Biomedical subjects

Yoji Urata

Publications and source records attributed to Yoji Urata.

9 recordsLinked to original sources

PubMed2006

Dynamic helical CT mammography of breast cancer.

PURPOSE: The purpose of this study was to determine whether dynamic helical computed tomography (CT)-mammography could assist in selecting the most appropriate surgical method in women with breast cancer. MATERIALS AND METHODS: Preoperative contrast-enhanced helical CT scanning of the breast was performed on 133 female patients with suspicion of breast cancer at the same time as clinical, mammographic, and/or ultrasonographic examinations. The patients were scanned in the prone position with a specially designed CT-compatible device. A helical scan was made with rapid intravenous bolus injection (3 ml/s) of 100 ml of iodine contrast material. Three-dimensional maximum intensity projection (MIP) images were reconstructed, and CT findings were correlated with surgical and histopathological findings. RESULTS: Histopathological analysis revealed 84 malignant lesions and seven benign lesions. The sensitivity, specificity, and accuracy levels of the CT scanning were 94.6%, 58.6%, and 78.9%. Helical scanning alone revealed additional contralateral carcinomas in three of four patients and additional ipsilateral carcinomas in three of five patients. However, the technique gave false-positive readings in 24 patients. The preoperative CT-mammogram altered the surgical method in six patients. CONCLUSION: Dynamic helical CT-mammography in the prone position may be one of the choices of adjunct imaging in patients with suspected breast cancer scheduled for surgery.

Adult↗

PubMed2003

Morphological abstraction of thyroid tumor cell nuclei using morphometry with factor analysis.

Various morphonuclear studies by digital image analysis have successfully been applied to quantify the nuclear morphology, including chromatin distribution pattern, in cytology of various organs; however, the majority of past reports have not shown correlation between the quantitative data by digital image analysis and cytological findings in practical diagnosis. In this report, we present the usefulness of morphological abstraction to combine the objective data and subjective observation in cytological diagnosis. Randomly selected, 100 cells in each Papanicolaou-stained ABC smear samples of 39 benign and malignant thyroid tumor cases were studied. Gray-level image data provided seven parameters for nuclear size, four parameters for nuclear shape, and 16 parameters showing the nuclear chromatin patterns from high-dimensional texture analysis of using co-occurrence and run-length matrices. To statistically abstract nuclear morphology, factor analysis was used. Factor analysis classified morphological nuclear characters as abstraction parameter into five abstract parameters composed of nuclear size, shape, heterogeneity, and contrast and homogeneity of chromatin pattern. The nuclei of papillary carcinoma showed larger size, more irregular shape, and higher contrast of chromatin pattern than those of the benign group. The follicular carcinomas have larger nucleus in each cell and more monotonous chromatin pattern among cells in each case than those of the benign group. Morphological abstraction by morphometry with factor analysis may provide a practical approach to the detection of the underlying characteristics of nuclear morphology in aspiration biopsy cytology.

Cell Nucleus↗

PubMed2003

Accumulation of 99mTc-PMT in renal metastasis of hepatocellular carcinoma.

We describe here a case in which 99mTc-Sn-N-pyridoxy-5-methyltryptophan (99mTc-PMT) scintigraphy was useful in diagnosing renal metastasis of hepatocellular carcinoma (HCC). A 62-year-old man who had undergone hepatectomy for HCC presented 6 years after initial diagnosis with left flank pain and was found on CT and MRI to have a tumor in the left kidney. Hepatobiliary scintigraphy using 99Tc-PMT was performed, and 99mTc-PMT accumulation was found in the tumor. Nephrectomy was performed and metastasis of HCC was confirmed.

Carcinoma, Hepatocellular↗

PubMed2003

Renal tubular regeneration by bone marrow-derived cells in a girl after bone marrow transplantation.

Recent studies have indicated that bone marrow cells can contribute to regeneration of the kidney in experimental models. However, renal regeneration by apparent bone marrow-derived cells has not been shown previously in humans. The authors here report on a 7-year-old girl who received whole bone marrow transplantation from a male donor, and the contribution of bone marrow cells to the regeneration after renal damage was shown by in situ hybridization for the Y chromosome on autopsy specimens of the kidney. This observation suggests the clinical potential of bone marrow cells as a therapeutic option for renal injury.

Bone Marrow Transplantation↗

PubMed2002

Detection of underlying characteristics of nuclear chromatin patterns of thyroid tumor cells using texture and factor analyses.

BACKGROUND: Aspiration biopsy cytology of thyroid tumors has been used more frequently in recent times to differentiate between malignant and benign lesions. Chromatin patterns of the tumor cell nuclei are one of most important factors for cytologic diagnosis. The interpretation of nuclear chromatin patterns is subjective and more difficult than that of nuclear size or shape. In the present report, we investigated how to detect underlying chromatin characteristics of benign and malignant thyroid tumor cells by means of texture and factor analyses. METHODS: We employed a computer-aided system in which light microscopy was combined with an image processor and monochrome camera. Using this system, 100 randomly selected cells in a Papanicolaou stained, aspiration biopsy cytologic smear in each case of 39 benign and malignant thyroid tumor cases were digitized. We applied two-dimensional and higher texture analyses with the use of co-occurrence and run-length matrices to analyze the chromatin patterns. Factor analysis was used to determine whether a large number of independent variables actually measured one or more underlying common variables. RESULTS: According to parameters with high factor-loading values, the morphologic chromatin characters were classified into three categories according to heterogeneity, contrast, and homogeneity of chromatin patterns. On the basis of analyses with these morphologic categories, nuclei of papillary carcinoma showed higher contrast of chromatin patterns than did those of the benign group. Moreover, there was a variety of contrasting chromatin patterns among cells in each papillary carcinoma case in comparison with the benign group. In contrast, follicular carcinomas showed a significant difference in the standard deviation of factor 3, which indicated more monotonous chromatin patterns among cells in each follicular carcinoma case than in each benign case. CONCLUSION: We believe that this technique, using texture and factor analyses, is useful in the detection of underlying characteristics of nuclear chromatin patterns in aspiration biopsy cytology.

Adenocarcinoma, Follicular↗

PubMed2002

Role of human interleukin-9 as a megakaryocyte potentiator in culture.

OBJECTIVE: This study investigated the effect of interleukin-9 (IL-9) on the proliferation and differentiation of human colony-forming unit megakaryocytic progenitor cells (CFU-Meg). MATERIALS AND METHODS: Peripheral blood-derived CD34(+)IL-6R(-) cells were sorted and cultured in the presence of IL-9, erythropoietin (Epo), stem cell factor (SCF), and thrombopoietin (TPO) alone or in combination. The number of pure and mixed megakaryocyte colonies, the size of pure megakaryocyte colonies, the ploidy distribution of megakaryocytes, and proplatelet formation were investigated. RESULTS: Apart from TPO, no single factor could support CFU-Meg-derived colony formation, but each two-factor combination among IL-9, Epo, and SCF supported a few CFU-Meg colonies. Interestingly, the combination of Epo+SCF+IL-9 induced four to six times as many CFU-Meg colonies as any of the two-factor combinations. Neutralizing monoclonal antibodies (mAbs) for IL-9 receptor and c-kit completely abolished this synergistic effect. In contrast, addition of neutralizing anti-c-Mpl or anti-CXCR4 Abs did not influence colony formation, indicating that this synergistic effect was independent of TPO or SDF-1. Moreover, the endogenous production of TPO by cultured CD34(+)IL-6R(-) cells in the presence of Epo+SCF+IL-9 was ruled out by reverse transcriptase polymerase chain reaction for TPO mRNA. Interestingly, the combination of TPO, Epo, SCF, and IL-9 supported the largest number of pure and mixed megakaryocyte colonies, suggesting that this combination of cytokines might recruit primitive megakaryocytic as well as multipotential progenitors. This combination also potently enhanced proplatelet formation compared with TPO alone or a combination of Epo, SCF, and IL-9. CONCLUSION: This study demonstrated for the first time that human IL-9 can potentiate human megakaryocytopoiesis in the presence of Epo and/or SCF.

Blood Platelets↗

PubMed2002

Elevated expression of inducible nitric oxide synthase and inflammatory cytokines in the alveolar macrophages after esophagectomy.

OBJECTIVE: To evaluate the role of inducible nitric oxide (NO) synthase (iNOS) and inflammatory cytokines in alveolar macrophages (AMs) after esophagectomy in the pathogenesis of acute lung injury. DESIGN: Prospective, exploratory, open-labeled clinical study. SETTING: Intensive care unit and operating room in a university hospital. PATIENTS: Thirteen patients receiving esophagectomy with carcinoma of the esophagus (postesophagectomy group), ten patients just before the surgery (preoperation group), and seven patents receiving surgery less invasive than esophagectomy (other surgery group) were selected. INTERVENTIONS: Bronchoalveolar lavage fluid (BALF) and blood samples were obtained from study groups. MEASUREMENTS AND MAIN RESULTS: The AMs in the BALF collected from each group were stained immunohistochemically with antibodies against iNOS, interleukin (IL)-6, and IL-8. The intensities of these expressions were determined by semiquantitative cytofluorometric system. NOx (NO2- + NO3-), IL-6, and IL-8 levels in the BALF and plasma were measured concurrently. The expressional intensities of iNOS, IL-6, and IL-8 in AMs obtained from the postesophagectomy group were maximal 24 hrs after the skin incision and significantly more evident than those from other groups. The IL-6, IL-8, and NOx levels in BALF and IL-6 and IL-8 levels in plasma in the postesophagectomy patients were also elevated. The intensities of iNOS and inflammatory cytokines expressions in AMs were closely related to postoperative respiratory failure. CONCLUSIONS: The activation of topical alveolar macrophages may be involved in the pathogenesis of pulmonary complications in the postoperative period after esophagectomy.

Aged↗

PubMedDate not supplied

Multiple enhancing lesions detected on dynamic helical computed tomography-mammography.

OBJECTIVES: To review pathologic diagnoses of multiple enhancing lesions in a unilateral breast detected on dynamic helical computed tomography (CT)-mammography and to correlate imaging findings with pathologic results. METHODS: From May 1998 to July 2001, preoperative contrast-enhanced helical CT scanning of the breast was performed in 200 female patients clinically diagnosed with breast cancer. The patients were scanned in the prone position in a specially designed CT-compatible device, with rapid intravenous bolus injection of 100 mL contrast material. Three-dimensional maximum intensity projection images were reconstructed. The cases with multiple enhancing lesions in a unilateral breast were retrospectively reviewed. The maximum diameter of the largest stain in each breast was measured, the patterns of multiple enhancing lesions were classified, and imaging findings were correlated with surgical and pathologic outcomes. RESULTS: Twenty-five of 200 (12.5%) patients (age range: 39-86 years, mean age: 56 years) showed multiple stains on CT-mammography. Two patients showed multiple stains in bilateral breasts. The maximum diameter of the largest stain in each breast ranged from 5 to 55 mm (average: 22 mm). Among cases with multiple stains, 21 (78%) were shown to be invasive ductal carcinoma with multiple satellite cancer nodules. Four cases were ductal carcinoma in situ with multiple satellite nodules. One case revealed multiple fibroadenomas, and another showed intraductal papilloma. CONCLUSIONS: Multiple enhancing lesions on CT-mammography in patients with breast cancer were relatively common, and most of them represented multiple cancer lesions. Dynamic CT-mammography is potentially useful in evaluating the spread of breast cancer.

Adult↗

PubMedDate not supplied

Benign or malignant?: differentiating breast lesions with computed tomography attenuation values on dynamic computed tomography mammography.

OBJECTIVE: To evaluate enhancement effects of breast lesions with dynamic computed tomography (CT) and to determine characteristics to aid in differential diagnosis of benign and malignant lesions. METHODS: One hundred seventy-six women underwent preoperative dynamic CT, in which they were scanned with rapid injection of contrast media (3 mL/s) after 30 seconds and 2 minutes (early and delayed phases, respectively). The CT values and enhancement patterns of malignant lesions (n = 154) were compared with those of benign lesions (n = 22), and the cut point of CT values with the best validity was analyzed. RESULTS: The CT values of malignant lesions were higher than those of benign lesions in both phases (P < 0.0001). The cut point was determined to be 60 Hounsfield units (HU) in the early phase (44% validity, 90% sensitivity). Washout and plateau patterns were more commonly seen in the malignant group (73% specificity). CONCLUSIONS: The analysis of enhancement effects on CT may lead to more appropriate differentiation of benign and malignant lesions.

Adult↗