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Biomedical subjects

M Taniguchi

Publications and source records attributed to M Taniguchi.

At least 433 records · Page 24Linked to original sources
PubMed1995

TCR repertoire in early fetal mouse thymus.

We investigated the rearrangement and expression of TCR genes in mouse fetal thymus organ culture, a system that avoids subsequent entry of hematopoietic precursor cells. The first observable rearranged TCR gene was homogeneous V gamma 2-J gamma 2, detectable as early as fetal day 11 (d11) in the thymic primordia. The productive TCR was homogeneous V gamma 5-J gamma 1, first detectable in d13 thymocytes, followed by adult-type TCR gamma (V gamma 4 and V gamma 7). Sequence analysis of TCR revealed five types of V-J junctional sequences. In the very early stage, a homogeneous V-J junction is generated via a short homology sequence in the coding region (Type I), while a short homology sequence in the P-nucleotide rather than the coding region is used in the following stage (Type II). In the later embryonic stages, diverse V-J junctions are generated by well-known mechanisms, such as P-nucleotide (Type III), N-region insertion (Type IV) or trimming of the coding ends (Type V). These findings suggest that the generation of homogeneous TCR gamma (V gamma 2 and V gamma 5) in the early fetal stages is due to the intrinsic rearrangement mechanisms and is in stage specific manner.

Animals↗
PubMed1995

Predominant expression of invariant V alpha 14+ TCR alpha chain in NK1.1+ T cell populations.

A novel T cell subset characterized by cell surface NK1.1+ TCR alpha beta+ expression was investigated for its TCR alpha usage, particularly that of invariant V alpha 14 TCR, which was found to be preferentially used in peripheral CD4-CD8- T cells developed at extrathymic sites. We found that NK+ alpha beta T cell subsets account for 0.4% in thymocytes, 5% in the splenic T cells and 40.5% in the bone marrow T cells. Among these NK+ alpha beta T cells, two distinct subsets were detected; cell surface TCR V alpha 14+ and V alpha 14- subpopulations. Almost all of NK+ alpha beta thymocytes express V alpha 14 mRNA; however, only < 20% were positive, while > 80% were negative or undetectable for V alpha 14 TCR expression on the cell surface in the thymus. Similarly, approximately 50% of NK+ alpha beta T cells in spleen and bone marrow are V alpha 14+ as revealed by FACS. TCR repertoire analysis by nucleotide sequences on inverse PCR products demonstrated that most NK+ alpha beta T cells express an invariant TCR encoded by the V alpha 14J alpha 281 gene with a 1 base N-region in all tissues. Thus, invariant V alpha 14 TCR is uniquely expressed on NK T cells, and can be a marker to distinguish NK, NK T and T cells.

Animals↗
PubMed1995

Comparison of 99Tcm-sestamibi and 201Tl-chloride to estimate right ventricular overload in children.

To evaluate right ventricular overload in paediatric patients with congenital cardiac disease (n = 25), the uptakes of 201Tl and 99Tcm-sestamibi (99Tcm-MIBI) were compared. 99Tcm-MIBI showed a clearer myocardial border and better contrast between the myocardium and ventricular cavity. Although hepatic activity may influence right ventricular myocardial activity, it did not have a significant effect on the quantitative data of myocardial uptake. The right ventricle-to-background (RV/BG) ratio and left ventricle-to-background (LV/BG) ratio were lower with 99Tcm-MIBI than with 201Tl, and the RV/LV count ratio was also significantly lower in the 99Tcm-MIBI study. The parameters of the RV/LV count ratios showed good correlations between the 201Tl and 99Tcm-MIBI studies. The RV/LV pressure ratio was estimated using the formula: RV/LV pressure ratio = 0.99 (RV/LVav) + 0.02 (R = 0.90, P < 0.0001). To estimate RV overload or the RV/LV pressure ratio scintigraphically, we conclude that 99Tcm-MIBI be used instead of 201Tl. 99Tcm-MIBI studies are a good adjunct to perfusion studies when estimating RV pressure.

Child, Preschool↗
PubMed1995

A gene encoding a cytochrome c oxidase-like protein is located closely to the cytochrome c-553 gene in the anaerobic bacterium, Desulfovibrio vulgaris (Miyazaki F).

The gene encoding cytochrome c-553 from Desulfovibrio vulgaris (Miyazaki F) was cloned using a synthetic oligodeoxyribonucleotide probe. The nucleotide sequence indicated that cytochrome c-553 was synthesized as a precursor protein with an NH2-terminal signal sequence of 23 residues. In the cloned DNA fragment, there are three other open reading frames whose products have 191, 157, 541 amino acid residues, respectively. The putative ORF-4 product is highly homologous with the cytochrome c oxidase subunit I from various organisms.

Amino Acid Sequence↗
PubMed1995

Costunolide and dehydrocostus lactone as inhibitors of killing function of cytotoxic T lymphocytes.

Costunolide and dehydrocostus lactone were isolated from an extract of mokko (Saussurea lappa Clarke) as inhibitors of killing activity of cytotoxic T lymphocytes (CTL). Mokko lactone was also isolated as an inactive compound from the extract. The structure-activity relationship indicated that alpha-methylene-gamma-butyrolactone is required for the inhibitory effect. Costunolide markedly inhibited the granule exocytosis and the production of inositol phosphates in response to anti-CD3 monoclonal antibody (mAb) stimulation at a concentration that did not affect the binding of anti-CD3 mAb. Tyrosine phosphorylation induced by crosslinking of CD3 molecules was significantly inhibited by costunolide in a dose-dependent manner. These results suggest that costunolide inhibits the killing activity of CTL through preventing the increase in tyrosine phosphorylation in response to the crosslinking of T-cell receptors.

4-Butyrolactone↗
PubMed1995

En bloc petrosectomy using a Gigli saw for petroclival lesions. Technical note.

The authors report a new technique for en bloc petrosectomy using a Gigli saw as an alternative to drilling the petrous bone in the combined supra- and infratentorial approach or the transpetrosal-transtentorial approach. It is simple and easy and avoids postoperative cosmetic deformity. This technique has been performed in 11 petroclival lesions without injuring the semicircular canals, the cochlea, or the facial nerve.

Craniotomy↗
PubMed1995

AKD-2A, B, C and D, new antibiotics from Streptomyces sp. OCU-42815. Taxonomy, fermentation, isolation, structure elucidation and biological activity.

An antibiotic complex, AKD-2, was isolated from the mycelial cake of Streptomyces sp. OCU-42815. The lipophilic substances in this complex were further purified by a recycling HPLC procedure and were designated AKD-2A, C and D. AKD-2B was obtained as a mixture of AKD-2B1 and AKD-2B2. These substances were identified as monoglycerides having branched chain fatty acids and exhibited both antibacterial and antifungal activities.

Antifungal Agents↗
PubMed1995

[A technique for removal of entrapped intra-aortic balloon catheter through the left axillary artery].

A case of intra-aortic balloon pumping (IABP) entrapment in which the ruptured catheter could be removed through the left axillary artery was reported. A 68-year-old man was admitted with persistent chest pain, and because of his poor cardiac condition, an IAB catheter was inserted by the Seldinger technique. During attempted extraction of the IAB catheter resistance was encountered and it turned out to be entrapped. Then a guide-wire was passed through the IAB lumen to the left axillary artery, the artery was exposed, and the tip of the guide-wire and IAB catheter were led to the arteriotomy site. After the balloon was dissected, the IAB catheter could be removed through the axillary artery. Finally, left femoro-left branchial artery bypass was performed with e-PTFE graft because of the arterial injury and ischemia of the involved arm. The patient recovered from this episode.

Aged↗
PubMed1995

[Serum phospholipase A2 activity in patients with aspirin-induced asthma].

Urinary excretion of leukotrienes is greater in patients with aspirin-induced asthma (AIA) than in other patients with asthma in remission, and is greater still during an aspirin-induced attack. We therefore hypothesized that increased phospholipase A2 (PLA2) activity leads to increased leukotriene synthesis when non-steroidal antiinflammatory drugs inhibit cyclooxygenase in patients with AIA, and that PLA2 activity increases further during an aspirin induced attack. To test this hypothesis, we measured the serum PLA2 activity in adult asthmatic patients, and compared the activity in those with AIA to the activity in those without AIA. The subjects were 43 patients with asthma in remission, 17 with AIA and 26 without AIA. Serum PLA2 activity was also measured before and after intravenous administration of lysine-aspirin in three patients with AIA and in one without AIA. Serum PLA2 activity was measured by radioimmunoassay. Serum PLA2 activity in patients with AIA, in those without AIA, and in healthy controls was 300.9 +/- 52.9, 294.4 +/- 65.3 and 171.7 +/- 41.8 pmol/ml/min, respectively. Serum PLA2 activity in asthmatic patients was significantly higher than in healthy controls (p < 0.01), but there was no difference between patients with and without AIA. Intravenous lysine-aspirin provoked asthmatic attacks in three patients with AIA. However, intravenous lysine-aspirin did not significantly change serum PLA2 activity in the three patients with AIA or in the patient without AIA. These results indicate that although PLA2 may be involved in the pathogenesis of bronchial asthma, it is not specific to AIA. Thus, the pathophysiology of AIA remains unclear and further investigation is needed.

Adult↗
PubMed1995

Lipoxygenase inhibitor-provoked acute asthma in a patient with asthma relieved by aspirin.

BACKGROUND: A very small number of patients with asthma show symptomatic improvement after administration of aspirin and other cyclooxygenase inhibitors. The clinical features of such patients with so-called aspirin-relieved asthma are similar to those with aspirin-induced asthma, but the pathogenesis is unclear. METHODS: We encountered one confirmed aspirin-relieved asthma patient and investigated the effects of cyclooxygenase and lipoxygenase inhibitors on his condition. RESULTS: Our patient showed a marked improvement of the forced expiratory volume in one second (FEV1) after administration of aspirin and three other cyclooxygenase inhibitors (indomethacin, mefenamic acid, and ketoprofen). A 5-lipoxygenase inhibitor (AA861, Takeda, Japan), however, evoked acute asthma, and repeated administration of this drug resulted in some desensitization, but not complete tolerance. CONCLUSIONS: These results suggest an altered balance of arachidonic acid metabolism may play a critical role in the pathophysiology of aspirin-relieved asthma.

Acute Disease↗
PubMed1995

[Usefulness of percutaneous instillation of antifungal agents for pulmonary aspergilloma].

We studied the usefulness of percutaneous instillation of antifungal agents for treatment of pulmonary aspergilloma. The subjects were six patients, four males and two females, with a mean age of 69 years (range, 45 to 90 years). In all cases, radiography revealed a fungus ball or thickened cavity wall in residual tuberculous cavities. The patients had clinical symptoms including hemoptysis, fever, cough and sputum, and most of them showed severe emaciation, anemia, hypoalbuminemia and hypoxia. Miconazole or fluconazole was instilled through an indwelling catheter inserted percutaneously into the cavity from the anterior chest wall or parascapular region under fluoroscopic observation. After treatment with a total dose of 610 to 2070 mg over a period of 6 to 18 weeks, clinical symptoms were diminished in all patients and radiographic findings were improved in five. Furthermore, Aspergillus fumigatus, which had been isolated from sputum samples of three patients, was eradicated. According to evaluation of the overall therapeutic effects, this therapy was considered to be effective in five patients, giving an efficacy rate of 83%. No recurrence has been detected in six patients during a mean follow-up of 13 months after treatment. Since percutaneous instillation involves less pain and stress than other kinds of

Aged↗
PubMed1995

[The effect of cardiopulmonary bypass on the cardiopulmonary function after open heart surgery].

The effect of cardiopulmonary bypass (CPB) on the cardiopulmonary function after open heart surgery was evaluated by multiple regression analysis in relation with preoperative factors. In cases without decompensated heart failure, the depression of cardiac function and its recovery after CPB were mostly related to cross-clamp time. The pulmonary oxygenation was affected with operation time, and the duration of artificial ventilation correlated with CPB time. From these results, we conclude that CPB is the most important factor determining the cardiopulmonary function after CPB.

Aged↗
PubMed1995

An electron microscopic study of the processes of nerve regeneration after lyophilized nerve homografting.

The objective of the present study was to investigate the role of the Schwann cell basal lamina in nerve regeneration. To achieve this goal, we observed the process of axonal regeneration within a lyophilized nerve graft, in which only the basal lamina of the Schwann cell persisted. Sciatic nerves were removed from rats and lyophilized to kill the Schwann cells and other components. These grafts were transplanted to rat sciatic nerve defects. The rats were then killed after lapses of time. We observed the processes of axonal regeneration using a transmission electron microscope. Regeneration of axons along the inner surface of the Schwann cell basal lamina was clearly seen. These results suggest that, if tubular basal laminae persist, Schwann cells are not always necessary, and axonal regeneration can be induced in the direction toward the basal lamina.

Animals↗