Clinical and serological characteristics of patients allergic to LTP.

BACKGROUND: Allergy to lipid transfer proteins (LPT) is common in Mediterranean Europe, and it causes severe reactions in patients and affects multiple foods, impairing the quality of life. OBJECTIVE: This study aimed to describe the clinical and sensitization profile of patients with LTP syndrome and to determine a clinical pattern of severity. Molecular diagnosis is shown in a broad population through microarrays. MATERIAL AND METHODS: This study was performed at the LTP Allergy Consultation of the Reina Sofia Hospital in Murcia, Spain. We analyzed the patients' characteristics, reactions, cofactors, food implicated, quality of life, skin prick test to food and aeroallergens, and serologic parameters, such as total immunoglobulin E, peach LTP (Pru p 3 IgE) and immunoglobulin G4, and microarray Immuno Solid-phase Allergen Chip (ISAC). We related the severity of the reactions with other variables. RESULTS: We presented a series of 236 patients diagnosed with LTP allergy, 54.66% suffering from anaphylaxis, 36.02% from urticaria angioedema, and 9.32% from oral allergy syndrome. The most frequently implicated food was peach, producing symptoms in 70% of patients, followed by walnut in 55%, peanut in 45%, hazelnut in 44%, and apple in 38% patients. Regarding the food that provoked anaphylaxis, walnut was the most frequent instigator, along with peach, peanut, hazelnut, almond, sunflower seed, and apple. According to the severity of LPT reaction, we did not discover significant differences in gender, age, food group involved, and serologic parameters. We found differences in the presence of cofactors, with 48.84% of cofactors in patients with anaphylaxis, compared to 27.1% in patients without anaphylaxis and in family allergy background (P < 0.0001). CONCLUSION: In our series of patients, 54% presented anaphylaxis, and the foods that most frequently produced symptoms were peaches, apples, and nuts. Cofactors and family allergy backgrounds were associated with the severity of LPT reaction.

Efficacy of pain management strategies in adults with Amyotrophic Lateral Sclerosis (ALS): A Systematic Review.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive muscle weakness. Presence of pain in ALS patients is heterogeneously reported in studies, and mostly underrepresented in symptom scales. The aim of this study is to evaluate the efficacy of pharmacological and non-pharmacological therapeutic modalities for pain management in patients with ALS. A systematic review was conducted in four databases; PubMed, Scopus, Clinicaltrials.gov, and Cochrane-Ovid. Five randomized controlled clinical trials were included regarding pharmacological and non-pharmacological pain management interventions in adult patients with confirmed diagnosis of ALS in whom pain was objectively evaluated. Risk of bias assessment was evaluated using the RoB2.0 tool. Eligible studies were reported as a descriptive analysis. This systematic review was registered with PROSPERO ID: CRD42024495009. Five clinical trials regarding pain management strategies in ALS were eligible for analysis. Two out of five were non-pharmacological approaches whilst the remaining three provided pharmacological therapies. Of these, Mexiletine was efficient in terms of pain relief, particularly between 600 and 900 mg per day, whereas Mecasin showed no pain relief at both, high and low doses. Non-pharmacological therapies, such as exercise and osteopathic manual treatment also lacked efficacy in regard to pain management. Clinical trials focusing on pain management strategies for ALS patients are limited. Medical professionals, understandably focused on immediate life-threatening aspects, may inadvertently sideline the nuanced and intricate dimension of pain experienced by patients with ALS.

Sirolimus to treat chronic and steroid-resistant allograft rejection-related fibrosis in pediatric liver transplantation.

This study aimed to report our experience with the use of sirolimus in pediatric liver transplant patients with chronic rejection or steroid-resistant rejection with hepatic fibrosis, focusing on their histological evolution. All pediatric liver transplant recipients who received off-label treatment with sirolimus for chronic ductopenic rejection or cortico-resistant rejection between July 2003 and July 2022 were included in the study. All nine patients included in the study showed improvement in liver enzymes and cholestasis parameters as soon as 1-month after postsirolimus introduction. A decrease in fibrosis stage was observed in 7/9 (77.7%) patients at 36 months. All but one patient experienced an improvement in the Rejection Activity Index and ductopenia at 12 months. A single patient had to discontinue sirolimus treatment owing to nephrotic proteinuria. In conclusion, sirolimus may be a safe and effective treatment for chronic and steroid-resistant rejection and may improve allograft rejection-related fibrosis and ductal damage.

Genomic Evolution Strategy in SARS-CoV-2 Lineage B: Coevolution of Cis Elements.

In the SARS-CoV-2 lineage, RNA elements essential for its viral life cycle, including genome replication and gene expression, have been identified. Still, the precise structures and functions of these RNA regions in coronaviruses remain poorly understood. This lack of knowledge points out the need for further research to better understand these crucial aspects of viral biology and, in time, prepare for future outbreaks. In this research, the in silico analysis of the cis RNA structures that act in the alpha-, beta-, gamma-, and deltacoronavirus genera has provided a detailed view of the presence and adaptation of the structures of these elements in coronaviruses. The results emphasize the importance of these cis elements in viral biology and their variability between different viral variants. Some coronavirus variants in some groups, depending on the cis element (stem-loop1 and -2; pseudoknot stem-loop1 and -2, and s2m), exhibited functional adaptation. Additionally, the conformation flexibility of the s2m element in the SARS variants was determined, suggesting a coevolution of this element in this viral group. The variability in secondary structures suggests genomic adaptations that may be related to replication processes, genetic regulation, as well as the specific pathogenicity of each variant. The results suggest that RNA structures in coronaviruses can adapt and evolve toward different viral variants, which has important implications for viral adaptation, pathogenicity, and future therapeutic strategies.

Zinc Recovery from a Water Supply by Reverse Osmosis Operated at Low Pressures: Looking for Sustainability in Water Treatment Advanced Processes.

Achieving sustainability in life involves increasing efforts to recover resources. This research proposes the recovery of Zn from the Milluni lagoons, an important water supply for Bolivia, where high concentrations of Zn have been identified that exceed permitted limits, exposing a risk to health and ecosystems. The application of reverse osmosis (RO), operated with low pressures, is proposed as a first stage for the concentration of Zn and subsequent recovery of this metal through chemical precipitation. The aim was to maintain the separation efficiency of the RO operated at low pressures without presenting operational problems. As a result, 98.83% metal concentration was achieved with a laboratory-scale pilot system. The above means an important potential for large-scale Zn concentration, apart from orienting the RO toward sustainability by working with low pressures that reduce energy costs during its operation. This study can be used as a valuable reference for the advancement of sustainable technologies in the field of water treatment that simultaneously allow the recovery of resources to promote a circular economy. Finally, this study exposes an alternative for regions with heavy metal water contamination in Bolivia and worldwide.

Perianal Ulcers from Antihemorrhoidal Ointment: A Case Report and Literature Review.

ABSTRACT: Perianal ulcers (PAUs) related to antihemorrhoidal product use have been recently reported in the literature through a few case reports. However, other etiologies of PAU must be ruled out, including infectious disease, inflammatory disease, malignancy, pressure injuries, radiotherapy, and other topical drugs. In this report, the authors describe two cases of PAUs due to an antihemorrhoidal ointment. In case 1, a 68-year-old woman with a history of hemorrhoids presented with PAUs after using an antihemorrhoidal ointment for 2 months. The ulcers were assessed through a histopathologic study and treated with calcium alginate dressings, with complete re-epithelialization occurring after 2 months. In case 2, a 58-year-old woman with a history of hemorrhoids developed painful PAUs while using an antihemorrhoidal ointment for 2 months. No other probable cause was found, and the ulcers were treated by discontinuing the ointment. The ulcers showed marked improvement, and complete re-epithelialization occurred after 6 weeks without additional treatment.

Interleukin 27, Similar to Interferons, Modulates Gene Expression of Tripartite Motif (TRIM) Family Members and Interferes with Mayaro Virus Replication in Human Macrophages.

BACKGROUND: The Tripartite motif (TRIM) family includes more than 80 distinct human genes. Their function has been implicated in regulating important cellular processes, including intracellular signaling, transcription, autophagy, and innate immunity. During viral infections, macrophages are key components of innate immunity that produce interferons (IFNs) and IL27. We recently published that IL27 and IFNs induce transcriptional changes in various genes, including those involved in JAK-STAT signaling. Furthermore, IL27 and IFNs share proinflammatory and antiviral pathways in monocyte-derived macrophages (MDMs), resulting in both common and unique expression of inflammatory factors and IFN-stimulated genes (ISGs) encoding antiviral proteins. Interestingly, many TRIM proteins have been recognized as ISGs in recent years. Although it is already very well described that TRIM expression is induced by IFNs, it is not fully understood whether TRIM genes are induced in macrophages by IL27. Therefore, in this study, we examined the effect of stimulation with IL27 and type I, II, and III IFNs on the mRNA expression profiles of TRIM genes in MDMs. METHODS: We used bulk RNA-seq to examine the TRIM expression profile of MDMs treated with IFNs or IL27. Initially, we characterized the expression patterns of different TRIM subfamilies using a heatmap. Subsequently, a volcano plot was employed to identify commonly differentially expressed TRIM genes. Additionally, we conducted gene ontology analysis with ClueGO to explore the biological processes of the regulated TRIMs, created a gene-gene interaction network using GeneMANIA, and examined protein-protein interactions with the STRING database. Finally, RNA-seq data was validated using RT-qPCR. Furthermore, the effect of IL27 on Mayaro virus replication was also evaluated. RESULTS: We found that IL27, similar to IFNs, upregulates several TRIM genes' expression in human macrophages. Specifically, we identified three common TRIM genes (TRIM19, 21, and 22) induced by IL27 and all types of human IFNs. Additionally, we performed the first report of transcriptional regulation of TRIM19, 21, 22, and 69 genes in response to IL27. The TRIMs involved a broad range of biological processes, including defense response to viruses, viral life cycle regulation, and negative regulation of viral processes. In addition, we observed a decrease in Mayaro virus replication in MDMs previously treated with IL27. CONCLUSIONS: Our results show that IL27, like IFNs, modulates the transcriptional expression of different TRIM-family members involved in the induction of innate immunity and an antiviral response. In addition, the functional analysis demonstrated that, like IFN, IL27 reduced Mayaro virus replication in MDMs. This implies that IL27 and IFNs share many similarities at a functional level. Moreover, identifying distinct TRIM groups and their differential expressions in response to IL27 provides new insights into the regulatory mechanisms underlying the antiviral response in human macrophages.

Synergistic impact of innate immunity hyper-activation and endothelial dysfunction on the magnitude of organ failure in the infection-sepsis continuum.

OBJECTIVES: Identifying host response biomarkers implicated in the emergence of organ failure during infection is key to improving the early detection of this complication. METHODS: Twenty biomarkers of innate immunity, T-cell response, endothelial dysfunction, coagulation, and immunosuppression were profiled in 180 surgical patients with infections of diverse severity (IDS) and 53 with no infection (nIDS). Those better differentiating IDS/nIDS in the area under the curve were combined to test their association with the sequential organ failure assessment score by linear regression analysis in IDS. Results were validated in another IDS cohort of 174 patients. RESULTS: C-reactive protein, procalcitonin, pentraxin-3, lipocalin-2 (LCN2), tumoral necrosis factor-α, angiopoietin-2, triggering receptor expressed on myeloid cells-1 (TREM-1) and interleukin (IL)-15 yielded an area under the curve ≥0.75 to differentiate IDS from nIDS. The combination of LCN2, IL-15, TREM-1, angiopoietin-2 (Dys-4) showed the strongest association with sequential organ failure assessment score in IDS (adjusted regression coefficient; standard error; P): Dys-4 (3.55;0.44; <0.001), LCN2 (2.24; 0.28; <0.001), angiopoietin-2 (1.92; 0.33; <0.001), IL-15 (1.78; 0.40; <0.001), TREM-1(1.74; 0.46; <0.001), tumoral necrosis factor-α (1.60; 0.31; <0.001), pentraxin-3 (1.12; 0.18; <0.001), procalcitonin (0.85; 0.12; <0.001). Dys-4 provided similar results in the validation cohort. CONCLUSIONS: There is a synergistic impact of innate immunity hyper-activation (LCN2, IL-15, TREM-1) and endothelial dysfunction (angiopoietin-2) on the magnitude of organ failure during infection.

Epidemiological and microbiological characteristics of S. aureus pediatric infections in Colombia 2018-2021, a national multicenter study (Staphylored Colombia).

Background: Staphylococcus aureus infections are a significant cause of morbidity and mortality in pediatric populations worldwide. The Staphylo Research Network conducted an extensive study on pediatric patients across Colombia from 2018 to 2021. The aim of this study was to describe the epidemiological and microbiological characteristics of S. aureus in this patient group. Methods: We analyzed S. aureus isolates from WHONET-reporting centers. An "event" was a positive culture isolation in a previously negative individual after 2 weeks. We studied center characteristics, age distribution, infection type, and antibiotic susceptibilities, comparing methicillin sensitive (MSSA) and resistant S. aureus (MRSA) isolates. Results: Isolates from 20 centers across 7 Colombian cities were included. Most centers (80%) served both adults and children, with 55% offering oncology services and 85% having a PICU. We registered 8,157 S. aureus culture isolations from 5,384 events (3,345 MSSA and 1,961 MRSA) in 4,821 patients, with a median age of 5 years. Blood (26.2%) and skin/soft tissue (18.6%) were the most common infection sources. Most isolates per event remained susceptible to oxacillin (63.2%), clindamycin (94.3%), and TMP-SMX (98.3%). MRSA prevalence varied by city (<0.001), with slightly higher rates observed in exclusively pediatric hospitals. In contrast, the MRSA rate was somewhat lower in centers with Antimicrobial Stewardship Program (ASP). MRSA was predominantly isolated from osteoarticular infections and multiple foci, while MSSA was more frequently associated with recurrent infections compared to MRSA. Conclusions: This is the largest study of pediatric S. aureus infections in Colombia. We found MSSA predominance, but resistance have important regional variations. S. aureus remains susceptible to other commonly used antibiotics such as TMP-SMX and clindamycin. Ongoing monitoring of S. aureus infections is vital for understanding their behavior in children. Prospective studies within the Staphylored LATAM are underway for a more comprehensive clinical and genetic characterization.

Linear mixed-effect models for correlated response to process electroencephalogram recordings.

A data set of clinical studies of electroencephalogram recordings (EEG) following data acquisition protocols in control individuals (Eyes Closed Wakefulness - Eyes Open Wakefulness, Hyperventilation, and Optostimulation) are quantified with information theory metrics, namely permutation Shanon entropy and permutation Lempel Ziv complexity, to identify functional changes. This work implement Linear mixed-effects models (LMEMs) for confirmatory hypothesis testing. The results show that EEGs have high variability for both metrics and there is a positive correlation between them. The mean of permutation Lempel-Ziv complexity and permutation Shanon entropy used simultaneously for each of the four states are distinguishable from each other. However, used separately, the differences between permutation Lempel-Ziv complexity or permutation Shanon entropy of some states were not statistically significant. This shows that the joint use of both metrics provides more information than the separate use of each of them. Despite their wide use in medicine, LMEMs have not been commonly applied to simultaneously model metrics that quantify EEG signals. Modeling EEGs using a model that characterizes more than one response variable and their possible correlations represents a new way of analyzing EEG data in neuroscience.

DRESS syndrome due to anti-TB drugs: A complex case with successful re-desensitization of group A drugs.

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome is a rare, life-threatening adverse reaction caused by certain medications. Clinical findings usually include rash, fever, lymphadenopathy, and eosinophilia, and in some cases, they may affect major organs. This reaction caused by antituberculosis (TB) medication poses a public health risk due to treatment discontinuation, adherence, or success in cure. We present a 23-year-old female patient who developed DRESS syndrome as a result of group A anti-TB drugs (ATDs), an exceedingly rare occurrence. The patient's medication was successfully retrieved using a re-desensitization protocol.

Physicochemical Characterization of Yogurt Fortified with Microencapsulated Cinnamon (Cinnamomum zeylanicum) and Its Effects on Metabolic Syndrome Induced in Rabbits (Oryctolagus cuniculus).

Chronic noncommunicable diseases are a global health problem causing increased rates of mortality and sick leaves, which can be reduced by controlling dyslipidemia and hyperglycemia. Experimental and clinical studies have demonstrated the antidiabetic, lipid-lowering, antiobesogenic, anti-inflammatory, and antihypertensive properties of cinnamon; therefore, its use in yogurt can help reverse the effects of these diseases. Our study aims to evaluate the effect of a microencapsulated aqueous extract of cinnamon (Cinnamomum zeylanicum) (MCE Cz) incorporated in a yogurt drink on metabolic syndrome (MS) in a rabbit (Oryctolagus cuniculus). Physicochemical, microbiological, and proximal chemical characterization; total phenol, flavonoid, and 2,2-diphenyl-1-picrylhydrazil activity quantification; intestinal bioaccessibility; sensory analysis; MS induction through diet; and treatment with 5, 10, and 20 mg/kg of flavonoids contained in the MCE Cz were performed to help evaluate morphological, biochemical, and lipid peroxidation measurements in the liver and heart. The results show that the addition of MCE Cz in the yogurt modified the yogurt texture, increased its adhesiveness and firmness, and imparted a characteristic cinnamon color and biological value by providing intestinally bioaccessible antioxidants with antioxidant potential by reducing lipoperoxidation in the liver and heart after treatment. MCE Cz reduced the weight of the animals by up to 38.5% and the abdominal circumference by 29%. Biochemically, it decreased glucose levels by 24.38%, total cholesterol levels by 69.2%, triglyceride levels by 72.69%, and low-density lipoprotein levels by 89.25%; it increased high-density lipoprotein levels by 67.08%. Therefore, adding MCE Cz in doses of 5 and 10 mg of flavonoids in drinkable yogurt can be an alternative to preparing functional foods with physicochemical attributes and biological properties that can be consumed at all stages of life without undesirable effects. Moreover, it can act as a potential adjuvant in the treatment of comorbidities related to MS.

Management of deceased and living kidney donor with lithiasis: a multicenter retrospective study on behalf of the renal transplant group of the Spanish urological association.

BACKGROUND: To maximize the availability of suitable grafts and ensure effective management, several reports have demonstrated successful outcomes when using kidney grafts with urolithiasis. This multicenter study reports on the management and long-term outcomes of kidney transplantation using renal grafts with lithiasis. METHODS: Retrospective data from three Spanish hospitals were analyzed for kidney transplants involving grafts with nephrolithiasis performed between December 2009 and August 2023. The study included adult patients, excluding those with incomplete records. It evaluated stone characteristics, complications, and outcomes in recipients and in living kidney donors. RESULTS: Out of 38 analyzed kidney transplants, 57.9% were cadaveric and 42.1% were from living kidney donors. Most diagnoses were incidental during donor evaluation, with an average stone size of 7.06 mm. After follow-up (median 26 months), all recipients but one had functioning grafts, and there were no stone recurrences in both recipients and living kidney donors. Conservative management was adopted in 28 cases, while 10 cases required ex-vivo flexible ureterorenoscopy for stone removal. Following conservative management, 5 patients needed additional treatments for stone-related events. CONCLUSIONS: Kidneys with lithiasis can be considered for transplantation in selected cases, resulting in good functional outcomes with no stone recurrence in recipients or living donors.

High-resolution, high-throughput analysis of Drosophila geotactic behavior.

Drosophila innate response to gravity, geotaxis, has been previously used to assess the impact of aging and disease on motor performance. Despite its rich history, fly geotaxis continues to be largely measured manually and assessed through simplistic metrics. The manual nature of this assay introduces substantial experimental variability while simplistic metrics provide limited analytic insights into the behavior. To address these shortcomings, we have constructed a fully automated, programable apparatus, and developed a multi-object tracking software capable of following sub-second movements of individual flies, thus allowing reproducible, detailed, and quantitative analysis of geotactic behavior. The apparatus triggers and monitors geotaxis of 10 fly cohorts simultaneously, with each cohort consisting of up to 7 flies. The tracking program isolates cohorts and records individual fly coordinate outputs allowing for simultaneous multi-group, multi-fly tracks per experiment, greatly improving throughput and resolution. The algorithm tracks individual flies during the entire run with ~97% accuracy, yielding detailed climbing curve, speed, and movement direction with 1/30 second resolution. Our tracking also allows the construction of multi-variable metrics and the detection of transitory movement phenotypes, such as slips and falls, which have thus far been neglected in geotaxis studies due to limited spatio-temporal resolution. Through a combination of automation and robust tracking, the platform is therefore poised to advance Drosophila geotaxis assay into a comprehensive assessment of locomotor behavior.

Could titanium screws be an appropriate disc stabilization technique in temporomandibular joint arthroscopy?

Multiple techniques for disc fixation through temporomandibular joint arthroscopy have been described. They can be classified as non-rigid, semi-rigid, and rigid. They all offer different advantages and disadvantages, and some have greater difficulties than others. Currently, multiple modifications to the basic techniques have been described in order to facilitate the technique since disc fixation corresponds to one of the procedures that most require skill. However, each technique requires extensive evaluation and monitoring in order to avoid complications and find the benefits of each technique. For this reason, the objective of this letter to the editor is to discuss two situations observed in the previously described fixation technique with osteosynthesis screws. The first issue is the fixation mechanism, and the second is the fixation time. This is in order to continue searching for the truth among all to achieve the best results and the benefit of patients.

Zika virus infection suppresses CYP24A1 and CAMP expression in human monocytes.

Monocytes are the primary targets of Zika virus (ZIKV) and are associated with ZIKV pathogenesis. Currently, there is no effective treatment for ZIKV infection. It is known that 1,25-dihydroxy vitamin D3 (VitD3) has strong antiviral activity in dengue virus-infected macrophages, but it is unknown whether VitD3 inhibits ZIKV infection in monocytes. We investigated the relationship between ZIKV infection and the expression of genes of the VitD3 pathway, as well as the inflammatory response of infected monocytes in vitro. ZIKV replication was evaluated using a plaque assay, and VitD3 pathway gene expression was analyzed by RT-qPCR. Pro-inflammatory cytokines/chemokines were quantified using ELISA. We found that VitD3 did not suppress ZIKV replication. The results showed a significant decrease in the expression of vitamin D3 receptor (VDR), cytochrome P450 family 24 subfamily A member 1 (CYP24A1), and cathelicidin antimicrobial peptide (CAMP) genes upon ZIKV infection. Treatment with VitD3 was unable to down-modulate production of pro-inflammatory cytokines, except TNF-α, and chemokines. This suggests that ZIKV infection inhibits the expression of VitD3 pathway genes, thereby preventing VitD3-dependent inhibition of viral replication and the inflammatory response. This is the first study to examine the effects of VitD3 in the context of ZIKV infection, and it has important implications for the role of VitD3 in the control of viral replication and inflammatory responses during monocyte infection.

Interleukin 27, like interferons, activates JAK-STAT signaling and promotes pro-inflammatory and antiviral states that interfere with dengue and chikungunya viruses replication in human macrophages.

Interferons (IFNs) are a family of cytokines that activate the JAK-STAT signaling pathway to induce an antiviral state in cells. Interleukin 27 (IL-27) is a member of the IL-6 and/or IL-12 family that elicits both pro- and anti-inflammatory responses. Recent studies have reported that IL-27 also induces a robust antiviral response against diverse viruses, both in vitro and in vivo, suggesting that IFNs and IL-27 share many similarities at the functional level. However, it is still unknown how similar or different IFN- and IL-27-dependent signaling pathways are. To address this question, we conducted a comparative analysis of the transcriptomic profiles of human monocyte-derived macrophages (MDMs) exposed to IL-27 and those exposed to recombinant human IFN-α, IFN-γ, and IFN-λ. We utilized bioinformatics approaches to identify common differentially expressed genes between the different transcriptomes. To verify the accuracy of this approach, we used RT-qPCR, ELISA, flow cytometry, and microarrays data. We found that IFNs and IL-27 induce transcriptional changes in several genes, including those involved in JAK-STAT signaling, and induce shared pro-inflammatory and antiviral pathways in MDMs, leading to the common and unique expression of inflammatory factors and IFN-stimulated genes (ISGs)Importantly, the ability of IL-27 to induce those responses is independent of IFN induction and cellular lineage. Additionally, functional analysis demonstrated that like IFNs, IL-27-mediated response reduced chikungunya and dengue viruses replication in MDMs. In summary, IL-27 exhibits properties similar to those of all three types of human IFN, including the ability to stimulate a protective antiviral response. Given this similarity, we propose that IL-27 could be classified as a distinct type of IFN, possibly categorized as IFN-pi (IFN-π), the type V IFN (IFN-V).

Coupling Miniaturized Stir Bar Sorptive Dispersive Microextraction to Needle-Based Electrospray Ionization Emitters for Mass Spectrometry: Determination of Tetrahydrocannabinol in Human Saliva as a Proof of Concept.

Direct coupling of sample preparation with mass spectrometry (MS) can speed up analysis, enabling faster decision-making. In such combinations, where the analysis time is mainly defined by the extraction procedure, magnetic dispersive solid-phase extraction emerges as a relevant technique because of its rapid workflow. The dispersion and retrieval of the magnetic sorbent are typically uncoupled stages, thus reducing the potential simplicity. Stir bar sorptive dispersive microextraction (SBSDME) is a novel technique that integrates both stages into a single device. Its miniaturization (mSBSDME) makes it more portable and compatible with low-availability samples. This article reports the direct combination of mSBSDME and MS using a needle-based electrospray ionization (NESI) emitter as the interface. This combination is applied to determine tetrahydrocannabinol in saliva samples, a relevant societal problem if the global consumption rates of cannabis are considered. The coupling requires only the transference of the magnet (containing the sorbent and the isolated analyte) from the mSBSDME to the hub of a hypodermic needle, where the online elution occurs. The application of 5 kV on the needle forms an electrospray on its tip, transferring the ionized analyte to the MS inlet. The excellent performance of mSBSDME-NESI-MS/MS relies on the sensitivity (limits of detection as low as 2.25 ng mL-1), the precision (relative standard deviation lower than 15%), and the accuracy (relative recoveries ranged from 87 to 127%) obtained. According to the results, the mSBSDME-NESI-MS/MS technique promises faster and more efficient chemical analysis in MS-based applications.