Showing papers in "Bulletin of National Institute of Hygienic Sciences in 1993"

Quantitative histopathological study on the adriamycin testicular toxicity in rats

Abstract: Testicular toxicity induced by adriamycin (ADR) was studied using quantitative histopathological methods. Nine-week old male rats were received a single dose of 8 mg/kg ADR. At 3, 7, 14 and 21 days after the treatment, animals were sacrificed for histopathological evaluation. Numbers of seminiferous epithelia were counted in seminiferous tubule of spermatogenic stages I, II, V, VII and XII. A decrease in spermatogonia was observed in seminiferous tubules of stages I, II and V at 3 days after the treatment. Thereafter, numbers of other types of seminiferous epithelia decreased following progress of spermatogenic cycle. Analysis of spermatogenic cycle movement and germ cell differentiation suggested that ADR was highly effective in killing spermatogonia type A, and the severity of ADR damage would be different depending on subtypes of spermatogonia type A and spermatogenic stages.

[Studies on identification of drugs of abuse by diode array detection. I. Screening-test and identification of benzodiazepines by HPLC-DAD with ICOS software system].

Abstract: For the establishment of screening-test and identification of 20 benzodiazepines (Alprazolam, Bromazepam, Chlordiazepoxide, Clonazepam, Clotiazepam, Cloxazolam, Diazepam, Estazolam, Fludiazepam, Flunitrazepam, Flurazepam, Lorazepam, Lormetazepam, Medazolam, Midazepam, Nimetazepam, Nitrazepam, Oxazepam, Prazepam, Triazolam), the optimum separation condition on HPLC was investigated by using Interactive Computer Optimization for HPLC Separation (ICOS) software. The two eluent systems of 0.02M KH2PO4 (pH 3.1)-methanol-acetonitrile (66.4:5.7:27.9) and 0.1% TFA-methanol-acetonitrile (61.6:16.1:22.3) were selected by HPLC analyses using ICOS. These optimum separation conditions enabled the screening test and identification of the 20 benzodiazepines on HPLC with photodiode array detection.

Colorimetric determination of the total protein eluted from latex gloves

Abstract: Recently type I hypersensitivity reactions caused by latex gloves have been reported. The protein from latex gloves is considered to be responsible for this allergy. We investigated the extraction conditions and the assay methods for the purpose of the colorimetric determination of the total protein eluted from latex gloves. In a series of experiments, it was demonstrated that elution of the protein was very rapid, and changes of the extraction buffer volume (1.7-20 ml/g) had no appreciable effect on the extraction efficiency. Moreover, comparison experiments of the four assay methods revealed that Ninhydrin method was significantly interfered by low molecular weight substances other than protein and that Bradford method suffered from the poor reproducibility. On the other hand, Lowry method and Bicinchoninic acid (BCA) method gave relatively good results. Based on these experimental results, we established a typical procedure for quantitative analysis of the total protein as follows. Two grams of latex gloves specimens are extracted with 10 ml portions of phosphate buffered saline pH 7.4 (PBS) at room temperature for two hours, and then the resulting solution is assayed by BCA method. According to this procedure, commercially available ten kinds of latex gloves were analyzed. We found that the amount of the extractable protein was considerably varied with the products.

[Studies on the identification of sulfadimidine in pork by high performance liquid chromatography with photodiode array detector and gas chromatograph-mass spectrometry].

Abstract: Sulfadimidine (SDD) was detected in pork imported from Mexico by HPLC with gradient elution system. UV spectrum of the peak was measured and confirmed by photodiode array detector, moreover identified by GC/MS after methylation with diazomethane. Content of SDD in the sample was 0.1 ppm and detection limit of SDD by the proposed method was 0.02 ppm. Application of this method to CLP, SMR, SMM, SDM and SQX was studied, and satisfactory results were obtained.

[Studies on the identification of psychotropic substances. IX. Preparation and various analytical data of reference standard of new psychotropic substances, N-ethyl methylenedioxyamphetamine, N-hydroxy methylenedioxyamphetamine, mecloqualone, 4-methylaminorex, phendimetrazine and phenmetrazine].

Abstract: The reference standards of N-Ethyl methylenedioxyamphetamine, N-Hydroxy methylenedioxy-amphetamine, Mecloqualone, 4-Methylaminorex. Phendimetrazine and Phenmetrazine were chemically prepared from commercial chemicals. Their purities determined by HPLC were more than 99.8%. The standard spectra and chromatograms of the standards such as TLC, UV, IR, HPLC, GC/MS and NMR were measured. For the identification of these six drugs in forensic laboratory, their mass fragmentation and NMR spectra were discussed.

[Dermatological evaluation of a flame retardant, hexabromocyclododecane (HBCD) on guinea pig by using the primary irritation, sensitization, phototoxicity and photosensitization of skin].

Abstract: As one of the projects in the safety evaluation of chemical constituents in common house-hold products, effects of hexabromocyclododecane (HBCD) were evaluated by primary skin irritation, skin sensitization, phototoxicity and photosensitization using guinea pigs. Primary skin irritation was not observed in HBCD emulsified in distilled water by the Draize test method. Skin sensitization test was carried out according to the maximization test method of Magnusson and Kligman. For this test, HBCD was dissolved in olive oil to give 5, 0.5 and 0.05%. When induction of sensitization occurred, challenged doses of 0.005, 0.05, 0.5 and 5% of HBCD (dissolved in acetone) were applied to its respective sensitized groups. The results showed that the induction dose of greater than 0.5% and the challenge dose of greater than 0.05% elicited a positive response. The increase in the concentration of induction and challenge doses did not further increase the percentage of positive response or the intensity of skin response. Phototoxicity test was carried out with 0, 0.5 and 5% of HBCD dissolved in acetone. Phototoxicity was not observed at all HBCD concentration tested. Photosensitization test was performed according to the Sato's adjuvant-strip method. The skin sensitization and challenge reaction doses were 5 and 0.5% and 0 and 0.5% HBCD (dissolved in acetone), respectively, and no positive reaction was observed. It is clear from the foregoing results that HBCD is a mild skin allergen.

Scientific basis in the setting of residue limits for veterinary drugs in food of animal origin taking into account the presence of their metabolites

Abstract: Maximum residue level (MRL) for veterinary drugs in food of animal origin has been proposed by FAO/WHO, as a new evaluation procedure taking into account the presence of metabolites for the regulation of veterinary drug residues. The MRL is the maximum concentration of residue resulting from the use of a veterinary drug that is recommended to be legally permitted as acceptable in a food. It is established from the Acceptable Daily Intake (ADI) obtained from the data of toxicological studies, the residue concentration of the drug when used according to good practice in the use of veterinary drugs, and the lowest level consistent with the practical analytical methods available for routine residue analysis. Among the veterinary drugs, some chemicals contain a large amount of bound residues that are neither extractable from tissues by the analytical method identical with that used in parent chemicals. Especially, the bioavailable residues which are probably absorbed when the food is ingested are of great toxicological concern. In this case, the FAO/WHO recommends that the MRL can be established after the calculation of daily intake of residues of toxicological concern by the addition of both the extractable and bioavailable bound residues.

[Hemolysis of isolated erythrocytes by UVA-sensitization of flavins].

Abstract: Riboflavin (RF), flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) caused hemolysis of isolated rabbit erythrocytes by UVA-sensitization. Hemolysis induced by UVA-sensitization with RF and FMN was inhibited by 1.0 mM histidine and EDTA, and was promoted by 0.15 mM histidine and 0.01 mM NaN3. Hemolysis induced by irradiation in anaerobic condition was smaller than those in aerobic condition. Hemolysis was proceeded in the dark for 5 hours after the UVA-irradiation with RF and FAD. Erythrocyte treated by UVA-sensitization with RF easily caused hypotonic hemolysis.