Glutathione-S-transferase gene polymorphisms in colorectal cancer patients: interaction between GSTM1 and GSTM3 allele variants as a risk-modulating factor

The distribution of polymorphisms in the glutathione S-transferase (GST) family genes has been studied in 355 healthy controls and 206 cancer (59 proximal and 147 distal) patients. All controls were subjected to flexible sigmoidoscopy. Odds ratios (OR) after stratification by age, gender and smoking were slightly higher in the cancer group as a whole for GSTM1-null (*0/*0), GSTT1-null (*0/*0) and GSTM3 *A/*B or *B/*B when compared with the control group, but the differences did not reach statistical significance. GSTP1 variants had no effect. Separate analysis of patients with proximal and distal tumours has shown stronger associations for the distal cancers, the GSTM3*B allele presence being significantly more frequent in these patients [OR = 1.77; 95% confidence interval (CI) = 1.15-2.74]. Taking into account strong linkage between the GSTM1*A and GSTM3*B alleles, a separate analysis of the GSTM1-nulled individuals was undertaken. The combination of GSTM1-null genotype with GSTM3*B allele presence (*A/*B or *B/*B) was significantly overrepresented among patients with proximal and distal tumours taken together (OR = 2.12; 95% CI = 1.24-3.63), and especially in distal cancer patients (OR = 2.75; 95% CI = 1.56-4.84). Male individuals displayed a stronger association between the presence of the GSTM1-null in combination with GSTM3 *A/*B or *B/*B and distal tumours with a higher odds ratio (OR = 3.57; 95% CI = 1.73-7.36). In contrast, the frequency of GSTM1 *B/*0 or *B/*B combined with GSTM3 *A/*A was significantly lower in patients with distal colorectal cancer, especially in males (OR = 0.37; 95% CI = 0.15-0.92). Neither of these combinations was associated with proximal tumours. Our findings suggest that interactions of polymorphic genotypes within the GSTM gene cluster affect individual susceptibility to colorectal carcinogenesis, the GSTM3*B variant presence being a risk factor especially in combination with the GSTM1-null genotype.

How frequently do large bowel diverticula perforate? An incidence and cross-sectional study

The aetiology of perforation of large bowel diverticula is poorly understood and a case-control study is required to identify the causes. Before such a study can be attempted, the incidence must be determined and groups at particular risk identified. Cases of perforated large bowel diverticula living in the Norwich postal code region treated between 1995 and 1997 were identified. Fifty-eight cases presented in a population of 531 241. The incidence was 4.0 cases per 100,000 per year, increased with age and was higher in men than women (5.8 vs 3.1). The most frequently used drugs were non-steroidal anti-inflammatory drugs (NSAIDs) (29%) and opiate analgesics (26% of cases). This is the first report of the incidence of perforated diverticular disease and allows a calculation of the population size needed to recruit sufficient cases for an aetiological investigation. The differences in incidence between genders should prompt a search for factors which differ between the sexes such as diet. NSAIDs are a known risk factor, although the data show that opiate analgesics should be investigated.

K-ras mutations, rectal crypt cells proliferation, and meat consumption in patients with left-sided colorectal carcinoma

It has been suggested that N-nitroso compounds derived from meat may increase the risk of K-ras mutations in the human colon. We sought evidence of associations between red meat consumption, frequency and type of K-ras mutations in resected tumours, and the rate of crypt cell proliferation (CCP) in the normal mucosa of patients with left-sided colorectal carcinoma. Meat consumption was assessed by food frequency questionnaire, and CCP was determined in rectal biopsies obtained prior to surgery. K-ras mutations in the resected tumours were determined using a PCR-based oligonucleotide hybridization assay. Fifteen K-ras mutations were detected in tumours from 43 patients; 13/15 in codon 12, 3/15 in codon 13, and 1/15 in both codons 12 and 13. All mutations were G-->A or G-->T transitions. There was no statistically significant difference between intakes of red meat in patients with a K-ras mutation (92.4 +/- 9.7 g/day) and those without (82.3 +/- 7.7 g/day). Rectal CCP was significantly higher in patients than in healthy controls, but there was no correlation with meat consumption or K-ras mutation. These data do not support the hypothesis that meat consumption is a risk factor for acquisition of K-ras mutations during colorectal carcinogenesis.

Consumption of fish oil leads to prompt incorporation of eicosapentaenoic acid into colonic mucosa of patients prior to surgery for colorectal cancer, but has no detectable effect on epithelial cytokinetics

Fish oil (FO) was previously reported to partially normalize colorectal crypt cell cytokinetics in patients with colorectal neoplasms. We determined the effect of FO on the fatty acid composition of colonic mucosa and mesenteric adipose tissue and on rectal crypt cell proliferation in patients undergoing surgery for colonic carcinoma. Patients (49-28 males; 21 females) were randomly assigned to consume FO capsules (2 g b.d.; FO group) containing 1.4 g eicosapentaenoic acid (EPA) and 1.0 g docosahexaenoic acid per day, or safflower oil capsules (2 g b.d.; placebo group) for an average of 12.3 +/- 0.5 d prior to surgery. Rectal biopsies were obtained at entry, at surgery, and 8-12 wk postsurgery. Colonic biopsies and samples of mesenteric adipose tissue were analyzed for fatty acids by gas-liquid chromatography. Mitosis was determined in whole crypt mounts. The proportion of EPA (g/100 g total fatty acids) in mucosal lipids was significantly greater in FO patients compared to the placebo group, but there was no effect on mesenteric adipose tissue. However self-reported use of FO supplements prior to surgery was associated with higher levels of EPA in adipose tissue. There was no significant effect of FO on the frequency or spatial distribution of crypt cell mitosis. EPA from marine oil supplements is rapidly incorporated into the colonic mucosal lipids of humans, but the levels achieved in the present study did not modify colorectal cytokinetics.

Amputations in diabetics

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Comparison of duplex ultrasonography and venography in the diagnosis of deep venous thrombosis

Sixty-five patients with suspected deep venous thrombosis (DVT) in 68 limbs were entered consecutively into a study to compare venography with duplex ultrasonography scanning. Both tests were performed on 64 limbs, venography being contraindicated in four. Overall, duplex scanning correctly identified 86 per cent of DVTs diagnosed on venography and correctly excluded 80 per cent with negative venograms. Nearly all errors arose in the diagnosis of calf DVT. In the femoral vein duplex scanning had a specificity of 100 per cent and a sensitivity of 95 per cent. In addition, duplex scanning provided data on the limb not undergoing venography. Of 55 limbs that underwent bilateral duplex scanning, five had thrombus in the femoropopliteal segment and a negative contralateral venogram. In addition, three Baker's cysts were diagnosed. Duplex scanning can be used in patients in whom venography is contraindicated and may also provide information about the contralateral limb. We regard femoropopliteal duplex scanning as sufficiently accurate that treatment can be initiated on the basis of the scan. Duplex scanning should replace venography as the standard method of diagnosing femoropopliteal DVT; radiographic studies should now be required only when the scan result is in doubt.

Effect of steroid hormones on human colorectal adenocarcinoma xenografts, of known steroid-receptor status, in nude mice

The effect of hormone therapy on the growth of human colonic adenocarcinoma xenografts in nude mice was evaluated. Primary xeno-transplantation for ten different human colorectal adenocarcinomas into nude mice yielded a tumour take of 50%. One of these host tumours was found to contain androgen receptors (8 fmol/mg cytosol protein; Kd 0.73 x 10(-9) M), which were maintained in the xenograft at the third and ninth passages, but not expressed at the tenth and twelfth passages. The host tumour and its xenograft did not express either oestrogen or progesterone receptors. Administration of dihydrotestosterone led to inhibition of xenograft growth at the ninth passage compared with untreated controls (P less than 0.05), but had no effect on xenograft growth at the tenth and twelfth passages when androgen receptors were absent. Stilboestrol and progesterone failed to influence xenograft growth. In conclusion, dihydrotestosterone administration led to inhibition of xenograft growth only in the presence of androgen receptor, suggesting that some colorectal cancers might be considered steroid-hormone-sensitive tumours.

Variations in steroid receptor status with disease stage in breast cancer

Oestrogen and progesterone receptor (ER and PgR) distribution in three clinical subgroups of 421 breast carcinomas was analysed. The groups comprised (1) early breast cancer (T1-2a, N0M0; n = 64); (2) untreated advanced fungating cancer (n = 27) and (3) advanced cancer relapsing after endocrine therapy (n = 29). Receptor distribution in each of the subgroups was compared to that of the total population. The advanced fungating group contained no ER--ve/PgR--ve tumours and the distribution was also significantly different from the total population (P less than 0.001 by Chi-squared test). The proportion of tumours in the total population that contained greater than 40 fmol/mg ER was 187/421 (44.4%). There was no significant difference between the early breast cancer group and the total population (P greater than 0.9). However, the proportion of tumours containing ER greater than 40 fmol/mg in the advanced fungating cancer group (16/27, 59.3%) was significantly higher than in the total population (P less than 0.01). This difference may be partially explained by the older age at presentation in this group. In the relapsed after endocrine therapy group only four of 29 (13.8%) contained ER greater than 40 fmol/mg which was significantly different from the total (P less than 0.001). There was a higher proportion of early breast cancers containing PgR greater than 40 fmol/mg than in the total population (P less than 0.001). There was no significant difference between PgR distribution in the advanced fungating and relapsed groups compared to the total population. The data suggest that patients presenting with advanced fungating cancer are more likely to respond to endocrine therapy than the population as a whole, and that in breast cancer that has relapsed following endocrine therapy receptor levels decrease with progression of the disease.

A hybrid ligand method for androgen receptor measurement

Existing techniques for androgen receptor (AR) assay are complicated by cross-reactivity of ligand binding affinities that can lead to incorrect estimation of receptor concentration. Two most frequently used ligands are [3H]dihydrotestosterone [( 3H]DHT) and [3H]methyltrienolone [( 3H]R1881), which in addition to binding to AR also bind to sex hormone binding globulin (SHBG; Kd = 1.5 nM) and progesterone receptors (PgR; Human Kd = 1 nM, rat Kd = 6 nM) respectively. Triamcinolone acetonide (TMA) is commonly used to block binding of [3H]R1881 to PgR, however at high concentrations TMA itself will bind AR (Kd = 7 microM). We have developed a hybrid ligand method for the measurement of AR in the presence of SHBG and PgR. This method used [3H]R1881 as the high specific activity labelled tracer and DHT as the unlabelled competitor of specific AR binding. Using this assay, 20% of human colorectal carcinomas were found to contain AR.

Androgen receptors in colorectal adenomas

To evaluate the potential effect of androgens on the development and growth of human colorectal adenomas, the prevalence and concentration of cytosolic androgen receptors (AR) were analysed in 26 adenomas and 19 samples of normal colonic mucosa by a hybrid ligand receptor-binding assay. AR were detected in 7 of the adenomas (26.9%), and in 6 of the normal mucosa samples (31.6%). In the adenomas, AR levels demonstrated were low, ranging from 6 to 31 fmol/mg cytosol protein, and dissociation constants (Kds) ranged from 0.17-2.7 X 10(-9) M. Of 13 adenomas excised from men, 6 (46%) had positive receptor activity, whereas only 1 of 13 (7.7%) from women was positive (P = 0.03, Fisher's exact test). There was no correlation between AR titre and patient age, or between adenoma size and histological type or degree of dysplasia. In normal mucosa, AR levels ranged from 7 to 33 fmol/mg and Kds ranges from 0.24-3.1 X 10(-9) M. There was no significant difference between either AR prevalence or levels in the adenomas and normal mucosa. The sex difference was exclusive to the adenoma. Endogenous androgen may play a role in adenoma development early in the promotional process.

Malignant cysts of the male breast

Two cases of male breast carcinoma presenting as cystic swellings are reported. Cysts of the male breast are rare, but unlike cysts in female breasts are more likely to represent significant pathology. We recommend consideration of excision biopsy of isolated cysts in male breasts.

Stab injury--the experience of an East London Hospital 1978-1983

A retrospective review of 201 patients with stab wounds admitted to an East London Hospital over a period of six years was performed. There was no striking increase in the annual incidence of these injuries over the period reviewed. The majority of patients were young males who arrived at the Accident and Emergency Department after 1800 h on a Friday, Saturday, or Sunday and had consumed alcohol prior to admission. There were 47 abdominal injuries (23%), 69 thoracic (34%), 51 limb injuries (25%) and 34 injuries involving the head and neck (17%). Forty patients (20%) had injuries involving more than one site. Abdominal stabbings were managed by a selective approach resulting in 28 laparotomies of which only 2 (7%) were negative. Evisceration of small bowel or omentum was always associated with significant intraperitoneal injury.

Androgen receptors in rectal and colonic cancer

To evaluate the potential effect of androgens on human colorectal cancer, the prevalence and concentration of cytosolic androgen receptors were analyzed in 23 rectal and 13 cecal adenocarcinomas by a hybrid radioligand assay. Androgen receptors were detected in nine of the rectal (39 percent) and five of the cecal tumors (38 percent). Androgen receptor levels demonstrated were low, ranging from three to 17 fmol/mg cytosol protein. Dissociation constants were 1 nM or less. The presence of androgen receptors was independent of age or sex of the patient, and of the state of histologic differentiation and Dukes' staging of the tumor. Androgen receptor prevalence was similar in mucosa adjacent to rectal and cecal adenocarcinomas and in mucosa from five of ten patients (50 percent) with diverticular disease. Our findings suggest that androgen dependency does not play a major role in endocrine control of the development of rectal cancer.

Perforated duodenal diverticulum: a report of two cases

Perforation is a rare complication of congenital duodenal diverticula. The case histories of 2 patients are reported. Operative treatment to excise the diverticulum and close the defect in the duodenum and to drain associated sepsis is required.