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Biomedical subjects

H Hagihara

Publications and source records attributed to H Hagihara.

14 recordsLinked to original sources
PubMed1995

Purification and characterization of an alkaline amylopullulanase with both alpha-1,4 and alpha-1,6 hydrolytic activity from alkalophilic Bacillus sp. KSM-1378.

The novel alkaline amylopullulanase produced by alkalophilic Bacillus sp. KSM-1378 was purified to an electrophoretically homogeneous state from culture medium. The purified enzyme was a glycoprotein with an apparent molecular mass of about 210 kDa and an isoelectric point of pH 4.8. The N-terminal amino acid sequence was Glu-Thr-Gly-Asp-Lys-Arg-Ile-Glu-Phe-Ser-Tyr-Glu-Arg-Pro and showed no homology to the N-terminal regions of other amylopullulanases reported to date. The enzyme was able to attack specifically the alpha-1,6 linkages in pullulan to generate maltotriose as the major end product, as well as the alpha-1,4 linkages in amylose, amylopectin and glycogen to generate various oligosaccharides. The pH and temperature optima for the pullulanase and alpha-amylase activities were pH 9.5 and 50 degrees C and pH 8.5 and 50 degrees C respectively. Both activities were strongly inhibited by well characterized inhibitors, such as diethyl pyrocarbonate and N-bromosuccinimide. The pullulanase activity was specifically inactivated by Hg2+ ions, alpha-cyclodextrin and beta-cyclodextrin while the amylase activity was strongly inhibited by EDTA and EGTA, although inhibition could be reversed by Ca2+ ions. It is suggested that the single alkaline amylopullulanase protein has two different active sites, one for the cleavage of alpha-1,4-linked substrates and one for the cleavage of alpha-1,6-linked substrates.

Amino Acid Sequence↗
PubMed1995

Left atrial plication combined with mitral valve surgery in patients with a giant left atrium.

The benefits of performing left atrial plication during mitral valve surgery for patients with a giant left atrium were evaluated by analyzing the short- and long-term surgical results and changes in the left atrial dimension (LAD) and respiratory function of 30 patients. Of the 30 patients, 2 (7%) died of multiple organ failure on postoperative days 26 and 117, but no other deaths occurred during the mean follow-up of 5.9 +/- 2.1 years. Valve thrombosis was observed in one patient and cerebral complications with no residual deficit were observed in two patients, with a 9-year event-free rate of 87 +/- 7%. The LAD decreased significantly from 69.0 +/- 8.5 mm to 53.7 +/- 9.1 mm (P < 0.01) shortly after surgery, and this decreased was maintained even 5 years after surgery (53.3 +/- 11.4 mm). The cardiothoracic ratio decreased from 74.8 +/- 8.3% to 62.8 +/- 9.0% (P < 0.01) and the vital capacity of the lungs increased from 71.1 +/- 18.0% to 82.9 +/- 22.2% (P < 0.01). Thus, we conclude that performing left atrial plication during mitral valve surgery is safe and effective for patients with giant left atrium.

Adult↗
PubMed1994

Adult mesenchymal hamartoma of the liver mimicking bile duct cystadenoma.

We report a rare case of mesenchymal hamartoma in the cirrhotic liver of a 52-year-old Japanese male. The tumor, 3.5 cm in diameter, contained a cystic lesion and was located in the lateral segment. Bile duct cystadenoma was considered most likely preoperatively because of the patient's age and the normal levels of tumor markers. However, since malignancy of the lesion could not be ruled out by preoperative imaging diagnosis, lateral segmentectomy was performed. Histological examination led to a diagnosis of mesenchymal hamartoma, since the lesion consisted of a multilocular abnormal bile duct accompanied by abundant myxomatous or loose collagen.

Bile Duct Neoplasms↗
PubMed1992

Styrene formation by the decomposition by Pichia carsonii of trans-cinnamic acid added to a ground fish product.

It is not well known how the formation of styrene by microorganisms can occur in foods. In this study, we described and characterized the production of styrene by a yeast isolated from chikuwa fish paste. The styrene was not detected in fresh and normal food products nor in the food package's plastic film. The food containing styrene contained cinnamic acid as an antimicrobial agent and spice, and it was contaminated by 5.4 x 10(6) CFU of a yeast per gram. On the basis of morphological and biochemical features, the yeast isolated was determined to be a strain of Pichia carsonii, now designated strain CHI. Strain CHI, which was able to grow on cinnamic acid, had the ability to form styrene from trans-cinnamic acid via trans-p-coumaric and caffeic acids. The MIC of trans-cinnamic acid against strain CHI was 230 micrograms/ml. Strain CHI thrived well at pH 5.0 and 26.0 degrees C and was tolerant to 20% NaCl. Styrene was subsequently produced in ground fish meat containing cinnamic acid into which strain CHI had been inoculated. The yeast was found to be an environmental contaminant in food processing plants of the chikuwa manufacturer.

Biodegradation, Environmental↗
PubMed1991

Role of inflammatory responses in initiation of atherosclerosis: effects of anti-inflammatory drugs on cuff-induced leukocyte accumulation and intimal thickening of rabbit carotid artery.

Immediately after a cuff-sheathing of rabbit carotid artery, a large number of leukocytes adhered to injured endothelium then infiltrated into the media. These inflammatory responses were followed by an atherosclerotic change, intimal thickening, of the artery. A simultaneous injection of dexamethasone (10 mg/kg i.m.) inhibited the leukocyte accumulation by 74% when evaluated 18 h thereafter. Similarly, 39% inhibition was obtained with the same dose of FR110302, a potent 5-lipoxygenase inhibitor. On the other hand, the same dose of indomethacin, a cyclooxygenase inhibitor, had little effect on the leukocyte accumulation. The intimal thickening which was evaluated 3 weeks after the cuff-treatment was attenuated by a daily dose (10 mg/kg i.m.) of dexamethasone or FR110302 but not by one of indomethacin. The inhibition by the two former drugs were 91 and 58%, respectively. In vitro, the three drugs in concentrations up to 10 microM hardly affected endothelial adhesion of PMN which was induced by LPS or IL-1. Though 10 microM of FR110302 and indomethacin significantly decreased PMN chemotaxis induced by LTB4, the decreases were less than that at 10 microM dexamethasone. These results confirm a possible linkage between inflammation and atherosclerosis, and suggest that 5-lipoxygenase products contribute to the initiation and development of atherosclerosis.

Animals↗
PubMed1990

[Surgery for postinfarction ventricular septal perforation under hypothermic fibrillatory arrest with pulsatile perfusion].

Surgery were performed by 2 different methods of myocardial protection in 17 patients with postinfarction ventricular septal perforation (VSP) from 1982 to 1989. Ten consecutive operations were performed using hypothermic fibrillatory arrest with pulsatile perfusion (VF group). Pulsatile flow was produced by an intra-aortic balloon pumping device. Other 7 consecutive VSP operations were performed using cardioplegic arrest (CP group). In the VF group, the mean age was 67 years (range 54 to 78 years), and VSP was located in the anterior wall in 7, in the inferior wall in 2, and in the anterior and inferior walls in 1 patients. The operation was performed 2.5 days after the onset of VSP. In the CP group, the mean age was 71 years (range 50 to 78 years), and VSP was located in the anterior wall in 6 and in the inferior wall in 1 patient. The operation was performed 4.7 days after the onset of VSP. Cardiogenic shock developed after septal rupture in 50% of the patients in the VF group and 71% in the CP group (N.S.). Prior to the operation, no significant differences were found in hemodynamic status between the 2 groups. Cardiac index in the VF group was higher than that of the CP group (p less than 0.05) shortly after cardiopulmonary bypass. The operative mortality rate was 10% in the VF group and 57% in the CP group. From these clinical results, hypothermic fibrillatory arrest with pulsatile perfusion can be beneficial as a method of myocardial protection during surgery for VSP and presently this has become the method of choice in our department.

Aged↗
PubMed1989

[Clinical studies on temporomandibular arthrosis in our dental clinic. 1. Subclinical female patients (20s-40s-year-old)].

Clinical study was done concerning to temporomandibular (TM) arthrosis for 168 female patients (mean age 35.5 ranged from 20 to 48 years) who visited our dental clinic. Among 168 patients, 16 cases (9.5%) had maxillofacial pain, 74 cases (44%) joint sounds and 49 cases (29.2%) alternations in the opening pathway. As a result, subclinical patients were 96 cases (57%). The mean value of maximum inter-incisal distance was 47.6mm +/- 5.3. The patients with subclinical TM arthrosis were mainly associated with stiffness of neck. They show in mothers with a number of infants. In female, it seems that delivery and nursing are associated with arising TM arthrosis.

Adolescent↗
PubMed1988

Smooth muscle cell migration induced by inflammatory cell products and its inhibition by a potent calcium antagonist, nilvadipine.

The chemotactic activities of inflammatory cell products for rat aortic smooth muscle cells (SMC) were examined in modified Boyden chambers. A checker board analysis revealed that interleukin-1 (IL-1), leukotriene B4 (LTB4), platelet-derived growth factor (PDGF) and inflammatory exudate from zymosan-activated air pouches stimulated chemotaxis of SMC. The chemotaxis, irrespective of the attractants used, was strongly inhibited by nilvadipine, a potent calcium antagonist, and the IC50 values were around 1 x 10(-10) M. Removal of extracellular calcium abolished the chemotactic activities of the attractants. These results suggest that inflammatory cells such as macrophages and polymorphonuclear leukocytes (PMN) have an important role in the migration of SMC into the intima during atherogenesis, and that nilvadipine might be useful for preventing and treating atherosclerosis.

Animals↗
PubMed1984

A highly sensitive photometric method for proton release or uptake: difference protometry.

A highly sensitive quantitative method was developed to detect protons released or taken up upon ligand binding. A small change in pH due to proton release or uptake was detected by measuring the difference in the absorbance of a pH indicator upon ligand addition. Owing to the difference detection of protons, the uncertainty of pH due to CO2 dissolution and unknown buffering capacities of sample solutes could be compensated with easy manipulations. Precise calibration of the absolute amount of protons could also be made very easily. The amount of protons measurable by the method is as small as 0.5 nmol that is 10 to 30 times more sensitive than the pH-stat method. We measured the Mg2+ ion-induced proton releases of ADP to confirm the accuracy and reliability of the method and of Escherichia coli ribosomes to show the improvement in sensitivity. The method is useful for protometric studies of biomolecules that are difficult to obtain in large amount.

Acid-Base Equilibrium↗
PubMed1984

Mg2+-induced proton release from Escherichia coli ribosome and ribosomal RNA.

Escherichia coli ribosome released protons upon addition of Mg2+. The Mg2+-induced proton release was studied by means of the pH-stat technique. The number of protons released from a 70 S ribosome in the Mg2+ concentration range 1-20 mM was about 30 at pH 7 and 7.6, and increased to about 40 at pH 6.5. The rRNA mixture extracted from 70 S ribosome showed proton release of amount and of pH dependence similar to those of the 70 S ribosome but the ribosomal protein mixture released few. This indicates that rRNA is the main source of the protons released from ribosome. The pH titration of rRNA showed that the pKa values of nucleotide bases were downward shifted upon Mg2+ binding. This pKa shift can account for the proton release. The Scatchard plots of proton release from rRNA and ribosome were concave upward, showing that the Mg2+-binding sites leading to proton release were either heterogeneous or had a negative cooperativity. A model assuming heterogeneous Mg2+-binding sites is shown to be unable to explain the proton release. Electrostatic field effect models are proposed in which Mg2+ modulates the electrostatic field of phosphate groups and the potential change induces a shift of the pKa values of bases that leads to the proton release. These models can explain the main features of the proton release.

Binding Sites↗
PubMed1983

Magnesium ion induced proton release as a probe for the polyelectrolytic structure of ribosomal RNAs and subunits.

E coli ribosomes and rRNA's released 20 to 50 protons upon jump of magnesium ion concentration from 1 mM to 20 mM. The Mg2+-induced proton release was measured separately for 16S rRNA, 23S rRNA, 30S subunit, and 50S subunit by a new spectrophotometric method that had a much better sensitivity than the pH-stat method. The proton release from the subunits and rRNA's were similar in the number of protons, the pH dependence that had a minimum at neutral pH, and the upward concaveness of the Scatchard plot. From these results, the main source of protons in ribosomal subunits was assigned to nucleotide bases of rRNA's that showed a downward pKa shift upon Mg2+-ion binding. The subunits and rRNA's, however, differed in the proton release. 16S rRNA released protons somewhat more effectively than 23S rRNA, while 30S subunit released protons 2 to 5 times more effectively than 50S subunit. The marked difference between the two subunits suggest that ionizable bases in 16S and 23S rRNA's are covered and their pKa values are shifted by ribosomal proteins to different extents. The association of 30S and 50S subunits induced little proton release, showing that few ionizable groups with pKa near neutral pH are involved in the association. E. coli tRNA and poly U also showed Mg2+-induced proton release. The amounts of protons released from rRNA's, tRNA, and poly U were roughly proportional to the amount of bases not hydrogen bonded. The Mg2+-induced proton release from the natural and synthetic RNA's can be explained by the electrostatic field effect of polyphosphate backbones on bases not hydrogen bonded, as proposed in a previous paper. It also reflects the conformational structure of each RNA molecule.

Escherichia coli↗