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Biomedical subjects

T Ohashi

Publications and source records attributed to T Ohashi.

At least 289 records · Page 16Linked to original sources
PubMed1989

Induction of resistance in mice against murine cytomegalovirus by cellular components of Lactobacillus casei.

Recently, we reported that heat-killed Lactobacillus casei (LC) protected mice from murine cytomegalovirus (MCMV) infection by augmentation of natural killer (NK) cell activity. In the present study, we examined which components of LC cell induce the nonspecific resistance most effectively. Whole cell preparation of original LC, susceptible to bacteriophages SG-T and J1, was more effective than its mutants resistant to either bacteriophage. Although the activity of LC cells decreased upon fractionation, cell wall fractions were more active than cytoplasmic fractions. Glycoprotein (GP), a cell wall constituent, was a potent inducer of the resistance. The relative activity of cellular components to induce the resistance was evaluated by a protection index, a ratio of plaque-forming units (PFU) per 50% lethal dose (LD50) for treated mice to that for untreated mice. The protection indices of LC cells and GP were approximately 80 and 28, respectively. The protective effect of GP was evidenced by a decrease in titers of infectious viruses replicated in the target organs. Not only LC cells but also GP, although to a lesser degree, enhanced NK cell activity both in uninfected mice and MCMV-infected mice. The activity of LC cells and GP to augment NK cell activity correlated with the protection index. GP treatment did not modify interferon (IFN) production during MCMV infection. Thus, GP of LC cells seems to be the active principle to endow mice with resistance to MCMV.

Animals↗
PubMed1989

Adaptive changes of vertical vestibulo-ocular reflex induced by tenectomy of vertical recti muscles and neuronal behavior related to vertical eye movement in the region of the interstitial nucleus of Cajal in alert cats.

Experiments were performed in alert cats to examine adaptive changes of the vertical vestibulo-ocular reflex (VOR) induced by tenectomy of the vertical recti muscles of one eye and behavior of neurons in the region of the interstitial nucleus of Cajal (INC) during this adaptation. Continuous pitch rotations (0.11 Hz) of a constant amplitude (+/- 10 degrees) with only the operated eye uncovered produced a gradual and significant increase in VOR gain that started within 15 min, reaching a plateau within 1 h. When only the normal eye was allowed to view again, VOR gain quickly decreased to the control values within 10 min. Such reversible gain change was not observed when visual input was not allowed to the operated eye, indicating that these changes are adaptive ones to reduce visual-vestibular conflict. A total of 18 neurons were recorded from the INC region during the VOR adaptation. These include 9 eye-movement-related neurons (8 vertical burst-tonic neurons and 1 vertical tonic neuron) and 9 other neurons that did not show close correlation with eye movement but were activated by pitch rotations (tentatively called pitch cells). During adaptive gain increase of the vertical VOR, all the vertical burst-tonic and tonic neurons showed a significant gain increase, whereas a significant change in response gain was observed in only 1 of the 9 pitch cells, indicating that vertical burst-tonic neurons in the INC region are involved in the adaptive gain increase in the vertical VOR.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Clinical significance of SP/AP ratio in inner ear diseases.

Electrocochleogram was recorded from 28 ears affected by Ménière's disease , 27 ears affected by sensorineural hearing loss resulting from hair cell damage and 22 normal ears as controls in response to tone bursts in order to evaluate diagnostic significance of the summating potential/action potential (SP/AP) ratio and the SP amplitude. The fundamental aspects of the SP/AP ratio were studied in relation to frequency, intensity and rate of tone burst stimuli. It was concluded from present results that the SP/AP ratio can be a useful indicator to detect -SP dominance, while the SP amplitude can be an indicator to detect cell damage in inner ear diseases.

Adult↗
PubMed1989

Electrocochleographic changes in endolymphatic hydrops induced by type II collagen immunization through the stylomastoid foramen.

Changes in action potential (AP) and summating potential (SP) were investigated in guinea pigs immunized with type II collagen through the stylomastoid foramen. Endolymphatic hydrops could be induced in four of 11 guinea pigs. The striking feature of the electrocochleographic waveform in guinea pigs with endolymphatic hydrops was the negative SP recording in response to high frequency tone bursts. Furthermore, abnormal changes in AP were observed in three of four hydropic guinea pigs. Morphologic study of the cochleas in these three guinea pigs with light microscopy revealed spiral ganglion cell degeneration in addition to endolymphatic hydrops and almost normal sensory hair cells. These results suggest that guinea pigs with hydrops as produced by our procedure can serve as a useful model of Meniere's disease, that autoimmune response may play an important role in the etiopathogenesis of Meniere's disease, and that spiral ganglion cell degeneration together with endolymphatic hydrops seems to contribute to abnormal changes in AP.

Action Potentials↗
PubMed1989

Retinol transport system in cattle and purification of retinol-binding protein from bovine serum.

Retinol transport system in cattle was investigated, followed by the purification and characterization of bovine serum retinol-binding protein (RBP). Gel filtration of serum from cow produced two retinol peaks, peak 1 and 2. The major, peak 1 having higher molecular weight corresponded to the retinol peak from human serum which consisted of RBP and prealbumin (PA). The peak 2 which was not presented in the human serum had lower molecular weight (about 20,000). In the presence of 3.0 M urea, the peak 1 was almost disappeared and peak 2 was increased. On the other hand, in the serum from calf, major retinol peak was corresponded to the peak 2 from cow. These results suggested that, in cow, retinol was transported by the complex of RBP and another protein, presumably PA, but in calf, mainly by RBP alone. Purification of bovine RBP was carried out by using four chromatographic steps as follows; 1. DEAE-cellulose (pH 6.0), 2. Sephadex G-100 (using the buffer containing 3.0 M urea), 3. DEAE-cellulose (pH 8.3), 4. Sephadex G-100. From 1,100 ml of serum, 14.1 mg of bovine RBP was finally obtained and the overall recovery was estimated to be about 32%. Its molecular weight, ultraviolet absorption and fluorescence spectra, electrophoretic mobility, and amino acid composition were similar to those of other species.

Amino Acids↗
PubMed1989

Cushing's syndrome due to huge nodular adrenocortical hyperplasia with fluctuation of urinary 17-OHCS excretion.

A 51-yr-old male patient with Cushing's syndrome due to huge nodular adrenocortical hyperplasia is described. Urinary 17-OHCS was not suppressed by a high dose of (8 mg) dexamethasone and showed rather a tendency to paradoxical response. There was no response to metyrapone. Plasma cortisol showed a hyperresponse to insulin-induced hypoglycemia and a rapid response to corticotropin releasing hormone-lysine vasopressin (CRH-LVP) administration without an obvious ACTH response. Plasma cortisol responded to synthetic ACTH. Urinary 17-OHCS did not show parallel changes with plasma cortisol. These results and computerized tomography data suggested huge multiple nodular adrenocortical hyperplasia, which was confirmed later by surgery. The left and right adrenal glands weighed 105 and 45 g, respectively. Hyper-reaction of the adrenal gland to a small change in plasma ACTH or "unknown factors" may cause not only the discrepancy between cortisol and ACTH response but also the development of autonomous nodules in the adrenal gland.

17-Hydroxycorticosteroids↗
PubMed1989

A case of unilateral adrenal medullary hyperplasia.

We report a case of unilateral hyperplasia of the adrenal medulla. The patient showed clinical features suggestive of pheochromocytoma. Removal of the hyperplastic adrenal gland resulted in complete disappearance of all prior symptoms, decrease of the plasma and urinary catecolamine levels and no high uptake in [133I] metaiodobenzylguanidine scintigraphy. A histological study revealed diffuse hyperplasia of the adrenal medulla. Up to now, there are relatively few reports of adrenal medullary hyperplasia in English literatures.

Adrenal Gland Neoplasms↗
PubMed1989

[Clinical and endocrinological studies of the luteinizing hormone-releasing hormone analogue therapy in prostatic cancer patients].

A luteinizing hormone-releasing hormone (LH-RH) analogue was administered for 3 to 32 months to 15 prostatic cancer patients in stage B-D (B:3, C:8, D:4). Intratesticular, intratubular and prostatic androgen levels were measured by radioimmunoassay before and after LH-RH analogue therapy. The measurement of serum prostatic acid phosphatase (PAP) and prostatic specific antigen (PA) levels was also conducted. Thereafter, we assessed the effect of the LH-RH analogue on androgen levels and the relation of prostatic tissue 5 alpha-dihydrotestosterone (DHT) level to the clinical response. The results were as follows: 1) Johnsen's mean germinal epithelium count was significantly decreased from 7.7 +/- 2.1 (mean +/- S.D.) to 4.3 +/- 2.3, and the wall thickness of seminiferous tubules was increased from 5.93 +/- 1.31 to 11.9 +/- 3.64 microns. 2) Plasma testosterone (T), intratesticular and intratubular androgen levels were significantly decreased (plasma T: from 4.40 +/- 1.84 to 0.61 +/- 0.32 ng/ml, intratesticular T: from 335.3 +/- 170.3 to 4.6 +/- 3.8 ng/g.t.w., DHT: from 25.3 +/- 11.7 to 3.7 +/- 2.7 ng/g.t.w., intratubular T: from 50.8 +/- 36.6 to 0.10 +/- 0.99 ng/g.t.w. and DHT: 7.54 +/- 3.20 to 0.63 +/- 0.90 ng/g.t.w.). 3) Crude nuclear DHT levels in prostatic tissue fell from 15.3 +/- 9.3 (N = 8) to 0.37 +/- 0.54 pg/mg protein (N = 3) and the level was non-detectable in 5 of 8 cases. 4) Complete remission was achieved in 1 patient, partial response in 5, objective stable in 8, and objective progression in 1 patient, according to Shimazaki's criteria.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1989

[Problems on the determination of intracellular free calcium concentration when measured by fura-2/AM in mast cells].

When rat peritoneal mast cells which had been loaded with fluorescent Ca2+ indicator fura-2/AM were exposed to compound 48/80, fura-2 fluorescence was increased in the presence of 1mM extracellular Ca2+, but remained unchanged in the Ca2(+)-eliminated medium. Only in the presence of 1mM extracellular Ca2+, both fura-2 fluorescence and histamine release were increased in response to compound 48/80, depending on the concentration of the stimulant. Both of these responses were attenuated in the same degree by such release inhibitors as disodium cromoglycate and HSR-6071. Fluorescent microscopic observation of fura-2/AM-loaded mast cells revealed that fura-2 fluorescence was densely localized in the granules and the nucleus, but less in the cytoplasm. All these results strongly suggest that increase in the fura-2 fluorescence might not result from the increase in cytoplasmic free Ca2+ concentration, but from binding of fura-2, which had been released together with chemical mediators from granules following stimulation, to extracellular Ca2+. Therefore, it seems likely that the fura-2/AM loading method is inadequate to investigate whether or not the increase in cytoplasmic free Ca2+ concentration triggers release of chemical mediators from mast cells.

Animals↗
PubMed1989

[Cohort study on cariostatic effect of 100ppmF- fluoride mouthrinsing].

The cariostatic effect of fluoride mouthrinsing with dilute fluoride solution in the school dental health programs was examined. The subjects were 138 children (75 of boys and 63 of girls) who carried out fluoride mouthrinsing with solution of 100 ppmF- for 6 years and 105 children (65 of boys and 40 of girls) who had no fluoride mouthrinsing were analysed by cohort study from 1983 to 1989. The cariostatic effect was evaluated by DMFT index and DMF rate for each tooth type in each erupted school grade. The increment of DMFT index was less than that of the control group. There was a clear cariostatic effect with the advance in the school grade. DMF rate for each tooth type of 1 in 2nd grade and 2 in 3rd grade students showed a statistically significant difference. Both that of upper and lower first molars in 1st and 2nd grade also showed the same result as that of upper incisors. In conclusion, a high cariostatic effect was obtained by introducing the use of fluoride mouthrinsing with a solution of 100ppmF- to the school dental health program, and the observation of DMF rate for each tooth type classified with each erupted school grade was a useful method to evaluate the cariostatic effect of fluoride mouthrinsing.

Child↗
PubMed1989

[Investigation on antibodies to human T cell leukemia virus type I in patients with primary glomerulonephritis].

We investigated on antibodies to human T cell leukemia virus type I (anti HTLV-I) in 101 patients with primary glomerulonephritis in Kagoshima prefecture, an endemic area of HTLV-I in Japan. The positive rate in patients with primary glomerulonephritis was 17.8%, which was not significantly higher than in healthy residents 4741 persons of 11.9% in the same area. Classified by renal biopsy findings, the positive rate in patients with membranous nephropathy was 21.4% (9/42), minimal change nephrotic syndrome 14.3% (2/14), IgA nephropathy 15.4% (2/26), and others 15.8% (3/19) respectively, which were not significantly differed from that in healthy residents. Positivity of aged patients (60 years or over) in membranous nephropathy on the contrary was significantly higher than that in healthy residents (p less than 0.01). Further study is required to clarify the relationship between HTLV-I infection and glomerulonephritis.

Adolescent↗
PubMed1988

Neuron-specific enolase in comatose children.

Sequential examination of neuron-specific enolase in cerebrospinal fluid and serum was performed in 20 comatose children with acute encephalitis, acute encephalopathy, or Reye's syndrome. Neuron-specific enolase activities corresponded to the degree of brain damage. As neuron-specific enolase levels increased to greater than 80 ng/mL, patients had more severe impairment or died. Neuron-specific enolase may be a useful marker for evaluating the degree of neuronal damage and prognosis.

Acute Disease↗
PubMed1988

Effect of recombinant DNA-produced tumor necrosis factor on various parameters of neutrophil function.

The effect of recombinant DNA-produced human tumor necrosis factor (TNF) on various parameters of neutrophil function was evaluated. TNF was a weak direct activator of oxygen radical production. It released the specific granule contents to a limited extent, but the azurophilic granule contents were retained even in the presence of cytochalasin B. It had a chemotactic activity for neutrophils, as determined by the use of a modified Boyden's chamber. Pretreatment of neutrophils with TNF increased phagocytosis of opsonized particles and markedly potentiated in a dose-dependent manner oxygen radical production induced by opsonized zymosan. The inhibitors of lipoxygenase, but not those of cyclooxygenase, reduced the potentiating effect of TNF on phagocytosis, suggesting that the products of lipoxygenase play an important role in mediating the effect of TNF on neutrophils.

Arachidonate 5-Lipoxygenase↗