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G R Corazza

Publications and source records attributed to G R Corazza.

At least 19 recordsLinked to original sources
PubMed2004

Review article: clinical implications of enteric and central D2 receptor blockade by antidopaminergic gastrointestinal prokinetics.

Antidopaminergic gastrointestinal prokinetics (bromopride, clebopride, domperidone, levosulpiride and metoclopramide) have been exploited clinically for the management of motor disorders of the upper gastrointestinal tract, including functional dyspepsia, gastric stasis of various origins and emesis. The prokinetic effect of these drugs is mediated through the blockade of enteric (neuronal and muscular) inhibitory D2 receptors. The pharmacological profiles of the marketed compounds differ in terms of their molecular structure, affinity at D2 receptors, ability to interact with other receptor systems [5-hydroxytryptamine-3 (5-HT3) and 5-HT4 receptors for metoclopramide; 5-HT4 receptors for levosulpiride) and ability to permeate the blood-brain barrier (compared with the other compounds, domperidone does not easily cross the barrier). It has been suggested that the serotonergic (5-HT4) component of some antidopaminergic prokinetics may enhance their therapeutic efficacy in gastrointestinal disorders, such as functional dyspepsia and diabetic gastroparesis. The antagonism of central D2 receptors may lead to both therapeutic (e.g. anti-emetic effect due to D2 receptor blockade in the area postrema) and adverse (including hyperprolactinaemia and extrapyramidal dystonic reactions) effects. As the pituitary (as well as the area postrema) is outside the blood-brain barrier, hyperprolactinaemia is a side-effect occurring with all antidopaminergic prokinetics, although to different extents. Extrapyramidal reactions are most commonly observed with compounds crossing the blood-brain barrier, although with some differences amongst the various agents. Prokinetics with a high dissociation constant compared with that of dopamine at the D2 receptor (i.e. compounds that bind loosely to D2 receptors in the nigrostriatal pathway) elicit fewer extrapyramidal signs and symptoms. A knowledge of central and peripheral D2 receptor pharmacology can help the clinician to choose between the antidopaminergic prokinetics to obtain a more favourable risk/benefit ratio.

Antiemetics↗
PubMed2004

Defective mucosal T cell death is sustainably reverted by infliximab in a caspase dependent pathway in Crohn's disease.

BACKGROUND AND AIMS: To verify whether targeting defective mucosal T cell death underlies the sustained therapeutic benefit of infliximab in Crohn's disease, we explored its in vivo proapoptotic effect after 10 weeks of treatment, and its in vitro killing activity on lamina propria T cells (LPT) and peripheral blood T cells (PBT), both isolated from Crohn's disease patients. METHODS: Endoscopic intestinal biopsies were collected from 10 Crohn's disease patients (six steroid refractory and four fistulising) before and after three consecutive infusions of infliximab, administered at week 0, 2, and 6 in a single intravenous dose (5 mg/kg), and from 10 subjects who proved to have functional diarrhoea. Apoptosis was determined in vivo by TUNEL assay, and in vitro by fluorescein isothiocyanate-annexin V/propidium iodide staining on LPT and PBT from Crohn's disease patients cultured with infliximab. The effect of the broad caspase inhibitor Z-VAD-FMK and the neutralising anti-Fas antibody ZB4 was tested in vitro on LPT and PBT treated with infliximab. Caspase-3 activity was determined by immunoblotting. RESULTS: In Crohn's disease patients, infliximab treatment induced a sustained LPT apoptosis, still evident four weeks after the last infusion. In vitro infliximab induced death of LPT from Crohn's disease patients occurred via apoptosis rather than necrosis. LPT showed a higher susceptibility to infliximab induced apoptosis than PBT in Crohn's disease patients. The signalling pathway underlying the restoration of infliximab induced LPT apoptosis occurred via the caspase pathway but not Fas-Fas ligand interaction in Crohn's disease. CONCLUSIONS: These findings demonstrate that apoptosis is the major mechanism by which infliximab exerts its killing activity on LPT in Crohn's disease. The sustained LPT proapoptotic action of infliximab, which extends far beyond its circulating half life, may be responsible for the sustained remission induced in Crohn's disease patients by infliximab retreatment.

Adult↗
PubMed2003

In patients with dermatitis herpetiformis distribution of transglutaminase in cutaneous tissue does not differ from controls.

BACKGROUND: Dermatitis herpetiformis may be regarded as the cutaneous counterpart of coeliac disease. These conditions are related to the ingestion of gluten and both are characterised by circulating antibodies against tissue transglutaminase. AIMS: To study the distribution of tissue transglutaminase in the skin of dermatitis herpetiformis patients and controls, and to investigate whether the dermal IgA deposits, diagnostic for dermatitis herpetiformis, are related to tissue transglutaminase expression in the skin. METHODS: A series of 11 patients with dermatitis herpetiformis had a 4 mm punch biopsy taken from the uninvolved perilesional skin. A group of 16 controls, undergoing surgical removal of benign nevi, gave perilesional skin. Biopsies were covered with OCT and frozen at -80 degrees C. After washing, skin biopsy sections were incubated with an IgG anti-tissue transglutaminase mouse monoclonal antibody. After washing, sections were incubated with anti-mouse IgG. RESULTS: The anti-tissue transglutaminase monoclonal antibody specifically recognised the basal epidermal cells. This staining was no different between patients and controls. CONCLUSION: Our results suggest that tissue transglutaminase can be recognised in the basal epidermal layer both of patients with dermatitis herpetiformis and controls. Since this distribution does not correspond to the distribution of dermal IgA deposits, it is concluded that dermatitis herpetiformis dermal IgA deposits are not due to antibodies directed against cutaneous tissue transglutaminase.

Adult↗
PubMed2003

Plasma cytokine profiles in patients with celiac disease and selective IgA deficiency.

Celiac disease (CD) and selective IgA deficiency (IgAD) are frequently associated, and share the same genetic background. The aim of the present study was to evaluate both Type 1 and 2 plasma cytokine levels in CD and in CD-IgAD. IL-2, TNF-alpha, IL-10, IL-4 and IL-13 plasma levels were measured both at diagnosis and after a gluten-free diet (GFD) in 32 CD patients, in 27 CD-IgAD patients and in 30 healthy controls. IFN-gamma levels were significantly higher in CD and CD-IgAD than in controls, TNF-alpha displayed significantly higher levels in CD-IgAD when compared both with controls and with CD, and IL-2 was in CD-IgAD significantly increased respect to controls. Kinetics of the Type 1 cytokine plasma levels did not show a clear relationship with the GFD in both groups of CD patients, and particularly in those with IgAD. IL-4 and IL-13, both at diagnosis and after a GFD, were not significantly different in controls and in celiac patients (with and without IgAD). IL-10, whose production is stimulated by the TNF-alpha, had significantly higher plasma levels in CD-IgAD, but not in CD patients, with a significant decrease after a GFD. CD and especially CD-IgAD patients display persistently higher pro-inflammatory cytokine levels, suggesting a persistent state of activation of pro-phlogistic signals in CD, particularly when IgAD coexists. Serial measurement of serum IL-10 may be an adjunctive evaluating criterion in the follow-up of CD-IgAD patients.

Adolescent↗
PubMed2003

Gliadin and tissue transglutaminase complexes in normal and coeliac duodenal mucosa.

Tissue transglutaminase (tTG) seems to be the target self-antigen for endomysial antibodies in coeliac disease (CD) and to catalyse the critical deamidation of gliadin which strengthens its recognition by HLA-restricted gut-derived T cells. To date, it has not been demonstrated whether gliadin is cross-linked to tTG within the gut wall, a phenomenon known to occur in vitro. We therefore investigated the putative presence of tTG and gliadin complexes directly in duodenal mucosa. The immunoprecipitation and Western blotting experiments were performed on mucosal biopsies obtained from untreated, treated CD patients and biopsied controls, by using either anti-tTG or anti-gliadin antibodies, in both denaturating/reducing or nondenaturating/nonreducing conditions. A subset of experiments was performed by using anti-tTG antibodies purified by affinity chromatography from sera of untreated coeliac patients. The localization of tTG and gliadin was studied by immunofluorescence at confocal laser microscopy on seriate sections of diseased and normal duodenal mucosa by using the same antibodies of the coimmunoprecipitation section. The amounts of tTG and gliadin coimmunoprecipitated with anti-tTG monoclonal antibody in untreated CD mucosa were significantly increased compared to those of the other two groups. When performing the experiments in nondenaturating/nonreducing conditions, a high molecular weight band formed by both molecules, was evidenciated. Also the anti-tTG antibodies purified from patients' sera turned out to be able to coimmunoprecipitate the two molecules. The analysis by confocal microscopy showed that tTG colocalizes with gliadin at the epithelial and subepithelial levels in active CD, and only in the lamina propria of the villi in normal mucosa. Our findings firstly demonstrated that gliadin was directly bound to tTG in duodenal mucosa of coeliacs and controls, and the ability of circulating tTG-autoantibodies to recognize and immunoprecipitate the tTG-gliadin complexes.

Adult↗
PubMed2003

Cytokine genotyping (TNF and IL-10) in patients with celiac disease and selective IgA deficiency.

OBJECTIVE: Selective IgA deficiency (IgAD) and celiac disease (CD) are frequently associated and share the ancestral haplotype human leukocyte antigen (HLA)-8.1, which is characterized by a peculiar cytokine profile. The aim of this study was to evaluate the role of tumor necrosis factor (TNF) and interleukin (IL)-10 alleles in CD and CD-IgAD. METHODS: The distribution of some biallelic polymorphisms of both cytokine promoters (-308G-->A and -863C-->A at TNF promoter sequence and -1082G-->A, -819C-->A, and -592C-->T at IL-10 promoter) were typed using biotilinated specific probes in 32 celiac patients, in 34 CD-IgAD patients, and in 96 healthy controls. RESULTS: In CD and CD-IgAD, the -308A allele was significantly more frequent than in controls, whereas no significant differences were observed for the biallelic polymorphisms at the -863 and for the three IL-10 promoter polymorphisms. The evaluation of combined TNF and IL-10 genotypes showed in CD-IgAD a significant reduction of -308G/-1082G homozygous subjects and both in CD and CD-IgAD groups an increase of 308AA/1082GG. Accordingly, CD-IgAD patients positive both for -308A TNF and -1082A IL-10 showed an increase of TNF-alpha and a reduction of IL-10 serum levels. CONCLUSIONS: Genetically determined increased production of TNF-alpha and reduction of IL-10 may be relevant for susceptibility to CD, mainly in IgAD, as the different allele expression at TNF and IL-10 loci seems to influence cytokine production profile.

Adult↗
PubMed2002

Coeliac disease.

In the last few decades, the comprehension of epidemiological, pathogenic and clinical aspects of coeliac disease has increasingly improved. Serological screening studies on the general population have shown that the true coeliac disease prevalence in Europe is higher than previously reported. It has become clear that tissue transglutaminase has a crucial role in the pathogenesis of coeliac disease pathogenesis, and there is evidence that substitution of deamidated amino acidic residues at a critical position along the gliadin sequence dramatically increases immunological activation. The toxicity of many gluten epitopes has been investigated, so far, but recent studies have indicated the region 57-75 of alpha gliadin as a possible candidate epitope in the pathogenesis of coeliac disease. However, the wide heterogeneity of gliadin and glutenin molecules complicate any attempts to identify the toxic epitope, and the fascinating idea to produce detoxified grains will represent a great challenge in the near future. From a clinical point of view, there is now evidence of a broad spectrum of gluten conditions. Extra-intestinal signs, i.e., alopecia, unexplained neurological disorders, cryptic hypertransaminasaemia, increased red cell width, frequently constitute the only clinical manifestation at the diagnosis.

Celiac Disease↗
PubMed2002

Clinical features of coeliac disease.

Aim of this review is to describe the extremely variable clinical presentation of coeliac disease. Moreover due to these varying manifestations, "coeliac literature" is characterised by a very rich terminology, which has not been unified, so far To help readers, not familiar with that terminology, we have given an explanation for the most common coeliac terms.

Celiac Disease↗
PubMed2002

Mechanisms of villous atrophy in autoimmune enteropathy and coeliac disease.

Since in coeliac disease mucosal flattening has been suggested to result from an increased enterocyte apoptosis triggered by Fas/Fas ligand system and perforin cytolytic granules, we looked for a similar mechanism in autoimmune enteropathy. Moreover, we tried to assess whether enterocyte autoantibodies, which are the hallmark of autoimmune enteropathy, may be involved in triggering enterocyte apoptosis in this condition. Immunohistochemical staining with anti-Fas, -FasL and -perforin MoAb, and TUNEL technique were applied on endoscopic duodenal biopsies of two autoimmune enteropathy patients, two untreated coeliac patients and two biopsied controls. Cytotoxicity assays were carried out by incubating peripheral blood mononuclear cells from a healthy subject (effectors) with enterocytes primed with patient or control sera (targets). In autoimmune enteropathy a large number of enterocytes were apoptotic, as in coeliac disease, whereas neither Fas/Fas ligand or perforin expressions were up-regulated. On the other hand, antibody-dependent cellular cytotoxicity assay revealed the ability of sera from patients with autoimmune enteropathy to mediate enterocyte death through apoptosis. These results point to enterocyte autoantibody-dependent cellular cytotoxicity as the prevalent mechanism of increased enterocyte apoptosis in autoimmune enteropathy but not in coeliac disease.

Antibody-Dependent Cell Cytotoxicity↗
PubMed2001

Mortality in patients with coeliac disease and their relatives: a cohort study.

BACKGROUND: Although previous studies have shown increased mortality in patients with coeliac disease and their relatives, no data are available in relation to different patterns of clinical presentation. We assessed mortality in patients with coeliac disease and their first-degree relatives. METHODS: We enrolled, in a prospective cohort study, 1072 adult patients with coeliac disease consecutively diagnosed in 11 gastroenterology units between 1962 and 1994, and their 3384 first-degree relatives. We compared the number of deaths up to 1998 with expected deaths and expressed the comparison as standardised mortality ratio (SMR) and relative survival ratio. FINDINGS: 53 coeliac patients died compared with 25.9 expected deaths (SMR 2.0 [95% CI 1.5-2.7]). A significant excess of mortality was evident during the first 3 years after diagnosis of coeliac disease and in patients who presented with malabsorption symptoms (2.5 [1.8-3.4]), but not in those diagnosed because of minor symptoms (1.1 [0.5-2.2]) or because of antibody screening (1.2 [0.1-7.0]). SMR increased with increasing delay in diagnosis and for patients with poor compliance with gluten-free diet. Non-Hodgkin lymphoma was the main cause of death. No excess of deaths was recorded in relatives with coeliac disease. INTERPRETATION: Prompt and strict dietary treatment decreases mortality in coeliac patients. Prospective studies are needed to clarify the progression of mild or symptomless coeliac disease and its relation to intestinal lymphoma.

Adult↗
PubMed2001

Intestinal permeability in Crohn's disease patients and their first degree relatives.

BACKGROUND: Family studies suggested that an altered intestinal permeability plays a role in the genesis of Crohn's disease. AIM: Aim of the present study was to investigate a possible genetic alteration of the mucosal barrier in Crohn's disease. SUBJECTS: 16 Crohn's disease patients and 26 of their cohabiting first degree relatives were studied. METHODS: To investigate intestinal permeability, Cellobiose/Mannitol test was administered to both groups. RESULTS: In the two groups, we found that the median intestinal permeability values were higher and statistically different from those obtained in 32 healthy control subjects as well as in five healthy control families. Six (37.5%) Crohn's disease patients and three (11.5%) of their first degree relatives showed increased individual intestinal permeability values. Intestinal permeability alteration in Crohn's disease patients was unrelated to sex, age, disease activity, localisation, duration, treatment schedule, as well as to serum anti-Saccharomyces cervisiae antibody positivity in a pilot study conducted in 7 Crohn's disease patients; anti-Saccharomyces cervisiae antibody values were negative in all 10 first degree relatives investigated. CONCLUSIONS: These findings demonstrate the increase in IP in 37% of the patients and in 11% of their relatives. More extensive investigation of the correlation between ASCA alterations and IP will be needed in both patients with Crohn's disease and their relatives.

Adult↗
PubMed2001

Small intestine bacterial overgrowth and metabolic bone disease.

Small intestine bacterial overgrowth is a malabsorption syndrome and, therefore, it may contribute to the occurrence of metabolic bone disease. However, studies that evaluate the magnitude of this problem and the potential underlying mechanisms are still needed. Fourteen patients with bacterial overgrowth and 22 comparable healthy volunteers took part in this study. All patients were affected by conditions known to predispose to bacterial overgrowth. Diagnosis was based on the following criteria: increased breath hydrogen levels in the fasting state and/or increased breath hydrogen excretion after the ingestion of 50 g of glucose solution, improvement after a 10-day course of antibiotic therapy of severity of symptoms and of H2 excretion parameters. Measurement of bone mineral density by dual-energy x-ray absorptiometry at lumbar spine and femoral level and evaluation of nutritional status were performed. Physical activity, sunlight exposure, and cigarette smoking were also evaluated. Patients showed lumbar and femoral bone mineral density values significantly lower than control group; also the prevalence of bone loss at both lumbar and femoral levels was higher in patient group than in healthy volunteers. Body mass index was significantly lower in patients than in healthy volunteers. Lumbar and femoral bone mineral density were significantly correlated and both correlated with body mass index and with duration of symptoms. No correlation between BMD values and physical activity, sunlight exposure, and cigarette smoking was evident. Our results show that small intestine bacterial overgrowth is an important cofactor in the development of metabolic bone disease. The severity of bone loss is related to poor nutritional status and duration of malabsorption symptoms.

Absorptiometry, Photon↗
PubMed2001

Apoptosis and peripheral blood lymphocyte depletion in coeliac disease.

In coeliac disease (CD) immunological abnormalities are not confined to the small bowel and it has been suggested that changes in peripheral blood lymphocytes (PBL), such as lymphopenia and increased T-cell activation, may predispose to malignant or autoimmune complications of this condition. In the light of the recent findings about the Fas-Fas ligand (FasL) system in regulating lymphocyte homeostasis, the aim of the present study was to investigate peripheral lymphocyte Fas-mediated apoptosis in CD to establish whether the homeostatic role of apoptosis in peripheral T-cell selection is maintained. Moreover, because a soluble form of Fas has been described to be functionally implicated in the Fas signalling system, suggesting a relationship between some disorders and soluble Fas function, we measured levels of soluble Fas in sera of coeliac patients and analysed the relationship between these levels and the proportions of apoptotic and Fas(+) PBL to further explore the function of the Fas-FasL pathway in this condition. Finally, we evaluated whether the increased prevalence of anticardiolipin antibodies, recently described in CD, could be related to PBL apoptosis in this condition. We demonstrated an increased apoptosis and higher levels of Fas and FasL expression in PBL isolated from untreated coeliac patients when compared to treated coeliac patients and controls. In addition, low levels of soluble Fas and a significant positive correlation between anticardiolipin antibodies and PBL apoptosis were found in untreated CD. Then, our results showed an increased susceptibility of PBL to undergo Fas-mediated apoptosis in active CD. This increased apoptosis could be responsible for both lymphopenia and immunogenic exposure of phospholipids with subsequent production of autoantibodies.

Adult↗
PubMed2001

Existence of a genetic risk factor on chromosome 5q in Italian coeliac disease families.

Coeliac disease (CD) is a malabsorptive disorder of the small intestine resulting from ingestion of gluten. The HLA risk factors involved in CD are well known but do not explain the whole genetic susceptibility. Several regions of potential linkage on chromosomes 3q, 5q, 10q, 11q, 15q and 19q have already been reported in the literature. These six regions were analyzed with the Maximum Lod Score method on a dense set of markers. A new sample of 89 Italian sibpairs was available for study. There was no evidence for linkage for any of the regions tested, except for chromosome 5q. For this region, our data, as well as a sample of 93 sibpairs from our first genome screen (Greco et al. 1998), are compatible with the presence of a risk factor for CD with a moderate effect.

Celiac Disease↗
PubMed2001

Lactose malabsorption and intolerance in the elderly.

BACKGROUND: Lactase activity declines with age in rats, but it is not clear whether this model is also shared by humans. Few studies have evaluated lactose intolerance and malabsorption in the elderly and no definite conclusions can be drawn. The aim of our study was therefore to verify the impact of age on lactose intolerance and malabsorption. METHODS: Eighty-four healthy subjects took part in the study. Thirty-three were <65 years, 17 were between 65 and 74 years and 34 were >74 years. All the subjects underwent a preliminary evaluation of intestinal gas production capacity and oro-cecal transit time by H2/CH4 breath test after lactulose. After a 3-day period, an H2/CH4 breath test after lactose was performed. The occurrence of intolerance symptoms during the test and in the 24 h after the test was recorded. RESULTS: Breath H2 and CH4 excretion parameters at fasting and after lactulose did not differ between the three groups. Cumulative breath H2 excretion after lactose was higher in subjects >74 years than in subjects <65 years and in subjects aged 65-74 years, while no difference was found between the latter two groups. In subjects >74 years, the prevalence of lactose malabsorption was higher than in the other two groups, while no significant difference was observed between subjects <65 years and subjects aged 65-74 years. Within the malabsorber subjects, the prevalence of lactose intolerance was higher in subjects <65 years than in those aged 65-74 years and in those aged >74 years. No significant difference was found between the latter two groups. No difference was found between the three groups in terms of daily calcium intake and a significant negative correlation between symptom score and daily calcium intake was only found in the group of subjects aged <65 years. CONCLUSIONS: As age increases, the prevalence of lactose malabsorption shows an increase while the prevalence of intolerance symptoms among malabsorbers shows a decrease. Accordingly, daily calcium intake was similar among the adults and elderly studied.

Aged↗
PubMed2001

Endomysial and tissue transglutaminase antibodies in coeliac sera: a comparison not influenced by previous serological testing.

BACKGROUND: Since transglutaminase was shown to be the antigen of endomysial antibodies (EMA), it has become possible to screen for coeliac disease (CD) with an enzyme-linked immunosorbent assay (ELISA) for transglutaminase antibodies (TTA). However, it is possible that sera used to show that TTA are found in CD were obtained from patients diagnosed because they were positive for EMA. So, a comparison between EMA and TTA has not been possible so far. METHODS: EMA and TTA were tested in sera from 52 controls and 56 untreated CD patients, who had not undergone serological testing. Samples were tested for TTA with an ELISA kit. Based on the ROC analysis of a pilot study, results were considered as either positive, borderline, or negative. EMA were analysed by indirect immunofluorescence on monkey oesophagus. RESULTS: Forty-nine CD patients were positive for TTA, six borderline, one negative. Forty-four controls were negative, seven borderline, one positive. If we consider borderline results to be positive, sensitivity is 98.2% and specificity 84.6%. EMA were positive in 53 CD patients; the controls were all negative. Performing TTA in all cases and EMA only in the few TTA borderline cases (12.0%) would have a sensitivity of 94.6% and a specificity of 98.1%. CONCLUSIONS: This study is the first to compare TTA with EMA. Due to 100% specificity and high sensitivity, EMA seems to be the most accurate coeliac antibody. Conversely, TTA offer advantages in terms of sensitivity and simplicity. A satisfactory strategy is to use TTA first and then EMA to confirm the borderline results.

Adult↗