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Biomedical subjects

K Adachi

Publications and source records attributed to K Adachi.

At least 667 records · Page 37Linked to original sources
PubMed1978

Demonstration of a delay time during aggregation of diluted solutions of deoxyhemoglobin S and hemoglobin CHarlem in concentrated phosphate buffer.

Diluted solutions (less than 100 mg/dl) of deoxygenated sickle hemoglobin (Hb S) and Hb CHarlem were found to aggregate with a clear demonstration of a delay time when dissolved in concentrated phosphate buffer. The delay time could be shortened by increasing the concentration of either hemoglobin or phosphate. Upon cooling or bubbling with carbon monoxide, the aggregates melted quickly. The logarithmic plot of reciprocal delay time versus hemoglobin or phosphate concentration shows a linear line with a slope of 2.7 for hemoglobin and 44 for phosphate. This suggests that diluted solutions of Hb S aggregate by the nucleation mechanism which is similar to that reported in the gelation of concentrated Hb S solution.

Buffers↗
PubMed1978

Stabilizing effect of various organic solvents on protein.

The rate of denaturation of hemaglobin and other proteins by mechanical shaking is strongly affected by organic solvents. A group pf solvents,including alcohols and ketones, was found to stabilize proteins at low concentrations, although these same organic solvents denatured proteins at high concentrations. The stabilizing effect of alcohols increased with increasing chain lenghts. The second group of solvents, including toluene and chloroform, showed only a destabilizing effect, while the third group of solvents such as formamide and pentane had no effect over a wide range of concentrations. Organic solvents may be used to protect or denature a specific protein in solutions containing various proteins.

Alcohols↗
PubMed1978

Comparative studies of Hb Lepore Boston, Hb A2, and Hb A.

Several functional tests were performed to compare Hb A, Hb A2, and Hb Lepore Boston, which has a delta-beta crossover in the region of residues 87 to 116. Oxygen equilibrium curves determined by an automatic apparatus in 0.1 M potassium phosphate buffer, pH 7.0, at 20 degrees showed that the p50 was 5.8 mm Hg for Hb Lepore Boston, in contrast to 8.1 and 10.3 mm Hg for Hb A2 and Hb A, respectively. The n values (Hill coefficinets) of Hb Lepore Boston and Hb A2 were slightly smaller than that of Hb A. The effect of 2,3-diphosphoglycerate and inositolhexophosphate on the p50 of Hb Lepore Boston and Hb A2 was less than that on the p50 of Hb A. The molecular stability to mechanical shaking of Hb Lepore Boston and Hb A2 showed that the oxy forms of Hb Lepore Boston and Hb A2 denatured at a rate 3 times faster than that of Hb A. MetHb Lepore Boston was more unstable than MetHb A2 to mechanical shaking. These results indicate that, although the molecular stability of Hb Lepore Boston is more similar to that of Hb A2 than that of Hb A, the oxygen-binding properties of Hb Lepore differ from both Hb A and Hb A2.

Carboxyhemoglobin↗
PubMed1978

Epinephrine activation of pig skin adenylate cyclase in vivo and subsequent refractoriness to activation.

Epinephrine injected intradermally activated pig skin adenylate cyclase and increased the epidermal cyclic AMP level in vivo. This biphasic response reached a maximum in 5 min and gradually decreased thereafter. The simultaneous injection of a cyclic AMP phosphodiesterase inhibitor, isobutyl methyl xanthin (IBMX) potentiated the increase. The simultaneous injection of a specific beta-adrenergic receptor inhibitor, propranolol, inhibited this accumulation of cyclic AMP. After the first activation by epinephrine in vivo, there was a marked refractoriness of the skin (epidermal) adenylate cyclase to subsequent epinephrine stimulation vivo and in vitro. This refractoriness was specific for catecholamine stimulation as responses to histamine were normal. Recovery from refractoriness started at 48 hr and was completed at 1 week after the injection of epinephrine.

Adenylyl Cyclases↗
PubMed1978

Cyclic nucleotide-phosphodiesterase in the uninvolved and involved skin of psoriasis.

In the present study we have compared cyclic nucleotide-phosphodiesterase activities and affinity of phosphodiesterase for substrates (Km) in enzyme preparations obtained from the involved and uninvolved skin of psoriatic patients. With crude skin homogenates we consistently obtained two Km values (high and low) for both the involved and uninvolved, and both Km values were nearly identical between the involved and uninvolved. The same conclusion is also drawn from the Km determinations with partially purified preparations. Cyclic AMP-phosphodiesterase activities with crude homogenates showed no statistically significant differences between the involved and the uninvolved skin. However, when cyclic AMP- and cyclic GMP-phosphodiesterase activities were compared with a highly sensitive assay method in "pure" epidermal samples, which were microdissected free from stratum corneum, dermis and skin appendages, the involved skin contained 40% more activity of the low Km enzyme and 100% more of the high Km enzyme of both cyclic AMP- and cyclic GMP-phosphodiesterase. It is suggested that this may be due to a higher proportion of germinative cells in the lesional epidermis.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1978

Cyclic AMP accumulation in psoriatic skin: differential responses to histamine, AMP, and einephrine by the uninvolved and involved epidermis.

Using the uninvolved and involved skin from psoriatic patients, we investigated the effects of histamine and AMP (or adenosine) in vitro on the intracellular cyclic AMP levels. Both agents activated adenylate cyclase of the uninvolved and involved resulting in the accumulation of cyclic AMP. Without a cyclic nucleotide phosphodiesterase (PDE) inhibitor, these responses were biphasic and the maximal accumulation was observed in 5 min. With the PDE inhibitor both responses were markedly potentiated and high levels of cyclic AMP were observed for more than 20 min. The response to histamine by the involved skin was much greater than that by the uninvolved. The degree of the response to adenosine was approximately equal. In accordance with our previous work, the response to epinephrine by the involved skin was much less than that by the uninvolved. Thus adenylate cyclases of involved skin from psoriatic patients exhibit a markedly diminished response to epinephrine while at the same time exhibiting a markedly enhanced response to histamine. This precludes the possibility that the unresponsiveness to epinephrine can be due to a generalized inability of the epidermal psoriatic plaque cell to make a functioning cell membrane.

Adenosine Monophosphate↗
PubMed1978

Aneurysm of the ductus arteriosus.

A 59-year-old man with an aneurysm of the ductus arteriosus is described. Macroscopically and histologically it was ascertained that the aneurysm had originated from the ductus arteriosus itself. We suggest the following pathogenesis: after obliteration of the pulmonary end, the aneurysm was formed, and as a result of a gradual increase in pressure in the lumen, the obliterated pulmonary end, the aneurysm was formed, and as a result of a gradual increase in pressure in the lumen, the obliterated pulmonary end recanalized.

Autopsy↗
PubMed1978

[General pharmacological studies on pepleomycin sulfate (NK 631) (author's transl)].

Pharmacological actions of pepleomycin sulfate (NK 631) which is a new antitumor agent derived from bleomycin were studied and the following results were obtained. NK 631 had no significant influences on the central, motor and sensory nervous systems at relatively higher doses (5 approximately 10 mg/kg, i.v., i.p., s.c.). NK 631 (5 approximately 10 mg/kg, i.v.) caused a slight decrease in blood pressure in anesthetized rats and slight increases in blood pressure, heart rate and peripheral blood flow in anesthetized dogs. NK 631 (1 approximately 3 mg) given close-arterially caused a slight increase in the developing tension in the isolated blood-perfused papillary muscle. NK 631 slightly contracted the isolated guinea pig ileum and rat uterus but did not affect the contraction of isolated guinea pig trachea. NK 631 caused significant increases in urine output and Cl excretion in saline loaded rats at 20 mg/kg, i.p. By the local injection of NK 631, a slight edema of rat paw and an increase in rabbit cutaneous permeability were observed. The intraperitoneal injection of NK 631 caused a significant increase in leakage of dye injected intravenously into the peritoneal cavity of mice. NK 631 did not affect hemolysis and prothrombin time at 10(-4) g/ml. In pharmacological actions, significant differences between NK 631 and pepleomycin were not observed.

Analgesics↗
PubMed1977

Specific refractoriness of adenylate cyclase in skin to epinephrine, prostaglandin E, histamine and AMP.

The cyclic AMP level in pig skin (epidermis) increases markedly after incubation with epinephrine, prostaglandin E, histamine or adenosine 5'-monophosphate. This increase is transient and "spiking" is the consistent response to these four stimulators. The "spiking" is due to a non-responsiveness or refractoriness which develops within minutes and is specific to any one stimulating hormone but not to the others. The addition of inhibitors of protein syntheses did not prevent the development of the refractoriness. Adenylate cyclase and phosphodiesterase activities measured in skin homogenates prepared from skin samples taken before, during and after the "spiking" did not change significantly. The hormone-induced refractoriness in this skin system appears to be due to a specific, localized loss of function of the adenylate cyclase system.

Adenosine Monophosphate↗
PubMed1977

Stability of glycolytic enzymes of human erythrocytes.

The stability of various glycolytic enzymes of human erythrocytes has been studied by the mechanical shaking method. The rate of denaturation apparently followed first order kinetics. The t1/2, the shaking time required to denature 50% of the original activity, for glucose-6-phosphate dehydrogenase, phosphofructokinase, and pyruvate kinase was less than 1 min; that for hexokinase, 6-phosphogluconate dehydrogenase, and monophosphoglyceromutase was between 2 and 13 min; that for all the other enzymes was more than 30 min. Since the t1/2 value for each enzyme is highly reproducible if the shaking conditions are kept constant, these parameters may be used as an indicator of protein stability in solution. The mechanical denaturation method may also be used to remove unstable components from a mixture of proteins with different stabilities.

Drug Stability↗
PubMed1977

A monomeric form of pyruvate kinase in human pyruvate kinase deficiency.

A mutant pyruvate kinase (ATP:pyruvate 2-O-phosphotransferase, EC 2.7.1.40) from human erythrocytes which is easily separated into monomers and dimers by gel chromatography is described. Tht mutant enzyme shows almost the same pH optimum and thermostability as normal enzyme, but has a decreased stability on shaking with air, a decreased Km for phosphoenolpyruvate and a loss of allosteric properties. The apparent Km values for phosphoenolpyruvate of tetramers and monomers were the same. The tetrameric enzyme was slightly activated by fructose-1,6-diphosphate but the monomeric form was not. The tetrameric enzyme was found to dissociate spontaneously to dimeric and monomeric forms.

Adenosine Diphosphate↗
PubMed1977

Epidermal adenylate cyclase systems: the retention of hormone responsiveness after enzymatic separation of pure epidermis.

Although it has been shown that keratome-sliced skin contains active adenylate cyclase systems which respond to various hormones and drugs, unequivocal proof that the epidermis contains these hormone-responsive systems is still lacking. We demonstrate in this study that "pure" epidermis obtained after either collagenase or trypsin treatment does contain the hormone-sensitive adenylate cyclase systems.

Adenosine Monophosphate↗
PubMed1977

Epidermal adenylate cyclase: stimulation of the histamine (H2) receptor by tolazoline.

Tolazoline (2-benzyl-2-imidazoline) activated adenylate cyclase in pig epidermal slices resulting in the accumulation of cyclic AMP. This effect was highly potentiated by the addition of the cyclic AMP-phosphodiesterase inhibitor, theophylline. Specific histamine (H2) receptor inhibitors (metiamide and cimetidine) completely blocked the tolazoline activation of adenylate cylase. At low concentrations (10-100 micrometer), a histamine (H1) receptor inhibitor (diphenhydramine) and a beta-adrenergic blocker (propranolol) did not inhibit this effect. The stimulation of cyclic AMP formation by the combination of tolazoline and histamine was about the same as the stimulation by histamine alone (nonadditive), whereas the stimulatory effects by tolazoline and epinephrine were additive. These data suggest that tolazoline, an alpha-adrenergic blocker, also activates adenylate cyclase at the histamine (H2) receptor site which is distinct from the beta-adrenergic receptor site. Another alpha-adrenergic blocker, phentolamine, did not have this effect.

Adenylyl Cyclases↗
PubMed1977

Noonan syndrome with hypertrophic obstructive cardiomyopathy.

A case of a 20 years old female who had Noonan syndrome associated with obstructive cardiomyopathy was presented. It is well known that Noonan syndrome is frequently complicated with cardiac anomaly, and although no autopsies were performed two cases have been diagnosed clinically as Noonan syndrome accompanied with idiopathic cardiomyopathy in our country. The present case would be the first autopsied case in Japan of Noonan syndrome associated with idiopathic obstructive cardiomyopathy.

Adult↗