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1.
Background: Soft denture lining‐materials are more susceptible to microbial adhesion than hard denture base acrylic resin. Poor oral hygiene and Candida albicans infection are common among elderly denture wearers as these patients usually have difficulty in keeping them clean. Purpose: To evaluate the influence of the oral hygiene methods on the formation of a biofilm over a soft denture‐lining material. Material and methods: Twenty volunteers were randomly separated into two groups: G1 and G2. Ten volunteers performed daily hygiene of the prostheses with a soft toothbrush and toothpaste. The G2 performed a treatment identical to G1 but also immersed the prostheses in sodium hypochlorite 0.5% for 20 min, once a week. Quantification of the mean score values of biofilm formation at different times were statistically analysed using analysis of variance and Tukey’s test (α = 0.05). Results: G1 (0.65 ± 0.52) showed the lowest mean score values of biofilm formation. There was statistical difference between G1 and G2. The highest mean score values were found at 6 weeks (1.3 ± 1.08) and were statistically different from other times. Conclusion: The oral hygiene methods had a significant effect in the formation of the biofilm over a soft denture‐lining material.  相似文献   

2.
This paper summarises a series of studies already published in German and presents new data related to the aetiology of the dry mouth' and its associated problems. Aims: to study factors affecting mucous and serous salivary gland secretion, the aetiology of the ‘dry mouth’ and its associated problems, causative factors for hyposalivation and it's treatment Setting : two university dental hospitals. Subjects: 587 denture wearers and 521 control subjects, and autopsy material Interventions : exercise, chewing, water, oestrogen, pilocarpine, and anetholtrithion theiapy, biopsy of the minor glands Main outcome measures : Palatal secretion (PAL, μL/cm2/min) and parotid salivary flow (PAR), subjective complaints and clinical findings. Results: resting flow rates for PAL between 0 and 65 μl/cm2/min were seen in every age group. The flow rates of PAR (0 to 3.7 ml/10 min) were not correlated with PAL. Most patients with a resting flow rate of PAL≤6.0 μl/cm2 suffer from a ‘dry mouth’ and Burning Mouth Syndrome (BMS) or oral dysaesthesia (OD) with or without chronic lesions of the oral mucosa. Etiological factors for the incidence of reduced PAL and associated problems include xerostomic drugs, oestrogen deficiency, ladiotherapy, thyroid dysfunction, smoking or continuous wearing of complete upper dentures. PAL also correlated with the retention of upper complete dentures. PAL was correlated with the water content of epithelial tissues. PAL and PAR were both increased by drinking ample fluid, improving their circulation by physical exercises, chewing intensively, or taking oestrogens, pilocarpine, anetholtrithion. Conclusions: Variation in palatal salivary secretion occurs and is clinically important.  相似文献   

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The creation of transgenic plants has contributed extensively to the advancement of plant science. Establishing homozygous transgenic lines is time‐consuming and laborious, and using antibiotics or herbicides to select transformed plants may adversely affect the growth of some transgenic plants. Here we describe a novel technology, which we have named FAST (fluorescence‐accumulating seed technology), that overcomes these difficulties. Although this technology was designed for use in Arabidopsis thaliana, it may be adapted for use in other plants. The technology is based on the expression of a fluorescent co‐dominant screenable marker FAST, under the control of a seed‐specific promoter, on the oil body membrane. The FAST marker harbors a fusion gene encoding either GFP or RFP with an oil body membrane protein that is prominent in seeds. The marker protein was only expressed in a specific organ (i.e. in dry seeds) and at a specific time (i.e. during dormancy), which are desirable features of selectable and/or screenable markers. This technique provides an immediate and non‐destructive method for identifying transformed dry seeds. It identified the heterozygous transformed seeds among the T1 population and the homozygous seeds among the T2 population with a false‐discovery rate of <1%. The FAST marker reduces the length of time required to produce homozygous transgenic lines from 7.5 to 4 months. Furthermore, it does not require sterilization, clean‐bench protocols or the handling of large numbers of plants. This technology should greatly facilitate the generation of transgenic Arabidopsis plants.  相似文献   

5.
Hemolysin as a marker for Serratia   总被引:3,自引:0,他引:3  
All Serratia marcescens strains (total of 33) of different sources were hemolytic including clinical strains previously classified as being nonhemolytic. DNA fragments of the two hemolysin genes hybridized with the chromosomal DNA of S. marcescens, S. liquefaciens, S. kiliensis, S. grimesii, S. proteamaculans, S. plymutica, S. rubridaea which were also hemolytic. The restriction pattern of the hemolysin locus differed in each strain. S. ficaria and S. marinorubra expressed a different hemolysin which was much smaller than the S. marcescens hemolysin since it diffused through dialysis membranes. The DNA of the latter strains did not hybridize with the S. marcescens hemolysin DNA probes. Some S. marcescens strains, S. kiliensis and S. liquefaciens also expressed in addition the small hemolysin. No hybridization was found with DNA of Escherichia coli, Salmonella typhimurium, Proteus mirabilis, Proteus vulgaris, Citrobacter freundii, Enterobacter cloacae, Klebsiella arerogenes, Klebsiella pneumoniae, Shigella dysenteriae, Yersinia enterocolitica, Yersinia pseudotuberculosus, Listeria sp., Aeromonas sp., Legionella sp. and a Meningococcus sp., indicating that the hemolysin DNA probes are specific for Serratia, or that the hemolysin genes occur rarely in genera other than Serratia.  相似文献   

6.
Four adult skeletal samples from the states of Uttar Pradesh, Andhra Pradesh, and Bihar in India have been studied for the incidence of mylohyoid bridge. The incidence, varying between 2.98% and 7.14%, has been compared with frequencies reported for other populations of the world. The range of variation for Indians, as a whole, falls within the lower levels of the spectrum of worldwide variation for this trait, ranging between 0.47% for French Europeans and 33.8% observed among Plains American Indians. While noting its possible significance for clinical purposes, the suitability of the mylohyoid bridge as a population genetic marker has been discussed. It is emphasized that its use as a genetic marker in isolation of other discrete traits has serious limitations. For meaningful population definition and relationships as many discrete variants as possible ought to be utilized.  相似文献   

7.
苏宇  农向群  张泽华 《菌物学报》2012,31(3):366-373
为了监测生防真菌绿僵菌菌株在田间释放后的回收,有必要建立菌株DNA分子标记,以此将应用的菌株与其他菌株或田间的土著分离株鉴别开来。作者采用16条随机引物扩增了51株绿僵菌菌株的基因组DNA,得到81个多态性位点。其中M189菌株多态性位点30个,分析得到1个特异性位点,并将该位点的DNA片段测序后转化成为特异性SCAR标记。检验确定了该标记的敏感性,可以从供试的51株菌株中准确鉴定出目的菌株M189。并用该标记检测了从田间回收的3个分离株,确定其中1个与应用菌株M189一致。  相似文献   

8.
In this work, reliable tools were developed to detect and identify the biocontrol strain CPA‐8 using DNA amplification techniques. As a first approach, the RAPD (random amplified polymorphic DNA) technique was applied to a collection of 77 related Bacillus species. Among the primers tested, the primer pair OPG1/OPG6 amplified a 668 bp specific product to the strain CPA‐8 that was sequenced and used to design SCAR (sequence‐characterised amplified regions) primer pairs. The SCAR‐4 marker amplified a semi‐specific fragment of 665 bp not only for the strain CPA‐8 but also for other 12 strains whose morphology was completely different from CPA‐8. Another approach was developed to obtain a strain‐specific genomic marker related to ecological adaptations of Bacillus amyloliquefaciens species. The primer pair F2/R2 obtained from RBAM 007760, a gene involved in surface adhesion, amplified a 265 bp fragment unique for strain CPA‐8. Our results revealed that these two molecular markers, SCAR‐4 and RBAM 007760 F2/R2 provide suitable monitoring tools to specifically identify the biocontrol CPA‐8 when applied against brown rot caused by Monilinia spp. in stone fruit. Moreover, our findings demonstrate that the strain CPA‐8 is affiliated with B. amyloliquefaciens species that was formerly designated as Bacillus subtilis.  相似文献   

9.
Phytoplasma classification established using 16S ribosomal groups and ‘Candidatus Phytoplasma’ taxon are mainly based on the 16S rDNA properties and do not always provide molecular distinction of the closely related strains such as those in the aster yellows group (16SrI or ‘Candidatus Phytoplasma asteris'‐related strains). Moreover, because of the highly conserved nature of the 16S rRNA gene, and of the not uncommon presence of 16S rDNA interoperon sequence heterogeneity, more variable single copy genes, such as ribosomal protein (rp), secY and tuf, were shown to be suitable for differentiation of closely related phytoplasma strains. Specific amplification of fragments containing phytoplasma groEL allowed studying its variability in 27 ‘Candidatus Phytoplasma asteris'‐related strains belonging to different 16SrI subgroups, of which 11 strains were not studied before and 8 more were not studied on other genes than 16S rDNA. The restriction fragment length polymorphism (RFLP) analyses of the amplified fragments confirmed differentiation among 16SrI‐A, I‐B, I‐C, I‐F and I‐P subgroups, and showed further differentiation in strains assigned to 16SrI‐A, 16SrI‐B and 16SrI‐C subgroups. However, analyses of groEL gene failed to discriminate strains in subgroups 16SrI‐L and 16SrI‐M (described on the basis of 16S rDNA interoperon sequence heterogeneity) from strains in subgroup 16SrI‐B. On the contrary, the 16SrI unclassified strain ca2006/5 from carrot (showing interoperon sequence heterogeneity) was differentiable on both rp and groEL genes from the strains in subgroup 16SrI‐B. These results indicate that interoperon sequence heterogeneity of strains AY2192, PRIVA (16SrI‐L), AVUT (16SrI‐M) and ca2006/5 resulted in multigenic changes – one evolutionary step further – only in the latter case. Phylogenetic analyses carried out on groEL are in agreement with 16Sr, rp and secY based phylogenies, and confirmed the differentiation obtained by RFLP analyses on groEL amplicons.  相似文献   

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In this study, we demonstrate a novel method for unmarked genetic modification of the methylotrophic yeast Pichia pastoris , in which the Escherichia coli toxin gene mazF was used as a counter-selectable marker. mazF was placed under the tightly controlled AOX1 promoter, and the induced expression of MazF in P. pastoris halted cell growth. A modular plasmid was constructed in which mazF and a Zeocin resistance gene acted as counter-selectable and active-selectable markers, respectively, and the MazF-ZeoR cassette was flanked by two direct repeats for marker recycling. Linearized delivery vectors constructed from the modular plasmid were integrated into the P. pastoris genome via homologous recombination, introducing genetic modifications. Upon counter-selection with methanol medium, which induces the AOX1 promoter, the markers were recycled efficiently via homologous recombination between the direct repeats. We used this method successfully to knock-out the ARG1 and MET2 genes, knock-in a green fluorescent protein expression cassette, and perform site-directed mutagenesis on the ARG1 gene, all without introducing unwanted selection markers. The novel method allows repeated use of the selectable marker gene for multiple modifications and will be a useful tool for P. pastoris studies.  相似文献   

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Ovarian cancer (OC) is the fifth leading cause of cancer-related death among women. The high mortality rate is due to lack of early symptoms, late diagnosis, limited treatment options, and also emerging of drug resistance. Todays, molecular markers have become promising in tumor-targeted therapy. Several molecular markers have been known in OC immunotherapy. Identification of the specific molecular markers with prognostic significance is interested. CD24 is a small sialoglycoprotein which is localized in lipid rafts through its glycosylphosphatidylinositol (GPI) anchor. It has been reported that CD24 is overexpressed in many cancers including OC. Also, CD24 is identified as a cancer stem cell marker in OC. The CD24 expression is associated with the development, invasion, and metastasis of cancer cells. The exact role of CD24 in cancer cells is not clearly understood. Recently, CD24 has been identified as an independent prognostic marker of survival in patients with OC. In this study, we reviewed the molecular targets in OC immune-targeted therapy and also presented an overview of the new molecular marker CD24 and its association with the OC by reviewing the recent literature.  相似文献   

14.
In plants, matK and rbcL have been selected as core barcodes by the Consortium for the Barcode of Life (CBOL) Plant Working Group (PWG), and ITS/ITS2 and psbA‐trnH were suggested as supplementary loci. Yet, research on DNA barcoding of non‐flowering seed plants has been less extensive, and the evaluation of DNA barcodes in this division has been limited thus far. Here, we evaluated seven markers (psbA‐trnH, matK, rbcL, rpoB, rpoC1, ITS and ITS2) from non‐flowering seed plants. The usefulness of each region was assessed using four criteria: the success rate of PCR amplification, the differential intra‐ and inter‐specific divergences, the DNA barcoding gap and the ability to discriminate species. Among the seven loci tested, ITS2 produced the best results in the barcoding of non‐flowering seed plants. In addition, we compared the abilities of the five most‐recommended markers (psbA‐trnH, matK, rbcL, ITS and ITS2) to identify additional species using a large database of gymnosperms from GenBank. ITS2 remained effective for species identification in a wide range of non‐flowering seed plants: for the 1531 samples from 608 species of 80 diverse genera, ITS2 correctly authenticated 66% of them at the species level. In conclusion, the ITS2 region can serve as a useful barcode to discriminate non‐flowering seed plants, and this study will contribute valuable information for the barcoding of plant species.  相似文献   

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Shifts in the psychometric function in the Free Operant Psychophysical Procedure (FOPP) have traditionally been explained by suggesting the pacemaker rate is proportional to the reinforcement rate (Behavioral Theory of Timing; BeT), or by direct associative competition between the two responses (Learning to Time; LeT). The application of these models assumes that the stimulus onset is the relevant time marker. Head-entries were reinforced in the second half of a stimulus (s1) and in the first half of a different stimulus (s2). During extinction, response times shifted earlier in s2 only, contrary to BeT. Competition between responses is an unlikely cause of the shift, contrary to LeT. We found a single-cycle correlation between the last food delivery and the time the rat stopped responding on s2. This correlation was also present in FOPP data. These results are consistent with the interpretation that the reinforcer, more than the stimulus onset, acted as the relevant time marker on this task.  相似文献   

18.
Summary Development of new selectable markers is needed to increase the efficiency and flexibility of plant transformation, and to overcome drawbacks sometimes associated with use of existing markers. A useful alternative to chemical-based selection systems would be a system using visual screening to obtain transgenic lines. Investigations were carried out to determine if the green fluorescent protein (gfp) gene could be utilized alone as a visual screenable marker to produce stably transformed, fertile oat plants. Twelve experiments were conducted in which gfp-based selection was utilized to obtain routinely stable transgenic lines in oat. A synthetic gfp gene under the control of the maize ubiquitin promoter was delivered into embryogenic oat callus via microprojectile bombardment. Cell clusters (1–3 mm) expressing gfp were visually identified using epifluorescence microscopy and physically isolated approximately 3 wk post-bombardment. Fertile, gfp-expressing T0 plants were regenerated from 78% of the glowing cell sectors placed on regeneration medium. T0 plants from 55% of the events produced gfp-expressing progeny in a 3∶1 Mendelian ratio. Southern blot and PCR analysis confirmed transgene integration and transmission to progeny. Expression of gfp did not reduce plant growth or fertility. Transgene copy number and integration patterns were similar to those in transgenic plants derived from chemical-based selection systems. The mean transformation frequency, based on fertile events obtained per bombarded plate, was 1.8%. Over 180 independent transgenic oat lines were produced, to date, using only visual screening for expression of gfp, demonstrating efficiency and repeatability of the selection system. Mention of a trademark or proprietary product does not constitute a guarantee or warranty by the University of Wisconsin or the US Department of Agriculture and does not imply its approval to the exclusion of other products that may be suitable.  相似文献   

19.
Due to its high proliferation capacity and rapid intracranial spread, glioblastoma (GBM) has become one of the least curable malignant cancers. Recently, the competing endogenous RNAs (ceRNAs) hypothesis has become a focus in the researches of molecular biological mechanisms of cancer occurrence and progression. However, there is a lack of correlation studies on GBM, as well as a lack of comprehensive analyses of GBM molecular mechanisms based on high‐throughput sequencing and large‐scale sample sizes. We obtained RNA‐seq data from The Cancer Genome Atlas (TCGA) and Genotype‐Tissue Expression (GTEx) databases. Further, differentially expressed mRNAs were identified from normal brain tissue and GBM tissue. The similarities between the mRNA modules with clinical traits were subjected to weighted correlation network analysis (WGCNA). With the mRNAs from clinical‐related modules, a survival model was constructed by univariate and multivariate Cox proportional hazard regression analyses. Thereafter, we carried out Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses. Finally, we predicted interactions between lncRNAs, miRNAs and mRNAs by TargetScan, miRDB, miRTarBase and starBase. We identified 2 lncRNAs (NORAD, XIST), 5 miRNAs (hsa‐miR‐3613, hsa‐miR‐371, hsa‐miR‐373, hsa‐miR‐32, hsa‐miR‐92) and 2 mRNAs (LYZ, PIK3AP1) for the construction of a ceRNA network, which might act as a prognostic biomarker of GBM. Combined with previous studies and our enrichment analysis results, we hypothesized that this ceRNA network affects immune activities and tumour microenvironment variations. Our research provides novel aspects to study GBM development and treatment.  相似文献   

20.
Photographic capture–recapture is a valuable tool for obtaining demographic information on wildlife populations due to its noninvasive nature and cost‐effectiveness. Recently, several computer‐aided photo‐matching algorithms have been developed to more efficiently match images of unique individuals in databases with thousands of images. However, the identification accuracy of these algorithms can severely bias estimates of vital rates and population size. Therefore, it is important to understand the performance and limitations of state‐of‐the‐art photo‐matching algorithms prior to implementation in capture–recapture studies involving possibly thousands of images. Here, we compared the performance of four photo‐matching algorithms; Wild‐ID, I3S Pattern+, APHIS, and AmphIdent using multiple amphibian databases of varying image quality. We measured the performance of each algorithm and evaluated the performance in relation to database size and the number of matching images in the database. We found that algorithm performance differed greatly by algorithm and image database, with recognition rates ranging from 100% to 22.6% when limiting the review to the 10 highest ranking images. We found that recognition rate degraded marginally with increased database size and could be improved considerably with a higher number of matching images in the database. In our study, the pixel‐based algorithm of AmphIdent exhibited superior recognition rates compared to the other approaches. We recommend carefully evaluating algorithm performance prior to using it to match a complete database. By choosing a suitable matching algorithm, databases of sizes that are unfeasible to match “by eye” can be easily translated to accurate individual capture histories necessary for robust demographic estimates.  相似文献   

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