Biomedical subjects

K Adachi

Publications and source records attributed to K Adachi.

At least 307 records · Page 17Linked to original sources

PubMed1995

[Effects of vanadate on glucose metabolism in the lens of rats with streptozotocin-induced diabetes--ketohexokinase and aldolase activity].

The effects of vanadate, an oxidized form of vanadium, on glucose metabolism of the lens in diabetic rats were studied. Five-week-old male Sprague-Dawley rats were rendered diabetic with intraperitoneal injection of streptozotocin (50 mg/kg). One week later, the diabetic rats were given 0.2 g/l NaVO3 -5g/l NaCl solution in drinking water ad libitum for 2 weeks and biochemical parameters in their lenses were determined. Blood glucose levels significantly decreased in the vanadate-administered diabetic rats (DV group), compared with the diabetic rats given no vanadate (D group). In the DV group, a significant decrease was observed in lens fructose content compared with the D group. Lens ketohexokinase activity tended to be higher and lens aldolase activity was significantly higher in the DV group than in the D group. These results indicate that vanadate accelerates the metabolic reaction from sorbitol pathway to glycolysis.

Animals↗

PubMed1995

Follow-up observation of a patient with left ventricular thrombus by echocardiography.

We report a case of left ventricular thrombus which caused systemic embolism during warfarin therapy. A 66-year-old man admitted to our hospital with intermittent loss of consciousness and incomplete palsy. The patient had a past history of cerebral infarction, hypertension and diabetes mellitus. Electrocardiography showed abnormal Q waves at II, III, and aVF. Echocardiography showed a mobile protruding thrombus at the left ventricular apex. Left ventricular cineangiography showed a filling defect at the left ventricle. Coronary angiography confirmed total occlusion of the right coronary artery and significant stenosis of the left coronary artery. After administration of warfarin, the patient suddenly fell down to the comatose state. His left arm became pale without pulsation. The thrombus in the left ventricle disappeared by echocardiography and systemic embolism was suspected. Thromboembolectomy from his left arm was performed. Two weeks after the day brain computed tomography showed low density area at the posterior lobe of the cerebrum. Although the eyesight of the patient was lost, he could stand and walk with some help two months later. This is a rare case of systemic embolism during warfarin therapy due to left ventricular thrombus whose process was constantly observed by echocardiography.

Aged↗

PubMed1995

[Cardiac dysfunction in female gene carriers of Duchenne muscular dystrophy].

Cardiac dysfunction and its correlation with skeletal muscle dysfunction were examined in 16 definite female gene carriers of Duchenne muscular dystrophy (DMD). Five out of 16 carriers (31.3%) had cardiac symptoms and 8 carriers (50.0%) showed an increased cardio-thoracic ratio on chest X-ray. Electrocardiographic abnormalities including a high R:S ratio (> or = 1.0) in the V1 lead, deep Q wave (> 3 mm) in the I, II, aVL, V5, and V6 leads, complete right bundle branch block and premature ventricular beats, were observed in 9 carriers (56.3%). On echocardiographic examination, an increase in the end-diastolic dimension of the left ventricle and a decrease in the ejection fraction suggestive of dilated cardiomyopathy were found in 12 carriers (75.0%). Tl-201 myocardial SPECT scan was performed in 2 symptomatic carriers and showed an area of hypoperfusion in the inferio-posterior wall. These findings were similar to previously reported findings in DMD patients. A biopsy of the myocardium was obtained in one carrier with her informed consent for the biopsy. Immunohistochemical staining demonstrated that 75.4% of the myocardial fibers were negative for dystrophin, suggesting that her cardiac dysfunction is caused by the abnormal expression of dystrophin in the cardiac muscle. On examination of the skeletal muscle function, none of the carriers had clinical evidence of muscle weakness or atrophy. However serum creatine kinase activity was elevated in 14 of 16 carriers (87.5%). Computed tomography (CT) of the lower limb muscles demonstrated widened spaces among muscles and moss-eaten appearance of low density areas within muscles and CT value was decreased, suggesting the subclinical involvement of the skeletal muscle. In the carriers without cardiac symptoms, there was a negative correlation (p < 0.05) between the end-diastolic dimension of the left ventricle and the CT value of the biceps femoris muscle (a muscle with the lowest CT value among the lower limb muscles). This indicates that there was an apparent correlation between the cardiac and skeletal muscle dysfunction. These findings suggest a high frequency of clinical and subclinical involvement of the cardiac and skeletal muscles in DMD carriers. To protect them from cardiac failure, cardiac dysfunction in DMD carriers needs to be examined closely and treated appropriately before the carriers become symptomatic.

Adult↗

PubMed1994

Role of hydrophobicity of phenylalanine beta 85 and leucine beta 88 in the acceptor pocket for valine beta 6 during hemoglobin S polymerization.

Characterization of the hydrophobic EF acceptor pocket involving Phe-beta 85 and Leu-beta 88 as well as the Val-beta 6 donor site is critical for understanding the polymerization of deoxy Hb S. Glu substitutions at beta 85 or beta 88 in Hb S were made and expressed in yeast in an effort to evaluate the role of hydrophobicity in the acceptor pocket during polymerization of Hb S. Both substitutions result in decreased tetramer stability, increases in oxygen affinity, and inhibition in polymerization compared with Hb S. Critical concentrations for polymerization of Hb SF beta 85E and Hb SL beta 88E were 2.4- and 7-fold higher, respectively, than that of Hb S, while the value for Hb SL beta 88E was intermediate between those previously reported for Hb SL beta 88A and Hb SL beta 88F (Adachi, K., Konitzer, P., Paulraj, C. G., and Surrey, S. (1994) J. Biol. Chem. 269, 17477-17480). Kinetics of polymerization of Glu-beta 85 and Glu-beta 88 deoxy Hb S tetramers were biphasic at lower hemoglobin concentrations like deoxy Hb SL beta 88A, suggesting formation of two types of polymers during polymerization. The time required to form half the total amount of polymer (t1/2) for deoxy Hb SF beta 85E was 10-fold shorter than that for deoxy Hb SL beta 88E. In addition, t1/2 for deoxy Hb SF beta 85E was 2.5-fold shorter, while that for Hb SL beta 88E was 4-fold longer than deoxy Hb SL beta 88A at equivalent concentrations. These results suggest that hydrophobicity of the amino acid at beta 88 appears more critical than that at beta 85 in the acceptor pocket for Val-beta 6. Furthermore, stereospecificity of the acceptor pocket in addition to hydrophobicity of beta 88 are critical for stable hydrophobic interactions with Val-beta 6 during deoxy Hb S polymerization.

Globins↗

PubMed1994

Implantation and growth of epidermal growth factor (EGF) receptor expressing human ovarian cancer xenografts in nude mice is dependent on EGF.

BACKGROUND: The importance of epidermal growth factor (EGF) receptor-dependent growth has not been clarified for in vivo growth of primary human ovarian cancers. METHODS: Seventeen primary human ovarian cancer tissue samples were examined for the presence of EGF receptors by a 125I-EGF-binding study. Three groups of mice were inoculated with EGF receptor expressing and not-expressing cancer tissues. The groups were as follows: control group, Sx group (mice that underwent sialoadenectomy; EGF depleted mice), and Sx+EGF (EGF-replaced) group. The ability of the inoculated tissues to implant and grow then was studied. RESULTS: Of the 17 primary ovarian cancers, 12 expressed EGF receptors and 5 did not. Eight of 12 EGF-receptor expressing cancer tissues implanted and formed growing tumors in control animals. None implanted in the Sx animals. Epidermal growth factor receptor-expressing cancers implanted in Sx animals that received EGF administration. Two of five EGF receptor-negative ovarian cancers implanted and grew in both control and Sx animals. CONCLUSION: Growth of EGF receptor-expressing primary human ovarian cancers may be dependent on EGF in vivo.

Animals↗

PubMed1994

Polymerization and instability of a recombinant hemoglobin containing valine beta 7.

A recombinant hemoglobin containing Val beta 7 (Hb beta E7V) was engineered and expressed in yeast to evaluate amino acid specificity of the Glu beta 6-->Val mutation (Hb beta E6V) in promoting polymer formation of deoxyhemoglobin. The purified CO Hb beta E7V migrated as a single band on electrophoresis with a slightly decreased positive charge compared with CO Hb S. The oxygen affinity of Hb beta E7V was slightly higher than Hb S, while the absorption spectrum of the mutant was similar to Hb S. Critical concentrations for polymerization in 1.8 M phosphate of the deoxy forms of Hb beta E7V and Hb A were 15- and 25-fold, respectively, higher than Hb S. Oversaturated deoxy Hb beta E7V polymerized without a delay time prior to polymerization like deoxy Hb beta E6F and Hb beta E6W. These results demonstrate that Val beta 6 in Hb S is critical for rapid polymerization of deoxyhemoglobin. The oxy form of Hb beta E7V was approximately 2-3-fold more unstable to heat and mechanical agitation than oxy Hb S, suggesting that instability and polymerization of hemoglobin are distinct properties.

Biopolymers↗

PubMed1994

Crystallization of recombinant hemoglobins with basic amino acid substitutions (Lys and Arg) at the beta 6 position.

We have produced recombinant hemoglobins (rHbs) alpha 2 beta 2(6Glu-->Lys) (rHb beta E6K) and alpha 2 beta 2(6Glu-->Arg) (rHb beta E6R) using a yeast expression system coupled with a polymerase chain reaction (PCR)-based mutagenesis strategy for studies focused on defining determinants that facilitate crystallization of Hb C (alpha 2 beta 2(6Lys)). rHb beta E6K had the same electrophoretic mobility as native human Hb C, whereas rHb beta E6R migrated slightly slower than Hb C on cellulose acetate electrophoresis. The carbonmonoxy (CO) forms of rHb beta E6K and rHb beta E6R formed tetrahedral crystals in vitro in 2.3 mol/L phosphate buffer just like native Hb C. The Hb concentration required for crystallization of CO-rHb beta E6R was lower than that of CO-rHb beta E6K, suggesting that stronger basic amino acids at the beta 6 position accelerate crystallization of Hb. However, the size of rHb beta E6R crystals was smaller than that of rHb beta E6K. Crystallization of native Hb C and both rHbs was inhibited by Hb F. These results suggest that alpha 2 beta gamma-heterohybrids that have basic amino acids at the beta 6 position behave similarly and are unable to crystallize like Hb C.

Amino Acid Sequence↗

PubMed1994

Role of Leu-beta 88 in the hydrophobic acceptor pocket for Val-beta 6 during hemoglobin S polymerization.

X-ray crystallographic studies indicate that the hydrophobic acceptor pocket made by E and F helices involving Leu-beta 88 and Phe-beta 85 is critical for the formation of stable hydrophobic interactions with Val-beta 6 on an adjacent deoxy-hemoglobin (Hb) S tetramer. Ala and Phe substitutions at the beta 88 position in Hb S were made using a yeast expression system in an effort to clarify the role of Leu-beta 88 in creating a suitable acceptor site for Val-beta 6 during polymerization of Hb S. Both Ala- and Phe-beta 88 substitutions in Hb S inhibited polymerization compared with Hb S. Critical concentrations for polymerization of alpha 2 beta 2 Val-6,Ala-88 and alpha 2 beta 2Val-6,Phe-88 were 6- and 10-fold higher, respectively, than that of Hb S (alpha 2 beta 2Val-6,Leu-88). Deoxy-Hb S containing Phe-beta 88 polymerized without a delay time like Trp-beta 6- and Phe-beta 6-substituted hemoglobins (Adachi, K., Konitzer, P., Kim, J., Welch, N., and Surrey, S. (1993) J. Biol. Chem. 268, 21650-21656). In contrast, oversaturated deoxy-Hb S containing Ala-beta 88 also polymerized without a delay time; however, with decreasing hemoglobin concentrations, the kinetics of polymerization were biphasic. At lower hemoglobin concentrations, closer to the critical concentration for polymerization, deoxy-Hb S containing Ala-beta 88 polymerized after a distinct delay time. These results suggest that bulky beta 88 hydrophobic replacements like Phe may sterically inhibit insertion of Val-beta 6 into the acceptor pocket. In contrast, smaller sized, less hydrophobic amino acids like Ala compared with Leu-beta 88 may allow insertion of Val-beta 6 into the acceptor pocket but may not promote stable protein-protein interactions with an adjacent Hb molecule. Stereospecificity and hydrophobicity of the Val-beta 6 hydrophobic acceptor pocket as well as the beta 6 amino acid are, therefore, critical for polymerization of deoxy-Hb S.

Biopolymers↗

PubMed1994

Lactate-dependent killing of Escherichia coli by nitrite plus hydrogen peroxide: a possible role of nitrogen dioxide.

The killing of Escherichia coli by nitrite plus hydrogen peroxide was observed in lactate, but not in phosphate or acetate. Although nitrite or hydrogen peroxide alone caused a slight decrease in bacterial survival, nitrite plus hydrogen peroxide killed bacteria synergistically in time-, dose-, and pH-dependent manners. The killing was increased with decreasing pH. The plot of viable cells versus [nitrous acid] was linear. Among the hydroxyl radical scavengers used, only benzoate and formate at concentrations higher than that of lactate inhibited the killing by nitrite plus hydrogen peroxide, whereas dimethyl sulfoxide enhanced it. The generation of peroxynitrous acid during the reaction of nitrite and hydrogen peroxide was confirmed by the formation of malondialdehyde using deoxyribose as a hydroxyl radical-like oxidant detector. The nitration of glycyl-tryosine was observed only in lactate buffer, but not in phosphate and acetate buffers. Benzoate and formate inhibited the nitration, whereas dimethyl sulfoxide and ethanol enhanced it. No evidence for the formation of nitric oxide and superoxide during the reaction of nitrite and hydrogen peroxide was found. These data suggest that nitrogen dioxide from the decomposition of peroxynitrous acid or secondary oxidants formed from the reaction of peroxynitrous acid with lactate is responsible for the lactate-dependent killing of E. coli induced by the reaction of protonated nitrite and hydrogen peroxide.

Animals↗

PubMed1994

Possible gene dose effect of a mutant cardiac beta-myosin heavy chain gene on the clinical expression of familial hypertrophic cardiomyopathy.

We have examined for a mutation in the cardiac beta myosin heavy chain gene from Japanese patients with familial hypertrophic cardiomyopathy. A missense mutation due to a G to A transition in codon 935, leading to a replacement of Glu with Lys, was found in one patient. Family members of this patient were then examined. It was revealed that both the proband and his elder brother, who was also a symptomatic patient, were homozygous for the mutation. The proband eventually died of intractable heart failure, and his brother died suddenly in their thirties. On the other hand, his parents, who were first cousins and heterozygous for the mutation, had cardiac hypertrophy without clinical symptoms. His elder sister was also heterozygous for the mutation, however, she did not manifest with cardiac hypertrophy. These observations suggest a gene-dose-like effect of the mutant cardiac beta myosin heavy chain gene on the clinical manifestation of familial hypertrophic cardiomyopathy.

Adenine↗

PubMed1994

Role of gamma 87 Gln in the inhibition of hemoglobin S polymerization by hemoglobin F.

Previous studies suggested that gamma 87 Gln in hemoglobin (Hb) F is an important site for promoting inhibition of Hb S (alpha 2 beta 2(6 Glu-->Val) polymerization by Hb F. We engineered and isolated the double mutant (Hb alpha 2 beta 2(6 Glu-->Val,87 Thr-->Gln) using a yeast expression system and characterized polymerization properties of this modified tetramer in an effort to clarify the role of Gln at position 87 in inhibiting Hb S polymerization. Electrophoretic mobility and absorption spectra of this double mutant were the same as that of Hb S, while oxygen affinity was higher, and effects of organic phosphates on oxygen affinity were reduced. The deoxy form of the double mutant showed a characteristic delay time prior to polymerization in vitro. The critical concentration for polymerization of the double mutant was about 1.5 times higher than Hb S, and delay and polymerization times were much longer than Hb S at the same hemoglobin concentrations. The logarithmic plot of delay time versus hemoglobin concentration for the double mutant showed a straight line that was intermediate between lines for AS and FS mixtures. These results and those of kinetics of polymerization of Hb S/double mutant mixtures indicate that substitution of Gln for Thr at beta 87 in Hb S prolongs delay time and inhibits polymerization, although the double mutant forms polymers like Hb S.

Amino Acid Sequence↗

PubMed1994

Further studies on physicochemical properties of mitochondrial membranes during the formation process of megamitochondria in the rat liver by hydrazine.

Physicochemical properties of lipids extracted from hepatic mitochondria of rats fed with 1% hydrazine diet for 3 days (3H-mitochondria) and 7 days (7H-mitochondria) were studied using differential scanning calorimetry and the fluorescence polarization measurements. Results obtained from lipids extracted from 3H-mitochondria were as follows: (1) Thermotropic phase transition temperatures (Tm) were elevated with a distinct increase in transition enthalpy (delta H) compared to those of the control due to increases in relative amounts of phosphatidylethanolamine (PE) and phosphatidylserine (PS) in phospholipid species. (2) Tm in lipids and phospholipids extracted from 3H-mitochondria was elevated with decreases in delta H after the addition of Ca2+, whereas delta H of the control was increased after the addition of Ca2+. (3) Phosphatidylcholine (PC) liposomes containing PE or PS at concentrations corresponding to PE/PC or PS/PC ratio in 3H-mitochondria showed elevations of transition temperatures with decreases in delta H values after the addition of Ca2+, whereas those containing PE or PS ratio at concentrations corresponding to PE/PC or PS/PC in the control mitochondria showed increases in delta H values after the addition of Ca2+. (4) There were essentially no changes in membrane fluidity between lipids extracted from 3H-mitochondria and those extracted from the control mitochondria. Addition of Ca2+ to lipids extracted from 3H-mitochondria, however, caused elevation of membrane fluidity while those extracted from the control mitochondria showed no changes in membrane fluidity after the addition of Ca2+. (5) Increases in the ratio of unsaturated fatty acids to saturated fatty acids (U/S ratio) in phospholipids extracted from 3H-mitochondria were found to be mainly due to those in PS. These data may suggest that hydrazine modifies the membrane of mitochondria favorable for the membrane fusion via enhanced acidic phospholipid-Ca2+ interactions.

Animals↗

PubMed1994

Enzymic synthesis of the trisaccharide core region of the carbohydrate chain of N-glycoprotein.

Transmannosylation from mannotriose (Man beta 1-4Man beta 1-4Man) to the 4-position at the nonreducing end N-acetylglucosaminyl residue of N,N'-diacetylchitobiose was regioselectively induced through the use of beta-D-mannanase from Aspergillus niger. The enzyme formed the trisaccharide Man beta 1-4GlcNAc beta 1-4GlcNAc (3.7% of the enzyme-catalysed net decrease of N,N'-diacetylchitobiose) from mannotriose as a donor and N,N'-diacetylchitobiose as an acceptor. Mannobiose (Man beta 1-4Man) was also shown to be useful as a donor substrate for the desired trisaccharide synthesis.

Aspergillus niger↗

PubMed1994

Mobilization of intracellular Ca2+ and stimulation of cyclic AMP production by kappa opioid receptors expressed in Xenopus oocytes.

The intracellular metabotropic pathway, following kappa opioid receptor activation, was investigated in the Xenopus oocyte translation system. When oocytes were injected with cRNA for kappa opioid receptor cDNA, U50488H rarely evoked phospholipase C-mediated, oscillatory Cl- current responses. However, after the oocytes were incubated with staurosporine, both the occurrence and the amplitude of U50488H-evoked responses were increased. The U50488H-evoked response was antagonized by naloxone and inhibited by pretreatment of the oocytes with pertussis toxin. When oocytes were coinjected with RNAs encoding kappa opioid receptor and cystic fibrosis transmembrane conductance regulator (CFTR), treatment of the oocytes with forskolin and 3-isobutyl-1-methylxanthine (IBMX) evoked a smooth-shaped Cl- current flowing through the CFTR channels. The forskolin/IBMX-evoked response was never inhibited but was greatly potentiated in the presence of U50488H, indicating stimulation of adenylyl cyclase by U50488H. This U50488H-induced potentiation of CFTR channel opening was antagonized by naloxone and inhibited by pretreatment with pertussis toxin. These results suggest that kappa opioid receptors mobilize intracellular Ca2+ and stimulate cyclic AMP production by coupling positively to both phospholipase C and adenylyl cyclase via pertussis toxin-sensitive GTP-binding proteins in the oocytes.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗

PubMed1994

Quantitative evaluations of male pattern baldness.

Several methods for the evaluation of hair growth have been reported; however, none of the hitherto reported methods are satisfactory as unbiased double blind studies to evaluate the efficacy of hair growth agents. In the present paper, we describe quantitative evaluation methods for hair growth by measuring the anagen ratio and hair diameters in 56 Japanese subjects aged 23-56 for 3 years. The average anagen ratio decreased by 3.8% in 3 years. The average hair diameters showed a statistically significant decrease each year totalling 3.4 microns. Subjects were sorted according to their anagen ratio into 4 groups. Each group showed different distribution patterns of hair diameters. The higher anagen ratio group has a high frequency peak at thicker hair diameters and the lower anagen ratio group has a high frequency peak at thinner hair diameters. The number of thicker hairs decreased and the high frequency peak shifted to thinner hair diameters in 3 years. These methods are useful to evaluate both the progression of male pattern baldness and the effects of hair growth agents with double blind studies in an unbiased quantitative fashion.

Adult↗

PubMed1994

A device for automatic measurement of writhing and its application to the assessment of analgesic agents.

A device was developed for automatically measuring writhing in mice so as to be applied to the assessment of analgesic agents. The device was composed of a specially designed container equipped with a detector, namely, a mechanoelectro transducer for writhing. The detector was made up of units of a string, two plates, and two strain gauges. In the unit, each end of the string was connected to either of the plates to which either of the strain gauges was attached. The change in tension of the string due to writhing was converted into the mechanical strain of the plates and then the resistance change of the strain gauges. The resistance change was amplified by a Wheatstone bridge circuit that was connected to a differential amplifier, a high-pass filter, comparator(s), and a monostable multivibrator to obtain the electrical signal for writhing. Using this device, writhing was continuously measured, and evaluation of various types of analgesic agents was performed. The result suggests that this device has sufficient accuracy both for the detection of writhing and the evaluation of analgesics. It has the advantage of automatic measurement of writhing in contrast to the conventional visual observation method.

Acetates↗

PubMed1994

Lupus erythematosus-like syndrome induced by thiamazole and propylthiouracil.

A 17-year-old Japanese woman developed a lupus erythematosus-like syndrome during treatment for Graves' disease with thiamazole and propylthiouracil. Erythema, arthralgia, and low grade fever developed during therapy with thiamazole; purplish-red erythema developed during therapy with propylthiouracil. Antinuclear antibodies, anti-single-stranded DNA antibodies, and anti-double-stranded DNA antibodies were positive throughout the administration of these two drugs. Eruptions and other symptoms improved after their discontinuation. The titers of autoantibodies also decreased two months after withdrawal. The patient had HLA DR4.

Adolescent↗

PubMed1994

Poor response to intensive chemotherapy in de novo acute myeloid leukaemia with trilineage myelodysplasia. Japan Adult Leukaemia Study Group (JALSG).

The findings of morphologically dysplastic features in haemopoietic cells in de novo acute myeloid leukaemia (AML) has been named AML with trilineage myelodysplasia (AML/TMDS). We analysed the clinical data, karyotypes, and treatment outcomes of 230 de novo AML patients treated with the Japan Adult Leukaemia Study Group AML-87 protocol. 40 (17%) patients had AML/TMDS. Platelet count was significantly higher (P = 0.006) and bone marrow blasts were fewer (P = 0.01) in the AML/TMDS group than in the AML without TMDS. Abnormal karyotype was shown in 12/30 patients (40%) analysed. The complete remission (CR) rate for AML/TMDS was significantly lower than AML without TMDS (63% v 81%) (P = 0.01). The overall survival curves showed that the 40 patients with TMDS had a significantly worse survival than the 190 without TMDS (P = 0.0005). AML/TMDS also showed significantly worse disease-free survival (DFS) (P = 0.0001). Multivariate analysis revealed that the absence of TMDS in AML was the most significant factor in obtaining CR (P = 0.01) and a significant factor in predicting longer DFS (P = 0.04). Our data suggest that AML/TMDS responds poorly to intensive chemotherapy. Further study is required to determine the best treatment strategy for AML/TMDS and the biological differences between AML/TMDS and other types of AML.

Adult↗