Potential predictive biomarkers of obesity in Burmese cats     

Peter Lee  Akihiro Mori  Marcia Coradini  Nobuko Mori  Fumi Sagara  Ichiro Yamamoto  Jacquie S. Rand  Toshiro Arai 《Veterinary journal (London, England : 1997)》2013,195(2):221-227

Australian Burmese cats are predisposed to diabetes mellitus and, compared to other breeds, have delayed triglyceride clearance that may result in subtle changes within cells and tissues that trigger specific alterations in gene expression within peripheral blood leucocytes (PBLs). Expression of genes involved in energy metabolism (glucose-6-phosphate dehydrogenase and malate dehydrogenase), lipogenesis (ATP citrate lyase [ACL], fatty acid synthase [FAS] and sterol regulatory binding protein-1c [SREBP-1c]), and insulin signalling (insulin receptor substrates 1 and 2, and phosphatidylinositol-3 kinase), as well as cholesterol lipoprotein subfraction profiling were carried out on PBLs from lean Burmese cats and compared with similar profiles of age and gender matched lean and obese Australian domestic shorthaired cats (DSHs) in an attempt to identify possible biomarkers for assessing obesity.For the majority of the genes examined, the lean Burmese cats demonstrated similar PBL gene expression patterns as age and gender matched obese Australian DSH cats. Lean Burmese had increased expression of ACL and FAS, but not SREBP-1c, a main upstream regulator of lipid synthesis, suggesting possible aberrations in lipogenesis. Moreover, lean Burmese displayed a 3- to 4-fold increase in the very low density cholesterol fraction percentage, which was double that for obese DSH cats, indicating an increased degree of lipid dysregulation especially in relation to triglycerides. The findings suggest that Burmese cats may have a particular propensity for dysregulation in lipid metabolism.  相似文献   

Silicon budget of eutrophic Lake Kasumigaura, Japan     

Hiroyuki Arai  Takehiko Fukushima 《Journal of Soils and Sediments》2012,12(10):1501-1507

Purpose

Determining the dynamics of silicon in lakes, one of the essential nutrients for diatoms, is valuable for understanding aquatic environmental problems. The dissolved silicon (DSi) and biogenic silicon (BSi) budgets in Lake Kasumigaura, a shallow eutrophic lake in Japan, during the last three decades were assessed based on the analysis of dated sediment cores and a water quality database.

Materials and methods

Sediment cores (100?cm long) were taken at the center of Lake Kasumigaura in 2005, 2007, and 2009 and at two other sites in 2007. BSi contents of the dated sediments were determined by wet alkaline digestion. The net sedimentation rates of BSi were defined as the difference between the DSi load from inflowing rivers and the DSi and BSi loads from the outflow of the lake, calculated using DSi concentrations and diatom abundances in the lake from 1980 to 2007 and DSi concentrations of the inflowing rivers during 1994, 2007, and 2009. The gross sedimentation rates of BSi were estimated by multiplying BSi concentrations in lake water by the diatom sinking rate reported by previous studies.

Results and discussion

Budgetary calculations based on the database showed that 60?C70?% of DSi inputs from the inflowing rivers during the 27?years could ultimately be accumulated as diatom frustules in bottom sediments in the lake. The sediment analysis revealed that the amount of BSi accumulated in the lake from 1980 to 2007 was 2.0?C2.6?×?10¹¹?g, similar to the amount based on the database of 1.3?C2.4?×?10¹¹?g. Although the gross sedimentation rates of BSi likely increased, the net sedimentation rates of BSi decreased significantly from 6?C10?×?10⁹?g?year^?1 in the 1980s to 2?C6?×?10⁹?g?year^?1 in the 2000s, suggesting a fast recycling of BSi in recent years caused by an increase in sediment resuspension and regeneration.

Conclusions

The sediment core information and the water quality database can be used for calculating the long-term silicon budgets in Lake Kasumigaura. An increase in the DSi release rates was identified, which is consistent with recent sediment resuspension. Comparing the sediment core information with the database suggests the long-term dissolution of sediment BSi; however, analysis of the BSi content in sediment cores representing a much longer time period is needed to confirm this.  相似文献   

Genetic characterization of the progeny of a pair of the tetraploid silver crucian carp Carassius auratus langsdorfii     

Jie Dong  Masaru Murakami  Takafumi Fujimoto  Etsuro Yamaha  Katsutoshi Arai 《Fisheries Science》2013,79(6):935-941

Silver crucian carp Carassius auratus langsdorfii comprises a diploid-polyploid complex in wild Japanese populations. Bisexually reproducing diploids are sympatrically distributed with gynogenetically developing triploids and tetraploids. Triploid and tetraploid males are very rare among Japanese silver crucian carp due to their gynogenetic reproduction. We examined the genetic characteristics of progeny that arose in a tank by natural spawning of a tetraploid silver crucian carp pair. The ploidy status of 120 samples randomly collected from these progeny was determined to be tetraploid by DNA content flow cytometry. DNA fingerprints from a random amplified polymorphic DNA assay indicated that almost all the progeny examined had genotypes identical to the maternal tetraploid female with no paternally derived fragments. Selected specimens’ cytogenetic analyses revealed that the progeny examined had tetraploid chromosome numbers, categorized into 40 metacentric, 80 submetacentric, and 80 subtelocentric or telocentric chromosomes, which were arranged into quartets and six supernumerary microchromosomes. Fluorescence in situ hybridization signals were detected in four homologous chromosomes in all analyzed metaphases prepared from diploid goldfish specimens. Contrary, tetraploid silver crucian carp gave eight rDNA signals. These results suggest that gynogenetic development in eggs spawned by tetraploid females should be triggered by tetraploid males’ homospecific sperm.  相似文献   

Heavy Metals in a Tropical Eel Anguilla marmorata from The Central Part of Vietnam     

Quang Dung Le  Kotaro Shirai  Duc Cu Nguyen  Nobuyuki Miyazaki  Takaomi Arai 《Water, air, and soil pollution》2009,204(1-4):69-78

In order to understand the present status of heavy metal contamination and the risk associated with human consumption, commercial freshwater eels in Vietnam were examined. The concentration of eight elements (Cr, Mn, Co, Cu, Zn, Sr, Cd, and Pb) was determined in muscle tissue of tropical eel Anguilla marmorata collected in four provinces, Quang Tri, Quang Ngai, Binh Dinh, and Phu Yen, from the central part of Vietnam. Concentrations of Cu, Zn, Cd, and Sr were found to be highest, whereas Co concentration showed the lowest at Quang Tri. Cr was recorded to be lowest in Quang Ngai, while the amounts of Mn and Pb did not vary among locations. Although the metal concentrations in the muscle of A. marmorata did not represent a risk for human consumption, elevated Cd concentrations in Quang Tri related to agriculture activities suggest that further investigations should be undertaken to clarify the potential risk to the eel population.  相似文献   

cDNA cloning and mRNA expression of canine pancreatic and duodenum homeobox 1 (Pdx-1)     

Takemitsu H  Yamamoto I  Lee P  Ohta T  Mori N  Arai T 《Research in veterinary science》2012,93(2):770-775

  相似文献   

A simple and rapid immunocytochemical technique for detection of cytokeratin, vimentin, and S-100 protein in veterinary diagnostic cytology     

Sawa M  Yabuki A  Miyoshi N  Arai K  Yamato O 《Research in veterinary science》2012,93(3):1341-1345

The objective of this study was to establish a simple and rapid immunocytochemical technique that can be used in veterinary diagnostic cytology. Air-dried impression smears were collected from canine tumors. Samples of epithelial tumors, mesenchymal tumors, and malignant peripheral nerve sheath tumors and melanomas were used for detection of cytokeratin, vimentin, and S-100 protein, respectively. The labeled streptavidin-biotin system was used in the present study. Optimal fixation was determined using standard immunocytochemical procedures, and acetone fixation was found to be the most effective. Optimal concentrations of primary and secondary antibodies were determined at a preset 5-min incubation. Omission of H(2)O(2) treatment, shortening the time for blocking and labeled-streptavidin incubation, and simplifying washing did not decrease immunopositive intensities or enhance false-positive reactions. The described rapid protocol requires approximately 45min without the use of any special equipment.  相似文献   

Long term intensive exercise training leads to a higher plasma malate/lactate dehydrogenase (M/L) ratio and increased level of lipid mobilization in horses     

Li G  Lee P  Mori N  Yamamoto I  Arai T 《Veterinary research communications》2012,36(2):149-155

Continuous high intensity training may induce alterations to enzyme activities related to glucose and lipid metabolism in horses. In our study, five Thoroughbred race horses (3 male and 2 female, avg age=5 yrs old) were compared against five riding horses (1 male, 1 female, 3 gelding, avg age=13 yrs old) in terms of energy metabolism, by examining plasma malate (MDH) and lactate (LDH) dehydrogenase activities and M/L ratio. MDH is involved in NADH and ATP generation, whereas LDH can convert NADH back into NAD(+) for ATP generation. An increase in plasma M/L ratio can reflect heightened energy metabolism in the liver and skeletal muscle of horses adapted to continuous intensive exercise. Moreover, plasma lipid metabolism analytes (adiponectin, NEFA, total cholesterol (T-Cho), and triglycerides (TG)) can reflect changes to lipolysis rate, which can also indicate a change in energy metabolism. Overall, race horses demonstrated increased MDH and LDH activity in plasma (4x and 2x greater, respectively), in addition to a plasma M/L ratio twice as high as that of riding horses (2.0 vs 1.0). In addition, race horses also demonstrated significantly higher levels of plasma NEFA (50% greater), TG (2x greater), and T-Cho (20% greater) as compared to riding horses. Therefore, race horse muscles may have adapted to prolonged high intensity endurance exercise by gaining a higher oxidative capacity and an increased capacity for fat utilization as an energy source, resulting in heightened energy metabolism and increased rate of lipid mobilization.  相似文献   

Biomass allocation and nitrogen limitation in a Cryptomeria japonica plantation chronosequence     

Ryunosuke Tateno  Keitaro Fukushima  Reiji Fujimaki  Tetsuya Shimamura  Masami Ohgi  Hirotsugu Arai  Nobuhito Ohte  Naoko Tokuchi  Takahito Yoshioka 《Journal of Forest Research》2009,14(5):276-285

We investigated soil net nitrogen mineralization rate, above- and belowground biomass allocation, and nitrogen use in a Cryptomeria japonica plantation chronosequence. Total biomass accumulation showed an asymptotic accretion pattern, and the peak total biomass accumulation rate occurred approximately 30 years after afforestation. Soil net nitrogen mineralization rate was lowest 30 years after afforestation. Between years 30 and 88, net nitrogen mineralization increased again. These results indicate that an imbalance in soil nitrogen supply and plant nitrogen demand occurred approximately 30 years after afforestation. Furthermore, leaf nitrogen concentration, which was used as an index of plant nitrogen status, was lower in mature forest than in young forest, suggesting that mature stands did not take up nitrogen as successfully. If soil resources such as nitrogen limit plant growth, plants may increase biomass allocation to fine root structure; however, fine root biomass was not higher in 30- and 88-year-old stands than in younger stands, suggesting that changes in biomass allocation may not be effective against nitrogen deficiency in a C. japonica plantation chronosequence.  相似文献   

Supplementing transglucosidase with a high-fiber diet for prevention of postprandial hyperglycemia in streptozotocin-induced diabetic dogs     

Toshinori Sako  Akihiro Mori  Peter Lee  Hiroshi Goto  Hiroko Fukuta  Hitomi Oda  Kaori Saeki  Yohei Miki  Yuki Makino  Katsumi Ishioka  Hisashi Mizutani  Yuzo Kojima  Satoshi Koikeda  Toshiro Arai 《Veterinary research communications》2010,34(2):161-172

Indigestible oligosaccharides have been shown to normalize blood glucose and insulin concentration thereby promoting good health and preventing diseases, such as diabetes. Transglucosidase (TG, α-glucosidase, enzyme code (EC) 3.2.1.20) is an enzyme capable of converting starch to oligosaccharides, such as iso-malto-oligosaccharides from maltose, via the action of amylase. The aim of this study was to evaluate whether oral administration of TG with maltose or dextrin is capable of reducing post-prandial serum glucose concentration in experimentally streptozotocin (STZ)-induced diabetic dogs fed on a high-fiber diet. Five healthy and five STZ-induced diabetic dogs were employed in this study. TG supplementation with dextrin or maltose had no detrimental effect in healthy dogs. In fact, TG and dextrin exhibited a flatlined serum glucose pattern, while reducing mean post-prandial serum insulin and glucose concentration as compared to control diet alone. When TG supplementation was tested in STZ-induced diabetic dogs under the context of a high fiber diet, a 13.8% and 23.9% reduction in mean glucose concentration for TG with maltose and dextrin, respectively was observed. Moreover, TG with dextrin resulted in a 13% lower mean post-prandial glucose concentration than TG with maltose, suggesting that dextrin may be a more efficient substrate than maltose when used at the same concentration (1 g/kg). Our results indicate that TG supplementation with diet can lead to lower postprandial glucose levels versus diet alone. However, the efficacy of TG supplementation may depend on the type of diet it is supplemented with. As such, TG administration may be useful for preventing the progression of diabetes mellitus and in its management in dogs.  相似文献   

Effect of salinity on strontium:calcium ratios in the otoliths of Sakhalin taimen, <Emphasis Type="Italic">Hucho perryi</Emphasis>     

Takaomi Arai 《Fisheries Science》2010,76(3):451-455

In order to determine the salinity effect on otolith strontium (Sr):calcium (Ca) ratios, the Sr and Ca contents of otoliths of Sakhalin taimen, Hucho perryi, reared for 60 days in four salinities (freshwater, one-third seawater, two-thirds seawater, and full seawater) were examined. The Ca and Sr contents and the resultant Sr:Ca ratios in the rearing water increased linearly with salinity. Otolith Sr:Ca ratios were also found to be positively correlated with salinity. However, the Sr:Ca did not correspond to temperature fluctuations during the experiment. These results indicate that Sr:Ca ratios in otoliths can be used to reconstruct the migratory history of the fish by differentiating when the fish migrated between freshwater and seawater.  相似文献