Expansion of CD14+CD16+ peripheral monocytes among patients with aseptic loosening

OBJECTIVE AND DESIGN

In this study, we have investigated the relevance of peripheral blood inflammatory CD14(+)CD16(+) monocytes phenotype to patients with aseptic loosening (AL).

MATERIAL AND TREATMENT

Immunophenotypes of monocytes were examined among patients with AL (n = 43), patients with mechanical loosening (ML, n = 30), patients with stable implant (SI, n = 16), and patients with osteoarthritis (OA, n = 17) using flow cytometry.

METHODS

Immunological assay was used to measure TNF-alpha and IL-1 beta levels in both sera and culture media of implant wear stimulated CD14(+)CD16(+) and CD14(++)CD16(-) monocytes. Periprosthetic tissues were collected during surgery for histological assessment.

RESULTS

The frequency of CD14(+)CD16(+) monocytes showed significant increase in AL patients than in ML, SI, and OA patients. A positive association was found between the subpopulation of CD14(+)CD16(+) monocytes and plasma TNF-alpha and IL-1 beta level in AL patients. Furthermore, a positive correlation existed between the subpopulation of CD14(+)CD16(+) monocytes and the total histopathology score.

CONCLUSION

The results indicate that CD14(+)CD16(+) monocytes represent a sensitive marker for the disease activity of AL, and may serve as an effective prognostic index to identify total joint replacement recipients who are at increased risk for osteolysis and progression of AL.

Inhibition of the development of collagen-induced arthritis in Wistar rats through vagus nerve suspension: a 3-month observation

OBJECTIVE AND DESIGN

In this study, we have investigated the effects of vagus nerve suspension in a rat model of collagen-induced arthritis (CIA) .

MATERIALS AND TREATMENT

CIA was induced in male Wistar rats and vagus nerve suspension or sham operation was performed on day 10 after the second immunization. All rats were monitored for macroscopic signs of clinical arthritis and cytokine titres within 2 months after the second immunization. Radiological and histological examination were performed 3 months after the second immunization.

RESULTS

Rats subjected to vagus nerve suspension (the test group) showed nerve activities that resemble electrical stimulation of the vagus nerve in the control group. Compared to control, the test group had reduced soft-tissue swelling, arthritic scores, TNF-alpha level and Collagen-II antibody titre, throughout the course of the experiment. Sham operation produced similar suppression on the CIA symptoms as the test group but most of the effects produced by sham operation subsided after 27 or 35 days.

CONCLUSION

Vagus nerve suspension is a novel approach to achieve sustained long-term stimulation of the vague nerve. This procedure can suppress the development of CIA in rats.

Doppler-guided intra-operative fluid management during major abdominal surgery: systematic review and meta-analysis

BACKGROUND

Peri-operative fluid therapy is a controversial area with few randomised trials to guide practice. Recently, a number of trials have suggested that intra-operative therapy guided by oesophageal Doppler acquired haemodynamic variables may improve postoperative outcome.

METHODS

Abstract databases and conference proceedings were searched to identify randomised controlled trials comparing Doppler-guided intra-operative fluid management to standard practice in patients undergoing major abdominal surgery. Pooled odds ratios (POR) and weighted mean differences (WMD) were calculated for categorical and continuous outcomes respectively.

RESULTS

Four trials, comprising 393 patients, were identified. Use of an oesophageal Doppler-guided fluid management algorithm resulted in fewer postoperative complications (POR 0.32; 95% CI: 0.19-0.52; p < 0.0001) and shorter hospital stays (WMD 1.68 days; 95% CI: 2.39-0.98; p < 0.0001). There were no significant differences in the quantities of intra-operative fluids administered although there was some evidence of heterogeneity with respect to this outcome.

CONCLUSION

Oesophageal Doppler-guided fluid management may improve outcome following major intra-abdominal surgery. However, comparison with fluid restriction strategies, including a cost-effectiveness analysis are required.

Perioperative fluid management: prospective audit

BACKGROUND

Postoperative fluid management is a core surgical skill but there are few data regarding current fluid management practice and the incidence of potential fluid-related complications in general surgical units. We conducted a prospective audit of postoperative fluid management and fluid-related complications in a consecutive cohort of patients undergoing midline laparotomy.

METHODS

Over a 6-month period, the peri-operative fluid management of 106 consecutive patients was prospectively audited. Serum electrolyte data, fluid balance data, co-morbidities, operative and anaesthetic variables and quantities of fluid and electrolytes prescribed were recorded. The development of fluid-related and other complications was noted.

RESULTS

There were no correlations between routinely available fluid balance parameters and the quantities of fluid and electrolytes prescribed, suggesting that doctors do not consult fluid balance data when prescribing. Fifty-seven patients (54%) developed at least one fluid-related complication. These patients received significantly greater volumes of fluid and sodium each day postoperatively. They had higher rates of other non-fluid-related complications and death. They had a longer hospital stay. In a multivariate model, mean daily fluid load predicted the development of fluid-related complications.

CONCLUSION

Fluid prescription practice in general surgical units is sub-optimal, resulting in avoidable iatrogenic complications. Involvement of senior staff, education and possibly the introduction of prescribing protocols may improve the situation.

Cardioprotection by remote ischaemic preconditioning †

Perioperative myocardial infarction is a leading cause of morbidity and mortality after major non-cardiac surgery. Pharmacological agents such as beta-blockers may reduce the risk but are associated with side-effects and may be contra-indicated in some patients. Basic scientific experiments and preliminary clinical trials in humans suggest that remote ischaemic preconditioning (RIPC), where brief ischaemia in one tissue confers resistance to subsequent sustained ischaemic insults in another tissue, may provide a simple, cost-effective means of reducing the risk of perioperative myocardial ischaemia. The Medline and Pubmed databases were searched for articles concerning RIPC. The mechanism may be humoral, neural, or a combination of both, and involves adenosine, opioids, bradykinins, protein kinase C, and K-ATP channels, although the precise end-effector remains unclear. Small randomized trials in humans undergoing major surgery suggest that RIPC induced by brief lower limb ischaemia significantly reduces myocardial injury. It may also reduce other ischaemic complications of surgery and anaesthesia. Small studies provide some evidence that RIPC could reduce myocardial injury and other ischaemic complications of surgery. However, large-scale clinical trials to assess the effect of RIPC on mortality and morbidity are required before RIPC can be recommended for routine clinical use.

Enterobacter sakazakii bacteraemia with multiple splenic abscesses in a 75-year-old woman: a case report

Enterobacter sakazakii is an uncommon bacterium that is known to cause severe neonatal infection and is rare among adults. We present a peculiar case of E. sakazakii bacteraemia with multiple splenic abscesses in a 75-year-old institutionalised woman, who was successfully treated with 6 weeks of imipenem and percutaneous drainage of the abscesses.

VBHOM, a data economic model for predicting the outcome after open abdominal aortic aneurysm surgery

Background

Vascular Biochemistry and Haematology Outcome Models (VBHOM) adopted the approach of using a minimum data set to model outcome. This study aimed to test such a model on a cohort of patients undergoing open elective and non-elective abdominal aortic aneurysm (AAA) repair.

Methods

A binary logistic regression model of risk of in-hospital mortality was built from the 2002–2004 submission to the UK National Vascular Database (NVD) (2718 patients). The subset of NVD data items used comprised serum levels of urea, sodium and potassium, haemoglobin, white cell count, sex, age and mode of admission. The model was applied prospectively using Hosmer–Lemeshow methodology to a test data set from the Cambridge Vascular Unit.

Results

The validation set contained 327 patients, of whom 208 had elective AAA repair and 119 had emergency repair of a ruptured AAA. Outcome following elective and non-elective AAA repair could be described accurately using the same model. The overall mean predicted risk of death was 14·13 per cent, and 48 deaths were predicted. The actual number of deaths was 53 (χ2 = 8·40, 10 d.f., P = 0·590; no evidence of lack of fit). The model also demonstrated good discrimination (c-index = 0·852).

Conclusion

The VBHOM approach has the advantage of using simple, objective clinical data that are easy to collect routinely. The VBHOM data items potentially allow prediction of risk in an individual patient before aneurysm surgery.

An audit of compliance with motor traffic regulations and use of green warning lights by consultants recalled to hospital to attend emergencies

OBJECTIVES

To determine consultants' compliance with motor traffic regulations on recall to hospital to attend emergencies, and ownership and use of green warning lights (GWLs). To determine the views of senior police officers on consultants complying with traffic regulations on emergency recall with and without GWLs.

METHOD

Questionnaire survey of all consultants in obstetrics and gynaecology, paediatrics and emergency medicine in the Yorkshire Deanery, UK, and members of the Association of Chief Police Officers (ACPO).

RESULTS

220 consultant questionnaires were distributed and 166 replies were received; 21% of respondents owned a GWL. Almost 50% of consultants would consider exceeding speed limits when returning to an emergency. Between 43% and 80% consultants would cross red traffic lights; driving habits varied with usage and ownership of a GWL. 12.7% (21) of respondents had been stopped for traffic violations attending emergencies, 2.4% (4) had been prosecuted and 4.8% (8) had been involved in accidents. The ACPO advised that consultants should observe all traffic regulations at all times.

CONCLUSION

Consultants recalled to their hospitals for emergencies disregard speed restrictions and traffic light signals both with and without GWLs and risk both accident and prosecution for ignoring traffic legislation. They should consider using a GWL to ease their progress through traffic when attending an emergency and observe all traffic laws.

Giant colonic diverticulum: an unusual abdominal lump

Giant colonic diverticulum is a rare complication of diverticular disease of the colon and is thought to result, in most cases, from a "ball-valve" effect. The presentation and clinical course can be variable and confusing. The most common symptoms are abdominal pain and a palpable abdominal lump, with many patients presenting acutely with complications such as perforation and peritonitis. Preoperative diagnosis requires a high degree of suspicion and needs to be differentiated from sigmoid volvulus, caecal volvulus, intestinal duplication cyst, pneumatosis cystoidis intestinalis, and similar conditions. A plain x-ray and computed tomography (CT) scan of the abdomen shows a huge air-filled cyst termed "balloon sign" and confirms the diagnosis. The barium enema shows a communication with the bowel in most cases. In view of the high incidence of complications, treatment is advised even in asymptomatic cases and consists of excision of the cyst with resection of the adjacent colon with primary anastomosis. This treatment would, in most cases, be a sigmoid colectomy. Percutaneous drainage and Hartmann's procedure may be appropriate in some cases who present with a well-formed abscess or gross fecal peritonitis, respectively. A case is described, and the literature is reviewed.

Expression of the TAL1/SCL transcription factor in physiological and pathological vascular processes

The TAL1/SCL transcription factor is essential for haematopoietic commitment and vascular remodelling during embryonic development. To help clarify its role in postnatal vascular processes, we characterized the expression of mouse Tal1 protein by immunocytochemistry in several experimental models of blood vessel formation. In adult mice, Tal1 protein was expressed in rare microvascular endothelial cells and in extravascular cells provisionally identified as endothelial progenitors from their morphology, proximity to vessels and expression of vascular endothelial growth factor receptor-2. The number of Tal1-expressing endothelial cells increased significantly but transiently in all the models-hormone-induced ovulation, wound healing and tumour development. Finally, Tal1 protein was detected in the nuclei of newly formed lymphatic endothelial cells in tumour-bearing animals. These results show that TAL1 is expressed by vascular endothelial cells and endothelial progenitors at sites of physiological and pathological neovascularization and suggest a role for this transcription factor in adult vasculogenesis. This work also provides the first evidence for TAL1 expression in lymphangiogenesis.

Design of biomimetic fibrillar interfaces: 2. Mechanics of enhanced adhesion

This study addresses the strength and toughness of generic fibrillar structures. We show that the stress sigmac required to pull a fibril out of adhesive contact with a substrate has the form sigma(c) = sigma(0)Phi(chi). In this equation, sigma(0) is the interfacial strength, Phi(chi) is a dimensionless function satisfying 0 <or= Phi(chi) <or= 1 and chi is a dimensionless parameter that depends on the interfacial properties, as well as the fibril stiffness and radius. Pull-off is flaw sensitive for chi >> 1, but is flaw insensitive for chi < 1. The important parameter chi also controls the stability of a homogeneously deformed non-fibrillar (flat) interface. Using these results, we show that the work to fail a unit area of fibrillar surface can be much higher than the intrinsic work of adhesion for a flat interface of the same material. In addition, we show that cross-sectional fibril dimensions control the pull-off force, which increases with decreasing fibril radius. Finally, an increase in fibril length is shown to increase the work necessary to separate a fibrillar interface. Besides our calculations involving a single fibril, we study the concept of equal load sharing (ELS) for a perfect interface containing many fibrils. We obtain the practical work of adhesion for an idealized fibrillated interface under equal load sharing. We then analyse the peeling of a fibrillar surface from a rigid substrate and establish a criterion for ELS.

Strategies for evaluating B*18 allelic diversity by sequence-based typing applied to studies of a population from Singapore and African-Americans

Strategies to resolve B*18 alleles which carry a deletion in intron 1 close to the 5' end of exon 2 relative to other HLA-B alleles or a null allele mutation in exon 1 and to resolve ambiguities among allele combinations including B*18 are described. B*18 allele frequencies from volunteer donors recruited for two hematopoietic stem cell registries show the presence of two alleles, B*180101 and B*1802, in a population from Singapore and only B*180101 in African-Americans.

Inflammatory Abdominal Aortic Aneurysms

BACKGROUND

Inflammatory abdominal aortic aneurysms (IAAA) are a variant of aortic aneurysm characterised by extensive peri-aneurysmal fibrosis, thickened walls and dense adhesions and represent between 3 and 10% of all abdominal aortic aneurysms (AAA). Surgery is technically challenging and is still associated with an increased morbidity and mortality. Controversy exists about aetiology and pathogenesis.

METHODS

We review the literature on the current theories, the available imaging modalities and the current thinking on management of IAAA. A Medline database search was performed. Articles were cross-referenced.

RESULTS AND CONCLUSIONS

Aneurysm development is multifactorial with important genetic and environmental factors. The literature supports the theory that IAAA arise from the same antigenic stimulus that is responsible for the non-IAAA, representing one extreme of an inflammatory spectrum. The results after open repair have improved and there is now little difference in the mortality between non-IAAA and IAAA repair. However, there is likely to be a role for endovascular stenting in IAAA management and this requires further study. It is clear that closer follow-up of patients after IAAA repair with either technique is necessary to monitor the inflammatory process. No evidence-based follow-up protocol exists but three to six-monthly monitoring of renal function and erythrocyte sedimentation rate (ESR) for 24 months post-repair would seem a reasonable regime.