Biomedical subjects

K Ono

Publications and source records attributed to K Ono.

At least 217 records · Page 12Linked to original sources

PubMed2000

[Methodology and clinical implication of the identification of clonality in malignant lymphoma].

A variety of methods is now available to identify clonality of lymphoid neoplasia by recent progress in immunology and molecular biology. The target molecules for these include physiologically or pathologically altered genes/their products and virus-derived DNAs. Identification of clonality is important for more accurate diagnosis of lymphoma and, especially, related borderline lesions. It is also of considerable value in staging and follow-up study of the patients because higher sensitivity of polymerase-chain reaction made it possible to detect submicroscopic lesions including minimal residual disease after treatment. However, many lesions and phenomena which are clonal, but do not appear to be malignant, have been characterized. These may prompt an update of the conventional concept of "malignant lymphoma".

Animals↗

PubMed2000

Using HOS for characterization of periodical and time-varying waveform.

We applied an approach based on high order statistics (HOS) to classification of time series. This is different from most of the prior analyses in which signal features have been compared. In our approach, we investigate an input signal deformed non-linearly in time and contaminated with additional different forms of noise, e.g. Gaussian, non-Gaussian and their mixed form. The bispectrum-averaging technique (third order statistics) which preserves information about both amplitude and phase of the Fourier transform is studied for the reconstruction of the predictable waveform. The technique does require neither an initial estimate nor a peak-to-peak synchronization of the realizations. Thus, the normal waveform is considered ideally to be smooth and entirely predictable. The residual is characterized by subtracting the predictable part from the original waveform. Under non-linearity assumption, we propose that the Volterra process tool is suitable for analysis and differentiation between the patterns contained in the time series residual. We present and classify some results of the output of the linear transfer function of the process. The approach is numerically tested with the use of computer-generated data. Its effectiveness in dealing with electrocardiogram (ECG)-related data is also demonstrated.

Computer Simulation↗

PubMed2000

[A case of glioblastoma multiforme which indicated the early stage on brain MRI].

A 57-year-old male was urgently carried to our hospital because of sudden loss of consciousness, lasting about 10 minutes. He had resumed consciousness before he arrived at our hospital. Neurologically, he had mild muscle weakness of the right arm. Deep tendon reflexes in the right upper extremity were reduced. In high level functions, speech disturbance, dysgraphia (disturbed ability to write Hiragana), and constructive apraxia were noted. A brain MRI upon admission showed a poorly demarcated, high signal intensity area in the cortical and subcortical layers of the left temporal and parietal lobes. This was visible on T 2 weighted images(T 2 WI), although no abnormalities were visible on T 1 weighted images(T 1 WI). No contrast enhancement was effected by Gd-DTPA. The patient was therefore suspected of having a tumor or degenerative disease and was monitored closely. About 4 months later after onset, his symptoms became aggravated, and brain MRI disclosed a marked low signal intensity area on T 1 WI and a heterogeneous high signal intensity area on T 2 WI. The abnormal signal intensity area was surrounded by extensive edema and mass effect. Ring-shaped, irregular, contrast enhanced areas were also visible. Cerebral angiography revealed a poorly demarcated tumor stain in the area supplied by the middle cerebral artery. The tumor was removed surgically and was histopathologically rated as glioblastoma multiforme(GBM). Because this case represents a valuable example of early stage of GBM, it will be discussed in this paper, along with differential diagnoses.

Brain Neoplasms↗

PubMed2000

[Intravenous contrast echocardiography].

Intravenous contrast echocardiography has become possible in Japan because of the release of the commercially available contrast agent, Levovist. Intravenous administration of Levovist satisfactorily stains the left ventricular cavity, which makes it possible to clearly delineate the endocardial border. Clear delineation of the endocardial border provides easy and accurate measurement of left ventricular dimension and wall thickness, and wall motion abnormalities can be easily and accurately judged, too. Another benefit of intravenous contrast echocardiography is the assessment of myocardial perfusion. Our preliminary experimental and clinical experiences showed the possibility of myocardial staining with intravenous contrast echocardiography. Impressive myocardial staining is obtainable with the combined use of intermittent and contrast harmonic power Doppler imaging. In order to obtain reproducible and clear myocardial contrast images, we have to pay attention to how to inject contrast and settings of ultrasound equipment, i.e., mechanical index, gain setting, depth of focus point, and pulse repetition frequency, artifacts. In the near future, a lot of issues should be standardized to make it possible to compare myocardial contrast echo studies.

Contrast Media↗

PubMed2000

Simulation of body surface Laplacian maps during ventricular pacing in a 3D inhomogeneous heart-torso model.

A computer simulation study has been conducted to investigate the performance of body surface Laplacian maps (BSLMs) in localizing and imaging spatially separated myocardial electrical events. A cellular automaton model of ventricles simulates cardiac electrical activity using a two-site pacing protocol to induce dual simultaneously active myocardial electrical events. The heart model is embedded in a realistically shaped inhomogeneous volume conductor. The BSLMs are numerically computed from the induced electrical activity in the heart model. The present computer simulation results show that the BSLM can provide better separation and localization of two regional myocardial electrical events as compared with the body surface potential map (BSPM).

Artifacts↗

PubMed2000

Permanent cardiac pacing following surgery for acquired valvular disease.

Between January 1980 and January 1998, implantation of a permanent pacemaker (PP) was performed in 22 patients (6.7%) following 327 acquired valvular surgeries. The indications for implantation of a PP were bradycardia with atrial fibrillation in 12 cases, sick sinus syndrome in 7 cases and complete atrioventricular block in 3 cases. These patients received an implantation after surgery for mitral valvular disease in 14 cases, aortic valvular disease in 3 cases and combined valvular disease in 5 cases. These cases were also concomitant with a tricuspid valve annuloplasty in 6 cases for secondary regurgitation and with a maze procedure in 4 cases. For the purpose of this study, these patients were compared to patients who did not require implantation of a PP after surgery. Univariate analysis showed the significant factors to be female gender (p = 0. 041), preoperative atrial fibrillation (p = 0.013), redo cardiac surgery (p < 0.0001), and the use of blood cardioplegia (p = 0.003). There were no differences in valvular disease, age at the last valvular operation, addition of tricuspid valve annuloplasty, extracorporeal circulation times, or aortic cross-clamp times between those patients with and those without PP. Among these factors, logistic regression analysis showed female gender, redo surgery and the use of blood cardioplegia to be more significant predictors for the requirement of PP after acquired valvular disease operation. Maze procedure was not a significant predictor for the requirement of PP after surgery.

Adult↗

PubMed2000

[5-FU concentration in the serum and the tumor tissue after administration of UFT 200 mg/day to patients over 80 years of age with oral cancer].

UFT was administered orally at a dosage of 200 mg/day, 2 times a day, to patients over 80 years of age with oral cancer. The concentration of 5-FU in the serum and tumor tissue, as well as the side effects, were investigated. The results were as follows: 1. The concentration of 5-FU in the serum peaked (0.017 to 0.066 microgram/ml) 1 or 2 hours after UFT administration. The concentration 8 hours after administration was relatively high (0.016 to 0.041 microgram/ml). 2. The 5-FU concentrations in the tumor tissues in 3 out of 5 cases were greater than 0.05 microgram/g, which is considered to be the effective level. The concentration tended to be higher with increased duration of administration. 3. A minor side effect, bone marrow dysfunction, was observed. No effect on the function of the liver or digestive system was observed.

Aged↗

PubMed2000

[Thallium-201 single photon emission tomography of intracranial angiomas].

We herein describe thallium-201 single photon emission tomography (T1-201 SPECT) findings in three cases with intracranial angioma. One of the lesions which was associated with chronic encapsulated intracerebral hematoma showed moderate accumulation of T1-201, but, others demonstrated no accumulation. The usefulness and limitations of T1-201 SPECT in differential diagnosis of intracranial mass lesions are discussed.

Adult↗

PubMed2000

[Clinical study of three myelodysplastic syndrome (MDS) patients with BOOP-like pulmonary disease].

Three cases of myelodysplastic syndrome (MDS) associated with BOOP-like pulmonary disease were reported. They were diagnosed from transbronchial biopsies and clinical features. In two cases, chest radiographs showed ground glass opacities or air space consolidation in both lung fields, and air space consolidation in the right lower lobe in the other case. BALF showed a marked increase of lymphocytes in one case, and organizing pneumonia and alveolitis, and alveolar spaces filled with foamy macrophages were identified histologically. Although no steroid therapy was employed, all three cases improved. However, one patient suffered a relapse 6 months later and thereafter did not respond to corticosteroid therapy.

Aged↗

PubMed2000

Contamination of soil with helminth parasite eggs in Nepal.

Contamination of soil with helminth eggs in Kathmandu Valley (n=122) and outside of Valley (n=34) in Nepal was investigated with the use of centrifugal floatation technique using sucrose solution (sp gr 1.200). The overall soil contamination rate was 36.5% (57/156). The prevalence was uniform in Kathmandu Valley (36.9%) and outside of the valley (35.3%). A mean of six helminth eggs per sample were detected out of which more than half were embryonated (potentially infective). In Kathmandu Valley, soil contamination rate was higher (48.3%) during wet season compared with that observed in dry season (33.3%) but without significant difference (p>0.05). Multiple species of helminth eggs were detected in 22.8% of total positive samples (n=57). Altogether five species of nematoda (Ascaris lumbricoides, Toxocarta sp, Trichuris trichiura, Capillaria sp and Trichostrongylus sp) and two species of cestoda (Hymenolepis nana and H. diminuta) were recovered. A. lumbricoides was predominant in Kathmandu Valley while Trichostrongylus was the commonest one in outside of valley.

Animals↗

PubMed2000

Thymic neuroendocrine carcinoma: a clinicopathologic study in four patients.

BACKGROUND: Thymic neuroendocrine carcinoma (carcinoid) is rare. Here we present four cases of this unusual neoplasm to provide more clinical, radiologic, and prognostic data. MATERIALS AND METHODS: Four male patients with an average age of 44 years (range 27-63) were identified as having thymic neuroendocrine carcinoma and were reviewed retrospectively. RESULTS: One patient had Cushing's syndrome with elevated serum ACTH. Three others were asymptomatic with normal laboratory findings, one case was associated with MEN type 1. All underwent complete resection along with invaded adjacent structures. Local recurrence developed in two patients at 45 and 98 months after the initial excision. Both patients died at 90 and 105 months, respectively. The other two patients are alive and have been disease-free for 27 and 120 months, respectively. CONCLUSIONS: Thymic neuroendocrine carcinomas have a rather poor prognosis based on their tendency to recur and metastasize many years after the initial operation. Therefore, prolonged follow-up is essential for these tumors.

Adult↗

PubMed2000

[Current spread of HPN and its forecast--especially in the dual therapy of HPN and HOT].

In 1999, Terumo's home healthcare network 'Home-Joint' managed more than 1,000 patients who underwent home parenteral nutrition (HPN). This spread of HPN led some patients to undergo another home medical treatment during the same period. This report evaluates the patients who underwent dual home therapy (HPN and HOT: home oxygen therapy) in comparison with patients who underwent HPN only. 1. Single HPN patients in 1999. Number: 1,034 (male 57%), age: 1-99 (mean 65, 43% over 70), diagnosis: cancer 52%, therapeutic periods: 1-437 days (mean 81). 2. Dual HPN-HOT patients in 1999. Number: 27 (male 70%), age: 44-94 (mean 75, 70% over 70), diagnosis: cancer 59%, therapeutic periods: HPN 1-388 days (mean 91), HOT 1-827 days (mean 99). 3. Adoption of dual HPN-HOT therapy. It is suggested that the dual HPN-HOT therapy may be adopted for at least the following two types of patients. 1) Pulmonary failure with HPN, 2) Malnutrition on HOT.

Adolescent↗

PubMed2000

[Staged total callosotomy for medically intractable seizures].

For the treatment of intractable generalized epilepsies, two-staged total callosotomy was performed in five patients. In all patients, preceded anterior callosotomy failed to obtain satisfactory seizure control. All patients showed mental retardation with various degrees. Mean age at the first operation was 10.2 years and 4 patients were operated in their childhood. All patients showed various types of seizures; drop attack (DA) in 3 patients, tonic seizure (TS) in 2, myoclonus (MY) in 2, complex partial seizure (CPS) in 2, atypical absence (AA) in 1, and head drop (HD) in 2. After anterior callosotomy, complete cessation of CPS and 50-80% reduction of DA was obtained in one, respectively. However, only less than 50% reduction of seizures was obtained in other types of seizures. Two years after anterior callosotomy, posterior portion of the corpus callosum was divided. After staged total callosotomy, complete cessation of DA was obtained in all patients and 80-100% reduction of AA was obtained in one patient. One adult patient showed the disconnection syndrome which did not affect activities of his daily life. Our study revealed the efficacy of posterior callosotomy in DA patients with unsatisfactory results after anterior callosotomy. This strategy should be considered especially in childhood cases, since obvious complication was not observed in such cases.

Adolescent↗

PubMed1999

Development of macroglial cells in the embryonic chick optic nerve.

Macroglia development in the embryonic chick optic nerve was immunohistochemically examined. The astrocytes with glial fibrillary acidic protein immunoreactivity were initially restricted to the retinal end of the optic nerve at stage 40, but had widely dispersed within the optic nerve in an out-side-in manner by stage 44. Oligodendrocytes with myelin basic protein immunoreactivity appeared at stage 38, and were widely distributed at stage 40. Electron microscopic observation confirmed the presence of intermediate filaments in the glial fibers and developing myelin at stages 40-41. The present results suggest that oligodendrocyte precursors undergo terminal differentiation slightly earlier than astrocyte precursors with respect to the expression of marker proteins.

Animals↗

PubMed1999

Contribution of endothelin-1 to myocardial injury in a murine model of myocarditis: acute effects of bosentan, an endothelin receptor antagonist.

BACKGROUND: Endothelin (ET) is one of the most important contributing factors in the pathophysiology of cardiovascular diseases. However, little is known about its role in myocarditis. METHODS AND RESULTS: Four-week-old DBA/2 mice were inoculated with the encephalomyocarditis virus. Expression levels of ET-converting enzyme-1 (ECE-1) and prepro-ET-1 mRNA were significantly increased at 7 and 14 days after virus inoculation. Plasma and myocardial ET-1 levels were significantly higher in infected than noninfected mice between 5 and 14 days after virus inoculation. Immunohistochemical analyses revealed that not only endothelial cells and myocytes but also infiltrating mononuclear cells produced ET-1 protein at 7 days. Oral bosentan, a mixed ET-1 receptor antagonist, was administered after virus inoculation in doses of 0 (control group), 10, or 100 mg. kg(-1). d(-1), and the animals were killed on day 14. Mean heart weight/body weight ratios were 8.3+/-1.8 versus 11.2+/-2.4 versus 10. 8+/-2.4 in the bosentan 100 mg. kg(-1). d(-1) versus 10 mg. kg(-1). d(-1) versus control groups, respectively (P<0.05). Corresponding histological scores for myocardial necrosis were 2.0+/-0.2 versus 2. 9+/-0.3 versus 3.0+/-0.4 (P<0.05), and cellular infiltration scores were 2.3+/-0.3 versus 2.9+/-0.4 versus 3.3+/-0.4 (P<0.05). Animals killed on day 5 had significantly smaller necrotic areas after treatment with bosentan 100 mg. kg(-1). d(-1) than the group treated with a lower dose or the control group, despite the absence of differences in virus titers. CONCLUSIONS: This study suggests that ET-1 plays an important pathophysiological role in viral myocarditis. Treatment with bosentan had a cardioprotective effect without modifying viral replication.

Animals↗

PubMed1999

Mast cells cause apoptosis of cardiomyocytes and proliferation of other intramyocardial cells in vitro.

BACKGROUND: Mast cells are multifunctional cells containing various mediators such as cytokines, proteases, and histamine. They are found in the human heart and have been implicated in ventricular hypertrophy and heart failure. However, their roles in pathogenesis of these diseases are unknown. METHODS AND RESULTS: Cultured cardiomyocytes from neonatal rats were incubated with mast cell granules (MCGs) for 24 hours. The highest concentration of diluted MCGs caused the death of approximately 70% of cardiomyocytes. This cell death was proved to be apoptosis, as quantified by electron microscopy and biochemical criteria. MCG-mediated cytotoxicity was prevented by pretreatment of MCGs with protease inhibitors or a neutralizing antibody against rat mast cell chymase 1 (RMCP 1). RMCP 1 by itself was proved to induce cell death of cardiomyocytes. These results suggest that RMCP 1 contained in MCGs causes the death of cardiomyocytes. In contrast, MCGs induced the proliferation of intramyocardial cells other than myocytes. RMCP 1 was also proved to induce their proliferation. CONCLUSIONS: Mast cells cause apoptosis of cardiomyocytes and proliferation of other intramyocardial cells via the activity of RMCP 1. Our results suggest that mast cell chymase may play a role in the progression of heart failure, because loss of cardiomyocytes and proliferation of nonmyocardial cells exaggerate its pathophysiology.

Animals↗

PubMed1999

FTY720, a new immunosuppressant, promotes long-term graft survival and inhibits the progression of graft coronary artery disease in a murine model of cardiac transplantation.

Background-Effective immunosuppression is a critical determinant of organ and patient survival in cardiac transplantation. The present study was designed to determine the potency of FTY720, a new synthesized immunosuppressant, and examine its clinical potential as an immunosuppressant. Methods and Results-Hearts of DBA/2 mice were transplanted heterotopically in C57BL/6 mice. Recipients were treated with oral FTY720 in doses of 0.3, 1, 3, or 10 mg. kg(-1). d(-1) or with 40 mg. kg(-1). d(-1) of cyclosporin A (CsA) as a comparative treatment. The median graft survival time (MST) was significantly prolonged by treatment with FTY720 10 mg. kg(-1). d(-1). MST was not prolonged by FTY720 1 mg. kg(-1). d(-1) or CsA. However, FTY720 1 mg. kg(-1). d(-1) combined with CsA 40 mg. kg(-1). d(-1) resulted in a significant prolongation of MST. Histopathological studies performed 5 days after transplantation demonstrated remarkable suppression of inflammatory response by treatment with FTY720 10 mg. kg(-1). d(-1). Interleukin (IL)-2 and interferon (IFN)-gamma production was not suppressed; however, cytotoxic T lymphocyte activity was strongly suppressed in vitro. In addition, IL-2-stimulated T-cell proliferation and class I and class II MHC antigen expression on IFN-gamma-stimulated macrophages were strongly inhibited by FTY720. Histopathological studies 60 days after transplantation (DBA/2-B10.D2) demonstrated a beneficial effect on graft atherosclerosis. Conclusions-FTY720 promoted long-term cardiac graft survival and strongly inhibited the progression of graft atherosclerosis. These observations suggest that FTY720 has a promising clinical potential in cardiac transplantation.

Animals↗

PubMed1999

Migration of exogenous immature hematopoietic cells into adult mouse brain parenchyma under GFP-expressing bone marrow chimera.

Bone marrow transplantation with GFP-expressing cells from GFP-transgenic mice resulted in migration of GFP-positive cells into peripheral tissues and brain parenchyma. Most of these cells were observed as colony-like clusters. GFP-positive clusters in the brain were stained by antibody for ER-MP12, but those in the peripheral tissues were not. Since ER-MP12 antigen has been reported as a marker for murine early-stage myeloid precursor, this might suggest that some parts of phagocytic cells in the brain parenchyma such as microglia are derived from undifferentiated pluripotent hematopoietic cells.

Animals↗