Non-invasive prenatal screening & diagnosis of ?-thalassaemia in an affected foetus

Background & objectives: Non-invasive prenatal testing (NIPT) of maternally inherited alleles of ?-thalassaemia (MIB) remains to be a challenge. Furthermore, current techniques are not available for use as routine tests. NIPT for ?-thalassaemia disease was developed by using a specific droplet digital polymerase chain reaction (ddPCR) assay to analyze the cell-free foetal DNA (cffDNA) derived from maternal plasma. Methods: Pregnant women and their spouses who are at risk of bearing an offspring with ?-thalassaemia disease from common MIB mutations (CD 41/42-TCTT, CD17A>T, IVS1-1G>T and CD26G>A) were enrolled. The ddPCR assay sets were constructed for each of the four mutations. All cell-free DNA samples were first screened for the paternally inherited ?-thalassaemia (PIB) mutation. The PIB-negative samples were considered as non-disease and were not further analyzed. For PIB-positive samples, DNA fragments of 50-300 base pairs in size were isolated and purified, and further analyzed for MIB mutation. The allelic ratio between the mutant and the wild-type was used to determine the presence of MIB in cffDNA. All cases underwent a prenatal diagnosis by amniocentesis for a definite diagnosis. Results: Forty two couples at risk were enrolled. Twenty two samples were positive for PIBs. Among these 22 samples, there were 10 cases with allelic ratio >1.0 (MIB positive). All foetuses with over-represented mutant alleles were further diagnosed with ?-thalassaemia disease; eight with compound heterozygous and two with homozygous mutations. The 20 PIB-negative and 12 MIB-negative foetuses were non-affected. Interpretation & conclusions: The results of this study suggest that NIPT utilizing the ddPCR assay can be effectively used for the screening and diagnosis of foetal ?-thalassaemia in at risk pregnancies.

An improved fixation method for preparing mouse brown adipose tissue for transmission electron microscopy / 解剖学报

Objective To improve the fixation method of the transmission electron microscope for better morphological preservation of mitochondria and lipid droplets in mouse brown adipose tissue. Methods The fixation method for mouse brown adipose tissue was optimized, mainly including an increased concentration of paraformaldehyde from 2% to 4% in the pre-fixative, employment of transcardial perfusion followed by immersion fixation in pre-fixation, and using imidazole-buffered osmium tetroxide as the post-fixative. The ultrastructures of brown adipocytes prepared by the improved method were observed and compared with those of a known standard protocol (3 mice in each group). The improved method was further validated in the quantitative analysis of mitochondrial cristae density and lipid droplets. Results The mitochondrial cristae and membrane structure of other organelles of brown adipocytes were better preserved using the optimized method compared with those of the standard method. Lipid droplets were presented as round structures with high electron density instead of vacuolated appearances. Using this method, we observed that the density of mitochondrial cristae and the content of lipid droplets increased in brown adipocytes after cold adaptation. Conclusion The optimized method can better preserve the ultrastructure of organelles in brown adipocytes, especially mitochondria and lipid droplets, and ma)' be applicable for studying the ultrastructures remodeling of brown adipose tissue under different physiological or pathological conditions.

Effect of Atglistatin on PA-induced VSMCs proliferation and ATGL expression / 中国临床药理学与治疗学

AIM: With building a proliferation model of PA-induced VSMC, the effect of ATGL, a key fat metabolism enzyme, on the phenotype transformation of VSMC was preliminarily explored. METHODS: 40 μmol/L Atglistatin was added to the proliferation model of VSMC induced by PA (50 μmol/L, 100 μmol/L, and 200 μmol/L, respectively) at separately administered concentrations, and cell viability and cell proliferation were detected by CCK-8 and EDU; cell migration ability was detected by scratch assay; oil red staining was used to detect the accumulation of lipid droplets in VSMC was detected by oil red staining; the effects of PA on ATGL as well as the effects of smooth muscle contraction phenotype proteins were examined by Western blot. RESULTS: PA at a concentration of 100 μmol/L could significantly induce VSMC proliferation, promote lipophagy and increase lipid droplet accumulation in VSMC; meanwhile, Atglistatin could exacerbate these changes caused by PA and increase lipid droplet accumulation in VSMC. CONCLUSION: Atglistatin exacerbates PA-induced VSMC proliferation and increases VSMC lipid droplet accumulation, and exacerbates transformation of proliferative phenotype of VSMC.

Virus aerosol transmission, dispersion, and infection probability simulation: A case study in subway carriages / 环境与职业医学

Background Subways are typical congregate settings and may facilitate aerosol transmission of viruses. However, quantified transmission probability estimates are lacking. Purpose To model spread and diffusion of respiratory aerosols in subways by simulation and calculation of infection probabilities. Methods The internal environment of carriages of Shanghai Metro Line 10 was used to establish a study scene. The movement of tiny particles was simulated using the turbulent model. Trend analysis of infection probabilities and viral quantum doses was conducted in a closed subway carriage scene by a quantum emission-infection probability model. Results Under a typical twelve-vent air conditioning configuration, respiratory droplet aerosols within a subway carriage dispersed rapidly throughout various regions due to airflow, with limited short-term diffusion to other carriages. Concurrently, owing to the uncertainty of airflow patterns, the airflow might circulate and converge within carriages, causing delayed outward dispersion or hindered dispersion of droplet aerosols upon entry into these zones. Passengers boarding the carriage could exacerbate the formation of these zones. When the air conditioning system functioned adequately (air exchange rate=23.21 h−1), the probability of a virus carrier transmitting the virus to other passengers within the same carriage via aerosol transmission was approximately 3.8%. However, in the event of air conditioning system failure (air exchange rate=0.5 h−1), this probability escalated dramatically to 30%. Furthermore, a super-spreader (with virus spreading exceeding 90% of the average) elevated the infection probability to 14.9%. Additionally, due to the complexity of turbulence within the carriage, if local diffusion occurred in 1/2 zones of a carriage, the anticipated infection probability would increase to 8.9%, or during the morning or evening rush hours leading to elevated aerosol concentrations, the infection probability would rise to 4.7%. The subway transmission probability for common coronaviruses diminished to as low as 0.9%. Conclusion Combined computational fluid dynamics and infection probability analysis reveals that in the prevalent twelve-vent air conditioning configurations, despite being a major transportation hub with substantial spatial-temporal overlap, the internal space of subway carriages exhibits a certain level of resistance to virus aerosol transmission owing to built-in ventilation capabilities. However, turbulence and passenger positioning may lead to localized hovering of droplet aerosols, thereby increase the risk of virus transmission. Furthermore, super-spreaders, poor operational status of built-in air conditioning system, and high passenger volume at morning or evening peak hours exert profound effects on virus transmission and infection probability.

Application and evaluation of droplet digital polymerase chain reaction in detection of severe acute respiratory syndrome corona virus-2 / 中国热带医学

@#Abstract: Objective　To analyze the nucleic acid detection results of severe acute respiratory syndrome corona virus-2 (SARS-CoV-2) by droplet digital PCR (ddPCR) and compare with the detection results of real-time fluorescence quantitative RT-PCR (qRT-PCR), so as to evaluate the advantages and disadvantages of detection, and to provide data support for optimizing the nucleic acid detection scheme of SARS-CoV-2. Methods　According to the SARS-CoV-2 specific primer probe published by the China Center for Disease Control and Prevention, a ddPCR detection method for SARS-CoV-2 was designed. One sample was selected for sensitivity test after gradient dilution; six respiratory virus nucleic acid positive samples including seasonal H3N2 influenza virus and SARS-CoV-2 positive samples were selected for specificity test; five SARS-CoV-2 positive samples were selected for repeatability test; in addition, 30 positive and 20 negative SARS-CoV-2 samples were selected for multiple clinical samples testing, and the results were analyzed and compared with those of qRT-PCR. Results　The ddPCR method can specifically detect SARS-CoV-2, and directly obtain the original copy number of the sample target gene to achieve accurate quantification; the sensitivity test of gradient dilution positive samples showed that qRT-PCR detected target genes in part of the 10-5 dilution of samples, and no target genes were detected in 10-6 dilution, while ddPCR detected all target genes in both 10-5 and 10-6 dilution of samples. The detection limit of ddPCR was two orders of magnitude higher than that of qRT-PCR, and the sensitivity was higher than that of qRT-PCR; in the comparison of the repeatability test results of the two methods, the coefficient of variation of ddPCR was 1.266%-11.814%, lower than 1.729%-26.174% of qRT PCR, and the repeatability was higher than qRT-PCR; among 50 clinical samples, 30 positive samples of confirmed cases of Coronavirus Disease 2019 (COVID-19) were detected by both methods, SARS-CoV-2 was successfully detected by both methods, and 20 negative samples of COVID-19 were detected by both methods, and the results were negative, with a coincidence rate of 100.00% (50/50). Conclusion　The ddPCR method can accurately quantify SARS-CoV-2 with strong specificity, and its sensitivity and repeatability are higher than those of qRT-PCR, but it also has certain detection limitations and is more suitable for the detection of low load samples. In the actual detection, the two methods can be reasonably combined to improve the detection accuracy.

Application prospect of reaction engineering approach in studying drying behavior of single droplet during spray drying of traditional Chinese medicine / 中国中药杂志

Spray drying technology is one of the most commonly used unit operations in the production of traditional Chinese medicine(TCM) preparations, offering advantages such as short drying time and uniform product quality. However, due to the properties of TCM extracts, such as high viscosity, strong hygroscopicity, and poor flowability, there is limited scope to solve the problems of wall adhesion and clumping in spray drying from the macroscopic perspective of pharmaceutical production. Therefore, it has become a trend to study and optimize the spray drying process from the microscopic point of view by investigating single droplet evaporation behavior. Based on the reaction engineering approach(REA), the single droplet drying system, as a novel method for studying droplets, collects parameter data on individual TCM droplets during the drying process and uses the REA to process the data and establish predictive models. This approach is crucial for understanding the mechanism of TCM spray drying. This paper summarized and analyzed the cha-racteristics of various single droplet systems, the application of REA in single droplet drying systems, and its significance in optimizing the process, predicting drying states, and shortening the development cycle in the field of TCM spray drying, and looked ahead to the prospects of this method, including the introduction of new parameters and imaging techniques, aiming to provide a reference for further research in the field of TCM spray drying.

Development of national standards for genomic titer determination of recombinant type 5 adeno-associated virus / 中国生物制品学杂志

@#ObjectiveTo develop a national standard for genomic titer determination of recombinant type 5 adeno-associated virus(rAAV5).MethodsThe rAAV5-GFP stock solution prepared by the three-plasmid system was identified and verified for the appearance,pH,sterility,genomic titer,purity and infection titer according to the relevant requirements of Chinese Pharmacopoeia(Volume Ⅲ,2020 edition),which was diluted and subpackaged to prepare candidate standards according to the results;The stability of candidate standards was investigated by thermal acceleration test;Three laboratories were organized to collaboratively calibrate the candidate standards using droplet digital PCR(ddPCR).ResultsAll the detection indexes of the candidate standard and the stock solution met the relevant requirements;The genomic titer showed no significant decrease at 25,4,-20,-40,-80 ℃ for 1,3,4,6 months;Through collaborative calibration by three laboratories,the candidate standard was assigned a value of 2. 56 × 10(12)copies/mL,and the 95% confidence interval was 2. 48 ×10(12)copies/mL,and the 95% confidence interval was 2. 48 ×10(12)copies/mL ～ 2. 64 × 10(12)copies/mL ～ 2. 64 × 10(12)copies/mL.ConclusionThe developed national standard for the determination of rAAV5 genomic titer had good stability and might be used for the quality evaluation of rAAV5 related products.

Cell-loaded hydrogel microspheres based on droplet microfluidics: a review / 生物工程学报

Droplet microfluidics technology offers refined control over the flows of multiple fluids in micro/nano-scale, enabling fabrication of micro/nano-droplets with precisely adjustable structures and compositions in a high-throughput manner. With the combination of proper hydrogel materials and preparation methods, single or multiple cells can be efficiently encapsulated into hydrogels to produce cell-loaded hydrogel microspheres. The cell-loaded hydrogel microspheres can provide a three-dimensional, relatively independent and controllable microenvironment for cell proliferation and differentiation, which is of great value for three-dimensional cell culture, tissue engineering and regenerative medicine, stem cell research, single cell study and many other biological science fields. In this review, the preparation methods of cell-loaded hydrogel microspheres based on droplet microfluidics and its applications in biomedical field are summarized and future prospects are proposed.

Polyunsaturated fatty acids alter the formation of lipid droplets and eicosanoid production in Leishmania promastigotes

BACKGROUND The knowledge about eicosanoid metabolism and lipid droplet (LD) formation in the Leishmania is very limited and new approaches are needed to identify which bioactive molecules are produced of them. OBJECTIVES Herein, we compared LDs and eicosanoids biogenesis in distinct Leishmania species which are etiologic agents of different clinical forms of leishmaniasis. METHODS For this, promastigotes of Leishmania amazonensis, L. braziliensis and L. infantum were stimulated with polyunsaturated fatty acids (PUFA) and LD and eicosanoid production was evaluated. We also compared mutations in structural models of human-like cyclooxygenase-2 (GP63) and prostaglandin F synthase (PGFS) proteins, as well as the levels of these enzymes in parasite cell extracts. FINDINGS PUFAs modulate the LD formation in L. braziliensis and L. infantum. Leishmania spp with equivalent tissue tropism had same protein mutations in GP63 and PGFS. No differences in GP63 production were observed among Leishmania spp, however PGFS production increased during the parasite differentiation. Stimulation with arachidonic acid resulted in elevated production of hydroxyeicosatetraenoic acids compared to prostaglandins. MAIN CONCLUSIONS Our data suggest LD formation and eicosanoid production are distinctly modulated by PUFAS dependent of Leishmania species. In addition, eicosanoid-enzyme mutations are more similar between Leishmania species with same host tropism.

Series of experiments performed with the droplet evaporation method on low potencies

Homeopathic preparations in low potencies, containing still measurable quantities of the starting substance, constitute a unique research field in homeopathic basic research. Here a series of experiments is presented carried out by means of the droplet evaporation method (DEM), investigating the specificity of the method, and presumed effects of the succussion procedure applied in the production of homeopathic preparations. Methods:DEM analysis consisted in the evaporation of droplets of the potencies perse placed on microscope slides. Resulting patterns were photographed. Images were evaluated by means of ImageJ software, by measuring grey level distribution, texture, and fractality. The experimentation consisted of four series: (i) screening (1x­6x potencies from 19 substances), (ii) differentiation experiments (2x­6x potencies of Echinacea, Baptisia, Luffa, and Spongia), (iii) differentiation between succussed (100 or 10 times) and unsuccussed samples (Echinacea 2x, Baptisia 3x, Baptisia 4x, Luffa 4x, and Spongia 6x). (iv) investigation of the influence upon the patterns of single compounds present in a remedy complex. The experimental set-up stability was examined by systematic positive control experiments. Results:(i) Homeopathic preparations of mineral origin showed the greatest form variety, whereas those of vegetal origin created fractal patterns in the potency range 2x­4x. (ii) Differentiation of potencies of different origin at the same dilution level was possible from 2x to 4x. (iii) In all potency levels, succussed (100 and 10 times) and unsuccussed variants could be significantly differentiated. Significant differences between all variants were found in some cases in potency levels 4x and higher. In general, application of succussion reduced size, homogeneity, and complexity of the DEM patterns. (iv) Patterns of a remedy complex Luffa 4x -Mercurius bijodatum 9x showed a clear predominance of the Luffa 4x; however also the second component, present in a much lower concentration, influenced significantly the pattern of the remedy complex as also differed significantly from the pattern of succussed water control. Conclusions:The results suggest that DEM is a suitable tool for scientific investigation of homeopathic preparations in the low potency range. DEM might be applied to assess further research questions, such different potentization procedures (vessel shape, overhead volume, material), storing time, and difference between batches.

Formation of Self-organized Structures in Drying Droplets: a Promising Analytical Tool for Homeopathy Basic Research

The droplet evaporation method (DEM) is based on the evaporation-induced pattern formation in droplets and is applied mainly for medical diagnosis[1].Here, we present aseries of experiments performed by our team showing DEMs potential also forhomeopathy basic research, in particular, for the investigation of(i) low potencies, (ii) low potency complexes (physical model), and (iii) the action of high potencies (plant-based model).Methods:(i) DEM differentiated significantly between Luffa, Baptisia, Echinacea, and Spongiauntil 4x[2]. Furthermore, the patterns varied in function of the numberof succussion strokes (0, 10, or 100) applied during potentization[3]. The performance of chaotic succussions vs. laminar flow vs. slight mixing during the potentization of Viscum album quercus3x influenced the DEM patterns; the chaotic succussions reduced, whereas laminar flow enhanced the patterns complexity vs. the unsuccussed control.(ii) The addition of Mercurius bijodatus9x to Luffa4x changed significantly the DEM patterns, even if the material quantity present in the 9x potency lied far beyond that of ultrapure water.(iii) Leakages obtained by placing healthy or arsenic-damaged wheat-seeds into Arsenicum album45x orheat-damaged intoZincum metallicum30c vs. water created significantly different DEM structures [4, 5]. Results:The damaged seeds put into the potency created structures characterized by a higher complexity than those obtained from damaged seeds put into control water. Furthermore, the potency action seemed to increase with rising numbers ofsuccussion strokes applied during potentization,ascould be shown by means of DEM patterns and germination rate using the same wheat-seed model[6].In all our studies, the pattern evaluation was computerized (texture and fractal analysis performed by means of ImageJ) or based on deep-learning algorithms and the robustness of the experimental system was checked by means of systematic control experiments.Conclusion:DEM together with other similarmethods has also been reviewed by our team for what concerns theapplication in homeopathy basic research[7].

Application of Duplex Droplet Digital PCR Detection of miR-888 and miR-891a in Semen Identification / 法医学杂志

OBJECTIVES@#To establish a system for simultaneous detection of miR-888 and miR-891a by droplet digital PCR (ddPCR), and to evaluate its application value in semen identification.@*METHODS@#The hydrolysis probes with different fluorescence modified reporter groups were designed to realize the detection of miR-888 and miR-891a by duplex ddPCR. A total of 75 samples of 5 body fluids (including peripheral blood, menstrual blood, semen, saliva and vaginal secretion) were detected. The difference analysis was conducted by Mann-Whitney U test. The semen differentiation ability of miR-888 and miR-891a was evaluated by ROC curve analysis and the optimal cut-off value was obtained.@*RESULTS@#There was no significant difference between the dual-plex assay and the single assay in this system. The detection sensitivity was up to 0.1 ng total RNA, and the intra- and inter-batch coefficients of variation were less than 15%. The expression levels of miR-888 and miR-891a detected by duplex ddPCR in semen were both higher than those in other body fluids. ROC curve analysis showed that the AUC of miR-888 was 0.976, the optimal cut-off value was 2.250 copies/μL, and the discrimination accuracy was 97.33%; the AUC of miR-891a was 1.000, the optimal cut-off value was 1.100 copies/μL, and the discrimination accuracy was 100%.@*CONCLUSIONS@#In this study, a method for detection of miR-888 and miR-891a by duplex ddPCR was successfully established. The system has good stability and repeatability and can be used for semen identification. Both miR-888 and miR-891a have high ability to identify semen, and the discrimination accuracy of miR-891a is higher.

Production of multi-scale fluorocarbon droplets mediated by microwave-induced thermal phase transition and its synergistic efficacy of microwave ablation / 中华超声影像学杂志

Objective:To explore the mechanism of phase-transition fluorocarbon nanomaterials and evaluate its synergistic efficacy on microwave ablation (MWA).Methods:A novel phase transition nanodroplet (PTN) was designed with poly (lactic-co-glycolic acid) (PLGA) as the shell and perfluorocarbon (PFC) mixture as the core. Based on that, a phase-transition mechanism of microwave droplet vaporization (MWDV) was explored, which was based on the thermal phased transition. The basic physicochemical properties and biological characteristics of PTN were monitored by scanning electron microscope (SEM), dynamic laser light scattering (DLS), in vitro hemolysis and CCK-8 experiment.Based on the gel-hole model experiment in vitro, the phase transition of PTN were monitored; based on the live/dead cell double staining kit, flow cytometry and cytotoxicity test, the synergistic efficacy of phase-transition PTN on microwave ablation, which was mediated by MWDV was evaluated. Results:The phase-transition temperature of PTN was exactly the boundary temperature of microwave ablation (60 ℃) when the ratio between perfluoropentane (PFP) and perfluorohexane (PFH) in the core of PTN was 3∶2. Furthermore, the smart proportional PTN didn′t only have good stability and biocompatibility, but also could enhance the two-dimensional ultrasonic imaging and increase the efficacy of MWA under the mediation of MWDV.Conclusions:MWDV can be treated as a phase-transition mechanism of fluorocarbon nanomaterials, which provides a potential synergistic strategy for the thermal ablation of tumors.

The novel ER stress inducer Sec C triggers apoptosis by sulfating ER cysteine residues and degrading YAP via ER stress in pancreatic cancer cells

Pancreatic adenocarcinoma (PAAD) is one of the most lethal malignancies. Although gemcitabine (GEM) is a standard treatment for PAAD, resistance limits its application and therapy. Secoemestrin C (Sec C) is a natural compound from the endophytic fungus Emericella, and its anticancer activity has not been investigated since it was isolated. Our research is the first to indicate that Sec C is a broad-spectrum anticancer agent and could exhibit potently similar anticancer activity both in GEM-resistant and GEM-sensitive PAAD cells. Interestingly, Sec C exerted a rapid growth-inhibiting effect (80% death at 6 h), which might be beneficial for patients who need rapid tumor shrinkage before surgery. Liquid chromatography/mass spectrometry and N-acetyl-l-cysteine (NAC) reverse assays show that Sec C sulfates cysteines to disrupt disulfide-bonds formation in endoplasmic reticulum (ER) proteins to cause protein misfolding, leading to ER stress and disorder of lipid biosynthesis. Microarray data and subsequent assays show that ER stress-mediated ER-associated degradation (ERAD) ubiquitinates and downregulates YAP to enhance ER stress via destruction complex (YAP-Axin-GSK-βTrCP), which also elucidates a unique degrading style for YAP. Potent anticancer activity in GEM-resistant cells and low toxicity make Sec C a promising anti-PAAD candidate.

Theoretical Model Study on Morphology of Lipid Droplet on Inner Vascular Wall / 医用生物力学

Objective To establish the theoretical model for morphology of lipid droplets adhering to inner vascular wall, so as to provide the theoretical model for the study and analysis of the overall morphology of lipid droplets on inner vascular wall of patients with fat embolism. MethodsThe model of the droplet with variable radius on inner wall of the cylindrical tube was established to describe morphology of lipid droplets on inner vascular wall, and accuracy of the theoretical model was verified by Surface Evolver (SE) software simulation results. According to the theoretical model, the influencing patterns of lipid droplet volume and contact angle on dimensionless adhesion area Sb0 and blockage ratio κ of lipid droplets in blood vessels were analyzed. Results The theoretical model could predict contour parameters of adhesion morphology for lipid droplets on inner vascular wall, including the height and arc radius of lipid droplet at azimuth angle of 0 and π/2. The relative errors between contour parameters obtained from the theoretical model and corresponding parameters obtained from the SE simulation were smaller than 10%. For lipid droplets with the same dimensionless volume V0, Sb0 of inner vascular wall decreased with contact angle increasing, and blockage ratio κ increased with contact angle increasing. At the same contact angle, the smaller V0 , the smaller Sb0 and κ would be. Conclusions The established theoretical model with variable radius can well describe morphological characteristics of lipid droplets on inner vascular wall. The influening pattern of volume, contact angle and other parameters on height, adhesion area and cross-sectional area of lipid droplets can be accurately and quickly obtained through the theoretical model, indicating that the larger the contact angle of lipid droplets or the smaller the dimensionless volume, the lower the probability of embolism. The research findings provide theoretical support for the analysis on related diseases.

Detection of NPM1 Mutation in Acute Myeloid Leukemia by Droplet Digital PCR and Its Clinical Application Value / 中国实验血液学杂志

OBJECTIVE@#To establish the droplet digital PCR (ddPCR) assay for the detection of NPM1 type A mutation in patients with acute myeloid leukemia (AML), and to evaluate its specificity, sensitivity and its value in clinical application.@*METHODS@#NPM1 mutant and wildtype plasmids were used to verify the performance of ddPCR. Both ddPCR and Sanger sequencing were used to detect the bone marrow samples of 87 AML patients, which were confirmed by next generation sequencing (NGS). Moreover, NPM1 mutation burden was dynamically monitored in five patients by ddPCR.@*RESULTS@#The limit of blank (LOB) of ddPCR established for NPM1 mutation detection was 1.1 copies/μl, and the limit of detection (LOD) was 2.43 copies/μl, which had good linearity. Among the 87 newly diagnosed AML patients, ddPCR identified seventeen cases positive for NPM1 mutation (19.5%)， which was consistent with Sanger sequencing. NGS confirmed 12 positive cases, including 8 of type A mutations, 2 of type D mutations, and 2 of rare type mutations. The results of dynamic monitoring of NPM1 mutation burden in 5 patients showed that the NPM1 mutation burden decreased obviously even close to 0, when patients achieve complete remission after chemotherapy. However, the mutation burden was increased again at the time of relapse.@*CONCLUSION@#In this study, we established a ddPCR method for detection of NPM1 mutation with good sensitivity and repeatability, which can be used for screening NPM1 mutation in newly diagnosed AML patients and for minimal residual disease monitoring after remission in positive AML patients to guide treatment.

Glucose, lipid and protein metabolism of hepatic stellate cells: a novel target against liver fibrosis / 中国药理学通报

Hepatic stellate cells (HSCs) are non-parenchymal pericytes resided in liver. In chronic liver injury, the cells are activated from quiescent state into myofibroblasts, and then drive liver fibrosis. The process, activated HSCs secreting extracellular matrix, is crucial to liver fibrosis, which needs enormous energy and triggers the metabolic reprogramming including Warburg effect, degradation of lipid droplets with increasing lipid metabolism and the change of amino acid metabolism. This paper mainly reviews the glucose, lipid and protein metabolic reprogramming of HSCs during the development of liver fibrosis and its potential applications, controbuting to design novel targeted therapies against liver fibrosis.

The role of LncRNA00602 in Ad36-induced differentiation of adipocytes / 中华内分泌代谢杂志

Objective:To investigate the possible role of long non-coding RNA (LncRNA) 00602 in promoting browning in adipocytes induced by adenovirus type 36 (Ad36).Methods:According to Ad36 infection, adipose tissue samples of obese patients were divided into Ad36-negative group and Ad36-infected group. Realtime fluorescent quantitative PCR (qRT-PCR) was used to detect the changes in the expression of LncRNA00602 mRNA in omental adipose tissue of the two groups, and analyze the differences between the two groups. The correlation between waist-to-hip ratio, systolic blood pressure, diastolic blood pressure, fasting blood glucose, triacylglyceride and other indicators of the patients in the group with LncRNA00602 mRNA expression were analyzed. HE staining was used to detect the size of adipocytes in the omental adipose tissue of the Ad36 negative group and the Ad36 infection group. qRT-PCR and Western blotting were used to detect the mRNA and protein expression levels of uncoupling protein 1 (UCP1) and PR domain containing 16 (PRDM16) in omental adipose tissue of two groups of patients. Human adipose-derived stem cells (hADSC) were isolated and cultured, using Ad36 to induce differentiation, and divided into control group and LncRNA00602 knockdown group. On 0, 2, and 4 days after LncRNA00602 knockdown, fluoroboron dipyrrole (BODIPY) and mitochondrial red fluorescence (Mito-Tracker Red) were used to stain intracellular lipid droplets and mitochondria. At the same time, qRT-PCR and Western blotting were used to detect changes in the expression of UCP1 and PRDM16.Results:The expression of LncRNA00602 gene in the Ad36 infection group was higher than that in the Ad36 negative group (all P<0.05). The expression of LncRNA00602 in the Ad36 negative group was not significantly different from the above clinical indicators, while the expression of LncRNA00602 was negatively correlated with serum fasting blood glucose and triacylglyceride ( r=-0.522, -0.486, P<0.05) in the Ad36 infection group; HE staining showed that the average adipocyte area of the Ad36 infection group was smaller than that of the Ad36 negative group. At the same time, UCP1 and PRDM16 gene expression were higher than the negative group (all P<0.05). At the cellular level, on the 2nd and 4th days after knockdown of LncRNA00602, the lipid droplet area of adipocytes in the LncRNA00602 knockdown group was larger than that of the control group, the number of mitochondria decreased compared with the control group, and difference was statistically significant ( P<0.05 or P<0.01); Compared with the control group, there was significantly lower expression of the browning marker genes UCP1, PRDM16, and protein in the adipocytes in the LncRNA00602 knockdown group (all P<0.05). Conclusion:In Ad36-induced adipocyte differentiation, LncRNA00602 may positively regulate the expression of UCP1, PRDM16 and lipid droplet metabolism, and promote the browning of adipocytes.

Establishment of a droplet digital PCR method for the detection of hepatitis B virus covalently closed circular DNA / 临床肝胆病杂志

ObjectiveTo establish a droplet digital PCR (ddPCR) method for detecting hepatitis B virus (HBV) covalently closed circular DNA (cccDNA). MethodsHBV cccDNA standard substance was constructed, and HBV cccDNA primers and probes were designed based on the structural differences between HBV cccDNA and relaxed circular DNA (rcDNA). HBV plasmid was amplified to obtain HBV cccDNA standard substance, and a ddPCR detection method was established with the standard substance after gradient dilution as the template for HBV cccDNA detection; the limit of detection and repeatability of this method were analyzed. Liver tissue samples were collected from 20 patients who attended Beijing YouAn Hospital, Capital Medical University, from June 2017 to October 2020, all of whom were diagnosed with HBV infection, and DNA of the samples was extracted and digested with plasmid-safe ATP-dependent DNA enzyme to obtain HBV cccDNA template; the ddPCR detection method was evaluated in clinical samples and was compared with the quantitative real-time PCR (qPCR) detection method. The chi-square test was used for comparison of categorical data between the two groups. ResultsThe HBV cccDNA detection method based on ddPCR was established, which accurately detected HBV cccDNA in standard substance after gradient dilution, with a limit of detection of 1 copy/μl, and the coefficients of variation of 1×103, 1×102, and 1×101 copies/μl standard substances were 441%, 3.98%, and 5.09%, respectively. HBV cccDNA was detected in the samples of 20 patients with HBV infection; the ddPCR detection method detected HBV cccDNA in 17 patients, with a positive rate of 85%, while the qPCR detection method detected HBV cccDNA in 11 patients, with a positive rate of 55%, and there was a significant difference between the two methods (χ2=4.286, P=0038). ConclusionThe established ddPCR method for detecting HBV cccDNA has a low limit of detection and good repeatability, which provides an effective tool for further clinical detection.

Determination of seven polycyclic aromatic hydrocarbons in water by dispersive liquid-liquid microextraction based on solidification of floating organic droplet with gas chromatography-mass spectrometry / 上海预防医学

Objective To develop a new method for the simultaneous determination of seven polycyclic aromatic hydrocarbons(PAHs)in water by dispersive liquid-liquid microextraction based on solidification of floating organic droplet(DLLME-SFO)with gas chromatography-mass spectrometry(GC-MS). Methods The experimental conditions of DLLME-SFO were determined with dodecanol as extractant solvent, methanol as dispersive solvent, inonic strength increased by adding 8% NaCl. After vortexed for 1 min and centrifuged at 4 000 r/min for 5 min, the water sample was cooled down in an ice bath till dodecanol became solid and formed a small ball. Then the solidified dodecanol phase was transferred, and directly detected by GC-MS method after it melted. Results Good linearities were obtained for the seven polycyclic aromatic hydrocarbons within the range of 5 μg/L-200 μg/L. The correlation coefficients were above 0.996. The detection limits ranged from 1.6 ng/L to 3.2 ng/L. The average recoveries ranged from 86.2% to 105% and the RSDs from 3.8% to 9.4%. Conclusion The method is sensitive, fast and simple. It has the advantage of little organic solvent consumption, which is friendly to environment and suitable for the detection of seven PAHs in water.