Current status of viroid taxonomy Di Serio, F; Flores, R; Verhoeven, J. Th. J ...
Archives of virology,
12/2014, Letnik:
159, Številka:
12
Journal Article
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Viroids are the smallest autonomous infectious nucleic acids known so far. With a small circular RNA genome of about 250-400 nt, which apparently does not code for any protein, viroids replicate and ...move systemically in host plants. Since the discovery of the first viroid almost forty-five years ago, many different viroids have been isolated, characterized and, frequently, identified as the causal agents of plant diseases. The first viroid classification scheme was proposed in the early 1990s and adopted by the International Committee on Taxonomy of Viruses (ICTV) a few years later. Here, the current viroid taxonomy scheme and the criteria for viroid species demarcation are discussed, highlighting the main taxonomic questions currently under consideration by the ICTV Viroid Study Group. The impact of correct taxonomic annotation of viroid sequence variants is also addressed, taking into consideration the increasing application of next-generation sequencing and bioinformatics for known and previously unrecognized viroids.
Elevated striatal dopamine synthesis capacity is thought to be fundamental to the pathophysiology of schizophrenia and has also been reported in people at risk of psychosis. It is therefore unclear ...if striatal hyperdopaminergia is a vulnerability marker for schizophrenia, or a state feature related to the psychosis itself. Relatives of patients with schizophrenia are themselves at increased risk of developing the condition. In this study we examined striatal dopamine synthesis capacity in both members of twin pairs discordant for schizophrenia.
In vivo striatal dopamine synthesis capacity was examined using fluorine-18-l-dihydroxyphenylalanine (18F-DOPA) positron emission tomography (PET) scans in seven twin pairs discordant for schizophrenia and in a control sample of 10 healthy control twin pairs.
Striatal 18F-DOPA uptake was not elevated in the unaffected co-twins of patients with schizophrenia (p=0.65) or indeed in the twins with schizophrenia (p=0.89) compared to the control group. Levels of psychotic symptoms were low in the patients with schizophrenia who were in general stable mean (s.d.) Positive and Negative Syndrome Scale (PANSS) total=56.8 (25.5) whereas the unaffected co-twins were largely asymptomatic.
Striatal dopamine synthesis capacity is not elevated in symptom-free individuals at genetic risk of schizophrenia, or in well-treated stable patients with chronic schizophrenia. These findings suggest that striatal hyperdopaminergia is not a vulnerability marker for schizophrenia.
Visual and verbal episodic memory deficits are putative endophenotypes for schizophrenia; however, the extent of any genetic overlap of these with schizophrenia is unclear. In this study, we set out ...to quantify the genetic and environmental contributions to variance in visual and verbal memory performance, and to quantify their genetic relationship with schizophrenia.
We applied bivariate genetic modelling to 280 twins in a classic twin study design, including monozygotic (MZ) and dizygotic (DZ) pairs concordant and discordant for schizophrenia, and healthy control twins. We assessed episodic memory using subtests of the Wechsler Memory Scale - Revised (WMS-R).
Genetic influences (i.e. heritability) contributed significantly to variance in immediate recall of both verbal memory and visual learning, and the delayed recall of verbal and visual memory. Liability to schizophrenia was associated with memory impairment, with evidence of significant phenotypic correlations between all episodic memory measures and schizophrenia. Genetic factors were the main source of the phenotypic correlations for immediate recall of visual learning material; both immediate and delayed recall of verbal memory; and delayed recall of visual memory that, for example, shared genetic variance with schizophrenia, which accounted for 88% of the phenotypic correlation (rph=0.41) between the two.
Verbal memory and visual learning and memory are moderately heritable, share a genetic overlap with schizophrenia and are valid endophenotypes for the condition. The inclusion of these endophenotypes in genetic association studies may improve the power to detect susceptibility genes for schizophrenia.
Potential difficulties associated with background silver salt clusters during matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) of nonpolar polymers are reported. Silver salt ...cluster ions were observed from
m/z 1500 to 7000 when acidic, polar matrices, such as 2,5-dihydroxybenzoic acid (DHB),
all-trans-retinoic acid (RTA) or 2-(4-hydroxyphenylazo)benzoic acid (HABA), were used for the analysis of nonpolar polymers. These background signals could be greatly reduced or eliminated by the use of nonpolar matrices such as anthracene or pyrene. Representative examples of these background interferences are demonstrated during the analysis of low molecular weight nonpolar polymers including polybutadiene and polystyrene. Nonpolar polymers analyzed with acidic, polar matrices (e.g., RTA) and silver cationization reagents can yield lower quality mass spectral results when interferences due to silver clusters are present. Replacing the polar matrices with nonpolar matrices or the silver salts with copper salts substantially improved the quality of the analytical results. In addition, it was found that silver contamination cannot be completely removed from standard stainless steel sample plates, although the presence of silver contamination was greatly reduced after thorough cleaning of the sample plate with aluminum oxide grit. Carry-over silver may cationize polymer samples and complicate the interpretation of data obtained using nonpolar matrices in the absence of added cationization reagents.
Deuterium neutral beams with energies up to 110 keV were injected into TFTR (Tokamak Fusion Test Reactor) plasmas at low magnetic field such that the beam injection velocities were comparable to the ...Alfvén velocity. Excitation of toroidal Alfvén eigenmodes was observed by Mirnov coils and beam emission spectroscopy.
Eukaryotic transcriptional regulation in different cells involves large numbers and arrangements of cis and trans elements. To survey the number of cis regulatory elements that are active in ...different contexts, we have devised a high-throughput selection procedure permitting synthesis of active cis motifs that enhance the activity of a minimal promoter. This synthetic promoter construction method (SPCM) was used to identify >100 DNA sequences that showed increased promoter activity in the neuroblastoma cell line Neuro2A. After determining DNA sequences of selected synthetic promoters, database searches for known elements revealed a predominance of eight motifs: AP2, CEBP, GRE, Ebox, ETS, CREB, AP1, and SP1/MAZ. The most active of the selected synthetic promoters contain composites of a number of these motifs. Assays of DNA binding and promoter activity of three exemplary motifs (ETS, CREB, and SP1/MAZ) were used to prove the effectiveness of SPCM in uncovering active sequences. Up to 10% of 133 selected active sequences had no match in currently available databases, raising the possibility that new motifs and transcriptional regulatory proteins to which they bind may be revealed by SPCM. The method may find uses in constructing databases of active cis motifs, in diagnostics, and in gene therapy.
Poultry industry paradigms: connecting the dots Castro, F.L.S.; Chai, L.; Arango, J. ...
Journal of applied poultry research,
March 2023, 2023-03-00, 2023-03-01, Letnik:
32, Številka:
1
Journal Article
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Providing high-quality food for the increasing world population with limited natural resources is a challenge for animal agriculture. Over the past decades, poultry production has undergone ...remarkable advancements to adapt to emerging challenges and evolving changes in consumer expectations. Among these changes, the need for an animal protein production system that considers the social, economic, and environmental aspects of sustainability has increased. With that in mind, efforts were and will continue to be made toward improving various aspects of the poultry production chain. Genetic selection has evolved from a simple phenotypic mass selection to the use of genomics, focusing not only on efficiency, but also on animal welfare and the demand from niche markets. Precision poultry farming technologies should be further innovated to develop the core component of an integrated imaging system for evaluating poultry production and wellbeing. Moreover, feed formulation will continue to be adjusted as the birds' nutritional requirements, feed ingredient availability, and cost change, and bird processing will continue to adopt technologies that can improve meat quality and reduce labor intensity and demand. These adaptations highlight a dynamic aspect of the poultry industry and its continuous effort to produce a safe, cost-effective, and environment friendly protein source while maintaining animal welfare.
Disruption of the anterior cruciate ligament (ACL) is a common injury. In active patients, it is routinely treated with ACL reconstruction surgery. Following reconstruction, one of the critical ...decisions that must be made is the optimal timing of return to sport. While a many of biomechanical, biological, and functional criteria have been proposed to determine return to play, these methods are limited at best. As criteria for return to play are multifactorial, there is a growing need for non-invasive technologies, such as magnetic resonance imaging (MRI), to objectively track graft healing, to better assess the graft itself. Measuring the changes in strength of the healing ligament has been shown to be a reliable means of objectively documenting graft healing in pre-clinical studies. While the initial studies of MR-based modeling of ACL graft healing are promising, this technology is still in its infancy and requires optimization. The goals of this review are: 1) to outline the shortcomings of current return to play criteria, 2) to highlight the ability of MRI to determine the status of ACL graft healing, and 3) to discuss the future of imaging technology to determine return to play and its potential role in the clinical evaluation of patients.
Monoclonal antibody-based two-site immunoradiometric assays are described for human insulin, proinsulin, 65-66 split and 32-33 split proinsulin. The detection limits of the assays lie in the range ...0.8-2.5 pM. The assays for 65-66 and 32-33 split proinsulins do not distinguish between these substances and their respective C-terminal di-desamino derivatives. The assay of 65-66 split proinsulin does not cross-react with insulin, proinsulin or 32-33 split proinsulin. This material was undetectable (less than 1.0 pM) in plasma taken after an overnight fast in eight normal male subjects and the maximum individual concentration reached in plasma taken during an oral glucose tolerance test of these subjects was 3.8 pM. The proinsulin assay cross-reacted 66% with 65-66 split proinsulin but not with insulin or 32-33 split proinsulin. The 32-33 split proinsulin assay cross-reacted 84 and 60% with proinsulin and 65-66 split proinsulin respectively. The insulin assay cross-reacted 5.3, 62 and 5.0% with intact proinsulin, 65-66 split proinsulin and 32-33 split proinsulin respectively. The very low concentration of 65-66 split proinsulin meant that this derivative did not interfere significantly with the specificity of the assays of proinsulin and insulin. The concentration of 32-33 split proinsulin could be calculated by subtracting the cross-reactivity of the measured proinsulin. The mean concentrations of insulin, proinsulin and 32-33 split proinsulin in eight young male subjects in the fasting state were (pM +/- S.E.M.) 20 +/- 0.3, 2.3 +/- 0.3 and 2.1 +/- 0.7 and at the maximum reached during an oral glucose tolerance test, 150 +/- 26, 9.9 +/- 1.4 and 19.7 +/- 6.0 respectively.
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