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Biomedical subjects

H Ohta

Publications and source records attributed to H Ohta.

At least 667 records · Page 37Linked to original sources
PubMed1987

Isolation and characterization of an amphipathic antigen from Corynebacterium diphtheriae.

Amphipathic antigen was isolated from Corynebacterium diphtheriae Park-Williams number 8 cells by extraction with 47.5% phenol, nuclease treatment and gel filtration on Sepharose 6B. The chemical composition of the amphipathic antigen was hexose (73.8%), pentose (4.6%), fatty acids (9.8%) and glycerol (4.5%). The amphipathic antigen contained arabinose and mannose as sugars at a molar ratio of 1:6 and the major fatty acids were palmitic (C16:0) acid and palmitoleic (C16:1) acid (64.2% and 26.2%, respectively). The amphipathic antigen sensitized sheep erythrocytes and had definite immunobiological activities: viz mitogenic activity on murine splenocytes, stimulatory activity on guinea pig peritoneal macrophages and human complement activation. Deacylation of the amphipathic antigen with alkali treatment lost the sheep erythrocyte-sensitizing ability and some immunobiological activities. The isolated amphipathic antigen described is not a lipoteichoic acid and is different from the teichoic acid of C. diphtheriae.

Amino Acids↗
PubMed1987

[The effects of hyperoxemia on cerebral blood flow in subarachnoid hemorrhage patients].

The effects of oxygen inhalation at atmospheric pressure (1 ATA.O2) on CBF were studied in subarachnoid hemorrhage (SAH) patients due to ruptured intracranial aneurysms to prove the usefulness of the "O2 response" test for the evaluation of the cerebral vascular response. "O2 response" means the CBF (or ICP) decrease during hyperoxemia. CBF was measured by 10 m Ci 133Xe intravenous injection method using rCBF analyzer BI-1400 (Valmet). Two-compartmental analysis was used for the calculation of initial slope index (ISI). Studied cases were 53 postoperative SAH patients and 100 times examinations were done under the condition of Rest-1 ATA.O2. The incidence of global disturbance of the O2 response was 33% from day 0 to 3, 31% during day 4 to 7, 30% during day 8 to 14, and 23% at day 15 to 30. But, after day 31, there was no case which revealed an impaired O2 response. It was not possible to detect focal or hemispheric abnormalities of the O2 response because of the limitation of noninvasive two-dimensional CBF measurement method employed. The causes of O2 response abnormality, within a month after the onset, were increased ICP, hydrocephalus and diffuse brain damage. Multiple regression analysis proved that elevated PaO2 is the major factor in reducing CBF. CBF and ICP correlation study showed that the higher the Rest ICP, the fewer the CBF decreases during pure O2 inhalation. This may indicate that the increase in ICP in the acute stage changes the O2 response according to the level of increased ICP.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

[Evaluation of CA 15-3 radioimmunoassay].

The CA 15-3 RIA kit (Centocor Co.) based on a solid-phase radioimmunoassay was evaluated both experimentally and clinically. The results of a basic study of the reproducibility, recovery and dilution were very satisfactory. Serum levels of CA 15-3 were determined in 211 patients with malignancies including 13 breast cancers, 81 patients with benign diseases and 13 controls. Elevated levels of this antigen (greater than 25 U/ml) were observed in 16.7% of esophageal cancers, 9.7% of gastric cancers, 7.9% of colon cancers, 10% of hepatocellular cancers, 10% of biliary tract cancers, 10% of pancreatic cancers, 33% of lung cancers, and 75% of recurrent breast cancers. Thus, in malignant diseases the positivity was low except for recurrent breast cancer. On the other hand, the false-positive rate in benign diseases was only 3.7% and the false-positive cases had a level of 40 U/ml or less. These results indicate that the serum levels of CA 15-3 may have diagnostic value in patients with recurrent breast cancer.

Antigens, Neoplasm↗
PubMed1987

Localization of human osteogenic sarcoma xenografts in nude mice by a monoclonal antibody labeled with radioiodine and indium-111.

Monoclonal antibody OST7 reacts specifically with human osteogenic sarcoma. Whole immunoglobulin G (IgG) and the F(ab')2 fragment of OST7 were labeled with radioiodine and indium-111 (111I), and injected into athymic nude mice bearing xenografts of human osteogenic sarcoma (KT005). All radiolabels retained their antigen-binding activities allowing clear visualization of transplanted tumors. Tissue distribution, however, varied. The net tumor concentration of 111In-lableled whole IgG was higher and was retained longer than that of radioiodinated one, but 111In-labeled antibody showed a lower tumor-to-liver and tumor-to-kidney ratio. In radioiodinated OST7, F(ab')2 fragments provided much better images with much higher tumor-to-tissue ratios than whole IgG. Using F(ab')2 fragments as a carrier for 111In, little image improvement was obtained due to the high radioactivity in the liver and kidney. The different distributions among these radiolabels suggest that the choice between intact igG and F(ab')2 fragments and between radioiodine and 111In depends on the intended use.

Animals↗
PubMed1987

Preparation and properties of antitumor monoclonal antibodies labeled with metallic radionuclides indium-111, gallium-67, and technetium-99m.

In this study, metallic radionuclides such as 111In, 67Ga, or 99mTc produced clear visualization in scintigraphic imaging of tumors; they have short half-lives and can easily be used in the radiolabeling of monoclonal antibodies by using bifunctional chelating agents. Under selected conditions, these radiolabeled antibodies were stable both in vitro and in vivo with no loss of the antigen-binding activity. Despite high background imaging of the liver and kidney, transplanted tumors in nude mice were clearly visualized with 111In-, 67Ga-, and 99mTc-labeled antibodies at 6, 24, or 48 hours after the injection. Although tissue distribution in the liver, kidney, and bone was different among radionuclides used for the labeling, all tumor to blood ratios were higher than those of radioiodinated monoclonal antibodies. These results provide a good basis for studies of the clinical usefulness of 111In-, 67Ga-, and 99mTc-labeled monoclonal antibodies for radioimmunoimaging.

Animals↗
PubMed1987

[Determination of serum DU-PAN-2 by enzyme immunoassay in patients with various digestive cancers].

In order to evaluate the usefulness of serum DU-PAN-2, we determined this antigen in 384 patients with various malignancies and in 215 patients with benign diseases using a sandwich enzyme immunoassay system (Kyowa Medex Co.). Elevated DU-PAN-2 levels (greater than 400 U/ml) were observed in 55% of hepatocellular cancers, 50% of pancreatic cancers, and 43% of biliary tract cancers. On the other hand, most false-positive cases with benign diseases were observed in patients with liver injury, especially in the acute phase of acute hepatitis, chronic active hepatitis, and liver cirrhosis. However, in only a few cases with other benign diseases including pancreatitis, increased levels were found. Moreover, among the pancreatic cancer or biliary tract cancer patients studied, DU-PAN-2 was positive in 7 of the 19 CA 19-9-negative (less than 37 U/ml) patients and 32 of the 68 CEA-negative (less than 5 ng/ml) patients. These results indicate that the assay of DU-PAN-2 by EIA may have diagnostic usefulness in digestive cancer, especially pancreatic cancer or biliary tract cancer.

Antigens, Neoplasm↗
PubMed1987

IgA1 & IgA2 distribution in the intestine.

The distribution of IgA1- and IgA2-containing cells was studied in 27 normal specimens taken from 3 parts of the intestine: the upper jejunum (8), the terminal ileum (5), and the large bowel (14). IgA1- and IgA2-containing cells were identified by an immunoperoxidase staining using mouse anti-IgA1 or IgA2 monoclonal antibody. The sum of IgA1-containing cells (IgA1+) and IgA2-containing cells (IgA2+) was greatest in the large bowel and least in the terminal ileum. IgA1+ were most frequent in the jejunum and least in the terminal ileum while IgA2+ were most frequent in the large bowel and least in the jejunum (p less than 0.005). The ratio of IgA1+/IgA2+ was 1.63 +/- 0.41 in the jejunum which was significantly higher than 0.65 +/- 0.46 in the terminal ileum (p less than 0.05) and 0.63 +/- 0.2 in the large bowel (p less than 0.001). These results lead to the new recognition that there is a shift in preponderance of IgA subclasses in the intestine, namely IgA1+ cells predominate in the jejunum and IgA2+ cells predominate in the intestine distal to the terminal ileum.

Adult↗
PubMed1987

[Reproducibility of somatosensory evoked potentials and EEG in normal humans under hyperbaric oxygenation].

Hyperbaric oxygenation (HBO) was reported to have a favorable influence on ischemic brain dysfunction, and also appeared to be useful in improving brain edema. Somatosensory evoked potentials (SEP) and EEG would be available as indicators of brain function. The purpose of this paper is to study reproducibility of the N1-amplitude of SEP and EEG under HBO. Materials were 10 normal volunteers, from 21 to 31 (mean age: 26) years old. Two stimulating needle electrodes were inserted into the skin at the wrist and somatosensory stimulations were applied to the median nerve with 1 msec duration square pulses. Stimulation pulses were generated regularly every 1 sec., and stimulus intensity was adjusted just above the thumb twitch threshold. Monopolar EEGs were recorded from 16 silver-cup electrodes on the scalp, and SEPs were recorded by averaging 250 responses in those EEGs using computer technique. N1-amplitude was determined by the vertical distance between peaks of the P1 and N1 components. EEGs were analyzed by Fast Fourier Transform and the square root of the averaged power of each frequency band (delta, theta, alpha 1, alpha 2, beta) was obtained and evaluated as the equivalent potential. EEGs under the influence of sleeping or artifacts, such as electromyograms, eye lid movements and wandering of the base line, were excluded in evaluating the EEGs. SEPs and EEGs recorded consecutively. The first record was taken before HBO under air breathing at 1ATA, the second during HBO under pure oxygen breathing at 2ATA, and the third after HBO under air breathing at 1ATA once again.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

[Effects of hyperoxia, glycerol and ventricular drainage on ICP and CBF in patients with increased ICP due to CSF circulatory-absorbance disturbance].

The effects of hyperoxia, glycerol and ventricular drainage on intracranial pressure (ICP) and cerebral blood flow (CBF) were studied in cases with cerebrospinal fluid (CSF) circulatory-absorbance disturbance due to subarachnoid hemorrhage (SAH) or intraventricular hematoma. Ventricular fluid pressure (VFP) was monitored through a controlled ventricular drainage (CVD) tube using a Statham P-50 pressure transducer. CBF was measured by the 10mCi133Xe intravenous injection method using a Valmet BI-1400 rCBF analyzer. ISI (initial slope index) was used for the CBF value. Studied cases were 19 SAH patients and 2 hypertensive intracerebral hematoma cases with intraventricular hematoma. Hyperoxia included hyperbaric oxygen (HBO), reduced ICP and CBF. During pure oxygen inhalation at atmospheric pressure (1ATA . O2), there was a tendency toward a relationship showing that the higher the resting state ICP, the lesser the likelihood of a CBF decrease. This may indicate that increased ICP impairs cerebral vascular reactivity to hyperoxia in relation to the degree of elevation. The effects of hyperoxia on ICP and CBF were temporary and they promptly returned to the resting state after cessation of oxygen inhalation. In some cases, there was a rebound phenomenon in ICP after HBO. Glycerol administration reduced ICP and increased CBF. There was no clear correlation between resting state ICP and CBF increase after glycerol administration. The effects of glycerol were also temporary. ICP control by opening CVD increased CBF. There was a correlation between the level of resting state ICP and the CBF increase after the opening of CVD. In cases with CSF circulatory-absorbance disturbance, elevated ICP reduced CBF and may further worsen the cerebral damage.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Serum CA 19-9 concentrations and computed tomography findings in patients with pancreatic carcinoma.

Carbohydrate antigen (CA) 19-9 is a new tumor marker, defined by a monoclonal antibody. Serum CA 19-9 concentrations and computed tomography (CT) findings were studied in 55 patients with histologically proven adenocarcinoma, and in 22 patients with chronic pancreatitis. CA 19-9 was useful in 83% of cases for the differential diagnosis between pancreatic carcinoma and chronic pancreatitis, and serum CA 19-9 levels in pancreatic carcinoma were highly related to the size of tumors. Serum CA 19-9 levels greater than 37 U/ml were seen in patients with a tumor of less than 3 cm, 3 to 5 cm, and greater than 5 cm in diameter 13% (1/8), 90% (19/21), and 92% (24/26) of cases, respectively. Tumor location, however, was unrelated to serum CA 19-9 value. These results indicated that the measurement of serum CA 19-9 concentrations would be useful in most, if not all, cases for the differential diagnosis between pancreatic carcinoma and chronic pancreatitis, and for the evaluation of tumor burden in patients with pancreatic carcinoma.

Antigens, Neoplasm↗
PubMed1986

Pharmacokinetics of TZU-0460, a new H2-receptor antagonist, in patients with impaired renal function.

We have studied pharmacokinetics of a new H2-receptor antagonist, TZU-0460, in patients with varying degrees of renal impairment. The apparent volume of distribution at steady-state was 1.70 l/kg, and the plasma protein binding of TZU-0460 or its active metabolite, desacetyl TZU-0460 was less than 10% in normal subjects. These variables were not altered with renal impairment. Sixty percent of TZU-0460 given orally was excreted via the kidney, mainly by tubular secretion. The half-time of elimination was 3.94 h in normal subjects, and was prolonged to 12.13 h in severe renal failure (creatinine clearance below 30 ml/min/1.48 m2). Dosage adjustment of TZU-0460 is necessary in renal failure.

Adult↗