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Biomedical subjects

H Nakata

Publications and source records attributed to H Nakata.

At least 253 records · Page 14Linked to original sources
PubMed1989

5'-N-ethylcarboxamido [3H] adenosine binding sites of mouse P815 mastocytoma cell membranes: solubilization and partial purification by affinity chromatography.

A 5'-N-ethylcarboxamido[3H]adenosine ([3H]NECA) binding site of mouse mastocytoma P815 cell membranes has been purified approximately 100-fold by affinity chromatography. This adenosine binding site, which has a similar specificity to that of the A2 adenosine receptor, was absorbed on NECA-linked Sepharose 6B and eluted with NECA. The adsorption of the [3H]NECA binding site to the affinity matrix was specifically blocked by NECA. The [3H]NECA binding site bound on the affinity matrix was also specifically eluted by NECA. This affinity matrix adsorbed approximately 90% of the digitonin-solubilized [3H]NECA binding activity applied, and after the gel was washed, 30-50% of the adsorbed binding activity could be eluted with 500 microM NECA with specific binding activity of 50-70 pmol/mg of protein. The affinity-purified [3H]NECA binding site retained the same ligand binding specificities as the original membrane preparation. The results indicate that the NECA-Sepharose Sepharose 6B should provide a powerful tool for the eventual purification of [3H]NECA binding sites of P815 cell membranes.

Adenosine↗
PubMed1989

5'-N-ethylcarboxamide[3H]adenosine binding sites of mouse mastocytoma P815 cell membranes: characterization and solubilization.

Mouse mastocytoma P815 cell membranes were found to possess adenosine binding sites as assessed by using the adenosine agonist [3H]5'-N-ethylcarboxamideadenosine (NECA). The Kd and Bmax for the [3H]NECA binding at 0 degrees C were 380 nM and 17 pmol/mg of protein, respectively. The rank order of potency for inhibition of [3H]NECA binding was NECA greater than 5'-N-cyclopropylcarboxamideadenosine greater than 2-chloroadenosine greater than 2',5'-dideoxyadenosine greater than isobutylmethylxanthine greater than theophylline greater than N6-[(R)-1-methyl-2-phenylethyl]adenosine = N6-[(S)-1-methyl-2- phenylethyl]adenosine. Thermodynamic analyses of the adenosine receptor agonist and antagonist binding showed that all such ligands displayed negative values of both enthalpy and entropy which suggested that the driving force for the binding was enthalpic. [3H]NECA binding sites of P815 cell membranes were solubilized with sodium cholate and retaining the same ligand-binding characteristics as those of the membrane-bound form. By gel filtration on a Sepharose CL-6B column, the adenosine binding site was estimated to have a Stokes radius of approximately 6.7 nm.

Adenosine↗
PubMed1989

[Clinical evaluation of fluconazole].

Clinical evaluation of fluconazole was performed on 12 cases of mycotic infections (7 cases of Candida esophagitis; one each case of cryptococcal meningitis with AIDS, Candida tropicalis fungemia and disseminated cryptococcosis in kidney transplant patient; 2 cases of Candida pneumonia). Satisfactory responses were obtained except 1 case of Candida pneumonia in which clinical efficacy could not be evaluated. Hiccup was noted in 1 case during the fluconazole treatment. No other adverse reaction was observed. When 150 mg and 200 mg of fluconazole were administered orally to a patient with hemodialysis (HD) after HD on separate occasions, concentrations of the drug in serum at 20 hours after ingestion were 5.9 micrograms/ml and 11.6 micrograms/ml, respectively, and in cerebrospinal fluid (CSF) were 3.5 micrograms/ml and 9.2 micrograms/ml, respectively. Two clinical benefits were obtained in our studies. First, it was possible to treat the AIDS-patient as an outpatient with Candida esophagitis using orally administered fluconazole. Second, it was possible to treat the case of cryptococcal meningitis, in which relapse often occurs, to complete the therapy when the cryptococcal antigen in serum and CSF diminished to an undetectable level and to maintain the therapy preventing relapse without severe adverse effects. Ongoing and future clinical trials will define the specific roles of fluconazole more clearly in the treatment of systemic mycosis.

Acquired Immunodeficiency Syndrome↗
PubMed1989

[Computed tomography of Pancoast tumor].

Computed tomography (CT) and chest radiography of 14 patients with Pancoast tumor were reviewed. The cross-sectional format and superior contrast resolution of CT demonstrated the relationship of the tumor to significant adjacent structures (ribs, vertebral bodies, root of spinal nerves, mediastinum and brachial plexus) better than conventional chest radiographies. CT provided additional information to the latter technique in all patients studied. An accurate assessment of the local extent of tumor was also provided by CT. Our study suggests that the obliteration of the fat plane between scalene muscles on CT indicates the tumor invasion of the brachial plexus. CT is useful in the evaluation of the patient with Pancoast tumor.

Aged↗
PubMed1989

Affinity chromatography of A1 adenosine receptors of rat brain membranes.

The A1 adenosine receptor of rat brain membranes has been solubilized with digitonin and purified approximately 150-fold by affinity chromatography. The digitonin-solubilized receptor, which can be labeled with 8-cyclopentyl-1,3-[3H]dipropylxanthine([3H]DPCPX), was adsorbed on xanthine amine congener (XAC)-linked agarose. The interaction of the solubilized receptor activity with the affinity gel was biospecific. Adenosine agents blocked adsorption of solubilized receptor activity to the XAC-agarose with the appropriate A1 adenosine selectivity. For agonists, 8-cyclopentyladenosine greater than (R)-phenylisopropyladenosine greater than CV-1808, whereas, for antagonists, 8-cyclopentyltheophylline (CPT) greater than XAC greater than isobutylmethylxanthine = theophylline. The same A1 adenosine receptor specificity was observed for elution of [3H]DPCPX binding activity from the gel. XAC-agarose adsorbed 65-80% of the solubilized [3H]DPCPX binding activity and, after the gel was washed, 30-40% of the adsorbed activity could be eluted with 100 microM CPT, with specific binding activity of approximately 60 pmol/mg of protein. The order of potency of adenosine agonists [8-cyclopentyladenosine greater than (R)-phenylisopropyladenosine greater than 5'-N-ethylcarboxamidoadenosine greater than (S)-phenylisopropyladenosine] and antagonists (DPCPX greater than XAC greater than CPT greater than isobutylmethylxanthine) with the affinity-purified preparation was found to be similar to that of the solubilized adenosine A1 receptor. This affinity chromatography procedure should prove to be valuable in the isolation and molecular characterization of A1 adenosine receptors.

Animals↗
PubMed1989

[Computed tomography of thymic hyperplasia in older children].

Computed tomography (CT) findings of 8 cases of thymic hyperplasia in children aged 7 to 15 years were retrospectively analyzed in comparison to 8 cases of tumors of anterior mediastinum. All cases of thymic hyperplasia retained a somewhat triangular or arrowhead-like shape at least on one side while tumors showed bilateral globular contour with lobulated border. No compression of the air way or pleural fluid was observed in thymic hyperplasia. These CT features are useful for making a diagnosis of thymic hyperplasia when an older child is presented with an anterior mediastinal mass on chest X-ray.

Adolescent↗
PubMed1989

[Two cases of Mycoplasma pneumonia showing nodular shadows: computed tomographic findings].

Two cases of Mycoplasmal pneumonia showing nodular shadows on roentgenogram, in a 31 year-old woman and a 28 year-old man, were reported. The consequence of a radiographical analysis reveals that the nodular shadows on the roentgenogram were revealed on CT by the thickness of the bronchoarterial bundles and the nodular opacities which had a cetriacinar or centrilobular distribution, at the ends of the branches of the pulmonary arteries and bronchi. These findings suggest that the pulmonary lesions of Mycoplasmal pneumonia were located in the peribronchial and periarterial interstitium and the bronchioles and their adjacent alveoli. CT is useful in the evaluation of nodular shadows on roentgenogram.

Adult↗
PubMed1988

Adenosine binding sites of rat pheochromocytoma PC 12 cell membranes: partial characterization and solubilization.

Rat pheochromocytoma PC 12 cell membranes were shown to possess A2-like adenosine binding sites as assessed by using 5'-N-ethylcarboxamide[3H]adenosine [( 3H]NECA). Specific [3H]NECA binding to PC 12 cell membrane at 0 degrees C was saturable and showed a monophasic saturation profile. In contrast, [3H]NECA binding to PC 12 cell membrane at 30 degrees C exhibited a biphasic profile suggesting the presence of two specific binding site. The rank order of potency for inhibition of [3H]NECA binding at 0 degrees C was NECA greater than 2-chloroadenosine greater than 2',5'-dideoxyadenosine greater than isobutylmethylxanthine much greater than phenylisopropyladenosine. These adenosine binding sites were solubilized with sodium cholate and the solubilized portion retained the same ligand binding characteristics as those of the membrane-bound form. Gel filtration experiments indicated an apparent Stokes radius of 6.7 nm for these adenosine binding sites/detergent complexes.

Adenosine↗
PubMed1988

[Estrogen receptors in human gastric, hepatocellular, and gallbladder carcinomas and normal liver tissues].

Steroid binding assay using the dextran coated charcoal (DCC) method was applied to human tissues including tumors of the digestive organs, and the results were compared with those of enzymeimmunoassay (EIA) and immunocytochemical assay (ICA) with monoclonal antibody against human estrogen receptor of MCF-7 breast cancer cells. Using the DCC method, estrogen receptor activity was detected in 6 of 26 cases (23.1%) with gastric carcinoma, 3 of 16 hepatocellular carcinoma cases (18.8%), 1 of 3 gallbladder carcinoma cases (33.3%), and both of the 2 cases (100%) with normal liver tissue. However, using EIA, no ER activity was detected in any case. Moreover, ER positive cells were not found by immunohistochemical staining in the gastric carcinoma cases or in normal liver tissue, both of which showed ER activity by the DCC method. These results suggest that the estrogen receptor like material exists in cytosol of the human digestive tumors and normal liver tissue, but that the specificity of the antibodies against estrogen receptor molecules in these tumors may be different from that of the breast tumors.

Breast Neoplasms↗
PubMed1988

[State III large cell carcinoma of the lung cured by radiotherapy--a case report].

Presented is the case of a 61-year-old male whose chief complaints were hoarseness, cough, and bloody sputum. Chest radiography demonstrated a left hilar mass with mediastinal widening, a peripheral localized infiltrate and the elevation of the left hemidiaphragm. By means of a mediastinoscopy, a biopsy was done on the enlarged mediastinal lymph node and a histological diagnosis of a large cell carcinoma was confirmed. He was graded as in Stage III (T2N2M0) and was placed under radiotherapy with 60Co. Complete response was obtained after a total dose of 6150 cGy. Following this radiotherapy, he was given multiple courses of mild chemotherapy and the disease as of this report has been under control for 7 years. This case may be unusual, but suggests the possibility of a cure of lung cancer by irradiation under certain conditions.

Antineoplastic Combined Chemotherapy Protocols↗