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21.
The 50S-70S RNA of a Moloney sarcoma-leukemia virus [Mo-MSV(MLV)] complex produced by a particular mouse cell line was shown by gel electrophoresis to contain a major (97%) 30S sarcoma-specific subunit species and a minor (3%) 38S leukemia virus-specific subunit. On the basis of its sedimentation coefficient and known complexity, the 30S Mo-MSV RNA was estimated to be a unique RNA molecule of about 6000 nucleotides. Hybridization experiments using viral RNA and DNA complementary to viral RNA (cDNA) made by viral DNA polymerase indicated that the 30S Mo-MSV RNA shared 70% of its sequences with Mo-MLV, 30% with another MLV derived from Mo-MLV, and 30% with Kirsten sarcoma-xenotropic leukemia virus. The 30S Mo-MSV RNA sequences shared with these viruses were not additive. The Tm of a Mo-MSV RNA-MLV cDNA hybrid was 83 degrees C, indicating that large contiguous nucleotide sequences were shared between the two nucleic acids. Mo-MSV RNA and Mo-MLV RNA shared possibly seven of 20-30 RNAase T1-resistant oligonucleotides, while Mo-MSV RNA contained three, and Mo-MLV RNA contained at least five specific oligonucleotides. We conclude that the 30S Mo-MSV RNA molecule consists of approximately 70% (about 4200 nucleotides) Mo-MLV-specific sequences and of 30% (1800 nucleotides) Mo-MSV-specific sequences covalently linked. Our results favor the hypothesis that 30S Mo-MSV RNA was generated by recombination between Mo-MLV and other genetic elements. We discuss whether all or only the MSV-specific sequences of the 30S Mo-MSV RNA function as sarcoma genes. Mo-MLV cDNA was hybridized about 45% by unfractionated Mo-MSV (MLV) RNA at RNA/DNA ratios of up to 10, about 50% by electrophoretically purified 30S Mo-MSV RNA at RNA/DNA ratios up to 500, but close to 100% by unfractionated Mo-MSV(MLV) RNA at RNA/DNA ratios over 900. This indicated that unfractionated RNA of our Mo-MSV(MLV) contained a complete complement of Mo-MLV, albeit at a low ratio. 相似文献
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Zuzana Kasanova Dennis Hernaus Thomas Vaessen Thérèse van Amelsvoort Oliver Winz Alexander Heinzel Jens Pruessner Felix M. Mottaghy Dina Collip Inez Myin-Germeys 《PloS one》2016,11(3)
Early life stress may have a lasting impact on the developmental programming of the dopamine (DA) system implicated in psychosis. Early adversity could promote resilience by calibrating the prefrontal stress-regulatory dopaminergic neurotransmission to improve the individual’s fit with the predicted stressful environment. Aberrant reactivity to such match between proximal and distal environments may, however, enhance psychosis disease risk. We explored the combined effects of childhood adversity and adult stress by exposing 12 unmedicated individuals with a diagnosis of non-affective psychotic disorder (NAPD) and 12 healthy controls (HC) to psychosocial stress during an [18F]fallypride positron emission tomography. Childhood trauma divided into early (ages 0–11 years) and late (12–18 years) was assessed retrospectively using a questionnaire. A significant group x childhood trauma interaction on the spatial extent of stress-related [18F]fallypride displacement was observed in the mPFC for early (b = -8.45, t(1,23) = -3.35, p = .004) and late childhood trauma (b = -7.86, t(1,23) = -2.48, p = .023). In healthy individuals, the spatial extent of mPFC DA activity under acute psychosocial stress was positively associated with the severity of early (b = 7.23, t(11) = 3.06, p = .016) as well as late childhood trauma (b = -7.86, t(1,23) = -2.48, p = .023). Additionally, a trend-level main effect of early childhood trauma on subjective stress response emerged within this group (b = -.7, t(11) = -2, p = .07), where higher early trauma correlated with lower subjective stress response to the task. In the NAPD group, childhood trauma was not associated with the spatial extent of the tracer displacement in mPFC (b = -1.22, t(11) = -0.67), nor was there a main effect of trauma on the subjective perception of stress within this group (b = .004, t(11) = .01, p = .99). These findings reveal a potential mechanism of neuroadaptation of prefrontal DA transmission to early life stress and suggest its role in resilience and vulnerability to psychosis. 相似文献
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Petri Tanska Petro Julkunen Rami K. Korhonen 《Biomechanics and modeling in mechanobiology》2018,17(3):689-699
Cartilage defects are a known risk factor for osteoarthritis. Estimation of structural changes in these defects could help us to identify high risk defects and thus to identify patients that are susceptible for the onset and progression of osteoarthritis. Here, we present an algorithm combined with computational modeling to simulate the disorganization of collagen fibril network in injured cartilage. Several potential triggers for collagen disorganization were tested in the algorithm following the assumption that disorganization is dependent on the mechanical stimulus of the tissue. We found that tensile tissue stimulus alone was unable to preserve collagen architecture in intact cartilage as collagen network reoriented throughout the cartilage thickness. However, when collagen reorientation was based on both tensile tissue stimulus and tensile collagen fibril strains or stresses, the collagen network architecture was preserved in intact cartilage. Using the same approach, substantial collagen reorientation was predicted locally near the cartilage defect and particularly at the cartilage–bone interface. The developed algorithm was able to predict similar structural findings reported in the literature that are associated with experimentally observed remodeling in articular cartilage. The proposed algorithm, if further validated, could help to predict structural changes in articular cartilage following post-traumatic injury potentially advancing to impaired cartilage function. 相似文献
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Reem Alajmi Mona Al-Shammari Rewaida Abdel-Gaber Dina Metwally Manal F. El-Khadragy Albandary Alrajeh 《Saudi Journal of Biological Sciences》2021,28(7):4096-4101
Although certain pollutants can be biologically degraded by microorganisms, rendering their impact short-term, others can not be impaired, such that their effect persists. The present study evaluates the effectiveness of using a field-collected aphid, Aphis gossypii, as a bio-indicator for heavy metals in tomato farms in Riyadh and Hafar Al-Batin, Saudi Arabia. Heavy metals were selected (Cd, Cu, Zn, and Pb) and measured for comparative screening in field-collected plants, soil, and aphids using inductively coupled plasma-mass spectrometry (ICP-MS). Field-collected aphids from both studied regions were identified as Aphis gossypii. In Riyadh, there was no significant difference observed for Cd, Cu, and Zn for all experimental samples, while, Pb was showed differences among samples especially tomato leaves None of the studied samples in Hafar Al-Batin were showed statistically significant differences in Cd, in reverse to significant differences in the other heavy metals. Comparing concentrations of selected heavy metals between the two studied regions was showed that neither region showed a significant difference in heavy metals except for Cu. This study demonstrates that tomato leaf samples showed the highest concentrations of most studied heavy metals, followed by soil, then aphids. Aphids were utilized as a bio-indicator of heavy metals in the studied regions. 相似文献
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Haider Karar Muhammad Amjad Bashir Reem Atalla Alajmi Dina M. Metwally Muneeba Haider Najeeba Haider Samad Raza Ali Bakhsh Rania Haddadi 《Saudi Journal of Biological Sciences》2021,28(7):3936-3942
In 2004–05, during the December to February about 141 mango farmers were interviewed during peak activity of mango mealy bug in southern Punjab, Pakistan. The objective was to know the farmers’ knowledge, perceptions and practices in the management of mango mealy bug. Most of the farmers (94.33%) reported that Chaunsa variety (king of all mango varieties) was susceptible to mango and irrigation water was the major source of flare up of this pest. Basudin and Supracide were the most commonly used insecticides as 72.92 and 51.77 percent farmers gave positive response and grease bands were applied for the control of mango mealy bug by the majority of the respondents. Hundred percent yield losses was told by 22.7 percent respondents whereas 75 percent, 50 percent and 25 percent losses were reported by 39.7, 31.9 and 14.2 insecticidal spray did not show satisfaction to the respondents for the control of fertilized females of mango mealy bug coming down from the trees. Lack of knowledge about the pest, lack of money, adulterated and shortage of pesticides, lack of unity amongst farmers Further the growers’ views were tested in the field for confirmation and small land holdings were the main constraints for the control of mango mealy bug. 相似文献
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Johanna T. W. Wigman Jim van Os Evert Thiery Catherine Derom Dina Collip Nele Jacobs Marieke Wichers 《PloS one》2013,8(3)