High red blood cell distribution width attenuates the effectiveness of Immune checkpoint inhibitor therapy: An exploratory study using a clinical data warehouse.

BACKGROUND: Immune checkpoint inhibitors (ICIs) have improved outcomes in cancer treatment but are also associated with adverse events and financial burdens. Identifying accurate biomarkers is crucial for determining which patients are likely to benefit from ICIs. Current markers, such as PD-L1 expression and tumor mutation burden, exhibit limited predictive accuracy. This study utilizes a Clinical Data Warehouse (CDW) to explore the prognostic significance of novel blood-based factors, such as the neutrophil-to-lymphocyte ratio and red cell distribution width (RDW), to enhance the prediction of ICI therapy benefit. METHODS: This retrospective study utilized an exploratory cohort from the CDW that included a variety of cancers to explore factors associated with pembrolizumab treatment duration, validated in a non-small cell lung cancer (NSCLC) patient cohort from electronic medical records (EMR) and CDW. The CDW contained anonymized data on demographics, diagnoses, medications, and tests for cancer patients treated with ICIs between 2017-2022. Logistic regression identified factors predicting ≤2 or ≥5 pembrolizumab doses as proxies for progression-free survival (PFS), and Receiver Operating Characteristic analysis was used to examine their predictive ability. These factors were validated by correlating doses with PFS in the EMR cohort and re-testing their significance in the CDW cohort with other ICIs. This dual approach utilized the CDW for discovery and EMR/CDW cohorts for validating prognostic biomarkers before ICI treatment. RESULTS: A total of 609 cases (428 in the exploratory cohort and 181 in the validation cohort) from CDW and 44 cases from EMR were selected for study. CDW analysis revealed that elevated red cell distribution width (RDW) correlated with receiving ≤2 pembrolizumab doses (p = 0.0008), with an AUC of 0.60 for predicting treatment duration. RDW's correlation with PFS (r = 0.80, p<0.0001) and its weak association with RDW (r = -0.30, p = 0.049) were confirmed in the EMR cohort. RDW also remained significant in predicting short treatment duration across various ICIs (p = 0.0081). This dual methodology verified pretreatment RDW elevation as a prognostic biomarker for shortened ICI therapy. CONCLUSION: This study suggests the utility of CDWs in identifying prognostic biomarkers for ICI therapy in cancer treatment. Elevated RDW before treatment initiation emerged as a potential biomarker of shorter therapy duration.

HLA-DQA1*01:03 and DQB1*06:01 are risk factors for severe COVID-19 pneumonia.

The clinical spectrum of COVID-19 includes a wide range of manifestations, from mild symptoms to severe pneumonia. HLA system plays a pivotal role in immune responses to infectious diseases. The purpose of our study was to investigate the association between HLA and COVID-19 severity in a Japanese population. The study included 209 Japanese COVID-19 patients aged ≥20 years. Saliva samples were collected and used to determine the HLA genotype by HLA imputation through genome-wide association analyses. The association between HLA genotype and COVID-19 severity was then evaluated. The allele frequency was compared between patients with respiratory failure (severe group: 91 cases) and those without respiratory failure (non-severe group: 118 cases), categorising the data into three time periods: pre-Omicron epidemic period, Omicron epidemic period, and total period of this study (from January 2021 to May 2023). In comparing the severe and non-severe groups, the frequencies of the HLA-DQA1*01:03 (35.1% vs. 10.5%, odds ratio [OR] = 4.57, corrected p [pc] = 0.041) and -DQB1*06:01 (32.4% vs. 7.9%, OR = 5.54, pc = 0.030) alleles were significantly higher in the severe group during the pre-Omicron epidemic period. During the Omicron epidemic period, HLA-DQB1*06 (32.4% vs. 7.9%, OR = 5.54, pc = 0.030) was significantly higher in the severe group. During total period of this study, HLA-DQA1*01:03 (30.2% vs. 14.4%, OR = 2.57, corrected pc = 0.0013) and -DQB1*06:01 (44.5% vs. 26.7%, OR = 2.20, pc = 0.013) alleles were significantly higher in the severe group. HLA-DQB1*06:01 and -DQA1*01:03 were in strong linkage disequilibrium with each other (r2 = 0.91) during total period of this study, indicating that these two alleles form a haplotype. The frequency of the HLA-DQA1*01:03-DQB1*06:01 in the severe group was significantly higher than in the non-severe group during pre-Omicron epidemic period (32.4% vs. 7.9%, OR = 5.59, pc = 0.00072), and total period of this study (28.6% vs. 13.1%, OR = 2.63, pc = 0.0013). During Omicron epidemic period, the haplotype did not demonstrate statistical significance, although the odds ratio indicated a value greater 1. Frequencies of the HLA-DQA1*01:03 and -DQB1*06:01 alleles were significantly higher in severe COVID-19 patients, suggesting that these alleles are risk factors for severe COVID-19 pneumonia in the Japanese population.

Geographic and economic influences on benralizumab prescribing for severe asthma in Japan.

Benralizumab, a monoclonal antibody targeting IL-5 receptors, reduces exacerbations and oral corticosteroid requirements for severe, uncontrolled eosinophilic asthma. In Japan, geographic disparities in asthma outcomes suggest differential prescribing and access. This study aimed to quantify regional prescribing variations for benralizumab nationwide. Using Japan's National Database (NDB) of insurance claims (2009-2019), benralizumab standardized claim ratios (SCRs) were calculated for 47 prefectures. Correlations between SCRs and other biologics' SCRs, economic variables like average income, and physician densities were evaluated through univariate analysis and multivariate regressions. Income-related barriers to optimal prescribing were examined. Wide variation emerged in benralizumab SCRs, from 40.1 to 184.2 across prefectures. SCRs strongly correlated with omalizumab (r = 0.61, p < 0.00001) and mepolizumab (r = 0.43, p = 0.0024). Average monthly income also positively correlated with benralizumab SCRs (r = 0.45, p = 0.0016), whereas lifestyle factors were insignificant. Respiratory specialist density modestly correlated with SCRs (r = 0.29, p = 0.047). In multivariate regressions, average income remained the most robust predictor (B = 0.74, p = 0.022). Benralizumab SCRs strongly associate with income metrics more than healthcare infrastructure/population factors. Many regions show low SCRs, constituting apparent prescribing gaps. Access barriers for advanced asthma therapies remain inequitable among Japan's income strata. Addressing affordability alongside specialist allocation can achieve better prescribing quality and asthma outcomes.

In Vitro Kinase Assay with Recombinant SnRK2s: An Example for Assaying Stress-Responsive Kinases in Plants.

Protein phosphorylation is one of the most important posttranslational modifications in cell signaling pathways. Kinases and phosphatases play essential roles in transferring information between sensors and effectors under stress conditions. Several methods have been developed to analyze the phosphorylation mechanisms. Each method has advantages and disadvantages. In vitro kinase assay using recombinant proteins is a method to analyze kinase activities under simplified conditions. It is a good strategy to understand each mechanism one by one, although it is not always suitable to estimate the feature of complex machinery in vivo. In this chapter, the purification of recombinant proteins produced in Escherichia coli followed by assaying a kinase activity using radioactivity is described.

Improved diagnostic accuracy with three lung tumor markers compared to six-marker panel.

Background: Combining multiple tumor markers increases sensitivity for lung cancer diagnosis in the cost of false positive. However, some would like to check as many as tumor markers in the fear of missing cancer. We though to propose a panel of fewer tumor markers for lung cancer diagnosis. Methods: Patients with suspected lung cancer who simultaneously underwent all six tests [carcinoembryonic antigen (CEA), cytokeratin-19 fragment (CYFRA), squamous cell carcinoma-associated antigen (SCC), neuron-specific enolase (NSE), pro-gastrin-releasing peptide (ProGRP), and sialyl Lewis-X antigen (SLX)] were included. Tumor markers with significant impact on the lung cancer in a logistic regression model were included in our panel. Area under the curve (AUC) was compared between our panel and the panel of all six. Results: We included 1,733 [median 72 years, 1,128 men, 605 women, 779 (45%) confirmed lung cancer]. Logistic regression analysis suggested CEA, CYFRA, and NSE were independently associated with the lung cancer diagnosis. The panel of these three tumor markers [AUC =0.656, 95% confidence interval (CI): 0.630-0.682, sensitivity 0.650, specificity 0.662] had better (P<0.001) diagnostic performance than six tumor markers (AUC =0.575, 95% CI: 0.548-0.602, sensitivity 0.829, specificity 0.321). Conclusions: Compared to applying all six markers (at least one marker above the upper limit of normal), the panel with three markers (at least one marker above the upper limit of normal) led to a better predictive value by lowering the risk of false positives.

Nationwide survey in Japan of the causative diseases of bloody sputum and hemoptysis in departments of respiratory medicine at university hospitals and core hospitals.

BACKGROUND: The Guidelines for the Management of Cough and Sputum (2019) of the Japanese Respiratory Society (JRS) were the first internationally published guidelines for the management of sputum. However, the data used to determine the causative diseases of bloody sputum and hemoptysis in these guidelines were not obtained in Japan. METHODS: A retrospective analysis was performed using the clinical information of patients with bloody sputum or hemoptysis who visited the department of respiratory medicine at a university or core hospital in Japan. RESULTS: Included in the study were 556 patients (median age, 73 years; age range, 21-98 years; 302 males (54.3%)). The main causative diseases were bronchiectasis (102 patients (18.3%)), lung cancer (97 patients (17.4%)), and non-tuberculous mycobacterial disease (89 patients (16%)). Sex and age differences were observed in the frequency of causative diseases of bloody sputum and hemoptysis. The most common cause was lung cancer in males (26%), bronchiectasis in females (29%), lung cancer in patients aged <65 years (19%), and bronchiectasis in those aged >65 years (20%). CONCLUSIONS: The present study is the first to investigate the causative diseases of bloody sputum and hemoptysis using data obtained in Japan. When investigating the causative diseases of bloody sputum and hemoptysis, it is important to take the sex and age of the patients into account.

ILD-GAP combined with the monocyte ratio could be a better prognostic prediction model than ILD-GAP in patients with interstitial lung diseases.

BACKGROUND: The ILD-GAP scoring system is known to be useful in predicting prognosis in patients with interstitial lung disease (ILD). An elevated monocyte count was associated with increased risks of IPF poor prognosis. We examined whether the ILD-GAP scoring system combined with the monocyte ratio (ILD-GAPM) is superior to the conventional ILD-GAP model in predicting ILD prognosis. METHODS: In patients with ILD treated between April 2013 and April 2017, we were retrospectively assessed the relationships between baseline clinical parameters, including age, sex, Charlson Comorbidity Index score (CCIS), ILD diagnosis, blood biomarkers, pulmonary function test results, and disease outcomes. In ILD patients were included idiopathic pulmonary fibrosis (IPF), idiopathic nonspecific interstitial pneumonia (iNSIP), collagen vascular disease-related interstitial pneumonia (CVD-IP), chronic hypersensitivity pneumonitis (CHP), and unclassifiable ILD (UC-ILD). We also assessed the ability to predict prognosis was compared between the ILD-GAP and ILD-GAPM models. RESULTS: A total of 179 patients (mean age, 73 years) were assessed. All of them were taken pulmonary function test, including percentage predicted diffusion capacity for carbon monoxide. ILD patients included 56 IPF cases, 112 iNSIP and CVD-IP cases, 6 CHP cases and 5 UC-ILD cases. ILD-GAPM provided a greater area under the receiver-operating characteristic curve (0.747) than ILD-GAP (0.710) for predicting 3-year ILD-related events. Furthermore, the log-rank test showed that the Kaplan-Meier curves in ILD-GAPM were significantly different by stage (P = 0.015), but not by stage in ILD-GAP (P = 0.074). CONCLUSIONS: The ILD-GAPM model may be a more accurate predictor of prognosis for ILD patients than the ILD-GAP model.

Serum heme oxygenase-1 as a prognostic biomarker in patients with acute exacerbation of interstitial lung disease.

Serum heme oxygenase (HO)-1 level has been reported as a clinically reliable diagnostic biomarker for acute exacerbation of interstitial lung disease (ILD); however, its utility for predicting mortality among these patients is unclear. Serum HO-1 levels of patients newly diagnosed with acute exacerbation of ILD were measured at the time of initiating steroid pulse therapy. The relationship between serum HO-1 and various other serum biomarkers, change in HRCT findings, and disease prognosis at 12 weeks after diagnosis of acute exacerbation was evaluated in 51 patients, of whom 17 (33%) had idiopathic pulmonary fibrosis (IPF). Serum HO-1 was higher in patients with acute exacerbation of IPF than in patients with acute exacerbation of other ILDs. Serum HO-1 levels were higher in patients who died within these 12 weeks than in survivors. Among age, sex, comorbidities, IPF diagnosis, HRCT findings, and blood biomarkers, serum HO-1 was a primary predictor of 12-week mortality. In 41 patients who underwent repeat HRCT, serum HO-1 was higher in patients with honeycomb progression than in those without. Serum HO-1 measurement could be useful for evaluating disease mortality and morbidity of patients with acute exacerbation of ILDs.

Whole-genome sequencing predicting phenotypic antitubercular drug resistance: meta-analysis.

BACKGROUND: For simultaneous prediction of phenotypic drug susceptibility test (pDST) for multiple anti-tuberculosis drugs, the whole genome sequencing (WGS) data can be analyzed using either catalogue-based approach, wherein one causative mutation suggests resistance, (e.g., WHO catalog) or non-catalogue-based approach using complicated algorithm (e.g., TB-profiler, machine learning). The aim was to estimate the predictive ability of WGS-based tests with pDST as the reference, and to compare the two approaches. METHODS: Following the systematic literature search, the diagnostic test accuracies for 14 drugs were pooled using a random-effect bivariate model. RESULTS: Out of 779 articles, 44 articles with 16,821 specimens for meta-analysis and 13 articles not for meta-analysis were adopted. The areas under summary receiver operating characteristic curve suggested "excellent" (0.97-1.00) for 2 drugs (isoniazid 0.975, rifampicin 0.975), "very good" (0.93-0.97) for 8 drugs (pyrazinamide 0.946, streptomycin 0.952, amikacin 0.968, kanamycin 0.963, capreomycin 0.965, para-aminosalicylic acid 0.959, levofloxacin 0.960, ofloxacin 0.958), and "good" (0.75-0.93) for 4 drugs (ethambutol 0.926, moxifloxacin 0.896, ethionamide 0.878, prothionamide 0.908). The non-catalogue-based and catalogue-based approaches had similar ability for all drugs. CONCLUSION: WGS accurately identifies isoniazid and rifampicin resistance. For most drugs, positive WGS results reliably predict pDST positive. The two approaches had similar ability.

＜Editors' Choice＞ Comparison of clinical features between patients with acute exacerbation of idiopathic interstitial pneumonia and collagen vascular disease-associated interstitial pneumonia.

Acute exacerbation (AE) of interstitial pneumonia (IP) shows poor prognosis, due to the typical histological pattern of diffuse alveolar damage superimposed upon lung fibrosis. The previous reports comparing clinical features between AE of idiopathic interstitial pneumonias (IIPs) and those of IPs with known etiology are limited. We retrospectively compared clinical parameters including age, sex, Charlson Comorbidity Index score (CCIS), blood biomarkers at diagnosis of AE, treatment, and 3-month mortality between patients with AE of IIPs and collagen vascular disease-associated interstitial pneumonia (CVD-IP). We assessed 85 patients, comprising 66 patients with AE of IIPs (78%) and 19 patients with AE of CVD-IP (22%). The least absolute shrinkage and selection operator regression selected CCIS (hazard ratio, 1.281; 95% confidence interval, 1.055-1.556; P = 0.012) and log serum lactate dehydrogenase (LDH) (hazard ratio, 6.267; 95% confidence interval, 2.172-18.085; P < 0.001) as significant predictors of 3-month mortality among these patients. Also, the adjusted survival curves using sex, CCIS, and serum LDH showed no significant differences between these two groups. In conclusion, among AE patients, CCIS and serum LDH level may be more important prognostic factors for 3-month mortality rather than two classification of IP subtypes: IIPs and CVD-IP.

The clinical impact of comorbidities among patients with idiopathic pulmonary fibrosis undergoing anti-fibrotic treatment: A multicenter retrospective observational study.

BACKGROUND: Among patients with idiopathic pulmonary fibrosis (IPF), few studies have investigated the clinical impact of anti-fibrotic treatment (AFT) with and without comorbidities. The aim of the study was to determine whether Charlson Comorbidity Index score (CCIS) can predict the efficacy of AFT in patients with IPF. METHODS: We retrospectively assessed data extracted from the medical records of IPF patients who received anti-fibrotic agents between 2009 and 2019. The collected data included age, sex, CCIS, pulmonary function test, high-resolution computed tomography (HRCT) pattern, gender/age/physiology (GAP) score, and 3-year IPF-related events defined as the first acute exacerbation or death within 3 years after starting AFT. RESULTS: We assessed 130 patients (median age, 74 years) who received nintedanib (n = 70) or pirfenidone (n = 60). Median duration of AFT was 425 days. Patients were categorized into high (≥ 3 points) and low (≤ 2 points) CCIS groups. There was no significant difference between the groups in terms of age, sex, duration of AFT, GAP score, or incidence of usual interstitial pneumonia pattern on HRCT except percentage predicted diffusion capacity of lung for carbon monoxide. Also, significant difference was not seen between the groups for 3-year IPF-related events (P = 0.75). Especially, in the low CCIS group but not the high CCIS group, the longer duration of AFT had better disease outcome. CONCLUSION: In the present study, we could not show any relation between CCIS and IPF disease outcomes in patients undergoing AFT, though the longer duration of AFT might be beneficial for IPF outcomes among patients with low CCIS.

ILD-GAP Combined with the Charlson Comorbidity Index Score (ILD-GAPC) as a Prognostic Prediction Model in Patients with Interstitial Lung Disease.

Background: The ILD-GAP scoring system has been widely used to predict the prognosis of patients with interstitial lung disease (ILD). The ability of the ILD-GAP scoring system combined with the Charlson Comorbidity Index score (CCIS) (ILD-GAPC) to predict ILD prognosis was investigated. Methods: In ILD patients, including idiopathic pulmonary fibrosis (IPF), idiopathic nonspecific interstitial pneumonia (iNSIP), collagen vascular disease-related interstitial pneumonia (CVD-IP), chronic hypersensitivity pneumonitis (CHP), and unclassifiable ILD (UC-ILD), treated between April 2013 and April 2017, the relationships between baseline clinical parameters, including age, sex, CCIS, ILD diagnosis, pulmonary function test results, and disease outcomes, were retrospectively assessed, and the ability to predict prognosis was compared between the ILD-GAP and ILD-GAPC models, respectively. Results: A total of 185 patients (mean age, 71.9 years), all of whom underwent pulmonary function testing, including percentage predicted diffusion capacity for carbon monoxide, were assessed. ILD diagnosis consisted of IPF in 57 cases, iNSIP and CVD-IP in 117 cases, CHP in 6 cases, and UC-ILD in 5 cases. The ILD-GAPC provided a greater area under the receiver operating characteristic curve (0.758) for predicting 3-year ILD-related events than the ILD-GAP (0.721). In addition, log-rank tests showed that the Kaplan-Meier curves differed significantly among low, middle, and high ILD-GAPC scores (P < 0.001), unlike ILD-GAP scores (P = 0.083). Conclusions: The ILD-GAPC model could provide more accurate information for predicting prognosis in patients with ILD than the ILD-GAP model.

Liquid biopsy for detecting epidermal growth factor receptor mutation among patients with non-small cell lung cancer treated with afatinib: a multicenter prospective study.

BACKGROUND: This study aimed to determine the effectiveness of liquid biopsy in detecting epidermal growth factor receptor (EGFR) mutations at diagnosis, disease progression, and intermediate stages. METHODS: This prospective, multicenter, observational study included 30 patients with non-small cell lung cancer treated with afatinib, harboring a major EGFR mutation confirmed by tumor tissue biopsy. We collected blood samples for liquid biopsy at diagnosis, intermediate stage, and progressive disease. Tissue and liquid biopsies were examined using Cobas ® EGFR Mutation Test v2. RESULTS: Liquid biopsy detected EGFR mutations in 63.6% of the patients at diagnosis. The presence of metastasis in the extrathoracic, brain, and adrenal glands correlated positively with the detection of EGFR mutations. Patients with positive EGFR mutations at diagnosis had significantly shorter overall and progression-free survival than patients with negative EGFR mutations. Four of the 18 patients (22.2%) who reached progressive disease had positive EGFR T790M mutations. Three of 10 patients (30.0%) with progressive disease were positive and negative for T790M using tumor re-biopsy and liquid biopsy, respectively. The results of EGFR mutation by tissue re-biopsy were the same as those of liquid biopsy in the three patients who were positive for significant EGFR mutations but negative for the T790M mutation using liquid biopsy at progressing disease. Only two patients were positive for major EGFR mutations at intermediate levels. CONCLUSIONS: Liquid biopsy can be a prognostic factor in EGFR-tyrosine kinase inhibitor treatments at diagnosis. Tumor re-biopsy can be omitted in patients with positive EGFR mutations by liquid biopsy at PD.

Assessment of diagnostic utility of serum hemeoxygenase-1 measurement for acute exacerbation of interstitial pneumonias.

The present study aimed to evaluate whether serum heme oxygenase (HO)-1 could be a reliable blood biomarker for diagnosing acute exacerbations (AEs) of both idiopathic interstitial pneumonia (IIP) and secondary interstitial pneumonia (SIP). Serum HO-1 levels of newly diagnosed patients with IP were measured, and the relationships between serum HO-1 and other serum biomarkers and high-resolution CT scores, were evaluated. Blood samples were collected from 90 patients with IIP, including 32 having an AE, and 32 with SIP, including 9 having an AE. The patients having an AE had significantly higher HO-1 levels than those not having an AE (35.2 ng/mL vs. 16.4 ng/mL; p < 0.001). On receiver operating characteristics (ROC) curve analysis for serum HO-1 ability to detect an AE, the area under the ROC curve (AUC) was 0.87 in patients with IIPs and 0.86 in those with SIPs. Also, in patients with both IIPs and SIPs, the combination of the serum HO-1 level and the GGO score showed favorable AUCs (IIPs: 0.92, SIPs: 0.83), though HO-1-not-including model (combination of LDH and GGO) also showed acceptable AUCs. Serum HO-1 could be a clinically useful biomarker for the accurate diagnosis of patients with AEs.

Clinical importance of serum heme oxygenase-1 measurement in patients with acute exacerbation of idiopathic pulmonary fibrosis triggered by coronavirus disease 2019.

A 70-year-old man diagnosed with idiopathic pulmonary fibrosis (IPF) one year earlier developed progressive exertional dyspnea 3 weeks after onset of coronavirus disease 2019 (COVID-19). High-resolution computed tomography showed new extensive ground-glass opacities with rapidly progressive honeycombing. Although he was diagnosed with acute exacerbation (AE) of IPF triggered by COVID-19 and received methylprednisolone pulse therapy twice within one month, there was no improvement of oxygenation and lung involvement. Three months after COVID-19 onset, it was decided to provide best supportive care. An AE of IPF as a sequela of COVID-19, which is recognized as macrophage activation syndrome, is fatal, and in this case, the measurement of serum heme oxygenase-1, which is a macrophage activation biomarker involved in pulmonary cellular protection against oxidative stress, was useful for tracking disease activity.

Diagnostic utility of transbronchial biopsy for Hodgkin's lymphoma: A case study.

Lung lesions of Hodgkin's lymphoma (HL) are rare and difficult to diagnose by nonsurgical biopsy. We herein present the case of a 72-year-old Japanese male who presented with accumulation of lung infiltrates and masses bilaterally on the lungs for 3 years. Although transbronchial lung biopsy (TBB) and computed tomography-guided biopsy were conducted several times, his diagnosis remained inconclusive. On further deterioration of lung lesions, the patient was transferred to our hospital. Positron emission tomography revealed increased accumulation in the bilateral lungs and right supraclavicular lymph nodes. Surgical biopsy of the lymph node was performed. He was finally diagnosed with HL and underwent chemotherapy with doxorubicin, vinblastine, dacarbazine, and brentuximab vedotin. After chemotherapy, the lung lesion showed significant regression. A literature review indicated that the diagnostic success rate of TBB was low (18.5%) in cases of lung lesions in HL.

Chemical activation of Arabidopsis SnRK2.6 by pladienolide B.

Abscisic acid (ABA) is an important phytohormone mediating osmotic stress responses. SUCROSE NONFERMENTING 1 (SNF1)-RELATED PROTEIN KINASE 2.6 (SnRK2.6, also named OPEN STOMATA1 and SNF1-RELATED KINASE 2E) is central in the ABA signaling pathway; therefore, manipulating its activity may be useful to confer stress tolerance in plants. Pladienolide B (PB) is an mRNA splicing inhibitor and enhances ABA responses. Here, we analyzed the effect of PB on Arabidopsis SnRK2.6. PB enhanced the activity of recombinant SnRK2.6 in vitro through direct physical interaction as predicted by molecular docking simulations followed by mutation experiments and isothermal titration calorimetry. Structural modeling predicted probable interaction sites between PB and SnRK2.6, and experiments with mutated SnRK2.6 revealed that Leu-46 was the most essential amino acid residue for SnRK2.6 activation by PB. This study demonstrates the feasibility of SnRK2.6 chemical manipulation and paves the way for the modification of plant osmotic stress responses.

EARLY RESPONSE TO DEHYDRATION 7 Remodels Cell Membrane Lipid Composition during Cold Stress in Arabidopsis.

Plants adjust to unfavorable conditions by altering physiological activities, such as gene expression. Although previous studies have identified multiple stress-induced genes, the function of many genes during the stress responses remains unclear. Expression of ERD7 (EARLY RESPONSE TO DEHYDRATION 7) is induced in response to dehydration. Here, we show that ERD7 plays essential roles in both plant stress responses and development. In Arabidopsis, ERD7 protein accumulated under various stress conditions, including exposure to low temperature. A triple mutant of Arabidopsis lacking ERD7 and two closely related homologs had an embryonic lethal phenotype, whereas a mutant lacking the two homologs and one ERD7 allele had relatively round leaves, indicating that the ERD7 gene family has essential roles in development. Moreover, the importance of the ERD7 family in stress responses was evidenced by the susceptibility of the mutant lines to cold stress. ERD7 protein was found to bind to several, but not all, negatively charged phospholipids and was associated with membranes. Lipid components and cold-induced reduction in PIP2 in the mutant line were altered relative to wild type. Furthermore, membranes from the mutant line had reduced fluidity. Taken together, ERD7 and its homologs are important for plant stress responses and development and associated with the modification in membrane lipid composition.

Evaluation of the Antifoaming Effect Using Hansen Solubility Parameters.

The appearance of foam in various industrial processes can cause challenges. Antifoaming agents are widely added to suppress foam. To exert a defoaming effect, affinity between the main foam-generating component and the antifoaming agent is an important criterion for selection of an antifoaming agent. The Hansen solubility parameter (HSP) can be used as an index to show the affinity between substances more quantitatively, simply, and accurately. The Hansen solubility sphere method was used to measure the HSPs of antifoaming agents and a foam-forming surfactant. Various antifoaming agents were added to a surfactant solution, and the defoaming effect was evaluated. Correlations of 0.953-0.860 confirmed a relationship between affinity of the antifoaming agents for the surfactant based on HSP theory and the defoaming effect. It is suggested that use of HSP as an indicator can facilitate selection of the most suitable antifoaming agent for the process.