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Biomedical subjects

K Adachi

Publications and source records attributed to K Adachi.

At least 649 records · Page 36Linked to original sources
PubMed1980

Aggregation of hemoglobin S and hemoglobin CHarlem with nonsickle hemoglobin in concentrated phosphate buffer.

The effect of HbA and HbF on both the aggregation and deaggregation of deoxy HbS and deoxy HbCHarlem in concentrated phosphate buffers was studied by a turbidimetric method. Although pure deoxy HbA is fully soluble in 2.4 M potassium phosphate buffer, the same concentration of deoxy HbAS was insoluble in the same buffer. Since there was little dissolved hemoglobin in the solute of a mixture of HbA and HbS, and since the intensity of turbidity was approximately twice that which would be expected from deoxy HbS alone, deoxy HbA must have coaggregated with deoxy HbS. Similar studies with mixtures of HbS and HbF showed different results. The rates of aggregation of deoxygenated mixtures of HbS and HbF were much slower than those of similar mixtures of HbS and HbA. Measurements of the absorption spectrum of the solute after centrifugation and the electrophoresis of both the aggregates and the solutes showed that a portion of the HbF was coaggregated with HbS, while some of the HbS was still in solution. The solubility of HbS and mixtures of sickle and nonsickle hemoglobins in 2.2 M phosphate buffer increased in the order of HbS, HbACHarlem, HbAS, HbCHarlem, HbSF, and HbFCHarlem.

Blood Protein Electrophoresis↗
PubMed1979

Formation of nuclei during delay time prior to aggregation of deoxyhemoglobin S in concentrated phosphate buffer.

The delay time prior to aggregation of deoxyhemoglobin S was found to be shortened significantly if monomeric deoxyhemoglobin S was added near the end of the expected delay time. This suggests the formation of a preaggregation complex of deoxyhemoglobin S, probably so-called "nuclei", near the end of the delay time. In fact, the molecular weight of deoxyhemoglobin S as measured by a low angle laser light scattering photometer increased exponentially during the delay time prior to the visible aggregation of deoxyhemoglobin S. These results support the nucleation-controlled aggregation mechanism for the aggregation of deoxyhemoglobin S in concentrated phosphate buffer.

Biopolymers↗
PubMed1979

The effect of magnesium starvation on the dissociation of ribosomal proteins from Escherichia coli K-12 ribosomes.

The effect of magnesium starvation upon the fate of individual ribosomal proteins was studied in Escherichia coli. During a 21 h incubation in the absence of Mg2+ the 30 S subunit was more susceptible to degradation, retaining an average 31.9% of its ribosomal proteins as compared to 40.0% for the 50 S subunit. An examination of those 50-S proteins dissociated to a lesser extent than the average value (L1, L2, L3, L7, L10, L13, L16, L17, L19, L21, L22, L23, and L29) revealed that, with the exception of L16, all were classified by Dohme and Nierhaus [5] as tightly bound. Of the ribosomal proteins dissocated during magnesium starvation only five were reincorporated (and these to a minimal degree) during recovery of cells in a medium containing Mg2+. These studies suggest that ribosomal proteins once released from the ribosome particles during magnesium starvation are not reutilized in the assembly of new subunits.

Bacterial Proteins↗
PubMed1979

The solubility of sickle and non-sickle hemoglobins in concentrated phosphate buffer.

A new turbidimetric method for the direct measurement of the solubility of oxy- and deoxyhemoglobins (Hb) in concentrated phosphate buffer has been established. The principle of the method is the formation of a homogeneous emulsion when hemoglobin is introduced in concentrated phosphate buffer. The solubility of the oxy and deoxy forms of Hb A, Hb S, Hb C, Hb F, and Hb CHarlem (beta 6Glu leads to Val, beta 73Asp leads to Asn) has been studied. The solubility of deoxy-Hb S was the lowest and the solubility curve was broader than those of the other hemoglobins indicating that the aggregates of deoxy Hb S require more water to be dissolved. The solubility of oxy- and deoxyhemoglobins depends on temperature and pH. The solubility of hemoglobins is increased as the temperature is lowered and the pH is raised. The pH dependency of the solubility of deoxy-Hb S in high phosphate buffer was opposite to that of the minimum gelling concentration of deoxy-Hb S. The order of the solubility of Hb CHarlem, Hb FS, Hb AS, Hb CS, and Hb S in concentrated phosphate buffer corresponds to the order of minimum gelling concentration of these hemoglobins or hemoglobin mixtures. Solubility studies of a 1:1 mixture of deoxy-Hb A and deoxy-Hb S show that deoxy-Hb A aggregates in 2.42 M phosphate buffer in which pure deoxy-Hb A is totally soluble. This result indicates that deoxy-Hb S interacts with deoxy-Hb A and decreases its solubility.

Buffers↗
PubMed1979

Cyclic GMP System in epidermis: I. Effect of ischemia.

When keratome-sliced pig epidermis was floated on Hank's balanced salt solution, we observed a rapid decrease in the intracellular level of cyclic GMP. A portion of the lost cyclic GMP was detected in the incubation medium. When the epidermis was kept in air at room temperature, the cyclic GMP level also decreased rapidly but to a lesser degree. Incubating the epidermal slice at 37 degrees C in Hank's balanced salt solution with the addition of 3-isobutyl-1-methyl xanthine (IBMX) prevented the decrease. Also, after the cyclic GMP level had fallen, it could be raised to be the in vitro level by the addition of IBMX. Increased amounts of cyclic GMP were detectable in the medium in this case. These data indicate that the decrease in cyclic GMP in ischemic epidermis is due to sudden activation of epidermal cyclic GMP-phosphodiesterase and also in part due to leakage of cyclic GMP extracellularly. In contrast to the rapid decline in the cyclic GMP level, ischemia caused a rapid and transient increase in epidermal cyclic AMP. This confirms previous data by ourselves and by others (Br J Dermatol 92: 249-254, 1975; J Invest Dermatol 68:125-127, 1977). These "ischemic effects" must be avoided in order to measure the "in vivo level" of cyclic nucleotides in epidermis.

1-Methyl-3-isobutylxanthine↗
PubMed1979

A combined alkali extraction--ethidium bromide technique for the measurement of DNA in small pieces of tissue.

Alkaline solutions (0.1--0.5 N NaOH) at elevated temperatures can be used to extract DNA from small pieces of tissue. RNA is destroyed by the treatment. In tissues which have been previously exposed to tritiated thymidine, aliquots from the extracting solution can be used directly for the determination of DNA by ethidium bromide fluorescence and radioactivity in both DNA and the nucleotide pool.

Animals↗
PubMed1979

Hereditary stomatocytosis: association of low 2,3-diphosphoglycerate with increased cation pumping by the red cell.

The levels of glycolytic intermediates have been measured in red cells from patients with both overhydrated and dehydrated varieties of the hereditary stomatocytosis syndrome. Red cell 2,3-diphosphoglycerate was reduced by 33% below normal in all patients with either stomatocyte or target cell morphologies (i.e. over or under hydrated varieties respectively). The relative decrement in 2,3-diphosphoglycerate was even greater when abnormal cells were compared with control cells with similar reticulocytosis. Red cell ADP concentrations in stomatocytosis were significantly increased above normal but ATP concentrations were not significantly changed. Whole blood oxygen affinity in stomatocytosis was increased in proportion to the lowered content of diphosphoglycerate. Some new parameters of membrane transport in hereditary stomatocytosis have been measured. Platelet K+ and Na+ concentrations and platelet K+ permeability were normal in stomatocytosis. The number of 3H-uridine transport sites in stomatocytes were increased by 9-39% above normal and this increment was the same as the increment in red cell lipids (0-38%). Hereditary stomatocytes contain 2-10-fold more cation pumps than normal and the increased active cation pumping may explain the high ADP, the low 2,3-diphosphoglycerate concentration and the increased oxygen affinity in this syndrome.

Adenosine Diphosphate↗
PubMed1979

[Treatment with NK 631 (new bleomycin analog) of oral and maxillofacial cancer (author's transl)].

Eight cases of malignant tumors of the head and neck were treated with NK 631 on a dosage schedule of 10 mg at a time 3 times weekly, by intravenous one-shot injection or intravenous drip infusion, to observe its therapeutic effects and adverse reactions. The treatment was assessed markedly effective in 3, moderately effective in 1 and ineffective in 4 of them. The treatment was also assessed moderately or markedly effective in 3 and ineffective in 2 out of squamous cell carcinoma cases. Hematologic findings, serum electrolytes and enzymologic findings were normal, but the pulmonary function examinations revealed a tendency for PaO2 to decrease slightly. In 1 case where frequent cough was observed, the cough was mitigated on withdrawal of the treatment. The adverse reactions that evolved included fever, alopecia, eruptions, nausea and vomiting, and pigmentation of the nail. To summarize these findings, the authors were impressed with NK 631 and that the agent would exert an excellent antitumor effect, compared with bleomycin, and that its effect would evolve at the early stage of its treatment. Fixed drug eruption was observed as an adverse reaction of this drug in 1 case; however, the adverse reactions of this bleomycin analog appear similar to those of its parent compound, bleomycin.

Adenocarcinoma↗