Deep Learning in Biomedical Optics

This article reviews deep learning applications in biomedical optics with a particular emphasis on image formation. The review is organized by imaging domains within biomedical optics and includes microscopy, fluorescence lifetime imaging, in vivo microscopy, widefield endoscopy, optical coherence tomography, photoacoustic imaging, diffuse tomography, and functional optical brain imaging. For each of these domains, we summarize how deep learning has been applied and highlight methods by which deep learning can enable new capabilities for optics in medicine. Challenges and opportunities to improve translation and adoption of deep learning in biomedical optics are also summarized. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

[Direct projection pathway between medial vestibular nucleus and vestibular efferent neurons in rats and its electrophysiological characteristics]

Objective: To confirm the direct projection pathway between the medial vestibular nucleus (MVN) and vestibular efferent (VE) neurons and explore its electrophysiological characteristics. Methods: Newborn [(9±1) day-old] male and female Wistar rats were used in the study. The postsynaptic currents of VE were recorded after stimulating neurons in MVN by the whole-cell patch clamp recording technique. The action potentials (APs) of the afferent neurons in MVN were recorded retrogradely after stimulating the area of VE neurons distribution medial to genu of facial nerve (g7), and the position and shape of the recorded neurons were determined by biocytin staining. Results: The resting membrane potentials of VE neurons located medial to g7 ranged between -70 mV and -55 mV in current clamp recordings. Excitatory postsynaptic currents (EPSCs) were recorded in the VE neurons medial to the g7 evoked by single-pulse (0.08 mA, 0.1 Hz, 100 μs) electrical stimulation of MVN. The mean values of amplitude and duration were (195.6±23.7) pA and (23.9±5.9) ms, respectively. APs were recorded in MVN after stimulating the distribution area of VE neurons. The mean amplitude of the action potentials was (62.0±4.3) mV, and the mean duration was (94.9±4.7) ms. Biocytin staining indicated that the recorded neurons located in MVN and the axons' terminals went into the area medial to g7 in which VE neurons located. Conclusions: There is a direct excitatory pathway projecting from MVN to VE neurons medial to g7. Its physiological function may be related to the feedback regulation of vestibular center to peripheral vestibular afferent signals.

[Relationship between age at menarche and obesity in women]

Objective: To explore the relationship between age at menarche and general obesity (based on BMI) and central obesity (based on WC or WHtR) in middle-aged and elderly women in China. Methods: A total of 6 363 women from the China Health and Retirement Longitudinal Study were included. Restricted cubic splines based on binary logistic regressions were used to analyze the relationship between age at menarche and the risk of obesity. Age at menarche was divided into four groups: ≤13, 14- (control group), 16- , and ≥18 years old. Binary logistic regressions were applied to analyze the relationship between the continuous or grouped variable of age at menarche and the risk of obesity. Results: After adjusting potential confounders, the age at menarche showed a negative linear relationship with the risk of general obesity and central obesity. The risk for obesity based on BMI, WC and WHtR significantly decreased by 6% (OR=0.94, 95%CI: 0.90-0.99), 4% (OR=0.96, 95%CI: 0.92-1.00), and 6% (OR=0.94, 95%CI: 0.90-0.99) for each 1 year increase in age at menarche. Compared with participants who had menarche at age 14- years old, the risk for obesity based on BMI (OR=0.71, 95%CI: 0.55-0.91), WC (OR=0.75, 95%CI: 0.62-0.92) and WHtR (OR=0.76, 95%CI: 0.61-0.96) significantly decreased by 29%, 25%, and 24% in participants who had menarche at age ≥18 years old. Conclusions: There was a negative linear relationship between age at menarche and the risk for general obesity and central obesity in middle-aged and elderly women in China. Older age at menarche might be negatively associated with risk for obesity in middle-aged and elderly women.

[The prevalence of allergic conjunctivitis based on outpatients in Baotou area]

Objective: To explore the prevalence and influencing factors of allergic conjunctivitis in Baotou area at different times. Methods: A cross-sectional study was conducted in January 2021, 111 patients with allergic conjunctivitis who were admitted to the Department of Ophthalmology, the Second Affiliated Hospital of Baotou Medical College, Inner Mongolia University of Science and Technology in 2020 were selected as the research subjects. The basic information, allergic conditions, living habits and other information of the patients were obtained by self-made questionnaire. The pollen concentration and allergy related indicators(allergic duration and frequency, eye itching score, eye burn score, eye foreign body sensation score, tears score and the total scores) of 2019 and 2020 were analyzed by paired sample t-test. The pollen concentration of 2019 and 2020 were analyzed by Wilcoxon signed rank test. The allergy related indicators of different genders were analyzed by independent sample t-test. The allergy related indicators of different ages were analyzed by one-way analysis of variance. The relationship between the length of wearing masks and the allergy related indicators were analyzed by Spearman correlation analysis. Results: Among the 111 patients with allergic conjunctivitis, 54 were males and 57 were females, ranging in age from 8 to 69 years old, with a median age of 35 years old and an average age of (36.77±13.18) years old. The average pollen concentration in Baotou in 2019 was (125.35±222.64) grains/1 000 square millimeter, and the average pollen concentration in Baotou in 2020 was (107.38±137.29) grains/1 000 square millimeter. There was no significant difference in pollen concentration between the two years(Z=-0.178, P=0.859). The severity of allergic indicators in all patients in 2020 is significantly lower than in 2019(t values were 4.701,3.587,2.582,3.661,4.444,2.784,2.555,3.886,respectively, with P<0.05). The severity of allergic indicators in male patients is lower than that of female patients (t values were -1.558, -1.257, -3.41, -3.085, -2.335, -2.897, -2.652, -4.124, respectively). The prevalence of allergic conjunctivitis dose not vary significant with age (P values were 0.504, 0.095, 0.499, 0.265, 0.284, 0.655, 0.421, 0.976, respectively). In 2020, the average time that patients wear masks is (6.55±3.28) h/d, and there is a correlation with the difference in allergy duration (r=0.191, P=0.045). Conclusion: The severity of allergic conjunctivitis in Baotou in 2020 was significantly improved compared with that in 2019, which may be related to masks wearing.

[Biocompatibility of extracellular matrix hydrogel with human iPSCs differentiated cardiomyocytes]

Objective: To observe the biocompatibility of porcine omental derived extracellular matrix (ECM) hydrogel with human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and the feasibility of ECM hydrogel as a delivery vector of cell transplantation. Methods: A series of chemical, physical and enzymatic methods were applied to acellularize the porcine omentum. Subsequently, the extracted ECM was prepared into thermosensitive hydrogel. The biochemical composition of the hydrogel was identified by histological staining. The microstructure was observed by scanning electron microscopy. The hydrogel was then injected into the myocardium of mice to observe its in situ gelation ability. Differentiation of human induced pluripotent stem cells into cardiomyocytes was achieved by small molecule induction, and then the obtained hiPSC-CMs were cultured. hiPSC-CMs cultured onto the prepared hydrogel were defined as the hydrogel group, while conventionally cultured hiPSC-CMs were defined as the control group. Cardiomyocyte viability and growth patterns were detected using live/dead staining, CCK-8 and phalloidin staining. Immunofluorescence staining and Western blot of cardiomyocytes were used to determine the survival and phenotypic maintenance markers of cardiomyocytes in materials. Results: The results of HE staining, oil red O staining and DAPI fluorescence staining showed that there was no significant cell debris, nucleus and lipid residue in the prepared ECM hydrogel. The Sirius red staining and Alcian blue staining showed that the hydrogel retained collagen and glycolaminoglycan, which were the main components of ECM. The prepared hydrogel behaves as a viscous liquid at 4 ℃ and as a gel state at 37 ℃. Scanning electron microscope results showed that the microstructure of the hydrogel was composed of irregular fibers and pores of different sizes. Under the guidance of ultrasound, the prepared ECM hydrogel could be successfully injected into the myocardium of mice. Immediately after the injection, the hyperechoic signal could be observed under ultrasound, suggesting that the hydrogel remained in the myocardium. HE staining of myocardial tissue evidenced that there was lump of gel in the injection area. The differentiated hiPSC-CMs were co-cultured with the prepared ECM hydrogel, and the results of live/dead staining showed that most of the hiPSC-CMs in the hydrogel group and the control group were alive, dead cells were scanty. The results of CCK-8 test showed that the absorbance values of the two groups were similar (P>0.05). The results of phalloidin staining showed that hiPSC-CMs could extend normally when co-cultured with ECM hydrogel. The cell morphology of the hydrogel group was similar with that of the control group, and there was no statistically significant difference in the F-actin coverage area per cell between the two groups (P>0.05). Immunofluorescence staining of cardiomyocyte markers showed that there was no significant difference in the coverage area of α-actinin and connexin-43 (Cx-43) per field between the hydrogel group and the control group (both P>0.05), the quantitative results of DAPI staining showed that there was no statistically significant difference in the number of cells between the two groups (P>0.05). Meanwhile, the results of Western blot showed that the expression levels of α-actinin and Cx-43 in cardiomyocytes in the hydrogel group were similar as those in the control group (both P>0.05). Conclusions: These results show that preparation of the ECM hydrogel from porcine omentum is successful. The hydrogel has good biocompatibility and no obvious cytotoxicity. Besides, the hydrogel can support the survival of hiPSC-CMs in vitro and maintain its phenotype. These properties make it a promising injectable cardiac tissue engineering material.

Targeting location relates to treatment response in active but not sham rTMS stimulation

Background:

Precise targeting of brain functional networks is believed critical for treatment efficacy of rTMS (repetitive pulse transcranial magnetic stimulation) in treatment resistant major depression.

Objective:

To use imaging data from a “failed” clinical trial of rTMS in Veterans to test whether treatment response was associated with rTMS coil location in active but not sham stimulation, and compare fMRI functional connectivity between those stimulation locations.

Methods:

An imaging substudy of 49 Veterans (mean age, 56 years; range, 27e78 years; 39 male) from a randomized, sham-controlled, double-blinded clinical trial of rTMS treatment, grouping participants by clinical response, followed by group comparisons of treatment locations identified by individualized fiducial markers on structural MRI and resting state fMRI derived networks.

Results:

The average stimulation location for responders versus nonresponders differed in the active but not in the sham condition (P = .02). The average responder location derived from the active condition showed significant negative functional connectivity with the subgenual cingulate (P < .001) while the nonresponder location did not (P = .17), a finding replicated in independent cohorts of 84 depressed and 35 neurotypical participants. The responder and nonresponder stimulation locations evoked different seed based networks (FDR corrected clusters, all P < .03), revealing additional brain regions related to rTMS treatment outcome.

Conclusion:

These results provide evidence from a randomized controlled trial that clinical response to rTMS is related to accuracy in targeting the region within DLPFC that is negatively correlated with subgenual cingulate. These results support the validity of a neuro-functionally informed rTMS therapy target in Veterans.

Elevated CISD2 expression predicts poor diagnosis and promotes invasion and migration of prostate cancer cells

OBJECTIVE

To explore roles of CDGSH iron-sulfur domain-containing protein 2 (CISD2) in the progression of prostate cancer (PCa) cells, and relationships between CISD2 expression and the prognosis and clinical pathological parameters in PCa patients.

PATIENTS AND METHODS

Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) analysis and Western blot analysis were used to detect the CISD2 expression in PCa tissues and cells. CISD2 siRNA was used to inhibit the CISD2 expression. Kaplan-Meier method and Log rank analysis were performed to determine survival analysis while Chi-square test was performed to analyze the association between CISD2 and clinicopathological parameters of PCa patients. Transwell assay and wound healing assay was conducted to examine the invasion and migration ability of PCa cells, respectively.

RESULTS

CISD2 was up-regulated in PCa tissues and cells, and showed positive association with the poor prognosis, T stage, lymphatic invasion, prostate-specific antigen (PSA) level, and distant metastasis of PCa patients. Besides, we found that inhibition of CISD2 significantly impaired the migration and invasion ability of PCa cells.

CONCLUSIONS

The paper demonstrated that CISD2 could act as a new target for the diagnosis and treatment of PCa patients.

[The pathological diagnosis and differential diagnosis of hematopoietic cell tumors of ambiguous lineage]

Objective: To explore the key points of the pathological and differential diagnoses of extra-medullary masses of hematopoietic cell tumors of ambiguous lineage, and to discuss the possible solutions. Methods: Five hematopoietic cell tumors of ambiguous lineage cases were collected, including myeloid sarcoma, mixed phenotype acute leukemia, B/myeloid, T-lymphoblastic lymphoma combined with acute myeloid leukemia, acute undifferentiated leukemia with cutaneous MPDCP and early T-precursor cell acute lymphoblastic leukemia. The data including morphology, immunostaining, and flow cytometry analysis were collected, and we explored the problems and differential diagnosis in the diagnosis of hematopoietic cell tumors of ambiguous lineage. Results: The five cases showed that the accurate pathological diagnosis and classification of hematopoietic cell tumors of ambiguous lineage should be based on lineage-specific antigens. Moreover, tumor cells have the potential of multi-directional differentiation. In different sites or different periods, the differentiation of tumor cells may be different. Biopsy and detection of all related markers should be performed for the initial diagnosis, and the detection should be repeated when the condition of the patient changes. Combined application of multi-techniques, including morphology and flow cytometry analysis, is recommend for the diagnosis of hematopoietic cell tumors of ambiguous lineage, since the conventional morphology and immunophenotyping methods are limited. Conclusion: Hematopoietic cell tumors of ambiguous lineage are derived from hematopoietic stem cells with a potential of multi-differentiation. The differentiation of tumor cells is variable. We need to integrate cell morphology, flow cytometry, pathology, clinical data, and molecular genetics to make a comprehensive diagnosis.

[Expert consensus on the treatment of oral and maxillofacial space infections]

Oral and maxillofacial space infections (OMSI) are common diseases of the facial region involving fascial spaces. Recently, OMSI shows trends of multi drug-resistance, severe symptoms, and increased mortality. OMSI treatment principles need to be updated to improve the cure rate. Based on the clinical experiences of Chinese experts and with the incorporation of international counterparts' expertise, the principles of preoperative checklist, interpretation of examination results, empirical medication principles, surgical treatment principles, postoperative drainage principles, prevention strategies of wisdom teeth pericoronitis-related OMSI, blood glucose management, physiotherapy principles, Ludwig's angina treatment and perioperative care were systematically summarized and an expert consensus on the diagnosis and treatment of OMSI was reached. The consensus aims to provide criteria for the diagnosis and treatment of OMSI in China so as to improve the level of OMSI treatment.

Sustainable Solar Evaporation while Salt Accumulation

Solar-driven water evaporation, as a cost-effective and eco-friendly way to produce high-quality freshwater from saline water, is a burgeoning and promising force in the battle against global thirst. However, unsustainable vapor generation caused by salt accumulation has always plagued researchers. Here, it is revealed that a solar thermal photo vapor generator (STPV), which utilizes infrared photons as a heat source, can evaporate water stably in the presence of salt accumulation. Thanks to the low reflection of the wet salt in the infrared band and the porous structure of the salt layer, the energy can be used effectively and the vapor escapes without hindrance. The STPV evaporates water at a stable rate of 1.04-1.19 kg m^-2 h^-1 under 2 sun illumination for 8 h in a highly concentrated sea salt solution (20 wt %). In contrast, the evaporation rate of conventional solar thermal vapor generators (STVs) decreased by >50% in 1 h and ≈70% in 8 h. This finding could inspire the future development of more advanced solar evaporators so as to ease the global water scarcity.

Human-driven spatiotemporal distribution of phosphorus flux in the environment of a mega river basin

Large river basins transport considerable nutrients to the ocean every year. However, phosphorus (P) generated by human activities not only threatens aquatic ecosystem health in the river basin, but also has a negative effect on the estuary water environment. To better understand the environmental effects of anthropogenic P in a mega basin, we examined its inputs and distribution characteristics, and analyzed the factors driving it in the Yangtze River Basin (YRB) and sub-catchments. Anthropogenic P flux in the sub-catchments gradually increased from upper to lower reaches, and hotspots were primarily concentrated in traditional agricultural areas such as the Sichuan Basin and the Middle-Lower Yangtze plains. Agricultural sources were the main anthropogenic P inputs, of which fertilizer P was the leading contributor and driver of P changes, but livestock manure also accounted for a high proportion. Presently, anthropogenic P inputs in the YRB are considerably higher than in other parts of the world. Although long-distance transportation allows some P from the entire basin to be deposited in freshwater, a large amount of P still reaches the estuary and has a negative effect on water quality, outweighing the influence of local coastal inputs. To maintain the ecological health of the river basin and estuary, it will be necessary to further improve P utilization efficiency and encourage greater cooperation between different regions in the river basin.

Low Concentrations of Silver Nanoparticles and Silver Ions Perturb the Antioxidant Defense System and Nitrogen Metabolism in N2-Fixing Cyanobacteria

Although toxic effects of silver nanoparticles (AgNPs) on aquatic organisms have been extensively reported, responses of nitrogen-fixing cyanobacteria to AgNPs/Ag⁺ under environmentally relevant concentrations are largely unknown. Here, cyanobacteria were exposed to different concentrations of AgNPs (0.01, 0.1, and 1 mg/L) or Ag⁺ (0.1, 1, and 10 μg/L) for 96 h. The impacts of AgNPs and Ag⁺ on photosynthesis and N₂ fixation in cyanobacteria (Nostoc sphaeroides) were evaluated. In addition, gas chromatography-mass spectrometry (GC-MS)-based metabolomics was employed to give an instantaneous snapshot of the physiological status of the cells under AgNP/Ag⁺ exposure. Exposure to high doses of AgNPs (1 mg/L) or Ag⁺ (10 μg/L) caused growth inhibition, reactive oxygen species overproduction, malondialdehyde accumulation, and decreased N₂ fixation. In contrast, low doses of AgNPs (0.01 and 0.1 mg/L) and Ag⁺ (0.1 and 1 μg/L) did not induce observable responses. However, metabolomics revealed that metabolic reprogramming occurred even at low concentrations of AgNP and Ag⁺ exposure. Levels of a number of antioxidant defense-related metabolites, especially phenolic acid and polyphenols (gallic acid, resveratrol, isochlorogenic acid, chlorogenic acid, cinnamic acid, 3-hydroxybenzoic acid, epicatechin, catechin, and ferulic acid), significantly decreased in response to AgNPs or Ag⁺. This indicates that AgNPs and Ag⁺ can disrupt the antioxidant defense system and disturb nitrogen metabolism even at low-dose exposure. Metabolomics was shown to be a powerful tool to detect "invisible" changes, not observable by typical phenotypic-based endpoints.

Radiomics-based machine-learning method for prediction of distant metastasis from soft-tissue sarcomas

AIM

To construct and validate a radiomics-based machine-learning method for preoperative prediction of distant metastasis (DM) from soft-tissue sarcoma.

MATERIALS AND METHODS

Seventy-seven soft-tissue sarcomas were divided into a training set (n=54) and a validation set (n=23). The performance of three feature selection methods (ReliefF, least absolute shrinkage and selection operator [LASSO], and regularised discriminative feature selection for unsupervised learning [UDFS]) and four classifiers, random forest (RF), logistic regression (LOG), K nearest neighbour (KNN), and support vector machines (SVMs), were compared for predicting the likelihood of DM. To counter the imbalance in the frequencies of DM, each machine-learning method was trained first without subsampling, then with the synthetic minority oversampling technique (SMOTE). The performance of the radiomics model was assessed using area under the receiver-operating characteristic curve (AUC) and accuracy (ACC) values.

RESULTS

The performance of the LASSO and SVM algorithm combination used with SMOTE was superior to that of the algorithm combination alone. The combination of SMOTE with feature screening by LASSO and SVM classifiers had an AUC of 0.9020 and ACC of 91.30% in the validation dataset.

CONCLUSION

A machine-learning model based on radiomics was favourable for predicting the likelihood of DM from soft-tissue sarcoma. This will help decide treatment strategies.

Toward High Precision XCO2 Retrievals From TanSat Observations: Retrieval Improvement and Validation Against TCCON Measurements

TanSat is the 1st Chinese carbon dioxide (CO2) measurement satellite, launched in 2016. In this study, the University of Leicester Full Physics (UoL-FP) algorithm is implemented for TanSat nadir mode XCO2 retrievals. We develop a spectrum correction method to reduce the retrieval errors by the online fitting of an 8th order Fourier series. The spectrum-correction model and its a priori parameters are developed by analyzing the solar calibration measurement. This correction provides a significant improvement to the O2 A band retrieval. Accordingly, we extend the previous TanSat single CO2 weak band retrieval to a combined O2 A and CO2 weak band retrieval. A Genetic Algorithm (GA) has been applied to determine the threshold values of post-screening filters. In total, 18.3% of the retrieved data is identified as high quality compared to the original measurements. The same quality control parameters have been used in a footprint independent multiple linear regression bias correction due to the strong correlation with the XCO2 retrieval error. Twenty sites of the Total Column Carbon Observing Network (TCCON) have been selected to validate our new approach for the TanSat XCO2 retrieval. We show that our new approach produces a significant improvement on the XCO2 retrieval accuracy and precision when compared to TCCON with an average bias and RMSE of -0.08 ppm and 1.47 ppm, respectively. The methods used in this study can help to improve the XCO2 retrieval from TanSat and subsequently the Level-2 data production, and hence will be applied in the TanSat operational XCO2 processing.

Foliar Application of SiO2 Nanoparticles Alters Soil Metabolite Profiles and Microbial Community Composition in the Pakchoi (Brassica chinensis L.) Rhizosphere Grown in Contaminated Mine Soil

Silica nanoparticles (SiO₂-NPs) are promising in nanoenabled agriculture due to their large surface area and biocompatible properties. Understanding the fundamental interaction between SiO₂-NPs and plants is important for their sustainable use. Here, 3 week-old pakchoi (Brassica chinensis L.) plants were sprayed with SiO₂-NPs every 3 days for 15 days (5 mg of SiO₂-NPs per plant), after which the phenotypes, biochemical properties, and molecular responses of the plants were evaluated. The changes in rhizosphere metabolites were characterized by gas chromatography-mass spectrometry (GC-MS)-based metabolomics, and the response of soil microorganisms to the SiO₂-NPs were characterized by high-throughput bacterial 16S rRNA and fungal internal transcribed spacer (ITS) gene sequencing. The results showed that the SiO₂-NP spray had no adverse effects on photosynthesis of pakchoi plants nor on their biomass. However, the rhizosphere metabolite profile was remarkably altered upon foliar exposure to SiO₂-NPs. Significant increases in the relative abundance of several metabolites, including sugars and sugar alcohols (1.3-9.3-fold), fatty acids (1.5-18.0-fold), and small organic acids (1.5-66.9-fold), and significant decreases in the amino acid levels (60-100%) indicated the altered carbon and nitrogen pool in the rhizosphere. Although the community structure was unchanged, several bacterial (Rhodobacteraceae and Paenibacillus) and fungal (Chaetomium) genera in the rhizosphere involved in carbon and nitrogen cycles were increased. Our results provide novel insights into the environmental effects of SiO₂-NPs and point out that foliar application of NPs can alter the soil metabolite profile.

LncRNA TP73-AS1 promotes malignant progression of hepatoma by regulating microRNA-103

OBJECTIVE

The aim of this study was to investigate long non-coding RNA (lncRNA) TP73-AS1 expression in hepatocellular carcinoma (HCC) tissues and cells, and to further investigate whether it can accelerate the progression of HCC by regulating microRNA-103.

PATIENTS AND METHODS

Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was performed to examine TP73-AS1 expression in 60 pairs of HCC tissues and adjacent ones, and the association between lncRNATP73-AS1 level and clinical indicators of HCC as well as patients' prognosis was analyzed. Meanwhile, qRT-PCR was used to further verify TP73-AS1 expression in HCC cell lines. The lncRNA TP73-AS1 knockdown model was constructed using lentivirus in the HCC cell lines, including Bel-7402 and HepG2. Cell counting kit-8 (CCK-8), 5-Ethynyl-2'-deoxyuridine (EdU), and flow cytometry assays were performed to figure out the influence of TP73-AS1 on the basic biological function of the HCC cells. Finally, the involved potential regulatory mechanism was explored using cell recovery experiments, and the relationship between TP73-AS1 and microRNA-103 was further studied.

RESULTS

QRT-PCR results indicated that TP73-AS1 expression in HCC samples was conspicuously enhanced compared with paracancerous tissues, and patients with a relatively high level of TP73-AS1 had a higher tumor stage and a lower overall survival rate. Meanwhile, the proliferation ability of cells in the sh-TP73-AS1 group was strikingly lower than that in the control group, while cell apoptosis showed the opposite trend. Besides, qRT-PCR results indicated a negative correlation between microRNA-103 and TP73-AS1 in HCC tissue specimens. The results of the luciferase reporting assay revealed that TP73-AS1 could be targeted by microRNA-103 through binding site. In addition, the cell recovery experiment demonstrated that TP73-AS1 and microRNA-103 might have a mutual regulation, and the two of which could together affect the malignant progression of HCC.

CONCLUSIONS

TP73-AS1 expression was conspicuously enhanced both in HCC tissues and cell lines, which were associated with advanced tumor stage and poor prognosis. In addition, TP73-AS1 could accelerate the proliferation of HCC cells by regulating microRNA-103.

[The surgical treatment of male perineum Paget's disease]

Objective: To evaluatethe clinical efficacy and complications of skin graft and flap plastic technique covered the defect in perineal Paget's disease postoperatively. Methods: The study comprised 6 patients diagnosed with perineal Paget's disease at Beijing Chao-Yang Hospital from June 2017 to July 2019, with all available clinical data reviewed. The defects after resection of lesions were reconstructed with skin graft, advancement skin flap during the operation, respectively. The operation time, the skin graft or flap survival situation, intraoperative and postoperative complications were recorded. Results: Of all 6 patients, Ray stage A1consisted of 1 case, A2 5 cases. The age was (68±9) years, the hospitalization time was (14.8±8.1) days, the BMI was (25.6±3.7) kg/m(2), the operation time was (132.0±80.7) min, and the average blood loss was (18.3±11.7) ml. Five cases was with Paget's disease, and 1 case with skin adenocarcinoma with Paget's disease were diagnosed by pathology. The defects of 4 cases and 2 cases after removal of the tumor were reconstructed with scrotal advancement skin flap and skin graft, respectively. The skin graft and flap survived well during afollow-up of (15.3±8.1) months.There has been no local recurrence. The foreskin edema and wound infection were noted in 4 cases and 1 case, respectively. There was no other related complications. Conclusion: Perineal Paget's disease can be managed by resection and immediate reconstruction with skin graft or flap according to the size and location of the defect, and the clinical efficacy is distinct.

[Clinical study of exploring new axillary zone in sentinel lymph node biopsy of breast cancer]

Objective: To explore the application of axillary reverse mapping (ARM) in breast cancer sentinel lymph node biopsy (SLNB), and to collect and record patient's data during operation. Through the specific experimental data, the anatomical location and morphology of the intercostal brachial nerve (ICBN) and the anatomic relationship of the axillary lymph nodes were analyzed to accurately locate the anatomical division of the axillary fossa of sentinel lymph node (SLN) and ARM lymph nodes. Methods: The technique of methylene blue staining for SLN combined with indocyanine green fluorescent staining for axillary reverse mapping was used to analyze the patients of Tianjin Central Hospital of Gynecology Obstetrics from June 2017 to June 2018. The clinical data of 35 patients with T1-2N0M0 breast cancer were analyzed. Results: Of the 35 patients, two cases were excluded from metastatic carcinoma of the SLN. Thirty-three cases were included in the data analysis. Three cases of ICBN were located 0-2.0 cm (9.09%) from the lower edge of the iliac vein, 27 cases were located at 2.0-4.0 cm (81.82%), and 3 cases of ICBN were located greater than 4.0 cm (9.09%). In the region of 0-2.0 cm from the lower edge of the iliac vein, 1-2 ARM lymph nodes were found in 5 cases; in the 2.0-4.0 cm area, SLN was found in 33 cases, 4 of which found 1 coincident lymph node; at>4.0 cm ARM lymph nodes and overlapping lymph nodes were not found in the cm region, and 1-2 SLNs were found in 3 cases. Conclusions: Individual ICBNs vary greatly, with different shapes and distances from the lower edge of the axillary vein. The axillary region below the iliac vein can be divided into three regions: ARM region (0-2.0 cm); SLN region (2.0-4.0 cm); and sentinel gate region (>4.0 cm). The position 2.0 cm from the lower edge of the iliac vein can be used as the boundary between the ARM lymph node and the SLN. 4. There is a certain proportion of coincidence rate between SLN and ARM lymph nodes.

[Molecular epidemiological characteristics of methicillin-resistant Staphylococcus aureus during 2017-2018 at a hospital in Shanghai]

Objective: To identify the epidemic clones of MRSA isolates at a hospital in shanghai. Methods: A total of 72 MRSA isolates have been isolated from a second grade hospital between 2017 and 2018, including 32 CA-MRSA isolates, 13 HA-MRSA isolates and 26 MRSA isolates from environment. In this study, MLST and PFGE typing methods were used to analyze the molecular epidemiology of the MRSA isolates. Results: A total of 72 MRSA isolates have been obtained including 46 isolates from clinical specimens, 26 isolates from environments. The 46 MRSA isolates from clinical specimens consisted of 33 CA-MRSA (community-acquired MRSA) and 13 HA-MRSA (hospital-acquired MRSA). Furthermore, these patients infected with MRSA isolates were mostly distributed in the department of geriatrics (34.8%, 16/46), internal medicine (26.1%, 12/46) and surgery (26.1%, 12/46). MLST typing results showed that ST764 was predominant in isolates from both clinical specimens and hospital environments. Furthermore, PFGE typing results showed that most ST764 MRSA had high homolog (>90%). Conclusion: ST764 MRSA isolates might spread in community, hospital and environments. Therefore, continuous monitoring of MRSA and its variation may be useful in understanding the involvement of epidemic clone, and in searching new strategies to control MRSA infection.

[A clinical analysis of 46 cases of neurotrophic keratitis]

Objective: To investigate the clinical characteristics and therapeutic effect of neurotrophic keratitis (NK). Methods: A retrospective case series study. A total of 46 patients (48 eyes) with clinically diagnosed NK in Beijing Tongren Hospital from May 2013 to July 2016 were analyzed, including 26 males (26 eyes) and 20 females (22 eyes), aged (51±18) years. The general condition, etiology, clinical features, stage of disease and curative effect of NK patients were summarized. Corneal sensation was measured by Cochet-Bonnet corneal sensor for 25 patients (26 eyes), and the correlation between corneal sensation and clinical staging was analyzed. The χ(2) test was performed on the distribution characteristics of patients with different clinical stages of NK. Correlation analysis of corneal sensation and the disease stage was performed using Spearman correlation analysis. Results: Forty-four cases of monocular disease (96.65%) and 2 cases (4.35%) of bilateral disease were enrolled. Four eyes (8.33%) were from young patients (aged 18-29 years), 23 (47.92%) were from middle-aged patients (aged 30-59 years), and 21 (43.75%) were from elderly patients (aged ≥60 years). The disease was at stage Ⅰ in 8 eyes (16.67%), at stage Ⅱ in 21 eyes (43.75%), and stage Ⅲ in 19 eyes (39.58%). There was no significant difference in clinical staging between the three age groups (χ(2)=2.452, P=0.658). The most common cause of NK was virus infection (17 eyes,35.42%), followed by neurosurgical sequelae (11 eyes, 22.92%) and diabetes in 10 eyes(20.83%). Corneal sensation of 26 eyes ranged from 0-3 cm. There was no significant correlation between clinical stage and corneal sensation (r(2)=0.284, P=0.753). The patients were followed up for an average of 7 months. Thirty-four eyes (70.83%) received conservative treatment, and 8 eyes(16.67%) had surgery. Six patients (6 eyes) were lost for follow-up. Conclusions: NK can occur in all ages, mainly in the elderly. The clinical manifestations are diverse. If time delays in the diagnosis and treatment, it often causes corneal ulcers. There is no significant correlation between corneal sensation and clinical stage. Early diagnosis and targeted treatment are important for protecting patients' visual function.(Chin J Ophthalmol, 2020, 56:274-298).

Seasonal and long-term trends of sulfate, nitrate, and ammonium in PM2.5 in Beijing: implication for air pollution control

Particulate matter pollution in Beijing is a serious environmental problem. In response to this, the Beijing government has implemented comprehensive emission reduction measures in recent years. To assess the effectiveness of these measures, the seasonal and long-term trends in chemical compositions of PM_2.5 in Beijing have been studied based on daily samples collected from July 2015 to April 2016 and literature investigation (2000-2014). Results show that the concentrations of sulfate, nitrate, and ammonium in PM_2.5 have significant seasonal variations, which are related to the changes in meteorological conditions and emission intensities. In addition, the long-term data display that the concentrations of sulfate, nitrate, and ammonium have significantly decreased between 2013 and 2016, which are consistent with the reduction in PM_2.5 levels (~ 11.2 μg/m³ per year). The declines could not be interpreted by the meteorological factors. It suggests that the air pollution control measures in Beijing (2013-2016), especially the decreasing consumption of coal, can effectively decrease the mass concentration of fine particles. To further improve the air quality, similar measures should be adopted in the areas around Beijing. These air pollution control measures taken in Beijing can provide invaluable guidance for mega-cities in China and other developing countries to decrease their PM_2.5 concentration and reduce health risk from particulate pollution.