WDR44 Loss-of-Function Promoter Deletion in a Male Newborn With a Ciliopathy Phenotype.

Gain-of-function variants in the WDR44 gene have recently been associated with an X-linked ciliopathy-related neurodevelopmental phenotype. Here, we report on a WDR44 loss-of-function (LOF) variant identified in the genome sequence from a male fetus enrolled in the Prenatal Genetic Diagnosis by Genomic Sequencing (PrenatalSEQ) multicenter study. The phenotype is consistent with the described X-linked ciliopathy that includes developmental delay, microcephaly, congenital heart defects, kidney abnormalities, cryptorchidism, musculoskeletal abnormalities, craniofacial dysmorphism, and effusions. This is the first report of a WDR44 LOF variant in an affected individual with a prenatal presentation and supports LOF as a mechanism for the X-linked WDR44 ciliopathy-related phenotype.

Genomic Sequencing for Newborn Screening: Results of the NC NEXUS Project.

Newborn screening (NBS) was established as a public health program in the 1960s and is crucial for facilitating detection of certain medical conditions in which early intervention can prevent serious, life-threatening health problems. Genomic sequencing can potentially expand the screening for rare hereditary disorders, but many questions surround its possible use for this purpose. We examined the use of exome sequencing (ES) for NBS in the North Carolina Newborn Exome Sequencing for Universal Screening (NC NEXUS) project, comparing the yield from ES used in a screening versus a diagnostic context. We enrolled healthy newborns and children with metabolic diseases or hearing loss (106 participants total). ES confirmed the participant's underlying diagnosis in 15 out of 17 (88%) children with metabolic disorders and in 5 out of 28 (∼18%) children with hearing loss. We discovered actionable findings in four participants that would not have been detected by standard NBS. A subset of parents was eligible to receive additional information for their child about childhood-onset conditions with low or no clinical actionability, clinically actionable adult-onset conditions, and carrier status for autosomal-recessive conditions. We found pathogenic variants associated with hereditary breast and/or ovarian cancer in two children, a likely pathogenic variant in the gene associated with Lowe syndrome in one child, and an average of 1.8 reportable variants per child for carrier results. These results highlight the benefits and limitations of using genomic sequencing for NBS and the challenges of using such technology in future precision medicine approaches.

The multivariable prognostic models for severe complications after heart valve surgery.

BACKGROUND: To provide multivariable prognostic models for severe complications prediction after heart valve surgery, including low cardiac output syndrome (LCOS), acute kidney injury requiring hemodialysis (AKI-rH) and multiple organ dysfunction syndrome (MODS). METHODS: We developed multivariate logistic regression models to predict severe complications after heart valve surgery using 930 patients collected retrospectively from the first affiliated hospital of Sun Yat-Sen University from January 2014 to December 2015. The validation was conducted using a retrospective dataset of 713 patients from the same hospital from January 2016 to March 2017. We considered two kinds of prognostic models: the PRF models which were built by using the preoperative risk factors only, and the PIRF models which were built by using both of the preoperative and intraoperative risk factors. The least absolute shrinkage selector operator was used for developing the models. We assessed and compared the discriminative abilities for both of the PRF and PIRF models via the receiver operating characteristic (ROC) curve. RESULTS: Compared with the PRF models, the PIRF modes selected additional intraoperative factors, such as auxiliary cardiopulmonary bypass time and combined tricuspid valve replacement. Area under the ROC curves (AUCs) of PRF models for predicting LCOS, AKI-rH and MODS are 0.565 (0.466, 0.664), 0.688 (0.62, 0.757) and 0.657 (0.563, 0.751), respectively. As a comparison, the AUCs of the PIRF models for predicting LOCS, AKI-rH and MODS are 0.821 (0.747, 0.896), 0.78 (0.717, 0.843) and 0.774 (0.7, 0.847), respectively. CONCLUSIONS: Adding the intraoperative factors can increase the predictive power of the prognostic models for severe complications prediction after heart valve surgery.

Somali, Latino and Hmong parents' perceptions and approaches about raising healthy-weight children: a community-based participatory research study.

OBJECTIVE: Immigrants in the USA are confronted with health disparities, including childhood obesity and obesity-related chronic diseases. We aimed to identify perceptions of childhood body weight, approaches to raising healthy children and desires for supportive programmes of Somali, Latino and Hmong (SLM) parents in the Twin Cities, Minnesota, USA. DESIGN: Using community-based participatory research, ten focus groups (FG) were conducted with sixty-seven parents (n 28 Somali, three FG; n 19 Latino, four FG; n 20 Hmong, three FG) of 3-12-year-old children in their native language. Demographic information was collected. RESULTS: SLM parents perceived that health is not necessarily weight-based; childhood obesity is caused by overeating, eating unhealthy foods and sedentary activities; traditional foods are generally healthy while American foods are generally unhealthy; and healthy children are inherently physically active. Parents identified their goals as feeding children so they would be healthy and happy, helping them be active and safe, and teaching them to cook traditional foods to be self-sufficient and maintain their cultural identity. Parents were challenged by children's unhealthy food and sedentary preferences, their own uncertainties about healthy foods and behaviours, and structural factors. Parents thought interventions could help them with these challenges, including information about healthy foods, age-appropriate portion sizes, safe places to be active and strategies tailored to their cultural norms. CONCLUSIONS: SLM parents are trying to raise healthy-weight children based on their understanding of children's health, weight, diet and physical activity, while dealing with social, economic and environmental challenges and trying to maintain cultural identity and traditions.

Large left circumflex coronary artery with a fistula to superior vena cava: Diagnosis by echocardiography.

The left circumflex coronary artery associated with a fistula to superior vena cava is a rare entity. We describe a 7-year-old girl who presented with a cardiac murmur and was diagnosed with a coronary artery fistula between the left circumflex artery and superior vena cava by echocardiography. The surgical occlusion of the fistula was successful.

Hypofractionated Radiotherapy followed by Hypofractionated Boost with weekly concurrent chemotherapy for Unresectable Stage III Non-Small Cell Lung Cancer: Results of A Prospective Phase II Study (GASTO-1049).

PURPOSE: We launched a prospective phase 2 clinical trial to explore the safety and efficacy of hypofractionated radiation therapy (hypo-RT) followed by hypofractionated boost (hypo-boost) combined with concurrent weekly chemotherapy in patients with unresectable locally advanced non-small cell lung cancer (LA-NSCLC). METHODS AND MATERIALS: Patients with newly diagnosed LA-NSCLC with unresectable stage III disease were recruited between June 2018 and June 2020. Patients were treated with hypo-RT (40 Gy in 10 fractions) followed by hypo-boost (24-28 Gy in 6-7 fractions) combined with concurrent weekly chemotherapy (docetaxel 25 mg/m2 and nedaplatin 25 mg/m2). The primary endpoint of the study was progression-free survival (PFS), and the secondary endpoints included overall survival (OS), locoregional failure-free survival (LRFS), distant metastasis-free survival (DMFS), objective response rate (ORR), and toxicities. RESULTS: From June 2018 to June 2020, 75 patients were enrolled with a median follow-up duration of 28.0 months. The ORR of the whole cohort was 94.7%. Disease progression or death was recorded in 44 (58.7%) patients, with a median PFS of 21.6 months (95% confidence interval [CI], 15.6-27.6 months). The 1- and 2-year PFS rates were 81.3% (95% CI, 72.5%-90.1%) and 43.3% (95% CI, 31.5%-55.1%), respectively. The median OS, DMFS, and LRFS had not been reached at the time of the last follow-up. The 1- and 2-year OS rates were 94.7% (95% CI, 89.6%-99.8%) and 72.4% (95% CI, 62.0%-82.8%), respectively. The most frequent acute nonhematologic toxicity was radiation esophagitis. Grade (G) 2 and G3 acute radiation esophagitis were observed in 20 (26.7%) and 4 (5.3%) patients, respectively. Thirteen patients (13/75, 17.3%) had G2 pneumonitis and no G3-G5 acute pneumonitis occurred during follow-up. CONCLUSIONS: Hypo-RT followed by hypo-boost combined with concurrent weekly chemotherapy could yield satisfactory local control and survival outcomes with moderate radiation-induced toxicity in patients with LA-NSCLC. The new potent hypo-CCRT regimen significantly shortened treatment time and provided the potential opportunity for the combination of consolidative immunotherapy.

Efficacy of Thymosin α1 in Management of Radiation Pneumonitis in Patients With Locally Advanced Non-Small Cell Lung Cancer Treated With Concurrent Chemoradiotherapy: A Phase 2 Clinical Trial (GASTO-1043).

PURPOSE: To evaluate the efficacy of thymosin α1 in management of radiation pneumonitis (RP) in patients with locally advanced non-small cell lung cancer (LANSCLC) treated with concurrent chemoradiotherapy (CCRT). METHODS AND MATERIALS: This phase 2, single-arm trial enrolled patients with unresectable LANSCLC of 18 to 75 years' old and an Eastern Cooperative Oncology Group performance status of 0 to 1. Eligible patients received definitive CCRT and weekly thymosin α1 from the start of CCRT until 2 months after CCRT. Patients were administered 51 Gy in 17 daily fractions or 40 Gy in 10 daily fractions in the first course followed by a re-evaluation and those patients without disease progression had an adaptive plan of 15 Gy in 5 daily fractions or 24 Gy in 6 daily fractions as a boost. Concurrent chemotherapy consisted of weekly docetaxel (25 mg/m2) and nedaplatin (25 mg/m2) during radiation therapy. The primary endpoint was the incidence of Grade (G) ≥2 RP. Secondary endpoints included the incidence of late pulmonary fibrosis, total lymphocyte count (TLC), serum C-reactive protein (CRP) levels, and the composition of gut microbiota. TLC and CRP data were collected at baseline, 2 to 3 weeks during CCRT, the end of CCRT, 2 and 6 months after CCRT. Fecal samples were collected at baseline and the end of CCRT. Patients treated with CCRT but without thymosin α1 intervention during the same period were selected as the control group by the propensity score matching method. RESULTS: Sixty-nine patients were enrolled in the study, and another 69 patients were selected as the control group. The incidence of G≥2 RP was lower in the study group compared with control cases (36.2% vs 53.6%, P = .040). G1 late pulmonary fibrosis occurred in 2 (3.7%) patients of the control group compared with no event in the study group (P = .243). Compared with the control group, the incidence of G3 to G4 lymphopenia (19.1% vs 62.1%, P < .001) was lower, and the median TLC nadir (0.51 k/µL vs 0.30 k/µL, P < .001) was higher in the study group. The proportion of patients with maximum CRP ≥100 mg/L was lower in the study group (13.8% vs 29.7% P = .029). The diversity and community composition of the gut microbiota were not significantly different between the 2 groups. CONCLUSIONS: Administration of thymosin α1 during and after CCRT was associated with significant reductions in G≥2 RP and G3 to G4 lymphopenia in patients with LANSCLC compared with historic controls.

CT radiomics-based long-term survival prediction for locally advanced non-small cell lung cancer patients treated with concurrent chemoradiotherapy using features from tumor and tumor organismal environment.

BACKGROUND: Definitive concurrent chemoradiotherapy (CCRT) is the standard treatment for locally advanced non-small cell lung cancer (LANSCLC) patients, but the treatment response and survival outcomes varied among these patients. We aimed to identify pretreatment computed tomography-based radiomics features extracted from tumor and tumor organismal environment (TOE) for long-term survival prediction in these patients treated with CCRT. METHODS: A total of 298 eligible patients were randomly assigned into the training cohort and validation cohort with a ratio 2:1. An integrated feature selection and model training approach using support vector machine combined with genetic algorithm was performed to predict 3-year overall survival (OS). Patients were stratified into the high-risk and low-risk group based on the predicted survival status. Pulmonary function test and blood gas analysis indicators were associated with radiomic features. Dynamic changes of peripheral blood lymphocytes counts before and after CCRT had been documented. RESULTS: Nine features including 5 tumor-related features and 4 pulmonary features were selected in the predictive model. The areas under the receiver operating characteristic curve for the training and validation cohort were 0.965 and 0.869, and were reduced by 0.179 and 0.223 when all pulmonary features were excluded. Based on radiomics-derived stratification, the low-risk group yielded better 3-year OS (68.4% vs. 3.3%, p < 0.001) than the high-risk group. Patients in the low-risk group had better baseline FEV1/FVC% (96.3% vs. 85.9%, p = 0.046), less Grade ≥ 3 lymphopenia during CCRT (63.2% vs. 83.3%, p = 0.031), better recovery of lymphopenia from CCRT (71.4% vs. 27.8%, p < 0.001), lower incidence of Grade ≥ 2 radiation-induced pneumonitis (31.6% vs. 53.3%, p = 0.040), superior tumor remission (84.2% vs. 66.7%, p = 0.003). CONCLUSION: Pretreatment radiomics features from tumor and TOE could boost the long-term survival forecast accuracy in LANSCLC patients, and the predictive results could be utilized as an effective indicator for survival risk stratification. Low-risk patients might benefit more from radical CCRT and further adjuvant immunotherapy. TRIAL REGISTRATION: retrospectively registered.

Increased glucose variability is associated with major adverse events in patients with infective endocarditis undergo surgical treatment.

BACKGROUND: This study aimed to investigate the prognostic value of glucose variability (GV) in predicting postoperative major adverse events (MAEs) in patients with infective endocarditis (IE) who underwent surgical treatment. METHODS: This retrospective observational study included a total of 381 consecutive patients who underwent surgical treatment in our institution from October 2007 to August 2019. The MAEs included all-cause death, stroke, myocardial infarction, acute heart failure, IE recurrence, acute renal failure and sepsis. Postoperative GV in the first 24 hours was measured by the mean 24-hour glucose, standard deviation, coefficient of variation (CV) and mean amplitude of glycemic excursions. Univariate and multivariate logistic regression analyses were performed to identify the independent association of GV with MAEs. RESULTS: Of the 381 patients, 79 (20.7%) developed MAEs. The 30-day mortality of the overall study cohort was 5.23%. The multivariate logistic regression analysis indicated that 24-hour GV, measured as the CV [odds ratio (OR) =1.49, 95% CI, 1.23-3.57, P=0.012], was significantly associated with MAEs in IE patients. For every 10% increase in 24-hour CV, there was a 49% increase in the risk of MAEs. Furthermore, compared to patients in the low tertile of GV, patients in the top tertile of 24-hour GV had a higher 30-day mortality and an increased incidence of heart failure and hemodialysis as well as longer ventilation support. CONCLUSIONS: The results of this retrospective investigation demonstrated that increased GV measured by CV is an independent predictor of postoperative MAEs in patients undergoing surgical treatment for IE.

Hypofractionated Intensity Modulated Radiation Therapy With Concurrent Chemotherapy in Locally Advanced Non-Small Cell Lung Cancer: A Phase II Prospective Clinical Trial (GASTO1011).

PURPOSE: We aimed to explore the efficacy and toxicity of split-course hypofractionated radiation therapy with concurrent chemotherapy (HRT-CHT) in patients with locally advanced non-small cell lung cancer (LANSCLC) in this single-arm, phase II study. METHODS AND MATERIALS: Patients with LANSCLC were considered eligible if their forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC%) and carbon monoxide diffusing capacity (DLCO%) were ≥40% and ≥45%, respectively. HRT-CHT using the intensity modulated radiation therapy technique was administered with 51 Gy in 17 fractions as the first course followed by a break. Patients without disease progression or persistent ≥grade 2 toxicities had an HRT-CHT of 15 to 18 Gy in 5 to 6 fractions as a boost. The primary endpoint was progression-free survival, and the secondary endpoint was overall survival (OS). RESULTS: Eighty-nine patients were enrolled and analyzed. The median follow-up was 29.5 months for all patients and 35.3 months for the survivors. The objective response rate was 97.8%; the median progression-free survival and OS were 11.0 and 27.0 months, respectively. Grade 3 acute esophagitis/pneumonitis occurred in 15 (16.9%)/7 (7.9%) patients. Grade 3/5 late pneumonitis occurred in 2 (2.2%)/1 (1.1%) patients. Of the 78 (87.6%) who completed the split-course HRT-CHT per protocol, patients with better FEV1/FVC% and DLCO% after the break had significantly better OS (for the FEV/FVC1% ≥ 80% vs 60%-79% vs 41%-59% groups, 2-year OS values were 57.2% vs 56.9% vs 0%, respectively, P = .024; for the DLCO% ≥ 80% vs 60%-79% vs 45%-59% groups, 2-year OS values were 70.4% vs 48.4% vs 37.5%, respectively, P = .049). CONCLUSIONS: Split-course HRT-CHT achieved a promising response rate and survival with tolerable toxicity in LANSCLC. Pulmonary function tests are necessary indicators for radiation treatment planning and dose escalation.

Hypo-fractionated radiotherapy with concurrent chemotherapy for locoregional recurrence of non-small cell lung cancer after complete resection: A prospective, single-arm, phase II study (GASTO-1017).

OBJECTIVES: To explore the efficacy and toxicities of split-course hypo-fractionated radiotherapy with concurrent chemotherapy (HFRT-CHT) with intensity modulated radiotherapy (IMRT) technique in non-small cell lung cancer (NSCLC) patients with postoperative locoregional recurrence (LRR). MATERIALS AND METHODS: NSCLC patients were eligible if confirmed as LRR disease without distant metastasis after complete resection. HFRT-CHT using IMRT technique was administered with 51 Gy in 17 fractions or 40 Gy in 10 fractions as the first course followed by a break. Patients with no disease progression and no persistent Grade ≥2 toxicities had the second course of 15 Gy in 5 fractions or 28 Gy in 7 fractions as a boost. The primary endpoint was progression-free survival (PFS). RESULTS: Fifty-eight patients were enrolled and analyzed. With a median follow-up of 23.9 months for all, the 2-year and 3-year PFS rate was 59.7 % and 46.4 %, the 2-year and 3-year OS rate was 72.5 % and 52.2 %, respectively, and a favorable objective response rate of 95.9 % was obtained after the whole courses protocol. Grade 3 acute pneumonitis and esophagitis occurred in 2 (3.4 %) and 7 (12.1 %) patients, and fatal pneumonitis was reported in one case (1.7 %). Exploratory subgroup analysis showed that performance status (PS) (PS 0 vs. 1: 2-year PFS, 88.1 % vs. 46.9 %,P = 0.001; 2-year OS, 100 % vs. 59.4 %, P < 0.001), recurrence site (single vs. multiple: 2-year PFS, 93.8 % vs. 47.4 %, P = 0.008; 2-year OS, 100 % vs. 63.0 %, P = 0.001), and gross tumor volume (GTV) (<50cm3 vs. ≥ 50cm3: 2-year PFS, 70.6 % vs. 46.2 %, P = 0.024; 2-year OS, 85.6 % vs. 57.4 %, P = 0.034) were significantly associated with PFS and OS. CONCLUSION: Split-course HFRT-CHT with IMRT technique achieved promising disease control and satisfactory survival with moderate toxicities in postoperative LRR of NSCLC. Good PS, a single recurrence site and GTV<50cm3 tended to have prolonged PFS and OS. Early detection of LRR may improve the efficacy of HFRT-CHT.

Aortic arch reconstruction with an autologous pulmonary arterial-roll tube in an interrupted aortic arch.

We report a case of aortic arch reconstruction with an autologous pulmonary arterial-roll tube in a 4-year-old child with a type A interrupted aortic arch. The autologous pulmonary arterial-roll tube dilated progressively after the operation, and some severe complications occurred, including formation of an aneurysm. A second operation was performed to resect the aortic aneurysm and to interpose a Dacron tube graft. We conclude that the aforementioned dilation may limit the use of an autologous pulmonary arterial-roll tube in the construction of the aortic arch.

Chylothorax and constrictive pericarditis in a woman due to generalized lymphatic anomaly: a case report.

BACKGROUND: Generalized lymphatic anomaly (GLA) is characterized by diffuse or multicentric proliferation of dilated lymphatic vessels resembling common lymphatic malformations. Compared with soft tissue or bone involvement, thoracic involvement may be associated with a worse prognosis. CASE PRESENTATION: We reported a case of GLA with chylothorax and constrictive pericarditis in a 29-year-old woman. This patient exhibited remarkable features, including a continuously hemorrhagic chylothorax, constrictive pericarditis, and involvement of bone and neck lymph nodes. After attempting to manage her condition with conservative treatment, the patient underwent pericardial stripping surgery. Exploration revealed abundant hyperplasia of tubular tissue in the aortopulmonary window in both pleural cavities. CONCLUSIONS: This case highlights the importance of maintaining the clinical suspicion of GLA during the follow-up of chylothorax patients. Aggressive pericardial surgery, which is important for both diagnosis and treatment, should be performed in patients with GLA with constrictive pericarditis.

Heading Date QTL in Winter Wheat (Triticum aestivum L.) Coincide with Major Developmental Genes VERNALIZATION1 and PHOTOPERIOD1.

In wheat (Triticum aestivum L.), time from planting to spike emergence is influenced by genes controlling vernalization requirement and photoperiod response. Characterizing the available genetic diversity of known and novel alleles of VERNALIZATION1 (VRN1) and PHOTOPERIOD1 (PPD1) in winter wheat can inform approaches for breeding climate resilient cultivars. This study identified QTL for heading date (HD) associated with multiple VRN1 and PPD1 loci in a population developed from a cross between two early flowering winter wheat cultivars. When the population was grown in the greenhouse after partial vernalization treatment, major heading date QTLs co-located with the VRN-A1 and VRN-B1 loci. Copy number variation at the VRN-A1 locus influenced HD such that RIL having three copies required longer cold exposure to transition to flowering than RIL having two VRN-A1 copies. Sequencing vrn-B1 winter alleles of the parents revealed multiple polymorphisms in the first intron that were the basis of mapping a major HD QTL coinciding with VRN-B1. A 36 bp deletion in the first intron of VRN-B1 was associated with earlier HD after partial vernalization in lines having either two or three haploid copies of VRN-A1. The VRN1 loci interacted significantly and influenced time to heading in field experiments in Louisiana, Georgia and North Carolina. The PPD1 loci were significant determinants of heading date in the fully vernalized treatment in the greenhouse and in all field environments. Heading date QTL were associated with alleles having large deletions in the upstream regions of PPD-A1 and PPD-D1 and with copy number variants at the PPD-B1 locus. The PPD-D1 locus was determined to have the largest genetic effect, followed by PPD-A1 and PPD-B1. Our results demonstrate that VRN1 and PPD1 alleles of varying strength allow fine tuning of flowering time in diverse winter wheat growing environments.

Surgical intervention for advanced valvular heart disease in 227 cases.

BACKGROUND: Although the results of surgical treatment in cardiac valve disease continue to improve, the postoperative mortality rate and the rate of complications in patients with advanced valvular heart disease (AVHD) are still very high. We did this retrospective study to summarize the surgical experience of heart valve replacement for patients with AVHD and discuss effective ways to improve the surgical outcome. METHODS: From January 1994 to October 2003, surgical procedures of heart valve replacement were performed on 227 (136 men and 91 women) patients with AVHD in our Department of Cardiothoracic Surgery. The clinical data of all patients were collected and analysed. Patients' age ranged from 10 years to 77 years. In preoperative cardiac function grading, 157 cases were NYHA III and 70 cases NYHA IV. Fifty-one patients had had cardiac operations. The ultrasonic cardiac graphs showed that 145 patients suffered from moderate or severe pulmonary hypertension and 73 had combined giant left ventricle. Mitral valve replacement was performed in 32 cases, aortic valve replacement in 90, tricuspid valve replacement in 1, combined mitral and aortic replacement in 103 and combined mitral and tricuspid replacement in 1. Nineteen patients also received surgical corrections for other minor abnormalities during the operations. A logistic model was established to evaluate the influence of perioperative factors on the mortality rate. RESULTS: The operative mortality rate was 13.2% (30/227). The main causes of death included multiple organ dysfunction syndrome (MODS), low cardiac output syndrome and ventricular fibrillation. From the results of the binary noncounterpart multivariate logistic regression, the following statistically significant factors were found to influence the operative mortality rate: redo operation, age >/= 55 years, preoperative NYHA cardiac function grading, extracorporeal circulation time >/= 120 minutes and postoperative usage of GIK (glucose, insulin and potassium) solution. All factors were risk ones except postoperative application of GIK. The Hosmer-Lemeshow goodness of fit coefficient of this model was 0.976. CONCLUSIONS: The risk factors associated with postoperative mortality rate in the patients with AVHD were redo operation, age >/= 55 years, preoperative NYHA cardiac function grading and extracorporeal circulation time >/= 120 minutes. Postoperative usage of GIK acted as a kind of metabolic therapy and will improve the recovery for patients with AVHD. Active perioperative management and care will play a very important role in reducing the operative risk and improving the short term outcome of surgical treatment for the patients with AVHD.

Potential for microbial oxidation of ferrous iron in basaltic glass.

Basaltic glass (BG) is an amorphous ferrous iron [Fe(II)]-containing material present in basaltic rocks, which are abundant on rocky planets such as Earth and Mars. Previous research has suggested that Fe(II) in BG can serve as an energy source for chemolithotrophic microbial metabolism, which has important ramifications for potential past and present microbial life on Mars. However, to date there has been no direct demonstration of microbially catalyzed oxidation of Fe(II) in BG. In this study, three different culture systems were used to investigate the potential for microbial oxidation of Fe(II) in BG, including (1) the chemolithoautotrophic Fe(II)-oxidizing, nitrate-reducing "Straub culture"; (2) the mixotrophic Fe(II)-oxidizing, nitrate-reducing organism Desulfitobacterium frappieri strain G2; and (3) indigenous microorganisms from a streambed Fe seep in Wisconsin. The BG employed consisted of clay and silt-sized particles of freshly quenched lava from the TEB flow in Kilauea, Hawaii. Soluble Fe(II) or chemically reduced NAu-2 smectite (RS) were employed as positive controls to verify Fe(II) oxidation activity in the culture systems. All three systems demonstrated oxidation of soluble Fe(II) and/or structural Fe(II) in RS, whereas no oxidation of Fe(II) in BG material was observed. The inability of the Straub culture to oxidize Fe(II) in BG was particularly surprising, as this culture can oxidize other insoluble Fe(II)-bearing minerals such as biotite, magnetite, and siderite. Although the reason for the resistance of the BG toward enzymatic oxidation remains unknown, it seems possible that the absence of distinct crystal faces or edge sites in the amorphous glass renders the material resistant to such attack. These findings have implications with regard to the idea that Fe(II)-Si-rich phases in basalt rocks could provide a basis for chemolithotrophic microbial life on Mars, specifically in neutral-pH environments where acid-promoted mineral dissolution and utilization of dissolved Fe(II) as an energy source is not likely to take place.

Genome-wide association study reveals novel quantitative trait Loci associated with resistance to multiple leaf spot diseases of spring wheat.

Accelerated wheat development and deployment of high-yielding, climate resilient, and disease resistant cultivars can contribute to enhanced food security and sustainable intensification. To facilitate gene discovery, we assembled an association mapping panel of 528 spring wheat landraces of diverse geographic origin for a genome-wide association study (GWAS). All accessions were genotyped using an Illumina Infinium 9K wheat single nucleotide polymorphism (SNP) chip and 4781 polymorphic SNPs were used for analysis. To identify loci underlying resistance to the major leaf spot diseases and to better understand the genomic patterns, we quantified population structure, allelic diversity, and linkage disequilibrium. Our results showed 32 loci were significantly associated with resistance to the major leaf spot diseases. Further analysis identified QTL effective against major leaf spot diseases of wheat which appeared to be novel and others that were previously identified by association analysis using Diversity Arrays Technology (DArT) and bi-parental mapping. In addition, several identified SNPs co-localized with genes that have been implicated in plant disease resistance. Future work could aim to select the putative novel loci and pyramid them in locally adapted wheat cultivars to develop broad-spectrum resistance to multiple leaf spot diseases of wheat via marker-assisted selection (MAS).

Fe-phyllosilicate redox cycling organisms from a redox transition zone in Hanford 300 Area sediments.

Microorganisms capable of reducing or oxidizing structural iron (Fe) in Fe-bearing phyllosilicate minerals were enriched and isolated from a subsurface redox transition zone at the Hanford 300 Area site in eastern Washington, USA. Both conventional and in situ "i-chip" enrichment strategies were employed. One Fe(III)-reducing Geobacter (G. bremensis strain R1, Deltaproteobacteria) and six Fe(II) phyllosilicate-oxidizing isolates from the Alphaproteobacteria (Bradyrhizobium japonicum strains 22, is5, and in8p8), Betaproteobacteria (Cupriavidus necator strain A5-1, Dechloromonas agitata strain is5), and Actinobacteria (Nocardioides sp. strain in31) were recovered. The G. bremensis isolate grew by oxidizing acetate with the oxidized form of NAu-2 smectite as the electron acceptor. The Fe(II)-oxidizers grew by oxidation of chemically reduced smectite as the energy source with nitrate as the electron acceptor. The Bradyrhizobium isolates could also carry out aerobic oxidation of biotite. This is the first report of the recovery of a Fe(II)-oxidizing Nocardioides, and to date only one other Fe(II)-oxidizing Bradyrhizobium is known. The 16S rRNA gene sequences of the isolates were similar to ones found in clone libraries from Hanford 300 sediments and groundwater, suggesting that such organisms may be present and active in situ. Whole genome sequencing of the isolates is underway, the results of which will enable comparative genomic analysis of mechanisms of extracellular phyllosilicate Fe redox metabolism, and facilitate development of techniques to detect the presence and expression of genes associated with microbial phyllosilicate Fe redox cycling in sediments.