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M Konno

Publications and source records attributed to M Konno.

At least 55 records · Page 3Linked to original sources
PubMed1996

Directly repeated insertion of 9-nucleotide sequence detected in penicillin-binding protein 2B gene of penicillin-resistant Streptococcus pneumoniae.

We investigated the molecular mechanism of 50 penicillin-resistant Streptococcus pneumoniae strains (penicillin: MIC, > or = 0.125 microgram/ml) having neither class A nor class B mutations in the penicillin-binding protein 2B gene (pbp2b). An analysis of the nucleotide sequences of the pbp2b genes from seven strains revealed an unique direct repeat of 9 nucleotides (TGGTATACT) between active-site serine (residue 385) and Ser-X-Asn (residues 442 to 444) motifs. The same insertion was detected in 13 strains.

Amino Acid Sequence↗
PubMed1996

Combinational detection of autolysin and penicillin-binding protein 2B genes of Streptococcus pneumoniae by PCR.

PCR was used to identify penicillin resistance in 1,062 clinical isolates of Streptococcus pneumoniae. Three sets of primers were designed to amplify (i) a 240-bp fragment of the penicillin-binding protein (PBP) 2B gene (pbp2b) of penicillin-susceptible S. pneumoniae (PSSP), (ii) a 215-bp fragment of the class A mutations of the pbp2b gene present in penicillin-resistant S. pneumoniae, and (iii) a 286-bp fragment of the class B mutation. In addition, a set of primers that amplify 273 bp of the autolysin (lytA) gene was applied in combination with the above to identify S. pneumoniae. Of 621 isolates for which MICs of penicillin were < or = 0.06 mu g/ml, 614 (98.9%) were ascertained as having DNA fragments amplified by the PSSP primers. Of 441 isolates for which MICs of penicillin were > or = 0.125 mu g/ml, a class A mutation was detected in only 8 (1.8%), a class B mutation was detected in 310 (70.3%), and neither class A nor class B mutations were found in the remaining 123 (27.9%). However, when analysis was limited to isolates for which MICs of penicillin were > or = 1.0 mu g/ml, 247 isolates (89.8%) of 275 were found to possess a class B mutation. When PBPs were analyzed in 12 isolates with unclear mutations of the pbp2b gene by using [3H]benzylpenicillin, low affinity to PBP 2B was observed in them all. These findings suggest that a pbp2b mutation other than class A or class B is present in these isolates. These results also indicate that it may be possible to identify PSSP and penicillin-resistant S. pneumoniae by applying PCR using a combination of primers to detect the susceptible pbp2b gene, resistant pbp2b gene mutations, and the lytA gene.

Aminoacyltransferases↗
PubMed1995

The pH-dependent changes of the enzymic activity and spectroscopic properties of iron-substituted manganese superoxide dismutase. A study on the metal-specific activity of Mn-containing superoxide dismutase.

Manganese-containing superoxide dismutases (Mn-SODs) and iron-containing superoxide dismutases (Fe-SODs) from aerobic bacteria often show high metal specificity for their enzymic activities by a standard assay system using xanthine-xanthine oxidase and cytochrome c. In this study, we have attempted to characterize the structural basis of the metal specificity of manganese-containing SOD (Mn-SOD) using Fe-substituted Mn-SOD prepared from apo-Mn-SOD from Serratia marcescens. The Fe3+ content of the Fe-substituted enzyme was 1.71 +/- 0.14 mol/mol dimer and the specific activity was 34.8 +/- 4.8 units.mg protein-1.mol Fe3+(-1).mol subunit-1. Fe-substituted Mn-SOD was found to react with the superoxide anion at pH 8.1 with a second-order rate constant of 6 x 10(6) M-1 s-1, which is approximately 1% of that of native Mn-SOD at the same pH. However, the rate constant increased with decreasing pH to approximately 10% (5 x 10(7) M-1 s-1) that of native Mn-SOD at pH 6.0 with a pK of 7.0. The visible absorption spectrum and EPR spectrum of Fe-substituted Mn-SOD also showed pH-dependent changes with pK values of 6.6 and 7.2, respectively. Similarly, the affinity of the azide ion, an analog of the superoxide ion, for iron of Fe-substituted Mn-SOD increased with decreasing pH, with a pK value of 7.0 (e.g. Kd = 0.1 mM at pH 6.2 and 0.9 mM at pH 8.2). The similarity of these pK values suggests that the activity, the spectral changes and the affinity of the azide ion for iron are derived from the same change in the metal environment. After comparison with the reported pK values (around 9) of similar pH-dependent changes in the spectra, the enzymic activity and the affinity of azide for iron of Fe-SOD from Escherichia coli, we proposed that the difference in the pK values of a hydroxide ion binding to iron between Fe-substituted Mn-SOD and Fe-SOD may cause the different pH dependencies of these changes in each SOD.

Azides↗
PubMed1995

Partial clinical improvement in Upshaw-Schulman syndrome following prostacyclin infusion.

We report on a Japanese girl with Upshaw-Schulman syndrome, a congenital disorder characterized by recurrent thrombocytopenia, microangiopathic hemolytic anemia, proteinuria and hematuria that can be transiently improved by the transfusion of plasma or various plasma components. Unusually Large von Willebrand Factor (ULvWF) multimers were found during both relapse and remission phases. Serial plasma levels of 6-keto-prostaglandin F1 alpha (PGF1 alpha), the stable metabolite of prostacyclin (PGI2), were low at relapse. When the patient was treated with continuous PGI2 infusion, the microangiopathic hemolytic process gradually subsided within 10 days. These results suggest that PGI2 may be partly involved in the pathogenesis of this congenital disorder.

Anemia, Hemolytic, Congenital↗
PubMed1995

Aromatase inhibitors: synthesis, biological activity, and structure of 1,2-imidazolylmethylcyclopentanol derivatives.

Two series of 1,2-disubstituted imidazolylmethylcyclopentanol derivatives (5a-d, 10a-d) were prepared by using easily available methyl 2-oxocyclopentanecarboxylate as the starting material. Evaluation of the aromatase inhibitory activities in vitro was performed. Their activities were compared with those of a steroidal aromatase inhibitor, Formestane, and a non-steroidal inhibitor, Fadrozole. Among these compounds, the aromatase inhibitory activities of 5d, 10a, 10b, 10c, 11a, 15a, and 15b were more potent than Formestane. One compound, 1-(4-chlorobenzyl)-cis-2-(1H-imidazol-1-ylmethyl)cyclopentanol+ ++ (10a) was in particular identified as a potent aromatase inhibitor in vitro, exhibiting an IC50 value of 4 x 10(-8)M. The enantiomers of 10a were separated, and their absolute configuration were determined by X-ray crystallography.

Androstenedione↗
PubMed1995

[A new protein titrator tape for self-assessment by outpatients with proteinuria].

ł- have invented a new dipstick (protein titrator tape) for measuring the volume of protein excreted in the 24-hour urine. The principle of the method is based on the protein error of indicators with the modification of a conventional dipstick test. The dipstick consists of two thick filter papers, containing differently adjusted pH indicators of tetrabromphenol blue, making it possible to detect a wide range of protein concentrations in the urine using a standard color chart that includes twenty color blocks. Two hundred and ninety outpatients had their urine samples assessed with this method as well as with the pyrogallol red test as a comparative study for quantitative measurement of protein concentrations. The new-type dipstick method exhibited good correlation with the results of the pyrogallol red test, especially in the range of protein concentrations from 50 mg/dl to 400 mg/dl, showing the linear equation of "y (Pyrogallol red) = 10.5 + 0.99 x (Dipstick) (r = 0.91, P < 0.01)". Although there was good correlation with the pyrogallol red test at higher concentrations from 400 mg/dl to 1,000 mg/dl, the dipstick method tended to exhibit lower concentrations than those indicated by the counterpart method. The rate of consistency between observers was quite high. This new-type dipstick method will offer a reliable method for patients or their family to assess their protein excretion in the urine every 24 hours at home using a portable urine sampling device.

Adult↗
PubMed1995

Syndactylic toe transfer for fingertip reconstruction.

In the case of multiple fingertip reconstruction requiring toe transfer, double toes can be elevated in the syndactylic fashion with a single vascular pedicle for transfer, followed by separation a few weeks later. The biggest advantage of this procedure is that the problem of limitation of recipient arteries for multiple toe transfer is solved. We reconstructed fingertips of three patients by this procedure with three variations based on combinations between the wrap-around flap and whole-toe transfer. All three patients survived completely and achieved an aesthetically pleasing result. This report introduces the concept and technique of the syndactylic toe transfer for fingertip reconstruction.

Adult↗
PubMed1994

[An epidemiological study of penicillin-resistant Streptococcus pneumoniae in Japan].

In order to investigate penicillin resistance (Pcr) in Streptococcus pneumoniae from clinical sources in Japan, a total 1,127 strains of S. pneumoniae was collected at random from 36 institutions participating to "Working group for Pcr S. pneumoniae" around the country in 1993-1994. These strains were isolated more frequently from sputum (38.2%), throat (31.4%), nasal discharge (16.4%), and otorrhea (5.7%). A small number of isolates from blood (19 strains; 1.8%), cerebrospinal fluid (11 strains; 1.0%), and pleural fluid (2 strains; 0.2%) were included respectively. Patients from whom S. pneumoniae was isolated have mostly been associated with children < or = 12 years of age and adults 60 < or = years olds. These isolates were tested for susceptibility to penicillin G, ampicillin, oxacillin, cefixime, cefdinir, imipenem, panipenem, erythromycin, clindamycin, minocycline, and vancomycin by an agar dilution method using Mueller Hinton agar supplemented with 10% sheep blood. Strains with the MICs > or = 0.125 micrograms/ml for penicillin G were defined as a Pc resistance. Of the 1,127 strains, 471 strains (41.8%) were identified as a Pc resistance. Pcr S. pneumoniae were almost resistant to other beta-lactams, including ampicillin, oxacillin, ceftizoxime, cefixime, cefdinir. Although, the MICs of imipenem and panipenem ragned from 0.004-2.0 micrograms/ml with 2 peaks distributions, these antibiotics inhibited the growth of most of Pcr S. pneumoniae at the lowest concentrations of < or = 0.5 microgram/ml. Only vancomycin resistant strain was not detected in these isolates. Most of the Pcr strains were simultaneously resistant to macrolides and minocycline. Further more, isolation frequencies of Pcr S. pneumoniae in west Japan, were relatively high compared with those of east Japan.

Adolescent↗
PubMed1994

[Serum adenosine deaminase and angiotensin converting enzyme activity in patients with endogenous uveitis].

Serum activity of adenosine deaminase (ADA) and angiotensin converting enzyme (ACE) was investigated in 32 patients with sarcoidosis, 22 patients with Behçet's disease, 22 patients with Vogt-Koyanagi-Harada's (VKH) disease and 253 healthy controls. In healthy controls, the ADA level was significantly higher in females than in males (p < 0.01). In patients with sarcoidosis, the serum ADA level was significantly higher in both males and females than in the controls (p < 0.01). In patients with Behçet's disease, the serum ADA level was significantly higher than in the controls (p < 0.01) in males only. In VKH disease, the serum ADA level showed no significant difference from the normal controls. Significant elevation of the serum ACE activity was observed only in patients with sarcoidosis (p < 0.01). Serum ACE activity was therefore considered to be more specific to sarcoidosis than serum ADA activity.

Adenosine Deaminase↗
PubMed1993

[Eosinophil kinetics].

The in vivo kinetics of autologous 111In-oxine labeled eosinophils were studied in 3 patients with reactive eosinophilia. Organ distribution and life span of 111In-oxine labeled eosinophils were evaluated. The disappearance curve of the labeled eosinophils showed two exponential components in all cases. Between these two factors, there was a slightly increase of radioactivity, suggesting the presence of recirculation. Radioactivity in the spleen, the liver and the bone marrow were observed 5 minutes after the infusion, suggesting the presence of marginal pool in these organs. Radioactivity in the spleen was increased rapidly during 1 and 24 hours after the infusion. Sequestration and/or destruction of increased eosinophils may exist in the splenic pool. The granulocyte turnover rate in eosinophilia was less than in CML or chronic neutrophilia. The results indicate that the migration of eosinophils is less active than that of neutrophils.

Animals↗
PubMed1992

The crystal structure of muscle phosphoglucomutase refined at 2.7-angstrom resolution.

A model of rabbit muscle phosphoglucomutase was refined at 2.7-A resolution by using two heavy atom derivatives for initial phasing and standard refinement procedures, including molecular replacement averaging about a 2-fold axis and dynamic simulation: final R-factor, 0.223 (no solvent modeling); RMS deviation from standard bond lengths and angles, 0.020 A and 3.6 degrees, respectively (all 8658 nonhydrogen atoms plus 36,953 reflections (F/sigma greater than or equal to 3) between 8- and 2.7-A resolutions); average of individually refined atomic B-factors, 40 A2 (all atoms) and 30 A2 (all atoms in domains I-III). An H-bonding scheme with 538 main chain H-bonds for the two monomers in the asymmetric unit and probable ligands for six uranyl ions in one heavy atom derivative is given. The monomer contains 42 strands/helices arranged into four alpha/beta-domains. Each of the first three domains contains an alpha 3 beta 4 alpha 1 motif, where the topology of beta 4 is 2,1,3,4:[arrows: see text] which is a topology not encountered in an extensive search among known protein structures. A spatial similarity is observed between corresponding residues in the three repetitions of this motif per monomer, but the minimal mutational distance between spatially corresponding residues is not statistically significant. The loop between the antiparallel strands in each of these domains is an important feature of the active site. In domain IV, beta-sheet topology is 2,1,3,4,5,6:[arrows:see text]. Noncovalent domain/domain interactions within the monomer are greatest between adjacent domains along the polypeptide chain, which are not substantially interdigitated and can be cleanly disengaged by altering the phi/psi torsional angles of three uniquely positioned residues in the model. The observed hierarchy of noncovalent interactions between structural units within the crystal, based on a semi-empirical paradigm, suggests that monomer-monomer contacts within the asymmetric unit are formed during growth of the lattice and provides a rationale for some of the diffraction characteristics of phosphoglucomutase crystals. An unusually deep crevice involving 58 residues is formed by the head-to-tail, twisted semicircular arrangement of the four domains of the monomer that places no atom more than 12 A from the water-accessible surface. The active site of the enzyme is extensively buried at the bottom of this crevice, at the approximate confluence of the four domains. Other features of the active site, including the surrounding helical dipoles, and the metal-ion binding pocket are described, together with structure/function comparisons with a number of other enzymes.

Amino Acid Sequence↗
PubMed1992

In vitro validation of a thermodilution right ventricular ejection fraction method.

A thermodilution catheter and computer system has been developed to measure right ventricular ejection fraction and volumes. To evaluate the performance of this method, the thermodilution system was evaluated in an in vitro pulsatile flow model. Thermodilution measurements of ejection fraction (EF), cardiac output (CO), stroke volume (SV), end-diastolic volume (EDV), and end-systolic volume (ESV) were compared with known values in a pulsatile flow bench. Thermodilution EF measurements correlated very well with the pulsatile flow model (r2 = 0.95, m [slope] = 0.85, SEE = 4.0 EFU). Thermodilution CO and SV were highly predictive of actual pulsatile flow (r2 = 0.99, m = 0.99, SEE = 187 ml/min and r2 = 0.98, m = 0.96, SEE = 2.5 ml, respectively). Thermodilution end-diastolic and end-systolic volume measurements resulted in low mean eror, -1.8% and 0.6%, respectively. The standard deviations of the error for EDV and ESV were 11.0% and 16.4%. The thermodilution measurements were repeatable, with CO, SV, and EF coefficients of variation of 3.2%, 3.3%, and 4.7%, respectively. EDV and ESV were slightly more variable, with coefficients of variation of 5.5% and 7.2%, respectively.

Cardiac Catheterization↗
PubMed1992

Rapid detection of the mecA gene in methicillin-resistant staphylococci by enzymatic detection of polymerase chain reaction products.

In order to identify methicillin-resistant staphylococci from clinical sources with ease and reliability, enzymatic detection of polymerase chain reaction (ED-PCR) was applied. ED-PCR is based on the capture of amplified products via biotin-streptavidin affinity and the detection of an incorporated hapten in amplified products with an enzyme-linked antibody. In order to identify methicillin-resistant staphylococci of all species, a 150-bp fragment of the mecA gene was targeted for ED-PCR. After PCR was performed with a pair of biotin and dinitrophenol 5'-labeled primers, the reaction mixture was applied to a microtiter well precoated with streptavidin. Thereafter, bound PCR products were detected colorimetrically with alkaline phosphatase-conjugated anti-dinitrophenol antibody. The extraction of DNA from staphylococcal cells for PCR was simplified so that it could be performed within one tube. The total assay, including PCR, took less than 3 h. The sensitivity of mecA gene detection ranged from greater than 5 x 10(2) CFU per tube for Staphylococcus aureus to greater than 5 x 10(3) CFU per tube for Staphylococcus epidermidis. Genotyping results obtained by ED-PCR of 161 tested strains from the colonies (97 strains of S. aureus and 64 strains of coagulase-negative staphylococci) were compared with the phenotypic susceptibilities of the strains to oxacillin. The results of ED-PCR showed excellent agreement with the MICs of oxacillin with very few exceptions; only one strain of S. aureus and two strains of coagulase-negative staphylococci were found to possess the mecA gene, which was discrepant with their phenotypes. Fifty-five blood culture samples were also tested by ED-PCR. For staphylococcal isolates in 33 of the cultures, oxacillin MICs were >4 microgram/ml; 31 of the 33 staphylococcal isolates were determined by ED-PCR to be mecA gene positive. These results suggest that ED-PCR can be used with reasonable confidence in the clinical microbiological laboratory.

Alkaline Phosphatase↗
PubMed1992

Detection of Epstein-Barr virus sequences in patients with Kawasaki disease by means of the polymerase chain reaction.

We used a selective DNA amplification technique to detect Epstein-Barr virus (EBV) DNA in peripheral blood mononuclear cells from patients with Kawasaki disease (KD). By means of the polymerase chain reaction EBV sequences were indentified directly in 21 (60%) of 35 KD patients within 2 weeks after the onset of KD. Furthermore, EBV sequences were detected in all of 6 repeatedly tested patients with KD within 3 months after disease onset. In contrast, only 2 (12%) of 17 control DNA samples were polymerase chain reaction positive. These results indicate that an unusual EBV-cell interaction may exist in KD.

Child, Preschool↗
PubMed1992

[Two cases of congenital cardiac anomaly associated with esophageal atresia].

Two cases of congenital cardiac anomaly associated with esophageal atresia and tracheo-esophageal fistula were presented. One case was HLHS, and the other was TAPVR. Esophageal procedures were performed earlier than cardiac procedures in both cases. Primary anastomosis for esophageal atresia just after birth in the latter case. Corrective procedures for cardiac anomalies were performed at 36 days and 35 days after birth, respectively. The HLHS case died perioperatively and the TAPVR case survived the operation and is alive one year postoperatively.

Esophageal Atresia↗
PubMed1992

[A case of straddling tricuspid valve associated with VSD].

A case of straddling tricuspid valve associated with VSD was presented, who was diagnosed as VSD with pulmonary hypertension but not diagnosed as straddling in preoperative state. Two-dimensional echocardiography did not demonstrate a small right ventricle and overriding of tricuspid valve to the ventricular septum. Operative findings were as follows; the VSD was common A-V canal type and anomalous chordae of septal leaflet of tricuspid valve crossed through the VSD and attached to the contralateral side of the ventricular septum. We tried to preserve the anomalous chordae to prevent tricuspid regurgitation, so that we carried out patch closure of VSD. To avoid injury conduction system stitches were placed from upper margin of the VSD, and to keep away tricuspid regurgitation we plicated a depression of septal leaflet which caused by anomalous chordae in VSD patch closure. In postoperative state, A-V block did not arise and tricuspid regurgitation was shown a little as well as preoperative state.

Heart Septal Defects, Ventricular↗