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T Ohashi

Publications and source records attributed to T Ohashi.

At least 325 records · Page 18Linked to original sources
PubMed1987

Partial deficiency of beta-hexosaminidase activity in canine GM2-gangliosidosis.

4-Methylumbelliferyl-N-acetylglucosamine-6-sulfate (4MUGLc6S) which is known to be a specific substrate for human hexosaminidase A was used to determine enzymatic features of canine GM2-gangliosidosis. The enzyme activity using 4MUGlc6S in affected dog brain and liver was less than 20 to 30% of control tissues, whereas total 4-methylumbelliferyl beta-glucosaminidase activity in canine GM2-gangliosidosis was normal or elevated. However, when beta-hexosaminidase was fractionated by DEAE-Sepharose column chromatography, beta-hexosaminidase A like fraction in affected dog tissues was reduced to 20 to 30% of control. These data suggest that canine GM2-gangliosidosis is analogous to human juvenile.

Animals↗
PubMed1987

[Transcervical and transoral approach to clival and upper cervical chordoma: a case report].

The patient, a 48-year-old man, was first admitted in 1981 for the chief complaints of retropharyngeal tumor and anosmia. Computerized tomography scan disclosed destruction of the lower half of the clivus and retropharyngeal tumor predominantly located in the third prevertebral region. The tumor was removed partially via the transcervical approach and was histologically a typical chordoma. Two years later the tumor recurred and was operated on by the same approach. However, only partial removal of the tumor was realized due to difficulties in dissecting the fibrous adhesion. In 1986 (7 years after onset of the symptoms), the patient was readmitted due to severe dysphagia. The sagittal MRI scan demonstrated a huge oval retropharyngeal tumor with precise delineation between the tumor and clivus, clivus upper cervical spine and brain stem. The tumor was extirpated subtotally on the midline via the transoral approach. Dysphagia completely improved postoperatively and the patient regained normal smell sensation. The advantages and disadvantages of the transcervical and transoral approach to clival lesion are discussed and the advantage of the MRI imaging is stressed for preoperative information for the transoral approach.

Chordoma↗
PubMed1987

[Spermatogenesis].

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Androgen-Binding Protein↗
PubMed1986

Evaluation of neutrophil acetyltransferase activity in patients with inflammatory disorders.

The acetyltransferase activity of neutrophils from patients with inflammatory disorders was assayed using the homogenate preparation of neutrophils. The enzyme activity was evaluated on both non-stimulated and stimulated neutrophils. The enzyme activity of neutrophils from 21 patients with rheumatoid arthritis and 10 patients with Behcet's disease was not significantly different from that of the control group. In contrast, it was significantly elevated in patients with bacterial infection, especially that of non-stimulated cells. The increase in the enzyme activity best correlated with the degree of fever. The elevated enzyme activity tended to normalize during convalescence.

Acetyltransferases↗
PubMed1986

Separable function of platelet release reaction and clot retraction.

Amiloride, a known Na+/H+ exchange inhibitor, inhibited platelet serotonin release in a dose-dependent manner (100 microM for 50% inhibition, and 1mM for the nearly complete inhibition), although amiloride (1mM) accelerated clot retraction when it was measured at decreased platelet concentration. On the contrary, cytochalasin B (10 micrograms/ml) accelerated platelet serotonin release, but it inhibited clot retraction. These results demonstrate that release reaction and clot retraction, both of which are important processes involved in platelet activation, can be functionally separated.

Actins↗
PubMed1986

A comparative study on the effects of inhibitors of the lipoxygenase pathway on neutrophil function. Inhibitory effects on neutrophil function may not be attributed to inhibition of the lipoxygenase pathway.

The effects of five inhibitors of the lipoxygenase pathway were evaluated on oxygen radical production, degranulation, chemotaxis, leukotriene B4 (LTB4) production by neutrophils. The lipoxygenase inhibitors tested were nordihydroguaiaretic acid (NDGA), esculetin, eicosatetraynoic acid (ETYA), 2-(12-hydroxydodeca-5,10-diynyl)-3,5,6-trimethyl-1,4-benzoqu inone (AA-861), and 6,9-deepoxy-6, 9-(phenylimino)-delta 6.8-prostaglandin I1 (U-60,257). Neutrophils were activated by n-formyl-methionyl-leucyl-phenylalanine (fMLP), phorbol myristate acetate (PMA), A23187, or platelet activating factor (PAF). The effects of these inhibitors on NADPH oxidase activity and phospholipase A2 activity of isolated particulate fraction of neutrophils were also evaluated. ETYA inhibited neutrophil function induced by all the stimulators except PMA. AA-681 was unique in that it did not inhibit PAF-induced neutrophil activation. U-60,257 had virtually no effect on oxygen radical production and degranulation, but chemotaxis was moderately suppressed. NDGA effectively inhibited neutrophil function, except for chemotaxis. Esculetin inhibited only oxygen radical production, but this was due to inhibition on NADPH oxidase activity of neutrophil membrane. The inhibitory effect on neutrophil function and that of LTB4 production were not closely correlated. It is suggested that lipoxygenase inhibitors may modify neutrophil function by the mechanism not involving the lipoxygenase pathway. It is also suggested that LTB4 may not be a mediator in neutrophil oxygen radical production and degranulation induced by the stimulators used in the present study.

5,8,11,14-Eicosatetraynoic Acid↗
PubMed1986

Regulation of human interleukin-2 gene: functional DNA sequences in the 5' flanking region for the gene expression in activated T lymphocytes.

Interleukin-2 (IL-2) is a lymphokine that plays a crucial role in the immune system, especially in the growth control of T lymphocytes. Expression of this lymphokine is restricted to activated T lymphocytes. Here we demonstrate the presence of unique DNA sequences in the 5' flanking region of the human IL-2 gene that control induced T-cell-specific gene expression. We also show that the DNA sequences function in an orientation-independent manner and activate a heterologous promoter which is otherwise inert in induced T cells. The DNA, which spans about 200 bp, contains regions with sequence homology to LTR sequences of HTLV-III (or LAV) and the 5' upstream region of the IL-2 receptor and interferon-gamma genes.

Base Sequence↗
PubMed1986

Partial dependency of 1-oleoyl-2-acetyl-glycerol-induced superoxide production by human neutrophils on calcium ions and cytochalasin B.

Superoxide production by neutrophils induced by 1-oleoyl-2-acetyl-sn-glycerol at concentrations below 100 microM was enhanced by extracellular calcium ions, while that of phorbol myristate acetate was unaffected. Verapamil, a calcium-channel blocker, more effectively inhibited the superoxide production induced by 1-oleoyl-2-acetyl-sn-glycerol than that of phorbol myristate acetate. Cytochalasin B at 5 micrograms/ml significantly potentiated superoxide production by 1-oleoyl-2-acetyl-sn-glycerol at concentrations below 100 microM, but not that of phorbol myristate acetate. It is suggested that neutrophil activation induced by the former have different features from that of the latter.

Calcium↗
PubMed1986

Oxygen radical production by neutrophils from patients with bacterial infection and rheumatoid arthritis. Measurement of hydrogen peroxide may most accurately represent enhancement of oxygen radical production during infection.

The production of three kinds of oxygen radicals (superoxide, hydrogen peroxide, and hydroxyl radicals) by neutrophils from patients with bacterial infection or rheumatoid arthritis was measured. The stimulators used in this study were opsonized zymosan (1 mg/ml), phorbol myristate acetate (20 ng/ml), A23187 (1 microM), and platelet activating factor (1 microM). Oxygen radical production by neutrophils from patients with rheumatoid arthritis was not significantly different from that of the control group. Hydrogen peroxide production by the neutrophils from patients with bacterial infection was significantly enhanced by only opsonized zymosan, but the production of the other kinds of oxygen radicals was not. Cytochalasin B reduced the production of hydrogen peroxide induced by opsonized zymosan more markedly than that of any other kind of oxygen radical. The measurement of hydrogen peroxide is suggested to be the most accurate indicator of the enhancement of intracellular production of oxygen radicals by neutrophils during infection.

Arthritis, Rheumatoid↗