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Biomedical subjects

M Kondo

Publications and source records attributed to M Kondo.

At least 1,315 records · Page 73Linked to original sources
PubMed1982

Induction of delta-aminolevulinic acid synthase and delta-aminolevulinic acid dehydratase in normal human bone marrow cultures.

Activities of delta-aminolevulinic acid (ALA) synthase and ALA dehydratase, the first and the second enzymes of the heme biosynthetic pathway, were determined in erythroid colonies derived from normal human bone marrow in culture. ALA synthase and ALA dehydratase were induced when normal human bone marrow cells were incubated in the presence of erythropoietin (Ep) in culture, and the extent of induction of ALA synthase as well as ALA dehydratase was dependent on Ep concentrations and culture periods. Both ALA synthase and ALA dehydratase were increased in cultured erythroid cells before the appearance of morphologically recognizable hemoglobinized colonies, corroborating the sequential induction of heme biosynthetic pathway enzymes in human bone marrow erythroid cells.

5-Aminolevulinate Synthetase↗
PubMed1982

[Dynamic wallpaper phenomenon and fusional hysteresis].

Two experiments were conducted with six and three subjects, respectively, to examine the "dynamic" wallpaper phenomenon in which the apparent location of a uniform repeating pattern shifted abruptly at a certain convergence distance when the pattern was viewed with the gradual change of convergence. Experiment 1 demonstrated that the critical convergence distances (shift points), at which the apparent location of the pattern shifted, differed between the two directions of the change of convergence, converging and diverging. It was greater in the diverging condition than in the converging condition. This fact shows a tendency to keep the same fusional state as far as possible when the convergence changes gradually. Experiment 2 showed that the difference of the critical convergence distance between the converging and diverging conditions is systematically related to the convergence level, that is, the difference increased as the convergence angle increased. The implications of the results of the two experiments were discussed in the context of the fusional hysteresis.

Adult↗
PubMed1982

[Psychophysical and vergence responses of normal and stereoanomalous observers to pulse-disparity stimulus].

The relations between psychophysical and oculo-motor responses to retinal disparity were examined in two experiments. Experiment I examined the subject's discriminability of the depth produced by 2 degrees crossed, 2 degrees uncrossed, and zero disparities with the durations of 100 and 1000 ms. As a result, six stereonormal, one crossed stereoanomalous, and one stereoblind observers were identified. In Experiment II, eye movement responses of three subjects with the different types of stereoscopic vision to the disparity pulses were monitored by the photo-electric method. The results of Experiment II indicated that the normal observer showed normal vergence, the crossed stereoanomalous observer showed anomalous convergence, and the stereoblind observer did not show any vergences but saccadic movements. Several theoretical implications of the results are discussed.

Adult↗
PubMed1981

A cryptobiosis-specific 19S protein complex of Artemia salina gastrulae.

The postribosomal supernatant of Artemia salina cryptobiotic embryos contains a large quantity of a 19S protein complex. An amount of 3.6 mg/g of cysts is measured by immunoprecipitation with anti-(19S protein complex) antibody. The quantity of this complex decreases during further development to nauplius larvae to only 15% of the quantity present in cryptobiotic embryos. The complex was no longer detectable after 7 days of growth. The 27000-Mr protein subunit of the 19S complex is not synthesized by mRNA isolated from cryptobiotic embryos. The cryptobiosis-specific complex has Mr 573000 and 610000 as calculated from light-scattering and sedimentation-diffusion measurements respectively. The 19S homocomplex contains 20-23 27000-Mr proteins and has no function in the translation of homologous mRNA. From hydrodynamic data a hydration of 1.25 g of water/g of protein is calculated. The abundant presence of the 19S protein complex in cryptobiotic embryos and the absence of synthesis during development to nauplius larvae indicate a functional role during the cryptobiotic process in early embryogenesis. A role in maintaining the water content of the cytoplasm above a critical threshold during desiccation is suggested.

Animals↗
PubMed1981

Biophysical characterization of Artemia salina (L.) extracellular haemoglobins.

Sedimentation coefficients (s0 20,w) of 11.57 +/- 0.10 S and 11.52 +/- 0.09 S were assigned for Artemia salina (L.) extracellular haemoglobins II and III respectively. These values are not significantly different. The molecular weights, M0w and M0z, of the native haemoglobins as determined by the high-speed sedimentation-equilibrium method were for haemoglobin II 239 400 +/- 7200 and 240 400 +/- 2600 respectively, and for haemoglobin III 216 300 +/- 6500 and 219 300 +/- 4500 respectively. The observed increase of Mapp. with concentration suggested that association was occurring over the concentration range investigated. Exposure of haemoglobin II to either 6 M-guanidinium chloride or to low pH (pH 4) resulted in dissociation to units of approximately half the size of the native protein, with molecular weights approx. 115 000. Electron-microscopic observations indicated a molecular structure composed of two stacked lobed discs. These results strongly support the dimeric model for Artemia haemoglobins proposed by Moens & Kondo [(1978) Eur. J. Biochem. 82, 65-72].

Animals↗
PubMed1981

Experimental model of disseminated intravascular coagulation induced by sustained infusion of endotoxin.

Experimental disseminated intravascular coagulation (DIC) was induced by sustained infusion of endotoxin into the femoral vein in rats. The severity of DIC was determined with reference to various parameters, such as fibrinogen and fibrin degradation products (FDP), prothrombin time (PT), partial thromboplastin time (PTT), platelet count, and number of renal glomeruli having fibrin thrombi. Experimental DIC could be induced by a 4-h sustained infusion of endotoxin in a dose of 100 mg/kg. The DIC induced in rats showed a close resemblance to human DIC as judged from such changes as an elevation in FDP, prolongation of PT and PTT, depression in fibrinogen and platelet count, and increase in glomeruli having fibrin thrombi. This experimental model has an advantage in that severity of DIC can be determined by measuring various parameters. It will be of use in the studies aimed at the establishment of a therapy for DIC as well as in the studies on DIC in rats.

Animals↗
PubMed1981

The protection of coenzyme Q10 against carbon tetrachloride hepatotoxicity.

It has been suggested that lipid peroxidation is an important factor in the pathogenesis of carbon tetrachloride (CCl4) hepatotoxicity. In the present study, experimental liver injury induced by CCl4 could be inhibited by Coenzyme Q10 (CoQ10) and in spite of exposure to CCl4 the liver tissue levels of thiobarbituric acid (TBA) reacting substances were not increased in rats pretreated with CoQ10. In the in vitro experiment as well, the apparent liver tissue levels of TBA were decreased after addition of CoQ10. These facts provided evidences that CoQ10 possessed a direct antioxidative effect and protected against CCl4 hepatotoxicity by this antioxidative effect.

Animals↗
PubMed1981

Echocardiographic features of the false tendons in the left ventricle.

M mode and two dimensional echocardiographic features consistent with previously reported autopsy findings of false tendons were seen in 5 of approximately 1,000 consecutive echocardiographic examinations. Later, the presence of false tendon was proved at autopsy in one of the five cases. Examination in three cases revealed heart disease: aortic regurgitation, third degree atrioventricular (A-V) block with aortic regurgitation and invasive thymoma with pericardial effusion; examination in two cases revealed no heart disease. In three cases, M mode echocardiograms revealed in the outflow tract of the left ventricle abnormal linear echoes that strongly mimicked those in other disorders such as discrete subaortic stenosis or flail aortic valve. In two cases, there were abnormal linear echoes in the left ventricle toward the apex. In three cases, two dimensional echocardiograms revealed long-string-like echoes stretching from the upper part of the interventricular septum across the ventricular cavity to the lateral wall of the left ventricle in long and short axis views or in four chamber views. In two cases, long slender echoes between the lower parts of the interventricular septum and the left ventricle were seen in apical long axis views. These string-like echoes seem to represent the false tendons previously reported at autopsy, although actual pathologic confirmation was available in only one of the five cases. It is concluded that (1) M mode and two dimensional echocardiograms can demonstrate the presence of false tendons, (2) two dimensional echocardiograms are useful in differentiating false tendons from other conditions causing abnormal linear echoes in the outflow tract of the left ventricle on M mode echography.

Adult↗
PubMed1981

The use of Taka-diastase in a[3H]poly(A) hybridization assay of oligo(U) sequences in RNA.

A reliable assay of uridylate sequences longer than 10 is described. The procedure is based on the hybridization of [3H]poly(A) with poly(U) or oligo(U) sequences in high ionic conditions and a subsequent degradation of single stranded polynucleotides with purified Taka-diastase. A 1:2 complex between poly(A) and poly(U) is formed on which on poly(U) strand is digested by Taka-diastase. The procedure is especially suitable for the detection and quantitation of Un (n greater than 10) in RNA preparation.

Amylases↗
PubMed1981

Protein synthesis in the isolated forespores from sporulating cells of Bacillus subtilis.

Developing forespores were isolated from Bacillus subtilis at different stages of sporulation and protein synthesis in the forespore compartment was examined. Pulse-labeling experiments indicated that [14C]phenylalanine was continuously incorporated into the sporangium throughout sporulation, and at t5 (early stage V of sporulation) 58% of the radioactivity was located in the forespore compartment. Significantly high incorporation of [14C]phenylalanine was observed when the isolated forespores at t5 were incubated with the corresponding mother-cell cytoplasmic fraction or an amino acid mixture. About 73% of the radioactivity incorporated into the isolated forespore at t5 was found in the cytoplasmic fraction and 26% in the membranous fraction. Analysis by sodium dodecyl sulfate-gel electrophoresis showed that the 14C-labeled cytoplasmic protein had a molecular weight of about 20,000, and that a protein having the same molecular weight was present in the t5 forespore as a slight protein band and also in the mature spore as a clear protein band. Gel electrophoresis also revealed that the 14C-labeled membranous-soluble protein (prepared by solubilization with detergents) had broad peaks with molecular weights of about 74,000, 33,000, 20,000, and 12,000.

Bacillus subtilis↗