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Biomedical subjects

H Ohtani

Publications and source records attributed to H Ohtani.

At least 361 records · Page 20Linked to original sources

[Measurement of small quantities of alpha 2-macroglobulin in bronchoalveolar lavage fluid by enzyme-labelled immunoassay, and its clinical implication in pulmonary disease].

We established an enzyme labelled immunoassay for the determination of alpha 2 macroglobulin (alpha 2M). The assay range was from 2 to 140 ng/ml and the within-assay coefficient of variation (CV) were 5.2% at 31.2 ng/ml and 6.4% at 62.5 ng/ml. Between-day CV ranged from 6.9% to 15.4%. Using this method, alpha 2 M was determined in the bronchoalveolar lavage fluid (BALF) from patients with interstitial lung diseases. Those diseases were active and inactive sarcoidosis, hypersensitivity pneumonitis and idiopathic pulmonary fibrosis (IPF, including collagen disease). We divided the IPF patients into two groups, 'acute type' and 'chronic type', judging from the prognosis. alpha 2 M/Albumin ratio in BALF in the active sarcoidosis and acute type IPF groups is significantly higher than that in the inactive sarcoidosis and chronic type IPF. These findings suggest that alpha 2 M in BALF can be a sensitive marker of the interstitial lung disease.

Bronchoalveolar Lavage Fluid↗

Measurement of small quantities of alpha 2-macroglobulin in cell cultures by enzyme labelled immunoassay.

We established an enzyme labelled immunoassay (EIA) for the determination of alpha 2-macroglobulin (alpha 2M). The sensitivity was high enough to measure trace amount of alpha 2M secreted into the medium of cell culture. The assay range in medium was from 2 to 140 ng/ml and the within-assay coefficients of variation (CV) were 10.1% and 6.7% at 31.2 ng/ml and 62.5 ng/ml, respectively. Between-day CV ranged from 9.3% to 15.9%. Using this method, alpha 2M was detected in the medium of a cultured human melanoma cell line. In addition, the immunoreactive alpha 2M in the medium was identified with serum alpha 2M by the method of SDS-PAGE and Western blotting. Our results indicate that the EIA method could be a useful tool for the determination of alpha 2M in cell cultured medium.

Blotting, Western↗

Radioreceptor assay of clonazepam and diazepam in blood for therapeutic drug monitoring.

Rat cerebral cortex was used to prepare a suspension of benzodiazepine receptors. The suspension was mixed with an extract of specimen and [3H]flunitrazepam. The mixture was filtered through a membrane, and radioactivity on the membrane was measured. Clonazepam concentrations in patient plasma specimens determined by radioreceptor assay and gas-liquid chromatography agreed well. However, diazepam equivalent concentrations determined by radioreceptor assay were close to the sum of diazepam and desmethyldiazepam concentrations determined by high-performance liquid chromatography, as desmethyldiazepam had binding activity for the receptor. This receptor assay method is accurate, simple, requires less than 0.5 ml of plasma, and is therefore suitable for analyzing numerous samples in a short time.

Adolescent↗

[Clinical trial of 111In-antimyosin antibody imaging: (3) Comparison with 99mTc-pyrophosphate imaging].

Clinical value of 111In-antimyosin monoclonal antibody F ab (AM) was compared with 99mTc-pyrophosphate (PYP) in 13 patients with myocardial infarction and 3 patients with myocarditis. Following PYP injection, PYP imaging was performed 3 hours later. Immediately after PYP imaging, AM was administrated and AM images were obtained 48 hours later. Abnormal accumulation in the infarcted myocardium was observed in 11 patients (85%) on AM images but only in 3 patients (23%) on PYP images. All patients within 8 days after the onset of infarction showed abnormal uptake on both images. Of 5 patients with 1 to 2 weeks after the onset of infarction, abnormal uptake was observed in all of them on AM images but only in one of them on PYP imaging. Furthermore, of 6 patients with more than 2 weeks after the onset, AM imaging showed abnormal uptake in 4 (67%) but PYP imaging did not show abnormal uptake in any of them. Similarly. Of 3 patients with myocarditis, diffuse uptake in the myocardium ws observed in 2 of them on AM images but none of them showed abnormal uptake on PYP images. We conclude that AM imaging is a useful means for identifying not only acute stages but also subacute stages of myocardial necrosis where PYP imaging did not show any abnormality.

Adult↗

[Analysis of P-glycoprotein in patients with acute leukemias by flow cytometry].

The identification of a P-glycoprotein product of multidrug-resistant gene (mdr 1) was reported recently. To examine the expression of the P-glycoprotein in acute leukemias of various types, we have prepared leukemic blast cells from patients and measured their positivity of P-glycoprotein using monoclonal anti-P-glycoprotein antibody (C219) by flow cytometry. P-glycoprotein is expressed in 8 out of 44 cases including leukemic blast cells but not lymphocytes and monocytes. In these cases showed drug resistance was shown clinically. In addition, the expression of the P-glycoprotein was not observed in the drug-sensitive cases and at the time of initial chemotherapy. Our results suggest that measurement of P-glycoprotein in acute leukemias by flow cytometry may prove to be a valuable tool for the design of chemotherapy protocols.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

[Expression of P-glycoprotein (multidrug-resistance gene product) in haematological tumors].

The fact that cancer cell acquires multidrug resistance to carcinostatics at cancer treatment is a very important subject clinically. The mode of multidrug-resistance is complicated, but the gene associated with multidrug resistance (MDR 1) has been isolated. It has become evident that MDR 1 gene carries membrane glycoprotein (P-glycoprotein) which occurs in the cell acquired drug-resistance. Assessment has been made this time regarding the occurrence of P-glycoprotein in the tumorous cells and tissues by the use of monoclonal antibody (C 219) to P-glycoprotein. Occurrence of P-glycoprotein in malignant lymphoma exhibited positivity in 9 cases out of 36 immunohistologically. 170 KD P-glycoprotein was detected in 4 cases out of 10 at Western blotting analysis of the protein isolated from the nuclear cell in the peripheral blood in the patients with leukemia. Further, P-glycoprotein positive cases were all progressive cases clinically and showed resistance to treatment. From these results, it has been clarified that occurrence of P-glycoprotein in haematological tumors is related to multidrug resistance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

[Assessment of myocardial viability by quantitative analysis of stress Tl-SPECT--comparison with FDG-PET].

Stress Tl-201 tomography (SPECT) is widely used for evaluating myocardial viability. To assess its value, redistribution (RD) on SPECT was compared with metabolic imaging using FDG. Thirty patients with coronary artery disease underwent stress-3 hour Tl-201 SPECT and PET using N-13 ammonia and FDG. RD was classified into 4 grading, including complete RD (CR), incomplete RD (IR), persistent defect (PD) and additional minimal RD (MR) defined as no definite RD on visual analysis but faint RD with Bull's eye quantitative analysis (QNT). All but one segment with CR or IR were viable regions (normal or ischemic regions) by PET. Of 74 segments without RD on visual analysis, 31 segments (42%) had RD by QNT (MR). All of them were viable regions by PET. Thus, QNT identified 31 segments (63%) of the metabolically viable segments which the visual Tl-201 analysis did not show RD and classified as myocardial scar. However, even such QNT cannot detect ischemic myocardium in 18 segments (42%) containing metabolic activity on PET. These data indicate that QNT of RD on Tl-201 SPECT is considered as a valuable means for assessing myocardial ischemia.

Aged↗

Low responsiveness of lymphocytes from normal individuals against the stimulation with pokeweed mitogen.

The responsiveness of peripheral blood lymphocytes stimulated with pokeweed mitogen (PWM) and purified protein derivative of tuberculin (PPD) as B cell activator was studied in adult healthy subjects by immunoglobulin synthesis system in culture. We have shown that lymphocytes from some healthy subjects have low responsiveness in the polyclonal antibodies secretion following PWM stimulation but not PPD stimulation by Protein A-reverse hemolytic assay. In this system, when irradiated T cells (CD4+) as helper T cell were added to B cells from autologous or allogeneic subjects, helper T cell function of immunoglobulin synthesis on the low response groups to PWM significantly decreased. Whereas normal responses to PPD stimulation were observed in the presence of helper T cells (CD4+). The low responsiveness of lymphocytes stimulated with PWM but not PPD may be related to reduced functions of helper T cell populations. Thus the healthy subjects were classified into high, normal and low response groups with PWM on the basis of antibody production.

Antibody Formation↗

Expression of p21 ras protein in human melanoma cell lines.

Samples obtained from six human melanoma cell lines have been tested for the presence of p21 ras oncogene product by Western blotting analysis. The overexpression of p21 was detected in two cell lines out of the six samples. These DNA samples have not been shown to be transformants by transfection assay. Moreover, amplification or rearrangement of DNAs from these cell lines was not found by Southern blotting analysis. Northern blotting analysis, however, detected the expression of Ki-ras gene in RNA extracted from the two cell lines. Thus, it was suggested that the overexpression of p21 might be a result of increased normal mRNA transcript of Ki-ras gene.

Blotting, Northern↗

[Serial assessment of cardiac function during and after exercise by an ambulatory ventricular function monitor (VEST)].

Cardiac function was serially assessed during and after exercise by an ambulatory ventricular function monitor (VEST) in 31 patients who received coronary angiography. Based on the study of fluctuation during the baseline recording, greater than or equal to 6% change in ejection fraction (EF) was considered significant. The serial changes in EF during exercise was divided into 5 types, including continuous increase (type A), initial increase but return to the baseline (type B), no change (type C), initial increase but later decrease below the baseline (type D), and continuous decrease (type E). Among 8 normal subjects, their EF changes during exercise showed type A in 3, type B in 2, type C in 2, and type D in 1. Among 21 patients with coronary artery disease, the EF changes showed type A in 5, type B in 4, type C in 4, type D in 5 and type E in 3. Thus, there was a significant overlap in EF response between normal and coronary patients. However, every patient showing type A and B had single-vessel disease, and 63% of them had persistent thallium defect without redistribution. After the exercise, 29 patients showed rapid increase in EF. The time to the peak EF was significantly longer in coronary patients (1.88 +/- 1.24 min) than that in normal cases (0.88 +/- 0.55 min) (p less than 0.05) particularly in patients with multi-vessel disease (2.22 +/- 1.29 min). In addition, those showing type C, D or E tended to have a longer time to peak EF and more increase in EF after exercise than those showing type A or B. These data suggest that VEST is suitable for continuous measurement of cardiac function during and after exercise which provided valuable indices for assessment of severity of ischemia in coronary artery disease.

Adult↗

Quantitative analysis of regional wall motion by gated myocardial positron emission tomography: validation and comparison with left ventriculography.

Electrocardiographically gated positron emission tomography (ECG-gated PET) with [13N] ammonia was used to assess regional myocardial wall motion of left ventricle (LV) based on a nongeometric method in nine healthy volunteers and 16 patients with coronary artery disease (CAD). Three transverse sections (upper, middle, and lower) with 16-mm intervals at end-diastole (ED) and end-systole (ES) were analyzed. The LV wall was divided into eight segments with every 30 degrees from septal wall to lateral wall. Based on circumferential profile analysis, the percent count increase [( ES count - ED count) divided ED count x 100) in each segment was analyzed as an index of regional wall motion. In the study of normal controls, the percent count increase was the lowest (32.9 +/- 7.2%) at septal wall of the lower slice and the highest (72.8 +/- 26.5%) at lateral wall of the upper slice (p less than 0.01). In five normal controls, the percent count increase was compared with the percent systolic wall thickening analyzed by magnetic resonance imaging, and a good correlation was observed (r = 0.84). In the study of patients with CAD, the percent count increase was compared with wall motion assessed by left ventriculography (LVG). The percent count increase significantly decreased as wall motion on LVG worsened. In addition, the value in normal controls tended to be higher than that in the segments with normal wall motion in patients with CAD. Thus, quantitative analysis of regional wall thickening was feasible by ECG-gated PET, which should be useful for combined analysis of regional function, perfusion and metabolism in patients with CAD.

Adult↗

Ultrastructural immunolocalization of lysozyme in paneth-like cells in undifferentiated (gastric)-type carcinoma of the stomach.

Five cases of gastric carcinoma of undifferentiated (gastric) type containing Paneth-like cells were studied by immunoelectron microscopy for lysozyme using two methods. The Paneth-like cells in these carcinomas had lost their cellular polarity and possessed electron-dense granules. These granules varied in size (0.5-3 micron in diameter), electron density and shape. Post-embedding method revealed immunolocalization of lysozyme in these granules in all cases, similar to that in normal Paneth cells. Pre-embedding method showed immunoreactivity diffusely or focally located in the cytoplasm, but this approach was unable to reveal immunoreactivity in the granules, a feature also common to normal cells. Our study therefore confirmed that Paneth-like carcinoma cells and normal Paneth cells had the same features, and indicated that undifferentiated-type gastric carcinoma could possess specially differentiated cells, providing further support that such carcinoma could express multipotentiality. The difference in the results obtained by the two immunoelectron microscopy methods was discussed.

Carcinoma↗