[The effect of anti-VEGF therapy on the expression levels of TGF-β and related microRNAs in the vitreous of patients with proliferative diabetic retinopathy]

Objective: To investigate the effect of anti-vascular endothelial growth factor (VEGF) therapy on the expression levels of transforming growth factor-beta (TGF-β) and its related microRNAs in the vitreous of patients with proliferative diabetic retinopathy (PDR). Methods: This cross-sectional study included 67 patients (67 eyes), 38 males and 29 females, aged (54.37±11.70) years, who underwent vitrectomy from June 2020 to February 2021. There were 45 PDR patients (45 eyes), including 29 patients (29 eyes) without anti-VEGF therapy in the disease group and 16 patients (16 eyes) who were admitted at 7 days after anti-VEGF therapy in the treatment group. The other 22 idiopathic macular hole patients (22 eyes) were in the negative control group. The microRNA (hsa-miR-24-3p and hsa-miR-197-3p) levels in the vitreous of 36 patients (12 cases randomly chosen from each group) were detected by quantitative reverse transcription polymerase chain reaction. The levels of TGF-β and VEGF-A in the vitreous of 67 patients were detected by enzyme-linked immunosorbent assay. Target gene prediction of hsa-miR-24-3p and hsa-miR-197-3p was performed on RNAhybrid, miRanda and TargetScan7.2 databases, and pathway enrichment analyses were conducted for all target mRNAs. One-way ANOVA was used to compare the levels of growth factors and microRNAs among the three groups, and the least significant difference method was used for multiple comparisons between groups. Pearson correlation test was used to analyze the correlation between growth factors and microRNAs. Results: The expression levels of VEGF-A, TGF-β, hsa-miR-24-3p and hsa-miR-197-3p were (158.15±17.72) pg/ml, (640.47±24.80) pg/ml, 0.81±0.11 and 1.07±0.15 in the control group, (1 047.54±26.61) pg/ml, (3 553.17±92.61) pg/ml, 8.50±2.33 and 12.23±3.38 in the disease group, and (778.10±27.73) pg/ml, (3 376.02±78.83) pg/ml, 4.54±0.67 and 3.90±0.65 in the treatment group, respectively. All indicators were significantly higher in the disease group than those in the control group (F=355.581, 440.538, 7.546 and 7.546; all P<0.05). The expression levels of VEGF-A, hsa-miR-24-3p and hsa-miR-197-3p in the treatment group were significantly lower than those in the disease group (all P<0.05). The concentration of TGF-β was not statistically significantly lower in the treatment group compared to the disease group. The concentrations of VEGF-A and TGF-β were significantly positively correlated with the expression levels of hsa-miR-24-3p and hsa-miR-197-3p in the vitreous of randomly chosen 36 patients (r=0.48, 0.51, 0.40 and 0.42; all P<0.05). Pathway enrichment analysis showed that some target mRNAs of hsa-miR-24-3p and hsa-miR-197-3p were involved in VEGF and TGF-β signal pathways. Conclusions: In the vitreous of patients with PDR, hsa-miR-24-3p and hsa-miR-197-3p were positively related to VEGF-A and TGF-β, and may be potential risk factors. Anti-VEGF treatment can significantly reduce the expression level of TGF-β-related microRNAs, namely hsa-miR-24-3p and hsa-miR-197-3p, but cannot effectively reduce the concentration of TGF-β, suggesting that combined anti-TGF treatment may be beneficial for delaying the progression of PDR. Furthermore, it may be a new research direction of PDR to validate the target mRNAs of hsa-miR-24-3p and hsa-miR-197-3p involved in VEGF and TGF-β signal pathways. (Chin J Ophthalmol, 2021, 57: 922-929).

[A summary of 70 years' progress of uveitis subspecialty in China]

Uveitis is one of the most common causes of blindness worldwide. Clinical and basic studies on uveitis began in the 1980s in China. With the efforts of several generations, great progress has been made in the last 30 years with a global reputation. However, there are still challenges concerning the prevention and treatment of uveitis as well as the elucidation of the mechanisms underlying this disease. Therefore, we should continuously push the uveitis subspecialty in China to a new level. The achievements obtained in the uveitis studies during the past decades are offered as a gift to the 70th anniversary of the Chinese Journal of Ophthalmology. (Chin J Ophthalmol, 2020, 56:881-890).

Mapping the near-field spin angular momenta in the structured surface plasmon polariton field

Optical spin angular momenta in a confined electromagnetic field exhibit a remarkable difference with their free space counterparts; in particular, the optical transverse spin that is locked with the energy propagating direction lays the foundation for many intriguing physical effects such as unidirectional transportation, quantum spin Hall effects, photonic Skyrmions, etc. In order to investigate the underlying physics behind the spin-orbit interactions as well as to develop the optical spin-based applications, it is crucial to uncover the spin texture in a confined field, yet it faces challenges due to their chiral and near-field vectorial features. Here, we propose a scanning imaging technique which can map the near-field distributions of the optical spin angular momenta with an achiral dielectric nanosphere. The spin angular momentum component normal to the interface can be uncovered experimentally by employing the proposed scanning imaging technique and the three-dimensional spin vector can be reconstructed theoretically with the experimental results. The experiment is demonstrated on the example of surface plasmon polaritons excited with various vector vortex beams under a tight-focusing configuration, where the spin-orbit interaction emerges clearly. The proposed method, which can be utilized to reconstruct the photonic Skyrmion and other photonic topological structures, is straightforward and of high precision, and hence it is expected to be valuable for the study of near-field spin optics and topological photonics.

[Preliminary application value of ultrasound contrast agent with enteral nutritional suspension as mixed medium in locating indwelling nasointestinal tube in critically ill patients]

Objective: To evaluate the value of ultrasound contrast agent with enteral nutrition suspension as mixed medium in locating indwelling nasointestinal tube in critically ill patients. Methods: Total of 45 critically ill patients had nasointestinal tube indwelled were collected from June 1,2018 to April 1,2019 in the Intensive Care Unit of Zhejiang Provincial People's Hospital, including 30 males and 15 females, with an average age of (63±17) years.Enteral nutritional suspension Peptisorb Liquid was used as research medium,with the ultrasonic imaging performance of it confirmed by in vitro and in vivo experiments.The optimal mixing ratio of microbubble ultrasound contrast agent and Peptisorb Liquid was confirmed by in vitro experiment, then the mixture was quietly placed and its stability was dynamically observed. The nasointestinal tube was confirmed in the digestive tract by conventional ultrasound and then the ultrasound contrast mode turned on. Ultrasound contrast agent with Peptisorb Liquid as mixed medium was injected into the nasointestinal tube and the tube direction and end position were observed and recorded in real time. Abdominal X-ray examination or CT was used as the gold standard for verifying the location of the nasointestinal tube and the same result represented successful positioning. Results: The in vitro and in vivo experiments showed that Peptisorb Liquid had good ultrasound imaging uniformity and penetrating power, which could clearly show the range and boundary of the filling intestine cavity; the in vitro experiment showed that the ultrasound contrast agent prepared with the microbubble ultrasound contrast agent and Peptisorb Liquid by the ratio of 1∶1 000 and 1∶500 which had the best imaging effect and the best distribution uniformity, with the best stability within 10 minutes after quietly placed. Nasointestinal tubes were successfully located by using ultrasound contrast agent with enteral nutritional suspension as mixed medium in 95.6%(43/45) of the patients collected in this study,including success at one attempt in 39 cases, the operating time was (1.6±0.5) minutes and 4 cases were successfully located after multiple operations with (5.1±0.5) minutes, the tube bent in the stomach in one case and flexed back into the stomach from the descending duodenum in another. The operation failed in 2 cases (4.4%). No significant complications occurred during the examination. Conclusion: The ultrasound contrast agent with enteral nutritional suspension as mixed medium has the advantages of both, which can conveniently, safely and effectively locate the direction and end position of nasointestinal tube in critically ill patients.

Optical transverse spin coupling through a plasmonic nanoparticle for particle-identification and field-mapping

Electromagnetic fields at near-field exhibit distinctive properties with respect to their free-space counterparts. In particular, an optical transverse spin appearing in a confined electromagnetic field provides the foundation for many intriguing physical effects and applications. We present a transverse spin coupling configuration where plasmonic nanoparticles are employed to couple the transverse spin in a focused beam to that of a surface plasmon polariton. The plasmonic resonance of nanoparticles on a metal film plays a significant role in transverse spin coupling. We demonstrate in experiments that Ag and Au nanoparticles yield distinct imaging patterns when scanned over a focused field, because of their different plasmonic responses to the transverse and longitudinal electric fields. Such resonance-dependent spin-coupling enables the identification of nanoparticles using a focused field, as well as electric field mapping of a specific field component of a focused beam using a plasmonic nanoparticle. These interesting findings regarding the transverse spin coupling with a plasmonic nanoparticle may find valuable applications in near-field and nano-optics.

The first inhibitor-based fluorescent imaging probe for aminopeptidase N

Höltke and his co-workers firstly reported the synthesis and characterization of an inhibitor-based fluorescent imaging probe for aminopeptidase N. This fluorescent probe demonstrated high binding affinity to APN and could specifically bind to APN high expressed cells, thus revealed the distribution of APN. As a milestone, this outstanding work provided a useful tool to understand APN pathophysiology.

[Px gene of rice-field eels primed in situ labeling]

Peroxidase (Px) gene of rice-field eels (Monopterus albus) was successfully localized to the segments of two bivalents, 8q15-q26 and 11q32-q37 with digoxigenin labeled primed in situ labeling (PRINS) technique, which is utilized for localization of single copy gene of fish for the first time. Our results demonstrated the possibility of mapping genes in fish by the DNA probes of other species and PRINS technique.