Comparison of measurements of time outdoors and light levels as risk factors for myopia in young Singapore children

Aims

To compare methods to measure time outdoor and light levels, two possible predictors of myopia, in Singapore children.

Methods

Outdoor time from a diary and portable light meter over a 1-week period was compared in 117 Singapore children aged 6–12 years with and without myopia. All children wore a (HOBO Pendant temp/light Part # UA-002-64) light meter for 1 week and the parents filled the 7-day outdoor diary to track the outdoor activity.

Results

Mean outdoor time from diary and time with light levels was 5.44 hours per week and 7.91 hours per week, respectively, during school term and school holidays. Time spent with light levels of >1000 Lux from the light meter were 7.08 h per week and 9.81 h per week, respectively, during school term and school holidays. The intraclass correlation coefficients were 0.21 and 0.28 for outdoor time from the diary and light meter (1000 Lux cut-off) during the school term and holidays, respectively. The correlation coefficient was 0.34 (95% CI 0.05, 0.58) for a weekday during school holidays, 0.17 (−0.14, 0.45) for a weekday during school term, 0.07 (−0.16, 0.29) for a weekday during school term, and 0.25 (0.02, 0.46) for a weekend during school term.

Conclusions

The agreement between the light meter and 1-week diary was poor to fair. Both instruments measure different parameters, time outdoors and light intensity, and could therefore capture different aspects of risk in future myopia studies.     

光照节律改变对大鼠视网膜中Cry2表达的影响

背景 Cry2存在于哺乳动物视网膜上,是生物钟振荡器环路中重要的调控因子. 目的 探讨光照节律改变对大鼠视网膜中Cry2表达的影响.方法 将清洁级健康无眼疾SD大鼠30只按随机数字表法分成2个组,正常对照组大鼠在自然昼夜光线照明下喂养,实验组大鼠饲养在光照控制室内,大鼠活动平面光照度为(533±16) lx,设定每日光照明(6:00 ～24:00)、暗(24:00 ～6:00)循环交替时间为18 h/6 h,持续时间为3个月.于实验后3个月时在光学显微镜及透射电子显微镜下观察大鼠视网膜组织结构和超微结构的改变,采用免疫组织化学法检测各组大鼠视网膜中Cry2蛋白的表达,采用实时荧光定量PCR法检测Cry2mRNA在视网膜组织中的表达变化.结果 光学显微镜下可见,正常对照组大鼠喂养3个月时视网膜各层结构清晰,排列整齐,而实验组大鼠视网膜萎缩变薄,排列紊乱.透射电子显微镜下观察表明,正常对照组大鼠光感受器细胞外节膜盘结构清晰,内节线粒体嵴连续,外核层细胞核形态规则,但实验组大鼠光感受器内外节结构紊乱,外节膜盘间隙增大,出现溶解、空泡变,光感受器内节线粒体空泡变,视网膜外核层细胞核染色质浓集,部分出现核碎裂、边集,核膜皱缩、内陷.免疫组织化学检测显示,2个组大鼠Cry2蛋白均在视网膜节细胞及内核层部分细胞的细胞质和核膜阳性表达,实验组大鼠Cry2蛋白表达评分为(0.833±0.197)分,明显低于正常对照组的(1.700±0.245)分,差异有统计学意义(P=0.009).实时荧光定量PCR定量检测结果显示,正常对照组大鼠视网膜中Cry2 mRNA表达量为0.962±0.125,实验组为0.615±0.100,差异有统计学意义(P=0.006).结论 533 lx的光照强度长期节律性照射可导致大鼠视网膜组织结构损伤,其机制可能与视网膜中Cry2的表达下调有关,调整Cry2的表达是否是临床上稳定生物节律的一个重要环节值得探讨.     

三氧化二砷诱导的视网膜母细胞瘤SO-Rb50细胞白噬的研究

背景细胞的自噬是肿瘤细胞非凋亡形式的死亡过程,研究证实三氧化二砷（As2O3）可诱导肿瘤细胞凋亡,但As2O3是否可致SO—Rb50细胞发生自噬的研究鲜有报道。目的探讨As2O3体外诱导SO—Rb50细胞自噬的作用。方法用浓度为0．5、1．0、2．0、4．0μmol／L的As2O3培养液及不含As2O3的未处理组处理SO—Rb50细胞系48h,采用MTT法测定各As2O3,浓度组SO—Rb50细胞的吸光度（As2O3）值。构建自噬标志物磷酸化绿色荧光蛋白（pGFP）-LC3体外转染SO—Rb50细胞,并分为新鲜RPMI一1640培养组（未处理组）、As2O3,RPMI一1640培养组（As2O3处理组）和rapamycin培养组（阳性对照组）,于48h后行激光共焦显微镜检测细胞自噬;用自噬特异性染料单丹磺酰戊二胺（MDC）行荧光染色检测SO—Rb50细胞的自噬,并用透射电子显微镜检测SO—Rb50细胞的自噬表现,采用流式细胞仪定量检测不同浓度As2O3,处理组自噬泡阳性细胞百分比。结果未处理组和0．5、1．0、2．0、4．0txmolAs2O3,作用48h后SO—Rb50细胞的A570值分别为2．194＋0．066、1．841±0．213、1．035±0．046、0．374±0．042和0．167±0．019,总体比较差异有统计学意义（F=547．636,P〈0．05）,其中各浓度As2O3组A。值均明显低于未处理组,差异均有统计学意义（均P=0．000）。As2O3处理组和阳性对照组可见GFP—LC3融合蛋白呈点状聚集在相应的自噬泡,未处理组GFP—LC3呈弥散分布。透射电子显微镜检查可见未处理组SO—Rb50细胞超微结构正常,As2O3处理组和阳性对照组见大量双层膜状结构及自噬溶酶体。未处理组48h见极少量MDC阳性荧光颗粒,As2O3处理组及阳性对照组48h可见明显的MDC阳性荧光颗粒,聚集在细胞质相应的自噬发生区。流式细胞术检测发现未处理组和0．5、1．0、2．0、4．0μmol／LAs2O3及rapamycin作用48h后自噬泡阳性的SO—Rb50细胞百分比分别为0、15．6％、42．7％、57．9％、79．5％和89．0％,随As2O3,浓度的增加MDC阳性细胞百分比递增。结论As2O3,抑制SO—Rb50细胞的生长和增生,并致SO—Rb50细胞发生自噬;SO—Rb50细胞经As2O3处理后,自噬的发生早于细胞核的改变,早中期自噬程度呈明显的As2O3浓度依赖性。     

A simple approach for enhanced immune response using engineered dendritic cell targeted nanoparticles

In this study, we demonstrate a simple strategy for enhanced immune response using a two-component dendritic cell (DC) targeted antigen delivery system. One component consists of a recombinant bifunctional fusion protein (bfFp) used for DC targeting, whereas, the other component is made of biotinylated PLGA nanoparticles that encapsulate the antigen. The fusion protein (bfFp) made of a truncated core-streptavidin fused to anti-DEC-205 single chain antibody (scFv) was mixed with ovalbumin-loaded biotinylated NPs that were formulated using biotin–PEG (2000)–PLGA, and the combination, bfFp functionalized NPs was used for DC targeted antigen delivery. In vitro DC uptake studies revealed a 2-fold higher receptor-mediated uptake of bfFp functionalized NPs when compared to non-targeted NPs. Immunization of the mice with the bfFp functionalized NPs in conjunction with DC maturation stimulus (anti-CD40 mAb) enhanced OVA-specific IgG and IgG subclass responses. Splenocytes of these mice secreted significantly higher levels of Th1 (IFN-γ and IL-2) cytokines upon ex vivo restimulation with OVA. The promising outcomes of the bfFp functionalized DC targeted system support its use as a versatile vaccine delivery system for the design of monovalent or polyvalent vaccines.     

Structural characterisation, stability and antibody recognition of chimeric NHBA-GNA1030: an investigational vaccine component against Neisseria meningitidis

A new generation multi-component vaccine, principally directed against serogroup B Neisseria meningitidis (4CMenB), has recently been developed. One of its components, identified through reverse vaccinology, is the neisserial heparin-binding antigen (NHBA) which is included in the formulation as a novel NHBA-GNA1030 fusion protein (NHBA-FP). We describe here the biophysical characteristics of this vaccine antigen to understand better its structural properties in solution and concurrent immunogenicity prior to formulation. By deliberately stressing the protein to lose its immune responses, we were able to study the protein's structural changes at the molecular level. The unmodified NHBA-FP was found to be mainly monomeric with mass of 67kDa and secondary structure dominated by β-sheets and turns (57% average). The antigen was very stable in storage buffer. It could be forced to unfold in a low-salt buffer resulting in the exposure of one of its two tryptophan residues at 50°C. Long-term stress studies (10-15 days at 37°C) showed modification in the chromatographic and electrophoretic profiles with progressive degradation and aggregation. Since there was little change in secondary structure (as monitored by circular dichroism and tryptophan fluorescence spectroscopy), the loss of functional immunogenicity of the thermal stressed protein could be mainly attributed to the observed fragmentation and aggregation. We therefore conclude that the maintenance of the intact, non-fragmented state of the NHBA-FP is important to preserve its functional immunogenicity. This may thus be utilised as an assay for the control testing of the protein.     

肾脏轻链-重链沉积病一例并文献复习

目的 报告1例肾脏轻链-重链沉积病（IgGκ轻链-γ1重链）.方法 分析临床表现,血清免疫固定电泳,血、尿中轻、重链异常,骨髓活检和肾活检病理资料.结果 临床表现大量蛋白尿,镜下血尿,高血压,贫血,肾功能正常.免疫固定电泳见κ型IgG条带,伴血、尿液中轻链升高.骨髓浆细胞4％.肾活检肾小球呈“结节样病变”,刚果红染色阴性.免疫荧光κ轻链和IgG1（y1重链单抗）沿肾小球基膜（GBM）和肾小管基膜（TBM）线样沉积.电镜见GBM内侧及TBM外侧高电子致密物沉积.结论 肾脏轻-重链沉积病（IgGκ轻链-γ1重链）的诊断,应临床结合病理,特别是进行免疫病理检查.     

Effects of continuous light exposure on antioxidant enzymes,porphyric enzymes and cellular damage in the Harderian gland of the Syrian hamster

The Syrian hamster Harderian gland (HG), an organ present in the male two secretory cell types (type-I and type-II cells), is physiologically exposed to high oxidative stress because of high concentrations of porphyrins and their precursor, 5-aminolevulinic acid. Because of its juxtaorbital location, the HG is accessible to light, and subject to phototoxic effects of these substances. After having previously demonstrated circadian rhythms in antioxidant enzymes, porphyric enzymes and oxidative damage of proteins and lipids, as well as influences of melatonin on these parameters, we have now studied the effects of continuous light (LL), which suppresses melatonin secretion by the pineal gland. Measurements were performed in two different circadian phases, in order to detect the presence or absence of day/night differences. In LL, no differences between circadian phases of subjective day and subjective night were demonstrable for 5-aminolevulinate synthase, 5-aminolevulinate dehydratase, porphobilinogen deaminase, or superoxide dismutase; temporal differences in glutathione reductase and catalase were markedly diminished, whereas all these parameters showed marked day/night differences in the rats exposed to a light/dark cycle of 14:10. In LL, oxidative damage to lipids was minimally effected, while protein damage was enhanced. LL also caused a reduction in the percentage of type-II cells. Therefore, cell differentiation in the HG does not seem to be controlled only by the androgen, but, unexpectedly, also by melatonin.     

Myocardial Composition in Light-Chain Cardiac Amyloidosis More Than 1 Year After Successful Therapy

ObjectivesThe goals of this study were to characterize myocardial composition during the active and remission phases of light-chain (AL) cardiac amyloidosis.BackgroundCardiac dysfunction in AL amyloidosis is characterized by dual insults to the myocardium from infiltration and toxicity from light chains during the active phase and by infiltration alone in the remission phase.MethodsProspectively enrolled subjects with cardiac AL amyloidosis (21 remission AL amyloidosis; age: 63.4 ± 7.3 years; 47.6% male; and 48 active AL amyloidosis; age: 62.5 ± 7.4 years; 60.4% male) underwent contrast-enhanced cardiac magnetic resonance with T₁ and T₂ mapping and measurement of extracellular volume (ECV). By definition, serum free light-chain levels were normal for at least 1 year following successful AL therapy in the remission group and abnormal in the active group.ResultsMyocardial ECV was similarly expanded in the remission and active AL amyloidosis groups (0.488 ± 0.082 vs 0.519 ± 0.083, respectively; P = 0.15). However, myocardial T₂ relaxation times (47.7 ± 3.2 ms vs 45.5 ± 3.0 ms; P = 0.008) as well as native T₁ times (1,368 ms [IQR: 1,290-1,422 ms] vs 1,264 ms [IQR: 1,203-1,380 ms]; P = 0.024) were significantly higher in the remission compared to the active AL amyloidosis group.ConclusionsMyocardial ECV is substantially expanded in the active AL and remission AL cardiac amyloidosis groups, but native T₁ values were higher, suggesting a different myocardial composition. There is no evidence of myocardial edema in active AL cardiac amyloidosis. Future phenotyping studies of AL cardiac amyloidosis need to consider complementary myocardial markers that define the interstitial milieu in addition to changes in extracellular volume. (Molecular Imaging of Primary Amyloid Cardiomyopathy; NCT02641145)