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Abstract Background Neurofibromatosis type 1 (NF1) is a frequent genetic disease characterized by multiple benign tumours with increased risk for malignancy. There is currently no biomarker for tumour load in NF1 patients. Methods In situ hybridization and quantitative real-time polymerase reaction were applied to investigate expression of cartilage-specific genes in mice bearing conditional inactivation of NF1 in the developing limbs. These mice do not develop tumours but recapitulate aspects of NF1 bone dysplasia, including deregulation of cartilage differentiation. It has been recently shown that NF1 tumours require for their growth the master regulator of cartilage differentiation SOX9. We thus hypothesized that some of the cartilage-specific genes deregulated in an Nf1Prx1 mouse model might prove to be relevant biomarkers of NF1 tumours. We tested this hypothesis by analyzing expression of the SOX9 target gene product melanoma-inhibitory activity/cd-rap (MIA) in tumour and serum samples of NF1 patients. Results Increased expression of Mia was found in Nf1-deficient cartilage in mice. In humans, MIA was expressed in all NF1-related tumours and its serum levels were significantly higher in NF1 patients than in healthy controls. Among NF1 patients, MIA serum levels were significantly higher in those with plexiform neurofibromas and in those with large number of cutaneous (> 1,000) or subcutaneous (> 100) neurofibromas than in patients without such tumours. Most notably, MIA serum levels correlated significantly with internal tumour burden. Conclusions MIA is a potential serum biomarker of tumour load in NF1 patients which could be useful in following the disease course and monitoring the efficacy of therapies.

Abstract Background Array genomic hybridization is being used clinically to detect pathogenic copy number variants in children with intellectual disability and other birth defects. However, there is no agreement regarding the kind of array, the distribution of probes across the genome, or the resolution that is most appropriate for clinical use. Results We performed 500 K Affymetrix GeneChip® array genomic hybridization in 100 idiopathic intellectual disability trios, each comprised of a child with intellectual disability of unknown cause and both unaffected parents. We found pathogenic genomic imbalance in 16 of these 100 individuals with idiopathic intellectual disability. In comparison, we had found pathogenic genomic imbalance in 11 of 100 children with idiopathic intellectual disability in a previous cohort who had been studied by 100 K GeneChip® array genomic hybridization. Among 54 intellectual disability trios selected from the previous cohort who were re-tested with 500 K GeneChip® array genomic hybridization, we identified all 10 previously-detected pathogenic genomic alterations and at least one additional pathogenic copy number variant that had not been detected with 100 K GeneChip® array genomic hybridization. Many benign copy number variants, including one that was de novo, were also detected with 500 K array genomic hybridization, but it was possible to distinguish the benign and pathogenic copy number variants with confidence in all but 3 (1.9%) of the 154 intellectual disability trios studied. Conclusion Affymetrix GeneChip® 500 K array genomic hybridization detected pathogenic genomic imbalance in 10 of 10 patients with idiopathic developmental disability in whom 100 K GeneChip® array genomic hybridization had found genomic imbalance, 1 of 44 patients in whom 100 K GeneChip® array genomic hybridization had found no abnormality, and 16 of 100 patients who had not previously been tested. Effective clinical interpretation of these studies requires considerable skill and experience.

Abstract Background Genomic deletions and duplications are important in the pathogenesis of diseases, such as cancer and mental retardation, and have recently been shown to occur frequently in unaffected individuals as polymorphisms. Affymetrix GeneChip whole genome sampling analysis (WGSA) combined with 100 K single nucleotide polymorphism (SNP) genotyping arrays is one of several microarray-based approaches that are now being used to detect such structural genomic changes. The popularity of this technology and its associated open source data format have resulted in the development of an increasing number of software packages for the analysis of copy number changes using these SNP arrays. Results We evaluated four publicly available software packages for high throughput copy number analysis using synthetic and empirical 100 K SNP array data sets, the latter obtained from 107 mental retardation (MR) patients and their unaffected parents and siblings. We evaluated the software with regards to overall suitability for high-throughput 100 K SNP array data analysis, as well as effectiveness of normalization, scaling with various reference sets and feature extraction, as well as true and false positive rates of genomic copy number variant (CNV) detection. Conclusion We observed considerable variation among the numbers and types of candidate CNVs detected by different analysis approaches, and found that multiple programs were needed to find all real aberrations in our test set. The frequency of false positive deletions was substantial, but could be greatly reduced by using the SNP genotype information to confirm loss of heterozygosity.

Acute thrombosis in native arterio-venous fistulae (AVF) results in considerable patient morbidity. Interventional radiology (IR) comprising thrombolysis and percutaneous transluminal angioplasty (PTA) is well established in the management of thrombosed polytetrafluoroethylene (PTFE) grafts. However its role in thrombosed AVF is uncertain. We looked retrospectively at the role of IR in re-establishing blood flow in acutely throm-bosed AVF. Between 1992-2000, 21 episodes of acutely thrombosed AVF in 15 patients (9 females; age range 29-80yrs) were referred for intervention. All fistulae were being used for haemodialysis at the time. Diagnosis was established by angiography and thrombolysis with recombinant tissue plasminogen activator (rTPA) was attempted in all patients. Discrete stenoses when present (n=12) were then treated with PTA and resistant or recurrent stenoses were managed by stent insertion (n=3). Patients were then heparinised for 24 hours. Technical success as defined by radiological patency was achieved in 86% cases. Clinical success i.e. the ability to reuse of the fistula for haemodialysis was achieved in 62% of the interventions, where patency rates at 3 and 6 months were 92% and 69% respectively. Five patients had recurrence of thrombosis >3 months after the primary procedure, 3 had successful reintervention. Minor local bleeding was the only complication. Our retrospective study shows rTPA and PTA is successful in the management of acutely thrombosed AVF. We advocate the routine use of IR as a valuable technique for prolonging the life of native AVF in patients on maintenance haemodialysis.

Background: Peripheral thrombolysis is advocated by some as the best initial treatment for acute leg ischaemia; but this may not be true for elderly patients. This study reviewed the management of acute leg ischaemia in patients aged over 75 years., Methods: Over a 5-year interval, 91 events of acute leg ischaemia in 84 patients were managed in a single district general hospital according to a local protocol. There were 60 women and 24 men of median age 81 (range 75-100) years. Fifteen patients were too elderly and infirm for active treatment and received anticoagulation alone. Some 76 events (84 per cent) occurred in patients suitable for active therapy: 33 were managed by initial surgery and 43 by peripheral thrombolysis with tissue plasminogen activator., Results: Overall outcome after 30 days was limb salvage in 48 (53 per cent), amputation in five (5 per cent) and death in 38 (42 per cent). In actively treated patients the corresponding values were 43 (57 per cent), four (5 per cent) and 29 (38 per cent). Initial successful revascularization was more likely following surgery (29 of 33 versus 25 of 43 events with thrombolysis, P < 0.01), but the 30-day outcome was similar in the actively treated groups owing to subsequent morbidity and mortality., Conclusion: A group of patients (mostly women) with emboli could be identified, using clinical criteria, who had a high chance of successful revascularization following embolectomy. Late outcome remained poor due to associated co-morbid conditions. Thrombolysis is associated with substantial risk in the elderly, and with high complication rates.

Background: Acute leg ischaemia is both life threatening and limb threatening. This audit was designed to determine the incidence and outcome of acute leg ischaemia in a single county., Methods: Using multisource data collection for a 1-year interval in 1994 all patients with acute leg ischaemia were identified prospectively using hospital and general practice records in the county of Gloucestershire, population 540,000., Results: Seventy-seven patients with 84 events of acute leg ischaemia were identified, giving an incidence of one per 7000 per year rising to one per 6000 per year when bypass graft occlusions were included. All but four patients were treated in hospital. Sixteen of 80 hospital events involved conservative treatment; after 30 days nine patients had died and two required amputation. The remaining five patients had borderline ischaemic rest pain and accepted their symptoms without intervention. Sixty-four of 80 events were managed by either primary surgery and angioplasty (n = 31) or thrombolysis (n = 33). The 30-day outcome in patients treated actively was: limb salvage in 50 (78 per cent), amputation in four (6 per cent) and death in ten (16 per cent)., Conclusion: In Gloucestershire almost all cases of acute leg ischaemia are managed by, or discussed with vascular surgeons. A flexible integrated policy of surgery and peripheral thrombolysis has resulted in a limb salvage rate of 78 per cent in patients suitable for active treatment.

The cost of attempting limb salvage in patients who presented with acute lower limb ischaemia was recorded prospectively for 20 months. Seventy-five patients were admitted during the study; 45 were treated primarily by radiological intervention and 18 had primary surgery. The remainder were treated conservatively. Patients who had primary surgery required fewer visits to the operating theatre than those who had primary thrombolysis, but there was no difference in the total time that the theatre or radiology suite was occupied: median 2.3 (10th centile range 1.5-5.0) h and 3.0 (2.0-5.0) h respectively. Median (range) cost of disposables for performing surgery was Pounds 82 (58-169) and for thrombolysis was Pounds 407 (252-596). When the costs of using the theatre or radiology suite were included, the costs of both treatments were similar: surgery Pounds 683 (309-1438) and lysis Pounds 861 (611-1244). Median (10th centile range) inpatient stay for surgical patients was 9 (3-18) days and for those having thrombolysis 11 (2-29) days. Median (10th centile range) costs for bed occupancy were similar in both groups: surgery Pounds 2497 (643-9115) and lysis Pounds 2189 (902-6020). Mean cost for attempting limb salvage by surgery was Pounds 3429 (1094-10065) compared with Pounds 3230 (1543-8353) for thrombolysis.

Low dose intra-arterial thrombolysis is too slow for many patients with severe acute limb ischaemia. Accelerated thrombolysis with high dose bolus t-PA was used in a consecutive series of 43 patients. Complete or clinically useful lysis was achieved in 39 patients, with a median duration of 7 h. Lysis occurred in 46% in under 4 h. Fifty-six per cent of patients required further procedures after lysis. Eleven per cent suffered a major bleed. The limb salvage rate at 30 days was 56%. Amputation was required in 22% and 22% died. Most deaths were due to associated thrombotic conditions: myocardial infarction (5), pulmonary embolism (1) and malignant thrombosis (1). One patient died from pneumonia two weeks after lysis and two died from renal failure within a week of thrombolysis. The high mortality rate was not associated with bleeding but may reflect the high risks involved in treating this group of patients. High dose bolus t-PA infusion appears to predict immediate outcome of thrombolysis as well as reducing infusion times. It may expand the indications for the non-surgical treatment of acute limb ischaemia to include most patients with the condition. Careful case selection is still necessary for optimal results.

One hundred and twenty-seven intravenous urograms of patients with acute epididymitis were evaluated during a period of 9 years. The majority of these patients had normal urograms. A tuberculous renal lesion was found in only one case. Twenty-seven patients had prostatic enlargement and 10 of these were under 50 years of age. Other abnormalities which were found were not related to epididymitis. It is suggested that intravenous urography is indicated in patients with acute epididymitis only when there is evidence of previous tuberculosis or when laboratory findings arouse suspicion of genitourinary tuberculosis.