Biomedical subjects

Tetsuo Kondo

Publications and source records attributed to Tetsuo Kondo.

16 recordsLinked to original sources

PubMed2005

RET gene rearrangements (RET/PTC1 and RET/PTC3) in papillary thyroid carcinomas from an iodine-rich country (Japan).

BACKGROUND: The frequency of RET rearrangements (RET/PTC) in papillary thyroid carcinomas varies significantly according to geographic area, with the greatest incidence reported in the Belarus region, which is iodine-deficient and was contaminated severely after the Chernobyl reactor accident, and with the lowest incidence in iodine-rich, nonirradiated Japan. The authors investigated the prevalence of RET/PTC in a large number of thyroid tumors from Japanese patients. METHODS: Fresh and paraffin embedded tumor tissues from 215 Japanese patients were examined for RET rearrangements (RET/PTC1 and RET/PTC3) by means of reverse transcriptase-polymerase chain reaction analysis, with primers flanking the chimeric region, followed by direct-sequence analysis. RESULTS: RET/PTC was found only in papillary carcinomas and was not observed in other histologic types of thyroid tumors. The overall frequency of RET/PTC in papillary carcinomas was 28.4%, with a greater frequency in younger patients, including 41.9% of younger patients age < 20 years, 27.6% of patients age 20-40 years, and 24.8% of patients age > 40 years. Among the patients in these 3 age groups, the prevalence rate of RET/PTC1 was similar, but RET/PTC3 was observed most frequently among patients age < 20 years. When the tumors were grouped further according to histologic subtypes, the prevalence of RET/PTC3 was greater in solid/solid-follicular papillary carcinomas than in classic papillary carcinomas. CONCLUSIONS: The results indicated that RET/PTC may be useful as a specific molecular marker for papillary thyroid carcinomas. Furthermore, its incidence in such tumors was not low in Japanese patients, and it seemed to be associated with patient age. Therefore, the current results raise questions regarding the belief that the frequency of RET/PTC differs geographically and is especially low in Japan.

Adult↗

PubMed2005

Compression behavior of Langmuir-Blodgett monolayers of regioselectively substituted cellulose ethers with long alkyl side chains.

Regioselectively substituted alkylcellulose ethers having long alkyl side chains, 6-O- (6C18), 2,3-di-O- (23C18), and tri-O-octadecyl-cellulose (triC18) were successfully synthesized. The key step of these syntheses was removal of the residual alkylation reagent by an isothermal crystallization procedure to isolate and purify the compounds, since a physical entanglement between the long alkyl side chains in the cellulose derivatives and the reagent had caused difficulty in obtaining the purified derivatives. After the monolayers from these cellulose ethers were fabricated on a water surface, they were deposited on substrates by a vertical dipping method to be Langmuir-Blodgett (LB) monolayers. During the compression process of each monolayer, a surface pressure (pi)-area (A) isotherm behaved in a different way. Atomic force microscopy (AFM) was employed to interpret changes of the surface topography of the obtained LB monolayers depending on the surface pressure. The compressed 23C18 LB monolayer was observed to be more homogeneous than other samples. On the basis of the LB monolayer thickness estimated by AFM as well as X-ray reflection measurements, the 23C18 LB monolayer was assumed to possibly possess the vertical arrangement of an up-ordering of all the alkyl side chains on the individual glucose ring against the water surface. In other words, with increase in the surface pressure, the usual conformation of a 2(1) screw of cellulose backbone may be changed into an unusual conformation with a certain phi-psi dihedral angle resulting in 1-fold axis without a symmetry element. These results suggest that the formation of such compressed LB monolayers was strongly influenced by the hydrophobic interaction among the distribution of the long alkyl side chains in the anhydroglucose unit and further lack of inter- and/or intramolecular hydrogen bonds engaged in cellulose ethers, and as a result, those effects may even change the main chain conformation.

Journal Article↗

PubMed2005

Stromal elastosis in papillary thyroid carcinomas.

Stromal elastosis, defined as dense aggregations of elastic fibers, is found in some neoplastic tissues especially in malignant tumors of the breast and lung. Although also found in thyroid tissue, stromal elastosis in thyroid neoplasms have received little attention. To clarify the histopathological significance of stromal elastosis in the thyroid, we examined neoplastic (n = 223) and hyperplastic (n = 82) thyroid tissues in conjunction with cancer tissues (n = 193) of various other organs. Stromal elastosis was observed as deposits of pale homogeneous material in hematoxylin and eosin stain, and distinctively highlighted by elastic-van Gieson's stain. On immunohistochemical examination, elastin and tropoelastin were confirmed in these deposits. Stromal elastosis was found in 66% of papillary thyroid carcinomas (PTCs), although it was not identified in other histological types of thyroid neoplasms. In PTCs, deposits of elastic fibers varied in size and shape, and were more frequently distributed in the periphery of the tumor tissue. The histological subtypes of PTC varied in prevalence of elastosis with the follicular variant's (9%) prevalence being significantly lower than that of the classical type (72%). The frequency of stromal elastosis in PTCs was very similar to the frequencies in breast and lung adenocarcinomas, and higher than the frequencies in carcinomas of other organs. In conclusion, our results suggest that stromal elastosis is a characteristic histological finding of PTCs, presumably associated with their growth pattern and/or histological architecture. It is, therefore, reasonable to propose that stromal elastosis is an ancillary feature in the histopathological diagnosis of PTCs.

Carcinoma, Papillary↗

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

Endocervical adenocarcinomas associated with lobular endocervical glandular hyperplasia: a report of four cases with histochemical and immunohistochemical analyses.

We report on four cases of endocervical adenocarcinoma associated with lobular endocervical glandular hyperplasia using histochemical and immunohistochemical analyses. The patients ranged in age from 59 to 67 years (mean 62 years). Chief complaints were watery vaginal discharge in two cases, genital bleeding in one and no subjective symptoms in one. Cytological examinations of the cervical smears revealed adenocarcinoma cells and benign-looking glandular cells with intracytoplasmic golden-yellow mucin in all cases. Radical hysterectomy was performed in three patients, and simple total hysterectomy was performed in one. From surgical specimens, three tumors were diagnosed as mucinous adenocarcinoma and one was adenocarcinoma in situ. All adenocarcinomas were located proximally on the cervix, and did not involve the transformation zone. Adjacent to carcinoma tissues in the cervix, lobular endocervical glandular hyperplasia was detected. The cells of lobular endocervical glandular hyperplasia were dominantly positive with neutral mucin, and immunohistochemistry revealed that these cells had prominent pyloric gland mucin (HIK1083). Focal immunopositivity for pyloric mucin was also observed in three adenocarcinomas. Either CEA or p53 were immunopositive in all adenocarcinomas and negative in the tissues of lobular endocervical glandular hyperplasia. Histopathological features of the present cases suggest that some endocervical adenocarcinomas may originate from lobular endocervical glandular hyperplasia.

Adenocarcinoma↗

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↗

PubMed2004

Fabrication of honeycomb-patterned cellulose films.

This paper reports for the first time on the fabrication of honeycomb-patterned cellulose films by casting water in oil emulsion of cellulose acetate onto a glass substrate and subsequent deacetylation treatment. The honeycomb pore size could be controlled from 1 to 100 microm under a saturated water vapor condition. Both cellulose and cellulose acetate films with honeycomb-pattern are expected to be a two-dimensional model of plant cell walls as well as of micro-wells for single cell cultivation. Surface topographic image of a honeycomb-patterned cellulose film (scalebar: 50 microm).

Biocompatible Materials↗

PubMed2004

Mixed papillary adenocarcinoma and transitional cell carcinoma of the uterine cervix.

A mixed papillary adenocarcinoma and transitional cell carcinoma (MAcTcc) was discovered in the uterine cervix of a 38-year-old woman. A condylomatous papillary lesion was found in the uterine cervix during a colposcopic study and histopathological examination showed that the tumor was composed of two different neoplastic subtypes. One was an adenocarcinoma (AC) component showing papillary and tubular structure with endocervical and intestinal differentiation; the other was a transitional cell carcinoma (TCC) component showing papillary excrescence mimicking papillary TCC of urothelial origin. To characterize the tumor, an immunohistochemical study of cytokeratins (CK) was performed. The AC component showed immunoreactivities similar to conventional adenocarcinomas: positive immunoreactivity of low-molecular-weight cytokeratins 7, 8 and 19, and negative immunoreactivity of CK20 and high-molecular-weight cytokeratin (34betaE12). The lower epithelial layer of the TCC component showed different immunoreactivity, but the superficial epithelial layer had similar immunohistochemical findings to the AC component. These findings indicate that the TCC component had the cellular character of AC rather than that of TCC or squamous cell carcinomas. This is thought to be the first report of a MAcTcc of the uterine cervix.

Adenocarcinoma, Papillary↗

PubMed2004

[Hormone production and secretion in thyroid tumors].

Thyroid epithelial cells can be classified into 2 types according to embryonic origin, those of foregut endoderm (follicular cells) and those of neuroectodermal deviation (C cells) origin. The production of TG, T4, and T3 is frequently evident with the immunoperoxidase methods is nontoxic thyroid tumors derived from follicular cells. In contrast, medullary thyroid carcinoma originated from thyroid C cells produces and secretes calcitonin. Thyroid transcription factor-1 (TTF-1) regulates the expression of all hormones produced in thyroid. In recent years, evidence has been accumulating for the existence of a tumor group with traits of both follicular and medullary carcinoma, designated as mixed follicular and medullary carcinoma.

Calcitonin↗

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

Expression of human pendrin in diseased thyroids.

We examined pendrin expression in various diseased thyroid tissues by immunohistochemistry (IHC) using antiserum raised against human pendrin and by real-time quantitative RT-PCR. In normal thyroids the antiserum reacted with the apical membrane of follicular cells and its immunoreactivity was faint. In Graves' thyroids, the IHC expression of pendrin appeared in a pattern similar to that of normal thyroids but it was more extensive and stronger, especially in areas showing marked proliferation of follicular cells. The immunoreactivities of pendrin in nodular goiters varied from case to case. In follicular adenomas, pendrin was localized in the follicle-forming parts of the tumor but was negative in trabecular parts. Pendrin was negative in all follicular carcinomas, papillary carcinomas, and in one case of medullary carcinoma. In quantitive mRNA analysis, the relative values of pendrin mRNA were significantly low in papillary carcinoma (p<0.01), whereas the values in other diseased thyroids were not significantly different from those in normal thyroids. These results suggest that pendrin may play a role in thyroid hormone production as the apical porter of chloride/iodide and investigation of pendrin leads to a better understanding of functional aspects of the iodine transportation system in thyroid diseases.

Carrier Proteins↗

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↗

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

Biodirected epitaxial nanodeposition of polymers on oriented macromolecular templates.

Biodirected epitaxial nanodeposition of polymers was achieved on a template with an oriented molecular surface. Acetobacter xylinum synthesized a ribbon of cellulose I microfibrils onto a fixed, nematic ordered substrate of glucan chains with unique surface characteristics. The substrate directed the orientation of the motion due to the inverse force of the secretion during biosynthesis, and the microfibrils were aligned along the orientation of the molecular template. Using real-time video analysis, the patterns and rates of deposition were elucidated. Field emission scanning electron microscopy revealed that a strong molecular interaction allowed for the deposition of nascent biosynthesized 3.5-nm cellulose microfibrils with inter-microfibrillar spacings of 7-8 nm on the surface of the template. The cellulose was deposited parallel to the molecular orientation of the template. Directed cellulose synthesis and ordered movement of cells were observed only by using a nematic ordered substrate made from cellulose, and not from ordered crystalline cellulose substrates or ordered cellulose-related synthetic polymers such as polyvinyl alcohol. This unique relationship between directed biosynthesis and the ordered fabrication from the nano to the micro scales could lead to new methodologies for the design of functional materials with desired nanostructures.

Acetobacter↗

PubMed2002

Recent progress in cellulose biosynthesis.

Cellulose comprises the major polymer of the plant cell wall. It consists of a set of parallel chains composed of glucans and these chains are highly oriented to form a structure known as a microfibril. The orientation of the microfibrils controls the extension of the direction of the plant cell. Extensive studies on the cellulose biosynthesis have been carried out for over three decades, and recently (1996) genes for cellulose biosynthesis in plants ( CesA) were isolated. In the year 2002, a specific primer for cellulose biosynthesis reaction has been discovered and cellulose synthetic activity has been also confirmed by recombinant protein derived from the plant CesA gene. Furthermore, other proteins involved in cellulose biosynthesis besides CesA proteins were also proposed at the same time. One of these proteins, Korrigan cellulase, was suggested to act by removing sitosterol from the primer for biosynthesis reaction of cellulose. A membrane-bound sucrose synthase was also suggested to provide UDP-glucose as a substrate for cellulose biosynthesis. On the basis of these results, a new pathway for cellulose biosynthesis was proposed. Now, the research field of cellulose biosynthesis is facing a major turning point.

Journal Article↗

PubMedDate not supplied

Novel tool for characterization of noncrystalline regions in cellulose: a FTIR deuteration monitoring and generalized two-dimensional correlation spectroscopy.

Our previous results indicated that noncrystalline regions in a regenerated cellulose film comprised at least three domains engaged in different manners of molecular assembly [Kondo et al. In Cellulose Derivatives; Heinze, T. J., Glasser, W. G., Eds.; ACS Symposium Series 688; American Chemical Society: Washington, DC, 1998; Chapter 12]. In this article, we attempt to characterize each of the three noncrystalline domains in the film. The method used was a FTIR monitoring of deuteration from hydroxyl (OH) groups to OD, leading to the two-dimensional (2D) correlation analysis. The time-scan spectra in the OH-OD exchanging reaction were transformed into two kinds of 2D correlation spectra, the synchronous and the asynchronous spectra. Of the two, some cross-peaks were found in the latter spectrum. This suggests that the asynchronous 2D correlation spectrum could differentiate the contribution of OH groups due to different frequencies of hydrogen bonds in each domain. Here we will show the validity of this 2D correlation method as a powerful tool to predict hydrogen-bonding networks of the noncrystalline domains in cellulose.

Biotechnology↗