Biomedical subjects

Makiko Hayashida

Publications and source records attributed to Makiko Hayashida.

9 recordsLinked to original sources

PubMed2005

Effects of long-term administrations of aconitine on electrocardiogram and tissue concentrations of aconitine and its metabolites in mice.

Aconitum alkaloids are well known for their acute and high toxicity, for example, in the causation of severe arrhythmias leading to death. Aconitine, one of the major Aconitum alkaloids, is a highly toxic compound from the Aconitum species. However, there has been no studies reported on the influence of the chronic administration of aconitine. Thus, this study was conducted to investigate the influence of chronic administration of aconitine in experimental animal models. A dose of 1mg/kg per day was administered to the experimental animal models. We determined the concentration of aconitine and its metabolites (benzoylaconine and aconine) in organs and blood with gas chromatography/selected ion monitoring (GC/SIM). In addition, we concurrently recorded the electrocardiogram (ECG). Fifteen minutes after administration on day 0, the early aconitine administered group (acute group) revealed peak organ and blood concentration levels of aconitine with a gradual decrease, thereafter. The concentration of aconitine in organs and blood (from days 0 to 22; 90 min after the last administration of aconitine) gradually decreased according to repeated administration, whereas benzoylaconine and aconine increased. ECG revealed various types of arrhythmias. However, the frequency of arrhythmias remarkably decreased with time and repeated administration of aconitine. These results indicate two possibilities. First, the increase in the activity of aconitine metabolism. Secondly, the decrease of effectiveness to the heart due to long-term (chronic) administration of aconitine.

Aconitine↗

PubMed2005

Diagnostic performance of Triage for benzodiazepines: urine analysis of the dose of therapeutic cases.

We evaluated the diagnostic performance of Triage for benzodiazepines in 74 urine specimens from outpatients given therapeutic doses of benzodiazepines and compared the results of EMIT assays. Results obtained in all urine samples were confirmed using liquid chromatography-mass spectrometry (LC-MS). Overall agreement between results of Triage and EMIT assays was 73%. All of the Triage-positive samples were also positive by EMIT assays. Results of Triage and EMIT assays were different for 20 samples obtained from patients given thienodiazepines (etizolam, brotizolam, and clotiazepam) and nitrobenzodiazepines (nitrazepam, flunitrazepam, and clonazepam). LC-MS confirmed parent drugs in urine specimens, consistent with the prescriptions of drugs. The low agreement between Triage and EMIT results in this study might be due to low sensitivity of Triage for thienodiazepines. Thienodiazines are frequently prescribed benzodiazepines, and Triage panel is the most frequently used screening kit in Japan. It should be noted that negative results obtained by a Triage test might not mean the absence of thienodiazepines.

Benzodiazepines↗

PubMed2005

Diagnostic Performance of Triagetrade mark for Benzodiazepines: Urine Analysis of the Dose of Therapeutic Cases.

Journal Article↗

PubMed2004

[GC-MS analysis of methamphetamine and amphetamine in hair of Thai drug addicts].

UNLABELLED: Psycho-stimulant dependence in young individuals has become a serious problem in Thailand, where consumption of the so-called YaBa methamphetamine tablets has become a fashionable trend. Due to its easy availability in the form of a tablet, young individuals abuse methamphetamine. Methamphetamine tablets are known to be potently addictive and its difficulty in cessation of drug use and to be abstinent from the drug. We herein report the results obtained from GC-MS analysis of methamphetamine and amphetamine in 33 samples of urine and hair from patients with psycho-stimulant dependence. These samples were collected from patients registered at the outpatient clinic in the Department of Psychiatry, Chiang Mai University Hospital and were sent to Nippon Medical School, Department of Legal Medicine (Tokyo, Japan) for further analysis by Dr. Werawan Ruangyttikarn, Department of Forensic Medicine, Chiang Mai University. Sample preparation: Hairs samples were cropped near the hair root. After washing, they were cut into 1.2-cm sections and extracted with methanol/5N HCl (2:1) for an hour and then, solid-phase extraction was conducted using Bond-Elut Certify. Following extraction, GC-MS analysis was performed. Urine samples were subjected to GC-MS analysis after preparation with Bond Elut Certify. RESULTS AND DISCUSSION: In 6 samples, both urine and hair samples analyzed were negative for detection of the stimulant drugs. In those cases individuals might stop taking drug for about 5 months. In 18 samples, urine samples were negative whereas hair samples were positive. These results suggest that individuals might stop using drugs for a few days before they went to the hospital but they abuse drugs continuously. In 9 samples, both urine and hair samples were positive. These results show that individuals always abuse drugs. In order to treat drug dependence effectively it is necessary to obtain the patient history of drug use and to evaluate and determine short-term and long-term drug use with urinalysis and hair analysis, respectively. Our present data revealed that useful information concerned with the long term drug abuse can be obtained from hair analysis, and that this method of analysis is applicable not only to forensic cases but also for evaluating clinical cases.

Adolescent↗

PubMed2003

Polymer-coated fibrous extraction medium for sample preparation coupled to microcolumn liquid-phase separations.

Polymer-coated fibrous material has been introduced as the extraction medium for a miniaturized sample preparation method being coupled with microcolumn liquid chromatography. The preconcentration and the subsequent liquid chromatographic separation of tricyclic antidepressants (TCAs) drugs, amitriptyline, imipramine, nortriptyline and desipramine, was carried out with the hyphenated system. Several basic experimental parameters, such as extraction and separation conditions, were investigated along with the applicability of the method for the analysis of biological fluids. The results clearly showed that the on-line coupled system could be a powerful tool for the analysis of complex mixtures in biological matrix without a large solvent consumption and specially designed instruments. The lowest limit of quantification was quite acceptable for the analysis of TCAs in clinical and forensic situations.

Antidepressive Agents, Tricyclic↗

PubMed2003

A column-switching LC/MS/ESI method for detecting tetrodotoxin and Aconitum alkaloids in serum.

A liquid chromatography-mass spectrometry-electrospray ionization (LC/MS/ESI) method coupled with a column-switching technique has been developed for the determination of tetrodotoxin (TTX) and Aconitum alkaloids and their metabolites, such as aconitine, mesaconitine, hypaconitine, jesaconitine, benzoylaconine, benzoylmesaconine, benzoylhypaconine and 14-anisoylaconine, in serum. An on-column column-switching technique was employed to analyze TTX and Aconitum alkaloids and their metabolites without pretreatment of the serum. Combination of a multimode column with reversed phases and cation exchange for TTX, and use of a multimode column with reversed phases and a hydrophobic polymer column for Aconitum alkaloids and their metabolites provided successful separation and MS determination in ESI positive mode. A 100 microl serum sample was directly injected into a precolumn. For TTX monitored at m/z 320.1 in the selected ion monitoring mode, the calibration curve was linear within the range 0.1-100 ng/ml and the limit of detection was 0.1 ng/ml. For aconitine, mesaconitine, hypaconitine and jesaconitine, linear calibration curves were obtained up to 500 ng/ml and the limit of detection ranged from 0.2 to 1 ng/ml. For benzoylaconine, benzoylmesaconine, benzoylhypaconine and 14-anisoylaconine, linear calibration curves were obtained up to 500 ng/ml and the limit of detection ranged from 2 to 50 ng/ml. Recoveries from serum samples were within the range 78-119% for all the compounds studied.

Aconitine↗

PubMed2002

Miniaturized sample preparation and separation methods for environmental and drug analyses.

Miniaturized extraction and separation media have been successfully developed from precisely controlled technologies. In this article, recent developments in these high performance analytical methods, such as miniaturized sample preparation methods and the coupling of these techniques with microscale separation systems, have been reviewed, along with some applications to environmental and biological analysis. The advantage of the miniaturization is not only for the environmental compatibility but also for the developments of the high performance analytical systems. Down-sizing also makes it possible to investigate and introduce various compounds and materials as novel media (such as tailor-made materials and devices) in separation science. As a typical example of the novel miniaturized sample preparation system, the applications of fibrous materials for microcolumn liquid-phase separation methods are described.

Environmental Monitoring↗

PubMed2002

[Analysis of MDMA and PCP by GC-MS from patients admitted to the critical care medical center].

In our country, abuse of methamphetamine has increased. Furthermore, dealings of other drugs by using internet have increased. But, the poison cases of 3,4-methylenedioxymethamphetamine (MDMA) and phencyclidine (PCP) have never been reported in our country. We report an MDMA poison case and a PCP poison case. We could detect MDMA, MDA or PCP by GC-MS from urine and serum of patients admitted to the critical care medical center of Nippon Medical School. Case 1: A 23-year-old foreign female was admitted to our hospital because of disturbance of consciousness. Her friend said that she had been found lying on the floor of the bathroom after taking a tablet. The screening test by Triage showed AMP positive. Not methamphetamine but MDMA and MDA were detected from urine and serum of the patient by GC-MS. Case 2: A 27-year-old foreign female was admitted to our hospital because of restlessness and excitement. Her friend said that she had become restless and excited after taking 15-30 tablets of Tylenol. The screening by Triage showed BZO and PCP positive. Not acetaminophen but PCP was detected in the patient's sample by GC-MS. Drug abuse has expanded to Japan over the border. New responses to abuse drugs with respect to medical treatment and drug analyses should be established.

Adult↗

PubMedDate not supplied

Sensitive determination of tetrodotoxin using column-switching liquid chromatography-mass spectrometry with electrospray ionization in mouse serum.

A liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) method coupled with a column-switching technique was developed for the determination of tetrodotoxin (TTX) in serum. An on-column, column-switching technique was employed to analyze TTX without pretreatment of the serum. The combination of a multimode column with reversed phases and cation exchange for TTX provided successful separation and MS determination in the ESI-positive mode. A 100-microL serum sample was injected directly into a precolumn. For TTX monitored at m/z 320.1 in the selective ion monitoring mode, the calibration curve was linear within the range 0.1-100 ng/mL, and the limit of detection was 0.5 ng/mL. Recoveries were around 90% for TTX. The present method allows successful analysis of TTX in serum. In conclusion, this new method is simple, accurate, and useful for the determination of TTX and should be of benefit to both forensic and clinical toxicology.

Animals↗