Papers by Stefano Guandalini
Gastroenterology, Apr 1, 1998
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Journal of Pediatric Gastroenterology and Nutrition, Feb 1, 1999
ABSTRACT
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Journal of Pediatric Gastroenterology and Nutrition, Sep 1, 1999
Little information is available about the relationships between Helicobacter pylori cytotoxin-ass... more Little information is available about the relationships between Helicobacter pylori cytotoxin-associated protein (CagA) and clinicopathologic features in children. The purpose of this study was to test whether determining serum IgG antibodies to CagA is a useful tool for detecting more severe disease. One hundred twenty-seven consecutive children (age range, 0.75-17.8 years; median, 9.4 years) referred for gastroscopy were included in the study. Antral and corpus biopsies were taken for gastric histology and H. pylori detection. Major symptoms and endoscopic findings were recorded. A serum sample was drawn from each child and assayed for IgG antibodies CagA by a commercial enzyme-linked immunosorbent assay. Sixty-three (50%) children had no evidence of H. pylori infection, 28 (22%) were H. pylori positive/CagA positive, and 36 (28%) were H. pylori positive/CagA negative. There were no differences in clinical diagnosis and occurrence of any predominant symptom according to H. pylori and CagA status. Findings of antral nodularity were more frequent (p = 0.003) in H. pylori-positive/CagA-positive children than in H. pylori-positive/CagA-negative children. The gastritis score was significantly higher in H. pylori-positive/CagA-positive children than in H. pylori-positive/CagA-negative children (5.7 +/- 1.9 vs. 3.8 +/- 1.6, respectively; p = 0.0003), either in the antral (p = 0.0002) or in the corpus (p = 0.001) mucosa. Inflammation (p = 0.0001) and activity (p = 0.0001) scores were both higher in H. pylori-positive/CagA-positive children than in H. pylori-positive/CagA-negative children, but the H. pylori density score was not significantly different (p = NS). In no case was normal gastric mucosa found in H. pylori-positive/ CagA-positive children. Lymphocytic gastritis (p = 0.0008) and lymphoid follicles (p = 0.000003) were a more frequent finding in H. pylori-positive children than in H. pylori negative children, irrespective of CagA status. Testing for serum IgG to CagA detects higher grades of gastric inflammation among children with H. pylori infection. It may be useful in targeting H. pylori-positive/ CagA-positive children for antimicrobial therapy while reducing the need for endoscopy and gastric biopsy.
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Gut, 1988
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Frontiers in Medicine
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Saudi Journal of Gastroenterology
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Gastroenterology, 1995
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Gastroenterology, 1995
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Drugs, 1988
Absorption of water from the intestine occurs in response to the osmotic gradient as a passive co... more Absorption of water from the intestine occurs in response to the osmotic gradient as a passive consequence of the active transfer of solutes (nutrients and electrolytes, with Na absorption playing a key role) from the intestinal lumen to the serosal side. During intestinal infections, several possible derangements of such a situation may occur, ultimately leading to the shift of net water absorption to secretion and, thus, to diarrhoea. In rotaviral diarrhoea, the mature enterocytes are invaded by the virus and exfoliate, thus inducing villous atrophy and crypt hyperplasia. Consequently, undigested and unabsorbed nutrients cause an osmolar diarrhoea, while the ongoing process of crypt secretion contributes by adding active anion and water secretion. In bacterial intestinal infections, the pathogenetic mechanisms are essentially mucosal invasion, adherence, cytotoxicity or release of enterotoxins. The pathophysiology of bacterial diarrhoea is best known for the latter mechanism; heat-labile and heat-stable families of enterotoxins have been described and characterised that act by inducing, respectively, an increase in the enterocyte's cyclic AMP or cyclic GMP content. Such alteration leads, in a morphologically intact mucosa, to changes in the major electrolyte transport processes that reverse net absorption of ions and water to net secretion and thus to secretory diarrhoea. As for nutrient absorption, although experimental evidence indicates an impairment of glucose and amino acid absorption in rotaviral diarrhoea, many clinical trials have shown the successful use of oral rehydration solutions in such circumstances. The same applies to bacterial-induced diarrhoeas; the well-established observation that, in enterotoxic diarrhoea of all kinds, the coupled transport of Na and nutrients such as glucose or amino acids is intact has proved to be the cornerstone of the highly successful, widespread use of oral rehydration solutions.
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Clinical and Applied Immunology Reviews, 2002
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An in-house enzyme-linked immunosorbent assay (ELISA) for measurement of Helicobacter pylori-spec... more An in-house enzyme-linked immunosorbent assay (ELISA) for measurement of Helicobacter pylori-specific immunoglobulin G (IgG) and IgA in saliva was evaluated by comparison with histopathologic (Giemsa staining) and biochemical (urease quick test) examination of gastric biopsy specimens obtained from 112 children referred for diagnostic gastroscopy. Serum H. pylori IgG was also measured in a subgroup of 50 children by the same
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Gastroenterology, 2015
The mechanisms of tissue destruction during progression of celiac disease are poorly defined. It ... more The mechanisms of tissue destruction during progression of celiac disease are poorly defined. It is not clear how tissue stress and adaptive immunity contribute to activation of intraepithelial cytotoxic T cells and development of villous atrophy. We analyzed epithelial cells and intraepithelial cytotoxic T cells in family members of patients with celiac disease, who are without any signs of adaptive anti-gluten immunity, and in potential celiac disease patients, who have antibodies against tissue transglutaminase 2 in absence of villous atrophy. We collected blood and intestinal biopsies from 268 patients at tertiary medical centers in the US and Italy from 2004 to 2012. All subjects had had normal small intestinal histology. Study groups included healthy individuals with no family history of celiac disease or antibodies against tissue transglutamianse 2 (controls), healthy family members of patients with celiac disease, and potential celiac disease patients. Intraepithelial cytotoxic T cells were isolated and levels of inhibitory and activating natural killer (NK) cells were measured by flow cytometry. Levels of heat shock protein (HSP) and interleukin-15 (IL15) were measured by immunohistochemistry and ultrastructural alterations in intestinal epithelial cells (IEC) were assessed by electron microscopy. IEC from subjects with a family history of celiac disease, but not from subjects who already have immunity to gluten, expressed higher levels of HS27, HSP70, and IL15 than controls; their IEC also had ultrastructural alterations. Intraepithelial cytotoxic T cells from relatives of patients with celiac disease expressed higher levels of activating NK receptors than cells from controls, although at lower levels than patients with active celiac disease, and without loss of inhibitory receptors for NK cells. Intraepithelial cytotoxic T cells from potential celiac disease patients failed to upregulate activating NK receptors. A significant subset of healthy family members of patients with celiac disease with normal intestinal architecture has epithelial alterations, detectable by immunohistochemistry and electron microscopy. The adaptive immune response to gluten appears to act in synergy with epithelial stress to allow intraepithelial cytotoxic T cells to kill epithelial cells and induce villous atrophy in patients with potential celiac disease.
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Gastroenterology, 2014
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European Journal of Gastroenterology & Hepatology, 2000
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The Pediatric Infectious Disease Journal, 1995
Little information is available on asymptomatic carriage of Cryptosporidium in immunocompetent an... more Little information is available on asymptomatic carriage of Cryptosporidium in immunocompetent and immunodeficient children. We prospectively studied a group of asymptomatic children, 78 immunocompetent and 50 immunodeficient, to document the incidence of asymptomatic carriage of cryptosporidiosis in such a population. We also investigated whether the treatment of children who carried asymptomatic cryptosporidiosis could help in reducing their risk of gastrointestinal symptoms as well as the shedding of infectious oocysts. The occurrence of multiple infections with common intestinal pathogens including Giardia lamblia was also investigated. Asymptomatic cryptosporidiosis was documented in 6.4% of immunocompetent and 22% of immunodeficient children. In a control symptomatic population Cryptosporidium was found in 4.4% of immunocompetent and 4.8% of immunodeficient children. Asymptomatic carriage of Cryptosporidium was documented in 2 human immunodeficiency virus-infected children, one of whom also carried Giardia asymptomatically. Treatment with spiramycin (100 mg/kg daily for 14 days) reduced significantly the duration of the shedding of potentially infectious oocysts. Finally no gastrointestinal symptoms developed in children treated for asymptomatic infection with Cryptosporidium, whereas children who were not treated developed gastrointestinal symptoms.
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Journal of Pediatric Gastroenterology and Nutrition, 2000
A 9-year-old boy was brought to our gastrointestinal clinic with intermittent episodes of bleedin... more A 9-year-old boy was brought to our gastrointestinal clinic with intermittent episodes of bleeding from the rectum of 1 month's duration. He first noted a pink color on the toilet paper after wiping. Subsequently, he had fresh, bright red blood streaking otherwise normal stools ...
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Journal of Pediatric Gastroenterology and Nutrition, 2010
: Irritable bowel syndrome (IBS) is a common problem in pediatrics, for which no safe and effecti... more : Irritable bowel syndrome (IBS) is a common problem in pediatrics, for which no safe and effective treatment is available. Probiotics have shown some promising results in adult studies, but no positive study has been published on pediatric age. We aimed at investigating the efficacy of VSL#3 in a population of children and teenagers affected by IBS, in a randomized, double-blind, placebo-controlled, crossover study conducted in 7 pediatric gastroenterology divisions. : Children 4 to 18 years of age, meeting eligibility criteria, were enrolled. The patients were assessed by a questionnaire for a 2-week baseline period. They were then randomized to receive either VSL#3 or a placebo for 6 weeks, with controls every 2 weeks. At the end, after a "wash-out" period of 2 weeks, each patient was switched to the other group and followed for a further 6 weeks. : A total of 59 children completed the study. Although placebo was effective in some of the parameters and in as many as half of the patients, VSL#3 was significantly superior to it (P < 0.05) in the primary endpoint, the subjective assessment of relief of symptoms; as well as in 3 of 4 secondary endpoints: abdominal pain/discomfort (P < 0.05), abdominal bloating/gassiness (P < 0.05), and family assessment of life disruption (P < 0.01). No significant difference was found (P = 0.06) in the stool pattern. No untoward adverse effect was recorded in any of the patients. : VSL#3 is safe and more effective than placebo in ameliorating symptoms and improving the quality of life in children affected by IBS.
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Journal of Pediatric Gastroenterology and Nutrition, 2005
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Journal of Pediatric Gastroenterology & Nutrition, 1998
The probiotic Lactobacillus GG is effective in promoting a more rapid recovery of acute, watery d... more The probiotic Lactobacillus GG is effective in promoting a more rapid recovery of acute, watery diarrhea in children with rotavirus enteritis. Very limited information is available, however, on the potential role of such agents in non-rotaviral diarrheal episodes. Furthermore, no evidence is available concerning the efficacy of Lactobacillus GG administered in the oral rehydration solution during oral rehydration therapy. A multicenter trial was conducted to evaluate the efficacy of Lactobacillus GG administered in the oral rehydration solution to patients with acute-onset diarrhea of all causes. Children 1 month to 3 years of age with acute-onset diarrhea were enrolled in a double-blind, placebo-controlled investigation. Patients were randomly allocated to group A, receiving oral rehydration solution plus placebo, or group B, receiving the same preparation but with a live preparation of Lactobacillus GG (at least 10(10) CFU/250 ml). After rehydration in the first 4 to 6 hours, patients were offered their usual feedings plus free access to the same solution until diarrhea stopped. One hundred forty children were enrolled in group A, and 147 in group B. There were no differences at admission between the groups in age, sex, previous types of feeding, previous duration of diarrhea, use of antibiotics, weight, height, weight-height percentile, prevalence of fever, overall status, degree of dehydration, and percentage of in- versus outpatients. Duration of diarrhea after enrollment was 71.9 +/- 35.8 hours in group A versus 58.3 +/- 27.6 hours in group B (mean +/- SD; P = 0.03). In rotavirus-positive children, diarrhea lasted 76.6 +/- 41.6 hours in group A versus 56.2 +/- 16.9 hours in groups B (P < 0.008). Diarrhea lasted longer than 7 days in 10.7% of group A versus 2.7% of group B patients (P < 0.01). Hospital stays were significantly shorter in group B than in group A. Administering oral rehydration solution containing Lactobacillus GG to children with acute diarrhea is safe and results in shorter duration of diarrhea, less chance of a protracted course, and faster discharge from the hospital.
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Papers by Stefano Guandalini