AimTo investigate the difference in adhesion and rebubbling rate between eye bank and surgeon prepared Descemet membrane endothelial keratoplasty (DMEK) tissues.MethodsLaboratory and clinical retrospective comparative interventional case series. Research corneal tissues were obtained for laboratory investigation. The clinical study involved patients with endothelial dysfunction who underwent DMEK surgery and tamponade with air. Tissues were stripped using a standard DMEK stripping technique (SCUBA) and shipped as prestripped or loaded in a 2.2 intra-ocular lens cartridge with endothelium facing inwards (preloaded) before transporting from the eye bank to the surgeon. For surgeon prepared tissues, all the grafts were stripped in the theatre and transplanted or stripped in the laboratory and tested immediately. Adhesion force and elastic modulus were measured in the centre and mid-periphery in a laboratory ex vivo investigation using atomic force microscopy, while rebubbling rates were recorded in the clinical study.ResultsThere was no difference in endothelial cell viability between surgeon or eye bank prepared tissue. Surgeon-stripped DMEK grafts in the laboratory investigation showed significantly higher elastic modulus and adhesion force compared to prestripped and preloaded tissues (p<0.0001). In the clinical data, rebubbling rates of 48%, 40% and 15% were observed in preloaded, prestripped and surgeon-stripped DMEK grafts, respectively. Rebubbling rates were significantly associated with combined cataract surgery (p=0.009) and with time from harvesting the graft to the surgery (p=0.02).ConclusionsDecreased adhesion forces and elastic modulus in eye bank prepared tissues may contribute to increased rebubbling rates.

BackgroundOsteomyelitis is a bone infection, most often caused by Staphylococcus aureus, in which neutrophils play a key role. Cathepsin G (CTSG) is a bactericidal serine protease stored in the neutrophil azurophilic granules. CTSG regulates inflammation, activating matrix metalloproteinases (MMPs), and coagulation. Lactoferrin (LF), a neutrophil glycoprotein, increases CTSG catalytic activity and induces inflammation. The aim of this study was to analyze a potential association between a CTSG gene polymorphism (Asn125Ser or N125S, rs45567233), that modifies CTSG activity, and could affect susceptibility to, or outcome of, bacterial osteomyelitis.MethodsCTSG N125S polymorphism was genotyped in 329 osteomyelitis patients and 415 controls), Blood coagulation parameters, serum CTSG activity, LF, MMP-1, MMP-13, and soluble receptor activator for nuclear factor κ B ligand (sRANKL) levels were assessed in carriers of the different CTSG genotypes.ResultsCTSG N125S (AG) genotype was significantly more frequent among osteomyelitis patients than controls (15.5% vs. 9.4%, p = 0.014). CTSG N125S variant G allele (AG +GG) was also more frequent among osteomyelitis patients (8.1% vs. 4.7%, p = 0.01). Serum CTSG activity and LF levels were significantly higher in osteomyelitis patients carrying the G allele compared to those with the AA genotype, (p<0.04). Serum MMP-1 was lower in the G allele carriers (p = 0.01). There was no association between these genotypes and clinical characteristics of osteomyelitis, or coagulation parameters, MMP-13, and sRANKL serum levels.ConclusionsDifferences in the CTSG gene might enhance osteomyelitis susceptibility by increasing CTSG activity and LF levels.

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Primary responses in sepsis-mediated inflammation are regulated by pro-inflammatory cytokines. Variations in the cytokine genes might modify their transcription or expression, plasma cytokines levels and response to sepsis. Activation protein-1 (AP-1) and NF-κB regulate cytokines gene expression in sepsis. A total of 90 severely septic and 91 non-infected patients were prospectively studied. IL-1α ( –889 C/T), IL-1β ( +3954 C/T), IL-6 ( –174 G/C), TNF-α ( –238 G/A), TNF-α ( –308G/A), IL-8 ( –251A/T) and IL-10 ( –1082 G/A) SNPs, plasma IL-1β, IL-4, IL-6, IL-8, IL-10, IL-13, IFN-γ, TNF-α and monocyte chemoattractant protein 1 (MCP-1) levels, and AP-1 and NF-κB gene expression by neutrophils were assessed. A allele carriers of TNF-α ( –238 G/A) SNP were less frequent among septic patients. IL-6, IL-8, IL-10, TNF-α and MCP-1 levels were higher, and AP-1 and NF-κB gene expressions lower in septic patients. Sepsis was independently associated with higher fibrinogen, neutrophils counts and IL-8 levels, lower prothrombin, absence of the variant A allele of the TNF-α (–238 G/A) SNP, and haemodynamic failure. Death was independently associated with a higher APACHE II score, higher IL-8 levels, and the diagnosis of sepsis. TNF-a ( –238 G/A) SNP could protect against sepsis development. Higher IL-8 levels are predictive of sepsis and mortality.