Effects of blue light on the development of the dioptric system in guinea pigs / 眼科新进展

Objective To investigate the effect of blue light on the dioptric development of the eyes of lens-induced myopia(LIM)guinea pigs.Methods Three-week-old trichromatic guinea pigs were randomly divided into three groups:control group,white light LIM(WL)group,and blue light LIM(BL)group(420 nm LED light,with an illuminance of 700 lx);guinea pigs in the latter two groups wore-10.00 D lenses in their right eyes to induce myopia.All guinea pigs under-went a 12 h light/12 h dark treatment cycle.Before and 2,4 weeks after the intervention,the diopter,axial length,retinal thickness and choroidal thickness were measured in all groups.After 4 weeks of intervention,the corneal fluorescent stai-ning and retinal Hematoxylin and Eosin(HE)staining were conducted.Results Compared with the control group,from week 0 to week 2 of the intervention(changes in weeks 0-2),the eyes in the WL group drifted(-2.22±1.28)D towards myopia,the axial length lengthened by(0.40±0.05)mm,and the retinal and choroidal thicknesses reduced by(-7.42± 7.04)μm and(-6.29±4.66)μm,respectively;compared with the WL group,in the BL group,the eyes drifted toward hyperopia by(0.48±1.16)D,the axial length increased by(0.20±0.10)mm,and retinal and choroidal thicknesses in-creased by(1.36±7.46)μm and(8.05±8.08)μm,respectively(all P＜0.05).From week 2 to week 4(changes in weeks 2-4),compared with the control group,the diopter in the WL and BL groups progressed towards myopia,with changes of(-4.64±0.50)D and(-2.11±2.02)D,respectively(both P＜0.05);the axial length lengthened,and reti-nal and choroidal thicknesses reduced in the WL group,with changes of(0.44±0.06)mm,(-7.35±5.87)μm and(-4.84±2.61)μm,while the choroidal thickness and the retinal thickness decreased in the BL group,with changes of(-0.33±5.95)μm and(-4.78±4.96)μm,respectively.Observations of corneal fluorescence staining and retinal HE staining indicated that prolonged blue light exposure could lead to damage to corneal and retinal cells.Conclusion Blue light may influence the development of myopia through choroid-related mechanisms,but its inhibitory effect is not positive-ly correlated with time.Prolonged exposure to blue light can damage the cornea and retina,thereby reducing the inhibitory effect.

Preventive and therapeutic effects of compound wild chrysanthemum eye pad on blue light-induced alteration of meibomian gland function in mice and its mechanism / 中华实验眼科杂志

Objective:To investigate the preventive and therapeutic effects of compound wild chrysanthemum eye pad on blue light-induced alteration of meibomian gland function in mice and its mechanism.Methods:Sixty-four 15-week-old male C57BL/6J mice were divided into two groups of 32 mice each according to random numbers for the prevention test and the treatment test.The respective 32 mice in the prevention and treatment experiments were randomly divided into normal group, blue light group, solvent group and eye pad group according to random numbers, with eight mice in each group, respectively.In the prevention experiments, mice in each group were exposed to blue light at a wavelength of 460 nm and a light intensity of 2 000 lx for 6 hours per day for 15 consecutive days to establish a mouse model of meibomian gland function changes except for the normal group.The solvent group and the eye pad group were treated with the corresponding eye pad before and after the blue light exposure for 25 minutes daily for the 15 consecutive days.The blue light group was treated with blue light exposure only for 15 days, and the mice were photographed at the edge of the meibomian gland on day 15 to observe the function of the meibomian gland except for the normal group.In the treatment test, all groups of mice except the normal group were induced the altered function of the mouse meibomian gland by the above method.The solvent and eye pad groups were treated with corresponding eye pads for 25 minutes in the morning and afternoon of each day for 15 consecutive days after blue light exposure.The blue light group was kept in a standard environment for 15 days and the changes in meibomian gland function of mice were detected by meibomian gland photographs on day 15.Photography of the eyelid margin in vitro, oil red O staining, and hematoxylin-eosin staining were performed to observe the histologic changes in the meibomian glands of mice after the preventive and experimental treatment.The relative expression of interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ) mRNA in mouse meibomian gland tissues was detected by real-time fluorescence quantitative PCR.The expression of nuclear factor-κB (NF-κB) and phosphorylation of NF-κB (p-NF-κB) proteins in mice meibomian gland tissues was detected by Western blot to assess the degree of amelioration of blue light-induced inflammation in mouse meibomian glands by the compound wild chrysanthemum eye pad.This study was conducted in accordance with the Statement of the Association for Research in Vision and Ophthalmology on the Use of Animals in Ophthalmology and Vision Research, and was approved by the Animal Ethics Committee of Xiamen University (No.XMULAC20220258). Results:Compared with the normal group, a gradually increased number of blocked meibomian gland openings, and a gradually decreased remaining area of lower meibomian gland, were observed in the mice after 15 days of blue light group, and all the differences were statistically different (all at P<0.05). In the prevention test, the number of obstructed opening in the eye pad group was 1.833±0.753, which was significantly less than 3.667±1.033 in the solvent group ( P<0.05). The relative remaining area of the lower lid meibomian gland in the eye pad group was 0.718±0.091, which was significantly greater than 0.624±0.130 in the solvent group ( P<0.05). Hematoxylin-eosin staining showed inflammatory cell infiltration in mouse meibomian gland in the blue light and solvent groups.There was no inflammatory cell infiltration in eye pad group, and the morphology of the acini was similar to that of the normal group.Oil red O staining showed that there was no significant lipid deposition in the groups.The relative expressions of IL-1β, IL-6, TNF-α, and IFN-γ mRNA were significantly lower, and the relative expressions of NF-κB and p-NF-κB proteins were significantly lower in the eye pad group than in the solvent group, showing statistically significant differences (all at P<0.05). In the treatment test, the number of obstructed openings in the eye pad group and solvent group was 4.333±1.211 and 4.833±1.722, respectively, and the relative remaining area of the lower meibomian gland was 0.572±0.151 and 0.588±0.154, respectively, showing no statistically significant differences (both at P>0.05). Hematoxylin-eosin staining showed inflammatory cell infiltration in mouse meibomian glands in the blue light and solvent groups, with a similar morphology of acini as in the normal group.There was no inflammatory cell infiltration in eye pad group.Oil red O staining showed that there was no significant lipid deposition in the groups.The relative expressions of IL-1β, IL-6, and IFN-γ mRNA were significantly lower and the relative expressions of NF-κB and p-NF-κB proteins were significantly lower in the eye pad group than in the solvent group (all at P<0.05). Conclusions:Compound wild chrysanthemum eye pad may have preventive and therapeutic effects on blue light-induced changes in meibomian gland function by reducing the inflammatory response of meibomian gland tissue through the inhibition of the NF-κB signaling pathway.

Prevention and treatment of lipoic acid-niacin on blue-light-induced retinal damage in rats / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the preventive effect and optimal drug dose of lipoic acid-niacin(N2L)against blue light-induced retinal damage in SD rats, and to explore its possible protective mechanism.METHODS: A total of 36 specific pathogen free-grade male SD rats of 150-200 g were selected and randomly divided into normal control group, blue light injury group, N2L low-dose group(1.0 mg/kg), N2L medium-dose group(2.5 mg/kg), N2L high-dose group(5.0 mg/kg), and physiological saline group, with 6 rats in each group. The normal control group was reared in a 12 h dark and light cycle, and the rest of the groups received 9 h of daily light exposure, 3 h of blue light irradiation with a wavelength of 455 nm and an intensity of 3000±50 lx, and 12 h of darkness to establish the injury model, and were exposed to light exposure for 14 d. For 14 consecutive durations, a 1 mL dose of the corresponding drug was injected intraperitoneally. The rats were reared for another 5 d with a regular 12 h light-dark cycle and were examined by electroretinography. Specimens were prepared by over anesthesia, HE staining, and the thickness of the outer nuclear layer was observed under a optical microscope; superoxide dismutases(SOD)activity was detected by CheKineTM SOD Activity Assay Kit; and the retinal Caspase-3, quinone oxidoreductase 1(NQO1), glutathione S transferase(GST), Bcl-2, and Bax protein expression in rat retina were detected by Western blot.RESULTS: The amplitude of b-wave in dark-vision ERG 3.0 and 10.0(cd·s)/m2 stimulated light, b-wave in bright-vision ERG 3.0(cd·s)/m2 stimulated light, and the amplitude of the 2nd wave peak of oscillatory potential were significantly lower in blue light injury group than that in the normal control group(all P&#x0026;#x003C;0.01), while the amplitude was significantly higher in the N2L medium-dose group than in the blue light injury group(all P&#x0026;#x003C;0.05), and was not statistically different from that of the normal control group; the thickness of the retina in the blue light injury group was decreased in the ONL compared with that of the normal control group(P&#x0026;#x003C;0.001), while in the N2L medium dose group, it was thicker than that of the blue light injury group(P&#x0026;#x003C;0.001), and there was no statistically significant difference from the normal control group; SOD activity was significantly higher in the N2L medium-dose group than in the remaining 5 groups(P&#x0026;#x003C;0.05); the expression of Caspase-3, Bax, and NQO1 in the blue light injury group was higher than that of the normal control group(all P&#x0026;#x003C;0.01), and expression of Bax and Caspase-3 was significantly lower in the N2L medium-dose group compared with the blue light injury group(all P&#x0026;#x003C;0.001), whereas GST, NQO1 and Bcl-2 were significantly increased(all P&#x0026;#x003C;0.01).CONCLUSION:A concentration of 2.5 mg/kg N2L can effectively antagonize the damaging effect of blue light on the retina of SD rats, and it is expected to be a preventive and curative drug for it.

Effect of Negative-pressure Wound Therapy with Irrigation Combined with Red and Blue Light on Diabetic Foot Wounds / 医学研究杂志

Objective To evaluate the effect of negative-pressure wound therapy with irrigation(NPWTi)combined with red and blue light on diabetic foot wounds.Methods According to random number method,a total of 80 patients with type 2diabetes combined with diabetic foot admitted to Xuzhou Central Hospital from December 2021 to May 2022 were selected and divided into two groups:con-trol group and NPWTi + red and blue light group,with 40 cases in each group.All patients received basic treatment,while the control group received NPWTi treatment,NPWTi + red and blue light group was treated with red and blue light on the basis of NPWTi.The chan-ges of wound healing speed rate,serum inflammatory markers[erythrocyte sedimentation rate(ESR),C-reactive protein(CRP),pro-calcitonin(PCT)]and growth factors[vascular endothelial growth factor(VEGF),epidermal growth factor(EGF),basic fibroblast growth factor(bFGF)]were observed before and 7days after treatment.After 12 weeks of follow-up,the wound healing rate of the two groups were observed,and the cumulative wound healing rate of the two groups was evaluated through Kaplan-Meier curve.Results Af-ter 7days of treatment,the wound healing rate of NPWTi + red and blue light group was faster than that of the control group(P<0.01).The average levels of VEGF,EGF and bFGF in NPWTi + red blue light group were higher than those in the control group(P<0.05),while the average levels of ESR,CRP and,PCT in NPWTi + red and blue light group were lower than those in the control group(P<0.05).The wound healing rate of NPWTi + red and blue light group at 12 weeks was higher than that of the control group(P<0.05).Kaplan-Meier curve analysis showed that the cumulative wound healing rate of NPWTi + red and blue light group was higher than that of the control group(P<0.05).Conclusion NPWTi combined with red and blue light is effective in treating diabetic foot wounds,and it is worthy of clinical application.

Effect of blue light on the biological activity of human skin keratinocytes, fibroblasts and melanocytes: a preliminary study / 中华皮肤科杂志

Objective:To preliminarily investigate the effect of blue light on the biological activity of human skin keratinocytes, fibroblasts and melanocytes.Methods:Discarded foreskin tissues were collected from 10 healthy children aged from 3 to 12 years after circumcision surgery in the First Affiliated Hospital of Kunming Medical University from June 2021 to December 2021. After epidermis-dermis separation, selective culture was performed to isolate keratinocytes, fibroblasts, and melanocytes. According to the pre-experiment results, the above three types of cells were irradiated with 440 - 450 nm blue light at doses of 0, 5, 10, 20, 30, and 40 J/cm 2, and then continued to be cultured for 0, 6, 24, and 48 hours. Cell counting kit 8 (CCK8) assay was performed to evaluate cellular proliferative activity at each time point, enzyme-linked immunosorbent assay (ELISA) to detect levels of interleukin (IL) -18, IL-33, nerve growth factor (NGF), and granulocyte-macrophage colony-stimulating factor (GM-CSF) secreted by keratinocytes, as well as levels of IL-33 and keratinocyte growth factor (KGF) secreted by fibroblasts, NaOH lysis method to determine melanin synthesis rates in melanocytes, and Western blot analysis to determine the relative expression of tyrosinase (TYR), tyrosine-related protease 1 (TRP-1) and dopachrome isomerase (DCT) in melanocytes. Two-way analysis of variance was used to analyze group effects, time effects and interaction effects. Results:After irradiation with blue light, the cellular proliferative activity significantly differed among different doses of blue light irradiation groups and different time points in keratinocytes ( Ftime = 516.20, Fdose = 421.20, Finteraction = 25.05, all P < 0.003), fibroblasts ( Ftime = 129.30, Fdose = 477.80, Finteraction = 10.91, all P < 0.003), and melanocytes ( Ftime = 77.61, Fdose = 138.70, Finteraction = 3.50, all P < 0.003) ; immediately after irradiation, the proliferative activity of keratinocytes and fibroblasts was significantly lower in the 20 - 40 J/cm 2 blue light group than in the 0 J/cm 2 blue light group (all P < 0.003), and the proliferative activity of melanocytes was significantly higher in the 5 J/cm 2 blue light group than in the 0 J/cm 2 blue light group ( P < 0.003) ; the proliferative activity of the 3 types of cells showed decreasing trends with the increase of blue light irradiation doses and culture time. ELISA showed that the concentrations of IL-18, IL-33, NGF, and GM-CSF secreted by keratinocytes, as well as the concentrations of IL-33 and KGF secreted by fibroblasts, tended to increase with the increase of blue light irradiation doses and culture time. The melanin synthesis rates in melanocytes significantly differed among different doses of blue light irradiation groups and different time points ( Ftime = 833.50, Fdose = 249.40, Finteraction = 81.38, all P < 0.003) ; during 0 - 24 hours after blue light irradiation, the melanin synthesis rates tended to increase with the increase of blue light irradiation doses and time; during 24 - 48 hours, the melanin synthesis rates showed decreasing trends with the increase of blue light irradiation doses and culture time compared with that at 24 hours after irradiation; 24 hours after irradiation, the melanin synthesis rates were significantly higher in the 5, 10, 20, 30 and 40 J/cm 2 blue light groups (159.50% ± 10.88%, 218.76% ± 8.49%, 333.72% ± 7.72%, 393.29% ± 6.00%, 427.21% ± 8.39%, respectively) than in the 0 J/cm 2 blue light group (102.29% ± 6.57%, all P < 0.003). The relative expression of TYR ( Ftime = 67.94, Fdose = 28.99, Finteraction = 3.71, all P < 0.003), TRP-1 ( Ftime = 21.73, Fdose = 8.38, both P < 0.003) and DCT ( Ftime = 34.51, Fdose = 11.79, both P < 0.003) in melanocytes significantly differed among different doses of blue light irradiation groups and different time points, and tended to increase with the increase of blue light irradiation doses and culture time. Conclusion:Blue light irradiation at doses of 5 - 40 J/cm 2 could inhibit the proliferative activity of human skin keratinocytes, fibroblasts, and melanocytes, and the inhibitory effect tended to increase with the increase of blue light irradiation doses, except an enhancing effect on the proliferative activity of melanocytes observed immediately after irradiation with blue light at 5 J/cm 2; additionally, blue light irradiation at 5 - 40 J/cm 2 could enhance the expression of melanin synthesis-related enzymes in melanocytes, and increase the melanin synthesis rate in melanocytes over a short period of time.

Characterization the response of Chlamydomonas reinhardtii serine/threonine protein kinase mutant to blue light / 生物工程学报

In order to investigate the molecular mechanism of silk/threonine protein kinase (STK)-mediated blue light response in the algal Chlamydomonas reinhardtii, phenotype identification and transcriptome analysis were conducted for C. reinhardtii STK mutant strain crstk11 (with an AphvIII box reverse insertion in stk11 gene coding region) under blue light stress. Phenotypic examination showed that under normal light (white light), there was a slight difference in growth and pigment contents between the wild-type strain CC5325 and the mutant strain crstk11. Blue light inhibited the growth and chlorophyll synthesis in crstk11 cells, but significantly promoted the accumulation of carotenoids in crstk11. Transcriptome analysis showed that 860 differential expression genes (DEG) (559 up-regulated and 301 down-regulated) were detected in mutant (STK4) vs. wild type (WT4) upon treatment under high intensity blue light for 4 days. After being treated under high intensity blue light for 8 days, a total of 1 088 DEGs (468 upregulated and 620 downregulated) were obtained in STK8 vs. WT8. KEGG enrichment analysis revealed that compared to CC5325, the crstk11 blue light responsive genes were mainly involved in catalytic activity of intracellular photosynthesis, carbon metabolism, and pigment synthesis. Among them, upregulated genes included psaA, psaB, and psaC, psbA, psbB, psbC, psbD, psbH, and L, petA, petB, and petD, as well as genes encoding ATP synthase α, β and c subunits. Downregulated genes included petF and petJ. The present study uncovered that the protein kinase CrSTK11 of C. reinhardtii may participate in the blue light response of algal cells by mediating photosynthesis as well as pigment and carbon metabolism, providing new knowledge for in-depth analysis of the mechanism of light stress resistance in the algae.

Promoting fucoxanthin accumulation in Phaeodactylum tricornutum by multiple nitrogen supplementation and blue light enhancement / 生物工程学报

The aim of this study was to promote fucoxanthin accumulation in Phaeodactylum tricornutum by photo-fermentation through optimizing the mode of multiple nitrogen supplementation and blue light enhancement. The results showed that the mixed nitrogen source (tryptone: urea=1:1, N mol/N mol; total nitrogen concentration at 0.02 mol/L) added to the culture system by six times was the best mode in shake flasks. Two-phase culture with light adjustment was then carried out in 5 L photo-fermenter with an enhanced blue light (R: G: B=67.1:16.7:16.3) in the second phase, leading to improved cell density (1.12×108 cells/mL), biomass productivity (330 mg/(d·L)), fucoxanthin content (19.62 mg/g), titer (69.71 mg/L) and productivity (6.97 mg/(d·L)). Compared with one-phase culture under red/blue (R: G: B=70.9:18.3:10.9) light and six-times nitrogen supplementation, the fucoxanthin content was significantly increased by 7.68% (P < 0.05) but the productivity did not change significantly (P > 0.05). Compared with one-phase culture under red/blue (R: G: B=70.9:18.3:10.9) light and one-time nitrogen supplementation, the content and productivity of fucoxanthin were significantly increased by 45.98% and 48.30% (P < 0.05), respectively. This study developed a two-phase culture mode with multiple nitrogen supplementation and blue light enhancement, which effectively promoted the accumulation of fucoxanthin and improved the efficiency of nitrogen source utilization, thus providing a new approach for fucoxanthin accumulation in P. tricornutum by photo-fermentation.

Experimental study on the structural and functional changes of the retinal tissue induced by intense blue light irradiation in rats / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To observe the structural and functional changes of retinal tissue in rats after different duration of intense blue light irradiation.METHODS: A total of 48 healthy 8-week-old SD male rats were selected and randomly divided into the control group(n=12)and 3, 6 and 12h experimental groups(n=36). The rats in the control group received natural light, and the rats in the experimental groups received blue light with a wavelength of 465±5nm and the illumination of 1000±100lx for 3, 6, and 12h each day. Optical coherence tomography(OCT), fundus fluorescein angiography(FFA)and haematoxylin-eosin(HE)staining of paraffin pathological section were used to observe the changes of the retinal thickness, retinal tissue structure and the function in different directions and layers.RESULTS: The OCT results showed that the retinal thickness in the superior, inferior, nasal, and temporal sides of rats in different groups was statistically significant(P&#x0026;#x003C;0.05), and there was no statistical significant difference between the control group and the 3h experimental group in the total retinal thickness(P&#x0026;#x003E;0.05), while the differences between any other two groups were statistically significant(P&#x0026;#x003C;0.05); The mean total retinal thickness, internal limiting membrane(ILM)-inner nuclear layer(INL)thickness, outer plexiform layer(OPL)-outer segment(OS)thickness and retinal pigment epithelium(RPE)of rats in each group were statistically significant(P&#x0026;#x003C;0.05), and the mean total retinal thickness and OPL-OS thickness were statistically significant between any two groups(P&#x0026;#x003C;0.05). The ILM-INL thickness of rats in the control group and 3 and 12h experimental groups was statistically significant(P&#x0026;#x003C;0.05), and the thickness of RPE layer in the 12h experimental group was statistically different from that of the 3 and 6h experimental groups(P&#x0026;#x003C;0.05). FFA results showed that there was no obvious fluorescence leakage in the fundus of rats in the control group and the 3h experimental group, while there was obvious fluorescence leakage and hyperfluorescence in the retina of the 6 and 12h experimental groups, and the background fluorescence of choroid was enhanced. HE staining showed the atrophy and apoptosis of cells in the optic cell layer, and some lightly stained nucleus. In addition, RPE layer showed atrophy and thinned with the increase of light time, and there was significant difference in the number of the optic cells between the control group and experimental group(P&#x0026;#x003C;0.05).CONCLUSION: The intense blue light irradiation could cause thinning of the retina in rats, with varying degrees of thinning in different layers of the retina. It could also led to decrease and even disappearance of the number of cells in the visual cell layer, the focal atrophy of the RPE layer, and the change of vascular permeability. With the extension of the light time, the structural and functional changes in retinal tissue became more obvious.

Inhibitory effect of blue light intervention on lens-induced myopia development in guinea pigs and the mechanism of cone density change / 中华实验眼科杂志

Objective:To observe the effects of blue light intervention on the development of optical defocus-induced myopia in guinea pigs and investigate its underlying mechanisms.Methods:Forty-eight normal-grade two-week-old tricolor guinea pigs were randomly divided into a blue light group and a white light group, with 24 animals in each group.The right eye of guinea pigs was fitted with a -5.00 D lens to establish an optical defocus model as the experimental eye, while the left eye served as the control without any covering.Before the experiment and after 8-week intervention, the refractive power of guinea pigs was measured by streak retinoscopy.The anterior chamber depth, lens thickness, and axial length were measured by A-scan ultrasonography.Corneal curvature radius was determined using a keratometer.After 8-week intervention, the guinea pigs were euthanized through overanesthesia, and the right eyeballs were enucleated and the retinas were isolated.The density of S and M cone cells of the guinea pig retinal sections were observed via immunofluorescence staining.The expression of retinal retinoic acid was assessed by high-performance liquid chromatography.The expressions of retinoic acid receptor (RAR-β) in the retina and matrix metalloproteinase-2 (MMP-2), tissue inhibitor of metalloproteinase-2 (TIMP-2), and type Ⅰ collagen in the sclera were detected by real-time fluorescence quantitative PCR.Changes in scleral thickness were observed through hematoxylin-eosin staining.The use and care of the animals complied with Regulations for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission.The study protocol was approved by the Ethics Committee of Eye and ENT Hospital of Fudan University (No.2022ETKLD10032).Results:After 8 weeks of intervention, guinea pigs in the blue light group showed (0.63±0.12)D of relative hyperopia and a deceleration of axial elongation by (0.08±0.00)mm compared with the white light group in the right eye.In the left eye, guinea pigs in the blue light group showed (0.42±0.09)D of relative hyperopia and a deceleration of axial elongation by (0.08±0.00)mm compared with the white light group.The guinea pigs in blue light group showed (1.52±0.09)D of myopia in the right eye compared with the left eye, with an increase in axial elongation of (0.06±0.00)mm.The guinea pigs in white light group showed (1.66±0.07)D of myopia in the right eye compared with the left eye, with an increase in axial elongation of (0.13±0.00)mm, and the differences were statistically significant (all at P<0.05). The density of M cone cells was lower and density of S cone cells was higher in the blue light group in the dorsal and ventral sides of the retinal sections compared with the white light group, showing statistically significant differences ( t=32.33, 52.23, 42.09, 25.02; all at P<0.05). The deceleration of myopia progression in the blue light group was strongly positively correlated with the increase in S cone cell density on the ventral side ( r=0.95, P<0.01). The expression levels of retinoic acid, RAR-β, and MMP-2 were decreased, and expression levels of TIMP-2 and type Ⅰ collagen were increased in blue light group compared with the white light group, showing statistically significant differences ( t=18.73, 7.45, 3.72, 6.19, 9.03; all at P<0.05). The scleral thickness in the blue light group was (125.0±7.8)μm, which was significantly thicker than (102.0±6.3)μm in the white light group ( t=26.93, P<0.05). Conclusions:Blue light intervention can inhibit the progression of defocus-induced myopia in guinea pigs.Refractive power changes in guinea pigs may be influenced by alterations in retinal cone cell density, retinoic acid expression, and scleral collagen expression.

Research progress on the mechanism of ocular damage caused by blue light / 国际眼科杂志(Guoji Yanke Zazhi)

With the development of high technology, people spend more and more time on screens. Most screens contain a lot of blue light. As one of the important components of visible light, blue light has high energy. It may lead to many ocular diseases, such as myopia, cataract, dry eye, glaucoma and keratitis when eyes exposure to blue light for a long time. At present, the harm of blue light and how to prevent blue light have become a hot topic. Its mechanism mainly includes increasing the photosensitivity of lipofuscin, destroying the mitochondria, lysosome, lens and tear film. According to the mechanism of blue light damage, physical protective measures can be adopted. And the antioxidant, free radical scavengers, anti-inflammatory drugs and gene therapy can be used to protect eye tissue. This paper mainly summarizes the harmful mechanism of blue light to eye and the corresponding prevention and treatment measures.

Mechanism of blue light-induced ferroptosis in retinal pigment epithelium cells / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the occurrence and possible mechanism of blue light-induced ferroptosis in retinal pigment epithelial cells.METHODS: ARPE-19 cells cultured in vitro were irradiated by 405 nm blue light at 50 mW/cm2 irradiance with different duration and were divided into control, 16.3J/cm2, 32.6J/cm2, and 65.2J/cm2 groups; the 65.2J/cm2 group was defined as the high-level blue light irradiation group and cells were further divided into control, high-level blue light irradiation group and high-level blue light irradiation + ferroptosis inhibitor group. CCK-8 assay was used to detect cell viability, commercial kits were used to detect intracellular glutathione(GSH), ferrous iron and malondialdehyde(MDA)concentration, and Western blot was used to detect the relative expression of glutathione peroxidase 4(GPX4)and xCT proteins in cells.RESULTS: The decrease of ARPE-19 cell viability caused by blue light irradiation was dose-dependent, and the reduction of intracellular GSH concentration, the increase of ferrous iron concentration and MDA concentration were all caused by high-level blue light irradiation(all P&#x0026;#x003C;0.05); the ferroptosis inhibitor partially restored cell viability and recovered intracellular GSH, reduced concentrations of MDA and ferrous iron in the blue light irradiation group(all P&#x0026;#x003C;0.05). The relative expressions of GPX4 and xCT proteins were significantly decreased in the blue light irradiation group, and such change was alleviated by the ferroptosis inhibitor(P&#x0026;#x003C;0.05).CONCLUSION: Blue light irradiation may induce ferroptosis in RPE cells by targeting the xCT and GPX4-associated antioxidant pathways.

Enhancing fucoxanthin production in Phaeodactylum tricornutum by photo-fermentation / 生物工程学报

The aim of this study was to develop a technical system for high-efficient production of fucoxanthin by photo-fermentation of Phaeodactylum tricornutum. In a 5 L photo-fermentation tank, the effects of initial light intensity, nitrogen source and concentration as well as light quality on biomass concentration and fucoxanthin accumulation in P. tricornutum were investigated systematically under mixotrophic condition. The results showed that the biomass concentration, fucoxanthin content and productivity reached the highest level of 3.80 g/L, 13.44 mg/g and 4.70 mg/(L·d) under the optimal conditions of initial light intensity of 100 μmol/(m2·s), 0.02 mol TN/L of tryptone: urea (1:1, N mol/N mol) as mixed nitrogen source, and a mixed red/blue (R: B=6:1) light, 1.41, 1.33 and 2.05-fold higher than that before optimization, respectively. This study developed a key technology for enhancing the production of fucoxanthin by photo-fermentation of P. tricornutum, facilitating the development of marine natural products.

Blue and red light photoemitters as approach to inhibit Staphylococcus aureus and Pseudomonas aeruginosa growth / Fotoemissores de luz azul e vermelha como abordagem para inibir o crescimento de Staphylococcus aureus e Pseudomonas aeruginosa

The ability of pathogenic bacteria acquire resistance to the existing antibiotics has long been considered a dangerous health risk threat. Currently, the use of visible light has been considered a new approach to treat bacterial infections as an alternative to antibiotics. Herein, we investigated the antimicrobial effect of two range of visible light, blue and red, on Staphylococcus aureus and Pseudomonas aeruginosa, two pathogenic bacterial commonly found in healthcare settings-acquired infections and responsible for high rate of morbidity and mortality. Bacterial cultures were exposed to blue or red light (470 nm and 660 nm) provided by light-emitting diodes - LED. The fluencies and irradiance used for blue and red light were 284.90 J/cm2, 13.19 mW/cm2 and 603.44 J/cm2, 27.93 mW/cm2 respectively. Different experimental approaches were used to determine the optimal conditions of light application. Only exposure to blue light for 6 hours was able to inhibit about 75% in vitro growth of both bacterial species after 24 hours. The surviving exposed bacteria formed colonies significantly smaller than controls, however, these bacteria were able to resume growth after 48 hours. Blue light was able to inhibit bacterial growth upon inoculation in both saline solution and BHI culture medium. We can conclude that blue light, but not red light, is capable of temporarily retarding the growth of gram negative and gram positive bacteria.

A capacidade das bactérias patogênicas adquirirem resistência aos antibióticos existentes há muito tempo é considerada uma ameaça perigosa à saúde. Atualmente, o uso da luz visível tem sido considerado uma nova abordagem no tratamento de infecções bacterianas como alternativa aos antibióticos. Neste trabalho, investigamos o efeito antimicrobiano de duas faixas de luz visível, azul e vermelha, em Staphylococcus aureus e Pseudomonas aeruginosa, duas bactérias patogênicas comumente encontradas em infecções adquiridas em instituições de saúde e responsáveis por alta taxa de morbimortalidade. As culturas bacterianas foram expostas à luz azul ou vermelha (470 nm e 660 nm) fornecida por diodos emissores de luz - LED. As fluências e irradiâncias utilizadas para luz azul e vermelha foram 284,90 J/cm2, 13,19 mW/cm2 e 603,44 J/cm2, 27,93 mW/cm2, respectivamente. Várias abordagens experimentais foram utilizadas para determinar as condições ótimas de aplicação da luz. Apenas a exposição à luz azul por 6 horas foi capaz de inibir cerca de 75% o crescimento in vitro de ambas as espécies bacterianas após 24 horas. As bactérias expostas sobreviventes formaram colônias com um tamanho significativamente menor do que os controles, contudo, essas bactérias conseguiram retomar o crescimento normal após 48 horas. A luz azul foi capaz de inibir o crescimento das bactérias após sua inoculação em solução salina ou no meio de cultura rico em nutrientes BHI. Podemos concluir que a luz azul mas não a luz vermelha é capaz de retardar temporariamente o crescimento de bactérias Gram-negativas e Gram-positivas.

Effect of vitamin E on retinal pigment epithelial cells injured by high dose blue light / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To study the effect of vitamin E on the injury of human retinal pigment epithelial(hRPE)cells induced by high-dose blue light, and provide experimental evidence for intercepting blue light damaged hRPE cells. <p>METHODS: The hRPE cell injury model was established with 3000±150Lx blue light. The apoptosis rate and reactive oxygen species(ROS)of the six groups of hRPE cells were detected by flow cytometry at 0, 3, 6, 9, 12 and 24h respectively. Apoptosis and ROS in hRPE cells were detected by cytometry in 0h-irradiation group, 6h-irradiation group, and vitamin E added groups(vitamin E concentration 10, 50, 100μmol/L)before or after 6h-irradiation. The fluorescence intensity of hRPE cells was observed under a fluorescence microscope using Hoechst 33258 staining reagent.<p>RESULTS: Compared with the 0h-irradiation group, the relative amount of reactive oxygen species increased significantly in 3, 6, 9, 12 and 24h groups(all <i>P</i><0.01), the apoptosis rate of hRPE cells increased significantly in 6, 9, 12 and 24h groups(all <i>P</i><0.01), the apoptosis rate of the 3h-irradiation group was not statistically significantly increased(<i>P</i>=0.46). Compared with the 6h-irradiation group, the relative amounts of ROS and apoptotic rate of the six groups of hRPE cells added vitamin E were significantly decreased, and the blue fluorescence of Hoechst 33258 released in the cells gradually decreased, which was concentration dependent(all <i>P</i><0.01),except for apoptosis rate of hRPE cells in the 10 μmol/L vitamin E group before irradiation(<i>P</i>=0.66). Compared with the 0h-irradiation group, the difference in the relative amount of ROS and apoptosis rate of hRPE cells in added groups were statistically significant(all <i>P</i><0.01). At the same concentration of vitamin E, the relative amount of ROS and apoptosis rate of hRPE cells added vitamin E after irradiation were significantly lower than those added vitamin E before irradiation(all <i>P</i><0.01), except for apoptosis rate of hRPE cells in the 10 μmol/L vitamin E group, which had no difference between added before and after irradiation(<i>P</i>=0.08).<p>CONCLUSION: After hRPE cells had been irradiated by blue light, the increase in the relative amount of intracellular ROS was earlier than that of apoptosis. Elimination of intracellular ROS is the idea of intercepting high doses of blue light induced hRPE cell injury. Vitamin E protects RPE cell against damage induced by high doses of blue light, and the effect becomes stronger as the concentration of vitamin E increases, which is better when added after irradiating. However, it doesn't take effect until the concentration reaches a certain level. And the damage can't be completely repaired.

Application value of multiple colostrum feedings in reducing the incidence of neonatal jaundice / 中国基层医药

Objective:To investigate the clinical efficacy of multiple colostrum feedings in reducing the incidence of neonatal jaundice.Methods:We randomly selected 100 full-term neonates delivered in Xiaoshan Hospital from January 2018 to January 2019 and randomly allocated them into control and observation groups ( n = 50/group). The control group was administered colostrum < 4 times/day, and the observation group was administered colostrum > 12 times/day. The incidence of neonatal jaundice, the severity of jaundice, the duration of jaundice, serum bilirubin level 7 days after birth, and the satisfaction of neonatal close relatives were compared between the two groups. Results:Neonatal jaundice was significantly milder in the observation group than in the control group ( P < 0.05). The proportion of healthy neonates was significantly higher in the observation group than in the control group ( P < 0.05). The duration of jaundice was shorter in the observation group than in the control group [(2.10 ± 0.35) days vs. (4.25 ± 1.53) days, t = 8.66, P < 0.001]. There was a significant difference in serum bilirubin level 1-5 days after birth between the two groups (all P < 0.05). The satisfaction of the close relatives of neonates was significantly higher in the observation group than in the control group (96.00% vs. 84.00%, χ2 = 4.00, P = 0.045). All neonates with jaundice healed after multiple short-term blue light phototherapies and had no obvious adverse reactions. Conclusion:Multiple colostrum feedings can greatly reduce the incidence of neonatal jaundice, improve the satisfaction of the close relatives of neonates, play a positive role in promoting maternal and infant health, and thereby are worthy of popularization.

CERKL attenuates blue light-induced oxidative stress in human retinal pigment epithelial cells by activating the SIRT1/E2F1 axis / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To investigate whether ceramide kinase-like protein(CERKL)alleviates oxidative stress injury of retinal pigment epithelial(RPE)cells induced by blue light via activating the silent information regulator 1(SIRT1)/E2F transcription factor 1(E2F1)axis. METHODS:Cultured human retinal pigment epithelial-19(ARPE-19)cells were irradiated with blue light to observe the morphological changes, and the expression of CERKL was detected by PCR and Western blot. ARPE-19 cells were transfected with siRNA-CERKL and pcDNA3.1-CERKL respectively. After exposure to blue light, cell viability was determined by MTT assay, apoptosis was detected by TUNEL assay, content of oxidative stress markers and the expression of SIRT1/E2F1 axis was analyzed. Then siRNA-SIRT1 was transfected into ARPE-19 cells, and the oxidative stress damage of ARPE-19 cells under blue light irradiation was detected again.RESULTS:ARPE-19 cells gradually contracted into spheres and appeared vacuoles after exposure to blue light. Blue light irradiation led to the increase of CERKL expression level(P<0.05), meanwhile, the rate of cell viability was decreased(P<0.05), the rate of the apoptosis was increased(P<0.05), contents of reactive oxygen species, malondialdehyde and 8-hydroxydeoxyguanosine were increased(P<0.05). Silence of CERKL aggravated this phenomenon, while up-regulation of CERKL could alleviate this change(P<0.05). Up-regulation of CERKL also activated the expression of SIRT1 and promoted the deacetylation of E2F1(P<0.05). Silencing SIRT1 could reverse the alleviating effect of up-regulating CERKL on oxidative stress injury of ARPE-19 cells induced by blue light(P<0.05). CONCLUSION: CERKL can reduce oxidative stress damage of ARPE-19 cells induced by blue light via activating SIRT1 expression and promoting the deacetylation of E2F1.

Comparison of five therapeutic methods in treatment of moderate acne vulgaris / 中华医学美学美容杂志

Objective:To observe the efficacy of drug combined with red-blue light irradiation, chemical peeling by glycolic acid and intense pulsed light (IPL) in the treatment of moderate acne vulgaris.Methods:A total of 187 patients with moderate acne vulgaris were divided into five groups. There were 59 males and 128 females, aged from 16 to 29 years (21.79±2.52). In group A, patients were treated with oral medicines; the patients were treated with oral medicines combined with red-blue light irradiation, chemical peeling by glycolic acid and IPL respectively in group B, group C and group D. In group E, patients were treated with oral medicines combined with chemical peeling by glycolic acid and IPL. The number of different types of skin lesions (comedoes, papules, pustules) were compared between before and after treatment in five groups. The clinical effect of five treatment groups was evaluated by comparing regression rates of different types of skin lesions and total skin lesions and treatment efficiency.Results:All the patients with moderate acne vulgaris were brought into this study. The regression rates of comedoes, papules and total skin lesions were (86.37±9.64)%, (94.25±9.79)% and (88.80±9.40)% respectively in group E, and significantly higher than that of other four groups ( P<0.05). The treatment efficiency of group E also were significantly higher than that of other four groups ( P<0.05). Then, the regression rates of comedoes (70.91±18.52) in group C was significantly higher than that of group A and group B ( P<0.05). The regression rates of papules (91.42±13.86) in group D was significantly higher than that of group A and group B ( P<0.05). Conclusions:Oral medicines combined with chemical peeling by glycolic acid and IPL has obvious clinical efficacy in treatment of patients with moderate acne vulgaris. Oral medicines combined with chemical peeling by glycolic acid can obviously improve comedoes, and oral medicines combined with IPL can obviously improve papules.

A makeshift blue light filter for endoscopic identification of traumatic cerebrospinal fluid leak using fluorescein

Objective@#To describe a makeshift blue light filter for endoscopic visualization of a traumatic cerebrospinal fluid leak repair using intrathecal fluorescein and its application in one patient.@*Methods@# Study Design:Surgical Instrumentation Setting:Tertiary Government Training Hospital Patient:One @*Results@#Intra-operative endoscopic identification of fistulae sites was achieved using intrathecal injection of fluorescein that fluoresced using our makeshift blue light filter in a 43-year-old man who presented with a 3-month history of rhinorrhea due to skull base fractures along with multiple facial and upper extremity fractures he sustained after a fall from a standing height of 6 feet. He underwent transnasal endoscopic repair of cerebrospinal fluid fistulae in the planum sphenoidale, clivus and sellar floor. Post-operatively, there was complete resolution of rhinorrhea with no complications noted. @*Conclusion@#Our makeshift blue light filter made from readily available materials may be useful for endoscopic identification of CSF leaks using fluorescein in a low- to middle-income country setting like ours.

Clinical application of LASEREO endoscopic system in early gastric cancer / 中华内科杂志

Objective:To evaluate the clinical application of LASEREO endoscopic system in early gastric cancer (EGC).Methods:A total of 68 patients diagnosed with EGC were retrospectively analyzed between August 2017 to December 2020 in Fuding Hospital Affiliated to Fujian University of Traditional Chinese Medicine. There were 50 males and 18 females finally enrolled with a median age of 64 years. EGCs were analyzed from subjective and objective aspect, as well as from magnification and non-magnification status. Six endoscopists evaluated the visibility of the EGC (RSC) and calculated the color difference (ΔEC) between EGC and the surrounding mucosa in white light imaging (WLI), blue light imaging-bright (BLI-Bri) and linked color imaging (LCI) modes. In the case of magnification (×80), the visibility of the microstructures and microvessels (RSV) was analyzed and the color difference (ΔEV) between microvessels and non-vessels areas were calculated in WLI, BLI and LCI modes. The visibility was evaluated using visibility ranking scale(RS) and the color difference (ΔE) was calculated using L*a*b* color space.Results:In WLI, BLI-Bri, and LCI modes, the mean (±SD) RSC were 2.56±0.68, 2.63±0.59 and 3.17±0.50, and the mean(±SD) ΔEC were 15.71±5.58, 12.04±3.73, and 22.84±8.46, respectively, which in LCI were higher than those in WLI and BLI-Bri modes ( P<0.001).Regarding the data evaluated by senior endoscopists, the RSC was higher in BLI-Bri than that in WLI mode (2.98±0.58 vs. 2.79±0.73, P<0.001), but as to those evaluated by junior endoscopists, there were no significant differences between the WLI and BLI-Bri modes(2.29±0.72 vs. 2.23±0.72,P =0.218).In magnifying endoscopy with WLI, BLI, and LCI modes, the mean(±SD) RSV were 2.95±0.28, 3.46±0.40, and 3.38±0.33, and the mean (±SD) ΔEV were 21.68±7.52, 44.29±10.94, and 45.38±14.29, respectively.The RSV and ΔEV in LCI and BLI were higher than that in WLI mode ( P<0.001). Conclusions:LCI improves the visibility of EGC by increasing ΔEC, especially in junior endoscopists. Both BLI and LCI improve the visibility of microstructures and microvessels under magnification.

Diagnostic value of blue light imaging-bright and linked color imaging for early esophageal cancer / 中华消化内镜杂志

Objective To investigate the diagnostic value of blue light imaging-bright (BLI-bright) and linked color imaging (LCI) for early esophageal cancer (EEC).Methods:Data of 63 consecutive patients with EEC who underwent gastroscopy under BLI-bright, LCI and white-light imaging (WLI) and endoscopic submucosal dissection (ESD) from May 2018 to August 2020 at Fuding Hospital Affiliated to Fujian University of Traditional Chinese Medicine were analyzed retrospectively in the cohort study. Subjective visibility analysis was performed by 6 endoscopists who were divided into 2 groups (expert group and trainee group) with 3 endoscopists in each group. The main observation index was the visibility score (ranking score, RS). The objective color difference (Δ E) between lesions of EEC and surrounding mucosa under 3 modes were analyzed by using the L *a *b * color space. Results:The overall RS of 6 endoscopists under WLI mode (2.57±0.81) was significantly lower than that under LCI (3.25±0.67) ( t=9.71, P<0.001) and BLI-bright (3.18±0.67) ( t=9.31, P<0.001). In the expert group, the RS of WLI (2.71±0.80) was significantly lower than that of LCI (3.33±0.66) ( t=7.16, P<0.001) and BLI-bright (3.42±0.62) ( t=8.09, P<0.001). In the trainee group, the RS of WLI (2.40±0.90) was also significantly lower than that of LCI (3.15±0.83) ( t=9.62, P<0.001) and BLI-bright (2.89±0.92) ( t=5.69, P<0.001), and the RS of LCI was higher than that of BLI-bright ( t=4.07, P<0.001). The Δ E between lesions of EEC and surrounding mucosa under WLI (11.52±3.40) was significantly lower than that under LCI (16.64±4.70) ( t=7.10, P<0.001) and BLI-bright (15.72±3.84) ( t=7.88, P<0.001). Conclusion:BLI-bright and LCI can effectively improve EEC visibility and color difference between EEC and surrounding mucosa. Furthermore, LCI is more conducive to the detection of EEC for the trainees.