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Biomedical subjects

T Toyoda

Publications and source records attributed to T Toyoda.

At least 91 records · Page 5Linked to original sources
PubMed1996

Influenza virus PB1 protein is the minimal and essential subunit of RNA polymerase.

RNA polymerase of influenza virus with the subunit structure PB1-PB2-PA is involved in both transcription and replication of the genome RNA. The RNA polymerase with transcription activity was reconstituted from three P proteins, which were separately isolated from insect cells infected with recombinant baculoviruses, each carrying cDNA for one P protein. Nuclear extracts of the insect cells infected with each of the recombinant baculoviruses or various combinations of these viruses were examined for transcription and replication activities. The nuclear extract of cells expressing all three P proteins catalyzed model template-directed RNA synthesis in the absence of primers (an indication of RNA replication), supporting the notion that the complete set of three P proteins is required for RNA replication. All the nuclear extracts containing the PB1 subunit, including the extract containing PB1 alone, were able to catalyze model template-directed dinucleotide-primed RNA synthesis (an indication of transcription). These observations not only confirm that the PB1 protein is a catalytic subunit of influenza virus RNA polymerase, but also indicate that PB1 alone is able to catalyze RNA synthesis in the absence of PB2 and PA subunits.

Animals↗
PubMed1996

Nucleic acid binding by zinc finger-like motif of human papillomavirus type 16 E7 oncoprotein.

Human papillomavirus (HPV) types 16 and 6b E7 proteins and their chimeric or mutant proteins were analyzed for oligonucleotide-binding activity by surface plasmon resonance-based biomolecular interaction analysis. The results indicated that type 16 E7 protein has stronger nucleic acid-binding activity than that of type 6b E7 protein. In addition, the results also indicated that the zinc finger-like motif in the C-terminal region of the type 16 E7 protein plays an important role in this activity.

Binding Sites↗
PubMed1996

Thoracoscopic en bloc total esophagectomy with radical mediastinal lymphadenectomy.

OBJECTIVE: Total esophagectomy with en bloc mediastinal lymphadenectomy for cancer carries a substantial morbidity and mortality rate. To investigate the feasibility of thoracoscopic technique, we carried out an extensive laboratory study. Encouraged by our excellent results, we conducted a clinical trial. METHODS: From September 1994 to September 1995, 39 patients thoracic esophageal cancer lesions not invading surrounding organs underwent total esophagectomy with mediastinal lymphadenectomy by means of thoracoscopy. Ages ranged from 47 to 86 years. The procedures were conventional except for the thoracic portion, which was performed as a thoracoscopic procedure with six trocar holes instead of thoracotomy. All harvested lymph nodes were counted for each station. Spirometric data and plethysmographically determined vital capacity were measured before and after operation for all patients. RESULTS: All procedures were accomplished as scheduled, and none was converted to open thoracotomy. The operating time was 200 +/- 41 minutes (mean +/- standard deviation). Estimated blood loss was 270 +/- 157 ml. The harvested lymph nodes numbered 19.7 +/- 11.1 per patient. Seventeen patients (45%) had positive lymph nodes. There were no in-hospital deaths within 30 days. Twenty-two patients did not require postoperative ventilatory support. Vital capacity decreased to 85% +/- 11% of the preoperative values, and forced expiratory volume in 1 second decreased to 82% +/- 16%. CONCLUSIONS: Thoracoscopic mediastinal lymphadenectomy is technically feasible, and its completeness is comparable to that of the open technique. The decline in pulmonary function is significantly less than that seen in our previous experience with the open technique.

Aged↗
PubMed1996

Analysis of the thromboxane/prostacyclin balance in human urine by gas chromatography/selected ion monitoring: abnormalities in diabetics.

We microanalyzed 2,3-dinor-6-keto-prostaglandin F1 alpha (2,3-dinor-6-keto-PGF1 alpha 1) and 11-dehydrothromboxane B2 (11-dehydro-TXB2, 2) in human urine. Samples containing a [2H4]-analogue as an internal standard were extracted by chromatography using Sep Pak tC18 and silica gel. The compounds were then analysed by means of the lactone ring opening reaction and dimethylisopropylsilylation. The conversion of 1 to 1-methyl ester (ME)-propylamide (PA)-9, 12, 15-dimethylisopropylsilyl (DMIPS) ether derivative and of 2 to 1-ME-6-methoxime (MO)-9, 12, 15-tris-DMIPS ether derivative was followed by gas chromatography/selected ion monitoring (GC/SIM). Interfering substances from the urine matrix were eliminated during GC/SIM analysis using a DB-5 column. We were able to detect 1 (222-1031 pg/mg creatinine) and 2 (18-155 pg/mg creatinine) in human urine. Furthermore, the thromboxane/prostacyclin (IX/PGI) ratio in the urine of diabetics was higher than that of healthy volunteers. This method can be used to determine the TX/PGI balance in human urine.

6-Ketoprostaglandin F1 alpha↗
PubMed1996

Magnetic resonance images in patients with acute traumatic injury of the temporomandibular joint: a preliminary report.

Condylar or subcondylar fractures are severe traumatic lesions of the temporomandibular joint (TMJ) but the damage to the intracapsular soft tissues is not fully defined. In this study, twelve joints in ten patients with condylar and subcondylar fractures of the TMJ between two and twelve days after injury, were examined by magnetic resonance imaging to evaluate the damage to the intracapsular soft tissues in the acute phase. The joint capsule and the retrodiscal tissue were both swollen and showed increased signal intensity. Tears were recognized in the capsule of the eight joints and in the retrodiscal tissue of six joints. All discs were displaced in an anteromedial direction along with the fractured condylar fragments, but tear (rupture) was not recognized. In all cases, high signal intensity was seen in the joint spaces, and haemarthrosis was recognized in six joints during open reduction surgery.

Acute Disease↗
PubMed1996

Intraischemic hypothermia attenuates neutrophil infiltration in the rat neocortex after focal ischemia-reperfusion injury.

OBJECTIVE: The mechanisms by which hypothermia influences postischemic outcome remain a matter of discussion. One mechanism thought to play an important role in neuronal damage after ischemia/reperfusion is the accumulation of polymorphonuclear leukocytes in compromised brain tissue. To better understand the potential impact of hypothermia on this injurious mechanism, the present study examined the effect of intraischemic hypothermia on polymorphonuclear leukocyte accumulation after transient focal ischemia. METHODS: The effect of intraischemic hypothermia (30 degrees C) on the accumulation of polymorphonuclear leukocytes was quantified by measuring myeloperoxidase (MPO) activity in the neocortex of Sprague-Dawley rats. Reversible focal ischemia was created by subjecting rats to temporary occlusion of the left middle cerebral artery and both carotid arteries for 3 hours; animals were killed 24 hours after reperfusion. RESULTS: Normothermic animals exhibited significantly greater MPO activity in the infarction core (P < 0.05) and the pericore areas (P < 0.05), compared with corresponding areas in sham-operated animals. Hypothermic animals exhibited significantly greater MPO activity in the core (P < 0.05) but not in the pericore region, compared with sham-operated animals. MPO activity in the pericore region of the hypothermic group was significantly less than that observed in the corresponding region of the normothermic group (P < 0.01). In addition, the total volume of cerebral infarction was reduced by 59% in the hypothermic group. CONCLUSION: These findings demonstrate that intraischemic hypothermia attenuates the inflammatory response to transient focal ischemia in the pericore region, i.e., the region spared from infarction under hypothermic conditions. The findings raise the possibility that a reduction in the inflammatory response after ischemia/reperfusion contributes to the neuroprotective effects of hypothermia.

Animals↗
PubMed1996

Molecular assembly of the influenza virus RNA polymerase: determination of the subunit-subunit contact sites.

Influenza virus RNA polymerase with the subunit structure PB1-PB2-PA is involved in both transcription and replication of the RNA genome. By transfection of various combinations of cDNA encoding wild-type and serial deletion mutants of each P protein subunit and co-immunoprecipitation with subunit-specific antibodies, the subunit-subunit contact sites on all three of the P proteins were determined. Results indicate that binary complexes are formed between PB1-PB2 and PB1-PA but not between PB2-PA. Therefore, we concluded that PB1 is the core subunit for assembly of the virus RNA polymerase. The C-terminal 158 amino acids of PB1 bound to the N-terminal 249 amino acids of PB2, while the N-terminal 140 amino acids of PB1 bound to the C-terminal two-thirds of PA. PB2-PA binding was not detected when they were expressed in the absence of the PB1 subunit.

Animals↗
PubMed1996

Treatment of focal cerebral ischemia with synthetic oligopeptide corresponding to lectin domain of selectin.

BACKGROUND AND PURPOSE: Synthetic oligopeptides with amino acid sequences of the lectin domain of selectin block selectin-mediated cell adhesion in vitro, which may be applied to a therapeutic intervention to attenuate acute inflammatory reactions. To evaluate the efficacy of such treatment against ischemic brain injury, the effects of administering a selectin oligopeptide that selectively blocks selectin-mediated cell adhesion on histological outcome and on cerebral blood flow (CBF) were studied in models of rodent focal cerebral ischemia. METHODS: Spontaneously hypertensive rats were anesthetized with halothane. Permanent focal cerebral ischemia was induced by tandem left middle cerebral artery (MCA) and common carotid artery (CCA) occlusion. Focal cerebral ischemia with partial reperfusion was introduced by reperfusing the CCA after 2 hours of tandem MCA/CCA occlusion. A synthetic oligopeptide (amino acid residues 23-30 from N terminal) of E-selectin was dissolved in physiological saline and was injected intravenously at a dosage of 2 mg/kg or 10 mg/kg before artery occlusion. Control animals received equivalent volumes of physiological saline or 10 mg/kg of synthetic oligopeptide with a scrambled amino acid sequence. Twenty-four hours after the occlusion, seven coronal brain slices were stained with 2,3,5-triphenyltetrazolium chloride, and the volume of ischemic injury was calculated. In a separate set of animals, regional CBF was monitored with laser-Doppler flowmetry at the dorsolateral cerebral cortex during 2-hour ischemia and 30 minutes after partial reperfusion. RESULTS: The volume of ischemic injury did not differ among groups in permanent ischemia. In ischemia with partial reperfusion, 10 mg/kg selectin oligopeptide, but not the same dosage of scrambled oligopeptide, significantly reduced the volume of ischemic injury (95 +/- 13, 73 +/- 11, 55 +/- 6, and 111 +/- 14 mm3 for saline [n = 11]; 2 mg/kg [n = 10] and 10 mg/kg [n = 16] selectin oligopeptide and 10 mg/kg scrambled oligopeptide [n = 6], respectively; P < .01 by one-way ANOVA followed by the Tukey test). Laser-Doppler flowmetry demonstrated a larger increase in CBF after reperfusion of the CCA in the 10-mg/kg selectin oligopeptide group. CONCLUSIONS: Our data demonstrate that administration of a synthetic oligopeptide corresponding to the lectin domain of selectin decreases the size of ischemic injury after transient, but not after permanent, focal cerebral ischemia as evaluated at 24 hours after onset of ischemia. These effects were associated with an improved CBF at the dorsolateral cerebral cortex after partial reperfusion.

Analysis of Variance↗
PubMed1996

Frequency, significance, and mechanism of myocardial ischemia during daily activities detected by Holter dynamic electrocardiogram.

Exercise testing (EX) and Holter ECG (DCG) were performed consecutively in 52 patients with ischemic heart disease. A total of 100 episodes of myocardial ischemia (IE) were recorded during DCG in 30 patients, who constituted 94% of the patients with myocardial ischemia under 6 metabolic equivalents (METs) during EX. A significant increase in heart rate (HR) was observed before the development of IE. The duration of this increase in HR was longer in IE than in periods in which the HR increased above the ischemic threshold, but without ischemia. The incidence of IE showed two peaks at 8-10 am and 4-6 pm. The frequency of IE among all of the periods with increased HR was highest at 8-10 am (51%). IE in the morning was associated with a lower HR than that in the afternoon, and LF/HF, which reflects sympathetic activity, evaluated using power spectral analysis, increased before IE in the morning. The early appearance of myocardial ischemia in EX can predict its appearance in daily life. The increase in HR and its duration appear to be associated with the development of IE. The increases in sympathetic activity in the morning and the increase in myocardial oxygen demand accompanied by physical activity in the afternoon most likely contributed to the circadian variation in the incidence of ischemic episodes.

Activities of Daily Living↗
PubMed1996

Clinical presentation of pulmonary tuberculosis associated with acquired immunodeficiency syndrome in metropolitan Tokyo.

The clinical features of pulmonary tuberculosis associated with acquired immunodeficiency syndrome (AIDS) in Japan were surveyed utilizing questionnaires completed by 48 institutes around the Tokyo metropolitan area. We found 11 Japanese and six foreign patients. The average number of patients per institute was 0.37. The Japanese patients had advanced human immunodeficiency virus (HIV) infection. A middle aged man, with fever and cough, nonspecific chest X-ray infiltrates, decreased lymphocyte counts, and a negative tuberculin skin test was the typical presentation of the Japanese patients. The clinical diagnosis was often difficult. The smear positive rate was high among those from whom smears were obtained, suggesting high communicability. None of the isolates indicated multidrug-resistant tuberculosis at the time of diagnosis. In conclusion, sputum smear and culture remain the keys to diagnosing tuberculosis in patients with AIDS, although the clinical picture may be atypical for pulmonary tuberculosis.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Bone loss of the radius in rheumatoid arthritis. Comparison between 34 patients and 40 controls.

We measured bone mineral density (BMD) in the radius by dual energy X-ray absorptiometry in 34 patients with rheumatoid arthritis (RA) and in 40 healthy controls. The BMD in RA patients in their fifties and sixties, but not in their forties and seventies, was significantly lower than that in the control subjects. The decrease in total radial BMD correlated with grip strength, RA activity and RA stage. The decrease in distal radial BMD correlated with RA activity, but not with grip strength. The levels of serum parathyroid hormone, alkaline phosphatase, and urinary hydroxyproline/creatinine were significantly higher in the patients. From these findings, we suggest that the bone loss in RA patients is affected by severity of inflammation, disuse, postmenopausal osteoporosis and secondary hyperparathyroidism.

Absorptiometry, Photon↗
PubMed1996

[A case of AIDS with bronchial tuberculosis].

A case is 48 years-old Japanese man who had a history of frequent sexual contact with prostitutes in Thailand and the Philippines. He presented with chief complaint of chest discomfort in April 1995. His chest X-ray film showed right mediastinal lymph node swelling in other hospital and the sputum smear was strongly positive for acid fast bacilli. In May 1995, he was admitted to our hospital and serological tests for HIV were positive both by EIA and Western blot methods. The CD4 lymphocyte count was 167/microliters. He was diagnosed as a case of AIDS according to the criteria proposed by the AIDS surveillance committee of the Japanese Ministry of Health and Welfare. Although numerous tubercule bacilli were detected in sputum, the chest X-ray did not show abnormal shadow in lung fields. So the diagnosis of bronchial tuberculosis was suspected by these apparently contradictory findings and the bronchoscopy was performed. Biopsy specimen of the bronchial mucous membrane obtained by bronchoscopy confirmed the presence of acid fast bacilli by Ziehl-Neelsen's staining method, however, histological findings were atypical of tuberculosis. A month after the initiation of treatment with isoniazid, rifampicin and ethambutol and AZT, his clinical symptoms improved and the sputum smear and the culture tests for tubercule bacilli converted to negative. Complications of AIDS, (Pneumocystis carinii infection, Cytomegalo virus infection, Kaposi's sarcoma, etc) other than tuberculosis have not developed to date. In the past reports, we could not find reports of bronchial tuberculosis with AIDS. Tuberculous granuloma formation was scarce in this case, and it was suspected that bronchial tuberculosis with AIDS would show characteristic sign as same as pulmonary tuberculosis with AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1996

[Two cases of tubercle bacilli infected pulmonary bulla].

Two cases of tubercle bacilli infected bulla are reported. Case 1; A 78-year-old man visited our hospital complaining of fever and chest pain. The chest radiograph revealed the bulla with air fluid level in the left upper lung field. Mycobacterium tuberculosis was detected in the fluid obtained by percutaneous lung aspiration. He was treated with anti-mycobacterial drugs and showed improvement. Case 2; A 66-year-old man visited our hospital complaining of fever, chest pain and dry cough. The chest radiograph revealed the bulla with air fluid level in the left upper lung field. A diagnosis of tubercle bacilli infected bulla was considered because of high level of ADA in the fluid obtained by percutaneous lung aspiration, and anti-mycobacterial drugs were administered. His symptoms were improved and the frequent chest radiograph showed gradual absorption of the fluid. It is suggested that ADA and bacteriological examinations of the fluid obtained by percutaneous lung aspiration are useful for early diagnosis of tubercle bacilli infected bulla.

Aged↗
PubMed1996

[Detection of Mycobacterium tuberculosis in clinical specimens other than sputum by the Mycobacterium Tuberculosis Direct Test (MTD)--assessment of sample preparation methods and clinical evaluation].

The Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (MTD) has been widely used as a rapid test for the identification of Mycobacterium tuberculosis complex in clinical samples, and several research groups have verified its clinical usefulness. However, most of the specimens they tested were sputum, and there have been few reports on other specimens. In particular, there have been no reports on assessments of methods of preparing samples other than sputum for the MTD. We assessed methods of preparing samples other than sputum and the influence of a local anesthetic and an anticoagulant that may be present in samples, and also evaluated the MTD as a means of detecting M. tuberculosis in pleural fluid, bronchial lavage cerebrospinal fluid, urine and ascitic fluid. 1. Assessment of three sample preparation methods, i.e., the NALC-NaOH method GuSCN-Diatom nucleic acid extraction method, and the ultrasonication method, revealed that the combination of the NALC-NaOH method and the ultrasonication method, widely used to prepare sputum samples, is also a valid method of preparing other samples. 2. The local anesthetic and the anticoagulant used clinically and remained in specimens did not affect the results of the MTD. 3. Seven (36.8%) of 19 pleural fluid samples from patients diagnosed as tuberculous pleurisy were positive of M. tuberculosis by the MTD, while five (27.8%) of 18 pleural fluid samples cultured for bacteria were positive for M. tuberculosis complex. None of the 20 pleural fluid samples from patients diagnosed as non-tuberculous pleurisy were positive for M. tuberculosis complex either by MTD or culture. 4. Eight (32.0%) of 25 bronchial lavage samples from patients diagnosed as pulmonary tuberculosis were positive for M. tuberculosis complex by the MTD, while 3 (12.0%) were positive by culture. None of the 18 bronchial lavage samples from patients diagnosed as non-tuberculous disease were positive for M. tuberculosis complex either by the MTD or culture. Based on these results, it is concluded that the MTD is a very useful method of detecting M. tuberculosis in clinical samples other than sputum because it is more sensitive than culture on Ogawa's egg medium in detecting M. tuberculosis complex in pleural fluid samples, bronchial lavage samples, and so on, with the same preparation method as used for sputum.

Bacteriological Techniques↗
PubMed1996

[Evaluation of a new detection method of Mycobacterium tuberculosis in clinical specimens by amplification of ribosomal RNA and its clinical application].

A new rapid M. tuberculosis detection method, the Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (MTD), which allows direct detection of M.tuberculosis in clinical specimens by amplification of M.tuberculosis ribosomal RNA (rRNA), was evaluated. In the present study, MTD and conventional smear and culture examinations were performed on 225 sputum, 36 pleural fluid (PF), nine cerebrospinal fluid (CSF) and 41 bronchoalveolar lavage fluid (BALF) specimens. Among 225 sputum specimens from 132 patients, 20 culture-negative specimens from 14 patients and one specimen which was culture-positive for M.fortuitum on Ogawa's egg medium were MTD-positive. On the other hand, there were 6 M.tuberculosis culture-positive but MTD-negative specimens from 6 patients. The amount of bacilli in all six cases, however, was very few. The sensitivity of M.tuberculosis detection by MTD, as compared with Ogawa's egg medium and MB-Check, was 93 and 92%, respectively, in sputum specimens, and the specificity of MTD was 80 and 85%, respectively. Taking into account not only culture-positive specimens but also MTD-positive specimens from patients clinically diagnosed as active tuberculosis, the sensitivity and specificity of MTD were 93% and 99%, respectively. Among 36 PF specimens from 31 patients, of which 20 specimens from 16 patients were clinically diagnosed as tuberculous, only 4 from 4 patients were culture-positive for M.tuberculosis while 7 from 5 patients were MTD-positive. The results of MTD in 9 CSF specimens coincided well with those of MB-Check, but one MTD-positive specimen yielded a false-negative result with Ogawa's egg medium. Among 41 BALF specimens from 39 patients, only one was culture-positive while one culture-positive and 7 culture-negative specimens were positive on MTD. All these MTD-positive patients were later verified as having pulmonary tuberculosis either by transbronchial lung biopsy and other examinations, or by the clinical course of the disease, particularly the response to anti-tuberculosis drugs. Inconsistent results were seen in 21 sputum specimens from 15 patients, 4 PF specimens from 3 patients and 7 BALF specimens from 7 patients, all of which were culture-negative for M.tuberculosis but MTD-positive. None of these patients had any clinical findings inconsistent with diagnosis as tuberculosis. It was noted that MTD was very useful for rapid detection of M.tuberculosis in sputum as well as other clinical specimens. We observed the clinical course of 20 pulmonary tuberculosis patients by monthly examinations of sputum, using smears, Ogawa's egg medium, MB-Check and MTD. MTD-positivity rates fell down in parallel with decreased pulmonary tuberculous activity. During the clinical course, out of 61 MTD-negative specimens only 4 (6.6%) were culture-positive for M.tuberculosis, while out of 63 smear-and-culture-negative specimens 6 (9.5%) were MTD-positive. These data suggest that MTD is useful to assess the clinical activity and course of tuberculosis.

Adult↗
PubMed1996

[Two cases of pulmonary disease caused by Mycobacterium chelonae subsp. abscessus].

We encountered two-cases of pulmonary disease caused by M. chelonae subsp. abscessus, [Case 1] A 72-year-old man was admitted to the hospital because of fever. He had been observed for one year after being given a diagnosis of pulmonary disease caused by Myocobacterium avium complex. Sputum examination revealed acid-fast bacilli (Gaffky 9). He recovered after administration of clarithromycin (CAM) and other drugs. [Case 2] A 61-year-old man was admitted to the hospital because of coughing and sputum production. He had been observed for 4 years after being given a diagnosis of pulmonary M. fortuitum disease. Sputum examination revealed acid-fast bacilli (Gaffky 7). His symptoms deteriorated even though he received anti-tuberculosis agents and CAM. After measurement of minimal inhibitory concentration (MIC), he was given amikacin (AMK). In both cases, the bacilli found in sputum obtained on admission were identified as M. chelonae subsp. abscessus by DNA hybridization. They were completely resistant to all anti-tuberculosis agents. However, the disk method show that they were sensitive to AMK, imipenem and CAM. The MIC value of those strains to CAM was 0.78 microgram/ml in case I and more than 100 micrograms/ml in case 2. The results obtained by MIC measurement were consistent with the clinical outcome. AMK, cefoxitin (CFX), and CAM had been used to treat M. chelouae subsp. abscessus in Europe, but the MIC value differed from strain to strain within a species. Thus the present data suggest that measurement of the MIC value of CAM would be necessary to predict its therapeutic effect.

Aged↗