Acute Phase Pulmonary Responses to a Single Intratracheal Spray Instillation of Magnetite (Fe3O4) Nanoparticles in Fischer 344 Rats

Iron nanomaterials are of considerable interest for application to nanotechnology-related fields including environmental catalysis, biomedical imaging, drug delivery and hyperthermia, because of their superparamagnetic characteristics and high catalytic abilities. However, information about potential risks of iron nanomaterials is limited. The present study assessed pulmonary responses to a single intratracheal spray instillation of triiron tetraoxide nanoparticles (magnetite) in rats. Ten-week-old male and female Fischer 344 rats (n=5/group) were exposed to a single intratracheal spray instillation of 0 (vehicle), 5.0, 15.0 or 45.0 mg/kg body weight (BW) of magnetite. After 14 days, the rats were sacrificed, and biological consequences were investigated. The lung weights of the 15.0 and 45.0 mg/kg BW male and female groups were significantly higher than those of the control groups. The lungs of treated rats showed enlargement and black patches originating from the color of magnetite. The typical histopathological changes in the lungs of the treated rats included infiltration of macrophages phagocytosing magnetite, inflammatory cell infiltration, granuloma formation and an increase of goblet cells in the bronchial epithelium. The results clearly show that instilled magnetite causes foreign body inflammatory and granulating lesions in the lung. These pulmonary responses occur in a dose-dependent manner in association with the increase in lung weight.     

Screening and cDNA cloning of Kv1 potassium channel toxins in sea anemones

When 21 species of sea anemones were screened for Kv1 potassium channel toxins by competitive inhibition of the binding of (125)I-α-dendrotoxin to rat synaptosomal membranes, 11 species (two species of Actiniidae, one species of Hormathiidae, five species of Stichodactylidae and three species of Thalassianthidae) were found to be positive. Furthermore, full-length cDNAs encoding type 1 potassium channel toxins from three species of Stichodactylidae and three species of Thalassianthidae were cloned by a combination of RT-PCR, 3'RACE and 5'RACE. The precursors of these six toxins are commonly composed of signal peptide, propart and mature peptide portions. As for the mature peptide (35 amino acid residues), the six toxins share more than 90% sequence identities with one another and with κ(1.3)-SHTX-She1a (Shk) from Stichodactyla helianthus but only 34-63% identities with the other type 1 potassium channel toxins.     

Discrimination of nursery locations of juvenile Japanese flounder Paralichthys olivaceus on the Pacific coast of northern Japan based on carbon and nitrogen stable isotope ratios

Fisheries Science - To test whether stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) can be used to understand the ecological connectivity of Japanese flounder Paralichthys...     

Luteal toxicity evaluation in rats

The corpora lutea (CL) are endocrine glands that form in the ovary after ovulation and secrete the steroid hormone, progesterone (P4). P4 plays a critical role in estrous and menstrual cycles, implantation, and pregnancy. The incomplete rodent estrous cycle stably lasts 4–5 days and its morphological features can be distinguished during each estrous cycle stage. In rat ovaries, there are two main types of CL: newly formed ones due to the current ovulation (new CL), and CL remaining from prior estrous cycles (old CL). In the luteal regression process, CL were almost fully regressed after four estrous cycles in Sprague-Dawley rats. P4 secretion from CL in rodents is regulated by the balance between synthesis and catabolism. In general, luteal toxicity should be evaluated by considering antemortem and postmortem data. Daily vaginal smear observations provided useful information on luteal toxicity. In histopathological examinations, not only the ovaries and CL but also other related tissues and organs including the uterus, vagina, mammary gland, and adrenal glands, must be carefully examined for exploring luteal changes. In this review, histological and functional characteristics of CL in rats are summarized, and representative luteal toxicity changes are presented for improved luteal toxicity evaluation in preclinical toxicity research.     

Isolation of an algal morphogenesis inducer from a marine bacterium

Ulva and Enteromorpha are cosmopolitan and familiar marine algal genera. It is well known that these green macroalgae lose their natural morphology during short-term cultivation under aseptic conditions and during long-term cultivation in nutrient-added seawater and adopt an unusual form instead. These phenomena led to the belief that undefined morphogenetic factors that were indispensable to the foliaceous morphology of macroalgae exist throughout the oceans. We characterize a causative factor, named thallusin, isolated from an epiphytic marine bacterium. Thallusin induces normal germination and morphogenesis of green macroalgae.     

Extensive Screening for Plant Foodstuffs in Okinawa,Japan with Anti-Obese Activity on Adipocytes <Emphasis Type="Italic">In Vitro</Emphasis>

To search for plant foodstuffs with potent anti-obese activity, we conducted a large scale screening based on the inhibitory activity on adipogenesis and the facilitating activity on adipolysis in vitro. That is, inhibition of intracellular lipid accumulation and facilitation of lipid degradation in 3T3-L1 adipocytes were extensively screened from ethanol and hexane extracts of approximately 100 kinds of plant foodstuffs marketed in Okinawa prefecture, which has been famous for the highest prevalence of exceptionally long-lived individuals in the world. Among them thirty one foodstuffs showed potent inhibitory activity on intracellular lipid accumulation in 3T3-L1 adipocytes, whereas only four foodstuffs showed clear facilitating effect on lipid degradation in 3T3-L1 adipocytes. Although further study to examine the in vivo effects on adipogenesis and adipolysis is required, this is the first study to investigate anti-obese characteristics of wide range of traditional Okinawa foodstuffs so that the results give useful information to take another look at Okinawa food culture.     

Actin polymerization-driven molecular movement of mDia1 in living cells

mDia1, a Rho effector, belongs to the Formin family of proteins, which shares the conserved tandem FH1-FH2 unit structure. Formins including mDia1 accelerate actin nucleation while interacting with actin filament fast-growing ends. Here our single-molecule imaging revealed fast directional movement of mDia1 FH1-FH2 for tens of microns in living cells. The movement of mDia1 FH1-FH2 was blocked by actin-perturbing drugs, and the speed of mDia1 FH1-FH2 movement appeared to correlate with actin elongation rates. In vitro, mDia1 FH1-FH2 associated persistently with the growing actin barbed end. mDia1 probably moves processively along the growing end of actin filaments in cells, and Formins may be a molecular motility machinery that is independent from motor proteins.     

Assisted hatching of poor-quality bovine embryos increases pregnancy success rate after embryo transfer

Embryos of good, fair and poor quality were collected from superovulated cows and subjected to zona cutting (ZC) treatment using a needle under either an inverted microscope or a stereomicroscope. One (single transfer) or 2 (twin transfer) embryos with or without prior ZC treatment were transferred nonsurgically to recipients. Without the ZC treatment, lower embryonic quality resulted in lower pregnancy success rates. However, the ZC treatment increased the pregnancy success rate following transfer of poor-quality embryos, but not the pregnancy rate after transfer of good- or fair-quality embryos. No differences were observed between the pregnancy success rates after the transfer of embryos treated under the inverted microscope and those after transfer of embryos treated under the stereomicroscope, and this was the same after single and twin transfer. Moreover, ZC treatment of embryos prior to transfer did not result in an increased abortion rate, irrespective of the number of transferred embryos. In conclusion, ZC treatment improves pregnancy success rates following transfer of poor-quality embryos. Moreover, the results indicate that ZC treatment by using a stereomicroscope is practical for on-farm application.     

Examination of milk microbiota,fecal microbiota,and blood metabolites of Jersey cows in cool and hot seasons

Microbiota of individual cow milk, bulk tank milk, and feces of Jersey cows were examined. Samples were collected from two farms (F1 and F2) in cool (November, Nov) and hot (July, Jul) seasons. Milk yield and milk composition were similar between the two farms and between the two seasons. Prevalent taxa of the fecal microbiota, i.e. Ruminococcaceae, Bacteroidaceae, Lachnospiraceae, Rikenellaceae, and Clostridiaceae, were unaffected by the farm and season. Relative abundance of milk microbiota for Pseudomonadaceae, Enterobacteriaceae, and Streptococcaceae (F1 > F2) and Lactobacillaceae, Bifidobacteriaceae, and Cellulomonadaceae (F1 < F2) were different between the two farms, and those for Staphylococcaceae, Bacillaceae, Ruminococcaceae, and Veillonellaceae (Nov < Jul) and Methylobacteriaceae and Moraxellaceae (Nov > Jul) were different between the two seasons. The microbiota of bulk tank milk was numerically different from that of individual cow milk. Principal coordinate analysis indicated that the milk microbiota was unrelated to the fecal microbiota. The finding that relative abundance of Pseudomonadaceae and Moraxellaceae appeared greater than those reported for Holstein milk suggested that higher protein and fat content may result in a greater abundance of proteolytic and lipolytic taxa in Jersey cow milk.