Biomedical subjects

H Ogino

Publications and source records attributed to H Ogino.

At least 55 records · Page 3Linked to original sources

PubMed2000

Effect of additives on transesterification activity of Rhizopus chinensis lipase.

The transesterification activity of powder lipase prepared from the purified lipase of Rhizopus chinensis cells by freeze-drying was quite low compared with that of acetone-dried cells. Additives which could enhance the transesterification activity of the freeze-dried powder lipase were screened. The freeze-dried lipases prepared with certain fatty acid methylesters or certain types of surfactants exhibited high transesterification activity. It was shown that not only the solubility of the freeze-dried lipase in n-hexane but also the organic solvent-stability was enhanced when methyl stearate was added to the lipase solution at the freeze-drying step.

Journal Article↗

PubMed2000

[Development of DICOM image browser for Macintosh computer].

Although many medical image browsers are available today, most are extremely expensive. To solve this problem, we developed a Digital Imaging and Communications in Medicine (DICOM) image browser (Medical Image Browser) for Macintosh computers. A comparison between this software, Advantage Workstation, NIH Image, and Graphic Converter suggested that this software is useful for diagnosis on the Macintosh desktop. This software is available at wwwl.odn.ne.jp/cak42860.

Computer Communication Networks↗

PubMed2000

[Surgical results of the Senning operation and arterial switch operation for complete transposition of the great arteries].

From March 1980 to August 1997, 42 patients with complete transposition of the great arteries (TGA) type I and II underwent arterial switch procedure (n = 20) or Senning (n = 22) procedure in our institution. In arterial switch procedure group, there were two operative death. No late death occurred, and one patient underwent reoperation and one underwent balloon pulmonary angioplasty for right sided obstruction. The freedom from the intervention rate for right sided obstruction was 83.0% at 5 years, subsequently. In Senning procedure group, operative death occurred in two patients with TGA type II, and one patient with TGA type II and two patients with type I died because of cardiac events in the late stage. In this group, two patients died from accident. The survival rate excluding accidental deaths was 77.7% and 77.7% at 5 and 10 years, respectively. However, those patients who died in the late stage had severe pre-operative and post-operative complication. In conclusion, mid-term results of arterial switch procedure is satisfactory, however, reintervention rate was not so low. Long term results of Senning procedure without preoperative or postoperative complication was satisfactory.

Cardiac Surgical Procedures↗

PubMed2000

[Long-term effect of polystan monocusp ventricular outflow patch after right ventricular outflow tract reconstruction].

Forty-eight patients who underwent right ventricular outflow tract reconstruction with Monocusp Ventricular Outflow Patch (MVOP) fifty-five times and survived surgery, were reviewed in this study. Mean age at surgery was 6.4 years-old and mean follow-up interval was 75.2 months. There was no late death, however reoperation was performed 7 times. Freedom from reoperation rate was 97.2% and 80.7% after 5 and 10 years after surgery, respectively. The main cause for reoperation were right ventricular outflow obstruction RVOTO (5 cases). All of the RVOTO occurred at the distal end of the anastomosis. However, there was no RVOTO in patients who underwent RVOTR with MVOP during the past ten years. So, we considered the cause of RVOTO a technical problem. Pulmonary regurgitation was one to two degree early after surgery, and had worsened by almost two or three degrees more than 5 years after surgery. Moreover, five of six patients who underwent cardiac catheterization more than 10 years after surgery had three degrees of pulmonary regurgitation as well as a large CTR. In conclusion, according to long-term results, especially more than 10 years post operatively, pulmonary regurgitation was the most important problem.

Adolescent↗

PubMed2000

[Long-term results of right ventricular outflow reconstruction with valved conduit].

Twenty-nine patients who underwent right ventricular outflow tract reconstruction using a valved conduit 37 times and survived surgery, were reviewed in this study. Hancock, Ionescu-Shiley, Carpentier-Edwards and Polystan was used for RVOTR. Freedom from reoperation rates of Hancock, Ionescu-Shiley and Carpentier-Edwardsat at five and ten years after surgery were 100%, 85.7%, 89.2% and 75%, 28.6%, 89.2%, respectively. The freedom from reoperation rates of Hancock and Carpentier-Edwards were significantly higher than that of Ionescu-Shiley. In conclusion, the freedom from reoperation rate at ten years was high for both Hancock and Carpentier-Edwards.

Adolescent↗

PubMed1999

Introduction of chromosome 7 suppresses telomerase with shortening of telomeres in a human mesothelial cell line.

Introduction of human chromosome 7 by microcell-mediated chromosome transfer induced senescence in a telomerase-positive human mesothelial cell line, MeT5A. In microcell hybrids which underwent senescence, telomerase activity was decreased before entering senescence and telomeric sequences were shortened as cell division proceeded. Concomitantly, expression of the gene encoding telomerase catalytic subunit was abolished, whereas the genes encoding the RNA component of telomerase and its associated protein TEP1 were not affected. In revertants which arose from such microcell hybrids, telomerase activity was restored and the telomeric sequences were elongated. In microcell hybrids which showed no growth arrest, telomerase activity was unaltered. These results suggest that a putative mortality gene on chromosome 7 negatively regulates the telomere maintenance mechanism in MeT5A.

Chromosomes, Human, Pair 7↗

PubMed1999

Regulation of lens fiber cell differentiation by transcription factor c-Maf.

To elucidate the regulatory mechanisms underlying lens development, we searched for members of the large Maf family, which are expressed in the mouse lens, and found three, c-Maf, MafB, and Nrl. Of these, the earliest factor expressed in the lens was c-Maf. The expression of c-Maf was most prominent in lens fiber cells and persisted throughout lens development. To examine the functional contribution of c-Maf to lens development, we isolated genomic clones encompassing the murine c-maf gene and carried out its targeted disruption. Insertion of the beta-galactosidase (lacZ) gene into the c-maf locus allowed visualization of c-Maf accumulation in heterozygous mutant mice by staining for LacZ activity. Homozygous mutant embryos and newborns lacked normal lenses. Histological examination of these mice revealed defective differentiation of lens fiber cells. The expression of crystallin genes was severely impaired in the c-maf-null mutant mouse lens. These results demonstrate that c-Maf is an indispensable regulator of lens differentiation during murine development.

Animals↗

PubMed1999

Early and mid-term outcomes of cardiac and thoracic aortic surgery in over-75-year-olds with postoperative quality of life assessment.

The early and mid-term outcomes of cardiac and thoracic aortic surgery were reviewed in seventy-two consecutive patients aged 75 years and older, together with assessment of postoperative quality of life. Twenty-six patients had ischemic heart disease, twenty had valvular heart disease, one had congenital heart disease, and twenty-five had thoracic aortic aneurysm. Twenty-five (34.7%) required an emergency operation. There were 6 early deaths (8.3%) and 11 late deaths (17.2%), of which the emergency cases had higher mortality of 5 early deaths (20.0%) and 3 late deaths (15.0%). In particular, most cases with a ruptured thoracic aortic aneurysm died eventually from various complications including neurological dysfunction. The others with a non-ruptured aneurysm also had atherosclerotic aortic or arterial lesions which caused a lethal cerebrovascular accident or ischemic heart disease. The quality of life of 51 of 53 survivors was assessed using the Rosser and Watts index being based on disability and distress scores. The response was satisfactory--the disability score was 2.6 +/- 1.9 and the distress score was 1.4 +/- 0.4. The patients with a thoracic aortic aneurysm had worse quality of life scores than those of the ischemic heart disease or valvular heart disease patient-groups because of various perioperative complications. Our experiences demonstrate that the results including the postoperative quality of life following cardiac and aortic surgery in the elderly is satisfactory except for emergency cases. The results would prompt us to operate, if possible, electively in their stable conditions, even on elderly over-75-year-olds.

Age Factors↗

PubMed1999

Coronary artery bypass grafting in a case with severe aortic atheromatosis associated with abdominal aortic aneurysm.

A 69-year-old man with coronary artery disease associated with abdominal aortic aneurysm underwent a one-stage operation utilizing a low-flow cardiopulmonary bypass. Ordinary cardiopulmonary bypass was abandoned as a result of severe atheromatous finding in the entire aorta. However, coronary artery bypass grafting without cardiopulmonary bypass was hazardous as a result of heart enlargement and deteriorating function. Therefore, the abdominal aortic aneurysm was first replaced with a bifurcated graft. Coronary artery bypass grafting with two arterial grafts was then performed successfully on the beating heart with the support of a low-flow cardiopulmonary bypass connected to the bifurcated graft.

Aged↗

PubMed1999

High origin of the right coronary artery with congenital heart disease.

We encountered a case of anomalous high origin of the right coronary artery associated with ventricular septal defect and patent ductus arteriosus. The right coronary artery originated from the distal part of the ascending aorta resulting in unsuccessful induction of cardiac arrest by cardioplegia. We describe this rare case with anomalous origin of the right coronary artery.

Aorta↗

PubMed1999

Distance between mitral anulus and papillary muscles: anatomic study in normal human hearts.

BACKGROUND: Preservation of the annulo-papillary muscle continuity in mitral valve replacement is important. Even in patients who require excision of the mitral apparatus, the continuity can be restored. However, there is no guide to the proper length for the resuspension. METHODS: In 57 normal cadaveric hearts, the distance from the tip of the papillary muscle to its corresponding mitral anulus was directly measured. RESULTS: The distance from the tip of the anterolateral papillary muscle to the left trigone (10-o'clock position: D10) and to the point between the anterior and the middle scallops of the mural leaflet (8-o'clock position: D8) was 23.5 +/- 3.7 mm and 23.2 +/- 3.6 mm, respectively. The distance from the tip of the posteromedial papillary muscle to the right trigone (2-o'clock position: D2) and to the point between the middle and the posterior scallops of the mural leaflet (4-o'clock position: D4) was 23.5 +/- 4.0 mm and 23.5 +/- 3.9 mm, respectively. There was no statistically significant difference among the 4 distances (P =.96). Each distance was significantly longer than the corresponding chordae tendineae (D10 vs the anterior main chorda: 17.2 +/- 3.9 mm, D8 vs the anterior cleft chorda: 14.5 +/- 3.2 mm, D2 vs the posterior main chorda: 17.9 +/- 4.3 mm, and D4 vs the posterior cleft chorda: 14.9 +/- 3.2 mm, respectively; P =.0001). The mean distance had a significant correlation with the mitral annular diameter (r = 0.31, P =.019). CONCLUSIONS: In normal hearts, the annulo-papillary muscle distances of the mitral apparatus are similar in 2-, 4-, 8-, and 10-o'clock positions and correlate with the mitral annular diameter.

Adult↗

PubMed1999

Theoretical investigation of fructose 1,6-diphosphate production and simultaneous ATP regeneration by conjugated enzymes in an ultrafiltration hollow-fiber reactor.

The performance of an ultrafiltration hollow-fiber reactor, in which enzymatic synthesis of fructose 1,6-diphosphate (FDP) from glucose and enzymatic ATP regeneration are performed simultaneously, was analyzed theoretically. The reaction system consists of three-step synthetic reactions catalyzed by glucokinase (GK), phosphoglucose isomerase and phosphofructokinase, and the ATP regeneration reaction catalyzed by acetate kinase. Based on a simple analytical model developed previously in which the liquid flowing in a tube was assumed to be plug flow and the radial concentration gradients in the tubes and shell side space were both neglected, a computer program was developed to calculate the concentration profiles of all the components along the flow direction in the tubes and shell side space of the reactor. From the FDP concentrations at the reactor outlet calculated under various operational conditions, reactor performances such as the FDP yield and the ATP recycle number were determined. The calculation showed the interesting phenomenon that under some conditions the FDP yield was higher when GK concentration was lower.

Journal Article↗

PubMed1999

Experimental investigation of fructose 1,6-diphosphate production and simultaneous ATP regeneration by conjugated enzymes in an ultrafiltration hollow-fiber reactor.

The enzymatic synthesis of fructose 1,6-diphosphate (FDP) from glucose and the enzymatic ATP regeneration were performed simultaneously in an ultrafiltration hollow-fiber reactor using both the purified enzymes and the crude cell extract of Bacillus stearothermophilus. The process consisted of the three-step synthetic reactions catalyzed by glucokinase, phosphoglucose isomerase and phosphofructokinase, and the ATP regeneration reaction catalyzed by acetate kinase. The experimental results of the yield and the recycle number agreed well with the theoretical predictions calculated using a computer program developed in our preceding study. This proved the validity of this computer program for predicting or analyzing the reactor performance.

Journal Article↗

PubMed1999

Peptide synthesis catalyzed by organic solvent-stable protease from Pseudomonas aeruginosa PST-01 in monophasic aqueous-organic solvent systems.

The equilibrium yields of the peptide Cbz-Arg-Leu-NH2 synthesized from Cbz-Arg and Leu-NH2 using the PST-01 protease in the presence of organic solvents were investigated under various conditions. The equilibrium yields depended little on the concentration of the carboxyl component, but significantly on the concentration of the nucleophile. The optimum temperature and pH for a high equilibrium yield were 30 degrees C and greater than 5.0, respectively. Under optimum conditions the equilibrium yields were 71.6% and 87.7% in the presence of 50% (v/v) DMF and 60% (v/v) DMSO, respectively. Furthermore, the PST-01 protease also catalyzed the syntheses of the dipeptides Cbz-Lys-Leu-NH2, Cbz-Ala-Leu-NH2, Cbz-Ala-Phe-NH2, Cbz-Arg-Leu-NH2, and Cbz-Lys-Phe-NH2 with equilibrium yields of more than 60% in the presence of 50% (v/v) DMF and 50 mM sodium phosphate buffer (pH 7.0).

Journal Article↗

PubMed1999

Purification and characterization of lipase from Rhizopus chinensis cells.

Lipase from Rhizopus chinensis cells was purified and characterized. The molecular mass of purified lipase was 28.4 kDa and the optimal temperature and pH for its activity were 37 degrees C and 5.5, respectively. Purified lipase exhibited high hydrolytic activity against fatty acid methyl esters such as methyl caprylate, methyl laurate, and methyl palmitate. Freeze-dried lipase catalyzed the transesterification between olive oil and methyl laurate in n-hexane.

Journal Article↗

PubMed1999

Purification and characterization of organic solvent-stable protease from organic solvent-tolerant Pseudomonas aeruginosa PST-01.

An organic solvent-stable protease (PST-01 protease) in a culture broth of organic solvent-tolerant Pseudomonas aeruginosa PST-01 was purified by successive hydrophobic interaction chromatography using Butyl-Toyopearl gels. The purified enzyme was homogeneous as determined by SDS-polyacrylamide gel electrophoresis. PST-01 protease had a molecular mass of 38 kDa. The optimum temperature and pH for casein hydrolysis were 55 degrees C and 8.5, respectively. PST-01 protease was stable at pH 8-12 and below 50 degrees C and was determined to be a metalloprotease which was inhibited by EDTA, 1,10-phenanthroline, and phosphoramidon. PST-01 protease inhibited by EDTA was reactivated completely by the addition of zinc or cobalt ions. The stability of PST-01 protease in solutions containing water-soluble organic solvents or alcohols was higher than that in the absence of organic solvent. Furthermore, in general, PST-01 protease was more stable than commercially available proteases, namely, subtilisin Carlsberg, thermolysin, and alpha-chymotrypsin, in the presence of water-soluble organic solvents or alcohols.

Journal Article↗

PubMed1999

Enzymatic synthesis of fructose 1,6-diphosphate with ATP regeneration in a batch reactor and a semibatch reactor using purified enzymes of Bacillus stearothermophilus.

The enzymatic synthesis of fructose 1,6-diphosphate (FDP), an important glycolytic intermediate whose applications in the field of medicine have generated a great deal of interest, was performed in a batch reactor and a semibatch reactor. Using the batch reactor, FDP was first synthesized from glucose by three enzymatic reactions and the ATP consumed was regenerated simultaneously using conjugated enzymes, all of which were purified from crude cell extract of thermophilic Bacillus stearothermophilus. The results of the experiments performed using several enzyme concentrations suggest the existence of an optimum concentration for each enzyme at which the maximum FDP yield can be attained. Since the thermal decomposition of acetyl phosphate reduced the yield of FDP in the batch reactor, the use of a semibatch reactor in which acetyl phosphate was fed continuously was examined. The yield of FDP was improved but the time required to complete the reaction was longer, resulting in a lower productivity of FDP. The yields observed in the two reactors using various enzyme and substrate concentrations were in good agreement with the theoretical predictions calculated based on differential equations derived for the system using the rate equations and the kinetic parameters determined previously. This means that these equations can be used for the analysis of the experimental results as well as for determining the optimum experimental conditions.

Journal Article↗

PubMed1999

Enzymatic production of fructose 1,6-diphosphate using crude cell extract of Bacillus stearothermophilus.

The enzymatic production of fructose 1,6-diphosphate (FDP) from glucose was performed in a batch reactor and a semibatch reactor using the crude cell extract of Bacillus stearothermophilus which contains all four enzymes required for the synthesis. The experimental results of the yield and the time courses of FDP production obtained using various enzyme concentrations were in good agreement with the theoretical predictions calculated based on the differential equations including the rate equations of the four enzymes, which were determined using the purified enzymes of B. stearothermophilus.

Journal Article↗