Determination of sterigmatocystin in grain using gas chromatography-mass spectrometry with an on-column injector

Sterigmatocystin (STC) is a mycotoxin produced by several species of Aspergillus and other fungi. STC is a precursor of the carcinogen aflatoxin B1 and exerts carcinogenic, teratogenic, and mutagenic effects. A reliable GC-MS-based analytical method using on-column injection was developed and validated to determine STC content in grain. In this method, STC was extracted with acetonitrile (84%), and the filtered extract was diluted with phosphate buffer before immunoaffinity column (IAC) cleanup. After elution and N2 evaporation, the sample containing STC was dissolved in acetone and injected into the GC-MS system without derivatization. Separation of STC was carried out by a capillary column (0.25 mm i.d.×30 m, 0.25 μm) with a deactivated pre-column (0.53 mm i.d.×0.6 m). The matrix effect was investigated in maize, wheat, and rice, and an insignificant matrix effect was observed after IAC cleanup. The calibration curve was linear in the range of 20-300 pg (equivalent to 8-120 μg/kg in grain) with a coefficient of determination (R2) of 0.999, and the relative standard deviation of repeatability (RSDr) was less than 10 %. The limit of detection (LOD) of the method was 6 pg (equivalent to 2.4 μg/kg in grain), and the limit of quantification (LOQ) was 20 pg (equivalent to 8 μg/kg). The method described in this report is sensitive, reliable, and can be used to monitor STC contamination in grain.

Fabrication of hydroxyapatite thin films on zirconia using a sputtering technique

Hydroxyapatite (HA) thin films were prepared on a zirconia (ZrO2) substrate using a sputtering technique, and the film was also coated on a titanium (Ti) substrate for comparison. The coated films were recrystallised using a hydrothermal treatment to reduce film dissolution. The films were then characterised by X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The osteocompatiblity of the films was evaluated by investigating the alkaline phosphatase (ALP) activity and the size of the bone formation area of osteoblast cells. In the XRD patterns of the as-sputtered films on the ZrO2 substrate, there are no peaks except for those from the ZrO2 substrate. After the hydrothermal treatment, HA peaks appeared in the patterns. Nanoparticles (less than 20 nm) were observed on the ZrO2 substrates in the SEM images of the as-sputtered films. After the hydrothermal treatment, particles of 20-40 nm were observed on the film, whereas the HA film on the Ti substrate was covered by a larger number of globular particles (20-60 nm). In the osteoblast cell cultures, the ALP activity and bone formation area on the HA films on both the ZrO2 and Ti substrates increased after the hydrothermal treatment of the films, and the values for the ZrO2 substrate were higher than those for the Ti substrate.

The efficacy of lidocaine to prevent laryngospasm in children: a systematic review and meta-analysis

The purpose of this meta-analysis was to determine the efficacy of lidocaine in preventing laryngospasm during general anaesthesia in children. An electronic search of six databases was conducted. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were adhered to. We included randomised controlled trials reporting the effects of intravenous and/or topical lidocaine on the incidence of laryngospasm during general anaesthesia. Nine studies including 787 patients were analysed. The combined results demonstrated that lidocaine is effective in preventing laryngospasm (risk ratio (RR) 0.39, 95% CI 0.24-0.66; I(2)  = 0). Subgroup analysis revealed that both intravenous lidocaine (RR 0.34, 95% CI 0.14-0.82) and topical lidocaine (RR 0.42, 95% CI 0.22-0.80) lidocaine are effective in preventing laryngospasm. The results were not affected by studies with a high risk of bias. We conclude that, both topical and intravenous lidocaine are effective for preventing laryngospasm in children.

Magneto-optic spatial light modulator with submicron-size magnetic pixels for wide-viewing-angle holographic displays

Spatial light modulators (SLMs) with submicron-size pixels are promising devices for use in wide-viewing-angle glasses-free holographic 3D displays. In accordance with estimations, an SLM with 1 μm pitch pixels can display holographic images over viewing angles of 30 deg. In the present work, we have studied magneto-optic SLMs (MOSLMs) with submicron-size pixels for wide-viewing-angle holographic displays that are driven by thermomagnetic recording. Amorphous TbFe films were used as a magneto-optic material. The MOSLM with an 800 nm diameter pixels array displayed wide-viewing-angle holographic images. These results demonstrated that MOSLMs with submicron-size pixels have promise for glasses-free holographic 3D displays.

Development of an analytical method for the determination of sterigmatocystin in grains using LCMS after immunoaffinity column purification

The mycotoxin sterigmatocystin (STC) is produced mainly by some Aspergillus and Penicillium fungi; it naturally contaminates cereals, peanuts, and products derived from these crops, and is both mutagenic and carcinogenic. As an intermediate of aflatoxin (AF) biosynthesis, its structure is similar to that of AF. Although immunoaffinity columns (IACs) are a popular approach to sample clean-up, no IAC is commercially available for STC, but a commercially available IAC for AF shows cross reactivity to STC. We here developed a new method for analyzing STC in grains using such an IAC and liquid chromatography mass spectrometry (LCMS), and validated this method using six different grains. The STC limit of detection (signal-to-noise ratio, S/N = 3) was 2.5 pg (1.0 μg/kg in the product), and the calibration curve was linear in the range of 7.5-375 pg (3.0-150 μg/kg in the product). The within-day recovery of STC from samples spiked with STC at 5.0 and 50 μg/kg was 83.2-102.5% and the RSDr (relative standard deviation of repeatability) of these samples was 1.9-6.5%; the RSDr of STC-pretreated grain samples was 3.1-14.0%. Average recovery of STC from samples spiked with STC in the range of 5.0-100 μg/kg STC was 83.2-102.5%, with an RSDr of 0.24-6.5%; the RSDr of STC-pretreated grain samples was 2.4-14.0%. In an intermediate precision study, the average STC recovery from STC-spiked samples by three analysts was 95.2-107.5%, with RSDRi (intermediate precision) of 4.0-7.1%; the RSDRi of the STC-pretreated samples was 4.8-10.4%. Thus, the proposed method was effective for STC analysis in grains, and holds potential for a novel application of a commercial IAC, intended for AFs, in STC analysis.

202 EFFECT OF LEUKEMIA INHIBITORY FACTOR AND FORSKOLIN ON ESTABLISHMENT OF RAT EMBRYONIC STEM CELL LINES

Rat embryonic stem (ES) cell lines can be established in culture medium containing inhibitors for glycogen synthase kinase 3 (GSK3) and mitogen-activated protein kinase (MEK). We confirmed reproducibility of the 2i culture system in establishing rat ES cell lines (Hirabayashi et al. 2010 Mol. Reprod. Dev. 77, 94) and the likelihood of successful germline transmission (genuine) of rat ES cell lines established in leukemia inhibitory factor (LIF)- and forskolin (FK)-supplemented 2i medium (Hirabayashi et al. 2013 Transgenic Res. 22, 411–416). This study was designed to investigate whether LIF and/or FK supplemented to the 2i medium support establishment of germline-competent rat ES cell lines. E4.5 blastocysts were recovered from BLK rat females, and zona-free embryos were plated on mitomycin-treated mouse embryonic fibroblasts in N2B27 medium containing 1 mM MEK inhibitor PD0325901 and 3 mM GSK3 inhibitor CHIR99021, with rat 1000 U mL–1 LIF and/or 10 μM FK. Outgrowth rate of the blastocysts after 1 wk culture and establishment efficiency of ES cell lines after third passage were analyzed by Fisher's exact probability test. Arcsin-transformed percentage data on full-term development of ES cell-injected blastocysts, chimeric rat production, and germline-competent chimeras were analyzed by Fisher's least significant difference test after one-way ANOVA. Because of the higher outgrowth rates of blastocysts, supplementation of rat LIF, FK, or both contributed to the higher (P < 0.05) establishment efficiency of ES cell lines in BLK rat strain (76% to 92% v. 50% in LIF/FK-free 2i medium). Neither efficiency of producing chimeric rats (14% to 39% of blastocysts injected) nor germline transmission competency of the chimeric rats (67% to 100% of cell lines analyzed) was influenced by the pre-treatment of ES cell lines. When the LIF/FK-supplemented 2i medium was used, rat strain for blastocyst donor such as F344 or WI was a possible factor negatively influencing the establishment efficiency of ES cell lines. Once ES cell lines were established, however, all of them (9/9 in overall) were found to be germline-competent by progeny test of chimeric rats. In conclusion, both LIF and FK are not essential, but can play a beneficial role, for the establishment of genuine rat ES cell lines. This work was supported by a grant-in-aid for basic research from Japan Society for the Promotion of Science (No. 25290037; to M.H.).

Near- and mid-infrared spectroscopy as efficient tools for detection of fungal and mycotoxin contamination in agricultural commodities

In the last decade, near-infrared (NIR) and mid-infrared (MIR) spectroscopy have proven to be most promising tools for the detection of fungal contamination and estimation of mycotoxins in agricultural commodities, particularly of cereals. Owing to significant economic losses incurred from fungal contamination of foodstuffs, producers and processors are looking for fast, reliable, and less-expensive methods for the detection of fungal damage. In this context, NIR and MIR spectroscopy offer a fast, less-expensive, non-destructive, and relatively simple analytical method. Results from published studies indicate that NIR and MIR spectroscopy can be successfully applied to identifying fungal contamination and estimating specific mycotoxins. This review will focus on the applications of NIR and MIR spectroscopy to the classification of fungal contamination and the determination of specific mycotoxin contamination levels, and to compare this technology with traditional analytical methods.

Ovarian yolk sac tumor associated with pregnancy: a case report and review of the literature

BACKGROUND

Ovarian yolk sac tumor (YST) that is diagnosed during pregnancy is extremely rare.

CLINICAL CASE

A 22-year-old pregnant woman diagnosed with Stage IIIc YST at 17 weeks of gestation is presented. A 20-cm multilocular cystic tumor containing solid components with massive ascites was detected. Subsequently she underwent left salpingo-oophorectomy and cytoreductive surgery for peritoneal dissemination at 18 weeks of gestation, and the tumors were diagnosed as YST. After vaginal termination at 20 weeks of gestation, she received five cycles of combination therapy with bleomycin, etoposide, and cisplatin. There was no evidence of recurrence at 85 months after primary treatment.

CONCLUSION

Considering the rarity, treatment strategy for advanced-staged YST should be further investigated in international collaborative studies.

A retrospective analysis of the risk factors for allergic reactions induced by the administration of oxaliplatin

This study retrospectively investigated the clinical features and risk factors of allergic reactions induced by oxaliplatin administration. This study investigated the incidence of allergic reactions and analysed the background and laboratory data in patients with colorectal cancer treated with oxaliplatin-based chemotherapy at Kyushu Medical Center between April 2012 and September 2012. A total of 62 patients were included in this study. The number of patients in the allergic and non-allergic groups was 7 and 55 respectively. The incidence of allergic reactions was 11.3%. We compared the patients' characteristics and laboratory data between the two groups and found that the average dose of dexamethasone in the allergic group was significantly lower than that observed in the non-allergic group (P = 0.0111). Furthermore, the incidence of allergic reactions in the group that received prophylaxis of less than 12 mg of dexamethasone was significantly higher than that observed in the group that received more than 12 mg of dexamethasone (P = 0.0103). In conclusion, a lower dexamethasone dose is a possible risk factor for allergic reactions induced by the administration of oxaliplatin; however, given the retrospective design used in this study, further validation of this finding is warranted.

Selection for reluctance to avoid humans during the domestication of mice

Many animal species have been domesticated over the course of human history and became tame as a result of domestication. Tameness is a behavioral characteristic with 2 potential components: (1) reluctance to avoid humans and (2) motivation to approach humans. However, the specific behavioral characteristics selected during domestication processes remain to be clarified for many species. To quantify these 2 different components of tameness separately, we established 3 behavioral tests: the ‘active tame’, ‘passive tame’ and ‘stay-on-hand’ tests. We subjected genetically diverse mouse strains to these tests, including 10 wild strains (BFM/2Ms, PGN2/Ms, HMI/Ms, BLG2/Ms, NJL/Ms, KJR/Ms, SWN/Ms, CHD/Ms, MSM/Ms and CAST/Ei), a fancy strain (JF1/Ms) and 6 standard laboratory strains (C3H/HeNJcl, CBA/J, BALB/cAnNCrlCrlj, DBA/2JJcl, 129^+Ter/SvJcl and C57BL/6JJcl). To analyze the effects of domestication, these 17 strains were divided into 2 groups: domesticated strains (fancy and laboratory strains) and wild strains. Significant differences between strains were observed in all traits, and the calculated estimates of broad-sense heritability were 0.15–0.72. These results illustrate that tameness in mice is significantly influenced by genetic background. In addition, they clearly show the differences in the features of tameness in domesticated and wild strains. Most of the domesticated strains showed significantly greater reluctance to avoid humans than wild strains, whereas there was no significant difference in the level of motivation to approach humans between these 2 groups. These results might help to clarify the genetic basis of tameness in mice.