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Biomedical subjects

T Yoshihara

Publications and source records attributed to T Yoshihara.

223 records · Page 13Linked to original sources
PubMedDate not supplied

Ultrastructural and histochemical study of the motor end plates of the intrinsic laryngeal muscles in amyotrophic lateral sclerosis.

Motor end plates of the intrinsic laryngeal muscles in amyotrophic lateral sclerosis (ALS) were examined light and electron microscopically. Light microscopically, typical neurogenic changes such as small angulated fibers and grouped atrophy were found in the intrinsic laryngeal muscles. Acetylcholinesterase (AchE) activities of the neuromuscular junctions (NMJ) of many fibers in ALS were decreased as compared with those of the controls. Some end-plate areas on each fiber detected by AchE histochemistry were larger than those of the controls. Ultrastructurally, muscle fibers in ALS specimens showed several changes; increased number of lipofuscin granules and/or nuclei, numerous mitochondria, and disappearance of the myofilaments. The NMJ also showed various degrees of structural changes. Some NMJ appeared almost normal. Others showed the absence of nerve terminals and Schwann cells covering the former junctional sites. Their primary synaptic clefts were flattened, and the secondary synaptic clefts were relatively well preserved. On occasion, several small nerve terminals were seen on the severely distorted postsynaptic folds, suggesting regenerative findings. In severely degenerated muscle fibers, the NMJ could not be found.

Acetylcholinesterase↗
PubMedDate not supplied

Effect of recombinant human granulocyte-colony stimulation factor (rhG-CSF) on immune system in pediatric patients with aplastic anemia.

To determine the effect of recombinant human granulocyte-colony stimulation factor (rhG-CSF) on the immune system, serum immunoglobulins, lymphocyte subsets, and serum cytokines were analyzed in eight pediatric patients with aplastic anemia (AA) during 8-week rhG-CSF therapy. The rhG-CSF was administered either subcutaneously (200 micrograms/m2 x 4 weeks, followed by 400 micrograms/m2 x 4 weeks) or intravenously (400 micrograms/m2 x 4 weeks, followed by 800 micrograms/m2 x 4 weeks). In response to rhG-CSF therapy, neutrophil counts exceeded the pretreatment counts by twofold during the first week except for one case that did not attain twofold increase until day 41. While serum IgG and IgA were not affected, serum IgM was elevated during treatment in six of the eight cases to more than 1.2-fold basal levels (P < 0.04); however, there was no increase in serum interleukin (IL)-6 and interferon-gamma levels. On the other hand, CD56 positive NK cells significantly dropped from 7.7% to 4.5% (P < 0.02). These results indicate that systemic administration of rhG-CSF affects not only the neutrophil count, but also serum IgM levels and the natural killer cell population in patients with AA.

Adolescent↗
PubMedDate not supplied

Radiotherapy with concurrent docetaxel and carboplatin for head and neck cancer.

BACKGROUND: This study was designed to evaluate the concomitant use of docetaxel and carboplatin for radiosensitization in head and neck cancer. MATERIALS AND METHODS: One dose of docetaxel at 10 mg/m2 and five doses of carboplatin at AUC of 0.4 per week were administered to patients during the first two weeks of radiotherapy. Sixteen patients were treated with this regimen. Radiotherapy was given to a total dose of 64.8 to 82.0 Gy. Altered fractionation radiotherapy was performed in 12 patients with untreated advanced tumors. RESULTS: The complete response (CR) rate was 81%, with a partial response (PR) rate of 19%. Toxicities included grade 3 mucositis in 69% of patients and grade 2 dermatitis in 56% of patients. CONCLUSION: This schedule of docetaxel and carboplatin combined with radiotherapy may become a useful approach for the management of head and neck cancer with proper management of mucositis.

Adult↗
PubMedDate not supplied

Ultracytochemical study of ouabain-sensitive, potassium-dependent p-nitrophenylphosphatase activity in the inner ear of the squirrel monkey.

The localization of ouabain-sensitive, K+-dependent p-nitrophenylphosphatase (K+-NPPase) activity of the Na+, K+-ATPase complex was studied ultracytochemically in the squirrel monkey inner ear. In the stria vascularis the reaction products showing K+-NPPase activity were limited to the cytoplasmic side of the plasmalemmal infoldings of the marginal cells. In the spiral prominence, a weak reaction was also found on the cytoplasmic process of the stromal cell, while no or little reaction was detected on the spiral prominence epithelium. In the dark cells of vestibular labyrinth the reaction products were observed on the basolateral interdigitation of the plasmalemma. In contrast, no reaction was observed on the apical cell surface. K+-NPPase activity was most intense in the strial marginal cell, followed by the dark cell of the ampulla and the utricle. The present results revealed that the dark cells in the vestibular labyrinth are involved in endolymph homeostasis.

4-Nitrophenylphosphatase↗
PubMedDate not supplied

An ultrastructural study of the nasal mucosa by rapid freezing and freeze-substitution.

We demonstrated the ultrastructures of the nasal mucosa of the rat by rapid freezing and freeze substitution with OsO4. Liquid helium was used for the rapid freezing. The depth of the good preservation was approximately 20 micron below the cut surface of the tissue. The characteristic features of the nasal mucosa obtained here are as follows: 1) The cross-section profiles of the cilium were round and smooth. 2) Mitochondrial matrix was electron dense and a few dense granules were observed in it. 3) Secretory granules of the goblet cells were enclosed by a limited membrane. 4) Extracellular space was of variable widths. 5) Cytoplasmic filaments were well preserved.

Animals↗
PubMedDate not supplied

Increased levels of alpha V-associated integrins in association with growth inhibition of cultured tumor cells by bromodeoxyuridine.

Treatment of three small-round-cell-tumor cell lines, TC-32 (peripheral neuroepithelioma), 6647 (Ewing's sarcoma), and GOTO (neuroblastoma), with bromodeoxyuridine (BrdU) (5 micrograms/ml) for 6 days markedly inhibited cell growth in both culture medium and soft agar and induced morphological alteration into large flat cells. These BrdU-treated cells showed markedly increased levels of alpha V-associated integrins, including alpha V beta 3, and no uniform changes in other beta 1 subfamilies (alpha 1-6). Cell attachment to vitronectin was found to be increased in these BrdU-treated cells. These results suggest that increased levels of alpha V-associated integrins are associated with growth inhibition of cultured tumor cells induced by BrdU.

Androgens↗