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Biomedical subjects

A Hara

Publications and source records attributed to A Hara.

At least 577 records · Page 32Linked to original sources
PubMed1982

Studies on subunit components of immunoglobulin M from a bony fish, the chum salmon (Oncorhynchus keta).

Immunoglobulin M (IgM) was isolated from serum of the chum salmon (Oncorhynchus keta) by means of ion-exchange chromatography followed by gel filtration. The purified chum salmon IgM had a mol. wt of 730,000 and a tetrameric structure. However, a fraction of tetrameric IgM was considered to be non-covalently associated molecules. The amino acid composition was determined for the chum salmon micro-and L-chains and was found to be similar to that reported for other teleost fish micro- and L-chains. No J-chain- like component could be identified in the salmon IgM by either alkaline urea polyacrylamide gel electrophoresis or by the immunological cross-reaction with antisera to the human and chicken J-chain. The immunoglobulin cross-reactivity between the chum salmon micro-chain and that of 22 other fishes was tested, and only micro-chains from the family Salmonidae revealed cross-reactivity.

Amino Acids↗
PubMed1982

Chemotherapy by intravenous administration of conjugates of daunomycin with monoclonal and conventional anti-rat alpha-fetoprotein antibodies.

Monoclonal antibodies to rat alpha-fetoprotein (AFP) were produced by hybridization of mouse myeloma cells with spleen cells from mice immunized with rat AFP. The monoclonal antibodies as well as horse anti-rat AFP were coupled via a dextran bridge to daunomycin. Both types of conjugates were tested in vitro and in vivo for their anti-tumor activity. They were equally cytotoxic to rat AH66 hepatoma cell line in culture. Rats challenged with hepatoma cells were treated with the conjugates either by intraperitoneal or intravenous injections. Daunomycin conjugates with horse anti-AFP and monoclonal mouse anti-AFP were capable of delaying the tumor development more efficiently than the controls of antibodies or free drug, mixtures of drug with antibodies, and a conjugate of drug and normal immunoglobulin. The specific conjugates were considerably more effective when the treatments were given intravenously. The specific conjugates produced 60% long-term survival, whereas the controls delayed only slightly tumor development.

Animals↗
PubMed1982

Kinetic mechanisms in the reduction of aldehydes and ketones catalyzed by rabbit liver aldehyde reductases and hydroxysteroid dehydrogenases.

The kinetic properties of the NADPH-dependent reduction of aromatic aldehydes and ketones catalyzed by low- and high-molecular-weight aldehyde reductases [alcohol : NADP oxidoreductase, EC 1.1.1.2] and 3 alpha- and 3 beta-hydroxysteroid dehydrogenases [EC 1.1.1.50 and 1.1.1.51] of rabbit liver were compared. Initial velocity measurements with pyridine-4-aldehyde, 4-benzoylpyridine and androstadione as substrates and inhibition studies with their products indicated that all the enzymes followed an ordered Bi Bi reaction mechanism with coenzyme binding first and leaving last. However, phenylpyruvic acid inhibited 3 alpha-hydroxysteroid dehydrogenase and low-molecular-weight aldehyde reductase noncompetitively with respect to either NADPH or substrate, whereas it inhibited 3 beta-hydroxysteroid dehydrogenase and high-molecular-weight aldehyde reductase uncompetitively. Cibacron blue F3GA dye was a dead-end inhibitor of the enzymes, being competitive with respect to NADPH and noncompetitive with respect to the other substrate, but the Ki value of 3 alpha-hydroxysteroid dehydrogenase for this dye was much higher than those of the other enzymes.

3-Hydroxysteroid Dehydrogenases↗
PubMed1982

Isolation of proteins with carbonyl reductase activity and prostaglandin-9-ketoreductase activity from chicken kidney.

Kidney has the greatest capacity among the tissues of chicken for reducing aromatic ketones, and two ketone reductases were separated from this tissue by DEAE-cellulose chromatography and isolated. Though both are monomeric proteins with a molecular weight of 29,500, and with similar amino acid compositions and immunological properties, they differ in their pI values. The two enzyme species show no apparent difference in catalytic properties; aromatic ketones, aldehydes and quinones are reduced at high rates and alicyclic ketones such as 3-ketosteroids and prostaglandin E2 at low rates. The substrate affinity for several representative substrates at pH 7.2 is higher than that at the optimal pH of 6.3. Both enzymes prefer NADPH to NADH as a cofactor. Low NADP+-dependent reverse reactions occur with 9- and 15-hydroxyprostaglandins and certain alcohols as substrates. The enzymes show similar sensitivities to heavy metal ions, SH-reagents, quercitrin, indomethacin, and FMN.

Alcohol Oxidoreductases↗
PubMed1982

Partial purification and characterization of angiotensin-converting enzyme in mouse and human skin.

The chemical properties of skin angiotensin-converting enzyme were characterized in mouse and human. In newborn mice, dermis contained almost all activity (1.3 mU/mg), of which 30% was in the 22,000 kappa g supernatant and 70% in the pellet which could be solubilized by Triton X-100. The activity increased sharply during the first 6 weeks after the birth. By gel filtration, the enzyme in the supernatant was Mr 330,000, but the solubilized enzyme was Mr 430,000 in the presence of Triton X-100. By electrophoresis, the 2 enzyme fractions demonstrated a charge difference. The enzymes showed the same pH optima of around 8.1 and 7.7, and Km values of 2.6 and 0.11 mm for Hip-His-Leu and angiotensin I, respectively. Sensitivity to known inhibitors and heat stability of the enzymes in 2 fractions were similar. In the human, 56% of the activity in skin homogenates (1.5 mU/mg) appeared in this supernatant and 44% in the pellet. Both soluble and solubilized preparations showed enzyme activity with 2 different molecular weights, 330,000 and 430,000. The human enzymes had chemical properties similar to the mouse enzymes, but their affinity for Hip-His-Leu and angiotensin I were 1.6 and 2 times higher than those of the mouse enzymes.

Aging↗
PubMed1982

Characterization of serum protein components from Donryu rats which were immune to hepatoma AH-66 tumor cells.

Immune serum from Donryu rats which resisted rechallenge with 5 X 10(6) AH-66 tumor cells (1000 X Threshold) was examined for reactivity with these cells using three assays: 1) tumor cell agglutination 2) immunofluorescence and 3) complement mediated cytotoxicity. Whole immune serum and its components had different levels of activities in the various assays and differences in their antigenic specificities were also observed. Whole immune serum showed some activity in all assays to AH-66 tumor cells. Its specificity and that of the IgG "enriched" fraction (insoluble in 40% sat. AmSO4) was studied using the agglutination assay. A general cross-reactivity was seen with all tumor cell lines. These reactions could be eliminated by absorption of the serum or serum fraction with tumor lines other than AH-66 or with embryonic tissue. An IgG "free" derived from the 40% sat. AmSO4 precipitate showed only agglutinin activity but this reactivity, even to AH-66 tumor cells, was abrogated by absorption with embryonic tissue. Incubation of the IgG "free" fraction with tumor target cells blocked the complement mediated cytotoxicity and the immunofluorescence reactivities of the whole immune serum. The alpha 2 macroglobulin component of the IgG "free" fraction appeared to be responsible for its agglutinin activity.

Agglutination Tests↗
PubMed1982

Tissue angiotensin-converting enzyme and lysosomal enzyme levels in skin diseases.

The activities of tissue angiotensin-converting enzyme (ACE) were investigated in several skin diseases. Biopsy specimens were taken from 49 patients with granulomatous lesions, including sarcoidosis, 16 patients with nongranulomatous lesions, and 13 normal individuals. The ACE level was measured fluorometrically and the lysosomal enzyme levels were measured by established techniques. It was found that ACE activity increased in all granulomatous skin lesions, but not in other inflammatory lesions. The enzyme activity showed an increase that paralleled the time course of the disease. In contrast, lysosomal enzymes increased in various types of skin lesions, suggesting that they reflect nonspecific inflammation. These findings indicate that the tissue ACE level may be a marker for granulomatous inflammation, but one that is not specific for sarcoidosis.

Acid Phosphatase↗
PubMed1982

Abnormalities in cerebral lipids and hepatic cholesterol glucuronide of a patient with GM1-gangliosidosis type 2.

The brain tissue of a patient with GM1-gangliosidosis Type 2 showed an abnormal distribution pattern of lipids, that is, a marked increase in GM1-ganglioside, asialo-GM1 and cholesterol ester, a significant increase of glucosylceramide, lactosylceramide and asialo-GM2, and a decrease in galactocerebroside and sulfatide. On the other hand, the liver tissue showed a normal pattern of glycolipids, that is, the presence of normal amounts of glucosylceramide, lactosylceramide, globotriaosylceramide, globoside, hematoside (GM3) and GD3. However, it was found that the patient's liver contained a larger amount of cholesterol glucuronide than normal liver and that it was present only in the liver and not in the other tissues. This represents the first report of elevated cholesterol glucuronide in liver of GM1-gangliosidosis.

Brain↗
PubMed1981

Studies of heterogeneity of angiotensin-converting enzyme and acid phosphatase in granulomatous lesions of skin.

Activities of angiotensin-converting enzyme and acid phosphatase were markedly elevated in the lesions of metal-induced hypersensitivity and foreign body types of granulomas. We biochemically studied these enzymes by means of gel filtration and electrophoresis and compared them with the same enzymes of normal dermis. Two forms of angiotensin-converting enzyme found in normal dermis were increased proportionally. Catalytic properties and heat stability of the enzyme in the lesions and normal dermis were the same. On the other hand, acid phosphatase in the lesions showed a different isozyme pattern from that seen in normal dermis. The enzyme from normal dermis had apparent molecular weight of 150000 and 90000, whereas an additional enzyme with a molecular weight of 230000 was detected in granulomatous lesions. Three isozymes were demonstrable in normal dermis but two additional isoenzymes appeared in granulomatous lesions: the isozyme patterns between the foreign body and hypersensitivity granulomas are different.

Acid Phosphatase↗
PubMed1981

Purification of specific antibody to alpha-foetoprotein and its immunological effect on cancer cells.

Human of rat alpha-foetoprotein (AFP) was highly purified from ascitic fluid or serum of hepatoma bearers. The purification was carried out mainly by means of immunoadsorbent chromatography using Sepharose coupled to specific anti-AFP antibody with BrCN activation, and by Sephadex gel filtration. Horses were immunized with the purified AFP and the specific antibody was isolated from the antiserum by means of an immunoadsorbent coupled to purified AFP. The specific antibody was found to bind specifically with AFP-producing tumour cells. The antibody was applied for radio immunodetection of the tumour. 125I-labelled antibody was administered to patients or rats with hepatoma, and radioactivity localized in the tumours was scintiscanned with a scintillation camera. In this way, the location of the tumour was detected in about 50% of the hepatoma bearers. The cytotoxicity of the antibody was clearly demonstrated both in vitro and in vivo in animal experiments. The antibody was administered to patients with advanced hepatoma. Although no improvement of the disease was demonstrated, serum AFP levels decreased greatly and in some cases low AFP levels were maintained for long periods suggesting that the antibody suppressed AFP-producing hepatoma cells. No significant side effects were observed in patients who had been administered with the horse antibody.

Animals↗