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Suspension cell protoplasts of albino Petunia hybrida have beentransformed by isolated Agrobacterium tumefaciens Ti plasmid.Uptake of octopine Ti plasmid (pTiACH5) into protoplasts wasstimulated by poly-L-ornithine and polyethylene glycol (PEG).The frequency and efficiency of transformation of protoplaststo phytohormone autotrophy was compared using the two uptakeagents with various concentrations of plasmid. Transformationwas most efficient with PEG-mediated uptake, 5 µg of Tiplasmid per 106 protoplasts giving a frequency of 6?10–5.Octopine was not synthesised in any of the transformants afterthe second subculture on hormone-free medium. DNA-DNA hybridisationshowed the presence of DNA homologous to the T-DNA region ofpTiACH5 in all clones analysed. (Received November 9, 1981; Accepted January 29, 1982)  相似文献   
34.
In the present study, we used osteoprotegerin (OPG), which blocks osteoclastogenesis, to correct and thus explain the hypercalcemia that is seen during dietary Mg deficiency in the mouse. Control and Mg-deficient mice received injections for 12 days of either OPG or vehicle only. Serum Ca was similar in Mg-deficient mice treated with OPG and in control mice receiving OPG (9.2±0.3 mg/dl vs. 9.2±0.5). Both groups had significantly higher serum Ca than controls or Mg-deficient animals receiving vehicle alone. Surprisingly, Mg-depleted mice that received OPG in doses that inhibit osteoclastic bone resorption remained hypercalcemic. Because mature osteoclasts still present in the marrow might be hyperactive, we examined osteoclast morphology at the light microscopic and ultrastructural level. Light microscopic examination of trabecular bone showed few osteoclasts in OPG-treated mice. Ultrastructural examination revealed that osteoclasts in OPG-treated mice have decreased contact with the endosteal bone surface and absence of a ruffled border. Because the morphology of the existing pool of mature osteoclasts did not enhance resorption, another mechanism, such as increased intestinal absorption of Ca in Mg-deficient mice, likely contributes to the hypercalcemia observed during Mg deficiency.  相似文献   
35.
Abstract

In this study, we analyzed the intracellular and extracellular stability of an oligdeoxyribonucleotide (oligo 293) which exhibits antiviral activity against Herpes Simplex Virus Type 1 (HSV-1) in tissue culture. The uptake and stability of oligo 293 varied when cell type or internucleoside linkage was changed.  相似文献   
36.
Producing a comprehensive overview of the chemical content of biologically-derived material is a major challenge. Apart from ensuring adequate metabolome coverage and issues of instrument dynamic range, mass resolution and sensitivity, there are major technical difficulties associated with data pre-processing and signal identification when attempting large scale, high-throughput experimentation. To address these factors direct infusion or flow infusion electrospray mass spectrometry has been finding utility as a high throughput metabolite fingerprinting tool. With little sample pre-treatment, no chromatography and instrument cycle times of less than 5 min it is feasible to analyse more than 1,000 samples per week. Data pre-processing is limited to aligning extracted mass spectra and mass-intensity matrices are generally ready in a working day for a month’s worth of data mining and hypothesis generation. ESI-MS fingerprinting has remained rather qualitative by nature and as such ion suppression does not generally compromise data information content as originally suggested when the methodology was first introduced. This review will describe how the quality of data has improved through use of nano-flow infusion and mass-windowing approaches, particularly when using high resolution instruments. The increasingly wider availability of robust high accurate mass instruments actually promotes ESI-MS from a merely fingerprinting tool to the ranks of metabolite profiling and combined with MS/MS capabilities of hybrid instruments improved structural information is available concurrently. We summarise current applications in a wide range of fields where ESI-MS fingerprinting has proved to be an excellent tool for “first pass” metabolome analysis of complex biological samples. The final part of the review describes a typical workflow with reference to recently published data to emphasise key aspects of overall experimental design.  相似文献   
37.

Objective

The incidence of gastroschisis, a congenital anomaly where the infant abdominal wall is defective and intestines protrude from the abdominal cavity, is increasing in many countries. The role of maternal stress in some adverse birth outcomes is now well established. We tested the hypothesis that major stressful life events in the first trimester are risk factors for gastroschisis, and social support protective, in a case-control study in the United Kingdom.

Methods

Gastroschisis cases and three controls per case (matched for maternal age) were identified at routine 18-20 week fetal anomaly ultrasound scan, in 2007-2010. Face to face questionnaire interviews were carried out during the antenatal period (median 24 weeks gestation) asking about serious stressful events and social support in the first trimester. Data were analysed using conditional logistic regression.

Results

Two or more stressful life events in the first trimester (adjusted OR 4.9; 95% CI 1.2-19.4), and moving address in the first trimester (aOR 4.9; 95% CI 1.7-13.9) were strongly associated with risk of gastroschisis, independent of behavioural risk factors including smoking, alcohol, and poor diet. Perceived availability of social support was not associated with reduced risk of gastroschisis (aOR 0.8; 95% CI 0.2-3.1).

Conclusions

Stressful maternal life events in the first trimester of pregnancy including change of address were strongly associated with a substantial increase in the risk of gastroschisis, independent of stress related high risk behaviours such as smoking, alcohol consumption and poor diet. This suggests that stress pathways are involved in the aetiology of gastroschisis.  相似文献   
38.
The Iberian mountain spiny fescues are a reticulate group of five diploid grass taxa consisting of three parental species and two putative hybrids: F. × souliei (F. eskia × F. quadriflora) and F. × picoeuropeana (F. eskia × F. gautieri). Phenotypic and molecular studies were conducted with the aim of determining the taxonomic boundaries and genetic relationships of the five taxa and disentangling the origins of the two hybrids. Statistical analyses of 31 selected phenotypic traits were conducted on individuals from 159 populations and on nine type specimens. Molecular analyses of random amplified polymorphic DNA (RAPD) markers were performed on 29 populations. The phenotypic analyses detected significant differences between the five taxa and demonstrated the overall intermediacy of the F. × picoeuropeana and F. × souliei between their respective parents. The RAPD analysis corroborated the genetic differentiation of F. eskia, F. gautieri and F. quadriflora and the intermediate nature of the two hybrids; however, they also detected genetic variation within F. × picoeuropeana. These results suggest distinct origins for F. × picoeuropeana in the Cantabrian and Pyrenean mountains, with the sporadic Pyrenean populations having potentially resulted from recent hybridizations and the stabilized Cantabrian ones from older events followed by potential displacements of the parents. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 173 , 676–706.  相似文献   
39.
The mosquito innate immune response is able to clear the majority of Plasmodium parasites. This immune clearance is controlled by a number of regulatory molecules including serine protease inhibitors (serpins). To determine whether such molecules could represent a novel target for a malaria transmission-blocking vaccine, we vaccinated mice with Anopheles gambiae serpin-2. Antibodies against Anopheles gambiae serpin-2 significantly reduced the infection of a heterologous Anopheles species (Anopheles stephensi) by Plasmodium berghei, however this effect was not observed with Plasmodium falciparum. Therefore, this approach of targeting regulatory molecules of the mosquito immune system may represent a novel approach to transmission-blocking malaria vaccines.  相似文献   
40.
Palmitoylated proteins have been implicated in several disease states including Huntington's, cardiovascular, T-cell mediated immune diseases, and cancer. To proceed with drug discovery efforts in this area, it is necessary to: identify the target enzymes, establish efficient assays for palmitoylation, and conduct high-throughput screening to identify inhibitors. The primary objectives of this review are to examine the types of assays used to study protein palmitoylation and to discuss the known inhibitors of palmitoylation. Six main palmitoylation assays are currently in use. Four assays, radiolabeled palmitate incorporation, fatty acyl exchange chemistry, MALDI-TOF MS and azido-fatty acid labeling are useful in the identification of palmitoylated proteins and palmitoyl acyltransferase (PAT) enzymes. Two other methods, the in vitro palmitoylation (IVP) assay and a cell-based peptide palmitoylation assay, are useful in the identification of PAT enzymes and are more amenable to screening for inhibitors of palmitoylation. To date, two general types of palmitoylation inhibitors have been identified. Lipid-based palmitoylation inhibitors broadly inhibit the palmitoylation of proteins; however, the mechanism of action of these compounds is unknown, and each also has effects on fatty acid biosynthesis. Conversely, several non-lipid palmitoylation inhibitors have been shown to selectively inhibit the palmitoylation of different PAT recognition motifs. The selective nature of these compounds suggests that they may act as protein substrate competitors, and may produce fewer non-specific effects. Therefore, these molecules may serve as lead compounds for the further development of selective inhibitors of palmitoylation, which may lead to new therapeutics for cancer and other diseases.  相似文献   
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