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Biomedical subjects

M Ohta

Publications and source records attributed to M Ohta.

At least 1,027 records · Page 57Linked to original sources

[Assessment of myocardial perfusion using digital subtraction angiography].

To assess myocardial perfusion, intra-aortic digital subtraction angiography (IADSA) was performed. Functional images are generated by taking a series of myocardial enhancement images. For each pixel, maximum density of enhancement (Cmax), integrated enhancement area under the curve (Cinteg), mean transit time (MTT) and Cmax/MTT or Cinteg/MTT were extracted. DSA was applicable for evaluating myocardial perfusion in patients with ischemic heart disease.

Contrast Media↗

[Significance of CA19-9 values in the feces of patients with colorectal carcinoma].

We measured CA19-9 value in feces of 119 cases with malignant disease, 78 cases with benign diseases and 36 healthy volunteers, and studied its usefulness for the diagnosis of digestive tract cancer. Mean value of CA19-9 in feces of healthy volunteer was 276.4 +/- 643.3 U/ml (mean +/- 2S.D.) and cut off value was defined as 1000 U/ml. The positive ratio of CA19-9 in feces of patients with malignant diseases as 44.5%. On the other hand, the mean of the false positive ratio was only 1.4% in benign diseases. Regarding to its breakdown, CA19-9 in feces revealed the highest positive ratio as 68% in colonic cancer. In colonic cancer, CA19-9 in feces showed a high positive ratio of 83% at advanced stage. Histologically, the positive ratios of CA19-9 in feces were higher, such as in more than 80% of the reaching degree of depth ss, a1, more than 82% of the disease due to higher parasites of lymph vessel ly1 and more than 95% of the metastasis of lymph node n1. Moreover, all CA19-9 in feces were positive in positive cases of CEA in serum.

Adult↗

Functional heterogeneity of human monocytes--with a special reference to flow cytometric assays.

A large number of human mononuclear cells were simultaneously separated into fractions enriched in B cells, T cells, large granular lymphocytes (LGL) and monocytes by centrifugal elutriation. Lymphocyte populations were analyzed using monoclonal antibodies. In particular, highly enriched natural killer cells, Leu7+ cells, were collected in the intermediate fractions. Monocytes, which were identified as esterase positive cells, and Leu M3 cells were collected at higher counterflow rates and in the final fraction. The purity of monocytes in the final fraction was 81%. The oxidative metabolic activity (H2O2 production) and non-specific esterase activity of individual monocytes was estimated in the analysis of functional heterogeneity of monocytes using flow cytometry. 2',7'-dichlorofluorescein diacetate (DCFH-DA) and fluorescein diacetate (FDA) were used as indicators in the measurement of H2O2 generation and esterase activity. Intracellular generation of a fluorescence product (H2O2 Production; average percentage of fluorescence positive cells) of monocytes in the stimulation of phorbol myristate acetate (PMA, 100 ng/ml) was greater in larger than smaller cells. H2O2 production gradually increased from 6% and 25-38% and 60% in the intermediate and final fractions respectively. Furthermore, the average fluorescence intensity of the large monocyte population in the final fraction was 1.13-1.31 fold more active than that of the smaller cells. Thus, the functional heterogeneity of human monocytes was further confirmed in the assays of H2O2 production exposed to PMA and FDA hydrolysis using flow cytometry. Furthermore, the CCE system can isolate lymphocyte subsets and LGL.

Antigens, Surface↗

[An analysis of 117 cases of patients who died from tumor recurrence or from the progression of ovarian malignancies].

Out of 403 patients with ovarian with malignancies during 1978 to, 1985, 117 (29.0%) died from the progression of a non-curative cancer (56 cases, 47.9%) or from a cancer recurrence (61 cases, 52.1%). The mean survival rate 117 cases was 13.4 months, of which 103 (88.0%) cases concerned patients who died within 2 years and 114 (97.4%) who died within 3 years. A histological analysis revealed that patients with a serous or an endometrial cancer had a longer survival rate than others. Among 61 recurrent cases, 59 (96.7%) fell into recurrence within 2 years. Regarding the relationship between a recurrent of cancer and its prognosis, patients with a recurrence of an ascitic or a metastatic disease had a poorer prognosis than patients with a pelvic or an abdominal mass. An aggressive operation, such as a resection of a recurrent tumor, even if small in volume, led to a better prognostic result than no therapy.

Female↗

Sera from patients with multiple sclerosis react with human cell T lymphotropic virus-I gag proteins but not env proteins--Western blotting analysis.

To study the possible involvement of human T cell lymphotropic virus type I (HTLV-I)-related agent in Japanese multiple sclerosis (MS), we performed a Western blotting analysis, using purified viral antigens, on sera from 46 patients with MS, nine patients with other neurologic diseases, and 11 healthy controls. Of 46 MS patients, 11 (24%) had antibodies reactive with antigens corresponding to the group-specific antigen (gag) proteins (p15, p19, and p24), although the prevalence was lower than that reported in a recent study using an enzyme-linked immunosorbent assay (ELISA). Despite the lower frequency of immunoreactivity, Western blotting technique had merits of identification of multiple antigens and higher specificity for detection of antibodies than ELISA. Those sero-positive patients consisted of four cases with IgG antibodies reactive mainly to the gag p24 and/or p15, four with IgM antibodies mainly to the gag p24 and/or p19, and three with both IgG and IgM antibodies. These immunostaining patterns of MS sera were clearly distinguishable from those of adult T cell leukemia patients who had antibodies to the envelope (env) proteins and its precursors in addition to the gag proteins. The antibody in MS sera was generally of low titer and reactive at a high serum concentration (1/10 dilution). None of the sera from patients with other neurologic diseases and healthy controls had the viral antibodies. These findings indicate that at least one quarter of Japanese MS patients have antibody responses to a hitherto unidentified agent related to HTLV-I, which possibly plays a part, primarily or secondarily, in the pathogenesis of those patients.

Adolescent↗

Close evolutionary relationship between the chromosomally encoded beta-lactamase gene of Klebsiella pneumoniae and the TEM beta-lactamase gene mediated by R plasmids.

Sixty-three percent homology of nucleotide sequence and 67% homology of deduced amino acid sequence were found between the chromosomally encoded beta-lactamase gene of Klebsiella pneumoniae and the TEM beta-lactamase of transposon Tn3. Moreover, 22 out of 24 amino acid residues are identical around the predicted active site. It is therefore suggested that these two kinds of beta-lactamases share a common evolutionary origin. The 0.5 kb DNA fragment of the cloned gene hybridized specifically with the chromosomal DNA of all the K. pneumoniae strains tested which had been isolated in Japan, USA and Europe.

Amino Acid Sequence↗

Influence of chemotherapy on superoxide anion-generating activity of polymorphonuclear leukocytes in patients with lung cancer.

The superoxide anion (O2-) generating activity of polymorphonuclear leukocytes (PMN) in peripheral venous blood obtained from 15 patients with lung cancer was measured weekly after drug treatment. The amount of O2- generated by the cells before chemotherapy was 5.74 +/- 0.42 nmol/minute/10(6) cells (mean +/- SE). The value decreased gradually and reached a nadir of 1.98 +/- 0.24 at 2 weeks after chemotherapy, at which time PMN count also reached a nadir of 1359 +/- 251/microliters (mean +/- SE). The decreased O2- generating activity of the PMN recovered gradually thereafter and reached the level seen before the chemotherapy at 4 weeks. Expression of Fc receptors on the plasma membrane in PMN was measured after chemotherapy by the binding of iodine 125 (125I)-immune complexes to the cells. Almost 40% decrease of the binding was observed in the cells obtained at 2 weeks after chemotherapy, compared with that in the cells before chemotherapy. These results indicate that PMN present in peripheral blood at 2 weeks after chemotherapy are not fully matured, in terms of O2- generating activity and the expression of Fc receptors.

Adenocarcinoma↗

The effect of age on the adaptation of the brain to the anticonvulsant effect of phenobarbital in mice.

The anticonvulsant effect of phenobarbital was examined in young (6 month old) and old (24 month old) BDF1 female mice consisting of three groups each (one control and two chronically dosed phenobarbital groups), using the abolition of the tonic hindlimb extensor component of maximal electroshock seizure as the index. The minimal effective concentrations (MEC) of phenobarbital in plasma and brain in old control mice that were given a vehicle (tragacanth) for one week were significantly lower in comparison to the respective values in young adult control mice with the same treatment, confirming our previous findings. In young mice chronically treated with phenobarbital for one week (20 mg/kg daily for two days followed by daily dose of 50 mg/kg for 5 days), the MECs in both plasma and brain were significantly higher compared with respective control values. The 3 week treatment also produced an increase in MEc comparable to the one-week treatment. The same one-week treatment with phenobarbital in old mice similarly caused significantly higher plasma and brain MEC values but 3-week-treatment values were not significantly different from corresponding control values. It is concluded that the development of brain adaptation to phenobarbital is almost equal for young and old mice, so that the reduction in MEC with age indicates the need for lowered dosages for the aged, even when the age effect on brain adaptation developed to chronic dosing is taken into consideration.

Adaptation, Physiological↗

Age-dependent increase in the threshold for pentylenetetrazole induced maximal seizure in mice.

The thresholds for inducing the maximal seizure by pentylenetetrazole (PTZ) were compared for BDF1 mice of both sexes with varying ages after intraperitoneal administration of various doses of PTZ. The minimal effective PTZ concentrations (MECs) in the brain for inducing the maximal seizure were significantly higher in 24-month or older mice than in 6-month-old animals of both sexes. Some mice of 30 months did not demonstrate the maximal seizure but died within the 15-min observation period, a phenomenon never observed in mice of 24 months or younger. The relationship between plasma and brain concentrations of PTZ changed little during aging. It was concluded that the brain becomes less sensitive to PTZ with age in regard to its convulsant activity, as was previously shown for electroshock by the authors. This observation, coupled with our earlier observations on anticonvulsants, appears to support the classical hypothesis that age has a dual effect on drug sensitivity i.e. a decrease for stimulants but an increase for sedative (or depressant) drugs.

Aging↗