S. Gullini

Elevated Expression of A3 Adenosine Receptors in Human Colorectal Cancer Is Reflected in Peripheral Blood Cells

Purpose: Adenosine is a ubiquitous nucleoside that accumulates at high levels in hypoxic regions of solid tumors, and A3 adenosine receptors have been recently demonstrated to play a pivotal role in the adenosine-mediated inhibition of tumor cell proliferation. In the present work, we addressed the question of the putative relevance of A3 subtypes in colorectal adenocarcinomas. Experimental Design: Seventy-three paired samples of tumor and surrounding peritumoral normal mucosa at a distance of 2 and 10 cm from the tumor and blood samples obtained from a cohort of 30 patients with colorectal cancer were investigated to determine the presence of A3 receptors by means of binding, immunocytochemistry, and real-time reverse transcription-polymerase chain reaction studies. Results: As measured by receptor binding assays, the density of A3 receptor was higher in colon carcinomas as compared with normal mucosa originating from the same individuals (P < 0.05). Overexpression of A3 receptors at the protein level was confirmed by immunohistochemical studies, whereas no changes in A3 mRNA accumulation in tumors as compared with the corresponding normal tissue were revealed. The overexpression of A3 receptors in tumors was reflected in peripheral blood cells, where the density was approximately 3-fold higher compared with healthy subjects (P < 0.01). In a cohort of 10 patients studied longitudinally, expression of A3 receptors in circulating blood cells returned to normal after surgical resection for colorectal cancer. Conclusions: This study provides the first evidence that A3 receptor plays a role in colon tumorigenesis and, more importantly, can potentially be used as a diagnostic marker or a therapeutic target for colon cancer.

Postprandial Gallbladder Motor Function: Refilling and Turnover of Bile in Health and in Cholelithiasis

BACKGROUND & AIMS Impaired gallbladder emptying is implicated in gallstone disease. Ultrasonography and scintigraphy have shown conflicting results because the former is influenced by postprandial refilling, whereas the latter is not influenced by refilling. The aim of this study was to measure postprandial refilling and turnover of bile by combining the two techniques. METHODS Simultaneous scintigraphy and ultrasonography were used in 14 patients with gallstones and 11 healthy controls. Measurements were performed while the patients were fasting and at 10-minute intervals after a standard meal for 90 minutes, and the measurements were used to calculate postprandial refilling, turnover of bile (in milliliters), and turnover index. RESULTS Ultrasonography and scintigraphy provided different gallbladder emptying patterns. Compared with controls, patients with gallstones had impaired emptying by both scintigraphy (P < 0.0001) and ultrasonography (P < 0.01). Postprandial refilling and turnover were both reduced between 60 and 90 minutes (P < 0.05), and the turnover index was markedly reduced (1.8 vs. 3.5; P < 0.001). CONCLUSIONS Simultaneous scintigraphy and ultrasonography provide a new model of gallbladder motor function showing that refilling begins immediately postprandially. In healthy controls, the gallbladder postprandially handles up to six times its basal volume within a period of 90 minutes, but this turnover of bile is markedly reduced in cholelithiasis causing a reduced washout effect of the gallbladder contents, including cholesterol crystals.

Validation of the 13C-urea breath test for the diagnosis of Helicobacter pylori infection in children: a multicenter study.

OBJECTIVE:The 13C-urea breath test (13C-UBT) is a safe, noninvasive, and accurate test for the detection of Helicobacter pylori (H. pylori) infection in adults. The aim of this study was to evaluate sensitivity and specificity of 13C-UBT in children using different types of test meal, doses of 13C-urea and breath sampling intervals. As yet, a validated, standardized 13C-UBT protocol for children has not been formulated.METHODS:13C-UBT was performed in 115 children and repeated within 3 days, modifying the test meal or the dose of 13C-urea. H. pylori status was assessed by histology and rapid urease test. 13C-UBT was performed using 100 mg or 50 mg of 13C-urea and a fatty test meal (100 FA; 50 FA), 50 mg of 13C-urea, and a carbohydrate test meal (50 CA). Breath samples were collected every 10 min for 60 min.RESULTS:The 13C-UBT in children was highly sensitive and specific with all three protocols used. The best combination of sensitivity (97.92%) and specificity (97.96%) was obtained with Protocol 50 FA at 30 min with a cut-off of 3.5 per mil.CONCLUSIONS:The 13C-UBT is an accurate test for the detection of H. pylori infection also in children. Administration of 50 mg of 13C-urea, a fatty test meal, and breath sampling at 30 min appears to be the most convenient protocol.

Frequent aberrant methylation of the CDH4 gene promoter in human colorectal and gastric cancer

Gene promoter methylation causes loss of tumor suppressor genes function in human cancer. Here, we show that the CDH4 gene, a member of the cadherin family encoding for R-cadherin, contains a CpG island located at the 5′ of the first exon, which functions as a promoter element and is frequently affected by methylation in human cancer. By using methylation-specific PCR and reverse transcription-PCR in human cancer cell lines, promoter methylation could be directly linked to loss of gene expression. After treatment with the demethylating agent 5-aza-2-deoxycytidine, expression could be restored. Analysis of human primary tumors revealed that the CDH4 gene is methylated in 78% (38 of 49) of colorectal and 95% (20 of 21) of gastric carcinomas. CDH4 methylation was not detected in nonneoplastic colonic (0 of 10) and stomach (0 of 10) tissues or in peripheral blood (0 of 17). CDH4 methylation was detected in histologically normal tissues located in proximity of the neoplasms, indicating that CDH4 methylation is an early event in gastrointestinal tumor progression. We also proved that CDH4 methylation can be revealed in the peripheral blood of cancer patients. Our results indicate that CDH4 may act as a tumor suppressor gene in human gastrointestinal tumors and can potentially be used as an early diagnostic marker for gastrointestinal tumorigenesis.

Clinical trial on the efficacy of a new symbiotic formulation, Flortec, in patients with irritable bowel syndrome: a multicenter, randomized study.

Objectives Efficacy of symbiotics in patients with irritable bowel syndrome (IBS) remains unknown. Methods Patients were randomized to a prebiotic (n=135), or a symbiotic formulation containing Lactobacillus paracasei B21060 (Flortec, n=132). Primary efficacy was the responder rate for pain and global relief of symptoms in the overall population and in patients with predominant diarrhea (n=47). Post hoc time-trend analyses for changes within each treatment were carried out. Results Patients with absent/mild pain amounted to 54.7% in the symbiotic group and to 57.4% in the prebiotic group at treatment week 4, and to 53.9% and 53.4% at the end of treatment. Patients with amelioration of well-being were, respectively, 60.7% versus 61.7% at treatment week 4, and 63.3% versus 60.9% at the end of treatment. Within each treatment group, patients with absent/mild pain increased in the Flortec and the prebiotic group, but time trend analyses were significant only for Flortec (P=0.019). In IBS-predominant diarrhea, Flortec significantly reduced bowel movements, pain, and IBS scores. Conclusions To improve pain and well-being, Flortec is encouraging in patients with diarrhea predominant IBS. To establish its efficacy for the majority of IBS patients, Flortec has to be compared with an inert placebo in future work.

Biliary sludge: the sluggish gallbladder.

Biliary sludge is a mixture of particulate matter which has precipitated from bile. It generally consists of cholesterol monohydrate crystals, calcium bilirubinate or other calcium salts. In a clinical setting, biliary sludge is almost always an ultrasonographic diagnosis. Although it is less clinically applicable, direct microscopic examination of gallbladder bile is far more sensitive than ultrasonography into sludge detection, and has to be regarded as the diagnostic gold standard. The overall prevalence of sludge in the general population is relatively low. However, several clinical conditions are associated with a particularly high prevalence of biliary sludge, including pregnancy, rapid weight loss, total parenteral nutrition, octreotide therapy, bone marrow or solid organ transplantation. The clinical course of biliary sludge varies, and complete resolution, a waxing and waning course, and progression to gallstones are all possible outcomes. It may cause complications usually associated with gallstones, such as biliary colic, acute cholecystitis, and acute pancreatitis. The main pathogenic mechanism involved in sludge formation is probably gallbladder dismotility, and in selected patients measures aimed to maintain adequate gallbladder contractions has been shown to effectively prevent sludge development.

Multigene methylation analysis of gastrointestinal tumors: TPEF emerges as a frequent tumor-specific aberrantly methylated marker that can be detected in peripheral blood.

BACKGROUND Gene promoter methylation is a mechanism for tumor suppressor gene silencing and inactivation. The development of highly sensitive methods for revealing aberrant cancer-associated DNA methylation allows the identification of tumor markers not only in tumor samples, but also in body fluid, an approach that can be useful in the early detection of neoplasms. METHODS We analyzed the methylation status at 16 loci in tumor samples of the gastrointestinal tract and in early or pre-neoplastic lesions of the colon. RESULTS Tumor samples revealed that methylation at the transmembrane protein containing epidermal growth factor and follistatin domains (TPEF) locus had the best ratio of discrimination between tumor samples versus normal tissues (83 versus 0%). Its combination with hypermethylated in cancer 1 (HIC1), death-associated protein kinase (DAPK) and O-6-methylguanine DNA methyltransferase (MGMT), allowed the detection of aberrant methylation in 98% of colorectal carcinomas and 100% of gastric carcinomas. The same alterations were also detected in colon adenomas and tissues surrounding the adenomas, indicating that hypermethylation at these loci occurred early in tumor progression. Analysis of DNA from peripheral blood revealed that TPEF methylation was detectable in colorectal tumor patients and patients with early or pre-neoplastic lesions, but not in healthy volunteers. CONCLUSIONS Our results identify TPEF as a tumor marker that could be useful in the follow-up of gastrointestinal cancer patients or the screening of individuals at risk of developing gastrointestinal neoplasms.

Evaluation of a new rapid immunoassay for the detection of Helicobacter pylori in faeces: a prospective pilot study

Background : Detection of Helicobacter pylori antigen in faeces is a valid method to diagnose H. pylori infection. Presently available stool tests are performed in the laboratory, and diagnostic report is delayed.

Different production of soluble HLA‐G antigens by peripheral blood mononuclear cells in ulcerative colitis and Crohn's disease: A noninvasive diagnostic tool?

Background: HLA‐G antigens are nonclassical major histocompatibility complex (MHC) class I molecules characterized by tolerogenic and antiinflammatory properties. Recently, a different expression of HLA‐G antigens has been observed between intestinal biopsies of ulcerative colitis (UC) and Crohns disease (CD) patients. These data suggested a functional role for HLA‐G molecules in the diseases and proposed the HLA‐G modulation as a marker for the diagnosis of UC and CD. The soluble HLA‐G antigens (sHLA‐G) are circulating molecules mainly produced by activated peripheral blood CD14+ monocytes. Methods: We tested, by specific enzyme‐linked immunosorbent assay (ELISA), the sHLA‐G molecule levels in the supernatants of unstimulated and bacterial lipopolysaccharide (LPS)‐stimulated cultures of peripheral blood mononuclear cells (PBMC) from 30 healthy subjects, 10 CD, and 18 UC patients. The data were not influenced by treatment or disease activity. Results: The results confirmed a different sHLA‐G expression between the diseases, with a spontaneous secretion of sHLA‐G in CD patients but not in UC and healthy subjects. Moreover, a lack of sHLA‐G antigens has been reported in UC patient cultures after LPS activation but not in healthy subjects and CD patients. The defective sHLA‐G production was related to an impaired IL‐10 secretion in UC but not in CD. Conclusions: Overall, these results confirm the presence of a different biological characteristic between CD and UC patients and suggest sHLA‐G production by PBMC as a noninvasive diagnostic tool in the early phases of the diseases.

Multigene Methylation Analysis of Gastrointestinal Tumors

AbstractBackground: Gene promoter methylation is a mechanism for tumor suppressor gene silencing and inactivation. The development of highly sensitive methods for revealing aberrant cancer-associated DNA methylation allows the identification of tumor markers not only in tumor samples, but also in body fluid, an approach that can be useful in the early detection of neoplasms. Methods: We analyzed the methylation status at 16 loci in tumor samples of the gastrointestinal tract and in early or pre-neoplastic lesions of the colon. Results: Tumor samples revealed that methylation at the transmembrane protein containing epidermal growth factor and follistatin domains (TPEF) locus had the best ratio of discrimination between tumor samples versus normal tissues (83 versus 0%). Its combination with hypermethylated in cancer 1 (HIC1), death-associated protein kinase (DAPK) and O-6-methylguanine DNA methyltransferase (MGMT), allowed the detection of aberrant methylation in 98% of colorectal carcinomas and 100% of gastric carcinomas. The same alterations were also detected in colon adenomas and tissues surrounding the adenomas, indicating that hypermethylation at these loci occurred early in tumor progression. Analysis of DNA from peripheral blood revealed that TPEF methylation was detectable in colorectal tumor patients and patients with early or pre-neoplastic lesions, but not in healthy volunteers. Conclusions: Our results identify TPEF as a tumor marker that could be useful in the follow-up of gastrointestinal cancer patients or the screening of individuals at risk of developing gastrointestinal neoplasms.