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Biomedical subjects

T Ueno

Publications and source records attributed to T Ueno.

At least 361 records · Page 20Linked to original sources
PubMed1994

Total syntheses of (2S)-antafumicins A and B.

To clarify the absolute configurations of antafumicins A and B, which are antifungal substances from Aspergillus niger NH-401, the total synthesis of (2S)-antafumicins was accomplished by starting from (S)-malic acid in 12 steps. Based upon the physicochemical data of the synthetic samples, the absolute configurations of naturally occurring antafumicins A and B were determined as (2R,4S)- and (2R,4R)-4-(3-acetyl-2,6-dihydroxyphenyl)-2-methoxy-4-butanolide, respectively.

4-Butyrolactone↗
PubMed1994

Parabolic flight experiments on physiological data acquisition and processing technologies using small jet aircraft (MU300).

The parabolic aircraft flight provides a short low gravity environment for approximately 20 seconds, which may not be sufficient for a research on the physiological phenomenon induced by actual weightlessness in space. However, the method is still useful to reveal essential and characteristic feature of physiological signs, and is available for testing hardware and also training of crew member during altered gravity. This paper reports the summary of parabolic flight experiments recently conducted as a NASDA program (1990-1992). The program is providing opportunities in low gravity research with small jet aircraft for researchers and agencies. The flight experiments in the life science area have been conducted mostly focused on a physiological changes and basic methodology which may be effective under the altered gravity condition. In this study, the following research team, NASDA, Research Institute of Environmental Medicine, Nagoya University, Toyohashi University of Technology, Tokyo Metropolitan Hospital, Torey Research Center and JSUP were involved and coordinated for the research.

Aircraft↗
PubMed1994

[Effects of "low dose" aprotinin in open heart surgery and its plasma concentration].

To determine the effects of "low dose" aprotinin in open heart surgery, we administrated it in 109 cases of CABG or prosthetic valve replacement. Patients in Group A (Aprotinin) received continuous infusion of aprotinin at the rate of 6*10(5) KIU/hr from the induction of anesthesia to the start of ECC (extra corporeal circulation), and from the end of ECC to the end of blood stanching. They also received additional 5*10(5) KIU aprotinin in ECC prime volumes. 50 patients in Group C (Control) received neither aprotinin nor placebo. Bleeding after ECC (Group A: 315.7 +/- 203.1 ml, Group C: 484.3 +/- 598.5 ml p < 0.01), the first 6 hours drainage (Group A: 273.0 +/- 210.0 ml, Group C: 404.7 +/- 243.2 ml p < 0.01), the first 24 hours drainage (Group A: 510.2 +/- 248.0 ml, Group C: 721 +/- 317.7 ml p < 0.01) was significantly reduced in Group A. Amounts of homologous blood transfusion were significantly reduced in group A. (Group A: 4.7 +/- 5.3 units, Group C: 8.5 +/- 6.4 units p < 0.01). Among the patients with autologous blood transfusion, the rate of the patients without homologous transfusion was significantly higher in Group A (group A: 40/66 cases, Group C: 8/33 cases p < 0.01). The ECC time and the operation time was significantly shorter in Group A. There were 69 patients (Group A: 40, Group C: 29) whose ECC time was longer than 120 minutes.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Vibration exposure and prevention in Japan.

Working conditions of vibration exposure have generally improved, but many difficult problems must be solved such as (1) hygienic improvements in a variety of vibrating tools; (2) improving working conditions, for example, by limiting the time of operation in spite of economic difficulties such as those faced by those who work on a piece rate basis; (3) gathering more complete information about the risk population because of the large number of self-employed in informal employment sectors; and (4) finding work places after rehabilitation for patients, particularly in mountainous rural areas or in small scale industries. Historical observation of vibration and preventive measures in Japanese national forests was presented on the basis of the results of a retrospective cohort study in Kyushu, Japan. Prevalence rate of VWF remarkably changed from 58.4% in the groups that began to operate chain saws in 1960 to only a few cases in the groups who started the operation after 1971. When we compare the relationships between the results of long term cohort study and the consequences of preventive measures of vibration syndrome, the most important factor is the decrease of vibration exposure (improvement in chain saws plus the time restriction system). The comprehensive prevention system used in Japanese national forests consists of the following: (1) Health care system; (2) Work regulation system; (3) System for improving mechanized tools; (4) Warming system to protect against cold conditions; and (5) Education and training system.

Humans↗
PubMed1994

[A case of pneumonitis induced by PL granules].

We report a case of pneumonitis induced by PL granules. A 45-year-old man took PL granules and other drugs for fever and headache. Because he subsequently developed high grade fever, cough and diarrhea, he was admitted to our hospital. His chest X-ray film revealed multiple patchy shadows in both lung fields. Analysis of bronchoalveolar lavage fluid (BALF) disclosed a high number of cells (total), lymphocytes, and a high CD4/CD8 ratio. Microscopic examination of transbronchial lung biopsy (TBLB) specimens showed infiltration of mononuclear cells and thickening of the alveolar wall. After discontinuation of drugs, his condition (symptoms, laboratory data, and chest X-ray findings) promptly improved. Lymphocyte stimulation tests (LST) for PL granules and acetaminophen were positive and an oral challenge test with PL granules was also positive. Based on these findings, we diagnosed this as a case of pneumonitis and enteritis due to PL granules. To our knowledge, this is the first reported case of pneumonitis due to PL granules.

Acetaminophen↗
PubMed1994

[Aortic valve replacement in patients older than 75 years of age].

From 1988 to 1992, 16 patients older than 75 years underwent AVR (14 cases) or AVR+MVR (two cases). All patients were followed up for an average of 2.4 years after the operation and follow-up totaled to 38 patient-years. There were no hospital death and one late death. The survival rate was 93.8% through 1 to 5 years and 15 patients are now in NYHA class I or II. The problems of AVR for elderly patients were calcification and small annulus. Decalcification using CUSA was effective technique and supraannular fixing of bioprosthetic valve avoided from aortic annular enlargement. The improved quality of life after AVR supports the aggressive surgery in elderly population.

Aged↗
PubMed1994

[Two fibrinopulurent empyema cases--treatment with early mini-thoracotomy and transcatheter urokinase instillation].

We successfully treated two male patients with nontuberculous multiloculated empyemas by early mini-thoracotomy 3 and 6 weeks, respectively, after the onset of the disease. Transcatheter urokinase instillation facilitated drainage of a hemorrhagic loculated pleural collection in one patient after the operation. We believe that these treatments are less invasive and more effective than standard methods in providing early and complete resolution fibrinopurulent empyema in patients in whom this disorder might become chronic.

Aged↗
PubMed1994

Protection against spinal cord ischaemia: one-shot infusion of hypothermic solution.

The protective effect of a one-short infusion of a range of low-temperature hypothermic solutions against spinal cord ischaemia was investigated. Forty rabbits were allocated into five groups each of eight animals. The abdominal aorta of each rabbit was clamped distal to the left renal artery, and also occluded for 30 min above the iliac bifurcation with an inflated 50-gauge French balloon catheter. Ringer's solution with lactate was infused through the catheter port distal to the balloon, at various temperatures (group I, uninfused control; group II, 33 degrees C; group III, 23 degrees C; group IV, 13 degrees C; and group V, 3 degrees C). The neurological status of the hind limbs was assessed on the second postoperative day using the criteria of Tarlov. A further eight rabbits underwent laminectomy at L2 or L3. Temperature probes were inserted into the spinal cord and the cord temperature monitored continuously during infusion in four rabbits from each of groups I and V. Spastic paraplegia occurred in five rabbits in group I, three in group II, and two in group III. Four rabbits in groups II and III, seven in group IV and all eight in group V showed complete recovery of neurological function. The infusion of 3 degrees C solution achieved significantly lower spinal cord temperatures in group V after aortic clamping, compared with the temperatures in group I (P < 0.001-0.005). It was concluded that protection against spinal cord ischaemia and prevention of postoperative paraplegia are promoted as the temperature of the hypothermic infusion solution is lowered.

Animals↗
PubMed1994

[A surgical treatment of ruptured arch aneurysm].

A 83-year-old woman was admitted to our hospital because of back pain and shock. Her chest X-ray and CT scan demonstrated a large arch aneurysm and hemothorax, suggesting ruptured aortic arch aneurysm. The ruptured aortic arch aneurysm was replaced with a woven Dacron graft under selective cerebral perfusion (SCP). Her postoperative course was uneventful without any neurological deficits. For the past three years, we have utilized SCP in 12 cases of arch aneurysms. There were three early deaths in this series. The cause of death were bleeding in one patient and cerebral accident in two patients. The latter two patients had severe atheromatous changes in the aortic wall. The SCP technique was a useful method of cerebral protection, especially for elderly patient with aortic arch aneurysm.

Aged↗
PubMed1993

Retinoic acid induces insulin-like growth factor II expression in a neuroblastoma cell line.

Insulin-like growth factor II (IGF-II) is implicated in the development of the vertebrate neural circuitry, and increases neurite growth in vitro and in vivo. We examined the relationship of IGF-II expression to the in vitro differentiation induced by retinoic acid (RA). We find that RA stimulates an increase in IGF-II messenger RNA (mRNA) in the SK-N-SH (SH) neuroblastoma cell line. An increase of IGF-II mRNA is detected within 12 h of treatment and precedes morphological differentiation. A RA dose response test indicates that an increase in IGF-II mRNA occurs within 2 days in SH cells treated with doses of RA from 1 x 10(-8) to 1 x 10(-5) M. We suggest that IGF-II expression may be regulated either directly or indirectly by RA in vitro and may lead to neuroblastoma differentiation.

Cell Differentiation↗
PubMed1993

Gene structure and expression of the MboI restriction--modification system.

The genes from Moraxella bovis encoding the MboI restriction--modification system were cloned and expressed in Escherichia coli. Three open reading frames were found in the sequence containing the genes. These genes, which we named mboA, mboB, and mboC, had the same orientation in the genome. Genes mboA and mboC encoded MboI methyltransferases (named M.MboA and M.MboC) with 294 and 273 amino acid residues, respectively. The mboB gene coded for MboI restriction endonuclease (R.MboI) with 280 amino acid residues. Recombinant E.coli-MBOI, which contained the whole MboI system, overproduced R.MboI. R.MboI activity from E.coli-MBOI was 480-fold that of M.bovis. The amino acid sequences deduced from these genes were compared with those of other restriction--modification systems. The protein sequences of the MboI system had 38-49% homology with those of the DpnII system.

Amino Acid Sequence↗
PubMed1993

Cyclic flow variations in a conscious dog model of coronary artery stenosis and endothelial injury correlate with acute ischemic heart disease syndromes in humans.

OBJECTIVES: The purpose of this study was to test the hypothesis that episodes of cyclic flow variations (CFVs) in conscious dogs with coronary stenoses and endothelial injury correlate with acute ischemic heart disease syndromes in humans. BACKGROUND: Although the canine model with CFVs has proved to be a useful model of coronary thrombosis, whether CFVs progress to these syndromes has not been clearly described. METHODS: Cyclic flow variations were produced by an external constrictor placed at the site of the left anterior descending coronary artery with injured endothelium. Blood flow in this artery and 24-h Holter electrocardiogram (ECG) were recorded during the 1st 5 postoperative days. RESULTS: Of 41 dogs that underwent the initial operative procedure successfully, 29 developed an episode of CFVs. In five dogs in which CFVs persisted throughout the monitoring period, the left anterior descending coronary artery flow decreased until day 3 and thereafter increased through day 5. Transient coronary occlusion during CFVs induced ST segment changes that returned to baseline after reflow. In 12 dogs, CFVs progressed to persistent coronary occlusion, and histologic examination revealed thrombus formation at the stenotic site and evidence of myocardial infarction. Four of these 12 dogs died suddenly of ventricular arrhythmias during persistent coronary occlusion; another 5 dogs died of reperfusion arrhythmias during CFVs with no evidence of myocardial infarction. CONCLUSIONS: Conscious dogs with CFVs closely correlated with clinical acute ischemic heart disease syndromes, suggesting them to be a useful model for investigating the complex mechanisms of cellular interactions in the pathogenesis of these syndromes.

Animals↗