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I Endo

Publications and source records attributed to I Endo.

16 recordsLinked to original sources
PubMed1992

Light-induced oxidation of iron atoms in a photosensitive nitrile hydratase.

The photoactivation process of a photosensitive nitrile hydratase (NHase) from Rhodococcus sp. N-771 has been investigated by 57Fe Mössbauer spectroscopy and magnetic susceptibility measurements in order to clarify the behavior of iron atoms in the enzyme. Mössbauer spectra of inactive NHase gave two symmetric-doublet components indicating the presence of two iron species, while that of the active NHase gave a single symmetric doublet indicating the presence of a single iron species. Magnetic susceptibility measurements of the inactive and active HNase both showed small effective magnetic moments. These results led us to conclude that one of the two iron atoms incorporated in the NHase is oxidized during photoactivation, namely from a low spin ferrous to a low spin ferric state. This is the first observation of an intramolecular photooxidation phenomena involving iron in a single protein molecule.

Enzyme Activation↗
PubMed1992

Object-oriented fuzzy expert system for on-line diagnosing and control of bioprocesses.

An object-oriented fuzzy expert system to support on-line control of an automated fermentation plant is described. The major elements of the system consist of a fuzzy inference engine, a database, a knowledge base, and an expression evaluater. The expression evaluater calculates specific rates for growth, and substrate and product formation at different physiological states during the cultivation from the measured data. The specific rates are then compared with the standard target rates stored in the database. If differences outside the set tolerances were observed, the inference engine analyses the reasons for the faults on the basis of the knowledge represented in the form of a knowledge network and fuzzy membership functions of the process variables. The fuzzy expert system was developed on the basis of a shell constructed by using the object oriented Smalltalk/V Mac programming environment, with Lac-tobacillus casei lactic acid fermentation as the example of process application.

Biotechnology↗
PubMed1992

A human genome analysis system (HUGA-I) developed in Japan.

A part of the Japanese human genome project has resulted in the development of a world original human genome analysis system. Circumstances of the project, objective, design concept, and constitution of the system are described in the paper.

Base Sequence↗
PubMed1992

Fuzzy reasoning system for fault diagnosis of physiological activities in a cultivating process.

Aiming at development of a system which supports cultivating operations, a method to diagnose physiological activities in a cultivating process is presented, and a fuzzy expert system for diagnosing Lactobacillus casei cultivating process is implemented in this paper. This system can calculate specific rates of cell growth, substrate consumption, and product formation with measuring cell mass concentration, substrate concentration, and product concentration by using a turbidity sensor and HPLC. A database is implemented, where standard curves on specific rates representing characteristics of microorganisms are stored according to normalized substrate consumption. Comparing the calculated specific rates with standard values derived from the database, the system diagnoses physiological activities of the microorganisms. As a case study, a knowledge base for diagnosing lactic acid production process is implemented. The use of fault diagnosis on pH malfunctions by the expert system proves its reasonable performance.

Biotechnology↗
PubMed1991

Crystallization of a photosensitive nitrile hydratase from Rhodococcus sp. N-771.

A photosensitive nitrile hydratase from Rhodococcus sp. N-771 has been crystallized in two different crystal forms in its inactive form. One crystal form belongs to an orthorhombic space group P2(1)2(1)2 with unit cell dimensions of a = 117.4 A, b = 145.7 A and c = 52.1 A, and the other form belongs to a hexagonal space group P6(3)22 with unit cell dimensions of a = 110.2 A and c = 412.1 A.

Crystallization↗
PubMed1991

Human genome analysis system.

An automated DNA sequencing system, the collaborative effort of Japanese scientists and engineers, which has a potential output of up to 108,000 bases per day is described.

Base Sequence↗
PubMed1990

Purification of inactivated photoresponsive nitrile hydratase.

Photoresponsive nitrile hydratase from Rhodococcus sp. N-771 was purified in its inactivated form. The enzyme had a molecular weight of approximately 60 kDa and consisted of 2 subunits each having molecular weight of 27.5 and 28 kDa. The enzyme also contained 2 iron atoms/enzyme as a cofactor. The enzyme was more stable in its inactivated form, rather than the activated during storage in the dark. The enzyme was most stable in the temperature region of 0-35 degrees C, and lost its activity above 40 degrees C. The enzyme was most stable in the pH region of 6-8. The optimum temperature and pH for the enzyme activity was 30 degrees C and 7.8, respectively. The enzyme showed wide substrate specificity, and most of the metal ions did not affect enzyme activity significantly. The absorption spectrum revealed the presence of some cofactor which changed form after photoirradiation.

Enzyme Activation↗
PubMed1990

A tubular bioreactor for high density cultivation of microorganisms.

By simulating the functions of the animal intestine, the authors have developed a novel tubular bioreactor (TBR) which is capable of containing both the reaction and separation of products in a single system. This reactor consisted of inorganic ultra filtration membrane modules in the primary part of the system, a heat exchanger and a recycling pump. The operation characteristics of the TBR were studied by cultivating Lactobacillus casei at a laboratory scale. The cell density obtained was up to 10 times higher than the density obtained by using the conventional jar fermentor. Furthermore, 40 g l-1 of cell mass was obtained in only 14 hours with 20 l of fresh medium when the dilution rate was increased according to the cellular growth. Afterwards, the cultivation time and the volume of fresh medium were reduced to 44% and 74%, respectively, of the values in the cultivation operation at constant dilution rate.

Bacteriological Techniques↗
PubMed1989

Selective utilization of L-isomer of lactate in the smooth muscle of the guinea pig taenia caeci.

Utilization of D- and L-lactate in the isolated intestinal smooth muscle of the guinea pig taenia caeci was examined by measuring contractile tension, oxygen consumption, and adenosine triphosphate (ATP) and creatine phosphate (PCr) concentrations. In the absence of glucose in the medium, muscle contraction induced by a high concentration of K+ was inhibited and the rate of oxygen consumption and the concentrations of ATP and PCr were decreased. Addition of glucose, L-lactate, and D,L-lactate, but not D-lactate, led to recovery of muscle contraction, rate of oxygen consumption, and ATP and PCr concentrations when the tissue had been incubated in the high K+, glucose-free solution. These results suggest that the isolated guinea pig taenia caeci selectively utilizes the L-isomer of lactate as a substrate for energy metabolism.

Adenosine Triphosphate↗
PubMed1988

Method for simultaneous determination of creatine phosphate and adenine nucleotides in the intestinal smooth muscle of guinea-pig taenia caeci using high-performance liquid chromatography.

A method for simultaneous determination of adenosine 5'-triphosphate (ATP), adenosine 5'-diphosphate (ADP) and creatine phosphate (PCr) by high-performance liquid chromatography is described. This method was applied to the isolated intestinal smooth muscle tissue of guinea pig taenia caeci weighing approximately 30 mg. It was found that one g of the muscle tissue contained 3.55 mumol PCr, 2.40 mumol ATP and 0.477 mumol ADP.

Adenosine Diphosphate↗
PubMed1979

On the Mirizzi syndrome--benign stenosis of the hepatic duct induced by a stone in the cystic duct or the neck of the gallbladder.

Three cases of Mirizzi Syndrome are reported. One of them was induced by the stone in gallbladder remnant. On the cholangiogram, one case showed narrowing of common hepatic duct near the porta hepatis, and one case revealed a tapered narrowing-like stenosis. Those findings resembled malignancy but closer examination could differentiate this syndrome from malignancy. Selective angiography was useful to differentiate the syndrome from malignancy. Even in the cases where stricture is severe, exstirpation of gallbladder or cystic duct, freeing the anterior wall of extrahepatic bile duct from marked hyperplasia of fibrous tissues and insertion of a T-tube as an internal splint through the stenosis were effective. It is the opinion of the authors, therefore, that the reconstruction of a strictured bile duct may not necessarily be done by resection of stricture and a hepatojejunostomy.

Aged↗