W. O. Kirwan

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.

Surgical audit: The value of a morbidity and mortality conference

SummaryA Regular morbidity and mortality conference has been conducted over a period of 18. months. The conference has been a useful forum for postgraduate surgical education and continuous assessment of surgical trainees. The data from each conference have been combined to provide a comprehensive audit of general surgery at a busy teaching hospital.

How Safe is Splenectomy

The increased risk of sepsis in patients following splenectomy has been well documented. Fear of over-whelming post-splenectomy sepsis (OPSI) has resulted in a generalised trend towards splenic salvage among surgeons. However, splenorrhaphy and attempts at splenic salvage may of themselves predispose to significant morbidity, sometimes more serious than increased susceptibility to infection associated with splenectomy. This study aims to assess the risk of splenectomy and subsequent asplenia.We reviewed 246 patients who underwent splenectomy over a 16 year period. Indications for splenectomy were considered under the following headings: haematological (N = 116), trauma (N = 69), visceral carcinoma (N = 28), incidental (N = 13) and miscellaneous (N = 20).There were 28 deaths in the series, primarily among those in the intra-abdominal carcinoma (13) and multiple trauma (13) groups. Two deaths were recorded among patients undergoing elective splenectomy for benign disease. Thrombo-embolic complications were recorded in nine patients; respiratory tract infection in 36 patients and intra-abdominal abscess in two patients. Two cases of post-splenectomy pneumococcal septicaemia were documented, neither of which was fatal.While not an entirely benign procedure, splenectomy can be performed relatively safely, especially when performed for benign disease in an adult population.

Biliary surgery for benign disease a study of 500 consecutive operations.

SummaryAn analysis of 500 consecutive operations on the biliary tract for benign disease, performed over a 5 year period is presented. Twenty-two per cent of patients had common duct exploration, and the incidence of choledochotomy increased with advancing age. The overall incidence of choledocholithiasis was 15.2% and calculi in the common duct were found more frequently in the elderly. The use of operative cholangiography increased over the 5 year study period, but was not associated with any change in the incidence of common bile duct exploration or choledocholithiasis. Four patients had re-exploration for retained calculus (0.8%). The overall operative mortality was 0.6%.

Pulmonary injury due to ischaemia-reperfusion is ameliorated by hypertonic saline infusion

ConclusionResuscitation with HTS attenuates the pulmonary oedema and tissue injury due to lower torso IR.