The aim of the present study was to analyse the long-term histology and immunohistochemistry of the plaque composition and cellular infiltration of SVGs (saphenous vein grafts) containing metallic stents. Percutaneous interventions in SVGs have a worse long-term clinical outcome compared with stenting of coronary arteries. Whether the pathological features of old degenerated SVGs condition the efficacy of drug-eluting stents is also unknown. Histology and immunohistochemistry of seven SVGs in the coronary circulation containing 12 metallic stents implanted 5 to 61 months before retrieval were analysed in patients undergoing a second aorto-coronary bypass surgery at a mean time of 11±6 years. The pathology of the old SVGs showed an important thrombotic and necrotic composition of the plaque, with plaque protrusion through the stent wires and a fragile media layer that could easily be damaged by stent placement with subsequent neointimal proliferation; indeed, stents with medial fracture had significantly greater mean neointimal thickness than those without (1.37±0.68 compared with 0.81±0.47 mm 2 ; P <0.02). Neointimal inflammatory cell density correlated with increased neointimal thickness in patent vessels ( r 2 =0.43, P <0.001). Immunostaining showed the total absence of ERs (oestrogen receptors), a poor cellular proliferative state as indicated by the presence of the Ki-67 marker, and persistent inflammation close to the stent wires as revealed by KP-1 and ACE (angiotensin-converting enzyme) immunostaining in most inflammatory cells in contact with the metal. These pathological findings may contribute to the more severe progression of disease and worse clinical outcome observed after conventional stented angioplasty of SVGs and might also interfere with the efficacy of drug-eluting stents in this specific atherosclerotic milieu.

Cholecystokinin (CCK) release after a standard test meal is decreased in coeliac patients. The aim of the study was to determine the origin of the CCK deficiency and the relationship between the distinctive types of mucosal lesions observed in coeliac disease and the number of duodenal CCK cells and their peptide and mRNA content. Duodenal biopsies were obtained in ten controls and nineteen coeliac patients [seven with atrophic mucosa, six with increased numbers of intraepithelial lymphocytes (IELs) and six with fully normalized mucosa]. Immunocytochemistry was performed with a CCK C-terminal-specific polyclonal antiserum. The CCK cells were counted and related to the epithelial area using a semi-automated image analyser. CCK content in mucosal extracts was determined by radioimmunoassay. mRNA was measured with a semi-quantitative reverse transcriptase–PCR method using specific CCK and ribosomal protein L19 (RPL19) primers. CCK tissue concentration and CCK mRNA were significantly reduced in patients with atrophic mucosa [12.2 (range 6.9–17.5) pmol/g; CCK/RPL19 ratio 0.64 (0.30–0.99)] compared with patients with normal mucosa [40.5 (30.4–50.7) pmol/g; CCK/RPL19 ratio 1.40 (0.41–2.40)] or controls [42.7 (18.2–67.2) pmol/g; CCK/RPL19 ratio 1.35 (1.09–1.62)]. A similar decrease was observed in patients with an excess of IELs, 13.9 (3.8–31.8) pmol/g and 0.86 (0.57–1.15) pmol/g respectively. The number of CCK cells was, however, similar in all groups. Duodenal CCK concentration and mRNA are decreased not only in the mucosa presenting atrophic changes but also when disease activity is limited to infiltration by IELs. Reduced expression of the CCK gene could therefore be related to suppressive factors induced by the inflammatory infiltrate.

Ischaemia/reperfusion (I/R) lung injury using University of Wisconsin solution (UW) as perfusate has not been well studied. Isolated rat lungs were challenged with various periods of ischaemia and/or reperfusion. Haemodynamics, lung weight gain (LWG), capillary filtration coefficient ( K fc ), tissue pathology, the concentrations of cytokines in the perfusate, and mRNAs for the various cytokines in the lung tissues were measured. I/R induced a permeability type of pulmonary oedema, as reflected by increases in LWG and K fc . LWG and K fc in the I 45 R 60 (UW) group (45 min of ischaemia followed by 60 min of reperfusion with UW) were only 2% and 5% respectively of those in the I 45 R 60 (NS) group (where NS is normal saline). LWG and K fc in the UW group had both increased by 180 min, to values similar to those in the I 45 R 60 (NS) group. However, these findings show that UW was remarkably effective at preventing LWG after 60 min of reperfusion, and was more than 3-fold more effective than NS in delaying LWG. For longer ischaemic times only, or the same period of ischaemia followed by longer reperfusion periods, greater lung injury occurred. I/R lung injury also induced increased concentrations of tumour necrosis factor-α (TNF-α), interleukin 1 and interleukin 6 in the perfusate, and increased the mRNAs for these cytokines in lung tissue. A significant correlation was obtained between TNF-α concentration and LWG. TNF-α production in the I 45 R 60 (UW) group was only 7% of that in the I 45 R 60 (NS) group. However, TNF-α mRNA expression in the I 45 R 60 (UW) group was 80% of that in the I 45 R 60 (NS) group. This indicates that transcription/translation do not correlate well with cytokine production, and also suggests that one reason for the effectiveness of UW in delaying LWG may be because it delays TNF-α production. In summary, ischaemia or I/R caused a permeability-type pulmonary oedema that was associated with leucocyte infiltration and the up-regulation of various cytokines, regardless of the perfusion fluid. Except for pulmonary hypertension, less severe I/R lung injury and delayed cytokine production in lungs perfused with UW, the pattern of injury associated with I/R challenge was similar to that in lungs perfused with NS. We propose that more or long-acting protective agents are required as additives in order to modify UW to produce an optimal preservation solution.

The choice of an intravenous solution for the attenuation of ischaemia/reperfusion (I/R) lung injury is still a difficult one. Although 10% (w/v) pentastarch has been used in ICU settings, its use in I/R lung injury has not been well explored. We hypothesized that this synthetic colloid substance, which maintains colloid osmotic pressure and potentially ‘seals’ capillary leaks, in combination with an anti-inflammatory agent (i.e. dexamethasone), would ameliorate I/R lung injury. After 60 min of lung ischaemia in an isolated rat lung model, lungs were reperfused for 60 min in a closed circulating system with one of the following solutions: (1) NS (0.9% normal saline), (2) NS+Dex (dexamethasone), (3) NS+Penta (pentastarch), or (4) NS+Penta+Dex. Haemodynamic changes, lung weight gain (LWG), capillary filtration coefficient ( K fc ) and lung pathology were analysed. Results showed significantly lower values of K fc and LWG in pentastarch- or dexamethasone-perfused groups as compared with those in the NS group. Dexamethasone as an additive to NS+Penta further decreased K fc and LWG. Histopathological studies showed similar decreases in injury profiles. We conclude that reperfusion with dexamethasone and pentastarch can attenuate I/R lung injury, and that dexamethasone and pentastarch have additive effects. Our data thus suggest that the combination of a colloid substance with ‘sealing effects’ and an anti-inflammatory agent may provide a better reperfusion solution for patients with I/R lung injury or for lungs stored for transplant.