ACYL-ACYL CARRIER PROTEIN DESATURASE2 and 3 are responsible for making omega-7 fatty acids in the Arabidopsis aleurone

Omega-7 monounsaturated fatty acids (ω-7s) are specifically enriched in the aleurone of Arabidopsis (Arabidopsis thaliana) seeds. We found significant natural variation in seed ω-7 content and used a Multiparent Advanced Generation Inter-Cross population to fine-map a major quantitative trait loci to a region containing ACYL-ACYL CARRIER PROTEIN DESATURASE1 (AAD1) and AAD3. We found that AAD3 expression is localized to the aleurone where mutants show an approximately 50% reduction in ω-7 content. By contrast, AAD1 is localized to the embryo where mutants show a small reduction in ω-9 content. Enzymatic analysis has previously shown that AAD family members possess both stearoyl- and palmitoyl-ACP Δ9 desaturase activity, including the predominant isoform SUPPRESSOR OF SALICYLIC ACID INSENSITIVE2. However, aad3 ssi2 aleurone contained the same amount of ω-7s as aad3. Within the AAD family, AAD3 shares the highest degree of sequence similarity with AAD2 and AAD4. Mutant analysis showed that AAD2 also contributes to ω-7 production in the aleurone, and aad3 aad2 exhibits an approximately 85% reduction in ω-7s. Mutant analysis also showed that FATTY ACID ELONGASE1 is required for the production of very long chain ω-7s in the aleurone. Together, these data provide genetic evidence that the ω-7 pathway proceeds via Δ9 desaturation of palmitoyl-ACP followed by elongation of the product. Interestingly, significant variation was also identified in the ω-7 content of Brassica napus aleurone, with the highest level detected being approximately 47% of total fatty acids

Genome wide analysis of fatty acid desaturation and its response to temperature

Plants modify the polyunsaturated fatty acid content of their membrane and storage lipids in order to adapt to changes in temperature. In developing seeds, this response is largely controlled by the activities of the microsomal ω-6 and ω-3 fatty acid desaturases, FAD2 and FAD3. Although temperature regulation of desaturation has been studied at the molecular and biochemical levels, the genetic control of this trait is poorly understood. Here, we have characterized the response of Arabidopsis (Arabidopsis thaliana) seed lipids to variation in ambient temperature and found that heat inhibits both ω-6 and ω-3 desaturation in phosphatidylcholine, leading to a proportional change in triacylglycerol composition. Analysis of the 19 parental accessions of the multiparent advanced generation intercross (MAGIC) population showed that significant natural variation exists in the temperature responsiveness of ω-6 desaturation. A combination of quantitative trait locus (QTL) analysis and genome-wide association studies (GWAS) using the MAGIC population suggests that ω-6 desaturation is largely controlled by cis-acting sequence variants in the FAD2 5′ untranslated region intron that determine the expression level of the gene. However, the temperature responsiveness of ω-6 desaturation is controlled by a separate QTL on chromosome 2. The identity of this locus is unknown, but genome-wide association studies identified potentially causal sequence variants within ∼40 genes in an ∼450-kb region of the QTL

Glutathione affects the transport activity of Rhizobium leguminosarum 3841 and is essential for efficient nodulation

As glutathione (GSH) plays an essential role in growth and symbiotic capacity of rhizobia, a glutathione synthetase (gshB) mutant of Rhizobium leguminosarum biovar viciae 3841 (Rlv3841) was characterised. It fails to efficiently utilise various compounds as a sole carbon source, including glucose, succinate, glutamine and histidine, and shows 60%–69% reduction in uptake rates of glucose, succinate and the non-metabolisable substrate α-amino isobutyric acid. The defect in glucose uptake can be overcome by addition of exogenous GSH, indicating GSH, but not its bacterial synthesis, is required for efficient transport. GSH is not involved in the regulation of the activity of Rlv3841’s transporters via the global regulator of transport, PtsNTR. Although lack of GSH reduces transcription of the branched amino acid transporter, this was not the case for all uptake transport systems, for example, the amino acid permease. This suggests GSH alters activity and/or assembly of transport systems by an unknown mechanism. In interaction with plants, the gshB mutant is not only severely impaired in rhizosphere colonisation, but also shows a 50% reduction in dry weight of plants and nitrogen-fixation ability. This reveals that changes in GSH metabolism affect the bacterial–plant interactions required for symbiosis

Glutathione affects the transport activity of Rhizobium leguminosarum 3841 and is essential for efficient nodulation

As glutathione (GSH) plays an essential role in growth and symbiotic capacity of rhizobia, a glutathione synthetase (gshB) mutant of Rhizobium leguminosarum biovar viciae 3841 (Rlv3841) was characterised. It fails to efficiently utilise various compounds as a sole carbon source, including glucose, succinate, glutamine and histidine, and shows 60%–69% reduction in uptake rates of glucose, succinate and the non-metabolisable substrate α-amino isobutyric acid. The defect in glucose uptake can be overcome by addition of exogenous GSH, indicating GSH, but not its bacterial synthesis, is required for efficient transport. GSH is not involved in the regulation of the activity of Rlv3841’s transporters via the global regulator of transport, PtsNTR. Although lack of GSH reduces transcription of the branched amino acid transporter, this was not the case for all uptake transport systems, for example, the amino acid permease. This suggests GSH alters activity and/or assembly of transport systems by an unknown mechanism. In interaction with plants, the gshB mutant is not only severely impaired in rhizosphere colonisation, but also shows a 50% reduction in dry weight of plants and nitrogen-fixation ability. This reveals that changes in GSH metabolism affect the bacterial–plant interactions required for symbiosis

Heart Rate and Mortality in Patients With Acute Symptomatic Pulmonary Embolism

Background: The association between heart rate (HR) and pulmonary embolism (PE) outcomes has not been well studied. Furthermore, optimal cutoffs to identify low-risk and intermediate- to high-risk patients are not well known. Research Question: Does an association exist between baseline HR and PE outcome across the continuum of HR values? Study Design and Methods: The current study included 44,331 consecutive nonhypotensive patients with symptomatic PE from the Registro Informatizado de la Enfermedad TromboEmbólica registry between 2001 and 2021. Outcomes included 30-day all-cause and PE-specific mortality. We used hierarchical logistic regression to assess the association between admission HR and outcomes. Results: A positive relationship was found between admission HR and 30-day all-cause and PE-related mortality. Considering an HR of 80 to 99 beats/min as a reference, patients in the higher HR strata showed higher rates of all-cause death (adjusted OR, 1.5 for HR of 100-109 beats/min; adjusted OR, 1.7 for HR of 110-119 beats/min; adjusted OR, 1.9 for HR of 120-139 beats/min; and adjusted OR, 2.4 for HR of ≥ 140 beats/min). Patients in the lower strata of HR showed significantly lower rates of 30-day all-cause mortality compared with the same reference group (adjusted OR, 0.6 for HR of 60-79 beats/min; and adjusted OR, 0.5 for HR of < 60 beats/min). The findings for 30-day PE-related mortality were similar. For identification of low-risk patients, a cutoff value of 80 beats/min (vs 110 beats/min) increased the sensitivity of the simplified Pulmonary Embolism Severity Index (sPESI) from 93.4% to 98.8%. For identification of intermediate- to high-risk patients, a cutoff value of 140 beats/min (vs 110 beats/min) increased the specificity of the Bova score from 93.2% to 98.0%. Interpretation: In nonhypotensive patients with acute symptomatic PE, a high HR portends an increased risk of all-cause and PE-related mortality. Modifying the HR cutoff in the sPESI and the Bova score improves prognostication of patients with PE

Incidence of major adverse cardiovascular events among patients with provoked and unprovoked venous thromboembolism: Findings from the Registro Informatizado de Enfermedad Tromboemb\uf3lica Registry

Objective: Overlap exists between the risk factors for coronary artery disease and venous thromboembolism (VTE). However, a paucity of data is available on the incidence of major acute cardiovascular events (MACE) and major adverse limb events (MALE) among patients presenting with VTE. Moreover, it is unknown whether the rate of cardiovascular outcomes differs among patients with unprovoked vs provoked VTE. Methods: We analyzed the data from 2009 to 2017 in the Registro Informatizado de Enfermedad Tromboemb\uf3lica registry, an ongoing, multicenter, international registry of consecutive patients with a diagnosis of objectively confirmed VTE. The query was restricted it to patients with data entry for the arterial outcomes. The baseline prevalence of coronary artery disease risk factors was compared between patients with provoked (ie, immobility, cancer, surgery, travel &gt;6 hours, hormonal causes) and unprovoked VTE. After the initial VTE event, we followed up patients for the composite primary outcome of incident MACE (ie, stroke, myocardial infarction, unstable angina) and/or MALE (ie, major limb events). We used the \u3c72 test for baseline associations and a Cox proportional hazard for multivariate analysis. We used IBM SPSS, version 24 (IBM Corp, Armonk, NY) for statistical analysis. A P value of &lt;.05 was considered statistically significant. Results: We analyzed the data from 41,259 patients with VTE, of whom 22,633 (55.6%) had experienced a provoked VTE. During follow-up, the patients with provoked VTE were more likely to develop MACE or MALE than were patients with unprovoked VTE (hazard ratio [HR], 1.3; 95% confidence interval [CI], 1.1-1.5). The association of arterial events with recent immobility (HR, 1.4; 95% CI, 1.5-12.1) and cancer (HR, 1.7; 95% CI, 1.4-1.9) was strong. After adjusting for multiple conventional cardiovascular risk factors, provoked VTE, compared with unprovoked VTE, was significantly associated with an increased hazard for MACE (HR, 1.4; 95% CI, 1.1-1.7). Cancer remained a significant adjusted predictor for both MACE (HR, 1.7; 95% CI, 1.4-2.1) and MALE (HR, 2.1; 95% CI 1.01-4.6) in those with provoked VTE. Conclusions: Among patients with VTE, provoked cases, specifically those with cancer-associated VTE, have an increased risk of major arterial events

Systolic blood pressure and mortality in acute symptomatic pulmonary embolism

BACKGROUND: The optimal cutoff for systolic blood pressure (SBP) level to define high-risk pulmonary embolism (PE) remains to be defined. METHODS: To evaluate the relationship between SBP levels on admission and mortality in patients with acute symptomatic PE, the current study included 39,257 consecutive patients with acute symptomatic PE from the RIETE registry between 2001 and 2018. Primary outcomes included all-cause and PE-specific 30-day mortality. Secondary outcomes included major bleeding and recurrent venous thromboembolism (VTE). RESULTS: There was a linear inverse relationship between admission SBP and 30-day all-cause and PE-related mortality that persisted after multivariable adjustment. Patients in the lower SBP strata had higher rates of all-cause death (reference: SBP 110-129 mmHg) (adjusted odds ratio [OR] 2.9; 95% confidence interval [CI], 2.0-4.2 for SBP 190 mmHg). Consistent findings were also observed for 30-day PE-related death. CONCLUSIONS: In patients with acute symptomatic PE, a low SBP portends an increased risk of all-cause and PE-related mortality. The highest mortality was observed in patients with SBP <70 mmHg.status: publishe

Early use of echocardiography in patients with acute pulmonary embolism: Findings from the RIETE registry

Background\u2014Transthoracic echocardiography (TTE) is often considered for risk stratification of patients with acute pulmonary embolism (PE). We sought to determine the contemporary utilization of early TTE (within 72 hours of PE diagnosis) and explored the association between TTE findings and PE-related mortality. Methods and Results\u2014Data from the RIETE (Registro Informatizado Enfermedad TromboEmbolica) registry, a multicenter registry of consecutive patients with acute PE, were used (2001-July 2017). We used a generalized linear mixed model to determine predictors of early TTE performance. Moreover, the association between 3 TTE variables (right atrial enlargement, right ventricular hypokinesis, and presence of right heart thrombi) and 30-day PE-related mortality was assessed in generalized linear mixed models adjusted for PE severity index, and other comorbidities. Among 35 935 enrollees with acute PE, 15 375 (42.8%) underwent early TTE. There was an increase in early TTE utilization rate over time (P&lt;0.001 for trend). Younger age, female sex, enrollment in countries other than Spain, history of coronary disease, heart failure, atrial fibrillation, tachycardia, and hypotension were the main predictors of early TTE (P&lt;0.01 for all). In multivariable analyses, right atrial enlargement (adjusted odds ratio: 3.74; 95% confidence interval, 2.10-6.66), right ventricular hypokinesis (adjusted odds ratio: 3.11, 95% confidence interval: 1.85-5.21) and right heart thrombi (adjusted odds ratio: 4.39, 95% confidence interval, 1.99-9.71) were associated with increased odds for PErelated mortality. Conclusions\u2014Early TTE is commonly performed for acute PE and utilization rates have increased over time. Right atrial enlargement, right ventricular hypokinesis, and right heart thrombi are predictive of worse outcomes. Clinical Trial Registration\u2014URL: http://www.clinicaltrials.gov. Unique identifier: NCT02832245

Outpatient Parenteral Antibiotic Treatment for Infective Endocarditis: A Prospective Cohort Study From the GAMES Cohort

BACKGROUND: Outpatient parenteral antibiotic treatment (OPAT) has proven efficacious for treating infective endocarditis (IE). However, the 2001 Infectious Diseases Society of America (IDSA) criteria for OPAT in IE are very restrictive. We aimed to compare the outcomes of OPAT with those of hospital-based antibiotic treatment (HBAT). METHODS: Retrospective analysis of data from a multicenter, prospective cohort study of 2000 consecutive IE patients in 25 Spanish hospitals (2008-2012) was performed. RESULTS: A total of 429 patients (21.5%) received OPAT, and only 21.7% fulfilled IDSA criteria. Males accounted for 70.5%, median age was 68 years (interquartile range [IQR], 56-76), and 57% had native-valve IE. The most frequent causal microorganisms were viridans group streptococci (18.6%), Staphylococcus aureus (15.6%), and coagulase-negative staphylococci (14.5%). Median length of antibiotic treatment was 42 days (IQR, 32-54), and 44% of patients underwent cardiac surgery. One-year mortality was 8% (42% for HBAT; P < .001), 1.4% of patients relapsed, and 10.9% were readmitted during the first 3 months after discharge (no significant differences compared with HBAT). Charlson score (odds ratio [OR], 1.21; 95% confidence interval [CI], 1.04-1.42; P = .01) and cardiac surgery (OR, 0.24; 95% CI, .09-.63; P = .04) were associated with 1-year mortality, whereas aortic valve involvement (OR, 0.47; 95% CI, .22-.98; P = .007) was the only predictor of 1-year readmission. Failing to fulfill IDSA criteria was not a risk factor for mortality or readmission. CONCLUSIONS: OPAT provided excellent results despite the use of broader criteria than those recommended by IDSA. OPAT criteria should therefore be expanded

Antimicrobial management of Tropheryma whipplei endocarditis: the Spanish Collaboration on Endocarditis (GAMES) experience

OBJECTIVES: Tropheryma whipplei has been detected in 3.5% of the blood culture-negative cases of endocarditis in Spain. Experience in the management of T. whipplei endocarditis is limited. Here we report the long-term outcome of the treatment of previously reported patients who were diagnosed with infective endocarditis (IE) caused by T. whipplei from the Spanish Collaboration on Endocarditis-Grupo de Apoyo al Manejo de la Endocarditis Infecciosa en Espana (GAMES) and discuss potential options for antimicrobial therapy for IE caused by T. whipplei. PATIENTS AND METHODS: Seventeen patients with T. whipplei endocarditis were recruited between 2008 and 2014 in 25 Spanish hospitals. Patients were classified according to the therapeutic regimen: ceftriaxone and trimethoprim/sulfamethoxazole, doxycycline + hydroxychloroquine and other treatment options. RESULTS: Follow-up data were obtained from 14 patients. The median follow-up was 46.5 months. All patients completed the antibiotic treatment prescribed, with a median duration of 13 months. Six patients were treated with ceftriaxone and trimethoprim/sulfamethoxazole (median duration 13 months), four with doxycycline + hydroxychloroquine (median duration 13.8 months) and four with other treatment options (median duration 22.3 months). The follow-up after the end of the treatments was between 5 and 84 months (median 24 months). CONCLUSIONS: All treatment lines were effective and well tolerated. Therapeutic failures were not detected during the treatment. None of the patients died or experienced a relapse during the follow-up. Only six patients received antibiotic treatment in accordance with guidelines. These data suggest that shorter antimicrobial treatments could be effective