Cr:LiSAF激光在组织自体荧光光谱研究中的应用

目的　该文以Cr:liSAF激光作为激发光源 ,针对生物大分子设计了荧光实验 ,以探讨其在组织自体荧光研究中的应用。方法　氙灯泵浦Cr:LiSAF二次谐波用来产生可调谐蓝光脉冲激光输出 ,并设计了自体荧光试验。结果　最后设计并实现了可调谐蓝光脉冲激光输出 ,得到了良好的输出特性。结论　氙灯泵浦Cr:LiSAF二次谐波产生可调谐蓝光脉冲激光输出得到了良好的输出特性 ,该实验为进一步研究肿瘤组织与正常组织自体荧光产生机制打下了基础。     

Ultraviolet Laser-Induced Fluorescence Spectroscopy Diagnosis of Human Stomach Malignant Tissues

To evaluate the potential of laser-induced autofluorescence spectroscopy for the detection of premalignant lesions of human stomach, fluorescence properties of stomach tissues have been investigated in vitro and in vivo. A specially made optical fibre probe and the multichannel fluorescence collection system have been used successfully in our research. Paper received 26 June 1997; accepted in revised form 31 October 1997.     

A cytoplasmic component of pyridine nucleotide fluorescence in rat diaphragm: evidence from comparisons with flavoprotein fluorescence

Pyridine nucleotide (PN) and flavoprotein (Fp) fluorescence were monitored in the isolated intact rat diaphragm. A substantial increase in PN fluorescence occurred when N₂ replaced O₂ in glucose medium. This response was much reduced in pyruvate medium and/or by pretreatment with iodoacetic acid (IAA). The anaerobic levels of Fp fluorescence were less affected by substrate and IAA. Substitution of glucose by pyruvate did not alter the PN fluorescence of the resting aerobic tissue, but increased Fp fluorescence. After a tetanus with glucose present the PN of the anaerobic muscle, but not the Fp underwent a substantial transient oxidation. This oxidation was absent in pyruvate medium. It is concluded that a cytoplasmic component of the PN fluorescence is present in skeletal muscle. The levels of Fp fluorescence in the resting and contracting aerobic tissue supplied with pyruvate suggest that the resting tissue respiration was ADP limited. On this basis the level of PN fluorescence in the aerobic resting state was less than expected; the source of the PN fluorescence was both mitochondrial and cytoplasmic.     

Fluorescence lifetime imaging ophthalmoscopy

Imaging techniques based on retinal autofluorescence have found broad applications in ophthalmology because they are extremely sensitive and noninvasive. Conventional fundus autofluorescence imaging measures fluorescence intensity of endogenous retinal fluorophores. It mainly derives its signal from lipofuscin at the level of the retinal pigment epithelium. Fundus autofluorescence, however, can not only be characterized by the spatial distribution of the fluorescence intensity or emission spectrum, but also by a characteristic fluorescence lifetime function. The fluorescence lifetime is the average amount of time a fluorophore remains in the excited state following excitation. Fluorescence lifetime imaging ophthalmoscopy (FLIO) is an emerging imaging modality for in vivo measurement of lifetimes of endogenous retinal fluorophores. Recent reports in this field have contributed to our understanding of the pathophysiology of various macular and retinal diseases.Within this review, the basic concept of fluorescence lifetime imaging is provided. It includes technical background information and correlation with in vitro measurements of individual retinal metabolites. In a second part, clinical applications of fluorescence lifetime imaging and fluorescence lifetime features of selected retinal diseases such as Stargardt disease, age-related macular degeneration, choroideremia, central serous chorioretinopathy, macular holes, diabetic retinopathy, and retinal artery occlusion are discussed. Potential areas of use for fluorescence lifetime imaging ophthalmoscopy will be outlined at the end of this review.     

Dominant ARL3-related retinitis pigmentosa

Purpose: To clinically and genetically characterise a second family with dominant ARL3-related retinitis pigmentosa due to a specific ARL3 missense variant, p.(Tyr90Cys).

Methods: Clinical examination included optical coherence tomography, electroretinography, and ultra-wide field retinal imaging with autofluorescence. Retrospective data were collected from the registry of inherited retinal diseases at Oslo university hospital. DNA was analysed by whole-exome sequencing and Sanger sequencing. The ARL3 missense variant was visualized in a 3D-protein structure.

Results: The phenotype was non-syndromic retinitis pigmentosa with cataract associated with early onset of decreased central vision and central retinal thinning. Sanger sequencing confirmed the presence of a de novo ARL3 missense variant p.(Tyr90Cys) in the index patient and his affected son. We did not find any other cases with rare ARL3 variants in a cohort of 431 patients with retinitis pigmentosa-like disease. By visualizing Tyr90 in the 3D protein structure, it seems to play an important role in packing of the α/β structure of ADP-ribosylation factor-like 3 (ARL3). When changing Tyr90 to cysteine, we observe a loss of interactions in the core of the α/β structure that is likely to affect folding and stability of ARL3.

Conclusion: Our study confirms that the ARL3 missense variant p.(Tyr90Cys) causes retinitis pigmentosa. In 2016, Strom et al. reported the exact same variant in a mother and two children with RP, labelled ?RP83 in the OMIM database. Now the questionmark can be removed, and ARL3 should be added to the list of genes that may cause non-syndromic dominant retinitis pigmentosa.