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71.
An aminopeptidase, Jc-peptidase, was purified from Japanese cedar pollen by seven steps, including precipitation with ammonium sulfate, ion-exchange chromatography, gel filtration, hydrophobic interaction chromatography on phenyl-agarose, and high-performance liquid chromatography. Purified Jc-peptidease has a molecular weight of 42 kDa and hydrolyzes the synthetic substrates of L-phenylalanyl-4-methylcoumaryl-7-amide (Phe-MCA) with Km = 5 x 10(-5) M, Tyr-MCA with Km = 7 x 10(-4) M, Leu-MCA with Km = 1 x 10(-3) M, and Met-MCA with Km = 1 x 10(-3) M. Other MCA analogues such as Arg-MCA or Glu-MCA failed to serve as its substrates. The activity was inhibited in the presence of phebestin, [(2S,3R)-3-amino-2-hydroxy-4-phenylbutanoyl-L-valyl]-L-phenylalanine, with Ki = 4.7 x 10(-5) M, or bestatin, [(2S,3R)-3-amino-2-hydroxy-4-phenylbutanoyl]-L-leucine, with Ki = 1.1 x 10(-4) M. According to amino acid sequence analysis, the N-terminal amino group seems to be blocked. The physiological function of the aminopeptidase (Jc-peptidase) has not been clarified in vivo.  相似文献   
72.
ABSTRACT This experiment was conducted to investigate leptin mRNA expression, adipocyte size, and their relationship in several adipose tissues of fattening steers. Subcutaneous, perirenal, intermuscular and intramuscular adipose tissues were collected from three crossbred steers (Japanese Black cattle X Holstein) aged 21 months. The mRNA level and adipocyte diameter were determined in these adipose tissues. The intramuscular adipose tissue had a lower leptin mRNA level than the intermuscular and perirenal adipose tissues (P < 0.05). Leptin mRNA level was lower in the subcutaneous depot than in the intermuscular depot (P < 0.05). Adipocyte diameter was larger in the intermuscular adipose tissue than in the subcutaneous and intramuscular adipose tissues (P < 0.05). Leptin mRNA level was positively correlated with adipocyte diameter (r2 = 0.81, P < 0.05). These results suggest that the cattle have fat depot‐specific differences in leptin gene expression, which are a result of a difference in adipocyte size.  相似文献   
73.
 ‘巨峰’葡萄主梢花粉粒大于副梢, 花粉染色率与副梢差异不显著, 发芽率低于副梢, 但花粉发芽率不影响种子的形成。主梢小花雌蕊在减数分裂后形成的功能大孢子小于副梢。同时开花前主梢胚囊的发育状况优于副梢, 开花期正常胚囊率主梢也明显低于副梢。因此, 开花前后主梢异常胚囊的出现是导致受精发生障碍并使结籽率低下的原因。  相似文献   
74.
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   
75.
We investigated the relationship between CD8+ T cell anti-feline immunodeficiency virus (FIV) activity and FIV proviral DNA load integrated in mononuclear cells. The anti-FIV activity and the proviral DNA load were correlated, and the number of proviral DNA copies was high in cats with decreased anti-FIV activity. Particularly, no anti-FIV activity was detected in the cats staged as having an acquired immunodeficiency syndrome (AIDS)-related complex or AIDS, and the number of proviral DNA copies was obviously increased compared to those in the cats in the asymptomatic stage. These results suggest that decreased anti-FIV activity destroys the control of in vivo FIV replication, which leads to an increased proviral DNA load with the progression of the clinical stage of disease.  相似文献   
76.
Interleukin 4 (IL-4) is an important regulatory cytokine produced by activated T lymphocytes and mast cells, and regulates the growth and differentiation of cells such as B and T lymphocytes. In the present study, recombinant thioredoxin (Trx)-porcine IL-4 (pIL-4) fusion protein was prepared by Escherichia coli (E. coli), and by using this protein as an immunogen, monoclonal antibodies (mAbs) against pIL-4 were produced to establish a basis for a research on immune responses in pigs. Six stable hybridoma cell lines were successfully established and specific binding of each mAb to recombinant pIL-4 produced by E. coli and insect cells infected with recombinant baculovirus was shown by enzyme-linked immunosorbent assay (ELISA) and/or immunoblot analysis. Isotype analyses of these mAbs revealed that the subclass of 5 out of 6 mAbs was IgG1 and the rest was IgG2b. Further, assessment of their epitopes by competition binding assay indicated that the mAbs obtained in this study bound to 4 different epitopes. The recombinant proteins and mAbs produced in this study will be useful tools for the assessment of porcine immune system.  相似文献   
77.
Infectivity of a novel type of Cryptosporidium andersoni to laboratory mice   总被引:3,自引:0,他引:3  
Previously, we reported 'a novel type' of Cryptosporidium andersoni detected from cattle in Japan, and showed that the isolate was infective to mice. In the present study, we examined the patterns of oocyst shedding in both immunocompromised and immunocompetent mice, as well as pathological lesions in the infected mice. After oral inoculation with 1 x 10(6) oocysts, all five severe combined immunodeficiency (SCID) mice began to shed endogenously produced oocysts on day 6 post-inoculation (p.i.). The number of oocysts per day (OPD) reached 1 x 10(6) on day 17 p.i., and an OPD level of 1 x 10(6) to 10(7) was maintained until 91 days p.i. when the mice were sacrificed. In the five immunocompetent mice inoculated with 1 x 10(6) oocysts, the pre-patent and patent periods were 6 and 19 days, respectively, and the maximal OPD level was 1.5 x 10(5) on average. On histological examinations of infected SCID mice, a large number of parasites were present on the surface of the gastric glands of the stomach, but not in other organs examined. In conclusion, the novel type of C. andersoni, which genetically coincides with C. andersoni reported in other countries, is infective to mice, but susceptibility was lower than that of Cryptosporidium muris infecting rodents from the perspective of infectivity to immunocompetent mice.  相似文献   
78.
Molecule possessing ankyrin-repeats induced by lipopolysaccharide (MAIL) is known as an IkappaB protein induced after administration of bacterial lipopolysaccharide (LPS) to mice. In the present study, we cloned bovine MAIL cDNA and examined its mRNA expression in white blood cells isolated from Holstein cows. Bovine MAIL had more than 80% amino acid identities with murine and human MAILs, highly conserved ankyrin-repeat motifs and PEST-like sequences. Bovine MAIL mRNA was undetectable in isolated peripheral white blood cells, but rapidly induced (<1h) after stimulation by LPS and lipid A in vitro in a dose-dependent manner. The lipid A-induced MAIL mRNA expression was found in polymorphonuclear cells, monocytes/macrophages and total lymphocytes, but not in T-lymphocytes. MAIL mRNA was also induced in vivo in peripheral blood leukocytes of cows after intramammary injection of Escherichia coli derived from coliform mastitis. Thus, bovine MAIL, as rodent MAILs, is induced by inflammatory stimuli in specific immune cells in vitro and in vivo, suggesting a role in inflammatory responses to bacterial infection in cattle.  相似文献   
79.
Tumor necrosis factor (TNF) receptor-associated factors (TRAFs) were identified as signal transducers for the tumor necrosis factor receptor (TNFR) superfamily. In this study, we cloned and characterized two genes that encode chicken TNFR-II and TRAF5. The initial cDNA fragments were obtained by suppressive subtractive hybridization (SSH) of chicken spleen cells with or without lipopolysaccharide stimulation (Salmonella typhimurium SL1181 (RE-mutant)). The results showed that chicken TNFR-II is 1518 bp in length with an open reading frame (ORF) of 1386 bp having 31% homology with human TNFR-II. Expression analysis of chicken TNFR-II revealed that it is highly expressed in the spleen and bursa of Fabricius. The chicken cell lines IN24, MSB1 and 1104B express TNFR-II abundantly. The time course analysis of expression in spleen, bursa of Fabricius and IN24 cell line showed that TNFR-II is maximally expressed at 6 h after stimulation in bursa of Fabricius and after 8 h stimulation in the IN24 cell line. With regard to TRAF5, the complete sequence was 1936 bp in length with an ORF of 1671 bp that showed 71.3% homology with human TRAF5. Expression analysis showed that, among the tissues examined, TRAF5 was strongly expressed in spleen and bursa of Fabricius, while among the cell lines examined, it was maximally expressed in IN24. Thus, both genes were expressed in the same tissues and cell line among examined materials. These results suggest that chicken TNFR-II may interact with TRAF5 adaptor protein to complete its signal transduction pathway.  相似文献   
80.
The existence of CD3(+)CD4(-)CD8(-) T cells in thymus and spleen has already been known. However, because of the presence of large amounts of thrombocytes in peripheral blood (PB), the proportion of CD3(+)CD4(-)CD8(-) T cells in PB has yet to be investigated. Therefore, the proportion of peripheral T cell-subsets was investigated in 6-week-old chickens. The percentage of CD3(+) cells, CD4(+) cells, CD8 alpha(+) cells, CD8 beta(+), and CD3(+)CD4(-)CD8(-) cells was 76%, 41%, 14%, 5%, and 15%, respectively. The proportion of CD3(+)CD4(-)CD8(-) cells in PB increased during egg-laying periods and in chickens treated with an analog of estrogen, while it decreased with age and in response to restraint stress. All of the CD3(+)CD4(-)CD8(-) cells expressed TCR1, and did not have NK activity. CD3(+)CD4(-)CD8(-) cells represent about 60% of peripheral TCR1(+) cells. These findings indicate that the proportion of CD3(+)CD4(-)CD8(-) cells is regulated by the endocrine and nerve systems.  相似文献   
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