Your browser doesn't support javascript.
loading
: 20 | 50 | 100
1 - 20 de 20
1.
Cancer Imaging ; 24(1): 45, 2024 Mar 28.
Article En | MEDLINE | ID: mdl-38549132

BACKGROUND/PURPOSE: Risk factors for re-bleeding and death after acute variceal bleeding (AVB) in cirrhotic HCC patients are not fully understood.We aimed to (1) explore how the combination of high-risk esophageal varices, HCC status, and portal vein tumor thrombus (i.e., HCC Portal Hypertension Imaging Score [HCCPHTIS]) helps predict increased risk of variceal re-bleeding and mortality; (2) assess predictability and reproducibility of the identified variceal re-bleeding rules. METHODS: This prospective study included 195 HCC patients with first-time AVB and liver cirrhosis, and conducted multivariable Cox regression analysis and Kaplan-Meier analysis. Receiver operating characteristic curve analysis was calculated to find the optimal sensitivity, specificity, and cutoff values of the variables. The reproducibility of the results obtained was verified in a different but related group of patients. RESULTS: 56 patients (28.7%) had re-bleeding within 6 weeks; HCCPHTIS was an independent risk factor for variceal re-bleeding after AVB (Odd ratio, 2.330; 95% confidence interval: 1.728-3.142, p < 0.001). The positive predictive value of HCCPHTIS cut off value > 3 was 66.2%, sensitivity 83.9%, and specificity 82.3%. HCCPHTIS area under the curve was higher than Child-Pugh score (89% vs. 75%, p < 0.001). 74(37.9%) death occurred within 6 weeks; HCCPHTIS > 4 was associated with increased risk of death within 6 weeks after AVB (p < 0.001). CONCLUSION: HCCPHTIS > 3 is a strong predictor of variceal re-bleeding within the first 6 weeks. However, patients with HCCPHTIS > 4 were at increased risk of death within 6 weeks.


Carcinoma, Hepatocellular , Esophageal and Gastric Varices , Hypertension, Portal , Liver Neoplasms , Humans , Esophageal and Gastric Varices/etiology , Esophageal and Gastric Varices/complications , Gastrointestinal Hemorrhage/etiology , Gastrointestinal Hemorrhage/complications , Carcinoma, Hepatocellular/complications , Carcinoma, Hepatocellular/diagnostic imaging , Prospective Studies , Reproducibility of Results , Liver Neoplasms/complications , Liver Neoplasms/diagnostic imaging , Hypertension, Portal/complications , Hypertension, Portal/diagnostic imaging , Liver Cirrhosis/complications , Tomography, X-Ray Computed/adverse effects
2.
ACS Nano ; 18(9): 7123-7135, 2024 Mar 05.
Article En | MEDLINE | ID: mdl-38390866

Inflammatory bowel disease (IBD) is strongly related to the occurrence of accumulation of toxic reactive oxygen species (ROS), inflammation of the mucosa, and an imbalance of intestinal microbes. However, current treatments largely focus on a single factor, yielding unsatisfactory clinical outcomes. Herein, we report a biocompatible and IBD-targeted metabolic nanoregulator (TMNR) that synergistically regulates cellular and bacterial metabolism. The TMNR comprises a melanin-gallium complex (MNR) encapsulated within a thermosensitive and colitis-targeting hydrogel, all composed of natural and FDA-approved components. The TMNR confers superior broad-spectrum antioxidant properties, effectively scavenging reactive oxygen species (ROS) and blocking inflammatory signaling pathways. The presence of Ga3+ in TMNR selectively disrupts iron metabolism in pathogenic microorganisms due to its structural resemblance to the iron atom. Additionally, incorporating a thermosensitive injectable hydrogel enables targeted delivery of TMNR to inflammatory regions, prolonging their retention time and providing a physical barrier function for optimizing IBD treatment efficacy. Collectively, TMNR effectively modulates the redox balance of inflamed colonic epithelial tissue and disrupts iron metabolism in pathogenic microorganisms, thereby eliminating inflammation and restoring intestinal homeostasis against IBD. Hence, this work presents a comprehensive approach for precise spatiotemporal regulation of the intestinal microenvironmental metabolism for IBD treatment.


Inflammatory Bowel Diseases , Humans , Reactive Oxygen Species/metabolism , Inflammatory Bowel Diseases/drug therapy , Inflammation/metabolism , Hydrogels/pharmacology , Iron
3.
Foods ; 11(23)2022 Nov 30.
Article En | MEDLINE | ID: mdl-36496675

Chinese water chestnut (CWC) is popular among consumers due to its unique flavor and crisp and sweet taste. Thus far, the key substances affecting the taste compound of CWC are still unclear. In this study, we used UPLC-MS/MS and an electronic tongue system to study the effects of four typical steaming and cooking methods, cooking without peel for 10 min (PC), steaming without peel for 15 min (PS), cooking with peel for 30 min (WPC), steaming with peel for 30 min (WPS), on the taste compound generation and variation of CWC, and revealed the secret of its crisp and sweet taste. The results show that the electronic tongue can effectively identify the taste profile of CWC, and the effective tastes of CWC were umami, bitterness, saltiness, and sweetness. We screened 371 differential compounds from 640 metabolic species. Among them, nucleotides and their derivatives, carbohydrates, organic acids and their derivatives, and amino acids and their derivatives are closely related to the key taste of CWC, and these compounds affected the taste of CWC through six related metabolic pathways: oxidative phosphorylation and purine metabolism; alanine, aspartate, and glutamate; bile secretion; amino sugar and nucleotide sugar metabolism; the phenylpropane pathway; and toluene degradation. This study reveals the potential metabolic causes of taste compound generation and variation in the taste of CWC.

4.
Front Nutr ; 9: 1037652, 2022.
Article En | MEDLINE | ID: mdl-36438777

The reduction of oil uptake in vacuum-fried Pleurotus eryngii chips by ultrasound assisted pretreatment was investigated regarding the pore structure changes. Pore structure of P. eryngii chips with four pretreatments, such as blanching, blanching + osmosis, blanching + ultrasound and blanching + ultrasound assisted osmosis was determined by mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM). In addition, the quality parameters of vacuum-fried P. eryngii chips such as hardness, rehydration ratio, reducing sugar, protein and oil content were also measured. The results showed that the oil absorption of vacuum fried P. eryngii chips was affected by the porous structure. The oil content of vacuum fried P. eryngii chips was significantly and positively correlated with the pores with diameters above 50, 5-50, and 0.5-5 µm in the samples both before and after vacuum frying, while negatively correlated with the pores with diameters below 0.5 µm. Ultrasound pretreatment changed the microporous structure of P. eryngii chips, effectively hindering the oil absorption of samples. In particular, ultrasound assisted osmosis pretreatment induced the formation of more micropores. It was concluded that blanching + ultrasound assisted osmosis pretreatment is a promising method to reduce oil absorption and improve the quality of vacuum fried foods.

5.
Cancer Manag Res ; 14: 2055-2064, 2022.
Article En | MEDLINE | ID: mdl-35761822

Background: The correlation between the preoperative lymph node count (LNC) on multidetector computed tomography (MDCT) and the prognosis of gastric carcinoma (GC) remains to be defined. This research aims to evaluate the prognostic value of LNC on MDCT in GC patients based on tumor-node-metastasis (TNM) staging, using different size criteria for counting. Methods: The clinical data of 126 patients with gastric adenocarcinoma undergoing gastrectomy were retrospectively analyzed. Lymph nodes greater than 8mm and 5mm on MDCT were counted and recorded. The prognostic implications of LNC on MDCT for patient survival were analyzed according to different size criteria for counting and tumor TNM staging. Results: When 8mm was used as the counting criterion, LNC on MDCT had no significant effect on the overall survival (OS) of the entire cohort. In addition, the OS of T1-T2 GC patients with LNC on MDCT ≥1 was significantly worse than that of patients with LNC on MDCT <1. When 5mm was used as the counting criterion, LNC on MDCT was found to be significantly associated with the OS of the entire cohort. In the subgroup analysis, patients with relatively advanced (T3-T4, N+ and III) GC with LNC on MDCT >7 showed a significantly worse OS than those with LNC on MDCT ≤7. LNC on MDCT >7 with 5mm as the counting criterion and Stage III were independent risk factors for adverse prognosis. Conclusion: The prognostic value of LNC on MDCT based on different size criteria varies in patients with different stages of GC. LNC of a smaller size (5mm) on MDCT may be a prognostic factor for patients with relatively advanced GC.

6.
J Math Biol ; 82(4): 32, 2021 03 10.
Article En | MEDLINE | ID: mdl-33694015

We consider a model of extracellular signal-regulated kinase regulation by dual-site phosphorylation and dephosphorylation, which exhibits bistability and oscillations, but loses these properties in the limit in which the mechanisms underlying phosphorylation and dephosphorylation become processive. Our results suggest that anywhere along the way to becoming processive, the model remains bistable and oscillatory. More precisely, in simplified versions of the model, precursors to bistability and oscillations (specifically, multistationarity and Hopf bifurcations, respectively) exist at all "processivity levels". Finally, we investigate whether bistability and oscillations can exist together.


Extracellular Signal-Regulated MAP Kinases , Models, Biological , Extracellular Signal-Regulated MAP Kinases/metabolism , Phosphorylation
7.
Front Immunol ; 11: 595700, 2020.
Article En | MEDLINE | ID: mdl-33240285

Recently, the immuno-enhancing potential of polysaccharide from Auricularia auricula (AAP) has been an area of research interest. However, the immune-stimulatory activity and mechanisms of AAP in immunosuppressive mice treated with cyclophosphamide (CTX) are still poorly understood. This study aimed to evaluate the immuno-enhancing effects of AAP and mine its possible mechanisms. Firstly, polysaccharides were isolated from A. auricula and purified. Secondly, the immune-stimulatory activities of the first AAP fraction (AAP1) were evaluated in the CTX-treated mice. Results showed that AAP1 significantly enhanced immune organ indexes, remarkably stimulated IFN-γ, IL-2, IL-4, IL-10, and TNF-α levels in the serum, and dramatically up-regulated the mRNA levels of Claudin-1, Occludin and ZO-1. Compared to the CTX group, AAP1 administration restored the gut microbiota composition similar to that of the control group by decreasing the ratio of Firmicutes/Bacteroidetes and increasing the relative abundances of short-chain fatty acid-producing microbiota. This study provides useful information for its further application as an immune-stimulator in foods and drugs.


Adjuvants, Immunologic/pharmacology , Auricularia , Fungal Polysaccharides/pharmacology , Gastrointestinal Microbiome/drug effects , Animals , Cecum/chemistry , Cyclophosphamide , Cytokines/blood , Fatty Acids, Volatile/analysis , Immunosuppressive Agents , Male , Mice, Inbred BALB C
8.
Sci Rep ; 10(1): 16093, 2020 09 30.
Article En | MEDLINE | ID: mdl-32999391

Sarcopenia is an independent predictor of mortality in patients with liver cirrhosis. However, evidence has emerged that skeletal muscles mediate their protective effect against sarcopenia by secreting myokines. Therefore, we investigated whether irisin was associated with sarcopenia in patients with liver cirrhosis. This was an observational cross-sectional study of data collected from 187 cirrhotic patients. Sarcopenia was defined by computed tomography (CT) scans using specific cutoffs of the 3rd lumbar vertebra skeletal muscle index (L3 SMI). Morning irisin levels were obtained in all patients. Of the 187 patients, sarcopenia was noted in 73 (39%). Irisin concentrations were lower in sarcopenic patients (32.40 pg/ml [interquartile range (IQR): 18.70, 121.26], p < 0.001) than in nonsarcopenic patients. There was a weak correlation between L3 SMI and irisin levels (r = 0.516, p < 0.001). Multivariable regression analysis including L3 SMI, body mass index (BMI), very-low-density lipoprotein (VLDL)-cholesterol, aspartate aminotransferase (AST), adiponectin, and irisin levels showed that L3 SMI (odds ratio [OR] = 0.915, p = 0.023), adiponectin levels (OR = 1.074, p = 0.014), irisin levels (OR = 0.993, p < 0.001) and BMI (OR = 0.456, p = 0.004) were independently associated with sarcopenia. Irisin levels are associated with sarcopenia in patients with liver cirrhosis. This paper addresses a gap in the literature and facilitates the future transition into clinical treatment.


Fibronectins/blood , Liver Cirrhosis/blood , Liver Cirrhosis/complications , Sarcopenia/blood , Sarcopenia/complications , Adiponectin/blood , Aged , Cross-Sectional Studies , Female , Humans , Lumbar Vertebrae , Male , Middle Aged , Multivariate Analysis , Muscle, Skeletal/diagnostic imaging , Retrospective Studies , Risk Factors , Sarcopenia/diagnostic imaging , Tomography, X-Ray Computed
9.
Proc Inst Mech Eng H ; 234(11): 1187-1196, 2020 Nov.
Article En | MEDLINE | ID: mdl-32748686

Coronary arterial disease, as the most devastated cardiovascular disease, is caused by the atherosclerosis in the coronary arteries, which blocks the blood flow to the heart, resulting in the deficient supply of oxygen and nutrition to the heart, and eventually leading to heart failure. To date, haemodynamic mechanisms for atherosclerosis development are not fully understood although it is believed that the haemodynamic disturbance at the region of the arterial bifurcation, particular, bifurcation angle, plays an important role in the atherosclerosis development. In this study, two types of computational fluid dynamics models, lesion-specific and idealized models, combined with the computer tomography imaging techniques, are used to explore the mechanism of formation and distribution of the atherosclerosis around the bifurcation of left coronary artery and its association with the bifurcation angle. The lesion-specific model is used to characterize the effect of personalized features on the haemodynamic performance, while the idealized model is focusing on the effect of single factor, bifurcation angle, on the haemodynamic performance. The simulated results from both types of the models, combined with the clinical observation, revealed that the three key areas around the bifurcations are prone to formation of the atherosclerosis. Unlike the idealized models, lesion-specific modelling results did not show the significant correlation between the wall shear stress and bifurcation angle, although the mean value of the wall shear stress in smaller bifurcation angles (less than 90°) is higher than that with larger bifurcation angles (greater than 90°). In conclusion, lesion-specific computational fluid dynamics modelling is an efficient and convenient way to predict the haemodynamic performance around the bifurcation region, allowing the comprehensive information for the clinicians to predict the atherosclerosis development. The idealized models, which only focus on single parameter, may not provide the sufficient and reliable information for the clinical application. A novel multi-parameters modelling technique, therefore, is suggested to be developed in future, allowing the effects of many parameters on the haemodynamic performance to be evaluated.


Coronary Artery Disease , Computer Simulation , Coronary Artery Disease/diagnostic imaging , Coronary Vessels/diagnostic imaging , Hemodynamics , Humans , Hydrodynamics , Models, Cardiovascular , Stress, Mechanical
10.
J Math Biol ; 79(4): 1515-1549, 2019 09.
Article En | MEDLINE | ID: mdl-31346693

This work concerns the question of how two important dynamical properties, oscillations and bistability, emerge in an important biological signaling network. Specifically, we consider a model for dual-site phosphorylation and dephosphorylation of extracellular signal-regulated kinase (ERK). We prove that oscillations persist even as the model is greatly simplified (reactions are made irreversible and intermediates are removed). Bistability, however, is much less robust-this property is lost when intermediates are removed or even when all reactions are made irreversible. Moreover, bistability is characterized by the presence of two reversible, catalytic reactions: as other reactions are made irreversible, bistability persists as long as one or both of the specified reactions is preserved. Finally, we investigate the maximum number of steady states, aided by a network's "mixed volume" (a concept from convex geometry). Taken together, our results shed light on the question of how oscillations and bistability emerge from a limiting network of the ERK network-namely, the fully processive dual-site network-which is known to be globally stable and therefore lack both oscillations and bistability. Our proofs are enabled by a Hopf bifurcation criterion due to Yang, analyses of Newton polytopes arising from Hurwitz determinants, and recent characterizations of multistationarity for networks having a steady-state parametrization.


Extracellular Signal-Regulated MAP Kinases/metabolism , Metabolic Networks and Pathways , Models, Theoretical , Signal Transduction , Biochemical Phenomena , Enzyme Stability , Extracellular Signal-Regulated MAP Kinases/chemistry , Extracellular Signal-Regulated MAP Kinases/genetics , Humans , Kinetics , Phosphorylation
11.
Bull Math Biol ; 81(5): 1527-1581, 2019 05.
Article En | MEDLINE | ID: mdl-30788691

Many dynamical systems arising in biology and other areas exhibit multistationarity (two or more positive steady states with the same conserved quantities). Although deciding multistationarity for a polynomial dynamical system is an effective question in real algebraic geometry, it is in general difficult to determine whether a given network can give rise to a multistationary system, and if so, to identify witnesses to multistationarity, that is, specific parameter values for which the system exhibits multiple steady states. Here we investigate both problems. First, we build on work of Conradi, Feliu, Mincheva, and Wiuf, who showed that for certain reaction networks whose steady states admit a positive parametrization, multistationarity is characterized by whether a certain "critical function" changes sign. Here, we allow for more general parametrizations, which make it much easier to determine the existence of a sign change. This is particularly simple when the steady-state equations are linearly equivalent to binomials; we give necessary conditions for this to happen, which hold for many networks studied in the literature. We also give a sufficient condition for multistationarity of networks whose steady-state equations can be replaced by equivalent triangular-form equations. Finally, we present methods for finding witnesses to multistationarity, which we show work well for certain structured reaction networks, including those common to biological signaling pathways. Our work relies on results from degree theory, on the existence of explicit rational parametrizations of the steady states, and on the specialization of Gröbner bases.


Metabolic Networks and Pathways , Models, Biological , Kinetics , Linear Models , Mathematical Concepts , Signal Transduction , Systems Biology
12.
Water Res ; 147: 223-232, 2018 12 15.
Article En | MEDLINE | ID: mdl-30312795

In an effort to provide early warnings for the occurrence of eutrophication, it is highly desirable to develop an accurate and efficient technique to ensure continuous monitoring of dissolved reactive phosphorus (DRP) in the aquatic environment from the viewpoint of environmental management. Herein, a new diffusive gradient in thin film (DGT) technique was developed and evaluated for in situ measurement of DRP in waters, in which Zr-based metal organic frameworks (MOFs, UiO-66) were utilized as aqueous binding agent (abbreviated as UiO-66 DGT). As expected, the UiO-66 DGT demonstrated high uptake capacity towards phosphorus (20.8 µg P cm-2). Meanwhile, an excellent linearity between the accumulated DRP mass and deployment time over 5 d (R2 = 0.996) was obtained regardless of high or low phosphate solution. In addition, effective diffusion coefficients (D) of DRP increased exponentially with increasing ionic strengths (R2 = 0.99). Based on the rectified D, the performance of the UiO-66 DGT was independent of solution pH (6.5-8.5) and ionic strengths (ranging from 0.01 to 100 mmol L-1). Furthermore, field deployments of the UiO-66 DGT were undertaken in a natural eutrophic lake (Lake Chaohu, China). It was noteworthy that DRP could be continually accumulated by the UiO-66 DGT for more than 14 d and good agreements were obtained between the concentrations measured by DGT (CDGT) and those by ex situ chemical extraction method in solution (Csol), as reflected by CDGT/Csol of 0.9-1.1. In situ determination of DRP speciation was also carried out at different sites across Lake Chaohu. Overall, this study contributed to a better constructing of liquid binding phase DGT for the measurement of DRP in waters, facilitating the widespread application of the UiO-66 DGT as a routine monitoring technique and for large-scale environmental analysis.


Metal-Organic Frameworks , Phosphorus , China , Diffusion , Environmental Monitoring , Zirconium
13.
PLoS One ; 12(9): e0184290, 2017.
Article En | MEDLINE | ID: mdl-28880916

The fast and accurate segmentation of lung nodule image sequences is the basis of subsequent processing and diagnostic analyses. However, previous research investigating nodule segmentation algorithms cannot entirely segment cavitary nodules, and the segmentation of juxta-vascular nodules is inaccurate and inefficient. To solve these problems, we propose a new method for the segmentation of lung nodule image sequences based on superpixels and density-based spatial clustering of applications with noise (DBSCAN). First, our method uses three-dimensional computed tomography image features of the average intensity projection combined with multi-scale dot enhancement for preprocessing. Hexagonal clustering and morphological optimized sequential linear iterative clustering (HMSLIC) for sequence image oversegmentation is then proposed to obtain superpixel blocks. The adaptive weight coefficient is then constructed to calculate the distance required between superpixels to achieve precise lung nodules positioning and to obtain the subsequent clustering starting block. Moreover, by fitting the distance and detecting the change in slope, an accurate clustering threshold is obtained. Thereafter, a fast DBSCAN superpixel sequence clustering algorithm, which is optimized by the strategy of only clustering the lung nodules and adaptive threshold, is then used to obtain lung nodule mask sequences. Finally, the lung nodule image sequences are obtained. The experimental results show that our method rapidly, completely and accurately segments various types of lung nodule image sequences.


Algorithms , Lung/pathology , Solitary Pulmonary Nodule/pathology , Cluster Analysis , Databases, Factual , Imaging, Three-Dimensional , Radiographic Image Interpretation, Computer-Assisted , Tomography, X-Ray Computed
14.
Water Res ; 122: 455-470, 2017 10 01.
Article En | MEDLINE | ID: mdl-28624729

The occurrence and related risks from cyanobacterial blooms have increased world-wide over the past 40 years. Information on the abundance and distribution of cyanobacteria is fundamental to support risk assessment and management activities. In the present study, an approach based on Empirical Orthogonal Function (EOF) analysis was used to estimate the concentrations of chlorophyll a (Chla) and the cyanobacterial biomarker pigment phycocyanin (PC) using data from the MODerate resolution Imaging Spectroradiometer (MODIS) in Lake Chaohu (China's fifth largest freshwater lake). The approach was developed and tested using fourteen years (2000-2014) of MODIS images, which showed significant spatial and temporal variability of the PC:Chla ratio, an indicator of cyanobacterial dominance. The results had unbiased RMS uncertainties of <60% for Chla ranging between 10 and 300 µg/L, and unbiased RMS uncertainties of <65% for PC between 10 and 500 µg/L. Further analysis showed the importance of nutrient and climate conditions for this dominance. Low TN:TP ratios (<29:1) and elevated temperatures were found to influence the seasonal shift of phytoplankton community. The resultant MODIS Chla and PC products were then used for cyanobacterial risk mapping with a decision tree classification model. The resulting Water Quality Decision Matrix (WQDM) was designed to assist authorities in the identification of possible intake areas, as well as specific months when higher frequency monitoring and more intense water treatment would be required if the location of the present intake area remained the same. Remote sensing cyanobacterial risk mapping provides a new tool for reservoir and lake management programs.


Chlorophyll , Cyanobacteria , Drinking Water , China , Chlorophyll A , Environmental Monitoring , Eutrophication , Lakes , Risk Assessment
15.
Leg Med (Tokyo) ; 24: 56-62, 2017 Jan.
Article En | MEDLINE | ID: mdl-28081790

The underlying mechanism of non-ionic iodinated contrast media-related immediate reactions was evaluated in this study. Patients presenting at least grade II immediate reactions after non-ionic iodinated contrast media injection were enrolled. Basophil activation was evaluated by flow cytometry. The plasma concentration of human terminal complement complex SC5b-9, as well as concentrations of serum chymase, tryptase, human mast cell carboxypeptidase A3, human prostaglandin D2, and total IgE were measured by enzyme-linked immunosorbent assay. The basophil activation percentage was significantly higher in the study group than in the control group (17.94±21.06% vs 3.45±1.49%). The plasma concentration of human terminal complement complex SC5b-9 and concentrations of serum chymase, human mast cell carboxypeptidase A3, prostaglandin D2, tryptase, and total IgE were also significantly increased (236.99±318.21 vs 49.70±30.41ng/mL, 0.41±0.49 vs 0.09±0.06ng/mL, 1.17±0.67 vs 0.30±0.17ng/mL, 203.52±137.27 vs 102.28±48.72pg/mL, 3.81±0.22 vs 2.70±0.16ng/mL, 102.00±51.84 vs 19.97±2.75ng/mL, respectively). Both mast cells and basophils were activated in non-ionic iodinated contrast media to mediate immediate hypersensitivity, and mast cells may be involved. Different mechanisms, including IgE-dependent, complement-dependent, and direct membrane effects, contributed to mast cell and basophil activation. Individual patients may use a single or combined mechanism involving single or combined mast cells and basophils. Immediate reactions following non-ionic iodinated contrast media injection may be a mechanically heterogenous disease.


Contrast Media/adverse effects , Drug Hypersensitivity/diagnosis , Drug Hypersensitivity/physiopathology , Adult , Contrast Media/chemistry , Drug Hypersensitivity/blood , Female , Humans , Male , Middle Aged
16.
Biometrika ; 104(4): 901-922, 2017 Dec.
Article En | MEDLINE | ID: mdl-29422694

Evolutionary relationships are represented by phylogenetic trees, and a phylogenetic analysis of gene sequences typically produces a collection of these trees, one for each gene in the analysis. Analysis of samples of trees is difficult due to the multi-dimensionality of the space of possible trees. In Euclidean spaces, principal component analysis is a popular method of reducing high-dimensional data to a low-dimensional representation that preserves much of the sample's structure. However, the space of all phylogenetic trees on a fixed set of species does not form a Euclidean vector space, and methods adapted to tree space are needed. Previous work introduced the notion of a principal geodesic in this space, analogous to the first principal component. Here we propose a geometric object for tree space similar to the [Formula: see text]th principal component in Euclidean space: the locus of the weighted Fréchet mean of [Formula: see text] vertex trees when the weights vary over the [Formula: see text]-simplex. We establish some basic properties of these objects, in particular showing that they have dimension [Formula: see text], and propose algorithms for projection onto these surfaces and for finding the principal locus associated with a sample of trees. Simulation studies demonstrate that these algorithms perform well, and analyses of two datasets, containing Apicomplexa and African coelacanth genomes respectively, reveal important structure from the second principal components.

17.
Fa Yi Xue Za Zhi ; 31(3): 188-90, 2015 Jun.
Article Zh | MEDLINE | ID: mdl-26442369

OBJECTIVE: To investigate the diagnostic significance of basophil activation test (BAT) in anaphylaxis to non-ionic contrast media through testing the content of CD63, mast cell-carboxypeptidase A3 (MC-CPA3), and terminal complement complex SC5b-9 of the individuals by testing their levels in the normal immune group and the anaphylaxis groups to ß-lactam drugs and non -ionic contrast media. METHODS: The CD63 expression of basophilic granulocyte in blood was detected by flow cytometry. The levels of MC-CPA3 in blood serum and SC5b-9 in blood plasma were detected by ELISA. RESULTS: The CD63 expression of basophilic granulocyte in blood, the levels of MC-CPA3 and SC5b-9 of anaphylaxis to non-ionic contrast media and ß-lactam drugs were significantly higher than that in normal immune group (P < 0.05). CONCLUSION: There is activation of basophilic granulocytes, mast cells and complement system in anaphylaxis to non-ionic contrast media. BAT can be used to diagnose the anaphylaxis to non-ionic contrast media.


Anaphylaxis/diagnosis , Basophils/cytology , Contrast Media , Carboxypeptidases A/metabolism , Complement Membrane Attack Complex/metabolism , Flow Cytometry , Granulocytes/cytology , Humans , Mast Cells/cytology , Tetraspanin 30/metabolism
18.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 30(3): 326-9, 2013 Jun.
Article Zh | MEDLINE | ID: mdl-23744325

OBJECTIVE: To investigate the molecular genetic basis of samples with ABO typing discrepancy and provide the guidline for identification and clinical transfusion for these samples. METHODS: Six cases with similar serological characteristics were collected. Serological method, PCR-SSP and direct sequencing of ABO gene were used to explore the underlying mechanism. Condition of clinical transfusion of patients was also reviewed. RESULTS: Three conditions were related with the ABO blood type discrepancy, which included weaken antigen (2 cases), weakened antibody (3 cases) and ABO subtype (1 case). The satisfactory effect of transfusion was achieved in all patients with the principle of the same blood type or the compatible crossmatch. CONCLUSION: Heterogeneity has existed with the ABO group. Indivianals with same reaction pattern may result in different mechanisms.


ABO Blood-Group System/genetics , Blood Grouping and Crossmatching , Blood Transfusion , Adult , Base Sequence , Exons , Genotype , Humans , Middle Aged , Young Adult
20.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 15(4): 888-91, 2007 Aug.
Article Zh | MEDLINE | ID: mdl-17708827

The purpose of this study was to explore the clinical value of the platelet antibody screening and typing in platelets transfusion by using microcolumn gel immunoassay (MGIA). The platelets antigen-antibody reactions including the antibody screen and blood crossmatch were detected by MGIA. The results indicated that the detection of platelet antibody showed positive in 30 cases of aplastic anemia (AA), 11 cases of myelodysplastic syndrome (MDS), 24 out of 25 cases of leukemia and 1 out of cases of other diseases, while detection of platelet antibody showed negative in 20 normal volunteer donors. The number of platelet antibody crossmatch coincidence in 112 specimens of AA, 42 specimens of MDS and 95 specimens of leukemia were 45, 20 and 40, the coincidence rates were 40.18%, 47.62% and 42.11%. The mean corrected count increment (CCI) in 20 patients received platelet transfusion many times was 18.2 after crossmatch and 4.7 before crossmatch. It is concluded that the positive rate of platelet antibody screening is very high in patients with hematologic malignancies, the coincidence rate of platelet antibody crossmatch in 249 blood samples is between 40% and 48%, and the efficiency of using crossmatched platelets in clinic is enhanced significantly.


Antigens, Human Platelet/immunology , Blood Grouping and Crossmatching , Blood Platelets/immunology , Isoantibodies/blood , Anemia, Aplastic/immunology , Hematologic Neoplasms/immunology , Humans , Immunoassay/methods , Isoantibodies/immunology , Platelet Transfusion/methods
...