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Biomedical subjects

K Ikebukuro

Publications and source records attributed to K Ikebukuro.

49 records · Page 3Linked to original sources
PubMed1997

Novel DNA detection system of flow injection analysis (2). The distinctive properties of a novel system employing PNA (peptide nucleic acid) as a probe for specific DNA detection.

In order to realize immediate detection of a double stranded DNA amplified by Polymerase Chain Reaction (PCR), we applied Peptide Nucleic Acid (PNA) to the probe of DNA detection system using Surface Plasmon Resonance (SPR). We report our success in immediate detection of PCR products solution with high sequence-specificity.

Bacterial Toxins↗
PubMed1996

Optimization of the rate of DNA hybridization and rapid detection of methicillin resistant Staphylococcus aureus DNA using fluorescence polarization.

The hybridization rate of two complementary single-stranded DNA 24-mers was determined at various NaCl concentrations using a fluorescence polarization method. The rate was taken as the rate constant of the second order reaction, obtained by mathematical fitting of the time course curves of hybridization. The rate increased with the NaCl concentration, plateauing in the concentration range of about 1-2 M. Over the temperature range of 46 degrees C to 56 degrees C, it was found that in 0.8 M NaCl, hybridization was complete in under 10 min and that the difference in the polarization values between specific hybridization and non-specific binding was greater at lower temperatures. Under the optimized conditions of 0.8 M NaCl at 46 degrees C, the time for DNA hybridization to reach 90% completion decreased to less than 5 min. The assay time for one sample was 10 min and the detection limit was of the order of 10(-10) M (40 fmol per assay). Under the optimized conditions, the DNA of methicillin resistant Staphylococcus aureus (MRSA), which had been multiplied by PCR, could be detected within 10 min.

Base Sequence↗
PubMed1996

Microbial cyanide sensor for monitoring river water.

A microbial cyanide sensor using Saccharomyces cerevisiae for monitoring a river water is described. This sensor is based on the inhibition of S. cerevisiae's respiration by cyanide. This sensor is a reactor type flow system and composed of two oxygen electrodes and a reactor which contains S. cerevisiae immobilized beads. The S. cerevisiae's respiration activity is measured using the oxygen electrodes. The sensor showed a linear response in the range from 0 to 15 microM and maintained stable response for 9 days at ambient temperature. The sensor was optimized for the monitoring of river water and was applied to river water analysis.

Biosensing Techniques↗
PubMed1996

Determination of cyanide using a microbial sensor.

A microbial cyanide sensor was prepared, consisting of immobilized Saccharomyces cerevisiae and an oxygen electrode. When the electrode was inserted into a solution containing glucose, the respiration activity of the microorganisms increased. The change in the respiration activity is monitored with the oxygen electrode. When cyanide is added to the sample solution, the electron transport chain reaction of the respiration system in the mitochondria is inhibited, resulting in a decrease in respiration. The inhibition is caused by cyanide binding with respiration enzymes such as the cytochrome oxidase complex in the mitochondrial inner membrane. Therefore, the cyanide concentration can be measured from the change in the respiration rate. When the sensor was applied to a batch system at pH 8.0 and 30 degrees C, the cyanide calibration curve showed linearity in the concentration range between 0.3 microM and 150 microM CN-.

Cyanides↗
PubMed1995

Relief of airway compression by enlarged pulmonary artery--modified palliative suspension of the artery after plication.

A new modification of the technique for plication and suspension of the pulmonary artery in critically ill infants and children is described. The technique consists of (1) left lobe thymectomy, (2) insertion of a polytetrafluoroethylene sheet to provide complete coverage of pericardium, (3) plication of dilated pulmonary artery and (4) suspension of plicated pulmonary artery to the left side of the anterior chest wall. We employed this technique in 7 patients with respiratory distress due to tracheal and/or broncheal compression with massive left-to-right shunt (5 patients) and with absent pulmonary valve (2 patients). Five of these patients (71%) could be weaned from the respirator in the postoperative phase with this surgery. Although this procedure is palliative, this simple technique might be one of the choices for critically ill infants and children.

Airway Obstruction↗
PubMed1995

[Postoperative bronchial stenosis associated with IAA complex and transendoscopic resection of intrabronchial granulation].

Problem with stenosis of the left bronchus was encountered in a patient with type B interrupted aortic arch complex after the arch reconstruction and pulmonary artery banding. Bronchoscopic study disclosed the intraluminal granulation of left bronchus and transendoscopic resection of the granulation successfully relieved the stenosis and brought the patient to full recovery.

Airway Obstruction↗
PubMed1994

Micromachined electroporation system for transgenic fish.

Luciferase gene was introduced into fertilized eggs of medaka by a localized electric field between thin film electrodes formed on a glass plate. Miniaturization of the electrodes enabled us to apply a localized electric field to the animal pole of the fertilized egg. Biochemical luminescence and an electrophoresis pattern showed expression and integration of the gene, respectively. The presented system had a higher ratio of gene introduction than the conventional electroporation method.

Animals↗
PubMed1992

[Surgical managements of the compression of trachea and/or bronchus associated with congenital cardiovascular anomalies].

From 1987 through 1990, 17 cases with tracheal and/or bronchial compression due to congenital cardiovascular malformations were experienced at our institutes. Respirator was required preoperatively in 10 patients (59%) due to severe respiratory symptoms by airway compression and narrowing. In all cases, bronchoscopy was carried out pre- or intra-operatively for the precise diagnosis and for the decision of operative procedures. Postoperatively 12 cases were successfully extubated and remained free of respiratory distress. We investigated the relationships among pre- and post-operative pressure ratio, preoperative flow ratio, requirement of preoperative respirator and indication for plication and suspension of pulmonary artery in the group of the patients, who had airway compression by the dilated pulmonary artery due to large left to right shunt. As a result of this investigation, these factors have no significant correlation. The severity of associated tracheomalacia might be a most susceptible cause, which required the preoperative managements with respirator and the surgical interventions to the dilated pulmonary artery. Infant with patent ductus arteriosus (PDA) could be surgically treated by the division of PDA through left lateral thoracotomy. If the left main bronchus shows complete obstruction after division of PDA, the additional surgical intervention like suspension of aortic arch is needed. Two cases were lost with reoperation and these suggested not only the priority of simultaneous repair of trachea and cardiovascular anomaly, but the necessity of minor intervention against adhesion (insertion of Gore-Tex sheet between suspended pulmonary artery and sternum) in the first-step palliative operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Aorta↗
PubMed1990

A new technique for the excision of the first branchial cleft fistula--turn-inside-out method of the fistula.

Conventional surgery of the first branchial cleft fistula has been highly complicated. Especially the management of the facial nerve and the complete removal of the fistula in the ear canal side were very difficult. According to the anatomical and embryological studies, we designed a new operative technique. We applied this method successfully in two cases, and we consider it to be very safe, easy and effective.

Branchioma↗
PubMed1989

Computerized analysis of anorectal manometry.

A computer system was designed and applied to anorectal manometry that allows pressure data to be analysed in various ways. Two kinds of applications were presented. Image analysis enabled anorectal movements to be visualized as a three-dimensional image. This technique was shown to be useful in studying the pathophysiology of chronic constipation in children. Radial variation analysis demonstrated that there was no significant radial difference in the anal-canal pressure.

Anal Canal↗
PubMedDate not supplied

Detection of toxic chemicals with high sensitivity by measuring the quantity of induced P450 mRNAs based on surface plasmon resonance.

In this study we describe a novel sensor system to detect toxic chemicals based on measurement of the quantity of Saccharomyces cerevisiae P450 mRNAs induced by them. Detection was conducted using a flow-injection-type sensor system based on surface plasmon resonance (SPR). The DNA and peptide nucleic acid (PNA) probes containing a complementary sequence to a part of P450 mRNA were immobilized on the sensor chip and the P450 mRNAs hybridized to the probes were quantified. We succeeded in detecting 10 ng/L (10 ppt) of atrazine using both DNA and PNA probes. Using this sensor system, we were able to detect bisphenol A in addition to atrazine. Furthermore, we achieved higher sensitivity by amplifying the target P450 mRNA based on nucleic acid sequence-based amplification (NASBA). This method allows for sensitive, rapid, and easy detection of some toxic chemicals.

Atrazine↗
PubMedDate not supplied

Proteasome inhibitor 1 enhances paclitaxel-induced apoptosis in human lung adenocarcinoma cell line.

Paclitaxel is a chemotherapeutic drug that induces apoptosis in tumor cells by stabilizing microtubules, prevents normal mitosis, and blocks the cell cycle at the G2/M phase. We have previously reported that the activation of caspase-3 and caspase-8 plays a crucial role in paclitaxel-induced apoptosis. Anti-tumor reagents including paclitaxel, irradiation, and other stimuli activate the transcription factor NF-kappaB, which has the ability to suppress the apoptotic potential of those stimuli. Using a human lung adenocarcinoma cell line (LC-2-AD), we therefore examined whether the inhibition of NF-kappaB activity by proteasome inhibitor 1 (PS1) could become a new adjuvant therapy for cancer. A synergistic effect on apoptosis induction was observed with the combination of more than 0.1 microg/ml paclitaxel and 0.5 microM PS1. An increase in the cell number of apoptotic cells is correlated with the loss of Deltaphim and the activation of caspase-3 and caspase-8. Furthermore, augmented apoptosis is related to NF-kappaB activation. Based on these findings, we propose that the combination of paclitaxel with PS1 could be a new strategy for cancer treatment.

Adenocarcinoma↗