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Biomedical subjects

T Yoshihara

Publications and source records attributed to T Yoshihara.

At least 145 records · Page 8Linked to original sources
PubMed1991

Nerve growth factor-like activity detected in equine peripheral blood after running exercise.

Addition of sera, collected from Thoroughbred horses after sprint exercise, induced significant neurite outgrowth from chick embryo dorsal root ganglia after a 24-hour culture. The nerve growth factor (NGF)-like activity was detected in sera collected immediately, or 1 hour or more, after the exercise. These findings suggest a possible role of serum NGF-like activity under stress conditions (running exercise) of horses.

Animals↗
PubMed1991

Ultrastructural and histochemical study of the neuromuscular junctions in the denervated intrinsic laryngeal muscle of the cat.

Morphological changes and acetylcholinesterase (AchE) activity in the neuromuscular junctions (NMJ) of the normal and denervated posterior cricoarytenoid muscle (PCA muscle) of the cat were studied. Two days after denervation, the nerve terminals at the NMJ had almost disappeared. Six weeks after denervation, intensity of AchE activity at the former junctional site (FJS) was unchanged histochemically. At this stage, primary synaptic clefts were distorted and the Schwann's cells covered the FJS. Fourteen weeks after denervation, AchE activity at the FJS had decreased in contrast to that of the non-affected side. Calcitonin gene-related peptide (CGRP) was also investigated at the NMJ of the normal PCA muscles immunocytochemically. The present study shows that CGRP coexists with Ach in the nerve terminals of the PCA muscles and may be involved in the regulation of the contractile function of the intrinsic laryngeal muscle.

Acetylcholinesterase↗
PubMed1991

Expression of CD56/NCAM on hematopoietic malignant cells. A useful marker for acute monocytic and megakaryocytic leukemias.

We investigated the expression of CD56 (a neural cell adhesion molecule, NCAM) and CD57 in various hematopoietic and non-hematopoietic malignant cells, using Leu-19 and Leu-7 monoclonal antibodies. Although both molecules are commonly defined as a natural killer cell marker, we found that CD56 was highly expressed on blasts from patients with acute monocytic (4/6) and megakaryocytic (3/3) leukemias. In the latter, FACS two-color analysis revealed that leukemic megakaryoblasts simultaneously expressed CD56 and platelet-related antigens. Among leukemic cell lines, one myelocytic, three monocytic, and two megakaryocytic lines were positive for CD56. On the other hand, except for one large granular lymphocytic leukemia and one multiple myeloma cell line, none of the lymphoid leukemia cell lines or lymphoblasts from patients with acute lymphocytic leukemia (ALL) (0/15), non-Hodgkin's lymphoma (NHL) (0/2), and central nervous system (CNS) leukemia (0/2) reacted with Leu-19 antibody for CD56. The expression of CD56 in leukemia cells was not significantly affected by 12-O-tetradecanoylphorbol-13-acetate (TPA). By contrast, all hematopoietic materials were negative for CD57, while non-hematopoietic neuroblastoma cell lines expressed this molecule (4/5) as well as CD56 (5/5). Cytogenetically, the NCAM gene is located at chromosome 11q23, and chromosome breaks were often observed at this location in various leukemias. Blasts from all five acute non-lymphocytic leukemia (ANLL) patients and cell lines with 11q23-proximal chromosomal breaks were positive, while those from one ALL patient with an 11q23 abnormality were negative for CD56, necessitating further studies to clarify the link between the 11q23 abnormality and CD56 expression.

Adolescent↗
PubMed1991

Clinico-pathological analysis of foal diseases from 237 autopsy cases.

To elucidate the current status of foal diseases in Japan, clinico-pathological analysis was conducted on 237 foal autopsy cases. As a result, bacterial infection was identified as an important cause of foal death. Most of the bacteria isolated from these cases were ubiquitous, opportunistic, environmental organisms, known to be non-pathogenic to mature animals. Most of cases with bacterial infection were diagnosed as having hypogammaglobulinemia, i.e., failure of passive transfer. In addition, the mean weight of thymuses in foals affected by bacterial infection tended to be lower than that of foals without infection. These findings suggest that the common cause of foal diseases were mainly due to the opportunistic bacterial infections associated with the weakened immune function, serving as precursor to or promotor of infection.

Animals↗
PubMed1990

[Multi-drug chemotherapy for patients with peritonitis carcinomatosa associated with ascites].

Between 1973 and 1987, 257 patients with ascites were seen in our divisions and 101 deaths due to cancer out of those who received multi-drug anticancer chemotherapy were surveyed: 1) They consisted of 45 ovarian cancers, 15 uterine corpus cancers, 5 uterine cervical cancers and 36 unknown primary cancers, or cancers other than gynecologic malignancies. 2) Survival time from the time of aspiration of ascites tended to be longer in four years from 1977 and 1981 than in four years from 1973. 3) The survival time was different in each patient groups having various combination chemotherapy and the longest was seen in the group of patients who received THP-ADM and CDDP-containing regimen as the next. 4) Patients survived for the longest period when a total amount of ascites less than 100 ml was aspirated and patients whose ascites was drained out more than 50,000 ml were the next longest survivors. 5) Clinical efficacy by multi-drug chemotherapy for malignant ascites was possibly predicted by our drug sensitivity assay by using primary cultured cancer cells.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

Morphology of equine allantochorion at the tip of the pregnant horn.

The morphology of the equine allantochorion at the tip of the pregnant horn was studied in the membranes of 14 mares. The findings in the allantochorion at the tip of the pregnant horn were of two types; one was growth retardation (hypoplastic villi, tunica adventitia of the vessels resembling embryonal connective tissue and the extended spaces of remnants of the extraembryonic coelom), the other was placental hypoxia or ischaemia (parakeratosis, stratified squamous metaplasia, necrosis of the trophoblasts, thickening of the basement membrane and fibrous hyperplasia of villous stroma). It seems likely that hypoplastic villi are caused by disordered formation of the microcotyledon accompanying the progression of pregnancy.

Animals↗
PubMed1990

Oxytocin is the major prolactin releasing factor in the posterior pituitary.

Although the posterior pituitary is known to contain the PRL releasing activity or factor (PRF), its chemical identification has been a matter of dispute. In the present study, we purified PRF in porcine posterior pituitary extracts to chemically determine the primary structure. PRF activity was assessed during purification by the release of immunoreactive PRL from superfused rat pituitary cells. Two hundred seventy porcine posterior pituitaries were boiled, homogenized, and extracted with 2 M acetic acid. The acid extract was precipitated with 67% acetone, and the supernatant was absorbed onto a C18 column. The column was eluted step-wise with 10, 20, 30, 40, 50, and 60% acetonitrile (CH3CN) in 0.1% trifluoroacetic acid (TFA). The greatest PRF activity was recovered in the 30% CH3CN/0.1% TFA fraction and was further purified by ion-exchange chromatography on SP-Sephadex, followed by gel-filtration on Sephadex G-50. The Sephadex G-50 fractions with major PRF activity were finally purified by two cycles of reverse phase HPLC, yielding a single peak of PRF. Amino acid, as well as sequence analyses, indicated that the highly purified PRF was oxytocin. Authentic oxytocin showed the same chromatographic behavior and biological activity as those of the isolated peptide. In another experiment, desalted crude extracts of rat and porcine posterior pituitary tissues were directly chromatographed by reverse phase HPLC, and each fraction was assayed for PRF activity. Only two areas showed PRF activity; the largest activity coeluted with oxytocin and the smaller one co-eluted with vasopressin. The fractions which coeluted with oxytocin also showed oxytocin immunoreactivity, as examined by RIA. The results clearly indicated that the major PRF in these posterior pituitary extracts was oxytocin.

Amino Acid Sequence↗
PubMed1989

Primary squamous cell carcinoma of the parotid gland: a case report with electron microscopic findings.

Primary squamous cell carcinoma of the parotid gland is a rare tumor. Histological and ultrastructural features of a primary squamous cell carcinoma arising in the right parotid gland is presented. Light microscopically the tumor consisted of poorly differentiated squamous cell nests. PAS reaction was negative. Ultrastructurally the tumor cells were oval or spindle shaped and the cytoplasmic processes were frequently found. The majority of the tumor cells contained numerous intermediate filaments in their cytoplasm. No secretory granule was found. The desmosomes were well developed. It is known that mucoepidermoid carcinoma may be often misdiagnosed as squamous cell carcinoma. These findings can enable us to distinguish primary squamous cell carcinoma from mucoepidermoid carcinoma of the parotid gland.

Carcinoma, Squamous Cell↗
PubMed1989

Effect of physical exercise prelabyrinthectomy on locomotor balance compensation in the squirrel monkey.

This study examines the effectiveness of physical exercise, during a prepathology state, on locomotor balance compensation after subsequent unilateral labyrinthectomy in squirrel monkeys. An experimental group underwent 3 hr. of daily running exercise on a treadmill for 3 mo. prior to the surgery, whereas a control group was not exercised. Postoperatively, the locomotor balance function of both groups was tested for 3 mo. There was no significant difference in gait deviation counts in the acute phase of compensation. However, in the chronic compensation maintenance phase, the number of gait deviation counts was fewer in the exercise group, which showed significantly better performance stability.

Animals↗
PubMed1989

[Histochemical study of acetylcholine receptors at the neuromuscular junctions of the cat posterior cricoarytenoid muscle using erabutoxin B].

Acetylcholine receptors (AchRs) at the neuromuscular junctions of the cat posterior cricoarytenoid muscle (PCA muscle) were demonstrated by using erabutoxin b (Eb) which has a curare-like action. Eb is one of the short-chain neurotoxins which is obtained from Laticauda-semifasciata. At the light microscopic level, the localization of the neuromuscular junctions was detected on the muscle fiber by rhodamine-labeled Eb (TMR-Eb) under a fluorescein microscopy. For the electron microscopy horseradish peroxidase-labeled Eb (HRP-Eb) was used. After incubation with HRP-Eb conjugate the tissue was fixed in a mixture of paraformaldehyde and glutaraldehyde, then embedded in Epon. The reaction products were largely restricted to the postsynaptic membrane at the neuromuscular junction. Acetylcholinesterase (AchE) activity was also demonstrated electron microscopically by Karnovsky's and Lewis' methods respectively. The reaction products were localized at the subneural apparatus of the neuromuscular junction. Both these results were compared.

Animals↗
PubMed1989

[An adolescent case of myelodysplastic syndrome following aplastic anemia].

A male with myelodysplastic syndrome (MDS) following aplastic anemia is reported. The patient had been diagnosed as aplastic anemia at 8 years of age, and treated with blood transfusions, anabolic and glucocorticoid steroid hormones. Over a period of subsequent twelve years, he had remission and deterioration. At the age of 21, the patient developed a sudden progression of severe anemia, when his bone marrow showed hyperplasia with prominent dyshematopoiesis and excess of blasts, compatible with MDS by the definition of FAB classification. He received low dose Ara-C therapy, which was ineffective. Nine months later he developed acute monocytic leukemia (M5b) and died. Chromosomal analysis revealed 46, XY at the onset of aplastic anemia, 46, XY, del (6) (q21 q27) at the MDS and 46, XY, -7, +21, 6q-/47, XY, +Y, -7, +21, 6q- at the acute leukemic stage.

Adult↗
PubMed1989

[Malignant lymphoma of the central nervous system in a boy with immotile cilia syndrome].

Malignant lymphoma of the central nervous system in a thirteen-year-old boy with immotile cilia syndrome (ICS) is reported. He had frequent upper respiratory tract infections, chronic sinusitis and pneumonia during in childhood. Bronchiectasis was demonstrated by bronchography. The diagnosis of ICS was confirmed by the lack of dynein arms of cila in the nasal mucosa with electronmicroscopy. In 1987, he complained of headache and vomiting and a space occupied mass lesion in the left frontoparietal lobe was found by head CT scan, which was subtotally resected. Histological studies showed large cell type non-Hodgikin lymphoma of B-cell phenotype. He received radiotherapy (41Gy) to the whole brain and systemic chemotherapy consisting of adriamycin, cyclophosphamide, vincristine, prednisolone, L-asparaginase and intrathecal methotrexate, and the patient maintained complete remission for eight months. However, relapse occurred and the patient died twelve months after the initiation of treatment.

Adolescent↗
PubMed1988

Cytochemical demonstration of actin filaments in myoepithelial cells of the human parotid gland.

Ultrastructurally, myoepithelial cells were shown to contain numerous fine filaments in their cytoplasm and resembled smooth muscle cells. The myoepithelial cell of the salivary gland has been considered to play an important role in the secretion of saliva. The present study showed that all the thin filaments (actin filaments) in the myoepithelial cell of the human parotid gland bound heavy meromyosin (HMM) and formed characteristic arrowhead structures. These filaments ran in two opposite directions with the poles at different ends. On the other hand, there was no binding of HMM with thicker filaments (10-nm filaments), plasma membrane, nuclear membrane, collagen fibrils, basement membrane or other cytoplasmic organelles. The present results strongly suggest that myoepithelial cells possess a contractile function parallel to the long axis of the cell for supporting the secretion of saliva in the parotid gland.

Actin Cytoskeleton↗
PubMed1988

An electronmicroscopic study of the lateral line organ of the guppy, Poecilia reticulatus var.

We examined the ultrastructure of the lateral line of the guppy, Poecilia reticulatus var. by using both scanning electron microscopy and transmission electron microscopy. The neuromast was seen to be composed of receptor cells, supporting cells and mantle cells. The receptor cell has one kinocilium and approximately 29 stereocilia. Two kinds of nerve endings were found in the basal portion of the receptor cells. These two types of nerve endings were similar to the efferent and afferent nerves reported previously. The cytoplasm of the supporting cells contains numerous mitochondria, filaments and melanin-like granules. The lateral wall of the neuromast is covered by a few layers of crescent-shaped mantle cells.

Animals↗