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Biomedical subjects

T Ono

Publications and source records attributed to T Ono.

At least 721 records · Page 40Linked to original sources
PubMed1993

Monkey hippocampal neurons related to spatial and nonspatial functions.

1. Neural activity in the monkey hippocampal formation (HF) was analyzed during a spatial moving task in which the monkey was guided by auditory and visual cues and when stimuli were presented from various directions. The monkey could control a motorized, movable device (cab) and its route to a target location by pressing the proper one of five available bars in an appropriate sequence (spatial moving task). In any of several locations in the field, neural responses were evident in relation to the presentation of various objects or human movement in some relative direction (left, anterior, right) as a directional stimulus test. 2. Of 238 hippocampal neurons analyzed, 172 (72.3%, 238-66) responded in either the spatial moving task, or to the direction from which stimulation was presented, or to the location of the monkey in the field, or to some combination of these. 3. The activity of 79 (33.2%) neurons was higher when the monkey was in some specific location in the field during the spatial moving task, regardless of the approach route or other task parameters (place related neurons). 4. Responses to the task cues in the spatial moving task were evident in 110 (46.3%) neurons (task related neurons). Of these, 77 (32.4%) neurons were not place related. The remaining 33 (13.9%) neurons were both task related and place related. These neurons responded to task cues in only that part of the field in which place related responses occurred. The neural response to the task cues disappeared when the monkey moved out of the place response region. The place related and task related neural responses disappeared when the room light was switched off. Thus information from the environment outside of the cab contributed to the place related and task related responses. 5. Stimuli presented from certain specific directions induced responses, selectively, in 41 (17.2%) of the neurons (direction related neurons). The dependence of the preferred direction was described in one of three ways--egocentric, allocentric, or place-direction specific. Nineteen egocentric neurons responded to a stimulus only when it was presented from a certain direction relative to the orientation of the monkey, regardless of the location of the monkey. Eleven allocentric neurons responded to a stimulus only when it was presented at a particular position in the room, regardless of the location or orientation of the monkey.(ABSTRACT TRUNCATED AT 400 WORDS)

Acoustic Stimulation↗
PubMed1993

Comparison of the age- and tumor-associated changes in the c-myc gene methylation in mouse liver.

Study of DNA methylation of the c-myc gene in liver tumors of BCF1 mice treated with various agents revealed frequent alteration from that in normal liver. The alteration, however, was complex and showed either an increase or a decrease of methylation to various degrees. On the other hand, the tumors obtained from middle-aged C3H/He mice, which develop liver tumors spontaneously at a high incidence rate starting in middle age, showed predominantly increases of methylation in the c-myc gene, while the large tumors found in older mice revealed decreases. The normal part of the liver showed a slight gradual age-dependent increase. These suggest that hypermethylation of the c-myc gene is common to aging and early tumor development in liver. Thus the alteration of DNA methylation seems to be a good clue to investigate why the tumor incidence rate increases rapidly as individuals grow older.

Aging↗
PubMed1993

Clonal analysis of human T-cell responses to fractionated house dust mite antigens (Dermatophagoides pteronyssinus).

In the present study, we investigated the cellular basis of house dust mite-driven immune responsiveness in an atopic individual with perennial rhinitis. We established 40 human T-cell clones (CD3+, 4+, 8-) reactive to Dermatophagoides pteronyssinus (Dp) antigen under the restriction of HLA-DR. By using the crude Dp antigen and its 14 molecular weight (MW) fractions, we analyzed the distribution of T-cell-recognizing sites in the whole Dp extract. We tested T-cell-mediated immunity through two parameters; the identification of Dp fractions inducing T-cell proliferation, and the ability of T-cell clones to secrete IL-2, IL-4, and IFN-gamma. According to a prominent peak among fraction-driven T-cell proliferation, we observed that T-cell clones that recognized 45,000- to 95,000-MW fractions were common, while clones reactive to 15,000- to 25,000-MW fractions were less frequent. Several clones were also reactive to antigens of Dermatophagoides farinae or other insects. Based on the responses of cloned T cells, we observed at least 9 distinct T epitopes in crude Dp antigen. These T-cell clones had a heterogenous secretory pattern of cytokines. T-cell clones showed no association between their ability to produce regulatory cytokine and their recognition of particular Dp fractions.

Adult↗
PubMed1993

Regressing nevoid nail melanosis in childhood.

The natural course of nail pigmentation was documented in 4 Japanese children. Although initial progression of melanosis concerning size and degree of pigmentation was noted, all cases showed a tendency to fade during the follow-up period. The published cases of nevoid nail melanosis in childhood were reviewed, and we concluded that they were essentially benign. However, should there be any suspicion of malignant changes, punch biopsy is indicated for medico-legal reasons. Management of growing pigmented nail streaks in childhood is one of the most difficult and delicate problems facing dermatologists, as they can be precursors of malignant melanoma. There is a condition of the nail known as longitudinal melanonychia or naevus striae unguis, possibly of nevoid nature. Prevalence rates of nevoid diseases showing pigmentation of the skin vary depending on the ethnic origin. In order to understand the natural course of nail area pigmentation in childhood, we have followed 4 Japanese children with such a condition. We report our observations and review the literature.

Child↗
PubMed1993

Effect of an aromatase inhibitor in human follicular fluid on DNA synthesis of granulosa cells, theca cells, and follicles.

An aromatase inhibitor was identified in human follicular fluid. We sought to examine the effects of this inhibitor on granulosa cells, theca cells, a mixture of granulosa and theca cells, and follicles. Granulosa cells, theca cells, the mixture of granulosa and theca cells, and follicles were incubated with [3H]-thymidine and aromatase inhibitor at 37 degrees C for 40 h in Ham F-10 medium. The radioactivities of acid-soluble fractions were counted. Aromatase inhibitor markedly inhibited the DNA synthesis of granulosa cells and follicles, but it did not inhibit the mixture of granulosa and theca cells. This suggested that aromatase inhibitor was a factor in the follicle paracrine system and acted mainly on granulosa cells.

Animals↗
PubMed1993

The pharmacological characterization of FK 739, a new angiotensin II-receptor antagonist.

The pharmacological properties of FK 739, a new angiotensin II-receptor antagonist, were examined. FK 739 inhibited the specific binding of [125I]-angiotensin II to rat aortic smooth muscle cell membrane with an IC50 value of 8.6 nM, but did not displace the specific binding of [125I]-angiotensin II to bovine cerebellum membrane. In isolated helical strips of rabbit aorta, FK 739 shifted the concentration-response curve of angiotensin II-induced contraction in parallel to the right, and the values of the slope and pA2 were 1.06 and 8.45, respectively. In in vivo studies, oral administration of FK 739 at 10 mg/kg significantly inhibited the angiotensin I-induced pressor response in normotensive rats and dogs, and it caused a fall of mean blood pressure in renal hypertensive rats and dogs. In spontaneously hypertensive rats, FK 739 at 32 and 100 mg/kg significantly decreased the mean blood pressure in a dose-dependent manner. Additionally, we studied whether FK 739 would cause side effects such as dry cough, like other ACE inhibitors did. Oral administration of FK 739 (10 and 32 mg/kg) did not affect the capsaicin-induced bronchial edema. On the other hand, captopril (10 mg/kg) significantly enhanced capsaicin-induced bronchial edema. These results indicate that FK 739 is a potent and competitive antagonist for AT1-type receptors, and suggest that FK 739 might be a safe and useful agent for the treatment of hypertension in clinical trials.

Angiotensin I↗
PubMed1993

The mouse Mel-18 "RING-finger" gene: genomic organization, promoter analysis and chromosomal assignment.

The chromosome gene for mouse Mel-18 (mMel-18) protein has been isolated and characterized. The entire mMel-18 gene is composed of thirteen exons spanning about 15 kilobases, in which the protein is encoded by exons 5-13. The "RING-finger" motif of Mel-18 protein that displays a significant evolutionary resemblance to other RING-finger nuclear proteins is encoded by exons 5 and 6. Exon 13 encodes a C-terminal proline/serine-rich domain that is homologous to some transactivator proteins. Sequence analysis of the 5'-flanking region revealed the presence of potential binding sites for transcription factors such as SP-1, NF-1, NF-kappa B and c-myc/max. At least two major cap sites and three minor cap sites were identified by S1 mapping and primer extension analysis. We propose that the mMel-18 gene is regulated by two different types of promoters, the CAAT-TATA box promoter and the GC-rich TATA-less promoter. The 2.4 kb DNA fragment of the 5'-flanking region exhibited constitutive promoter activity when transfected into L cells. By the in situ hybridization method, the mMel-18 gene was assigned to mouse chromosome 10C3.

Animals↗
PubMed1993

[Serum levels of soluble ICAM-1 in asthmatic patients].

Serum soluble intercellular adhesion molecule-1 (sICAM-1) levels were measured in 54 asthmatic patients and 32 healthy subjects by sandwich enzyme-linked immunosorbent assay. Serum sICAM-1 levels in the asthmatic patients not undergoing steroid therapy were significantly higher than those in the healthy subjects and those in the asthmatic patients undergoing steroid therapy (p < 0.01 and p < 0.001, respectively). Serum sICAM-1 levels in the asthmatic patients during attack were not significantly different from those in the patients in remission. We studied changes in serum ICAM-1 levels in 13 asthmatic patients in remission and during attack and found that serum ICAM-1 levels during attack were significantly higher than those in remission (p < 0.05). The origin of serum soluble ICAM-1 in asthmatic patients still remains unclear, but the up-regulated expression of ICAM-1 on the endothelium of the respiratory tract may contribute to the recruitment of eosinophils, neutrophils and lymphocytes to the airway in bronchial asthma.

Adult↗
PubMed1993

[Serum soluble CD23 and soluble CD25 in bronchial asthmatic patients].

Serum sCD23 and sCD25 levels in asthmatic patients and healthy subjects were assayed. Serum sCD23 levels in asthmatic patients were significantly higher than those in healthy subjects (p < 0.05). Serum sCD25 levels in asthmatic patients were also significantly higher than those in healthy subjects (p < 0.02). There was a significant correlation between serum sCD23 and sCD25 levels in asthmatic patients (r = 0.52, p < 0.001). It is well known that sCD23 and sCD25 levels are regulated by different cytokines, and this study suggests that T cells play important roles in the pathogenesis of asthma.

Adult↗
PubMed1993

[Serum levels of soluble CD25 (soluble interleukin 2 receptor) in asthmatic patients].

Serum sCD25 levels were measured in 64 asthmatic patients and 22 healthy subjects by enzyme-liked immunosorbent assay. Serum sCD25 levels in the asthmatic patients were significantly higher than those in the healthy subjects (p < 0.02). Serum sCD25 levels in the asthmatic patients during attack were slightly higher than in those in remission, but there was no significant difference between the two groups. We studied changes of serum sCD25 level in 13 asthmatic patients in remission and during attack and found that serum sCD25 levels were significantly higher during attack than in remission (p < 0.02). Serum sCD25 levels in the asthmatic patients undergoing steroid therapy were significantly lower than in those who were not (p < 0.05). The significance of serum sCD25 in bronchial asthma still remains unclear, but these results suggest that T cells play an important role in bronchial asthma.

Adult↗
PubMed1993

[A case of long-standing isolated traumatic tricuspid regurgitation with remarkably dilated right cardiac chambers and pancytopenia].

We report a rare case of tricuspid regurgitation due to nonpenetrating chest trauma 33 years previously. A 79-year-old man suffered a blunt trauma due to a piece of wood at work in 1958. He suffered multiple rib fractures on the right side and was admitted. Since then, he began having shortness of breath on exertion and was treated with medication. The patient was transferred to the Division of Cardiology, Hakodate National Hospital in 1984. A chest x-ray film revealed a marked cardiomegaly. Cardiac catheterization showed severe tricuspid regurgitation. Hepatomegaly and pancytopenia was observed. He was readmitted because of general fatigue in July 1991. Two-dimensional echocardiography demonstrated systolic excursion of septal and posterior tricuspid leaflets with ruptured chordae tendineae into the right atrium, and a remarkably enlarged right ventricule, right atrium and vena cava interior. Cardiac catheterization was performed. The right atrial pressure-wave form resembled the right ventricular pressure recording (ventricularization of the atrial pressure). Right ventricular cineangiography revealed severe tricuspid regurgitation, grade 4. Laboratory data showed pancytopenia. Thrombocytopenia progressed (3 x 10(4)/mm3), and a hemorrhagic tendency developed. The liver edge was palpable 4 finger breadths below the right costal margin. Pancytopenia due to congestive hepatomegaly and hypersplenism would have complicated this case.

Accidents, Occupational↗
PubMed1993

Medullasin levels in neutrophils of patients with pustulosis palmaris et plantaris.

Medullasin is one of the serine proteases found in human bone marrow cells. The protease in granulocytes is assumed to play an important role in the induction of chronic inflammation. We measured the medullasin levels as a parameter of neutrophil function in granulocytes from patients with pustulosis palmaris et plantaris. All 17 patients studied underwent tonsillectomies, and the changes in the amount of medullasin were followed after surgery. Seven of the 17 patients were cured during the follow-up period (average: 21 months). In all the patients in whom PPP improved, the medullasin levels decreased significantly from the period of active disease when pustules were present to the inactive period. The amount of medullasin did not fall significantly in patients whose PPP did not improve. It is concluded that medullasin levels may reflect the activity of PPP and may serve as a criterion for performing a tonsillectomy.

Adult↗
PubMed1993

[Two episodes of fatal ventricular arrhythmia associated with use of electrosurgical unit during redo MVR procedure].

We report a case of ventricular fibrillation in the first episode and ventricular tachycardia in the second episode that occurred with use of electrosurgical unit during redo MVR procedure. Both arrhythmia occurred five to ten seconds after application of the electrosurgical knife in the coagulation mode to the sternal periosteum. The patient was immediately resuscitated with return to sinus rhythm using direct-current electroshock. In the literature, it was reported that large direct-current potentials were generated during electrosurgery and that these potentials increased with increasing sparking at the active electrode. Care should be always taken because they may cause fatal ventricular arrhythmia.

Adult↗
PubMed1993

[A case of smoldering ATL associated with hypersensitivity pneumonitis].

A 37-year-old woman was admitted to our hospital with the complaints of cough, lymph node swelling. Chest X-ray film showed diffuse small nodular shadows in the bilateral lower lung fields. Bronchoalveolar lavage fluid revealed an increased proportion of lymphocytes (71%) with low OKT4/T8 ratio (0.26). Lung tissue biopsied by bronchofiberscopy showed the existence of interstitial pneumonia. Precipitating antibodies in this patient's serum against various antigens including Trichosporon cutaneum were positive. After admission, all symptoms resolved gradually without specific therapy. But, as soon as the patient was discharged and returned to her home, all symptoms including fever, cough, dyspnea and lymphadenopathy recurred rapidly. The diagnosis of hypersensitivity pneumonitis was made on the basis of these laboratory findings and clinical course. The patient died from respiratory failure after detection of anti-HTLV-I antibody, and autopsy revealed massive ATL cell infiltration of lung tissue, and immunoenzymatic analysis showed a high OKT4/T8 ratio (3.5). Chronic HTLV-1 infection since infancy was suspected in this case, to have modified the immune regulation of the lung, and to have led to the onset of hypersensitivity pneumonitis and the active immune response in the lungs, finally followed by the acute exacerbation of ATL.

Adult↗
PubMed1993

Significance of endothelial deposition of von Willebrand factor in thrombotic thrombocytopenic purpura: autopsy findings of a case complicated with systemic lupus erythematosus.

We report the renal immunohistochemical findings of a patient with thrombotic thrombocytopenic purpura complicated with systemic lupus erythematosus. Aggregated platelets were observed adhering to the arteriole walls. Intense deposition of von Willebrand factor (vWF) was noted in the endothelium, even in areas where thrombi were not seen. This difference in the distribution of platelets and vWF suggested that the endothelium was damaged prior to platelet aggregation.

Aged↗
PubMed1993

[An experimental study evaluating the efficacy of platelet aggregation inhibitory (OKY-046) for hepatic metastasis of VX2 carcinoma].

To investigate whether a platelet aggregation inhibitor (OKY-046) can inhibit VX2 tumor metastasis, VX2 tumor cells (1 x 10(7) cells) were inoculated into the portal vein and OKY-046 (an inhibitor of thromboxane A2 synthesis) was administered continuously at 0.2 mg/kg/hour (group A), and 0.6 mg/kg/hour (group B) into the portal vein from 30 min, before tumor cell inoculation through the following 2 days. In group C, adriamycin (ADM) 1 mg/kg was administered via the portal vein on the next day, 3rd, and 5th day after OKY-046 infusion was completed. Only ADM was administered into the portal vein on the 3rd, 5th and 7th day in group D and immediately and on the 2nd and 4th day after tumor cell inoculation in group E. The numbers of tumor nodules on the whole liver surface at three weeks after tumor inoculation in the control, group A, B, C, D and E were 546 +/- 79, 504.5 +/- 74, 438.8 +/- 59.9, 8 +/- 6.1, 130 +/- 89.7, and 9.5 +/- 5.3, respectively. These results suggest that the inhibitory effect of the tumor growth of OKY-046 depended on inhibition of extravasation of the portally inoculated VX2 tumor cells.

Animals↗