Use of bone meal amendments to immobilise Pb, Zn and Cd in soil: A leaching column study.

The aim of this study is to test the stabilisation of metals in contaminated soils via the formation of low-solubility metal phosphates. Bone apatite, in the form of commercially available bone meal, was tested as a phosphate source on a mine waste contaminated made-ground with high levels of Pb, Zn and Cd. Triplicate leaching columns were set up at bone meal to soil ratios of 1:25 and 1:10, in addition to unamended controls, and were run for 18 months. The columns were irrigated daily with a synthetic rain solution at pH of 2, 3, and 4.4. After 100 days, the leachate Pb, Zn and Cd concentrations of all amended columns were significantly reduced. For 1:10 treatments, release of these metals was suppressed throughout the trial. For 1:25 treatments, Zn and Cd concentrations in the leachates began to increase after 300 days. DTPA and water extractions showed that Pb and Cd were more strongly held in the amended soils. This study concludes that the complexity of soil processes and the small quantities of metals sequestered precluded determination of a metal immobilisation mechanism.

Patterns of local disease failure and outcome after salvage surgery in patients with anal cancer.

BACKGROUND: Salvage surgery for anal cancer is usually reserved for local disease failure, but issues relating to the prediction of local failure and surgical outcome are ill defined. METHODS: Between 1988 and 2000, 254 patients with non-metastatic anal epidermoid carcinoma were treated at a regional cancer centre with radiotherapy (n = 127) or chemoradiotherapy (n = 127). RESULTS: There were 99 local disease failures (39.0 per cent), all but five occurring within 3 years of initial treatment. Increasing age (P < 0.001, Cox model), total radiation dose (P = 0.004) and tumour stage (P = 0.010) were independent predictors of local failure. The overall 3- and 5-year survival rates after local disease failure were 46 and 29 per cent; the corresponding rates after salvage surgery (73 patients) were 55 and 40 per cent. A positive resection margin was the strongest negative predictor of survival after salvage surgery (P = 0.008, log rank test). Of 52 patients treated before the routine consideration of primary plastic reconstruction, delayed perineal wound healing occurred in 22 (42 per cent). CONCLUSION: In the management of anal cancer, local disease failure is a major clinical problem requiring early detection followed by radical surgery, often accompanied by plastic reconstruction. By implication, these factors favour the centralization of treatment for this uncommon cancer to a multidisciplinary oncology team.

Acute compartment syndrome of the legs after colorectal surgery.

This review considers the causes, diagnosis and management of compartment syndrome affecting the legs after colorectal surgery.

Femoral nerve injury as a complication of pelvic surgery.

Femoral nerve injury is a rare complication of pelvic surgery but may lead to medicolegal actions. The common cause is the use of a long-bladed self-retaining pelvic retractor. The injury is not well recognised in coloproctology practice and this brief article is to draw attention to this complication.

Inguinal hernia: medicolegal implications.

Repair of an inguinal hernia is one of the commonest operations undertaken by surgeons but the role of trauma in causing inguinal hernia is not well understood. This paper does not attempt to discuss the cause of inguinal hernia but seeks to analyse the cases which may be accepted by the Courts as being due to trauma.

Development of X-ray photoemission electron microscopy (X-PEEM) at the SRS.

The use of synchrotron radiation sources for X-ray spectroscopy is a well known and developed field. The majority of applications, however, have been limited to studies of materials containing only a single phase of the element of interest. Owing to limited availability of suitable instrumentation, the study of materials comprising intergrowths of different phases has presented difficulties in analysis. The majority of natural materials, including mineralogical samples, fall into this category. However, by applying the technique of photoemission electron microscopy (PEEM) to view the X-ray stimulated photoemission generated at an absorption edge, micro-area-selectable spectroscopy becomes possible. An instrument for X-ray PEEM (X-PEEM) is being developed at the Daresbury SRS and this paper shows how it can be used to obtain characteristic L-edge XANES spectra from finely intergrown iron oxide minerals.

Effect of anorectal eversion on long-term clinical outcome of restorative proctocolectomy.

Eversion of the rectum during restorative proctocolectomy with stapled ileal pouch-anal anastomosis (IPAA) remains a controversial surgical manoeuvre because of concern that it may impair anal sphincter function and adversely affect outcome. We have reviewed the long-term results in 41 patients whose operation included formation of a 20 cm J-pouch with stapled IPAA by the technique of rectal eversion. At median follow-up of 4 years (range 1-6 years), 4 pouches (10%) had been removed (2 for pelvic sepsis, 1 for rectovaginal fistula and 1 for Crohn's disease). In 34 patients with functioning pouches in situ, median stool frequency was 5 per 24 h (range 2-10). 11 patients (33%) regularly had to evacuate their pouch at night and 4 (12%) used antidiarrhoeal medication. No patients reported major incontinence; 2 (6%) had minor leakage, and in another 2 minor leakage had now ceased. 4 patients had had episodes of pouchitis. These favourable results offer no support for the contention that rectal eversion substantially worsens the long-term results of restorative proctocolectomy.

Transforming growth factor beta 1 expression in human colorectal tumours: an independent prognostic marker in a subgroup of poor prognosis patients.

Members of the transforming growth factor beta (TGF-beta family, in particular TGF-beta 1, are some of the most potent inhibitory growth factors in a variety of cell types. Resistance to TGF-beta 1-induced growth inhibition is frequently observed in colorectal carcinomas and is associated with tumour progression. Perturbations of TGF-beta 1 expression and function, therefore, may contribute to the loss of some constraints on tumour cell growth. In this study we have examined the expression of TGF-beta 1 and its precursor latency-associated peptide (LAP)-TGF-beta in human colorectal tumours using immunohistochemical techniques. In 86% of the tumours the LAP-TGF-beta complex was present in both the stromal and epithelial cells, whereas the mature TGF-beta 1 peptide was expressed in the glandular epithelium of 58.3% of these tumours. Intense staining for TGF-beta 1 was positively associated with advanced Dukes' stage. Furthermore, there was a significant correlation between the presence of TGF-beta 1 in the tumours and a shorter post-operative survival. This was most significant in a subgroup of patients who had received only a palliative operation. These results suggest that TGF-beta 1 expression may be useful as an independent prognostic indicator for a subgroup of patients who have a particularly poor prognosis.

Definition of local recurrence after surgery for rectal carcinoma.

Local recurrence rates of rectal carcinoma have been analysed among 284 patients in a prospective randomized multicentre trial of adjuvant preoperative radiotherapy for locally advanced rectal carcinoma. Wide variations in local recurrence rates are demonstrated depending on the definition of local recurrence employed and the subgroup studied. Thus after surgical operation alone, rates as high as 43.3 per cent or as low as 12.7 per cent can be calculated. After both adjuvant preoperative radiotherapy and operation the overall local recurrence rate is 12.8 per cent, although the local recurrence rate inside the radiotherapy field (true recurrence) may be as low as 2.3 per cent. It is recommended that local recurrence after operation for rectal carcinoma be defined as any detectable local disease at follow-up, occurring either alone or in conjunction with generalized recurrence, in patients who have undergone resection. A rate should be given both for all patients and for those operated on for cure, but not for the latter group alone as this could introduce bias.

2p X-ray Absorption Spectroscopy in the Earth Sciences.

A complete knowledge of 3d transition-metal valencies, site occupancies and site symmetries is essential for a full understanding of mineral/melt energetics and behaviour. Over the last few years, significant advances in both instrumentation and theory associated with synchrotron radiation sources and experiments have enabled the development of 2p X-ray absorption spectroscopy as a sensitive, element-specific site and valency probe. The potential of this technique in the Earth sciences is discussed in this paper with examples reflecting the variety of problems set by 3d transition metals in natural systems.

Adjuvant preoperative radiotherapy for locally advanced rectal carcinoma. Results of a prospective, randomized trial.

PURPOSE: A prospective, randomized clinical trial was conducted by the Northwest Rectal Cancer Group to study the effects of preoperative radiotherapy given one week before surgery in locally advanced (tethered or fixed) rectal carcinoma. METHODS: A total of 284 patients were entered into the trial between 1982 and 1986; 141 were allocated to receive surgical treatment alone, and 143 were allocated to receive preoperative radiotherapy. A 10 x 10 x 10 cm volume in the posterior pelvis, centered on the tumor, was irradiated at a dose of 20 Gy, divided into four daily fractions of 5 Gy each. RESULTS: No differences were observed in any of the clinicopathologic variables in the two arms of the trial; there were no striking down-staging effects in the irradiated tumors. After a minimum follow-up period of 96 months, the overall and cancer-related mortality rates were similar in both arms of the study (P = 0.21 and P = 0.09, respectively). There was a highly significant reduction in local recurrences in the irradiated group (12.8 percent x-ray therapy vs. 36.5 percent surgery; P = 0.0001). The majority of local recurrences after preoperative radiotherapy occurred inside the radiotherapy field (10 cases; 7 percent), with only six cases (5 percent) outside the field. No significant difference was observed in the rates of distant metastasis between the two treatment groups (P = 0.73). CONCLUSIONS: Although there is no statistically significant survival benefit in the whole series, there is a survival benefit for the subset of patients considered by the surgeon to have undergone a curative operation. We recommend that this form of adjuvant therapy should be offered to all patients with locally advanced rectal cancer who are to undergo radical surgery.

An evaluation of five different methods for estimating proliferation in human colorectal adenocarcinomas.

Five different methods of determining cell proliferation have been compared in samples taken from a group of 125 human colorectal tumours labelled in vivo with iododeoxy-uridine (IUdR). The labelling index (LI) was obtained immunocytochemically using monoclonal antibodies against proliferating cell nuclear antigen (PCNA), the Ki67 antigen and IUdR (IUdRimm). Incorporation of IUdR was also determined flow cytometrically (IUdRfcm) and PCNA expression was measured in both formalin- and methanol-fixed tissue (PCNAf and PCNAm respectively). There was significant variation in the results obtained both within and between the different assays. Paired analysis of the data showed that the correlation between the different methods of determining the LI was poor. However, the IUdRfcm LI was significantly correlated with both IUdRimm (r = 0.39; n = 78; P < 0.001 by Spearman's test) and Ki67 LIs (r = 0.32; n = 87; P < 0.001). The IUdRimm LI was also significantly related to the Ki67 LI (r = 0.44; n = 60; P < 0.001). The median IUdRfcm and IUdRimm LIs were significantly higher in the aneuploid vs. the diploid tumours (17.4% vs. 6.2% for IUdRfcm; 23.2% vs. 18.9 for the IUdRimm; P < 0.001 and P = 0.014 respectively by Mann-Whitney U-test) but none of the other proliferative indices showed this relationship. Finally, none of the LIs showed a significant association with the clinical characteristics of the tumours such as stage, grade, age, sex or fixity. The findings of this investigation highlight the need for carefully controlled studies when assessing the value of proliferation markers in solid human tumours.

Distribution of gelatinase B (MMP-9) and type IV collagen in colorectal carcinoma.

Gelatinase B (92 kD, matrix metalloproteinase-9, MMP-9), an enzyme capable of degrading several connective tissue components, was demonstrated by immunolocalization in all specimens of colorectal carcinoma (n = 40), but its distribution between specimens was variable. MMP-9 expression was more frequently observed in advanced tumour stages and was especially prevalent at the side and deep margins of the tumours, and ulceration sites. MMP-9 staining was observed for transformed epithelial cells, macrophages and neutrophils, but seldom for vascular or stromal cells. By contrast, the enzyme was absent from epithelial cells of normal mucosal tissue. Immunostaining of type IV collagen, the major structural component of basement membranes, revealed a general depletion or loss of these structures both within the tumours and at the tumour margins. Dual immunolocalization of MMP-9 and type IV collagen demonstrated that MMP-9 expression at specific sites in the tumour was often inversely related to the distribution of type IV collagen. MMP-9 expression was most pronounced at the invasive tumour margins and in microfoci where tumour cells were in close proximity to inflammatory cells. Such observations support the concept that localized proteolytic and collagenolytic activities contribute to the invasive properties of colorectal tumours.

Prognostic significance of 5T4 oncofetal antigen expression in colorectal carcinoma.

The 5T4 oncofetal antigen is a 72 kDa glycoprotein defined by a monoclonal antibody raised against human placental trophoblast and is expressed in many different carcinomas but detected only at low levels in some normal epithelia. Immunohistochemical analysis of the patterns of expression in colorectal carcinomas has indicated a significant association between the presence of the antigen in tumour cells and metastatic spread. The 5T4 antigen phenotype of 72 colorectal cancers has been compared with the clinical outcome of the patients in order to assess its relationship with prognosis. Forty per cent of tumours were 5T4 positive; the remainder were either unlabelled or exhibited stroma-associated labelling only. There was a significant correlation between 5T4 expression in the malignant cells and unfavourable course of disease (P < 0.001). The 5 year survival with 5T4-positive tumours was 22% compared with 75% for patients with 5T4-negative tumours; median survival was 24 versus > 90 months respectively. Stratified analysis showed that 5T4 antigen tumour positivity was acting independently of each of stage, site of tumour, age or sex. There were significant differences in survival for patients with Dukes' B and C stage carcinomas (P = 0.001 and P = 0.034). The results suggest that in colorectal cancer immunohistochemical assessment of 5T4 expression may be useful in identifying patients at high risk for tumour recurrence and for whom additional treatment strategies might be most appropriate.