Experimental studies of remarkable monoamine releases and neural resistance to the transient ischemia and reperfusion.

INTRODUCTION: The literature described that neural damage caused by ischemia definitely occurs in brain areas. However, few studies have shown real-time changes of extracellular monoamine levels at the time of transient ischemia. METHODS: We examined changes in the responses of dopamine (DA) and serotonin (5-HT) release in the nucleus accumbens (ACC) of rats treated with four-vessel occlusion (4VO) in experiment 1. In the second experiment, we investigated the selective neural vulnerabilities among the ACC, lateral hypothalamus (LH), and frontal cortex (FC) of rats treated with 4VO and four days of reperfusion. RESULTS: The extracellular levels of DA and 5-HT were remarkably increased 200- and 20-fold upon the 10-min clipping of both common carotid arteries in transient cerebral ischemia, respectively. Each increased monoamine release returned to the baseline levels immediately. The release of DA in the ACC and FC was significantly decreased in the rats treated with the coagulation of bilateral vertebral arteries (2VO), compared with that of sham-operated rats. K(+)-induced DA release in the ACC and FC of 4VO-treated rats was increased without alteration of DA content. DISCUSSION: Surviving dopaminergic neurons in the ACC and FC showed neural hyperfunction associated with the monoamine release, serotonergic neurons in particular these areas exhibiting functional resistance to the transient ischemic change. CONCLUSION: It is suggested that the remarkable extracellular release of DA and 5-HT was not the cause of the ischemic delayed neural degeneration in each brain area, and that the functions of neurotransmitter release involved remarkable resistance to the transient ischemia.

Detection of abused drugs in human blood by using the on-site drug-screening device Oratect® III.

A simple and precise drug screening method was developed for the detection of abused drugs in whole blood by using the Oratect® III device that is usually employed for the detection of drugs in saliva. Whole blood was acidified with phosphoric acid, following which the hemolyzed solution was filtered through the ultrafiltration column Vivaspin 2 Hydrosart®. The filtrate was then tested for the presence of drugs using Oratect III. The detection limit of the device for methamphetamine, amphetamine, morphine, codeine, dihydrocodeine, diazepam, alprazolam, estazolam, and prazepam in whole blood was 125, 125, 50, 50, 50, 25, 60, 15, and 75ng/mL, respectively. The concentration range detected was between therapeutic and toxic drug levels; therefore, the proposed method can be applied for detecting the presence of abused drugs in blood. Our method is a novel, optimized technique for use in forensic laboratories to screen whole blood for drugs of abuse.

[Cross-reactivity of Instant-View M-1 for detection of benzodiazepine-related drugs and their metabolites in urine].

Immunoassays are useful methods for the determination of regulated drugs in clinical and forensic laboratories. Although the Instant-View M-1 (IV M-1) immunoassay kit is frequently used to screen drugs in laboratories in Japan, basic information about the IV M-1 such as its specificity and reactivity is not available. In this study, we determined the specificity and cross-reactivity of IV M-1 for the detection of benzodiazepine-related drugs and their metabolites in urine. The IV M-1 could detect triazolobenzodiazepines such as triazolam in urine at concentrations > or = 300 ng/mL. However, thienodiazepines such as etizolam could not be detected because of lack of cross reactivity. A correlation was observed between the structure of the metabolites and the reactivity of the kit; 4-hydroxy metabolites of alprazolam and triazolam were detectable, whereas a-hydroxy metabolites were not. Furthermore, 7-amino metabolites such as nitrazepam could not be detected at any concentration, including high concentrations. The specificity and reactivity of various kits used for detection of drugs in urine are different. Therefore, it is necessary to consider the basic features of the kit used while assessing the results obtained.

Gender differences in D-aspartic acid content in skull bone.

In forensic medicine, the personal identification of cadavers is one of the most important tasks. One method of estimating age at death relies on the high correlation between racemization rates in teeth and actual age, and this method has been applied successfully in forensic odontology for several years. In this study, we attempt to facilitate the analysis of racemized amino acids and examine the determination of age at death on the basis of the extent of aspartic acid (Asp) racemization in skull bones. The specimens were obtained from 61 human skull bones (19 females and 42 males) that underwent judicial autopsy from October 2010 to May 2012. The amount of D-Asp and L-Asp, total protein, osteocalcin, and collagen I in the skull bones was measured. Logistic regression analysis was performed for age, sex, and each measured protein. The amount of D-Asp in the female skull bones was significantly different from that in the male skull bones (p = 0.021), whereas the amount of L-Asp was similar. Thus, our study indicates that the amount of D-Asp in skull bones is different between the sexes.