Cytokine gene polymorphisms predict acute graft rejection following renal transplantation

BACKGROUND

The proinflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) has been implicated in the pathogenesis of acute rejection, while animal models suggest a role for interleukin-10 (IL-10) in promoting graft survival. It has also been shown that polymorphisms in the TNFA gene promoter (position -308) and in the IL-10 gene promoter (position -1082) correlate with differential production of these cytokines in vitro. The aim of this study was to determine whether TNF-alpha and IL-10 gene polymorphisms influence the incidence and severity of acute rejection in the first six months following renal transplantation.

METHODS

The cytokine genotypes of 115 consecutive first cadaveric kidney allograft recipients and their donors were screened. The rejection episodes (REs) were defined clinically and confirmed histologically where possible and further classified according to severity (RS), namely steroid-resistant or responsive REs. The genotypes were then correlated with the REs and RS.

RESULTS

The recipient TNF-alpha high producer genotype and IL-10 high producer genotype were significantly associated with multiple REs (>/=2) in human leukocyte antigen (HLA)-DR mismatched transplants (P = 0.0047 and P = 0.045, respectively), whereas only the TNF-alpha high producer genotype was associated with steroid-resistant REs (P = 0.025). When recipient cytokines were analyzed together, the TNF-alpha high/IL-10 high producer genotype had the worst prognosis, whereas TNF-alpha low/IL-10 low producer genotype was protective.

CONCLUSIONS

We conclude that recipient TNF-alpha and IL-10 gene polymorphisms are determinants of REs and RS following kidney transplantation. Routine screening of these gene polymorphisms may have a clinical role in identifying patients at risk of multiple REs and severe rejections.

Regulation of senescence associated signaling mechanisms in chondrocytes for cartilage tissue regeneration

Adult articular chondrocytes undergo slow senescence and dedifferentiation during in vitro expansion, restricting successful cartilage regeneration. A complete understanding of the molecular signaling pathways involved in the senescence and dedifferentiation of chondrocytes is essential in order to better characterize chondrocytes for cartilage tissue engineering applications. During expansion, cell fate is determined by the change in expression of various genes in response to aspects of the microenvironment, including oxidative stress, mechanical stress, and unsuitable culture conditions. Rapid senescence or dedifferentiation not only results in the loss of the chondrocytic phenotype but also enhances production of inflammatory mediators and matrix-degrading enzymes. This review focuses on the two groups of genes that play direct and indirect roles in the induction of senescence and dedifferentiation. Numerous degenerative signaling pathways associated with these genes have been reported. Upregulation of the genes interleukin 1 beta (IL-1β), p53, p16, p21, and p38 mitogen-activated protein kinase (MAPK) is responsible for the direct induction of senescence, whereas downregulation of the genes transforming growth factor-beta (TGF-β), bone morphogenetic protein-2 (BMP-2), SRY (sex determining region Y)-box 9 (SOX9), and insulin-like growth factor-1 (IGF-1), indirectly induces senescence. In senescent and dedifferentiated chondrocytes, it was found that TGF-β, BMP-2, SOX9, and IGF-1 are downregulated, while the levels of IL-1β, p53, p16, p21, and p38 MAPK are upregulated followed by inhibition of the normal molecular functioning of the chondrocytes. This review helps to elucidate the underlying mechanism in degenerative cartilage disease, which may help to improve cartilage tissue regeneration techniques.

A critical appraisal of endorectal ultrasound and transanal endoscopic microsurgery and decision-making in early rectal cancer

AIM

Transanal endoscopic microsurgery (TEM) for early rectal cancer (ERC) gives results similar to major surgery in selected cases. Endorectal ultrasound (ERUS) is an important part of the preoperative selection process. This study reports its accuracy and impact for patients entered on the UK TEM database.

METHOD

The UK TEM database comprises prospectively collected data on 494 patients. This data set was used to determine the prevalence of ERUS in preoperative staging and its accuracy by comparing preoperative T-stage with definitive pathological staging following TEM.

RESULTS

ERUS was performed in 165 of 494 patients who underwent TEM for rectal cancer. It inaccurately staged rectal cancer in 44.8% of tumours: 32.7% were understaged and 12.1% were overstaged. There was no significant difference in the depth of TEM excision or R1 rate between the patients who underwent ERUS before TEM and those who did not (P = 0.73).

CONCLUSION

The data show that ERUS is employed in a minority of patients with rectal cancers undergoing TEM in the UK and its accuracy in this 'Real World' practice is disappointing.

Effect of dietary supplementation of prebiotics and probiotics on intestinal microarchitecture in broilers reared under cyclic heat stress

This study was designed to evaluate the effect of dietary supplementation of prebiotics, mannanoligosaccharides (MOS) and/or probiotics (LBP) on intraepithelial lymphocytes (IEL) count, goblet cells (GC) count and differentiation and intestinal micro-architecture in broilers reared under cyclic heat stress. Day-old broilers (n = 250) were randomly divided into five groups. Fifty birds were reared within the thermoneutral zone (TNZ). Remaining birds were subjected to cyclic heat stress from day 21 to 42 (35° C, 75% RH, 8 h/d). The birds were fed corn-soy-based basal diet or the same diet supplemented with 0.5% MOS (HS-MOS), or 0.1% LBP (HS-LBP), or their combination (HS-SYN). The birds were slaughtered on day 42. Tissue samples were collected from mid-duodenum, jejunum and ileum, and stained with haematoxylin and eosin or combined Alcian blue and PAS technique. All differences were considered significant at p < 0.05. The IEL count increased in all intestinal segments of the HS group compared with the TNZ group and decreased in all supplemented groups compared with the HS group. Compared with the TNZ, heat stress reduced villus height, crypt depth and surface area in duodenum and ileum, and increased crypt depth in ileum. Villus width decreased in duodenum and jejunum compared with the TNZ group. Supplementation of LBP, MOS and SYN reversed all these changes in duodenum, while only increased villus height and surface area in ileum. In jejunum, the villus height and surface area increased with HS-LBP, and crypt depth increased with HS-MOS. The number of GC containing acid mucins (duodenum and ileum) and mixed mucins (ileum) were increased in the HS compared with the TNZ. Supplementation of MOS, LBP and SYN maintained the enhanced activity of goblet cells. In conclusion, dietary supplementation of MOS and/or LBP may be helpful in alleviating some of the detrimental effects of heat stress on microstructure of the broiler gut.

Complications in surgery for Crohn's disease after preoperative antitumour necrosis factor therapy

BACKGROUND

The use of biological therapy (biologicals) is established in the treatment of Crohn's disease. This study aimed to determine whether preoperative treatment with biologicals is associated with an increased rate of complications following surgery for Crohn's disease with intestinal anastomosis.

METHODS

All patients receiving biologicals and undergoing abdominal surgery with anastomosis or strictureplasty were identified at six tertiary referral centres. Demographic data, and preoperative, operative and postoperative details were registered. Patients who were treated with biologicals within 2 months before surgery were compared with a control group who were not. Postoperative complications were classified according to anastomotic, infectious or other complications, and graded according to the Clavien-Dindo classification.

RESULTS

Some 111 patients treated with biologicals within 2 months before surgery were compared with 187 patients in the control group. The groups were well matched. There were no differences between the treatment and control groups in the rate of complications of any type (34·2 versus 28·9 per cent respectively; P = 0·402), anastomotic complications (7·2 versus 8·0 per cent; P = 0·976) and non-anastomotic infectious complications (16·2 versus 13·9 per cent; P = 0·586). In univariable regression analysis, biologicals were not associated with an increased risk of any complication (odds ratio (OR) 1·33, 95 per cent confidence interval 0·81 to 2·20), anastomotic complication (OR 0·89, 0·37 to 2·17) or infectious complication (OR 1·09, 0·62 to 1·91).

CONCLUSION

Treatment with biologicals within 2 months of surgery for Crohn's disease with intestinal anastomosis was not associated with an increased risk of complications.

Differences in structural and pain phenotypes in the sodium monoiodoacetate and meniscal transection models of osteoarthritis

OBJECTIVES

To characterize differences in joint pathology and pain behavior between two rat models of osteoarthritis (OA) in order to inform selection of animal models for interventional studies.

METHOD

Knee OA was induced in Sprague Dawley rats by either meniscal transection (MNX) or intra-articular injection of monosodium iodoacetate (MIA). Controls were subjected to sham surgery or saline-injection. In a separate experiment, a single intra-articular injection of triamcinolone acetonide was administered 14 days after MNX or MIA arthritis induction. Pain behavior and joint pathology were quantified.

RESULTS

Both models displayed synovial inflammation, chondropathy and osteophytosis. Chondropathy scores increased with time similarly in the two models. Inflammation and osteophyte scores were greater in MNX model compared to the MIA model. At day 49, the MNX model exhibited a greater number of channels crossing the osteochondral junction compared to all other groups. The MNX model exhibited greater weight bearing asymmetry compared to the MIA model, whereas the MIA model displayed more consistent hindpaw allodynia. Triamcinolone attenuated weight bearing asymmetry and distal allodynia to control levels in the MNX model, but distal allodynia was unaltered in the MIA model.

CONCLUSIONS

The comparison of the two models of OA in rats, using identical assessment tools has demonstrated that although both models display features of OA, there are differences between the models which may represent different aspects of human OA. Thus, model selection should be based on the pathological aspects of OA under investigation.

Colloid solutions for fluid resuscitation

BACKGROUND

Colloids are widely used in the replacement of fluid volume. However doubts remain as to which colloid is best. Different colloids vary in their molecular weight and therefore in the length of time they remain in the circulatory system. Because of this and their other characteristics, they may differ in their safety and efficacy.

OBJECTIVES

To compare the effects of different colloid solutions in patients thought to need volume replacement.

SEARCH STRATEGY

We searched the Cochrane Injuries Group specialised register, CENTRAL (2007, Issue 1), MEDLINE (1994 to March 2007), EMBASE (1974 to March 2007), and the National Research Register (2007, issue 1). Bibliographies of trials retrieved were searched, and drug companies manufacturing colloids were contacted for information. The search was last updated in March 2007.

SELECTION CRITERIA

Randomised and quasi-randomised trials comparing colloid solutions in critically ill and surgical patients thought to need volume replacement. The outcomes measured were death, amount of whole blood transfused, and incidence of adverse reactions.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted the data and assessed the quality of the trials.

MAIN RESULTS

Seventy trials, with a total of 4375 participants, met the inclusion criteria. Quality of allocation concealment was judged to be adequate in 24 trials and poor or uncertain in the rest. Deaths were obtained in 46 trials. For albumin or PPF versus hydroxyethyl starch (HES) 25 trials (n = 1234) reported mortality. The pooled relative risk (RR) was 1.14 (95% CI 0.91 to 1.43). For albumin or PPF versus gelatin, seven trials (n = 636) reported mortality. The RR was 0.97 (95% CI 0.68 to 1.39). For albumin or PPF versus Dextran four trials (n = 360) reported mortality. The RR was 3.75 (95% CI 0.42 to 33.09). For gelatin versus HES 18 trials (n = 1337) reported mortality and RR was 1.00 (95% CI 0.80 to 1.25). RR was not estimable in the gelatin versus dextran and HES versus dextran groups.Thirty-seven trials recorded the amount of blood transfused, however quantitative analysis was not possible due to skewness and variable reporting. Nineteen trials recorded adverse reactions, but none occurred.

AUTHORS' CONCLUSIONS

From this review, there is no evidence that one colloid solution is more effective or safe than any other, although the confidence intervals are wide and do not exclude clinically significant differences between colloids. Larger trials of fluid therapy are needed if clinically significant differences in mortality are to be detected or excluded.

"Low-dose" aprotinin modifies hemostasis but not proinflammatory cytokine release

BACKGROUND

Cytokines are implicated in the pathogenesis of the "whole-body inflammatory response" that may complicate the period after cardiopulmonary bypass (CPB). Low-Dose aprotinin in the pump during CPB has been shown to improve postoperative hemostasis and platelet preservation. We tested the hypothesis that low-dose aprotinin influences the inflammatory reaction (in terms of cytokine release) after CPB.

METHODS

In a prospective, randomized study, 36 patients undergoing elective coronary artery bypass grafting were investigated. Nineteen patients received low-dose aprotinin (2 x 10(6) KIU (280 mg] in the pump), and a control group of 19 did not. Complement activation, cytokine production, leukocyte elastase release. D-dimer level, full blood count, postoperative blood loss, and transfusion requirements were analyzed before, during, and after after CPB.

RESULTS

Interleukin-1 beta was not detected in either group, whereas traces of tumor necrosis factor-alpha were infrequently observed. Plasma elastase, interleukin-6, interleukin-8, and neutrophil count increased (p < 0.001) during and after CPB compared with the baseline levels, reaching a peak at 2 hours after protamine administration in both groups before returning toward baseline at 24 hours. Proinflammatory cytokine markers did not differ significantly (p > 0.1) between the groups throughout the study period. The C5b-9 level increased (p < 0.001) in both groups perioperatively, reaching its peak 15 minutes after protamine. Twenty-four-hour postoperative blood loss was significantly (p < 0.001) reduced in the aprotinin group in association with markedly reduced D-dimer levels (p < 0.001). Patients in the aprotinin group also received significantly less banked blood postoperatively than the control group (p < 0.01).

CONCLUSIONS

Low-dose aprotinin fails to modify proinflammatory cytokine release, yet confers hemostatic improvement through reduced fibrinolysis in patients undergoing routine coronary artery bypass grafting.

Low heparinization with heparin-bonded bypass circuits: is it a safe strategy?

BACKGROUND

The use of heparin-bonded cardiopulmonary bypass circuits with reduced doses of heparin sodium has been shown to give hemostatic benefits to the patient. However, fears persist that the use of less heparin may put the patient at risk for thrombotic events. This work tested the hypothesis that heparin-bonded circuits per se are effective in preserving cells and reducing thrombin generation when a reduced dose of heparin is used in vitro.

METHODS

Simulated extracorporeal circulation was carried out using the same unit of fresh heparinized (1.1 U/mL) human blood to simultaneously perfuse a heparin-bonded circuit and a nonbonded circuit. Samples were taken at 30, 60, 120, and 360 minutes and analyzed for markers of cell activation and thrombin generation.

RESULTS

The concentrations of platelet and white blood cell activation markers were found to be significantly lower in the heparin-bonded circuits compared with the nonbonded circuits. In addition, markers of thrombin generation were significantly lower in bonded circuits. Scanning electron microscopy revealed fewer adherent cells and less debris on the bonded surface compared with the nonbonded surface.

CONCLUSIONS

Cell activation and thrombin generation were significantly reduced as a result of the presence of immobilized heparin in a system of cardiopulmonary bypass with reduced plasma heparin. However, evidence of contact activation in the bonded circuits was found after 120 minutes, indicating that anticoagulation in the system was not adequate. This becomes more important clinically where the extrinsic pathway of coagulation is also involved.

Cytokine and S100B levels in paediatric patients undergoing corrective cardiac surgery with or without total circulatory arrest

OBJECTIVES

Neurological damage following cardiopulmonary bypass (CPB) is difficult to objectively evaluate in infants. In adults, serum elevations of astroglial S100B correlate with proven brain injury independent of operative temperature. The deleterious effects of inflammatory cytokines, generated during CPB, on the brain have not been studied in infants using S100B as a marker for cerebral injury.

METHODS

Twelve neonates, weighing 3.3 +/- 0.2 kg (total circulatory arrest group (TCA)) and 12 infants weighing 7.0 +/- 1.0 kg (cardiopulmonary bypass group (CPB)) underwent corrective cardiac surgery for various pathologies. Serial blood samples on induction, at the end of CPB, 30 min, 2 h and 24 h after the administration of protamine, were taken. The resultant plasma was frozen to -80 degrees C and stored for batch analysis. Cytokines were measured using ELISAs and S100B using a luminometric assay.

RESULTS

The TCA group were younger and experienced a longer perfusion time than the CPB group (137 +/- 8 vs. 113 +/- 7, P = 0.04). The mean TCA time was 23 +/- 4 min. The TCA group had significantly higher levels of IL-6 (P = 0.001), IL-8 (P = 0.005) and S100B (P = 0.002) at 24 h. C5b-9 levels were significantly lower in the TCA group: end of CPB (P = 0.001), 30 min (P < 0.001), 2 h (P = 0.002). There was a weak, but significant correlation between IL-6 levels at the end of CPB and S100B levels 2 h later (r = 0.55, P = 0.03). Long extubation times were associated with high 24-h S100B levels (r = 0.52, P = 0.01).

CONCLUSIONS

(1) The TCA group have prolonged rises of IL-6, IL-8 and S100B. (2) The TCA group generates significantly lower complement. (3) Astroglial injury, seen after surgery, may, in part, be cytokine mediated.

Banff criteria as predictors of outcome following acute renal allograft rejection

BACKGROUND

The Banff classification of renal allograft rejection grades acute tubulointerstitial rejection (AIR) by severity of tubulitis and acute vascular rejection (AVR) by severity of arteritis. The intensity of tubulitis has not, however, been demonstrated to be of prognostic value and other features such as glomerulitis and eosinophil infiltration are of uncertain significance. This study was performed in order to determine the clinical value of this pathological classification.

METHODS

Banff criteria were correlated with outcome in 134 consecutive graft recipients transplanted in our unit over a 3-year period (1994 1996) who experienced at least one biopsy-confirmed acute rejection episode. Of 197 biopsies performed for the diagnosis of rejection, 177 contained at least one artery and were suitable for Banff grading. Tissue eosinophil counts were available for 101 biopsies. Clinical severity of rejection was classified as mild (fully responsive to pulse steroid therapy), moderate (partially steroid responsive) and severe (steroid unresponsive/requiring ATG therapy).

RESULTS

Graft failure ensued in 18 of 58 patients with AVR compared with 10 of 65 patients with AIR (P= < 0.05). Clinical severity of rejection correlated with the presence of arteritis, but not severity of tubulitis; rejections graded I, IIA and IIB according to the Banff' 93 classification were clinically severe in 3/68 (4%), 2/28 (7%) and 15/67 (22%) respectively (P= <0.05). The presence of glomerulitis showed no correlation with clinical severity or graft loss. Tissue eosinophilia (>10 eosinophils/mm2) was present in 18 of 33 patients who had at least one episode of AVR (v1/2), compared with 11 of 45 patients who suffered only AIR (P= <0.02).

CONCLUSIONS

We conclude that: arteritis, but not severe tubulitis or glomerulitis, is an adverse prognostic factor in acute rejection and that tissue eosinophilia is associated with vascular rejection. Our findings support the 1997 revision of the Banff classification, replacing grades with types of acute rejection.

Release of proinflammatory cytokines during pediatric cardiopulmonary bypass: heparin-bonded versus nonbonded oxygenators

BACKGROUND

Heparin bonding of the cardiopulmonary bypass (CPB) circuit may be associated with a reduced inflammatory response and improved clinical outcome. The relative contribution of a heparin-bonded oxygenator (ie, >80% of circuit surface area) to these effects was assessed in a group of pediatric patients.

METHODS

Twenty-one pediatric patients undergoing CPB operations were assigned randomly to receive either a heparin-bonded oxygenator (group H, n = 11) or a nonbonded oxygenator (group C, n = 10) in otherwise nonbonded circuits. The two groups were similar in pathology, age, weight, CPB time, and cross-clamp time. Plasma levels of the cytokines tumor necrosis factor-alpha, interleukin-6, and interleukin-8, as well as terminal complement complex, neutrophils, and elastase, were analyzed before, during, and after CPB.

RESULTS

Significant levels of tumor necrosis factor-alpha were not detected in either group. Plasma levels of all other markers increased during and after CPB compared with baseline. Plasma levels of interleukin-6 peaked in both groups 2 hours after the administration of protamine but remained significantly higher in group C 24 hours after operation. Plasma concentrations of interleukin-8 peaked at similar levels in both groups 30 minutes after protamine administration and returned to baseline thereafter. Levels of terminal complement complex and elastase peaked in both groups 30 minutes after protamine administration. Plasma levels of terminal complement complex were significantly higher at the end of CPB and after protamine administration in group C. Elastase levels were significantly higher 2 and 24 hours after CPB in group C. The ventilation time of patients in group H was significantly lower than that of patients in group C: 10 (range, 3 to 24) versus 22 (range, 7 to 24) hours, respectively (p < 0.01).

CONCLUSIONS

The present study confirms the proinflammatory nature of pediatric operations and demonstrates a lessened systemic inflammatory response with the use of heparin-bonded oxygenators. This is achieved without bonding of the entire circuit, which could have significant cost-benefit implications by negating the need for custom-built heparin-bonded circuitry.

Inflammatory mediators in adults undergoing cardiopulmonary bypass: comparison of centrifugal and roller pumps

BACKGROUND

The nonocclusive centrifugal pump is used for cardiopulmonary bypass (CPB) and mechanical cardiac assistance. This study examined its impact on proinflammatory cytokine release.

METHODS

Forty-one patients undergoing elective coronary artery bypass grafting were randomized prospectively to either a standard roller pump group (n = 21) or a centrifugal vortex pump group (n = 20) for CPB. The two groups were well matched in age, sex, severity of disease, and duration of CPB and aortic cross-clamping. Plasma levels of the cytokines tumor necrosis factor-alpha, interleukin-1beta, interleukin-6, and interleukin-8, as well as terminal complement, neutrophil counts, and leukocyte elastase, were analyzed before, during, and after CPB.

RESULTS

In both groups, traces of tumor necrosis factor-alpha were observed infrequently and interleukin-1beta was not detected. Plasma levels of interleukin-6 and interleukin-8 increased during and after CPB, reaching a peak at 2 hours after protamine administration in both groups before returning toward baseline at 24 hours. The release of interleukin-6 was significantly greater in the centrifugal group (p < 0.05), whereas the interleukin-8 concentration did not differ between the groups throughout the study period. Levels of terminal complement increased in both groups perioperatively, reaching a peak 30 minutes after protamine administration, whereas neutrophil counts and elastase peaked 2 hours after protamine administration. Plasma terminal complement, neutrophil counts, and elastase release were significantly higher in the centrifugal group (p < 0.05). Peak terminal complement correlated (r = 0.64, p < 0.01) with peak elastase in the centrifugal group only.

CONCLUSIONS

This study confirms the proinflammatory nature of CPB in adults and demonstrates that use of the centrifugal pump induces a greater systemic inflammatory response than use of the standard roller pump.

Human islets derived from donors after cardiac death are fully biofunctional

Islets from brain-dead donors (BDDs) are being used in the treatment of Type 1 diabetes. However, both donor numbers and islet survival are limited. We explored the clinical potential for islets from non-heart-beating donors (NHBDs), who have lower circulating cytokines, by comparing islets from 10 NHBDs against 12 identically-isolated islets from BDDs over the same time period. The quantity and quality of islets from NHBDs was good. NHBD yielded approximately 12.6% more islets than those of BDDs (505,000 +/- 84,230 vs. 400,970 +/- 172,430 islet equivalent number [IEQ]/pancreas, p = 0.01) with comparable viability. ATP and GTP contents were lower (6.026 +/- 3.076 vs. 18.105 +/- 7.8 nM/mg protein, p = 0.01 and 1.52 +/- 0.87 vs. 3.378 +/- 0.83 nM/mg protein, p = 0.04) and correlated negatively to warm ischemia time (R(2)= 0.8022 and R(2)= 0.7996, respectively). Islets from NHBDs took longer to control hyperglycemia in diabetic mice, but were equally able to sustain euglycemia. With a warm ischemia time (WIT) of <or=25 min, islets from NHBDs are at least as competent as islets from BDDs and should be suitable for clinical use.

Optimal dissection for transanal total mesorectal excision using modified CO2 insufflation and smoke extraction

AIM

The new approach of transanal total mesorectal excision is technically challenging and demands a stable field of dissection with optimal view of anatomical landmarks. We aimed to describe and demonstrate a modification of both the insufflation of carbon dioxide and smoke evacuation, in order to optimize dissection.

METHOD

The comparison of standard insufflation to an AirSeal platform demonstrates a clear difference. This is shown in the accompanying video-recordings.

RESULTS

A more stable pneumorectum and better smoke evacuation as well as more convenient and precise dissection were achieved with the AirSeal platform.

CONCLUSION

Using the technique outlined, the operating surgeon is able to perform the surgical dissection in a stable operating environment with increased visibility compared to the standard approach.

Lymphatic vessels in osteoarthritic human knees

OBJECTIVES

The distribution and function of lymphatic vessels in normal and diseased human knees are understood incompletely. This study aimed to investigate whether lymphatic density is associated with clinical, histological or radiographic parameters in osteoarthritis (OA).

METHODS

Sections of synovium from 60 knees from patients with OA were compared with 60 post mortem control knees (from 37 individuals). Lymphatic vessels were identified using immunohistochemistry for podoplanin, and quantified as lymphatic vessel density (LVD) and lymphatic endothelial cell (LEC) fractional area. Effusion status was determined by clinical examination, radiographs were scored for OA changes, and inflammation grading used haematoxylin and eosin stained sections of synovium.

RESULTS

Lymphatic vessels were present in synovia from both disease groups, but were not identified in subchondral bone. Synovial lymphatic densities were independent of radiological severity and age. Synovia from patients with OA displayed lower LVD (z=-3.4, P=0.001) and lower LEC fractional areas (z=-4.5, P<0.0005) than non-arthritic controls. In patients with OA, low LVD was associated with clinically detectable effusion (z=-2.2, P=0.027), but not with histological evidence of synovitis. The negative associations between lymphatics and OA/effusion appeared to be independent of other measured confounders.

CONCLUSION

Lymphatic vessels are present in lower densities in OA synovia. Abnormalities of synovial fluid drainage may confound the value of effusion as a clinical sign of synovitis in OA.

The absence of autonomic perivascular nerves in human colorectal liver metastases

The peptidergic/aminergic innervation of normal liver and tumour blood vessels was investigated in order to determine vascular control with a view to improving the efficacy of hepatic arterial cytotoxic infusion in the treatment of colorectal liver metastases. Selected areas of liver metastases and macroscopically normal liver from resection specimens (n = 13) were studied using light microscope immunohistochemistry for the presence of protein gene product 9.5 (PGP), vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), calcitonin gene-related peptide (CGRP), substance P (SP) and tyrosine hydroxylase (TH). The ultrastructure of blood vessels supplying liver metastases and their perivascular innervation were also examined by transmission electron microscopy. In the normal liver, perivascular immunoreactive nerve fibres containing PGP, NPY and TH were observed around the interlobular blood vessels and along the sinusoids and the central vein of the hepatic lobule. The greatest density of immunoreactive nerve fibres was seen for PGP, followed (in decreasing order) by NPY and TH. VIP, SP and CGRP immunoreactivity was observed only in nerve bundles associated with the large interlobular blood vessels. In contrast, no perivascular immunoreactive nerves were observed in colorectal liver metastases. Electron microscopy confirmed the absence of perivascular nerves in liver metastases. In addition, it showed that the walls of these blood vessels were composed of a layer of endothelial cells surrounded by an incomplete or, very rarely in the periphery of the tumour, a complete, layer of synthetic phenotype of smooth muscle-like cells. These results imply that the blood vessels supplying liver metastases are bereft of normal neuronal regulation; whether there is a role for endothelial cell control of blood flow in these vessels is not yet known.

Blood vessels in liver metastases from both sarcoma and carcinoma lack perivascular innervation and smooth muscle cells

Hepatic arterial infusion (HAI) chemotherapy as treatment for human colorectal liver metastases is promising, but not entirely satisfactory. Improved drug delivery during HAI may be achieved by manipulating the different control mechanisms of normal versus tumour blood vessels. The peptidergic/aminergic innervation of vessels in normal liver and in two animal models of liver metastasis (Lister Hooded rat with syngeneic MC28 sarcoma; athymic (nude) rat with human HT29 carcinoma) was investigated to assess the suitability of these models for future pharmacological studies. Normal liver and metastases were studied immunohistochemically for the presence of protein gene product 9.5 (PGP), neuropeptide Y (NPY), tyrosine hydroxylase (TH), calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP) and substance P (SP). Perivascular innervation was also examined by transmission electron microscopy. In Lister rat normal livers, perivascular immunoreactive nerve fibres containing PGP, NPY, TH, CGRP and SP were observed around the interlobular blood vessels near the hilum and in the portal tracts. The highest density was seen for PGP, followed in decreasing order, by NPY, TH, CGRP and SP. VIP-immunoreactive nerves were absent. No immunoreactive nerves were observed in the hepatic lobule. In athymic rat livers, the pattern of innervation was similar, except that SP immunoreactivity was more sparse. No perivascular immunoreactive nerves were observed in either MC28 or HT29 tumours. Electron microscopy confirmed the absence of perivascular nerves. Smooth muscle cells were not observed in tumour blood vessel walls. These results are comparable with previous observations on human liver metastases and suggest that the animal models may be suitable for pharmacological studies on vascular manipulation of HAI chemotherapy.

Postoperative complications of colorectal cancer

Colorectal cancer is the third most common cancer, and surgery is the most common treatment. Several surgical options are available, but each is associated with a range of potential complications. The timely and efficient identification of these complications is vital for effective clinical management of these patients in order to minimise their morbidity and mortality. This review aims to describe the range of commonly performed surgical treatments for colorectal surgery. In addition, frequent post-surgical complications are explored with investigative options explained and illustrated.

Primary ocular relapse in acute lymphoblastic leukemia

Relapse of acute lymphoblastic leukaemia (ALL) occurred in the anterior segment of four children. All cases had been treated according to the Medical Research Council's UK Acute Lymphoblastic Leukaemia trial protocol (UKALL) including 2 years of continuation chemotherapy. In three cases the diagnosis was confirmed by anterior chamber aspirate while in one case the diagnosis was presumed on clinical grounds alone. All four cases experienced isolated leukaemic relapse in the anterior segment within 2 months of stopping therapy. The months immediately following cessation of continuation chemotherapy as part of the UKALL regime appear to represent a 'high-risk' period for primary anterior segment relapse of ALL. Children with ALL presenting with uveitis should be regarded as having leukaemic relapse and anterior chamber taps with or without an iris biopsy should be considered to confirm this diagnosis. Early diagnosis and treatment of ocular leukaemic relapse is likely to give these children the best chance of ultimate cure.

Two-stage repair of adult coarctation of the aorta with congenital valvular lesions

BACKGROUND

Coarctation of the aorta associated with intracardiac pathologic conditions presenting in adult life poses some technical and management challenges. When deciding on the best surgical strategy, the surgeon must pay careful attention to the changes that will occur in the circulation.

METHODS

In our small series of 3 patients, the intracardiac pathologic lesions were corrected first, and the coarctation was repaired as a second-stage procedure 2 to 3 months later.

RESULTS

All patients had an uneventful recovery from both operations. The potential problems of renal impairment caused by inadequate perfusion during bypass and perioperative systemic hypertensive complications resulting from coarctation of the aorta were not observed. At the time of coarctation repair as a second-stage procedure, anticoagulation was easily controlled. All 3 patients had short intensive care unit and hospital stays.

CONCLUSIONS

Staged surgical repair of this complex pathologic combination in adult patients is a safe option and is easy to manage perioperatively.

Endoscopically assisted extralevator abdominoperineal excision

AIM

Extralevator abdominoperineal excision (ELAPE) has been advocated to optimize clearance of lower third rectal cancers with an involved or threatened circumferential resection margin. ELAPE could reduce positive margins and specimen perforation compared with standard abdominoperineal excision. However, there can be difficulties with ELAPE, particularly in identifying the anterior plane in male patients. Usually, the dissection is performed in the prone position, which can be hazardous, particularly in obese patients in whom wound problems are commonly encountered. We describe an endoscopically assisted approach for ELAPE in the lithotomy position.

METHOD

Three male patients with a rectal tumour located at the anorectal junction underwent an endoscopically assisted ELAPE in the lithotomy position after preoperative radiotherapy.

RESULTS

All the procedures were performed successfully with operation times of 180, 390 and 420 mins. There were no instances of intra-operative perforation or other complications. One patient developed postoperative intestinal obstruction which resolved on conservative management. There were no wound complications. Histopathological examination demonstrated clear margins and intact mesorectal planes in each patient.

CONCLUSION

We report a good outcome in three patients after endoscopically assisted ELAPE. This approach allows the patient to be operated on in the lithotomy position giving excellent views of the anterior dissection.

Serum S100beta release after coronary artery bypass grafting: roller versus centrifugal pump

BACKGROUND

Microemboli generated during cardiopulmonary bypass (CPB) are implicated in the cerebral injury seen after coronary artery bypass grafting. Centrifugal pumps generate fewer microemboli than roller pumps. Increased S100beta levels have been reported after coronary artery bypass grafting, with levels greater than 1 ng/mL resulting in poorer neuropsychologic outcome. This study investigated the potential neurologic benefits of centrifugal pumps, by using S100beta as a marker for cerebral injury.

METHODS

Thirty-two patients who had coronary artery bypass grafting were randomly assigned to two groups. Serial blood samples (preoperative, end of bypass, 30 minutes, and 2 and 24 hours after cardiopulmonary bypass) were taken and the serum analyzed for S100beta using a new immunoluminometric assay.

RESULTS

Both groups were matched for age, number of grafts, and cardiopulmonary bypass and cross-clamp times. Postoperative serum S100beta levels were significantly higher in both groups than preoperative levels. Peak S100beta levels did not correlate with cardiopulmonary bypass time; however, 24-hour S100beta levels correlated with intubation time r = 0.40, p = 0.04). Th ere was no significant difference in S100beta levels between the groups at any of the time points.

CONCLUSIONS

S100beta levels increased after coronary artery bypass grafting. Centrifugal pumps do not significantly decrease S100beta release. Persistently increased S100beta levels are associated with longer intubation times.