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Biomedical subjects

K Hibi

Publications and source records attributed to K Hibi.

At least 19 recordsLinked to original sources
PubMed2005

Plasminogen activator inhibitor-1 as a potential marker for the malignancy of colorectal cancer.

To test the hypothesis that plasminogen activator inhibitor-1 (PAI-1) may serve as a candidate marker for the malignancy of colorectal cancer (CRC), we performed a quantitative RT-PCR for PAI-1 gene and evaluated the possible relationship between PAI-1 gene expression levels and clinicopathological findings in CRC. A significant increase in PAI-1 expression scores was observed in lymph node metastasis-positive CRCs (2.19 +/- 0.43) compared to negative ones (0.35 +/- 0.42) (P = 0.0037) as well as in distant metastasis-positive CRCs (3.50 +/- 1.18) compared to negative ones (0.99 +/- 0.30). The PAI-1 expression score markedly increased with the tumour stage (P = 0.0063; ANOVA test). Moreover, multivariate analysis revealed the PAI-1 expression score to be a strong and independent prognostic factor for CRC (P = 0.0432). These results suggested that PAI-1 might serve as a new parameter for the prediction of prognoses in CRC.

Adult↗
PubMed2005

Bioelectronic detector with monoamine oxidase for halitosis monitoring.

Methyl mercaptan (MM) is known as one of the major chemicals of halitosis (bad breath). In this study, a bioelectronic gas sensor (bio-detector) for gaseous MM was developed and was applied to measure halitosis in breath. The bio-detector consisted of a Clark-type dissolved oxygen electrode, a monoamine oxidase type-A (MAO-A) immobilized membrane and a reaction unit that had liquid and gaseous compartments separated by a hydrophobic porous polytetrafluoroethylene (PTFE) diaphragm membrane. The tip of the electrode covered with MAO-A membrane was placed into the liquid compartment as touching to the PTFE diaphragm membrane. In order to amplify the bio-detector output, a substrate regeneration cycle caused by coupling the monooxygenase with l-ascorbic acid as reducing reaction with reagent system, was applied. The results of MM vapor measurements showed the calibration range of the bio-detector for MM vapor was from 0.087 to 11.5 ppm (correlation coefficient: 0.993) and included the human sense of smell level 5 (0.2 ppm). The bio-detector had good selectivity being attributed to enzyme specificity was obtained for several substances (trimethyl amine, ammonia, dimethyl sulfide, etc.). The bio-detector was applied for halitosis measurement. Expired gases in five subjects were sampled every hour and the concentrations of MM in the expired gases were monitored. The output of bio-detector showed behaviour of halitosis level changes in a day such as increasing with passage of time and decreasing after eating.

Biosensing Techniques↗
PubMed2004

Methylation pattern of CDH13 gene in digestive tract cancers.

Recently, the loss of CDH13 (T-cadherin, H-cadherin) gene expression accompanied by CDH13 promoter methylation was identified in colon cancers. We examined CDH13 methylation in oesophageal and gastric carcinomas. Five of 37 oesophageal cancers (14%) and 23 of 66 gastric cancers (35%) demonstrated abnormal methylation of the CDH13 promoter. Abnormal methylation was frequently found in gastric cancers of patients at all clinical stages just as in E-cadherin, another of the cadherin family, suggesting that these cancers could be methylated at an early stage. These results suggested that CDH13 might play a variety of roles depending on the tissue type.

Cadherins↗
PubMed2004

CDH13 promoter region is specifically methylated in poorly differentiated colorectal cancer.

It has recently become clear that CDH13 (H-cadherin, T-cadherin) expression is frequently silenced by aberrant methylation in colorectal cancers and adenomas. In this study, we investigated the methylation status of CDH13 gene and detected aberrant promoter methylation in 27 of 84 (32%) colorectal cancers. We then correlated the results with the clinicopathological features of affected patients. We found a significant difference in histology (P=0.0053) when we compared the CDH13 methylation of poorly differentiated colorectal cancers to that of differentiated ones. This result suggested that poorly differentiated colorectal cancers specifically exhibited CDH13 methylation, and since CDH13 might be responsible for selective cell recognition and adhesion, inactivation of CDH13 could lead to the formation of scattered carcinoma cells in these cancers.

Cadherins↗
PubMed2001

Detection of mitochondrial DNA alterations in primary tumors and corresponding serum of colorectal cancer patients.

We previously examined colorectal cancer patients using mutation-specific mismatch ligation assay for genetic alterations in primary tumors and paired serum samples and proved that genetic alterations present in the tumors of cancer patients can be detected in the serum of those same patients. Recent evidence has proved that various cancers frequently have mutations in the D-loop region of mitochondrial DNA (mtDNA). Therefore, we thought that mutations in the mitochondrial genome might also become a genetic marker of colorectal cancer to detect tumor DNA in the serum of patients. We first sequenced the D-loop region of mtDNA in colorectal cancers. We then proceeded with a sensitive method, i.e., mismatch ligation assay to examine the possibility that mtDNA alterations can be found in the serum DNA. We analyzed the D-loop region of mtDNA in 77 primary colorectal cancers, 7 of which (9%) contained true somatic mutations in this region. We then examined whether mtDNA alterations can be found in the serum DNA using mismatch ligation assay. Of 7 alterations that were examined, 1 (14%) could be detected in the serum. This result suggested that the mtDNA alteration could also be used as a tumor marker to detect tumor DNA in the serum.

Base Pair Mismatch↗
PubMed2001

Detecting colorectal cancer in stool with the use of multiple genetic targets.

BACKGROUND: Colorectal cancer cells are shed into the stool, providing a potential means for the early detection of the disease using noninvasive approaches. Our goal was to develop reliable, specific molecular genetic tests for the detection of colorectal cancer in stool samples. METHODS: Stool DNA was isolated from paired stools and primary tumor samples from 51 colorectal cancer patients. Three genetic targets-TP53, BAT26, and K-RAS-were used to detect tumor-associated mutations in the stool prior to or without regard to the molecular analyses of the paired tumors. TP53 gene mutations were detected with a mismatch-ligation assay that detects nine common p53 gene mutations. Deletions within the BAT26 locus were detected by a modified solid-phase minisequencing method. Mutations in codons 12 and 13 of K-RAS were detected with a digital polymerase chain reaction-based method. RESULTS: TP53 gene mutations were detected in the tumor DNA of 30 patients, all of whom had the identical TP53 mutation in their stools. Tumors from three patients contained a noninherited deletion at the BAT26 locus, and the same alterations were identified in these patients' stool specimens. Nineteen of 50 tumors tested had a K-RAS mutation; identical mutations were detected in the paired stool DNA samples from eight patients. In no case was a mutation found in stool that was not also present in the primary tumor. Thus, the three genetic markers together detected 36 (71%) of 51 patients (95% confidence interval [CI] = 56% to 83%) with colorectal cancer and 36 (92%) of 39 patients (95% CI = 79% to 98%) whose tumors had an alteration. CONCLUSION: We were able to detect the majority of colorectal cancers by analyzing stool DNA for just three genetic markers. Additional work is needed to determine the specificity of these genetic tests for detecting colorectal neoplasia in asymptomatic patients and to more precisely estimate the prevalence of the mutations and sensitivity of the assay.

Aged↗
PubMed2001

Mitochondrial DNA alteration in esophageal cancer.

It has been reported that various cancers frequently have mutations in the D-loop region of mitochondrial DNA (mtDNA). We examined the genetic alterations in this region of esophageal cancer using direct sequencing. Of 68 sequence variants, 15 have not been reported to date. Tumor mtDNA with these variants were compared with mtDNA from corresponding normal esophageal mucosa. Two of 37 primary esophageal cancers (5%) contained somatic mutations in the D-loop region of mtDNA. Although the mutation rate of mitochondrial tumor DNA within the D-loop was not high, this result suggested that mtDNA mutations play a role in the development of esophageal cancer.

DNA Mutational Analysis↗
PubMed2001

p53 associates with and targets Delta Np63 into a protein degradation pathway.

A human p53 homologue, p63 (p40/p51/p73L/CUSP) that maps to the chromosomal region 3q27-29 was found to produce a variety of transcripts that encode DNA-binding proteins with and without a trans-activation domain (TA- or Delta N-, respectively). The p63 gene locus was found to be amplified in squamous cell carcinoma, and overexpression of Delta Np63 (p40) led to increased growth of transformed cells in vitro and in vivo. Moreover, p63-null mice displayed abnormal epithelial development and germ-line human mutations were found to cause ectodermal dysplasia. We now demonstrate that certain p63 isotypes form complexes with p53. p53 mutations R175H or R248W abolish the association of p53 with p63, whereas V143A or R273H has no effect. Deletion studies suggest that the DNA-binding domains of both p53 and p63 mediate the association. Overexpression of wild type but not mutant (R175H) p53 results in the caspase-dependent degradation of certain Delta Np63 proteins (p40 and Delta Np63 alpha). The association between p53 and Delta Np63 supports a previously unrecognized role for p53 in regulation of Delta Np63 stability. The ability of p53 to mediate Delta Np63 degradation may balance the capacity of Delta Np63 to accelerate tumorigenesis or to induce epithelial proliferation.

Animals↗
PubMed2001

Pharmacodynamics induced by direct electric current for the treatment of 5-fluorouracil resistant tumor: an animal experiment.

The repeated use of chemotherapy to treat patients with colorectal carcinoma may be limited by the fact it creates resistance cells. However, we have observed a remarkable decrease in certain types of drug resistance in patients treated with direct electric current. Experimental studies were therefore performed in animals to determine the differences in pharmacodynamics between chemotherapy with and that without electric treatment. Tumors were created in BALB/c mice by intradermal injection of 0.25 ml 4 x 10(6) Colon 26 cells/ml in the abdomen. Seven days later the mice were divided into two groups: controls and those that underwent electric treatment. Direct electric current (1,000 V, 0.2-0.8 microA) was passed between a platinum electrode inserted intradermally and the earth during and for 1 h after a single intravenous injection of 5-fluorouracil (5-FU; 12.5 mg ml(-1) kg(-1)). Peripheral blood samples were collected before and 5, 10, 20, 30, 45, and 60 min after the injection of 5-FU. Concentrations of 5-FU in the sera and tissues were measured by HPLC. The intratumoral concentrations of 5-FU in the electric treatment group were higher than those in the controls (P<0.05, two-factor analysis of variance), but the serum concentrations were not statistically different between the two groups. Pharmacodynamic changes were thus observed as a result of electrostatic treatment during chemotherapy. This elevated 5-FU concentration in the tumor tissue is considered one of the reasons for the effective inhibition of 5-FU resistance in clinical cases.

Animals↗
PubMed2001

Paired tumor marker of soluble E-selectin and its ligand sialyl Lewis A in colorectal cancer.

BACKGROUND: Better diagnosis of metastatic disease has been pursued by oncologists: however, many of the tumor markers have been still controversial. Our purpose was to estimate the usefulness of soluble E-selectin and its ligand sialyl Lewis A for more accurate diagnosis as a combined tumor marker for metastases in colorectal cancer. METHODS: E-selectin and sialyl Lewis A, collected from preoperative blood, were measured of its levels in 54 patients with colorectal cancer classified according to Dukes' stage. E-selectin was assayed by enzyme-linked immunosorbent assay, whereas sialyl Lewis A was quantified by enzyme immunoassay using immunoclone kit. RESULTS: The elevation in the level of E-selectin was significantly higher in Dukes' D group than that of healthy volunteers (P < 0.001, Fisher's procedure of least significance test), Dukes' A (P = 0.01), B (P = 0.025) and C (P < 0.01). Significantly higher level of sialyl Lewis A was shown in the group of metastases than that of non-metastases (P < 0.0068. Student's t-test). Paired elevation of E-selectin and sialyl Lewis A was significantly higher in the hematogenous metastases than non-metastases (P < 0.001, Fisher exact test). CONCLUSIONS: These results suggest that E-selectin could play some role in the progress of hematogenous metastases. The elevation of E-selectin alone or both E-selectin and sialyl Lewis A may be one of the useful indexes for more precise diagnosis of hematogenous metastases of human colorectal cancer.

Adult↗
PubMed2001

Small incisional esophagectomy with endoscopic assistance: evaluation of a new technique.

Laparoscopic surgery now can be performed safely and efficiently for various types of cancer; however, reconstruction of the gastric tube may be technically demanding. We attempted to make a breakthrough by designing and employing a new technique for performing a small incisional operation with endoscopic assistance. A midline incision, 10cm in length, was made in the upper abdomen. Some procedures were performed through the incision under direct vision, while other procedures required in the lateral extremes of the abdominal cavity, that are inaccessible by direct vision, were performed by laparoscopic-assisted surgery. Similarly, intrathoracic procedures were essentially performed through a minithoracotomy, 10-15cm in length, made without dissection of the dorsal latissmus or anterior serratus muscles. The postoperative courses of 20 consecutive patients who underwent this procedure were generally uneventful, and significant improvements in terms of intensive care and analgesic requirements were observed.

Aged↗
PubMed2001

The influence of plaque orientation (pericardial or myocardial) on coronary arterial remodeling.

BACKGROUND: Many systemic, regional and lesion factors have been identified which may influence arterial remodeling, but little is known about the importance of extravascular resistance to vessel enlargement. As myocardial systolic splinting may significantly affect vessel expansion the effect of plaque orientation on arterial remodeling in eccentric coronary atherosclerotic lesions was examined. METHODS: Using intravascular ultrasound imaging to obtain cross-sectional vessel area (VA), plaque area (PA) and lumen area (LA), remodeling in eccentric left anterior descending coronary artery lesions was compared which predominantly involved the pericardial or free arc (P, n=25) and the myocardial side (M, n=40) of the vessel wall. Normalized vessel area (NVA, VA(lesion)/VA(reference)) was compared as a continuous and categorical variable (positive>1.05, intermediate 0.95-1.05, negative<0.95) as well as remodeling index (RI, VA(lesion)-VA(reference)/PA(lesion)-PA(reference)). RESULTS: The two groups were well matched for clinical and lesion characteristics known to affect remodeling. Reference segments areas were similar in the two groups; while lesion LA was also similar, in the pericardial group there was significantly greater lesion PA (P 12.78+/-0.72, M 10.26+/-0.50 mm(2), P<0.05) and VA (P 15.71+/-0.90, M 12.82+/-0.57 mm(2), P<0.05) demonstrating enhanced compensatory remodeling. Outward remodeling was significantly greater in P than in M by both NVA (P 1.03+/-0.03, M 0.86+/-0.03, P<0.01) and RI (P 0.02+/-0.07, M -1.10+/-0.32, P<0.01). Positive, intermediate and negative remodeling occurred in nine, nine and seven lesions in P and in four, ten and 26 lesions in M (P<0.01). CONCLUSIONS: Remodeling compensates more for plaque growth in eccentric coronary lesions which are surrounded by the pericardium than those surrounded by the myocardium. Extravascular resistance appears to influence arterial remodeling.

Aged↗
PubMed2001

AIS overexpression in advanced esophageal cancer.

We examined AIS status in digestive tract cancers and found that all eight esophageal cancer cell lines (100%) showed AIS/TA-AIS gene overexpression, whereas 1 of 12 (8%) gastric cancer and 0 of 14 (0%) colon cancer cell lines showed AIS/TA-AIS gene expression. We then confirmed that the AIS gene, not the TA-AIS gene, was dominantly expressed in esophageal cancers by reverse transcription-PCR. AIS protein was also expressed in AIS gene-positive cell lines. Subsequently, we tested AIS gene expression in paired esophageal normal tissues and cancers. Twenty-five of 39 (64%) primary esophageal cancers demonstrated an obviously higher expression of AIS gene compared to paired normal tissues. Moreover, high AIS gene expression was significantly associated with lymph node metastases in esophageal cancer (P = 0.0271). These results suggested that AIS may be useful as a marker for advanced esophageal cancer.

Aged↗
PubMed2001

Molecular detection of p16 promoter methylation in the serum of patients with esophageal squamous cell carcinoma.

PURPOSE AND EXPERIMENTAL DESIGN: Recent evidence shows that the presence of promoter hypermethylation of tumor suppressor genes has been demonstrated in the serum DNA of patients with various cancers such as lung, liver, and head and neck cancer. We have examined promoter hypermethylation of the p16 gene in esophageal squamous cell carcinoma (SCC) using methylation-specific PCR to detect tumor DNA in the serum. RESULTS: Aberrant promoter methylation of the p16 gene was detected in 31 of 38 (82%) esophageal SCCs. Subsequently, we tested for promoter methylation in the paired serum DNA of 31 patients with a p16 alteration in the primary tumor. We found that 7 of these 31 (23%) patients had the same methylation changes in the serum DNA. CONCLUSIONS: This result indicates that promoter methylation present in the tumors of esophageal SCC patients can be detected in the serum of the same patient and that this approach can potentially be used for the screening and monitoring of the disease.

Carcinoma, Squamous Cell↗
PubMed2000

Feasibility of a novel blood noise reduction algorithm to enhance reproducibility of ultra-high-frequency intravascular ultrasound images.

BACKGROUND: Ultra-high-frequency (40- to 50-MHz) intravascular ultrasound (IVUS) improves image quality compared with conventional 20- to 30-MHz IVUS. However, as the frequency of IVUS increases, high-intensity backscatter from blood components may cause visual difficulties in discrimination between the lumen and arterial wall structure. The purpose of this study was to evaluate the effect of a novel blood noise reduction algorithm (BNR) on quantitative coronary ultrasound measurements. METHODS AND RESULTS: IVUS studies using a 40-MHz transducer were performed in 35 patients with coronary artery disease. A total of 620 gray-scale images (310 pairs) were processed with and without the BNR, and lumen cross-sectional area (CSA) was determined by 2 independent observers. With the BNR, the intraobserver and interobserver correlation coefficients for lumen CSA were significantly improved (0.85 to 0.99 and 0.80 to 0.98, respectively). In the 270 images (135 pairs) in which vessel wall measurements were possible, the BNR significantly improved the intraobserver and interobserver correlation coefficients for plaque plus media CSA (0.83 to 0.99 and 0.76 to 0.97, respectively), whereas no influence was observed for external elastic membrane CSA (1.00 to 1.00 and 0.99 to 0.99, respectively). CONCLUSIONS: This study demonstrates the feasibility of this novel algorithm to reduce blood noise, thereby enabling accurate lumen border delineation and providing reproducible measurements of both the lumen and plaque plus media CSAs. Incorporating a digital BNR may serve as an important adjunct to ultra-high-frequency IVUS imaging for improving accurate quantitative evaluation of vessel dimensions.

Algorithms↗
PubMed2000

Frequent gain of the p40/p51/p63 gene locus in primary head and neck squamous cell carcinoma.

We have identified a new human p53 homologue, p40 (p51/p63). This gene was mapped to the distal arm of 3q and was found to be essential for normal epithelial development. We used microsatellite and FISH analyses to search for genetic alterations of p40 in primary HNSCC. A more precise localization of p40 was completed using 6 known markers on 3q and a newly isolated microsatellite marker within the p40 gene. We also determined the genomic organization of the p40 gene using human YAC and BAC clones. Microsatellite analysis revealed that 14 of 26 (54%) primary HNSCC had allelic imbalance in at least 1 of the 7 microsatellite loci. However, FISH analysis with a p40 probe showed that a majority of HNSCC had an increased copy number of the locus regardless of allelic status. Thus, overrepresentation of the p40 locus may play an important role in the development of HNSCC.

Alleles↗
PubMed2000

AIS is an oncogene amplified in squamous cell carcinoma.

We and others recently isolated a human p53 homologue (p40/p51/p63/p73L) and localized the gene to the distal long arm of chromosome 3. Here we sought to examine the role of p40/p73L, two variants lacking the N-terminal transactivation domain, in cancer. Fluorescent in situ hybridization (FISH) analysis revealed frequent amplification of this gene locus in primary squamous cell carcinoma of the lung and head and neck cancer cell lines. (We named this locus AIS for amplified in squamous cell carcinoma.) Furthermore, amplification of the AIS locus was accompanied by RNA and protein overexpression of a variant p68(AIS) lacking the terminal transactivation domain. Protein overexpression in primary lung tumors was limited to squamous cell carcinoma and tumors known to harbor a high frequency of p53 mutations. Overexpression of p40(AIS) in Rat 1a cells led to an increase in soft agar growth and tumor size in mice. Our results support the idea that AIS plays an oncogenic role in human cancer.

Alternative Splicing↗