Genetic improvement of Trichoderma ability to induce systemic resistance

The beneficial applications of Trichoderma spp. in agriculture include not only the control of plant pathogens, but also the improvement of plant growth, micronutrient availability, and plant tolerance to abiotic stress. In addition, it has been suggested that these fungi are able to increase plant disease resistance by activating induced systemic resistance (ISR) . The mode of action of these beneficial fungi in the Trichoderma -plant-pathogen interaction are many, complex and not completely understood. Numerous lytic enzymes have been characterized, the encoding genes (ech42 gluc78, nag1 from T. atroviride strain P1) cloned, and their role in biocontrol demonstrated. The corresponding biocontrol-related inducible promoters have been used in a reporter system based on the Aspergillus niger glucose oxidase gene (goxA) to monitor biocontrol activity. Glucose oxidase catalyzes the oxygen-dependent oxidation of D-glucose to D-glucono-1,5-lactone and hydrogen peroxide; this latter compound is known to have an antifungal effect and activate the plant defence cascade, thus increasing resistance to pathogen attack. T. atroviride P1 transformants with various promoters gox were tested as seed coating treatments on bean seeds planted in soil infested with a soilborne fungal pathogen. Successively, the emergent leaves were inoculated with a foliar pathogen to determine the effect of the GOX transformants on biocontrol and resistance to pathogen attack. Inoculations with the P1-GOX transformants not only reduced disease symptoms caused by a soil pathogen, but also the lesions of various foliar pathogens applied far from the Trichoderma colonization, thus activating ISR. A similar approach is being use to genetically improve T. harzianum T22, a rhizosphere competent and commercially marketed strain not transformed yet, by using four different gox gene constructs under the control of constitutive and inducible promoters. Plasmids have been introduced in Trichoderma by protoplasts co-transformation. hygromicin resistant progeny selected, and mitotically stable transformants analysed to confirm the presence of the novel enzyme activity. Progenies are being tested for biocontrol ISR inducing activity.

Bacillus cereus AR156 primes induced systemic resistance by suppressing miR825/825 and activating defense-related genes in Arabidopsis

Small RNAs play an important role in plant immune responses. However, their regulatory function in induced systemic resistance（ISR） is nascent. Bacillus cereus AR156 is a plant growth-promoting rhizobacterium that induces ISR in Arabidopsis against bacterial infection. Here,by comparing small RNA profiles of Pseudomonas syringae pv. tomato（Pst） DC3000-infected Arabidopsis with and without AR156 pretreatment, we identified a group of Arabidopsis micro RNAs（mi RNAs） that are differentially regulated by AR156 pretreatment. mi R825 and mi R825 are two mi RNA generated from a single mi RNA gene.Northern blot analysis indicated that they were significantly downregulated in Pst DC3000-infected plants pretreated with AR156, in contrast to the plants without AR156 pretreatment. mi R825 targets two ubiquitin-protein ligases,while mi R825 targets toll-interleukin-like receptor（TIR）-nucleotide binding site（NBS） and leucine-rich repeat（LRR）type resistance（R） genes. The expression of these target genes negatively correlated with the expression of mi R825 and mi R825. Moreover, transgenic plants showing reduced expression of mi R825 and mi R825 displayed enhanced resistance to Pst DC3000 infection, whereas transgenic plants overexpressing mi R825 and mi R825 were more susceptible. Taken together, our data indicates that Bacillus cereus AR156 pretreatment primes ISR to Pst infection by suppressing mi R825 and mi R825 and activating the defense related genes they targeted.

Systemic acquired resistance, NPR1, and pathogenesis-related genes in wheat and barley

In Arabidopsis, systemic acquired resistance （SAR） is established beyond the initial infection by a pathogen or is directly induced by treatment with salicylic acid （SA） or its functional analogs, 2,6-dichloroisonicotinic acid （INA） and benzothiadiazole （BTH）. NPR1 protein is considered the master regulator of SAR in both SA signal sensing and transduction. In wheat （Triticum aesfivum） and barley （Hordeum vulgare）, both pathogen infection and BTH treatment can induce broad-spectrum resistance to various diseases, including powdery mildew, leaf rust, Fusarium head blight, etc. However, three different types of SAR-like responses including acquired resistance （AR）, systemic immunity （SI）, and BTH-induced resistance （BIR） seem to be achieved by activating different gene pathways. Recent research on wheat and barley NPR1 homologs in AR and SI has provided the initial clue for understanding the mechanism of SAR in these two plant species. In this review, the specific features ofAR, Si, and BIR in wheat and barley were summarized and compared with that of SAR in model plants of Arabidopsis and rice. Research updates on downstream genes of SAR, including pathogenesis-related （PR） and BTH-induced genes, were highlighted.

Articulating beneficial rhizobacteria-mediated plant defenses through induced systemic resistance:A review

Induced systemic resistance(ISR)is a mechanism by which certain plant beneficial rhizobacteria and fungi produce immunity,which can stimulate crop growth and resilience against various phytopathogens,insects,and parasites.These beneficial rhizobacteria and fungi improve plant performance by regulating hormone signaling,including salicylic acid(SA),jasmonic acid(JA),prosystemin,pathogenesis-related gene 1,and ethylene(ET)pathways,which activate the gene expression of ISR,the synthesis of secondary metabolites,various enzymes,and volatile compounds that ultimately induce defense mechanisms in plant.To protect themselves from disease,plants have various advanced defense mechanisms in which local acquired resistance,systemic gene silencing,systemic wound response,systemic acquired resistance(SAR),and ISR are involved.Several rhizobacteria activate the SA-dependent SAR pathway by producing SA at the root’s surface.In contrast,other rhizobacteria can activate different signaling pathways independent of SA(SA-independent ISR pathways)such as those dependent on JA and ET signaling.The main objective of this review is to provide insight into the types of induced resistance utilized for plant defense.Further to this,the genetic approaches used to suppress disease-causing genes,i.e.,RNA interference and antisense RNA,which are still underutilized in sustainable agriculture,along with the current vision for virus-induced gene silencing are also discussed.

Systemic Acquired Resistance and Signal Transduction in Plant

Systemic acquired resistance (SAR), known as the broad-spectrum, inducible plant immunity, is a defense response triggered by pathogen infection. The response starts from the recognition of plant resistance (R) with the corresponding avirulence (avr) gene from the pathogen. There are some genes for convergence of signals downstream of different R/avr interacting partners into a single signaling pathway. Salicylic acid (SA) is required for the induction of SAR and involved in transducing the signal in target tissues. The SA signal is transduced through NPR1, a nuclear-localized protein that interacts with transcription factors that are involved in regulating SA-mediated gene expression. Some chemicals that mimic natural signaling compounds can also activate SAR. The application of biochemical activators to agriculture for plant protection is a novel idea for developing green chemical pesticide.

Intraoperative systemic vascular resistance is associated with postoperative nausea and vomiting after laparoscopic hysterectomy

BACKGROUND The incidence of postoperative nausea and vomiting(PONV)in patients undergoing laparoscopic hysterectomy is very high compared with other surgeries,even when many prophylactic measures have been taken.However,the pathogenesis of PONV is multifactorial.Female sex,a history of motion sickness or PONV,nonsmokers,and perioperative opioid use are the most closely related factors.Among the multiple risk factors,suboptimal gastrointestinal(GI)perfusion may be attributed to some cases of PONV,and increased systemic vascular resistance(SVR)may lead to GI ischemia.The hypothesis of this research was that SVR is related to PONV.AIM To investigate the relationship between SVR and PONV in patients undergoing laparoscopic hysterectomy.METHODS A total of 228 patients who underwent elective laparoscopic hysterectomy were included in this prospective observational study.SVR was monitored using a noninvasive hemodynamic monitoring system.Four indices of SVR,the baseline,mean,area under the curve(AUC),and weighted AUC,were used for analysis.The incidence and severity of nausea and vomiting were evaluated while patients were awake and throughout the intervals from 0 to 2 h,2 to 6 h,and 6 to 24 h starting upon arrival at the post-anesthesia care unit.The associations between various SVR indices and PONV were investigated by logistic regression.P<0.05 was considered statistically significant.RESULTS The incidence of PONV in the study was 56.14%(128/228),and PONV tended to appear within 6 h after surgery.Five variables were significant in univariate analyses,however,only SVR mean[odds ratio(OR)=1.015,95%CI:1.005-1.109,P=0.047]and duration of surgery(OR=1.316,95%CI:1.003-2.030,P=0.012)were associated with PONV after logistic regression analysis.Furthermore,patients with high SVR mean were more likely to suffer from PONV after laparoscopic hysterectomy.On average,patients who developed PONV needed more time to tolerate diet and demonstrated poorer sleep quality on the first night after surgery.CONCLUSION In this study,PONV was a common complication after laparoscopic hysterectomy.SVR was associated with PONV,and high SVR mean was associated with a significantly increased risk of PONV.

Hemodynamic Profiling Using a Cardiac Index–Systemic Vascular Resistance Plot in Patients with Fontan Circulation

Background: Elevated Fontan pressure (FP) alone cannot fully predict clinical outcomes. We hypothesized thathemodynamic profiling using a cardiac index (CI)-systemic vascular resistance (SVR) plot could characterize clinicalfeatures and predict the prognosis of post-Fontan patients. Methods: We included post-Fontan patients whounderwent cardiac catheterization at age < 10 years. Patients were classified into four categories: A, CI ≥ 3, SVRindex (SVRI) ≥ 20;B, CI < 3, SVRI ≥ 20;C, CI ≥ 3, SVRI < 20;and D, CI < 3, SVRI < 20. The primary outcome wasfreedom from the combined endpoint: new onset of protein-losing enteropathy or plastic bronchitis, heart transplant,and death. Clinical and hemodynamic variables and freedom from the endpoint were compared betweenthe hemodynamic categories and outcome predictors were evaluated. Results: Eighty-three patients wereincluded. Median follow-up was 5.3 years. Category A/B/C/D consisted of 4/15/53/11 patients, respectively. Allthe patients in category A were New York Heart Association I/II and had a significantly lower pulmonary vascularresistance index (PVRI). Patients in category C had lower pulmonary/systemic blood flow. Patients in category Dhad a higher PVRI and had the poorest freedom from the endpoint (44% at 5 years). Elevated FP and category Dwere outcome predictors. Conclusions: CI-SVR plots was a novel adjunctive method for Fontan hemodynamicprofiling.

Induced Resistance of Tomato against Gray Mold (Botrytis cinerea) by Salicylic Acid (SA)

[ Objective ] The paper was to explore the induced resistance of tomato against gray mold （Botrytis cinerea） by salicylic acid. [ Method ] SA was used as an inducer to treat tomato seedlings, the effects of SA on mycelial diameter and spore germination of B. cinerea were studied, and the changes of 4 defense enzyme activities containing catalase （CAT）, peroxidase （POD）, polyphenol oxidase （PPO） and phenylalanine ammonia lyase （PAL）, as well as malondialdehyde （MDA） content during the production process of induced resistance were also measured. [ Result] SA had no inhibitory effect against spore germination and myce- lial growth of B. cinerea within the concentration range, and the relative induced effect had different degrees of improvement after treatment. The induced effect was the best as B. cinerea was challenged to inoculate at the third day after using 150 mg/L SA in tomato plants, and the duration of resistance was 10 -15 d. After treated by SA, CAT, POD, PPO and PAL first increased and then decreased in systemic induced resistance against B. cinerea, which were significantly higher than control. Meanwhile, MDA content showed ascendant trend in wavy line form. [ Conclusion ] The use of SA within a certain concentration range is safe; CAT, POD, PPO and PAL activities have positive correlation with induced resistance against B. cinerea, the increase of MDA content also has close relationship with the imvrovement of disease resistance.

Increasing of Resistance and Resilience of an Urban System against Calamities in the Light of the Maximum Ordinality Principle

The present paper aims at showing how it is possible to requalify the structures of an urban system, in order to increase its resistance and its correlative resilience, against natural calamities (earthquakes, hurricanes, etc.), by adopting as reference criterion the Maximum Ordinality Principle (MOP). In this sense, the paper opens a radically new perspective in this field. In fact, the village assumed as a case study was modelled as a Self-Organizing System. This is because, although the village is usually considered as being solely made of buildings, streets, places and so on, in reality it has been conceived, planned and realized by human beings during several centuries. In addition, the people who actually leave in such an urban center, systematically deal with its maintenance, in order to possibly increase its functionality. This justifies the assumption of the village as being a Self-Organizing System and, consequently, it has been analyzed in the light of the MOP, which represents a valid reference principle for analyzing both “non-living”, “living” and “conscious” self-organizing systems.

Effect of Chaetomium globosum ND35 on Plant Growth and Preliminary Study of Its Biocontrol Efficacy

[Objective] The aim was to study effect of Chaetomium globosum ND35 on plant growth and preliminary study of its biocontrol efficacy, and provide basis for popularization and application of this strain.[ Method] With endophytic fungus C. globosum ND35 as a tested strain, effect of C. globosumND35 on plant growth and its biocontrol on five plant diseases were investigated in the greenhouse and field,[Result]The results showed that ND35 promoted growth of lateral root and diameter of breast height of poplar. ND35 can induce poplar to resist Poplar Valsa Canker caused by Valsa sordida and Poplar Rust caused by Melampsora puplicola. ND35 was also able to induce tomato and bean to resist Botrytis cinera. Biocontrol of Bean Stem Rot Rhizoctonia by ND35 was effective as well. [Conclusion] Induced systemic resistance by endophytic C. globosum ND35 plays an important role in biocontrol of plant diseases.

The Trichoderma-plant interaction is mediated by avirulence proteins produced by this fungus

The molecular basis of Trichoderma -plant interaction is very complex and still not completely understood. The colonization of the root system by rhizosphere competent strains of Trichoderma results in increased development of root/aerial systems, in improved yields and in plant disease control. Other beneficial effects, such as the induction of plant systemic resistance, have also been described. To understand the mechanisms involved we are using different approaches, including the making of transformants expressing genes that encode for compounds able to affect plant response to pathogens. Trichoderma transformants carrying the avirulence gene Avr4 from Cladosporium fulvum under the control of constitutive and inducible promoters were obtained and tested on tomato plants having the Cf4 resistance gene. Necrosis and suberification zones, similar to the symptoms appearing during Cladosporium-tomato interaction, were found when the roots of the Cf4 plants were treated with Avr4-Trichoderma. This demonstrates that selected Trichoderma strains are able to transfer to the plant molecules that may deeply affect metabolism, disease resistance etc. Therefore, these beneficial fungi can be regarded as biotechnological tools to provide a variety of crops with useful compounds. Moreover, in in vitro competition assays the transformants were found to be more effective as antagonists against Alternaria alternata than the wild type. Trichoderma sends a variety of biochemical signals to the plants including avirulence molecules; therefore the presence of avr-like proteins in the fungus proteome was investigated. Proteome analysis has permitted us to isolate and sequence many proteins potentially having this function. From the extracellular protein extracts, we have purified and sequenced a protein with structural characteristics similar to Avr4 of C. fulvum. The protein, Hytra1, was found to be a hydrophobin with chitin binding activity, the typical 8 cysteine residues, and 4 disulfide bridges. Infiltrations of the extracellular protein fractions containing Hytra1 resulted in a strong HR reaction on tobacco and tomato leaves, and induction of a novel phytoalexin.

Acute renal dysfunction in liver diseases

Renal dysfunction is common in liver diseases,either as part of multiorgan involvement in acute illness or secondary to advanced liver disease.The presence of renal impairment in both groups is a poor prognostic indicator.Renal failure is often multifactorial and can present as pre-renal or intrinsic renal dysfunction.Obstructive or post renal dysfunction only rarely complicates liver disease.Hepatorenal syndrome(HRS)is a unique form of renal failure associated with advanced liver disease or cirrhosis,and is characterized by functional renal impairment without significant changes in renal histology.Irrespective of the type of renal failure,renal hypoperfusion is the central pathogenetic mechanism,due either to reduced perfusion pressure or increased renal vascular resistance.Volume expansion,avoidance of precipitating factors and treatment of underlying liver disease constitute the mainstay of therapy to prevent and reverse renal impairment.Splanchnic vasoconstrictor agents,such as terlipressin,along with volume expansion,and early placement of transjugular intrahepatic portosystemic shunt(TIPS)may be effective in improving renal function in HRS.Continuous renal replacement therapy(CRRT)and molecular absorbent recirculating system(MARS)in selected patients may be life saving while awaiting liver transplantation.

Glycosylation of N-hydroxy-pipecolic acid equilibrates between systemic acquired resistance response and plant growth

N-hydroxy-pipecolic acid(NHP)activates plant systemic acquired resistance(SAR).Enhanced defense responses are typically accompanied by deficiency in plant development and reproduction.Despite of extensive studies on SAR induction,the effects of NHPmetabolismon plant growth remain largely unclear.In this study,we discovered that NHP glycosylation is a critical factor that fine-tunes the tradeoff between SAR defense and plant growth.We demonstrated that a UDP-glycosyltransferase(UGT76B1)forming NHP glycoside(NHPG)controls the NHP to NHPG ratio.Consistently,the ugt76b1 mutant exhibits enhanced SAR response and an inhibitory effect on plant growth,while UGT76B1 overexpression attenuates SAR response,promotes growth,and delays senescence,indicating that NHP levels are dependent on UGT76B1 function in the course of SAR.Furthermore,our results suggested that,upon pathogen attack,UGT76B1-mediated NHP glycosylation forms a‘‘hand brake’’on NHP accumulation by attenuating the positive regulation of NHP biosynthetic pathway genes,highlighting the complexity of SAR-associated networks.In addition,we showed that UGT76B1-mediated NHP glycosylation in the local site is important for fine-tuning SAR response.Our results implicate that engineering plant immunity through manipulating the NHP/NHPG ratio is a promising method to balance growth and defense response in crops.

Gut-liver axis in cirrhosis:Are hemodynamic changes a missing link?

Recent evidence suggests that the condition of the gut and its microbiota greatly influence the course of liver disease,especially cirrhosis.This introduces the concept of the gut-liver axis,which can be imagined as a chain connected by several links.Gut dysbiosis,small intestinal bacterial overgrowth,and intestinal barrier alteration lead to bacterial translocation,resulting in systemic inflammation.Systemic inflammation further causes vasodilation,arterial hypotension,and hyperdynamic circulation,leading to the aggravation of portal hypertension,which contributes to the development of complications of cirrhosis,resulting in a poorer prognosis.The majority of the data underlying this model were obtained initially from animal experiments,and most of these correlations were further reproduced in studies including patients with cirrhosis.However,despite the published data on the relationship of the disorders of the gut microbiota with the complications of cirrhosis and the proposed pathogenetic role of hemodynamic disorders in their development,the direct relations between gut dysbiosis and hemodynamic changes in this disease are poorly studied.They remain a missing link in the gut-liver axis and a challenge for future research.

Regulatory and Functional Aspects of Indolic Metabolism in Plant Systemic Acquired Resistance

Tryptophan-derived, indolic metabolites possess diverse functions in Arabidopsis innate immunity to microbial pathogen infection. Hers, we investigate the functional role and regulatory characteristics of indolic metabolism in Arabidopsis systemic acquired resistance （SAR） triggered by the bacterial pathogen Pseudomonas syringae. Indolic metabolism is broadly activated in both P. syringae-inoculated and distant, non-inoculated leaves. At inoculation sites, camalexin, indol-3-ylmethylamine （13A）, and indole-3-carboxylic acid （ICA） are the major accumulating compounds. Camalexin accumulation is positively affected by MYB122, and the cytochrome P450 genes CYP81F1 and CYP81F2. Local 13A production, by contrast, occurs via indole glucosinolate breakdown by PEN2- dependent and independent pathways. Moreover, exogenous application of the defense hormone salicylic acid stimulates 13A generation at the expense of its precursor indol-3-ylmethylglucosinolate （13M）, and the SAR regulator pipecolic acid primes plants for enhanced P. syringae-induced activation of distinct branches of indolic metabolism. In uninfected systemic tissue, the metabolic response is more specific and associated with enhanced levels of the indolics 13A, ICA, and indole-3-carbaldehyde （ICC）. Systemic indole accumulation fully depends on functional CYP79B2/3, PEN2, and MYB34/51/122, and requires functional SAR signaling. Genetic analyses suggest that systemi- cally elevated indoles are dispensable for SAR and associated systemic increases of salicylic acid. However, soil-grown but not hydroponically -cultivated cyp79b2/3 and pen2 plants, both defective in indolic secondary metabolism, exhibit pre-induced immunity, which abrogates their intrinsic ability to induce SAR.

Diclofop-methyl affects microbial rhizosphere community and induces systemic acquired resistance in rice

Diclofop-methyl（DM）,a widely used herbicide in food crops,may partly contaminate the soil surface of natural ecosystems in agricultural area and exert toxic effects at low dose to nontarget plants.Even though rhizosphere microorganisms strongly interact with root cells,little is known regarding their potential modulating effect on herbicide toxicity in plants.Here we exposed rice seedlings（Xiushui 63） to 100 μg/L DM for 2 to 8 days and studied the effects of DM on rice rhizosphere microorganisms,rice systemic acquired resistance（SAR） and rice-microorganisms interactions.The results of metagenomic 16 S rDNA Illumina tags show that DM increases bacterial biomass and affects their community structure in the rice rhizosphere.After DM treatment,the relative abundance of the bacterium genera Massilia and Anderseniella increased the most relative to the control.In parallel,malate and oxalate exudation by rice roots increased,potentially acting as a carbon source for several rhizosphere bacteria.Transcriptomic analyses suggest that DM induced SAR in rice seedlings through the salicylic acid（but not the jasmonic acid） signal pathway.This response to DM stress conferred resistance to infection by a pathogenic bacterium,but was not influenced by the presence of bacteria in the rhizosphere since SAR transcripts did not change significantly in xenic and axenic plant roots exposed to DM.The present study provides new insights on the response of rice and its associated microorganisms to DM stress.

Prognostic value of hemodynamic indices in patients with sepsis after fluid resuscitation

BACKGROUND Sepsis usually causes hemodynamic abnormalities.Hemodynamic index is one of the factors to identify the severity of sepsis and an important parameter to guide the procedure of fluid resuscitation.The present study investigated whether the assessment of hemodynamic indices can predict the outcomes of septic patients undergoing resuscitation therapy.AIM To evaluate the prognostic value of hemodynamic indices in patients with sepsis after fluid resuscitation.METHODS A retrospective study was conducted in 120 patients with sepsis at Hainan General Hospital/Hainan Affiliated Hospital of Hainan Medical University between October 2016 and October 2019.All patients were treated with sodium chloride combined with dextran glucose injection for fluid resuscitation.Patients’hemodynamic parameters were monitored,including heart rate(HR),cardiac index(CI),systemic vascular resistance index(SVRI),mean arterial pressure(MAP),central venous pressure(CVP),and central venous oxygen saturation.The prognostic value of hemodynamic indices was determined based on the prognosis status.RESULTS During fluid resuscitation,86 patients developed septic shock and 34 did not.Ninety-nine patients survived and 21 patients died at 28 d after the treatment.Heart rate,CI,mean arterial pressure,SVRI,and CVP were higher in patients with septic shock and patients who died from septic shock than in non-shock patients and patients who survived,and central venous oxygen saturation was lower in patients with shock and patients who died than in non-shock patients and thesurvivors (P < 0.05). When prognosis was considered as a dependent variable andhemodynamic parameters was considered as independent variables, the results ofa logistic regression analysis showed that CI, SVRI, and CVP were independentrisk factors for septic shock, and CI was an independent risk factor for 28-dmortality (P < 0.05).CONCLUSIONHemodynamic indices can be used to evaluate the prognosis of septic patientsafter fluid resuscitation.

Differences in Heart Stroke Volume between Han and Korean-Chinese Nationalities and Correlative Factors

Objective To compare the differences in stroke volume （SV） and stroke volume index （Sl） between Han and Korean-Chinese and to investigate the correlated risk factors. Methods A total of 1 647 Han and 876 Korean-Chinese aged 10-80 years were investigated. SV, SI, cardiac output, cardiac output index, heart rate （HR）, systemic vascular resistance （SVR）, systemic vascular resistance index （SVRI）, and blood pressure were measured. Results SV/SI values in Korean-Chinese were lower than those in the Han of the same sex and age. Covariance analysis showed that, apart from the effect of sex, age and body mass index （BMI）, the differences in SV and SI between the two cohorts were still significant （P〈O.O01）. Multiple regression analysis revealed that the SV difference between the two ethnicities was affected （in descending order from a strong to weak correlation） by SVR, SVRI, HR, diastolic blood pressure, mean arterial pressure, BMI, and systolic blood pressure, while the SI difference was affected by SVR, SVRI, HR, mean arterial pressure, diastolic and systolic blood pressure, and BMI. Conclusion The Fact that SV and SI in Korean-Chinese are lower than those in Han is related with higher SVR, HR and blood pressure in the Korean-Chinese.

Cardiovascular Function during First 24 Hours after Off-Pump and On-Pump CABG—A Prospective Observational Comparative Study

Purpose: Myocardial revascularization by coronary artery bypass grafting (CABG) in ischemic heart disease patients has direct impact on hemodynamic parameters in the immediate post-operative period. The peri-operative cardiovascular functioning is an important determinant for outcome of surgery. In On-Pump CABG (ONCAB), the cardiopulmonary bypass has a negative effect on myocardium. Off-Pump CABG (OPCAB) avoids the effect of CPB but complete revascularization with difficult positioning of heart is technically demanding. This study is aimed to compare the cardiovascular functioning in the immediate post-operative period after OPCAB and ONCAB. Methods: Total 106 patients were operated for CABG from January 2015 to June 2016, of which 75 patients were operated for OPCAB and 31 patients were operated for ONCAB. For the comparison, hemodynamic parameters were measured during anesthesia before surgery, postoperatively after 1 and 4 hours (h) in the ICU, and in the morning after surgery, approximately after 20 h. Results: The time-dependent rise of hemodynamic parameters like Cardiac Output (CO), Cardiac Index (CI), Stroke volume (SV) and Left Ventricular Stroke Work Index (LVSWI) in the immediate post-operative hours (1 h and 4 h) are more predominant in OPCAB group than ONCAB group although the difference is eliminated mostly at 20 h. The better peripheral vasodilation after OPCAB causes immediate fall of Systemic Vascular Resistance Index (SVRI) after OPCAB. Conclusion: Better cardiovascular functioning immediately after OPCAB than ONCAB may be important for better hemodynamic stability. The difference is however eliminated after 24 hours indicating little significance in long term outcome.

Effects of arbuscular mycorrhizal fungi on carbon assimilation and ecological stoichiometry of maize under combined abiotic stresses

Arbuscular mycorrhizal fungi(AMF)enhance plant tolerance to abiotic stresses like salinity and improve crop yield.However,their effects are variable,and the underlying cause of such variation remains largely unknown.This study aimed to assess how drought modifed the effect of AMF on plant resistance to high calcium-saline stress.A pot experiment was performed to examine how AMF inoculation affects the growth,photosynthetic activity,nutrient uptake and carbon(C),nitrogen(N)and phosphorus(P)stoichiometric ratio(C:N:P)of maize under high calcium stress and contrasting water conditions.The results showed that high calcium stress signifcantly reduced mycorrhizal colonization,biomass accumulation,C assimilation rate and C:N stoichiometric ratio in plant tissues.Besides,the adverse effects of calcium stress on photosynthesis were exacerbated under drought.AMF inoculation profoundly alleviated such reductions under drought and saline stress.However,it barely affected maize performance when subjected to calcium stress under well-watered conditions.Moreover,watering changed AMF impact on nutrient allocation in plant tissues.Under well-watered conditions,AMF stimulated P accumulation in roots and plant growth,but did not induce leaf P accumulation proportional to C and N,resulting in increased leaf C:P and N:P ratios under high calcium stress.In contrast,AMF decreased N content and the N:P ratio in leaves under drought.Overall,AMF inoculation improved maize resistance to calcium-salt stress through enhanced photosynthesis and modulation of nutrient stoichiometry,particularly under water defcit conditions.These results highlighted the regulatory role of AMF in carbon assimilation and nutrient homeostasis under compound stresses,and provide signifcant guidance on the improvement of crop yield in saline and arid regions.