不同温度下充氧包装的活品海湾扇贝品质变化     

潘澜澜  蒋洁兰  张宁  黄代钰  高晓晴  刘豪  张国琛 《水产科学》2019,(2):182-187

为延长海湾扇贝贮运过程中的存活期并保证其品质,将海湾扇贝平铺放入HDPE材质的包装袋(32 cm×25 cm),并充入体积分数为99.9%的氧气,密封后将充氧包装的海湾扇贝分别置于0、5、10、15℃4个不同温度下,探讨不同温度对其品质的影响。试验结果显示,密封充氧包装的海湾扇贝较低温条件下的存活率、感官评价分值和糖原明显高于同一时间的较高温条件,同时较高温条件下质量损失率、色度差、细菌总数上升速度均高于较低温条件。其中,0℃条件下无水保活效果最好,11 d出现死亡,15 d全部死亡。首次出现死亡时间比5、10、15℃组分别延长5、7、9 d;全部死亡时间比5、10、15℃组分别延长4、5、9 d。0℃条件下,其感官评价分值在0～4 d内接近满分,颜色变化最小,其色度差为3.98。综合各项指标变化,0℃条件下有利于延长充氧包装内海湾扇贝的保活时间,有效保持海湾扇贝活品品质。研究结果为活品海湾扇贝密封充氧保活保鲜技术提供数据参考。  相似文献   

Mouse in vivo-derived late 2-cell embryos have higher developmental competence after high osmolality vitrification and −80°C preservation than IVF or ICSI embryos     

Erika HAYASHI  Sayaka WAKAYAMA  Daiyu ITO  Ayumi HASEGAWA  Keiji MOCHIDA  Masatoshi OOGA  Atsuo OGURA  Teruhiko WAKAYAMA 《The Journal of reproduction and development》2022,68(2):118

Mammalian embryos are most commonly cryopreserved in liquid nitrogen; however, liquid nitrogen is not available in special environments, such as the International Space Station (ISS), and vitrified embryos must be stored at −80°C. Recently, the high osmolarity vitrification (HOV) method was developed to cryopreserve mouse 2-cell stage embryos at −80°C; however, the appropriate embryo is currently unknown. In this study, we compared the vitrification resistance of in vivo-derived, in vitro fertilization (IVF)-derived, and intracytoplasmic sperm injection (ICSI)-derived mouse 2-cell embryos against cryopreservation at −80°C. The ICSI embryos had lower survival rates after warming and significantly lower developmental rates than the in vivo and IVF embryos. Further, IVF embryos had a lower survival rate after warming, but a similar rate to the in vivo embryos to full-term development. This result was confirmed by simultaneous vitrification of in vivo and IVF embryos in the same cryotube using identifiable green fluorescent protein-expressing embryos. We also evaluated the collection timing of the in vivo embryos from the oviduct and found that late 2-cell embryos had higher survival and developmental rates to full-term than early 2-cell embryos. Some early 2-cell embryos remained in the S-phase, whereas most late 2-cell embryos were in the G2-phase, which may have affected the tolerance to embryo vitrification. In conclusion, when embryos must be cryopreserved under restricted conditions, such as the ISS, in vivo fertilized embryos collected at the late 2-cell stage without long culture should be employed.  相似文献   

Seroprevalence of antibodies against severe acute respiratory coronavirus 2 (SARS-CoV-2) in household dogs in Japan     

Genta ITO  Yuko GOTO-KOSHINO  Yudai KURODA  Park EUNSIL  Ken MAEDA  Takehisa SOMA  Yasuyuki MOMOI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(11):1722

We investigated the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among dogs in the Tokyo area via enzyme-linked immunosorbent assay (ELISA) using the spike protein as the target antigen. Plasma samples from 494 household dogs and blood-donor dogs were tested from July 2020 to January 2021. Of these samples, three showed optical densities that were higher than the mean plus two standard deviations of the mean of the negative-control optical densities (ODs). Of these three samples, only the sample with the highest OD by ELISA was confirmed positive by virus neutralization testing. The positive dog presented no SARS-CoV-2-related symptoms. The positivity rate of SARS-CoV-2 infections among dogs in the Tokyo area was approximately 0.2%.  相似文献   

Dynamics of invasion and dissemination of H5N6 highly pathogenic avian influenza viruses in 2016–2017 winter in Japan     

Kosuke SODA  Hiroichi OZAKI  Hiroshi ITO  Tatsufumi USUI  Masatoshi OKAMATSU  Keita MATSUNO  Yoshihiro SAKODA  Tsuyoshi YAMAGUCHI  Toshihiro ITO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(12):1891

Large highly pathogenic avian influenza (HPAI) outbreaks caused by clade 2.3.4.4e H5N6 viruses occurred in Japan during the 2016–2017 winter. To date, several reports regarding these outbreaks have been published, however a comprehensive study including geographical and time course validations has not been performed. Herein, 58 Japanese HPAI virus (HPAIV) isolates from the 2016–2017 season were added for phylogenetic analyses and the antigenic relationships among the causal viruses were elucidated. The locations where HPAIVs were found in the early phase of the outbreaks were clustered into three regions. Genotypes C1, C5, and C6–8 HPAIVs were found in specific areas. Two strains had phylogenetically distinct hemagglutinin (HA) and non-structural (NS) genes from other previously identified strains, respectively. The estimated latest divergence date between the viral genotypes suggests that genetic reassortment occurred in bird populations before their winter migration to Japan. Antigenic differences in 2016–2017 HPAIVs were not observed, suggesting that antibody pressure in the birds did not contribute to the selection of HPAIV genotypes. In the late phase, the majority of HPAI cases in wild birds occurred south of the lake freezing line. At the end of the outbreak, HPAI re-occurred in East coast region, which may be due to the spring migration route of Anas bird species. These trends were similar to those observed in the 2010–2011 outbreaks, suggesting there is a typical pattern of seeding and dissemination of HPAIV in Japan.  相似文献   

Expression and regulation of estrogen receptor 2 and its coregulators in mouse granulosa cells     

Chihiro EMORI  Takuya KANKE  Haruka ITO  Yuki AKIMOTO  Wataru FUJII  Kunihiko NAITO  Koji SUGIURA 《The Journal of reproduction and development》2022,68(2):137

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Regression of viral pathogen indicators due to improvement of hygiene protocols on boots in a bovine farm     

Satoru TAKAHASHI  Md. Amirul HASAN  Mariko ITO  Miyuki KOMURA  Chisato DAIO  Mizuki ONO  Makiko YAMAGUCHI  Md. Shahin ALAM  Md. Humayun KABIR  Yu MIYAOKA  Dany SHOHAM  Kazuaki TAKEHARA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2020,82(12):1793

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Characterization of novel avian paramyxovirus strain APMV/Shimane67 isolated from migratory wild geese in Japan     

Eiji YAMAMOTO  Hiroshi ITO  Yukiko TOMIOKA  Toshihiro ITO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(9):1079-1085

An avian paramyxovirus (APMV) isolated from goose feces (APMV/Shimane67) was biologically, serologically and genetically characterized. APMV/Shimane67 showed typical paramyxovirus morphology on electron microscopy. On hemagglutination inhibition test, antiserum against APMV/Shimane67 revealed low reactivity with other APMV serotypes and vice versa. The fusion (F) protein gene of APMV/Shimane67 contained 1,638 nucleotides in a single open reading frame encoding a protein of 545 amino acids. The cleavage site of F protein contained a pair of single basic amino acid (VRENR/L). The nucleotide and deduced amino acid sequences of the F gene of APMV/Shimane67 had relatively low identities (42.9–62.7% and 28.9–67.3%, respectively) with those of other APMVs. Phylogenetic analysis showed that APMV/Shimane67 was related to NDV, APMV-9 and APMV-12, but was distinct from those APMV serotypes. These results suggest that APMV/Shimane67 is a new APMV serotype, APMV-13.  相似文献   

Ultrastructural study on the morphological changes in indigenous bacteria of mucous layer and chyme throughout the rat intestine     

Youhei MANTANI  Eri ITO  Miho NISHIDA  Hideto YUASA  Natsumi MASUDA  Wang-Mei QI  Junichi KAWANO  Toshifumi YOKOYAMA  Nobuhiko HOSHI  Hiroshi KITAGAWA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(9):1121-1128

Indigenous bacteria in the alimentary tract are exposed to various bactericidal peptides and digestive enzymes, but the viability status and morphological changes of indigenous bacteria are unclear. Therefore, the present study aimed to ultrastructurally clarify the degeneration and viability status of indigenous bacteria in the rat intestine. The majority of indigenous bacteria in the ileal mucous layer possessed intact cytoplasm, but the cytoplasm of a few bacteria contained vacuoles. The vacuoles were more frequently found in bacteria of ileal chyme than in those of ileal mucous layer and were found in a large majority of bacteria in both the mucous layer and chyme throughout the large intestine. In the dividing bacteria of the mucous layer and chyme throughout the intestine, the ratio of area occupied by vacuoles was almost always less than 10%. Lysis or detachment of the cell wall in the indigenous bacteria was more frequently found in the large intestine than in the ileum, whereas bacterial remnants, such as cell walls, were distributed almost evenly throughout the intestine. In an experimental control of long-time-cultured Staphylococcus epidermidis on agar, similar vacuoles were also found, but cell-wall degeneration was never observed. From these findings, indigenous bacteria in the mucous layer were ultrastructurally confirmed to be the source of indigenous bacteria in the chyme. Furthermore, the results suggested that indigenous bacteria were more severely degenerated toward the large intestine and were probably degraded in the intestine.  相似文献   

Improved rapid and efficient method for Staphylococcus aureus DNA extraction from milk for identification of mastitis pathogens     

Hirotaka UNNO  Mika INADA  Akiyoshi NAKAMURA  Michie HASHIMOTO  Keiko ITO  Koji HASHIMOTO  Masaru NIKAIDO  Tomohito HAYASHI  Eiji HATA  Ken KATSUDA  Yoshio KIKU  Yuichi TAGAWA  Kazuhiro KAWAI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(8):1007-1009

A rapid and efficient DNA extraction method was developed for detecting mastitis pathogens in milk. The first critical step involved cell wall disruption by bead-beating, as physical disruption using beads was more effective for DNA extraction from Gram-positive bacteria, such as Staphylococcus aureus, than enzymatic disruption using proteinase K. The second critical step involves the use of acetic acid and ammonium sulfate in the purification process, as these reagents effectively and efficiently remove the lipids and proteins in milk. Using these methods, DNA suitable for loop-mediated isothermal amplification was obtained within 30 min. Also, the rapid and sensitive detection of S. aureus in milk was possible at levels as low as 200 cfu/ml.  相似文献   

Effect of sevoflurane concentration on visual evoked potentials with pattern stimulation in dogs     

Yosuke ITO  Seiya MAEHARA  Yoshiki ITOH  Miri HAYASHI  Akira KUBO  Takaharu ITAMI  Tomohito ISHIZUKA  Jun TAMURA  Kazuto YAMASHITA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(2):155-160

The purpose of this study was to investigate the effects of sevoflurane concentration on canine visual evoked potentials with pattern stimulation (P-VEPs). Six clinically normal laboratory-beagle dogs were used. The minimum alveolar concentration (MAC) of sevoflurane was detected from all subjects by tail clamp method. The refractive power of the right eyes of all subjects was corrected to −2 diopters after skiascopy. For P-VEP recording, the recording and reference electrode were positioned at inion and nasion, respectively, and the earth electrode was positioned on the inner surface. To grasp the state of CNS suppression objectively, the bispectral index (BIS) value was used. The stimulus pattern size and distance for VEP recording were constant, 50.3 arc-min and 50 cm, respectively. P-VEPs and BIS values were recorded under sevoflurane in oxygen inhalational anesthesia at 0.5, 1.0, 1.5, 2.0, 2.5 and 2.75 sevoflurane MAC. For analysis of P-VEP, the P100 implicit time and N75-P100 amplitude were estimated. P-VEPs were detected at 0.5 to 1.5 MAC in all dogs, and disappeared at 2.0 MAC in four dogs and at 2.5 and 2.75 MAC in one dog each. The BIS value decreased with increasing sevoflurane MAC, and burst suppression began to appear from 1.5 MAC. There was no significant change in P100 implicit time and N75-P100 amplitude with any concentration of sevoflurane. At concentrations around 1.5 MAC, which are used routinely to immobilize dogs, sevoflurane showed no effect on P-VEP.  相似文献