排序方式: 共有49条查询结果,搜索用时 31 毫秒
1.
Putative new expression of genes in ixodid tick salivary gland development during feeding. 总被引:2,自引:0,他引:2
J F Oaks J L McSwain J A Bantle R C Essenberg J R Sauer 《The Journal of parasitology》1991,77(3):378-383
Poly(A+) mRNA-enriched fractions from salivary glands of partially fed Amblyomma americanum female ticks were translated in vitro with a rabbit reticulocyte translation system. Translated proteins were labeled with [35S]methionine, separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis, and identified by autoradiography. Thirty major identifiable polypeptides with molecular weights ranging from 14 to 136 kDa were synthesized from mRNA isolated from salivary glands of ticks weighing less than 100 mg. Polypeptides that comigrated at the same molecular weight were translated by mRNA from ticks at a more advanced stage of feeding (more than 300 mg) as were 8 others with molecular weights of 31, 71, 91, 106, 113, 118, and 128 kDa. Results demonstrated that differential gene expression may be stimulated in the developing salivary glands as the tick feeds. 相似文献
2.
The effect of NADP+ on light-induced steady-state redox changes of membrane-bound cytochromes was investigated in membrane fragments prepared from the blue-green algae Nostoc muscorum (Strain 7119) that had high rates of electron transport from water to NADP+ and from an artificial electron donor, reduced dichlorophenolindophenol (DCIPH2) to NADP+. The membrane fragments contained very little phycocyanin and had excellent optical properties for spectrophotometric assays. With DCIPH2 as the electron donor, NADP+ had no effect on the light-induced redox changes of cytochromes: with or without NADP+, 715- or 664-nm illumination resulted mainly in the oxidation of cytochrome f and of other component(s) which may include a c-type cytochrome with an α peak at 549 nm. With 664 nm illumination and water as the electron donor, NADP+ had a pronounced effect on the redox state of cytochromes, causing a shift toward oxidation of a component with a peak at 549 nm (possibly a c-type cytochrome), cytochrome f, and particularly cytochrome b559. Cytochrome b559 appeared to be a component of the main noncyclic electron transport chain and was photooxidized at physiological temperatures by Photosystem II. This photooxidation was apparent only in the presence of a terminal acceptor (NADP+) for the electron flow from water. 相似文献
3.
BS Sabna Thankappan Bency Mahendran Ramasamy Muthusamy Gayathri Femil selta Daniel Raja Angayarkanni Jayaraman 《Probiotics and antimicrobial proteins》2021,13(4):993-1004
Probiotics and Antimicrobial Proteins - Gamma-aminobutyric acid (GABA) is a principal inhibitory neurotransmitter in the central nervous system and is produced by irreversible decarboxylation of... 相似文献
4.
Anderson O. Lobo Erica F. Antunes Mariana BS Palma Cristina Pacheco‐Soares Vladimir J. Trava‐Airoldi Evaldo J. Corat 《Cell biology international》2010,34(4):393-398
Monolayer formation of SaOS‐2 (human osteoblast‐like cells) was observed on VACNT (vertically aligned multiwalled carbon nanotubes) scaffolds without purification or functionalization. The VACNT were produced by a microwave plasma chemical vapour deposition on titanium surfaces with nickel or iron as catalyst. Cell viability and morphology studies were evaluated by LDH (lactate dehydrogenase) release assay and SEM (scanning electron microscopy), respectively. The non‐toxicity and the flat spreading with monolayer formation of the SaOs‐2 on VACNT scaffolds surface indicate that they can be used for biomedical applications. 相似文献
5.
The immunophenotype of HT29 human colon cancer cells implanted into severe combined immunodeficient mice was assessed in primary
tumours and their metastases in the lungs using an indirect immunohistochemical method. After primary tumours were surgically
removed, the metastases were given time to develop, thus paralleling the clinical situation. While vimentin was negative in
both primary and secondary tumours, E-cadherin was present as membrane-bound labelling in the primary tumours only. Whereas
the markers p53, MIB1, PCNA and CEA were consistently positive in both primary and metastatic tumours, CD44 variant 6 and
CA125 were negative in metastases but positive in the primary tumours. There was a significant increase in the percentage
of cells labelled for p53 in the primary tumours compared with the metastases. For the proliferation markers, there was no
significant difference in labelling between primary tumours and metastases for MIB1. Of the cytokeratins examined, CK 20 gave
the strongest and most consistent reaction in both primary and secondary tumours. The results indicate that, for certain immunohistochemical
markers, results are the same in both primary tumours and metastases. Hence, in these cases, antigens that are expressed on
the primary tumour as well as on the metastases can serve as target molecules for immunologically based forms of treatment
of metastases.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
6.
7.
S. Venkata Mohan Christina Falkentoft Y. Venkata Nancharaiah Belinda S. McSwain Sturm Pierre Wattiau Peter A. Wilderer Stefan Wuertz Martina Hausner 《Bioresource technology》2009,100(5):1746-1753
The aim of this study was to investigate the effectiveness of bioaugmentation and transfer of plasmid pWWO (TOL plasmid) to mixed microbial populations in pilot and laboratory scale sequencing batch biofilm reactors (SBBRs) treating synthetic wastewater containing benzyl alcohol (BA) as a model xenobiotic. The plasmid donor was a Pseudomonas putida strain chromosomally tagged with the gene for the red fluorescent protein carrying a green fluorescent protein labeled TOL plasmid, which confers degradation capacity for several compounds including toluene and BA. In the pilot scale SBBR donor cells were disappeared 84 h after inoculation while transconjugants were not detected at all. In contrast, both donor and transconjugant cells were detected in the laboratory scale reactor where the ratio of transconjugants to donors fluctuated between 1.9 × 10?1 and 8.9 × 10?1 during an experimental period of 32 days. BA degradation rate was enhanced after donor inoculation from 0.98 mg BA/min prior to inoculation to 1.9 mg BA/min on the seventeenth day of operation. Survival of a bioaugmented strain, conjugative plasmid transfer and enhanced BA degradation was demonstrated in the laboratory scale SBBR but not in the pilot scale SBBR. 相似文献
8.
Comparisons of the molecular evolutionary process at rbcL and ndhF in the grass family (Poaceae) 总被引:2,自引:1,他引:1
We examine rate heterogeneity among evolutionary lineages of the grass
family at two plasmid loci, ndhF and rbcL, and we introduce a method to
determine whether patterns of rate heterogeneity are correlated between
loci. We show both that rates of synonymous evolution are heterogeneous
among grass lineages and that are heterogeneity is correlated between loci
at synonymous sites. At nonsynonymous sites, the pattern of rate
heterogeneity is not correlated between loci, primarily due to an aberrant
pattern of rate heterogeneity at nonsynonymous sites of rbcL. We compare
patterns of synonymous rate heterogeneity to predictors based on the
generation time effect and the speciation rate hypotheses. Although there
is some evidence for generation time effects, neither generation time
effects nor speciation rates appear to be sufficient to explain patterns of
rate heterogeneity in the grass plastid sequences.
相似文献
9.
10.
We used simulated data to investigate a number of properties of maximum-
likelihood (ML) phylogenetic tree estimation for the case of four taxa.
Simulated data were generated under a broad range of conditions, including
wide variation in branch lengths, differences in the ratio of transition
and transversion substitutions, and the absence of presence of
gamma-distributed site-to-site rate variation. Data were analyzed in the ML
framework with two different substitution models, and we compared the
ability of the two models to reconstruct the correct topology. Although
both models were inconsistent for some branch-length combinations in the
presence of site-to-site variation, the models were efficient predictors of
topology under most simulation conditions. We also examined the performance
of the likelihood ratio (LR) test for significant positive interior branch
length. This test was found to be misleading under many simulation
conditions, rejecting too often under some simulation conditions. Under the
null hypothesis of zero length internal branch, LR statistics are assumed
to be asymptotically distributed chi 2(1); with limited data, the
distribution of LR statistics under the null hypothesis varies from chi
2(1).
相似文献