Beta-lactam-induced immediate hypersensitivity reactions: A genome-wide association study of a deeply phenotyped cohort.

BACKGROUND: ß-lactam antibiotics are associated with a variety of immune-mediated or hypersensitivity reactions, including immediate (type I) reactions mediated by antigen-specific IgE. OBJECTIVE: We sought to identify genetic predisposing factors for immediate reactions to ß-lactam antibiotics. METHODS: Patients with a clinical history of immediate hypersensitivity reactions to either penicillins or cephalosporins, which were immunologically confirmed, were recruited from allergy clinics. A genome-wide association study was conducted on 662 patients (the discovery cohort) with a diagnosis of immediate hypersensitivity and the main finding was replicated in a cohort of 98 Spanish cases, recruited using the same diagnostic criteria as the discovery cohort. RESULTS: Genome-wide association study identified rs71542416 within the Class II HLA region as the top hit (P = 2 × 10-14); this was in linkage disequilibrium with HLA-DRB1∗10:01 (odds ratio, 2.93; P = 5.4 × 10-7) and HLA-DQA1∗01:05 (odds ratio, 2.93, P = 5.4 × 10-7). Haplotype analysis identified that HLA-DRB1∗10:01 was a risk factor even without the HLA-DQA1∗01:05 allele. The association with HLA-DRB1∗10:01 was replicated in another cohort, with the meta-analysis of the discovery and replication cohorts showing that HLA-DRB1∗10:01 increased the risk of immediate hypersensitivity at a genome-wide level (odds ratio, 2.96; P = 4.1 × 10-9). No association with HLA-DRB1∗10:01 was identified in 268 patients with delayed hypersensitivity reactions to ß-lactams. CONCLUSIONS: HLA-DRB1∗10:01 predisposed to immediate hypersensitivity reactions to penicillins. Further work to identify other predisposing HLA and non-HLA loci is required.

Detection of Serum-Specific IgE by Fluoro-Enzyme Immunoassay for Diagnosing Type I Hypersensitivity Reactions to Penicillins.

Diagnosis of type I hypersensitivity reactions (IgE-mediated reactions) to penicillins is based on clinical history, skin tests (STs), and drug provocation tests (DPTs). Among in vitro complementary tests, the fluoro-enzyme immunoassay (FEIA) ImmunoCAP® (Thermo-Fisher, Waltham, MA, USA) is the most widely used commercial method for detecting drug-specific IgE (sIgE). In this study, we aimed to analyze the utility of ImmunoCAP® for detecting sIgE to penicillin G (PG) and amoxicillin (AX) in patients with confirmed penicillin allergy. The study includes 139 and 250 patients evaluated in Spain and Italy, respectively. All had experienced type I hypersensitivity reactions to penicillins confirmed by positive STs. Additionally, selective or cross-reactive reactions were confirmed by DPTs in a subgroup of patients for further analysis. Positive ImmunoCAP® results were 39.6% for PG and/or AX in Spanish subjects and 52.4% in Italian subjects. When only PG or AX sIgE where analyzed, the percentages were 15.1% and 30.4%, respectively, in Spanish patients; and 38.9% and 46% in Italian ones. The analysis of positive STs showed a statistically significant higher percentage of positive STs to PG determinants in Italian patients. False-positive results to PG (16%) were detected in selective AX patients with confirmed PG tolerance. Low and variable sensitivity values observed in a well-defined population with confirmed allergy diagnosis, as well as false-positive results to PG, suggest that ImmunoCAP® is a diagnostic tool with relevant limitations in the evaluation of subjects with type I hypersensitivity reactions to penicillins.

Astrobiology of life on Earth.

Astrobiology is mistakenly regarded by some as a field confined to studies of life beyond Earth. Here, we consider life on Earth through an astrobiological lens. Whereas classical studies of microbiology historically focused on various anthropocentric sub-fields (such as fermented foods or commensals and pathogens of crop plants, livestock and humans), addressing key biological questions via astrobiological approaches can further our understanding of all life on Earth. We highlight potential implications of this approach through the articles in this Environmental Microbiology special issue 'Ecophysiology of Extremophiles'. They report on the microbiology of places/processes including low-temperature environments and chemically diverse saline- and hypersaline habitats; aspects of sulphur metabolism in hypersaline lakes, dysoxic marine waters, and thermal acidic springs; biology of extremophile viruses; the survival of terrestrial extremophiles on the surface of Mars; biological soils crusts and rock-associated microbes of deserts; subsurface and deep biosphere, including a salticle formed within Triassic halite; and interactions of microbes with igneous and sedimentary rocks. These studies, some of which we highlight here, contribute to our understanding of the spatiotemporal reach of Earth'sfunctional biosphere, and the tenacity of terrestrial life. Their findings will help set the stage for future work focused on the constraints for life, and how organisms adapt and evolve to circumvent these constraints.

Engineered nanoparticles of titanium dioxide (TIO2): Uptake and biological effects in a sea bass cell line.

With the rapid development of nanotechnology there has been a corresponding increase in the application of titanium dioxide nanoparticles (TiO2-NPs) in various consumer and industrial products, consequently their potential health hazards and environmental effects are considered an aspect of great concern. In the present study, in order to assess the impact of TiO2-NPs in the marine environment, the biological effects of TiO2-NPs on a sea bass cell line (DLEC) were investigated. Cells were exposed for 24 h to different concentrations of TiO2-NPs (1, 8, 40, 200 and 1000 µg/ml) or co-exposed with CdCl2 (Cd). The effects of UV light irradiation were also investigated in cells treated with TiO2-NPs and/or Cd. The internalization of TiO2-NPs and the morphological cell modifications induced by the treatments were examined by transmission and scanning electron microscopy, this latter coupled with energy dispersive X-ray spectroscopy (EDS) for particle element detection. In addition, the effects of controlled exposures were studied evaluating the cytotoxicity, the DNA damage and the expression of inflammatory genes. Our study indicates that TiO2-NPs were localized on the cell surface mainly as agglomerates revealed by EDS analysis and that they were uptaken by the cells inducing morphological changes. Photoactivation of TiO2-NPs and/or co-exposure with Cd affects ATP levels and it contributes to induce acute cellular toxicity in DLEC cells dependent on Ti concentration. The inflammatory potential and the DNA damage, this latter displayed through a caspase-3 independent apoptotic process, were also demonstrated. Overall our data suggest that the interaction of TiO2-NPs with marine water contaminants, such as cadmium, and the UV irradiation, may be an additional threat to marine organisms.

Rapid flow-based peptide synthesis.

A flow-based solid-phase peptide synthesis methodology that enables the incorporation of an amino acid residue every 1.8 min under automatic control or every 3 min under manual control is described. This is accomplished by passing a stream of reagent through a heat exchanger into a low volume, low backpressure reaction vessel, and through a UV detector. These features enable continuous delivery of heated solvents and reagents to the solid support at high flow rate, thereby maintaining maximal concentration of reagents in the reaction vessel, quickly exchanging reagents, and eliminating the need to rapidly heat reagents after they have been added to the vessel. The UV detector enables continuous monitoring of the process. To demonstrate the broad applicability and reliability of this method, it was employed in the total synthesis of a small protein, as well as dozens of peptides. The quality of the material obtained with this method is comparable to that for traditional batch methods, and, in all cases, the desired material was readily purifiable by RP-HPLC. The application of this method to the synthesis of the 113-residue Bacillus amyloliquefaciens RNase and the 130-residue DARPin pE59 is described in the accompanying manuscript.

Flow-based enzymatic ligation by sortase A.

Sortase-mediated ligation (sortagging) is a versatile, powerful strategy for protein modification. Because the sortase reaction reaches equilibrium, a large excess of polyglycine nucleophile is often employed to drive the reaction forward and suppress sortase-mediated side reactions. A flow-based sortagging platform employing immobilized sortase A within a microreactor was developed that permits efficient sortagging at low nucleophile concentrations. The platform was tested with several reaction partners and used to generate a protein bioconjugate inaccessible by solution-phase batch sortagging.

Sex-related genomic sequences in cartilaginous fish: an overview.

Sex determination and differentiation are key events in the development of either the testis or ovary in fish. Sex determination mechanisms include environmental and genetic regulation. Research on sex determination systems and their related genes have been implemented in the teleost species, but the amount of information about these genes in cartilaginous fish is very scarce. This paper summarizes the few available data on molecular studies and chromosome localization of specific sequences useful to discriminate between various chromosome pairs in the common torpedo, Torpedo torpedo, and in the scyliorhinid coral catshark, Atelomycterus marmoratus, species that do not have morphologically distinct sex chromosomes. In addition, recent results obtained by sequence analysis of foxl2, a female-specific gene expressed during early phases of gonadal development in interesting key-species, such as the holocephalian Callorhinchus milii, is discussed. Nevertheless, the mechanism of sex determination in cartilaginous fish remains largely unknown. Further research needs to be carried out regarding the importance of basic and applied sex determination studies in fish, including chromosomal distribution of sex-related sequences.

Protein thioester synthesis enabled by sortase.

Proteins containing a C-terminal thioester are important intermediates in semisynthesis. Currently there is one main method for the synthesis of protein thioesters that relies upon the use of engineered inteins. Here we report a simple strategy, utilizing sortase A, for routine preparation of recombinant proteins containing a C-terminal (α)thioester. We used our method to prepare two different anthrax toxin cargo proteins: one containing an (α)thioester and another containing a D-polypeptide segment situated between two protein domains. We show that both variants can translocate through protective antigen pore. This new method to synthesize a protein thioester allows for interfacing of sortase-mediated ligation and native chemical ligation.

Personality disorders among patients accessing alcohol detoxification treatment: prevalence and gender differences.

BACKGROUND: Alcohol abuse and dependence are frequently associated with psychiatric disorders and personality disorders (PDs) with differences among gender. However, only few studies investigated gender differences in PDs among alcoholics. The aim of this study was to investigate PDs in a sample of patients accessing inpatient alcohol detoxification treatment and to describe gender differences in prevalence and comorbidity of PDs. METHODS: The study population consisted of 206 patients entering alcohol detoxification treatment in a specialized clinic in Italy. At enrollment, patients filled in the Millon Clinical Multiaxial Inventory-III for the assessment of PDs. RESULTS: The sample consisted of 150 males and 56 females. Twenty-five percent of males vs 12.5% of females had 1 PD; 16% vs 23%, 2 PDs; and 46% vs 48%, more than 3 PDs. A statistically significant higher proportion of females got high scores on avoidant (21.4% vs 9.3%), self-defeating (50.0% vs 24.0%), and borderline scales (42.9% vs 25.3%). Depressive, self-defeating, and borderline PDs were frequently associated both to other PDs and among each other, particularly among females. CONCLUSIONS: Borderline PD is confirmed to be more frequent among females than among males accessing alcohol detoxification treatment. More studies are needed to clarify prevalence and associations of PDs, prognosis, and gender differences in alcoholics patients.

Evaluation of drug seeking behavior on nicotine conditioned place preference in zebrafish.

Seeking of drugs is commonly evaluated in a specific environment for assessing drug preference. However, cognitive strategies involved in drug seeking are mostly unknown. To assess the strength of environmental cues that can be associated with nicotine in the zebrafish brain reward circuitry, we have designed herein a modified conditioned place preference (CPP) paradigm. This task was devised to identify salient environmental cues relevant for strong nicotine-environment association and drug seeking induction. During test sessions, background colors of the CPP tank chambers were shifted and preference for colors associated to nicotine was assessed. We have compared several tank designs and different compartment colors. Our findings indicated that zebrafish seeking behavior was strongly dependent on compartment color shades. Combination of red and yellow environments, which were preferred and avoided compartments, respectively, was the most effective design presenting the highest CPP-score. Interestingly, animals that stayed for longer periods in the environment conditioned to nicotine during a first testing interval were also able to follow the background color shade conditioned to nicotine to the other compartment immediately after background colors were relocated between compartments. During a second testing period, zebrafish also stayed for longer periods in the colored compartment paired to nicotine during conditioning. These findings suggest that under salient environmental conditions, zebrafish voluntarily followed a shifting visual cue previously associated with nicotine delivery. Furthermore, our findings indicate that zebrafish exhibit spatial associative learning and memory, which generates a repertoire of conspicuous locomotor behaviors induced by nicotine preference in the CPP task.

Sexual function in women with type 1 diabetes matched with a control group: depressive and psychosocial aspects.

INTRODUCTION: Sexual dysfunction in women with diabetes, despite its important consequences to their quality of life, has been investigated only recently with conflicting results about its prevalence and association with complications and psychological factors. AIMS: To assess the prevalence of the alteration of sexual function and the influence of metabolic control and psychological factors on female sexuality. METHODS: Seventy-seven adult Italian women with type 1 diabetes, matched with a control group (n=77), completed questionnaires evaluating sexual function (Female Sexual Function Index, FSFI), depressive symptoms (Self-Rating Depression Scale, SRDS), social and family support (Multidimensional Scale of Perceived Social Support), and diabetes-related quality of life (Diabetes Quality of Life). Clinical and metabolic data were collected. MAIN OUTCOME MEASURES: Prevalence and magnitude of sexual dysfunction in terms of alteration of sexual functioning as measured by the FSFI scores. RESULTS: The prevalence of sexual dysfunction was similar in diabetes and control groups (33.8% vs. 39.0%, not significant), except for higher SRDS scores in the diabetes group (47.39 ± 11.96 vs. 43.82 ± 10.66; P=0.047). Diabetic patients with an alteration of sexual function showed a significantly higher SRDS score (53.58 ± 14.11 vs. 44.24 ± 9.38, P=0.004). Depression symptoms and good glycemic control (A1C<7.0%) were predictors of alteration of sexual function only in diabetic patients (odds ratio [OR]=1.082; 95% confidence interval [CI]: 1.028-1.140; OR=5.085; 95% CI: 1.087-23.789), since we have not found any significant predictor of sexual dysfunction in the control group. CONCLUSIONS: The prevalence of sexual dysfunction in our type 1 diabetes patients' sample is similar to those reported in other studies. Diabetic patients are similar to healthy people except for higher depression scores. Further studies are necessary to understand whether the correlation between an alteration of sexual function and good glycemic control may be related to the role of control as a mental attitude.

Does social capital determine health? Evidence from eight transition countries.

There is growing interest in the role of social relationships in explaining patterns of health. We contribute to this debate by investigating the impact of social capital on self-reported health for eight countries from the Commonwealth of Independent States. We rely on three indicators of social capital at the individual level (trust, participation in local organisations, social isolation) and employ alternative procedures to estimate consistently the impact of social capital on health. The three social capital indicators are choice variables and are hence, by definition, endogenously determined. We attempt to circumvent the endogeneity problems by using instrumental variable estimates. Our results show that the individual degree of trust is positively and significantly correlated with health, this being true with least squares estimators as well as when relying on instrumental variable estimators with (and without) community fixed effects. Similarly, social isolation is negatively and significantly associated with health, irrespective of the procedure of estimation. On the other hand, the effect of being a member of a Putnamesque organisation is more ambiguous and usually not significantly related to health.

Asymmetric Total Synthesis of C9'-epi-Sinefungin.

The natural nucleoside (+)-sinefungin, structurally similar to cofactor S-adenosyl-l-methionine, inhibits various SAM-dependent methyltransferases (MTs). Access to sinefungin analogues could serve as the basis for the rational design of small molecule methyltransferase inhibitors. We developed a route to the unnatural C9' epimer of sinefungin that employed a diastereoselective Overman rearrangement to install the key C6' amino stereocenter. The ability for late-stage modification is highlighted, opening an avenue for the discovery of new MT inhibitors.

A well-tolerated new amino acid-based formula for cow's milk allergy.

OBJECTIVES: Infants with cow's milk allergy (CMA) are in need of a substitute formula up to 2 years. The are three requisites for a substitute of milk in CMA: tolerability, nutritional adequacy, and cost-effectiveness. We evaluate here the tolerability of a new amino acid-based infant formula for the management of CMA. METHODS: In a phase III/IV prospective, multicentre, open-label, international study, infants and children with immunoglobulin E-mediated CMA were exposed to a diagnostic double-blinded, placebo-controlled food challenge with a new amino acid formula by Blemil Plus Elemental using Neocate as the placebo. If tolerant to it, the study formula was integrated into the patients' usual daily diet for 7 days. Efficacy on day 7 was assessed in terms of symptoms associated with CMA, amount of formula consumed, nutritional and energy intake, and anthropometric data. RESULTS: Thirty children (17 M and 13 F; median age, 1.58; range, 0.08-12.83 years) completed the open challenge and were able to consume the study formula for at least 7 days. No signs or symptoms of allergic reactions were recorded among children assuming either the test or the control formula, with a lower 95% one-sided confidence interval for the proportion of subjects who did not experience allergic reactions above 90%. Sixteen patient under the age of two continued with the optional extension phase. CONCLUSIONS: The study formula meets the American Academy of Pediatric criteria for hypoallergenicity and is well tolerated in short-term use. During optional phase, growth of the patients was not hindered by the study formula.

A Multicenter Retrospective Study on Hypersensitivity Reactions to Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) in Children: A Report from the European Network on Drug Allergy (ENDA) Group.

BACKGROUND: Diagnosis of hypersensitivity (HS) reactions to nonsteroidal anti-inflammatory drugs (NSAIDs) in children is complex. The real prevalence of NSAID HS remains unknown because a drug provocation test (DPT) is not always performed with the culprit NSAID. OBJECTIVE: To describe and compare the diagnostic workup among different European centers and to find out the real proportion of NSAID HS by performing a DPT with the culprit drug. METHODS: We retrospectively collected data from children (0-10 years) and adolescents (10-18 years) with a history of NSAID reactions and who underwent a complete allergy workup including DPTs with the culprit in 6 different pediatric centers: Belgrade, Florence, Geneva, Madrid, Porto, and Rome. RESULTS: A total of 693 children with a history of NSAID reactions were enrolled, and a total of 526 DPTs were performed with the culprit NSAID. The diagnosis of NSAID HS was confirmed in 19.6% (103 of 526) of children by performing a DPT with the culprit drug. The major differences in the allergy workup among the 6 centers concerned the duration of the DPT and the practical use of skin tests for diagnosing NSAID HS. In addition, the use of acetyl salicylic acid to differentiate single reactor or cross-intolerance patients is not common, except in Spain. CONCLUSION: The value of this study is that although different approaches are used around Europe to diagnose NSAID HS, we found that the percentage of confirmed NSAID HS is less than 20%. This highlights the importance of the DPT in confirming or excluding NSAID HS in the pediatric population.

The Third International Symposium on Fungal Stress - ISFUS.

Stress is a normal part of life for fungi, which can survive in environments considered inhospitable or hostile for other organisms. Due to the ability of fungi to respond to, survive in, and transform the environment, even under severe stresses, many researchers are exploring the mechanisms that enable fungi to adapt to stress. The International Symposium on Fungal Stress (ISFUS) brings together leading scientists from around the world who research fungal stress. This article discusses presentations given at the third ISFUS, held in São José dos Campos, São Paulo, Brazil in 2019, thereby summarizing the state-of-the-art knowledge on fungal stress, a field that includes microbiology, agriculture, ecology, biotechnology, medicine, and astrobiology.

Sensitization-dependent nicotine place preference in the adult zebrafish.

Sensitization of motor activity is a behavioural test to evaluate the effects of psychostimulants. Conditioned place preference (CPP) is an associative learning procedure to examine the rewarding properties of drugs. We aimed to assess whether motor sensitization to drugs of abuse can make zebrafish more vulnerable to establishing drug-induced CPP. We first evaluated sensitization of locomotor activity of zebrafish to repeated administrations of nicotine and cocaine during 5 days and after 5 days of withdrawal. After withdrawal, when zebrafish were re-exposed to the same dose of nicotine or cocaine locomotor activity was increased by 103% and 166%, respectively. Different groups of zebrafish were sensitized to nicotine or cocaine and trained on a nicotine-CPP task the day after withdrawal. The nicotine dose selected for sensitization was not effective for developing CPP in naïve zebrafish whereas it elicited CPP in zebrafish that were previously sensitized to nicotine or cocaine. Levels of nicotinic acetylcholine receptor ß2, α6 and α7 subunit, Pitx3, and tyrosine hydroxylase 1 (TH1) mRNAs were increased in the brain of nicotine- and cocaine-sensitized zebrafish. Nicotine-CPP performed with drug-sensitized zebrafish provoked further enhancements in the expression of α6 and α7 subunit, Pitx3, and TH1 mRNAs suggesting that the expression of these molecules in the reward pathway is involved in both processes. Our findings indicate that repeated exposures to low doses of drugs of abuse can increase subject's sensitivity to the rewarding properties of the same or different drugs. This further suggests that casual drug intake increases the probability of becoming addict.

Introducing Vibrio natriegens as a Microbial Model Organism for Microgravity Research.

Microbial contamination of human-tended spacecraft is unavoidable, making the study of microbial growth under space conditions essential for the preservation of astronauts' health and equipment integrity. Previous studies suggested that spaceflight conditions, such as microgravity, cause a range of physiological microbial alterations including increased growth yields and decreased antibiotic susceptibility. Because of its fast generation time, Vibrio natriegens could be used as a model organism for a variety of studies where generation time is a critical factor. In this study, V. natriegens was used as a tool to study growth characteristics by determining the viable cell number and antibiotic susceptibility under simulated microgravity using a 2-D clinostat (60 rpm) to establish a test system that resolves changes in microbial growth on a solid surface (agar) under microgravity. The data show that V. natriegens biomass increases significantly after 24 h at 37°C under simulated microgravity. The final cell population after cultivation under simulated microgravity was 60-fold greater than when cultivated under normal terrestrial gravity (1 × g). No change in susceptibility to the antibiotic rifampicin after cultivation under simulated microgravity or normal gravity was detected. These data show that V. natriegens is a new and innovative model organism for microbial microgravity research.

High-Affinity Alkynyl Bisubstrate Inhibitors of Nicotinamide N-Methyltransferase (NNMT).

Nicotinamide N-methyltransferase (NNMT) is a metabolic enzyme that methylates nicotinamide (NAM) using cofactor S-adenosylmethionine (SAM). NNMT overexpression has been linked to diabetes, obesity, and various cancers. In this work, structure-based rational design led to the development of potent and selective alkynyl bisubstrate inhibitors of NNMT. The reported nicotinamide-SAM conjugate (named NS1) features an alkyne as a key design element that closely mimics the linear, 180° transition state geometry found in the NNMT-catalyzed SAM → NAM methyl transfer reaction. NS1 was synthesized in 14 steps and found to be a high-affinity, subnanomolar NNMT inhibitor. An X-ray cocrystal structure and SAR study revealed the ability of an alkynyl linker to span the methyl transfer tunnel of NNMT with ideal shape complementarity. The compounds reported in this work represent the most potent and selective NNMT inhibitors reported to date. The rational design principle described herein could potentially be extended to other methyltransferase enzymes.

NaCl-saturated brines are thermodynamically moderate, rather than extreme, microbial habitats.

NaCl-saturated brines such as saltern crystalliser ponds, inland salt lakes, deep-sea brines and liquids-of-deliquescence on halite are commonly regarded as a paradigm for the limit of life on Earth. There are, however, other habitats that are thermodynamically more extreme. Typically, NaCl-saturated environments contain all domains of life and perform complete biogeochemical cycling. Despite their reduced water activity, ∼0.755 at 5 M NaCl, some halophiles belonging to the Archaea and Bacteria exhibit optimum growth/metabolism in these brines. Furthermore, the recognised water-activity limit for microbial function, ∼0.585 for some strains of fungi, lies far below 0.755. Other biophysical constraints on the microbial biosphere (temperatures of >121°C; pH > 12; and high chaotropicity; e.g. ethanol at >18.9% w/v (24% v/v) and MgCl2 at >3.03 M) can prevent any cellular metabolism or ecosystem function. By contrast, NaCl-saturated environments contain biomass-dense, metabolically diverse, highly active and complex microbial ecosystems; and this underscores their moderate character. Here, we survey the evidence that NaCl-saturated brines are biologically permissive, fertile habitats that are thermodynamically mid-range rather than extreme. Indeed, were NaCl sufficiently soluble, some halophiles might grow at concentrations of up to 8 M. It may be that the finite solubility of NaCl has stabilised the genetic composition of halophile populations and limited the action of natural selection in driving halophile evolution towards greater xerophilicity. Further implications are considered for the origin(s) of life and other aspects of astrobiology.