Rossana Alloni

Ursodeoxycholic acid improves muscle contractility and inflammation in symptomatic gallbladders with cholesterol gallstones

Objective: To examine the mechanisms of action of ursodeoxycholic acid (UDCA) on gallbladder (GB) muscle cells in patients with symptomatic cholesterol gallstones (GSs) as it reduces the incidence of acute cholecystitis. Design and patients: A double-blind study was performed on 15 patients, 7 randomised to UDCA and 8 to placebo, treated for 4 weeks before cholecystectomy. Muscle contraction induced by cholecystokinin (CCK)-8, acetylcholine (ACh) and potassium chloride (KCl) was determined in enzymatically isolated GB muscle cells, and cholesterol levels were determined in plasma membranes. H2O2, lipid peroxidation, platelet-activating factor (PAF)-like lipids, prostaglandin E2 (PGE2) and catalase activity were determined as biochemical markers of oxidative stress and inflammation in muscle cells. Results: UDCA significantly increased GB muscle cell contraction induced by all concentrations of CCK-8, ACh and KCl, and reduced the plasma membrane cholesterol (mean (SD) 0.32 (0.16) vs 0.72 (0.5) μmol/mg of protein) compared with placebo. In GB muscle cells, UDCA treatment significantly decreased the levels of H2O2 (4.4 (1.9) vs 13.7 (5.3) μmol/mg of protein), lipid peroxidation (malondialdehyde levels 1.3 (0.4) vs 2.52 (0.7) nmol/100 mg of protein), PAF-like lipids (8.9 (4.9) vs 29.6 (7.1) pg/mg of protein) as well as the production of PGE2 (142 (47) vs 365 (125) pg/mg of protein) and catalase activity (14.5 (9.4) vs 35.8 (12.7) units/mg of protein) when compared with placebo. Conclusion: These studies suggest that UDCA treatment improves GB muscle contractility by decreasing the cholesterol content in the plasma membrane of muscle cells, and the biochemical parameters of oxidative stress, thus explaining its possible therapeutic mechanisms in patients with symptoms of cholesterol GSs.

On the electrical intestine turbulence induced by temperature changes

Paralytic ileus is a temporary syndrome with impairment of peristalsis and no passage of food through the intestine. Although improvements in supportive measures have been achieved, no therapy useful to specifically reduce or eliminate the motility disorder underlying postoperative ileus has been developed yet. In this paper, we draw a plausible, physiologically fine-tuned scenario, which explains a possible cause of paralytic ileus. To this aim we extend the existing 1D intestinal electrophysiological Aliev-Richards-Wikswo ionic model based on a double-layered structure in two and three dimensions. Thermal coupling is introduced here to study the influence of temperature gradients on intestine tissue which is an important external factor during surgery. Numerical simulations present electrical spiral waves similar to those experimentally observed already in the heart, brain and many other excitable tissues. This fact seems to suggest that such peculiar patterns, here electrically and thermally induced, may play an important role in clinically experienced disorders of the intestine, then requiring future experimental analyses in the search for possible implications for medical and physiological practice and bioengineering.

Antioxidant Activity of Inulin and Its Role in the Prevention of Human Colonic Muscle Cell Impairment Induced by Lipopolysaccharide Mucosal Exposure

Background Fructans, such as inulin, are dietary fibers which stimulate gastro-intestinal (GI) function acting as prebiotics. Lipopolysaccharide (LPS) impairs GI motility, through production of reactive oxygen species. The antioxidant activity of various fructans was tested and the protective effect of inulin on colonic smooth muscle cell (SMC) impairment, induced by exposure of human mucosa to LPS, was assessed in an ex vivo experimental model. Methods The antioxidant capacity of fructans was measured in an in vitro system that simulates cooking and digestion processes. Human colonic mucosa and submucosa, obtained from disease-free margins of resected segments for cancer, were sealed between two chambers, with the mucosal side facing upwards with Krebs solution with or without purified LPS from a pathogenic strain of Escherichia coli (O111:B4) and inulin (Frutafit IQ), and the submucosal side facing downwards into Krebs solution. The solutions on the submucosal side were collected following mucosal exposure to Krebs in the absence (N-undernatant) or presence of LPS (LPS-undernatant) or LPS+inulin (LPS+INU-undernatant). Undernatants were tested for their antioxidant activity and the effects on SMCs contractility. Inulin protective effects on mucosa and submucosa layers were assessed measuring the protein oxidation level in the experimental conditions analyzed. Results Antioxidant activity of inulin, which was significantly higher compared to simple sugars, remained unaltered despite cooking and digestion processes. Inulin protected the mucosal and submucosal layers against protein oxidation. Following exposure to LPS-undernatant, a significant decrease in maximal acetylcholine (Ach)-induced contraction was observed when compared to the contraction induced in cells incubated with the N-undernatant (4±1% vs 25±5% respectively, P<0.005) and this effect was completely prevented by pre-incubation of LPS with Inulin (35±5%). Conclusions Inulin protects the human colon mucosa from LPS-induced damage and this effect appears to be related to the protective effect of inulin against LPS-induced oxidative stress.

Effect of acute mucosal exposure to Lactobacillus rhamnosus GG on human colonic smooth muscle cells.

Aim To define whether human colonic mucosa exposure to Lactobacillus rhamnosus GG (LGG), American Type Culture Collection (ATCC) 53103, may influence intestinal muscle cell contractility. Methods Human colon specimens were obtained from disease-free margins of resected segments for cancer. The mucosa and submucosa, after dissection, were sealed between 2 chambers, with the luminal side of the mucosa facing upward and covered with 5 mL of Krebs solution and the submucosal side facing downward into 20 mL of Krebs solution. LGG or normal undernatant (N-undernatant) were added to the luminal side of the mucosa for 30 minutes. Smooth muscle cells (SMCs), isolated from the circular muscle layer, were exposed to undernatant for 30 minutes from the submucosal chamber of mucosa that was either preexposed to N-undernatant or to LGG (36×10−9 colony forming units/mL) (LGG-undernatant). Acetylcholine (Ach) dose-response was obtained for SMCs. Results SMCs exposed to N-undernatant presented a dose-response to Ach (maximal contraction: 32%±5% with 1-μM Ach) that is similar to unstimulated SMCs. Exposure to LGG-undernatant resulted both in an 18%±3% cell shortening and a 78%±7% inhibition of maximal Ach-induced contraction. When SMCs were directly exposed to LGG, a significant impairment of contraction (70%±5%, compared with control cells) and a dose-dependent and time-dependent shortening were observed. Conclusions After acute exposure of colonic mucosa to LGG, a significant shortening of SMCs is observed that possibly contributes to the reduced contractile response to Ach. Further studies are needed to establish the mechanisms of this effect that could account for the clinical efficacy of probiotics in intestinal disorders.

Solitary splenic metastasis of ovarian carcinoma: Report of two cases

Capsular splenic metastasis from ovarian cancer, which is associated with peritoneal spread, is not uncommon. Conversely, solitary involvement of the splenic parenchymal is unusual, and secondary debulking may improve the prognosis if there is no sign of residual disease. Thus, splenectomy is indicated for this type of isolated splenic metastasis. We report two cases of successful splenectomy for solitary splenic metastasis of ovarian carcinoma and review the relevant literature.

Experience with two cases of intestinal tuberculosis: utility of the QuantiFERON-TB Gold test for diagnosis.

BACKGROUND Intestinal tuberculosis is rare in Western countries, with incidence rates of 35.7 and 0.43 per 100,000 per year for the immigrant and native populations, respectively. Despite a clear increase in the frequency of extrapulmonary tuberculosis in immunosuppressed patients, the clinical features of intestinal tuberculosis are seen rarely. A typical clinical presentation includes abdominal pain, weight loss, fever, weakness, nausea, vomiting, obstruction, and bleeding. Intestinal tuberculosis often mimics inflammatory bowel disease or malignant neoplasia, and its preoperative diagnosis is a challenge. Microbiologic diagnosis often is difficult because the causative microorganism requires a long incubation period. METHODS Two case reports and review of the pertinent literature. RESULTS We report two cases of colonic tuberculosis mimicking cecal carcinoma in one patient and periappendiceal abscess in the other. A 75 year-old man underwent right hemicolectomy for a right colon mass. Preoperative laboratory, radiologic, and endoscopic evaluations were negative for tuberculosis and carcinoma. The QuantiFERON-TB Gold test was positive. Surgical specimen histologic review showed non-caseating granulomas and rare Ziehl-Neelsen-positive bacilli. A 35 year-old man, born in Sri Lanka but living in Italy for 10 years, came to our attention for a periappendiceal abscess. Multiple peritoneal micro-nodules were found at laparotomy. Their extemporaneous histologic examination showed granulomas and giant-cell inflammation. A right hemicolectomy was performed. The QuantiFERON-TB Gold test, performed on peritoneal fluid and blood, was positive in both. CONCLUSIONS The QuantiFERON-TB Gold test may hold promise for use in intestinal inflammatory diseases when tuberculosis is suspected but conventional workup is not diagnostic.

Decreased number of activated macrophages in gallbladder muscle layer of cholesterol gallstone patients following ursodeoxycholic acid

We recently reported that, in symptomatic cholesterol gallstone patients, ursodeoxycholic acid (UDCA) improves gallbladder (GB) muscle contractility and decreases the biochemical parameters of oxidative stress and inflammation.1 UDCA also antagonises the hydrophobic bile acid damage to the liver by preventing hydrophobic bile acid-induced stimulation of macrophage oxidative processes.2 3 Macrophages also play a dominant role in the inflammatory and oxidative response in other conditions associated with impairment of intestinal motility, such as post-operative ileus.4–6 Following these findings, we carried out additional studies aimed at examining: the presence of macrophage infiltration and cyclooxygenase-2 (COX-2) expression in the GB muscle layer and the effect of short-term UDCA administration. From February 2004 to August 2007, …

Effect of surgical stress on nuclear and mitochondrial DNA from healthy sections of colon and rectum of patients with colorectal cancer

Surgical resection at any location in the body leads to stress response with cellular and subcellular change, leading to tissue damage. The intestine is extremely sensitive to surgical stress with consequent postoperative complications. It has been suggested that the increase of reactive oxygen species as subcellular changes plays an important role in this process. This article focuses on the effect of surgical stress on nuclear and mitochondrial DNA from healthy sections of colon and rectum of patients with colorectal cancer. Mitochondrial DNA copy number, mitochondrial common deletion and nuclear and mitochondrial 8-oxo-2′-deoxyguanosine content were measured. Both the colon and rectal tissue were significantly damaged either at the nuclear or mitochondrial level. In particular, mitochondrial DNA was more damaged in rectum than in colon. The present investigation found an association between surgical stress and nuclear and mitochondrial DNA damage, suggesting that surgery may generate an increase in free radicals, which trigger a cascade of molecular changes, including alterations in DNA.

Ultrasonographic assessment of gallbladder bile exchanges in healthy subjects and in gallstone patients

Impaired gallbladder motility may contribute to gallstone pathogenesis by providing time for nucleation and aggregation of cholesterol crystals. Simultaneous scintigraphic-ultrasonographic techniques have been proposed to assess alternating phases of gallbladder emptying and filling. To evaluate patterns of gallbladder motility and of postprandial bile flow by means of a single ultrasonographic technique, 12 healthy volunteers and 20 gallstone patients underwent minute-by-minute gallbladder ultrasonography for 3 h postprandially. Mathematical analysis of volume measurements was used to estimate hepatic and cholecystic bile flux through the gallbladder. Compared to controls, gallstone patients showed greater amounts of unexchanged cholecystic-to-hepatic bile (11% vs. 1%, p <.001) and most of them showed impaired gallbladder washout efficacy. Utrasonographic values of bile exchanges were similar to those derived from scintigraphic-sonographic studies in comparable groups of subjects. This study provides new ultrasonographic variables, which better express gallbladder bile retention in gallstone patients and strongly discriminate gallstone patients from controls.

Experimental evidence and mathematical modeling of thermal effects on human colonic smooth muscle contractility

It has been shown, in animal models, that gastrointestinal tract (GIT) motility is influenced by temperature; nevertheless, the basic mechanism governing thermal GIT smooth muscle responses has not been fully investigated. Studies based on physiologically tuned mathematical models have predicted that thermal inhomogeneity may induce an electrochemical destabilization of peristaltic activity. In the present study, the effect of thermal cooling on human colonic muscle strip (HCMS) contractility was studied. HCMSs were obtained from disease-free margins of resected segments for cancer. After removal of the mucosa and serosa layers, strips were mounted in separate chambers. After 30 min, spontaneous contractions developed, which were measured using force displacement transducers. Temperature was changed every hour (37, 34, and 31°C). The effect of cooling was analyzed on mean contractile activity, oscillation amplitude, frequency, and contraction to ACh (10(-5) M). At 37°C, HCMSs developed a stable phasic contraction (~0.02 Hz) with a significant ACh-elicited mean contractile response (31% and 22% compared with baseline in the circular and longitudinal axis, respectively). At a lower bath temperature, higher mean contractile amplitude was observed, and it increased in the presence of ACh (78% and 43% higher than the basal tone in the circular and longitudinal axis, respectively, at 31°C). A simplified thermochemomechanical model was tuned on experimental data characterizing the stress state coupling the intracellular Ca(2+) concentration to tissue temperature. In conclusion, acute thermal cooling affects colonic muscular function. Further studies are needed to establish the exact mechanisms involved to better understand clinical consequences of hypothermia on intestinal contractile activity.