2,962 research outputs found
Amplification of genome-integrated BeYDV replicons by transient expression of Rep in Arabidopsis thaliana
Bean yellow dwarf geminivirus (BeYDV) has been used as a potential
vector to improve foreign gene expression, specifically, to achieve
higher yields of vaccine proteins in plants. Previously, we have shown
that when the BeYDV replication initiator protein Rep was provided in
trans, replication and gene expression of GUS were enhanced enormously
from a BeYDV expression vector in a transient assay system. In this
paper, transgenic lines of Arabidopsis (cv. Columbia) were generated
harboring the BeYDV cis-acting elements required for replication.
Constructs encoding BeYDV Rep or intronless Rep open reading frames
(ORFs) were transiently introduced into transgenic plants via
Agrobacterium-mediated infiltration in order to examine the relative
levels of replication and expression of the genome-integrated GUS
reporter gene. This study shows that expression of Rep protein was
regulated in trans from a separate cassette which enabled the rescue,
replication and enhancement of the genome-integrated GUS gene in
transgenic Arabidopsis. We conclude that Rep expression can be
effectively controlled in Arabidopsis plants, and that regulation of
Rep expression can result in the amplification of a genome-integrated
foreign gene by circumventing the negative effects of gene silencing
Actin Cytoskeleton and Golgi Involvement in Barley stripe mosaic virus Movement and Cell Wall Localization of Triple Gene Block Proteins.
Barley stripe mosaic virus (BSMV) induces massive actin filament thickening at the infection front of infected Nicotiana benthamiana leaves. To determine the mechanisms leading to actin remodeling, fluorescent protein fusions of the BSMV triple gene block (TGB) proteins were coexpressed in cells with the actin marker DsRed: Talin. TGB ectopic expression experiments revealed that TGB3 is a major elicitor of filament thickening, that TGB2 resulted in formation of intermediate DsRed:Talin filaments, and that TGB1 alone had no obvious effects on actin filament structure. Latrunculin B (LatB) treatments retarded BSMV cell-to-cell movement, disrupted actin filament organization, and dramatically decreased the proportion of paired TGB3 foci appearing at the cell wall (CW). BSMV infection of transgenic plants tagged with GFP-KDEL exhibited membrane proliferation and vesicle formation that were especially evident around the nucleus. Similar membrane proliferation occurred in plants expressing TGB2 and/or TGB3, and DsRed: Talin fluorescence in these plants colocalized with the ER vesicles. TGB3 also associated with the Golgi apparatus and overlapped with cortical vesicles appearing at the cell periphery. Brefeldin A treatments disrupted Golgi and also altered vesicles at the CW, but failed to interfere with TGB CW localization. Our results indicate that actin cytoskeleton interactions are important in BSMV cell-to-cell movement and for CW localization of TGB3
Effect of Irradiation on the Degradation of Nucleotides in Turkey Meat
The degradation of nucleotides in cured ready-to-eat (RTE) as well as uncured raw and cooked turkey meat products by irradiation were determined to evaluate the potential impact of nucleotides on the taste changes in irradiated turkey meat. Four irradiation doses (0, 1.5, 3.0 and 4.5 kGy) were applied to cured RTE and uncured turkey meat products, and the amounts of nucleotides and their degradation products were measured. Results showed that irradiation had a significant impact to the amount of nucleotides (adenosine diphosphate, adenosine monophosphate and inosine monophosphate) and the breakdown of these nucleotides (inosine and hypoxanthine) in uncured turkey meat when irradiated at \u3c 3.0 kGy. However, significant decreases in inosine and hypoxanthine were observed when the uncured turkey meat were irradiated at \u3e 3.0 kGy might attribute to uric acid and other compounds formation. The increase in K-value (the percentage of inosine and hypoxanthine over the total content of adenosine triphosphate) at lower irradiation dose in uncured cooked than raw turkey meat indicated that cooked meat is more susceptible to oxidation. But little effect was found on the nucleotides and nucleotides degradation products in cured RTE turkey meat products because of the antioxidant effect of sodium nitrite
Hippocampal sclerosis and encephalomalacia as prognostic factors of tuberculous meningitis-related and herpes simplex encephalitis-related epilepsy
AbstractBackgroundTuberculous meningitis (TBM) and herpes simplex encephalitis (HSE) are common neurological diseases involving the brain parenchyma, and both can result in chronic epilepsy. Here, we identified possible variables affecting the prognosis of central nervous system (CNS) infection-related epilepsy.MethodsThe clinical seizure characteristics and demographic data of 20 TBM- and 55 HSE-related epilepsy patients were compared. Statistically significant prognostic variables were identified using multiple regression analysis.ResultsSex, age at infection, age at epilepsy onset, presence of seizures at the time of infection, latency period, and seizure characteristics between two groups were similar except for the pattern of brain lesions observed on the MRI and their overall prognosis. Patients with hippocampal sclerosis (HS) only comprised 30% and 52.7% of the TBM and HSE groups, respectively. Encephalomalacia had a positive effect in the HSE group while HS had a negative effect in this group, but no significant effects were found in the TBM group. Through a multiple regression analysis with a correction for group effects, HS was associated with a poor prognosis. However, encephalomalacia was concomitantly associated with a good prognosis. In addition, a short latency period, with a one-year interval, and being male were both associated with a good prognosis, while the age at the onset of epilepsy was associated with a poor prognosis.ConclusionsThis study suggests that HS and encephalomalacia could have mutual but contradictory effects on the prognosis of CNS infection-related epilepsy
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Is poststroke complex regional pain syndrome the combination of shoulder pain and soft tissue injury of the wrist?: A prospective observational study STROBE of ultrasonographic findings in complex regional pain syndrome
Patients with poststroke complex regional pain syndrome (CRPS) show different symptoms compared to other types of CRPS, as they usually complain of shoulder and wrist pain with the elbow relatively spared. It is thus also known by the term āshoulder-hand syndrome.ā
The aim of this study is to present a possible pathophysiology of poststroke CRPS through ultrasonographic observation of the affected wrist before and after steroid injection at the extensor digitorum communis (EDC) tendon in patients suspected with poststroke CRPS.
Prospective evaluation and observation, the STROBE guideline checklist was used.
Twenty-three patients diagnosed as poststroke CRPS in accordance to clinical criteria were enrolled. They had a Three Phase Bone Scan (TPBS) done and the cross-sectional area (CSA) of EDC tendon was measured by using ultrasonography. They were then injected with steroid at the EDC tendon. The CSA of EDC tendon, visual analogue scale (VAS), and degree of swelling of the wrist were followed up 1 week after the injection.
TPBS was interpreted as normal for 4 patients, suspected CRPS for 10 patients, and CRPS for 9 patients. Ultrasonographic findings of the affected wrist included swelling of the EDC tendon. After the injection of steroid to the wrist, CSA and swelling of the affected wrist compared to that before the treatment was significantly decreased (P < 0.001). The VAS score declined significantly after the injection (P < 0.001).
Our results suggest that the pathophysiology of poststroke CRPS might be the combination of frozen shoulder or rotator cuff tear of shoulder and soft tissue injury of the wrist caused by the hemiplegic nature of patients with stroke
Red Ginseng Extract Facilitates the Early Differentiation of Human Embryonic Stem Cells into Mesendoderm Lineage
Human embryonic stem cells (hESCs) have capacities to self-renew and differentiate into all cell types in vitro. Red ginseng (RG) is known to have a wide range of pharmacological effects in vivo; however, the reports on its effects on hESCs are few. In this paper, we tried to demonstrate the effects of RG on the proliferation and differentiation of hESCs. Undifferentiated hESCs, embryoid bodies (EBs), and hESC-derived cardiac progenitors (CPs) were treated with RG extract at 0.125, 0.25, and 0.5āmg/mL. After treatment of undifferentiated hESCs from day 2 to day 6 of culture, BrdU labeling showed that RG treatment increased the proliferation of hESCs, and the expression of Oct4 and Nanog was increased in RG-treated group. To find out the effects of RG on early differentiation stage cells, EBs were treated with RG extract for 10 days and attached for further differentiation. Immunostaining for three germ layer markers showed that RG treatment increased the expressions of Brachyury and HNF3Ī² on EBs. Also, RG treatment increased the expression of Brachyury in early-stage and of Nkx2.5 in late-stage hESC-derived CPs. These results demonstrate facilitating effects of RG extract on the proliferation and early differentiation of hESC
Antimicrobial Effect of 7-O-Butylnaringenin, a Novel Flavonoid, and Various Natural Flavonoids against Helicobacter pylori Strains
Abstract: The antimicrobial effect of a novel flavonoid (7-O-butylnaringenin) on Helicobacter pylori 26695, 51, and SS1 strains and its inhibitory effect on the urease activity of the strains were evaluated and compared with those of several natural flavonoids. First, various flavonoids were screened for antimicrobial activities using the paper disc diffusion method. Hesperetin and naringenin showed the strongest antimicrobial effects among the natural flavonoids tested, and thus hesperetin and naringenin were selected for comparison with 7-O-butylnaringenin. The antimicrobial effect of 7-O-butylnaringenin was greater than that of the hesperetin and naringenin. H. pylori 51 was more sensitive to 7-O-butylnaringenin (2 log reduction of colony forming units, p \u3c 0.05) than the other two strains at 200 Ī¼M. 7-O-Butylnaringenin also showed the highest inhibitory effect against urease activity of H. pylori. Morphological changes of H. pylori 26695 treated with these flavonoids indicated that both hesperetin and 7-O-butylnaringenin at 200 Ī¼M damaged the cell membranes
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