关节镜下双排缝合桥固定与单排固定治疗肩袖全层撕裂的疗效对比及术后早期再撕裂的危险因素分析

摘要 目的：对比关节镜下双排缝合桥固定和单排固定治疗肩袖全层撕裂的疗效,并分析术后早期再撕裂的危险因素。方法：回顾性分析广州中医药大学附属北碚中医院2018年1月~2021年12月期间收治的200例肩袖全层撕裂患者的临床资料,根据手术方案的不同分为A组（n=97,接受单排固定治疗）和B组（n=103,接受双排缝合桥固定治疗）。对比两组的疼痛、肩关节功能情况、肩关节活动度及术后早期再撕裂发生率。采用单因素和多因素Logistic回归分析肩袖全层撕裂患者术后早期再撕裂的危险因素。结果：术后6个月,B组视觉疼痛模拟评分量表（VAS）评分低于A组,美国加州大学肩关节评分系统（UCLA）评分、美国肩肘外科医师学会（ASES）评分高于A组（P<0.05）。术后6个月,B组前屈、外展、体侧外旋角度大于A组（P<0.05）。B组的术后早期再撕裂总发生率低于A组（P<0.05）。术后早期再撕裂的发生与糖尿病史、撕裂大小、吸烟史、年龄、术前肌肉质量、性别、脂肪浸润、注射皮质类固醇有关（P<0.05）。多因素Logistic回归分析结果显示：年龄≥60岁、性别为男性、吸烟史、糖尿病史、撕裂大小为巨大型再撕裂、脂肪浸润、注射皮质类固醇是术后早期再撕裂发生的危险因素（P<0.05）。结论：关节镜下双排缝合桥固定治疗肩袖全层撕裂,可更好的减轻疼痛症状,改善关节功能和关节活动度。此外,糖尿病史、脂肪浸润、吸烟史、高龄、撕裂大小为巨大型再撕裂、男性、注射皮质类固醇等是肩袖全层撕裂患者术后早期再撕裂的危险因素。     

老年翼状胬肉患者翼状胬肉切除与角膜缘干细胞移植联合治疗的疗效观察

摘要 目的：分析评估老年翼状胬肉患者实施翼状胬肉切除与角膜缘干细胞移植联合治疗的临床效果。方法：回顾性纳入的本院2018年08月至2020年07月期间295例翼状胬肉患者（共442只眼）的临床资料,根据术式差异将患者分为联合组（150例,共224只眼）和参照组（145例,共218只眼）,参照组病患仅择取翼状胬肉切除手术,联合组病患于以上基础实施角膜缘干细胞移植术,比较两组病患术前及术后各时间点（1周、1个月、3个月）的BUT、SIt、UCVA、CAD、CAA,统计病患术后3个月的复发情况。结果：两组BUT在术后1周较术前显著缩短（P<0.05）,而在术后1月和3月较术前显著延长（P<0.05）,两组BUT在术后1周对比差别明显（P<0.05）,而其他时间点对比没有明显差别（P>0.05）。两组术前术后SIt对比没有明显差别（P>0.05）,术后1月和3月的两组UCVA均高于术前（P<0.05）,而两组在各时间点UCVA对比没有明显差别（P>0.05）,两组术后各时间点的角膜CAD较术前显著性降低（P<0.05）,而两组角膜CAD在各时间点无明显差别（P>0.05）。两组术后CAA术后3月与术前比较,WR比例显著降低,AR、OA比例显著增加（P<0.05）,而组间对比没有明显差别（P>0.05）。术后复发率联合组（6.67%）与参照组（32.26%）对比有明显差别（P<0.05）。结论：与翼状胬肉切除术比较 ,老年翼状胬肉病患实施翼状胬肉切除与角膜缘干细胞移植术联合治疗对患者早期眼表无较大影响,两种术式均不影响泪液分泌,且能够改善裸眼视力、散光度及轴向,但联合治疗在降低术后复发率方面优势明显。     

Elastohydrodynamics of the Eyelid Wiper

This paper presents an elastohydrodynamic model of the human eyelid wiper. Standard lubrication theory is applied to the fluid layer between the eyelid wiper and ocular surface. The role of the lubrication film is to reduce the shear stresses by preventing solid to solid contact between the eyelid wiper and ocular surface. For the lubrication film to be effective, it is required that the orientation of the eyelid wiper changes between the opening and closing phases of a blink. In order to model this, the hydrodynamic model is coupled with an elastic mattress model for the soft tissue of the eyelid wiper and ocular surface. This leads to a one-dimensional non-linear partial differential equation governing the fluid pressure in the lubrication film. In order to solve the differential equation, a loading condition or constraint equation must be specified. The resulting system is then solved numerically. The model allows predictions of the tear film flux from under the upper eyelid, as well as normal and shear stresses acting on the ocular surface. These factors are important in relation to dry eye syndrome, deformation of the cornea and contact lens design. It is found that the pressure and shear stress under the eyelid act across a length of approximately 0.1 mm which is consistent with clinical observations. It order to achieve a flow of tears from under the upper eyelid during a blink, the model requires that the normal force the eyelid applies to the ocular surface during the closing phase of the blink is significantly higher than during the opening phase of the blink. Electronic Supplementary Material The online version of this article () contains supplementary material, which is available to authorized users.     

Interaction of ceramides and tear lipocalin

The distribution of lipids in tears is critical to their function. Lipids in human tears may retard evaporation by forming a surface barrier at the air interface. Lipids complexed with the major lipid binding protein in tears, tear lipocalin, reside in the bulk (aqueous) and may have functions unrelated to the surface. Many new lipids species have been revealed through recent mass spectrometric studies. Their association with lipid binding proteins has not been studied. Squalene, (O-acyl) omega-hydroxy fatty acids (OAHFA) and ceramides are examples. Even well-known lipids such as wax and cholesteryl esters are only presumed to be unbound because extracts of protein fractions of tears were devoid of these lipids. Our purpose was to determine by direct binding assays if the aforementioned lipids can bind tear lipocalin. Lipids were screened for ability to displace DAUDA from tear lipocalin in a fluorescence displacement assay. Di- and tri-glycerides, squalene, OAHFA, wax and cholesterol esters did not displace DAUDA from tear lipocalin. However, ceramides displaced DAUDA. Apparent dissociation constants for ceramide-tear lipocalin complexes using fluorescent analogs were measured consistently in the submicromolar range with 3 methods, linear spectral summation, high speed centrifugal precipitation and standard fluorescence assays. At the relatively small concentrations in tears, all ceramides were complexed to tear lipocalin. The lack of binding of di- and tri-glycerides, squalene, OAHFA, as well as wax and cholesterol esters to tear lipocalin is consonant with residence of these lipids near the air interface.     

Structural and catalytic polymorphism of human enzymes: Novel potential platforms for biomedical diagnostics

This review focuses on some intermediate results on the path from the gene and enzyme structure to physiological responses and personalised medicine. Bioinformatics of genetic and protein-structural polymorphisms, theoretical methods of predicting the influence of single amino acid substitutions on the structure and catalytic activity of enzymes are considered. For a large group of enzymes, interrelations between genetic modifications, structural changes of the proteins and the detected physiological and clinical manifestations are discussed. In this respect, highly productive techniques to determine the catalytic activity of an enzyme as well as non-invasive proteomic approaches are of particular interest. A non-invasive proteomic analysis using mass-spectrometric protein identification of human exhaled breath condensate and tear fluids has been chosen.     

Proteomic analysis of rabbit tear fluid: Defensin levels after an experimental corneal wound are correlated to wound closure

The cornea is the major refracting optical element of the eye and therefore critical for forming a retinal image. The exposed surface of the eye is protected from pathogens by the innate immune system whose components include defensins, naturally occurring peptides with antimicrobial properties, and the physical barrier formed by the outer epithelial layer of the cornea. The proteomic approach has revealed that tear levels of defensins are correlated with the course of healing of an experimental corneal wound. Tears were collected from New Zealand White rabbits prior to (day 0) and daily for 5 days (days 1-5) following a standard unilateral 6 mm diameter corneal epithelial abrasion. Tear protein profiles obtained from wounded and contra-lateral control eyes were compared using SELDI ProteinChip technology. Peptides and proteins of interest were purified by RP-HPLC and characterized by nanoESI-MS/MS. Mass spectra of tears on post-wound day 1, revealed 13 peaks whose level decreased and five that increased. During wound healing the tear protein profile correlated with wound closure. An important finding was that the levels of rabbit defensins (NP-1 and NP-2), which were elevated after wounding returned to normal levels by the time the corneal abrasion healed. Relative quantification of NP-2 in tear fluid prior to (day 0) and after corneal wounding (days 1- 3) was determined using iTRAQ technology. A corneal wound eliminates the barrier function of innate immunity and puts the cornea at risk from microbial attack until the epithelial cells restore the surface barrier. The increased availability of defensins in the tears during healing suggests that these peptides could protect the cornea from microbial attack during a period of increased vulnerability.     

Diadenosine tetraphosphate contributes to carbachol-induced tear secretion

The purpose of this study is to investigate if the cholinergic stimulation by carbachol on tear secretion is a direct process or if it is also mediated by purinergic mechanisms. Experiments were performed in New Zealand male rabbits. The amount of tear secretion was measured with Schirmer’s test and then analyzed by a HPLC protocol in order to study the nucleotide levels. Animal eyes were instilled with carbachol (a cholinergic agonist), pirenzepine, gallamine and 4-DAMP (muscarinic antagonists), PPADS, suramin and reactive blue 2 (purinergic antagonists), and a P2Y₂ receptor small interfering RNA (siRNA). Tear secretion increased with the instillation of carbachol, approximately 84 % over control values 20 min after the instillation and so did Ap₄A and ATP release. When we applied carbachol in the presence of muscarinic antagonists, tear volume only increased to 4 % with atropine, 12 % in the case of pirenzepine, 3 % with gallamine, and 8 % with 4-DAMP. In the presence of carbachol and purinergic antagonists, tear secretion was increased to 12 % (all values compared to basal tear secretion). By analyzing tear secretion induced with carbachol in presence of a P2Y₂ receptor siRNA, we found that tear secretion was diminished to 60 %. The inhibition of tear secretion in the presence of carbachol and purinergic antagonists or P2Y₂ siRNA occurred with no apparent change in the tear amount of Ap₄A. These experiments demonstrated the participation of Ap₄A in lacrimal secretion process.     

Spectroscopic evaluation of human tear lipids

Infrared and fluorescence spectroscopies were applied to characterize the molecular conformational/structure and dynamics of human meibum (ML) and tear lipids (SSL). ML lipids contained more CC and CH3 moieties than SSL. SSL contained OH groups that were not apparent in the spectra of ML. The CO stretching band observed in the infrared spectra of SSL and ML revealed that the CO groups are not involved in hydrogen bonds. Bands due to the polar moieties CO and PO2- did not change significantly with increasing temperature, suggesting that they may not play an appreciable thermodynamic role in the lipid hydrocarbon chain phase transition. Components in tears bind to SSL and exclude water at the water-lipid boundary where the polar headgroups of phospholipids are located. If similar interactions occur in vivo at the tear film lipid-aqueous interface, they would reduce the rate of evaporation. The results provide a foundation for future studies to assess possible differences with age and sex in tears from normal and dry eye subjects.     

Single unit filter-aided method for fast proteomic analysis of tear fluid

Human tear fluid is a complex mixture containing high concentrations of proteins and is increasingly becoming an important source for studying protein biomarkers of eye-related diseases such as Graves’ ophthalmopathy. Today, the Schirmer tear test is the most widely used technique for tear collection. However, sample handling and protein extraction from these strips have been highly challenging. Cutting and removal of the Schirmer strips after extraction, which may lead to sample loss prior to downstream analysis, are some of the challenges to consider. To address some of these limitations, we have developed a single-unit filter-aided method for both sample handling and protein extraction. In addition, we systematically investigated the most suitable conditions for protein extraction from these strips. Among the different extraction conditions applied, extraction with 100 mM ammonium bicarbonate containing 50 mM NaCl resulted in the highest number of identified proteins using one-dimensional liquid chromatography tandem mass spectrometry (LC–MS/MS). Moreover, 1526 proteins were identified when the optimized extraction method was combined with two-dimensional LC–MS/MS analysis, demonstrating the applicability of this novel approach to the study of the tear proteome. This dataset of identified proteins represents a comprehensive catalogue of the tear proteome and may serve as a list for future biomarker research.     

Influence of tendon tears on ultrasound echo intensity in response to loading

Acoustoelastic (AE) ultrasound image analysis is a promising non-invasive approach that uses load-dependent echo intensity changes to characterize stiffness of tendinous tissue. The purpose of this study was to investigate whether AE can detect localized changes in tendon stiffness due to partial and full-thickness tendon tears. Ovine infraspinatus tendons with different levels of damage (Intact, 33%, 66% and full thickness cuts initiated on the articular and bursal sides) were cyclically loaded in a mechanical testing system while cine ultrasound images were recorded. The load-induced changes in echo intensity on the bursal and articular side of the tendon were determined. Consistent with AE theory, the undamaged tendons exhibited an increase in echo intensity with tendon loading, reflecting the strain-stiffening behavior of the tissue. In the intact condition, the articular region demonstrated a significantly greater increase in echo intensity during loading than the bursal region. Cuts initiated on the bursal side resulted in a progressive decrease in echo intensity of the adjacent tissue, likely reflecting the reduced load transmission through that region. However, image intensity information was less sensitive for identifying load transmission changes that result from partial thickness cuts initiated on the articular side. We conclude that AE approaches may be useful to quantitatively assess load-dependent changes in tendon stiffness, and that disruption of AE behavior may be indicative of substantial tendon damage.