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Biomedical subjects

Y Taguchi

Publications and source records attributed to Y Taguchi.

At least 19 recordsLinked to original sources
PubMed1992

Histamine N-methyltransferase from rat kidney. Cloning, nucleotide sequence, and expression in Escherichia coli cells.

Complementary DNA clones encoding rat kidney histamine N-methyltransferase have been isolated using synthetic oligonucleotide probes based on partial amino acid sequences of tryptic peptides of the purified enzyme. The 1.3-kilobase cDNA consisted of a 5'-noncoding region of 8 nucleotides, a coding region of 885 nucleotides, and a 3'-noncoding region of 369 nucleotides. The encoded protein of 295 amino acid residues had a calculated molecular weight of 33,940.2. After introduction of a prokaryotic expression vector containing the isolated cDNA, Escherichia coli cells expressed histamine N-methyltransferase activity. The enzyme expressed in these cells was isolated and purified as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, whose mobility was identical to the natural enzyme purified from rat kidney. The recombinant enzyme had Vmax and Km values for both histamine and S-adenosylmethionine identical to those of the natural enzyme. All of the inhibitors of the natural enzyme tested showed similar Ki values on both recombinant and natural enzyme.

Amino Acid Sequence↗
PubMed1992

Construction and characterization of a fusion protein with epidermal growth factor and the cell-binding domain of fibronectin.

An efficient expression system was constructed for C-EGF, a fusion protein made of a fragment of the cell-binding domain of human fibronectin (FN) bound with epidermal growth factor (EGF). C-EGF was produced in Escherichia coli HB101 cells carrying the recombinant plasmid pCE102 as inclusion bodies, which were solubilized and refolded after purification. C-EGF had both cell-adhesive and EGF activities, so it might be more effective than EGF in therapeutic applications. This fusion system would be useful for the construction of a recombinant drug delivery system for cells that have fibronectin receptors (integrins).

Cell Adhesion↗
PubMed1992

Comparative study of magnetic resonance and CT scan imaging in cases of severe head injury.

The distribution, frequency, and appearance of head injuries were evaluated with MRI and CT in a prospective study of 155 patients with acute (n = 124) and chronic (n = 31) head injuries. MRI was significantly more sensitive than CT in the detection of intraaxial injury at any stage. In severe cases, central structure lesions were detected in approximately 80% of patients. Severity on admission was compatible with MR findings. However it was difficult to decide on neurobehavioural prognosis from initial MRI findings only.

Adolescent↗
PubMed1992

Progress in primary immunodeficiency.

Clinically, primary immunodeficiencies can be grouped into several well-defined syndromes. This consistent clinical picture, however, belies the enormous complexity of lymphocyte maturation and activation, and it has long been suspected that numerous distinct underlying defects give rise to primary immunodeficiencies. At a recent workshop, the molecular and genetic characterization of a handful of such defects provided tacit support for such suspicions.

Adenosine Deaminase↗
PubMed1992

Assessment of liver graft function after cold preservation using 31P and 23Na magnetic resonance spectroscopy.

We investigated the functional damages of the cytoplasm and the cell membrane of liver grafts in male Wister Kyoto rats after 24-hr and 48-hr cold preservations using the University of Wisconsin solution in vitro. Fructose (10 mM) or NH4Cl (50 mM) was added to the perfusate, and synthesis of fructose-1-phosphate (F-1-P) and Na- and H-ion transports through the cell membrane were evaluated by magnetic resonance spectroscopy (MRS), 31P-MRS and 23Na-MRS. After 30 min of reperfusion, beta-ATP/(inorganic phosphate: Pi) of the 48-hr preserved group was significantly lower than the control group and the 24-hr preserved group. The changes of F-1-P in the control group and the 24-hr preserved group were almost the same, but F-1-P synthesis was lower in the 48-hr preserved liver than those of the other groups. Intracellular pH began to drop after the cessation of NH4Cl loading, and then it recovered to the preloading level. At the same time Nain+ was increased in the control group. However, in the other two groups, the increasing rates of Nain+ were lower, and the recoveries of Nain+ were less. In conclusion, the function of cell membrane was more fragile than that of mitochondria and cytoplasmic sugar metabolism in the liver graft.

Adenosine Triphosphate↗
PubMed1992

Primary immunodeficiency diseases and Epstein-Barr virus-induced lymphoproliferative disorders.

Increased incidence of malignant disorders is noted in patients with both primary and acquired immunodeficiency diseases. The pathogenetic mechanism(s) for these disorders remain unclear. Defective immunosurveillance of these patients, however, is mainly postulated to be responsible for the increased risk of these malignant disorders. Of the malignant disorders, Epstein-Barr virus (EBV)-induced lymphoproliferative disorders (LPD) have been increasingly reported, possibly due to improved therapeutic management techniques such as bone marrow transplantation, which results in prolonged survival periods for the primary immunodeficiency; the dramatic development of immunosuppressive treatments for transplant recipients; and the growing numbers of acquired immunodeficiency syndrome (AIDS) patients. This review focuses on the primary immunodeficiency diseases and EBV-induced LPD, and discusses pathogenetic mechanism(s) for the increased incidence of these malignant disorders.

Adolescent↗
PubMed1992

[Culture-positive Legionella pneumonia in Japan, 1980-1990. Working Party for Legionellosis, Japanese Ministry of Health and Welfare].

The Working Party for Legionellosis headed by the Japanese Ministry of Health and Welfare processed to standardize the diagnostic procedures for Legionella pneumonia, as the first step to clarify the actual occurrence of patients with this respiratory disease. All the clinical data were collected and analysed on the 28 culture-confirmed patients in Japan during the past 11 years, from 1980 through 1990. The 28 patients were distributed throughout Japan, from Hokkaido to Kyushu. Out of 28 patients, 18 were community-acquired and 10 were nosocomially infected. In 8 of 18 community-acquired patients, any significant underlying disease was not observed. Though it was dominant in the age group in their 60s & 70s, victims were distributed in adults over 20 years of age and even in a new born baby. Only 5 out of 28 patients recovered successfully. From the autopsy findings, in 5 out of the remaining 23 expired patients, Legionella pneumonia seemed to be successfully treated, but other disease or other bacterial pneumonia put an end to the patients. The results of clinical laboratory tests and the efficacy of antibiotics to Legionella pneumonia were essentially the same as those reported in the literature.

Adult↗
PubMed1992

[Analysis of chest radiographs of culture positive Legionella pneumonia in Japan, 1980-1990. Working Party for Legionellosis, Japanese Ministry of Health and Welfare].

We analyzed the initial and follow-up chest radiographs of 28 patients with culture-positive Legionella pneumonia, and developed a scoring system to quantitate the severity of radiological findings for pneumonia. Intrapulmonary shadows were observed on the initial chest radiograph in 26 patients, but pleural effusion was noted in only one. In one patient the initial chest radiograph had probably been obtained too early to reveal any pulmonary change. Alveolar shadows were noted on the initial radiograph in 21 (81%) patients, and interstitial shadows in 5 (19%). In ten (38%) patients shadows were present in both lung fields. Shadows were prominent in the middle and lower lung fields. A cavity was noted in only one patient, and pleural effusion was also noted at some time during the clinical course in 19 (70%). A large amount of pleural effusion was observed in four patients. The average pneumonia severity score was 3.3 in the 9 patients who survived, and 5.1 in the 17 who died (p > 0.05). The mortality rate was 53% in the 17 patients with pneumonia severity score of 5 or less and 89% in the 9 patients with a score of 6 or more (p > 0.05). Twelve patients died within one week after the initial chest radiograph was obtained. There were no differences among patients with community-acquired infection with or without underlying disease and those with nosocomial infection in characteristic and extension of shadow, presence of pleural effusion, or pneumonia score. The chest radiograph of Legionella pneumonia include bilateral shadow findings characteristic, pleural effusion and rapid progression of shadow, and are clinically useful for diagnosis.

Adolescent↗
PubMed1992

Clinical significance of late potentials in patients after intracardiac operation for congenital heart disease.

The aim of this study was to evaluate the late potentials (LPs) in postoperative patients with congenital heart disease (CHD) and to study the association with the clinical characteristics in the postoperative patients with LPs. Signal averaged electrocardiogram (SA-ECG) was recorded in 119 postoperative patients aged 4 to 23 years and compared with those in age matched 49 healthy volunteers with and without right bundle branch block. Based on control data, criterias of LP were defined and altered in the presence of bundle branch block. Abnormal SA-ECGs were not detected in the patients with non-cyanotic CHD. However, abnormal and borderline SA-ECGs were recognized in 5 (12%) of 42 patients after intracardiac operation for tetralogy of Fallot and 3 (30%) of 9 patients after Rastelli's operation. The patients with abnormal and borderline SA-ECGs were significantly older at the time of operation, and had more frequent ventricular arrhythmias (7/8: 3/111, p less than 0.01) and depression of the ST-T segment on ECG (7/8: 11/111, p less than 0.01), compared with the normal SA-ECG group. Abnormal SA-ECGs including those of borderline patients were 50% sensitive and 96% specific for documented ventricular arrhythmias. However, there was no association between abnormalities of SA-ECGs and cardiomegaly on chest X-ray or left ventricular ejection fraction on echocardiogram. These results indicate that prolonged exposure to hypoxia may be the main cause of the primary role in the development of LPs. And late surgical intervention may result in histological background for the development of LPs.

Action Potentials↗
PubMed1992

Effects of inhibitors of protein kinase C on the release and synthesis of histamine in rat basophilic leukemia cells (2H3).

In rat basophilic leukemia cells (2H3), a tumor analog of mast cells, the aggregation of IgE receptors results in histamine secretion and the increase in histidine decarboxylase activity which synthesizes histamine. Using inhibitors of protein kinases C, we studied the relationships between these events and protein kinase C which is activated by antigens. Histamine release is suppressed by inhibitors of protein kinase C, staurosporine, K252-a and H-7, in this decreasing order of effectiveness; and the IC50 values are 1.5 nM, 29.9 nM and 3.8 microM, respectively. The changes in the intracellular Ca concentration monitored by fura-2 fluorescence is not modified by staurosporine, although the histamine response is suppressed. Meanwhile, the increase of histidine decarboxylase was abolished by inhibitors of protein kinase C; staurosporine was the strongest, K-252a of moderate activity and H-7, the weakest, having IC50 values of 0.8 nM, 100 nM and 11.5 microM, respectively. The inhibitors of protein kinase C suppress both histamine secretion and synthesis. Therefore, the histamine synthesis may be stimulated via activation of protein kinase C to supplement the released histamine.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1992

[Abnormalities in the signal-averaged electrocardiogram in Ebstein's anomaly].

Abnormalities in the signal-averaged electrocardiogram (SAECG) of patients with Ebstein's anomaly were studied. A SAECG was obtained in 4 patients with Ebstein's anomaly, aged 3 to 25 years. The control groups included 8 patients with atrial septal defect (ASD group), 10 with right bundle branch block (RBBB group), 8 with Wolff-Parkinson-White (WPW) syndrome (WPW group), and 40 normal subjects (Normal group). The SAECG was calculated by the vector-magnitude method using the VCM-3000. The root-mean-square during the initial 20 msec of the filtered QRS (i-RMS) was very small in 2 older patients with Ebstein's anomaly compared to the ASD group, the RBBB group and the Normal group, and was as small as that in the WPW group. This probably was affected by the delta wave associated with Ebstein's anomaly or concealed accessory pathway. The root-mean-square during the terminal 40 msec of the filtered QRS (t-RMS) was small in the patients with Ebstein's anomaly and the RBBB group. Two patients with Ebstein's anomaly had a smaller t-RMS than the RBBB group, suggesting pathological changes of an atrialized right ventricle. In conclusion, SAECG is useful for evaluating patients with Ebstein's anomaly, especially older patients.

Adolescent↗
PubMed1992

[Proposal of a new classification of adult bronchial asthma--child onset asthma, adult onset asthma and adult relapse asthma. Project Team for Research into Adult Bronchial Asthma in Japan].

The first nationwide research into adult bronchial asthma in Japan proposed a new classification of adult asthma. Adult asthma was categorized into child onset asthma, adult onset asthma and adult relapse asthma. The frequency of child onset asthma, adult onset asthma and adult relapse asthma in adult asthma was 11.2%, 77.3% and 3.7%, respectively. The frequency of child onset asthma decreased markedly in the older age group. On the other hand, the frequency of adult onset asthma increased, and reached more than 90%, in the older age group. The frequency of the following factors: atopic asthma, complications with other atopic diseases, mild asthma, male patients, experience of mechanical ventilation, visits to night clinics and oxygen therapy on acute attack, was significantly higher in the child onset asthma group than in the adult onset asthma group. The frequency of infectious type, aspirin intolerance, steroid dependent asthma, severe asthma and regular medication was significantly higher in the adult onset asthma group. Adult relapse asthma seemed to fall between these two groups. Based on the above observations, we proposed a new classification of adult asthma which includes child onset asthma, adult onset asthma and adult relapse asthma.

Asthma↗
PubMed1992

[Mitochondrial energy synthesis during cold preservation and after reperfusion in liver transplantation].

In liver transplantation, primary graft nonfunction (PGN) occurred 5 to 10% in all cases. For preventing PGN it is necessary to elucidate a reliable assessment procedure for graft function before transplantation. In addition, methods of harvest or preservation which can maintain good viability of the graft are also needed. The purpose of this study is to clarify whether mitochondrial respiratory ratio (RCR), which is ability of ATP synthesis, is a reliable marker of the graft viability and whether a harvesting method with an artificial heart and lung is effective for keeping high energy synthesis of mitochondria or not. Pigs were used for this study. In a standard harvest method RCR decreased gradually during cold preservation. Grafts with values of RCR more than 3.0 had good function after transplantation. RCR depended on mitochondrial ATP, not tissue ATP. Grafts harvested with artificial heart and lung kept RCR more than 4.0 at 12 hours after preservation. Five of 6 pigs transplanted 12 hours preserved liver harvested from the donor with an artificial heart and lung survived more than 5 days. These results suggested that mitochondrial ATP synthesis has strong relation to PGN and RCR is a reliable marker for graft viability.

Adenosine Triphosphate↗