Thrombosis density ratio can predict the occurrence of pulmonary embolism and post-thrombotic syndrome in lower-extremity deep vein thrombosis patients.

OBJECTIVE: Deep vein thrombosis (DVT) formation of lower extremities can lead to serious complications including pulmonary embolism (PE) and chronic post-thrombotic syndrome (PTS). We aimed to explore the relationship between the ratio of thrombotic density and the occurrence of PE and PTS in patients with DVT of the lower extremities. METHODS: A retrospective analysis was conducted in patients who performed computed tomography venography, dividing into DVT with PE group (54 patients) and DVT-alone group (34 patients), The clinical data were recorded. Univariate and multivariate logistic regression analysis were used to analysis variables associated with PE. The ability of thrombosis density ratio and Wells score to diagnose PE was evaluated by using the receiver operating characteristic curve (ROC) area under the curve (AUC). According to the treatment and follow-up results, subgroup analysis was performed, and the Villata score was used to determine the presence or absence of PTS and its severity. RESULTS: Compare with the DVT-alone group, more patients had dyspnea and chest pain in the DVT with PE group. DVT with PE group had lower the percentage of neutrophils, white blood cell count and platelet count, while had higher blood cell count, D-dimer, wells score, thrombus and thrombus density ratio. Multivariate logistic analysis showed that percentage of neutrophils (OR(95% CIs)=1.15 (1.01,1.31), P = 0.040), platelets (OR(95% CIs)=0.96 (0.93,0.99), P = 0.011), and thrombus density ratio (OR(95% CIs)=5.99 (1.96,18.35), P = 0.002) are independent predictors of PE. The Wells score and thrombosis density ratio were consistent in the diagnostic efficacy of PE. In the subgroup analysis, there was a relevance between the ratio of thrombosis density and the Villalta score. CONCLUSION: Percentage of neutrophils, platelets, and thrombus density ratio are independent predictors of PE. The thrombosis density of DVT patients may be an index to predict the risk of PE and PTS in DVT patients.

PuMYB21/PuMYB54 coordinate to activate PuPLDß1 transcription during peel browning of cold-stored "Nanguo" pears.

Refrigeration is commonly used to extend the storage life of "Nanguo" pears, but fruit in long-term refrigeration is prone to peel browning, which is related to membrane lipid degradation. To determine the mechanism of membrane lipid degradation, we identified two R2R3-MYB transcription factors (TFs), PuMYB21 and PuMYB54, from "Nanguo" pears, which were notably expressed in response to cold stress and during the peel-browning process. The results from yeast one-hybrid, electrophoretic mobility shift, and transient expression assays indicated that both PuMYB21 and PuMYB54 directly bind to the promoter of PuPLDß1 (a key enzyme catalyzing the hydrolysis of membrane phospholipids) and activate its expression, which probably enhances the degradation of membrane phospholipids and eventually results in peel browning. Moreover, the overexpression of PuMYB21 and PuMYB54 can greatly activate the transcription of endogenous PuPLDß1 in both "Nanguo" pear fruits and calli, and their silencing can inhibit its transcription. Furthermore, yeast two-hybrid, bimolecular fluorescence complementation, and pull-down assays verified that PuMYB21 interacts with PuMYB54 to enhance the expression of PuPLDß1. In summary, we demonstrate that PuMYB21 and PuMYB54 may have roles in membrane lipid metabolism by directly binding to the downstream structural gene PuPLDß1 during the low temperature-induced peel browning of "Nanguo" pears.

Low-temperature stress-induced aroma loss by regulating fatty acid metabolism pathway in 'Nanguo' pear.

Low temperatures retard postharvest ripening and prolong the supply period of 'Nanguo' pears. However, quality deterioration, or more specifically, a faded aroma occurs in long-term cold-stored fruits. To understand the implicit mechanism, we analyzed the change in content of the main aroma esters and fatty acids by chromatography-mass spectrometry (GC-MS), and the expression patterns of the main genes in fatty acid metabolism pathways. The results showed that hexyl hexanoate disappeared completely and the content of five other aromas declined significantly in cold-stored fruit during the optimal taste period. The content of saturated and unsaturated fatty acids significantly increased and decreased, respectively in cold-stored fruit. fadD, fadE, fadJ, atoB, fabF, SCD, FAD2, LOX2S, LOX1_5 and HPL genes down-regulated in fatty acid metabolism during shelf life in the fruit after cold storage. In conclusion, the faded aroma of cold-stored fruit was mainly regulated by fatty acid metabolism pathway.

miRNAs play important roles in aroma weakening during the shelf life of 'Nanguo' pear after cold storage.

Cold storage is commonly employed to delay senescence in 'Nanguo' pear after harvest. However, this technique also causes fruit aroma weakening. MicroRNAs are regulators of gene expression at the post-transcriptional level that play important roles in plant development and in eliciting responses to abiotic environmental stressors. In this study, the miRNA transcript profiles of the fruit on the first day (C0, LT0) move in and out of cold storage and the optimum tasting period (COTP, LTOTP) during shelf life at room temperature and after cold storage were analyzed, respectively. 314 known miRNAs were identified in 'Nanguo' pear; 176 and 135 miRNAs were significantly differentially expressed on the C0 vs. LT0 and on the COTP vs. LTOTP, respectively. After prediction the target genes of these differentially expressed miRNAs, 9 s-lipoxygenase (LOX2S), 13 s-lipoxygenase (LOX1_5), hydroperoxide lyase (HPL), and alcohol dehydrogenase (ADH1) were found differentially expressed, which were the key genes during aroma formation. The expression pattern of these target genes and the related miRNAs were identified by RT-PCR. mdm-miR172a-h, mdm-miR159a/b, mdm-miR160a-e, mdm-miR395a-i, mdm-miR399a/b/c, mdm/ppe-miR535a/b, and mdm-miR7120a/b may negatively regulate the target genes expression. These results indicate that miRNAs may play key roles in aroma weakening in cold storage 'Nanguo' pear and provide valuable information for studying the molecular mechanisms of miRNAs in the aroma weakening of fruit due to low temperature.

Membrane lipid metabolism changes and aroma ester loss in low-temperature stored Nanguo pears.

Cold storage is an effective method used to retard the senescence of Nanguo pears after harvest. However, this causes aroma loss in the fruit. To elucidate the role of membrane lipid metabolism in aroma reduction, we investigated the contents of total aroma eaters and major fatty acid components, the membrane permeability, and the activity and gene expression of key enzymes in membrane lipid metabolism and aroma formation. The results showed that the contents of total aroma esters, oleic acid and linoleic acid, and alcohol dehydrogenase activity were at a lower level in cold stored fruit than that in control fruit. However, the palmitic acid content, membrane permeability, and the activities and gene expression of alcohol acyltransferase, lipoxygenase, phospholipase D, and lipase were higher. In conclusion, the loss of aroma esters may be caused by membrane lipid metabolism disruption during cold storage.

[Etiology and risk factors of infantile wheezing].

OBJECTIVE: To study the etiology and risk factors of infantile wheezing. METHODS: The clinical data of 180 infants with wheezing were retrospectively studied. The risk factors for wheezing attacks were investigated by logistic regression analysis. RESULTS: Viral infection (33.3%) was the most common cause for wheezing attacks, followed by asthma (19.4%), parental smoking and special environments (15.6%), gastroesophageal reflux disease (12.8%), premature delivery (7.8%), Mycoplasma infection (6.7%), and bronchopulmonary dysplasia (4.4%). The multivariate logistic regression analysis showed 7 factors that significantly correlated with wheezing attacks: allergic history of parents, sensitization to alimentary or inspiratory allergens, viral or Mycoplasma infection, premature delivery and special environments. CONCLUSIONS: The commonest cause of infantile wheezing is viral infection, followed by asthma. Genetic factors, individual atopic constitution and environmental factors play important roles in wheezing attacks.