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Biomedical subjects

K Kubota

Publications and source records attributed to K Kubota.

At least 19 recordsLinked to original sources

Structure of tumor antigen on hybrid cells between mouse mammary ascites tumor and mouse fibroblast L cells.

Somatic cell hybrids between mouse fibroblast L cells and MM2 mouse mammary ascites tumor grown in BALB/c mice were isolated and the structures of tumor-associated surface antigen of the hybrid cells, and parental MM2 and mouse L cells were investigated by the methods of radioiodination of membrane proteins, immunoprecipitation with a specific antiserum against tumor-associated surface antigens of MM2 tumor (anti-MM2 serum), and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Two molecules of 105,000 and 76,000 daltons were detected on the MM2 cell surface, but no MM2 tumor antigen was detected on the mouse L cells. On the hybrids between these two kinds of cells, in addition to the two MM2 tumor antigens, molecules of 48,000-51,000 and 12,000 daltons were observed. On Sendai-virus-infected mouse L cells only a molecule of 68,000 daltons was detected by the anti-MM2 serum, and furthermore this molecule was also detected by normal mouse serum, indicating that antibodies against Sendai virus were contaminating in both the anti-MM2 and normal mouse sera used, and thus the molecules detected on the hybrid cells were distinguishable from possible viral components of Sendai virus on the hybrid cells. The results indicate that somatic cell hybrids between mouse L cells and MM2 tumor grown in BALB/c mice expressed on their cell surface the molecules that were not exposed on either parent cell. The experiments comparing newly detected molecules with the H-2 antigen suggested that they were similar to H-2 in their electrophoretic pattern.

Animals

Fate and comparative toxicity of metallothioneins with differing Cd/Zn ratios in rat kidney.

Metallothioneins with differing Cd/Zn ratios were prepared in vitro from rat liver zinc-thionein by replacing zinc with cadmium and were injected intraperitoneally to female rats. The distribution of cadmium, zinc, and copper in the kidney supernatant fraction was determined using a Sephadex G-75 column. The distribution pattern of cadmium and zinc changed dramatically within 24 hr after the injection. The changes were explained by the degradation and re-synthesis of metallothionein in the kidneys. The necrotic changes of renal tubular lining cells were correlated to the amount of cadmium in the metallothionein but not to the amount of metallothionein (protein).

Animals

Cortical projection to hand-arm motor area from post-arcuate area in macaque monkeys: a histological study of retrograde transport of horseradish peroxidase.

In four macaque monkeys horseradish peroxidase (HRP) was injected into physiologically defined hand-arm motor area. Ipsilaterally, HRP labeled neurons were found in both upper and lower limbs of the posterior bank of the arcuate sulcus and in an area surrounding the arcuate spur. Contralaterally, labeled neurons were found in the same areas, though less dense in concentration. Labeled neurons were found mostly in layer III of the cortex.

Animals

Stimulation of microsomal drug oxidation activities by incorporation into microsomes of purified NADPH-cytochrome c (P-450) reductase.

The effects of addition of purified NADPH-cytochrome c (P-450) reductase on microsomal activities of aniline hydroxylation, p-phenetidine O-deethylation and ethylmorphine and aminopyrine N-demethylations were investigated utilizing microsomes from untreated, phenobarbital-treated and 3-methylcholanthrene-treated rats. The purified reductase was incorporated into microsomes. The drug oxidation activities were increased by the fortification of microsomes with the reductase while the extent of increase in the activities varied with the substrate and microsomes employed. The most pronounced enhancement was seen in p-phenetidine O-deethylation, followed by aniline hydroxylation and aminopyrine and ethylmorphine N-demethylations. The enhancement was more remarkable in microsomes from rats treated with 3-methylcholanthrene or phenobarbital. alpha-Naphthoflavone inhibited p-phenetidine O-deethylation activity markedly when the reductase was incorporated into microsomes, indicating that a larger amount of a species of cytochrome P-450 sensitive to the inhibitor was capable of participating in the oxidation of this substrate in the presence of the added reductase. One of the two Km values seen with higher concentrations of aniline or aminopyrine was altered by the fortification of microsomes with the purified NADPH cytochrome c (P-450) reductase. From these results, we propose that NADPH-cytochrome c (P-450) reductase transfers electrons to the selected one or two of multiple species of cytochrome P-450 more preferentially depending upon the substrate and the concentration of the substrate in microsomal membranes.

Animals

Muscle spindle supply to the masticatory muscles in the Japane ermine (Carnivora).

Histological examination of the jaw muscles of the Japanese ermine showed that 4 jaw-closing muscles have 13 muscle spindles on one side of the face. The temporal muscle has 99 muscle spindles, 68 being in the anterior vertical and 31 in the posterior horizontal belly. The masseter muscle has 33 muscle spindles, 23 being in the profound and 10 in the superficial belly. The medial pterygoid muscle has 7 muscle spindles and the zygomaticomandibular muscle contains 4 muscle spindles. The lateral pterygoid and the jaw-opening muscles have no spindles.

Animals

An improved plasma culture system for the production of megakaryocyte colonies in vitro.

A modified culture system has been developed to grow and quantitate megakaryocyte colonies from mouse bone marrow more efficiently than described in other reports. Using this method, it was shown that 30% of CFU-M in normal marrow cells and 70 to 90% of CFU-M in regenerating marrow cells were killed by high specific activity 3H-TdR in vitro. These results indicate that CFU-M are proliferating even in normal adult hemopoietic tissue, but that the proportion of cells that are proliferating is greater in regenerating marrow than in normal intact mice.

Animals

Horseradish peroxidase-labelled cells in cervical sympathetic and trigeminal nervous systems after injection of HRP into tooth pulp in monkeys and tree shrews (a preliminary report).

The neurons that project to the tooth pulp were examined by the HRP-retrograde transport technique, using 4 monkeys (3 Japanese monkeys and a crab-eating monkey) and 6 tree shrews. The present investigation showed that a large number of sympathetic cervical ganglion neurons, small and medium in size, project to the molar teeth from the superior, middle and inferior ganglia and a small number of Gasserian gangilon neurons (small in size) to the molar teeth ipsilaterally.

Animals

Serial studies on in vitro colony formation in patients with acute leukemia in relation to the maintenance of remission.

For the purpose of preventing a relapse of acute leukemia which is currently the major problem in the successful treatment of the disease, repeated consolidation or intensification therapy during the first year following remission is important. To evaluate these therapies, we investigated the serial changes in CFU-C's of the marrow cells from 12 patients with acute nonlymphocytic leukemia in remission and tried to estimate the relationship between the intensity of consolidation or intensification therapy and the duration of remission, utilizing the degree of reduction in CFU-C's seven days after these treatments as an indicator. As a result, after 21 out of 22 courses of therapy where CFU-C's were reduced significantly after the therapy, the patients were still in remission at the time of the next intensificiation therapy (at most for about 100 days). On the other hand, after five out of ten courses where CFU-C's were not reduced significantly, the patients were in relapse at the time of the next intensification therapy. From these results, it may be inferred that cases whose CFU-C's are not reduced significantly should be treated intensively again within a short period.

Acute Disease

A new method of pancreatic juice collection in the conscious dog.

A simplified method for the collection of pancreatic juice in a conscious dog is described and the results of pancreatic secretions in response to both exogenous and endogenous stimulations are presented. This new method, simple to perform and providing easy collection of pancreatic juice, is also applicable to the intraduodenal infusion experiments.

Animals