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Biomedical subjects

O Katoh

Publications and source records attributed to O Katoh.

At least 109 records · Page 6Linked to original sources
PubMed1989

[Susceptibility of clinical isolates to aztreonam].

In vitro antibacterial activities of 9 antibiotics including aztreonam (AZT) against clinically isolated Gram-negative bacteria were determined using MIC-2000 plus system. Bacteria were isolated from clinical materials in Saga Medical School during a period from May 1987 to March 1988. Summarized results were as follows: 1. AZT showed excellent antibacterial activities against Escherichia coli, Klebsiella pneumoniae, Proteus sp. and Haemophilus influenzae, and MIC80 values of AZT against these organisms were lower than 0.20 microgram/ml. 2. Antibacterial activities of AZT were superior to cephem antibiotics compared against Enterobacter aerogenes, Enterobacter cloacae, Citrobacter freundii and Serratia marcescens. 3. The MIC50 and MIC80 of AZT against Pseudomonas aeruginosa were 12.5 micrograms/ml and 25 micrograms/ml, respectively. 4. AZT did not show any antibacterial activity against Acinetobacter sp. and Xanthomonas maltophilia.

Acinetobacter↗
PubMed1989

Biological significance of the hst-1 gene.

hst-1, or HSTF1 in human gene nomenclature, was originally identified as a transforming gene in DNA samples from human stomach cancer by NIH3T3 transfection assay. Many reports have followed to show the presence of a transforming hst-1 gene in various types of cancerous and noncancerous tissues, suggesting that the hst-1 gene is the most common non-ras transforming gene. We cloned the hst-1 genomic fragments from DNAs of a normal individual and a patient with leukemia and also from NIH3T3 cells themselves. All of these clones transformed NIH3T3 cells upon transfection. Sequence analysis of the cDNA and genomic hst-1 led us to conclude that the normal hst-1 protein transforms NIH3T3 cells when its expression is deregulated. The hst-1 protein has 40-50% homology to basic and acidic fibroblast growth factors (FGFs) and to the int-2 protein. The purified hst-1 protein synthesized in a baculovirus system was a potent heparin-binding growth factor for a variety of cells, including human endothelial cells. The hst-1 protein, when it was added to the culture medium, induced morphological transformation of NIH3T3 cells and anchorage-independent growth of NRK cells. The hst-1 gene is located 35 kbp downstream of one of its homologous genes, int-2, on human chromosome 11 at band q13.3. As in the case with the int-2 gene, the hst-1 transcripts were not detected in adult mice but found in mouse embryos. A relatively large amount of the hst-1 message was present in a mouse teratocarcinoma cell line, F9, while the int-2 mRNA was barely detected. Upon induction of differentiation in vitro, the hst-1 transcription was depressed to almost nil, and the int-2 message increased dramatically. The hst-1 and int-2 genes were coamplified in a variety of cancer cells, most notably in more than 50% of esophageal cancers.

Animals↗
PubMed1989

[A pancreatico-bronchial fistula with right hydropneumothorax].

A 39-year-old heavy drinker was admitted to Saga Medical School Hospital on February 21th, 1987. He had suffered from dyspnea, chest pain and lumbago three weeks prior to admission. His chest X-ray showed right hydropneumothorax and right lower lobe atelectasis and his CT scan showed a cystic lesion in the mediastinum. His laboratory data showed a high level of amylase in serum, urine and pleural effusion. A fistula connecting the pancreas to right pleural cavity was demonstrated by endoscopic retrograde cholangiopancreatography (ERCP). In addition, bronchoscopy showed complete obstruction of the right lower bronchus (B7). These bronchoscopic findings and hydropneumothorax on his chest X-ray suggested the leakage of pancreas juice through the pancreatico-pleural fistula injured the lung tissue directly and produced a bronchopleural fistula. In this case, hyperalimentation and drug therapy using protease inhibitor resulted in successful closure of the fistula and reexpansion of the collapsed lung.

Adult↗
PubMed1989

Progression activity for platelet-derived growth factor in plasma of patients with idiopathic thrombocytopenic purpura and aplastic anemia.

Progression activity for competence induced by platelet-derived growth factor (PDGF) was measured in plasma of patients with idiopathic thrombocytopenic purpura (ITP) and aplastic anemia (AA), in order to clarify the mechanism operating to maintain the wound healing system of these chronically thrombocytopenic patients. Progression activity in both ITP and AA patients was significantly higher than in normal subjects. There was a positive correlation between the activity and the duration of thrombocytopenia in AA patients who had thrombocytopenia for less than 100 months. The level of insulin like growth factor-I (IGF-I), which is a progression factor for PDGF, was lower in patients, than in normal controls. These results suggest that some plasma progression factor(s) for PDGF, other than IGF-I, plays an important role in maintaining the wound healing system of blood vessels in chronically thrombocytopenic patients.

Adolescent↗
PubMed1989

[The usefulness of preoperative exercise stress myocardial single photon emission CT with thallium-201 to predict the responses to coronary revascularization].

To evaluate the usefulness of preoperative exercise stress (Ex) myocardial single photon emission CT (SPECT) with thallium-201 to predict the responses to coronary revascularization (CRV), Ex-SPECT's were obtained in 42 patients with coronary artery disease (CAD). In 34 patients angioplasty was performed and in 18 patients coronary bypass surgery was undergone. Before and after CVR, Ex-SPECT's were obtained both at immediately after Ex (Initial) and 3 hours later (RD) by the rotating gamma camera. Initial images before CRV showed definite perfusion defects (+3) in 76 myocardial segments. Perfusion abnormalities at RD images were graded into 4 (+3 to 0) by visual interpretation. "+3" indicated fixed defect and "0" indicated no perfusion abnormality. At RD images 17 segments showed fixed defect and 59 segments showed improved perfusion more than one grade. After CRV, all 59 segments with improved perfusion at RD images showed improvement of perfusion in comparison with initial images before CRV. Out of 17 segments with fixed defect before CRV, 14 segments showed perfusion defect with +3, while 3 segments showed improved perfusion after CRV. These 3 segments had ECG evidence of myocardial infarction. In these 3 segments, Ex-SPECT's before CRV showed abnormally low myocardial T1 washout rate (WOR) despite they indicated fixed defect visually. On the contrary, other 14 segments with fixed defect showed normal WOR before CRV. In conclusion, visually interpreted Ex-SPECT's before CRV predict the myocardial perfusion after CRV in most of cases.2+n a small

Adult↗
PubMed1988

Differential expression of two homologous and clustered oncogenes, Hst1 and Int-2, during differentiation of F9 cells.

HST1 (or HSTF1 in human gene nomenclature) transforming gene encodes a novel heparin-binding growth factor which has 40-50% homology with fibroblast growth factors and mouse Int-2 protein. Expression of mouse Hst1 or Int-2 is rare in adult tissues, but both of them are transcribed in embryos. We found that mouse Hst1 and Int-2, like their human counterparts, were located close to each other on the genome: the distance was less than 20 kbp. Hst1 was expressed in an undifferentiated mouse teratocarcinoma cell line, F9. Upon induction of differentiation of F9 cells, the amount of Hst1 transcript was markedly decreased, while that of Int-2 transcripts increased concomitantly.

Animals↗
PubMed1988

Two homologous oncogenes, HST1 and INT2, are closely located in human genome.

Pulsed field gel electrophoresis and Southern blot analysis showed that the human oncogenes, HST1 and INT2, which code for proteins homologous to fibroblast growth factors, are less than 45 kb apart on the long arm of chromosome 11. Moreover, analysis of two overlapping cosmid clones, one containing INT2 and the other HST1 sequences, showed that HST1 is located about 35 kb downstream of INT2 in the same transcriptional orientation. The observed close proximity of the INT2 and HST1 genes may provide important insight on the origin and regulation of expression of these related genes.

Blotting, Southern↗
PubMed1988

Platelet-derived growth factor is decreased in patients with myeloproliferative disorders.

Platelet-derived growth factor (PDGF) has been suggested to play some role in the pathogenesis of myelofibrosis frequently encountered in patients with myeloproliferative disorders (MPD). In this study we measured PDGF activity and PF4 content in circulating platelets of patients with MPD. Both factors were lower than those of normal controls. PDGF activity in patients with myelofibrosis was slightly lower than in those without fibrosis. However, when adjusted to whole blood volume, there was a positive correlation between platelet count and PDGF activity per ml whole blood. Nevertheless, no correlation was found between activity and grade of bone marrow fibrosis. These results may support the idea that an abnormal release of PDGF occurs from platelets or megakaryocytes in the bone marrow environment, resulting in the stimulation of fibroblast proliferation, and hence, the occurrence of myelofibrosis in patients with MPD.

Adult↗
PubMed1988

Effects of platelet derived growth factor, epidermal growth factor and transforming growth factor-beta on the growth of human marrow fibroblasts.

The effects of three growth factors contained in platelets on human bone marrow fibroblasts as well as fibroblast colony-forming cells were investigated to clarify the pathogenesis of marrow fibrosis frequently associated with myeloproliferative disorders. Two growth factors, platelet derived growth factor (PDGF) and epidermal growth factor (EGF), cooperatively stimulated the growth of passaged fibroblasts as well as fibroblast colony-forming cells. Transforming growth factor-beta augmented the growth of fibroblasts at low concentrations in the presence of EGF and/or PDGF, but inhibited that of colony-forming cells in the presence of PDGF or EGF. These results suggest that the growth of fibroblasts causing marrow fibrosis might be finely regulated, depending on the concentrations of growth factors released or leaked from platelets or megakaryocytes into marrow environment.

Adult↗
PubMed1988

Marrow fibroblasts from patients with myeloproliferative disorders show increased sensitivity to human serum mitogens.

The growth of marrow fibroblasts from patients with myeloproliferative disorders (MPD) was investigated using platelet derived growth factor (PDGF) and human serum as mitogens in the presence of human plasma derived serum. The proliferation of fibroblasts in MPD patients was increased compared to normal individuals, especially in patients with chronic myelocytic leukaemia and essential thrombocythaemia. This increment of proliferation might be due to higher sensitivity of the fibroblasts to plasma derived serum than to PDGF, because the ratio of proliferation with PDGF to that without PDGF, when compared between patients and normals, remained unchanged. These results suggest that MPD fibroblasts are more sensitive to some factor(s) in plasma, and this fact could partially explain the pathogenesis of myelofibrosis in MPD patients.

Adult↗
PubMed1988

The role of intracoronary thrombus in unstable angina: angiographic assessment and thrombolytic therapy during ongoing anginal attacks.

Intracoronary thrombus is regarded as a potentially important factor in the etiology of unstable angina, but the incidence of intracoronary thrombus in unstable angina has not been clearly defined. To determine the occurrence of intracoronary thrombus during ongoing angina pectoris, coronary angiography was performed during spontaneous ischemic attacks in 37 patients with prolonged rest angina. All patients exhibited significant (greater than 50%) stenoses of at least one major coronary artery. Of the 37 patients, 21 (57%) had intracoronary thrombus in major coronary arteries, whereas 14 (38%) had fixed narrowings without evidence of intracoronary thrombus and two exhibited coronary spasm. ST segment elevation was observed in 16 of 21 patients with thrombus and in all of the patients with coronary spasm, but all the patients with organic stable obstruction showed ST segment depression. Twenty of the 21 patients with thrombus improved after thrombolytic therapy with intracoronary injection of urokinase; obstructed arteries were reopened, or narrowings were attenuated, with relief of ischemic symptoms. In patients with fixed obstructions, the rate-pressure product during active symptoms was significantly higher than during an asymptomatic period, indicating that a transient increase in myocardial oxygen demand may contribute to the ischemic attack in these patients. A high incidence (71%) of recurrent symptoms was observed in patients with intracoronary thrombus even after successful thrombolysis, in contrast to a much lower incidence (36%) in those without intracoronary thrombus. Myocardial infarction within 4 weeks after catheterization was observed more frequently in patients with intracoronary thrombus (24%) than in those without thrombus (7%).(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1987

Immediate and long-term prognoses of acute myocardial infarction: analysis of determinants of prognosis.

In order to investigate the immediate and long-term prognoses of acute myocardial infarction, we followed up 790 consecutive patients who were admitted to the Sakurabashi Watanabe Hospital within 24 hours after the onset of infarction from January 1975 to December 1984 and evaluated early mortality, cumulative survival rate after discharge, cause of death and occurrence of recurrent myocardial infarction during follow-up. Early mortality (within 30 days after the onset) in all patients was 17.6% and declined serially in the most recent five years. Pump failure was the most common cause of death, followed by cardiac rupture and arrhythmias. Age, gender (female), presence of a previous infarct and anterior infarction were important contributing factors to the immediate prognosis. One hundred and thirty-five of the 651 patients who survived one month after the onset of infarct died during the follow-up period (mean follow-up interval: 41.0 +/- 29.9 (SD) months). Cumulative survival rates calculated by the life-table method at one and 5 years after the onset were 91.0% and 76.0%, respectively, and the average annual mortality in the first 5 years was 4.8%. Age and reinfarction were the important determining factors of long-term prognosis. Recurrent myocardial infarction, pump failure and sudden cardiac death were common causes of late death. One hundred and two reinfarctions in 93 patients occurred during the follow-up period. Thirty-two of 93 patients (34.4%) died due to fatal reinfarction. These results indicate that the immediate prognosis of acute myocardial infarction has improved serially, but the long-term prognosis is still poor.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗