Reproductive biology of the cardinalfish Apogon lineatus in Tokyo Bay, Japan     

Gen Kume  Atsuko Yamaguchi  Ichiro Aoki and  Toru Taniuchi 《Fisheries Science》2000,66(5):947-954

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Factors that limit maintenance of recombinant rumen bacterium in sheep rumen     

Yasuo KOBAYASHI  Mayu YAMAMOTO 《Animal Science Journal》2002,73(2):131-136

Factors limiting the maintenance of recombinant ruminal bacterium in the rumen were evaluated in vitro , using batch culture prepared from rumen fluid of sheep. Butyrivibrio fibrisolvens expressing a foreign xylanase gene ( B. fibrisolvens NO4) was used as a tested recombinant that was selectable on an erythromycin-containing agar medium. The recombinant tended to reduce its level slowly in the rumen fluid of sheep on a high hay diet, while its initial decrease was more apparent in the rumen fluid of sheep on a high concentrate diet. Incubation with cell-free ruminal fluid revealed a significant decrease of inoculated recombinant, suggesting the presence of antibacterial factors limiting maintenance of the recombinant. In particular, during the first 12 h of incubation this inhibition was more notable in culture prepared from rumen fluid of sheep given the high concentrate diet. Autoclaving the cell-free rumen fluid inactivated the inhibition. Numbers of the recombinant for inoculation did not influence the final level of survived recombinant, that is, the initial depression was larger as more recombinant was inoculated. Subculturing with xylan before inoculation and/or direct addition of xylan to the batch culture did not improve survival of the recombinant. From these results it is suggested that the level of survived recombinant is limited to 10^2–4/mL of in vitro batch culture with restricted energy supply and that initial depression of the recombinant is mainly caused by the heat-sensitive antibacterial factors not associating with microbial cells in the rumen.  相似文献   

Dengue hemorrhagic fever with special emphasis on immunopathogenesis   总被引：3，自引：0，他引：3  

Kurane I 《Comparative immunology, microbiology and infectious diseases》2007,30(5-6):329-340

Dengue virus infections are a serious cause of morbidity and mortality in most tropical and subtropical areas of the world; Southeast and South Asia, Central and South America, and the Caribbean. Dengue virus infection can be asymptomatic or causes two forms of illness, dengue fever (DF) and dengue hemorrhagic fever (DHF), which is the severe form of dengue illness and often fatal. Pathogenesis of DHF has been analyzed, and two mechanisms are considered to be responsible. These include dengue serotype cross-reactive immune responses and virulence of the virus. The immunopathological mechanisms include a complex series of immune responses. Rapid increase in the levels of cytokines, especially TNF-, and chemical mediators play a key role in inducing unique clinical manifestations of DHF such as plasma leakage, shock, and hemorrhagic manifestations. It is understood that the process is initiated by infection with a virulent dengue virus, often in the presence of antibodies that enhance dengue virus infection in secondary infection, and then triggered by rapidly elevated cytokines and chemical mediators that were produced by intense immune activation. However, complete understanding of the entire pathological mechanism is far from complete, and further studies are still needed.  相似文献   

Validation of a food-frequency questionnaire for cohort studies in rural Japan     

Ogawa K  Tsubono Y  Nishino Y  Watanabe Y  Ohkubo T  Watanabe T  Nakatsuka H  Takahashi N  Kawamura M  Tsuji I  Hisamichi S 《Public health nutrition》2003,6(2):147-157

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Rearing technique for proturans (Hexapoda: Protura)     

Ryuichiro Machida  Ichiro Takahashi 《Pedobiologia》2004,48(3):227-229

A chamber for rearing proturans is described. The chamber is double-walled, and was used successfully to rear proturans for one generation.  相似文献   

Structure of the rotor of the V-Type Na+-ATPase from Enterococcus hirae     

Murata T  Yamato I  Kakinuma Y  Leslie AG  Walker JE 《Science (New York, N.Y.)》2005,308(5722):654-659

The membrane rotor ring from the vacuolar-type (V-type) sodium ion-pumping adenosine triphosphatase (Na+-ATPase) from Enterococcus hirae consists of 10 NtpK subunits, which are homologs of the 16-kilodalton and 8-kilodalton proteolipids found in other V-ATPases and in F1Fo- or F-ATPases, respectively. Each NtpK subunit has four transmembrane alpha helices, with a sodium ion bound between helices 2 and 4 at a site buried deeply in the membrane that includes the essential residue glutamate-139. This site is probably connected to the membrane surface by two half-channels in subunit NtpI, against which the ring rotates. Symmetry mismatch between the rotor and catalytic domains appears to be an intrinsic feature of both V- and F-ATPases.  相似文献   

Lipogenic gene expression in abdominal adipose and liver tissues of diet-induced overweight cats     

Lee P  Mori A  Takemitsu H  Yamamoto I  Arai T 《Veterinary journal (London, England : 1997)》2011,190(2):e150-e153

The effect of overweight status on the expression of SREBP-1c and downstream lipogenic genes, such as ATP citrate lyase (ACL) and fatty acid synthase (FAS), in abdominal adipose and liver tissues was determined in cats using a diet-induced weight gain model. ACL and SREBP-1c mRNA expression was significantly reduced (～65% and 20%, respectively) in liver tissue, whereas FAS and SREBP-1c expression was significantly increased (～80% and 45%, respectively) in abdominal omental adipose tissue of overweight animals as compared to healthy animals. Additionally, ACL, FAS, and SREBP-1c expression was significantly reduced by ～50%, 75%, and 70%, respectively, in abdominal subcutaneous adipose tissue of overweight animals. Omental adipose tissue appeared to foster, whereas subcutaneous adipose and liver tissues appeared to defer lipid storage based on differences in SREBP-1c mRNA expression. Overall, reduced lipogenic gene mRNA expression patterns support the hypothesis that SREBP-1c expression is reduced in overweight and possibly obese cats, reflecting down-regulation of the lipogenic pathway to prevent further fat accumulation and weight gain.  相似文献   

Soil properties and the macrofauna community in abandoned irrigated rice fields of northeastern Argentina     

Patricia J. Folgarait  Fabien Thomas  Thierry Desjardins  Michel Grimaldi  Ichiro Tayasu  Pierre Curmi  Patrick M. Lavelle 《Biology and Fertility of Soils》2003,38(6):349-357

This study compared soil physical, chemical, and biological characteristics between natural grassland and recently abandoned rice fields in order to identify those variables that might explain the observed increase of Camponotus punctulatus anthills in abandoned rice paddy fields from Northern Argentina. Mainly due to a reduction of macropores and mesopores, overall porosity decreased by around 6% and bulk density was about 7% greater, in the 0- to 10- and 10- to 20-cm layers of the abandoned rice fields. Carbon and nitrogen content from organic matter increased (29% and 41% respectively for the 0- to 20-cm horizon) during cultivation but decreased (38% and 24%) 2 years after the last rice harvest. Forty percent of natural grassland-organic matter and 30% of abandoned rice-organic matter mineralized in less than 2 years. There was a different community structure between the abandoned rice fields and the undisturbed natural grassland and only a 20.6% (i.e. only 19 species from a total of 92) overlap in species composition. The abundance of macrofauna was greater in abandoned rice fields (2,208 individuals m^–2) in comparison to natural grasslands (288 ind m^–2) due to higher densities of small earthworms and Camponotus punctulatus ants; however, the Shannon index showed lower values in comparison to natural grasslands. Earthworms and C. punctulatus in the abandoned rice fields showed a change in their ¹³C signature indicating a switch in diet from natural grassland organic matter (C4) to organic matter from rice (C3). Our results indicate that the effects of rice cultivation practices did not seem to produce any physical or trophic limitations to recolonization by the macrofauna. It seems that changes in overall soil conditions have favored a change in the construction behavior of C. punctulatus which, in combination with population increases, could explain the explosion in number of anthills.  相似文献   

Watercore in Japanese pear. III. Changes in the activities of some enzymes relating to the degradation of cell walls and the accumulation of sugar     

Shohei Yamaki  Ichiro Kajiura  Mitsuo Omura  Koyu Matsuda 《Scientia Horticulturae》1977,6(1):45-53

The relationship between cellular breakdown and the activities of some cell-wall degrading enzymes (endocellulase, exocellulase, polygalacturonase, pectin methylesterase and β-galactosidase) was investigated in the watercored tissue of Japanese pear fruit, Pyrus serotina Rehder var. ‘Culta’ Rehder, cultivar ‘93-3’. In watercored tissue at an early stage, endocellulase activity, especially neutral form, was higher than that in healthy tissue. As the symptom of the watercore developed, polygalacturonase and β-galactosidase activities in the watercored tissue increased compared with those in healthy tissue. This indicated that in tissues at an early stage of watercore, these cell-wall degrading enzymes were activated, and operative in the breakdown of the cell wall. However, exocellulase and pectin methylesterase were not activated in the watercored tissue. The breakdown of cellular tissue was also supported by the fact that the DNA and protein contents decreased in the watercored tissue. Invertase activity decreased in the watercored tissue, compared with healthy tissue, and it was suggested that its decrease could be one of the causes of sucrose accumulation in the watercored tissue.  相似文献   

Effect of the strain combination of the donor and recipient on the production efficiency of W‐bearing sperm in mixed‐sex germline chimeric chickens     

Hiroshi KAGAMI  Jun YASUDA  Takahiro TAGAMI  Mitsuru NAITO  Yuko MATSUBARA  Takashi HARUMI  Takamasa NOGUCHI  Yasuhiro YAMAMOTO  Taikai TAKAHASHI  Junichi MATSUYAMA  Hiroyuki KOMATSU  Tamao ONO 《Animal Science Journal》2002,73(6):453-456

Effect of the strain combination of the donor and recipient on production efficiency of W‐bearing sperm in mixed‐sex chimeric testes was analyzed. The combinations of the donors and recipients were White Leghorn (WL) and Rhode Island Red (RIR), and vice versa. Generated mixed‐sex chimeras that had the male phenotype at sexual maturity were classified into four groups: (1) a female WL donor and a male RIR recipient; (2) a male WL donor and a female RIR recipient; (3) a female RIR donor and a male WL recipient; (4) a male RIR donor and a female WL recipient. The mean number of W‐bearing sperm detected by in situ hybridization among 10 000 sperm observed were 147, 165, 30 and 45 in groups 1, 2, 3 and 4, respectively. The numbers in groups 1 and 2 were both significantly higher than those of groups 3 and 4 (P < 0.05). The combination of a WL donor and a RIR recipient produced W‐bearing sperm more efficiently than the reverse combination.  相似文献