Roles of raccoons in the transmission cycle of severe fever with thrombocytopenia syndrome virus

The present study investigated severe fever with thrombocytopenia syndrome virus (SFTSV) infection in raccoons in Wakayama Prefecture from 2007 to 2019. To perform surveillance, an enzyme-linked immunosorbent assay (ELISA) was established, and the sensitivity and specificity of the ELISA were 100% in comparison with a 50% focus-reduction neutralization assay. Using the established ELISA, we performed serosurveillance of SFTSV infection in 2,299 raccoons in Tanabe region, Wakayama Prefecture from 2007 to 2019. The first anti-SFTSV-positive raccoon was captured in October 2009. The seroprevalence of SFTSV infection was <10% between April 2009 and March 2013, 23.9% between April 2013 and March 2014, 37.5% between April, 2014 and March 2015, and over 50% from April 2015. Next, we performed detection of SFTSV genes in sera of raccoons captured in Wakayama Prefecture after April 2013. The results indicated that 2.4% of raccoons were positive for SFTSV genes and that the frequency of SFTSV infection among raccoons between January and March (0.7%) was lower than that between April and June (3.4%). In addition, virus genes were detected from many specimens, including sera and feces of two raccoons, and viral antigens were detected in lymphoid cells in lymphoid follicles in the colon by immunohistochemical staining. In conclusion, SFTSV had recently invaded the area and had rapidly spread among wild animals. The first patient in this area was reported in June 2014, indicating that raccoons are good sentinels for assessing the risk of SFTSV in humans.     

Effect of dietary protein quantity and quality on the brain protein synthesis rate in ovariectomized female rats

The purpose of this study was to determine whether the quantity and quality of dietary protein affected the rate of brain protein synthesis in ovariectomized female rats. Two experiments were conducted on the ovariectomized female rats (12 weeks old) given diets containing 20%, 5%, or 0% casein (experiment 1) and 20% casein, 20% soy protein, 20% gluten, or 20% gelatin (experiment 2) for 10 d, respectively. The fractional rates of protein synthesis in the brain declined with a decrease of the quantity and quality of dietary protein. In the brain, the RNA activity [g of protein synthesized/((g of RNA) d)] was significantly correlated with the fractional rate of protein synthesis. The RNA concentration (mg of RNA/g of protein) was not related to the fractional rate of protein synthesis in any organ. The results suggest that the rate of protein synthesis in the brain declines with the decrease of the quantity and quality of dietary protein in ovariectomized female rats, and that RNA activity is at least partly related to the fractional rate of brain protein synthesis.     

Comparison of the functions of the barley nicotianamine synthase gene HvNAS1 and rice nicotianamine synthase gene OsNAS1 promoters in response to iron deficiency in transgenic tobacco

Barley ( Hordeum vulgare L.) nicotianamine synthase gene ( HvNAS1 ) expression in barley is strongly induced by Fe deficiency in the roots and rice ( Oryza sativa L.) nicotianamine synthase gene ( OsNAS1 ) expression in rice is induced by Fe deficiency both in the roots and in the shoots. In dicots, NAS genes are not strongly induced by Fe deficiency, and they function to maintain Fe homeostasis. Rice OsNAS1promoter::GUS or barley HvNAS1promoter::GUS was introduced into tobacco ( Nicotiana tabacum L.) and tissue specificities and systemic regulation of their expression were compared. A split-root experiment revealed that the HvNAS1 promoter exhibited functions similar to those of Fe-acquisition-related genes in tobacco roots, suggesting that this promoter responded to certain Fe-deficiency systemic signals and to the Fe concentration in the rhizosphere. The HvNAS1 promoter might harbor a type of universal system of gene expression for Fe acquisition. However, the OsNAS1 promoter did not respond to local application of Fe to the roots and induced GUS activities in mature leaves in response to Fe deficiency. This promoter might possess numerous types of cis -acting sequences that are involved in Fe metabolism.     

Commensal bacteria coated by secretory immunoglobulin A and immunoglobulin G in the gastrointestinal tract of pigs and calves

A large amount of secretory immunoglobulin A (S‐IgA) is secreted in the alimentary tract of mammals. It has been reported that S‐IgA coats a portion of commensal intestinal bacteria in human and mouse. However, S‐IgA‐coated bacteria have not been studied in pigs and calves. In this study, we evaluated the distribution of S‐IgA‐coated commensal intestinal bacteria in each portion of the gastrointestinal tracts of pigs and calves. Immunoglobulin G (IgG)‐coated bacteria were also analyzed because a considerable amount of IgG is secreted in the gastrointestinal tracts of pigs, and in particular, calves. S‐IgA‐ or IgG‐coated bacteria were detected in all the segments of the gastrointestinal tracts of pigs and calves. The proportion of S‐IgA‐coated bacteria to total bacteria (i.e. S‐IgA coating ratio) varied in the segments of the gastrointestinal tract in pigs, whereas those of calves were nearly the same throughout the gastrointestinal tract. The S‐IgA and IgG coating ratios were higher in pigs than in calves for all segments of the gastrointestinal tract.     

Effect of different methods for conserving rice grain on in situ ruminal degradation and in vivo nutrient digestion and rumen fermentation in steers

We investigated the effects of different rice conservation techniques on in situ ruminal degradation and in vivo nutrient digestibility and rumen fermentation in steers. Raw rice grain was dried before crushing (DRY), ensiled after crushing (ENS‐A), or ensiled before crushing (ENS‐B). Six ruminally cannulated steers were used in a replicated 3 × 3 Latin square design with three dietary treatments: diets containing DRY, ENS‐A, or ENS‐B at 36% of the dietary dry matter. The in situ rapidly degradable fraction and effective ruminal degradability were higher for ensiled rice than for DRY, and higher for ENS‐A than for ENS‐B. The ruminal pH was lower and the lactic acid and total volatile acid concentrations were higher for the steers fed ensiled rice than those fed the DRY diet, but a treatment effect was not observed in the comparison between ENS‐A and ENS‐B. The whole‐tract digestibility of crude protein and ether extract was improved when the rice grain was ensiled, but there were no differences in nutrient digestibility between ensiling methods. These results show that ensiling treatment can be a strategy to improve the nutrient value of rice grain, but the ensiling method has little impact on in vivo digestion.     

A case of nontraumatic gas gangrene in a common marmoset (Callithrix jacchus)

The common marmoset is widely used in neuroscience and regenerative medicine research. However, information concerning common marmoset disorders, particularly infectious diseases, is scarce. Here, we report a case of a female common marmoset that died suddenly due to gas gangrene. The animal presented with gaseous abdominal distention at postmortem, and Clostridium perfringens type A was isolated from several tissues. Vacuoles, a Gram-positive bacteremia and intravascular hemolysis were observed microscopically in the muscles, liver and lungs. On the basis of these findings, we diagnosed nontraumatic gas gangrene caused by Clostridium perfringens type A in this common marmoset.     

CR1aa-卵丘细胞共培养牛体外受精卵的卵裂率及囊胚率

牛卵母细胞用5％CS的TCM－199培养液体外成熟培养（IVM）22h；以BO液＋咖啡因作精子获能处理1.5h；BO液＋BSA的培养液体外受精（IVF）5h；受精卵（含卵丘细胞）用5％CS的CR1aa培养液在5％CO2、955空气、38.5℃、饱和湿度的培养环境中体外培养（IVC）7－8d，结果受精卵裂率为72.4%（56.3%－81.0%），囊胚率23.7%(12.5%-40.9%）。     

A cell preparation of Enterococcus faecalis strain EC-12 stimulates the luminal immunoglobulin A secretion in juvenile calves

The immune system in juvenile calves is immature, so calves are susceptible to several diarrheal and respiratory diseases. Oral administration of lactic acid bacteria (LAB) is known to improve the growth performance and prevent diarrheal and respiratory diseases by stimulating the immune system in juvenile calves. Most of the immunostimulation by LAB is achieved by their cell wall components, and therefore we evaluated the immunostimulation of the cell preparation of Enterococcus faecalis strain EC-12 (EC-12) in juvenile calves in a clinical field. Twenty-nine 1-week old calves were used. Fourteen calves were administered 0.2% (w/w) of an EC-12 preparation that supplemented a milk replacer, and other calves were not supplemented. Feces and serum was collected at day 0, 7 and 49 after the administration to measure the IgA and IgG concentration. The fecal IgA concentration was increased by EC-12 administration at day 49, and the serum IgA concentration was also increased at day 7. These results suggested that oral administration of EC-12 in juvenile calves might have an immunostimulatory effect and provide earlier recovery of IgA levels in mucosal immunity.