Genotypic and phenotypic characterization of the first Latin America isolates of Corynebacterium rouxii, a recently described member of the Corynebacterium diphtheriae complex reported in Europe.

The genus Corynebacterium is the largest genera among corynebacteria and has a range of species widely spread in ecological niches, some with epidemic potential and capable of causing fatal diseases. In recent years, due to the reclassifications and discoveries of new potentially toxin-producing species, microbiological identification and epidemiological control have been compromised, becoming possible only with sequencing techniques. Two bacterial strains isolated from a cat were identified by MALDI-TOF mass spectrometry as Corynebacterium diphtheriae and sent to the collaborating center of the Brazilian Ministry of Health for molecular identification and determination of toxigenicity potential, which were initially performed by multiplex PCR method. In addition, the antimicrobial susceptibility profile was determined according to BrCAST. Finally, for the final identification at the species level and effective epidemiological monitoring, the sequencing of the 16S rRNA and rpoB housekeeping genes was carried out. The isolates were identified as nontoxigenic C. diphtheriae strains by mPCR. Both strains were found susceptible to all antimicrobial agents. Although the identification at the species level was not possible through similarity analysis of  S rRNA and rpoB housekeeping genes, the phylogenetic analysis showed that the isolates belonged to the species Corynebacterium rouxii with a high value of reliability. This is the first report of the isolation of C. rouxii in Latin America. Molecular identification, whether by the MALDI-TOF mass spectrometry or PCR techniques, does not discriminate C. rouxii from C. diphtheriae, requiring gene sequencing and phylogenetic analysis for correct identification at the species level.

Outcome of Expanded Newborn Screening Among 194 000 Neonates at Northeast México.

Objectives. To describe the results of a 16-year experience of a state-coverage expanded newborn screening program (NBSP) in Northeast México. Methods. Between 2002 and 2017, dried blood spots of newborns were screened for congenital hypothyroidism (CH), congenital adrenal hyperplasia (CAH), biotinidase deficiency, galactosemia, cystic fibrosis, and glucose-6-phosphate dehydrogenase (G6PD) deficiency via immunofluorescence and amino and fatty acid disorders and organic acidemias using tandem mass spectrometry. Frequency rates were determined. Results. Overall, 192 487 samples were processed; 99.4% had negative results, and 598 were diagnosed. The frequency was 3.01/1000 newborns. G6PD deficiency, CH, amino acidemia, organic acidemia, cystic fibrosis, CAH, fatty acid oxidation disorder, galactosemia, and biotinidase deficiency cases were 1:773, 1:962, 1:4277, 1:4476, 1:11,322, 1:10,693, 1:10,693, 1:38,497, and 1:64,162, respectively. Conclusion. Using different technologies in NBSP increased the number of conditions detected, facilitating infant morbidity and mortality prevention. The frequency of disorders depends on the population's genetic background and diagnostic capacity.

Untargeted Liquid Chromatography-High-Resolution Mass Spectrometry Metabolomic Investigation Reveals Altered Lipid Content in Leishmania infantum Lacking Lipid Droplet Protein Kinase.

Leishmaniasis is a complex disease caused by different species of Leishmania. To date, no vaccine for humans or ideal therapy has been developed owing to the limited efficacy and toxicity of available drugs, as well as the emergence of resistant strains. Therefore, it is necessary to identify novel therapeutic targets and discover therapeutic options for leishmaniasis. In this study, we evaluated the impact of deleting the lipid droplet protein kinase (LDK) enzyme in Leishmania infantum using an untargeted metabolomics approach performed using liquid chromatography and high-resolution mass spectrometry. LDK is involved in lipid droplet biogenesis in trypanosomatids. Thirty-nine lipid metabolites altered in the stationary and logarithmic growth phases were noted and classified into five classes: (1) sterols, (2) fatty and conjugated acids, (3) ceramides, (4) glycerophosphocholine and its derivatives, and (5) glycerophosphoethanolamine and its derivatives. Our data demonstrated that glycerophosphocholine and its derivatives were the most affected after LDK deletion, suggesting that the absence of this enzyme promotes the remodeling of lipid composition in L. infantum, thus contributing to a better understanding of the function of LDK in this parasite.

Synthesis and characterization of the dental adhesive monomer 10-MDP.

Many studies have demonstrated the excellent performance of 10-MDP (10-methacryloyloxydecyl dihydrogen phosphate) as a functional monomer for dental adhesive materials and as a primer for ceramic surfaces. Although adhesive performance is affected by the purity level of 10-MDP, this parameter is rarely described, and possible byproducts have been suggested in the literature, but have not been identified to date. The present study aims to present an accessible 10-MDP synthesis strategy with easily handled reagents and address the characterization challenges, especially in identifying byproducts. 10-MDP was synthesized from 10-hydroxydecyl methacrylate and phosphorus pentoxide in acetone. The final product was characterized by nuclear magnetic resonance (NMR), infrared spectroscopy (FTIR) and mass spectrometry MALDITOF/TOF. The main chemical groups associated with 10-MDP were identified by 1H, 31P, and 13C NMR analyses. Only mass spectrometry analyses (MALDITOF/TOF) could identify the presence of dimers as byproducts. Its proposed chemical structure indicates that the dimers were formed by the reaction between the phosphate ester groups and others formed by the reaction of the methacrylic group of 10-MDP molecules. Careful adjustment of the synthesis conditions to reduce the formation of these byproducts is also described. The results indicate that the characterization of 10-MDP batches as raw materials is an important task because, depending on the byproduct present, its ability to polymerize or acid etching capacity may be compromised.

Magnetic particle spray mass spectrometry for the determination of beta-blockers in plasma samples.

Magnetic particle spray mass spectrometry (MPS-MS), an innovative ambient ionization technique proposed by our research group, was employed to determine beta-blockers in human plasma samples. A dispersive solid phase extraction of atenolol, metoprolol, labetalol, propranolol, nadolol, and pindolol was carried out using magnetic molecularly imprinted polymer (M-MIP) particles that were attached to the tip of a metal probe, which was placed in the mass spectrometer inlet. A solvent (1% formic acid in methanol) was dispensed on the particles, and the Taylor cone was formed around them (in high voltage). The analytes were desorbed/ionized and determined by a triple quadrupole mass spectrometer. M-MIP was synthesized with oxprenolol as a pseudo-template, demonstrating good selectivity to beta-blockers compared with no-analog molecules, with an adsorption process occurring in monolayers, according to isotherm studies. Kinetic experiments indicated chemisorption as the predominant M-MIP/analyte interaction. The analytical curves were linear (R2 > 0.98), and the limit of quantification was 3 µg L-1 for all the analytes. Limits of detection ranged from 0.64 to 2.41 µg L-1. Precisions (relative standard deviation) and accuracies (relative error) ranged from 3.95 to 21.20% and -17.05 to 18.93%, respectively. MPS-MS proved to be a simple, sensitive, and advantageous technique compared with conventional approaches. The analyses were fast, requiring no chromatographic separation and without ionic suppression. The method is aligned with green chemistry principles, requiring minimal sample, solvent, and sorbent amounts. MPS-MS successfully integrates sample preparation and ambient ionization mass spectrometry and holds great potential for application with other sorbents, samples, and analytes.

GC-MS metabolomics of French lettuce (Lactuca Sativa L. var capitata) leaves exposed to bisphenol A via the hydroponic media.

INTRODUCTION: Bisphenol A (BPA), an organic compound used to produce polycarbonate plastics and epoxy resins, has become a ubiquitous contaminant due to its high-volume production and constant release to the environment. Plant metabolomics can trace the stress effects induced by environmental contaminants to the variation of specific metabolites, making it an alternative way to study pollutants toxicity to plants. Nevertheless, there is an important knowledge gap in metabolomics applications in this area. OBJECTIVE: Evaluate the influence of BPA in French lettuce (Lactuca Sativa L. var capitata) leaves metabolic profile by gas chromatography coupled to mass spectrometry (GC-MS) using a hydroponic system. METHODS: Lettuces were cultivated in the laboratory to minimize biological variation and were analyzed 55 days after sowing (considered the plant's adult stage). Hexanoic and methanolic extracts with and without derivatization were prepared for each sample and analyzed by GC-MS. RESULTS: The highest number of metabolites was obtained from the hexanoic extract, followed by the derivatized methanolic extract. Although no physical differences were observed between control and contaminated lettuce leaves, the multivariate analysis determined a statistically significant difference between their metabolic profiles. Pathway analysis of the most affected metabolites showed that galactose metabolism, starch and fructose metabolism and steroid biosynthesis were significantly affected by BPA exposure. CONCLUSIONS: The preparation of different extracts from the same sample permitted the determination of metabolites with different physicochemical properties. BPA alters the leaves energy and membrane metabolism, plant growth could be affected at higher concentrations and exposition times.

Stability in human serum and plasma of the HIV peptide drug candidate CIGB-210 and improved variants.

The peptide CIGB-210 inhibits HIV replication, inducing a rearrangement of vimentin intermediate filaments. The assessment of the in vitro serum and plasma stability of this peptide is important to develop an optimal pharmacological formulation. A half-life of 17.68 ± 0.59 min was calculated for CIGB-210 in human serum by reverse-phase high-performance liquid chromatography (HPLC) and mass spectrometry (MS). Eight metabolites of CIGB-210 were identified with this methodology, all of them lacking the N-terminal moiety. A previously developed CIGB-210 in-house competitive ELISA was used to compare the stability of CIGB-210 derivatives containing either D-amino acids, acetylation at the N-terminus, or both modifications. The half-life of CIGB-210 in serum was five times higher when measured by ELISA than by HPLC/MS, and twice higher in plasma as compared to serum. The substitution of D-asparagine on position 6 doubled the half-life, while D-amino acids on positions 8 and 9 did not improve the stability. The acetylation of the N-terminus resulted in a 24-fold more stable peptide in plasma. The positive effect of N-terminal acetylation on CIGB-210 serum stability was confirmed by the HPLC/MS method, as the half-life of the peptide was not reached after 2 h of incubation, which represents more than a 6.8-fold increase in the half-life with respect to the original peptide.

Ethion food poisoning outbreak in Pereira, Colombia, 2022.

INTRODUCTION: Ethion is an organophosphate used as an acaricide and insecticide, that is restricted worldwide. In Colombia, pesticide poisoning is the third most common cause of chemical intoxication. On 9 October 2022, an outbreak of ethion poisoning occurred in Pereira. The aim of this study was to describe the clinical and epidemiological characteristics of the outbreak. METHODS: This is a descriptive study of an outbreak of organophosphate poisoning. The onset of symptoms occurred on 9 October 2022, following the consumption of empanadas. Information was collected on sociodemographic characteristics and clinical manifestations, as well as from paraclinical examinations. Data were obtained from clinical histories, field epidemiological investigations, and inspection visits. Food samples were collected for analysis by gas chromatography-mass spectrometry. Attack rates, proportions, and measures of central tendency, dispersion, and position were calculated. RESULTS: The case definition was met by 37 individuals with a median age of 30 years; all presented with muscarinic symptoms, 29 patients presented with nicotinic symptoms, and 20 patients presented with neurological symptoms. Males were the most affected (57%), and the most common time of symptom onset was 10:00 am. Twenty-three patients (62%) required intensive care unit admission, of whom 14 (38%) required mechanical ventilation. No deaths were reported. Erythrocyte acetylcholinesterase activity was reduced in all patients. Ethion was detected in mass-prepared maize and empanadas at concentrations greater than 0.1 mg/kg. The consumption of empanadas was identified as the common source. DISCUSSION: In Colombia, pesticide poisonings are the third most common type of poisoning caused by chemical substances reported to the National Health Institute through the National Public Health Surveillance System. In the present outbreak, ethion was in empanadas, likely due to contamination of cooking oil. CONCLUSIONS: We describe a large ethion-contaminated food poisoning outbreak reported in Colombia. The main symptoms were muscarinic, and the main treatment measures employed were atropine and respiratory support. Increased awareness of pesticide poisoning and training for food handlers are needed.

Contamination by microplastics and sorbed organic pollutants in the surface waters of the Tietê River, São Paulo-SP, Brazil.

Microplastics (MPs) are particles between 1 µm and 5 mm in size, originating mainly from poor solid waste and effluent management, that can reach water bodies from various sources. In freshwater environments, the occurrence, distribution, and characterization of this new class of pollutants are still little explored, especially in Brazil. The aim of this study was to assess the occurrence of MPs, as well as the presence and concentration of polychlorinated biphenyls (PCBs) sorbed to these particles in the surface waters of the Tietê River - SP. Surface water samples were collected in duplicate during the dry and wet seasons. The identification and characterization of the MPs was carried out through visual inspection and the chemical identity of the particles was verified using Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR). For the analysis of PCBs adsorbed to the MPs, the sample extracts were analyzed by gas chromatography coupled with mass spectrometry (GC-MS). The MPs were found in concentrations ranging from 6.67 to 1530 particles m-3, with a predominance of the polymers polyethylene (PE, with 58.17 %) and polypropylene (PP, with 23.53 %). The main morphological categories identified were fragments (56.63 %), fibers (28.42 %), and transparent films (13.06 %). Higher abundances of PCBs were observed in the lower size range, between 0.106 and 0.35 mm. The total concentrations of PCBs in MPs ranged from 20.53 to 133.12 ng g-1. The results obtained here are relevant for understanding the dynamics and level of contamination of MPs and organic pollutants sorbed to these particles in the Tietê River, as well as helping with mitigation measures for the restoration and preservation of this ecosystem.

Análisis de los niveles de ácidos orgánicos en orina de la primera infancia y recién nacidos: un estudio de cromatografía gaseosa acoplada a espectrometría de masas con evaluación de rangos de referencia / Analysis of urinary organic acid levels in early childhood and newborns: a gas chromatography-mass spectrometry study with evaluation of reference ranges / Análise dos níveis de ácidos orgânicos na urina da primeira infância e dos recém-nascidos: um estudo por cromatografia gasosa acoplada a espectrometria de massa com avaliação de intervalos de referência

Resumen El análisis de los ácidos orgánicos urinarios juega un papel crucial en el diagnóstico y seguimiento de pacientes con trastornos metabólicos congénitos. La falta de datos completos, las variaciones en los hábitos alimentarios entre países y el aumento del consumo de alimentos procesados subrayan la necesidad de realizar investigaciones actualizadas. Con el fin de establecer los intervalos de confianza y medianas de ácidos orgánicos urinarios se evaluaron mediante cromatografía gaseosa acoplada a espectrometría de masas, 125 muestras de orina de pacientes sanos, con edades comprendidas entre 2 días y 13 años. Los resultados fueron analizados teniendo en cuenta el grupo etario, y evidenciaron que las concentraciones de la mayoría de los ácidos orgánicos urinarios varían de acuerdo a la edad, lo que enfatiza la importancia de los valores de referencia emparejados con la edad para interpretar los datos de los pacientes. Existen pocos informes en esta área; sin embargo, la comparación de estos resultados con los valores de referencia informados por otros trabajos muestra una concordancia razonable y las pocas disparidades podrían atribuirse a factores genéticos o influencias dietéticas. Se presentan resultados e interpretaciones de niños previamente diagnosticados con trastornos metabólicos y otras afecciones, lo que confirma la confiabilidad de nuestros datos y métodos analíticos. Este estudio proporciona datos de referencia esenciales para los profesionales clínicos, destaca la importancia de los valores de referencia específicos de la edad para diagnosticar y tratar con precisión a pacientes con trastornos metabólicos y sirve como recurso fundamental para futuras investigaciones en este campo.

Abstract Analysis of urinary organic acids plays a crucial role in the diagnosis and monitoring of patients with congenital metabolic disorders. The lack of complete data, variations in dietary habits between countries, and increasing consumption of processed foods highlight the need for up-to-date research. In order to establish the confidence intervals and medians of urinary organic acids, 125 urine samples from healthy patients, aged between 2 days and 13 years, were evaluated by gas chromatography coupled to mass spectrometry. The results were analysed taking into account the age group, showing that the concentrations of most urinary organic acids vary according to age, which emphasises the importance of paired age reference values to interpret patient data. There are few reports in this area; however, comparing our results with those reference values reported by other papers demonstrates reasonable agreement, and minor disparities could be attributed to genetic factors or dietary influences. Results and interpretations from children previously diagnosed with metabolic disorders and other conditions are presented, confirming the reliability of our data and analytical methods. This study provides essential reference data for clinicians, highlighting the importance of age-specific reference values to accurately diagnose and treat patients with metabolic disorders and serves as a critical resource for future research in this field.

Resumo A análise dos ácidos orgânicos urinários desempenha um papel crucial no diagnóstico e monitoramento de pacientes com distúrbios metabólicos congênitos. A falta de dados completos, as variações nos hábitos alimentares entre países e o aumento do consumo de alimentos processados destacam a necessidade de realizar pesquisas atualizadas. Para estabelecer os intervalos de confiança e medianas de ácidos orgânicos urinários, 125 amostras de urina de pacientes saudáveis, com idades entre 2 dias e 13 anos, foram avaliadas por cromatografia gasosa acoplada à espectrometria de massa. Os resultados foram analisados levando em consideração o grupo etário, evidenciando que as concentrações da maioria dos ácidos orgânicos urinários variam de acordo com a idade, o que destaca a importância dos valores de referência pareados com a idade para interpretar os dados dos pacientes. Há poucos relatos nesta área; no entanto, a comparação destes resultados com os valores de referência informados por outros trabalhos demonstra uma concordância razoável, e as poucas disparidades poderiam ser atribuídas a fatores genéticos ou influências dietéticas. São apresentados resultados e interpretações de crianças previamente diagnosticadas com distúrbios metabólicos e outras condições, o que confirma a confiabilidade de nossos dados e métodos analíticos. Este estudo fornece dados de referência essenciais para profissionais clínicos, enfatizando a importância dos valores de referência específicos da idade para diagnosticar e tratar com precisão pacientes com distúrbios metabólicos, e serve como recurso fundamental para futuras pesquisas nesse campo.

Development of a unified method for the determination of legacy and metabolites of current pesticides in serum for exposure assessment.

The use of pesticides is often regarded as a fundamental aspect of conventional agriculture. However, these compounds have gained recognition as some of the oldest and most widely employed xenobiotic contaminants, necessitating effective strategies for human biomonitoring. In this context, a method was developed for the determination of 16 legacy organochlorine pesticides, 6 metabolites of current pesticides (2,4-D, malathion, parathion, fipronil, pyraclostrobin, cypermethrin, permethrin, cyfluthrin), and 1 triazine herbicide (atrazine) in serum. Samples were prepared with water, formic acid, acetonitrile, and ultrasound irradiation, followed by solid-phase extraction with Oasis Prime HLB. Subsequently, metabolites from current pesticides underwent derivatization using MTBSTFA with 1% TBDMSCl for analysis via gas chromatography-tandem mass spectrometry (GC-MS/MS), employing an SLB-5MS fused silica capillary column. Analytical curves were generated with limits of quantification from 0.3 to 4.0 ng.mL-1. Accuracy ranged from 69 to 124%, and the coefficient of variation from 2 to 28%. Moreover, determining 1-(4-chlorophenyl)-1H-pyrazol-3-ol was suggested as a biomarker for pyraclostrobin biomonitoring. This analytical approach facilitated the determination of both legacy and metabolites of current pesticides in the same serum sample, presenting an interesting and cost-effective option for large cohorts, and multi-omics studies that evaluate time-dependent biomarkers in blood samples, thereby enabling biomonitoring within the same matrix. Furthermore, a proof-of-concept involving 10 volunteers demonstrated exposure to 9 pesticides at mean concentrations measured in ng mL-1, consistent with findings from various biomonitoring initiatives.

Porphyrin Production by Corynebacterium diphtheriae Strains from Clinical Isolates.

Porphyrins are intermediate metabolites involved in the biosynthesis of vital molecules, including heme, cobalamin, and chlorophyll. Bacterial porphyrins are known to be proinflammatory and are associated with biofilm formation. This study investigated porphyrin production by strains of Corynebacterium diphtheriae using emission spectroscopy, high-performance liquid chromatography with fluorescence detection, diode array detector, and mass spectrometry. Emission spectroscopy revealed characteristic porphyrin emission spectra in all strains, with coproporphyrin III predominating. Qualitative analysis by different chromatographic methods identified coproporphyrin III, uroporphyrin I, and protoporphyrin IX in all strains. Quantitative analysis revealed strain-dependent coproporphyrin III production. Further studies are required to investigate the relationship between porphyrin production and the virulence potential of Corynebacterium diphtheriae.

Heme metabolism in Strigomonas culicis: Implications of H2O2 resistance induction and symbiont elimination.

Monoxenous trypanosomatid Strigomonas culicis harbors an endosymbiotic bacterium, which enables the protozoa to survive without heme supplementation. The impact of H2O2 resistance and symbiont elimination on intracellular heme and Fe2+ availability was analyzed through a comparison of WT strain with both WT H2O2-resistant (WTR) and aposymbiotic (Apo) protozoa. The relative quantification of the heme biosynthetic pathway through label-free parallel reaction monitoring targeted mass spectrometry revealed that H2O2 resistance does not influence the abundance of tryptic peptides. However, the Apo strain showed increased coproporphyrinogen III oxidase and ferrochelatase levels. A putative ferrous iron transporter, homologous to LIT1 and TcIT from Leishmania major and Trypanosoma cruzi, was identified for the first time. Label-free parallel reaction monitoring targeted mass spectrometry also showed that S. culicis Iron Transporter (ScIT) increased 1.6- and 16.4-fold in WTR and Apo strains compared to WT. Accordingly, antibody-mediated blockage of ScIT decreased by 28.0% and 40.0% intracellular Fe2+concentration in both WTR and Apo strains, whereas no effect was detected in WT. In a heme-depleted medium, adding 10 µM hemin decreased ScIT transcript levels in Apo, whereas 10 µM PPIX, the substrate of ferrochelatase, increased intracellular Fe2+ concentration and ferric iron reduction. Overall, the data suggest mechanisms dependent on de novo heme synthesis (and its substrates) in the Apo strain to overcome reduced heme availability. Given the importance of heme and Fe2+ as cofactors in metabolic pathways, including oxidative phosphorylation and antioxidant systems, this study provides novel mechanistic insights associated with H2O2 resistance in S. culicis.

Recent advances in the chromatographic analysis of endocannabinoids and phytocannabinoids in biological samples.

Endocannabinoid system, including endocannabinoid neurotransmitters (eCBs), has gained much attention over the last years due to its involvement with the pathophysiology of diseases and the potential use of Cannabis sativa (marijuana). The identification of eCBs and phytocannabinoids in biological samples for forensic, clinical, or therapeutic drug monitoring purposes constitutes a still significant challenge. In this scoping review, the recent advantages, and limitations of the eCBs and phytocannabinoids quantification in biological samples are described. Published studies from 2018-2023 were searched in 8 databases, and after screening and exclusions, the selected 38 articles had their data tabulated, summarized, and analyzed. The main characteristics of the eCBs and phytocannabinoids analyzed and the potential use of each biological sample were described, indicating gaps in the literature that still need to be explored. Well-established and innovative sample preparation protocols, and chromatographic separations, such as GC, HPLC, and UHPLC, are reviewed highlighting their respective advantages, drawbacks, and challenges. Lastly, future approaches, challenges, and tendencies in the quantification analysis of cannabinoids are discussed.

Fish Fillet Analogue Using Formulation Based on Mushroom (Pleurotus ostreatus) and Enzymatic Treatment: Texture, Sensory, Aromatic Profile and Physicochemical Characterization.

The growing demand for alternative sources of non-animal proteins has stimulated research in this area. Mushrooms show potential in the innovation of plant-based food products. In this study, the aim was to develop prototype fish fillets analogues from Pleurotus ostreatus mushrooms applying enzymatic treatment (ß-glucanase and transglutaminase-TG). A Plackett-Burman 20 experimental design was used to optimize forty variables. Oat flour (OF) exerted a positive effect on the hardness and gumminess texture parameters but a negative effect on cohesiveness and resilience. Soy protein isolate (SPI) exhibited a positive effect on elasticity, gumminess and chewiness, while acacia gum had a negative effect on elasticity, cohesiveness and resilience. After sensory analysis the assay with 1% cassava starch, 5% OF, 5% SPI, 0.1% transglutaminase (240 min/5 °C), 1% coconut oil, 1% soybean oil, 0.2% sodium tripolyphosphate, 0.6% ß-glucanase (80 °C/10 min) and without ß-glucanase inactivation was found to exhibit greater similarity to fish fillet. The classes hydrocarbons, alcohols and aldehydes are the predominant ones in aromatic profile analysis by chromatography and electronic nose. It is concluded that a mushroom-based analogue of fish fillet can be prepared using enzymatic treatment with TG.

On the PhyloQuant protein expression profiles approach to the taxonomic problem.

Inferring evolutionary relationships among organisms has been a fundamental problem in evolutionary biology. The current phylogenetic molecular methods serve as the baseline model to test new evolutionary hypotheses with taxonomic purposes. Leishmaniinae trypanosomatids subfamily includes protozoan parasites of clinical importance to humans. They have an intricate taxonomic history defined by morphological elements, host range, and molecular phylogenies. Unraveling the increasing diversity of this group has shown limitations in reconstructing the true evolutionary relationships among Trypanosomatidae species. Toward the goal of inferring evolutionary relationships that help to resolve phylogenetic and taxonomic controversies among parasites of the subfamily Leishmaniinae, Mule et al. propose the method PhyloQuant as a valuable approach, based on differential protein expression obtained from high throughput mass spectrometry data. Employing a pioneering methodological approach, Mule et al. assess the taxonomic problem for species hypothesis within Leishmaniinae, from quantitative phenetic protein expression profiles, in contrast to the standard multilocus phylogenetic approaches.

Proteomic changes of the bovine blood plasma in response to heat stress in a tropically adapted cattle breed.

Background: Identifying molecular mechanisms responsible for the response to heat stress is essential to increase production, reproduction, health, and welfare. This study aimed to identify early biological responses and potential biomarkers involved in the response to heat stress and animal's recovery in tropically adapted beef cattle through proteomic analysis of blood plasma. Methods: Blood samples were collected from 14 Caracu males during the heat stress peak (HSP) and 16 h after it (heat stress recovery-HSR) assessed based on wet bulb globe temperature index and rectal temperature. Proteome was investigated by liquid chromatography-tandem mass spectrometry from plasma samples, and the differentially regulated proteins were evaluated by functional enrichment analysis using DAVID tool. The protein-protein interaction network was evaluated by STRING tool. Results: A total of 1,550 proteins were detected in both time points, of which 84 and 65 were downregulated and upregulated during HSR, respectively. Among the differentially regulated proteins with the highest absolute log-fold change values, those encoded by the GABBR1, EPHA2, DUSP5, MUC2, DGCR8, MAP2K7, ADRA1A, CXADR, TOPBP1, and NEB genes were highlighted as potential biomarkers because of their roles in response to heat stress. The functional enrichment analysis revealed that 65 Gene Ontology terms and 34 pathways were significant (P < 0.05). We highlighted those that could be associated with the response to heat stress, such as those related to the immune system, complement system, hemostasis, calcium, ECM-receptor interaction, and PI3K-Akt and MAPK signaling pathways. In addition, the protein-protein interaction network analysis revealed several complement and coagulation proteins and acute-phase proteins as important nodes based on their centrality and edges. Conclusion: Identifying differentially regulated proteins and their relationship, as well as their roles in key pathways contribute to improve the knowledge of the mechanisms behind the response to heat stress in naturally adapted cattle breeds. In addition, proteins highlighted herein are potential biomarkers involved in the early response and recovery from heat stress in tropically adapted beef cattle.

Bilirubin Molecular Species Play an Important Role in the Pathophysiology of Acute-on-Chronic Liver Failure.

Bilirubin plays a key role in early diagnosis, prognosis, and prevention of liver diseases. Unconjugated bilirubin (UCB) requires conversion to a water-soluble form through liver glucuronidation, producing monoglucuronide (BMG) or diglucuronide bilirubin (BDG) for bile excretion. This study aimed to assess the roles of bilirubin's molecular species-UCB, BMG, and BDG-in diagnosing and understanding the pathogenesis of liver cirrhosis in patients with acute-on-chronic liver failure (ACLF), compensated liver cirrhosis (LC) patients, and healthy individuals. The study included patients with ACLF and compensated LC of diverse etiologies, along with healthy controls. We collected laboratory and clinical data to determine the severity and assess mortality. We extracted bilirubin from serum samples to measure UCB, BMG, and BDG using liquid chromatography-mass spectrometry (LC-MS). The quantification of bilirubin was performed by monitoring the mass charge (m/z) ratio. Of the 74 patients assessed, 45 had ACLF, 11 had LC, and 18 were healthy individuals. Among ACLF patients, the levels of molecular species of bilirubin were UCB 19.69 µmol/L, BMG 47.71 µmol/L, and BDG 2.120 µmol/L. For compensated cirrhosis patients, the levels were UCB 11.29 µmol/L, BMG 1.49 µmol/L, and BDG 0.055 µmol/L, and in healthy individuals, the levels were UCB 6.42 µmol/L, BMG 0.52 µmol/L, and BDG 0.028 µmol/L. The study revealed marked elevations in the bilirubin species in individuals with ACLF compared to those with compensated cirrhosis and healthy controls, underscoring the progression of liver dysfunction. The correlation of BMG and BDG levels with commonly used inflammatory markers suggests a relationship between bilirubin metabolism and systemic inflammation in ACLF.

The autophagy proteome in the brain.

As one of the most important cellular housekeepers, autophagy directly affects cellular health, homeostasis, and function. Even though the mechanisms behind autophagy are well described, how molecular alterations and dysfunctions can lead to pathology in disease contexts still demands deeper investigation. Proteomics is a widely employed tool used to investigate molecular alterations associated with pathological states and has proven useful in identifying alterations in protein expression levels and post-translational modifications in autophagy. In this narrative review, we expand on the molecular mechanisms behind autophagy and its regulation, and further compile recent literature associating autophagy disturbances in context of brain disorders, utilizing discoveries from varying models and species from rodents and cellular models to human post-mortem brain samples. To outline, the canonical pathways of autophagy, the effects of post-translational modifications on regulating each step of autophagy, and the future directions of proteomics in autophagy will be discussed. We further aim to suggest how advancing proteomics can help further unveil molecular mechanisms with regard to neurological disorders.