Biomedical subjects

M Maeta

Publications and source records attributed to M Maeta.

At least 37 records · Page 2Linked to original sources

PubMed1999

The expression of thymidine phosphorylase correlates with angiogenesis and the efficacy of chemotherapy using fluorouracil derivatives in advanced gastric carcinoma.

The expression of thymidine phosphorylase (TP) and the density of microvessel in advanced gastric carcinoma were examined by immunohistochemistry to evaluate the significance of TP. The expression of TP was negative in 72 cases, positive in 54. The microvessel density correlated with the expression of TP. In total cases, patients with TP-positive tumours survived longer than those with TP-negative tumours. In patients treated with fluorouracil derivatives (FUs), the expression of TP significantly correlated with favourable prognosis and with unfavourable prognosis in those not treated with FUs. The patients with TP-positive tumours, the prognosis of patients treated with FUs was significantly better than that of those not treated with FUs. In patients with TP-positive tumours, treatment with FUs and lymph node metastasis were independent prognostic factors according to the Cox proportional hazards model. Depth of invasion and lymph node metastasis were independent prognostic factors in patients with TP-negative tumours. The determination of the expression of TP might be useful for predicting the efficacy of post-operative chemotherapy using FUs to prevent recurrence in advanced gastric carcinoma patients who undergo curative gastrectomy.

Adenocarcinoma↗

PubMed1999

De-epithelialised anterior (anterolateral and anteromedial) thigh flaps for dead space filling and contour correction in head and neck reconstruction.

Anterior (anterolateral and anteromedial) thigh flaps based on the descending branch of the lateral circumflex femoral vessels provide a long vascular pedicle and a large flap without sacrificing main vessels and muscles. Twenty-eight de-epithelialized anterior thigh flaps were transferred for reconstruction of head and neck defects following tumour ablation. Two flaps were lost in patients that had previously undergone high-dose radiotherapy following free tissue transfer. Vascularised fibula, vascularised iliac bone and other tissues were combined with anterior thigh flaps in 13 cases utilising the distal end or derivative branches of the vascular pedicle. Salivary fistula was seen in only one case, although there were many minor and major complications. In five cases, double skin flaps were harvested from the ipsilateral thigh. One of these flaps was used for coverage of intraoral defects, while the other was placed in the submandibular area to fill dead space. Compared with other methods, this multi-flap method is considered to be most suitable for dead space filling and contour correction.

Adult↗

PubMed1999

Computerized nuclear morphometry: a new morphologic assessment for advanced gastric adenocarcinoma.

OBJECTIVE: To evaluate the correlation between the morphologic nuclear features and clinicopathologic parameters in patients with advanced gastric cancer. SUMMARY BACKGROUND DATA: Nuclear profiles have been reported as useful prognostic predictors in various cancers. Data from computerized morphometries are objective and quickly derived using conventional microscopic analysis. However, this image analysis of nuclear features has rarely been applied to investigations of gastric adenocarcinoma. Moreover, it remains to be shown what types of biologic factors influence the nuclear features. METHODS: Morphometric nuclear features (nuclear area, perimeter, and shape) were analyzed in 202 patients with serosal-invaded gastric cancer (stage II and III) who underwent curative gastrectomy. In each case, 300 cancer nuclei were analyzed on routine hematoxylin and eosin-stained slides through the use of a computer-assisted image analysis system by tracing the nuclear profiles (magnification x400) on a computer monitor. The morphometric data were compared with patient survival, clinicopathologic status, DNA ploidy pattern of tumors, expression of p53 protein, and proliferative activity of cancer cells. RESULTS: Lymph node metastasis, lymphatic invasion, and venous invasion were more frequently detected in patients with large nuclear areas. Significant correlations were detected between the size of the nuclear area of cancer cells and the biologic factors of tumors, such as expression of p53, Ki-67 labeling index, and DNA ploidy pattern. The 5-year survival rate of the 100 patients in the large-nuclear group (nuclear area >45.3 microm2) was 47.6% and was significantly lower than the 74.4% rate of the 98 patients in the small-nuclear group (nuclear area < or =45.3 microm2). Moreover, the nuclear area was found to be an independent prognostic factor in the multivariate analysis. CONCLUSIONS: Gastric cancer cells with a large nuclear area express mutated p53 protein and have high proliferative activity. Moreover, such cancer cells have high potential for invasion to the microvessels in the gastric wall. Thus, nuclear morphometry is a new and useful morphologic predictor for metastatic potential in advanced gastric cancer.

Adenocarcinoma↗

PubMed1999

Clinical significance of the detection of thymidine phosphorylase activity in esophageal squamous cell carcinomas.

In this study, we obtained fresh samples of tissue (tumors, adjacent normal mucosas, and metastatic lymph nodes) from 64 patients (metastatic lymph nodes were obtained from 16 patients) with esophageal cancer who underwent esophagectomy between 1993 and 1998. The thymidine phosphorylase (dThdPase) levels of tumors as determined by the ELISA method were compared with clinicopathological findings of tumors and were evaluated for their usefulness as a prognostic parameter for these patients. The dThdPase levels of tumors (221 +/- 21 U/mg protein) and metastatic lymph nodes (253 +/- 51 U/mg protein) were significantly higher than the dThdPase level of normal mucosas (53 +/- 7 U/mg protein, p < 0. 001). The dThdPase levels of tumors did not correlate with the histopathological grading of tumors, the depth of tumor invasion, and lymph node metastasis. The 3-year survival rate of 32 patients with a high level of dThdPase (42%) was not different from that of 32 patients with a low level of dThdPase (52%, p = 0.267). Moreover, the dThdPase level of tumors was not an independent prognostic factor for patients with esophageal cancer. These findings suggest that the level of dThdPase activity in esophageal cancers may not correlate with tumor progression and may not be a useful prognostic marker for patients with esophageal squamous cell carcinoma.

Aged↗

PubMed1999

Detection of loss of heterozygosityat microsatellite loci in esophageal squamous-cell carcinoma.

Microsatellite alterations at 3 genetic loci (chromosomes 2p, 3p and 17p) were analyzed in 25 tumors (20 primary tumors and 5 metastatic lymph nodes) from 20 patients after surgical treatment for esophageal cancer. DNA samples from tumors were compared with control DNA from lymphocytes obtained from the peripheral blood of the individual patients. Microsatellite alterations [microsatellite instability (MSI) and loss of heterozygosity (LOH)] were detected in 15% of 20 primary tumors with marker D2S123 (chromosome 2p), 55% with marker D3S1067 (chromosome 3p) and 50% with marker TP53 (chromosome 17p). The 3-year disease-free survival rate of the 10 patients who had tumors without alterations or with an alteration at only 1 of 3 microsatellite loci was 75% and it was better than that of the 10 patients who had tumors with alterations at 2 or 3 microsatellite loci (48%, p = 0.049). This finding suggests that esophageal cancer with alterations at multiple microsatellite loci might have strong malignant potential. However, MSI was only detected in one of 20 patients, which suggests that MSI might not play an important role in the development of this cancer. Three of 5 metastatic lymph nodes showed no LOH even though primary tumors of these patients exhibited LOH with 1 or 2 markers, and 1 metastatic lymph node had LOH that was detected with D3S1067 even though the primary tumor of this patient had no LOH with all markers. Thus, clonal heterogeneity might exist in esophageal squamous-cell carcinomas.

Aged↗

PubMed1999

Soluble CD44 variant 6 as a prognostic indicator in patients with colorectal cancer.

The expression of CD44v6 is well known as a useful marker of tumor progression and prognosis in colorectal cancer. In this study, we evaluated the serum levels of soluble CD44 splice variants containing exon v6 (sCD44v6) and examined the histological expression of CD44v6 in patients with colorectal cancer. Serum samples were obtained from 44 primary colorectal cancer patients before surgery. We used enzyme-linked immunosorbent assay to determine the serum levels of sCD44v6. The expression of CD44v6 was examined by immunohistochemical staining of the primary tumors obtained from the same patients. Both the serum concentration of sCD44v6 and the expression of CD44v6 were significantly associated with lymph node metastasis (p < 0.05). Furthermore, the serum level of sCD44v6 was higher in those patients with CD44v6-positive tumor tissues (154.4 +/- 34.8 ng/ml) than in those with CD44v6-negative ones (130.7 +/- 32.3 ng/ml; p < 0.05). The 5-year survival rate was significantly lower in patients with high serum levels of sCD44v6 (52.4%) than in those with low levels of sCD44v6 (78.0%; p < 0.05), and it was also significantly lower in patients with CD44v6-positive cancer (42.1%) than in those with CD44v6-negative cancer (84%; p < 0. 01). We concluded that preoperative elevation in the serum levels of sCD44v6 might be a prognostic indicator for patients with colorectal cancer.

Adenocarcinoma↗

PubMed1999

Serum level of a soluble receptor for interleukin-2 as a prognostic factor in patients with gastric cancer.

Increased levels of a soluble receptor for interleukin-2 (sIL-2R) have been found in the serum from patients with a variety of malignancies. Levels of sIL-2R have not previously been examined in a large group of patients with gastric cancer as a possible indicator of prognosis. Serum levels of sIL-2R were measured preoperatively by an enzyme-linked immunosorbent assay in 121 patients with gastric cancer. The preoperative levels of sIL-2R in patients with gastric cancer were significantly higher than those in normal controls. An elevated level of sIL-2R was significantly correlated with certain clinicopathologic features, which included depth of invasion, lymph node metastasis, lymphatic vessel invasion, blood vessel invasion and clinical stage. The postoperative survival time of patients with elevated levels of sIL-2R was significantly shorter than that of patients with normal levels. Furthermore, a multivariate analysis using Cox's proportional hazards model showed that the combination of levels of carcinoembryonic antigen and sIL-2R was an independent indicator of prognosis. Thus, the serum level of sIL-2R might be a useful prognostic indicator in patients with gastric cancer.

Adenocarcinoma↗

PubMed1999

Administration in a hypotonic solution is preferable to dose escalation in intraperitoneal cisplatin chemotherapy for peritoneal carcinomatosis in rats.

An animal model of intraperitoneal (i.p.) cisplatin chemotherapy using hypotonic solutions of sodium chloride has been developed as a treatment for peritoneal carcinomatosis. The concentrations of platinum in the plasma and in the i.p. fluid of Donryu rats were measured after i.p. injection of hypotonic (103 or 154 mosm/l) and isotonic (308 mosm/l) solutions that contained an equal amount of cisplatin. The maximum concentration (Cmax) and the area under the curve of concentration versus time (AUC) of platinum in the plasma increased proportionately with increases in the dose of cisplatin and they were significantly higher in rats given cisplatin in hypotonic solutions than in those given the drug in isotonic solution. The Cmax and AUC of total platinum were similar for the solution of 103 mosm/l with 2.5 mg/kg cisplatin and the isotonic solution with 5.0 mg/kg cisplatin. The Cmax and AUC of free platinum in the plasma did not increase with increases in the dose of cisplatin in isotonic solution but did increase after hypotonic injection. However, the solutions of lower osmolarity gave a decreased AUC of platinum in the i.p. fluid. Hypotonic conditions continued for 30 min at most after i.p. injection of hypotonic solutions. When the same dose of cisplatin was given to rats with tumors derived from AH100B carcinoma cells, the amount of platinum taken by i.p. solid tumors from the solution of 103 mosm/l was about twice that from the isotonic solution and was much the same as that taken up from the isotonic solution with twice the amount of cisplatin. These results indicate that hypotonic i.p. cisplatin chemotherapy might be preferable to escalation of the dose of i.p. cisplatin in the treatment of peritoneal carcinomatosis.

Animals↗

PubMed1999

Neoangiogenesis and relationship to nuclear p53 accumulation and vascular endothelial growth factor expression in advanced gastric carcinoma.

Recent studies have shown that tumor suppressor genes, particularly p53, may play a crucial regulatory role in the control of angiogenesis. Accordingly, we analyzed the correlation between p53 accumulation and the expression of vascular endothelial growth factor (VEGF) and microvessel counts in a series of human gastric adenocarcinomas by immunohistochemical staining. p53 expression was absent in 35 cases (29.7%), weak in 34 cases (28.8%), moderate in 35 cases (29.7%), and strong in 14 cases (11.8%). The prognosis of patients with both absent and weak expression of p53 was significantly better than that of patients with both moderate and strong expression of p53. VEGF expression was significantly associated with increased p53 expression. Moreover, increasing expression of p53 significantly correlated with an increase in microvessel counts. Nuclear p53 accumulation may correlate with tumor angiogenesis through VEGF upregulation in gastric carcinomas.

Adenocarcinoma↗

PubMed1999

Less invasive surgery for early gastric cancer based on the low probability of lymph node metastasis.

BACKGROUND: Less invasive treatment is the current trend in many surgical fields. Most patients with early gastric cancer do not have lymph node metastasis. Thus extensive resection of the stomach and extended lymph node dissection do not appear to be necessary. METHODS: In a retrospective study, 890 consecutive patients with early gastric cancer who had undergone standard gastrectomy were assessed for depth of invasion, gross appearance, and maximum diameter of the tumor to examine the possibility of limiting the extent of lymph node dissection. A variety of limited gastrectomies have been developed and now include endoscopic mucosal resection, wedge resection, segmental gastrectomy, limited proximal gastrectomy, and distal hemigastrectomy. RESULTS: A retrospective study revealed that extensive lymph node dissection did not improve the survival of patients with early gastric cancer. Endoscopic mucosal resection was suitable for cancers of the depressed type of less than 1 cm in diameter and the elevated type of less than 2 cm in diameter. Wedge, segmental, or limited proximal gastrectomy was suitable for the elevated type of 2 to 3 cm in diameter. The elevated type of more than 3 cm in diameter and the depressed type of 1 to 3 cm in diameter sometimes involved metastasis to group 1 nodes. The depressed type of more than 3 cm in diameter sometimes involved metastasis to group 2 nodes. Thus such cases should be treated by gastrectomy with dissection of potentially metastatic lymph nodes. CONCLUSIONS: Limitation of the extent of gastrectomy and lymph node dissection may be possible, depending on the gross appearance and size of the tumor.

Adult↗

PubMed1999

Expression of vascular endothelial growth factor correlates with hematogenous recurrence in gastric carcinoma.

BACKGROUND: It has recently been reported that the microvessel density in a tumor correlates with hematogenous metastasis in gastric carcinoma. The aim of this study was to evaluate the relationship between the expression of vascular endothelial growth factor (VEGF), which was thought to be a potent angiogenesis-promoting factor, and hematogenous recurrence in advanced gastric carcinoma. METHODS: The expression of VEGF and the density of the microvessels were examined by immunohistochemistry in patients with advanced gastric carcinoma with serosal invasion who had undergone curative resection. RESULTS: The prognosis of patients with a VEGF-negative tumor was significantly better than that of patients with a VEGF-positive tumor. Multivariate analysis by Cox proportional hazards model showed that the expression of VEGF was an independent prognostic indicator. The expression of VEGF provided a significant estimate of relative risk for the development of hematogenous recurrence by multivariate logistic regression analysis. The microvessel count in VEGF-positive tumors was significantly higher than that in VEGF-negative tumors. CONCLUSIONS: VEGF is associated with hematogenous recurrence. Assessment of the expression of VEGF may therefore prove valuable in identifying patients with gastric carcinoma at high risk for recurrence who would benefit from adjuvant therapy.

Adult↗

PubMed1999

A prospective pilot study of extended (D3) and superextended para-aortic lymphadenectomy (D4) in patients with T3 or T4 gastric cancer managed by total gastrectomy.

BACKGROUND: Japanese surgeons have been actively performing extended lymphadenectomy (D2, removal of perigastric nodes and nodes along the left gastric, common hepatic, celiac and splenic arteries; or D3, D2 plus removal of nodes in the hepatoduodenal ligament, in the retropancreatic space and along the vessels of the transverse mesocolon). In recent years interest has expanded to superextended lymphadenectomy (D4) of nodes around abdominal aorta (para-aortic lymph nodes from aortic hiatus to aortic bifurcation). Because the therapeutic value of this D4 procedure remains controversial, we initiated a prospective study to compare D3 and D4 lymphadenectomy. METHODS: Seventy patients with T3 or T4 gastric cancer and without macroscopic metastasis to the para-aortic nodes treated by potentially curative total gastrectomy were randomized to D4 (group A, n = 35) and D3 (group B, n = 35) lymphadenectomies. RESULTS: Metastases to para-aortic nodes were found in 4 patients. Postoperative survival after D4 resection was not statistically significant between the groups. Postoperative morbidity for group A was greater. In group A 4 patients had postoperative retention of intra-abdominal fluid (lymphorrhea) and 4 others had prolonged diarrhea. One patient in each group died of postoperative complications. CONCLUSIONS: Surgical treatment of microscopic disease in grossly normal para-aortic lymph nodes may generate occasional long-term survivors. Selecting appropriate candidates who might benefit from D4 resections needs to be refined. On the basis of this study, a nationwide study should be considered.

Aged↗

PubMed1998

Serum concentration of CD44 variant 6 and its relation to prognosis in patients with gastric carcinoma.

BACKGROUND: The expression of variant isoforms of CD44 is correlated with the ability of tumor cells to metastasize in some clinical carcinomas. In this study, the serum concentration of soluble splice isoforms of CD44 that shared exon variant 6 (sCD44v6) were measured and the histologic expression of CD44v6 in tumors from patients with gastric carcinoma examined. METHODS: Serum samples were obtained from 102 patients with primary gastric carcinoma before surgery and serum levels of sCD44v6 were determined with an enzyme-linked immunoadsorbent assay. The expression of CD44v6 in tumors was examined by immunohistochemical staining. RESULTS: Both the serum concentration of sCD44v6 and its expression in tumors were associated significantly with the depth of invasion of the tumor, lymph node metastasis, and clinical stage in patients with diffuse type gastric carcinoma. Among patients with gastric carcinoma, the serum level of sCD44v6 was higher in those with CD44v6 positive tumor cells than in those with CD44v6 negative tumor cells. The serum level of sCD44v6 was a prognostic indicator in patients with diffuse type gastric carcinoma, as was the histologic expression of CD44v6. However, neither CD44v6 nor sCD44v6 was a predictor of survival time in patients with intestinal type gastric carcinoma. CONCLUSIONS: It appears that CD44v6 and sCD44v6 are related to the progression of diffuse type gastric carcinoma. An elevated serum level of sCD44v6 may be useful as a prognostic indicator in patients with diffuse type gastric carcinoma.

Adult↗

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

Combined anterior thigh flaps and vascularised fibular graft for reconstruction of massive composite oromandibular defects.

Six massive, composite oromandibular defects were reconstructed using combined anterior (anterolateral and anteromedial) thigh flaps and vascularised fibular graft in bridge or chimeric fashion. Except for minor dehiscence in one case and infection in another, all flaps survived without complication. Anterior thigh flaps provide large-calibre, long vascular pedicles while derivative branches from the lateral circumflex femoral system facilitate simultaneous transplantation of multiple components. Because the pedicle of the vascularised fibular graft is of insufficient length, the lateral circumflex femoral vessels provide a remote vascular source as a flow-through vascular conduit. A combined flap using the lateral circumflex femoral system is considered to be most suitable for reconstruction of through-and-through defects of the head and neck. The authors describe the advantages of this method and the detailed anatomy of the cutaneous perforators of the anterior thigh flaps.

Adult↗

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↗