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Biomedical subjects

M Taniguchi

Publications and source records attributed to M Taniguchi.

At least 397 records · Page 22Linked to original sources
PubMed1996

Intravenous trimethaphan during epidural plus general anesthesia decreases the direct radial artery pressure lower than the brachial artery pressure.

STUDY OBJECTIVE: To determine whether vasodilators such as sodium nitroprusside (SNP) and trimethaphan (TMP) produce a pressure difference between the radial artery and the brachial artery during epidural plus general anesthesia or simple general anesthesia. DESIGN: Randomized study and prospective study. SETTING: Operating rooms of two hospitals. PATIENTS: 36 and 6 adult patients in the first and second studies, respectively, who received spherical acetabular osteotomy with induced hypotensive anesthesia. INTERVENTIONS: In the first study, 18 patients received epidural plus general anesthesia (epidural group) and 18 patients received general anesthesia alone (general group). All patients received the hypotensive drugs for more than 50 minutes each. In the second study, 6 patients received TMP-induced hypotension for 20 minutes under epidural plus general anesthesia. MEASUREMENTS AND MAIN RESULTS: In the first study, radial intra-arterial blood pressure (RIBP) and tonometric blood pressure (TBP) calibrated with oscillometric blood pressure of the arm were compared. In the second study, RIBP and the brachial intra-arterial blood pressure (BIBP) were compared. In the first study, the bias between RIBP and TBP for systolic, mean and diastolic blood pressure were significantly less during TMP-induced hypotension in the epidural group (-11.5 +/- 2.5 (mean +/- SD), -6.0 +/- 3.1, and -2.8 +/- 3.7 mmHg, respectively] than during SNP-induced hypotension in the epidural group and SNP- and TMP-induced hypotension in the general group (p < 0.01). The precision of systolic and mean pressures were significantly greater during TMP-induced hypotension in the epidural group (11.8 +/- 2.3 and 7.1 +/- 1.9 mmHg, respectively) than the other three hypotension groups (p < 0.01). In the second study, the bias between RIBP and BIBP for systolic, mean, and diastolic pressures were significantly less (p < 0.01), and precision was significantly greater during hypotension than during normotension (p < 0.01). CONCLUSIONS: Our results demonstrate that TMP decreases the direct radial artery systolic and mean pressures to levels below the brachial artery systolic and mean pressures in patients who received epidural plus general anesthesia.

Adult↗
PubMed1996

V alpha 14+ NK T cells: a novel lymphoid cell lineage with regulatory function.

A novel lymphoid lineage, NK T cells, was recently found. The NK T cells are the major population in the periphery comprising 5% of splenic T cells and 40% of bone marrow T cells. They express a unique TCR composed of invariant V alpha 14J alpha 281 and V beta 8.2 together with NK receptor (NKRPI). Surprisingly, the invariant V alpha 14+ TCR is exclusively expressed on NK T cells but not on conventional T cells. As the selective decrease in V alpha 14+ NK T cell population in the periphery is tightly correlated with autoimmune disease development, V alpha 14+ NK T cells control development of autoimmune diseases. We also found that V alpha 14 TCR gene rearrangement and transcripts were detected at an early embryogenesis (d9.5) before the thymus formation. Therefore NK T cells are in the distinct category from conventional T cells. The target of NK T cells is found to be CD1 (class 1b, monomorphic class I MHC-like molecule) present on bone marrow-derived cells and is killed by Fas-FasL interaction or perforin-mediated mechanisms. These results indicate that NK T cells consist of an immunoregulatory system different from defense system in terms of homogeneous repertoire, extrathymic development in early stage of gestation, and their regulatory functional role.

Animals↗
PubMed1996

Possible involvement of an environmental agent in the development of acute eosinophilic pneumonia.

BACKGROUND: Although the pathogenesis of acute eosinophilic pneumonia remains largely unknown, it has been suggested that it may include a hypersensitivity phenomenon induced by inhaled environmental antigens. METHODS: To investigate this possibility, we studied the effect of environmental challenges in three patients with acute eosinophilic pneumonia. Symptoms and laboratory findings were evaluated before and after the challenge tests in the patient's homes and their places of work. RESULTS: After the provocation challenges to their homes, all three patients developed fever, cough, and fatigue and two of them presented with dyspnea. Inspiratory crackles became audible in all cases, and there was a decreased Pao2 level in two. Similar challenges at their workplaces were negative. After moving out of their homes, the patients engaged in their usual work but had no recurrent episodes. CONCLUSIONS: These results suggest that environmental factors in the home can be the cause of acute eosinophilic pneumonia. In order to elucidate the pathogenesis of the disease, it is important to further investigate environmental factors.

Acute Disease↗
PubMed1996

Production of monoclonal antibodies against quail Pax-1.

Monoclonal antibodies (MAbs) against quail Pax-1 were generated using a fusion protein of the C-terminal part of Pax-1 and glutathione S-transferase. The MAbs generated could detect quail Pax-1 protein by Western blotting and immunoprecipitate it from whole cell extracts of quail embryos, indicating their usefulness for biochemical analyses of Pax-1 protein function in development or oncogenesis.

Animals↗
PubMed1996

Difference in behavior between responses to forskolin and general odorants in turtle vomeronasal organ.

To elucidate the signal transduction mechanisms in the turtle vomeronasal receptor neurons, the effects of forskolin, changes in mucosal Ca2+ concentrations and ruthenium red on the responses of the accessory olfactory bulb to general odorants were examined. Forskolin elicited a large response, suggesting that there are cAMP-gated channels in the vomeronasal neurons. On the other hand, the dependence of the responses to general odorants on Ca2+ concentrations was different from that of the response to forskolin. A large response to an odorant (n-amyl acetate) appeared after the cAMP-mediated pathway was fully desensitized by application of 50 microM forskolin. These results suggest that the cAMP-mediated pathway does not contribute significantly to generation of the response to general odorants. A concentration of 50 microM ruthenium red significantly reduced the responses to n-amyl acetate alone and after 50 microM forskolin desensitization, suggesting that the inositol triphosphate-mediated pathway contributes partly to generation of the responses to general odorants in the vomeronasal neurons.

Animals↗
PubMed1996

Somatosensory evoked potential phase reversal and direct motor cortex stimulation during surgery in and around the central region.

In 99 patients with mass lesions in and around the central region, the central sulcus was intraoperatively localized with the use of somatosensory evoked potential (SEP) phase reversal. In 33 of these patients, the motor cortex was directly stimulated and electromyographic responses were recorded from the forearm flexor, thenar, and hypothenar muscles. An additional 25 patients, with subcortical lesions or lesions directly located at the pyramidal tract, were continuously monitored during surgery by motor evoked potentials (MEPs). An exact determination of the central sulcus and tumor localization was possible in all patients; a phase reversal was obtained in 90.8% of the patients, and localization was possible as a result of anatomic structures and the loss of N20 or P20 of SEPs in the other 9.2%. MEPs were obtained in 32 of 33 patients and also in all 25 patients who underwent MEP monitoring at the beginning of tumor removal. From this study, it can be concluded that the combination of SEP phase reversal and modified electrical cortex stimulation is compatible with general anesthesia, although anesthesia was not systematically controlled according to a protocol. Although this study demonstrates that the combined SEP/MEP technique was feasible, it is not yet possible to demonstrate benefit in improving the outcome of patients. Concerning the safety of stimulation, the exact localization of the central sulcus by the noninvasive SEP method, compared with direct electrical stimulation, offered more safety for the patient. The modified technique of direct motor cortex stimulation needed much less charge density than did the common technique. The recording of electromyographic responses instead of movements made objective documentation possible, and the analysis of amplitudes and latencies will supply quantitative information about the motor system.

Adolescent↗
PubMed1996

The first case of insulin-dependent diabetes mellitus with prominent spurious hyperglucagonemia due to interference of immunoglobulin G in glucagon radioimmunoassay (OAL-123) system.

A 51-year-old male was admitted to our hospital because of diabetic ketoacidosis. His symptoms were promptly improved with intensive insulin therapy, but his plasma glucagon immunoreactivity measured by the OAL-123 radioimmunoassay (RIA) system showed persistently high values (3,090-3,210 pg/ml). A computed tomographic scan, abdominal angiography and endoscopic examination of his gastrointestinal tract showed no evidence of glucagonoma. After removing the immunoglobulin fraction from the plasma, his immunoreactive plasma glucagon level returned to normal. Moreover, the immunoglobulin G fraction purified from the patient's plasma inhibited the binding of [125I]glucagon to rabbit antiglucagon antiserum, OAL-123. Dot-blot analysis demonstrated that the immunoglobulin G of this patient cross-reacted against OAL-123. Therefore, it was considered that the prominent hyperglucagonemia in this patient was due to the presence of IgG, which interfered with the measurement of plasma-immunoreactive glucagon.

Diabetes Mellitus, Type 1↗
PubMed1996

A role for mel-18, a Polycomb group-related vertebrate gene, during theanteroposterior specification of the axial skeleton.

Segment identity in both invertebrates and vertebrates is conferred by spatially restricted distribution of homeotic gene products. In Drosophila, the expression of Homeobox genes during embryogenesis is initially induced by segmentation gene products and then maintained by Polycomb group and Trithorax group gene products. Polycomb group gene homologs are conserved in vertebrates. Murine mel-18 and closely related bmi-1 are homologous to posterior sex combs and suppressor two of zeste. Mel-18 protein mediates a transcriptional repression via direct binding to specific DNA sequences. To gain further insight into the function of Mel-18, we have inactivated the mel-18 locus by homologous recombination. Mice lacking mel-18 survive to birth and die around 4 weeks after birth after exhibiting strong growth retardation. Similar to the Drosophila posterior sex combs mutant, posterior transformations of the axial skeleton were reproducibly observed in mel-18 mutants. The homeotic transformations were correlated with ectopic expression of Homeobox cluster genes along the anteroposterior axis in the developing paraxial mesoderm. Surprisingly, mel-18-deficient phenotypes are reminiscent of bmi-1 mutants. These results indicate that the vertebrate Polycomb group genes mel-18 and bmi-1, like Drosophila Polycomb group gene products, might play a crucial role in maintaining the silent state of Homeobox gene expression during paraxial mesoderm development.

Animals↗
PubMed1996

Identification of low molecular weight probes on perforin- and Fas-based killing mediated by cytotoxic T lymphocytes.

Perforin- and Fas-based killing pathways are two major mechanisms of cytotoxic T lymphocytes (CTL)-mediated cytotoxicity. In this paper, we have reported the identification of low molecular weight probes on CTL-mediated cytolysis. In addition to inhibitors of acidification so far reported, three other groups of compounds have been identified to block perforin-based cytolysis by the CD8+ CTL clone: (1) an inhibitor of actin polymerization (cytochalasin D), (2) respiratory inhibitors (antimycin A and oligomycin A), and (3) protein kinase inhibitors (calphostin C, herbimycin A, K252a, and staurosporine). Since Fas-based cytolysis by CD4+ CTL clone was inhibitable or rather increased by these agents, only vacuolar type H(+)-ATPase inhibitors such as concanamycin A have been shown to be highly specific probes to block perforin-based CTL-mediated cytotoxicity.

Anti-Bacterial Agents↗
PubMed1996

A clinical study of minocycline-induced pneumonitis.

We studied the clinical features of minocycline-induced pneumonitis in seven patients. Acute symptoms included fever, dry cough and dyspnea, indicating acute respiratory failure. Diffuse ground glass shadows with Kerley's B lines, bronchial wall thickening, swelling of vascular bundles and pleural effusion were visible on radiography. Bronchoalveolar lavage or transbronchial lung biopsy confirmed pulmonary eosinophilia. Cessation of minocycline led to rapid remission with no treatment or only short-term steroid therapy. The lymphocyte stimulation test for minocycline with peripheral blood lymphocytes was not found to be useful for diagnosis.

Acute Disease↗
PubMed1996

Chronic encapsulated expanding hematoma in association with gamma knife stereotactic radiosurgery for a cerebral arteriovenous malformation. Case report.

The authors report a rare case of a patient with a chronic encapsulated expanding hematoma and progressive neurological deterioration who presented 2 years after gamma knife radiosurgery for a cerebral arteriovenous malformation (AVM). A tough capsule containing multiple layers of organized hematoma resulting from previous bleeding was confirmed surgically. Histological examination revealed that the capsule consisted of a dense collagenous outer layer and a granulomatous newly vascularized inner layer with marked fibrosis. Hemosiderin deposits were frequently observed in the inner layer, which suggested recurrent minor bleeding from fragile vessels in this layer. An AVM was found in the hematoma, which had degenerated as the result of radiosurgery. A cross-section of the abnormal vessels showed various stages of obliteration due to intimal hypertrophy. The clinical course, radiological features, and histological findings in this case were compatible with those of previously reported chronic encapsulated hematomas. A possible mechanism of hematoma formation and its expansion are discussed.

Adult↗
PubMed1996

UK-2A, B, C and D, novel antifungal antibiotics from Streptomyces sp. 517-02. I. Fermentation, isolation, and biological properties.

Novel antifungal antibiotics, UK-2A, B and a mixture of C and D, were obtained from the mycelial cake of Streptomyces sp. 517-02. All of the UK-2 compounds were similar in structure to antimycin A. The antifungal activities of UK-2 compounds were as strong as that of antimycin A. However, the UK-2 compounds demonstrated weak cytotoxicity compared to antimycin A.

Animals↗
PubMed1996

Third complementarity determining region sequence analysis of low-grade bronchus-associated lymphoid tissue lymphoma: genotypic analysis reveals heterogeneity in maturation.

It has recently been suggested that autoimmunity may play a role in the pathogenesis of low-grade mucosa-associated lymphoid tissue lymphomas, but precise genotypic analysis of antigen binding sites of low-grade bronchus-associated lymphoid tissue (BALT) lymphomas has not been reported. We analyzed the third complementarity determining region (CDR3) in eight cases of low-grade BALT lymphoma by 2-step PCR and sequencing analysis. All cases showed a distinct monoclonal band (about 100 base pairs) on electrophoresis. In seven cases, a single major CDR3 sequence was identified with five to nine clones among 10 vector clones being identical; and in the remaining case, two major sequences were obtained, with four clones among nine vector clones being identical. Findings suggestive of the autoimmunity of low-grade BALT lymphoma were obtained: (1) VHDJH rearrangements in seven of the eight lymphoma cell clones were potentially functional; (2) genotypically, two lymphoma cell clones showed 60 to 74% homology with G6 positive lymphocyte clones; and (3) five lymphoma cell clones showed 61 to 71 % homology with lymphocyte clones derived from fetal liver or cord blood. In one case, the N-D-N length of the neoplastic clone was very short and lacked N nucleotides at the D-JH junction. Therefore, our study demonstrates genotypic heterogeneity in maturation in low-grade BALT lymphoma.

Adult↗
PubMed1996

[Pneumonia and mortality in patients requiring prolonged mechanical ventilation].

We examined patients who required prolonged (>60 days) mechanical ventilation. A total of 31 patients were studied, 23 with pulmonary disease, 4 with neurologic disease and 4 with other conditions. Many of these patients were elderly. The survival rates one year and two years after the start of mechanical ventilation were 40% and 33%, respectively. Respiratory tract infection was the most common and most serious complication, and ventilator-associated pneumonia was the main cause of death. It is difficult but quite important to prevent these complications, especially ventilator-associated pneumonia.

Adult↗
PubMed1996

[Sinus bradyarrhythmia during administration of all-trans retinoic acid in a patient with acute promyelocytic leukemia].

A case of acute promyelocytic leukemia (APL) complicated by sinus bradyarrhythmia during the course of all-trans retinoic acid (ATRA) administration is reported. A 3-year-old boy was admitted for evaluation of petechiae and APL was diagnosed. He was initially treated with 45 mg/m2 of ATRA without success, and a complete remission was achieved when the dose was increased to 135 mg/m2. Sinus bradyarrhythmia was first recognized 3 days after the induction therapy with ATRA. It did not disappear even when the patient stopped taking the medication. However, the arrhythmia tended to be augmented whenever he received ATRA again. Close observation of his cardiac condition was mandatory to continue ATRA as an integral part of the therapy for APL, combined with multidrug chemotherapy including anthracyclines, which themselves are potentially toxic to myocardium. In conclusion, the present case revealed the possibility that ATRA therapy induces sinus node arrhythmia, or that it can potentiate preexisting node dysfunctions.

Arrhythmia, Sinus↗
PubMed1996

[A case of middle cranial fossa meningioma extending into the infratemporal fossa: an approach to the pterygoid extension of the sphenoid sinus via the infratemporal fossa].

A case of middle cranial fossa meningioma extending into infratemporal fossa and the pterygoid process is presented. The patient had a sphenoid sinus extending inferolaterally into the pterygoid process, which is known as pterygoid extension of the sphenoid sinus. This type of variation of the sphenoid sinus allowed a safe and well-oriented approach to the pterygoid process via the infratemporal fossa. The tumor extending into the pterygoid process was removed successfully without damaging any surrounding structures, e.g. maxillary nerve or Vidian nerve. However, pterygoid extension of the sinus is seen in only 40% of cases. Therefore, close preoperative examination with bone window CT scan is mandatory before employing this approach.

Cranial Fossa, Posterior↗