PHK from phenol hydroxylase of Pseudomonas sp. OX1. Insight into the role of an accessory protein in bacterial multicomponent monooxygenases

Bacterial multicomponent monooxygenases (BMMs) are members of a wide family of diiron enzymes that use molecular oxygen to hydroxylate a variety of aromatic compounds. The presence of genes encoding for accessory proteins not involved in catalysis and whose role is still elusive, is a common feature of the gene clusters of several BMMs, including phenol hydroxylases and several soluble methane monooxygenases. In this study we have expressed, purified, and partially characterized the accessory component PHK of the phenol hydroxylase from Pseudomonas sp. OX1, a bacterium able to degrade several aromatic compounds. The phenol hydroxylase (ph) gene cluster was expressed in Escherichia coli/JM109 cells in the absence and in the presence of the phk gene. The presence of the phk gene lead to an increase in the hydroxylase activity of whole recombinant cells with phenol. PHK was assessed for its ability to interact with the active hydroxylase complex. Our results show that PHK is neither involved in the catalytic activity of the phenol hydroxylase complex nor required for the assembly of apo-hydroxylase. Our results suggest instead that this component may be responsible for enhancing iron incorporation into the active site of the apo-hydroxylase

Diagnosing and Treating Food Allergy

t Food allergy (FA) is defined as an abnormal immunological reaction to food proteins. Over 90 % of FAs in childhood are caused by eight foods: cow’s milk, hen’s egg, soy, peanuts, tree nuts, wheat, fish and shellfish. The diagnostic work up for a child with suspected FA includes detailed medical history, physical examination, FA screening tests and response to elimination diet and to oral food challenge. Sometimes additional diagnostic tools to explore intestinal damage and function could be adopted. Currently, the only treatment for FA relies on strict elimination diets supervised by the nutritionist. Main new therapeutic strategies for FA include allergen-specific (oral, sublingual, epicutaneous, subcutaneous immunotherapy and heat treatment of food) and nonallergen-specific therapies (humanized monoclonal antibodies, anti-IgE and anti-IL5, probiotics). An incorrect diagnosis is likely to result in unnecessary dietary restrictions, which, if prolonged, may adversely affect the child’s nutritional status and growt

Tolerance to a new free amino acid-based formula in children with IgE or non-IgE-mediated cow's milk allergy: a randomized controlled clinical trial.

BACKGROUND: Amino acid-based formulas (Aaf) are increasingly used in children with cow's milk allergy (CMA). To be labeled hypoallergenic these formulas must demonstrate in clinical studies that they don't provoke reactions in 90% of subjects with confirmed CMA with 95% confidence when given in prospective randomized, double-blind, placebo-controlled challenge (DBPCFC) trials. The majority of available safety data on Aaf derived from patients with IgE-mediated CMA. Considering substantial differences in the immunologic mechanism and clinical presentation of non-IgE-mediated CMA it's important to investigate the hypoallergenicity of these formulas also in these patients. We prospectively assessed the tolerance to a new commercially available Aaf in children affected by IgE- or non-IgE-mediated CMA. METHODS:Consecutive patients affected by IgE- or non-IgE-mediated CMA, aged ≤ 4 years, were enrolled. DBPCFC was carried out with increasing doses of the new Aaf (Sineall, Humana, Milan, Italy), using validated Aaf as placebo. Faecal concentrations of calprotectin (FC) and eosinophilic cationic protein (ECP) were monitored. RESULTS:Sixty patients (44 male, 73.3%, median age 37, 95%CI 34.5-39.6 months, IgE-mediated CMA 29, 48.3%) were enrolled. At the diagnosis clinical symptoms were gastrointestinal (46.6%), cutaneous (36.6%), respiratory (23.3%), and systemic (10.0%). After DBPCFC with the new Aaf, no patient presented early or delayed clinical reactions. Faecal concentration of calprotectin and of ECP remained stable after the exposure to the new Aaf. CONCLUSIONS:The new Aaf is well tolerated in children with IgE- or non-IgE-mediated CMA, and it could be used as a safe dietotherapy regimen for children with this condition. TRIAL REGISTRATION:The trial was registered in the ClinicalTrials.gov Protocol Registration System (ID number: NCT01622426)

Tolerance to a new free amino acid-based formula in children with IgE or non-IgE-mediated cow's milk allergy: a randomized controlled clinical trial.

BACKGROUND: Amino acid-based formulas (Aaf) are increasingly used in children with cow's milk allergy (CMA). To be labeled hypoallergenic these formulas must demonstrate in clinical studies that they don't provoke reactions in 90% of subjects with confirmed CMA with 95% confidence when given in prospective randomized, double-blind, placebo-controlled challenge (DBPCFC) trials. The majority of available safety data on Aaf derived from patients with IgE-mediated CMA. Considering substantial differences in the immunologic mechanism and clinical presentation of non-IgE-mediated CMA it's important to investigate the hypoallergenicity of these formulas also in these patients. We prospectively assessed the tolerance to a new commercially available Aaf in children affected by IgE- or non-IgE-mediated CMA. METHODS:Consecutive patients affected by IgE- or non-IgE-mediated CMA, aged ≤ 4 years, were enrolled. DBPCFC was carried out with increasing doses of the new Aaf (Sineall, Humana, Milan, Italy), using validated Aaf as placebo. Faecal concentrations of calprotectin (FC) and eosinophilic cationic protein (ECP) were monitored. RESULTS:Sixty patients (44 male, 73.3%, median age 37, 95%CI 34.5-39.6 months, IgE-mediated CMA 29, 48.3%) were enrolled. At the diagnosis clinical symptoms were gastrointestinal (46.6%), cutaneous (36.6%), respiratory (23.3%), and systemic (10.0%). After DBPCFC with the new Aaf, no patient presented early or delayed clinical reactions. Faecal concentration of calprotectin and of ECP remained stable after the exposure to the new Aaf. CONCLUSIONS:The new Aaf is well tolerated in children with IgE- or non-IgE-mediated CMA, and it could be used as a safe dietotherapy regimen for children with this condition. TRIAL REGISTRATION:The trial was registered in the ClinicalTrials.gov Protocol Registration System (ID number: NCT01622426)

Fine-needle aspiration biopsy and flow cytometry immunophenotyping of lymphoid and myeloproliferative disorders of the spleen.

BACKGROUND: Flow cytometry (FC) is a useful adjunct to fine-needle aspiration biopsy (FNAB) in the evaluation of lymphoproliferative disorders. The application of FC to FNAB of the spleen (sFNAB) is reported. METHODS: Flow cytometry was performed on 18 sFNAB collected over 3 years. The series comprised 10 cases of non- Hodgkin lymphomas (NHL), 2 cases insufficient for diagnosis, 2 cases of reactive hyperplasia (RH), and 4 cases of myeloid metaplasia (MM). FNAB was performed under ultrasound guidance using a 22-gauge needle. One or two passes were sufficient to prepare a conventional smear that was immediately evaluated to select the cases studied and to prepare a cell suspension for FC. The following fluoresceinated antibodies were used: CD3, CD19/kappa/lambda, FMC7/CD23/CD19, Bcl-2, and CD13/HLA-DR. In six cases, cytospins were also prepared for immunocytochemistry and were tested for CD20 (L26), CD45Ro, and kappa and lambda light chain expression. RESULTS: Flow cytometry contributed to the diagnosis of all cases of NHL by assessing light chain restriction. The specific subtype was also diagnosed by CD19/CD5 and CD 19/CD10 coexpression in two cases. Flow cytometry quantified the percentage of myeloid cells in MM cases and contributed to the cytologic diagnosis showing a polyclonal light chain expression in RH cases.Immunocytochemistry was effective and concordant in four cases. Patients tolerated the sFNAB well and no complications were reported. Cytologic and FC diagnoses were confirmed by follow-up and by histologic evaluation in cases in which splenectomy was performed for therapeutic purposes. CONCLUSION: Flow cytometry applied to sFNAB corroborates the cytologic diagnosis in lymphoid and myeloproliferative disorders of the spleen and allows therapeutic decisions avoiding splenectomy

Precision medicine and machine learning towards the prediction of the outcome of potential celiac disease

Potential Celiac Patients (PCD) bear the Celiac Disease (CD) genetic predisposition, a significant production of antihuman transglutaminase antibodies, but no morphological changes in the small bowel mucosa. A minority of patients (17%) showed clinical symptoms and need a gluten free diet at time of diagnosis, while the majority progress over several years (up to a decade) without any clinical problem neither a progression of the small intestine mucosal damage even when they continued to assume gluten in their diet. Recently we developed a traditional multivariate approach to predict the natural history, on the base of the information at enrolment (time 0) by a discriminant analysis model. Still, the traditional multivariate model requires stringent assumptions that may not be answered in the clinical setting. Starting from a follow-up dataset available for PCD, we propose the application of Machine Learning (ML) methodologies to extend the analysis on available clinical data and to detect most influent features predicting the outcome. These features, collected at time of diagnosis, should be capable to classify patients who will develop duodenal atrophy from those who will remain potential. Four ML methods were adopted to select features predictive of the outcome; the feature selection procedure was indeed capable to reduce the number of overall features from 85 to 19. ML methodologies (Random Forests, Extremely Randomized Trees, and Boosted Trees, Logistic Regression) were adopted, obtaining high values of accuracy: all report an accuracy above 75%. The specificity score was always more than 75% also, with two of the considered methods over 98%, while the best performance of sensitivity was 60%. The best model, optimized Boosted Trees, was able to classify PCD starting from the selected 19 features with an accuracy of 0.80, sensitivity of 0.58 and specificity of 0.84. Finally, with this work, we are able to categorize PCD patients that can more likely develop overt CD using ML. ML techniques appear to be an innovative approach to predict the outcome of PCD, since they provide a step forward in the direction of precision medicine aimed to customize healthcare, medical therapies, decisions, and practices tailoring the clinical management of PCD children

High exposure to advanced glycation End-products could facilitate the occurrence of pediatric Eosinophilic Esophagitis

Eosinophilic esophagitis (EoE) is a major cause of upper gastrointestinal morbidity in the pediatric age. It has been hypothesized that the interaction between genetic and environmental factors (i.e., dietary habits) may induce the development of EoE. Among dietary factors, it has been postulated that advanced glycation end-products (AGEs), present at high level in ultra-processed foods (UPFs), could be involved in the pathogenesis of several inflammatory diseases, including food allergy. AGEs are ligands to the RAGE receptor and, mimicking signals provoked by tissue damage, are capable to increase tissue permeability, inflammation and Th2 response. We aimed to evaluate the potential pathogenic role elicited by AGEs in pediatric EoE

Atopy patch test are useful to predict oral tolerance in children with gastrointestinal symptoms related to non-IgE-mediated cow's milk allergy.

Atopy patch tests (APTs) have been proposed for the diagnostic approach in children with non-IgE-mediated cow's milk allergy and gastrointestinal symptoms. We aimed to investigate the benefit of APTs in predicting oral tolerance in these patients. We prospectively evaluated 172 subjects with a sure diagnosis of non-IgE-mediated CMA and gastrointestinal symptoms (97 boys, 56.4%; age, 6.37 m; range, 212 m). At diagnosis, 113/172 (65.7%) children had positive APTs to cow's milk proteins (CMP). After 12 months of exclusion, diet APTs were repeated immediately before OFC. APTs significantly correlated (P < 0.001) with the OFC outcome (r 0.579). Diagnostic accuracy was sensitivity of 67.95%, specificity of 88.3%, PPV of 82.81%, NPV of 76.85%, and a +LR of 5.80. APTs are a valuable tool in the follow-up of children with non-IgE-mediated CMA-related gastrointestinal symptoms by contributing in determining whether an OFC can safely be undertaken

Direct peroral cholangioscopy in the management of difficult biliary stones: a new tool to confirm common bile duct clearance. Results of a preliminary study

Background and aims: Endoscopic sphincterotomy (ES) with stone extraction is the standard treatment for choledocholithiasis. After stone retrieval, balloon-occluded cholangiography is generally performed to confirm bile duct clearance but can miss residual stones particularly in patients with residual small-sized stones, a large bile duct or pneumobilia. In addition, difficult common bile duct (CBD) stones requiring advanced endoscopic techniques for retrieval are a potential risk factor for choledocholithiasis recurrence. Methods: We performed a retrospective evaluation of a prospectively maintained procedures database. From July 2016 to December 2017, all patients with difficult CBD stones who underwent endoscopic retrograde cholangiopancreatography (ERCP) with papillary balloon dilation-assisted stone retrieval and subsequent direct per-oral cholangioscopy (DPOC) using standard gastroscopes to confirm CBD clearance were analyzed. Results: Thirty-six patients who underwent ERCP and DPOC were included. Technical success, defined as deep intubation of CBD with hepatic hilum visualization, was achieved in 31 of 36 patients (86%). During DPOC, residual CBD stones were visualized and removed in 7 of 31 patients (22.5%). After a mean of 241 +/- 56 days of follow-up post-DPOC, no serious adverse events were reported, and there was no evidence or suspicion of recurrent choledocholithiasis. Conclusions: Direct per-oral cholangioscopy immediately following difficult CBD stone removal was safe, feasible and accurate. In this setting, DPOC at the time of ERCP appears to be a very useful tool to achieve complete clearance of choledocholithiasis.info:eu-repo/semantics/publishedVersio