Preliminary report on the safety and utility of a novel automated mechanical endoscopic tissue resection tool for endoscopic necrosectomy: a case series.

Background and study aims Endoscopic drainage of walled-off necrosis and subsequent endoscopic necrosectomy has been shown to be an effective step-up management strategy in patients with acute necrotizing pancreatitis. One of the limitations of this endoscopic approach however, is the lack of dedicated and effective instruments to remove necrotic tissue. We aimed to evaluate the technical feasibility, safety, and clinical outcome of the EndoRotor, a novel automated mechanical endoscopic tissue resection tool, in patients with necrotizing pancreatitis. Methods Patients with infected necrotizing pancreatitis in need of endoscopic necrosectomy after initial cystogastroscopy, were treated using the EndoRotor. Procedures were performed under conscious or propofol sedation by six experienced endoscopists. Technical feasibility, safety, and clinical outcomes were evaluated and scored. Operator experience was assessed by a short questionnaire. Results Twelve patients with a median age of 60.6 years, underwent a total of 27 procedures for removal of infected pancreatic necrosis using the EndoRotor. Of these, nine patients were treated de novo. Three patients had already undergone unsuccessful endoscopic necrosectomy procedures using conventional tools. The mean size of the walled-off cavities was 117.5 ± 51.9 mm. An average of two procedures (range 1 - 7) per patient was required to achieve complete removal of necrotic tissue with the EndoRotor. No procedure-related adverse events occurred. Endoscopists deemed the device to be easy to use and effective for safe and controlled removal of the necrosis. Conclusions Initial experience with the EndoRotor suggests that this device can safely, rapidly, and effectively remove necrotic tissue in patients with (infected) walled-off pancreatic necrosis.

Unfiltered coffee increases plasma homocysteine concentrations in healthy volunteers: a randomized trial.

BACKGROUND: An elevated plasma homocysteine concentration is a putative risk factor for cardiovascular disease. Observational studies have reported an association between coffee consumption and plasma homocysteine concentrations. OBJECTIVE: We studied the effect of coffee consumption on plasma homocysteine in a crossover trial. We used unfiltered coffee so as to include the possible effects of coffee diterpenes, which are removed by filtering. DESIGN: Sixty-four healthy volunteers (31 men and 33 women) with a mean (+/-SD) age of 43 +/- 11 y were randomly assigned to 2 groups. One group (n = 30) drank 1 L unfiltered cafetière (French press) coffee daily for 2 wk. Such coffee is rich in the cholesterol-raising diterpenes kahweol and cafestol. The other group (n = 34) received water, milk, broth, tea, and chocolate drinks instead of coffee. After a washout period of 8 wk, both groups received the alternate intervention for another 2 wk. RESULTS: Consumption of 1 L unfiltered coffee/d for 2 wk significantly raised fasting plasma homocysteine concentrations by 10%, from 12.8 to 14.0 micromol/L. CONCLUSIONS: Unfiltered coffee increases plasma homocysteine concentrations in volunteers with normal initial concentrations. It is unclear whether the effect is caused by the cholesterol-raising diterpenes present exclusively in unfiltered coffee or by factors that are also present in filtered coffee.

Role of bile acids in colorectal carcinogenesis.

Dietary factors are considered important environmental risk determinants for colorectal cancer development. Epidemiological studies have shown that a high fat (or meat) intake is associated positively and a high starch, fibre (non-starch polysaccharide), vegetable and fruit intake negatively with colorectal cancer incidence. One mechanism by which these effects are possibly exerted is through the metabolism of secondary bile acids. Secondary bile acids are formed after enzymatic deconjugation and dehydroxylation of primary bile acids in the large bowel by anaerobic bacteria. It has been shown that these compounds can have tumour-promoting capacities in animal experiments. In epidemiological studies, colonic cancer risk is related to the faecal bile acid concentration. In serum and bile of patients with colonic adenomas, more deoxycholic acid was detected than in healthy controls. Secondary bile acids are toxic to several cell systems at physiological concentrations. The exact mechanism by which these amphiphilic molecules exert their action is not well understood. It might act through membrane damage, intracellular mitochondrial action or genotoxic effects. So far the evidence that bile acids are involved in colonic carcinogenesis is largely circumstantial. It is, however, well accepted that environmental factors, such as dietary habits influence genetic susceptibility. Bile acids could play a promoting role in this process.

Meat consumption and meat preparation in relation to colorectal adenomas among sporadic and HNPCC family patients in The Netherlands.

Meat consumption and meat preparation methods are thought to be associated with the risk of sporadic colorectal cancer, and possibly adenomas. As the same somatic mutations occur in sporadic adenomas and hereditary non-polyposis colorectal cancer (HNPCC)-related adenomas, similar exogenous factors may play a role in the development of both types of adenoma. In a case control study among 57 sporadic colorectal adenoma cases and 62 adenoma cases from HNPCC families (and 148 adenoma-free controls) from the Netherlands, we examined whether meat consumption and preparation are similarly associated with sporadic and suspected HNPCC colorectal adenomas. Frequency of meat consumption was not significantly associated with adenoma risk in our population of sporadic and HNPCC family cases and controls (Odds Ratios (OR) for high versus low consumption were 1.0 and 0.6, respectively). Interestingly, consumption of red meat and specific preparation methods (i.e., "not adding any water" and " closed lid with most meat types") slightly, but non-significantly, increased the risk of adenomas in the sporadic group only (OR, 95% Confidence Interval (CI): 4.1, 0.7-23.0, 2.0, 0.6-6.5 and 2.6, 0.9-7.2, respectively). This is the first study to examine possible differences or similarities in risk factors for sporadic and HNPCC colorectal carcinogenesis. Our results do not provide support for meat consumption as a risk factor for adenoma formation in HNPCC family members. Some characteristics of habitual meat preparation in the Netherlands may, however, increase the risk of sporadic adenomas.

Meat consumption and preparation, and genetic susceptibility in relation to colorectal adenomas.

Epidemiological evidence suggests that a high meat consumption and/or animal fat intake may increase the risk of colorectal cancer. The objective of this study is to examine the role of dietary factors, in particular meat preparation and consumption, in relation to colorectal adenomas, the pattern of DNA-mutations (e.g. K-ras and p53), and genetic susceptibility (NAT2, HNPCC). In a case control study on diet and colorectal adenomas (sporadic and HNPCC), acetylator status (NAT2) of cases and controls as well as K-ras and p53 mutations in adenomas will be assessed. Consumption and preparation of meat, the primary interest of this study, will be assessed by a food frequency questionnaire designed especially for this purpose.

The effect of unfiltered coffee on potential biomarkers for colonic cancer risk in healthy volunteers: a randomized trial.

BACKGROUND: Epidemiologic studies suggest that coffee use might protect against colorectal cancer. Inconsistencies as to the effect of coffee use and colorectal cancer between epidemiologic studies might be related to the type of coffee brew. OBJECTIVE: We studied the effect of unfiltered coffee consumption on putative biomarkers for colonic cancer risk. DESIGN: A total of 64 healthy volunteers (31 men and 33 women), with a mean age of 43 +/- 11 years were randomly assigned to two groups in a crossover design, with two intervention periods of 2 weeks separated by a washout period of 8 weeks. Treatments were 1 L of cafetière (French press) coffee daily or no coffee. At the end of each intervention period, fasting blood samples, colorectal biopsies and 48 h faeces were collected. RESULTS: No effect of coffee on colorectal cell proliferation, assayed by estimating the Proliferating Cell Nuclear Antigen labelling index, was seen. Additionally, no effects were seen on the concentrations of faecal soluble bile acids and colorectal mucosal glutathione S-transferase activity. However, unfiltered coffee significantly increased the glutathione content in the colorectal mucosa by 8% and in plasma by 15%. Other aminothiols in plasma also increased on coffee. CONCLUSION: Unfiltered coffee does not influence the colorectal mucosal proliferation rate, but might increase the detoxification capacity and anti-mutagenic properties in the colorectal mucosa through an increase in glutathione concentration. Whether this effect indeed contributes to a lower colon cancer risk remains to be established.

Pleuro-pulmonary involvement in patients with connective tissue disease. The role of open lung biopsy.

Pleuro-pulmonary involvement is frequently encountered in connective tissue disease. The pathological changes due to connective tissue disease are multifold. They include pleural, interstitial and nodular manifestations as well as airway lesions and vascular changes. In clinical decision making it is important to differentiate between effects of the underlying connective tissue disease, complications due to treatment, such as opportunistic infections, toxic and idiosyncratic drug reactions, and unrelated primary pulmonary diseases. We describe 2 patients with a connective tissue disease and pleuro-pulmonary complications. The diagnostic procedures are discussed. The result of the open lung biopsy was consistent with the diagnosis of rheumatic disease and also Sjögren's disease in the first patient and excluded infection and vasculitis in the second patient. Whenever histological investigation is needed to establish and/or exclude a diagnosis of pulmonary involvement in connective tissue disease, the open lung biopsy remains the "gold standard". We therefore propose a flow-chart for use in the clinical approach to the patient with interstitial lung disease of unknown origin.

Duodenal metastasis: an uncommon cause of occult small intestinal bleeding.

Duodenal metastases are a very uncommon and peculiar cause of upper gastrointestinal bleeding. However, they should be considered in a patient presenting with upper gastrointestinal bleeding and a previous history of malignancy. The importance of recognising the unusual presentation of duodenal metastasis has to be emphasised. We describe two patients with upper gastrointestinal bleeding due to duodenal metastases. In the first patient a periampullary bleeding due to a metastasis of a renal cell carcinoma was detected five years after nephrectomy of the right kidney. In the second patient an occult bleeding caused by a duodenal metastasis of a melanoma was diagnosed. The first manifestation of this melanoma was eight years earlier.

The glutathione biotransformation system and colorectal cancer risk in humans.

Evidence for a protective role of the glutathione biotransformation system in carcinogenesis is growing. However, most data on this system in relation to colorectal cancer originate from animal studies. Here we review the human data. In humans, a significant association was found between glutathione S-transferase (GST) activity in the mucosa along the gastrointestinal tract and the corresponding tumour incidence. Low activity was correlated with high tumour incidence and vice versa. Also, in normal colonic mucosa, GST activity is lower in patients at risk of colon cancer than in healthy controls and therefore interventions which increase the glutathione detoxification capacity may reduce cancer incidence. Consumption of vegetables and fruit is associated with a lower risk of colorectal cancer. Human intervention studies showed that (components from) vegetables induced colonic glutathione detoxification capacity. Such an effect could contribute to a lower colon cancer risk, but further data are needed. The human GSTs consist of four main classes--alpha (A), mu (M), pi (P) and theta (T)--each of which is divided into one or more isoforms. Functional polymorphisms are known for the GST genes M1, P1 and T1 and they all lead to less active enzymes compared to the wild-type gene products. However, studies that compared these GST polymorphisms in relation to colon cancer risk were not conclusive with respect to an increased or decreased risk of a particular genotype. Diet or medication can also influence the expression levels of specific isoenzymes and the effect of such interventions on cancer risk deserves more attention.

Low colonic glutathione detoxification capacity in patients at risk for colon cancer.

BACKGROUND: Colon carcinogenesis is a multifactorial process influenced by hereditary as well as environmental factors. The glutathione/glutathione S-transferase detoxification system in the colon is important for protection against carcinogens. We investigated the levels of glutathione/glutathione S-transferase in normal colon mucosa of patients with colorectal cancer and in patients at high risk for colorectal cancer compared with those in healthy controls. MATERIALS AND METHODS: Glutathione content was analyzed by high-performance liquid chromatography, and glutathione S-transferase enzyme activity by spectrophotometric determination with 1-chloro 2,4-dinitrobenzene. Normal colon tissue of patients with colon adenoma (n = 64), colorectal cancer (n = 37), familial adenomatous polyposis (FAP; n = 19), hereditary non-polyposis colorectal cancer families with (HNPCC+Ad; n = 34) or without (HNPCC-Ad; n = 33) adenoma was investigated. RESULTS: Glutathione levels were significantly lower in the normal colon mucosa of patients with cancer, FAP, HNPCC-Ad or HNPCC+Ad compared with adenoma patients or healthy controls. Glutathione S-transferase enzyme activity in the distal colon was significantly lower in patients with cancer or FAP compared with the adenoma patients or healthy controls, whereas values in carcinoma patients were significantly lower compared with both the HNPCC-Ad and HNPCC+Ad groups. CONCLUSIONS: An association of low colonic glutathione/glutathione S-transferase activity levels and high clinical risk for the development of colorectal cancer was observed. This low glutathione detoxification capacity might contribute to the colon cancer risk.

Low levels of colonic glutathione S-transferase in patients with X-linked agammaglobulinaemia.

BACKGROUND: Patients with X-linked agammaglobulinaemia, a primary immunodeficiency disorder, suffer from recurrent infections of the respiratory and intestinal tract. Rapidly progressive colorectal cancer was diagnosed in three unrelated young adults with X-linked agammaglobulinaemia. This finding implies a 30-fold increase of risk for this cancer in this patient group. Glutathione S-transferases are a family of biotransformation enzymes involved in the detoxification of cytotoxic and carcinogenic compounds, that may function in the prevention of carcinogenesis. We investigated the possible role of the glutathione S-transferase enzyme system in the apparently increased colorectal cancer risk in X-linked agammaglobulinaemia patients. MATERIALS AND METHODS: We analysed the glutathione levels and the glutathione S-transferase enzyme activity and iso-enzyme composition in normal colonic biopsies of eight X-linked agammaglobulinaemia patients, 25 patients with a recent history of colonic adenomas and 10 healthy volunteers. RESULTS: X-linked agammaglobulinaemia patients had significantly lower glutathione S-transferase enzyme activities at all sites in the normal colonic mucosa as compared to adenoma patients. In X-linked agammaglobulinaemia patients the rectal glutathione S-transferase enzyme activity was lower than in the proximal colon and significantly lower as compared to controls. CONCLUSION: This lower glutathione S-transferase enzyme activity might play a role in the apparently increased colorectal cancer risk in X-linked agammaglobulinaemia patients, assuming that detoxification of carcinogenic compounds plays a role in the aetiology of colon cancer of these patients.

Effects of consumption of Brussels sprouts on intestinal and lymphocytic glutathione S-transferases in humans.

A high intake of glucosinolate-containing cruciferous vegetables, such as Brussels sprouts (Brassica oleraceae), has been linked to a decreased cancer risk, but the underlying mechanism is still unclear. The aim of this study was to reveal possible modulating effects of consumption of Brussels sprouts on duodenal, rectal and lymphocytic (i) glutathione S-transferase (GST) enzyme activity, (ii) GST isozyme levels and (iii) glutathione (GSH) content. Ten healthy non-smoking volunteers were randomly assigned to two groups in a cross-over design. Five persons started on a glucosinolate-free diet (control period), while the other five consumed 300 g/day cooked Brussels sprouts, at the expense of 300 g glucosinolate-free vegetables (sprouts period). After 7 days the regimen was changed for a further week. At the end of both periods blood samples and duodenal and rectal biopsies were taken. Mean GST activity showed marked differences between duodenal, rectal and lymphocytic cytosols (737 +/- 54, 321 +/- 29 and 154 +/- 14 nmol/min/mg protein respectively), but was uninfluenced by the dietary regimen. Isozyme distribution varied greatly between the tissues. In duodenum GST-alpha, -pi, and -mu isozymes were expressed in considerable amounts (8441 +/- 1365, 3002 +/- 223 and 536 +/- 248 ng/mg protein respectively). Rectal biopsies also contained above three GST classes, but here GST-pi was the most pronounced expressed isozyme (2849 +/- 246) followed by GST-mu (495 +/- 242), while GST-alpha was only present in minor quantities (149 +/- 31). In lymphocytes only GST-pi (755 +/- 96) and GST-mu (83 +/- 54) could be detected. As a result of the dietary regimen rectal GST-alpha and -pi levels were slightly increased at the end of the sprouts period, by 30 and 15% respectively. GSH contents were uninfluenced by the dietary regimen. In conclusion, consumption of glucosinolate-containing Brussels sprouts for 1 week results in increased rectal GST-alpha and -pi isozyme levels. We hypothesize that these enhanced detoxification enzyme levels may partly explain the epidemiological association between a high intake of glucosinolates (cruciferous vegetables) and a decreased risk of colorectal cancer.

Effect of resistant starch on potential biomarkers for colonic cancer risk in patients with colonic adenomas: a controlled trial.

Resistant starch decreases the concentration of secondary bile acids in the feces and the proliferation rate of colonic mucosal cells in healthy volunteers. This may reduce the risk of colon cancer. We investigated 23 patients with recently removed colonic adenoma(s) in a controlled parallel trial. They consumed 45 g of maltodextrin per day as placebo for four weeks and were randomly assigned to either 45 g of native amylomaize starch, containing 28 g of resistant starch type II or 45 g of maltodextrin for another four weeks. No effect on colorectal cell proliferation, fecal wet and dry weights, pH, and short-chain fatty acid excretion was seen. The bile acid concentration in fecal water decreased by 15% (P = 0.048) and the percentage secondary bile acids decreased by 14% (P = 0.002) on resistant starch relative to placebo. Whether this has a substantial role in colon cancer prevention in these patients remains to be established.

Tissue levels of fish fatty acids and risk of colorectal adenomas: a case-control study (Netherlands).

Epidemiological and animal studies have suggested that a high ratio of n-3 fish fatty acids to arachidonic acid (AA), might protect against colorectal carcinogenesis. Competition of n-3 and n-6 fatty acids, especially AA, for the enzyme cyclooxygenase-2 may be responsible for this effect. To examine the relation between fish intake and colorectal adenomas, data from a Dutch case-control study were analysed. All 52 cases and 57 controls filled out a food questionnaire, underwent a full colonic examination and have had a fat biopsy from the buttock. Intake of fish and fish fatty acids was inversely associated with colorectal adenomas although not statistically significant. For the ratio of fish fatty acids to AA, the ORs in the second and third tertile were 1.2 and 0.8 (p-trend = 0.78). Tissue levels of fish fatty acids were inversely associated and tissue levels of AA were positively associated with adenomas, although not statistically significant. However, the OR for the ratio of fish fatty acids to AA was 0.2 in the second and third tertile (p-trend = 0.002). In line with the hypothesis, a high ratio of fish fatty acids to AA in adipose tissue was associated with a lower risk of colorectal adenomas.

Identification of novel Bruton's tyrosine kinase mutations in 10 unrelated subjects with X linked agammaglobulinaemia.

Mutations of the Bruton's tyrosine kinase (Btk) gene cause X linked agammaglobulinaemia (XLA). This inherited immunodeficiency disease causes an arrest in B cell differentiation of pre-B cells to mature B cells. In this study we report the characterisation of mutations in the Btk gene in 10 unrelated XLA families. The screening approach we used was based on reverse transcriptase PCR and direct cycle sequencing of the amplified products followed by analysis of the observed mutations at the level of genomic DNA. The single strand confirmation polymorphism (SSCP) technique was used for assessment of the carriers in some of these families. Various mutations throughout the coding gene were observed, including missense and nonsense mutations, a deletion, and several splicing defects. None of the mutations except one has been previously described. There were three point mutations resulting in a single amino acid substitution. One of these missense mutations was observed in a conserved region of the PH domain, the other two were found in the src homology domain 2 that is involved in phosphotyrosyl peptide binding. Two mutations were single base pair substitutions resulting in premature stop codons. In four patients abnormal Btk transcripts were found that were the result of aberrant splicing. One small deletion was observed causing a frameshift and a secondary premature termination signal. Characterisation of the mutations responsible for XLA allowed us to diagnose the disease conclusively and identify the phenotypically normal female carriers.