Biomedical subjects

Shin-Ichi Murata

Publications and source records attributed to Shin-Ichi Murata.

8 recordsLinked to original sources

PubMed2006

Expression of aquaporin 3 (AQP3) in normal and neoplastic lung tissues.

Aquaporin 3 (AQP3) acts as the membrane channel of water and other small solutes and plays a major role in fluid homeostasis. To investigate the expression of AQP3 in normal and neoplastic lung tissues, we studied a series of 149 lung carcinoma tissues and 2 cell lines by immunohistochemistry, Western blotting, and reverse transcriptase-polymerase chain reaction. In normal lung tissues, immunohistochemical expression of AQP3 was demonstrated in bronchial basal cells, alveolar type II cells, bronchiolar epithelial cells, and secretory cells of submucosal glands. In lung carcinomas, AQP3 expression was observed in 59 (70.2%) of 84 adenocarcinomas. Squamous cell carcinoma and large cell carcinoma had rather low positive ratios (35.8% and 13.4%, respectively). No AQP3 expression was demonstrated in small cell carcinoma, pleomorphic carcinoma, or metastatic colon adenocarcinoma. In adenocarcinomas, AQP3 was detected in all tumors of bronchioloalveolar subtype. Papillary subtype also showed a higher positive ratio of AQP3 compared with that in acinar and solid with mucin subtypes. In addition, AQP3 expression was related to tumor differentiation and clinical stage in adenocarcinomas. Western blotting and reverse transcriptase-polymerase chain reaction analyses confirmed the expression of AQP3 protein and messenger RNA in cell lines and tissues of lung adenocarcinoma. We conclude that AQP3 is widely expressed in the normal respiratory tract and can play an important role in the maintenance of water homeostasis. In addition, lung carcinomas, especially adenocarcinomas, can produce AQP3, possibly in connection with their functional and/or biological nature, although the detailed mechanism of AQP3 expression in lung carcinomas remains to be clarified.

Adenocarcinoma↗

PubMed2006

p16INK4a overexpression independent of human papillomavirus infection in lobular endocervical glandular hyperplasia.

A high rate of human papillomavirus (HPV) infection has been reported in cervical cancer and precancerous lesions. Many studies also have shown that p16INK4a overexpression is of diagnostic value for high-risk HPV-related cervical cancer and precursors. Lobular endocervical glandular hyperplasia (LEGH) is a rare lesion of the uterine cervix. There is one report about HPV infection and few studies on p16INK4a expression in LEGH. Therefore, we 1) detected HPV infection and examined p16INK4a expression and 2) observed the relationship between HPV and p16INK4a overexpression in LEGH. The immunohistochemical expression of p16INK4a was studied in 24 cases of LEGH. HPV DNA was also evaluated in these cases using a polymerase chain reaction technique. Strong (++) p16INK4a immunoreactivity was observed in 10 (41.7%) of the 24 LEGH cases; a moderate (+) pattern was observed in 9 (37.5%) cases; a weak (+) pattern was observed in 2 (8.3%) cases; and the remaining 3 (12.5%) cases showed negative expression. Overall, p16INK4a overexpression was seen in 87.5% of the cases (21/24). HPV DNA was not detected in any of the 24 LEGH cases. These results suggest that p16INK4a overexpression is independent of HPV infection in LEGH.

Adult↗

PubMed2005

Identification of plasma membrane macro- and microdomains from wavelet analysis of FRET microscopy.

In this study, we sought to characterize functional signaling domains by applying the multiresolution properties of the continuous wavelet transform to fluorescence resonance energy transfer (FRET) microscopic images of plasma membranes. A genetically encoded FRET reporter of protein kinase C (PKC)-dependent phosphorylation was expressed in COS1 cells. Differences between wavelet coefficient matrices revealed several heterogeneous domains (typically ranging from 1 to 5 microm), reflecting the dynamic balance between PKC and phosphatase activity during stimulation with phorbol-12,13-dibutyrate or acetylcholine. The balance in these domains was not necessarily reflected in the overall plasma membrane changes, and observed heterogeneity was absent when cells were exposed to a phosphatase or PKC inhibitor. Prolonged exposure to phorbol-12,13-dibutyrate and acetylcholine yielded more homogeneous FRET distribution in plasma membranes. The proposed wavelet-based image analysis provides, for the first time, a basis and a means of detecting and quantifying dynamic changes in functional signaling domains, and may find broader application in studying fine aspects of cellular signaling by various imaging reporters.

Adaptor Proteins, Signal Transducing↗

PubMed2005

Mucinous carcinoma (poorly differentiated carcinoma with extensive extracellular mucin deposition) of the thyroid: a case report with immunohistochemical studies.

We report on a case of mucinous carcinoma of the thyroid in an 82-year-old Japanese woman. The 3 x 2 x 2-cm thyroid tumor located in the patient's right lateral lobe was soft and yellowish gray on the cut section. Microscopically, the tumor was composed entirely of strands or solid clusters accompanied by extensive extracellular mucin. Extracellular mucin was positive with Alcian blue stain and negative with periodic acid-Schiff stain. Immunohistochemically, the tumor cells were positive for thyroglobulin, thyroid-specific transcription factor 1, and low-molecular-weight cytokeratin but negative for carcinoembryonic antigen, calcitonin, and high-molecular-weight cytokeratin. The MIB-1 labeling index was rather high (11%), and immunoexpression of p53 was detectable in the nuclei of carcinoma cells. From these findings, we classified the present tumor as a mucinous carcinoma of the thyroid (poorly differentiated thyroid carcinoma producing massive extracellular mucin). The patient died of multiple metastases 4 years after the initial operation.

Adenocarcinoma, Mucinous↗

PubMed2005

Absence of human papillomavirus infection in minimal deviation adenocarcinoma and lobular endocervical glandular hyperplasia.

The human papillomavirus (HPV) is basically always detected in squamous cell carcinoma of the cervix and its precursors; a high incidence of HPV also has been reported in adenocarcinoma and adenocarcinoma in situ of the uterine cervix. Lobular endocervical glandular hyperplasia (LEGH) was first described by Nucci in 1999. It is difficult to differentiate minimal deviation adenocarcinoma (MDA) from LEGH preoperatively or postoperatively by clinical and pathologic features. The relationships between HPV and MDA or LEGH have not been studied well because of the rare incidence of the two diseases. To our knowledge, the HPV status in LEGH has not been reported. This study was designed to investigate HPV infection in MDA and LEGH, using the polymerase chain reaction (PCR) technique. Tumor tissue lesions were microdissected and the detection of HPV and its typing were analyzed by PCR-based assay. As the control, HPV DNA was detected in all cases of squamous cell carcinoma and three of five cases of adenocarcinoma. However, no HPV DNA was detected in any of the 10 cases of LEGH or in the 3 cases of MDA. These results suggest that MDA and LEGH are probably not related to HPV infection.

Adenocarcinoma↗

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

Wilms tumor gene immunoreactivity in primary serous carcinomas of the fallopian tube, ovary, endometrium, and peritoneum.

Wilms tumor gene (WT-1) expression has been reported in many human cancers, including most ovarian and peritoneal serous carcinomas, but has not been studied in carcinomas of the fallopian tube. In this study, the authors evaluated the immunohistochemical expression of WT-1 in serous carcinomas of the fallopian tube and compared their reactivity with that of ovarian, peritoneal, and endometrial serous carcinomas. All primary serous carcinomas of the fallopian tube (13 cases), ovaries (25 cases), and peritoneum (3 cases) were reactive with the WT-1 antibody, whereas all five primary endometrial serous carcinomas were nonreactive. WT-1 reactivity in an unknown primary serous carcinoma is therefore suggestive of an extrauterine site. The marked difference in WT-1 staining raises the possibility of genetic differences between serous carcinomas arising in the endometrium compared with those arising in the ovaries, fallopian tubes, and peritoneum.

Adult↗

PubMed2003

Spatial distribution analysis of AT- and GC-rich regions in nuclei using corrected fluorescence resonance energy transfer.

We employed microscopic intensity-based fluorescence resonance energy transfer (FRET) images with correction by donor and acceptor concentrations to obtain unbiased maps of spatial distribution of the AT- and GC-rich DNA regions in nuclei. FRET images of 137 bovine aortic endothelial cells stained by the AT-specific donor Hoechst 33258 and the GC-specific acceptor 7-aminoactinomycin D were acquired and corrected for the donor and acceptor concentrations by the Gordon's method based on the three fluorescence filter sets. The corrected FRET images were quantitatively analyzed by texture analysis to correlate the spatial distribution of the AT- and GC-rich DNA regions with different phases of the cell cycle. Both visual observation and quantitative texture analysis revealed an increased number and size of the low FRET efficiency centers for cells in the G(2)/M-phases, compared to the G(1)-phase cells. We have detected cell cycle-dependent changes of the spatial organization and separation of the AT- and GC-rich DNA regions. Using the corrected FRET (cFRET) technique, we were able to detect early DNA separation stages in late interphase nuclei.

AT Rich Sequence↗