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Biomedical subjects

O Miyaishi

Publications and source records attributed to O Miyaishi.

At least 19 recordsLinked to original sources
PubMed2004

Cyclooxygenase-2 is a possible target of treatment approach in conjunction with photodynamic therapy for various disorders in skin and oral cavity.

BACKGROUND: Anti-cancer effects of cyclooxygenase (COX)-2 inhibitors have been reported, but not fully investigated in skin and oral diseases. 5-aminolaevulinic acid (ALA)-based photodynamic therapy (PDT) for treating those patients with skin and oral lesions is a highly sophisticated procedure, but the incidence of disease recurrence after treatment is rather significant. OBJECTIVE: To confirm that COX-2 could be a molecular target in adjunctive therapy to ALA-based PDT, we investigated (i) COX-2 expression in various skin and oral diseases, and (ii) the inhibitory effects on cellular growth of COX-2 selective inhibitor (nimesulide), ALA-based PDT and their combination on human oral squamous cell carcinoma (SCC) cell lines. METHODS: A total of 129 biopsy samples from the skin and oral mucosal lesions were tested immunohistochemically for COX-2 expression. Then the in vitro effects of nimesulide, ALA-based PDT, and their combination were determined on two SCC cell lines, HSC-2 and HSC-4. Three different methods (MTT assay, double-staining for annexin V and propidium iodide, caspase-3/CPP32 fluorometric protease assay) were applied for evaluation of their inhibitory effects on these two cell lines. RESULTS: Among the skin diseases, a considerable number of COX-2 high expressers were found in actinic keratosis (15 of 25, 60%), Bowen's disease (13 of 17, 76%) and extramammary Paget's disease (15 of 15, 100%). In contrast, only one of 33 (3%) basal cell carcinoma tumours was a COX-2 high expresser. Among the oral mucosal biopsies, the proportion of COX-2 high expressers increased gradually from hyperplasia (one of six, 17%) through mild dysplasia (five of eight, 63%) and moderate dysplasia (20 of 23, 87%) to severe dysplasia (two of two, 100%). Nimesulide had an inhibitory effect in vitro on HSC-2 (proven to be a COX-2 high expresser), but not on HSC-4 (a COX-2 non-expresser). While ALA-based PDT showed an inhibitory effect on both HSC-2 and HSC-4, most importantly the combination of nimesulide and ALA-based PDT demonstrated a significant synergistic effect on the cellular growth inhibition of only HSC-2, but not of HSC-4. CONCLUSIONS: Our study strongly suggests that COX-2 can be one of the molecular targets in treating various skin and oral diseases. The results from our in vitro experiments also prompt us to develop a new protocol with a combination of COX-2 selective inhibitor and ALA-based PDT for more effective treatment of those diseases.

Aminolevulinic Acid↗
PubMed2001

Multi-faceted analyses of a highly metastatic human lung cancer cell line NCI-H460-LNM35 suggest mimicry of inflammatory cells in metastasis.

This study established and characterized low-metastatic revertant and parental clones of a highly metastatic human lung cancer cell line, NCI-H460-LNM35 (hereafter referred to as LNM35). Expression-profiling analysis revealed that up-regulation of various proinflammatory cytokines and angiogenic chemotactic chemokines was present in LNM35. Further, while COX-2 itself is known to be inducible in inflammation, COX-2 expression levels correlated well with the capabilities of these clones for not only in vitro motility and invasion but also in vivo metastasis, and COX-2 inhibitors were shown for the first time to reduce lung cancer metastasis in vivo. These findings suggest that lung cancer cells may mimic inflammatory cells in the process of metastasis.

Animals↗
PubMed2001

Macrophage colony-stimulating factor is expressed in neuron and microglia after focal brain injury.

In a previous study, we have demonstrated that damaged neurons within a boundary area around necrosis fall into delayed neuronal death owing to the cytotoxic effect of microglial nitric oxide (NO), and these neurons are finally eliminated by activated microglia. In this process, microglia are activated to release NO, increase in number, and accumulate toward the damaged area. In this study, we investigated the expression of macrophage colony-stimulating factor (M-CSF, also called colony stimulating factor-1; CSF-1) and other cytokines, which are reported to relate to activation, proliferation, or migration of microglia. The mRNA of M-CSF arose biphasically from 30 min to 1 hr and from 6 to 72 hr after the injury, as demonstrated by semiquantitative RT-PCR. However, another cytokine of granulocyte-macrophage CSF (GM-CSF) or interleukin-3 (IL-3), which causes proliferation of microglia in vitro, was not detected. From immunohistochemical studies, positive staining of M-CSF was observed mainly in neuron-specific enolase (NSE)-positive cells from 1 to 12 hr after the injury, and after that M-CSF became positive in Griffonia simplicifolia isolectin-B4 (GSA-I-B4)-positive cells from 24 to 72 hr in the boundary area around necrosis. These results suggest that neurons around the damaged area express M-CSF in the early phase after injury, which may initially activate microglia, and these activated microglia also express M-CSF later, causing further proliferation or migration of microglia themselves to eliminate damaged neurons or necrotic brain tissue.

Animals↗
PubMed2001

A group of five parameters as a new biological marker on F344/N rats.

The National Institute for Longevity Sciences (NILS) established an aging farm (A/F) for producing aging/aged laboratory rodents at the Experimental Animal Facility Wing under the NILS A/F Guide planned by the Laboratory Animal Research Facilities (LARF). Five parameters, the average life span, the number of days of 75, 50, and 25% survival points, and average of the top 10 longest life span among laboratory strains of rodents at NILS-A/F, were reproducible for F344/N rats specifically by strain and sex under the LARF A/F guide. These five parameters may serve as an effective and practical biological marker, especially in aging science including longevity science, to evaluate characteristics of strains of laboratory rodents. The five parameters can identify clear substrain differences between F344/N and F344/Du and breeder differences between F344/DuCrj and F344/DuCrl.

Journal Article↗
PubMed2001

Adrenal glands in small smooth-tailed tree shrew (Dendrogale murina).

Adrenal glands of small smooth-tailed tree shrews (Dendrogale murina), four males and two females, caught and fixed in Thailand were observed macroscopically and histologically. They were located at the cranio-medial sides of the kidney. They were elongated in shape and consisted of a cortex and medulla. The cortex could be subdivided into three zones by the cell arrangement and the morphology of nuclei, cytoplasm and cell strands, like in other mammalian species. The tree shrew seemed to share more morphological characteristics with some laboratory rodents than some of non-human primates.

Adrenal Glands↗
PubMed2001

[Assisted thoracoscopic resection of huge mediastinal neurogenic tumor with Horner syndrome and superior vena cava syndrome].

A 51-year-old female suffering from right shoulder pain had chest radiography, which showed the huge round shadow (10 x 8.5 x 8.0 cm) on the right upper lung field. Horner syndrome and superior vena cava syndrome were presented. Thoracoscopic appearance showed that the tumor with complete smooth capsulation was neurogenic. After that added ideal thoracotomy (compatible with location and length) was performed, from which tumor was carried out and made a pathologic diagnosis of neurilemoma originated from thoracic sympathetic nerve. Harmonic Scalpel, an ultrasonically activated surgical device was effective in such a case of using near by nerve and small vessels. After operation, superior vena cava syndrome except for Horner syndrome was improved. It is important that we should consider less invasive and safe approach with combination of thoracoscopic and thoracotomic procedures even in case of huge tumor.

Female↗
PubMed2000

The diagnostic significance of left auricular thrombus in F344/N rats.

In the process of assessing the main cause of death in F344/N rats from the aging farm of our institute, we have often found left auricular thrombus in autopsy cases of moribund animals. In 319 autopsy cases, 45 were of left auricular thrombus and 44 were accompanied by hematopoietic neoplasms, including overt leukemia and a pre-leukemic condition of leukemia. In cases without splenomegaly, this lesion was found in 13 of 21 animals (61.9%) whereas, in cases with splenomegaly, 31 of 239 were positive for this lesion (13.0%). Thus, left auricular thrombus may be an important macroscopic diagnostic criteria of hematopoietic neoplasms, especially when splenomegaly is absent. Furthermore, this lesion tended to arise in aged animals despite the presence of splenomegaly. These results would therefore greatly contribute to aging science by confirming the health condition of experimental rats and the accuracy of subsequent results.

Journal Article↗
PubMed2000

Cancer incidence in old age.

The incidence of all cancer increases with age through most of the human life span, but its real incidence at very old ages has not been well elucidated to date. Clarification of the real incidence of cancer in old age, especially among centenarians, may well provide pivotal information to understand the characteristics of humankind. In this study, autopsy records of the Annual of the Pathological Autopsy Cases in Japan, 1991-1996, vols. 34-39 (Japanese Society of Pathology, Tokyo) were used. Cases over 90 years old were studied individually for accurate analysis. The incidence of cancer peaked in the 6th decade and that of multiple cases in the 8th decade. In groups over 90 years of age, the incidence at 5-year intervals did not show any significant decrement. Moreover, the metastatic rate and rate of death due to cancer among centenarians was about three-fourths and two-thirds, respectively, of that of cases aged 90-94 years. The decrease in the metastatic ratio and less mortality due to cancer occurring at the oldest ages are considered due to the nature of cancer itself. The fact that the incidence of cancer does not increase would suggest that certain people among those of advanced age have a special resistance to it.

Aged↗
PubMed2000

Establishment and characterization of a human lung cancer cell line NCI-H460-LNM35 with consistent lymphogenous metastasis via both subcutaneous and orthotopic propagation.

Lymphogenous metastasis is a common feature of human lung cancers, but very little is known about the underlying mechanism. In the present study, in vivo selection was carried out to obtain a highly lymphogenous metastatic subline of a human large cell carcinoma of the lung, NCI-H460. The resulting subline, termed NCI-H460-LNM35 (LNM35), was shown to metastasize to regional lymph nodes with a 100% incidence not only as a result of orthotopic intrabronchial (i.b.) implantation, but also as a result of conventional s.c. implantation. LNM35 has a short latency period, allowing for the collection of experimental data within 28 days after i.b. inoculation and 45 days after s.c. inoculation. It was noted that orthotopically i.b.-propagated LNM35 closely mimicked the clinical manifestations of human lung cancer patients by infiltrating into lymphatic vessels and metastasizing to the mediastinal lymph nodes. The LNM35 cell line is, to the best of our knowledge, the first human lung cancer cell line to be reported as having lymphogenous metastatic properties, and the observed 100% incidence by s.c. inoculation gives LNM35 a significant advantage even over previously reported human cancer cell lines of other origins. Comparisons between LNM35 and its parental NCI-H460 cell lines were also made with regard to expression levels and/or activities of various molecules that are thought to play a part in the metastatic process. We show here that the expression of cyclooxygenase 2 is increased in LNM35 and that a specific cyclooxygenase 2 inhibitor, nimesulide, can inhibit the invasion of LNM35 in vitro through Matrigel containing basement membrane components.

Animals↗
PubMed2000

PTRF (polymerase I and transcript-release factor) is tissue-specific and interacts with the BFCOL1 (binding factor of a type-I collagen promoter) zinc-finger transcription factor which binds to the two mouse type-I collagen gene promoters.

We have used the yeast two-hybrid system to clone the protein that interacts with the BFCOL1 (binding factor of a type-I collagen promoter) zinc-finger transcription factor that was cloned previously as the factor that binds to the two mouse proximal promoters of the type-I collagen genes. We utilized as bait the N-terminal domain of BFCOL1 that includes the zinc-finger DNA-binding domain. One cDNA contained a potential open reading frame for a polypeptide of 392 amino acids and was identical to PTRF (polymerase I and transcript-release factor), which is involved in transcription termination of the RNA polymerase I reaction. Northern-blot analysis revealed that the pattern of mRNA expression was similar to that of the type-I collagen gene. In addition, we detected the mRNA expression only in a fibroblast cell line and two bone cell lines, but not in other blood and neuronal cell lines. Recombinant protein was shown to enhance the binding of BFCOL1 to its binding site in the mouse proalpha2(I) collagen proximal promoter in vitro. The transient-transfection experiment showed that PTRF had a suppressive effect on the mouse proalpha2(I) collagen proximal promoter activity. We speculate that PTRF might play a role in the RNA polymerase II reaction as well as that of RNA polymerase I.

Animals↗
PubMed2000

Cu/Zn- and Mn-superoxide dismutases are specifically up-regulated in neurons after focal brain injury.

In previous studies, we have demonstrated that damaged neurons within a boundary area around necrosis fall into delayed cell death due to the cytotoxic effect of microglial nitric oxide (NO), and are finally eliminated by activated microglia. In contrast, neurons in a narrow surrounding region nearby this boundary area remain alive even though they may encounter cytotoxic NO. To investigate the mechanism by which neurons tolerate this oxidative stress, we examined the in vitro and in vivo expression levels of superoxide dismutase (SOD) under pathological conditions. Results from our in situ hybridization and immunohistochemical studies showed up-regulation of Cu/Zn-SOD only in neurons outside the boundary area, whereas up-regulation of Mn-SOD was detected in both neurons and glial cells in the same region. In vitro experiments using rat PC12 pheochromocytoma and C6 glioma cell lines showed that induction of both Cu/Zn- and Mn-SOD mRNA could only be detected in PC12 cells after treatment with NO donors, while a slight induction of Mn-SOD mRNA alone could be seen in C6 glioma cells. The mechanism of resistance toward oxidative stress therefore appears to be quite different between neuronal and glial cells. It is assumed that these two types of SOD might play a critical role in protecting neurons from NO cytotoxicity in vivo, and the inability of SOD induction in damaged neurons seems to cause their selective elimination after focal brain injury.

Animals↗
PubMed2000

Age-dependent changes in projections from locus coeruleus to hippocampus dentate gyrus and frontal cortex.

Age-dependent changes in noradrenergic innervations of the hippocampal dentate gyrus (DG) and the frontal cortex (FC) have been studied in male F344 rats. The projections from the nucleus locus coeruleus (LC) to DG or FC with advancing age (from 7 to 27 months) in rats have been quantified by electrophysiological and immunohistochemical methods. In the electrophysiological study, we observed that the percentage of LC neurons activated antidromically by electrical stimulation (P-index) of DG or FC decreased with age. We found that the percentage of LC neurons showing multiple antidromic latencies (M-index), which suggests axonal branching of individual LC neurons, increased markedly between 15 and 17 months in DG or FC. In DG, the M-index increased steadily between 15 and 24 months. In contrast, the increased M-index in FC was maintained until 24 months. The increased M-index in both targets declined at 27 months. These results suggest that LC neurons give rise to axonal branching following the loss of projections to DG or FC with age. In the immunohistochemical study, the density of dopamine-beta-hydroxylase-positive axonal varicosities was measured in molecular, granule cell and polymorphic layers of DG. The density in the polymorphic layer significantly decreased in the earlier stage of ageing (7-19 months), whilst the density in the molecular and granule cell layers decreased in the later stage (27 months). These findings suggested that a layer-specific decline occurred with age in the noradrenergic axon terminals in DG.

Action Potentials↗
PubMed2000

Magnetic resonance imaging of myxoma in the mandible: a case report.

The findings of conventional radiography, computed tomography, and magnetic resonance imaging (MRI) are reported for an odontogenic myxoma arising in the mandible of a 48-year-old Japanese man. The MRI characteristics of an intraosseous myxoma are described for only the third time. MRI showed a well-defined and smooth-walled mass lesion with high-signal intensity on T2-weighted images and low-intermediate-signal intensity on TI-weighted images. Soft tissue myxomas have been reported to show low-signal intensity on TI-weighted images and high-signal intensity on T2-weighted images. However, the first MRI report of an intraosseous myxoma showed a higher-signal intensity on TI-weighted images and lower-signal intensity on T2-weighted images. The MRI findings in this study thus correspond to those of soft tissue myxomas and do not agree with observations of the first MRI report of the intraosseous myxoma. Further studies are needed to clarify the reasons for this difference.

Humans↗
PubMed2000

Differences in survivability among F344 rats.

Important parameters to identify and develop appropriate animal models for longevity science include survivability, age-related disorders, and easy handling of aged individuals. It is found that F334/Du and F344/N have distinctive strain difference in these parameters. The finding suggests F334/Du and F344/N, even though they are historically siblings, need clearly separate identification when used as animal models for aging science, in particular, longevity science.

Aging↗
PubMed1999

Relationship between hyaluronan production and metastatic potential of mouse mammary carcinoma cells.

To investigate the roles of hyaluronan produced by cancer cells in cancer metastasis, the metastatic potential of the highly metastatic mouse mammary carcinoma FM3A HA1 cell line was compared with those of hyaluronan-deficient mutant cells. Five different mutant clones showed markedly reduced hyaluronan production and lacked the ability to form hyaluronan-rich pericellular coats. These mutant clones displayed significant decreases in metastatic ability compared with the parental cells after i.v. injection into syngeneic mice. These results suggested that the decreased hyaluronan production caused not only the lack of matrix formation but also decreased metastatic potential of the cancer cells. Expression of mouse hyaluronan synthase 1 (HAS1) by transfection into HAS- cells defective in hyaluronan synthase activity rescued hyaluronan matrix formation as well as hyaluronan production. Lung metastasis after i.v. injection of HAS1 transfectants was also recovered significantly. The results provide direct evidence for the involvement of hyaluronan in cancer metastasis.

Animals↗
PubMed1998

Isolation, purification, and characterization of a collagen-associated serpin, caspin, produced by murine colon adenocarcinoma cells.

A 45-kDa serpin secreted by a murine colon adenocarcinoma cell line, colon26, was isolated, purified, and characterized. It was found to bind specifically to type I collagen with high affinity and to type III collagen with lower affinity. Immunohistochemical studies of murine embryonic tissues showed a specific distribution of this collagen-associated serpin, named caspin, in relation to the formation of bone, cartilage, teeth, and basement membrane. The expression of caspin in high and low lung metastatic subclones of colon26 cell lines was inversely correlated with their metastatic capacity: low lung metastatic cells secreted higher amounts of caspin than their high lung metastatic counterparts. Caspin also demonstrated high homology with human pigment epithelium-derived factor/early population doubling level cDNA-1, which reportedly induces neuronal differentiation of human retinoblastoma cells and is expressed in association with G0 growth arrest. These findings suggest that caspin/pigment epithelium-derived factor/early population doubling level cDNA-1 is a novel factor that might play a crucial role in embryogenesis and tumor metastasis through binding to the extracellular matrix.

Amino Acid Sequence↗