BASIC PENTACYSTEINE1 regulates ABI4 by modification of two histone marks H3K27me3 and H3ac during early seed development of Medicago truncatula.

Introduction: The production of highly vigorous seeds with high longevity is an important lever to increase crop production efficiency, but its acquisition during seed maturation is strongly influenced by the growth environment. Methods: An association rule learning approach discovered MtABI4, a known longevity regulator, as a gene with transcript levels associated with the environmentally-induced change in longevity. To understand the environmental sensitivity of MtABI4 transcription, Yeast One-Hybrid identified a class I BASIC PENTACYSTEINE (MtBPC1) transcription factor as a putative upstream regulator. Its role in the regulation of MtABI4 was further characterized. Results and discussion: Overexpression of MtBPC1 led to a modulation of MtABI4 transcripts and its downstream targets. We show that MtBPC1 represses MtABI4 transcription at the early stage of seed development through binding in the CT-rich motif in its promoter region. To achieve this, MtBPC1 interacts with SWINGER, a sub-unit of the PRC2 complex, and Sin3-associated peptide 18, a sub-unit of the Sin3-like deacetylation complex. Consistent with this, developmental and heat stress-induced changes in MtABI4 transcript levels correlated with H3K27me3 and H3ac enrichment in the MtABI4 promoter. Our finding reveals the importance of the combination of histone methylation and histone de-acetylation to silence MtABI4 at the early stage of seed development and during heat stress.

Breadth and Durability of SARS-CoV-2-Specific T Cell Responses following Long-Term Recovery from COVID-19.

T cell immunity is crucial for long-term immunological memory, but the profile of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific memory T cells in individuals who recovered from COVID-19 (COVID-19-convalescent individuals) is not sufficiently assessed. In this study, the breadth and magnitude of SARS-CoV-2-specific T cell responses were determined in COVID-19-convalescent individuals in Japan. Memory T cells against SARS-CoV-2 were detected in all convalescent individuals, and those with more severe disease exhibited a broader T cell response relative to cases with mild symptoms. Comprehensive screening of T cell responses at the peptide level was conducted for spike (S) and nucleocapsid (N) proteins, and regions frequently targeted by T cells were identified. Multiple regions in S and N proteins were targeted by memory T cells, with median numbers of target regions of 13 and 4, respectively. A maximum of 47 regions were recognized by memory T cells for an individual. These data indicate that SARS-CoV-2-convalescent individuals maintain a substantial breadth of memory T cells for at least several months following infection. Broader SARS-CoV-2-specific CD4+ T cell responses, relative to CD8+ T cell responses, were observed for the S but not the N protein, suggesting that antigen presentation is different between viral proteins. The binding affinity of predicted CD8+ T cell epitopes to HLA class I molecules in these regions was preserved for the Delta variant and at 94 to 96% for SARS-CoV-2 Omicron subvariants, suggesting that the amino acid changes in these variants do not have a major impact on antigen presentation to SARS-CoV-2-specific CD8+ T cells. IMPORTANCE RNA viruses, including SARS-CoV-2, evade host immune responses through mutations. As broader T cell responses against multiple viral proteins could minimize the impact of each single amino acid mutation, the breadth of memory T cells would be one essential parameter for effective protection. In this study, breadth of memory T cells to S and N proteins was assessed in COVID-19-convalescent individuals. While broad T cell responses were induced against both proteins, the ratio of N to S proteins for breadth of T cell responses was significantly higher in milder cases. The breadth of CD4+ and CD8+ T cell responses was also significantly different between S and N proteins, suggesting different contributions of N and S protein-specific T cells for COVID-19 control. Most CD8+ T cell epitopes in the immunodominant regions maintained their HLA binding to SARS-CoV-2 Omicron subvariants. Our study provides insights into understanding the protective efficacy of SARS-CoV-2-specific memory T cells against reinfection.

ABSCISIC ACID INSENSITIVE 4 coordinates eoplast formation to ensure acquisition of seed longevity during maturation in Medicago truncatula.

Seed longevity, the capacity to remain alive during dry storage, is pivotal to germination performance and is essential for preserving genetic diversity. It is acquired during late maturation concomitantly with seed degreening and the de-differentiation of chloroplasts into colorless, non-photosynthetic plastids, called eoplasts. As chlorophyll retention leads to poor seed performance upon sowing, these processes are important for seed vigor. However, how these processes are regulated and connected to the acquisition of seed longevity remains poorly understood. Here, we show that such a role is at least provided by ABSCISIC ACID INSENSITIVE 4 (ABI4) in the legume Medicago truncatula. Mature seeds of Mtabi4 mutants contained more chlorophyll than wild-type seeds and exhibited a 75% reduction in longevity and reduced dormancy. MtABI4 was necessary to stimulate eoplast formation, as evidenced by the significant delay in the dismantlement of photosystem II during the maturation of mutant seeds. Mtabi4 seeds also exhibited transcriptional deregulation of genes associated with retrograde signaling and transcriptional control of plastid-encoded genes. Longevity was restored when Mtabi4 seeds developed in darkness, suggesting that the shutdown of photosynthesis during maturation, rather than chlorophyll degradation per se, is a requisite for the acquisition of longevity. Indeed, the shelf life of stay green mutant seeds that retained chlorophyll was not affected. Thus, ABI4 plays a role in coordinating the dismantlement of chloroplasts during seed development to avoid damage that compromises the acquisition of seed longevity. Analysis of Mtabi4 Mtabi5 double mutants showed synergistic effects on chlorophyll retention and longevity, suggesting that they act via parallel pathways.

Nutritional Status and Feeding Regimen of Patients with Esophagus Cancer-A Study from Vietnam.

BACKGROUND: Esophagus cancer patients are at high risk of malnutrition. This study was performed to assess the nutritional status and dietary intake of newly diagnosed esophageal cancer patients in Vietnam National Cancer Hospital (NCH). METHODS: A cross-sectional study was conducted on 206 early esophageal cancer inpatients after gastrostomy from September 2017 to June 2018. The chi-squared test, Fisher exact test, and Mann-Whitney test were performed. The software of the Vietnam National Institute of Nutrition was used to evaluate the dietary intake of patients. RESULTS: All the participants were male with a mean age of 57.1 ± 8.5 years. Overall, 87.4% of patients had dysphagia. Furthermore, 82.5% and 90.8% of patients reported weight loss one and six months pre-diagnosis, respectively. Moreover, 52.9% of patients suffered from mild/moderate malnutrition and 29.6% of patients had severe malnutrition according to the Patient-Generated Subjective Global Assessment (PG-SGA). The body mass index (BMI) and mid upper arm circumference (MUAC) measurement revealed 47.6% and 50% of undernourished patients, respectively. The proportions of patients having malnutrition were 10.7%, 55.8%, and 27.2% according to albumin, prealbumin, and total lymphocyte counts, respectively. The means of energy, protein, lipid, and carbohydrate in the patients' 24 h preoperative diets were 973.6 ± 443.0 kcal/day, 42.4 ± 21.6 g/day, 31.0 ± 15.5 g/day, and 130.0 ± 64.5 g/day. The total energy, total protein, animal protein, total lipid, and plant lipid in the dietary intake of patients were strongly correlated with age, economic classification, and PG-SGA (each p < 0.05). The total energy intake increased day by day, with the average energy intake of 1343.9 ± 521.3 kcal on the seventh day. Energy and protein response rates increased day by day and were highest at 7 days post-operation at 18.0% and 19.4%. CONCLUSION: Malnutrition and insufficient intake are noteworthy in esophageal cancer patients. The PG-SGA is strongly correlated with the dietary intake of patients. The results from this study will help medical staff to prevent malnutrition and improve the nutritional status of esophageal cancer inpatients. Furthermore, public awareness should be raised on recognizing weight loss as an early symptom of esophageal cancer and the utilization of preoperative assessment tools for nutritional assessment and malnutrition management.

The seed-specific heat shock factor A9 regulates the depth of dormancy in Medicago truncatula seeds via ABA signalling.

During the later stages of seed maturation, two key adaptive traits are acquired that contribute to seed lifespan and dispersal, longevity and dormancy. The seed-specific heat shock transcription factor A9 is an important hub gene in the transcriptional network of late seed maturation. Here, we demonstrate that HSFA9 plays a role in thermotolerance rather than in ex situ seed conservation. Storage of hsfa9 seeds of Medicago truncatula and Arabidopsis had comparable lifespan at moderate storage relative humidity (RH), whereas at high RH, hsfa9 seeds lost their viability much faster than wild type seeds. Furthermore, we show that in M. truncatula, Mthsfa9 seeds acquired more dormancy during late maturation than wild type. Transient expression of MtHSFA9 in hairy roots and transcriptome analysis of Mthsfa9 Tnt1 insertion mutants identified a deregulation of genes involved in ABA biosynthesis, catabolism and signalling. Consistent with these results, Mthsfa9 seeds exhibited increased ABA levels and higher sensitivity to ABA. These data suggest that in legumes, HSFA9 acts as a negative regulator of the depth of seed dormancy during seed development via the modulation of hormonal balance.

Facilitators and barriers to a family empowerment strategy to improve healthcare worker hand hygiene in a resource-limited setting.

OBJECTIVES: The World Health Organization recommends empowering patients/families to remind healthcare workers (HCWs) to perform hand hygiene (HH). We sought to understand acceptability of a family empowerment strategy in a Vietnamese pediatric intensive care unit (PICU). METHODS: With end-user input, we designed a tool to help families in a PICU in Vietnam to remind HCWs to perform HH. We conducted 3 preliminary focus group discussions (FGDs) with patients' family members (n = 8), physicians (n = 9), and nurses (n = 8) to understand acceptability of preliminary tools, attitudes towards HH and barriers to HH. Tools were then modified and implemented in a 5-week intervention study. We then conducted 3 more FGDs with families (n = 7), physicians (n = 7), and nurses (n = 8). Discussions were analyzed using qualitative directed content analysis. Families who used the tool were asked to complete written surveys. FINDINGS: Both family members and HCWs felt that HCWs had a responsibility to perform HH. Barriers to performing HH were identified, including forgetfulness and time constraints. Family members felt shy reminding HCWs to perform HH. However, the HH reminder tool was acceptable, and some felt it could overcome barriers to reminding HCWs to perform HH. HCWs felt embarrassed when reminded to perform HH, but felt that the reminder was useful. Nearly all (99%) survey respondents felt that family members should speak up if they noticed HCWs omitting HH. CONCLUSIONS: A tool given to families to remind HCWs to perform HH was largely acceptable in a pediatric ICU in Vietnam. Perceived benefits of improving HH were felt to surmount barriers to tool use.

A family empowerment strategy is associated with increased healthcare worker hand hygiene in a resource-limited setting.

BACKGROUND: Guidelines recommend empowering patients and families to remind healthcare workers (HCWs) to perform hand hygiene (HH). The effectiveness of empowerment tools for patients and their families in Southeast Asia is unknown. METHODS: We performed a prospective study in a pediatric intensive care unit (PICU) of a Vietnamese pediatric referral hospital. With family and HCW input, we developed a visual tool for families to prompt HCW HH. We used direct observation to collect baseline HH data. We then enrolled families to receive the visual tool and education on its use while continuing prospective collection of HH data. Multivariable logistic regression was used to identify independent predictors of HH in baseline and implementation periods. RESULTS: In total, 2,014 baseline and 2,498 implementation-period HH opportunities were observed. During the implementation period, 73 families were enrolled. Overall, HCW HH was 46% preimplementation, which increased to 73% in the implementation period (P < .001). The lowest HH adherence in both periods occurred after HCW contact with patient surroundings: 16% at baseline increased to 24% after implementation. In multivariable analyses, the odds of HCW HH during the implementation period were significantly higher than baseline (adjusted odds ratio [aOR], 2.94; 95% confidence interval [CI], 2.54-3.41; P < .001) after adjusting for observation room, HCW type, time of observation (weekday business hours vs evening or weekend), and HH moment. CONCLUSIONS: The introduction of a visual empowerment tool was associated with significant improvement in HH adherence among HCWs in a Vietnamese PICU. Future research should explore acceptability and barriers to use of similar tools in low- and middle-income settings.

An approach for differentiating echovirus 30 and Japanese encephalitis virus infections in acute meningitis/encephalitis: a retrospective study of 103 cases in Vietnam.

BACKGROUND: In recent decades, Echovirus 30 (E30) and Japanese encephalitis virus (JEV) have been reported to be the common causative agents of acute meningitis among patients in South East Asia. An E30 outbreak in Vietnam in 2001-2002 gained our interest because the initial clinical diagnosis of infected patients was due to JEV infection. There are few clinical insights regarding E30 cases, and there are no reports comparing E30 and JEV acute meningitis/encephalitis cases based on clinical symptoms and case histories. We therefore aimed to identify reliable clinical methods to differentiate E30 and JEV acute meningitis/encephalitis. METHODS: A retrospective, cross-sectional study was conducted to compare E30 and JEV acute meningitis/encephalitis cases. We collected and analyzed the clinical records of 43 E30 confirmed cases (E30 group) and 60 JEV confirmed cases (JEV group). Clinical data were compared between the E30 and the JEV groups. Differences of clinical parameters were analyzed by certain statistical tests. RESULTS: Fever, headache, and vomiting were the most common symptoms in both the E30 and the JEV groups. Combined symptoms of headache and vomiting and the triad of symptoms of fever, headache, and vomiting were observed in more patients in the E30 group (E30 vs. JEV: 19% vs. 0%, p < 0.001; 74% vs. 27%, p < 0.001, respectively). On the other hand, strong neurological symptoms such as seizure (5% vs. 73%, p < 0.001) and altered consciousness (12% vs. 97%, p < 0.001) were manifested primarily in the JEV group. CSF leukocytosis was observed predominantly in the E30 group (80 vs. 18 cells/µL, p = 0.003), whereas decreasing CSF sugar level was observed predominantly in the JEV group (58.7 vs. 46.9 mg/dL, p < 0.001). CONCLUSION: Fever, headache, vomiting, absence of neurological symptoms (seizure, altered consciousness), and presence of CSF leukocytosis are important parameters to consider in differentiating E30 from JEV cases during early infection. Then, proper measures can be adopted immediately to prevent the spread of the disease in the affected areas.

Efficient algorithm for training interpolation RBF networks with equally spaced nodes.

This brief paper proposes a new algorithm to train interpolation Gaussian radial basis function (RBF) networks in order to solve the problem of interpolating multivariate functions with equally spaced nodes. Based on an efficient two-phase algorithm recently proposed by the authors, Euclidean norm associated to Gaussian RBF is now replaced by a conveniently chosen Mahalanobis norm, that allows for directly computing the width parameters of Gaussian radial basis functions. The weighting parameters are then determined by a simple iterative method. The original two-phase algorithm becomes a one-phase one. Simulation results show that the generality of networks trained by this new algorithm is sensibly improved and the running time significantly reduced, especially when the number of nodes is large.

Cloning, expression in Pichia pastoris, and characterization of a thermostable GH5 mannan endo-1,4-beta-mannosidase from Aspergillus niger BK01.

BACKGROUND: Mannans are key components of lignocellulose present in the hemicellulosic fraction of plant primary cell walls. Mannan endo-1,4-beta-mannosidases (1,4-beta-D-mannanases) catalyze the random hydrolysis of beta-1,4-mannosidic linkages in the main chain of beta-mannans. Biodegradation of beta-mannans by the action of thermostable mannan endo-1,4-beta-mannosidase offers significant technical advantages in biotechnological industrial applications, i.e. delignification of kraft pulps or the pretreatment of lignocellulosic biomass rich in mannan for the production of second generation biofuels, as well as for applications in oil and gas well stimulation, extraction of vegetable oils and coffee beans, and the production of value-added products such as prebiotic manno-oligosaccharides (MOS). RESULTS: A gene encoding mannan endo-1,4-beta-mannosidase or 1,4-beta-D-mannan mannanohydrolase (E.C. 3.2.1.78), commonly termed beta-mannanase, from Aspergillus niger BK01, which belongs to glycosyl hydrolase family 5 (GH5), was cloned and successfully expressed heterologously (up to 243 microg of active recombinant protein per mL) in Pichia pastoris. The enzyme was secreted by P. pastoris and could be collected from the culture supernatant. The purified enzyme appeared glycosylated as a single band on SDS-PAGE with a molecular mass of approximately 53 kDa. The recombinant beta-mannanase is highly thermostable with a half-life time of approximately 56 h at 70 degrees C and pH 4.0. The optimal temperature (10-min assay) and pH value for activity are 80 degrees C and pH 4.5, respectively. The enzyme is not only active towards structurally different mannans but also exhibits low activity towards birchwood xylan. Apparent Km values of the enzyme for konjac glucomannan (low viscosity), locust bean gum galactomannan, carob galactomannan (low viscosity), and 1,4-beta-D-mannan (from carob) are 0.6 mg mL-1, 2.0 mg mL-1, 2.2 mg mL-1 and 1.5 mg mL-1, respectively, while the kcat values for these substrates are 215 s-1, 330 s-1, 292 s-1 and 148 s-1, respectively. Judged from the specificity constants kcat/Km, glucomannan is the preferred substrate of the A. niger beta -mannanase. Analysis by thin layer chromatography showed that the main product from enzymatic hydrolysis of locust bean gum is mannobiose, with only low amounts of mannotriose and higher manno-oligosaccharides formed. CONCLUSION: This study is the first report on the cloning and expression of a thermostable mannan endo-1,4-beta-mannosidase from A. niger in Pichia pastoris. The efficient expression and ease of purification will significantly decrease the production costs of this enzyme. Taking advantage of its acidic pH optimum and high thermostability, this recombinant beta-mannanase will be valuable in various biotechnological applications.