The Role and Mechanism of MiR-451 in Multidrug Resistance of Leukemia Cell Line K562/A02 / 中国实验血液学杂志

OBJECTIVE@#To detect the differential expressions of miR-451, ABCB1 and ABCC2 in drug-sensitive leukemia cell line K562 and drug-resistant cell line K562/A02, and explore the regulatory relationship between miR-451 and the expressions of ABCB1 and ABCC2 , and the mechanism of miR-451 involved in drug resistance in leukemia.@*METHODS@#CCK-8 assay was used to detect the drug resistance of K562/A02 and K562 cells. Quantitative Real-time PCR (qRT-PCR) was used to verify the differential expressions of miR-451 in K562 and K562/A02 cells. MiR-451 mimic and negative control (miR-NC), miR-451 inhibitor and negative control (miR-inNC) were transfected into K562 and K562/A02 cells respectively, then qRT-PCR and Western blot were used to detect the expression levels of mRNA and protein of ABCB1 and ABCC2 in K562 and K562/A02 cells and the transfected groups.@*RESULTS@#The drug resistance of K562/A02 cells to adriamycin was 177 times higher than that of its parent cell line K562. Compared with K562 cells, the expression of miR-451 in K562/A02 cells was significantly higher (P <0.001), and the mRNA and protein expression levels of ABCB1 and ABCC2 in K562/A02 cells were significantly higher than those in K562 cells (P <0.001). After transfected with miR-451 inhibitor, the expression of miR-451 was significantly down-regulated in K562/A02 cells (P <0.001), the sensitivity to chemotherapy drugs was significantly enhanced (P <0.05), and the mRNA and protein expressions of ABCB1 and ABCC2 were significantly decreased (P <0.01). After transfected with miR-451 mimic, the expression of miR-451 was significantly upregulated in K562 cells (P <0.001), and the mRNA and protein expressions of ABCB1 and ABCC2 were significantly increased (P <0.01).@*CONCLUSION@#There are significant differences in the expressions of miR-451, ABCB1 and ABCC2 between the drug-sensitive leukemia cell line K562 and drug-resistant cell line K562/A02, which suggests that miR-451 may affect the drug resistance of leukemia cells by regulating the expression of ABCB1 and ABCC2.

The association of demodex infestation with pediatric chalazia.

PURPOSE: This study aimed to investigate the association of Demodex infestation with pediatric chalazia. METHODS: In a prospective study, 446 children with chalazia and 50 children with non-inflammatory eye disease (controls) who underwent surgical treatment were enrolled from December 2018 to December 2019. Patient ages ranged from 7 months to 13 years old. All patients underwent eyelash sampling for light microscope examination, and statistical correlation analysis between Demodex infestation and chalazia, including the occurrence, recurrence, and course of disease, morphological characteristics, and meibomian gland dysfunction (MGD) in chalazia patients was performed. RESULTS: Demodex was found in 236 (52.91%) patients with chalazia and zero control patients. Demodicosis was significantly more prevalent in chalazia patients than the control group (P < 1 × 10- 14). Recurrent chalazia (P = 0.006) and skin surface involvement (P = 0.029) were highly correlated with Demodex infestation. Demodicosis was also associated with multiple chalazia (P = .023) and MGD(P = .024). However, Demodex infestation was comparable in the course of disease (P = 0.15), seasonal change (P = 0.68) and blepharitis subgroups (P = 0.15). Within the group of chalazia patients who underwent surgical removal of cysts, 4 (0.9%) patients with concurrent demodicosis experienced recurrence. CONCLUSIONS: Demodex infestation was more prevalent in pediatric chalazia patients than healthy children, and was associated with recurrent and multiple chalazia. Demodicosis should be considered as a risk factor of chalazia. In children with chalazia, Demodex examination and comprehensive treatment of Demodex mites should be applied to potentially prevent recurrence.

A Deep Learning Based Framework for Diagnosing Multiple Skin Diseases in a Clinical Environment.

Background: Numerous studies have attempted to apply artificial intelligence (AI) in the dermatological field, mainly on the classification and segmentation of various dermatoses. However, researches under real clinical settings are scarce. Objectives: This study was aimed to construct a novel framework based on deep learning trained by a dataset that represented the real clinical environment in a tertiary class hospital in China, for better adaptation of the AI application in clinical practice among Asian patients. Methods: Our dataset was composed of 13,603 dermatologist-labeled dermoscopic images, containing 14 categories of diseases, namely lichen planus (LP), rosacea (Rosa), viral warts (VW), acne vulgaris (AV), keloid and hypertrophic scar (KAHS), eczema and dermatitis (EAD), dermatofibroma (DF), seborrheic dermatitis (SD), seborrheic keratosis (SK), melanocytic nevus (MN), hemangioma (Hem), psoriasis (Pso), port wine stain (PWS), and basal cell carcinoma (BCC). In this study, we applied Google's EfficientNet-b4 with pre-trained weights on ImageNet as the backbone of our CNN architecture. The final fully-connected classification layer was replaced with 14 output neurons. We added seven auxiliary classifiers to each of the intermediate layer groups. The modified model was retrained with our dataset and implemented using Pytorch. We constructed saliency maps to visualize our network's attention area of input images for its prediction. To explore the visual characteristics of different clinical classes, we also examined the internal image features learned by the proposed framework using t-SNE (t-distributed Stochastic Neighbor Embedding). Results: Test results showed that the proposed framework achieved a high level of classification performance with an overall accuracy of 0.948, a sensitivity of 0.934 and a specificity of 0.950. We also compared the performance of our algorithm with three most widely used CNN models which showed our model outperformed existing models with the highest area under curve (AUC) of 0.985. We further compared this model with 280 board-certificated dermatologists, and results showed a comparable performance level in an 8-class diagnostic task. Conclusions: The proposed framework retrained by the dataset that represented the real clinical environment in our department could accurately classify most common dermatoses that we encountered during outpatient practice including infectious and inflammatory dermatoses, benign and malignant cutaneous tumors.

The Feature Ambiguity Mitigate Operator model helps improve bone fracture detection on X-ray radiograph.

This study was performed to propose a method, the Feature Ambiguity Mitigate Operator (FAMO) model, to mitigate feature ambiguity in bone fracture detection on radiographs of various body parts. A total of 9040 radiographic studies were extracted. These images were classified into several body part types including 1651 hand, 1302 wrist, 406 elbow, 696 shoulder, 1580 pelvic, 948 knee, 1180 ankle, and 1277 foot images. Instance segmentation was annotated by radiologists. The ResNext-101+FPN was employed as the baseline network structure and the FAMO model for processing. The proposed FAMO model and other ablative models were tested on a test set of 20% total radiographs in a balanced body part distribution. To the per-fracture extent, an AP (average precision) analysis was performed. For per-image and per-case, the sensitivity, specificity, and AUC (area under the receiver operating characteristic curve) were analyzed. At the per-fracture level, the controlled experiment set the baseline AP to 76.8% (95% CI: 76.1%, 77.4%), and the major experiment using FAMO as a preprocessor improved the AP to 77.4% (95% CI: 76.6%, 78.2%). At the per-image level, the sensitivity, specificity, and AUC were 61.9% (95% CI: 58.7%, 65.0%), 91.5% (95% CI: 89.5%, 93.3%), and 74.9% (95% CI: 74.1%, 75.7%), respectively, for the controlled experiment, and 64.5% (95% CI: 61.3%, 67.5%), 92.9% (95% CI: 91.0%, 94.5%), and 77.5% (95% CI: 76.5%, 78.5%), respectively, for the experiment with FAMO. At the per-case level, the sensitivity, specificity, and AUC were 74.9% (95% CI: 70.6%, 78.7%), 91.7%% (95% CI: 88.8%, 93.9%), and 85.7% (95% CI: 84.8%, 86.5%), respectively, for the controlled experiment, and 77.5% (95% CI: 73.3%, 81.1%), 93.4% (95% CI: 90.7%, 95.4%), and 86.5% (95% CI: 85.6%, 87.4%), respectively, for the experiment with FAMO. In conclusion, in bone fracture detection, FAMO is an effective preprocessor to enhance model performance by mitigating feature ambiguity in the network.

Activating transcription factor 3 coordinates differentiation of cardiac and hematopoietic progenitors by regulating glucose metabolism.

The cardiac and hematopoietic progenitors (CPs and HPs, respectively) in the mesoderm ultimately form a well-organized circulation system, but mechanisms that reconcile their development remain elusive. We found that activating transcription factor 3 (atf3) was highly expressed in the CPs, HPs, and mesoderm, in zebrafish. The atf3 -/- mutants exhibited atrial dilated cardiomyopathy and a high ratio of immature myeloid cells. These manifestations were primarily caused by the blockade of differentiation of both CPs and HPs within the anterior lateral plate mesoderm. Mechanistically, Atf3 targets cebpγ to repress slc2a1a-mediated glucose utilization. The high rate of glucose metabolism in atf3 -/- mutants inhibited the differentiation of progenitors by changing the redox state. Therefore, atf3 could provide CPs and HPs with metabolic adaptive capacity to changes in glucose levels. Our study provides new insights into the role of atf3 in the coordination of differentiation of CPs and HPs by regulating glucose metabolism.

Effect of prone positioning on respiratory function in very preterm infants undergoing mechanical ventilation / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To explore the effect of prone positioning on respiratory function in very preterm infants undergoing mechanical ventilation.</p><p><b>METHODS</b>A total of 83 very preterm infants treated with mechanical ventilation were enrolled in the study and were randomly assigned to supine group and prone group. Four infants withdrew from the study and 79 infants completed treatment and observation (37 in the supine group and 42 in the prone group). Infants in both groups were mechanically ventilated in a volume assist-control mode. Infants in the prone group were ventilated in the supine position for 4 hours and in the prone position for 2 hours. Ventilator parameters, arterial blood gas analysis, and vital signs were recorded before grouping, every 6 hours in the supine group, and every hour after conversion into the prone position in the prone group, respectively.</p><p><b>RESULTS</b>Fraction of inspired oxygen (FiO), peak inspiratory pressure, mean inspiratory pressure, and duration of ventilation were significantly lower in the prone group than in the supine group (P<0.05); there were no significant differences in tidal volume or positive end-expiratory pressure between the two groups (P>0.05). The prone group had a significantly higher PO/FiO ratio but significantly lower oxygenation index and respiratory rate than the supine group (P<0.05). There were no significant differences in arterial oxygen tension, pH, base excess, heart rate, or mean blood pressure between the two groups (P>0.05).</p><p><b>CONCLUSIONS</b>Alternating ventilation between the prone position and supine position can improve oxygenation function, decrease the fraction of inspired oxygen, and shorten the duration of mechanical ventilation in very preterm infants undergoing mechanical ventilation.</p>

The pro-inflammatory signalling regulator Stat4 promotes vasculogenesis of great vessels derived from endothelial precursors.

Vasculogenic defects of great vessels (GVs) are a major cause of congenital cardiovascular diseases. However, genetic regulators of endothelial precursors in GV vasculogenesis remain largely unknown. Here we show that Stat4, a transcription factor known for its regulatory role of pro-inflammatory signalling, promotes GV vasculogenesis in zebrafish. We find stat4 transcripts highly enriched in nkx2.5+ endothelial precursors in the pharynx and demonstrate that genetic ablation of stat4 causes stenosis of pharyngeal arch arteries (PAAs) by suppressing PAAs 3-6 angioblast development. We further show that stat4 is a downstream target of nkx2.5 and that it autonomously promotes proliferation of endothelial precursors of the mesoderm. Mechanistically, stat4 regulates the emerging PAA angioblasts by inhibiting the expression of hdac3 and counteracting the effect of stat1a. Altogether, our study establishes a role for Stat4 in zebrafish great vessel development, and suggests that Stat4 may serve as a therapeutic target for GV defects.

[Multi-spectroscopy applied to study on a late neolithic colored stone from Yuhui Site in Huaihe Basin].

The unearthing of a large number of red-yellow colored stones in Yuhui Site, Bengbu city, Anhui province of China, which was the only site of Longshan culture appointed by "Origin of the Chinese Civilization Project" in the Huaihe River basin, has drawn a widespread attention in archaeology. The present research was undertaken to examine elements, mineral composition and thermal history of one red-yellow color stone in different positions, classified according to specialized colors, by means of synchrotron radiation X-ray fluorescence (SR-XRF), X-ray diffraction (XRD), laser Raman spectroscopy (LRS), electron probe micro-analysis (EPMA) and thermoluminescence (TL). The results show that the main body of the color stone is limonite with a large amount of quartz inclusion. The yellow substances on the surface layer of the color stone were identified as goethite (alpha-FeOOH), and the red ones as red ochre (alpha-Fe2O3+clay+silica). The internal yellow brown substances inside the stone are mainly aphanitic goethite with a number of chromites and manganese dioxide, and also with small quantity of barite and bismuth. And the color stones are without historical firing treatment. These kinds of special polymetallic ores with unique nature and complex geologic history, which were unearthed in the late neolithic site with large numbers, may be closely related to some kind of primitive religious beliefs and special sacrificial practices.

[Progress and application of zebrafish in regenerative medicine].

The phenomenon of "tissue regeneration" has attracted numerous biologists for many years. Regenerative capacity differs greatly across species. The lower vertebrates such as zebrafish have exceptionally high regeneration abilities, while most high vertebrate species including humans do not have a remarkable ability for regeneration. It has been found zebrafish has a strong ability to regenerate a variety of tissues and organs including fins, heart, retina, optic nerve, spinal cord, liver, and sensory hair cells. Thus, we can learn useful information from the zebrafish regeneration model to understand the human regeneration defects and promote the development of regenerative medicine. This review summarizes the current research status for regeneration of heart, nerve, liver, and fin regeneration in zebrafish.

Self-assembled biodegradable micellar nanoparticles of amphiphilic and cationic block copolymer for siRNA delivery.

A novel amphiphilic and cationic triblock copolymer consisting of monomethoxy poly(ethylene glycol), poly(epsilon-caprolactone) (PCL) and poly(2-aminoethyl ethylene phosphate) denoted as mPEG(45)-b-PCL(100)-b-PPEEA(12) was designed and synthesized for siRNA delivery. The copolymers were well characterized by (1)H NMR spectroscopy and gel permeation chromatography. Micelle nanoparticles' (MNPs) formation of this amphiphilic copolymer in aqueous solution was studied by dynamic light scattering, transmission electron microscopy and fluorescence technique. MNPs took uniform spherical morphology with zeta potential of around 45 mV and were stabilized by hydrophobic-hydrophobic interaction in the PCL core, exhibiting the critical micelle concentration at 2.7 x 10(-3) mg/mL. Such MNPs allowed siRNA loading post nanoparticle formation without change in uniformity. The average diameter of nanoparticles after siRNA binding ranged from 98 to 125 nm depending on N/P ratios. The siRNA loaded nanoparticles can be effectively internalized and subsequently release siRNA in HEK293 cells, resulting in significant gene knockdown activities, which was demonstrated by delivering two siRNAs targeting green fluorescence protein (GFP). It effectively silenced GFP expression in 40-70% GFP-expressed HEK293 cells and it was observed that higher N/P ratio resulted in more effective silence which was likely due to better cell internalization at higher N/P ratio. MTT assay demonstrated that neither MNPs themselves nor siRNA loaded MNPs showed cytotoxicity even at high concentrations. Such cationic MNPs made from biocompatible and biodegradable polymers are promising for siRNA delivery.

Microscale analysis of in vitro anaerobic degradation of lignocellulosic wastes by rumen microorganisms.

Anaerobic degradation of lignin in waste straw by ruminal microbes was directly observed using atomic force microscope (AFM). A series of high-resolution AFM images of the straw surface in the biodegradation show that the wax flakelets and lignin granules covering the straw surface were removed by the rumen microorganisms. Such degradation resulted in an exposure of cellulose fibers located inside the straw. The appearance of holes and microfibers in fermentation reveals that tunneling might be one of the ways for rumen microorganisms to attack the straw. Increases in the atomic ratio of oxygen to carbon (O/C) and the ratio C2/C3 in C1s spectra of X-ray photoelectron spectroscopy confirm that more cellulose was exposed on the surface after the anaerobic fermentation of straw. Gas chromatography/mass spectrometry analytical results demonstrate the decomposition of lignin by rumen microorganisms. Fourier transform infrared spectroscopy spectra and the measurement of degradation efficiency of the main straw components further verify these microscaled observations.

Biodegradable polycation and plasmid DNA multilayer film for prolonged gene delivery to mouse osteoblasts.

Sustained release of functional plasmid DNA from the surfaces of materials which support cell adhesion for tissue formation could have a significant impact on gene therapy and tissue engineering. We report here layer-by-layer assembled multilayer film from a degradable cationic poly(2-aminoethyl propylene phosphate) and plasmid DNA encoding for enhanced green fluorescent protein (EGFP) for mouse osteoblast cell adhesion and prolonged gene delivery. Multilayer film growth was monitored by UV spectrophotometry and intensity of absorbance at 260 nm related to incorporated DNA increased in an exponential manner with increase the number of deposited polymer and plasmid layers. It degraded upon incubation in phosphate-buffered saline (PBS) at 37 degrees C and sustained the release of bioactive plasmid DNA up to 2 months. The multilayer film facilitated initial mouse osteoblast cell adhesion onto the surface and enhanced cellular alkaline phosphatase activity and calcium accumulation. It sustained delivering transcriptional active DNA to mouse osteoblast cells cultured on the film, and directly prolonged gene expression in the presence of serum without any exogenous transfection agent. This biodegradable multilayer assembly is promising for the local and sustained delivery of plasmid DNA and such a layer-by-layer system suggests an alternative method for plasmid DNA incorporation which may be useful for surface modification of implanted materials or scaffold for gene therapy and tissue regeneration.

[Role of pancreatic hilar vascular occlusion in sophisticated pancreaticoduodenectomy].

OBJECTIVE: To discuss the value of a simple occlusive technique of the triple vessels, ie, portal vein, superior mesenteric vessels and splenic vein, in complicated pancreaticoduodenectomy. METHODS: The technique was fulfilled with a No.8 urethral catheter to encycle the portal vein, superior mesenteric vessels and its near tissue plus pancreatic tail and splenic vein than the neck of pancreas was transected and well exposure superior mesenteric vein and complete transaction of uncinate. From November 2005 to November 2006 the technique was applied to 12 cases of pancreatic malignancy which presented very infiltrated and adhesive to the hilar vascular structure. RESULTS: The 12 cases were accomplished according with this technique. The operating time was (292.4 +/- 36.3) min (270 - 390 min) and the intraoperative blood loss was (833.3 +/- 618.4) ml (300 - 2500 ml). The postoperative complication included one case of lymphatic leakage, two cases of pneumonia, one case of abdominal infection and two cases of wound infection. There was no perioperative mortality. The postoperative hospital stay was 17 d (11 - 29 d). CONCLUSIONS: Use this triple vessels occlusive technique can improve the safety and feasibility in complicated cases of pancreaticoduodenectomy.

[The strategy of isolated complete resection of the caudate lobe of the liver through the anterior liver-splitting approach: a report of 19 cases].

OBJECTIVE: To explore the strategy of isolated complete resection of the caudate lobe of the liver through the anterior liver-splitting approach. METHODS: From January 1995 to June 2006, isolated complete caudate resection of the caudate lobe of the liver through the anterior liver-splitting approach in which accessed the caudate lobe by separation the liver parenchyma along the interlobar plane, was performed on 19 patients with tumors originated in caudate lobe. They were included hepatocellular carcinoma in 13 cases, cholangiocarcinoma in 4 cases and hemangioma in 2 cases, the tumor size range from 4 - 12 cm. The approach to hepatic resection involved routine use of Peng's multifunctional operative dissector, inflow and outflow of hepatic vascular control before hepatic parenchyma transection, low central venous pressure and selective use of liver hanging maneuver, as well as retrograde caudate lobectomy. RESULTS: The operations were successful in 19 patients. Operating time averaged at (296 +/- 55) min. The average amount of blood loss were 1200 ml (ranged from 500 - 3000 ml). Postoperative complications included ascites in 2 cases, pleural effusion in 5 cases and bile leakage in 2 cases. They were cured by drainage. No mortality occurred in the perioperative period. CONCLUSIONS: The application of anterior approach for isolated caudate lobectomy can converse certain kind of caudate lobe tumor from non-resectable to respectable resulting in widening the indication. The intraoperative routine use of Peng's multifunctional operative dissector, application of inflow and outflow of hepatic vascular control, low central venous pressure and selective use of liver hanging maneuver, as well as retrograde caudate lobectomy make the anterior liver-splitting approach for isolated complete caudate lobectomy safer and easier.