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1.
Phys Rev Lett ; 121(8): 081307, 2018 Aug 24.
Article in English | MEDLINE | ID: mdl-30192596

ABSTRACT

We present the results of a search for dark matter weakly interacting massive particles (WIMPs) in the mass range below 20 GeV/c^{2} using a target of low-radioactivity argon with a 6786.0 kg d exposure. The data were obtained using the DarkSide-50 apparatus at Laboratori Nazionali del Gran Sasso. The analysis is based on the ionization signal, for which the DarkSide-50 time projection chamber is fully efficient at 0.1 keVee. The observed rate in the detector at 0.5 keVee is about 1.5 event/keVee/kg/d and is almost entirely accounted for by known background sources. We obtain a 90% C.L. exclusion limit above 1.8 GeV/c^{2} for the spin-independent cross section of dark matter WIMPs on nucleons, extending the exclusion region for dark matter below previous limits in the range 1.8-6 GeV/c^{2}.

2.
Phys Rev Lett ; 121(11): 111303, 2018 Sep 14.
Article in English | MEDLINE | ID: mdl-30265123

ABSTRACT

We present new constraints on sub-GeV dark-matter particles scattering off electrons based on 6780.0 kg d of data collected with the DarkSide-50 dual-phase argon time projection chamber. This analysis uses electroluminescence signals due to ionized electrons extracted from the liquid argon target. The detector has a very high trigger probability for these signals, allowing for an analysis threshold of three extracted electrons, or approximately 0.05 keVee. We calculate the expected recoil spectra for dark matter-electron scattering in argon and, under the assumption of momentum-independent scattering, improve upon existing limits from XENON10 for dark-matter particles with masses between 30 and 100 MeV/c^{2}.

3.
Mycopathologia ; 182(9-10): 839-845, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28555254

ABSTRACT

In immunocompromised patients, Aspergillus infections are important causes of morbidity and mortality. We describe a patient with cryoglobulinemic vasculitis who developed disseminated invasive aspergillosis with thyrotoxicosis caused by Aspergillus fumigatus. The diagnosis was based upon radiological, microbiological and pathological findings. The patient was treated successfully with voriconazole and caspofungin treatment followed by total thyroidectomy. We provide an overview of published reports on Aspergillus thyroiditis with an emphasis on therapeutic approaches.


Subject(s)
Antifungal Agents/administration & dosage , Aspergillosis/drug therapy , Aspergillosis/surgery , Drug Therapy, Combination/methods , Thyroidectomy , Thyroiditis, Suppurative/drug therapy , Thyroiditis, Suppurative/surgery , Aged , Aspergillosis/diagnosis , Aspergillus fumigatus/isolation & purification , Caspofungin , Cryoglobulinemia/complications , Cryoglobulinemia/diagnosis , Echinocandins/administration & dosage , Humans , Immunocompromised Host , Invasive Fungal Infections/complications , Invasive Fungal Infections/diagnosis , Invasive Fungal Infections/drug therapy , Invasive Fungal Infections/surgery , Lipopeptides/administration & dosage , Male , Thyroiditis, Suppurative/complications , Thyroiditis, Suppurative/diagnosis , Thyrotoxicosis/complications , Thyrotoxicosis/diagnosis , Thyrotoxicosis/surgery , Treatment Outcome , Voriconazole/administration & dosage
4.
Cell Signal ; 119: 111175, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38631405

ABSTRACT

G protein-coupled receptors (GPCRs) are a family of cell membrane receptors that couple and activate heterotrimeric G proteins and their associated intracellular signalling processes after ligand binding. Although the carboxyl terminal of the receptors is essential for this action, it can also serve as a docking site for regulatory proteins such as the ß-arrestins. Prokineticin receptors (PKR1 and PKR2) are a new class of GPCRs that are able to activate different classes of G proteins and form complexes with ß-arrestins after activation by the endogenous agonists PK2. The aim of this work was to define the molecular determinants within PKR2 that are required for ß-arrestin-2 binding and to investigate the role of ß-arrestin-2 in the signalling pathways induced by PKR2 activation. Our data show that PKR2 binds constitutively to ß-arrestin-2 and that this process occurs through the core region of the receptor without being affected by the carboxy-terminal region. Indeed, a PKR2 mutant lacking the carboxy-terminal amino acids retains the ability to bind constitutively to ß-arrestin-2, whereas a mutant lacking the third intracellular loop does not. Overall, our data suggest that the C-terminus of PKR2 is critical for the stability of the ß-arrestin-2-receptor complex in the presence of PK2 ligand. This leads to the ß-arrestin-2 conformational change required to initiate intracellular signalling that ultimately leads to ERK phosphorylation and activation.


Subject(s)
Protein Binding , Receptors, G-Protein-Coupled , beta-Arrestin 2 , beta-Arrestin 2/metabolism , Humans , HEK293 Cells , Receptors, G-Protein-Coupled/metabolism , Animals , Receptors, Peptide/metabolism , Receptors, Peptide/genetics , Signal Transduction , Binding Sites , Phosphorylation , Receptors, Gastrointestinal Hormone/metabolism , Receptors, Gastrointestinal Hormone/genetics
5.
J Endocrinol Invest ; 36(11): 1083-9, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24081139

ABSTRACT

AIMS: to confirm the diagnosis of 21-hydroxylase deficiency (21-OHD) by the analysis of CYP21A2 gene in infants with clinical and/or biochemical features of 21-OHD in order to clarify which patients to submit to genetic analysis; to analyze the genotype-phenotype concordance in these infants. SUBJECTS AND METHODS: We studied 25 children with clinical and/or biochemical features of 21-OHD. All of them and their parents were submitted to genetic analysis of CYP21A2. Patients were classified in 3 groups according to mutations' severity: severe (group A), moderate (group B) or mild (group C). RESULTS: CYP21A2 gene mutations were found in 17 children. Whereas all infants of groups A and B presented a classical form of 21- OHD, children of group C had a non-classical form of 21-OHD. Four infants resulted heterozygotes and 4 children were wildtype. A girl clinically presenting a non-classical form of 21-OHD resulted compound heterozygote with one of the mutations not described in literature (R25W) and whose residual enzymatic activity is not already known. All affected children presented a 17-OHP level after ACTH stimulation greater than 100 nmol/l. We found an optimal concordance between 17-OHP levels after ACTH test and genotype. CONCLUSIONS: CYP21A2 analysis permitted to confirm the diagnosis of 21-OHD in 68% of our children. To improve this percentage we suggest to perform the CYP21A2 analysis only when 17-OHP after ACTH test is greater than 100 nmol/l. Moreover, we found an optimal genotype-phenotype concordance in the 21-OHD patients.


Subject(s)
Adrenal Hyperplasia, Congenital/genetics , Steroid 21-Hydroxylase/genetics , 17-alpha-Hydroxyprogesterone/blood , Adrenocorticotropic Hormone , Child , Female , Genetic Association Studies , Humans , Infant , Male , Retrospective Studies
6.
J Endocrinol Invest ; 34(9): e265-7, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21666413

ABSTRACT

BACKGROUND: Whereas no clear relationship has been observed between varicocelectomy and serum inhibin B levels in men, in adolescents comparison between inhibin B levels before and after varicocelectomy is lacking. AIM: To evaluate the effect of varicocele surgical treatment on inhibin B levels in adolescents at the beginning of puberty compared to a group of healthy adolescents. SUBJECTS AND METHODS: We studied 28 adolescents in Tanner 2 pubertal stage with a grade III left-sided varicocele (patients) compared to 13 age and pubertal stage-matched healthy adolescents (controls). All patients underwent blood tests to determine serum inhibin B levels before and 6 months after varicocelectomy by Palomo procedure. For comparison we investigated inhibin B levels in controls and repeated this test 6 months later. Testicular ultrasound was performed for patients only. RESULTS: Baseline inhibin B concentrations of patients and controls were 109.90 ± 40.26 and 109.33 ± 38.34 pg/ml, respectively. No significant changes were observed in patients' inhibin B concentrations after varicocelectomy (116.00 ± 42.65 pg/ml), or in controls during the 6 months' follow-up (99.12 ± 30.09 pg/ml). Doppler examination after treatment shows a complete resolution of varicocele in all the patients without alterations in testicular parenchyma. CONCLUSIONS: Varicocelectomy performed on adolescents at T2 pubertal stage might be useful to avoid alteration in inhibin B production and consequently in testicular function. Further studies are necessary to confirm the prognostic value of inhibin B levels and the benefit of early varicocelectomy in preserving the fertility of these adolescents.


Subject(s)
Inhibins/blood , Varicocele/surgery , Adolescent , Child , Humans , Male , Testis/anatomy & histology , Testis/diagnostic imaging , Testis/physiology , Testis/surgery , Ultrasonography
7.
Mol Genet Metab Rep ; 24: 100632, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32793418

ABSTRACT

INTRODUCTION: Mitochondrial fatty acid oxidation disorders (FAODs) are a heterogeneous group of hereditary autosomal recessive diseases included in newborn screening (NBS) program in Italy. The aim of this study was to analyse FAODs cases, identified either clinically or by NBS,for clinical and genetic characterization and to evaluate a five years' experience of NBS, in the attempt to figure out the complexity of genotype-phenotype correlation and to confirm the clinical impact of NBS in our centre experience. MATERIALS AND METHODS: We analysed FAODs patients diagnosed either by NBS or clinically, followed since February 2014 to April 2019 at the Regional Screening Centre and Inherited Metabolic Diseases Unit of Verona. Diagnosis was confirmed by plasma acylcarnitines, urinary organic acids, enzymatic and genetic testing. For not clear genotypes due to the presence of variants of uncertain significance, in silico predictive tools have been used as well as enzymatic activity assays. Patients underwent clinical, nutritional and biochemical follow up. RESULTS: We diagnosed 30 patients with FAODs. 20 by NBS: 3 CUD, 6 SCADD, 5 MCADD, 4 VLCADD, 2 MADD. Overall incidence of FAODs diagnosed by NBS was 1:4316 newborns. No one reported complications during the follow up period. 10 patients were diagnosed clinically: 2 CUD, 2 CPT2D, 1 VLCADD, 5 MADD. Mean age at diagnosis was 29.3 years. Within this group, complications or symptoms were reported at diagnosis, but not during follow-up. 12 mutations not previously reported in literature were found, all predicted as pathogenic or likely pathogenic. DISCUSSION AND CONCLUSIONS: Our study highlighted the great phenotypic variability and molecular heterogeneity of FAODs and confirmed the importance of a tailored follow up and treatment. Despite the short duration of follow up, early identification by NBS prevented diseases related complications and resulted in normal growth and psycho-motor development as well.

8.
JIMD Rep ; 35: 29-31, 2017.
Article in English | MEDLINE | ID: mdl-27858373

ABSTRACT

Cobalamin A deficiency (cblA) is an inherited disorder of intracellular cobalamin metabolism, caused by impaired 5'-deoxy-adenosylcobalamin (AdoCbl) synthesis. Hydroxocobalamin (OHCbl) is the cornerstone of cblA treatment because vitamin B12 may completely restore AdoCbl deficiency. Parenteral administration, intravenous, subcutaneous or intramuscular, is generally required to achieve effect. Daily injections represent a problem for the parents and the caregivers, and this may lead to poor compliance and scarce adherence to the long-term treatment.Our report describes the case of a patient with cblA deficiency, diagnosed by newborn screening, positively treated with daily OHCbl administration by a subcutaneous injection port (i-port advanceTM). After the insertion of the device, we checked methylmalonic acid (MMA) levels weekly for the first month and then monthly. MMA level remained always in the normal range.To date, placement of a subcutaneous catheter to minimize the pain related to parenteral vitamin B12 punctures has been described only in a patient with deficiency of the enzyme methylmalonyl-CoA mutase (MUT). No other experiences are described in the literature.Our case shows that OHCbl administration using a subcutaneous catheter is safe and effective even in patients with cblA deficiency. The use of subcutaneous devices may reduce difficulties in providing parenteral daily injections which is the main reason discouraging physicians and families to use such an invasive treatment. Moreover, our experience may be translated to other inherited metabolic disorders, such as cobalamin C (cblC) disease, which may require daily parenteral drug administration.

9.
Biochim Biophys Acta ; 1453(1): 152-60, 1999 Jan 06.
Article in English | MEDLINE | ID: mdl-9989255

ABSTRACT

Coeliac disease (CD) is an inflammatory disorder of the upper small intestine in which gluten acts as an essential factor in its pathogenesis. Although it is generally accepted that cereal protein activation of the immune system is involved in CD progression, a non-immunomediated cytotoxic activity of gliadin-derived peptides on the jejunal/duodenal tract cannot be excluded. In this work, considering that (a) little has been reported about the intracellular metabolic events associated with gliadin toxicity, and (b) an important role for free radicals in a number of gastrointestinal disease has been demonstrated, we investigated the in vitro effects of gliadin-derived peptides on redox metabolism of Caco-2 intestinal cells during a kinetic study in which cells were exposed to peptic-tryptic digest of bread wheat up to 48 h. We found that the antiproliferative effects displayed by gliadin exposure was associated with intracellular oxidative imbalance, characterised by an increased presence of lipid peroxides, an augmented oxidised (GSSG)/reduced (GSH) glutathione ratio and a loss in protein-bound sulfhydryl groups. Significant structural perturbations of the cell plasma membrane were also detected. Additional experiments performed by using the specific GSH-depleting agent buthionine sulfoximine provide evidence that the extent of gliadin-induced cell growth arrest critically depends upon the 'basal' redox profile of the enterocytes. On the whole, these findings seem to suggest that, besides the adoption of a strictly gluten-free diet, the possibility for an adjuvant therapy with antioxidants may be considered for CD patients.


Subject(s)
Gliadin/toxicity , Oxidative Stress , Peptides/toxicity , Triticum/toxicity , Caco-2 Cells , Celiac Disease/etiology , Celiac Disease/therapy , Cell Division/drug effects , Cell Membrane/drug effects , Gliadin/chemistry , Glutathione/analysis , Glutathione Disulfide/analysis , Humans , Pepsin A , Trypsin
10.
Am J Clin Nutr ; 74(1): 137-40, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11451729

ABSTRACT

BACKGROUND: It was recently shown that antiendomysial antibodies (EMAs), which are highly sensitive and specific for celiac disease, are produced by intestinal mucosa. Furthermore, EMAs were detected previously in supernatant fluid from cultured duodenal mucosa specimens collected from untreated celiac disease patients and in culture media of biopsy specimens collected from treated celiac disease patients after an in vitro challenge with gliadin. Moreover, it was recently shown in vivo that oats are not toxic to celiac disease patients, suggesting the safety of oats in a gluten free-diet. OBJECTIVE: The objective was to better define the controversial role of oats in celiac disease to determine whether oats can be safely included in a gluten-free diet. DESIGN: We used an in vitro model to test whether oats induce EMA production in supernatant fluid from cultured duodenal mucosa specimens collected from 13 treated celiac disease patients. The biopsy specimens were cultured with and without peptic-tryptic digest (PT) of gliadin and avenin (from oats) and in medium alone. Samples from 5 of the 13 patients were cultured with the C fraction of PT-avenin. Indirect immunofluorescence was used to detect EMAs. RESULTS: EMAs were detected in specimens from all 13 patients after the challenge with gliadin but not after culture in medium alone. By contrast, no EMAs were detected in any of the specimens cultured with PT-avenin and its C fraction. CONCLUSIONS: Because the in vitro challenge with PT-avenin and its C fraction did not induce EMA production in treated celiac disease patients, it appears that oats have no harmful effect on celiac disease. Therefore, oats can be safely included in a gluten-free diet.


Subject(s)
Avena/adverse effects , Celiac Disease/immunology , Duodenum/immunology , Intestinal Mucosa/immunology , Adolescent , Adult , Antibody Formation , Biopsy , Case-Control Studies , Celiac Disease/diet therapy , Culture Media , Culture Techniques , Female , Fluorescent Antibody Technique, Indirect , Gliadin/immunology , Glutens , Humans , Male , Middle Aged , Plant Proteins/immunology , Prolamins , Safety
11.
Atherosclerosis ; 32(2): 121-8, 1979 Feb.
Article in English | MEDLINE | ID: mdl-222302

ABSTRACT

In 13 hypercholesterolemic children, re-screened for serum cholesterol after a 1-year interval, hypercholesterolemia was confirmed in only 61.5% of the cases. A tentative explanation seems to be the statistical principle of regression towards the mean. The lipid--lipoprotein analysis showed that serum and LDL cholesterol concentrations in the 13 hypercholesterolemic children and their parents were significantly higher compared to controls (children and parents). At re-screening, hyper-LDL cholesterolemia was present in only 8 of the 13 children (61.5%); 4 cases exhibited hyper-HDL cholesterolemia (30.7%). The high prevalence of the parents repeating the lipoprotein abnormality and the electrophoretic pattern found in the propositi (children) confirms the familial aggregation of the hypercholesterolemic states (hyper-LDL and hyper-HDL cholesterolemia). In conclusion the results of our study stress the importance of determining the lipid--lipoprotein composition, rather then merely evaluating total serum cholesterol in order to make a correct diagnosis of the hypercholesterolemic state. It should also be emphasized that the lipoprotein disturbances and their familial aggregation may be detected early in childhood, suggesting that the familial screening for risk factors of atherosclerosis should be done at pediatric age.


Subject(s)
Cholesterol/blood , Hypercholesterolemia/blood , Lipoproteins/blood , Triglycerides/blood , Adolescent , Adult , Age Factors , Child , Female , Humans , Hypercholesterolemia/diagnosis , Hypercholesterolemia/genetics , Lipoproteins, HDL/blood , Lipoproteins, LDL/blood , Lipoproteins, VLDL/blood , Male , Middle Aged , Phenotype
12.
Am J Cardiol ; 80(1): 88-90, 1997 Jul 01.
Article in English | MEDLINE | ID: mdl-9205029

ABSTRACT

Cardiac troponin I, a specific and sensitive marker of myocardial damage, was detected in the blood of 6 of 26 patients studied in our Heart Failure Clinic. In these patients functional class, ventricular function, and prognosis were significantly worse than in those without detectable troponin I. This study suggests that troponin I may represent the biochemical marker of myocardial damage occurring in severe heart failure.


Subject(s)
Heart Failure/blood , Troponin I/blood , Aged , Biomarkers/blood , Chi-Square Distribution , Female , Humans , Male , Middle Aged , Prospective Studies , Sensitivity and Specificity , Statistics, Nonparametric
13.
Am J Cardiol ; 83(1): 120-2, A9, 1999 Jan 01.
Article in English | MEDLINE | ID: mdl-10073799

ABSTRACT

Eighty-five consecutive patients with idiopathic dilated cardiomyopathy were categorized according to the presence (biventricular dysfunction) or absence (left ventricular [LV] dysfunction) of reduced right ventricular ejection fraction (<35%) along with reduced LV ejection fraction (<50%). Compared with the 36 patients with LV dysfunction, the 49 patients with biventricular dysfunction had significantly worse New York Heart Association functional class (2.7+/-0.6 vs 1.9+/-0.5; p <0.001), LV ejection fraction (26+/-10% vs 34+/-8%; p <0.0001), and outcome (transplant-free survival, 55% vs 89%; p <0.001). Thus, dilated cardiomyopathy is frequently characterized by biventricular involvement, which identifies a more severe disease and a worse long-term prognosis.


Subject(s)
Cardiomyopathy, Dilated/complications , Cardiomyopathy, Dilated/physiopathology , Ventricular Dysfunction, Left/etiology , Ventricular Dysfunction, Right/etiology , Ventricular Function, Left , Ventricular Function, Right , Adult , Female , Humans , Linear Models , Male , Middle Aged , Prognosis , Pulmonary Wedge Pressure , Severity of Illness Index , Stroke Volume , Ventricular Dysfunction, Left/physiopathology , Ventricular Dysfunction, Right/physiopathology
14.
Am J Cardiol ; 81(6): 790-2, 1998 Mar 15.
Article in English | MEDLINE | ID: mdl-9527097

ABSTRACT

We examined 40 patients with ventricular tachycardia (VT) and no evidence of heart disease, and found a 50% prevalence of ventricular late potentials (VLPs) on the signal-averaged electrocardiogram. This finding was associated with a significantly higher content of fibrous tissue on endomyocardial biopsy and a lower right ventricular ejection fraction. Thus, VLPs are frequently found in idiopathic VT, are a marker for subclinical anatomic and functional abnormalities of the right ventricle, and may be associated with a worse outcome.


Subject(s)
Endomyocardial Fibrosis/physiopathology , Heart Conduction System , Tachycardia, Ventricular/physiopathology , Ventricular Function, Left , Ventricular Function, Right , Adult , Electrocardiography , Endomyocardial Fibrosis/complications , Female , Humans , Male , Middle Aged , Signal Processing, Computer-Assisted , Tachycardia, Ventricular/complications
15.
Chest ; 98(2): 505-7, 1990 Aug.
Article in English | MEDLINE | ID: mdl-2376192

ABSTRACT

A case of coronary occlusion occurred seven days after successful percutaneous transluminal coronary angioplasty. The acute complication occurred shortly after a negative exercise stress test and was resolved with intracoronary urokinase.


Subject(s)
Angioplasty, Balloon, Coronary , Coronary Disease/etiology , Exercise Test/adverse effects , Thrombolytic Therapy , Urokinase-Type Plasminogen Activator/therapeutic use , Coronary Angiography , Coronary Disease/drug therapy , Humans , Male , Middle Aged , Time Factors
17.
J Hum Hypertens ; 6(3): 215-20, 1992 Jun.
Article in English | MEDLINE | ID: mdl-1629892

ABSTRACT

A random sample of 2,854 subjects aged 35-64 was examined in the town of Vicenza (Italy) as part of the 'Hypertension Management Audit Project'. Pearson's correlation coefficient and multivariate analysis considering systolic and diastolic blood pressure, age and body mass index (BMI) were performed. SBP was more closely correlated with age than DBP. BMI correlated with both SBP and DBP, but very little with age. Fifty-seven percent of the men had a BMI of 25.5 or more and 49% of the women had a BMI of 24.5 or more. The quality of BP control in the treated patients was worse in the overweight when compared with the lean patients, although overweight and lean patients are treated with the same frequency.


Subject(s)
Antihypertensive Agents/therapeutic use , Community Health Services , Health Surveys , Hypertension/complications , Obesity/complications , Adult , Blood Pressure , Body Mass Index , Female , Humans , Hypertension/drug therapy , Hypertension/physiopathology , Male , Middle Aged , Obesity/pathology
18.
Toxicology ; 132(2-3): 99-110, 1999 Feb 15.
Article in English | MEDLINE | ID: mdl-10433373

ABSTRACT

Experience gained through investigations on coeliac disease makes it possible to propose a screening method based on agglutination of isolated K562(S) cells to evaluate the occurrence in food protein of amino acid sequences that are able to adversely affect coeliac and related gluten-sensitive patients. The method consists of in vitro sequential peptic and tryptic digestion of food protein fractions under optimal pH, temperature and time conditions and in vitro incubation of the digest with K562(S) cells; the toxic potential is detected as an agglutination of K 562 (S) cells after a short incubation. Other in vitro test systems, including atrophic coeliac intestinal mucosa and rat fetal intestine, can be used to confirm the results obtained with the isolated cells. A fractionation step of the proteolytic digest on a sepharose-mannan column before exposure of the in vitro systems to the separated peptide fractions adds to the sensitivity of the method. This screening method is not only very useful to investigate action mechanisms in coeliac disease, but also to assess the safety of genetically-modified plant foods and novel foods for gluten-sensitive patients.


Subject(s)
Celiac Disease/metabolism , Edible Grain/adverse effects , Gliadin/adverse effects , Glutens/adverse effects , Plant Proteins/adverse effects , Amino Acid Sequence , Animals , Humans , Molecular Sequence Data , Prolamins , Rats
19.
Toxicology ; 120(3): 207-13, 1997 Jul 11.
Article in English | MEDLINE | ID: mdl-9217307

ABSTRACT

A peptide (m.w. 1157.5 Da) able to prevent the agglutination of K562(S) cells induced by the peptic-tryptic prolamine digests of the cereals toxic in coeliac disease (i.e. bread wheat, rye, barley and oat) was characterized as one of the components of the peptic-tryptic digest of durum wheat gliadin. This peptide was synthesized in a high degree of purity with the solid phase method with the Applied Biosystem 431A. An amino acid sequence was identified in the 1157.5 Da peptide as being related to the largest common sequences previously detected in a series of bread wheat toxic peptides by other authors.


Subject(s)
Agglutination/drug effects , Celiac Disease/chemically induced , Gliadin/chemistry , Leukemia, Myeloid/drug therapy , Oligopeptides/pharmacology , Celiac Disease/prevention & control , Cell Adhesion/drug effects , Chromatography, Affinity , Humans , Leukemia, Myeloid/pathology , Molecular Sequence Data , Oligopeptides/chemical synthesis , Oligopeptides/isolation & purification , Plant Proteins/toxicity , Prolamins , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Triticum , Tumor Cells, Cultured/pathology
20.
Toxicology ; 145(1): 63-71, 2000 Apr 07.
Article in English | MEDLINE | ID: mdl-10771132

ABSTRACT

Recent experimental evidence suggests that enterocyte apoptosis is greater than hitherto assumed and may be responsible for villous atrophy in coeliac disease. We have previously demonstrated that a small peptide (M.W. 1157.5 Da), identified as the sequence H(2)N-gln-gln-pro-gln-asp-ala-val-gln-pro-phe-COOH from durum wheat gliadin, is able to prevent K 562 (S) cell agglutination induced by the peptic-tryptic digests (PT) of prolamin fractions from the cereals which are not tolerated in coeliac disease (i.e. bread wheat, rye, barley and possibly oats), and toxic A-gliadin peptides in coeliac disease. In the present study we have investigated the effects of the bread wheat gliadin digest (PT) on apoptosis of Caco-2 cells and whether the '1157.5' Da peptide may in any way interfere with them. We evaluated both earlier biochemical and later morphological nuclear apoptotic events in the human colon adenocarcinoma cell line Caco-2. After 48 h exposure to the PT gliadin digest and the '1157.5' Da peptide, apoptosis was detected both for the early-stage apoptotic cells (adherent cells) and the late-stage apoptotic ones (detached cells which were floating in the culture medium). Exposure to the PT gliadin digest resulted in a high percentage of adherent cells that underwent cell death by apoptosis (about 30%), independent of the concentration range used; while the presence in the culture medium of peptide '1157.5' Da determined complete inhibition of cell death. On the other hand, morphological nuclear modifications observed in the floating cells showed a difference in the rate of the apoptosis dependent on the PT concentration, with partial protection in the presence of the peptide. These findings show an action of bread wheat gliadin peptides leading to cell death by apoptosis in the Caco-2 cell line and that the '1157.5' Da peptide is capable of preventing such an effect.


Subject(s)
Apoptosis/drug effects , Celiac Disease/etiology , Gliadin/toxicity , Intestines/drug effects , Caco-2 Cells , Celiac Disease/pathology , Humans , Intestines/pathology
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