Predicting Factors of Long-term Outcome of Gastrointestinal Behçet's Disease: A Chinese Retrospective Study.

PURPOSE: Behçet's disease (BD) is a complex disorder affecting multiple systems and organs, and gastrointestinal BD is poorly understood. We aimed to identify factors influencing the long-term outcomes of patients with gastrointestinal BD. METHODS: Consecutive patients with gastrointestinal BD were analyzed retrospectively. Data on the following clinical characteristics were collected: sex, age at diagnosis, symptoms, endoscopic findings, medical treatments, and surgery. Mucosal healing and surgical rates at 1, 2, and 5 years were evaluated. Log-rank test and Cox proportional hazards regression models were used to evaluate the factors affecting long-term outcomes. FINDINGS: Baseline data of 175 patients with gastrointestinal BD were included. The mean (SD) age at diagnosis was 38.3 (12.9) years. The typical clinical symptoms were oral ulcer (72.6%), abdominal pain (71.4%), and weight loss (41.1%). The most commonly involved location was the ileocecum; isolated oval ulcer was the most common ulcer type. Seventeen patients (9.7%) underwent 18 surgeries after inclusion. The cumulative surgical rates were 8.6% (n/N = 15/175), 8.6% (n/N = 15/175), and 9.1% (n/N = 16/175) in 1, 2, and 5 years, respectively. Data from 101 patients who underwent at least 2 endoscopies were included in the analysis for mucosal healing. Kaplan-Meier curve showed that the cumulative mucosal healing rates at 1, 2, and 5 years were 34.7% (n/N = 35/101), 41.6% (n/N = 42/101), and 61.4% (n/N = 62/101), respectively. We compared cumulative mucosal healing rates between 4 treatment groups, including 5-aminosalicylic acid (3% [n/N = 3/101]), mono-immunosuppressant (31.7% [n/N = 32/101]), combined therapy (36.6% [n/N = 37/101]), and escalation therapy (28.7% [n/N = 29/101]), and found that mono-immunosuppressant achieved earlier mucosal healing than combined therapy (P = 0.0008) and escalation therapy (P = 0.0008). The univariate analysis showed that moderate to severe disease activity (P = 0.013, P = 0.004), diameter of the maximal ulcer >4 cm (P = 0.002), and nonsimple esophageal involvement (P < 0.001) were risk factors, and number of ulcers between 2 and 5 was the protective factor of mucosal healing (P = 0.001). Multivariate regression analysis indicated that nonsimple esophageal involvement (P < 0.001) and the maximal ulcer >4 cm (P = 0.041) were independent risk factors of mucosal healing. IMPLICATIONS: Most patients with gastrointestinal BD need long-term treatment to achieve mucosal healing. The location and size of ulcers have a significant impact on the mucosal healing of gastrointestinal BD.

Structural basis for the activity regulation of a potassium channel AKT1 from Arabidopsis.

The voltage-gated potassium channel AKT1 is responsible for primary K+ uptake in Arabidopsis roots. AKT1 is functionally activated through phosphorylation and negatively regulated by a potassium channel α-subunit AtKC1. However, the molecular basis for the modulation mechanism remains unclear. Here we report the structures of AKT1, phosphorylated-AKT1, a constitutively-active variant, and AKT1-AtKC1 complex. AKT1 is assembled in 2-fold symmetry at the cytoplasmic domain. Such organization appears to sterically hinder the reorientation of C-linkers during ion permeation. Phosphorylated-AKT1 adopts an alternate 4-fold symmetric conformation at cytoplasmic domain, which indicates conformational changes associated with symmetry switch during channel activation. To corroborate this finding, we perform structure-guided mutagenesis to disrupt the dimeric interface and identify a constitutively-active variant Asp379Ala mediates K+ permeation independently of phosphorylation. This variant predominantly adopts a 4-fold symmetric conformation. Furthermore, the AKT1-AtKC1 complex assembles in 2-fold symmetry. Together, our work reveals structural insight into the regulatory mechanism for AKT1.

Mucosal healing and quality of life in therapeutic goals of ulcerative colitis: occurrence and related factors of functional bowel disorder-like symptoms.

Background: Mucosal healing (MH) is considered the preferred therapeutic target for ulcerative colitis (UC). Impaired quality of life (QoL), irritable bowel syndrome (IBS)-like symptoms, and functional bowel symptoms have been reported in several inactive patients with UC. This study aims to assess the occurrence of functional bowel disorders (FBD)-like symptoms and QoL in UC patients with MH, and to explore the factors related to FBD-like symptoms. Methods: UC patients with MH (Mayo endoscopic score, MES = 0 or 1) were required to complete the Rome IV diagnostic questionnaire, the 32-item version of Inflammatory Bowel Disease Questionnaire (IBDQ-32), the 36-item short form healthy survey questionnaire (SF-36), and the Hospital Anxiety and Depression Scale (HADS). UC patients who did not achieve MH (MES > 1) completed the IBDQ-32, the SF-36, and the HADS. Community-dwelling healthy controls (HCs) completed the SF-36 and the HADS. Results: Among the 119 UC patients with MH recruited, 45.4% reported functional bowel symptoms; functional constipation-like symptom (13.4%) was the most prevalent, followed by IBS-like symptom (10.9%), and functional diarrhea-like symptom (10.0%). The IBDQ-32 and SF-36 scores were significantly lower in MH patients with FBD-like symptoms than in those without FBD-like symptoms. Disease duration [odds ratio (OR): 1.022; p < 0.001], body mass index (BMI; OR: 0.726; p < 0.001) were independent predictors of FBD-like symptoms in UC patients with MH. Combining these two factors could attain area under the curve [0.786; 95% confidence interval (CI): 0.701-0.856, p < 0.001] to predict FBD-like symptoms in MH patients. Conclusion: A number of UC patients with MH had accompanying FBD-like symptoms and significantly impaired QoL. Disease duration, BMI could predict the occurrence of FBD-like symptoms.

Genome-wide Scan for Seed Composition Provides Insights into Soybean Quality Improvement and the Impacts of Domestication and Breeding.

The complex genetic architecture of quality traits has hindered efforts to modify seed nutrients in soybean. Genome-wide association studies were conducted for seed composition, including protein, oil, fatty acids, and amino acids, using 313 diverse soybean germplasm accessions genotyped with a high-density SNP array. A total of 87 chromosomal regions were identified to be associated with seed composition, explaining 8%-89% of genetic variances. The candidate genes GmSAT1, AK-HSDH, SACPD-C, and FAD3A of known function, and putative MtN21 nodulin, FATB, and steroid-5-α-reductase involved in N2 fixation, amino acid biosynthesis, and fatty acid metabolism were found at the major-effect loci. Further analysis of additional germplasm accessions indicated that these major-effect loci had been subjected to domestication or modern breeding selection, and the allelic variants and distributions were relevant to geographic regions. We also revealed that amino acid concentrations related to seed weight and to total protein had a different genetic basis. This helps uncover the in-depth genetic mechanism of the intricate relationships among the seed compounds. Thus, our study not only provides valuable genes and markers for soybean nutrient improvement, both quantitatively and qualitatively, but also offers insights into the alteration of soybean quality during domestication and breeding.

Molecular mapping of a non-host resistance gene YrpstY1 in barley (Hordeum vulgare L.) for resistance to wheat stripe rust.

Cultivated barley (Hordeum vulgare L.) is considered as a non-host or inappropriate host species for wheat stripe rust caused by Puccinia striiformis f. sp. tritici. Most barley cultivars show a broad-spectrum resistance to wheat stripe rust. To determine the genes for resistance to wheat stripe rust in barley, a cross was made between a resistant barley line Y12 and a susceptible line Y16. The two parents, F(1) and 147 BC(1) plants were tested at seedling stage with Chinese prevalent race CYR32 of Puccinia striiformis f. sp. tritici by artificial inoculation in greenhouse. The results indicated that Y12 possessed one dominant resistance gene to wheat stripe rust, designated YrpstY1 provisionally. A total of 388 simple sequence repeat (SSR) markers were used to map the resistance gene in Y12 using bulked segregant analysis. A linkage map, including nine SSR loci on chromosome 7H and YrpstY1, was constructed using the BC(1) population, indicating that the resistance gene YrpstY1 is located on chromosome 7H. It is potential to transfer the resistance gene into common wheat for stripe rust resistance.

QTL mapping for adult-plant resistance to stripe rust in Italian common wheat cultivars Libellula and Strampelli.

Italian common wheat cultivars Libellula and Strampelli, grown for over three decades in Gansu province of China, have shown effective resistance to stripe rust. To elucidate the genetic basis of the resistance, F(3) populations were developed from crosses between the two cultivars and susceptible Chinese wheat cultivar Huixianhong. The F(3) lines were evaluated for disease severity in Beijing, Gansu and Sichuan from 2005 to 2008. Joint- and single-environment analyses by composite interval mapping identified five quantitative trait loci (QTLs) in Libellula for reduced stripe rust severity, designated QYr.caas-2DS, QYr.caas-4BL, QYr.caas-5BL.1, QYr.caas-5BL.2 and QYr.caas-7DS, and explained 8.1-12.4, 3.6-5.1, 3.4-8.6, 2.6 and 14.6-35.0%, respectively, of the phenotypic variance across four environments. Six interactions between different pairs of QTLs explained 3.2-7.1% of the phenotypic variance. The QTLs QYr.caas-4BL, QYr.caas-5BL.1 and QYr.caas-7DS were also detected in Strampelli, explaining 4.5, 2.9-5.5 and 17.1-39.1% of phenotypic variance, respectively, across five environments. Three interactions between different pairs of QTLs accounted for 6.1-35.0% of the phenotypic variance. The QTL QYr.caas-7DS flanked by markers csLV34 and Xgwm295 showed the largest effect for resistance to stripe rust. Sequence analyses confirmed that the lines with the QYr.caas-7DS allele for resistance carried the resistance allele of the Yr18/Lr34 gene. Our results indicated that the adult-plant resistance gene Yr18 and several minor genes confer effective durable resistance to stripe rust in Libellula and Strampelli.