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Biomedical subjects

M Hatanaka

Publications and source records attributed to M Hatanaka.

At least 325 records · Page 18Linked to original sources
PubMed1983

Two distinct Ca2+ proteases (calpain I and calpain II) purified concurrently by the same method from rat kidney.

Two molecular species of calpain (Ca2+-dependent cysteine proteinases) were concurrently purified from rat kidney, both to homogeneity. Calpain I and calpain II having low and high Ca2+ requirements, respectively, were clearly separated on DEAE-cellulose chromatography at pH 7.5, and thereafter they were purified by separate but almost identical procedures which included (NH4)2SO4 fractionation and successive chromatographies on TSK-Gel G 3000 SWG, blue Sepharose CL-6B, and DEAE-Bio-Gel A. The purification folds and activity yields were 6170-fold and 17.8% for calpain I and 4160-fold and 11.9% for calpain II. Ca2+ concentrations for half-maximal activation were 2 microM for calpain I and 200 microM for calpain II. The specific activity of calpain II on casein as the substrate was more than twice higher than that of calpain I. Both enzymes are heterodimers, each composed of 80,000-Da and 25,000-Da subunits. The amino acid compositions of calpain I and calpain II are very similar but not identical. Calpain II is more acidic (pI 4.6) than calpain I (pI 5.3). This paper is the first to describe parallel isolation and characterization of low and high Ca2+-requiring proteases from one single nonmuscular tissue.

Amino Acids↗
PubMed1983

Similarity and dissimilarity in subunit structures of calpains I and II from various sources as demonstrated by immunological cross-reactivity.

The structural relationship between calpain I (low Ca2+-requiring) and calpain II (high Ca2+-requiring) molecules and their respective larger (80K) and smaller (30K) subunit proteins of several non-muscular tissues and cells was studied by testing immunological cross-reactivities. In addition to qualitative analyses by a conventional double immunodiffusion method, quantitative data were obtained, for the first time, by enzyme-linked immunosorbent assays using affinity-purified anticalpain I and anti-calpain II immunoglobulins. The enzyme sources included rat kidney, porcine kidney and erythrocytes, and human erythrocytes. It was concluded that the 30K subunits are immunologically almost indistinguishable between calpains, either I or II, not only from the same but also from different sources, while the 80K subunits of different origins are immunologically related to variable extents but always with discrimination between calpain I and calpain II. Similarity of the 30K subunit proteins and dissimilarity of the 80K counterparts were further substantiated by their chromatographic and electrophoretic behaviors.

Animals↗
PubMed1983

Synthetic cephalosporins. The synthesis and antibacterial activities of 7-[2-(2-(amino-1,3,4-thiadiazol-5-yl)acetamido]-cephalosporins.

Synthesis and antibacterial activities of 7-[2-(2-amino-1,3,4-thiadiazol-5-yl)acetamido]-cephalosporins and their derivatives having the methoxyimino group at the 2-position of the 7-acyl moiety are described. These compounds are of interest as structural analogues of potent antibiotics, 7-[2-(2-aminothiazol-4-yl)acetamido]cephalosporins. 7-[2-(2-Amino-1,3,4-thiadiazol-5-yl)acetamido]cephalosporins showed comparable activity with cefazolin. Introduction of methoxyimino group to the 7-side chain resulted in a lowering of activity.

Anti-Bacterial Agents↗
PubMed1983

Origin of adult T-cell leukemia virus. Implication for its zoonosis.

Adult T-cell leukemia virus (ATLV) is a retrovirus infecting man. The ATLV genome consists of long terminal repeat (LTR), gag, pol, env and pX sequences and does not carry a typical v-onc gene. The function of the pX sequence is unknown. To search for the origin of ATLV, segments of the ATLV genome were hybridized to DNAs of various species. The sequences homologous to the pX region of ATLV are represented in the genomes of mouse and rat but not in other species including primates and the human. Neither the pol nor U3 sequence of LTR is conserved in any cellular DNA examined. Sequences slightly homologous to the U3R sequence are found in rabbit, chicken and Xenopus. The results suggest that the pX sequence of ATLV might have derived from rodents. Since ATLV can infect primates, rabbit and rat, ATLV might have been prevalent among a wide variety of mammals and exchanged genetic segments (zoonotic) like influenza virus. If we assume that the original host of ATLV is a rodent rather than man, the pX sequence is homologous to host cellular sequences and reminiscent of the v-onc gene although the function of the pX sequence is not clear.

Animals↗
PubMed1983

Parallelism between regulatory effects of erythrocyte glycoproteins on phagocytosis and on the alternative complement pathway.

Major membrane glycoprotein fractions from erythrocytes of humans, rats, sheep and rabbits were isolated and reconstituted into dinitrophenyl (DNP)-haptenated liposomes, in an attempt to compare their effects on the phagocytic response of human polymorphonuclear leucocytes (PMN) and on the alternative pathway of human complement. These glycoproteins on liposomes, by themselves, barely induced the nitroblue tetrazolium blue (NBT)-reducing reaction in PMN cells, but exhibited a suppressive effect to a variable extent on the Fc receptor-mediated uptake of haptenated liposomes opsonized with IgG, as judged by NBT reaction. The rank order in the suppressive activity was human greater than rat, sheep greater than rabbit. In parallel to their effect on phagocytosis, these glycoproteins were also found to suppress the alternative pathway of human complement which was initiated by IgG molecules attached to the same liposome surface. The results are taken to suggest that a molecular mechanism analogous to that in the complement cascade might also be involved in the phagocytic recognition system.

Animals↗
PubMed1982

Anticancer drugs: effect on the cloning of Raji lymphoma cells in soft agar.

The effect of 11 anticancer drugs on the ability of Raji lymphoma cells to form colonies in soft agar was determined with the use of both a 1-hour and a continuous drug exposure. Three distinct patterns of drug sensitivities were observed: a) Dactinomycin, adriamycin, bleomycin, mitomycin C, vincristine, and cis-platinum II all produced a dose-dependent reduction in colony formation following a 1-hour exposure, which was further augmented by a continuous exposure to the drugs; b) the antimetabolites (methotrexate, beta-cytosine arabinoside, and 5-fluorouracil) and pentamethylmelamine had no suppressive effects on colony formation with a 1-hour exposure, but they produced marked cytotoxicity with continuous drug exposure; and c) L-phenylalanine mustard had the same degree of colony suppression with both a 1-hour and a continuous drug exposure. Preincubation of Raji cells with an enzyme mixture (DNase + pronase + collagenase) did not alter the degree of colony suppression observed with the anticancer drugs. These results indicate that continuous drug exposure should be compared to a 1-hour drug incubation to determine in vitro drug sensitivities of fresh human tumors in the soft agar clonogenic assay, because the 1-hour drug exposure may not identify certain drugs that are potentially clinically active.

Agar↗
PubMed1981

The cytosol of human erythrocytes contains a highly Ca2+-sensitive thiol protease (calpain I) and its specific inhibitor protein (calpastatin).

The cytosol of human erythrocytes was found to contain a Ca2+-dependent thiol protease (calpain) and its specific inhibitor (calpastatin) by DEAE-cellulose chromatography at pH 8.0, although no proteolytic activity toward casein was detected in the unfractionated hemolysate. The protease required only 40 microM Ca2+ for 50% activation, indicating that it belongs to the highly Ca2+-sensitive type of calpain, namely, calpain I. It was not inactivated by heating at 58 degrees C for 10 min at pH 7.2, the optimal pH for its action on casein. The inhibitor comprised major and minor components, calpastatin H (Mr = 280,000) and caplastatin L (Mr = 48,000). Both were heat-stable proteins which were readily inactivated by tryptic digestion. The inhibition of erythrocyte calpain by erythrocyte calpastatin H or L was not due to sequestering of Ca2+ from the reaction medium by the inhibitor protein. The calpain preparation preferentially digests bands III and IVa of human erythrocyte membrane proteins, with little or no cleavage of the bands corresponding to spectrin.

Calcium↗
PubMed1981

Identification of unintegrated forms of Kirsten murine sarcoma viral DNA and restriction endonuclease cleavage map of linear DNA.

We detected unintegrated linear 7.0-kilobase pair DNA and covalently closed circular DNA species in NIH3T3 cells recently infected with Kirsten murine sarcoma virus. Using the linear DNA, we constructed a restriction endonuclease cleavage map and compared it with the map of Harvey murine sarcoma virus. The restriction endonuclease maps of two segments, one 1.2 kilobase pairs (SmaI site) to 3.7 kilobase pairs (HindIII site) from the right end (corresponding to the viral 3' side) and the other 0.5 kilobase pair (SmaI and KpnI sites) to 0.9 kilobase pair (KpnI site) from the left end, were identical in the two virus types.

Animals↗
PubMed1981

[Thromboendarterectomy for cervical carotid occlusive lesions--technical note of our method (author's transl)].

In consecutive 13 cases of the carotid occlusive lesions the carotid thromboendarterectomy was performed with some of our devices as follows: 1) Superior cervical ganglionectomy was added to this operation, bringing efficacy to increase cerebral blood flow. 2) Removal of atheroma plaque en block, as far as possible, shortened the operation time and diminished the arterial wall damage. 3) We could approach to the carotid artery without dissection of the common facial vein by antero-medial retraction of the internal jugular vein. 4) The operation without internal shunt made the technique simple and shortened the operation time. 5) Interlacing vascular suture with microsurgical technique prevented narrowing or shortening of the carotid artery. 6) We used a pair of small needle holders with teeth for anterior wall suture. We could pick up the adventitia easily and exactly, and did not need change of the needle holding with these instruments. 7) Others: The clamping time ranged 15-45 minutes without any neurological deficits.

Carotid Arteries↗