Novel insights into the application of recombinant mutated phospholipases D as antigens for developing new strategies against Loxoscelism.

Loxoscelism is the pathological condition triggered by a brown spider bite. The venom of these spiders is rich in phospholipases D (PLDs), which can induce virtually all local and systemic manifestations. Recombinant mutated PLDs from clinically relevant Loxosceles species in South America have been investigated as potential antigens to develop novel therapeutic strategies for loxoscelism. However, certain gaps need to be addressed before a clinical approach can be implemented. In this study, we examined the potential of these recombinant mutated PLDs as antigens by testing some variations in the immunization scheme. Furthermore, we evaluated the efficacy of the produced antibodies in neutralizing the nephrotoxicity and sphingomyelinase activity of brown spider venoms. Our findings indicate that the number of immunizations has a greater impact on the effectiveness of neutralization compared to the amount of antigen. Specifically, two or three doses were equally effective in reducing dermonecrosis and edema. Additionally, three immunizations proved to be more effective in neutralizing mice lethality than one or two. Moreover, immunizations mitigated the signs of kidney injury, a crucial aspect given that acute renal failure is a serious systemic complication. In vitro inhibition of the sphingomyelinase activity of Loxosceles venoms, a key factor in vivo toxicity, was nearly complete after incubation with antibodies raised against these antigens. These findings underscore the importance of implementing an effective immunization scheme with multiple immunizations, without the need for high antigen doses, and enhances the spectrum of neutralization exhibited by antibodies generated with these antigens. In summary, these results highlight the strong potential of these antigens for the development of new therapeutic strategies against cutaneous and systemic manifestations of loxoscelism.

Correction: Boia-Ferreira et al. TCTP from Loxosceles Intermedia (Brown Spider) Venom Contributes to the Allergic and Inflammatory Response of Cutaneous Loxoscelism. Cells 2019, 8, 1489.

In the original publication [...].

Iron incorporation in red blood cells of pediatric sickle cell anemia: a stable isotope pilot investigation.

BACKGROUND/OBJECTIVES: Sickle cell anemia (SCA) is marked by hypoxia, inflammation, and secondary iron overload (IO), which potentially modulate hepcidin, the pivotal hormone governing iron homeostasis. The aim was to evaluate the iron incorporation in red blood cells (RBC) in SCA pediatric patients, considering the presence or absence of IO. SUBJECTS/METHODS: SCA children (n = 12; SCAtotal) ingested an oral stable iron isotope (57Fe) and iron incorporation in RBC was measured after 14 days. Patients with ≥1000 ng/mL serum ferritin were considered to present IO (SCAio+; n = 4) while the others were classified as being without IO (SCAio-; n = 8). Liver iron concentration (LIC) was determined by Magnetic Resonance Imaging (MRI) T2* method. RESULTS: The SCAio+ group had lower iron incorporation (mean ± SD: 0.166 ± 0.04 mg; 3.33 ± 0.757%) than SCAio- patients (0.746 ± 0.303 mg; 14.9 ± 6.05%) (p = 0.024). Hepcidin was not different between groups. Iron incorporation was inversely associated with serum ferritin level (SCAtotal group: r = -0.775, p = 0.041; SCAio- group: r = -0.982; p = 0.018) and sickle hemoglobin (HbS) presented positive correlation with iron incorporation (r = 0.991; p = 0.009) in SCAio- group. LIC was positively associated with ferritin (SCAtotal: r = 0.921; p = 0.026) and C reactive protein (SCAio+: r = 0.999; p = 0.020). CONCLUSION: SCAio+ group had lower iron incorporation in RBC than SCAio- group, suggesting that they may not need to reduce their intake of iron-rich food, as usually recommended. Conversely, a high percentage of HbS may indirectly exacerbate hypoxia and seems to increase iron incorporation in RBC. TRIAL REGISTRATION: This trial was registered at www.ensaiosclinicos.gov.br . Identifier RBR-4b7v8pt.

Iron absorption in adults with sickle cell anemia: a stable-isotope approach.

PURPOSE: Iron absorption in sickle cell anemia (SCA) remains unclear and studies in adults with SCA are scarce. The aim of this study was to evaluate the iron absorption SCA adults and its association with iron status and hepcidin concentration. METHODS: SCA patients (n = 13; SCAtotal) and control participants (n = 10) ingested an oral stable iron isotope (57Fe). Iron absorption was measured by inductively coupled plasma mass spectrometry (ICP-MS) 14 days after isotope administration. Patients with ≥ 1000 ng/mL serum ferritin were considered to present iron overload (IO) (SCAio+; n = 3) and others classified without IO (SCAio-; n = 10). RESULTS: Iron absorption in the control group ranged from 0.3 to 26.5% (median = 0.9%), while it varied from 0.3 to 5.4% in SCAio+ (median = 0.5%) and from 0.3 to 64.2% in the SCAio- (median = 6.9%). Hepcidin median values were 14.1 ng/mL (3.0-31.9 ng/mL) in SCAio-, 6.2 ng/mL (3.3-7.8 ng/mL) in SCAio + and 6.2 ng/mL (0.6-9.3 ng/mL) in control. Iron absorption was associated with ferritin level (r = - 0.641; p = 0.018) and liver iron concentration (LIC; r = - 0.786; p = 0.036) in the SCAtotal group. CONCLUSION: Our data suggest that SCAio- individuals may be at risk of developing primary IO. Simultaneously, secondary IO may induce physiological adaptation, resulting in reduced iron absorption. Further studies evaluating intestinal iron absorption using larger sample sizes should be conducted to help establish a safe nutrition approach to be adopted and to ensure the security of food-fortifying public policies for these patients. TRIAL REGISTRATION: This trial was registered at www.ensaiosclinicos.gov.br (Identifier RBR-4b7v8pt).

The impact of different levels of functional oil supplementation in combination with salinomycin on growth performance and intestinal microbiota of broilers undergoing Eimeria challenge: An analysis of dynamics.

The effect of salinomycin sodium alone and in combination with functional oils on performance and microbiota of broiler infected Eimeria were evaluated. 512 broilers were randomly assigned to 4 treatments (8 replicates, 16 birds/pen): a Control group (any additives); Ionophore group: salinomycin supplementation at 66 ppm (SS66); Ionophore +0.075% Functional oil (FO) group (SS66 + FO supplementation at 750 ppm); and Ionophore +0.10% FO group (SS66 + FO supplementation at 1000 ppm). At 14 days of age, birds were gavaged with 1 mL of a saline solution containing sporulated oocysts of E. tenella, E. acervulina and E. maxima. Performance indices were measured weekly. At 28 days, intestinal content was collected for microbiota analysis. Broilers of Control group presented the worst performance indices. Broilers of Ionophore + FO (0.075% and 0.10%) groups exhibited a higher BW at 28 days of age. The supplementation of Ionophore +0.075% FO resulted in a higher relative proportion of Firmicutes and a lower proportion of Actinobacteria in the ileum-jejunum. Lactobacillaceae was the dominant family in the jejunal, and ileal microbiotas of broilers fed diets supplemented with Ionophore, Ionophore +0.075% FO and Ionophore +0.10% FO. The supplementation of ionophore yielded higher numbers of Lactobacillaceae, Enterobactereaceae and Cloritridiaceae in the cecal. Ionophore associated with FO controlled the Lactobacillaceae, Enterobactereaceae and Cloritridiaceae families present in the cecum. Therefore, the combination of salinomycin with functional oil showed synergistic effect on performance and modulation of intestinal microbiota of broilers challenged with Eimeria.

Corrigendum Research priority-setting is an ethics exercise: lessons from the Global Forum on Bioethics in Research for the Region of the Americas / Corrigendum La priorización de la investigación es un ejercicio ético: lecciones del Foro Global de Bioética en la Investigación para la Región de las Américas / Corrigendum à Priorização da pesquisa é um exercício ético: lições do Fórum Global de Bioética em Pesquisa para a Região das Américas

The Pan American Journal of Public Health draws readers' attention to an error in the following article, pointed out by the authors: Saenz C, Carracedo S, Caballero C, Hurtado C, Leite Ribeiro A, Luna F, et al. Research priority-setting is an ethics exercise: lessons from the Global Forum on Bioethics in Research for the Region of the Americas. Rev Panam Salud Publica. 2024;48:e32. https://doi.org/10.26633/RPSP.2024.32 In article published on March 2024, reference 2 appears as follows: Global Forum on Bioethics in Research. GFBR 2023 Key- note presentation [Internet video]. Youtube. 2024 Feb 01 [cited 2024 Feb 13]. Available from: https://www.youtube.com/ watch?v=HlPgN6n6i8M The correct way to reference 2 is: Millum J. Ethics of health research priority setting [video]. Uploaded by Global Forum on Bioethics in Research, 1 February 2024. [Accessed on 13 February 2024] Available from: https://www.youtube.com/ watch?v=HlPgN6n6i8M.

Corrigendum La priorización de la investigación es un ejercicio ético: lecciones del Foro Global de Bioética en la Investigación para la Región de las Américas / Corrigendum Research priority-setting is an ethics exercise: lessons from the Global Forum on Bioethics in Research for the Region of the Americas / Corrigendum à Priorização da pesquisa é um exercício ético: lições do Fórum Global de Bioética em Pesquisa para a Região das Américas

La Revista Panamericana de Salud Pública llama la atención de los lectores sobre un error en el siguiente artículo, señalado por los autores: Saenz C, Carracedo S, Caballero C, Hurtado C, Leite Ribeiro A, Luna F, et al. La priorización de la investigación es un ejercicio ético: lecciones del Foro Global de Bioética en la Investigación para la Región de las Américas. Rev Panam Salud Publica. 2024;48:e26. https://doi.org/10.26633/RPSP.2024.26 En el artículo publicado en marzo 2024, la referencia 2 aparece de la siguiente manera: Global Forum on Bioethics in Research. GFBR 2023 Keynote presentation [video en internet]. Youtube. 1 de febrero de 2024 [citado 13 de febrero de 2024]. Disponible en: https://www.youtube.com/watch?v=HlPgN6n6i8M La forma correcta para la referencia 2 debe ser: Millum J. Ethics of health research priority setting [video]. Subido por Global Forum on Bioethics in Research, 1 de febrero de 2024. [citado 13 de febrero de 2024] Disponible en: https://www.youtube.com/ watch?v=HlPgN6n6i8M

Effects of Multistrain Probiotic Supplementation on Sows' Emotional and Cognitive States and Progeny Welfare.

The intensification of production systems has resulted in detrimental effects on sow welfare, which can have an adverse influence on their offspring. Considering the relevance of the microbiota-gut-brain axis, probiotics can mitigate such impacts. To investigate the effects of the dietary inclusion of probiotics on the welfare of sows and piglets, 147 multiparous sows were randomly assigned to two groups: a control group or a group supplemented with a multistrain probiotic from the beginning of pregnancy to the end of lactation. The human-animal relationship (HAR), stereotypic behavior, position changes, salivary cortisol, and plasma serotonin levels were assessed in the sows. The piglets' back test behavior and organ weight were analyzed. The probiotic-supplemented sows exhibited a better HAR index (p = 0.017), which indicated reduced aversion towards humans. The frequency of stereotypies was not influenced by the treatments. However, the supplemented sows spent more time standing (p = 0.054) and less time lying down (p = 0.008). The cortisol level of the supplemented sows was 50% lower (p = 0.047) and the serotonin levels were 11% higher (p = 0.034) than control animals. The multistrain piglets were more passive and less resistant (p = 0.076) in the back test. The organ weights were not influenced by treatments. In conclusion, the sows supplemented with probiotics showed less fear and more motivation indicators, while their piglets showed less aggression behaviors.

Research priority-setting is an ethics exercise: lessons from the Global Forum on Bioethics in Research for the Region of the Americas

This manuscript has been revised in accordance with the corrections outlined in the DOI: https://doi.org/10.26633/RPSP.2024.46 Following the 2023 meeting of the Global Forum on Bioethics in Research (GFBR), this letter to the editor makes a call to consider health research priority-setting as an ethical exercise in Latin America and the Caribbean. This implies that research priority-setting processes are not limited to a matter of procedures, but rather include an explicit discussion of the substantive ethical criteria that guide prioritization.

La priorización de la investigación es un ejercicio ético: lecciones del Foro Global de Bioética en la Investigación para la Región de las Américas

Este manuscrito ha sido corregido como se indica en el DOI: https://doi.org/10.26633/RPSP.2024.45 A raíz de la reunión del 2023 del Foro Global de Bioética en la Investigación (GFBR por su sigla en inglés), esta carta al editor hace un llamado a considerar la priorización de la investigación en salud como un ejercicio ético en América Latina y el Caribe. Ello implica que los procesos de priorización de la investigación no se limiten a cuestiones procedimentales, sino que incluyan una discusión explícita sobre los criterios éticos sustantivos que guían la priorización.

Comparative Biochemical, Structural, and Functional Analysis of Recombinant Phospholipases D from Three Loxosceles Spider Venoms.

Spiders of Loxosceles genus are widely distributed and their venoms contain phospholipases D (PLDs), which degrade phospholipids and trigger inflammatory responses, dermonecrosis, hematological changes, and renal injuries. Biochemical, functional, and structural properties of three recombinant PLDs from L. intermedia, L. laeta, and L. gaucho, the principal species clinically relevant in South America, were analyzed. Sera against L. gaucho and L. laeta PLDs strongly cross-reacted with other PLDs, but sera against L. intermedia PLD mostly reacted with homologous molecules, suggesting underlying structural and functional differences. PLDs presented a similar secondary structure profile but distinct melting temperatures. Different methods demonstrated that all PLDs cleave sphingomyelin and lysophosphatidylcholine, but L. gaucho and L. laeta PLDs excelled. L. gaucho PLD showed greater "in vitro" hemolytic activity. L. gaucho and L. laeta PLDs were more lethal in assays with mice and crickets. Molecular dynamics simulations correlated their biochemical activities with differences in sequences and conformations of specific surface loops, which play roles in protein stability and in modulating interactions with the membrane. Despite the high similarity, PLDs from L. gaucho and L. laeta venoms are more active than L. intermedia PLD, requiring special attention from physicians when these two species prevail in endemic regions.

Sertraline as a potential cancer therapeutic approach: Biological relevance of TCTP in breast cancer cell lines and tumors.

PURPOSE: This study aimed to evaluate the role of Translationally Controlled Tumor Protein (TCTP) in breast cancer (BC) and investigate the effects of sertraline, a serotonin selective reuptake inhibitor (SSRI), on BC cells. The objective was to assess the potential of sertraline as a therapeutic agent in BC treatment by examining its ability to inhibit TCTP expression and exert antitumor effects. MATERIAL AND METHODS: We utilized five different BC cell lines representing the molecular heterogeneity and distinct subtypes of BC, including luminal, normal-like, HER2-positive, and triple-negative BC. These subtypes play a crucial role in determining clinical treatment strategies and prognosis. RESULTS: The highest levels of TCTP were observed in triple-negative BC cell lines, known for their aggressive behavior. Sertraline treatment reduced TCTP expression in BC cell lines, significantly impacting cell viability, clonogenicity, and migration. Additionally, sertraline sensitized triple-negative BC cell lines to cytotoxic chemotherapeutic drugs (doxorubicin and cisplatin) suggesting its potential as an adjunctive therapy to enhance the chemotherapeutic response. Bioinformatic analysis of TCTP mRNA levels in TCGA BC data revealed a negative correlation between TCTP levels and patient survival, as well as between TCTP/tpt1 and Ki67. These findings contradict our data and previous studies indicating a correlation between TCTP protein levels and aggressiveness and poor prognosis in BC. CONCLUSIONS: Sertraline shows a promise as a potential therapeutic option for BC, particularly in triple-negative BC. Its ability to inhibit TCTP expression, enhance chemotherapeutic response, highlights its potential clinical utility in BC treatment, specifically in triple-negative BC subtype.

Brown Spider Venom Phospholipase-D Activity upon Different Lipid Substrates.

Brown spider envenomation results in dermonecrosis, characterized by an intense inflammatory reaction. The principal toxins of brown spider venoms are phospholipase-D isoforms, which interact with different cellular membrane components, degrade phospholipids, and generate bioactive mediators leading to harmful effects. The Loxosceles intermedia phospholipase D, LiRecDT1, possesses a loop that modulates the accessibility to the active site and plays a crucial role in substrate. In vitro and in silico analyses were performed to determine aspects of this enzyme's substrate preference. Sphingomyelin d18:1/6:0 was the preferred substrate of LiRecDT1 compared to other Sphingomyelins. Lysophosphatidylcholine 16:0/0:0 was preferred among other lysophosphatidylcholines, but much less than Sphingomyelin d18:1/6:0. In contrast, phosphatidylcholine d18:1/16:0 was not cleaved. Thus, the number of carbon atoms in the substrate plays a vital role in determining the optimal activity of this phospholipase-D. The presence of an amide group at C2 plays a key role in recognition and activity. In silico analyses indicated that a subsite containing the aromatic residues Y228 and W230 appears essential for choline recognition by cation-π interactions. These findings may help to explain why different cells, with different phospholipid fatty acid compositions exhibit distinct susceptibilities to brown spider venoms.

Polymorphisms in TPT1 Pathways in Pediatric Astrocytomas.

Central nervous system tumors, especially astrocytomas, are the solid neoplasms with the highest incidence and mortality rates in childhood. The diagnosis is based on histopathological characteristics, but molecular methods have been increasingly used. Translationally controlled tumor protein (TCTP) protein, encoded by the tumor protein, translationally controlled 1 (TPT1) gene, is a multifunctional protein with an important physiological role in the cell cycle. Expression of this protein has been associated with several neoplasms, including astrocytomas in adults. However, the role of this protein in pediatric astrocytomas is largely unknown. We aim to evaluate in cases of pediatric astrocytomas, the frequency of polymorphisms in the TPT1 gene and other genes associated with its molecular pathways, such as MTOR, MDM2, TP53, and CDKN1A, correlating it with protein expression and clinical variables, in formalin-fixed, paraffin-embedded (FFPE) samples. These samples were submitted to genotyping and immunohistochemistry analyses. The most revealing results refer to the MDM2 gene, rs117039649 [G/C], in which C polymorphic allele was observed only in the glioblastomas (p = .028). The CDKN1A gene, rs3176334 [T/C] presented a homozygous polymorphic genotype only in high-grade astrocytomas, when infiltrating tumors were compared (p = .039). The immunohistochemical expression of cytoplasmic MDM2 correlated with better survival rates in patients with glioblastoma (p = .018). The presence of polymorphisms in the MDM2 and CDKN1A genes, as well as a specific correlation between MDM2 expression, suggests a likely association with risk in pediatric astrocytomas. This study sought the probable role involved in the TCTP pathway, and associated proteins, in the tumorigenesis of pediatric astrocytomas, and some could have potential impact as prognostic markers in these patients.

Bacterial vaginosis and trichomoniasis: prevalence, associated factors, and performance of diagnostic tests

Introduction: Bacterial vaginosis and vaginal trichomoniasis are frequent causes of health care demand. Objective: To estimate the prevalence, identify associated factors, and investigate the performance of diagnostic tests for bacterial vaginosis and trichomoniasis. Methods: Cross-sectional study with participants over 18 years old. All of them were submitted to an interview and gynecological examination with evaluation of vaginal secretion, pH verification, collection of material for Pap smear, wet mount test, Whiff test, bacterioscopy, and polymerase chain reaction for trichomoniasis detection. Logistic regression analysis was applied to identify associated factors with bacterial vaginosis. Diagnostic performance for bacterial vaginosis was evaluated following Amsel criteria, the Ison and Hay score, and the Pap smear, considering the Nugent score as the gold standard. As for trichomoniasis, diagnostic performance was evaluated through the Pap smear and the wet mount test, using the polymerase chain reaction as the gold standard. Results: The prevalence of bacterial vaginosis was 33.7%, and for trichomoniasis, 0.5%. The complaint of abnormal vaginal secretion was associated with the diagnosis of bacterial vaginosis (odds ratio 2.2). The diagnostic accuracy by Amsel criteria, the Ison and Hay score, and the Pap smear was 35.6, 97.0, and 84.2%, respectively. The sensitivity for trichomoniasis through wet mount test was 0.0%, and through the Pap smear, 100%. Conclusion: The prevalence of bacterial vaginosis was high, and trichomoniasis was low. The only associated factor with bacterial vaginosis was the report of abnormal vaginal secretion. The methods with the most accurate diagnostic performance for bacterial vaginosis were the Ison and Hay score and the Pap smear and, for trichomoniasis, the Pap smear

Thromboprophylaxis in lower limb varicose vein surgery in Brazil.

Background: Despite all the investment in primary venous thromboembolism (VTE) prophylaxis for surgical patients in recent years, there are still no specific guidelines for those who undergo procedures to treat lower limb varicose veins. Objectives: To evaluate the profile of VTE prophylaxis practices among Brazilian vascular surgeons conducting lower limb varicose vein procedures. Methods: Survey design, sending an electronic questionnaire to Brazilian vascular surgeons. Respondents were divided between those who perform saphenous vein treatment with conventional surgery and those who perform thermoablation for the purpose of comparison between groups. Results: Of 765 respondents, 405 (53%) treat saphenous veins with conventional surgery for, 44 (6%) with foam, and 199 (26%) with thermoablation (endolaser or radiofrequency). Surgeons who perform thermoablation prescribed more pharmacoprophylaxis after varicose vein surgery than those who perform conventional surgery (67/199, 34% vs. 112/405, 28%; p = 0.002). The thermoablation group stratifies patients for thromboembolism risk more frequently than the conventional surgery group (102/199, 51% vs. 179/405, 44%; p = 0.004). Both groups use enoxaparin as the most frequent drug for prophylaxis, but the thermoablation group uses proportionally more direct oral anticoagulants than the conventional surgery group (26% vs. 10%, p<0.001). Conclusions: Brazilian vascular surgeons who perform saphenous vein treatment by thermoablation prescribe pharmacoprophylaxis more frequently and for a longer period than those who use conventional surgery.