Phytoplankton species composition as bioindicator in the largest fragmented channel of the Pearl River, China.

To test the serial discontinuity concept (SDC) predictions in a regulated river ecosystem, environmental parameters and phytoplankton community structure were determined in a subtropical river (China) which was regulated by 11 cascade dams. Our results showed that total phosphorus (TP) and silicate during the wet period in several dams supported the SDC predictions. Variations of phytoplankton species composition in several cascade dams, such as Datengxia (DTX) and Changzhou (CZ), also supported the SDC predictions. Moreover, the stations near the dams showed the maximum or minimum values of total species numbers in each cascade segment. Predictive model indicated that the types of phytoplankton decreased in the middle reaches, conforming to SDC predictions. In the whole system of cascading dams, an increase in silicate concentration and phytoplankton communities in the downstream was also consistent with SDC predictions. Therefore, these findings aligned with the SDC predictions in the aspects of both single dam and whole cascade dam system to some extent. In future research, our aim is to further investigate the effects of cascade damming on additional phytoplankton-related indices in this aquatic ecosystem. We hope to gather more comprehensive data to fully validate the SDC predictions.

Assessing limb apraxia after ischemic stroke: validation of the Chinese version of the diagnostic instrument for limb apraxia-short version (DILA-S) classic subtests.

OBJECTIVE: This study aimed to translate and validate the Chinese version of the Diagnostic Instrument for Limb Apraxia-Short Version (DILA-S) classic subtests in Chinese patients after ischemic stroke. METHODS: The DILA-S was translated and adapted for use in Mandarin-speaking Chinese patients. Internal consistency, test-retest reliability, dimensionality, convergent validity, divergent validity, and concurrent validity were tested. RESULTS: A total of 112 ischemic stroke patients were included. The internal consistency (Cronbach's alpha 0.85 ~ 0.92) and test-retest reliability (ICC 0.88 ~ 0.93) were found satisfactory. Exploratory factor analysis obtained two factors for the imitation subtests and the execution scale of the pantomime of tool use. Convergent validity was supported by strong correlations (ρ > 0.7) between the scores of the DILA-S subtests and the LOTCA motor praxis subscale. Divergent validity was acceptable for weak to moderate correlations (ρ ranged from -0.25~ -0.41) between the scores of the DILA-S subtests and the NIHSS. Concurrent validity was supported by strong correlations (ρ > 0.7) between the scores of the DILA-S subtests and the MoCA, as well as strong correlations (ρ > 0.6 < 0.7) between the scores of the DILA-S subtests and the BI. CONCLUSION: The Chinese version of the DILA-S classic subtests demonstrated satisfactory psychometric properties for assessing limb apraxia in Chinese patients after ischemic stroke.

Intelligent Algorithm-Based Picture Archiving and Communication System of MRI Images and Radiology Information System-Based Medical Informatization.

Objective: The study aimed to explore the application value of picture archiving and communication system (PCAS) of MRI images based on radial basis function (RBF) neural network algorithm combined with the radiology information system (RIS). Methods: 551 patients who required MRI examination in a hospital from May 2016 to May 2021 were selected as research subjects. Patients were divided into two groups according to their own wishes. Those who were willing to use the RBF neural network algorithm-based PCAS of MRI images combined with RIS were set as the combined group, involving a total of 278 cases; those who were unwilling were set as the regular group, involving a total of 273 cases. The RBF neural network algorithm-based PCAS of MRI images combined with RIS was trained and tested for classification performance and then used for comparison analysis. Result: The actual output (0.031259-0.038515) of all test samples was almost the same as the target output (0.000000) (P > 0.05). In the first 50,000 learnings, the iteration error of the RBF neural network dropped rapidly and finally stabilized at 0.038. The classification accuracy of the RBF neural network algorithm-based PCAS of MRI images combined with RIS for the head was 94.28%, that of abdomen was 97.22%, and it was 93.10% for knee joint, showing no statistically significant differences (P > 0.05), and the total classification accuracy was as high as 95%. The time spent in the examination in the combined group was about 2 hours, and that in the regular group was about 4 hours (P > 0.05). The satisfaction of the combined group (96.76%) was significantly higher than that of the control group (46.89%) (P > 0.05). Conclusion: The RBF neural network has good classification performance for MRI images. To incorporate intelligent algorithms into the medical information system can optimize the system. RBF has good application prospects in the medical information system, and it is worthy of continuous exploration.

Leukamenin E Induces K8/18 Phosphorylation and Blocks the Assembly of Keratin Filament Networks Through ERK Activation.

Leukamenin E is a natural ent-kaurane diterpenoid isolated from Isodon racemosa (Hemsl) Hara that has been found to be a novel and potential keratin filament inhibitor, but its underlying mechanisms remain largely unknown. Here, we show that leukamenin E induces keratin filaments (KFs) depolymerization, largely independently of microfilament (MFs) and microtubules (MTs) in well-spread cells and inhibition of KFs assembly in spreading cells. These effects are accompanied by keratin phosphorylation at K8-Ser73/Ser431 and K18-Ser52 via the by extracellular signal-regulated kinases (ERK) pathway in primary liver carcinoma cells (PLC) and human umbilical vein endothelial cells (HUVECs). Moreover, leukamenin E increases soluble pK8-Ser73/Ser431, pK18-Ser52, and pan-keratin in the cytoplasmic supernatant by immunofluorescence imaging and Western blotting assay. Accordingly, leukamenin E inhibits the spreading and migration of cells. We propose that leukamenin E-induced keratin phosphorylation may interfere with the initiation of KFs assembly and block the formation of a new KFs network, leading to the inhibition of cell spreading. Leukamenin E is a potential target drug for inhibition of KFs assembly.

Physical Mapping of Peroxidase Genes and Development of Functional Markers for TaPod-D1 on Bread Wheat Chromosome 7D.

Peroxidase (POD) activity in wheat (Triticum aestivum L.) grain influences natural carotenoid pigment content and is associated with the color of flour, and processing and product quality. Here, we report the molecular characterization and physical mapping of POD genes in bread wheat. The complete genomic DNA (gDNA) sequence of two POD genes (TaPod-A2 and TaPod-D1), and the partial gDNA sequence of two additional POD genes (TaPod-A3 and TaPod-B1) from wheat were characterized using in silico cloning and validated through laboratory experiments. Using a set of 21 nullisomic-tetrasomic (NT) lines, six group-7 ditelosomic (Dt) lines, and 38 group-7 deletion (Del) lines of Chinese Spring (CS), TaPod-A2 and TaPod-D1 were found to be physically located on 0.73-0.83 and on the most distal 0.39 fraction arm length (FL) of 7AS and 7DS in cv. CS, respectively; whereas, TaPod-A3 and TaPod-B1 were assigned to the 0.40-0.49 and 0.40-0.48 FL of 7AL and 7BL, respectively. Based on single nucleotide polymorphisms (SNPs) of two alleles at the TaPod-D1 locus, two functional markers POD-7D1 and POD-7D6 were developed, amplifying 540- and 640-bp, fragments in varieties with higher and lower POD activities, respectively. A total of 224 wheat varieties were analyzed and showed a significant association between the polymorphic fragments and POD activity using POD-7D1 and POD-7D6 markers. The analysis of variance (ANOVA) indicated the average POD activities of 115 varieties with TaPod-D1a were significantly lower than 109 varieties with TaPod-D1b (P < 0.01). This study provides useful information of the POD genes in bread wheat, insight into wheat genome synteny and structure, gene-specific markers, and contributes a valuable resource for quality improvement in wheat breeding programs.

Leukamenin E, an ent-kaurane diterpenoid, is a novel and potential keratin intermediate filament inhibitor.

Many ent-kaurane diterpenoids exhibit notable antitumor activity in vitro and in vivo, and some have been used as cancer therapeutic agents in China. In this study, we identified a novel molecular target of leukamenin E, an ent-kaurane diterpenoid, using an available whole-cell model in combination with immunofluorescence imaging and mass spectrometry (MS). The cytoskeleton-disrupting drugs cytochalasin B and colchicine caused the depolymerization of microfilaments and the collapse of microtubules and vimentin filaments, respectively, but had little effects on HepG2 and NCI-H1299 cells spreading as well as keratin filament (KF) reassembly, indicating that KFs are involved in cell spreading. Leukamenin E blocked HepG2 and NCI-H1299 cells adhesion/spreading and KF reassembly at subtoxic concentrations, indicating that leukamenin E may target KFs. Moreover, leukamenin E, at 3 µM for 24 h or 10 µM for 3 h, induced massive KF depolymerization in well-spread HepG2 and NCI-H1299 cells treated with/without cytochalasin B and colchicine. MS analysis indicated that leukamenin E could covalently modify amino acid residue(s) in a synthetic peptide based on keratin 1 and keratin 10 sequences, suggesting that covalent modification of the synthetic peptide by leukamenin E caused assembly inhibition or disrupted KF polymerization in HepG2 and NCI-H1299 cells. In addition, acridine orange/ethidium bromide staining and western blotting confirmed that there was no correlation between the KF-disrupting effects and apoptosis or keratin expression. Thus, we propose that leukamenin E is a novel inhibitor of KF assembly, and as such, can serve as a chemical probe of KF functions and a potential molecular target for ent-kaurane diterpenoid-based therapeutics.

Mapping quantitative trait loci for peroxidase activity and developing gene-specific markers for TaPod-A1 on wheat chromosome 3AL.

KEY MESSAGE: Three novel QTL for peroxidase activity were mapped, and gene-specific markers for TaPod-A1 were developed and validated using RILs derived from the Doumai/Shi 4185 cross and 281 wheat cultivars. TaPod-A1 is within one of the three QTL. Peroxidase (POD) activity in grain is an important factor determining the color of flour and end-use products of wheat, such as noodles and steamed bread. Mapping QTL for POD activity, characterization of POD genes and development of gene-specific markers are important for molecular marker-assisted selection in wheat breeding. Quantitative trait loci (QTL) for POD activity in common wheat were mapped using a recombinant inbred line (RIL) population derived from a Doumai/Shi 4185 cross grown in four environments and genotyped using the wheat 90 K iSelect assay. Three novel QTL for POD activity, QPod.caas-3AL, QPod.caas-4BS and QPod.caas-5AS, were identified on chromosomes 3AL, 4BS and 5AS, explaining 5.3-21.2% of phenotypic variance across environments. The full-length genomic DNA (gDNA) sequence of a POD gene, designated TaPod-A1, on chromosome 3A was characterized by homolog cloning and PCR verification. Two complementary dominant sequence-tagged site (STS) markers, POD-3A1 and POD-3A2, were developed based on single nucleotide polymorphisms (SNPs) between two alleles at the TaPod-A1 locus, amplifying 291- and 766-bp fragments in cultivars with lower and higher POD activities, respectively. The two gene-specific markers were mapped on chromosome 3AL using a set of Chinese Spring (CS) nulli-tetrasomic lines, and ditelosomic lines 3AL and 3AS. QTL analysis indicated that QPod.caas-3AL co-segregated with the gene-specific markers POD-3A1 and POD-3A2. POD-3A1 and POD-3A2 were verified on 281 wheat cultivars and advanced lines, and showed significant (P < 0.05) associations with POD activities. POD-3A1 and POD-3A2 may be useful as markers for improving color attributes in wheat breeding programs.