Biomedical subjects

Yumiko Ohno

Publications and source records attributed to Yumiko Ohno.

9 recordsLinked to original sources

PubMed2006

Effect of lectins on the transport of food factors in caco-2 cell monolayers.

The effect of three plant lectins, soybean lectin (SBA), Japanese jack bean lectin (CGA), and wheat germ lectin (WGA), on the transport of various food factors, such as isoflavones, quercetin, dipeptides, and calcium ions, were investigated by use of an intestinal tract model, Caco-2 cell monolayers. The lectins increased the isoflavone transport but had no effect on aglycon transport. SBA increased the transport of quercetin glycosides, whereas CGA and WGA had no effect. The lectins increased the transport of calcium ions but showed no effect on the transport of dipeptides, carnosine, and anserine. Although SBA did not change the transepithelial electrical resistance (TER) value of the Caco-2 cell monolayers, CGA and WGA decreased the TER value. These results indicate that plant lectins affect the transport of food factors in different manners, presumably due to their specific sugar binding activity.

Biological Transport↗

PubMed2005

Role of cyclooxygenase-2 in immunomodulation and prognosis of endometrial carcinoma.

Although there are several hypotheses explaining the mechanisms of immune-privileged status of malignant tumor, the exact pathway has yet to be explored. Cyclooxygenase (COX)-2 plays a vital role in prognosis of cancer patients in terms of contribution to neoangiogenesis and apoptosis inhibition; however, the impact of COX-2 in immunomodulation has not been reported. We have evaluated the expression of COX-2 and its impact on infiltration of immune-competent cells into the tumor cell nest in endometrial carcinoma. Tissue specimens from 70 endometrial carcinoma patients who had undergone a curative resection were evaluated for COX-2 expression and host immune status (CD8+ T cells). COX-2 expression was associated with FIGO stage and myometrial invasion, but there was no statistically significant impact. CD8+ T cells within cancer cell nest (Nest CD8) were inversely correlated with the expression level of COX-2 (p = 0.0006). Nest CD8 became an independent predictor of patient survival (Hazard ratio = 10.300, p = 0.0304) in Cox's multivariate analysis. The expression level of COX-2 was found to be a significant predictor of disease relapse in univariate analysis (p = 0.0294) but not in multivariate analysis (p = 0.5949). In conclusion, increased nest CD8 produced a survival advantage in endometrial carcinoma patients. Moreover, tumor-produced COX-2, which reduces the infiltration of CD8+ T cells into cancer cell nests, may allow tumors to avoid immune surveillance.

Adult↗

PubMed2003

Electron density measurement with dual-energy x-ray CT using synchrotron radiation.

Monochromatic x-ray computed tomography (CT) at two different energies provides information about electron density of human tissue without ambiguity due to the beam hardening effect. This information makes the treatment planning for proton and heavy-ion radiotherapy more precise. We have started a feasibility study on dual energy x-ray CT by using synchrotron radiation. A translation-rotation scanning CT system was developed for quantitative measurement in order to clarify what precision in the measurement was achieved. Liquid samples of solutions of K2HPO4 and solid samples of tissue equivalent materials were used to simulate human tissue. The experiments were carried out using monochromatic x-rays with energies of 40, 70 and 80 keV produced by monochromatizing synchrotron radiation. The solid samples were also measured in a complementary method using high-energy carbon beams to evaluate the electron densities. The measured electron densities were compared with the theoretical values or the values measured in the complementary method. It was found that these values were in agreement in 0.9% on average. Effective atomic numbers were obtained as well from dual-energy x-ray CT. The tomographic image based on each of the electron densities and the effective atomic number presents a different feature of the material, and its contrast drastically differs from that in a conventional CT image.

Connective Tissue↗

PubMed2000

[Fundamental Study on Heavy Ion CT Using Pencil Beam Scanning Method]

The feasibility of heavy ion computed tomography was investigated. A cylindrical polyethylene sample of 50 mm in diameter was used to establish the pencil beam scanning method and estimate the performance of the system. The sample was irradiated with carbon ions of 290 MeV/u and 400 MeV/u, and helium ions of 150 MeV/u. The residual beam energy was measured by a BGO scintillator in coincidence with two small plastic scintillators placed in front of and behind the sample to restrict the beam path and improve the spatial resolution in the CT reconstruction. The projection data were obtained by moving the sample only in the transverse direction because of its symmetrical structure. A Lucite sample with many holes of different diameters was used to demonstrate the spatial resolution of this CT system. From the reconstructed images the spatial resolution was estimated to be less than 2 mm under the conditions in this work. The electron density ratios of ethyl alcohol, water, and Lucite to polyethylene were obtained, which are in good agreement with the calculated values.

Journal Article↗

PubMedDate not supplied

Tumor-associated macrophages: foe or accomplice of tumors?

Macrophages are predominantly involved in the immune and inflammatory processes of solid tumors. Macrophages infiltrated into a tumor have an ambivalent relationship with the tumor, because they are innately very flexible and adaptable depending on the microenvironment of the tissue and the tissue-derived factors. The relationship between tumor-associated macrophages (TAMs) and a tumor is extremely complicated and has not yet been clearly elucidated. Now, the reintegration of biological knowledge including immunology, pathology and oncology is indispensable for the clinical application of TAMs to cancer therapy. In this review, we focus on the range of pro- and anti-tumor functions performed by TAMs and outline a new class of cancer therapies that aims at controlling the complex functions of TAMs.

Animals↗

PubMedDate not supplied

Correlation of histological localization of tumor-associated macrophages with clinicopathological features in endometrial cancer.

BACKGROUND: To clarify the pathophysiological role of tumor-associated macrophages (TAMs), we performed clinicopathological analysis of CD68+ cells in 70 cases of human endometrial cancer. MATERIALS AND METHODS: Using immunohistochemistry for CD68, we classified CD68+ cells into four groups: (a) those infiltrated into cancer cell nests or in close contact with cancer cells (nest TAM); (b) those in necrosis in the tumor center (hot-spot TAM); (c) those infiltrated into cancer stroma (stroma TAM); and (d) those distributed along the invasive margin of a tumor (Margin TAM). RESULTS: The aggregation of nest TAM related to high relapse-free survival rate after surgery. On the contrary, increased hot-spot TAM was a hazard to relapse-free survival and was proportionately-associated with clinical stage, myometrial invasion and histological differentiation. The extent of stroma TAM was associated with the presence of lymph node metastasis. CONCLUSION: Our findings demonstrate that the histological location of infiltrated TAMs may be taken into account in the clinical evaluation of endometrial cancer.

Adult↗

PubMedDate not supplied

Role of tumor-associated macrophages (TAM) in advanced gastric carcinoma: the impact on FasL-mediated counterattack.

BACKGROUND: Exactly what role does tumor-derived Fas ligand (FasL) play in cancer: maintaining the immune privilege site or inducing a pro-inflammatory effect? One possible hypothesis is that tumor-associated macrophages (TAM) act as the mediator that enables apoptosis of anti-tumor immune cells without FasL-related inflammation. We have evaluated the tumor FasL expression and TAM along the tumor margin and/or in cancer stroma, and their impact on the infiltration of immune-competent cells into the tumor nest. PATIENTS AND METHODS: Tissue specimens from consecutive 84 advanced gastric carcinoma patients, who had undergone a curative resection, were evaluated for TAM (CD68+ cells), tumor FasL expression and immune status (CD8 + T cells). RESULTS: A high number of TAM significantly correlated with lymph node metastasis, intestinal type tumor and FasL expression. Although TAM had a tendency for an inverse correlation with the number of CD8+ T cells within the tumor nest (nest CD8) (p=0.0592), there was no correlation between FasL expression and nest CD8 (p=0.2158). This inverse association was found to be stronger in cases with both FasL-positive and high TAM tumors than in others (p=0.0139). The combination parameter of FasL-positive and high TAM became an independent prognostic factor in Cox's multivariate analysis, along with the pT status, nest CD8 and tumor cell apoptosis. CONCLUSION: We suggest that TAM works harmoniously with tumor-derived FasL and serves as a barrier against the infiltration of CD8+ T cells into the cancer nest.

Adult↗

PubMedDate not supplied

Multiple roles of cyclooxygenase-2 in endometrial cancer.

Cyclooxygenase-2 (COX-2) plays a critical role not only in maintenance of the endometrium during the menstrual cycle, but also in the progression of endometrial cancer. The role of COX-2 in tumor growth and development is complex and multifaceted. This review presents evidence for the expression of COX-2 being linked to angiogenesis, tumor cell apoptosis, tumor cell growth, metastasis and local immunosuppression in cancer progression. It also outlines the clinicopathological and prognostic significance of COX-2 in endometrial cancer.

Animals↗

PubMedDate not supplied

Expression of Tn and sialyl-Tn antigens in endometrial cancer: its relationship with tumor-produced cyclooxygenase-2, tumor-infiltrated lymphocytes and patient prognosis.

BACKGROUND: Although many tumors arising from epithelial tissues produce mucins, little is known regarding the biological significance of mucins in cancer. Recent researches have revealed that mucins produced by cancer cells play a critical role in the initial induction of cyclooxygenase (COX)-2 in the tumor microenvironment. Moreover, the consequence of abnormal glycosylation and overexpression of mucins includes suppression of the host-immune function. MATERIALS AND METHODS: The expression of Tn/sialyl-Tn (s-Tn) antigen and its impact on COX-2 expression by tumor cells and infiltration of CD8+ T-cell into the cancer cell nest (nest CD8) in endometrial cancer was evaluated. Tissue specimens from 70 endometrial cancer patients who had undergone a curative resection were evaluated for Tn/s-Tn antigen, COX-2 and CD8 by immunohistochemistry. RESULTS: The overexpression of Tn and s-Tn antigen was significantly correlated with COX-2 overexpression (p <0.005 and p <0.001, respectively). There was a significant association between s-Tn overexpression and low infiltration of nest CD8 (p<0.05). Strong expression of s-Tn antigen was significantly associated with poor prognosis (p < 0. 005). Among several prognostic factors, s- Tn expression remained the strong independent predictor of survival by multivariate analysis (p<0.05). CONCLUSION: These results suggested that tumor-produced mucins, which were associated with COX-2 induction and immunosuppression, provided additional prognostic information in endometrial cancer patients.

Adult↗