Spontaneous bladder rupture mimicking a jejuno-ileal perforation.

Spontaneous urinary bladder perforation is a very rare disease. The main cause of urinary perforation, indeed, is a damage to the urinary bladder wall by blunt or penetrating trauma. There are only few idiopathic spontaneous rupture of urinary bladder (ISRUB) cases reported in the literature. Pre-operative diagnosis is very difficult due to similar symptoms, laboratory and imaging findings of a gastrointestinal perforation that is usually excluded intraoperatively. Herein we report a case of a 91-year-old man presented to the emergency department with a spontaneous bladder perforation mimicking an ileal perforation.

Helicobacter pylori HP(2-20) induces eosinophil activation and accumulation in superficial gastric mucosa and stimulates VEGF-alpha and TGF-beta release by interacting with formyl-peptide receptors.

Eosinophils participate in the immune response against Helicobacter pylori, but little is known about their role in the gastritis associated to the infection. We recently demonstrated that the Hp(2-20) peptide derived from H. pylori accelerates wound healing of gastric mucosa by interacting with N-formyl peptide receptors (FPRs) expressed on gastric epithelial cells. The aim of the present study was to investigate whether eosinophils play a role in the repair of gastric mucosa tissue during H. pylori infection. Immuno-histochemistry and transmission electron microscopy were used to detect eosinophils in gastric mucosal biopsies. Eosinophil re-distribution occurred in the gastric mucosa of H. pylori-infected patients: their density did not change in the deep mucosal layer, whereas it increased in the superficial lamina propria just below the foveolar epithelium; eosinophils entered the epithelium itself as well as the lumen of foveolae located close to the area harboring bacteria, which in turn were also engulfed by eosinophils. The H. pylori-derived peptide Hp(2-20) stimulated eosinophil migration through the engagement of FPR2 and FPR3, and also induced production of VEGF-A and TGF-beta, two key mediators of tissue remodelling. We also demonstrate that Hp(2-20) in vivo induced eosinophil infiltration in rat gastric mucosa after injury brought about by indomethacin. This study suggests that eosinophil infiltrate could modulate the capacity of gastric mucosa to maintain or recover its integrity thereby shedding light on the role of eosinophils in H. pylori infection.

Role of Formyl Peptide Receptors in Gastrointestinal Healing.

The wound healing and the barrier restoration of the gastrointestinal (GI) mucosa must be continuously ensured to allow homeostasis of the gastrointestinal tract and of all the surrounding tissues. Several lines of the evidence report a key role of innate immunity, and in particular of Pattern Recognition Receptors (PRRs), in controlling the homeostasis of GI tract by sensing commensal and pathogen bacteria, activating the immune response and regulating epithelial repair, thus guaranteeing the morphological and functional recovery of the injured tissue. We will discuss the role of a particular class of PRRs - the Formyl Peptide Receptors - in the homeostasis of GI mucosa. We here report the results of studies that strongly suggest the possibility that the activation of FPRs is crucial in the maintenance of homeostasis of the GI tract and provide indications of the potential clinical relevance of new treatment regimens involving FPR modulation for several GI disorders.

Peptide Hp(2-20) accelerates healing of TNBS-induced colitis in the rat.

BACKGROUND AND AIMS: Hp(2-20), a Helicobacter pylori-derived peptide interacting with N-formyl peptide receptors (FPRs), accelerates the healing of gastric injury in rats. Whether Hp(2-20) affects the recovery of inflamed colonic mucosa is unknown. We evaluated whether Hp(2-20) accelerated the healing of 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis and explored the mechanism(s) underlying any such effect. METHODS: Fifteen rats underwent rectal administration of Hp(2-20) 250-500 µg/kg/day, or of its control peptide Hp1 for 10 days, following induction of colitis with TNBS. Macroscopic and histological damage was quantified using predetermined injury scores. FPR1, COX-2, TNF-α, TGF-ß, HB-EGF and tissue transglutaminase (t-TG) messenger RNA (mRNA) expression in colonic tissue was determined by quantitative polymerase chain reaction; FPR1, TNF-α and COX-2 protein levels by Western blotting. RESULTS: (1) Hp(2-20) accelerated healing of TNBS-induced colitis compared to controls consistently with the expression of FPRs in colonic mucosa; (2) TNBS upregulated mRNA mucosal expression of COX-2, TNF-α, TGF-ß, HB-EGF and t-TG and (3) this, with the exception of HB-EGF, was significantly counteracted by Hp(2-20). CONCLUSIONS: Hp(2-20), an FPR agonist, accelerates the healing of TNBS-induced colitis in the rat. This effect is associated with a significant reduction in colonic tissue levels of COX-2, TGF-ß, TNF-α and t-TG. We postulate that FPR-dependent pathways may be involved in the repair of inflamed colonic mucosa.

Endogenous androgens and carotid intimal-medial thickness in women.

The influence of endogenous androgens on atherosclerotic disease in women is unknown. In this study involving 101 pre- and post-menopausal females, we evaluated the relationship between serum androgen levels and both carotid artery intimal-medial thickness (IMT) and major cardiovascular risk factors. In addition to evaluation of blood pressure, body mass index, and waist-to-hip ratio, serum dehydroepiandrosterone sulfate (DHEA-S), androstenedione (A), total testosterone (TTS), free testosterone (FTS), insulin, cholesterol (total and high density lipoproteins), triglycerides, and glucose were measured. All women underwent carotid ultrasonography. Spearman correlation coefficients showed that serum DHEA-S and A levels were negatively related (P < 0.03-0.0004) to several IMT measures. Higher tertiles of DHEA-S, A, and FTS corresponded to significantly lower measures of carotid thickness. DHEA-S, and all androgens were inversely related to age (P < 0.03 or less), showing no unfavorable association with major cardiovascular risk factors. In contrast, serum DHEA-S was negatively associated with WHR (P < 0.02), while A was negatively associated with body mass index (P < 0.02). Stepwise multiple regression analysis indicated that A and FTS showed an inverse association with IMT measures (P < 0.05-0.001). In conclusion, our data indicate that in women serum DHEA-S and androgens decline with age and that normal hormonal levels are not associated with major cardiovascular risk factors. They also show that higher DHEA-S and androgen concentrations are related to lower carotid wall thickness; for A this association is independent of cardiovascular risk factors. Our results suggest that, in the physiological range, DHEA-S and androgens in women are correlated with lower risk of carotid artery atherosclerosis.

Modifications in enterocyte diamine oxidase distribution induced by heparin in the rat.

Heparin releases diamine oxidase (DAO) of enterocytic origin from binding sites located on small bowel microvascular endothelium. In the villus tip enterocytes the enzyme is found in organelles (about 60%) and in cytosol (about 40%), while a negligible activity is present in the brush border. In this study we assessed the changes in DAO distribution into the enterocytes induced by a high dose of intraperitoneal heparin (1000 IU) in the rat, by assaying DAO activity on subcellular fractions obtained from ileal mucosa homogenate. Heparin injection induced a marked reduction of enzyme activity in the S2 fraction (cytosol): after 30 min less than 20% of DAO activity is still found and only 8% after 150 min. In the P1 fraction (organelles) DAO activity significantly decreased only after 60 min and a further consistent reduction was recorded after 150 min. Recovery of DAO activity was complete 4 days after the injection, though it was already clearly evident in the first 2 days. These results indicate that enterocytic DAO is distributed in two different compartments: DAO located in the cytosol is quickly released by heparin, while the organelles-linked enzyme is more slowly released. The finding that recovery in DAO activity happens earlier in the P1 fraction suggests that the enzyme supplies the cytosol after being synthesized in the enterocyte organelles.

Influence of endogenous androgens on carotid wall in postmenopausal women.

OBJECTIVE: There is increasing evidence of a direct association between normal androgen levels and reduced cardiovascular morbidity and mortality in women. After menopause the influence of estrogens declines, whereas that of androgens increases. Therefore, we investigated the effects of androgens on atherosclerosis in postmenopausal women, by using carotid artery intimal-medial thickness as a marker of vascular damage. DESIGN: Blood pressure, body mass index, waist-to-hip ratio, serum dehydroepiandrosterone sulfate, androstenedione, total and free testosterone, estrone, insulin, lipid profile, and glucose were evaluated in 44 women in stable physiological menopause. All subjects underwent carotid ultrasound (Biosound 2000 II s.a. high-resolution unit). RESULTS: Spearman correlation coefficients indicated that serum androstenedione and free testosterone were negatively associated with several carotid intimal-medial thickness measures with correlation coefficients (r) ranging from 0.477 to 0.397 (p < 0.01-0.04). Moreover, age-adjusted androstenedione and free testosterone highest tertiles showed intimal-medial thickness values significantly (p < 0.03-0.05) lower than the other tertiles. There was a favorable association between hormones and the most important cardiovascular risk factors. This association, however, did not reach statistical significance. Stepwise multiple regression analysis showed that the inverse relationships between the hormones (androstenedione and free testosterone) and several intimal-medial thickness measures were maintained (F: 4.15-6.07, p < 0.05-0.02) after adjustment for major cardiovascular risk factors. CONCLUSIONS: Our data demonstrate that in postmenopausal women endogenous steroid precursors and androgens are inversely related to carotid intimal-medial thickness, an established marker of atherosclerosis. In addition, these hormones show favorable associations with cardiovascular risk factors. Therefore, our study suggests that, after menopause, normal androgen levels may benefit the carotid artery wall.

Serotoninergic receptor activation by dextrofenfluramine enhances the blunted pituitary-adrenal responsiveness to corticotropin-releasing hormone in obese subjects.

To explore the interrelationships between the serotoninergic system and the hypothalamic-pituitary-adrenal (HPA) axis in human obesity, we evaluated cortisol and adrenocorticotropic hormone (ACTH) response to synthetic human corticotropin-releasing hormone (hCRH, 1 microgram/kg intravenously [IV]) before and after stimulation of the serotoninergic system by dextrofenfluramine (d-FF, 30 mg/d for 3 months) in nine obese women. These responses were compared with a CRH test (1 microgram/kg) carried out in nine age-matched normal-weight women. Plasma cortisol of obese subjects did not significantly increase after CRH (peak value 127.1 +/- 11.2 ng/mL v 104.1 +/- 9.5 ng/mL). This response was lower (P less than .005) than in the controls, in whom the basal cortisol value of 120.6 +/- 11.8 ng/mL reached a peak value of 221.2 +/- 13.4 ng/mL. However, after administration of d-FF, CRH significantly increased (P less than .0001) plasma cortisol (peak value 170.6 +/- 18.0 ng/mL v 111.5 +/- 10.8 ng/mL) and the response was enhanced (P less than .05) as compared with that obtained before d-FF. The ACTH levels of our patients showed a small increment after CRH injection (peak value 13.5 +/- 1.7 pg/mL v 9.6 +/- 1.1 pg/mL), but the hormonal response was lower (P less than .005) than in controls (peak value 38.1 +/- 5.5 pg/mL v 13.8 +/- 0.8 pg/mL). However, after d-FF, CRH induced a significant increment (P less than .05) in plasma ACTH at 30 minutes (20.4 +/- 3.7 pg/mL v 10.9 +/- 0.9 pg/mL) and 45 minutes (18.0 +/- 2.6 pg/mL), even though this response was not significantly different from that observed before d-FF administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Blunted growth hormone (GH) responsiveness to GH-releasing hormone in obese patients: influence of prolonged administration of the serotoninergic drug fenfluramine.

The aim of the present study was to ascertain if reduced central serotoninergic activity might contribute to the well-known blunted growth hormone (GH) response to GH-releasing hormone (GHRH) in obese patients. Thus, we studied the effect of prolonged stimulation of the serotoninergic system by fenfluramine (FF; 60 mg twice daily for 7 days) on GHRH-induced GH release in nine obese and seven normal subjects. In controls, GHRH (100 micrograms intravenously [IV]) injection increased GH levels from 2.3 +/- 1.8 (+/- SE) to 18.5 +/- 2.8 mU/L, P less than .002. FF administration enhanced both basal and GHRH-stimulated GH levels (peak, 38.4 +/- 8.3 v 6.9 +/- 2.6 mU/L, P less than .002). This response was significantly higher (P less than .02) than in pretreatment. In obese patients, GH responsiveness to GHRH was slight (peak, 7.1 +/- 2.0 v 0.6 +/- 0.18 mU/L, P less than .01) and lower (P less than .01) than in controls. FF administration did not affect this response. In controls, the enhanced FF-induced GH release after a maximal dose of GHRH indicates that serotoninergic activation influences GH secretion and that the mechanism involved is independent of endogenous GHRH. In obese patients, we found a blunted GH responsiveness to GHRH that was not affected by FF, thus supporting the hypothesis that the serotoninergic control on GH release is impaired.

Glutathione supplementation improves oxidative damage in experimental colitis.

BACKGROUND: The pathogenesis of inflammatory bowel disease is due, in part, to enhanced free-radical production and reduced antioxidant potential in mucosa cells. AIM: We evaluated in a rat model of trinitrobenzensulphonic acid (TNBS) colitis to see whether parenteral administration of glutathione is able to improve mucosal oxidative damage at onset (study A) and during chronic phases of colitis (study B). METHODS: In study A, the rats were injected with a single dose of glutathione (200 mg/kg, i.p.) or saline (0,2 ml, i.p.) 1 h before colitis induction and killed 1 h later. In study B, rats with induced colitis were treated with daily injection of glutathione (50 mg/kg, i.p.) or saline (0,2 ml, i.p.), and killed at 1, 2, 4 and 8 weeks. We evaluated on mucosal samples the macroscopic and histological damage and the oxidative stress assessed by the mucosal levels of lipoperoxides, malonyldialdehyde, glutathione and cysteine. RESULTS: In study A, colitis induction caused a significant increase to the total histological score (p<0.05), lipoperoxide and malonyldialdehyde levels (p<0.001), but did not affect glutathione and cysteine content. Glutathione pre-treatment decreased both total histological score (p<0.05) and lipoperoxide and malonyldialdehyde values (p<0.001). In study B, the extensive macroscopic and histological colonic damage induced by TNBS was accompanied by a reduction of glutathione and cysteine mucosal levels (p<0.01) and increased lipid peroxidation. Glutathione supplementation significantly improved colonic damage (p<0.01), restored glutathione and cysteine levels, and decreased, and even, if not totally, abolished lipid peroxidation (p<0.001). CONCLUSION: This paper further supports the pathogenic role of the imbalance in oxidant/antioxidant content in inducing mucosal colonic damage.

Up-regulation of heparin binding epidermal growth factor-like growth factor and amphiregulin expression in Helicobacter pylori-infected human gastric mucosa.

BACKGROUND: Host response plays a major role in pathogenesis of Helicobacter pylori-induced gastroduodenal disease including adenocarcinoma of distal stomach. Epidermal growth factor-related growth factors are important modulators of gastric homeostasis in normal and damaged gastrointestinal mucosa. AIM: To evaluate expression of heparin binding epidermal growth factor and amphiregulin in antral mucosa of Helicobacter pylori-infected and non-infected dyspeptic patients and to correlate levels of heparin binding-epidermal growth factor and amphiregulin mRNA with mitogenic activity of gastric epithelial cells. METHODS: A total of 10 Helicobacter pylori-infected and 15 Helicobacter pylori non-infected (10 with and 5 without gastritis) dyspeptic patients were studied. Diagnosis of Helicobacter pylori infection was based on rapid urease test and histology. Heparin binding-epidermal growth factor and amphiregulin mRNA expression in antral mucosa were assessed by reverse transcriptase-polymerase chain reaction. Protein expression and localization of both peptides were determined by immunohistochemistry. Mitogenic activity of antral gastric mucosa was assessed by determination of proliferating cell nuclear antigen labelling index by immunohistochemistry. RESULTS: Heparin binding-epidermal growth factor and amphiregulin mRNA expression increased in Helicobacter pylori-infected vs Helicobacter pylori non-infected patients. Heparin binding-epidermal growth factor and amphiregulin immunostaining was more intense and deeper in gastric gland compartment in infected mucosa than in non-infected mucosa. Increase in heparin binding-epidermal growth factor and amphiregulin mRNA expression significantly correlated with increase in proliferating cell nuclear antigen labelling index. CONCLUSIONS: Helicobacter pylori gastritis is associated with up-regulation of heparin binding-epidermal growth factor and amphiregulin which correlates with increased mitogenic activity of gastric mucosa. Increased heparin binding-epidermal growth factor and amphiregulin expression is postulated to contribute to reparative response of gastric mucosa to Helicobacter pylori infection.

Short-chain fatty acid in the human colon. Relation to inflammatory bowel diseases and colon cancer.

Short chain fatty acids (SCFAs) are the end products of anaerobic bacteria break down of carbohydrates in the large bowel. This process, namely fermentation, is an important function of the large bowel; SCFAs, mainly acetate, propionate and butyrate account for approximately 80% of the colonic anion concentration and are produced in nearly constant molar ratio 60:25:15. Among their various properties, SCFAs are readily absorbed by intestinal mucosa, are relatively high in caloric content, are metabolized by colonocytes and epatocytes, stimulate sodium and water absorption in the colon and are trophic to the intestinal mucosa. While the fermentative production of SCFAs has been acknowledged as a principal mechanism of intestinal digestion in ruminants, the interest in the effects of SCFAs production on the human organism has been raising in the last ten years. SCFAs are of major importance in understanding the physiological function of dietary fibers and their possible role in intestinal neoplasia. SCFAs production and absorption are closely related to the nourishment of colonic mucosa, its production from dietary carbohydrates is a mechanism whereby considerable amounts of calories can be produced in short-bowel patients with remaining colonic function and kept on an appropriate dietary regimen. SCFAs enemas or oral probiotics are a new and promising treatment for ulcerative colitis. The effects have been attributed to the oxidation of SCFAs in the colonocytes and to the ability of butyrate to induce enzymes (i.e. transglutaminase) promoting mucosal restitution. Evidence is mounting regarding the effects of butyrate on various cell functions the significance of which needs further considerations. Up until now, attention has been related especially to cancer prophylaxis and treatment. This article briefly reviews the role of SCFAs, particularly butyrate, in intestinal mucosal growth and potential clinical applications in inflammatory and neoplastic processes of the large bowel.

Influence of conjugated oestrogens on circulating oestradiol, oestrone, LH, FSH and prolactin levels in postmenopausal women.

The effects on plasma 17-beta-oestradiol (E2), oestrone (E1), LH, FSH and prolactin (PRL) levels of 1.5 mg conjugated oestrogen, administered daily per os for 20 consecutive days, was investigated in six postmenopausal women aged 60-68. Both E2 and E1 increased progressively and significantly (p less than 0.001) from 18 and 28 pg/ml to 32 and 108 pg/ml, respectively, at the end of treatment; five days after the last dose both E2 and E1 had fallen to pretreatment levels (p greater than 0.05). LH and FSH decreased progressively and significantly (p less than 0.001) from 114 and 105 mlU/ml (before therapy) to 43 and 36 mIU/ml, respectively, after oestrogen administration. One week after interruption of treatment, both LH and FSH were significantly higher (p less than 0.001) than that obtained at the end of therapy. No significant variation (0.05 greater than p greater than 0.02) was observed for plasma PRL during and after oestrogen administration. Such results indicate that in postmenopausal women the specific enzymatic mechanism of oestrogen interconversion are maintained and that there is no increase of prolactin. IN this was, the possible effects on the development of breast cancer by elevated levels of this hormone, usually observed during long-term oestrogen therapy, would be avoided.

Nutraceuticals for protection and healing of gastrointestinal mucosa.

Natural medicinal products have been used for millennia for the treatment of several ailments. Although many have been superseded by conventional pharmaceutical approaches, there is currently a resurgence in the interest in natural products by the general public and the use of complementary and alternative medicine is increasing rapidly in developed countries. Also, pharmaceutical industries are more and more interested in examining their potential as sources of novel medicinal compounds which may act as growth factor or show immunomodulatory or anti-microbial activity. The subgroup of natural bioactive compounds that bridge the gap between food products and drugs are termed nutraceuticals or functional foods. In contrast with most standard medicinal compounds, nutraceuticals are generally used to prevent rather than to treat disease. Many of the claims for such products are supported by very limited scientific evidence. However, there has recently been a great interest at evaluating the mechanism by which natural products exert their beneficial effects in the gastrointestinal tract. In particular, a major area of interest is for the use of biologically active chemical components of plants, i.e. phytochemicals, in a number of gastrointestinal disorders. While the major focus of phytochemical research has been on cancer prevention, several products of plant origin are being used and/or under study for a variety of other gastrointestinal problems. In this review we discuss the scientific evidence supporting the potential use of nutraceuticals as agents capable to prevent or accelerate healing of gastrointestinal mucosal damage, with a focus on polyphenol extracts obtained from apple.

Myenteric neuronal loss in rats with experimental colitis: role of tissue transglutaminase-induced apoptosis.

BACKGROUND AND AIMS: Transglutaminases are tissue enzymes involved in different neuronal processes including maintenance and signalling. However, their up-regulation elicited by a variety of noxae contributes to neurodegeneration. This study tested the hypothesis that experimental inflammation evoked transglutaminase up-regulation in myenteric neurons and that this event had an impact on neuronal survival. METHODS: Rats with or without trinitro-benzene-sulphonic acid-induced colitis were used. One week after colitis induction, longitudinal muscle-myenteric plexus preparations were obtained from left colon to assess tissue-transglutaminase activity, protein and mRNA expression. Double labelling immunofluorescence using antibodies to neuron-specific enolase and transglutaminase was performed to identify myenteric neurons expressing transglutaminase. Additional sets of experiments evaluated the involvement of transglutaminase in the apoptotic process of cultured myenteric neurons. RESULTS: Compared to controls, rats with colitis showed several tranglutaminase/neuron-specific enolase positive myenteric neurons. Western blot analysis and RT-PCR confirmed that in rats with colitis, the increased neuronal transglutaminase-immunoreactivity was associated with an increased enzyme expression. Similarly, transglutaminase activity was significantly higher than in controls (1100+/-280 m U/g vs. 725+/-119 m U/g, p<0.05). In cultured myenteric neurons incubation with the specific transglutaminase inducer, retinoic acid, significantly increased neuronal apoptosis, whereas the presence of cystamine significantly reduced the number of apoptotic neurons. CONCLUSIONS: Experimental colitis evoked transglutaminase up-regulation and increased activity in myenteric neurons. This mechanism enhances neuronal susceptibility to apoptosis and could contribute to neuropathic changes during gut inflammation.

Bowel sonography in adult celiac disease: diagnostic accuracy and ultrasonographic features.

BACKGROUND: Celiac disease (CD) is a chronic intolerance to gluten, which induces intestinal mucosal lesions in genetically predisposed individuals. Transabdominal bowel sonography (TABS) is a safe and noninvasive procedure that allows to detect intestinal abnormalities in many conditions, but actually is not routinely part of the diagnostic management of CD. AIM: To evaluate the diagnostic accuracy of TABS in CD patients. PATIENTS AND METHODS: Fifty CD patients and 50 dyspeptic subjects (control group) underwent TABS. The presence of fluid-distended small bowel loops with thickened valvulae conniventes and increased peristalsis was considered a TABS sign of CD. All clinical, biochemical, and TABS features were assessed at the diagnosis and revaluated after 1 year of gluten-free diet. RESULTS: TABS signs were present in 66% of CD patients. Sensitivity, specificity, positive and negative predictive value were 66%, 96%, 94%, and 74%, respectively. TABS findings were recorded in 82% of patients with endoscopical markers of CD, in 87.5% of symptomatic patients, and in 61% of patients without symptoms. After 1 year of gluten-free diet TABS was still abnormal in 20% patients, with no correlation with laboratory tests e/o symptoms. CONCLUSIONS: Patients with CD frequently present TABS signs of the disease and operators performing sonography every day have to consider the possibility to suggest CD diagnosis and aTTG determination in these subjects.

Apple polyphenol extracts prevent damage to human gastric epithelial cells in vitro and to rat gastric mucosa in vivo.

BACKGROUND: Fresh fruit and vegetables exert multiple biological effects on the gastrointestinal mucosa. AIM: To assess whether apple extracts counteract oxidative or indomethacin induced damage to gastric epithelial cells in vitro and to rat gastric mucosa in vivo. METHODS: Apple extracts were obtained from freeze dried apple flesh of the "Annurca" variety. Cell damage was induced by incubating MKN 28 cells with xanthine-xanthine oxidase or indomethacin and quantitated by MTT. In vivo gastric damage was induced by indomethacin 35 mg/kg. Intracellular antioxidant activity was determined using the (2,2'-azinobis (3-ethylbenzothiazolin-6-sulfonate) method. Malondialdehyde intracellular concentration, an index of lipid peroxidation, was determined by high pressure liquid chromatography with fluorometric detection. RESULTS: (1) Apple extracts decreased xanthine-xanthine oxidase or indomethacin induced injury to gastric epithelial cells by 50%; (2) catechin or chlorogenic acid (the main phenolic components of apple extracts) were equally effective as apple extracts in preventing oxidative injury to gastric cells; and (3) apple extracts (i) caused a fourfold increase in intracellular antioxidant activity, (ii) prevented its decrease induced by xanthine-xanthine oxidase, (iii) counteracted xanthine-xanthine oxidase induced lipid peroxidation, and (iv) decreased indomethacin injury to the rat gastric mucosa by 40%. CONCLUSIONS: Apple extracts prevent exogenous damage to human gastric epithelial cells in vitro and to the rat gastric mucosa in vivo. This effect seems to be associated with the antioxidant activity of apple phenolic compounds. A diet rich in apple antioxidants might exert a beneficial effect in the prevention of gastric diseases related to generation of reactive oxygen species.

Differential expression of multiple transglutaminases in human colon: impaired keratinocyte transglutaminase expression in ulcerative colitis.

BACKGROUND AND AIMS: Ulcerative colitis (UC) is characterised by refractory inflammatory ulceration and damage to the colon. The mechanisms underlying impaired healing have yet to be defined. As transglutaminase expression resulting in matrix protein cross linking is associated with increased wound healing in a rat model of colitis, we hypothesised that different types of transglutaminase might also play a role in UC. PATIENTS AND METHODS: Endoscopic and histological indices were studied in 26 patients with UC (10 active and 16 inactive) and in 20 normal controls undergoing colonoscopy. Transglutaminase activity was evaluated in plasma (factor XIIIa) by a radioenzymatic method. Factor XIIIa, tissue and keratinocyte transglutaminase protein content, and mRNA expression in the colon were evaluated by western blot analysis and semiquantitative reverse transcription-polymerase chain reaction (RT-PCR), respectively. Colonic location of transglutaminases and their reaction products, the epsilon-(gamma-glutamyl)lysine bonds, was evaluated by immunohistochemistry using specific monoclonal antibodies. RESULTS: Transglutaminase activity was significantly lower in the plasma of patients with active UC (4.2 (2.4) mU/ml; p<0.05 v controls) than in those with inactive UC and controls (10.6 (2.2) and 12.1 (1.7) mU/ml). As shown by western blot, protein levels of tissue transglutaminase and factor XIIIa were unchanged in active UC compared with inactive disease and controls, while the keratinocyte form was reduced in active UC. Tissue transglutaminase and factor XIIIa immunostaining was strongly present in damaged areas colocalising with isopeptide bonds. In contrast, the keratinocyte form was almost absent in active UC and localised in the upper part of the crypts in normal subjects. RT-PCR showed upregulation of tissue transglutaminase mRNA in active UC (320% compared with controls) while keratinocyte transglutaminase gene expression was downregulated in active UC. CONCLUSIONS: The results of the present study support the concept that, in the damaged colon, transglutaminases are needed in response to chronic injury and underline the key role of these enzymes in mucosal healing.

Comparison between the suppressive effects of dexamethasone and loperamide on cortisol and ACTH secretion in some pathological conditions.

Since in patients with Cushing's disease, unlike in normal subjects, tonic inhibitory opioid control of ACTH secretion does not operate, use of the opiate agonist loperamide (LOP) has recently been proposed in the diagnosis of hypercortisolemic states. We compared the sensitivity, specificity and diagnostic accuracy of the LOP test (16 mg orally) with corresponding results of the dexamethasone test (DXM, 1 mg orally overnight) in 23 normal subjects and in a total of 42 patients, affected by Cushing's disease (n = 8), incidentally discovered adrenal masses with impaired function of the hypothalamic-pituitary-adrenal (HPA) axis (n = 6), obesity (n = 21) and depression (n = 7). While in controls both DXM and LOP strongly suppressed plasma cortisol and ACTH, in Cushing's disease and in incidentalomas no patient showed a decrease in cortisol levels below 50 ng/ml or a reduction in plasma cortisol greater than 50% of basal values in response to LOP and DXM. In obese subjects both drugs significantly reduced plasma cortisol and ACTH without giving false positive results. In the depressed group only 3/7 patients showed a decrement in cortisol levels below 50 ng/ml after LOP in contrast to 6/7 after DXM. Thus, in patients with impairment of the HPA-axis, i.e. in Cushing's disease and in patients with adrenal incidentalomas and hormonal abnormalities, LOP and DXM test sensitivity was 100%. In controls and in obese patients specificity was 100% both with LOP and DXM, while in depressed patients it was 43% and 86% with LOP and DXM, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)