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Biomedical subjects

A Okano

Publications and source records attributed to A Okano.

At least 55 records · Page 3Linked to original sources
PubMed1999

A novel combretastatin A-4 derivative, AC-7700, shows marked antitumor activity against advanced solid tumors and orthotopically transplanted tumors.

AC-7700, a novel combretastatin A-4 derivative, suppresses the growth of solid tumors by inhibiting tumor perfusion. We evaluated the antitumor activity of AC-7700 on solid tumors in two experimental models, an advanced tumor model (murine colon 26 (c26) adenocarcinoma, colon 38 (c38) adenocarcinoma, MethA fibrosarcoma, Sarcoma 180 (S180), Lewis lung carcinoma (3LL), human LS180 adenocarcinoma) and an orthotopically transplanted tumor model (c26), compared with that of cisplatin (CDDP). The maximum tolerable dose (MTD) of CDDP suppressed early-stage c26 and c38 tumor growth when treatment was started after the tumor volume (TV) reached 0.2-0.5 cm3, but it showed reduced activity against the same tumors at an advanced growth stage when TV exceeded 2 cm3. At its MTD, AC-7700 was active against all tumors tested except 3LL in both early and advanced growth stages, reducing the tumor mass and having a curative effect in advanced c38 tumors. AC-7700 was also effective on orthotopically transplanted c26 tumors, showing a comparable activity to that on subcutaneous tumors. Unlike flavon acetic acid, which damages tumor vasculature by inducing endogenous tumor necrosis factor-alpha production, AC-7700 potently suppressed the growth of advanced c26 tumors in athymic as well as euthymic mice. These results suggest that AC-7700 is a novel antivascular agent that may have potent activity against advanced-stage cancer in the clinical setting.

Animals↗
PubMed1999

A dynamic change by 123I-15-(p-iodophenyl)-3-R,S-methyl pentadecanoic acid myocardial single photon emission computed tomography in a 55-year-old woman.

A 55-year-old woman was admitted to hospital with chest discomfort. Emergency angiography revealed no organic stenosis in the coronary artery, but there was akinesis in the apico-anteroseptal region of the left ventricle. Left ventriculography on the 5th day after admission was normal. On the 2nd day, initial imaging by 123I-15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) myocardial single photon emission computed tomography (SPECT) indicated a slight decrease in tracer uptake and delayed imaging revealed fill-in in the apicoanteroseptal regions in spite of akinesis in those areas. On the 4th day, initial imaging by 123I-BMIPP showed a moderate decrease in tracer uptake and delayed imaging revealed a high washout again in those areas. On the 12th day, initial imaging by 123I-BMIPP showed a severely reduced uptake in the apico-anteroseptal regions and delayed imaging disclosed a high washout, in the same areas that showed akinesis during the acute phase. On the 35th day, 123I-BMIPP identified no significant decrease in tracer uptake. It is suggested that these dynamic changes in 123I-BMIPP myocardial SPECT imaging may reflect the metabolic change of fatty acid in the ischemic state, the size and degree of turnover of the triacylglycerol pool.

Fatty Acids↗
PubMed1999

Acute liver injury that followed food-dependent exercise-induced anaphylaxis.

We describe an unusual case of acute liver injury that followed food-dependent exercise-induced anaphylaxis (FDEIAn). A 45-year-old man who experienced anaphylactic shock induced by postprandial exercise and took alcohol that night was admitted the following day to our hospital because of general fatigue. Laboratory examinations revealed elevated hepatic enzymes (aspartate aminotransferase (AST) 6,110 IU, alanine aminotransferase (ALT) 4,178 IU). He had two similar episodes in the past. We speculated that acute liver injury in this case might be induced by interaction of anaphylactic shock and alcohol.

Alcohol Drinking↗
PubMed1999

[The usefulness of 123I-BMIPP myocardial SPECT in diagnosis for silent myocardial ischemia induced by vasospasm].

This study was designed to evaluate the clinical usefulness of 123I-BMIPP myocardial SPECT in patients with silent myocardial ischemia induced by vasospasm. Ultrasonic echocardiography (UCG), Holter electrocardiogram recording (Holter ECG), exercise 201Tl myocardial SPECT (EX-Tl) and rest 123I-BMIPP myocardial SPECT (BMIPP) were performed in 8 patients with asymptomatic vasospasm without history of myocardial infarction. The sensitivity of each modality in detecting coronary artery spasm was 37.5% (3 of 8 cases) for UCG, 37.5% (3 of 8 cases) in Holter ECG, 25.0% (2 of 8 cases) in Ex-Tl, 62.5% (5 of 8 cases) on initial BMIPP images and 75.0% (6 of 8 cases) on delayed BMIPP images. Severity of regional left ventricular wall motion abnormality in UCG correlated with the severity of regionally decreased tracer uptake in BMIPP. The washout rate of BMIPP was 18.7 +/- 2.4 in normal controls, 32.4 +/- 5.9 in asymptomatic vasospasm, and 38.2 +/- 4.0 in asymptomatic vasospasm with abnormal left ventricular wall motion. It was suggested that 123I-BMIPP myocardial SPECT might be useful for assessing asymptomatic vasospasm.

Adult↗
PubMed1998

Ineffective use of a detachable snare for colonoscopic polypectomy of large polyps.

BACKGROUND: Colonoscopic polypectomy of large polyps may be associated with complications such as bleeding. Use of a detachable snare may reduce the risk of bleeding. We describe several instances in which the use of such a device proved to be ineffective. METHODS: A detachable snare was used for colonoscopic polypectomy of large polyps in 18 patients (20 polyps), also applied at the residual stalk after conventional polypectomy in 5 patients (5 polyps), and evaluated retrospectively. RESULTS: Sixteen of the 20 polyps were pedunculated, and 4 were semi-pedunculated. In 3 of the 4 semi-pedunculated lesions, the loop slipped off after polypectomy because the lesions were cut close to the site of encirclement. Bleeding occurred in 4 cases because of transection by the loop of a thin stalk (4 mm) before polypectomy (1), slipping of the loop in a semi-pedunculated lesion (1), or insufficient tightening of the loop (2). After conventional polypectomy, we could not effectively snare the residual stalk because of flattening in 3 of the 5 lesions. CONCLUSIONS: Use of the detachable snare for polypectomy of thin stalked or semi-pedunculated lesions may result in technical failure of this technique. The stalk should be fully encircled with the snare before polypectomy. The detachable snare is difficult to apply at the residual stalk after conventional polypectomy.

Aged↗
PubMed1998

Digital image in cardiology now and for the future.

Siemens has a logical stepwise approach and employs proven technology. Siemens historically remains focused on efficiently handling image data in the cardiac cath lab as evidenced by: the 1990 introduction of HICOR and timely introduction of ACOM in 1995 together with the extension of the DICOM 3 standard by ACC/NEMA. Today and into the future Siemens is building the strength with the powerful synergy developed between our medical division and computer division (Siemens Nixdorf) to assure even greater success with tomorrow's ACOM.net (Figure 3). Siemens statement: All HICORs can be upgraded with ACOM. All ACOMs can be interfaced to the ACOM net.

Cardiology↗
PubMed1998

Fibrolamellar carcinoma of the liver with a mixture of ordinary hepatocellular carcinoma: a case report.

Fibrolamellar carcinoma (FLC) of the liver is a rare variant of hepatocellular carcinoma (HCC), and only 13 cases have been reported in Japan up to 1997. We described a histologically unusual case of FLC. A 52-yr-old man was admitted to our hospital for work-up of hepatic mass. Laboratory examinations revealed no abnormalities except elevated serum alpha-fetoprotein (AFP) (2098 ng/ml). A diagnosis of HCC was made by imaging findings, and left lobectomy of the liver was performed. Histologically, the tumor was composed of areas of FLC mixed with ordinary HCC and those of pure ordinary HCC. Staining for AFP was positive in the HCC component and negative in the FLC component. Some cases of such mixed tumors have been reported in Europe and the United States, but not in Japan. We regarded our case as the first of the mixed tumor in Japan.

Biomarkers, Tumor↗
PubMed1998

Calcified pseudoaneurysm of the left ventricle.

Left ventricular pseudoaneurysm following acute myocardial infarction generally has an extremely poor prognosis without surgical repair. A rare case of long term survival for 23 years following cardiac rupture with subsequent development of a left ventricular pseudoaneurysm after acute myocardial infarction is reported. The patient suffered acute inferoposterior myocardial infarction in July 1974 at the age of 58 years. Clinical course and findings obtained on reassessment in 1992 (transesophageal echocardiography, chest computed tomography and left ventriculography) confirmed a left ventricular pseudoaneurysm. The patient refused surgical resection of the lesion, but remained alive and well in 1997 (81 years old). In this case, it is considered that containment of hemorrhage by pericardial adhesion prevented immediate tamponade and sudden death.

Aged↗
PubMed1998

[Usefulness of myocardial scintigraphy with 99mTc-tetrofosmin for diagnosis in 2 cases of acute coronary syndrome].

Patients with acute coronary syndrome require accurate diagnosis and treatment. We found that emergency myocardial scintigraphy with 99mTc-tetrofosmin was useful for diagnosis in 2 patients with acute coronary syndrome. The first patient was a 66-year-old man, who was hospitalized with chest discomfort at rest. Blood tests, electrocardiography, and echocardiography revealed no unusual findings. Myocardial scintigraphy with 99mTc-tetrofosmin disclosed moderately reduced uptake extending from the anterior wall to the apex. Coronary arteriography revealed 75% stenosis of the left main trunk. He was diagnosed as having unstable angina pectoris and coronary bypass surgery was performed. The second patient was a 61-year-old man, who was hospitalized with chest discomfort. Slight leukocytosis and flat T waves in leads V5 and V6 on electrocardiogram were detected, but echocardiographic findings were not abnormal. Myocardial scintigraphy with 99mTc-tetrofosmin revealed a defect in the posterolateral wall. Coronary arteriography showed total obstruction of #14, and a diagnosis of acute myocardial infarction was established. PTCA of #14 was performed to achieve reperfusion.

Aged↗
PubMed1997

Simultaneous activation of signals through gp130, c-kit, and interleukin-3 receptor promotes a trilineage blood cell production in the absence of terminally acting lineage-specific factors.

We assessed the biologic role of signaling through gp130, a signal-transducing receptor (R) component, in human hematopoiesis in vitro. Although peripheral blood-derived CD34(+) cells ubiquitously expressed gp130 and interleukin-3 receptor alpha (IL-3Ralpha), IL-6Ralpha was only detected on 80% of these CD34(+) cells. We sorted CD34(+)IL-6R+ or CD34(+)IL-6R- cells and studied the effect on hematopoietic colony formation of signaling through gp130 activated by IL-6 or a combination of IL-6 and recombinant soluble human IL-6R (sIL-6R) in the presence or absence of stem cell factor (SCF ) and/or IL-3. Signals activated by SCF, IL-6, or IL-6/sIL-6R complex alone did not induce significant colony formation. However, a combination of IL-3, SCF, and IL-6/sIL-6R complex dramatically induced many neutrophil (colony-forming unit-granulocyte [CFU-G]), erythroid burst (burst-forming unit-erythrocyte [BFU-E]), erythrocyte-containing mixed (CFU-Mix), and megakaryocyte (CFU-Meg) colony formations when CD34(+)IL-6R- cells were used as the target. CFU-G colony formation induced by the three signals was more evident when CD34(+)IL-6R+ cells were used as the target. This distinct synergistic effect of the three different signals was confirmed by single-cell clone-sorting experiments. Moreover, colony formation (including CFU-G, BFU-E, CFU-Mix, and CFU-Meg) was observed even in the presence of neutralizing antibodies for granulocyte colony-stimulating factor, erythropoietin, and thrombopoietin (c-Mpl), whereas neutralizing antibodies for gp130, IL-6R, IL-3, and SCF partially or completely blocked the synergistic effect. The maturation of neutrophilic, erythroid, and megakaryocytic cells supported by the three signals in serum-free cultures was confirmed by immunostaining using anti-CD66b, antiglycophorin A, antihemoglobin alpha, and anti-CD41 monoclonal antibodies, respectively. In contrast, any two of the three signals were insufficient for effective blood cell production in the absence of maturation factors. These results suggest that simultaneous activation of the three signals through gp130, c-kit, and IL-3R can induce in vitro proliferation and differentiation of trilineage hematopoietic progenitors in the absence of terminally acting lineage-specific factors.

Animals↗
PubMed1997

An increase in peripheral blood progenitor cells in primates by coadministration of recombinant human interleukin 6 and recombinant human granulocyte colony-stimulating factor.

BACKGROUND: We recently demonstrated that coadministration of recombinant human interleukin 6 (rhIL-6) and recombinant human granulocyte colony-stimulating factor (rhG-CSF) in mice synergistically increases peripheral blood stem cells (PBSC), which can rescue lethally irradiated recipient mice. However, there is little information about the effect of coadministration of rhIL-6 and rhG-CSF on PBSC in a primate system. METHODS: In cynomolgus monkeys, rhG-CSF (5 microg/kg day) alone was administered for 5 days (first cycle). After the wash-out period, rhIL-6 (0, 10, or 20 microg/kg/day) and rhG-CSF were coadministered for 5 days (second cycle). RESULTS: Total peripheral colony-forming cells levels were increased earlier by coadministration of rhIL-6 and rhG-CSF than by the administration of rhG-CSF alone. The maximum level in the coadministration cycle was obtained on day 5, and a high level was obtained for a further 3 days after cessation. The maximum number of peripheral total colony-forming cells in the coadministration cycle was a mean of 2.12-fold (range 1.38 to 3.35) higher than that in the rhG-CSF alone cycle. Coadministration also increased the peripheral mixed colony-forming units by a mean of 3.62-fold (range 1.02 to 5.52). Interestingly, monkeys that showed a low response to the administration of rhG-CSF alone also had a higher response to the coadministration. No significant difference was observed between the two cycles of administration of rhG-CSF alone. CONCLUSIONS: These findings suggest that coadministration of rhIL-6 and rhG-CSF may be useful for clinical PBSC collection.

Alkaline Phosphatase↗
PubMed1997

Negative strand of hepatitis C virus RNA in the liver of patients with chronic hepatitis C after interferon treatment.

In patients receiving interferon therapy for chronic hepatitis C, serum hepatitis C virus (HCV) RNA often reverts from an undetectable to a detectable form after completion of treatment. Detection of the negative strand of HCV-RNA in liver tissue is regarded as an index of viral proliferation. Therefore, we investigated changes in the hepatic negative-strand HCV-RNA following interferon therapy to determine whether this parameter could predict the long-term response to treatment. The subjects of this study were 27 patients with chronic active hepatitis C. Serum positive-strand and hepatic tissue negative-strand HCV-RNA were detected using polymerase chain reaction. At the completion of interferon treatment, serum HCV-RNA was not detected in 21 patients. One year following treatment it remained undetectable in 14 of these patients but it had reverted to a detectable form in seven. The 14 patients in whom hepatic negative-strand RNA was not detected between 2 weeks and 12 months after treatment, had not relapsed after another year. In the 13 remaining patients, negative-strand RNA was found in liver tissue and serum RNA either reverted to a detectable form or remained detectable throughout. From these findings, we conclude that the detection of negative-strand HCV-RNA in liver tissue 2 weeks after the completion of interferon therapy is useful for predicting the long-term effect of therapy.

Adult↗