ions. The propofol-evoked increase in [Ca(2+)](i) in the HEK293 cells with the receptor was partially inhibited by capsazepine, a competitive antagonist of capsaicin. We conclude that propofol acts as an agonist for the receptor.

Anesthetics, Intravenous↗

PubMed2001

Animal model of para-aortic lymph node metastasis.

The purpose of this study was to establish a model of experimental lymph node metastasis by intra-rectal implantation of human cancer cells in nude mice. Four types of human cancer cell lines (TE-1, MKN-45, HT-29, and MIAPaca-2) were investigated. Tumor cells suspended in Matrigel were injected into the submucosal layer of the rectum. All cancer cell lines produced locally aggressive rectal tumors and, subsequently, para-aortic lymph node metastasis. We were unable to produce other distant metastases in the dying state in such locations as the liver, spleen, lung, and peritoneum. However, using this method, we were able to evaluate the effect of the anti-cancer agent uracil/tegafur (UFT) on primary tumor growth and lymph node metastasis. Oral intake of UFT significantly suppressed implanted tumor volume and inhibited lymph node metastasis. We expect that the process of lymph node metastasis shown in this model will be studied as an experimental model of lymph node metastasis simulating human cancers.

Adenocarcinoma↗

PubMed2001

Significance of contracted cholecystitis lesions as high risk for gallbladder carcinogenesis.

A precancerous change has been identified incidentally in resected specimens from patients who have undergone cholecystectomy. We focused on chronic cholecystitis, showing a thick and sclerotic wall caused by recurrent inflammation, e.g. contracted cholecystitis, and examined the malignant potential of these lesions. We studied 88 patients who had undergone cholecystectomy. Contracted cholecystitis was diagnosed, using our criteria, in 28 of these cases. Ordinary chronic cholecystitis was diagnosed in 50 cases and gallbladder carcinoma in ten cases. We examined the expression of p53, Ki-67, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) immunohistochemically. Severe dysplasia or carcinoma in situ in a very small portion of the specimen was identified with hematoxylin-eosin staining in four cases (14.3%) of contracted cholecystitis. These specimens revealed a positive expression of not only p53, but also Ki-67, iNOS, and COX-2. Statistical significance was shown among the three disease groups in terms of the incidence of p53 overexpression, respectively (P<0.05). The results of this study suggest that contracted cholecystitis could be an early change leading to carcinogenesis.

Cholecystitis↗

PubMed2001

Direct inhibition of Indian hedgehog expression by parathyroid hormone (PTH)/PTH-related peptide and up-regulation by retinoic acid in growth plate chondrocyte cultures.

Indian hedgehog (Ihh) is highly expressed in prehypertrophic chondrocytes in vivo and has been proposed to regulate the proliferation and maturation of chondrocytes and bone collar formation in the growth plate. In high-density cultures of rabbit growth-plate chondrocytes, Ihh mRNA was also expressed at the highest level in the prehypertrophic stage. To explore endogenous factors that regulate Ihh expression in chondrocytes, we examined the effects of various growth factors on Ihh mRNA expression in this system. Retinoic acid (RA) and bone morphogenetic protein-2 enhanced Ihh mRNA expression, whereas PTH/PTH-related peptide (PTHrP) markedly suppressed Ihh expression. RA at more than 10(-8) M induced the expression of Ihh and Patched 1 (Ptc1) within 3 h, before it increased the type X collagen mRNA level at 6-24 h. Cycloheximide blocked the up-regulation of Ihh by RA, indicating the requirement of de novo protein synthesis for this stimulation. These findings suggest that RA is involved in the up-regulation of Ihh during endochondral bone formation. In contrast to RA, PTH (1-84) at 10(-7) M abolished the mRNA expression of Ihh and Ptc1 within 2-4 h, before it suppressed the expression of type X collagen at 12-24 h. The inhibition of Ihh expression by PTH (1-84) did not require de novo protein synthesis. PTH (1-34), PTHrP (1-34), and (Bu)(2)cAMP also suppressed Ihh expression. On the other hand, Ihh has been reported to induce PTHrP synthesis in the perichondrium. Consequently, the direct inhibitory action of PTH/PTHrP on Ihh appears to be a negative feedback mechanism that prevents excess PTHrP accumulation in cartilage.

Animals↗

PubMed2001

Differential gene expression profiles of scirrhous gastric cancer cells with high metastatic potential to peritoneum or lymph nodes.

Scirrhous gastric cancer is often accompanied by metastasis to the peritoneum and/or lymph nodes, resulting in the highest mortality rate among gastric cancers. Mechanisms involved in gastric cancer metastasis are not fully clarified because metastasis involves multiple steps and requires the accumulation of altered expression of many different genes. Thus, independent analysis of any single gene would be insufficient to understand all of the aspects of gastric cancer metastasis. In this study, we performed global analysis on differential gene expression of a scirrhous gastric cancer cell line (OCUM-2M) and its derivative sublines with high potential for metastasis to the peritoneal cavity (OCUM-2MD3) and lymph nodes (OCUM-2MLN) in a nude mice model. By applying a high-density oligonucleotide array method, expression of approximately 6800 genes was analyzed, and selected genes were confirmed by the Northern blot method. In our observations in OCUM-2MD3 cells, 12 genes were up-regulated, and 20 genes were down-regulated. In OCUM-2MLN cells, five genes were up-regulated, and five genes were down-regulated. The analysis revealed two functional gene clusters with altered expression: (a) down-regulation of a cluster of squamous cell differentiation marker genes such as small proline-rich proteins [SPRRs (SPRR1A, SPRR1B, and SPRR2A], annexin A1, epithelial membrane protein 1, cellular retinoic acid-binding protein 2, and mesothelin in OCUM-2MD3 cells; and (b) up-regulation of a cluster of antigen-presenting genes such as MHC class II (DP, DR, and DM) and invariant chain (II) in OCUM-2MLN cells through up-regulation of CIITA (MHC class II transactivator). We then analyzed six gastric cancer cell lines by Northern blot and observed preferential up-regulation of trefoil factor 1, alpha-1-antitrypsin, and galectin 4 and down-regulation of cytidine deaminase in cells prone to peritoneal dissemination. Genes highly correlated with invasion or peritoneal dissemination of gastric cancer, such as E-cadherin or integrin beta4, were down-regulated in both of the derivative cell lines analyzed in this study. This is the first demonstration of global gene expression analysis of gastric cancer cells with different metastatic potentials, and these results provide a new insight in the study of human gastric cancer metastasis.

Adenocarcinoma, Scirrhous↗

PubMed2001

Morphologic study and syntheses of type I collagen and fibronectin of human periodontal ligament cells cultured on poly(ethylene-co-vinyl alcohol) (EVA) with collagen immobilization.

The purpose of this study was to regenerate the human periodontal ligament (PDL) around dental implants by using a hybrid structure of cells with materials, such as PDL cells + collagen + poly(ethylene-co-vinyl alcohol) (EVA) on titanium implant. Human PDL cells were cultured on the EVA surface coated with type I collagen and the cell adhesion and extension were investigated. Furthermore, collagen type I and fibronectin syntheses were analyzed. The serum free culture was also tried, to investigate the role of collagen in detail. The results showed that: 1. Satisfactory adhesion, extension, and proliferation of the PDL cells on the EVA films coated with collagen were observed, but were not good without collagen. 2. Immunostaining of cultured PDL cells revealed the syntheses of type I collagen, when cultured on the EVA coated with collagen or conventional culture dish, though fibronectin synthesis was observed even in the EVA without collagen. 3. Only PDL cells on the EVA coated with collagen proliferated well in the absence of serum. These results indicate that our novel implant material (EVA coated with collagen) provides a possibility of PDL regeneration on dental implants.

Cell Culture Techniques↗

PubMed2001

Reconstruction of breast using a laser lithographic model: a case report.

A three-dimensional laser scanner enables the measurement of surface data from objects with no contact, both quickly and in three dimensions. A 40-year-old woman with a right breast cancer had undergone a simple mastectomy. The surface of the chest was then measured with the non-contact three-dimensional laser scanner. Using the mirror image of data obtained by the same system, a mask-like model of the breast was made using laser lithography technology. This model was used for reconstruction of the breast after mastectomy. It was effective in determining the position and form of the breast which was to be repaired.

Adult↗

PubMed2001

Experimental analysis of a new flexible neck model for low-speed rear-end collisions.

Whiplash injuries occur frequently in rear-end automobile accidents even at low-speed. The hybrid III dummy has been used for various tests in order to investigate the mechanism of whiplash injuries. However, since this dummy neck is too rigid for low-speed collisions, we developed a new flexible neck model for low-speed rear-end collisions. Each component of this new flexible neck model is made of polymers with material properties close to those of the human body. Sled tests were conducted to measure the displacements of cervical vertebrae of the new flexible neck model at 11 km/h. The figures of s-shape and shear displacement in the plane of the intervertebral disks were observed, and it was recognized that shear displacement resulted from the inconsistency of motion between the head and neck. The regions of shear displacement agreed well with the statistics of the critical regions where whiplash injuries have frequently occurred. It is assumed that shear displacement is one of the causes of the mechanism of whiplash injuries.

Accidents, Traffic↗

PubMed2001

Calcium phosphate clusters.

The potential energy surfaces associated with [Ca3(PO4)2n clusters are analyzed in detail using ab initio calculations for n ranging from one to four. Considering separated clusters, energy criteria favor the so-called Posner's cluster Ca9(PO4)6, which is the core of the actual structural model of amorphous calcium phosphate. This is rationalized through the existence of a distinct CaO bonding pattern in this cluster. Considering aggregated clusters as a possible model for amorphous calcium phosphate, the aggregation of Ca3(PO4)2 clusters appears as an alternative to Posner's hypothesis.

Biocompatible Materials↗

PubMed2001

Clinical significance of soluble form of HLA class I molecule in Japanese patients with pancreatic cancer.

In recent studies a soluble form of human leukocyte antigen class I (sHLA-I) has been found in blood, urine, ascitic fluid, and various other tissues. Research has been focused on the role of sHLA-I in the induction of immunotolerance in organ transplantation. To examine the role of sHLA-I in the immune system of patients with malignancy, we examined serum sHLA-I levels in patients with pancreatic, biliary, hepatic malignancy, and other diseases. We examined sHLA-I levels in the sera of patients with pancreatic cancer (n = 19), benign biliary disease and chronic pancreatitis (n = 20), hepatocellular carcinoma (n = 51), gallbladder cancer (n = 6), cholangiocellular carcinoma (n = 6), and in normal controls (n = 22), using enzyme-linked immunosorbent assay (ELISA). In patients with pancreatic cancer we also analyzed the relationship between sHLA-I and CA19-9, and the specificity and sensitivity of sHLA-I. When patients with acute or chronic hepatitis were excluded from analysis, the mean sHLA-I level in patients with pancreatic cancer was significantly higher than that of normal controls (p < 0.01) and patients with benign disease (p < 0.01), hepatocellular carcinoma (p < 0.01), gallbladder cancer (p < 0.05), and cholangiocarcinoma (p < 0.05). We determined a serum sHLA-I cutoff level for normal controls of 2000 ng/ml; serum levels of sHLA-I were higher than the cutoff in ten patients with pancreatic cancer, and serum levels of CA19-9 were lower than 37 IU/l in 9 of 14 patients; sensitivity and specificity were 88.2% and 85.5%, respectively. Serum levels of sHLA-I in pancreatic cancer patients were higher than in the other diseases, although we found that pancreatic cancer cell lines did not produce the sHLA-I. The evaluation of serum sHLA-I levels could have clinical significance in pancreatic cancer.

Biomarkers↗

PubMed2001

A surgical simulation system of skin sutures using a three-dimensional finite element method.

OBJECTIVE: To establish a surgical simulation system of skin sutures using a three-dimensional finite element method. DESIGN: Three-dimensional finite element models were developed from point data obtained with a rapid three-dimensional surface-measuring device and postoperative profiles were evaluated using these models. BACKGROUND: Since suturing a wound may result in undesirable skin extrusion, it is important to make the extrusion as inconspicuous as possible. We have investigated a means of determining appropriate suture methods to decrease the extrusion. METHODS: Affected body parts were measured non-invasively with a rapid three-dimensional surface-measuring device. Finite element models were prepared, and an appropriate method for reducing skin extrusion was evaluated by attempting various suturing methods. RESULTS: Two kinds of finite element models were prepared: a conventional spindle model and a modified S-shape model. The height of the extrusion of the modified S-shape model was decreased by 40% in comparison with that of the spindle model. These results agreed with clinical findings. CONCLUSIONS: Due to this surgical simulation system of skin sutures, with a rapid three-dimensional surface-measuring device and three-dimensional finite element analysis, it was possible to design an appropriate suturing method and to evaluate the postoperative skin profiles. The modified S-shape suture method would be a recommendable method. RELEVANCE: Using this surgical simulation system of skin sutures, a surgeon can evaluate an appropriate suturing method before operation. It is expected that this system will reduce a surgeon's labor.

Computer Simulation↗

PubMed2001

Chondrocyte-derived ezrin-like domain containing protein (CDEP), a rho guanine nucleotide exchange factor, is inducible in chondrocytes by parathyroid hormone and cyclic AMP and has transforming activity in NIH3T3 cells.

OBJECTIVE: The purpose of this study is to investigate stage- and hormone-dependent expression of chondrocyte-derived ezrin-like domain containing protein (CDEP), a putative guanine nucleotide exchange factor (GEF) for Rho in chondrocytes, and demonstrate the guanine nucleotide exchange activity of this protein in vitro, as well as the transforming activity in NIH3T3 cells. METHODS: The expression of CDEP mRNA in growth plate chondrocytes in vivo and in vitro was examined by RT-PCR Southern analysis. The guanine nucleotide exchange activity was determined using a recombinant CDEP peptide containing the DH and PH domains in Sf9 cell lysates. The transforming activity was examined using NIH3T3 cells transiently transfected with a truncated CDEP cDNA. RESULTS: CDEP mRNA was expressed at the highest level in the hypertrophic (terminal) stage of chondrocytes in vivoand in vitro. Parathyroid hormone (PTH) elicited a biphasic increase of CDEP mRNA in chondrocytes. The CDEP mRNA level increased within 1 h, then decreased nearly to the control level at 3 h. Thereafter the mRNA level started to increase at 6 h, reaching a plateau at 24 h. Dibutyryl cyclic AMP had a similar effect on CDEP expression in chondrocytes. The dissociation of [3H]GDP from RhoA was stimulated dose-dependently by Sf9 cell lysates containing the CDEP peptide. Furthermore, transfection of a truncated CDEP cDNA induced focus formation in NIH3T3 cultures. CONCLUSIONS: CDEP is a novel GEF for Rho family GTPases with the transforming activity. CDEP may play a role in mediating or modulating the action of cAMP-elevating hormones on maturing chondrocytes.

Animals↗

PubMed2001

2'-O,4'-C-ethylene-bridged nucleic acids (ENA) with nuclease-resistance and high affinity for RNA.

Novel nucleosides, 2'-O,4'-C-ethylene nucleosides and their corresponding phosphoramidites, were synthesized as building blocks for antisense oligonucleotides. The 2'-O,4'-C-ethylene linkage of these nucleosides, as well as the linkage of 2'-O,4'-C-methylene nucleosides which are known as bridged nucleic acids (BNA) or locked nucleic acids (LNA), restricts the sugar puckering to the N-conformation. The ethylene-bridged nucleic acids (ENA) showed a high binding affinity for the complementary RNA strand (delta Tm = degrees C/modification) and were approximately 400 and 80 times more nuclease-resistant than natural DNA and BNA/LNA, respectively. These results indicate that ENA have better antisense activity than BNA/LNA.

Base Sequence↗

PubMed2001

Gene structure and chromosomal location of a human bHLH transcriptional factor DEC1 x Stra13 x SHARP-2/BHLHB2.

DEC1/BHLHB2 is a novel cAMP-inducible basic helix-loop-helix (bHLH) transcriptional factor isolated from human chondrocyte cultures by the subtraction method [Shen et al. (1997) Biochem. Biophys. Res. Commun. 236, 294--298]. DEC1 seems to be involved in controlling the proliferation/differentiation of some cell lineages. We determined the structure of the human DEC1 gene and its chromosomal locus. Phylogenetic analysis and comparison of the gene structure showed that the DEC1 protein is a member of a new subgroup of the proline bHLH protein family that diverged earlier than other proline bHLH proteins including HES, hairy and E(spl). The human DEC1 gene spans approximately 5.7 kb and contains 5 exons. The putative promoter region contains multiple GC boxes but no TATA box. A primer extension study showed multiple transcriptional initiation sites. In the 5'-flanking region of the DEC1 gene, several transcriptional factor binding sites, including a cAMP-responsive element (CRE), were found using the transcription factor database. The DEC1 gene locates at Chromosome 3p25.3--26 by the FISH method. This is the first study to determine the genomic structure of the DEC1 gene subgroup.

Amino Acid Sequence↗

PubMed2001

Phenotypic expression of colorectal adenocarcinomas with reference to tumor development and biological behavior.

The purpose of this study is to clarify the correlation between cell differentiation and tumor development, including tumor aggressiveness and biological behavior. Eighty-three cases of advanced colorectal adenocarcinoma were randomly selected. Using immunohistochemical staining with antibodies to CD10, MUC2 and human gastric mucin (HGM), the colorectal adenocarcinomas could be classified into five types (18 small intestinal, 27 large intestinal, 2 gastric, 9 mixed and 27 unclassified). Each type had characteristic features. The small-intestinal type showed a relatively lower incidence of lymphatic permeation and higher venous invasion. The large-intestinal type showed a low incidence of venous invasion and lymph node metastasis. The mixed type revealed female and right-side-dominant distribution, large tumor size, high incidence of mucinous carcinoma, and low incidence of venous invasion. Gastric type was seen in only two cases (2%), which exhibited high histologic grade, lymphatic permeation and lymph node metastasis with no venous invasion. Such phenotypic classifications are considered to be useful not only for evaluation of the biological behavior of the carcinoma, but also for analysis of tumorigenesis.

Adenocarcinoma↗

PubMed2001

NSAIDs induce both necrosis and apoptosis in guinea pig gastric mucosal cells in primary culture.

A major clinical problem encountered with the use of nonsteroidal anti-inflammatory drugs (NSAIDs) such as indomethacin is gastropathy. In this study, we examined, using guinea pig gastric mucosal cells in primary culture, how NSAIDs damage gastric mucosal cells. The short-term treatment of cells with high concentrations of indomethacin decreased cell viability in the absence of apoptotic DNA fragmentation, chromatin condensation, or caspase activation. Cells lost membrane integrity with this short-term indomethacin treatment, suggesting that indomethacin induced necrosis under these conditions. In contrast, the long-term treatment of cells with low concentrations of indomethacin decreased cell viability and was accompanied by apoptotic DNA fragmentation, chromatin condensation, and caspase activation. Pretreatment of cells with inhibitors of caspases or protein synthesis suppressed cell death caused by long-term indomethacin treatment, suggesting that apoptosis was induced when the inhibitors were not present. These results imply that NSAIDs cause gastric mucosal damage through both necrosis and apoptosis of gastric mucosal cells.

Amino Acid Chloromethyl Ketones↗

PubMed2001

Geranylgeranylacetone protects guinea pig gastric mucosal cells from gastric stressor-induced necrosis by induction of heat-shock proteins.

Gastric mucosal cell death due to various gastric stressors can cause several types of gastric diseases, such as gastric ulcers. In this study, we examined cell death following the short-term treatment of guinea pig gastric mucosal cells in primary culture with various gastric stressors. The short-term treatment of cells with ethanol, hydrogen peroxide or hydrochloric acid caused, in a dose-dependent manner, cell death in the absence of apoptotic DNA fragmentation and chromatin condensation. Cells lost membrane integrity following the treatment with each of these gastric stressors, suggesting that necrosis was induced in gastric mucosal cells by short-term treatment of the cells with gastric stressors. Geranylgeranylacetone, an anti-ulcer drug with heat-shock protein inducing properties, protected gastric mucosal cells from the necrotic cell death caused by each of these gastric stressors. Pretreatment of cells with low concentrations of ethanol (3%), which also induced heat-shock protein, made cells resistant to the necrotic cell death caused by the gastric stressors. These results suggest that heat-shock proteins is involved in the cytoprotective effect of geranylgeranylacetone against necrotic cell death.

Animals↗

PubMed2001

Metastatic brainstem tumor manifesting as hearing disturbance--case report.

A 53-year-old male, who had undergone a left upper lung lobectomy for cancer 2 years previously, presented with metastatic brainstem tumor manifesting as hearing disturbance. At first an otorhinolaryngologist treated him for senile sensorineural hearing disturbance. However, he suffered gait ataxia and was referred to our department. On admission, neurological examination found mild cerebellar ataxia on the left and gait unsteadiness. Neurootological analysis revealed central-type sensorineural hearing disturbance on the left both in the pure tone audiogram and speech discrimination test. Neuroimaging studies revealed a ring-like enhanced mass centered in the ventral left middle cerebellar peduncle, partly extending to the inferior cerebellar peduncle. Peritumoral edema extending to the ipsilateral cochlear nucleus was recognized. He underwent surgery via a left lateral suboccipital transcondylar approach. The histological diagnosis was adenocarcinoma identical with the primary lung cancer. Intra-axial brainstem metastatic lesion can be a cause of hearing disturbance, so should be included in the differential diagnosis for a patient complaining of hearing disturbance, especially with a past history of cancer.

Adenocarcinoma↗