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Biomedical subjects

K Tashiro

Publications and source records attributed to K Tashiro.

At least 523 records · Page 29Linked to original sources
PubMed1986

Level of histone H4 mRNA in Xenopus laevis embryonic cells cultured in the absence of cell adhesion.

The amount of histone H4 mRNA per embryo was followed during early development of Xenopus laevis by Northern blot analyses using a cloned histone H4 cDNA as the probe. The H4 mRNA content was nearly constant until the blastula stage, increased greatly at the gastrula stage and then decreased at the neurula stage. Experiments with actinomycin D suggested that most H4 mRNA molecules detected at the late gastrula and neurula stages were maintained depending on new transcription of H4 genes during these stages. To see if the H4 mRNA level is affected by cell adhesion, we prepared dissociated cells and measured H4 mRNA content under conditions that inhibit cellular reaggregation. It was found that the amount of H4 mRNA per embryo in dissociated and reaggregation-inhibited cells was nearly equal to that of the control embryo at the neurula stage. Therefore, we conclude that the synthetic activity of histone H4 mRNA is not dependent on the cellular adhesion during development.

Animals↗
PubMed1986

[Spinal dural AVM--report of three cases].

A new type of spinal AVM is reported. The characteristics are as follows: All the patients are male over 50-years-old. Their symptoms are insiduous and progressive ischemic pattern. All the lesions locate at the thoracic and lumbar levels. Selective intercostal angiography shows a fistulous AVM adjacent to the intervertebral foramen fed by spinal dural branch and drain into tortuous veins on the spinal cord via radiculomedullary vein. No typical hair-pin configuration by radiculomedullary and spinal cord arteries contributes to the AVM. This type of spinal AVM must be distinguished from so-called singled coiled type spinal cord AVM since pathophysiological features presumably are different from each other; the former is "dural" on anatomical basis, whereas the latter is "pial". Embolization should be recommended as a first choice of treatment to spinal dural AVM.

Aged↗
PubMed1986

[Radiation-induced bilateral common carotid artery stenosis--a report of a case].

A case of radiation-induced bilateral common carotid artery stenosis is reported. This 60 years old housewife was hospitalized in 1982 because of sudden onset of mild left hemiparesis. Twenty-five years ago, she underwent radiation therapy of approximately 5,000 rads to the anterior cervical region because of thyroid cancer. Angiograms in 1982 revealed bilateral common carotid artery stenosis, especially in the right common carotid artery, the legion of which were included within the field of radiation performed in 1952. Right thromboendarterectomy was performed in 1983. At operation, slight periarterial fibrosis with calcified arteriosclerotic change was found, and dissection between the thickened intima and the media was not so difficult. Histological change of resected thromboendarterium was similar to the one observed in the pure arteriosclerotic disease.

Arterial Occlusive Diseases↗
PubMed1986

[A case of complete remission of distant metastases of a renal pelvic tumor by combination chemotherapy with mitomycin, cyclophosphamide and 5-fluorouracil].

A 48-year-old woman was admitted to our hospital with the complaint of gross hematuria in March, 1982. The diagnosis of left renal pelvic tumor and bilateral neck lymph-node metastasis was made. Left nephroureterestomy and partial cystectomy were carried out in April, 1982. After the operation, combination chemotherapy with mitomycin, cyclophosphamide and 5-fluorouracil was carried out. The neck lymph-node disappeared completely in May, 1982. No recurrence or metastasis has been detected up to April 1985.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1986

[A case of multiple teratomas combined with embryonal carcinoma].

It is rare to find primary multiple teratomas among intracranial tumors. We report a case of multiple teratomas combined with embryonal carcinoma. A 22-year-old man was admitted to our hospital because of loss of appetite and emaciation. Neurological examination was negative except bilateral optic nerve atrophy and generalized hyperreflexia. The endocrinological study showed panhypopituitarism and partial DI. CT scan revealed irregularly enhanced abnormal masses involving suprasellar cistern and the septum pellucidum. The tumors were removed by the transcallosal approach, and the histopathological study showed mature teratoma which contained cartilage, epithelium of GI tract, ciliated epithelium, smooth muscle, fat tissue. Within the tumor of the septum pellucidum, nests of markedly pleomorphic epithelial tumor cells with necrosis, nuclear pleomorphism and mitosis were identified, embryonal carcinoma. At necropsy, no carcinomatous lesions were identified in other organs. Multiple teratomas from nonmetastatic, separate origins have been rate by reported in the literature. In our case, histologically, the mass in the suprasellar cistern was diagnosed as mature teratoma and the mass of the septum pellucidum was mature teratoma combined with embryonal carcinoma. It seemed likely that each of the tumors was developed from different origins.

Adult↗
PubMed1985

Identification of thalamic neurons with vasoactive intestinal polypeptide-like immunoreactivity in the rat.

Cell bodies with vasoactive intestinal polypeptide-like immunoreactivity (VIP-LI) were found in the thalamus of the rat. They were distributed throughout the ventrolateral nucleus (VL) and in the whole extent of the thalamic reticular nucleus (R) except for its most rostral part. On the basis of soma diameters, VIP-LI cells in the VL and R were assumed to be projection neurons.

Animals↗
PubMed1985

Isolation and characterization of an activated C-H-ras-1 gene from a squamous-cell lung carcinoma cell line.

We determined a complete nucleotide sequence of an activated form of the c-H-ras-1 proto-oncogene cloned from the human cell line (QG56), using the DNA transfection technique and NIH3T3 cells as recipients. This cell line was established from a squamous-cell lung carcinoma of a Japanese patient, and the activated gene had 2 nucleotide substitutions. One substitution of a thymidine for an adenosine was found at position 1069 of the 2898 nucleotide sequence in a restriction endonuclease (SacI) fragment, which corresponds to the second base of the 61st codon of the gene encoding P21 protein. This nucleotide replacement was assumed to be responsible for the transforming activity. Another substitution of a guanosine for an adenosine which was detected at position 746 in the first intron was thought to be a genetic polymorphism unassociated with the transforming activity. Comparison of the various lengths of restricted fragments suggested that the activity was markedly influenced by certain sequences flanking the c-H-ras-1 gene.

Animals↗
PubMed1985

Association of maternal and newly synthesized ribosomes with membranous noncytoskeletal structures in Xenopus laevis embryonic cells.

In Xenopus laevis embryos a high concentration of both KCl and 0.5% DOC (sodium deoxycholate) is needed for maximal extraction of ribosomes and polysomes. We studied the nature of the structures that keep ribosomes and polysomes immobilized within the cytoplasm of embryonic cells at cleavage through tailbud stages, using various combinations of a low-salt buffer (20 mM KCl), a high-salt buffer (500 mM KCl), 0.5% DOC, and 0.5% Triton X-100. With a low-salt buffer and 0.5% DOC, but not Triton X-100, 80S ribosomal monomers and polysomes were liberated from the cytoplasmic rapidly sedimenting structures (RSS) to the soluble fraction. With a high-salt buffer (500 mM KCl), ribosomes were solubilized as 60S and 40S subunits together with about one-half of the total polysomes. When cells were homogenized in a low-salt buffer with added inhibitors of the cytoskeleton (cytochalasin B or colchicine), the majority of polysomes but not ribosomes were solubilized. These results provide evidence for the following conclusions. 1) Polysomes are bound to cytoskeletal structures in Xenopus embryos, but ribosomes, both maternal and newly synthesized, are associated with membranous noncytoskeletal structures. 2) The membranous structures consist of two compartments, one high-salt sensitive and the other high-salt resistant. 3) Ribosomes of the high-salt resistant group increase in amount with developmental stage and appear to be the precursor to the ribosomes of the high-salt sensitive group.

Animals↗
PubMed1985

Pattern of protein synthesis in dissociated embryonic cells of Xenopus laevis whose reaggregation was inhibited by Ca2+-deprivation and by mechanical interference.

Protein synthesis was studied in dissociated Xenopus embryonic cells whose reaggregation was inhibited either chemically (deprivation of Ca2+) or mechanically (cultivation on sintered glass filter). Under reaggregation-inhibited conditions, synthesis of several proteins was inhibited in neurula but not in blastula and gastrula cells. Under reaggregating conditions, pattern of protein synthesis in blastula cells became 'neurula-cell-type' after 17 h. However, under non-reaggregating conditions, activation of many proteins was inhibited. The inhibition was mostly reversible and similar to that observed in neurula cells inhibited by actinomycin D. Thus, synthesis of many proteins directed by new transcripts at the neurula stage appears to depend on the maintenance of cell-to-cell contact.

Age Factors↗
PubMed1985

Selective regulation of chemotactic lymphokine production. I. Selective potentiation of eosinophil chemotactic lymphokine production in alum hydroxy gel- and Bordetella pertussis vaccine-treated guinea pigs.

Delayed tissue eosinophilia in DNP-ovalbumin-induced allergic inflammatory skin lesions of guinea pigs was markedly enhanced by previous treatment with alum hydroxy gel (Alum) or Bordetella pertussis vaccine. This enhancement seemed due to increased production of a lymphocyte-derived eosinophil chemotactic factor (ECF) at the skin site. Treatment of animals with Alum potentiated antigen-induced in vitro ECF production by lymphoid cells from spleen and mesenteric lymph node of sensitized animals. The co-culture supernatants of lymphoid cells from Alum-treated animals also potentiated concanavalin A (Con A)-induced in vitro ECF production. The potentiating effect of Alum on ECF production seemed to be ascribed to the release of soluble factors from macrophages of the Alum-treated animals. The macrophage-derived soluble factor ECF-potentiating factor (ECF-PF) selectively potentiated ECF production but not macrophage chemotactic lymphokine production by Con A-stimulated lymphoid cells from normal animals. ECF-PF activity was associated with two separate m.w. fractions: one was 50,000 to 70,000 and the other was 10,000 to 20,000. The present study provides one of the explanations for enhanced ECF production by adjuvants, such as Alum and Bordetella pertussis vaccine.

Adjuvants, Immunologic↗
PubMed1985

Dexamethasone suppresses concanavalin A-induced production of chemotactic lymphokines by releasing a soluble factor from splenic T lymphocytes.

Treatment of guinea-pig spleen cells with glucocorticoids, such as dexamethasone (DEX), reduces concanavalin A (Con A)-induced production of chemotactic lymphokines (CLK), such as eosinophil chemotactic factor and macrophage chemotactic factor. The decreased CLK production is not caused by a direct effect of DEX on the spleen cells producing CLK, because Con A-induced CLK production is suppressed when the cells are cultured together with cell-free culture supernatants of the spleen cells which had been pretreated with DEX. A soluble suppressive factor, termed CLK-SF, with a MW of about 20,000, seems to be responsible for the suppression of both CLK production. CLK-SF is produced from DEX-treated T lymphocytes. CLK-SF probably exerts a critical role in the early stage of CLK production. In contrast, CLK-SF fails to inhibit Con A-induced lymphocyte proliferation, although DEX itself suppresses lymphocyte proliferation. This suggests that DEX suppresses Con A-induced CLK production by a different mechanism from that for lymphocyte proliferation.

Animals↗
PubMed1985

The regulation of tissue eosinophilia. III. In vitro production of eosinophil-directed chemotactic inhibitory factor by T lymphocytes of complete Freund's adjuvant-treated guinea-pigs.

Guinea-pig spleen cells treated with complete Freund's adjuvant (CFA) produce eosinophil-directed chemotactic inhibitory factors (ECIF). The inhibition is selective for the response of eosinophils to delayed ECF-a, which had been isolated from 24-hr-old inflamed skin lesions induced by DNP-Ascaris extract in sensitized animals and had been confirmed as being a T lymphocyte-derived lymphokine. ECIF activity is absorbed by incubation with eosinophils, but not with macrophages or neutrophils. The cells spontaneously release ECIF; pretreatment with a protein synthesis inhibitor reduces ECIF production, indicating that protein synthesis is essential. The source of ECIF seems to be lymphocytes, probably T lymphocytes. ECIF activity is recovered in two separate fractions: one elutes near bovine serum albumin (MW 70,000) and the other near cytochrome c (MW 12,500). ECIF binds to peanut agglutinin- or Limulus polyphemus agglutinin-coupled agarose beads. Furthermore, ECIF activity is blocked when eosinophils are incubated with D-galactose or sialic acid. These results suggest that ECIF derived from T lymphocytes of CFA-treated animals modulate the delayed ECF-a-mediated tissue eosinophilia, and that terminal galactose and/or sialic acid residues are essential for ECIF activity.

Animals↗