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Y Akimoto

Publications and source records attributed to Y Akimoto.

At least 55 records · Page 3Linked to original sources
PubMed1996

Heat shock-enhanced T cell apoptosis with heat shock protein 70 on T cell surface in multicentric Castleman's disease.

We report here that T cells from patients with multicentric Castleman's disease (MCD) are sensitive to hyperthermia. T cells from two of three patients with MCD revealed DNA ladder formation and chromatin condensation following heat shock (30 min at 41.5 degrees C). Peripheral blood mononuclear cells (PBMC) from the same MCD patients exhibited high levels of spontaneous apoptosis after 72 h in culture and elevated apoptosis after heat shock, as evaluated by a quantitative flow cytometric assay. Heat shock protein 70 (hsp70) was detected on the cell surface of T cells in all three patients after heat shock. Furthermore, hsp70 was detected on T cells in the two MCD patients with apoptosis even in the absence of heat shock. T cells from normal samples did not show either heat-shock-induced expression of cell-surface hsp70 or apoptosis. Thus, heat shock treatment augmented hsp70 expression on the cell surface of T cells and enhanced apoptosis. Our studies suggest that hyperthermia may influence the clinical course of MCD.

Antigens, Surface↗
PubMed1996

Distribution of beta1 integrin during development of chick tarsometatarsal skin in vivo and in vitro.

To determine the role of beta1 integrin in chick tarsometatarsal skin development, we examined the localization of the beta1 integrin immunohistochemically in vivo and in vitro by light and electron microscopy. Beta1 integrin was present over the entire cell surface of undifferentiated epidermis at early stages (Days 5, 9, 13). Marked changes in the localization of beta1 integrin occurred during epidermal keratinization and stratification, i.e., expression of beta1 integrin decreased in the superficial and intermediate cell layers from Day 13 to Day 17. After 17 days in vivo, when keratinization of the epidermis was completed, the distribution of beta1 integrin was confined to the basal layer of the epidermis in a pericellular distribution. During all stages examined, fibroblasts in the dermis were also stained. Immunoelectron microscopic study revealed that beta1 integrin was located on the plasma membrane of keratinocytes and dermal fibroblasts. The change in beta1 integrin localization that occurred in vivo could be reproduced in cultures of developing skin in which keratinization (differentiation) or mucous metaplasia (transdifferentiation) had been induced in vitro by hydrocortisone or retinol treatment, respectively. A monoclonal antibody against beta1 integrin caused striking changes in the epidermal keratinization process and in the basement membrane structure in vitro, i.e., inhibition of keratinization and detachment of the basement membrane from the basal surface of the epidermis. These results indicate that beta1 integrin plays an important role in cell-cell and cell-extracellular matrix interactions, which are important for epidermal development of the tarsometatarsal skin.

Animals↗
PubMed1996

Angiotensin II induces ovulation and oocyte maturation in rabbit ovaries via the AT2 receptor subtype.

The present study was undertaken to investigate the role of angiotensin II (Ang II) in ovulation and ovarian steroidogenesis and prostaglandin (PG) production via the Ang II receptors in rabbit ovaries. In in vitro perfused rabbit ovaries, PD123319, a selective nonpeptide antagonist for AT2 receptors, reduced the Ang II-induced ovulation in a dose-dependent manner, whereas CV-11974, a selective nonpeptide antagonist for AT1 receptor, did not affect the Ang II-induced ovulation. Ang II also significantly stimulated the meiotic maturation of ovulated ova and follicular oocytes in the absence of gonadotropin. The addition of PD123319 at 10 (-6) M to the perfusate significantly inhibited the Ang II-induced oocyte maturation. Ang II did not stimulate the production of progesterone by perfused rabbit ovaries but significantly stimulated the production of estradiol (E2) and PGs. When PD123319 at 10(-6) M was added to the perfusate 30 min before the onset of Ang II administration, the Ang II-stimulated production of E2 and PGs was significantly blocked. Saralasin, a peptide analog of Ang II, inhibited the specific binding of [125I] iodo-[Sar1, Ile8] Ang II to rabbit ovarian membranes in a concentration-dependent manner, yielding an inhibitory constant (IC50) value of 1.58 x 10(-9) M. PD123319 and CV-11974 also inhibited the binding of [125I]iodo-[Sar1, Ile8] Ang II; however, PD123319 and CV-11974 were 15 and 40 times less potent than saralasin, respectively. Autoradiographic study revealed that an intense localization of Ang II receptors in the rabbit ovaries was present in the granulosa cell layers and the stroma of the preovulatory follicles. AT2 receptors were predominantly located in granulosa cells, whereas AT1 receptors were more concentrated in the stroma and thecal cell layers. In summary, Ang II induced ovulation and oocyte maturation and stimulated the production of E2 and PG by perfused rabbit ovary in vitro via the AT2 receptor. Thus, locally produced Ang II may be part of a novel intraovarian paracrine or autocrine control mechanism during the ovulatory process.

1-Sarcosine-8-Isoleucine Angiotensin II↗
PubMed1996

MR of the submandibular gland: normal and pathologic states.

PURPOSE: To evaluate the MR appearance of normal and pathologic states of the submandibular gland. METHODS: MR images of 22 healthy subjects and 21 patients with histopathologically confirmed disorders of the submandibular gland (five pleomorphic adenomas, two hemangiomas, two malignant lymphomas, one adenoid cystic carcinoma, one squamous cell carcinoma, and 10 cases of sialadenitis) were reviewed. RESULTS: All normal submandibular glands showed higher signal intensity than surrounding muscle but lower intensity than fat on T1-weighted and T2-weighted images. Postcontrast images showed moderate enhancement of the gland. All the tumors had lower signal intensity than the normal submandibular gland on T1-weighted images and had intermediate to high (n = 8) or high (n = 3) signal intensity relative to the normal submandibular gland on T2-weighted images. Six of seven benign tumors were well defined, and three of four malignant tumors were poorly defined. In all cases of sialadenitis, the submandibular gland showed diffusely different signal intensities from the normal gland on both T1-weighted and T2-weighted images. Eight cases of chronic sialadenitis showed lower T2-weighted signal intensities than the normal gland, and this can be explained histopathologically by marked fibrosis and cellular infiltration. CONCLUSIONS: MR imaging can show the presence, extent, margins, and signal intensity changes of pathologic conditions of the submandibular gland.

Adenoma, Pleomorphic↗
PubMed1995

Immunocytochemical localization of the protein reactive to human beta-1, 4-galactosyltransferase antibodies during chick embryonic skin differentiation.

BACKGROUND: beta-1, 4-Galactosyltransferase (GalTase) transfers galactose from UDP-galactose to terminal N-acetylglucosamine in glycoconjugates and is located both in the Golgi apparatus and in the plasma membrane. The cell surface GalTase is thought to be involved in cell-to-cell recognition and cell-to-extracellular matrix interaction. METHODS: By the use of specific monoclonal antibodies against human GalTase, changes in cell surface localization of the protein reactive to the antibodies in chick embryonic skin during its differentiation in vivo and in vitro were detected immunohistochemically at both light- and electron microscopic levels. The distribution of glycoconjugates having terminal N-acetylglucosamine residues was detected by staining with succinylated wheat germ agglutinin (s-WGA). RESULTS: Under the light microscope, intense immunostaining was observed in the keratinized epidermis, particularly in the intermediate layer. Marked changes in the localization of the staining were observed in vitamin A-induced mucus-secreting skin, in which keratinization was suppressed. The localization of the immunostaining was in parallel with that of glycoconjugates having terminal N-acetylglucosamine residues. Immunoelectron microscopically the immunostaining was located on the cell surface and in the intercellular space of the desmosomes in the intermediate cells of the keratinized epidermis. However, the staining was not present on the cell surface but was detected on the limiting membrane of the mucous granules, in the mucous metaplastic epidermis. In contrast, the staining was always found in the Golgi apparatus in all of the cells. CONCLUSIONS: These results suggest that the protein reactive to human GalTase antibody may be involved in chick epidermal differentiation.

Animals↗
PubMed1995

Changes in expression of two endogenous beta-galactoside-binding isolectins in the dermis of chick embryonic skin during development in ovo and in vitro.

In order to elucidate the roles of metal-independent animal lectins, we systematically investigated changes in expression of 2 kinds of beta-galactoside-binding isolectins (MW 14 and 16 kDa) in the dermis of chick embryonic tarsometatarsal skin during the course of development. These lectins were immunohistochemically located at different stages of development both in ovo and in vitro by light and electron microscopy. Light-microscopic observation showed that while positive staining for the 14-kDa lectin was weak at days 8 and 10 it became intense after day 13. In contrast, staining for the 16-kDa lectin was intense at days 8, 10, and 13, but it became weak after day 17 when keratinization of the epidermis was completed. Immuno-electron-microscopic observation revealed that both the 14 and 16-kDa lectins were located on the basement membrane, in the extracellular matrix, and in both the cytoplasm and the nucleus of dermal fibroblasts. Distribution of the 2 isolectins was also examined in cultured skin explants in vitro. The results were almost the same as those obtained in ovo when the skin explant was keratinized in the presence of hydrocortisone. However, in the skin explant where keratinization was prevented and mucous metaplasia was induced by the addition of vitamin A, the distribution of the 14-kDa lectin in the epidermis was significantly affected. These results indicate that (1) the expression of the 2 isolectins is differently regulated in both the dermis and epidermis, (2) the 16-kDa lectin is involved in the early stage of the formation of the dermis and the basement membrane and is replaced by the 14-kDa lectin as keratinization of the epidermis occurs, and (3) the expression of the 2 isolectins in the dermis is not significantly affected by the induction of mucous metaplasia, in contrast to their drastic changes in the epidermis.

Animals↗
PubMed1995

Expression of the endogenous 14-kDa beta-galactoside-binding lectin galectin in normal human skin.

The localization of an endogenous 14-kDa beta-galactoside-binding lectin (galectin) and its pattern of gene expression were examined in normal human skin by light- and electron microscopy. Under the light microscope, immunostaining of 14-kDa galectin was observed in the cell membrane of cells in the basal and spinous layers of the epidermis. Galectin was also found in the Langerhans cells, as shown by double labeling using anti-14-kDa galectin and anti-CD1a antibodies. In the dermis, immunostaining for the 14-kDa galectin was positive in the extracellular matrix and fibroblasts. At the electron-microscopic level of resolution, galectin was located primarily along the plasma membrane of keratinocytes, and in both the cytoplasm and nucleus of Langerhans cells in the epidermis, whereas in the dermis it was detected in the extracellular matrix and in both the nucleus and cytoplasm of fibroblasts. The gene expression of 14-kDa galectin was visualized by the HRP-staining method following in situ hybridization techniques. The expression was detected in the cytoplasm of cells in the basal and spinous layers of the epidermis; whereas, in the dermis, it was detected in the cytoplasm of fibroblasts. Moreover, SDS-polyacrylamide gel electrophoresis and lectin-blot analysis revealed that this galectin bound to glycoproteins of approximately 17, 62, and 72 kDa in the epidermis and to those of 29, 54, and 220 kDa in the dermis. The present study indicates that 1) normal human skin produces the beta-galactoside-binding 14-kDa galectin, and 2) this galectin is located in both the epidermis, particularly in the keratinocytes and Langerhans cells, and in the dermis. These results suggest that galectin is important for cell-cell contact and/or adhesion in the epidermis and for cell-extracellular matrix interaction in the dermis.

Base Sequence↗
PubMed1995

Magnetic resonance imaging of osteomyelitis in the mandible. Comparative study with other radiologic modalities.

Magnetic resonance imaging of 14 histopathologically confirmed cases of osteomyelitis of the mandible was retrospectively reviewed. The findings of magnetic resonance imaging were compared with conventional radiography, computed tomography, bone scintigraphy, and histopathologic examinations. All lesions in bone marrow were shown as areas of low (64%) or low-to-intermediate (36%) signal intensity on T1-weighted images, and areas of high (29%), mixed (high and low, 21%; high and intermediate, 36%) or low (14%) signal intensity on T2-weighted images. Histopathologically, high T2-weighted signal intensity areas that showed enhancement after contrast injection corresponded to active infection. These were not collections of pus but were predominantly areas of granulation tissue. Magnetic resonance imaging showed larger areas of abnormality than plain radiography or computed tomography. Bone scintigraphy did not accurately reveal the locations of lesions but showed heterogeneous increased uptake in all patients. MRI was an extremely useful technique for assessing osteomyelitis of the mandible.

Acute Disease↗
PubMed1995

Evaluation of jawbone calcification in osteopetrotic (op/op) mice using computed tomography.

The study was conducted to evaluate the degree of calcification in the jawbones of 3 pairs of 4-week-old male op/op mice and littermates using computed tomography (CT) numbers. The mean CT numbers for op/op mice (n = 3) were 251.3 HU (range, 226 to 278) in the maxillary bone and 353.7 HU (range, 320 to 398) in the mandibular bone. The mean CT numbers for littermates were 336.7 HU (range, 324 to 350) and 596.6 HU (range, 580 to 604), respectively. The CT numbers of littermates were higher than in op/op mice for both maxillary and mandibular bones. These results indicated that the degree of bony calcification in littermates was higher than that in 4-week-old op/op mice in both the maxillary and mandibular bones. CT is able to demonstrate the degree of bony calcification in the jawbones of op/op mice using CT numbers, and it is suggested that CT is an extremely effective tool for examining the conditions of bone in vivo. This study also shows that op/op mice are useful for investigation of bone calcification or maturation.

Aging↗
PubMed1995

[Multicentric Castleman's disease with lymphoid interstitial pneumonia died of aggressive course with adult respiratory distress syndrome].

A 49-year-old man was admitted to our hospital with anemia and hypergammaglobulinemia. Physical examination revealed superficial lymph node swelling and no hepatosplenomegaly. Laboratory findings showed WBC 5,300/microliters with normal hemogram, microcytic and hypochromic anemia. Total protein was 11.5 g/dl and immunoglobulinemia (IgG 10,100 mg/dl, IgA 295 mg/dl, IgM 160 mg/dl) was observed without M-component in serum and urine. The CD4/CD8 ratio of lymphocyte subsets was 0.58 and the tuberuculin skin test was negative. Urinary protein was positive and renal biopsy disclosed plasma cell infiltration. Lymph node biopsy revealed multiple lymphoid follicles and infiltration of plasma cells in the interfollicular areas. A diagnosis of multicentric Castleman's disease (MCD) was made baredon clinical findings and lymph node biopsy. After therapy with plasmapheresis and the CHOP regimen, he was given etoposide. Although discharged with clinical improvement and a decrease of serum IgG, he was readmitted because of pyrexia after 4 days and died of pneumonia with adult respiratory distress syndrome. The autopsy revealed lymphoid interstitial pneumonia. It seems important to notice that some of MCD have poor prognoses because of accompanying immunodeficiency.

Castleman Disease↗
PubMed1995

[A HBV carrier with fulminant hepatitis complicated by ATL, multiple myeloma and thyroid cancer].

A 75-year-old female, born in Tochigi Prefecture, was admitted because of lumbago in August of 1991. The leukocyte count was 11,800/microliters with 22.5% atypical lymphocytes. We demonstrated a lymphocyte surface marker, ATL-associated antigen, and proviral DNA. We also identified 2.60 g/dl of serum monoclonal protein, found to be IgG, lambda type, and punched out lesions in the skull. We made a diagnosis of ATL. She was also a HBV carrier. The patient was treated with a modification of CHOP therapy, because of increasing atypical lymphocytes in the peripheral blood in November of 1992. She died of acute hepatitis, suddenly, in March of 1993. Autopsy revealed multiple myeloma, fulminant hepatitis and occult thyroid cancer in addition to ATL.

Acute Disease↗
PubMed1995

Tenidap, an anti-inflammatory agent, discharges intracellular Ca++ store and inhibits Ca++ influx in cultured human gingival fibroblasts.

The effect of tenidap, (+/-)-5-chloro-2,3-dihydro-3-(hydroxy-2- thienylmethylene)-2-oxo-1H-indole-1-carboxamide, a new anti-inflammatory agent, was investigated on intracellular free Ca++ concentration ([Ca++]i) responses evoked by bradykinin and thapsigargin in gingival fibroblasts. Tenidap itself stimulated [Ca++]i response in a dose-dependent manner in the absence of extracellular Ca++. The pretreatment with tenidap inhibited [Ca++]i responses evoked by 5 nM bradykinin and 1 microM thapsigargin in a dose-dependent manner. This indicates that tenidap discharges intracellular Ca++ store, resulting in a depletion of intracellular Ca++ store. Tenidap partially depressed Ca++ influx across plasma membrane by 1 to 2 min pretreatment and almost completely by more than 5 min pretreatment. Thus, tenidap appears to be a valuable agent that functions on inhibition of Ca++ influx in nonexcitable cells, which is rare at the present time.

Aged↗
PubMed1995

Restricted expression of galactose/N-acetylgalactosamine-specific macrophage C-type lectin to connective tissue and to metastatic lesions in mouse lung.

We investigated expression of macrophage galactose/N-acetylgalactosamine-specific C-type lectin (MMGL) in normal mouse lung tissue and in lungs with metastatic nodules produced by OV2944-HM-1 mouse metastatic ovarian tumour cells. Cells expressing MMGL were detected in tissue sections using a rat monoclonal antibody (mAB) specific for MMGL, mAb LOM-14. The regions containing cells immunostained using mAb LOM-14 were restricted to the connective tissue surrounding blood vessels and respiratory epithelia, whereas alveolar regions of lung parenchyma were essentially devoid of these cells. In contrast, a significant number of cells in the alveolar regions was shown to express Mac-1 antigen (CD11b/CD18) and leucocyte common antigen (CD45). Immunoelectron microscopic study revealed the presence of MMGL in the intracellular vesicles of cells residing in connective tissue. In the tumour-bearing mice, MMGL-positive cells were also present within metastatic nodules. Their localization outside of the nodules was restricted to connective tissue. Cells with Mac-1 antigens were seen both in the nodules and in the alveolar regions. These results indicate that MMGL serves as a unique macrophage marker in mouse lung tissue due to its topographical site-dependent pattern of expression. The present results also suggest a possible involvement of macrophages expressing MMGL in the immune response directed against metastatic tumour cells.

Animals↗
PubMed1995

[Clinical significance of soluble interleukin-2 receptor in multiple myeloma].

Increased levels of soluble interleukin-2 receptor (sIL-2R) have been noted in the sera of patients with various diseases such as adult T cell leukemia, malignant lymphoma and autoimmune diseases. Using an enzyme-linked immunoabsorbent assay, we assessed sIL-2R levels in the sera of 16 patients with multiple myeloma (MM) and 27 normal subjects. There was a significant increase in the levels of sIL-2R in the patients with myeloma (963 +/- 523 U/ml) compared to normal subjects (213 +/- 80 U/ml). The levels of sIL-2R corresponded well with the clinical stage, M-protein, serum IL-6 and serum beta 2 microglobulin levels. Taking the evidence that the CD4/CD8 ratio decreased as the disease worsened into consideration, the increase in the serum sIL-2R levels of the patients with MM is considered to have some correlation with B and T cell activation through various cytokines including IL-6. Furthermore such evidence would support the role of sIL-2R as a disease monitor of MM.

Biomarkers, Tumor↗
PubMed1994

Effect of calcium-channel blockers on cell proliferation, DNA synthesis and collagen synthesis of cultured gingival fibroblasts derived from human nifedipine responders and non-responders.

Human gingival fibroblasts from six patients who developed gingival hyperplasia as a result of nifedipine medication and five who did not were studied for the effects of calcium-channel blockers (nifedipine, diltiazem, verapamil and nicardipine) on cell proliferation, DNA synthesis and collagen synthesis. Phenytoin was used as a positive control. The fibroblasts from reactive patients gave trends toward better cell proliferation rates, DNA synthesis ([3H]-thymidine incorporation), and collagen synthesis ([3H]-proline incorporation) than those from non-reactive patients in the presence of 1 microM of calcium-channel blockers or phenytoin.

Adult↗
PubMed1994

Imaging tumors of the minor salivary glands.

Magnetic resonance imaging evaluations of nine histopathologically confirmed minor salivary gland tumors were made retrospectively and compared with evaluations of images obtained by computed tomography. All tumors had low-to-intermediate T1 signal intensities and intermediate-to-high T2 signal intensities. Malignant tumors had an irregular margin in all but one case. Benign tumors invariably had well-defined margins. In terms of tumor margination, the magnetic resonance imaging findings correlated well with the histopathologic findings. Magnetic resonance imaging demonstrated the internal architecture of the minor salivary gland tumors multidirectionally and was superior to computed tomography in this respect and in the ability to locate the tumors.

Adenocarcinoma↗
PubMed1994

Cefadroxil concentrations in human serum, gingiva, and mandibular bone following a single oral administration.

Cefadroxil concentrations in human serum, gingiva, and mandibular bone were measured by a paper disk method following a single 500-mg oral dose. The mean peak concentrations in serum, gingiva, and mandibular bone occurred at the identical time, 3 hours, and were 12.92 micrograms/mL, 6.50 micrograms/g, and 2.67 micrograms/g, respectively. Mean cefadroxil concentration ratios of gingiva/serum and mandibular bone/serum at the peak time were 0.54 and 0.21, respectively. Mean concentrations in gingiva and mandibular bone at the peak time exceeded the minimum inhibitory concentrations for 90% of clinically isolated strains of a alpha-hemolytic streptococci.

Absorption↗