Biomedical subjects

M Ikeguchi

Publications and source records attributed to M Ikeguchi.

At least 73 records · Page 4Linked to original sources

PubMed1998

Computerized nuclear morphometry of hepatocellular carcinoma and its relation to proliferative activity.

BACKGROUND AND OBJECTIVES: Nuclear profiles have been reported as useful prognostic predictor in various cancers. Data from computerized morphometries are objective and can be quickly derived using conventional microscopic analysis. However, it remains to be shown what types of pathological and biological factors influence the nuclear features. The aim of this study was to evaluate the correlation between the morphological nuclear features and clinicopathological parameters in patients with hepatocellular carcinoma (HCC). METHODS: Morphometric nuclear features (nuclear area, perimeter, and shape) were analyzed in 76 patients with hepatocellular carcinoma who underwent hepatectomy at our hospital. In each case, 300 cancer nuclei were analyzed randomly on routine hematoxylin&eosin-stained slides through the use of a computer-assisted image analysis system that allowed us to trace the nuclear profiles (magnification x400) on a computer monitor. The morphometric data were compared with patient survival, clinicopathologic status, and the proliferative activity of cancer cells. RESULTS: The mean nuclear area of poorly differentiated carcinoma was significantly larger than that of moderately and well differentiated carcinoma (P = 0.0003). Significant correlation was detected between the nuclear area of cancer cells and proliferative activity associated with proliferating cell nuclear antigen labeling index (PCNA LI) of cancer cells (r = 0.372, P = 0.0008). Moreover, blood vessel invasion of cancer cells or intrahepatic metastasis were more frequently detected in patients with large nuclear areas. Even though the nuclear area was not an independent prognostic factor in the multivariate analysis, the 5-year survival rate of the 35 patients who had tumors with large nuclear areas (>50 microm2, 25.9%) was significantly lower than that of the 36 patients who had tumors with small nuclear areas (< or =50 microm2, 63.3%, P = 0.001). CONCLUSIONS: The nuclear area of HCC correlates with cell differentiation and cell proliferative activity. Moreover, HCC with a large nuclear area has high potential for blood vessel invasion and intrahepatic metastasis. Thus, nuclear morphometry can be used as an useful morphological predictor for malignant potential in patients with HCC.

Adolescent↗

PubMed1998

Transition state in the folding of alpha-lactalbumin probed by the 6-120 disulfide bond.

The guanidine hydrochloride concentration dependence of the folding and unfolding rate constants of a derivative of alpha-lactalbumin, in which the 6-120 disulfide bond is selectively reduced and S-carboxymethylated, was measured and compared with that of disulfide-intact alpha-lactalbumin. The concentration dependence of the folding and unfolding rate constants was analyzed on the basis of the two alternative models, the intermediate-controlled folding model and the multiple-pathway folding model, that we had proposed previously. All of the data supported the multiple-pathway folding model. Therefore, the molten globule state that accumulates at an early stage of folding of alpha-lactalbumin is not an obligatory intermediate. The cleavage of the 6-120 disulfide bond resulted in acceleration of unfolding without changing the refolding rate, indicating that the loop closed by the 6-120 disulfide bond is unfolded in the transition state. It is theoretically shown that the chain entropy gain on removing the cross-link from a random coil chain with helical stretches can be comparable to that from an entirely random chain. Therefore, the present result is not inconsistent with the known structure in the molten globule intermediate. Based on this result and other knowledge obtained so far, the structure in the transition state of the folding reaction of alpha-lactalbumin is discussed.

Animals↗

PubMed1998

Levels of serum-soluble receptor for interleukin-2 in patients with colorectal cancer.

The preoperative levels of serum-soluble receptor for interleukin-2 (IL-2R) were determined by an enzyme-linked immunosorbent assay in 38 patients undergoing surgery for colorectal cancer and 98 healthy controls. The levels of serum-soluble IL-2R in the patients with colorectal cancer were significantly higher than those in the normal controls (P < 0.05). Markedly elevated levels of serum-soluble IL-2R were recognized in patients with stage IV cancer, those with Dukes' stage D cancer, and those with liver metastasis. Moreover, the prognosis of patients with low levels of IL-2R (<531 U/ml) was significantly better than that of those with high levels (P < 0.05). These findings demonstrate that an elevated concentration of soluble IL-2R might be a useful indicator of liver metastasis and poor prognosis in patients with colorectal carcinoma.

Adenocarcinoma↗

PubMed1998

Expression of p53 and p21 are independent prognostic factors in patients with serosal invasion by gastric carcinoma.

To evaluate whether the expression of p53 and that of p21 are independent prognostic factors in patients with advanced gastric cancer, we investigated clinicopathological factors and the expression of p53 and p21 in 158 patients with gastric cancer that had invaded the serosa and who had undergone curative gastrectomy. In multivariate survival analysis of 156 surviving patients, we evaluated the size of the tumor, lymph node metastasis, venous invasion, lymph node dissection, expression of p53, and expression of p21 as independent prognostic factors. Moreover, we divided patients into four groups according to the expression of p53 and p21 in their tumors [group A, p53-/p21-, N = 40 (one died within 30 days of surgery); group B, p53-/p21+, N = 23; group C, p53+/p21-, N = 58; and group D, p53+/p21+, N = 37 (one died within 30 days of surgery)]. The 5- and 10-year survival rates of 39 patients in group A were 71.7% and 64.3%, those of 23 patients in group B were 81.4% and 81.4%, those of 58 patients in group C were 35.6% and 30.2%, and those of 36 patients in group D were 67.9% and 60.7%. The prognosis of patients in group C was poorer than that of patients in the other three groups. This result indicates that the evaluation of the expression of both p53 and p21 expression might provide prognostic information that is more accurate than that provided by evaluation of the expression of p53 alone.

Adult↗

PubMed1998

Relationship between the expression of vascular endothelial growth factor and the density of dendritic cells in gastric adenocarcinoma tissue.

It has been reported that decreased numbers of dendritic cells (DCs) are correlated with poor prognosis in some types of malignancy, such as gastric cancer. However, factors that determine the density of DCs have not been characterized. It was recently reported that vascular endothelial growth factor (VEGF) inhibits the functional maturation of DCs from CD34+ precursors. In this study, we analysed the relationship between the expression of VEGF and the density of DCs in gastric carcinoma tissues by immunohistochemical staining. The extent of infiltration by DCs was graded from marked to slight on the basis of the mean densities of DCs. The prognosis of patients with marked infiltration was significantly better than that of patients with slight infiltration among patients who had undergone curative resection. Multivariate analysis showed that infiltration by DCs was an independent prognostic indicator. Furthermore, there was an inverse correlation between the density of DCs and the expression of VEGF Our results suggest that expression of VEGF might be associated with tumour progression and poor prognosis not only because VEGF stimulates angiogenesis, but also because it allows tumours to escape from attack by the immune system in patients with gastric carcinoma.

Adenocarcinoma↗

PubMed1998

The region of alpha-lactalbumin recognized by GroEL.

The binding constants between disulfide-intact or various disulfide-reduced bovine alpha-lactalbumins and an Escherichia coli chaperonin, GroEL, were determined by using the equilibrium dialysis method. The disulfide-intact and one-disulfide (Cys6-Cys120)-reduced alpha-lactalbumins were shown not to bind with GroEL both in the presence and absence of Ca2+. The two-disulfide (Cys6-Cys120 and Cys28-Cys111)-reduced alpha-lactalbumin, which has the native-like tertiary structure in its beta-domain region and an unfolded alpha-domain in the presence of Ca2+, showed considerable binding with GroEL. The binding free energy of the two-disulfide-reduced alpha-lactalbumin in the presence of Ca2+ is close to that of the molten globule state of disulfide-intact alpha-lactalbumin. This result suggests that GroEL binds to the unfolded alpha-domain of alpha-lactalbumin regardless of the conformation of the beta-domain. The fully disulfide-reduced and two-disulfide-reduced alpha-lactalbumins were found to bind more strongly with GroEL in the absence of Ca2+ than the two-disulfide-reduced alpha-lactalbumin in the presence of Ca2+, thus indicating that the unfolding of the beta-domain of alpha-lactalbumin leads to stronger interaction with GroEL.

Binding, Competitive↗

PubMed1998

Remarkable destabilization of recombinant alpha-lactalbumin by an extraneous N-terminal methionyl residue.

A recombinant bovine alpha-lactalbumin, possessing an additional N-terminal methionyl residue, was expressed in Escherichia coli. In order to address the effects of the N-terminal methionyl residue on conformational stability, the thermal stability of the recombinant alpha-lactalbumin was investigated by measuring temperature-dependence of circular dichroism spectra, and it was compared with that of authentic alpha-lactalbumin from bovine milk. The thermal stability of the recombinant alpha-lactalbumin was significantly lower than that of authentic alpha-lactalbumin. The enthalpy change of unfolding of the recombinant protein was found to be the same as that of the authentic one when compared at the same temperature. Therefore, the N-terminal methionyl residue seems to destabilize the conformation of recombinant alpha-lactalbumin through some entropic effects.

Animals↗

PubMed1998

A progressive postoperative increase in the serum level of soluble receptors for interleukin-2 is an indicator of a poor prognosis in patients with gastric cancer.

Activated T lymphocytes release a soluble form of IL-2R (SoIL-2R) into the bloodstream, which can be detected by CD25 monoclonal antibody. Perioperative changes of serum levels of SoIL-2R and the number of CD25-positive cells were monitored simultaneously to clarify the clinical implications of SoIL-2R in patients with gastric cancer (n=91). Preoperative levels of SoIL-2R were significantly higher than in normal controls and levels were a useful indicator of possible lymph node involvement. Postoperative levels of SoIL-2R increased independently of the number of CD25-positive cells. Patients with progressive postoperative increases in levels of SoIL-2R had both a significantly high frequency of postoperative relapse and a poor prognosis. Increased SoIL-2R may reduce the availability of IL-2 by binding to it. Postoperative progressive increases in SoIL-2R appear to be a good indicator for a poor prognosis in patients with gastric cancer.

Adult↗

PubMed1998

Telomerase activity and microsatellite instability in colorectal cancer and adenoma.

In order to examine their roles in carcinogenesis or in progression of colorectal carcinoma, we investigated telomerase activity and microsatellite instability in 67 non-familial colorectal cancers and in 18 adenomas. The incidence of detectable telomerase activity increased from 22% of normal colorectal mucosas adjacent to carcinoma, and 33% of adenomas, to 75% of carcinomas. On the other hand, the incidence of detectable microsatellite instability in carcinomas (30%) was almost the same as in adenomas (22%). No significant correlation was detected in the incidence of telomerase activity and microsatellite instability in carcinomas or in adenomas. Moreover, the incidence of telomerase activity and microsatellite instability did not increase during the progression of carcinomas. These results indicate that telomerase activity and microsatellite instability are independent events in colorectal carcinogenesis, and that telomerase activity and microsatellite instability are not correlated with the progression of colorectal carcinoma. However, in 13 multiple cancers, the incidence of telomerase activity (92%) and the incidence of microsatellite instability (54%) was higher than that of telomerase activity (70%) and that of microsatellite instability (24%) in 54 sporadic cancers. Moreover, the incidence of telomerase activity and that of microsatellite instability in adenomas with carcinomas (45% and 36% respectively) was higher than that of telomerase activity and microsatellite instability in adenomas without carcinomas (14% and 0% respectively). These results indicate that telomerase activity and microsatellite instability may play an important role in multicentric carcinogenesis in colorectal carcinoma.

Adenoma↗

PubMed1998

[Telomerase activity in esophageal squamous cell carcinoma and in normal esophageal epithelium adjacent to carcinoma].

Telomerase activity was analyzed in 52 patients with resected esophageal squamous cell carcinoma by telomeric repeat amplification protocol (TRAP) assay. Telomerase activity was detected in 41 out of 52 (79%) carcinomas and detected in 46 out of 52 (89%) normal esophageal epitheliums adjacent to the carcinomas. In carcinoma, the telomerase activity was detected more frequently in relatively early stages of carcinoma (in 8 of 9 patients with stage 0, in 3 of 3 patients with stage I, and in 4 of 4 patients with stage II). However, the telomerase activity was detected in only 8 of 12 patients with stage III and in 16 of 21 patients with stage IV. Thus, the percentage of patients who had tumors without telomerase activity increased in more advanced stages. These results indicate that telomerase activity may correlate with carcinogenasis of esophageal cancer, however, it may not correlate with progression of esophageal squamous cell carcinoma.

Aged↗

PubMed1998

[Telomerase activity and genomic instability in colorectal cancers].

In this study, we investigated the correlation between the telomerase activity and the microsatellite instability in colorectal cancers and adenomas. Telomerase activity was detected in 75% of cancers and in 33% of adenomas. Microsatellite instability was detected in 24% of sporadic cancers, in 54% of multiple cancers, and in 22% of adenomas. Telomerase activity and microsatellite instability were independent events in colorectal carcinogenesis. The patients with telomerase activity and microsatellite instability showed poor prognosis. These results indicate that colorectal cancers with both telomerase activity and microsatellite instability may have more malignant potential, and adenomas with both them may be more intensive precursor of colorectal cancers.

Aged↗

PubMed1997

Expression of p21 (waf1/cip1/sdi1), but not p53 protein, is a factor in the survival of patients with advanced gastric carcinoma.

BACKGROUND: The authors examined whether expression of p21 (waf1/cip1/sdi1) and p53 protein was related to survival, rates in patients with advanced gastric carcinoma. METHODS: The expression of p21 and p53 protein was analyzed by immunohistochemistry in 93 patients with advanced gastric carcinoma with serosal invasion and lymph node metastasis. All patients underwent curative surgery. The probability of survival was calculated by the Kaplan-Meier method and compared by the generalized Wilcoxon test. RESULTS: Various levels of p21 and p53 immunoreactivities in carcinoma cells were detected in 30 (32%) and 60 (65%), respectively, of 93 samples. There was no correlation between p21 and p53 expression. The 5-year survival rate of patients with p21 expression was 69.4%, which was significantly better than that of patients without p21 expression (38.1%; P < 0.05). However, p53 protein expression did not correlate with patient survival. CONCLUSIONS: Expression of p21 protein may be a better prognostic factor than p53 protein expression in patients with advanced gastric carcinoma.

Adenocarcinoma↗

PubMed1997

Molten globule state of equine beta-lactoglobulin.

The acid-unfolded state of equine beta-lactoglobulin was characterized by means of circular dichroism, nuclear magnetic resonance, analytical gel-filtration chromatography, and analytical centrifugation. The acid-unfolded state of equine beta-lactoglobulin has a substantial secondary structure as shown by the far-ultraviolet circular dichroism spectrum but lacks persistent tertiary packing of the side chains as indicated by the near-ultraviolet circular dichroism and nuclear magnetic resonance spectra. It is nearly as compact as the native conformation as shown by the gel filtration and sedimentation experiments, and it has the exposed hydrophobic surface as indicated by its tendency to aggregate. All of these characteristics indicate that the acid-unfolded state of equine beta-lactoglobulin is a molten globule state. The alpha helix content in the acid-unfolded state, which has been estimated from the circular dichroism spectrum, is larger than that in the native state, suggesting the presence of nonnative alpha helices in the molten globule state. This result suggests the generality of the intermediate with nonnative alpha helices during the folding of proteins having the beta-clam fold.

Acids↗

PubMed1997

Biological characteristics of esophageal squamous cell carcinoma associated with contiguous intraepithelial carcinoma.

To evaluate the biological significance of esophageal squamous cell carcinoma that is associated with contiguous intraepithelial carcinoma, we analyzed 95 patients with operated esophageal carcinoma. Of these 95 patients, eight had in situ carcinoma. Among 87 cases in which the tumo had invaded more deeply than the lamina propria, there were 42 cases (48.3%) of contiguous intraepithelial carcinoma associated with the main tumor. The biological characteristics (proliferative activity of cells, as revealed by immunostaining with the Ki-67 monoclonal antibody) of 45 tumors without contiguous intraepithelial carcinoma (group A) were compared with those of 42 tumors with contiguous intraepithelial carcinoma (group B). The more advanced was the main lesion, the lower was the incidence of contiguous intraepithelial carcinoma. The mean Ki-67 score of the main tumors in group A was 51.6% and that of the main tumors in group B was 45.9%. The mean Ki-67 score of the main tumors in group B was very similar to that of the contiguous intraepithelial carcinomas that were associated with the main tumors (44.4%, P = 0.682). Furthermore, the mean Ki-67 score of contiguous intraepithelial carcinomas associated with main tumors was very similar to that of carcinomas in situ (41.2%, P = 0.529). From our results, it is suggested that tumors with high proliferative activity may be assumed to grow rapidly and, as a result, the region of intraepithelial carcinoma may develop into an invasive tumor. By contrast, tumors with low proliferative activity may grow slowly and, in such cases, the carcinoma may remain in the epithelium around the invasive tumor.

Aged↗

PubMed1997

Changes in levels of expression of p53 and the product of the bcl-2 in lines of gastric cancer cells during cisplatin-induced apoptosis.

Five lines (MKN-28, MKN-45, MKN-74, KATO-III, and HSC-39) of human gastric carcinoma cells were treated with 1 microgram/ml cisplatin for 12, 24, 36, 48, and 72 h. Apoptotic indices (percentages of apoptotic cells) were analyzed at each time point. After incubation with cisplatin, apoptotic cells were detected more frequently among MKN-45 and MKN-74 cells with a wild-type gene for p53 and without expression of the bcl-2 protein than among HSC-39, MKN-28, and KATO-III cells with a mutation or complete deletion of the gene for p53 and with overexpression of the bcl-2 protein. The levels of p53 protein increased after treatment with cisplatin in MKN-74 cells. However, levels of bcl-2 protein were reduced in KATO-III after treatment with cisplatin. Thus, p53 status and the expression of bcl-2 by tumor cells might be good indicators of sensitivity to chemotherapy for patients with gastric cancer.

Adult↗

PubMed1997

Clinicopathologic significance of the expression of mutated p53 protein and the proliferative activity of cancer cells in patients with esophageal squamous cell carcinoma.

BACKGROUND: The aim of this study was to investigate the relation between the expression of mutated p53 protein and the proliferative activity of cancer cells in esophageal squamous cell carcinoma. In addition, the clinical and biologic significance of p53 status and the proliferative activity of cancer cells were evaluated in these patients. STUDY DESIGN: Samples of esophageal tumors from 94 patients were subjected to immunohistochemical staining with a monoclonal antibody against p53 and with the monoclonal antibody Ki-67. The immunoreactivity against p53 and the proliferative activity of cancer cells were compared with the clinicopathologic findings in each sample. Prognostic factors including p53 status and Ki-67 labeling index (LI; percentage of Ki-67-immunostained cells) were evaluated for 81 surviving patients by univariate and multivariate analysis. RESULTS: The mean Ki-67 LI of 50 p53-positive patients was higher than that of 44 p53-negative patients (p = 0.009). The Ki-67 LI increased according to the progression of tumors. Overexpression of mutated p53 protein was observed in 40.9% of tumors that invaded to the submucosa, and this percentage was not significantly changed in tumors with invasion to the adventitia. Metastases to the regional lymph nodes were observed in 3 of 22 patients with tumors that invaded to the submucosa, and these 3 tumors had both over-expression of mutated p53 protein and high Ki-67 LI. In 81 surviving patients, only lymph node metastasis (p = 0.045) and the curability of tumors (p < 0.001) were identified as independent prognostic factors by multivariate analysis. CONCLUSIONS: Overexpression of mutated p53 protein is detected in the early stage of esophageal cancer. This mutated p53 protein may not play an important role for tumor invasion. When tumor invasion is limited to the submucosa, cancer cells that overexpress mutated p53 protein may acquire high proliferative activity. Such cells might have considerable potential for metastasis to the lymph nodes.

Adult↗

PubMed1996

Low frequency of apoptosis in Epstein-Barr virus-associated gastric carcinoma with lymphoid stroma.

In order to understand the character of Epstein-Barr virus (EBV)-associated gastric carcinoma with lymphoid stroma (GCLS), we examined cell proliferation and death in comparison with gastric carcinoma without prominent lymphoid stroma (conventional gastric carcinoma). The EBV-encoded small RNA I (EBER-1) and apoptotic cells were examined by in situ hybridization (ISH) and by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end-labeling (TUNEL), respectively, on formalin-fixed paraffin-embedded surgical specimens from 22 GCLSs and 23 conventional gastric carcinomas. Immunostaining was performed for the detection of Ki-67 antigen (Ki-67), P53 protein (P53) and bcl-2 oncoprotein (BCL-2). The percentages of apoptotic and Ki-67-positive cells were expressed as apoptotic indices (AI) and Ki-67 labeling indices (KI), respectively. EBER-1 was detected in 19 (86%) GCLSs in contrast to none in conventional carcinomas. Mean AI was 1.8 +/- 0.6 in the EBER-1-positive GCLSs and 3.3 +/- 1.7 in the conventional gastric carcinomas, the value being significantly lower in the former (p < 0.01). Mean KI was 40.0 +/- 10.8 in the GCLSs and 48.5 +/- 9.1 in the conventional gastric carcinomas, the value being significantly lower in the former (p < 0.05). P53 expression showed no significant difference between the 2 categories of carcinoma.

Adult↗

PubMed1996

Frequent coordinated overexpression of the MRP/GS-X pump and gamma-glutamylcysteine synthetase genes in human colorectal cancers.

We have recently shown that multidrug resistance-associated protein (MRP) and gamma-glutamylcysteine synthetase (gamma-GCS) heavy subunit genes are coordinately overexpressed in cisplatin-resistant human leukemia cells (T. Ishikawa et al. J. Biol. Chem., 271: 14981-14988, 1996). Using the RNase protection assay, we examined expression levels of these genes in colon tumor and nontumorous biopsy specimens from 32 cancer patients who had not been treated with chemotherapy. Increased mRNA levels (P < 0.001) of MRP and gamma-GCS genes were observed in 16 (50%) and 20 (62%) tumor samples, respectively. More importantly, all of the 16 (100%) MRP-overexpressing tumor specimens also exhibited higher levels of gamma-GCS mRNA than those in the matched nontumorous specimens. The correlation coefficient between MRP and gamma-GCS mRNA levels was r = 0.78 for all of the tumor samples studied. These results strongly suggest that MRP and gamma-GCS genes are coordinately up-regulated during colorectal carcinogenesis.

ATP-Binding Cassette Transporters↗