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1.
J Dairy Sci ; 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31477297

RESUMO

Monitoring Staphylococcus aureus with high sensitivity is very important for ensuring milk quality and food safety. In this study, we used a rapid nucleic acid isothermal amplification method, saltatory rolling circle amplification (SRCA), for the detection of Staph. aureus in milk. The results of the SRCA method can be assessed visually by the presence of white precipitate or by fluorescence measurement. Thirteen Staph. aureus strains and 31 non-Staph. aureus strains were used to evaluate the specificity of SRCA. The method exhibited excellent detection of Staph. aureus genomic DNA at a concentration of 7.8 × 101 fg/µL when assessed by visible precipitate, and at 7.8 × 100 fg/µL when detected by fluorescence after addition of the fluorochrome SYBR Green I. In artificially inoculated milk, the detection limits of SRCA were 5.6 × 102 cfu/mL by precipitate and 5.6 × 101 cfu/mL by fluorescence, respectively. Compared with conventional PCR approaches, the SRCA assay achieved at least 100-fold higher sensitivity. Moreover, the sensitivity, specificity, and accuracy of the SRCA-based system were calculated to be 100.00, 97.73, and 97.78%, respectively. These results indicate that SRCA has potential application as a sensitive and visual technique for the detection of Staph. aureus in milk.

2.
Cell Cycle ; : 1-9, 2019 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-31496367

RESUMO

Rab GTPases have multiple regulatory functions in intracellular vesicle transport. In recent years, there has been an increasing interest in the roles of Rab proteins in mammalian oocytes. In this paper, we show the specific distribution pattern of Rab24 during mouse oocyte meiosis. Furthermore, we find that Rab24 depletion results in the failure of maturational progression in mouse oocytes. Notably, the frequency of meiotic apparatus abnormality is significantly increased in Rab24-depleted oocytes relative to controls. In addition, lagging chromosomes are readily observed in anaphase/telophase oocytes with Rab24 knockdown. In support of this, the depletion of Rab24 disturbs the kinetochore-microtubule attachments in oocytes, and contributes to the production of aneuploid eggs. Taken together, the results of this study identify Rab24 as a novel factor in the modulation of meiotic apparatus assembly and meiotic progression during mouse oocyte maturation.

4.
Artigo em Inglês | MEDLINE | ID: mdl-31429173

RESUMO

Reactive oxygen species (ROS) can be used not only as a therapeutic agent for chemodynamic therapy (CDT), but also as a stimulus to activate release of antitumor drugs, achieving enhanced efficacy through the combination of CDT and chemotherapy. Here we report a pH/ROS dual-responsive nanomedicine consisting of ß-lapachone (Lap), a pH-responsive polymer, and a ROS-responsive polyprodrug. In the intracellular acidic environment, the nanomedicine can realize pH-triggered disassembly. The released Lap can efficiently generate hydrogen peroxide, which will be further converted into highly toxic hydroxyl radicals via the Fenton reaction. Subsequently, through ROS-induced cleavage of thioketal linker, doxorubicin is released from the polyprodrug. In vivo results indicate that the cascade of ROS generation and antitumor-drug release can effectively inhibit tumor growth. This design of nanomedicine with cascade reactions offers a promising strategy to enhance antitumor efficacy.

5.
Lab Chip ; 19(18): 3116-3122, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31429847

RESUMO

The integration of one more gain media in droplet microlasers with morphology-dependent modes, which can be employed in optofluidic systems as multi-wavelength lasing sources, is highly attractive and demands new cavity design and fabrication approaches. Here, cholesteric liquid crystal (CLC) droplets with an integrative triple-emulsion cavity are fabricated via glass-capillary-based microfluidic technologies and dual-gain lasing with variable modes, flexibly configured by the combination and incorporation of gain dyes and CLCs into both the core and shell. The distributed feedback (DFB) mode, formed by the feedback from the self-assembled helix periodic structure of CLCs, the whispering gallery (WG) mode, and the hybrid, is selectively excited by controlling the spatial coupling between the pump beam and the droplet with gain. With the merits of dual-gain and controllable lasing, a prototype dual-wavelength-ratiometric thermometer with self-calibration capability is expected to be developed. Furthermore, the anisotropic CLC core is substituted with an isotropic fluid and the gain from the CLC shell is additionally removed, DFB lasings in both shell and core are absent, and only Bragg-shell reflection-based hybrid modes are excited for lasing. The CLC droplet microlasers with an integrative cavity are expected to provide a new route to future lab-on-chip (LOC) applications.

6.
Hum Mol Genet ; 2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-31384951

RESUMO

Germ cell-derived genomic structure variants not only drive the evolution of species but also induce developmental defects in offspring. The genomic structure variants have different types, but most of them are originated from DNA double-strand breaks (DSBs). It is still not well known whether DNA DSBs exist in adult mammalian oocytes and how the growing and fully-grown oocytes repair their DNA DSBs induced by endogenous or exogenous factors. In this study we detected the endogenous DNA DSBs in the growing and fully-grown mouse oocytes, and found that the DNA DSBs mainly localized at the centromere-adjacent regions which are also copy number variation hotspots. When the exogenous DNA DSBs were introduced by Etoposide, we found that Rad51-mediated homologous recombination (HR) was used to repair the broken DNA. However, the HR repair caused the chromatin intertwined and impaired the homologous chromosome segregation in oocytes. Although we hadn't detected the indication about HR repair of endogenous centromere-adjacent DNA DSBs, we found that Rad52 and RNA:DNA hybrids colocalized with these DNA DSBs, indicating a Rad52 dependent DNA repair might exist in oocytes. In summary, our results not only demonstrated an association between endogenous DNA DSBs with genomic structure variants, but also revealed one specific DNA DSB repair manner in oocytes.

7.
Int J Biometeorol ; 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31414185

RESUMO

Rice (Oryza sativa) growth is always threatened by heat as well as cold stress, when it is exposed to natural environment. Heat growing degree hours (HGDH) and cold growing degree hours (CGDH1 and CGDH2) were firstly proposed to quantify heat and cold stress occurred during different growing stages. Information diffusion method was effectively used to fit the distribution and estimate probability of single stress at each station, with an advantage of no limitation in data series. In terms of single stress, highest probability was seen in HGDH, followed by CGDH1 and CGDH2. Seven copula functions, i.e., normal and t, Gumbel-Hougaard, Clayton, Frank, Joe, and Ali-Mikhail-Haq, were applied to fit the distribution of multi-stress with significant dependence, and simple calculation based on single stress was used to quantify the probability for multi-stress with independence. In these copulas, t was the most chosen one in the fitting of HGDH-CGDH1, HGDH-CGDH2, CGDH1-CGDH2, and HGDH-CGDH1-CGDH2, selected by the statistic of Akaike information criterion. Regarding bi-stress, higher joint probability was in HGDH-CGDH1, relative to HGDH-CGDH2 and CGDH1-CGDH2. As expected, the co-occurrence probability of tri-stress was lower than that of bi-stress in the magnitude and spatial extent, while joint probability of tri-stress was larger. Given the condition of occurrence of HGDH or CGDH1, the joint probability of HGDH-CGDH1 was higher than other pairs of bi-stress and tri-stress. It was special that higher joint probability of CGDH1-CGDH2 was detected under the condition of CGDH2 relative to CGDH1. Joint probability of tri-stress was lower under the condition of HGDH-CGDH1, in comparison with HGDH-CGDH2 and CGDH1-CGDH2. Hazards of single stress and multi-stress were expressed by the integration of intensity of stress index and corresponding probability. Most consistent conclusions agreed that central Fujian, Zhejiang, and northeastern Jiangxi were exposed to higher hazard, derived from not only single stress but also multi-stress. These results can be helpful in provision of information regarding prevention and adaptation strategies for rice cultivation as a response to extreme temperature stress.

8.
Artigo em Inglês | MEDLINE | ID: mdl-31347915

RESUMO

Human pluripotent stem cell (hPSCs)-derived ventricular (V) cardiomyocytes (CMs) display immature Ca2+-handing properties with smaller transient amplitudes and slower kinetics due to such differences in crucial Ca2+-handling proteins as the poor sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) pumpbut robust Na-Ca exchanger (NCX) activities in human embryonic stem cell (ESC)-derived VCMs compared to adult. Despite their fundamental importance in excitation-contraction coupling, the relative contribution of SERCA and NCX to Ca2+-handling of hPSC-VCMs remains unexplored.We systematically altered the activities of SERCA and NCX in hESC-VCMs and their engineered micro-tissues, followed by examining the resultant phenotypic consequences. SERCA overexpression in hESC-VCMs shortened the decay of Ca2+transient at low frequencies (0.5Hz) without affecting the amplitude, SR Ca2+content and Ca2+ baseline. Interestingly, shRNA-based NCX suppression did not prolong the transient decay, indicating a compensatory response for Ca2+removal. Although hESC-VCMs and their derived microtissues exhibited negative frequency-transient/force responses, SERCA overexpression rendered them less negative at high frequencies (>2 Hz) by accelerating Ca2+sequestration. We conclude that forhESC-VCMs and their microtissues, SERCA, rather than NCX, is the main Ca2+remover during diastole; poor SERCA expression is the leading cause for immature negative-frequency/force responses, which can be partially reverted by forced expression. Combinatorial approach to mature calcium handling in hESC-VCMs may help shed further mechanistic insights.

9.
ACS Appl Mater Interfaces ; 11(31): 28013-28022, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31282637

RESUMO

Recently, the growing demand for optical anticounterfeiting technology has motivated intensive research in newly emerging halide perovskite quantum dots (QDs). However, the poor stability and unsatisfactory fluorescence efficiency of such materials are the main obstacles to the application of reliable anticounterfeiting. In this work, we performed a well-controlled investigation of the effect of the surfactant (l-α-phosphatidylcholine, LP) and silica encapsulation on the stability and emission of the CsPbBr3 QDs. Because of the synergetic effect of the surfactant and core/shell configuration, the resulting CsPbBr3/LP/SiO2 QD composites demonstrated a higher photoluminescence quantum yield (>90%), a better color purity, and a significantly improved stability in heat, ultraviolet light, water, and ambient oxygen, which provide them the basic conditions as a high-tech security ink for anticounterfeiting. By inkjet printing technology, we demonstrated that our CsPbBr3/LP/SiO2 QD composites can act as a smart concealed ink for information encryption and decryption. More importantly, the anticounterfeiting effect can be efficiently sustained even though the paper with designable patterns was crudely treated by water-soaking, heating/cooling cycling, and continuous ultraviolet light switching (1500 cycles). The above results obtained provide effective strategies to improve emission efficiency and stability of perovskite QDs, thereby enduing them anticounterfeiting application potential.

10.
PLoS One ; 14(7): e0219735, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31318936

RESUMO

Coal and gas outburst is a common coal-rock dynamic disaster. Such accidents frequently occur, and the mechanism underlying the occurrence of these outbursts is complex. As a typical failure mode of a gas-filled and pressure-relieved coal body, the spallation mechanism should be investigated to reveal the mechanism of coal and gas outburst and guide outburst-prevention strategies. In this paper, a fluid-solid coupling model for coal seam gas flow is established. This model considers the adsorption characteristics of coal. Numerical calculations are used to simulate the stress field distribution and evolution of gas-filled coal bodies under different boundary conditions. The mechanical mechanism of the spallation occurrence after the pressure relief of coal is explained from the perspective of seepage breaking coal. The control of the flow and stress state of the gas to the spallation failure is analyzed. The mechanical-quantitative conditions for the initial failure of the coal body under seepage and the mechanical-qualitative conditions for the continuous advancement and termination of spallation are studied based on numerical solution results. The numerical calculation results show that the formation of a flow field after pressure relief will apply a drag force (tensile stress) on the porous media of coal. The presence of this force plays a crucial role in promoting the spallation and cracking of coal and, thus, the promotion of spallation. The tensile strength, initial adsorption pressure, and pressure relief rate of the coal body jointly control whether the initial failure can occur and the thickness of the fracture layer cracks. Spallation propulsion is mainly determined by the pressure relief conditions of the undestroyed coal body and pressure changes in the spallation space; the former can be quantitatively obtained by numerical calculations, whereas the latter is related to the thickness of the spalled layer and the degree of the layer-crack structure.

11.
Aquat Toxicol ; 214: 105257, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31336221

RESUMO

The interactions between nanoparticles (NPs) and metals in aquatic environments may modify the bioavailability and toxicity of metals to organisms. In this study, we investigated the effects of titanium dioxide NPs (n-TiO2) on the bioconcentration, depuration, and neurotoxic effects of lead (Pb) in zebrafish larvae. Transmission electron microscopy coupled with energy-dispersive X-ray spectroscopy showed that Pb2+ was adsorbed by n-TiO2 to form NP-Pb complexes in suspension, and these complexes were observed in larval tissues. The bioconcentration of Pb in larvae along with the depuration rates of Pb were higher in the presence of n-TiO2 compared to when n-TiO2 was absent. Exposure to Pb alone induced the expression of the biomarker metallothionein, downregulated neurodevelopment-related genes, and reduced swimming activity of larvae. However, the addition of n-TiO2 to the exposure solution alleviated these effects. The results suggest that n-TiO2 can act as a carrier of Pb to increase its bioconcentration; however, the formation of NP-Pb complexes likely reduces the amount of free Pb2+, thereby reducing toxicity to larvae.

12.
Artigo em Inglês | MEDLINE | ID: mdl-31352348

RESUMO

Molecular signatures of cancer, e.g., genes or microRNAs (miRNAs), have been recognized very important in predicting the occurrence of cancer. From gene-expression and miRNA-expression data, the challenge of identifying molecular signatures lies in the huge number of molecules compared to the small number of samples. To address this issue, in this work, we propose a heuristic algorithm to identify molecular signatures, termed HAMS, for cancer diagnosis by modeling it as a multi-objective optimization problem. In the proposed HAMS, an elitist-guided individual update strategy is proposed to obtain a small number of molecular signatures which are closely related with cancer and contain less redundant signatures. Experimental results demonstrate that the proposed HAMS achieves superior performance over seven state-of-the-art algorithms on both gene-expression and miRNA-expression datasets. We also validate the biological significance of the molecular signatures obtained by the proposed HAMS through biological analysis.

13.
Sci Data ; 6(1): 105, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31263100

RESUMO

While tick-borne zoonoses, such as Lyme disease and tick-borne encephalitis, present an increasing global concern, knowledge of their vectors' distribution remains limited, especially for China. In this paper, we present the first comprehensive dataset of known tick species and their distributions in China, derived from peer-reviewed literature published between 1960 and 2017. We searched for journal articles, conference papers and degree thesis published in both English and Chinese, extracted geographic information associated with tick occurrence, and applied quality-control procedures to remove duplicates and ensure accuracy. The dataset contains 5731 records of geo-referenced occurrences for 123 tick species distributed over 1141 locations distinguished at four levels of scale i.e., provincial, prefectural, county, and township and finer. The most frequently reported tick species include Haemaphysalis longicornis, Dermacentor silvarum, Ixodes persulcatus, Haemaphysalis conicinna, Rhipicephalus microplus, and Rhipicephalus sanguineus sensu lato. The geographical dataset provides an improved map of where ticks inhabit China and can be used for a variety of spatial analyses of ticks and the risk of zoonoses they transmit.

14.
Cell Death Dis ; 10(7): 474, 2019 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-31209201

RESUMO

Reproductive problem has been one of the top issues for women health worldwide in recent decades. As a typical female disease, primary ovarian insufficiency (POI) results in a loss of ovarian follicles and oocytes that thus destroys women fertility. However, due to the complex of POI etiology and rare resource of human POI oocytes, few biomarkers have been identified in clinics and no effective strategy could be applied to treat POI patients. In the search of possible association between DNA damage and POI by Smart-Seq2 and RT2 profiler PCR array, we find that BRCA2, a core DNA repair gene for homologous recombination shows significantly lower expression in two POI patient oocytes. In line with this, we generated oocyte-specific knockout mouse model driven by Gdf9-Cre. The Brca2-deficient mice are infertile because of the arrested follicle development and defective oocyte quality caused by the accumulation of DNA damage. Notably, ectopic expression of Brca2 in Brca2-deficient oocytes could partially restore the oocyte maturation and chromosome stability. Collectively, our data assign a definite deficiency to BRCA2 as a POI driver during follicle development and oocyte maturation, and provide a potential fertility treatment strategy for POI patients induced by BRCA2 deficiency.

15.
Environ Health Perspect ; 127(6): 67010, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31232609

RESUMO

BACKGROUND: Debates over whether climate change could lead to the amplification of Lyme disease (LD) risk in the future have received much attention. Although recent large-scale disease mapping studies project an overall increase in Lyme disease risk as the climate warms, such conclusions are based on climate-driven models in which other drivers of change, such as land-use/cover and host population distribution, are less considered. OBJECTIVES: The main objectives were to project the likely future ecological risk patterns of LD in Europe under different assumptions about future socioeconomic and climate conditions and to explore similarity and uncertainty in the projected risks. METHODS: An integrative, spatially explicit modeling study of the ecological risk patterns of LD in Europe was conducted by applying recent advances in process-based modeling of tick-borne diseases, species distribution mapping, and scenarios of land-use/cover change. We drove the model with stakeholder-driven, integrated scenarios of plausible future socioeconomic and climate change [the Shared Socioeconomic Pathway (SSPs) combined with the Representative Concentration Pathways (RCPs)]. RESULTS: The model projections suggest that future temperature increases may not always amplify LD risk: Low emissions scenarios (RCP2.6) combined with a sustainability socioeconomic scenario (SSP1) resulted in reduced LD risk. The greatest increase in risk was projected under intermediate (RCP4.5) rather than high-end (RCP8.5) climate change scenarios. Climate and land-use change were projected to have different roles in shaping the future regional dynamics of risk, with climate warming being likely to cause risk expansion in northern Europe and conversion of forest to agriculture being likely to limit risk in southern Europe. CONCLUSIONS: Projected regional differences in LD risk resulted from mixed effects of temperature, land use, and host distributions, suggesting region-specific and cross-sectoral foci for LD risk management policy. The integrated model provides an improved explanatory tool for the system mechanisms of LD pathogen transmission and how pathogen transmission could respond to combined socioeconomic and climate changes. https://doi.org/10.1289/EHP4615.

16.
J Am Chem Soc ; 141(25): 9937-9945, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31199131

RESUMO

Chemodynamic therapy (CDT) employs Fenton catalysts to kill cancer cells by converting intracellular H2O2 into hydroxyl radical (•OH), but endogenous H2O2 is insufficient to achieve satisfactory anticancer efficacy. Despite tremendous efforts, engineering CDT agents with specific and efficient H2O2 self-supplying ability remains a great challenge. Here, we report the fabrication of copper peroxide (CP) nanodot, which is the first example of a Fenton-type metal peroxide nanomaterial, and its use as an activatable agent for enhanced CDT by self-supplying H2O2. The CP nanodots were prepared through coordination of H2O2 to Cu2+ with the aid of hydroxide ion, which could be reversed by acid treatment. After endocytosis into tumor cells, acidic environment of endo/lysosomes accelerated the dissociation of CP nanodots, allowing simultaneous release of Fenton catalytic Cu2+ and H2O2 accompanied by a Fenton-type reaction between them. The resulting •OH induced lysosomal membrane permeabilization through lipid peroxidation and thus caused cell death via a lysosome-associated pathway. In addition to pH-dependent •OH generation property, CP nanodots with small particle size showed high tumor accumulation after intravenous administration, which enabled effective tumor growth inhibition with minimal side effects in vivo. Our work not only provides the first paradigm for fabricating Fenton-type metal peroxide nanomaterials, but also presents a new strategy to improve CDT efficacy.

17.
PLoS One ; 14(6): e0216460, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31170177

RESUMO

This study collected 183 Hemerocallis varieties to conduct numerical classification of flower color and provide valuable baseline data and foundational theory for normalization and precision of Hemerocallis. The color CIELab phenotypes were collected via colorimeter (CR-10 Plus), which separately measured three sepal and petal parts (throat, eye and limb). The colors of experimental samples were artificially named by the Royal Horticultural Society Colour Chart (RHSCC). All the data were analyzed using R software. The results showed that the throat was predominantly green-yellow, light yellow and yellow; green-yellow accounted for the largest proportion of sepals (67.76%) and petals (69.40%). The eye was more abundant, and there were significant differences between sepals and petals. The limb was clustered into five color groups (orange, yellow, pink, red and purple); the yellow group had the most varieties for both sepals and petals, containing 57.38% and 55.74%, respectively. Both sepals and petals had significant differences (p<0.0001) in color (△E), redness (a*) and color angle (h) for the throat, eye and limb. However, the difference in CIELab phenotypes between the eye and limb were not significant. According to "Dual Classification", the color classification standard was proposed as a 3-level standard. The color of sepal and petal consistency served as the first standard, and the color of limb was the second standard. The color pattern types of pure, gradual change, watermark and eye spot, served as the third standard. It has been proposed that all the 183 experimental varieties were divided into two categories, five groups and finally four types. This study provides a classification basis and reference for numeric and standardized color phenotype description for Hemerocallis.

18.
Int J Biol Macromol ; 135: 691-697, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31154038

RESUMO

In this study, hordein and hordein/N,N'-methylene bisacrylamide (MBA) nanofiber membranes were prepared by electrospinning technique. Then the fabricated membranes were modified with ß-cyclodextrin (ß-CD) to remove heavy metal ions from aqueous solution. The prepared nanofiber membranes were characterized by ATR-FTIR, SEM and XRD. The diameters of the nanofibers were determined to be around 600-910 nm and ß-CD was successfully attached to the nanofiber membrane, which was confirmed by ATR-FTIR and XRD analysis. Cu(II) was selected as the model ion to investigate the heavy metal adsorption properties of the membranes. Adsorption capacities of the membranes increased with a higher initial pH, adsorption temperature and a longer adsorption time before reaching the saturation point. The adsorption isotherm results were described with the Langmuir model. It was found that additions of MBA and ß-CD at proper concentrations could significantly improve the adsorption capacities and the maximum adsorption of hordein, hordein/MBA, and hordein/MBA/ß-CD nanofiber membranes were 64.94, 81.97, and 88.50 mg/g, respectively. Furthermore, regeneration study showed that these hordein nanofiber membranes possessed reasonably good reusability. The novel functionalized hordein/MBA/ß-CD nanofiber membranes have great potential in the application of water treatment.

19.
J Org Chem ; 84(14): 8859-8869, 2019 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-31203616

RESUMO

Anion transmembrane transport mediated by novel noncovalent interactions is of central interest in supramolecular chemistry. In this work, a series of oxacalix[2]arene[2]triazine-derived transporters 1 and 2 bearing anion-π-, hydrogen-, and halogen-bonding sites in rational proximity were designed and synthesized by a one-pot strategy starting from gallic acid ester derivatives and mono- or di-halogen-substituted triazines. 1H NMR titrations demonstrated efficient binding of 1 and 2 toward Cl- and Br- in solution, giving association constants in the range of 102-104 M-1. Cooperation of anion-π, hydrogen, and halogen bonding was revealed as a driving force for anion binding by single-crystal structures of two complexes and density functional theory calculations. Fluorescence assays indicated that compounds 1 are efficient chloride transporters with effective concentrations (EC50) falling in the range of 3.1-7.4 µM and following an order of 1a > 1b > 1c > 1d. The contribution of halogen bonding and cooperative noncovalent bonds to ion transport was then discussed. Significantly, transporters 1 exhibit high anticancer activity. In the presence of 1 and KCl (60 mM), the cell survival of HCT116 reduces to 11.9-24.9% with IC50 values in the range of 52.3-66.4 µM.

20.
Chin Med J (Engl) ; 132(12): 1441-1447, 2019 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-31205102

RESUMO

BACKGROUND: Diagnosis of heparin-induced thrombocytopenia (HIT) is challenging. This study aimed to compare the diagnostic performance of HIT expert probability (HEP) and 4T scores, and to evaluate the inter-observer reliability for the 4T score in a clinical setting. METHODS: This prospective study included HIT-suspected patients between 2016 and 2018. Three hematologists assessed the HEP and 4T scores. Correlations between scores and anti-platelet factor 4 (anti-PF4)/heparin antibodies were evaluated. Receiver operating characteristic curves and area under the curve (AUC) were used to assess the predictive accuracy of these two scoring models. The intraclass correlation coefficient (ICC) was used to assess the inter-observer agreement of 4T scores between residents and hematologists. RESULTS: Of the 89 subjects included, 22 (24.7%) were positive for anti-PF4/heparin antibody. The correlations between antibody titer and either HEP or 4T scores were similar (r = 0.392, P < 0.01 for the HEP score; r = 0.444, P < 0.01 for the 4T score). No significant difference in the diagnostic performance was displayed between these two scores (AUC for the HEP score: 0.778 vs. AUC for the 4T score: 0.741, P = 0.357). Only 72 4T scores were collected from the residents, with a surprisingly low percentage of observers (43.1%) presenting the four individual item scores which made up their 4T score. The AUC of 4T score assessed by residents and hematologists was 0.657 (95% confidence interval [CI]: 536-0.765) and 0.780 (95% CI: 0.667-0.869, P < 0.05), respectively. The ICC of 4T score between residents and hematologists was 0.49 (95% CI: 0.29-0.65, P < 0.01), demonstrating a fair inter-observer agreement. CONCLUSIONS: The HEP score does not display a better performance for predicting HIT than the 4T score. With the unsatisfactory completion rate, the inter-observer agreement of 4T score in a tertiary hospital is fair, underscoring the necessity for continuing education for physicians.

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