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Biomedical subjects

K Maeda

Publications and source records attributed to K Maeda.

At least 1,333 records · Page 74Linked to original sources
PubMed1985

Complete amino acid sequence of an alpha-amylase inhibitor in wheat kernel (0.19-inhibitor).

Amino acid composition of the 0.19-inhibitor from wheat kernel is very similar to that of the 0.53-inhibitor, but a marked difference in inhibitory activity towards human salivary and pancreatic alpha-amylases was detected between the two inhibitors. Elucidation of the primary structure of the 0.19-inhibitor and structural comparison with the 0.53-inhibitor is essential to understand not only the mechanism of the selective inhibitory behaviors but also evolutional relationship of these inhibitors. The complete amino acid sequence of the 0.19-inhibitor was determined after cleaving the protein with cyanogen bromide and trypsin. As in the case for the 0.53-inhibitor, the 0.19-inhibitor is composed of two identical subunits with 124 amino acid residues. Comparison of the sequence of the 0.53- and 0.19-inhibitor shows very high sequence homology with amino acid substitutions at seven positions.

Amino Acid Sequence↗
PubMed1985

Monoclonal antibodies against an alpha-amylase inhibitor from wheat kernel.

An alpha-amylase inhibitor (called the 0.53-inhibitor, Maeda, K., Takamori, Y. and Oka, O. (1982) Agric. Biol. Chem. 41, 2873-2875) and the carboxymethylated inhibitor were used to immunize mice (strain BALB/c) according to a procedure described earlier (McMaster, W.R. and Williams, A.F., (1979) Eur. J. Immunol. 9, 426-433). After fusion of spleen cells with NS-1 myeloma cells, three stable clones producing antibodies against the inhibitor were obtained. The binding characteristics of the monoclonal antibodies, AWAI-1, AWAI-2 and AWAI-3, to the inhibitor were analyzed by radioimmunoassay. Two of these monoclonal antibodies to the alpha-amylase inhibitor did not show any binding affinity towards carboxymethylated inhibitor, suggesting that the main antigenic determinant on the native inhibitor is tertiary-structure dependent. The monoclonal antibodies obtained cross-reacted with three other alpha-amylase inhibitors (the 0.19-, the 0.36- and the 0.38-inhibitor) in wheat and these were separated together with the 0.53-inhibitor from the rest of inhibitors by immunoaffinity chromatography. One stable clone producing antibody against the carboxymethylated inhibitor was also established, AWAI-4. The antigenic determinant to this antibody was found to be included in the region of Met(5)-Lys(25) on the carboxymethylated inhibitor.

Animals↗
PubMed1985

Multiple myeloma terminating in acute eosinophilic leukemia.

A 71-year-old woman with multiple myeloma was successfully managed for 8 years with melphalan (total dose 2056 mg). She developed a refractory anemia (myelodysplastic state), which terminated in acute eosinophilic leukemia. This form of acute leukemia, induced by chemotherapy, appears to be very rare. The cytogenetic changes, including 5q- and monosomy 7, were similar to those observed in other patients with acute nonlymphocytic leukemia as a secondary malignancy following treatments of other primary tumors.

Acute Disease↗
PubMed1985

Availability of 6-hydroxynicotinic acid for rapid identification of Pseudomonas aeruginosa and Serratia marcescens.

Gas chromatography--mass spectrometry has been used to identify specific metabolites produced by Gram-negative bacteria such as Pseudomonas aeruginosa, Serratia marcescens, Klebsiella pneumoniae and Escherichia coli in a defined medium. 6-Hydroxynicotinic acid was detected in spent culture media of Pseudomonas aeruginosa and Serratia marcescens, but could not be detected in those of Klebsiella pneumoniae and Escherichia coli. The production of 6-hydroxynicotinic acid was recognized by the addition of nicotinic acid in urine with Pseudomonas aeruginosa or Serratia marcescens, but not without the addition of nicotinic acid. Among 10(5) Pseudomonas aeruginosa per 1 ml of urine (criteria for the diagnosis of urinary tract infection), 0.15 microgram of 6-hydroxynicotinic acid was detected in urine at 4 h incubation with nicotinic acid at the optimum pH of 6.9, 38 degrees C. The production of 6-hydroxynicotinic acid was proportional to the number of the bacteria and displayed a time dependency. These results suggest that the availability of 6-hydroxynicotinic acid might make for more rapid identification of bacteria than current methods.

Culture Media↗
PubMed1985

Distribution and organelle specificity of melanoma-associated antigens identified by Mo 465.12 in human malignant melanoma.

Mo 465.12 (Mo 465) is a unique monoclonal antibody that detects cytoplasmic antigens highly restricted to the cells of human malignant melanoma (MM). As yet, it is not known which cytoplasmic components are reactive with Mo 465 within MM cells. This study, using the enzyme-linked immunosorbent assay (ELISA) technique, examines the distribution and specificity of Mo 465-reactive proteins in MM tissues that were isolated by cell fractionation and solubilized by a nonionic detergent (Brij 35). Light microscopically, Mo 465 bound strongly to the cytoplasm of MM cells, being localized as patchy or microgranular, but not to the normal epidermal melanocytes. When the cultured MM cells were fractionated, Mo 465 reacted with both soluble and membrane fractions and with the spent culture medium. To further identify the organelle specificity of Mo 465-reactive proteins, metastatic human MM and normal human liver tissues were separated into the fractions of large granules, small granules, Golgi apparatus, mitochondria, rough endoplasmic reticulum (ER), smooth ER, microsomes, and melanosomes. Mo 465-reactive proteins were detected in the fractions of crude homogenate, microsomes, and rough ER of MM tissue, and their reactivities were in parallel to the concentration of solubilized protein. the findings indicate that Mo 465-reactive proteins are localized in rough ER, that they are released into the cytoplasm, and that in the in vitro condition they are shed into the culture medium.

Antibodies, Monoclonal↗
PubMed1985

Activation and inactivation of a variety of mutagenic compounds by the reconstituted system containing highly purified preparations of cytochrome P-450 from rat liver.

Six cytochrome P-450 preparations from phenobarbital (PB)-treated rats and two preparations from beta-naphthoflavone (BNF)-treated rats were purified. Using Salmonella typhimurium TA98 the ability of these cytochrome P-450 preparations to mutagenically activate and inactivate a variety of carcinogens was examined. High- and low-spin forms of cytochrome P-448 isolated from BNF-treated rats (BNF-IIa and IId) activated various carcinogens. Both forms activated 2-aminofluorene, benzo[a]pyrene, and dibenz[a,c]anthracene. However, o-aminoazotoluene and 2-nitrofluorene were activated only by the low-spin form, and aflatoxin B1 only by the high-spin form. In contrast, only limited carcinogens were activated by some preparations from PB-treated rats. 2-Aminofluorene was activated by four PB-inducible preparations (PB-Ia, Ic, Id, and IIa), but only moderately. Unexpectedly, however, the most prominent activation of benzo[a]pyrene was observed with one preparation (PB-Id) from PB-treated rats. Direct mutagens to the S. typhimurium, 4-NQO and AF-2, were markedly inactivated by NADPH-cytochrome c (P-450) reductase without cytochrome P-450. One PB-inducible form (PB-Ic) inactivated 2-nitrofluorene, and the high-spin form of P-448 (BNF-IIa) inactivated AF-2.

Aflatoxin B1↗
PubMed1985

Successful surgical treatment of dissecting left atrial aneurysm after mitral valve replacement.

Dissecting aneurysm of the left atrium is extremely rare. A patient with such an aneurysm, which developed after mitral valve replacement is described. The diagnosis was established by cineventriculography of the left ventricle and two-dimensional echocardiography. The aneurysm was successfully treated by closure of the communicating opening through the left thoracotomy incision.

Adult↗
PubMed1985

Short bowel syndrome in infants and children.

This article defines short bowel syndrome and reviews the pathophysiology, medical management, and surgical manipulations proposed to improve intestinal absorption. Emphasis is also placed on possible future methods of management.

Animals↗
PubMed1985

Epidermodysplasia verruciformis associated with Bowen's carcinoma, B lymphocytopenia and decreased immune functions.

A case of epidermodysplasia verruciformis associated with Bowen's carcinoma, persistent B lymphocytopenia and decreased immune functions is reported. Human papilloma virus 5 (HPV-5) DNA was shown to be associated with the DNA from the tumor tissue by Southern blot hybridization using P-labeled HPV DNA sequences cloned on plasmid vectors. The associated Bowen's carcinoma in our case may be caused by multiple-factor relationships which include (a) an oncogenic potential of infected virus; (b) an inherited abnormality in immune function, and (c) the decreased immune function resulting from the viral infection itself. A marked B lymphocytopenia appears to be associated with persistent viral infection.

Aged↗
PubMed1985

Effects of diethyldithiocarbamate, a metabolite of disulfiram, on the pharmacokinetics of alcohol and acetaldehyde in the rat.

The effects of diethyldithiocarbamate (DDC), a metabolite of disulfiram which is known as Antabuse, on the blood concentrations of alcohol and acetaldehyde were determined simultaneously by head space gas chromatography in rats. After an intravenous injection of alcohol, the blood concentration of acetaldehyde was much lower than that of the alcohol. A pharmacokinetic model featuring the liver compartment for acetaldehyde was used to estimate pharmacokinetic parameters on the assumption that the distribution volumes of the central compartments were same for alcohol and acetaldehyde, and that the elimination rate of acetaldehyde from liver was large enough to isolate the liver compartment from the central compartment. The results showed that the clearance of alcohol was 0.0226 l/min/kg and the elimination rate constant of acetaldehyde from the liver compartment was very large and 35 min-1. The administration of DDC decreased the above significantly to 0.0132 l/min/kg and 20 min-1, respectively. After intravenous infusion of acetaldehyde, the time course of the blood concentration of acetaldehyde was analyzed by the one compartment model. The estimated elimination rate constants from blood and the distribution volume were in good agreement with those calculated from alcohol injection, indicating the appropriateness of the method used in this study. DDC had no effect on the elimination of infused acetaldehyde from blood indicating that the elimination may be due to the loss from lungs into breath, from skin surfaces and/or from the kidney but not by metabolism in the liver.

Acetaldehyde↗
PubMed1985

Surveys of workers occupationally exposed to PCBs and of yusho patients.

Surveys of workers occupationally exposed to polychlorinated biphenyls (PCBs) in the production of thread or of paint, and of yusho patients were carried out from 1973 to 1982. PCB concentrations in the plasma of the workers ranged from 2 to 521 ppb, and some showed higher PCB levels in the plasma than typical Japanese yusho patients. Gas chromatographic patterns of plasma PCBs of the workers with high PCB levels were shown to match the patterns of the PCBs to which they had been exposed in the workplace. Japanese yusho children showed remarkable decrease with time, but no such decrease was observed in the yusho adults and the workers. Polychlorinated quaterphenyls (PCQs) were detected in the blood of typical Japanese and Taiwanese yusho patients, but PCQ levels in the plasma of the workers were below the detection limit of 0.02 ppb. Clinical findings and subjective complaints of the workers were usually slight compared with typical yusho patients, though some of them had mild dermal manifestations and their PCB levels were suspected to be related to serum triglyceride values. On the basis of these results, we discussed the relationship between the health status of the subjects and their contamination with PCBs or related compounds.

Adult↗
PubMed1985

Exercise capacity correlating to exercise hemodynamics in coronary artery disease.

Forty-seven patients with coronary artery disease characterized by angina pectoris and/or old myocardial infarction underwent two maximal exercise tests, the supine ergometer test and the upright treadmill test, to study the relationship between exercise capacity and exercise hemodynamics. Subjects were divided into 3 groups: Group I (n = 19) achieved 25 or 50 watts, Group II (n = 15) achieved 75 watts and Group III (n = 13) achieved 100 or 125 watts. During ergometer exercise, the mean pulmonary capillary pressure elevated by 25.3 +/- 8.3 mmHg in Group I, 20.8 +/- 8.8 mmHg in Group II and 12.0 +/- 8.4 mmHg in Group III; the Group III value was significantly smaller than the other groups. The stroke volume index decreased by 3.6 +/- 8.8 ml/m2 in Group I, and increased by 10.9 +/- 8.7 ml/m2 in Group II and 10.7 +/- 14.7 ml/m2 in Group III. Thus, the impaired exercise capacity correlated with the abnormal exercise hemodynamics and its severity. In addition, the exercise capacity in the treadmill test was comparable to that in the ergometer test. It was concluded that the impaired exercise capacity in the both supine and upright exercise tests was well related to the development of abnormal exercise hemodynamics in patients with coronary artery disease.

Adult↗