Enhanced Resistance to Viruses in Nicotiana edwardsonii 'Columbia' Is Dependent on Salicylic Acid, Correlates with High Glutathione Levels, and Extends to Plant-Pathogenic Bacteria and Abiotic Stress.

Our earlier research showed that an interspecific tobacco hybrid (Nicotiana edwardsonii 'Columbia' [NEC]) displays elevated levels of salicylic acid (SA) and enhanced resistance to localized necrotic symptoms (hypersensitive response [HR]) caused by tobacco mosaic virus (TMV) and tobacco necrosis virus (TNV), as compared with another interspecific hybrid (Nicotiana edwardsonii [NE]) derived from the same parents. In the present study, we investigated whether symptomatic resistance in NEC is indeed associated with the inhibition of TMV and TNV and whether SA plays a role in this process. We demonstrated that enhanced viral resistance in NEC is manifested as both milder local necrotic (HR) symptoms and reduced levels of TMV and TNV. The presence of an adequate amount of SA contributes to the enhanced defense response of NEC to TMV and TNV, as the absence of SA resulted in seriously impaired viral resistance. Elevated levels of subcellular tripeptide glutathione (GSH) in NEC plants in response to viral infection suggest that in addition to SA, GSH may also contribute to the elevated viral resistance of NEC. Furthermore, we found that NEC displays an enhanced resistance not only to viral pathogens but also to bacterial infections and abiotic oxidative stress induced by paraquat treatments. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Reactive Oxygen Species Contribute to Symptomless, Extreme Resistance to Potato virus X in Tobacco.

Here we show that in tobacco (Nicotiana tabacum cultivar Samsun NN Rx1) the development of Rx1 gene-mediated, symptomless, extreme resistance to Potato virus X (PVX) is preceded by an early, intensive accumulation of the reactive oxygen species (ROS) superoxide (O2·-), evident between 1 and 6 h after inoculation and associated with increased nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activities. This suggests a direct contribution of this ROS to virus restriction during symptomless, extreme resistance. Superoxide inhibition in PVX-inoculated leaves by infiltration of antioxidants (superoxide dismutase [SOD] and catalase [CAT]) partially suppresses extreme resistance in parallel with the appearance of localized leaf necrosis resembling a hypersensitive resistance (HR) response. F1 progeny from crosses of Rx1 and ferritin overproducer (deficient in production of the ROS OH·) tobaccos also display a suppressed extreme resistance to PVX, because significantly increased virus levels are coupled to HR, suggesting a role of the hydroxyl radical (OH·) in this symptomless antiviral defense. In addition, treatment of PVX-susceptible tobacco with a superoxide-generating agent (riboflavin/methionine) results in HR-like symptoms and reduced PVX titers. Finally, by comparing defense responses during PVX-elicited symptomless, extreme resistance and HR-type resistance elicited by Tobacco mosaic virus, we conclude that defense reactions typical of an HR (e.g., induction of cell death/ROS-regulator genes and antioxidants) are early and transient in the course of extreme resistance. Our results demonstrate the contribution of early accumulation of ROS (superoxide, OH·) in limiting PVX replication during symptomless extreme resistance and support earlier findings that virus-elicited HR represents a delayed, slower resistance response than symptomless, extreme resistance.

Utility of percutaneous thrombin injection for treating visceral pseudoaneurysms.

PURPOSE: To assess the efficacy and outcome of percutaneous thrombin injection in treatment of visceral arterial pseudoaneurysms (PAs) in a selective group of patients. MATERIAL AND METHODS: Retrospective review of the institutional database showed 19 cases of visceral arterial pseudoaneurysms that were treated with percutaneous ultrasound-guided thrombin injection between January 2014 and December 2019 (13 men and 6 women). Of the pseudoaneurysms, 36% were due to pancreatitis, 35% were iatrogenic, 21% were infective and 8% traumatic. Most of the pseudoaneurysms arose from the hepatic artery (27%) followed by the splenic artery (26%) and renal artery (21%). Mean sac size of the pseudoaneurysms was 23 mm (range, 8 -40 mm). Technical success was defined as absence of flow within the PAs on follow-up ultrasonography (USG) 24 h and 3 days after thrombin injection. RESULTS: Overall technical success was seen in 10/19 patients. Technical success of thrombin injection was higher in cases of distal branch PAs as compared to main vessel PAs (9/13 vs. 1/6). Success rates were higher with smaller (<23mm) pseudoaneurysms (7/12) as compared to larger ones (3/7). There were no procedure-related complications. CONCLUSION: Ultrasound-guided percutaneous thrombin injection is a novel method of treating visceral pseudoaneurysms as a painless, cheap and radiation-free procedure. However, further large-scale studies are needed to prove the efficacy in treating visceral pseudoaneurysms.

Transversus Abdominis Plane Block Versus Wound Infiltration for Analgesia After Cesarean Delivery: A Randomized Controlled Trial.

BACKGROUND: Transversus abdominis plane (TAP) block and local anesthetic wound infiltration provide analgesia after cesarean delivery. Studies comparing the 2 techniques are scarce, with conflicting results. This double-blind, randomized controlled trial aimed to compare bilateral ultrasound-guided TAP block with single-shot local anesthetic wound infiltration for analgesia after cesarean delivery performed under spinal anesthesia. We hypothesized that the TAP block would decrease postoperative cumulative fentanyl consumption at 24 hours. METHODS: Eligible subjects were American Society of Anesthesiologists physical status II parturients with full-term singleton pregnancies undergoing elective cesarean delivery under spinal anesthesia. Exclusion criteria were: <19 years of age or >40 years of age; height <150 cm, weight <60 kg, body mass index ≥40 kg/m; contraindications to spinal anesthesia; history of recent opioid exposure; hypersensitivity to any of the drugs used in the study; significant cardiovascular, renal, or hepatic disease; and known fetal abnormalities. Eighty subjects were randomly allocated to 2 equal groups. In the infiltration group, participants received 15 mL of bupivacaine 0.25% in each side of the surgical wound (total 30 mL); and in the TAP group, participants received 20 mL of bupivacaine 0.25% bilaterally in the TAP block (total 40 mL). The TAP block and wound infiltration were performed by the primary investigator and the operating obstetrician, respectively. All participants received postoperative standard analgesia (ketorolac and paracetamol) and intravenous fentanyl via patient-controlled analgesia. Patients and outcome assessors were blinded to the study group. The primary outcome was the cumulative fentanyl consumption at 24 hours. Secondary outcomes were the time to the first postoperative fentanyl dose, cumulative fentanyl consumption at 2, 4, 6, and 12 hours, pain scores at rest and on movement at 2, 4, 6, 12, and 24 hours, the deepest level of sedation, the incidence of side effects (nausea and vomiting and pruritis), and patient satisfaction. RESULTS: Data from 78 patients (39 patients in each group) were analyzed. The mean ± SD of cumulative fentanyl consumption at 24 hours was 157.4 ± 63.4 µg in the infiltration group and 153.3 ± 68.3 µg in the TAP group (difference in means [95% confidence interval] is 4.1 [-25.6 to 33.8] µg; P = .8). There were no significant differences between the 2 groups in the time to the first postoperative fentanyl dose, cumulative fentanyl consumption at 2, 4, 6, and 12 hours, pain scores at rest and on movement at 2, 4, 6, 12, and 24 hours, the deepest level of sedation, and patient satisfaction. The incidence of side effects (nausea and vomiting and pruritis) was low in the 2 groups. CONCLUSIONS: TAP block and wound infiltration did not significantly differ regarding postoperative fentanyl consumption, pain scores, and patient satisfaction in parturients undergoing cesarean delivery under spinal anesthesia.

Up-regulation of antioxidants in tobacco by low concentrations of H2O2 suppresses necrotic disease symptoms.

Pretreatment of tobacco leaves with low concentrations (5 to 10 mM) of H2O2 suppressed hypersensitive-type necrosis associated with resistance to Tobacco mosaic virus (TMV) or Pseudomonas syringae pv. phaseolicola. The same pretreatment resulted in suppression of normosensitive necrosis associated with susceptibility to Botrytis cinerea. This type of H2O2-mediated, induced disease symptom resistance correlated with enhanced host antioxidant capacity, i.e., elevated enzymatic activities of catalase (CAT), ascorbate peroxidase (APX), and guaiacol peroxidase (POX) after viral and bacterial infections. Induction of genes that encode the antioxidants superoxide dismutase (SOD), CAT, and APX was also enhanced early after TMV infection. Artificial application of SOD and CAT suppressed necroses caused by viral, bacterial, or fungal pathogens similarly as H2O2 pretreatment, implying that H2O2-mediated symptom resistance operates through enhancement of plant antioxidant capacity. Pathogen multiplication was not significantly affected in H2O2-pretreated plants. Salicylic acid (SA), a central component of plant defense, does not seem to function in this type of H2O2-mediated symptom resistance, indicated by unchanged levels of free and bound SA and a lack of early up-regulation of an SA glucosyltransferase gene in TMV-infected H2O2-pretreated tobacco. Taken together, H2O2-mediated, induced resistance to necrotic symptoms in tobacco seems to depend on enhanced antioxidant capacity.

Application of novel Fe3O4/Zn-metal organic framework magnetic nanostructures as an antimicrobial agent and magnetic nanocatalyst in the synthesis of heterocyclic compounds.

Using the microwave-assisted method, novel Fe3O4/Zn-metal organic framework magnetic nanostructures were synthesized. The crystallinity, thermal stability, adsorption/desorption isotherms, morphology/size distribution, and magnetic hysteresis of synthesized Fe3O4/Zn-metal organic framework magnetic nanostructures were characterized by XRD patterns, TGA curve, BET adsorption/desorption technique, SEM image, and VSM curve, respectively. After confirming the Fe3O4/Zn-metal organic framework magnetic nanostructures, its antimicrobial properties against Gram-positive bacterial, Gram-negative bacterial, and fungal strains based on minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and minimum fungicidal concentration (MFC) values were studied. The MIC values in antimicrobial activity for Gram-positive and Gram-negative bacterial strains, between 16-128 µg/ml, and for fungal strain, 128 µg/ml were observed. The results showed that the high specific surface area of Fe3O4/Zn-metal organic framework magnetic nanostructures caused the antimicrobial power of nanoparticles to be high, and the observed antimicrobial effects were higher than some known commercial antimicrobial drugs. Another advantage of the specific surface area of Fe3O4/Zn-metal organic framework magnetic nanostructures was its high catalytic properties in the three-component reaction of isatin, malononitrile, and dimedone. New spiro [indoline-pyranopyrimidines] derivatives were synthesized with high efficiency. The catalytic activity results of Fe3O4/Zn-metal organic framework magnetic nanostructures showed that, in addition to recyclability, derivatives could be synthesized in less time than previously reported methods. The results of investigating the catalytic activity of Fe3O4/Zn-metal organic framework magnetic nanostructures showed that the spiro [indoline-pyranopyrimidines] derivatives were synthesized in the time range of 10-20 min with an efficiency of over 85%. As a final result, it can be concluded that the microwave synthesis method improves the unique properties of magnetic nanostructures, especially its specific surface area, and has increased its efficiency.

Influence of parent vessel dominancy on fluid dynamics of anterior communicating artery aneurysms.

BACKGROUND: Parent vessel plays an important role in aneurysm formation and rupture. The diameter of either the A1 arteries is the peculiar key controlling the flow of the anterior communicating artery (ACOMA) aneurysms (ANs). OBJECTIVE: The purpose is to study the effect of parent vessel dominancy, that is, the diameter of the A1 artery, on the flow characteristics of the ACOMA ANs. METHODS: Numerical simulations for the flow patterns in six artificial models have been studied. Three models are designed with aneurysms and three models without. The two A1s were equal in two models. In the other two models, the nondominant A1 diameters were decreased by 50%. Again, the nondominant A1s were decreased by another 50% in the last two models. Each pair was designed with and without aneurysms in the ACOMA. FINDINGS: The ACOMA shows lower velocity magnitudes and wall shear stresses when the two A1s are equal. However, if one A1 is dominant with a 50% difference from the other A1, there is higher shear stress on the ACOMA itself and in the inflow zone of the aneurysm that increases more with further reduction of the nondominant A1 by another 50%. An area of high corner pressure at the bifurcation of the dominant A1 into the ACOMA and A2 exists and increases in value with the decrease of diameter of the other nondominant A1. CONCLUSION: Aneurysms located in the ACOMA with differences of 50% or more between the two A1s are subjected to more flow stresses.

Superoxide (O2.-) accumulation contributes to symptomless (type I) nonhost resistance of plants to biotrophic pathogens.

Nonhost resistance is the most common form of disease resistance exhibited by plants against most pathogenic microorganisms. Type I nonhost resistance is symptomless (i.e. no macroscopically visible cell/tissue death), implying an early halt of pathogen growth. The timing/speed of defences is much more rapid during type I nonhost resistance than during type II nonhost and host ("gene-for-gene") resistance associated with a hypersensitive response (localized necrosis, HR). However, the mechanism(s) underlying symptomless (type I) nonhost resistance is not entirely understood. Here we assessed accumulation dynamics of the reactive oxygen species superoxide (O2.-) during interactions of plants with a range of biotrophic and hemibiotrophic pathogens resulting in susceptibility, symptomless nonhost resistance or host resistance with HR. Our results show that the timing of macroscopically detectable superoxide accumulation (1-4 days after inoculation, DAI) is always associated with the speed of the defense response (symptomless nonhost resistance vs. host resistance with HR) in inoculated leaves. The relatively early (1 DAI) superoxide accumulation during symptomless nonhost resistance of barley to wheat powdery mildew (Blumeria graminis f. sp. tritici) is localized to mesophyll chloroplasts of inoculated leaves and coupled to enhanced NADPH oxidase (EC 1.6.3.1) activity and transient increases in expression of genes regulating superoxide levels and cell death (superoxide dismutase, HvSOD1 and BAX inhibitor-1, HvBI-1). Importantly, the partial suppression of symptomless nonhost resistance of barley to wheat powdery mildew by heat shock (49 °C, 45 s) and antioxidant (SOD and catalase) treatments points to a functional role of superoxide in symptomless (type I) nonhost resistance.