Surgery for oesophageal cancer at Galway University Hospital 1993-2008

BACKGROUND

Surgical volume and outcome remain controversial in the management of oesophageal cancer.

AIMS

To assess the outcome of oesophagectomy for cancer at Galway University Hospital (GUH).

METHODS

Between 1994 and 2008, patients who underwent oesophagectomy were analysed.

RESULTS

During the study period, 126 oesophagectomies were performed for cancer. The average surgeon volume was 9 cases per year. The 30-day and overall in-hospital mortality rates were 6.3 and 7.9%, respectively. Restructuring of our critical care services has led to a reduction in 30-day mortality from 8.2 to 5.1%. The use of neoadjuvant chemoradiotherapy has increased from 17 to 35% during the study period. In patients who underwent resection, the 3 and 5-year overall survival rates were 45 and 29%, respectively.

CONCLUSIONS

Operative morbidity and mortality at GUH are comparable with worldwide outcomes. Improved resources and national restructuring of cancer services have significantly improved the quality of care and outcomes of patients.

Rates of loss of heterozygosity and mitotic recombination in NF2 schwannomas, sporadic vestibular schwannomas and schwannomatosis schwannomas

Biallelic inactivation of the NF2 gene occurs in the majority of schwannomas. This usually involves a combination of a point mutation or multiexon deletion, in conjunction with either a second point mutation or loss of heterozygosity (LOH). We have performed DNA sequence and dosage analysis of the NF2 gene in a panel of 239 schwannoma tumours: 97 neurofibromatosis type 2 (NF2)-related schwannomas, 104 sporadic vestibular schwannomas (VS) and 38 schwannomatosis-related schwannomas. In total, we identified germline NF2 mutations in 86 out of 97 (89%) NF2 patients and a second mutational event in 77 out of 97 (79%). LOH was by far the most common form of second hit. A combination of microsatellite analysis with either conventional comparative genomic hybridization (CGH) or multiplex ligation-dependent probe amplification (MLPA) identified mitotic recombination (MR) as the cause of LOH in 14 out of 72 (19%) total evaluable tumours. Among sporadic VS, at least one NF2 mutation was identified by sequence analysis or MLPA in 65 out of 98 (66%) tumours. LOH occurred in 54 out of 96 (56%) evaluable tumours, but MR only accounted for 5 out of 77 (6%) tested. LOH was present in 28 out of 34 (82%) schwannomatosis-related schwannomas. In all eight patients who had previously tested positive for a germline SMARCB1 mutation, this involved loss of the whole, or part of the long arm, of chromosome 22. In contrast, 5 out of 22 (23%) tumours from patients with no germline SMARCB1 mutation exhibited MR. High-resolution Affymetrix SNP6 genotyping and copy number (CN) analysis (Affymetrix, Santa Clara, CA, USA) were used to determine the chromosomal breakpoint locations in tumours with MR. A range of unique recombination sites, spanning approximately 11.4 Mb, were identified. This study shows that MR is a mechanism of LOH in NF2 and SMARCB1-negative schwannomatosis-related schwannomas, occurring less frequently in sporadic VS. We found no evidence of MR in SMARCB1-positive schwannomatosis, suggesting that susceptibility to MR varies according to the disease context.

SMARCB1 mutations are not a common cause of multiple meningiomas

BACKGROUND

Schwannomas and meningiomas are both part of the tumour spectrum of neurofibromatosis type 2 (NF2) and are associated with somatic loss of chromosome 22. They are also found commonly within the general population, unrelated to NF2. Germline SMARCB1 mutations have recently been identified as a pathogenic cause of a subset of familial schwannomatosis cases, and SMARCB1 is a candidate gene for causation of both schwannomas and meningiomas. Recently, Bacci et al reported a germline SMARCB1 mutation associated with familial schwannomatosis and multiple meningiomas. They concluded that SMARCB1 mutations can predispose to multiple meningiomas.

METHODS

We screened the SMARCB1 gene in a panel of 47 patients with multiple meningioma unrelated to NF2.

RESULTS

We found no germline mutations.

CONCLUSION

We conclude that while meningiomas may be associated with the schwannomatosis phenotype, SMARCB1 is not a major contributor to multiple meningioma disease.

Endovascular treatment of carotid blowout syndrome: who and how to treat

Carotid blowout syndrome (CBS) is a high-risk condition associated with significant morbidity and mortality that may result from invasion and destruction of the cervical carotid vasculature from head and neck squamous cell carcinoma. Endovascular approaches offer multiple modalities for treatment to prevent morbidity and death. In this paper we review our experience in addressing CBS and present an up-to-date algorithm of endovascular management. 16 lesions were identified in 8 patients treated with 9 procedures over the past year. Pseudoaneurysm and/or active extravasation were documented in at least one vessel in all 8 cases presenting with acute CBS. There were 13 pseudoaneurysms in external carotid artery (ECA) trunk (5), ECA branches (4), internal carotid artery (ICA) (1) and common carotid artery (CCA) (3). There were 3 additional ICA lesions due to tumor infiltration, resulting in ICA occlusion (2) and long segment stenosis (1). Permanent vessel occlusion was performed in 11 lesions of the ECA trunk (4), ECA branches (4) and ICA (3). Stent-grafts were placed in 5 lesions in the CCA (3), ICA (1) and ECA trunk (1). Technical success and immediate hemostasis were achieved in all patients. There were no procedural deaths or immediate complications. With a median follow-up of 2 months (range, 1-13 months), three patients died: one from recurrent CBS, one from global brain ischemia after a cardiac arrest event unrelated to CBS and one from systemic disease. There was no other recurrence of bleeding or neurological complication. Endovascular techniques offer an armamentarium to effectively address CBS, significantly affecting the care and outcome in this particular oncologic population. These techniques should be offered as early as possible in the context of a multidisciplinary approach.

Analysis of differential gene expression in colorectal cancer and stroma using fluorescence-activated cell sorting purification

Tumour stroma gene expression in biopsy specimens may obscure the expression of tumour parenchyma, hampering the predictive power of microarrays. We aimed to assess the utility of fluorescence-activated cell sorting (FACS) for generating cell populations for gene expression analysis and to compare the gene expression of FACS-purified tumour parenchyma to that of whole tumour biopsies. Single cell suspensions were generated from colorectal tumour biopsies and tumour parenchyma was separated using FACS. Fluorescence-activated cell sorting allowed reliable estimation and purification of cell populations, generating parenchymal purity above 90%. RNA from FACS-purified and corresponding whole tumour biopsies was hybridised to Affymetrix oligonucleotide microarrays. Whole tumour and parenchymal samples demonstrated differential gene expression, with 289 genes significantly overexpressed in the whole tumour, many of which were consistent with stromal gene expression (e.g., COL6A3, COL1A2, POSTN, TIMP2). Genes characteristic of colorectal carcinoma were overexpressed in the FACS-purified cells (e.g., HOX2D and RHOB). We found FACS to be a robust method for generating samples for gene expression analysis, allowing simultaneous assessment of parenchymal and stromal compartments. Gross stromal contamination may affect the interpretation of cancer gene expression microarray experiments, with implications for hypotheses generation and the stability of expression signatures used for predicting clinical outcomes.

Are silica defences in grasses driving vole population cycles?

Understanding the factors that drive species population dynamics is fundamental to biology. Cyclic populations of microtine rodents have been the most intensively studied to date, yet there remains great uncertainty over the mechanisms determining the dynamics of most of these populations. For one such population, we present preliminary evidence for a novel mechanism by which herbivore-induced reductions in plant quality alter herbivore life-history parameters and subsequent population growth. We tested the effect of high silica levels on the population growth and individual performance of voles (Microtus agrestis) reared on their winter food plant (Deschampsia caespitosa). In sites where the vole population density was high, silica levels in D. caespitosa leaves collected several months later were also high and vole populations subsequently declined; in sites where the vole densities were low, levels of silica were low and population density increased. High silica levels in their food reduced vole body mass by 0.5% a day. We argue that silica-based defences in grasses may play a key role in driving vole population cycles.

Low educational level: a risk factor for sexually transmitted infections among commercial sex workers in Quito, Ecuador

Few studies have assessed the effect of educational level on sexually transmitted infections (STIs) and risk-taking behaviours among commercial sex workers (CSWs). This study analysed this association among female CSWs in Quito, Ecuador. Eighty-five CSWs were given a Spanish-language questionnaire on behaviours, socioeconomics and demographics. The correlation between years of education and number of prior STIs was calculated. Three groups of varying education level were formed and risk factors were analysed by Chi-square tests and analysis of variances. Lower educational level was associated with more STIs (r= -0.36; F=4.2; P=0.04), poorer knowledge of HIV/AIDS (P=0.03), earlier first prostitution (P=0.05) and first sex (P=0.00), willingness to engage in group sex (P=0.05) and work on the street (P=0.02), and presence of non-paying sexual partners (P=0.05). CSWs with lower educational levels were disproportionately afflicted with STIs and participated in more high-risk behaviours. Low educational level may predispose CSWs to STIs and associated risk factors.

Alterations in the SMARCB1 (INI1) tumor suppressor gene in familial schwannomatosis

Schwannomatosis is a third major form of neurofibromatosis that has recently been linked to mutations in the SMARCB1 (hSnf5/INI1) tumor suppressor gene. We analyzed the coding region of SMARCB1 by direct sequencing and multiplex ligation-dependent probe amplification (MLPA) in genomic DNA from 19 schwannomatosis kindreds. Microsatellite markers in the SMARCB1 region were developed to determine loss of heterozygosity (LOH) in associated tumors. We detected four alterations in conserved splice acceptor or donor sequences of exons 3, 4 and 6. Two alterations that likely affect splicing were seen in introns 4 and 5. An additional four alterations of unclear pathogenicity were found to segregate on the affected allele in eight families including two non-conservative missense alterations in three families. No constitutional deletions or duplications were detected by MLPA. Nine of 13 tumors examined showed partial LOH of the SMARCB1 region consistent with 'second hits.' Alterations were detected in tumors both with and without somatic NF2 gene changes. These findings support the hypothesis that SMARCB1 is a tumor suppressor for schwannomas in the context of familial disease. Further work is needed to determine its role in other multiple and single tumor syndromes.

Factors affecting river health and its assessment over broad geographic ranges: the Western Australian experience

AusRivAS is an Australia-wide program that measures river condition using predictive models to compare the macroinvertebrate families occurring at a river site with those expected if the site were in natural condition. Results of assessment of 685 sites across all major rivers in Western Australia are presented. Most rivers were in relatively natural condition in the northern half of the state where the human population is low and pastoralism is the major land use. In the south, where the human population is higher and agriculture is more intensive, rivers were mostly more disturbed. AusRivAS assessment produced some erroneous results in rivers of the south-west cropping zone because of the lack of appropriate reference site groups and biased distribution of sampling sites. Collecting low numbers of animals from many forested streams, because of low stream productivity and samples that were difficult to sort, also affected assessments. Overall, however, AusRivAs assessment identified catchment processes that were inimical to river health. These processes included salinisation, high nutrient and organic loads, erosion and loss of riparian vegetation. River regulation, channel modification and fire were also associated with river degradation. As is the case with other assessment methods, one-off sampling at individual sites using AusRivAS may be misleading. Seasonal drought, in particular, may make it difficult to relate conditions at the time of sampling to longer-term river health. AusRivAS has shown river condition in Western Australia is not markedly different from other parts of Australia which, as a whole, lacks the substantial segments of severely degraded river systems reported in England.

The Australian Vascular Quality of Life Index (AUSVIQUOL): An Improved Clinical Quality of Life Tool for Peripheral Vascular Disease

OBJECTIVES

To validate the Australian Vascular Quality of Life Index (AUSVIQUOL) as a quality of life (QOL) tool appropriate for peripheral vascular disease patients in the clinical setting.

DESIGN

Cross-sectional study.

MATERIALS

The study group consisted of 71 patients with vascular claudication of varying severity attending a tertiary hospital outpatient department.

METHODS

The results of the AUSVIQUOL and Medical Outcomes Short Form Health Survey (SF-36) were compared through factor and regression analyses. A group of 12 patients was then reassessed to compare the reliability and internal consistency of the two indices.

RESULTS

The AUSVIQUOL took less time to complete than the SF-36 (3.27 v 10.79 min; p<0.0001) and fewer patients found the questions confusing (2% v 26%). The AUSVIQUOL was easier to administer and had a higher level of patient acceptance than the SF-36. The regression analysis showed that for each of the domains in the AUSVIQUOL there was a significant correlation with measures in the SF-36 (adjusted R-squared 0.420, 0.480 and 0.331). The AUSVIQUOL demonstrated a good level of internal consistency when compared to the SF-36 (Cronbach's alpha 0.8702 vs 0.6307).

CONCLUSION

In comparison with the SF-36, the AUSVIQUOL is an improved tool for the QOL assessment of patients with peripheral vascular disease in the clinical setting.

Salmonella typhimurium stimulation combined with tumour-derived heat shock proteins induces potent dendritic cell anti-tumour responses in a murine model

Appropriate activation of the immune system and effective targeting of tumour cells are the primary hurdles to be overcome for cancer immunotherapy to be successful and applicable to a wide range of tumour types. Our studies have examined the ability of bacterial-stimulated dendritic cells (DCs), loaded with tumour-associated antigens, to inhibit tumour growth in a murine model. Immature murine bone marrow-derived DCs were stimulated in vitro with the cytoplasmic fraction (CM) of Salmonella typhimurium in combination with heat shock proteins (hsps) from 4T1 tumours, isolated using heparin affinity chromatography. Activated DCs were administered subcutaneously. Tumours were generated by orthotopic inoculation of 4T1 cells in Balb/c mice. Primary tumour growth was measured using Vernier calipers, while lung metastases were measured using the clonogenic assay. S. typhimurium CM induced potent tumour necrosis factor (TNF)-alpha responses from DCs accompanied by significant up-regulation of CD80 and CD86 expression. When injected into mice, bacterial-stimulated DCs loaded with 4T1 hsps inhibited the formation of new 4T1 tumours and reduced the growth rate of established tumours. In addition, the number of lung metastatic nodules was reduced significantly in the DC-treated mice (1.6 +/- 0.6 versus 245.9 +/- 55.6, P = 0.0015). DCs stimulated with CM alone, exposed to tumour hsps alone or exposed to tumour hsps from an unrelated tumour cell line did not induce a protective immune response. Dendritic cells primed with a proinflammatory bacterial stimulus and tumour-associated antigens induce a protective anti-tumour immune response in this murine model.

Sentinel lymph node biopsy in elderly irish patients with malignant melanoma

In patients with malignant melanoma, Breslow depth increases with age. However, studies suggest that the frequency of sentinel lymph node metastases in malignant melanoma decreases with age. We investigated whether this applied to the cohort of patients undergoing sentinel lymph node biopsy (SLNB) in our institution. In a prospectively accrued database we identified 149 patients undergoing SLNB from 1997 to 2005. Tumour thickness as measured by Breslow depth was assessed in stratified age groups. We assessed the relationship between SLNB positivity and age using the Chi-square for trend. We directly examined the relationship between SLNB positivity in patients aged less than 65 and aged 65 years of age and over. Disease-free and overall survival in patients aged less than 65 and aged 65 years of age and over were also assessed. Comparing the age groups, there was no significant difference identified in Breslow depth (<65 years, median Breslow > or = 1.2 mm (range 0.2-9.7); > or =65 years, median Breslow > or = 1.4 mm (range 0.12-8.5); p > or = 0.06, Mann-Whitney U). Chi-square for trend identified no significant relationship between SLNB positivity and age. We found n=120 patients <65 had SLNB, of which 26 (21.7%) were positive. In patients =65, n=29 had SLNB of which 3 (10.3%) were positive. These differences were not statistically significant (Fisher's exact test, p > or = 0.2). There was no difference in disease-free or overall survival between patients aged <65 or > or =65 who had SLNB (median follow-up 37.5 months (range 5-70); disease-free survival, p > 0.08; overall survival, p > or = 0.3, Logrank test). We did not find that elderly patients with malignant melanoma had a demonstrable difference in tumour thickness when compared to younger patients. In those patients who underwent SLNB there was no significant difference in node positivity between the age groups. Disease-free and overall survival were not significantly different between the age groups. Further study and longer follow-up will help establish the relationship between age and SLNB positivity.

Quantifying the magnetic advantage in magnetotaxis

Magnetotactic bacteria are characterized by the production of magnetosomes, nanoscale particles of lipid bilayer encapsulated magnetite, that act to orient the bacteria in magnetic fields. These magnetosomes allow magneto-aerotaxis, which is the motion of the bacteria along a magnetic field and toward preferred concentrations of oxygen. Magneto-aerotaxis has been shown to direct the motion of these bacteria downward toward sediments and microaerobic environments favorable for growth. Herein, we compare the magneto-aerotaxis of wild-type, magnetic Magnetospirillum magneticum AMB-1 with a nonmagnetic mutant we have engineered. Using an applied magnetic field and an advancing oxygen gradient, we have quantified the magnetic advantage in magneto-aerotaxis as a more rapid migration to preferred oxygen levels. Magnetic, wild-type cells swimming in an applied magnetic field more quickly migrate away from the advancing oxygen than either wild-type cells in a zero field or the nonmagnetic cells in any field. We find that the responses of the magnetic and mutant strains are well described by a relatively simple analytical model, an analysis of which indicates that the key benefit of magnetotaxis is an enhancement of a bacterium's ability to detect oxygen, not an increase in its average speed moving away from high oxygen concentrations.

Effects of polycyclic aromatic hydrocarbons on germination and subsequent growth of grasses and legumes in freshly contaminated soil and soil with aged PAHs residues

The relevance of germination trials for screening plants that may have potential for use in the phytoremediation of PAH contaminated land was evaluated. The germination and subsequent growth of 7 grass and legume species were evaluated in soil spiked with a pure PAH mixture or coal tar and soil from a former coking plant heavily contaminated with aged PAHs. None of these treatments adversely affected germination of the plants. However, apart from Lolium perenne all species exhibited reduced growth in the coking plant soil after 12 weeks growth when compared to the untreated soil. In the coal tar spiked soil 4 out of the 7 species showed reduced growth, as did 3 out of the 7 in the soil spiked with a mixture of 7 PAHs. Therefore, germination studies alone would not predict the success of subsequent growth of the species tested in the ranges of soil PAH levels studied.

A heretofore undisclosed crux of eosinophilia-myalgia syndrome: compromised histamine degradation

In contrast to early epidemiological evidence offering links between eosinophilia-myalgia syndrome (EMS) and microimpurities of L-tryptophan-containing dietary supplements (LTCDS), this account shows why reliance on a finite impurity from one manufacturer is both unnecessary and insufficient to explain the etiology of EMS. Excessive histamine activity has induced blood eosinophilia and myalgia (Greek: mys, muscle + algos, pain). Termination of the multiple actions of histamine is dependent on particular amine oxidases and histamine-N-methyltransferase. Histamine metabolism is rapid when these degradative reactions are operative. The latent effects of incurred histamine can be potentiated and aggravating when these mechanisms are impaired. Overloads of tryptophan supplements cause - among other relevant side-effects - an increased formation of formate and indolyl metabolites, several of which inhibit the degradation of histamine. Moreover, (non-EMS) subjects with hypothalamic-pituitary- adrenal (HPA) axis dysregulation have also manifested greatly increased sensitivities to incurred tryptophan and histamine. A final common pathway for syndromes characterized by eosinophilia with myalgia is now evident.