Preliminary Results of a Prospective Randomized Trial of Restrictive Versus Standard Fluid Regime in Elective Open Abdominal Aortic Aneurysm Repair

Background: Open abdominal aortic aneurysm (AAA) repair is associated with a significant morbidity (primarily respiratory and cardiac complications) and an overall mortality rate of 4% to 10%. We tested the hypothesis that perioperative fluid restriction would reduce complications and improve outcome after elective open AAA repair.

Advanced glycation end products cause increased CCN family and extracellular matrix gene expression in the diabetic rodent retina

Aims/hypothesis: Referred to as CCN, the family of growth factors consisting of cystein-rich protein 61 (CYR61, also known as CCN1), connective tissue growth factor (CTGF, also known as CCN2), nephroblastoma overexpressed gene (NOV, also known as CCN3) and WNT1-inducible signalling pathway proteins 1, 2 and 3 (WISP1, -2 and -3; also known as CCN4, -5 and -6) affects cellular growth, differentiation, adhesion and locomotion in wound repair, fibrotic disorders, inflammation and angiogenesis. AGEs formed in the diabetic milieu affect the same processes, leading to diabetic complications including diabetic retinopathy. We hypothesised that pathological effects of AGEs in the diabetic retina are a consequence of AGE-induced alterations in CCN family expression.

Materials and methods: CCN gene expression levels were studied at the mRNA and protein level in retinas of control and diabetic rats using real-time quantitative PCR, western blotting and immunohistochemistry at 6 and 12 weeks of streptozotocin-induced diabetes in the presence or absence of aminoguanidine, an AGE inhibitor. In addition, C57BL/6 mice were repeatedly injected with exogenously formed AGE to establish whether AGE modulate retinal CCN growth factors in vivo.

Results: After 6 weeks of diabetes, Cyr61 expression levels were increased more than threefold. At 12 weeks of diabetes, Ctgf expression levels were increased twofold. Treatment with aminoguanidine inhibited Cyr61 and Ctgf expression in diabetic rats, with reductions of 31 and 36%, respectively, compared with untreated animals. Western blotting showed a twofold increase in CTGF production, which was prevented by aminoguanidine treatment. In mice infused with exogenous AGE, Cyr61 expression increased fourfold and Ctgf expression increased twofold in the retina.

Conclusions/interpolation: CTGF and CYR61 are downstream effectors of AGE in the diabetic retina, implicating them as possible targets for future intervention strategies against the development of diabetic retinopathy.

Efficacy of a standard meticillin-resistant Staphylococcus aureus decolonisation protocol in routine clinical practice

Summary

Decolonisation may reduce the risk of meticillin-resistant Staphylococcus aureus (MRSA) infection in individual carriers and prevent transmission to other patients. The aims of this prospective cohort study were to determine the long-term efficacy of a standardised decolonisation regimen and to identify factors associated with failure. Patients colonised with MRSA underwent decolonisation, which was considered to be successful if there was no growth in three consecutive sets of site-specific screening swabs obtained weekly post treatment. If patients were successfully decolonised, follow-up cultures were performed 6 and 12 months later. Of 137 patients enrolled, 79 (58%) were successfully decolonised. Of these 79, 53 (67%) and 44 (56%) remained decolonised at 6 and 12 months respectively. Therefore only 44/137 (32%) patients who completed decolonisation were MRSA negative 12 months later. Outcome was not associated with a particular strain of MRSA. Successful decolonisation was less likely in patients colonised with a mupirocin-resistant isolate (adjusted odds ratio: 0.08; 95% confidence interval: 0.02–0.30), in patients with throat colonisation (0.22; 0.07–0.68) and in patients aged >80 years (0.30; 0.10–0.93) compared with those aged 60–80 years. These findings suggest that although initially successful in some cases, the protocol used did not result in long-term clearance of MRSA carriage for most patients.

Advanced glycation end products in vitreous: Structural and functional implications for diabetic vitreopathy

PURPOSE. Advanced glycation end products (AGES) form irreversible cross- links with many macromolecules and have been shown to accumulate in tissues at an accelerated rate in diabetes. In the present study, AGE formation in vitreous was examined in patients of various ages and in patients with diabetes. Ex vivo investigations were performed on bovine vitreous incubated in glucose to determine AGE formation and cross-linking of vitreous collagen. METHODS. By means of an AGE-specific enzyme-linked immunosorbent assay (ELISA), AGE formation was investigated in vitreous samples obtained after pars plana vitrectomy in patients with and without diabetes. In addition, vitreous AGES were investigated in bovine vitreous collagen after incubation in high glucose, high glucose with aminoguanidine, or normal saline for as long as 8 weeks. AGEs and AGE cross-linking was subsequently determined by quantitative and qualitative assays. RESULTS. There was a significant correlation between AGEs and increasing age in patients without diabetes (r = 0.74). Furthermore, a comparison between age-matched diabetic and nondiabetic vitreous showed a significantly higher level of AGEs in the patients with diabetes (P < 0.005). Collagen purified from bovine vitreous incubated in 0.5 M glucose showed an increase in AGE formation when observed in dot blot analysis, immunogold labeling, and AGE ELISA. Furthermore, there was increased cross-linking of collagen in the glucose-incubated vitreous, when observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and protein separation. This cross-linking was effectively inhibited by coincubation with 10 mM aminoguanidine. CONCLUSIONS. This study suggests that AGEs may form in vitreous with increasing age. This process seems to be accelerated in the presence of diabetes and as a consequence of exposure to high glucose. Advanced glycation and AGE cross-linking of the vitreous collagen network may help to explain the vitreous abnormalities characteristic of diabetes.

Reconfigurable system-on-a-chip motion estimation architecture for multi-standard video coding

A new domain-specific, reconfigurable system-on-a-chip (SoC) architecture is proposed for video motion estimation. This has been designed to cover most of the common block-based video coding standards, including MPEG-2, MPEG-4, H.264, WMV-9 and AVS. The architecture exhibits simple control, high throughput and relatively low hardware cost when compared with existing circuits. It can also easily handle flexible search ranges without any increase in silicon area and can be configured prior to the start of the motion estimation process for a specific standard. The computational rates achieved make the circuit suitable for high-end video processing applications, such as HDTV. Silicon design studies indicate that circuits based on this approach incur only a relatively small penalty in terms of power dissipation and silicon area when compared with implementations for specific standards. Indeed, the cost/performance achieved exceeds that of existing but specific solutions and greatly exceeds that of general purpose field programmable gate array (FPGA) designs.