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Biomedical subjects

I Mori

Publications and source records attributed to I Mori.

At least 19 recordsLinked to original sources
PubMed2006

Mastopathic fibroadenoma of the breast: a pitfall of aspiration cytology.

OBJECTIVE: To assess the correlation between cytological diagnoses and histological subtypes of fibroadenoma (FA) and to clarify the cytological features of a specific group of FA displaying variable features similar to fibrocystic disease (mastopathic type, MFA), and to evaluate the significance of this subtype in cytological diagnosis. METHODS: A review of 141 cases of histologically proven FA was performed. We re-classified them into four subtypes according to Kinoshita's criteria [Jpn J Breast Cancer6 (1991) 377] and further selected 92 cases for which both fine needle aspiration (FNA) smears and histological specimens were available. Among them, 18 cases of MFA and their cytological smears were selected for the present study. RESULTS: There was significant correlation between MFA and cytological diagnosis of 'indeterminate' or 'suspicious for malignancy' (P < 0.01). Although no false-positive diagnosis was experienced in our series, 56% of the MFAs (10/18) had cytological diagnoses of indeterminate or were included in the category 'suspicious for malignancy'. Smears from MFA revealed high cellularity (9/18 smears had more than 10 epithelial clusters each composed of more than 50 cells), presence of cellular discohesiveness (13/18, 72.2%), but only mild nuclear atypia (5/18, 27.8%). Anisonucleosis was present in fewer than half the cases and no apparent condensed chromatin was identified. CONCLUSION: We highlight the significance of subclassification of MFA in aspiration cytology of breast. MFA had a significantly higher chance of falling into the 'suspicious for malignancy' or 'indeterminate' diagnostic category in aspiration cytology. It might be a diagnostic challenge for cytopathologist to identify this subtype of FA in FNA smears.

Adolescent↗
PubMed2005

Osteoclast-like cells express receptor activity modifying protein 2: application of laser capture microdissection.

Receptor activity modifying proteins (RAMPs) act as receptor modulators that determine the ligand specificity of receptors for the calcitonin (CT) family. The purpose of this study was to analyze the expression of RAMPs in osteoclast-like cells using the laser capture microdissection (LCM) technique. Mouse bone marrow and spleen cells were co-cultured on a film designed for LCM. After 10 days, 250 osteoclast-like cells were captured using the LCM system. Total RNA from these cells was used to synthesize cDNA and RT-PCR analysis was performed. Osteoclast-like cells expressed CT receptor (CTR), CT receptor-like receptor (CRLR) and RAMP2, but did not express RAMP1 or RAMP3. These results indicated (1) that a pure population of osteoclast-like cells can be prepared by LCM and gene expression of this population can be analyzed by RT-PCR and (2) that RT-PCR shows that osteoclast-like cells express RAMP2, CTR and CRLR, suggesting the potential for adrenomedullin binding to osteoclast-like cells. This is the first report that osteoclast-like cells express RAMP2.

Animals↗
PubMed2004

Papillary carcinoma of the thyroid in Japan: subclassification of common type and identification of low risk group.

AIMS: Papillary thyroid carcinoma (PTC) is classified into two subgroups-common type and other histological variants. Correlations between further subgrouping of the common type and patient prognosis are not well documented. AIMS: To introduce two novel histological parameters to characterise PTC-loss of cellular polarity and loss of cellular cohesiveness. To investigate a new subgroup of common type PTC with possible prognostic value. METHODS: In total, 213 patients with PTCs larger than 1 cm were studied. Histological characteristics of these PTCs, including tumour growth pattern, encapsulation, extrathyroidal invasion, loss of cellular polarity, and loss of cellular cohesiveness were examined and correlated with disease free survival (DFS). RESULTS: Multivariate analysis revealed that invasive growth of unencapsulated PTC, in addition to sex (male) and tumour size (>4 cm) were significant and independent parameters for poor DFS, whereas loss of cellular polarity and cohesiveness, old age (>60 years), extrathyroid invasion, and completeness of surgery were significant only in univariate analysis. PTCs that showed expansive growth and retained cellular polarity had a favourable course, with no recurrence and no cancer related deaths. In contrast, PTCs exhibiting loss of cellular polarity and/or invasive growth with no tumour capsule had a higher risk of recurrence. CONCLUSION: Cytological features alone cannot predict patient outcome in PTC. This study indicates for the first time that loss of cellular polarity and the tumour growth pattern are useful parameters for identifying the so called low risk group in common type PTC and in predicting patient outcome in terms of tumour recurrence and cancer related death.

Age Factors↗
PubMed2002

Automated quantification of aortic regurgitant volume and regurgitant fraction using the digital colour Doppler velocity profile integration method in patients with aortic regurgitation.

BACKGROUND: The recently introduced automated cardiac flow measurement (ACM) technique provides a quick and an accurate automated calculation of stroke volume and cardiac output. This is obtained by spatio-temporal integration of digital Doppler velocity profile data. OBJECTIVE: To evaluate the use of the ACM method in the non-invasive assessment of aortic regurgitant volume and per cent regurgitant fraction (%RF) in patients with aortic regurgitation. METHODS: Aortic outflow volume and mitral inflow volume were calculated by the ACM method in 22 patients with isolated aortic regurgitation. Aortic regurgitant volume and %RF were calculated using the following equations: aortic regurgitant volume = [aortic outflow volume] - [mitral inflow volume]; %RF = [aortic regurgitant volume]/[aortic outflow volume] x 100. The results were compared with those obtained using pulsed Doppler cross sectional echocardiography (PD-2D). RESULTS: Aortic regurgitant volumes measured by the ACM method showed a good correlation with the PD-2D measurements (r = 0.95, y = 0.9x + 3.9, SEE = 8.6 ml); the mean (SD) difference between the two methods was -1.5 (8.5) ml. %RF estimated by the ACM method also correlated well with the values obtained by the PD-2D method (r = 0.91, y = 0.9x + 4.9, SEE = 6.0%); the mean difference between the two methods was -1.5 (6.0)%. Total time required for aortic regurgitant volume (for one cardiac cycle) by the ACM method was significantly shorter than by the PD-2D method (130 (16) v 230 (32) s, p < 0.01). CONCLUSIONS: The newly developed the ACM method is quick and accurate in the automated assessment of aortic regurgitant volume and per cent regurgitant fraction in patients with isolated aortic regurgitation.

Adult↗
PubMed2002

Cancer mortality among man-made graphite electrode manufacturing workers: results of a 38 year follow up.

BACKGROUND AND AIMS: To examine the risk for cancer mortality among workers exposed to coal tar and coal tar pitch volatiles in a man-made graphite electrode factory. The risk for cancer mortality in this type of factory is still inconclusive, although coal tar and coal tar pitch are recognised as human carcinogens. METHODS: The study cohort consisted of 332 male employees who served more than five years in the period 1951-74. The cohort was traced until 1988. Analyses used standardised mortality ratios (SMRs) to compare cause specific mortality with that in the general and local population. Effect of smoking was estimated based on the information collected from the subgroup of the cohort. SMRs for leading causes of death were compared among different job titles, duration of employment, time since first employment, and observation subperiods. Exposure level for tar and benzo[a]pyrene (BaP) in the factory was also discussed, based on measurements done by other researchers in the past. RESULTS: During the study period, 52 deaths were identified (SMR 0.68), including 22 cancer deaths (SMR 1.01). The SMR for lung cancer was significantly increased in comparison with the general population (SMR 2.62). It was slightly decreased in comparison with the local population, but remained significant (SMR 2.35). Excess deaths were also observed for lymphatic and haematopoietic cancers (SMR 3.46). Smoking habits in the subgroup were similar to those in the general population; thus the increased SMR for lung cancer was unlikely to be explained by smoking. CONCLUSION: Previous environmental measurements suggested that considerable exposure to tar and BaP had existed in the factory. The results suggest a possible risk for lung cancer among the cohort, but the limitations of the study, such as the small study population and insufficient information on exposure, indicate that further study is required.

Adult↗
PubMed2001

Essential similarities between spontaneous and MeIQx-promoted aberrant crypt foci in the F344 rat colon.

Aberrant crypt foci (ACFs) in the Fischer 344 (F344) rat colon, of control or 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx)-treated groups, were compared morphologically, immunohistochemically, and at the molecular biological level in order to elucidate their biological characteristics. Male 3-week-old rats were fed a diet supplemented with or without MeIQx at doses of 100 ppm or less for 16 weeks. The incidence of ACFs was the highest (90%) in animals given 100 ppm MeIQx but that in untreated rats was also surprisingly high (57%). Nine ACFs from nine MeIQx-treated rats and ten ACFs from ten untreated control rats were selected for detailed examination for their large size. There were no morphological differences in macroscopic and microscopic features between MeIQx-promoted and spontaneous ACFs. There were also no differences in immunohistochemical labeling for proliferating cell nuclear antigen (PCNA) and p53 protein between these ACFs although in both cases labeling was higher than in normal crypts. Dot blot hybridization revealed no c-K-ras mutations in codon 12 except in one ACF (11.1%) developing in a rat treated with 100 ppm MeIQx, in which a GGT-->GAT single base substitution was detected. Our results thus suggest that in terms of morphology, cell proliferation, P53 expression and c-K-ras mutation, most ACFs found in rats given 100 ppm MeIQx are essentially identical to their spontaneous counterparts.

Animals↗
PubMed2001

Specification of thermosensory neuron fate in C. elegans requires ttx-1, a homolog of otd/Otx.

Temperature is a critical modulator of animal metabolism and behavior, yet the mechanisms underlying the development and function of thermosensory neurons are poorly understood. C. elegans senses temperature using the AFD thermosensory neurons. Mutations in the gene ttx-1 affect AFD neuron function. Here, we show that ttx-1 regulates all differentiated characteristics of the AFD neurons. ttx-1 mutants are defective in a thermotactic behavior and exhibit deregulated thermosensory inputs into a neuroendocrine signaling pathway. ttx-1 encodes a member of the conserved OTD/OTX homeodomain protein family and is expressed in the AFD neurons. Misexpression of ttx-1 converts other sensory neurons to an AFD-like fate. Our results extend a previously noted conservation of developmental mechanisms between the thermosensory circuit in C. elegans and the vertebrate photosensory circuit, suggesting an evolutionary link between thermosensation and phototransduction.

Amino Acid Sequence↗
PubMed2001

Synthesis, characterization, and photochemical properties of azobenzene-conjugated Ru(II) and Rh(III) bis(terpyridine) complexes.

We synthesized azobenzene-conjugated bis(terpyridine) Ru(II) and Rh(III) mononuclear and dinuclear complexes and investigated their photochemical properties on excitation of the azo pi-pi band upon 366 nm light irradiation. The Ru mononuclear complex underwent trans-to-cis photoisomerization to reach the photostationary state with only 20% of the cis form, while the Ru dinuclear complex did not isomerize at all photochemically. On the other hand, the mononuclear and dinuclear Rh complexes showed almost complete trans-to-cis photoisomerization behavior. Cis forms of the Rh complexes thermally returned to the trans form at a much slower rate than those of organic azobenzenes, but they did not isomerize photochemically. The reduction potential of the cis forms was 80 mV more negative than that of the trans forms. The photoisomerization quantum yields of the Rh complexes were strongly dependent on the polarity, viscosity, and donor site of the solvents as well as the size of the counterions. We investigated the photoisomerization process of these complexes using femtosecond absorption spectroscopy. For the Rh complexes, we observed S(n) <-- S(2) and S(n) <-- S(1) absorption bands similar to those of organic azobenzenes. For the Ru complexes, we observed very fast bleaching of the MLCT band of the Ru complex, which indicated that the energy transfer pathway to the MLCT was the primary cause of the depressed photoisomerization. The electronic structures, which were estimated from ZINDO molecular orbital calculation, supported the different photochemical reaction behavior between the Ru and Rh complexes.

Journal Article↗
PubMed2001

Impaired microglial activation in the brain of IL-18-gene-disrupted mice after neurovirulent influenza A virus infection.

Knockout of the interleukin-18 (IL-18) gene predisposed mice to impaired clearance of neurovirulent influenza A virus-infected neurons from the brain. In wild-type mice, IL-18 molecule-producing microglia/macrophages emerged in virally attacked regions as early as day 3 after infection. Microglial transformation into macrophages culminated at day 7 to 9, with upregulated expression of Iba1, a novel calcium-binding protein that controls phagocytic functions of microglia/macrophages. In IL-18-/- mice, microglial transformation was interrupted with reduced Iba1 expression. Interferon-gamma (IFN-gamma)-immunopositive neurons appeared in and around virally invaded regions in wild-type mice, peaking in number at day 7, whereas such cells were barely detected in IL-18-/- mice. Stereotaxic microinjection of recombinant IFN-gamma triggered microglial transformation in IL-18-/- mice and upregulated Iba1 expression, leading to effective eradication of virally infected neurons. Collectively, these results suggest that IL-18 plays a key role in activating microglial functions directed against the influenza virus infection by inducing neuronal IFN-gamma in the brain parenchyma.

Animals↗
PubMed2001

Phosphorylation of mitogen-activated protein kinase is inhibited by calcitonin in DU145 prostate cancer cells.

One of the causes of insensitivity to androgen ablation therapy in prostate cancer is thought to be attributable to elevated neuropeptides secreted by neuroendocrine cells in the tumor mass. Calcitonin (CT), one of these neuropeptides, is reported to be associated with the growth of prostate cancer. There is an increase in mitogen-activated protein (MAP) kinase activation as prostate cancer progresses to a more advanced and androgen-independent disease. We examined the effect of CT on signal transduction and the relation between CT and early-response genes in the human androgen-insensitive prostate cancer cell line, DU145. The basal phosphorylation level of extracellular signal-regulated kinase 1/2, which is a key kinase in the mediation of growth factor-induced mitogenesis in prostate cancer cells, was constitutively up-regulated. N-[2-(4-bromocinnamyl) aminoethyl]-5-isoquinoline-sulfonamide (H89), a specific inhibitor of protein kinase A, potentiated the effects of more increased phosphorylation of extracellular signal-regulated kinase 1/2. CT induced the inhibition of this MAP kinase phosphorylation, and this effect was completely abolished by pretreatment with H89. Our findings demonstrate that CT caused the inhibition of constitutive MAP kinase phosphorylation in a protein kinase A-dependent manner in DU145. The transient increase of c-fos expression was detected after CT treatment, whereas expression of c-jun RNA was down-regulated after CT treatment. These results suggest that CT may regulate early-response genes, c-fos and c-jun, via a MAP kinase cascade. In conclusion, these findings suggest that DU145 might be a useful model as a therapeutic approach of neuropeptides in androgen-independent prostatic carcinoma.

Calcitonin↗
PubMed2001

Prognostic significance of BRCA1 expression in Japanese sporadic breast carcinomas.

BACKGROUND: BRCA1 is a tumor suppressor gene that is responsible for hereditary breast and ovarian carcinoma syndrome. The primary objective of the current study was to investigate the influence of BRCA1 expression on the prognoses of sporadic breast carcinomas. METHODS: A cohort of 175 Japanese women with invasive breast carcinoma who had no family history in first-degree relatives was studied. Expression of BRCA1 was determined by an immunohistochemical procedure in which the MS110 monoclonal antibody was used. Kaplan--Meier and Cox proportional regression survival analyses were used to compare negative and positive BRCA1 patients. RESULTS: One hundred fifteen (65.7%) of the 175 specimens showed positive BRCA1 staining (> 10% cells were immunoreactive). During a median follow-up of 4.4 years, negative BRCA1 patients had worse disease free survival than positive BRCA1 patients (35 % vs. 7%, respectively; P < 0.0001). BRCA1 expression was significantly inversely correlated with histologic grade (P < 0.0001) but not with lymph node status or other conventional prognostic markers. In multivariate analysis using the Cox regression model, positive BRCA1 emerged as an independent prognostic indicator for disease free survival. CONCLUSIONS: The results of this study suggest that BRCA1 may be a valuable marker for identifying women with sporadic breast carcinoma at high risk of developing recurrence, and who may be candidates for trials investigating new therapies in combination with standard adjuvant therapy.

Adult↗
PubMed2001

Correlation between nuclear grade and biological prognostic variables in invasive breast cancer.

BACKGROUND: Grading of carcinomas is an estimation of differentiation. Nuclear grading is the cytological evaluation of tumor nuclei in comparison with the nuclei of normal mammary epithelial cells. Because nuclear grading does not involve an assessment of the growth pattern of the tumor, it applies not only to invasive ductal carcinoma but also to other subtypes of breast carcinoma. METHODS: A total of 215 primary breast carcinomas obtained from the Affiliated Kihoku Hospital of Wakayama Medical College were enrolled in our present study. Nuclear grade was evaluated according to the criteria of the National Surgical Adjuvant Study of Breast Cancer (NSAS-B) protocol. Immunohistochemistry was also performed to determine Bcl-2, p53, c-erbB-2, estrogen receptor (ER) and MIB-1 expression in paraffin-embedded tissues for all cases. RESULTS: Thirty-two (14.9%) of the patients were graded as 1,124 (57.7%) as 2, and 59 (27.4%) as 3. Nuclear grade displayed a negative correlation with Bcl-2 expression (r=-0.308, p<0.0001), and a positive correlation with c-erbB-2 overexpression (r= 0.172, p=0.0117) and tumor proliferative index labeling by MIB-1 (r=0.485, p<0.0001). CONCLUSIONS: These results imply that nuclear grade is related to the characteristics of tumor biology, indicating that the morphology and biology of breast cancer are tightly linked. Our present results also suggest that adding the nuclear grade to the pathological diagnosis of invasive breast carcinoma may be clinically useful for predicting tumor behavior, for example aggressiveness, and for prognostication.

Biomarkers, Tumor↗
PubMed2001

The CdTe detector module and its imaging performance.

UNLABELLED: In recent years investigations into the application of semiconductor detector technology in gamma cameras have become active world-wide. The reason for this burst of activity is the expectation that the semiconductor-based gamma camera would outperform the conventional Anger-type gamma camera with a large scintillator and photomultipliers. Nevertheless, to date, it cannot be said that this expectation has been met. METHODS: While most of the studies have used CZT (Cadmium Zinc Telluride) as the semiconductor material, we designed and fabricated an experimental detector module of CdTe (Cadmium Telluride). The module consists of 512 elements and its pixel pitch is 1.6 mm. We have evaluated its energy resolution, planar image performance, single photon emission computed tomography (SPECT) image performance and time resolution for coincidence detection. RESULTS: The average energy resolution was 5.5% FWHM at 140 keV. The intrinsic spatial resolution was 1.6 mm. The quality of the phantom images, both planar and SPECT, was visually superior to that of the Anger-type gamma camera. The quantitative assessment of SPECT images showed accuracy far better than that of the Anger-type camera. The coincidence time resolution was 8.6 ns. All measurements were done at room temperature, and the polarization effect that had been the biggest concern for CdTe was not significant. CONCLUSION: The results indicated that the semiconductor-based gamma camera is superior in performance to the Anger-type and has the possibility of being used as a positron emission computed tomography (PET) scanner.

Brain↗
PubMed2001

Biallelic inactivation of retinoic acid receptor beta2 gene by epigenetic change in breast cancer.

A growing body of evidence supports the hypotheses that retinoic acid receptor beta2 (RAR beta2) is a tumor suppressor gene. Although the loss of RAR beta2 expression has been reported in many malignant tumors, including breast cancer, the molecular mechanism is still poorly understood. We hypothesized that loss of RAR beta2 activity could result from multiple factors, including epigenetic modification and loss of heterozygosity (LOH). Using methylation-specific polymerase chain reaction and LOH analysis, we found that biallelic inactivation via epigenetic changes of both maternal and paternal alleles, or epigenetic modification of one allele combined with genetic loss of the remaining allele, could completely suppress RAR beta2 expression in breast cancer. Thus, it is possible that substantial numbers of human cancers arise through suppressor gene silencing via epigenetic mechanisms that inactivate both alleles. Because of this, chromatin-remodeling drugs may provide a novel strategy for cancer prevention and treatment.

Alleles↗
PubMed2001

Ca2+ signaling via the neuronal calcium sensor-1 regulates associative learning and memory in C. elegans.

On a radial temperature gradient, C. elegans worms migrate, after conditioning with food, toward their cultivation temperature and move along this isotherm. This experience-dependent behavior is called isothermal tracking (IT). Here we show that the neuron-specific calcium sensor-1 (NCS-1) is essential for optimal IT. ncs-1 knockout animals show major defects in IT behavior, although their chemotactic, locomotor, and thermal avoidance behaviors are normal. The knockout phenotype can be rescued by reintroducing wild-type NCS-1 into the AIY interneuron, a key component of the thermotaxis network. A loss-of-function form of NCS-1 incapable of binding calcium does not restore IT, whereas NCS-1 overexpression enhances IT performance levels, accelerates learning (faster acquisition), and produces a memory with slower extinction. Thus, proper calcium signaling via NCS-1 defines a novel pathway essential for associative learning and memory.

Animals↗
PubMed2001

Neuropathogenesis of influenza virus infection in mice.

The neurovirulent WSN strain of influenza A virus, introduced into the olfactory bulb of C57BL/6 mice, selectively attacks several brain nuclei which are highly implicated in the pathogenesis of neuropsychiatric disturbances. The virus-infected neurons are eradicated through apoptotic neurodegeneration. On the other hand, activated microglia serve the neuroprotection against virus infection.

Animals↗
PubMed2001

Allelic loss of chromosome 3p24 correlates with tumor progression rather than with retinoic acid receptor beta2 expression in breast carcinoma.

A tumor suppressor gene. retinoic acid receptor (RAR) beta2, has been mapped to chromosome 3p24, a region where loss of heterozygosity (LOH) has been observed commonly in carcinomas of various tumor tissues. RAR beta2 expression is reduced or lost in many malignant tumors including breast cancer, however, whether LOH accounts for the loss of expression of RAR beta2 in breast cancer is unknown. We, therefore, assessed LOH on chromosome band 3p24 to correlate it with RAR beta2 expression and other established prognostic parameters in 52 breast carcinomas. Based on three microsatellites, D3S 1283, D3S 1293 and D3S 1286. all of the tumors were informative, of these, 12 (23%) exhibited LOH. RAR beta2 expression was lost in 42% (19/45) of these samples. We found that LOH on chromosome band 3p24 was not correlated with loss of RAR beta2, but correlated with higher histological grade, p53-positivity, and loss of estrogen and progesterone receptors. Our findings suggest that LOH of the RAR beta2 gene does not account for the frequent loss of RAR beta2 expression in breast cancer but the genomic structural alteration at or close to the RAR beta2 gene locus are likely to be associated with tumor progression and/or loss of hormonal dependency.

Breast Neoplasms↗