Scandium Ion-Promoted Electron-Transfer Disproportionation of 2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-Oxide (PTIO•) in Acetonitrile and Its Regeneration Induced by Water.

2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO•), a persistent nitronyl nitroxide radical, has been used for the detection and trapping of nitric oxide, as a redox mediator for batteries, for the activity estimation of antioxidants, and so on. However, there is no report on the reactivity of PTIO• in the presence of redox-inactive metal ions. In this study, it is demonstrated that the addition of scandium triflate, Sc(OTf)3 (OTf = OSO2CF3), to an acetonitrile (MeCN) solution of PTIO• resulted in an electron-transfer disproportionation to generate the corresponding cation (PTIO+) and anion (PTIO-), the latter of which is suggested to be stabilized by Sc3+ to form [(PTIO)Sc]2+. The decay of the absorption band at 361 nm due to PTIO•, monitored using a stopped-flow technique, obeyed second-order kinetics. The second-order rate constant for the disproportionation, thus determined, increased with increasing the Sc(OTf)3 concentration to reach a constant value. A drastic change in the cyclic voltammogram recorded for PTIO• in deaerated MeCN containing 0.10 M Bu4NClO4 was also observed upon addition of Sc(OTf)3, suggesting that the large positive shift of the one-electron reduction potential of PTIO• (equivalent to the one-electron oxidation potential of PTIO-) in the presence of Sc(OTf)3 may result in the disproportionation. When H2O was added to the PTIO•-Sc(OTf)3 system in deaerated MeCN, PTIO• was completely regenerated. It is suggested that the complex formation of Sc3+ with H2O may weaken the interaction between PTIO- and Sc3+, leading to electron-transfer comproportionation to regenerate PTIO•. The reversible disproportionation of PTIO• was also confirmed by electron paramagnetic resonance (EPR) spectroscopy.

Diallyl Disulfide Mitigates DNA Damage and Spleen Tissue Effects After Irradiation.

BACKGROUND Several factors found in foods are beneficial to human health and they may contribute to radiation protection. Taking food factors could be an easy way to reduce the effects of radiation after nuclear accidents, as well as secondary radiation risks after cancer radiotherapy or space missions. Here, diallyl disulfide (DADS), a component of garlic oil, was studied for its ability to mitigate radiation damage. MATERIAL AND METHODS We investigated the effects of DADS on micronucleus (MN) formation and apoptosis in HepG2 cells by use of 4-Gy X-ray irradiation. We also assessed the effects of DADS on radiation damage in vivo by evaluating MN formation in bone marrow cells in mice (BALB/c, 8-week-old females) after oral intake of DADS prior to irradiation with 4 Gy. Several tissue effects were also investigated. RESULTS The presence of DADS inhibited MN formation, whereas DADS had no influence on the radiation-induced inhibition of cell cycle progression in HepG2 cells. An increase in apoptosis in HepG2 cells was induced after irradiation, and this effect was stronger in the presence of DADS than in its absence. In mice, when DADS was administered daily for 3 days prior to irradiation, MN formation in irradiated mice was decreased. The decrease in MN formation in mice was greater with 0.5% DADS compared to 1% DADS. Moreover, an increase in spleen weight observed 3 weeks after irradiation was suppressed in mice administered DADS. CONCLUSIONS DADS is a potential radiation-protective agent that effectively mitigates DNA damage, and its effects in the spleen observed after irradiation may be related to inflammation and carcinogenesis.

Proliferation following tetraploidization regulates the size and number of erythrocytes in the blood flow during medaka development, as revealed by the abnormal karyotype of erythrocytes in the medaka TFDP1 mutant.

BACKGROUND: For the delivery of oxygen, the correct size/number of erythrocytes is required for proper blood flow. RESULTS: By combined analyses of wild-type (WT) medaka and the kyoho (kyo) mutant, we found proliferation-mediated adaptation for size/number of erythrocytes in the blood flow during medaka development. Before the start of heart beating in the WT medaka, the karyotype of erythrocytes was 2N-4N. After the start of blood flow, the karyotype changed to 4N-8N with tetraploidization, and the cell size became larger. After the start of intersegmental and pharyngeal blood flow, the erythrocytes became smaller. The medaka mutant kyo showed erythrocytes of large size, and positional cloning of kyo demonstrated the candidate gene TFDP1, indicating higher polyploidization due to arrest in S-phase in erythrocytes of the kyo mutant. CONCLUSIONS: From our findings, we uncovered a previously unrecognized system for the regulation of the size/number in the blood flow:proliferation of erythrocytes following tetraploidization during embryonic development.

Evolutionary pathway of pseudogenization of globin genes, α5 and ß5, in genus Oryzias.

Hemoglobin transports oxygen in many organisms and consists of α- and ß-globin chains. Previously, using molecular phylogenetic analysis, we proposed that both α- and ß-globins of teleost could be classified into four groups. We also showed that the Hd-rR strain of medaka (Oryzias latipes) inhabiting southern Japan had all four groups of globin genes but that the α- and ß-globin genes of group III were pseudogenized (α5(ψα), ß5(ψß)). Based on the small degree of nucleotide variations, the pseudogenization of ß5 was assumed to have occurred at a relatively late stage of evolution. Here, we compared the α5(ψα)-ß5(ψß) of two other strains of O. latipes and found that both α5(ψα) and ß5(ψß) of the northern Japanese and Korean strains were pseudogenized similar to those of Hd-rR. In a Philippine population (Oryzias luzonensis), α5(ψα) was also pseudogenized, but the structure was different from that of O. latipes, and ß5(ψß) was almost deleted. Interestingly, an Indonesian population (Oryzias celebensis) had α5 and ß5 genes that were deduced to be functional. Indeed, they were expressed from the young to adult development stages, and this expression pattern was consistent with the expression of α2 and ad.α1 in Hd-rR. Because α2 and ad.α1 in Hd-rR were assigned to groups I and II, respectively, we speculate that their expression patterns might be altered by pseudogenization of group III genes. These results provide a basis for further investigations of recruiting and changing expression patterns of one globin gene after pseudogenization of other globin genes during evolution.

The Parapineal Is Incorporated into the Habenula during Ontogenesis in the Medaka Fish.

The parapineal is present in many teleost families, while it is absent in several others. To find out why the parapineal is absent at adult stages in the latter families, the development of the epithalamus was examined in the medaka fish (Oryzias latipes). For this purpose, a green fluorescent protein-transgenic medaka line, in which the pineal complex (pineal and parapineal) is visible fluorescently, was used. We found that a distinct parapineal was present in the roof plate at early developmental stages. Subsequently, however, the parapineal and the associated roof plate began to be incorporated into the habenula between embryonic stages 28 and 29. Between embryonic stages 29 and 30, the entire parapineal was incorporated into the habenula. That is, the parapineal became a small caudomedial region (termed the 'parapineal domain') within the left habenula in the majority of embryos, resulting in the left-sided asymmetry of the epithalamus. Thereby the left habenula became larger and more complex than its right counterpart. In the minority of embryos, the parapineal was incorporated into the right habenula or into the habenulae on both sides. In the majority of embryos, the parapineal domain projected a fiber bundle to a subnucleus (termed the 'rostromedial subnucleus') in the left habenula. The rostromedial subnucleus sent axons, through the left fasciculus retroflexus, to the rostral region of the left half of the interpeduncular nucleus. We further found that the ratio of the left-sided phenotype was temperature dependent and decreased in embryos raised at a high temperature. The present study is the first demonstration that the supposed lack of a distinct parapineal in adult teleost fishes is due to ontogenetic incorporation into the habenula.

Low-dose total-body carbon-ion irradiations induce early transcriptional alteration without late Alzheimer's disease-like pathogenesis and memory impairment in mice.

The cause and risk factors of Alzheimer's disease (AD) are largely unknown. Studies on possible radiation-induced AD-like pathogenesis and behavioral consequences are important because humans are exposed to ionizing radiation (IR) from various sources. It was reported that total-body irradiations (TBI) at 10 cGy of low linear energy transfer (LET) X-rays to mice triggered acute transcriptional alterations in genes associated with cognitive dysfunctions. However, it was unknown whether low doses of IR could induce AD-like changes late after exposure. We reported previously that 10 cGy X-rays induced early transcriptional response of several AD-related genes in hippocampi without late AD-like pathogenesis and memory impairment in mice. Here, further studies on two low doses (5 or 10 cGy) of high LET carbonion irradiations are reported. On expression of 84 AD-related genes in hippocampi, at 4 hr after TBI, 5 cGy induced a significant upregulation of three genes (Abca1, Casp3, and Chat) and 10 cGy led to a marked upregulation of one gene (Chat) and a downregulation of three genes (Apoe, Ctsd, and Il1α), and, at 1 year after TBI, one gene (Il1α) was significantly downregulated in 10 cGy-irradiated animals. Changes in spatial learning ability and memory and induction of AD-like pathogenesis were not detected by in vivo brain imaging for amyloid-ß peptide accumulation and by immunohistochemical staining of amyloid precursor protein, amyloid-ß protein, tau, and phosphorylated tau protein. These findings indicate that low doses of carbon-ion irradiations did not cause behavioral impairment or AD-like pathological change in mice.

Effects of alendronate or alfacalcidol on bone metabolic indices and bone mineral density in patients with ophthalmologic disease treated with glucocorticoid.

OBJECTIVES: Glucocorticoid (GC) is usually used for the treatment of systemic inflammatory diseases. We performed the prospective study to clarify the effects of alendronate or alfacalcidol on bone metabolic indices and bone mineral density (BMD) in 90 patients treated with GC for ophthalmologic diseases without systemic disorders for 12 months. METHODS: BMD was measured with dual-energy X-ray absorptiometry. Serum bone-specific alkaline phosphatase (BAP) and urinary Type I collagen cross-linked N-telopeptide (NTx) were measured as bone metabolic indices. RESULTS: BMD values in the alendronate group were significantly higher than those in the alfacalcidol group during 12 months. Alendronate significantly reduced urinary NTX levels from the baseline during 12 months, although alfacalcidol did not affect them. Serum BAP levels in the alendronate group were significantly lower than those in the alfacalcidol group during 9 months. The effects of alendronate on BMD and NTx in male patients seemed to be somewhat potent compared with those in female patients. CONCLUSIONS: Alendronate is effective to prevent BMD loss and bone resorption induced by GC treatment in patients with ophthalmic diseases without systemic disorders. There might be sex differences in the potency of alendronate effects.

DOSE ESTIMATION TO WILD MEDAKA AROUND FUKUSHIMA DAI-ICHI NUCLEAR POWER PLANT.

More than 10 y have passed since the Fukushima Dai-ichi Nuclear Power Plant (F1-NPP) accident, but there are still many areas with high levels of radioactive contamination, especially reservoirs and lakes, where the levels decrease slowly. The exposed dose to non-human biota is of great concern. In this work, the exposure dose to wild medaka (small aquarium fish) around F1-NPP was measured/estimated by two approaches: in situ measurement and with the ERICA assessment tool. S2 is a reservoir located 7.5 km from F1-NPP, and the ambient dose rate was 25.0 µSv per h in 2012, but decreased to 4.82 µSv per h in 2021. The external exposure dose rate to wild medaka living there was 0.8-11.8 µGy per h (2017-21) by in situ measurement, and the estimated dose rate with the ERICA assessment tool was 0.6-54.5 µGy per h (2012-21). The estimated and measured doses to wild medaka are not expected to cause any significant radiation effects.

In vivo visualization of the lymphatic vessels in pFLT4-EGFP transgenic medaka.

Feline McDonough Sarcoma (FMS)-like tyrosine kinase 4 (FLT4) is a marker for lymphatic vessels and some high endothelial venules in human adult tissues. We generated a transgenic medaka fish in which the lymphatic vessels and some blood vessels are visible in vivo by transferring the promoter of medaka flt4 driving the expression of enhanced green fluorescent protein (EGFP) using a see-through medaka line. To do this, we identified and cloned medaka flt4 and generated a construct in which the promoter was the 4-kb region upstream of the translation initiation site. The fluorescent signal of EGFP could be observed with little background, and the expression pattern correlated well with that of flt4 determined by whole-mount RNA in situ hybridization. Because a see-through medaka line is transparent until adult, the model is useful for visualizing the lymphatic vessels not only in embryo and fry but also in adult. This model will be a useful tool for analyzing lymphatic development.

Giant vesicles containing superparamagnetic iron oxide as biodegradable cell-tracking MRI probes.

A major breakthrough in in vivo cellular imaging has been the clinical/preclinical use of magnetic resonance imaging (MRI) with contrast agent. Superparamagnetic iron oxide (SPIO) is a promising candidate for the development of smart MRI probes for cell-tracking. In the present study, we describe biodegradable probes made of giant vesicles (GVs; closed lipid membranes with diameters >1 µm) that encapsulate SPIO for use as an MRI contrast agent. These SPIO-containing GVs (SPIO-GVs) exhibited excellent contrast enhancement in the single cell of medaka fish (Oryzias latipes) embryos immediately after their microinjection, and this enhancement disappeared when the GV membranes were destroyed. Our results demonstrate that SPIO-GVs are useful MRI probes for single cell-tracking that have minimum cytotoxicity and will greatly improve clinical/preclinical in vivo cellular imaging techniques.

Adaptive response of low linear energy transfer X-rays for protection against high linear energy transfer accelerated heavy ion-induced teratogenesis.

BACKGROUND: Adaptive response (AR) of low linear energy transfer (LET) irradiations for protection against teratogenesis induced by high LET irradiations is not well documented. In this study, induction of AR by X-rays against teratogenesis induced by accelerated heavy ions was examined in fetal mice. METHODS: Irradiations of pregnant C57BL/6J mice were performed by delivering a priming low dose from X-rays at 0.05 or 0.30 Gy on gestation day 11 followed one day later by a challenge high dose from either X-rays or accelerated heavy ions. Monoenergetic beams of carbon, neon, silicon, and iron with the LET values of about 15, 30, 55, and 200 keV/µm, respectively, were examined. Significant suppression of teratogenic effects (fetal death, malformation of live fetuses, or low body weight) was used as the endpoint for judgment of a successful AR induction. RESULTS: Existence of AR induced by low-LET X-rays against teratogenic effect induced by high-LET accelerated heavy ions was demonstrated. The priming low dose of X-rays significantly reduced the occurrence of prenatal fetal death, malformation, and/or low body weight induced by the challenge high dose from either X-rays or accelerated heavy ions of carbon, neon or silicon but not iron particles. CONCLUSIONS: Successful AR induction appears to be a radiation quality event, depending on the LET value and/or the particle species of the challenge irradiations. These findings would provide a new insight into the study on radiation-induced AR in utero.

A medaka model of cancer allowing direct observation of transplanted tumor cells in vivo at a cellular-level resolution.

The recent success with small fish as an animal model of cancer with the aid of fluorescence technique has attracted cancer modelers' attention because it would be possible to directly visualize tumor cells in vivo in real time. Here, we report a medaka model capable of allowing the observation of various cell behaviors of transplanted tumor cells, such as cell proliferation and metastasis, which were visualized easily in vivo. We established medaka melanoma (MM) cells stably expressing GFP and transplanted them into nonirradiated and irradiated medaka. The tumor cells were grown at the injection sites in medaka, and the spatiotemporal changes were visualized under a fluorescence stereoscopic microscope at a cellular-level resolution, and even at a single-cell level. Tumor dormancy and metastasis were also observed. Interestingly, in irradiated medaka, accelerated tumor growth and metastasis of the transplanted tumor cells were directly visualized. Our medaka model provides an opportunity to visualize in vivo tumor cells "as seen in a culture dish" and would be useful for in vivo tumor cell biology.

Enhanced Effects of Chronic Restraint-Induced Psychological Stress on Total Body Fe-Irradiation-Induced Hematopoietic Toxicity in Trp53-Heterozygous Mice.

Humans are exposed to both psychological stress (PS) and radiation in some scenarios such as manned deep-space missions. It is of great concern to verify possible enhanced deleterious effects from such concurrent exposure. Pioneer studies showed that chronic restraint-induced PS (CRIPS) could attenuate Trp53 functions and increase gamma-ray-induced carcinogenesis in Trp53-heterozygous mice while CRIPS did not significantly modify the effects on X-ray-induced hematopoietic toxicity in Trp53 wild-type mice. As high-linear energy transfer (LET) radiation is the most important component of space radiation in causing biological effects, we further investigated the effects of CRIPS on high-LET iron-particle radiation (Fe)-induced hematopoietic toxicity in Trp53-heterozygous mice. The results showed that CRIPS alone could hardly induce significant alteration in hematological parameters (peripheral hemogram and micronucleated erythrocytes in bone marrow) while concurrent exposure caused elevated genotoxicity measured as micronucleus incidence in erythrocytes. Particularly, exposure to either CRISP or Fe-particle radiation at a low dose (0.1 Gy) did not induce a marked increase in the micronucleus incidence; however, concurrent exposure caused a significantly higher increase in the micronucleus incidence. These findings indicated that CRIPS could enhance the deleterious effects of high-LET radiation, particularly at a low dose, on the hematopoietic toxicity in Trp53-heterozygous mice.

Fluorescence in situ hybridization analysis of chromosomal aberrations in mouse splenocytes at one- and two-months after total body exposure to iron-56 (Fe) ion particles or X-rays.

High atomic number and energy (HZE) particles such as iron-56 (Fe) ions are a major contributor to health risks in long-term manned space exploration. The aim of this study is to understand radiation-induced differential genotoxic effects between HZE particles and low linear energy transfer (LET) photons. C57BL/6J Jms female mice of 8 weeks old were exposed to total body irradiation of accelerated Fe-particles with a dose ranging from 0.1 to 3.0 Gy or of X-rays with a dose ranging from 0.1 to 5.0 Gy. Chromosomal aberrations (CAs) in splenocytes were examined by fluorescence in situ hybridization at 1- and 2-months after exposure. Clonal expansions of cells with CAs were found to be induced only by X-rays but not by Fe-particles. Dose-dependent increase in the frequencies of stable-type CAs was observed at 1- as well as 2-months after exposure to both radiation types. The frequencies of stable-type CAs in average were much higher in mice exposed to X-rays than those to Fe-particles and did not change significantly between 1- and 2-months after exposure to both radiation types. On the other hand, the frequencies of unstable-type CAs induced by X-rays and Fe-particles were not much different, and they appeared to decrease with time from 1- to 2-months after exposure. These results suggested that larger fraction of stable-type CAs induced by Fe-particles might be non-transmissible than those by X-rays because of some associating lethal alterations on themselves or on other chromosomes in the same cells and that these cells might be removed by 1-month after Fe-TBI. We also demonstrated that exposure to Fe-particles induced insertions at relatively higher frequency to other stable-type CAs than X-rays. Our findings suggest that insertions can be used as indicators of past exposure to high-LET particle radiation.

Bef medaka mutant reveals the essential role of c-myb in both primitive and definitive hematopoiesis.

Vertebrate hematopoiesis is characterized by two evolutionally conserved phases of development, i.e., primitive hematopoiesis, which is a transient phenomenon in the early embryo, and definitive hematopoiesis, which takes place in the later stages. Beni fuji (bef) was originally isolated as a medaka mutant that has an apparently reduced number of erythrocytes in its peripheral blood. Positional cloning revealed that the bef mutant has a nonsense mutation in the c-myb gene. Previous studies have shown that c-myb is essential for definitive hematopoiesis, and c-myb is now widely used as a marker gene for the onset of definitive hematopoiesis. To analyze the phenotypes of the bef mutant, we performed whole-mount in situ hybridization with gene markers of hematopoietic cells. The bef embryos showed decreased expression of alpha-globin and l-plastin, and a complete loss of mpo1 and rag1 expression, suggesting that the bef embryos had defects not only in erythrocytes but also in other myeloid cells, which indicates that their definitive hematopoiesis was aberrant. Interestingly, we observed a diminution in the number of primitive erythrocytes and a delay in the emergence of primitive macrophages in the bef embryos. These results suggest that c-myb also functions in the primitive hematopoiesis, potentially demonstrating a link between primitive and definitive hematopoiesis.

Radiation effects on wild medaka around Fukushima Dai-ichi Nuclear Power Plant assessed by micronucleus assay.

Since the Fukushima Dai-ichi Nuclear Power Plant (F1-NPP) accident in 2011, radiation effects on wildlife in the contaminated areas have been a major concern. The outskirts of the F1-NPP are mainly rural areas, where many rice fields, streams and reservoirs are located. We searched for wild medaka (small aquarium fish) around the F1-NPP and found two wild medaka habitats (S1 and S2). S1 is a stream located 4 km from the F1-NPP, where the ambient dose equivalent rate was 0.4-0.9 µSv/h (2013-14), and S2 is a reservoir located 7.5 km from the F1-NPP, where the ambient dose equivalent rate was 9.8-22 µSv/h (2013-14 and 2017-18). Dosimeters were placed for one day at the locations where the medaka were captured, and the absorbed dose rates were estimated. Radiation effects on wild medaka were examined using micronucleus assay between 2013 and 2018. No significant difference in frequency of micronucleated gill cells was observed among the wild medaka from S1, S2 and our cultivated medaka that were used as a control.

Reduced High-Dose Radiation-Induced Residual Genotoxic Damage by Induction of Radioadaptive Response and Prophylactic Mild Dietary Restriction in Mice.

Radioadaptive response (RAR) describes a phenomenon in a variety of in vitro and in vivo systems that a low-dose of priming ionizing radiation (IR) reduces detrimental effects of a subsequent challenge IR at higher doses. Among in vivo investigations, studies using the mouse RAR model (Yonezawa Effect) showed that RAR could significantly extenuate high-dose IR-induced detrimental effects such as decrease of hematopoietic stem cells and progenitor cells, acute radiation hematopoietic syndrome, genotoxicity and genomic instability. Meanwhile, it has been demonstrated that diet intervention has a great impact on health, and dietary restriction shows beneficial effects on numerous diseases in animal models. In this work, by using the mouse RAR model and mild dietary restriction (MDR), we confirmed that combination of RAR and MDR could more efficiently reduce radiogenotoxic damage without significant change of the RAR phenotype. These findings suggested that MDR may share some common pathways with RAR to activate mechanisms consequently resulting in suppression of genotoxicity. As MDR could also increase resistance to chemotherapy and radiotherapy in normal cells, we propose that combination of MDR, RAR, and other cancer treatments (i.e., chemotherapy and radiotherapy) represent a potential strategy to increase the treatment efficacy and prevent IR risk in humans.

Synergistic Effects of Chronic Restraint-Induced Stress and Low-Dose 56Fe-particle Irradiation on Induction of Chromosomal Aberrations in Trp53-Heterozygous Mice.

Astronauts can develop psychological stress (PS) during space flights due to the enclosed environment, microgravity, altered light-dark cycles, and risks of equipment failure or fatal mishaps. At the same time, they are exposed to cosmic rays including high atomic number and energy (HZE) particles such as iron-56 (Fe) ions. Psychological stress or radiation exposure can cause detrimental effects in humans. An earlier published pioneering study showed that chronic restraint-induced psychological stress (CRIPS) could attenuate Trp53 functions and increase carcinogenesis induced by low-linear energy transfer (LET) γ rays in Trp53-heterozygous (Trp53+/-) mice. To elucidate possible modification effects from CRIPS on high-LET HZE particle-induced health consequences, Trp53+/- mice were received both CRIPS and accelerated Fe ion irradiation. Six-week-old Trp53+/- C57BL/6N male mice were restrained 6 h per day for 28 consecutive days. On day 8, they received total-body Fe-particle irradiation (Fe-TBI, 0.1 or 2 Gy). Metaphase chromosome spreads prepared from splenocytes at the end of the 28-day restraint regimen were painted with the fluorescence in situ hybridization (FISH) probes for chromosomes 1 (green), 2 (red) and 3 (yellow). Induction of psychological stress in our experimental model was confirmed by increase in urinary corticosterone level on day 7 of restraint regimen. Regardless of Fe-TBI, CRIPS reduced splenocyte number per spleen at the end of the 28-day restraint regimen. At 2 Gy, Fe-TBI alone induced many aberrant chromosomes and no modifying effect was detected from CRIPS on induction of aberrant chromosomes. Notably, neither Fe-TBI at 0.1 Gy nor CRIPS alone induced any increase in the frequency of aberrant chromosomes, while simultaneous exposure resulted in a significant increase in the frequency of chromosomal exchanges. These findings clearly showed that CRIPS could enhance the frequency of chromosomal exchanges induced by Fe-TBI at a low dose of 0.1 Gy.

Suspected recurrent anaphylaxis in different forms during general anesthesia.

We report on a patient who presented with recurrent severe shock during general anesthesia. The patient was a man scheduled for lung surgery whose first attack was a coronary spasm, which was followed by a second shock with severe bronchospasm and hypotension 4 weeks later. An elevated serum tryptase concentration was observed, and subsequent skin testing revealed negative reactions to some drugs administered in this case. This case serves to alert anesthetists to the possibility of some different forms of allergy and highlights the importance of rigorous investigation of all the reagents and phenomena.

[Nine-month observation of effects of SO2 on the respiratory system in child Miyakejima citizens].

BACKGROUND: Mt. Oyama on Miyakejima Island erupted in June 2000 and all Miyake village citizens were forced to evacuate the island in the September, due to continuous eruptions and emission of unsafe amounts of volcanic gas, mainly sulfur dioxide (SO2). Beginning in February 2005, residents returned to live on the island despite the fact that volcanic gas was still being emitted. OBJECTIVE: To examine changes in the respiratory systems of included children from February 2006 to November 2006. METHODS: The study population was 141 children who participated in health checkups in November 2006, including 33 SO2 hypersusceptible children who had a current or past history of asthma, obstructive lung function, current symptoms of whistling and wheezing, and/or deterioration of respiratory symptoms. Respiratory effects were evaluated by a questionnaire for respiratory symptoms and by spirometry. SO2 was monitored at 7 sampling points within inhabited areas, and the mean SO2 concentration from February 2005 to November 2006 was 0.031 ppm. The area was categorized into four areas by average SO2 concentration, namely, areas L, H-1, H-2, and H-3, where the average SO2 levels were 0.019, 0.026, 0.032, and 0.045 ppm, respectively. RESULTS: Compared to children in area L, the frequencies of "phlegm" and "irritation of the nose" were significantly greater in the children in areas H-2 and H-3. %FVC and %FEV1 in hypersusceptible children were significantly reduced in November 2006 as compared to February 2006 (P = 0.047, 0.027), though no reduction observed in normosusceptible children. CONCLUSION: Respiratory functions in hypersusceptible Miyakejima children may be affected by SO2 exposure, and further follow-up observation is necessary.