[Recommendations for sedation during flexible bronchoscopy]

Flexible bronchoscopy is a standard examination today and is conducted not only in nearly every hospital but also in privately owned practices. The vast majority of patients want sedation for this examination. Such a procedure is nearly always necessary in complex and interventional procedures, irrespective of the patient's wish. The recommendation at hand to use sedation measures for flexible bronchoscopy is based on the results of numerous clinical studies and also takes account of individual experiences in this area. The structural and procedural requirements and the requirements for staff training are defined and should describe the minimum standard when it comes to conducting a bronchoscopy under sedation. Furthermore the drugs recommended for sedation are discussed and their methods of application shown. Finally the recommendations also include suggestions for patient clarification, monitoring and discharge. They should provide the examiner with concrete operating options and therefore above all increase patient safety.

X-ray holographic microscopy with zone plates applied to biological samples in the water window using 3rd harmonic radiation from the free-electron laser FLASH

The imaging of hydrated biological samples - especially in the energy window of 284-540 eV, where water does not obscure the signal of soft organic matter and biologically relevant elements - is of tremendous interest for life sciences. Free-electron lasers can provide highly intense and coherent pulses, which allow single pulse imaging to overcome resolution limits set by radiation damage. One current challenge is to match both the desired energy and the intensity of the light source. We present the first images of dehydrated biological material acquired with 3rd harmonic radiation from FLASH by digital in-line zone plate holography as one step towards the vision of imaging hydrated biological material with photons in the water window. We also demonstrate the first application of ultrathin molecular sheets as suitable substrates for future free-electron laser experiments with biological samples in the form of a rat fibroblast cell and marine biofouling bacteria Cobetia marina.

[Insulin allergy: background, diagnosis and treatment]

An allergic reaction develops in 2.4% of patients that use insulin. This ranges in severity from erythema and pruritus to life-threatening anaphylaxis. llergic reactions to insulin usually occur within a few hours after an injection and are usually due to a local or systemic type I IgE-mediated hypersensitivity reaction. Despite considerable research into the immunogenicity of insulin, this has not yet been clarified completely and allergic reactions to insulin still occur. A systematic diagnostic approach is essential for an adequate treatment plan. A blood test for anti-insulin antibodies and intradermal skin tests are of great importance. There are many options available for the treatment of insulin allergy and each patient must therefore be evaluated individually.

Are insulin resistance, impaired fasting glucose and impaired glucose tolerance all equally strongly related to age?

BACKGROUND

Insulin resistance (IR) has been considered an underlying cause of impaired glucose tolerance (IGT) and impaired fasting glucose (IFG). Whether IR increases with age has been debated. We investigated the age-associated deterioration in the homeostasis model assessment (HOMA) of IR and in glucose metabolism.

METHODS

Ten (nine including women) European studies contributed data on 6314 men and 6393 women aged 30-88 years. The cohort- and sex-specific top 25% of HOMA of IR in non-diabetic subjects was used to define HOMA-IR.

RESULTS

Compared with subjects aged 50-59 years, the cohort- and body mass index-adjusted odds ratio (95% confidence interval) for HOMA-IR was 0.83 (0.64, 1.08), 0.87 (0.74, 1.03), 1.20 (1.02, 1.42) and 1.45 (1.10, 1.92) in men and 0.84 (0.62, 1.14), 0.91 (0.77, 1.09), 1.38 (1.19, 1.62) and 1.71 (1.35, 2.17) in women, respectively, aged 30-39, 40-49, 60-69 and > or = 70 years (P < 0.0001 for trend test). The same increasing trend was also observed for IFG. In contrast, the corresponding odds ratios for IGT increased linearly and more strongly with age, being 0.37 (0.22, 0.63), 0.67 (0.52, 0.87), 1.55 (1.24, 1.92) and 2.96 (2.13, 4.13) in men and 0.51 (0.31, 0.85), 0.66 (0.52, 0.86), 1.92 (1.57, 2.35) and 3.85 (2.89, 5.12) in women, respectively.

CONCLUSIONS

Age is more strongly associated with IGT than with HOMA-IR or IFG in non-diabetic European populations.

Development, operation, and long-term performance of a full-scale biocurtain utilizing bioaugmentation

A full-scale field evaluation of bioaugmentation was conducted in a carbon tetrachloride (CT)- and nitrate-impacted aquifer at Schoolcraft, MI. The added organism was Pseudomonas stutzeri KC (strain KC), a denitrifying bacterium that cometabolically degrades CT without producing chloroform (CF). To introduce and maintain strain KC in the aquifer, a row of closely spaced (1-m) injection/extraction wells were installed normal to the direction of groundwater flow near the leading edge of the CT plume. The resulting system of wells was used to establish and maintain a "biocurtain" for CT degradation through the intermittent addition of base to create favorable pH conditions; inoculation; and weekly addition of acetate (electron donor), alkali, and phosphorus. Although half of the test zone was inoculated twice, the long-term performance of both sections was indistinguishable: both had high CT removal efficiencies (median of 98-99.9%) and similar levels of strain KC colonization (>10(5) strain KC/g). Sustained and efficient (98%) removal of CT has now been observed over 4 yr. Transient low levels of CF (<20 ppb) and H2S (<2 ppm) were observed, but both disappeared when the concentration of acetate in the weekly feed was reduced. Nitrate removal efficiencies ranged from 60% at low acetate concentrations to nearly 100% at high acetate concentrations. We conclude that closely spaced wells and intermittent substrate addition are effective means of delivering organisms and substrates to subsurface environments. At the Schoolcraft site, we achieved uniform removal efficiencies over a significant vertical depth (15 m), despite significant variability in hydraulic conductivity. This was accomplished by pumping 65% (v/v) of the natural gradient flow passing through the biocurtain during a given week in a single 6-h pumping event. Approximately 18,600 m3 of contaminated groundwater was treated during the project.

Acetaldehyde production and metabolism by human indigenous and probiotic Lactobacillus and Bifidobacterium strains

Many human gastrointestinal facultative anaerobic and aerobic bacteria possess alcohol dehydrogenase (ADH) activity and are therefore capable of oxidizing ethanol to acetaldehyde. We examined whether human gastrointestinal lactobacilli (three strains), bifidobacteria (five strains) and probiotic Lactobacillus GG ATCC 53103 are also able to metabolize ethanol and acetaldehyde in vitro. Acetaldehyde production by bacterial suspensions was determined by gas chromatography after a 1-h incubation with 22 mM ethanol. To determine the acetaldehyde consumption, the suspensions were incubated with 50 microM or 500 microM acetaldehyde as well as with 500 microM acetaldehyde and 22 mM ethanol, i.e. under conditions resembling those in the human colon after alcohol intake. The influence of growth media and bacterial concentration on the ability of lactobacilli to metabolize acetaldehyde and to produce acetate from acetaldehyde were determined. ADH and aldehyde dehydrogenase (ALDH) activities were determined spectrophotometrically. Neither measurable ADH nor ALDH activities were found in aerobically grown Lactobacillus GG ATCC 53103 and Lactobacillus acidophilus ATCC 4356 strains. All the lactobacilli and bifidobacteria strains revealed a very limited capacity to oxidize ethanol to acetaldehyde in vitro. Lactobacillus GG ATCC 53103 had the highest acetaldehyde-metabolizing capacity, which increased significantly with increasing bacterial concentrations. This was associated with a marked production of acetate from acetaldehyde. The type of the growth media had no effect on acetaldehyde consumption. Addition of ethanol to the incubation media diminished the acetaldehyde-metabolizing capacity of all strains. However, in the presence of ethanol, Lactobacillus GG ATCC 53103 still demonstrated the highest capacity for acetaldehyde metabolism of all strains. These data suggest a beneficial impact of Lactobacillus GG ATCC 53103 on high gastrointestinal acetaldehyde levels following alcohol intake. The possible clinical implications of this finding remain to be established in in vitro studies.

Staging of lymph nodes with FDG dual-headed PET in patients with non-small-cell lung cancer

Accurate assessment of mediastinal lymph node involvement in patients with non-small-cell lung cancer (NSCLC) is necessary to select patients for direct surgical treatment. The aims of the present study were to assess the feasibility of staging NSCLC with FDG using a dual-headed positron emission tomographic (PET) camera and to compare this non-invasive technique with computed tomography (CT) and lymph node sampling, since both modalities are currently used for staging NSCLC. Thirty-three patients (29 men and 4 women, mean age 60 years) with newly diagnosed NSCLC were studied. In all patients, CT, FDG dual-headed PET and mediastinoscopy were performed within 4 weeks. The results of mediastinoscopy were used to select patients for thoracotomy. For both the assessment of individual lymph node involvement and the patient-based classification, the results of FDG dual-headed PET and CT were compared using the McNemar test. Thirty-one of 187 lymph nodes studied contained tumour metastases. FDG dual-headed PET showed a significantly higher sensitivity (P < 0.001) and specificity (P < 0.001) than CT. FDG dual-headed PET and CT correctly staged 27 and 20 patients, respectively. Due to the significantly higher negative predictive value of FDG dual-headed PET versus CT (P = 0.012), it was a better non-invasive diagnostic tool for selecting patients for surgery. In seven of eight patients, additional intrapulmonary sites of increased uptake were found, which revealed malignancy on histological examination. CT was false-negative in three of these patients. In one patients, increased FDG uptake was caused by an infection. In conclusion, it is possible to stage mediastinal lymph nodes in patients with NSCLC using a dual-headed PET camera. The high negative predictive value of FDG dual-headed PET suggests that mediastinoscopy may be omitted in patients with NSCLC.

Ethanol oxidation and acetaldehyde production in vitro by human intestinal strains of Escherichia coli under aerobic, microaerobic, and anaerobic conditions

BACKGROUND

Many human colonic facultative anaerobic and aerobic bacteria are capable of alcohol dehydrogenase (ADH)-mediated ethanol oxidation. In this bacteriocolonic pathway for ethanol oxidation intracolonic ethanol is first oxidized by bacterial ADHs to acetaldehyde, which is further oxidized by either colonic mucosal or bacterial aldehyde dehydrogenases to acetate. The produced acetaldehyde is a highly toxic and carcinogenic agent. This study was aimed to investigate the ethanol oxidation capability and acetaldehyde formation of Escherichia coli IH 50546 and IH 50817. These intestinal E. coli strains expressed either high (IH 50546) or low (IH 50817) ADH activity.

METHODS

Strains were cultured for 48 h on agar plates supplemented with ethanol under aerobic, microaerobic (6% O2), and anaerobic conditions.

RESULTS

Under aerobic conditions both E. coli strains oxidized ethanol. The ethanol consumption rates (ECR) were 1.046+/-0.025 mM/h and 0.367+/-0.148 mM/h with IH 50546 and IH 50817, respectively. In the case of IH 50546 this was associated with significant acetaldehyde production (418+/-13 microM), suggesting ADH-mediated ethanol oxidation. Under microaerobic conditions only IH 50546 was able to oxidize ethanol (ECR, 0.498+/-0.074 mM/h) and to produce acetaldehyde (up to 440+/-76 microM) to significant extents. Under anaerobic conditions both strains fermented glucose to ethanol.

CONCLUSIONS

This study experimentally shows the potential of certain bacteria representing normal human colonic flora to produce acetaldehyde under various atmospheric conditions that may prevail in different parts of the GI tract. This bacterial adaptation may be an essential feature of the bacteriocolonic pathway to produce toxic and carcinogenic acetaldehyde from either endogenous or exogenous ethanol.

Characteristics of aldehyde dehydrogenases of certain aerobic bacteria representing human colonic flora

We have proposed the existence of a bacteriocolonic pathway for ethanol oxidation resulting in high intracolonic levels of toxic and carcinogenic acetaldehyde. This study was aimed at determining the ability of the aldehyde dehydrogenases (ALDH) of aerobic bacteria representing human colonic flora to metabolize intracolonically derived acetaldehyde. The apparent Michaelis constant (Km) values for acetaldehyde were determined in crude extracts of five aerobic bacterial strains, alcohol dehydrogenase (ADH) and ALDH activities of these bacteria at conditions prevailing in the human large intestine after moderate drinking were then compared. The effect of cyanamide, a potent inhibitor of mammalian ALDH, on bacterial ALDH activity was also studied. The apparent Km for acetaldehyde varied from 6.8 (NADP+-linked ALDH of Escherichia coli IH 13369) to 205 microM (NAD+-linked ALDH of Pseudomonas aeruginosa IH 35342), and maximal velocity varied from 6 nmol/min/mg (NAD+-linked ALDH of Klebsiella pneumoniae IH 35385) to 39 nmol/min/mg (NAD+-linked ALDH of Pseudomonas aeruginosa IH 35342). At pH 7.4, and at ethanol and acetaldehyde concentrations that may be prevalent in the human colon after moderate drinking, ADH activity in four out of five bacterial strains were 10-50 times higher than their ALDH activity. Cyanamide inhibited only NAD+-linked ALDH activity of Pseudomonas aeruginosa IH 35342 at concentrations starting from 0.1 nmM. We conclude that ALDHs of the colonic aerobic bacteria are able to metabolize endogenic acetaldehyde. However, the ability of ALDHs to metabolize intracolonic acetaldehyde levels associated with alcohol drinking is rather low. Large differences between ADH and ALDH activities of the bacteria found in this study may contribute to the accumulation of acetaldehyde in the large intestine after moderate drinking. ALDH activities of colonic bacteria were poorly inhibited by cyanamide. This study supports the crucial role of intestinal bacteria in the accumulation of intracolonic acetaldehyde after drinking alcohol. Individual variations in human colonic flora may contribute to the risk of alcohol-related gastrointestinal morbidity.

Role of catalase in in vitro acetaldehyde formation by human colonic contents

Ingested ethanol is transported to the colon via blood circulation, and intracolonic ethanol levels are equal to those of the blood ethanol levels. In the large intestine, ethanol is oxidized by colonic bacteria, and this can lead to extraordinarily high acetaldehyde levels that might be responsible, in part, for ethanol-associated carcinogenicity and gastrointestinal symptoms. It is believed that bacterial acetaldehyde formation is mediated via microbial alcohol dehydrogenases (ADHs). However, almost all cytochrome-containing aerobic and facultative anaerobic bacteria possess catalase activity, and catalase can, in the presence of hydrogen peroxide (H2O2), use several alcohols (e.g., ethanol) as substrates and convert them to their corresponding aldehydes. In this study we demonstrate acetaldehyde production from ethanol in vitro by colonic contents in a reaction catalyzed by both bacterial ADH and catalase. The amount of acetaldehyde produced by the human colonic contents was proportional to the ethanol concentration, the amount of colonic contents, and the length of incubation time, even in the absence of added nicotinamide adenine dinucleotide or H2O2. The catalase inhibitors sodium azide and 3-amino-1,2,4-triazole (3-AT) markedly reduced the amount of acetaldehyde produced from 22 mM ethanol in a concentration dependent manner compared with the control samples (0.1 mM sodium azide to 73% and 10 mM 3-AT to 67% of control). H2O2 generating system [beta-D(+)-glucose + glucose oxidase] and nicotinamide adenine dinucleotide induced acetaldehyde formation up to 6- and 5-fold, respectively, and together these increased acetaldehyde formation up to 11-fold. The mean supernatant catalase activity was 0.53+/-0.1 micromol/min/mg protein after the addition of 10 mM H2O2, and there was a significant (p < 0.05) correlation between catalase activity and acetaldehyde production after the addition of the hydrogen peroxide generating system. Our results demonstrate that colonic contents possess catalase activity, which probably is of bacterial origin, and indicate that in addition to ADH, part of the acetaldehyde produced in the large intestine during ethanol metabolism can be catalase dependent.

Characteristics of aldehyde dehydrogenases of certain aerobic bacteria representing human colonic flora

We have proposed the existence of a bacteriocolonic pathway for ethanol oxidation resulting in high intracolonic levels of toxic and carcinogenic acetaldehyde. This study was aimed at determining the ability of the aldehyde dehydrogenases (ALDH) of aerobic bacteria representing human colonic flora to metabolize intracolonically derived acetaldehyde. The apparent Michaelis constant (Km) values for acetaldehyde were determined in crude extracts of five aerobic bacterial strains, alcohol dehydrogenase (ADH) and ALDH activities of these bacteria at conditions prevailing in the human large intestine after moderate drinking were then compared. The effect of cyanamide, a potent inhibitor of mammalian ALDH, on bacterial ALDH activity was also studied. The apparent Km for acetaldehyde varied from 6.8 (NADP+-linked ALDH of Escherichia coli IH 13369) to 205 microM (NAD+-linked ALDH of Pseudomonas aeruginosa IH 35342), and maximal velocity varied from 6 nmol/min/mg (NAD+-linked ALDH of Klebsiella pneumoniae IH 35385) to 39 nmol/min/mg (NAD+-linked ALDH of Pseudomonas aeruginosa IH 35342). At pH 7.4, and at ethanol and acetaldehyde concentrations that may be prevalent in the human colon after moderate drinking, ADH activity in four out of five bacterial strains were 10-50 times higher than their ALDH activity. Cyanamide inhibited only NAD+-linked ALDH activity of Pseudomonas aeruginosa IH 35342 at concentrations starting from 0.1 nmM. We conclude that ALDHs of the colonic aerobic bacteria are able to metabolize endogenic acetaldehyde. However, the ability of ALDHs to metabolize intracolonic acetaldehyde levels associated with alcohol drinking is rather low. Large differences between ADH and ALDH activities of the bacteria found in this study may contribute to the accumulation of acetaldehyde in the large intestine after moderate drinking. ALDH activities of colonic bacteria were poorly inhibited by cyanamide. This study supports the crucial role of intestinal bacteria in the accumulation of intracolonic acetaldehyde after drinking alcohol. Individual variations in human colonic flora may contribute to the risk of alcohol-related gastrointestinal morbidity.

Inhibition of bacteriocolonic pathway for ethanol oxidation by ciprofloxacin in rats

Many colonic bacteria possess marked alcohol dehydrogenase (ADH) activity and are capable of oxidizing ethanol to acetaldehyde both in vitro and in vivo. We have recently shown that part of ingested ethanol is metabolized to acetaldehyde in the colon during normal alcohol metabolism. To assess the contribution of this bacteriocolonic pathway for ethanol oxidation to total ethanol metabolism, the elimination rate of ethanol, faecal aerobic flora and faecal ADH activity were determined in rats before and after the treatment with ciprofloxacin (200 mg/kg/day) for four days. Ciprofloxacin treatment decreased ethanol elimination rate from 310+/-9 to 282+/-13 mg/kg/h (mean+/-SE; p<0.02), markedly reduced faecal aerobic flora, and also lowered faecal ADH activity from 63+/-17 to 17+/-7 nmol/min/mg faeces (p<0.05). Neither hepatic ADH nor microsomal ethanol oxidizing system activities were affected by the ciprofloxacin treatment. On the contrary, an acute intraperitoneal dose of ciprofloxacin had no effect on the rate of ethanol elimination. These results support the significant role of the bacteriocolonic pathway in total ethanol elimination, and open a new, microbiological, perspective for studies on ethanol metabolism and pathogenesis of alcohol related organ damages.

A novel sodium channel mutation causing a hyperkalemic paralytic and paramyotonic syndrome with variable clinical expressivity

A point mutation A4078G predicting the amino acid exchange Met1360Val in segment IV/S1 of the human muscle sodium channel alpha-subunit was identified in a family presenting features of hyperkalemic periodic paralysis and paramyotonia congenita with sex-related modification of expression. In this family, only one male member is clinically affected, presenting episodes of flaccid weakness as well as paradoxical myotonia and cold-induced weakness. Three female family members who have the same mutation show only myotonic bursts on EMG. We studied the functional defect caused by this mutation by investigating recombinant wild type (WT) and mutant sodium channels expressed in a mammalian cell line (HEK293) using the patch-clamp technique. With mutant channels, the decay of the sodium currents was two times slower than with WT, the steady-state inactivation curve was shifted by -13 mV, and recovery from inactivation was 1.5 times faster. High extracellular potassium (9 mM) did not affect channel gating. Single-channel measurements revealed prolonged mean open times and an increased number of channel reopenings. The results are remarkable with respect to the lack of complete penetrance usually seen with sodium channelopathies and the site of mutation that was formerly not thought to be involved in channel inactivation.

High acetaldehyde levels in saliva after ethanol consumption: methodological aspects and pathogenetic implications

Chronic ethanol ingestion leads to an enhanced risk of upper gastrointestinal tract cancer. Although many hypotheses for the tumor promoting effect of alcohol exist, the pathogenetic mechanisms remain unclear since alcohol in itself is not carcinogenic. Acetaldehyde, the first metabolite of ethanol, has been shown to have multiple mutagenic effects and to be carcinogenic to animals. Previous research has revealed that acetaldehyde can be formed from ethanol via microbial alcohol dehydrogenase. Thus, at least part of the proposed tumorigenic effect of ethanol may be linked to local production of acetaldehyde from ethanol by oral microflora. In this study we demonstrate the production of marked amounts of acetaldehyde in saliva after ingestion of moderate amounts of ethanol. Considerable inter individual variation in acetaldehyde production capacity is also shown. In vivo acetaldehyde production is significantly reduced after a 3-day use of an antiseptic mouthwash (chlorhexidine). In vitro acetaldehyde production was shown to be linear in time, inhibited by 4-methylpyrazole and it could not be saturated under ethanol conditions that are relevant in vivo. There was a significant positive correlation between salivary acetaldehyde production in vitro and in vivo. We conclude, that the microbial formation of acetaldehyde in saliva could be one explanation for the tumor promoting effect of ethanol on the upper gastrointestinal tract. Moreover, this may support the epidemiological finding, that poor oral hygiene is an independent risk factor for oral cavity cancer.

Detection of a novel mutation at amino acid position 614 in the ryanodine receptor in malignant hyperthermia

Malignant hyperthermia (MH) is a potentially fatal autosomal dominant disorder of skeletal muscle and is triggered in susceptible people by all commonly used inhalation anaesthetics and depolarizing neuromuscular blocking agents. To date, eight mutations in the skeletal muscle ryanodine receptor gene (RYR1) have been identified in malignant hyperthermia susceptible (MHS) and central core disease (CCD) cases. We have screened the RYR1 gene in affected individuals for novel MHS mutations by single stranded conformational polymorphism (SSCP) analysis and have identified a G to T transition mutation which results in the replacement of a conserved arginine (Arg) at position 614 with a leucine (Leu). The Arg614Leu mutation was present in three unrelated MHS individuals of 151 investigated. The mutation was not detected in 148 normal chromosomes and segregated precisely with MHS in family members from one of the probands where DNA was available for analysis. This mutation occurs at the same position as the previously identified Arg to Cys mutation reported in all cases of porcine MH and in approximately 5% of human MH. A comparison of the phenotypes of the Arg614Leu and Arg614Cys probands is presented.

Characteristics of alcohol dehydrogenases of certain aerobic bacteria representing human colonic flora

We have recently proposed the existence of a bacteriocolonic pathway for ethanol oxidation [i.e., ethanol is oxidized by alcohol dehydrogenases (ADHs) of intestinal bacteria resulting in high intracolonic levels of reactive and toxic acetaldehyde]. The aim of this in vitro study was to characterize further ADH activity of some aerobic bacteria, representing the normal human colonic flora. These bacteria were earlier shown to possess high cytosolic ADH activities (Escherichia coli IH 133369, Klebsiella pneumoniae IH 35385, Klebsiella oxytoca IH 35339, Pseudomonas aeruginosa IH 35342, and Hafnia alvei IH 53227). ADHs of the tested bacteria strongly preferred NAD as a cofactor. Marked ADH activities were found in all bacteria, even at low ethanol concentrations (1.5 mM) that may occur in the colon due to bacterial fermentation. The Km for ethanol varied from 29.9 mM for K. pneumoniae to 0.06 mM for Hafnia alvei. The inhibition of ADH by 4-methylpyrazole was found to be of the competitive type in 4 of 5 bacteria, and Ki varied from 18.26 +/- 3.3 mM for Escherichia coli to 0.47 +/- 0.13 mM for K. pneumoniae. At pH 7.4, ADH activity was significantly lower than at pH 9.6 in four bacterial strains. ADH of K. oxytoca, however, showed almost equal activities at neutral pH and at 9.6. In conclusion, NAD-linked alcohol dehydrogenases of aerobic colonic bacteria possess low apparent Km's for ethanol. Accordingly, they may oxidize moderate amounts of ethanol ingested during social drinking with nearly maximal velocity. This may result in the marked production of intracolonic acetaldehyde. Kinetic characteristics of the bacterial enzymes may enable some of them to produce acetaldehyde even from endogenous ethanol formed by other bacteria via alcoholic fermentation. The microbial ADHs were inhibited by 4-methylpyrazole by the same competitive inhibition as hepatic ADH, however, with nearly 1000 times lower susceptibility. Individual variations in human colonic flora may thus contribute to the risk of alcohol-related gastrointestinal morbidity, such as diarrhea, colon polyps and cancer, and liver injury.