Olfactory behavioural and neural responses of planktivorous lacustrine sockeye salmon (Oncorhynchus nerka) to prey odours

Fish use a variety of sensory systems when foraging. Salmonids are generally considered visual feeders. However, some species feed on zooplanktons under dark conditions, suggesting they also detect prey using nonvisual cues. Under experimental conditions, hatchery-reared rainbow trout (Oncorhynchus mykiss) have been shown to use olfaction when searching for food pellets, but olfactory foraging has not been documented in wild salmonids. In the present study, to examine their behavioural response and neural activity in the olfactory nervous system using c-fos expression as a neural molecular marker, immature wild-caught lacustrine sockeye salmon (Oncorhynchus nerka) in a flow-through aquarium were exposed to zooplanktons (Daphnia spp.) extract including zooplanktons odorant and to dimethyl sulfide. The salmon exposed to zooplanktons odour increased their total swimming distance and time, numbers of turns and ascents, and c-fos expression in the olfactory bulb, suggesting that they can detect zooplanktons extract to locate prey in the laboratory experiments. However, no response was seen in those exposed to dimethyl sulfide. The results of this study suggest that prey odour may serve as a chemosensory cue for wild immature salmonids.

Gene expression levels of synaptic exocytosis regulator synaptophysin in the brain and the olfactory organ of anadromous salmon

Anadromous Pacific salmon (genus Oncorhynchus) are known for their homing behavior based on olfactory imprinting, which is formed during their seaward migration. Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE/Snare) complex is a minimum unit of vesicle exocytosis from the pre-synaptic membrane. Its component genes (synaptosome-associated protein 25, syntaxin 1, and vesicle-associated membrane protein 2) are more strongly expressed in the olfactory nervous system (olfactory epithelium, olfactory bulb, and telencephalon) at the migration stages related to olfactory imprinting and/or retrieval in salmon. This study focused on the mRNA synthesis of synaptophysin (Syp), one of the Snare regulatory factors. syp is strongly expressed in chum salmon (Oncorhynchus keta) olfactory nervous system during the seaward migration and temporarily increased during the homeward migration. In reference to our previous studies, these expression changes were similar to the snare genes in the chum salmon. Therefore, syp and Snare component genes were synchronously expressed reflecting the development and short-term plasticity of the olfactory nervous system that is essential for olfactory imprinting.

A non-coding RNA balancing act: miR-346-induced DNA damage is limited by the long non-coding RNA NORAD in prostate cancer

BACKGROUND

miR-346 was identified as an activator of Androgen Receptor (AR) signalling that associates with DNA damage response (DDR)-linked transcripts in prostate cancer (PC). We sought to delineate the impact of miR-346 on DNA damage, and its potential as a therapeutic agent.

METHODS

RNA-IP, RNA-seq, RNA-ISH, DNA fibre assays, in vivo xenograft studies and bioinformatics approaches were used alongside a novel method for amplification-free, single nucleotide-resolution genome-wide mapping of DNA breaks (INDUCE-seq).

RESULTS

miR-346 induces rapid and extensive DNA damage in PC cells - the first report of microRNA-induced DNA damage. Mechanistically, this is achieved through transcriptional hyperactivation, R-loop formation and replication stress, leading to checkpoint activation and cell cycle arrest. miR-346 also interacts with genome-protective lncRNA NORAD to disrupt its interaction with PUM2, leading to PUM2 stabilisation and its increased turnover of DNA damage response (DDR) transcripts. Confirming clinical relevance, NORAD expression and activity strongly correlate with poor PC clinical outcomes and increased DDR in biopsy RNA-seq studies. In contrast, miR-346 is associated with improved PC survival. INDUCE-seq reveals that miR-346-induced DSBs occur preferentially at binding sites of the most highly-transcriptionally active transcription factors in PC cells, including c-Myc, FOXA1, HOXB13, NKX3.1, and importantly, AR, resulting in target transcript downregulation. Further, RNA-seq reveals widespread miR-346 and shNORAD dysregulation of DNA damage, replication and cell cycle processes. NORAD drives target-directed miR decay (TDMD) of miR-346 as a novel genome protection mechanism: NORAD silencing increases mature miR-346 levels by several thousand-fold, and WT but not TDMD-mutant NORAD rescues miR-346-induced DNA damage. Importantly, miR-346 sensitises PC cells to DNA-damaging drugs including PARP inhibitor and chemotherapy, and induces tumour regression as a monotherapy in vivo, indicating that targeting miR-346:NORAD balance is a valid therapeutic strategy.

CONCLUSIONS

A balancing act between miR-346 and NORAD regulates DNA damage and repair in PC. miR-346 may be particularly effective as a therapeutic in the context of decreased NORAD observed in advanced PC, and in transcriptionally-hyperactive cancer cells.

Serotonin-manipulated juvenile green sea turtles Chelonia mydas exhibit reduced fear-like behaviour

Animals display fear-like behaviours before escaping from predators. This response triggers both behavioural and physiological changes in multiple body systems, allowing animals to escape danger and ensure survival. Fear-like behaviour is modulated by the serotonergic system in the brain of vertebrates, which shapes social behaviour and cooperative behaviours. Using fluoxetine (FLX), a common pharmaceutical that alters the levels of serotonin in the brain, we aimed to clarify whether the same is true in solitary animals like green turtles Chelonia mydas. Green turtles exhibit individual differences in their response to risk. If fear-related behaviours are regulated by the serotonin system in turtles, the fear-like responses of individuals injected with FLX could change. We therefore assessed the effect of FLX injection on the behavioural responses to a fear stimulus in 9 wild juvenile green turtles in an aquarium setting. We inserted a hand net as a stimulus into the aquarium (within a designated inspection zone) to elicit a fear-like behaviour and measured the time that turtles spent in this zone. All turtles exhibited fear-like behaviour and fled from the stimulus prior to any injection treatment. Turtles with control injection (no FLX) also fled and avoided the inspection zone with the fear stimulus. FLX injection appeared to reduce the turtles’ fear of the stimulus: The total time turtles injected with FLX spent in the inspection zone was significantly longer than for turtles that received a control medium injection. Control turtles fled from the stimulus and were initially vigilant and avoided the area with the stimulus, but then moved throughout the aquarium, including the inspection zone. These data suggest that fear-like behaviour is modulated by the serotonin-mediated nerve system in juvenile green turtles.

Gene expression of neuronal soluble N-ethylmaleimide-sensitive factor attachment protein receptor complex components in the olfactory organ and brain during seaward and homeward migration by pink salmon (Oncorhynchus gorbuscha)

The expression of synaptic vesicle exocytosis-regulator SNARE complex component genes (snap25, stx1 and vamp2) was examined in the olfactory nervous system during seaward and homeward migration by pink salmon (Oncorhynchus gorbuscha). The expression levels of snares in the olfactory organ were higher in seaward fry than in feeding and homeward adults, reflecting the development of the olfactory nervous system. The expression of snap25a, b and stx1a was upregulated or stable in the adult olfactory bulb and telencephalon. This upregulated expression suggested alterations in olfactory neuronal plasticity that may be related to the discrimination of natal rivers. The expression of stx1b was downregulated in the adult olfactory bulb, but remained stable in the adult telencephalon. The expression of vamp2 was initially strong in seaward fry, but was downregulated in adults in both the olfactory bulb and telencephalon. Pink salmon has the lowest diversity of maturation age, the largest population, and the most evolutional position in Pacific salmon (genus Oncorhynchus). The expression of snares in the olfactory center of pink salmon reflected the timing of sexual maturation and homeward migration. The present results and our previous studies indicate that snares show distinct expression patterns between two salmon species that depend on physiological and ecological features of migration.

CHANGES OF ABSORBED DOSE RATE IN AIR BY CAR-BORNE SURVEY IN NAMIE TOWN, FUKUSHIMA PREFECTURE AFTER THE FUKUSHIMA DAIICHI NUCLEAR POWER PLANT ACCIDENT

The latest car-borne survey was carried out by Hirosaki University in order to grasp the local distribution of the absorbed dose rate in air after the evacuation order was lifted on Namie Town in 2017. The car-borne survey of absorbed dose rate in air was carried out on most of the roads which were accessible by car in Namie Town using a 3-in × 3-in NaI(Tl) scintillation spectrometer. The range of the absorbed dose rate in air was calculated to be 0.041-11 μGy h-1. The distribution maps of the absorbed dose rate in air were drawn based on the data obtained during the surveys in 2011, 2015 and 2017. The comparison of these absorbed dose rates in air suggests that the elevated absorbed dose rate in air in Namie Town caused by the FDNPP accident may be decreasing faster than natural decline which includes weathering effect and physical decay due to the artificial decontamination.

IDENTIFICATION OF NOVEL BIOMARKERS FOR LUNG CANCER RISK IN HIGH LEVELS OF RADON BY PROTEOMICS: A PILOT STUDY

Radon is the second most important risk factor for lung cancer after tobacco smoking. In Chiang Mai, Thailand, the values of indoor radon activity concentrations are considerably higher than global average values and it is a highest level among East Asian countries. The aim of our study is to identify novel biomarkers for lung cancer risk in high radon areas using a proteomic approach. In our transitional study, a total of 81 participants of non-smokers were examined, consist of 25 lung cancer patients (LC), 16 healthy controls from low levels of natural radiation areas (LLNRA) and 40 healthy controls from high levels of natural radiation areas (HLNRA). The results showed that a total of 799 differentially expressed proteins were identified. Among these, a total of 25 proteins were observed in both LC and HLNRA, but not in LINRA. Owing to the results obtained from this study, we also point out the research direction regarding the validation of some new candidate protein as a biomarker to screen population with high risk for lung cancer in the area with high levels of radon.

ANNUAL EFFECTIVE DOSE ASSESSMENT DUE TO RADON AND THORON PROGENIES IN DWELLINGS OF KILIMAMBOGO, KENYA

Human beings are continuously exposed to ionising radiation originating from natural or artificial sources. Uranium-238 and Thorium-232 found in building materials are important sources of radon and thoron in the indoor environment. The concentration levels of radon, thoron and thoron progeny were measured in mud-walled, metallic or iron sheet-walled and stone-walled modern houses in Kilimambogo region, Kenya for 3 months. Radon and thoron concentration levels were measured using passive radon-thoron discriminative monitors (RADUET), while thoron progeny concentrations as the equilibrium equivalent thoron concentration (EETC) were measured using thoron progeny monitors. The mean radon concentration levels in mud, metallic and stone-walled dwellings were 67 ± 11, 60 ± 10 and 75 ± 10 Bq m-3, respectively. The mean thoron concentration levels in the corresponding dwellings were 195 ± 36, 71 ± 24 and 161 ± 31 Bq m-3, respectively, while EETCs were 12 ± 2, 3 ± 1 and 7 ± 1 Bq m-3, respectively. The annual effective doses for radon were 1.3 ± 0.2, 1.1 ± 0.1 and 1.4 ± 0.2 mSv y-1 in mud, metallic and stone-walled houses while those from thoron estimated from EETC were 2.4 ± 0.4, 0.5 ± 0.1 and 1.5 ± 0.2 mSv y-1 in the corresponding houses, respectively.

Detection and localization of the thyroid hormone receptor beta mRNA in the immature olfactory receptor neurons of chum salmon

Thyroid hormone (TH) plays an important role in regulating multiple cellular and metabolic processes, including cell proliferation, cell death, and energy metabolism, in various organs and tissues of vertebrates. It is generally accepted that anadromous Pacific salmon (Oncorhynchus spp.) imprint odorants from their natal stream during their seaward migration, and they then use olfaction to discriminate their natal stream during the spawning migration. Both serum TH levels and the specific binding values of TH in the salmon olfactory epithelium were markedly increased during the seaward migration. However, thyroid hormone receptor (TR) expression in the olfactory epithelium has not been confirmed in vertebrates. We investigated gene expression of TR isoforms in chum salmon (O. keta) by both molecular biological and histochemical techniques. Expression of TRβ mRNA was detected in the olfactory epithelium by reverse transcriptase polymerase chain reaction (RT-PCR). Nucleotide sequencing demonstrated the existence of a remarkable homology between the RT-PCR product and part of the ligand-binding domain of other teleost TRβ isoforms. By in situ hybridization using a digoxygenin-labeled salmon olfactory TRβ cRNA probe, signals for salmon olfactory TRβ mRNA were observed preferentially in the perinuclear regions of immature olfactory receptor neurons (ORNs), as protein gene product 9.5 (PGP9.5)-immunopositive ORNs. Our results provide the first detection of TRβ gene expression in the olfactory epithelium, and suggested the possibility that TRβ may be involved in cell maturation and/or cell differentiation of the ORNs in Pacific salmon.

Involvement of 11-ketotestosterone in hooknose formation in male pink salmon (Oncorhynchus gorbuscha) jaws

Mature male Pacific salmon (Oncorhynchus spp.) develop a hooknose, as a secondary male sexual characteristic, during the spawning period. It is likely that androgens regulate hooknose formation. However, endocrinological and histochemical details about the relationship between androgens and hooknose formation are poorly understood. In this study, we performed assays of serum androgens, detection of androgen receptor (AR) in hooknose tissues, external morphological measurement of hooknose-related lengths, and microscopic observation of hooknose tissues of pink salmon (O. gorbuscha) at different stages of sexual maturation. Expression of the arβ gene was detected in hooknose tissues of males but not females. The elongation of these tissues was mediated directly via androgens. Serum 11-ketotestosterone (11-KT) concentrations indicated a significant positive correlation with both jaw lengths during sexual maturation of males. In the upper jaw, cartilage tissue developed during hooknose formation, and AR-immunoreactive chondrocytes were located in the rostal-vetral regions of hooknose cartilage in maturing male. The chondrocytes in maturing males before entering into rivers exhibited rich-cytoplasm with high cell activity than at other sexual development stages. On the other hand, in the lower jaw, the development of the spongiosa-like bone meshworks. AR-immunoreactivity was detected in a proportion of the osteocytes and osteoblast-like cells in the spongiosa-like bone meshworks. These results indicate that hooknose formation in pink salmon, which is associated with the buildup of a structure with sufficient strength that it can be used to attack other males on the spawning ground, is regulated by 11-KT.

A potential role for the silent information regulator 2 homologue 1 (SIRT1) in periapical periodontitis

AIM

To investigate the role played by silent information regulator 2 homologue 1 (SIRT1) during angiogenesis of periapical periodontitis.

METHODOLOGY

Periapical granulomas were subjected to dual-colour immunofluorescence imaging and real-time polymerase chain reactions assaying the expression levels of SIRT1, vascular endothelial growth factor (VEGF) and VE-cadherin. The association between Ki-67 and SIRT1 expression was also examined. Human umbilical vein endothelial cells (HUVECs) were treated with a combination of lipopolysaccharide and resveratrol (a SIRT1 activator) or sirtinol (a SIRT1 inhibitor); and the levels of mRNAs encoding SIRT1, VEGF and VE-cadherin were determined. HUVEC tube formation was assayed in the presence of resveratrol or sirtinol. The Mann-Whitney U-test or the Tukey-Kramer test was used for statistical analysis.

RESULTS

Ki-67-expressing cells, including endothelial cells, lay adjacent to SIRT1-expressing cells in periapical granulomas. In addition, SIRT1-expressing cells were detected adjacent to VEGF-expressing cells and VEGF- or VE-cadherin-expressing endothelial cells. SIRT1, VEGF and VE-cadherin mRNA expression levels in periapical granulomas were significantly higher (P = 0.0054, 0.0090 and 0.0090, respectively) than those in healthy gingival tissues. HUVECs treated with resveratrol exhibited significantly higher expression of mRNAs encoding SIRT1, VEGF and VE-cadherin (P = 0.0019, 0.00005 and 0.0045, respectively) compared with controls, but sirtinol inhibited such expression. Resveratrol caused HUVECs to form tube-like structures, whilst sirtinol inhibited this process.

CONCLUSIONS

These findings suggest that SIRT1 may stimulate angiogenesis in periapical granulomas by triggering the proliferation of endothelial cells and inducing VEGF and VE-cadherin expression.

Comparative anatomy of the dorsal hump in mature Pacific salmon

Mature male Pacific salmon (Genus Oncorhynchus) demonstrate prominent morphological changes, such as the development of a dorsal hump. The degree of dorsal hump formation depends on the species in Pacific salmon. It is generally accepted that mature males of sockeye (O. nerka) and pink (O. gorbuscha) salmon develop most pronounced dorsal humps. The internal structure of the dorsal hump in pink salmon has been confirmed in detail. In this study, the dorsal hump morphologies were analyzed in four Pacific salmon species inhabiting Japan, masu (O. masou), sockeye, chum (O. keta), and pink salmon. The internal structure of the dorsal humps also depended on the species; sockeye and pink salmon showed conspicuous development of connective tissue and growth of bone tissues in the dorsal tissues. Masu and chum salmon exhibited less-pronounced increases in connective tissues and bone growth. Hyaluronic acid was clearly detected in dorsal hump connective tissue by histochemistry, except for in masu salmon. The lipid content in dorsal hump connective tissue was richer in masu and chum salmon than in sockeye and pink salmon. These results revealed that the patterns of dorsal hump formation differed among species, and especially sockeye and pink salmon develop pronounced dorsal humps through both increases in the amount of connective tissue and the growth of bone tissues. In contrast, masu and chum salmon develop their dorsal humps by the growth of bone tissues, rather than the development of connective tissue.

In-situ straining and time-resolved electron tomography data acquisition in a transmission electron microscope

This paper reports the preliminary results of a new in-situ three-dimensional (3D) imaging system for observing plastic deformation behavior in a transmission electron microscope (TEM) as a directly relevant development of the recently reported straining-and-tomography holder [Sato K et al. (2015) Development of a novel straining holder for transmission electron microscopy compatible with single tilt-axis electron tomography. Microsc. 64: 369-375]. We designed an integrated system using the holder and newly developed straining and image-acquisition software and then developed an experimental procedure for in-situ straining and time-resolved electron tomography (ET) data acquisition. The software for image acquisition and 3D visualization was developed based on the commercially available ET software TEMographyTM. We achieved time-resolved 3D visualization of nanometer-scale plastic deformation behavior in a Pb-Sn alloy sample, thus demonstrating the capability of this system for potential applications in materials science.

Randomized clinical trial comparing two vessel-sealing devices with crush clamping during liver transection

Background

Previous RCTs have failed to demonstrate the usefulness of combining energy devices with the conventional clamp crushing method to reduce blood loss during liver transection. Here, the combination of an ultrasonically activated device (UAD) and a bipolar vessel-sealing device (BVSD) with crush clamping was investigated.

Methods

Patients scheduled to undergo hepatectomy at the University of Tokyo Hospital or Nihon University Itabashi Hospital were eligible for this parallel-group, single-blinded randomized study. Patients were assigned to a control group (no energy device used), an UAD group or a BVSD group. The primary endpoint was the volume of blood loss during liver transection. Outcomes of the control group and the combined energy device groups (UAD plus BVSD) were first compared. Pairwise comparisons among the three groups were made for outcomes for which the combined energy device group was superior to the control group.

Results

A total of 380 patients were enrolled between July 2012 and May 2014; 116 patients in the control group, 122 in the UAD group and 123 in the BVSD group were included in the final analysis. Median blood loss during liver transection was lower in the combined energy device group (245 patients) than in the control group (116 patients): median 190 (range 0–3575) versus 230 (range 3–1570) ml (P = 0·048). Pairwise comparison revealed that blood loss was lower in the BVSD group than in the control group (P = 0·043).

Conclusion

The use of energy devices combined with crush clamping reduced blood loss during liver transection. Registration number: C000008372 (www.umin.ac.jp/ctr/index.htm).

The role of PSMB9 upregulated by interferon signature in the pathophysiology of cutaneous lesions of dermatomyositis and systemic lupus erythematosus

BACKGROUND

Dermatomyositis (DM) and systemic lupus erythematosus (SLE) have common skin features, including dermal mucin deposition and interferon signature, although their roles are unknown.

OBJECTIVES

To identify common or specific molecular changes in DM and SLE skin.

METHODS

Proteomic analysis was performed using DM and healthy skin. Glycosaminoglycans were analysed by high-performance liquid chromatography.

RESULTS

The expression of 60 proteins was upregulated or downregulated in DM skin compared with healthy skin in the proteomic analysis. Among those proteins, PSMB9, an immunoproteasome subunit, was upregulated in the epidermis of DM and SLE, but not in other skin diseases. Furthermore, versican V1, a core protein for glycosaminoglycans, was upregulated, while type I collagen was downregulated in the dermis of DM and SLE skin. Interferon stimulated PSMB9 expression in cultured keratinocytes and reduced collagen expression in dermal fibroblasts, but did not affect versican expression. The PSMB9 knock-down in keratinocytes led to significant suppression of transforming growth factor (TGF)-β2 and TGF-β3, inducers of versican synthesis. TGF-β3 expression was upregulated in both DM and SLE, while TGF-β2 expression was increased only in the DM epidermis. ΔDiHS-diS1, a component of heparan sulfate, was significantly increased only in DM. TGF-β2 expression significantly increased the ΔDiHS-diS1 expression in dermal fibroblasts in vitro.

CONCLUSIONS

The interferon signature in DM and SLE skin reduces collagen in dermal fibroblasts, whereas overexpression of PSMB9 induced by interferon stimulates versican inducers in epidermal keratinocytes. In addition, the TGF-β2-ΔDiHS-diS1 pathway may be responsible for the specific molecular change in DM skin.

Measurement and comparison of individual external doses of high-school students living in Japan, France, Poland and Belarus-the 'D-shuttle' project

Twelve high schools in Japan (of which six are in Fukushima Prefecture), four in France, eight in Poland and two in Belarus cooperated in the measurement and comparison of individual external doses in 2014. In total 216 high-school students and teachers participated in the study. Each participant wore an electronic personal dosimeter 'D-shuttle' for two weeks, and kept a journal of his/her whereabouts and activities. The distributions of annual external doses estimated for each region overlap with each other, demonstrating that the personal external individual doses in locations where residence is currently allowed in Fukushima Prefecture and in Belarus are well within the range of estimated annual doses due to the terrestrial background radiation level of other regions/countries.

Comparative dosimetry for radon and thoron in high background radiation areas in China

The present study focuses on internal exposure caused by the inhalation of radon and thoron progenies because the internal exposures have not yet been clarified. For their dose assessment, radon, thoron and thoron progeny concentrations were measured by passive monitors over a long period (for 6 months). Consequently, radon, thoron and equilibrium equivalent thoron concentrations were given as 124 ± 78, 1247 ± 1189 and 7.8 ± 9.1 Bq m(-3), respectively. Annual effective doses are estimated to be 3.1 ± 2.0 mSv for radon and 2.2 ± 2.5 mSv for thoron. Total dose are estimated to be 5.3 ± 3.5 mSv a(-1). The present study has revealed that the radon dose was comparable with the thoron dose, and the total dose was ∼2 times higher than the worldwide average.

Revision of the Massarineae (Pleosporales, Dothideomycetes)

We here taxonomically revise the suborder Massarineae (Pleosporales, Dothideomycetes, Ascomycota). Sequences of SSU and LSU nrDNA and the translation elongation factor 1-alpha gene (tef1) are newly obtained from 106 Massarineae taxa that are phylogenetically analysed along with published sequences of 131 taxa in this suborder retrieved from GenBank. We recognise 12 families and five unknown lineages in the Massarineae. Among the nine families previously known, the monophyletic status of the Dictyosporiaceae, Didymosphaeriaceae, Latoruaceae, Macrodiplodiopsidaceae, Massarinaceae, Morosphaeriaceae, and Trematosphaeriaceae was strongly supported with bootstrap support values above 96 %, while the clades of the Bambusicolaceae and the Lentitheciaceae are moderately supported. Two new families, Parabambusicolaceae and Sulcatisporaceae, are proposed. The Parabambusicolaceae is erected to accommodate Aquastroma and Parabambusicola genera nova, as well as two unnamed Monodictys species. The Parabambusicolaceae is characterised by depressed globose to hemispherical ascomata with or without surrounding stromatic tissue, and multi-septate, clavate to fusiform, hyaline ascospores. The Sulcatisporaceae is established for Magnicamarosporium and Sulcatispora genera nova and Neobambusicola. The Sulcatisporaceae is characterised by subglobose ascomata with a short ostiolar neck, trabeculate pseudoparaphyses, clavate asci, broadly fusiform ascospores, and ellipsoid to subglobose conidia with or without striate ornamentation. The genus Periconia and its relatives are segregated from the Massarinaceae and placed in a resurrected family, the Periconiaceae. We have summarised the morphological and ecological features, and clarified the accepted members of each family. Ten new genera, 22 new species, and seven new combinations are described and illustrated. The complete ITS sequences of nrDNA are also provided for all new taxa for use as barcode markers.

An improved phase shift reconstruction algorithm of fringe scanning technique for X-ray microscopy

The X-ray phase imaging method has been applied to observe soft biological tissues, and it is possible to image the soft tissues by using the benefit of the so-called "Talbot effect" by an X-ray grating. One type of the X-ray phase imaging method was reported by combining an X-ray imaging microscope equipped by a Fresnel zone plate with a phase grating. Using the fringe scanning technique, a high-precision phase shift image could be obtained by displacing the grating step by step and measuring dozens of sample images. The number of the images was selected to reduce the error caused by the non-sinusoidal component of the Talbot self-image at the imaging plane. A larger number suppressed the error more but increased radiation exposure and required higher mechanical stability of equipment. In this paper, we analyze the approximation error of fringe scanning technique for the X-ray microscopy which uses just one grating and proposes an improved algorithm. We compute the approximation error by iteration and substitute that into the process of reconstruction of phase shift. This procedure will suppress the error even with few sample images. The results of simulation experiments show that the precision of phase shift image reconstructed by the proposed algorithm with 4 sample images is almost the same as that reconstructed by the conventional algorithm with 40 sample images. We also have succeeded in the experiment with real data.

Discrimination of lymph node metastases using desorption electrospray ionisation-mass spectrometry imaging

Desorption electrospray ionisation mass spectrometry imaging (DESI-MSI) has been used for the identification of cancer within lymph nodes with accurate spatial distribution in comparison to gold standard matched immuno-histopathological images. The metabolic profile of the cancerous lymph nodes was similar to that of the primary tumour site.

Sulfurovum aggregans sp. nov., a hydrogen-oxidizing, thiosulfate-reducing chemolithoautotroph within the Epsilonproteobacteria isolated from a deep-sea hydrothermal vent chimney, and an emended description of the genus Sulfurovum

A novel mesophilic, strictly hydrogen-oxidizing, sulfur-, nitrate- and thiosulfate-reducing bacterium, designated strain Monchim33T, was isolated from a deep-sea hydrothermal vent chimney at the Central Indian Ridge. The non-motile, rod-shaped cells were Gram-stain-negative and non-sporulating. Growth was observed between 15 and 37 °C (optimum 33 °C; 3.2 h doubling time) and between pH 5.4 and 8.6 (optimum pH 6.0). The isolate was a strictly anaerobic chemolithoautotroph capable of using molecular hydrogen as the sole energy source and carbon dioxide as the sole carbon source. The G+C content of the genomic DNA was 42.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the novel isolate belonged to the genus Sulfurovum and was closely related to Sulfurovum sp. NBC37-1 and Sulfurovum lithotrophicum 42BKT (95.6 and 95.4 % similarity, respectively). DNA–DNA hybridization demonstrated that the novel isolate could be differentiated genotypically from Sulfurovum sp. NBC37-1 and Sulfurovum lithotrophicum . On the basis of the molecular and physiological traits of the new isolate, the name Sulfurovum aggregans sp. nov. is proposed, with the type strain Monchim33T ( = JCM 19824T = DSM 27205T).

Assessment of spontaneous platelet aggregation using laser light scattering in healthy subjects: an attempt to standardize

INTRODUCTION

When measuring platelet aggregation using laser light scattering, small aggregates forming without the addition of agonists may be observed. This event is called 'spontaneous platelet aggregation (SPA)'. The platelet hyperactivity observed in arterial thrombotic diseases can be detected with relative ease by measuring SPA. Standardization is urgently needed because of differences between measurement conditions among various laboratories.

METHODS

We conducted a systematic study of factors that affect SPA measurement, compared SPA results to flow cytometry detection of surface antigens expressed on activated platelet membranes (P-selectin, activated glycoprotein IIb/IIIa), and determined conditions that yield stable measurements.

RESULTS AND CONCLUSIONS

We evaluated results from 125 healthy volunteers and established conditions for a stable measurement of SPA. As the occurrence of SPA tended to increase with age, we determined conditions valid for subjects aged 20-60 years. Blood should be collected using a syringe, and the sample should be prepared after allowing the whole blood to rest for 30 min after collection. To isolate platelet-rich plasma, a 2-mL tube should be used and centrifuged at 150 g. The sample should be stored at room temperature, the platelet count of the sample should be (250 ± 10) × 10(9) /L, and the measurement should be completed within 90 min of blood collection.

Dorsal hump morphology in pink salmon (Oncorhynchus gorbuscha)

Mature male Pacific salmon (Genus Oncorhynchus) develop a dorsal hump, as a secondary male sexual characteristic, during the spawning period. Previous gross anatomical studies have indicated that the dorsal humps of salmon are mainly composed of cartilaginous tissue (Davidson [1935] J Morphol 57:169-183.) However, the histological and biochemical characteristics of such humps are poorly understood. In this study, the detailed microstructures and components of the dorsal humps of pink salmon were analyzed using histochemical techniques and electrophoresis. In mature males, free interneural spines and neural spines were located in a line near to the median septum of the dorsal hump. No cartilaginous tissue was detected within the dorsal hump. Fibrous and mucous connective tissues were mainly found in three regions of the dorsal hump: i) the median septum, ii) the distal region, and iii) the crescent-shaped region. Both the median septum and distal region consisted of connective tissue with a high water content, which contained elastic fibers and hyaluronic acid. It was also demonstrated that the lipid content of the dorsal hump connective tissue was markedly decreased in the mature males compared with the immature and maturing males. Although, the crescent-shaped region of the hump consisted of connective tissue, it did not contain elastic fibers, hyaluronic acid, or lipids. In an ultrastructural examination, it was found that all of the connective tissues in the dorsal hump were composed of collagen fibers. Gel electrophoresis of collagen extracts from these tissues found that the collagen in the dorsal hump is composed of Type I collagen, as is the case in salmon skin. These results indicate that in male pink salmon the dorsal hump is formed as a result of an increase in the amount of connective tissue, rather than cartilage, and the growth of free interneural spines and neural spines.

Galanin gene expression and effects of its knock-down on the development of the nervous system in larval zebrafish

Despite the known importance of galanin in the nervous system of vertebrates, the galanin gene structure and expression and the consequences of galanin deficiency in developing zebrafish are unknown. We cloned the galanin gene and analyzed its expression by using in situ hybridization, PCR, and immunocytochemistry throughout the early development of zebrafish until the end of the first week of life. The single zebrafish galanin gene encoded for a single amidated galanin peptide and a galanin message-associated peptide. Two forms resulting from alternative processing were identified. Galanin mRNA was maternally expressed and found in developing fish throughout early development. In situ hybridization showed the first positive neurons in three groups in the brain at 28 hours postfertilization. At 2 days postfertilization, three prosencephalic neuron groups were seen in the preoptic area and in rostral and caudal periventricular hypothalamus. In addition, two other groups of weakly stained neurons were visible, one in the midbrain and another in the hindbrain. Translation inhibition of galanin mRNA with morpholino oligonucleotides caused complete disappearance of galanin immunoreactivity in the brain until 7 dpf and did not induce known cascades of nonspecific pathways or morphological abnormalities. A minor disturbance of sensory ganglia was found. Galanin knockdown did not alter the expression of tyrosine hydroxylases 1 and 2, choline acetyltransferase, histidine decarboxylase, or orexin mRNA. The results suggest that galanin does not regulate the development of these key markers of specific neurons, although galanin-expressing fibers were in a close spatial proximity to several neurons of these neuronal populations.

Note: Near-field imaging of thermal radiation at low temperatures by passive millimeter-wave microscopy

Imaging of thermal radiation with a spatial resolution below the diffraction limit is demonstrated with a passive millimeter-wave microscope. This technique utilizes a sensitive radiometric receiver in combination with a scanning near-field microscope. Experiments were performed at 50 GHz (λ = 6 mm) with sample temperatures ranging from room temperature down to 160 K, and the performance was shown to be superior to that achieved with passive imaging systems in the infrared region. The images are affected by non-uniformities in the transmission of thermal radiation from the sample to the receiver via the near-field probe and the reflection of thermal radiation back to the receiver from the probe. The effects of these non-uniformities were successfully removed using a sample image acquired by active measurements using a vector network analyzer.

Relative importance of the area and intensity of the orange spots of male guppies Poecilia reticulata as mating traits preferred by females

Digitally modified videos of male guppies Poecilia reticulata were used to examine the relative importance of the area and intensity of the orange spots as mating traits preferred by females. The females prioritized the area of the orange spots over intensity for their mate preference.

The comparative neuroanatomy and neurochemistry of zebrafish CNS systems of relevance to human neuropsychiatric diseases

Modulatory neurotransmitters which signal through G protein-coupled receptors control brain functions which deteriorate in degenerative brain diseases. During the past decade many of these systems have been mapped in the zebrafish brain. The main architecture of the systems in zebrafish brain resembles that of the mammals, despite differences in the development of the telencephalon and mesodiencephalon. Modulatory neurotransmitters systems which degenerate in human diseases include dopamine, noradrenaline, serotonin, histamine, acetylcholine and orexin/hypocretin. Although the number of G protein-coupled receptors in zebrafish is clearly larger than in mammals, many receptors have similar expression patterns, binding and signaling properties as in mammals. Distinct differences between mammals and zebrafish include duplication of the tyrosine hydroxylase gene in zebrafish, and presence of one instead of two monoamine oxidase genes. Zebrafish are sensitive to neurotoxins including MPTP, and exposure to this neurotoxin induces a decline in dopamine content and number of detectable tyrosine hydroxylase immunoreactive neurons in distinct nuclei. Sensitivity to important neurotoxins, many available genetic methods, rapid development and large-scale quantitative behavioral methods in addition to advanced quantitative anatomical methods render zebrafish an optimal organism for studies on disease mechanisms.

Expressions of the multidrug resistance-related proteins in the rat olfactory epithelium: a possible role in the phase III xenobiotic metabolizing function

The xenobiotic metabolizing system is considered to play important roles in the olfaction by the chemical homeostasis. Several phase I and phase II xenobiotic metabolizing enzymes are expressed in the olfactory epithelium in vertebrates. Multidrug resistance-related proteins (MRPs) are the phase III xenobiotic metabolizing pumps that eliminate some conjugated ligands from cells. However, the MRP-expressions in the olfactory epithelium have not been confirmed in the mammals. We investigated gene and protein expressions of MRP type 1 (MRP1) and type 2 (MRP2) isoforms in the adult rat olfactory epithelium in order to clarify the existence of phase III xenobiotic metabolizing pumps in the olfactory organs. Expressions of MRP1 mRNA were detected in the nasal cavity by reverse transcriptase polymerase chain reaction (RT-PCR). The nucleoside sequence of the RT-PCR products were completely identical to that found in other organs of rat. On the contrary, the analysis did not detect expressions of MRP2 mRNA in the nasal cavity. By in situ hybridization using a digoxigenin-labeled MRP1 cRNA probe, signals for MRP1 mRNA were observed preferentially in the perinuclear regions of supporting cells. However, the respiratory epithelial cells did not show the signals for MRP1 mRNA. By immunohistochemistry using a specific antibody to MRP1, MRP1-immunoreactivities were seen mainly on the supporting cells. These findings suggest that MRP1 is involved in olfaction as a part of the "olfactory signal termination" by the chemical homeostasis in the "perireceptor events" of the olfactory epithelium.

Extraction behavior of rutherfordium into tributylphosphate from hydrochloric acid

The extraction behavior of rutherfordium (Rf) into tributylphosphate (TBP) from hydrochloric acid (HCl) has been studied together with those of the lighter group-4 elements Zr and Hf. The extractability of261Rf,169Hf, and85Zr into TBP was investigated under identical conditions in 7.2–8.0 M HCl by on-line reversed-phase extraction chromatography. The percent extractions of Rf, Hf, and Zr into the TBP resin increase steeply with increasing HCl concentration, and the order of extraction is Zr > Hf ≈ Rf. By considering the order of chloride complexation among these elements, it is suggested that the stability of the TBP complex of Rf tetrachloride is lower than those of Zr and Hf.

Morphometry of olfactory lamellae and olfactory receptor neurons during the life history of chum salmon (Oncorhynchus keta)

It is generally accepted that anadromous Pacific salmon (genus Oncorhynchus) imprint to odorants in their natal streams during their seaward migration and use olfaction to identify these during their homeward migration. Despite the importance of the olfactory organ during olfactory imprinting, the development of this structure is not well understood in Pacific salmon. Olfactory cues from the environment are relayed to the brain by the olfactory receptor neurons (ORNs) in the olfactory organ. Thus, we analyzed morphometric changes in olfactory lamellae of the peripheral olfactory organ and in the quantity of ORNs during life history from alevin to mature in chum salmon (Oncorhynchus keta). The number of lamellae increased markedly during early development, reached 18 lamellae per unilateral peripheral olfactory organ in young salmon with a 200 mm in body size, and maintained this lamellar complement after young period. The number of ORNs per olfactory organ was about 180,000 and 14.2 million cells in fry and mature salmon, respectively. The relationship between the body size (fork length) and number of ORNs therefore revealed an allometric association. Our results represent the first quantitative analysis of the number of ORNs in Pacific salmon and suggest that the number of ORNs is synchronized with the fork length throughout its life history.

Molecular characterization and histochemical demonstration of salmon olfactory marker protein in the olfactory epithelium of lacustrine sockeye salmon (Oncorhynchus nerka)

Despite the importance of olfactory receptor neurons (ORNs) for homing migration, the expression of olfactory marker protein (OMP) is not well understood in ORNs of Pacific salmon (genus Oncorhynchus). In this study, salmon OMP was characterized in the olfactory epithelia of lacustrine sockeye salmon (O. nerka) by molecular biological and histochemical techniques. Two cDNAs encoding salmon OMP were isolated and sequenced. These cDNAs both contained a coding region encoding 173 amino acid residues, and the molecular mass of the two proteins was calculated to be 19,581.17 and 19,387.11Da, respectively. Both amino acid sequences showed marked homology (90%). The protein and nucleotide sequencing demonstrates the existence of high-level homology between salmon OMPs and those of other teleosts. By in situ hybridization using a digoxigenin-labeled salmon OMP cRNA probe, signals for salmon OMP mRNA were observed preferentially in the perinuclear regions of the ORNs. By immunohistochemistry using a specific antibody to salmon OMP, OMP-immunoreactivities were noted in the cytosol of those neurons. The present study is the first to describe cDNA cloning of OMP in salmon olfactory epithelium, and indicate that OMP is a useful molecular marker for the detection of the ORNs in Pacific salmon.

Identification of proSAAS homologs in lower vertebrates: conservation of hydrophobic helices and convertase-inhibiting sequences

The prohormone convertases (PCs) 1/3 and 2 accomplish the major proteolytic cleavage events in neuroendocrine tissues; each of these convertases has a small associated binding protein that inhibits convertase action in the secretory pathway. The proSAAS protein binds to PC1/3, whereas the 7B2 protein binds to PC2. However, both convertase-binding proteins are more widely expressed than their cognate enzymes, suggesting that they may perform other functions as well. All known mammalian proSAASs are over 85% conserved; thus, identifying functionally important segments has been impossible. Here, we report the first identification of nonmammalian proSAAS molecules, from Xenopus and zebrafish (Danio rerio). Although these two proteins show an overall amino acid sequence identity of only 29 and 30% with mouse proSAAS, two 14-16 residue hydrophobic segments (predicted to form alpha-helices) and two, nine through 11 residue sequences containing basic convertase cleavage sites are highly conserved; therefore, these sequences may be of functional importance. Confidence that these nonmammalian molecules represent authentic proSAAS is supported by the finding that both inhibit mouse PC1/3 with nanomolar inhibition constants; human furin was not inhibited. In vitro, the two proteins were cleaved by PC2 and furin to three or more peptide products. Both zebrafish and Xenopus proSAAS exhibited neural and endocrine distributions, as assessed by in situ and PCR experiments, respectively. In summary, the identification of proSAAS molecules in lower vertebrates provides clues as to functional regions within this widely expressed neuroendocrine protein.

ABO blood type incompatible kidney transplantation without splenectomy prepared with plasma exchange and rituximab

We have designed a protocol for ABO-incompatible kidney transplantations based on preoperative plasmapheresis with a tacrolimus/mycophenolate mofetil/methylprednisolone/basiliximab protocol using low-dose rituximab (200 mg/body) instead of splenectomy to prevent antibody-mediated acute rejection. Eight patients successfully received transplants with this protocol. The titers of anti-A and -B antibodies as well as the number of CD20(+) cells were readily maintained at a low level posttransplantation. There were no side effects. All patients have renal transplant function with a follow-up of 1-34 months.

SOLVING THE INTERIOR PROBLEM OF COMPUTED TOMOGRAPHY USING A PRIORI KNOWLEDGE

The case of incomplete tomographic data for a compactly supported attenuation function is studied. When the attenuation function is a priori known in a subregion, we show that a reduced set of measurements is enough to uniquely determine the attenuation function over all the space. Furthermore, we found stability estimates showing that reconstruction can be stable near the region where the attenuation is known. These estimates also suggest that reconstruction stability collapses quickly when approaching the set of points that are viewed under less than 180 degrees. This paper may be seen as a continuation of the work "Truncated Hilbert transform and Image reconstruction from limited tomographic data" that was published in Inverse Problems in 2006. This continuation tackles new cases of incomplete data that could be of interest in applications of computed tomography.

Novel erythrocyte pits in the small tropical ruminant, lesser mouse deer

We examined unique erythrocyte pits of the peripheral blood and bone marrow in the lesser mouse deer, Tragulus javanicus, using scanning electron microscope (SEM) and transmission electron microscope (TEM). Under the SEM observation, the pit was observed as a hole on both mature erythrocytes of the peripheral blood and immature erythrocytes of the bone marrow. By the TEM, the mature erythrocytes had a vacuole, which showed complicated shape and occupied considerable space within the cytoplasm. The vacuole was communicated extracellularly by perforation, which corresponded to the hole on the cell surface. In the bone marrow, erythroblast and reticulocytes have a cytoplasmic vacuole. This abnormal feature of the erythrocytes is peculiar to the mouse deer, and not found in other tropical ruminants. Despite the disadvantage of volume loss from the small erythrocytes, the mouse deer were healthy and showed no signs of anaemia.

Effects of colloidal iron overload on renal and hepatic siderosis and the femur in male rats

Genetic hemochromatosis is an iron overload disorder, and osteopenic and osteoporotic. Femoral neck bone mineral density (BMD) appears to fall with rising hepatic iron concentrations. A critical role for iron in mediating tissue injury is played via hydroxyl radical formation in nephrotoxicity. We investigated the effects of a colloidal iron overload on renal function, organ siderosis, and femoral bone in male rats. Iron overload reduced body growth, and increased the weights of the liver and spleen. Marked deposition of iron was noted in liver and kidney. Activities of lactate dehydrogenase and alkaline phosphatase were decreased, and the concentrations of blood urea nitrogen and creatinine were increased with the reduction in plasma calcium and inorganic phosphorus levels, i.e. functions of the liver and kidney might be affected by reactive oxygen species such as the superoxide radical, H2O2, and the hydroxyl radical produced by overloaded iron. Damage to the proximal tubular epithelial cells of the kidney and a loss of connectivity of cancellous bone in the epiphysis and of trabecular bone in the metaphysis of the distal femur were observed in iron-overloaded rats with a reduction of femoral bone mineral density, i.e. reabsorption of calcium from the proximal tubular epithelial cells of the kidney might be affected and urinary discharge of calcium might be elevated. It was suggested that iron overload gave rise to osteoporosis combined with renal dysfunction and liver iron overload syndrome.