26 research outputs found
Bos d 13, a novel heat-stable beef allergen
[Scope]: Red meat, a staple food of Western diets, can also induce IgE-mediated allergic reactions. Yet, apart from the heat-labile protein serum albumin and the carbohydrate α-Gal, the molecules causing allergic reactions to red meat remain unknown.[Methods and results]: IgE reactivity profiles of beef-sensitized individuals are analyzed by IgE-immunoblotting with protein extracts from raw and cooked beef. Two IgE-reactive proteins are identified by peptide mass fingerprinting as myosinlight chain 1 (MYL1) and myosin light chain 3 (MYL3) in cooked beef extract and are designated Bos d 13 isoallergens. MYL1 and MYL3 are produced recombinantly in Escherichia coli. ELISAs proved their IgE reactivity and circular dichroism analysis showed that they represent folded molecules with remarkable thermal stability. In vitro gastrointestinal digestion experiments showed the higher stability of rMYL1 as compared to rMYL3. Exposure of a monolayer of Caco-2 cells to rMYL1 indicated that the molecule is able to cross intestinal epithelial cells without disturbing the integrity of the tight junctions, suggesting the sensitizing capacity of MYL1.[Conclusion]: MYLs are identified as novel heat-stable bovine meat allergens.This research was funded in whole by the Austrian Science Fund (FWF) P33867.Peer reviewe
Data Communication Magazine
Los multiplexores son herramientas importantes en la comunicaciĂłn de datos, debido a que se permiten en envĂo de diferentes señales a travĂ©s de un solo medio. En la actualidad, son aplicados en diversas ĂĄreas entres las que se encuentran seguridad, redes telefĂłnicas, redes internas, entre otras.Desarrollo e implementaciĂłn de un multiplexor y demultiplexor por divisiĂłn de timepo para la transmisiĂłn de señales digitales, triangualres y anĂĄlogas. -- Proyecto de simulaciĂłn de la trasformada de fourier discreta es sus aplicaciones fĂsicas (transmisiĂłn de datos). -- MediciĂłn de pĂ©rdida de potencia. -- Opnet: modelado de infiniband(iba). -- ConstrucciĂłn de un escenario para la transmisiĂłn de datos mediante el uso de telefonĂa ip. -- SimulaciĂłn de algoritmos de programaciĂłn. -- ConmutaciĂłn de paquetes. -- SimulaciĂłn de computacional. -- DescripciĂłn de procedimientos para el muestreo y reconstrucciĂłn de señales. -- PlaneaciĂłn, diseño y desarrollo de un software didĂĄctico. -- DescripciĂłn de los principales puertos usados en la comunicaciĂłn de datos. -- Esquemas de codificaciĂłn.Multiplexers are important tools in data communication because they allow different signals to be sent through a single medium. Currently, they are applied in various areas, including security, telephone networks, internal networks, among others
Role of age and comorbidities in mortality of patients with infective endocarditis
[Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality.
[Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65âŻyears,65 to 80âŻyears,andâŻâ„âŻ80âŻyears.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk.
[Results]: A total of 3120 patients with IE (1327âŻ<âŻ65âŻyears;1291 65-80âŻyears;502âŻâ„âŻ80âŻyears) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients â„80âŻyears who underwent surgery were significantly lower compared with other age groups (14.3%,65âŻyears; 20.5%,65-79âŻyears; 31.3%,â„80âŻyears). In-hospital mortality was lower in the <65-year group (20.3%,<65âŻyears;30.1%,65-79âŻyears;34.7%,â„80âŻyears;pâŻ<âŻ0.001) as well as 1-year mortality (3.2%, <65âŻyears; 5.5%, 65-80âŻyears;7.6%,â„80âŻyears; pâŻ=âŻ0.003).Independent predictors of mortality were ageâŻâ„âŻ80âŻyears (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32â3.34), CCIâŻâ„âŻ3 (HR:1.62; 95% CI:1.39â1.88),and non-performed surgery (HR:1.64;95% CI:11.16â1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65âŻyears(pâŻ<âŻ0.001) for both in-hospital and 1-year mortality.
[Conclusion]: There were no differences in the clinical presentation of IE between the groups. AgeâŻâ„âŻ80âŻyears, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group
Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)
Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters.
Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs).
Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001).
Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Summary
Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally.
Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies
have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of
the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income
countries globally, and identified factors associated with mortality.
Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to
hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis,
exomphalos, anorectal malformation, and Hirschsprungâs disease. Recruitment was of consecutive patients for a
minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical
status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary
intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause,
in-hospital mortality for all conditions combined and each condition individually, stratified by country income status.
We did a complete case analysis.
Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital
diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal
malformation, and 517 with Hirschsprungâs disease) from 264 hospitals (89 in high-income countries, 166 in middleincome
countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male.
Median gestational age at birth was 38 weeks (IQR 36â39) and median bodyweight at presentation was 2·8 kg (2·3â3·3).
Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income
countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups).
Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome
countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries;
pâ€0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients
combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88â4·11],
p<0·0001; middle-income vs high-income countries, 2·11 [1·59â2·79], p<0·0001), sepsis at presentation (1·20
[1·04â1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention
(ASA 4â5 vs ASA 1â2, 1·82 [1·40â2·35], p<0·0001; ASA 3 vs ASA 1â2, 1·58, [1·30â1·92], p<0·0001]), surgical safety
checklist not used (1·39 [1·02â1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed
(ventilation 1·96, [1·41â2·71], p=0·0001; parenteral nutrition 1·35, [1·05â1·74], p=0·018). Administration of
parenteral nutrition (0·61, [0·47â0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65
[0·50â0·86], p=0·0024) or percutaneous central line (0·69 [0·48â1·00], p=0·049) were associated with lower mortality.
Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome,
middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will
be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger
than 5 years by 2030
The α-Gal syndrome and potential mechanisms
The α-Gal syndrome is a complex allergic disease characterized by the development of specific IgE antibodies against the carbohydrate galactose-α-1,3-galactose (α-Gal), an oligosaccharide present in cells and tissues of non-primate mammals. Individuals with IgE antibodies to α-Gal suffer from a delayed form of anaphylaxis following red meat consumption. There are several features that make the α-Gal syndrome such a unique allergic disease and distinguish it from other food allergies: (1) symptoms causing IgE antibodies are directed against a carbohydrate moiety, (2) the unusual delay between the consumption of the food and the onset of the symptoms, and (3) the fact that primary sensitization to α-Gal occurs via tick bites. This review takes a closer look at the immune response against α-Gal, in healthy and in α-Gal allergic individuals. Furthermore, the similarities and differences between immune response against α-Gal and against the other important glycan moieties associated with allergies, namely cross-reactive carbohydrate determinants (CCDs), are discussed. Then different mechanisms are discussed that could contribute to the delayed onset of symptoms after consumption of mammalian meat. Moreover, our current knowledge on the role of tick bites in the sensitization process is summarized. The tick saliva has been shown to contain proteins carrying α-Gal, but also bioactive molecules, such as prostaglandin E2, which is capable of stimulating an increased expression of anti-inflammatory cytokines while promoting a decrease in the production of proinflammatory mediators. Together these components might promote Th2-related immunity and trigger a class switch to IgE antibodies directed against the oligosaccharide α-Gal. The review also points to open research questions that remain to be answered and proposes future research directions, which will help to get a better understanding and lead to a better management of the disease.The preparation of this manuscript was supported by research grant P33867 of the Austrian Science Fund (FWF).Peer reviewe
Only αâGal bound to lipids, but not to proteins, is transported across enterocytes as an IgEâreactive molecule that can induce effector cell activation
[Background]: The oligosaccharide galactoseâαâ1,3âgalactose (αâGal), present in mammalian proteins and lipids, causes an unusual delayed allergic reaction 3 to 6 hours after ingestion of mammalian meat in individuals with IgE antibodies against αâGal. To better understand the delayed onset of allergic symptoms and investigate whether proteinâbound or lipidâbound αâGal causes these symptoms, we analyzed the capacity of αâGal conjugated proteins and lipids to cross a monolayer of intestinal cells.[Methods]: Extracts of proteins and lipids from beef were prepared, subjected to in vitro digestions, and added to Cacoâ2 cells grown on permeable supports. The presence of αâGal in the basolateral medium was investigated by immunoblotting, thinâlayer chromatography with immunostaining and ELISA, and its allergenic activity was analyzed in a basophil activation test.[Results]: After addition of beef proteins to the apical side of Cacoâ2 cells, αâGal containing peptides were not detected in the basolateral medium. Those peptides that crossed the Cacoâ2 monolayer did not activate basophils from an αâGal allergic patient. Instead, when Cacoâ2 cells were incubated with lipids extracted from beef, αâGal was detected in the basolateral medium. Furthermore, these αâGal lipids were able to activate the basophils of an αâGal allergic patient in a doseâdependent manner.[Conclusion]: Only αâGal bound to lipids, but not to proteins, is able to cross the intestinal monolayer and trigger an allergic reaction. This suggests that the slower digestion and absorption of lipids might be responsible for the unusual delayed allergic reactions in αâGal allergic patients and identifies glycolipids as potential allergenic molecules.This study was funded by research grant P25868 of the Austrian Science Fund (FWF).Peer reviewe
Infection with Toxocara canis inhibits the production of IgE antibodies to α-Gal in humans: Towards a conceptual framework of the hygiene hypothesis?
α-Gal syndrome (AGS) is a type of anaphylactic reaction to mammalian meat characterized by an immunoglobulin (Ig)E immune response to the oligosaccharide α-Gal (Galα1-3GalÎČ1-4GlcNAc-R). Tick bites seems to be a prerequisite for the onset of the allergic disease in humans, but the implication of non-tick parasites in α-Gal sensitization has also been deliberated. In the present study, we therefore evaluated the capacity of helminths (Toxocara canis, Ascaris suum, Schistosoma mansoni), protozoa (Toxoplasma gondii), and parasitic fungi (Aspergillus fumigatus) to induce an immune response to α-Gal. For this, different developmental stages of the infectious agents were tested for the presence of α-Gal. Next, the potential correlation between immune responses to α-Gal and the parasite infections was investigated by testing sera collected from patients with AGS and those infected with the parasites. Our results showed that S. mansoni and A. fumigatus produce the terminal α-Gal moieties, but they were not able to induce the production of specific antibodies. By contrast, T. canis, A. suum and T. gondii lack the α-Gal epitope. Furthermore, the patients with T. canis infection had significantly decreased anti-α-Gal IgE levels when compared to the healthy controls, suggesting the potential role of this nematode parasite in suppressing the allergic response to the glycan molecule. This rather intriguing observation is discussed in the context of the âhygiene hypothesisâ. Taken together, our study provides new insights into the relationships between immune responses to α-Gal and parasitic infections. However, further investigations should be undertaken to identify T. canis components with potent immunomodulatory properties and to assess their potential to be used in immunotherapy and control of AGS.Peer reviewe