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Biomedical subjects

N Kameda

Publications and source records attributed to N Kameda.

At least 37 records · Page 2Linked to original sources
PubMed1998

Immunolocalization of myotonic dystrophy protein kinase in corbular and junctional sarcoplasmic reticulum of human cardiac muscle.

The subcellular localization of myotonic dystrophy protein kinase has been examined in human cardiac muscles with confocal laser-scanning microscopy and electron microscopy. A polyclonal antibody was produced against the synthesized peptide from a human kinase cDNA clone. We checked the antibody specificity for cardiac myotonic dystrophy protein kinase using an immunoblotting technique. Immunoblotting of extract from human cardiac muscles showed mainly 70 kDa and 55 kDa molecular weight bands. Confocal images of the protein kinase immunostaining showed striated banding patterns similar to those of skeletal muscles. In addition, the kinase was strongly detected around the intercalated disc. Immunoelectron microscopy showed that the kinase was mainly expressed in both corbular and junctional sarcoplasmic reticulum, but not in network sarcoplasmic reticulum. These results suggest that myotonic dystrophy protein kinase may be involved in the modulation of Ca2+ homeostasis in cardiac myofibres.

Blotting, Western↗
PubMed1998

Two cases of myelodysplastic syndrome with extramedullary polyclonal plasma cell proliferation and autoantibody production: possible role of soluble Fas antigen for production of excessive self-reactive B cells.

Two cases of myelodysplastic syndrome (MDS) with extramedullary polyclonal plasma cell proliferation and autoantibody production are reported. These cases, which showed leukemic change of refractory anemia with excess of blast (RAEB), developed lymph node swelling and muscle abscess; both were infiltrated mainly with plasma cells, without preceding infection. The proliferation of plasma cells was polyclonal and was proven by negative rearrangement of immunoglobulin heavy chain gene or polyclonal staining of immunoglobulin light chains. These patients showed polyclonal gammopathy and autoantibody production such as positive antinuclear factor and direct antiglobulin test. As was observed in one of the present cases, and as we reported previously, the elevated level of soluble Fas antigen in MDS patients, and its inhibition of apoptotic signaling may be responsible for the excessive accumulation of self-reactive B cells, resulting in these clinical manifestations.

Aged↗
PubMed1997

Malignant glomus tumor: a case report and review of the literature.

This report concerns a malignant glomus tumor, a rare soft tissue tumor that was examined immunohistochemically and ultrastructurally. It occurred in a 44-year-old male patient who had suffered from dull pain and stiffness in the right thigh for 10 months. Radiographic examination revealed a well-defined osteolytic lesion in the diaphysis of the right femur. Hypervascularity of the tumor was observed angiographically. Computed tomographic and magnetic resonance examinations showed an intramuscular mass invading the marrow space of the femur. Wide resection was performed after open biopsy. Histologically, round to polygonal tumor cells revealed a uniform appearance of round to ovoid nuclei with single large nucleoli and slightly eosinophilic cytoplasm, forming solid sheets of cells interrupted by vessels of varying size. A few mitotic figures and vascular invasion were observed. Immunohistochemically, vimentin and alpha-smooth muscle actin were stained intensely, and muscle actin was positive for tumor cells of the perivascular area. Tumor cells were negative for desmin, factor VIII-related antigen, S-100 protein, neurofilament, cytokeratin, and epithelial membrane antigen. Ultrastructurally, tumor cells were characterized by many cytoplasmic processes, pinocytotic vesicles, plasmalemmal dense plaques, and scattered microfilaments in the cytoplasm. Few cell junctions and focal basement membrane-like structures were observed. No recurrence or metastasis was noted 57 months after operation. This case was considered to be a malignant glomus tumor, that is, a glomangiosarcoma arising de novo.

Actins↗
PubMed1997

Novel isoform of myotonin protein kinase: gene product of myotonic dystrophy is localized in the sarcoplasmic reticulum of skeletal muscle.

It is quite important to know the exact localization and function of myotonin protein kinase (MtPK), identified as the gene product of myotonic dystrophy, the most prevalent disease with multisystem disorders among muscular dystrophies. To investigate the localization of MtPK, we raised a polyclonal antibody against a synthetic peptide chosen within the deduced sequence of MtPK. This antibody detected both a membrane-bound 70-kd protein and a soluble 55-kd protein on Western blots of human muscles. By using this antibody for immunohistochemical studies of both biopsied human skeletal muscle fibers and mature innervated cultured muscle fibers, we can now demonstrate by confocal laser scanning microscopy that MtPK is localized mainly in the I-band. By immunoelectron microscopy, it was determined that MtPK is a membrane-bound protein localized mainly in the terminal cisternae of the sarcoplasmic reticulum. To our knowledge, this is the first documentation of the ultrastructural localization of MtPK. This finding is quite important for clarifying the pathophysiological basis of myotonic dystrophy, which might be due to a dysregulation of calcium metabolism.

Actins↗
PubMed1995

Developmental studies of dystrophin and other cytoskeletal proteins in cultured muscle cells.

We studied the developmental changes of localization of dystrophin and other cytoskeletal proteins, especially actin, spectrin and dystrophin related protein (DRP) using immunocytochemistry and quick-freezing and deep-etching (QF-DE) method. In developmental studies of mouse and human muscle cultures, some myoblasts had positive-reactions to spectrin, DRP, and F-actin, but not dystrophin. In aneurally cultured myotubes, dystrophin, DRP, and spectrin were localized diffusely in the cytoplasm and later in discontinuous patterns on the plasma membrane, when myotubes became mature. Spectrin and DRP had more positive reactions in immature myotubes, compared with those of dystrophin. In some areas of myotubes, dystrophin/spectrin and spectrin/actin were localized reciprocally. In innervated cultured human muscle cells, dystrophin and DRP were localized in neuro-muscular junctions, which were co-localized with clusters of acetylcholine receptors. By using the QF-DE method, dystrophin was localized just underneath the plasma membrane, and closely linked to actin-like filaments (8-10 nm in diameter), most of which were decorated with myosin subfragment 1. In actin-poor regions, spectrin was detected as well-organized filamentous structures in highly interconnected networks with various diameters. DRP was distributed irregularly with granular appearance inside the cytoplasm and also under the plasma membrane in immature mouse myotubes. Our present studies show that dystrophin, spectrin, and DRP are localized differently at the developmental stages of myotubes. These results suggest that dystrophin, spectrin, and DRP are organized independently in developing myotubes and these cytoskeletal proteins might play different functions in the preservation of plasma membrane stability in developing myotubes.

Adult↗
PubMed1994

[Anti-inflammatory effect of a traditional Chinese medicine, ren-shen-yang-rong-tang (Japanese name: ninjin-youei-to), on alveolar macrophages stimulated by RANTES or TNF-alpha].

This study was performed to clarify the effect of RANTES or TNF-alpha on rabbit alveolar macrophages and the anti-inflammatory effect of NINJIN-YOUEI-TO on alveolar macrophages stimulated by RANTES or TNF-alpha. Phagocytosis of alveolar macrophages was dose-dependently stimulated by RANTES or TNF-alpha. However, phagocytosis of alveolar macrophages was completely suppressed to the basal level when alveolar macrophages were preincubated with NINJIN-YOUEI-TO at 37 degrees C for 20 min. These results suggest that NINJIN-YOUEI-TO has an anti-inflammatory effect on alveolar macrophages through a process still to be determined.

Animals↗
PubMed1993

Developmental studies of the expression of myosin heavy chain isoforms in cultured human muscle aneurally and innervated with fetal rat spinal cord.

To study the influence of innervation of human muscle fiber type differentiation, we performed immunohistochemical studies using three monoclonal antibodies (McAbs) to myosin heavy chain (MHC) on cultured human muscles at different developmental stages. McAbs QM 355 (McAb-1), E 35-3 (McAb-2) and SM 1-11-2 (McAb-3) bound to fiber types I, IIA, IIB and IIC, types IIA, IIB and IIC, and type I, respectively. At the mononucleated cell stage the majority was immunonegative to the three McAbs; however, a few myoblasts were immunopositive to the McAb-1. They were also weakly stained with McAb-2 but not with McAb-3. In aneurally cultured myotubes (AMs), all myotubes were stained with the McAb-1 and 92.1% of AMs were positive to the McAb-2, whereas only a few (0.9%) AMs were immunopositive to the McAb-3. In contracting muscle fibers in an innervated area (CMis), which were co-cultured with fetal rat spinal cord explants, the percentage of the McAb-3-positive CMis was significantly increased (8.3%; P < 0.01) compared with that of AMs (0.9%). The double staining with the McAbs-2 and -3 clearly showed that slow MHC-positive muscle fibers without fast MHC only appeared in CMis. This is the first report of the neuronal influence on the expression of human adult slow MHC isoform derived from adult human satellite cells in vitro.

Adenosine Triphosphatases↗
PubMed1993

[Syphilitic orchitis: report of a case].

Syphilitic orchitis ir recently a rare disease in Japan. A 44-year-old man visited our hospital with the complaint of swelling of the right scrotum. He first noticed it about a half year ago, but the swelling mitigated without any therapy. The right testis was about the size of a hen's egg, elastic hard, and slightly rugged when he first visited our hospital. Treponema pallidum hemagglutination assay (TPHA) and rapid plasma reagin (RPR) were positive. We performed high orchiectomy because we could not deny the possibility of testicular tumor. Pathologically, granulomatous inflammation with lympho-plasmacytic infiltration and endoarteritis obliterans of the small arteries were seen in the specimen. It was diagnosed as granulomatous inflammation possibly caused by syphilitic orchitis. Syphilitic orchitis is usually quite difficult to distinguish from other types of granulomatous diseases of the testes, for example tuberculous orchitis. Various types of stains and careful examination of the specimen were thought to be necessary to distinguish these diseases.

Adult↗
PubMed1992

[Bilateral multilocular cystic renal cell carcinoma].

A case of bilateral renal cell carcinoma with multilocular cysts is described. A 42-year-old female was admitted to our hospital for the purpose of further examination or right renal cystic mass discovered incidentally by ultrasonography. After she was examined by CT-scan and angiography, right nephrectomy was performed under the diagnosis of right renal cancer. Histological diagnosis was multilocular cystic renal cell carcinoma. One year later a small cystic legion was found in the left kidney. Under the diagnosis of left renal cancer, left partial nephrectomy was performed. Histological diagnosis was multilocular cystic renal cell carcinoma same as the right kidney. Multilocular renal cyst is classified into several classes by its style of development. This case of bilateral renal cell carcinoma which grew to be multilocular cysts is the first case in Japan as far as we can search.

Adult↗
PubMed1991

Developmental study of the expression of dystrophin in cultured human muscle aneurally and innervated with fetal rat spinal cord.

So far there have been no developmental studies including the influences of innervation and contractile activity on the expression of dystrophin in cultured human muscle. We performed immunocytochemical studies of the localization of dystrophin on aneurally cultured non-contracting (AMs) and innervated continuously contracting cross-striated human muscle fibers (ICMs) with fetal rat spinal cord from normal and Duchenne muscular dystrophy (DMD) biopsied muscles. In normal AMs, myoblasts and some immature AMs showed negative staining of dystrophin, but many AMs had a patchy (discontinuous) distribution of dystrophin in the subplasmalemmal region and with some granularity near the sarcolemma and in the deeper cytoplasm. In normal ICMs, dystrophin was localized continuously at the inner aspect of the sarcolemmal membrane and some periodic dense patterns were detected in some areas. Both AMs and ICMs from DMD had negative staining of dystrophin. To investigate the muscle contractile activity on the distribution of dystrophin, we paralyzed ICMs with tetrodotoxin (TTX) for two weeks from the first appearance of muscle contractions. In paralyzed innervated muscles (PIMs), dystrophin remained in a patchy (discontinuous) pattern at the inner aspect of the plasmalemma similar to that in AMs. It is strongly suggested that muscle contractile activity plays an important role in the continuous and even distribution of dystrophin at the sarcolemma during development.

Adult↗
PubMed1991

Ectopic atrial natriuretic peptide production in small cell lung cancer with the syndrome of inappropriate antidiuretic hormone secretion.

One autopsy case with small cell lung cancer and the syndrome of inappropriate antidiuretic hormone secretion (SIADH) is reported. Both plasma atrial natriuretic peptide (ANP) and arginine vasopressin (AVP) levels were high, and the presence of significantly high levels of ANP and AVP in tumor tissue was confirmed by gel chromatography and radioimmunoassay techniques. To the best of the authors' knowledge, this is the first case in which ectopic ANP production and its secretion into blood (leading to SIADH) were proved.

Aged↗
PubMed1991

Human myasthenia gravis thymic myoid cells: de novo immunohistochemical and intracellular electrophysiological studies.

Thymic myoid cells from myasthenia gravis (MG) patients and controls were successfully grown in explant cultures: we have compared them with skeletal muscle cells cultured from biopsies in morphological, immunohistochemical and electrophysiological studies. Some mononucleate cells in thymus cultures were myoglobin- or desmin-positive, but they were much rarer than the otherwise similar fusing myoblasts in muscle cultures. Frequencies of cultured myoglobin-positive cells showed no difference between MG and control and male or female, but were lower in samples of malignant thymoma, in younger cases and in those with less severe MG. Electrophysiologically the resting membrane potentials of cultured thymic multinucleate cells were significantly less than those of cultured skeletal muscle cells, and action potentials by electrical stimulation were rarely observed. In thymus cultures from only one case with malignant thymoma, desmin-positive myotubes had spontaneous irregular contractions followed by electrical firings. It is concluded that there are myoid cells in MG and control thymuses which have the potential to become skeletal muscle fibers morphologically and electrophysiologically, although their frequency and proliferation in culture are quite low.

Adolescent↗
PubMed1990

True malignant mixed tumor of the submandibular gland.

A case of true malignant mixed tumor of the submandibular gland is reported. The submandibular tumor, occurring in a 52-year-old man, started to grow rapidly after a long history without any change in size. Surgical resection was carried out and the resected tumor measured 5.5 cm with a cut surface showing mixed solid structures. Microscopically, the tumor had both carcinomatous and sarcomatous elements, the former consisting of poorly differentiated adenocarcinoma with squamous cell differentiation and the latter consisting of osteosarcoma with chondrosarcomatous and fibrosarcomatous elements. A remnant of benign pleomorphic adenoma could also be identified. Immunohistochemical study demonstrated keratin and epithelial membrane antigen in the carcinoma cells and vimentin in all elements of the osteosarcoma. It is assumed from these clinical and histological findings that the tumor had transformed from a pre-existing benign pleomorphic adenoma.

Adenoma, Pleomorphic↗
PubMed1988

Fluorescein labeling of Fab' while preserving single thiol.

We determined the conditions for labeling rabbit Fab' with fluorescein isothiocyanate to provide maximal fluorescence intensity compatible with the preservation of integrity of its single thiol residue. We found that we could reproducibly substitute Fab' with two fluorescein moieties in 30 min at room temperature at pH 8.9. We achieved a high level of fluorescence intensity while we preserved the integrity of more than half of the existing thiols.

Animals↗