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91.
Single immunoglobulin interleukin-1 receptor-related molecule (SIGIRR) is one of the immunoglobulin-like membrane proteins that is crucial for negative regulation of toll-like receptor 4 (TLR4) and interleukin-1 receptor. Despite the importance of understanding its expression and function, knowledge is limited on the regulatory mechanism in the epithelial tissues, such as the liver, lung, and gut, where its predominant expression is originally described. Here, we found expression of SIGIRR in non-epithelial innate immune cells, including primary peripheral blood monocytes, polymorphonuclear neutrophils, monocytic RAW264 cells, and neutrophilic-differentiated HL-60 cells. Consistent with previous findings in epithelial tissues, SIGIRR gene and protein expression were also down-regulated by LPS treatment in a time-dependent manner in primary blood monocytes and polymorphonuclear neutrophils. A reduction was also observed in RAW264 and differentiated HL-60 cells. Notably, exogenous introduction of the dominant negative form of TLR4 and siRNA of p38 resulted in inhibition of LPS-induced SIGIRR down-regulation, whereas treatment with p38 activator anisomycin showed a dose-dependent decrease in SIGIRR expression, suggesting TLR4-p38 signal as a critical pathway for LPS-induced SIGIRR down-regulation. Finally, reporter gene and chromatin immunoprecipitation assays demonstrated that Sp1 is a key factor that directly binds to the proximal promoter of SIGIRR gene and consequently regulates basal SIGIRR expression, which is negatively regulated by the LPS-dependent TLR4-p38 pathway. In summary, the data precisely demonstrate how LPS down-regulates SIGIRR expression and provide a role of LPS signal that counteracts Sp1-dependent basal promoter activation of SIGIRR gene via TLR4-p38 pathway in non-epithelial innate immune cells.  相似文献   
92.
Degradation of Triphenyltin by a Fluorescent Pseudomonad   总被引:2,自引:1,他引:1       下载免费PDF全文
Triphenyltin (TPT)-degrading bacteria were screened by a simple technique using a post-column high-performance liquid chromatography using 3,3′,4′,7-tetrahydroxyflavone as a post-column reagent for determination of TPT and its metabolite, diphenyltin (DPT). An isolated strain, strain CNR15, was identified as Pseudomonas chlororaphis on the basis of its morphological and biochemical features. The incubation of strain CNR15 in a medium containing glycerol, succinate, and 130 μM TPT resulted in the rapid degradation of TPT and the accumulation of approximately 40 μM DPT as the only metabolite after 48 h. The culture supernatants of strain CNR15, grown with or without TPT, exhibited a TPT degradation activity, whereas the resting cells were not capable of degrading TPT. TPT was stoichiometrically degraded to DPT by the solid-phase extract of the culture supernatant, and benzene was detected as another degradation product. We found that the TPT degradation was catalyzed by low-molecular-mass substances (approximately 1,000 Da) in the extract, termed the TPT-degrading factor. The other fluorescent pseudomonads, P. chlororaphis ATCC 9446, Pseudomonas fluorescens ATCC 13525, and Pseudomonas aeruginosa ATCC 15692, also showed TPT degradation activity similar to strain CNR15 in the solid-phase extracts of their culture supernatants. These results suggest that the extracellular low-molecular-mass substance that is universally produced by the fluorescent pseudomonad could function as a potent catalyst to cometabolite TPT in the environment.  相似文献   
93.
Procyanidin B-2 is a polyphenol compound we have identified in apple which acts as a hair-growing factor in the murine model both in vitro and in vivo. This report describes our investigation of the effects of 1% procyanidin B-2 tonic on human hair growth after sequential use for 6 months. A double-blind clinical test involving a total of 29 subjects was performed. Nineteen men in the procyanidin B-2 group and 10 men in the placebo control group were subjected to analyses. No adverse side effects were observed in either group. The hair-growing effect was evaluated using a macrophotography technique combined with measurements of the hair diameter of clipped hairs. The increase in number of total hairs in the designated scalp area (0.5 cm square = 0.25 cm2 area) of procyanidin B-2 group subjects after the 6-month trial was significantly greater than that of the placebo control group subjects (procyanidin B-2, 6.68 +/- 5.53 (mean +/- SD)/0.25 cm2; placebo, 0.08 +/- 4.56 (mean +/- SD)/0.25 cm2; P < 0.005, two-sample t test). The increase in number of terminal hairs, which are defined as hairs more than 60 microm in diameter, in the designated area (0.5 cm square = 0.25 cm2 area) of the procyanidin B-2 group subjects after the 6-month trial was significantly greater than that of the placebo control group subjects (procyanidin B-2, 1.99 +/- 2.58 (mean +/- SD)/0.25 cm2; placebo, -0.82 +/- 3.40 (mean +/- SD)/0.25 cm2; P < 0.02, two-sample t test). Procyanidin B-2 therapy shows potential as a safe and promising cure for male pattern baldness.  相似文献   
94.
Fucosylated alpha-fetoprotein (AFP) is a highly specific tumor marker for hepatocellular carcinoma (HCC). However, the molecular mechanism by which serum level of fucosylated AFP increases in patients with HCC remains largely unknown. Here, we report that the fucosylation of glycoproteins could be a possible signal for secretion into bile ducts in the liver. We compared oligosaccharide structures on glycoproteins in human bile with those in serum by several types of lectin blot analyses. Enhanced binding of biliary glycoproteins to lectins that recognize a fucose residue was observed over a wide range of molecular weights compared with serum glycoproteins. A structural analysis of oligosaccharides by two-dimensional mapping high performance liquid chromatography and matrix-assisted laser desorption ionization time-of flight mass spectrometry confirmed the increases in the fucosylation of biliary glycoproteins. Purification followed by structural analysis on alpha1-antitrypsin, alpha1-acid glycoprotein and haptoglobin, which are synthesized in the liver, showed higher fucosylation in bile than in serum. To find direct evidence for fucosylation and sorting signal into bile ducts, we used alpha1-6 fucosyltransferase (Fut8)-deficient mice because fucosylation of glycoproteins produced in mouse liver was mainly an alpha1-6 linkage. Interestingly, the levels of alpha1-antitrypsin and alpha1-acid glycoprotein were quite low in bile of Fut8-deficient mice as compared with wild-type mice. An immunohistochemical study showed dramatic changes in the localization of these glycoproteins in the liver of Fut8-deficient mice. Taken together, these results suggest that fucosylation is a possible signal for the secretion of glycoproteins into bile ducts in the liver. A disruption in this system might involve an increase in fucosylated AFP in the serum of patients with HCC.  相似文献   
95.
The purpose of this study was to examine the effect of graded conditioning contractions of the antagonist knee flexor muscles on the output characteristics of knee extensor muscles in healthy humans. Eight male university students performed maximum isometric contractions of knee extensors, preceded by isometric conditioning contractions of the antagonist knee flexors. The developed force and electromyographic (EMG) amplitudes of the knee extensors after the conditioning contraction were measured and compared with those of simple knee extension without conditioning. The forces of the conditioning flexor contraction were set at three levels: low (20% of maximum voluntary contraction: MVC), moderate (60% of MVC), and high (100% of MVC). The EMG amplitudes of the vastus medialis, vastus lateralis, and rectus femoris muscle were recorded and the root mean square amplitudes were calculated. The strongest enhancement of the extension force was obtained by moderate intensity conditioning contraction (108.95+/-1.87% of simple knee extension), although high intensity conditioning also induced a significant increase (105.41+/-2.69%). Low intensity conditioning did not cause a significant enhancement of the contraction force (103.17+/-2.99%). Similarly, the EMG amplitudes were significantly increased by moderate and/or high conditioning. These results suggest that antagonist conditioning contraction of moderate intensities is sufficient and may be optimal to potentiate knee extensor contraction.  相似文献   
96.
Eight microsatellite loci for the perennial herb Farfugium japonicum, including the rheophytic variety luchuense endemic to riparian areas of the Ryukyu Islands, Japan, were isolated and characterised. The number of alleles ranged from 5 to 14. The expected (H E) and observed (H O) heterozygosities were 0.344–0.885 and 0.121–0.754, respectively, from 69 individuals in one population. Six loci exhibited significantly fewer heterozygotes than expected under Hardy–Weinberg equilibrium (< 0.05). The primers amplifying microsatellite sequences in F. japonicum may provide a population genetics tool useful in the establishment of a conservation strategy.  相似文献   
97.
Hen egg lysozyme (HEL) is one of the sweet-tasting proteins. To understand why lysozyme is sweet, the enzyme was synthesized at high yields by a recombinant method. The mature HEL gene was cloned from a Taq polymerase-amplified PCR product into the Pichia pastoris expression and secretion vector pPIC6alpha. This expression vector contains both the Saccharomyces cerevisiae pre-pro alpha-mating factor secretion signal and the blasticidin resistance gene (bsd) for selection of transformants in bacteria and yeast. Expression of HEL was carried out in fermenter cultures. Culture supernatants were concentrated by ultrafiltration and purified by CM-ion exchange chromatography. Approximately 400 mgL-1 of recombinant HEL was obtained. The high yield of recombinant lysozyme enabled us to perform a sensory analysis in humans. The purified recombinant lysozyme elicited as a sweet taste sensation as does the lysozyme purified directly from egg white, and showed full lytic activity against cells of Micrococcus luteus. These results demonstrate that the P. pastoris expression system with the blasticidin S selection system is useful in producing recombinant sweet-tasting protein in active form at a high yield.  相似文献   
98.
X-ray fiber diffraction is one of the most useful methods for examining the structural details of live biological filaments under physiological conditions. To investigate biologically active or labile materials, it is crucial to finish fiber alignment within seconds before diffraction analysis. However, the conventional methods, e.g., magnetic field alignment and low-speed centrifugations, are time-consuming and not very useful for such purposes. Here, we introduce a new alignment method using a rheometer with two parallel disks, which was applied to observe fiber diffractions of axonemes, tobacco mosaic tobamovirus, and microtubules. We found that fibers were aligned within 5 s by giving high shear flow (1000-5000 s−1) to the medium and that methylcellulose contained in the medium (∼1%) was essential to the accomplishment of uniform orientation with a small angular deviation (<5°). The new alignment method enabled us to execute structure analyses of axonemes by small-angle x-ray diffraction. Since this method was also useful for the quick alignment of purified microtubules, as well as tobacco mosaic tobamovirus, we expect that we can apply it to the structural analysis of many other biological filaments.  相似文献   
99.
The LEC rat, which suffers from hereditary hepatitis, was examined for elucidation of its clinicopathological characteristics during development of the acute phase of hepatitis by quantitative analyses of histological observations of the liver in combination with laboratory data on various serum enzymes. The progression of acute hepatitis in the LEC rat was observed to begin insidiously early in life, i.e., a few enlarged hepatocytes and Councilman bodies appeared at around 8 weeks of age without clinical signs. Furthermore, it was revealed that the acute phase of hepatitis started with a remarkable increase of Councilman bodies, large nuclei and hepatocytes in mitosis in the liver 3 to 4 weeks before the onset of fulminant hepatitis, which is characterized by the elevation of serum enzyme activities such as GOT, GPT and gamma-GTP, and the onset of jaundice. From those observations, three stages were proposed for the progression of acute hepatitis in the LEC rat.  相似文献   
100.
Although phenotypic abnormalities frequently appear in the placenta following somatic cell nuclear transfer (SCNT), mouse trophoblast stem cells (TSCs) established from SCNT embryos reportedly show no distinct abnormalities compared with those derived from normal fertilization. In this study, we reexamined SCNT–TSCs to identify their imprinting statuses. Placenta-specific maternally imprinted genes (Gab1, Slc38a4, and Sfmbt2) consistently showed biallelic expression in SCNT–TSCs, suggesting their loss of imprinting (LOI). The LOI of Gab1 was associated with decreased DNA methylation, and that of Sfmbt2 was associated with decreased DNA methylation and histone H3K27 trimethylation. The maternal allele of the intergenic differentially methylated region (IG–DMR) was aberrantly hypermethylated following SCNT, even though this region was prone to demethylation in TSCs when established in a serum-free chemically defined medium. These findings indicate that the development of cloned embryos is associated with imprinting abnormalities specifically in the trophoblast lineage from its initial stage, which may affect subsequent placental development.  相似文献   
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