Yoko Hieda

Skin analysis following dermal exposure to kerosene in rats: the effects of postmortem exposure and fire

To evaluate the usefulness of skin analysis for the forensic examination of cases involving postmortem dermal exposure to kerosene and/or fire, an experimental study using rats was performed. Rats received dermal exposure to kerosene before or after death, and the effect of fire was determined by burning an area of exposed skin after death. Kerosene concentrations in skin and blood were determined by gas chromatography-mass spectrometry and microscopic observation was performed for skin samples. No differences were observed in skin kerosene levels between antemortem and postmortem exposure. Kerosene concentrations in mildly burned skin where the stratum corneum (SC) was retained were approximately 84% compared to those in non-burned exposed skin, whereas concentrations in severely burned skin where the SC was almost completely burned off were 28% of non-burned skin. Even in non-exposed control skin 14% of the original kerosene concentrations could be detected, which was considered to be caused by contamination during the experimental protocol combined with kerosene’s property of a high affinity for the SC. These results suggest that (1) skin analysis is useful in estimating the type of petroleum product involved in crimes or accidents even for postmortem exposure, (2) whether the SC is retained or not primarily determined the kerosene levels in burned skin, and (3) attention must be paid to evaluate the results obtained from skin samples in the light of the circumstances surrounding the case.

Comparative study on toxic effects induced by oral or intravascular administration of commonly used disinfectants and surfactants in rats

Accidental ingestion or injection of household products sometimes occurs due to their accessibility, but the toxic manifestations have not been well characterized when they are internally administered. The aim of this study was to investigate the toxic effects induced by ingestion or injection of different ionic surfactants and disinfectants in rats. The test drugs involved benzalkonium and benzethonium (BZK and BZT, both cationic surfactants used as disinfectants), alkyldiaminoethylglycine (AEG, an amphoteric surfactant used as a disinfectant), linear alkylbenzenesulfonate (LAS, an anionic surfactant), polyoxyethylene cetylether (PEC, a nonionic surfactant), chlorhexidine (CHX, not a surfactant but a disinfectant) and saline (control). Male Sprague–Dawley rats were administered one of the test drugs orally (p.o.), intravenously (i.v.) or intraarterially (i.a.). The fatal effects appeared rapidly (<30 min) in i.v.‐administered rats, while taking hours (>5 h) in i.a./p.o.‐administered rats after a dose of around LD50, although the progress and degree of toxic effects varied among the drugs tested. In intravascular administration, BZK and BZT were fatal at doses of 15–20 mg kg−1. Higher concentrations in lung and kidney than in blood were determined. CHX showed a high toxic effect compared with cationic surfactants. The rats administered anionic (LAS) or amphoteric (AEG) surfactant died in less than 24 h at doses over 100 mg kg−1. In p.o. administration, the toxic effects were concentration/dose‐dependent, and all rats administered high doses of surfactants except for PEC died at 5–20 h. The overall toxic ranks could be: cationic surfactant/CHX> anionic/amphoteric surfactant > nonionic surfactant. Copyright

One-step purification of mammalian deoxyribonucleases I and differences among pancreas, parotid, and pancreas-parotid (mixed) types based on species- and organ-specific N-linked glycosylation

Mammalian deoxyribonucleases I (DNase I) are classified into three types, namely, pancreas, parotid, and pancreas-parotid (mixed), based on differences in their tissue concentrations. In this study, DNase I purification by concanavalin A-wheat germ agglutinin mixture-agarose column from rat (parotid type), rabbit (mixed type), and pig (pancreas type) is described. This method permits a relatively easy one-step purification of DNase I from rat and rabbit parotid glands, the rat submaxillary gland, and porcine pancreas. To elucidate differences among the three types, these DNases I were subjected to enzymatic deglycosylation either by peptide N-glycosidase F (PNGase F) or endoglycosidase H (Endo H). Following deglycosylation, digests were separated on DNA-casting polyacrylamide gel electrophoresis. PNGase F produced a single lower mobility product in all samples. Endo H produced a double band in rat and rabbit parotid glands and porcine pancreas, and a single band in the rabbit pancreas corresponding with the PNGase F product. DNase I activity of the porcine pancreas was completely extinguished by deglycosylation, while that of the parotid glands and rabbit pancreas was unaffected. Our results suggest that the distinct properties of DNase I exhibited by the three types may be attributed to differences in the extent of post-translational N-linked glycosylation of the enzyme.

Analysis of Genetic Polymorphism of Deoxyribonuclease I in Ovambo and Turk Populations Using a Genotyping Method

Deoxyribonuclease I (DNase I) polymorphism has been used as a valuable marker in genetic and clinical investigations. Six codominant alleles are known for DNase I, DNASE1∗1, ∗2, ∗3, ∗4, and the recently discovered alleles ∗5 and ∗6. To detect these two new alleles, we added a new DNase I genotyping method based on both an allele-specific amplification and mismatched polymerase chain reaction (PCR). These methods were used to examine the distribution of DNase I genotypes in unrelated individuals from bloodstains of Ovambo and Turkish populations. The DNASE1∗1 allele was found to be most dominant in the Ovambos. In contrast, Turks showed the highest allele frequency for DNASE1∗2. This study is the first to demonstrate that there is a certain genetic heterogeneity in the worldwide distribution of DNase I polymorphism using the genotyping method of human DNase I polymorphism with PCR.

CYP2A6 Polymorphism Reveals Differences in Japan and the Existence of a Specific Variant in Ovambo and Turk Populations

ABSTRACT CYP2A6 is a polymorphic enzyme, and CYP2A6 genotype has been shown to be associated with smoking habits and lung cancer. We investigated CYP2A6 polymorphism in Japanese from four different geographic areas of Japan and in the Ovambo and Turk populations. Using two polymerase chain reaction restriction fragment length polymorphisms (PCR-RFLPs), we identified the functionally important variants of CYP2A6: *1A, *1B, *1F, *1G, *4A, and *4D. In the Japanese population the highest frequencies of the CYP2A6*1A allele were observed in subjects from the Fukuoka (Kyushu Island) and Ehime (Shikoku Island) prefectures, whereas subjects in Shimane and Tottori (both located on the Japan Sea side of Honshu Island) showed the highest frequencies of the CYP2A6*1B allele. In the Tottori and Shimane groups no subject was homozygous for the CYP2A6*4A allele, a whole gene deletion type that is prevalent among Asians. In the Ovambo and Turk populations the CYP2A6*1A allele was predominant. Furthermore, two alleles undetected in the Japanese were observed in these latter two ethnic groups: CYP2A6*1G was found solely in the Ovambos, and CYP2A6*1F was found solely in the Turks. The present study is the first to show interprefecture differences in CYP2A6 polymorphism in Japanese who live in relatively close but distinct geographic areas; this is also the first study to evaluate CYP2A6 variations among these Japanese and the Ovambo and Turk populations. The distribution results of these alleles could help to define the true significance of CYP2A6 polymorphism as a genetic susceptibility marker in worldwide populations.

Concurrent Chemoradiotherapy with Docetaxel, Cisplatin, and 5-fluorouracil Improves Survival of Patients with Advanced Esophageal Cancer Compared with Conventional Concurrent Chemoradiotherapy with Cisplatin and 5-fluorouracil

Purpose: To compare treatment outcomes and adverse events between concurrent chemoradiotherapy with docetaxel, cisplatin, and 5-fluorouracil (DCF-RT) and conventional concurrent chemoradiotherapy with cisplatin and 5-fluorouracil (CF-RT). Methods and Materials: We retrospectively investigated treatment outcomes and adverse events in 121 patients with advanced esophageal cancer who underwent concurrent chemoradiotherapy with CF-RT (n = 83) or DCF-RT (n = 38). In the CF-RT group, patients were administered cisplatin (70 mg/m2) and 5-fluorouracil (700 mg/m2) for 5 days; in the DCF-RT group, patients were administered docetaxel (50 mg/m2), cisplatin (50 mg/m2), and 5-fluorouracil (500 mg/m2) for 5 days. The radiotherapy dose was 1.8-2 Gy per session, up to a total of 50-60 Gy. Results: The complete response (CR) rate was 37.8% in the CF-RT group and 52.6% in the DCF-RT group. Overall survival (OS) rates at 2 and 3 years were 45.0% and 37.5%, respectively, in the CF-RT group and 62.9% and 56.7%, respectively, in the DCF-RT group, with a significant intergroup difference (p = 0.032). Progression-free survival rates at 2 and 3 years were 44.1% and 36.9%, respectively, in the CF-RT group and 45.0% and 45.0%, respectively, in the DCF-RT group (p = 0.10). Local control rates at 2 and 3 years were 59.1% and 54.6%, respectively, in the CF-RT group and 71.8% and 71.8%, respectively, in the DCF-RT group (p = 0.12). The incidence of Grade 3/4 leukopenia was 55.4% (n = 46) in the CF-RT group and 78.9% (n = 30) in the DCF-RT group, with a significant intergroup difference (p = 0.022). The incidence of Grade 3/4 neutropenia was 47.0% (n = 39) in the CF-RT group and 65.8% (n = 25) in the DCF-RT group, with a notable albeit not statistically significant difference between the groups (p = 0.054). There were no significant intergroup differences in anemia, thrombocytopenia, radiation-induced dermatitis, radiation esophagitis, or late adverse events. Conclusions: Rates of OS and CR were improved after treatment with DCF-RT compared with CF-RT. Although DCF-RT-treated patients had higher rates of leukopenia, treatment safety was ensured through proper management of myelotoxicity. DCF-RT is a promising treatment regimen for advanced esophageal cancer.