Receptor interactions of protoxin and activated Vip3Aa structural conformations in Spodoptera exigua.

BACKGROUND: The Vip3Aa insecticidal protein, produced by Bacillus thuringiensis, has been effectively used in commercial Bt-crops to manage lepidopteran pests. Upon ingestion by larvae, the protoxin is processed by midgut proteases into the activated protein and binds specifically to its receptors in the midgut, leading to insect mortality. Cryo-EM resolution of the trypsin-processed Vip3Aa protein unveiled structural remodelling of the N-terminal region during the transition from protoxin to activated protein. This conformational change has been demonstrated to be crucial for toxicity against Spodoptera exigua larvae, a major global lepidopteran pest. In this study, we investigated the relevance of the structural remodelling for the specific binding to midgut receptors. RESULTS: We conducted in vitro binding assays with radiolabelled proteins and brush border membrane vesicles (BBMV) from S. exigua, employing structural mutants that lock the protein in either its protoxin or its activated conformation. Our results indicate that both structural stages of the protein share binding sites in the midgut epithelium. Moreover, in vivo competition assays revealed that Vip3Aa is able to bind to functional receptors in S. exigua larvae both as protoxin and as activated protein. CONCLUSION: Altogether, our findings point to both structural conformations contributing to receptor binding. In vivo, either spontaneous structural shift upon proteolytic cleavage or receptor-mediated remodelling could be occurring. However, the timing and context in which the conformational change occurs could influence membrane insertion and toxicity. Our results show the complex interplay between proteolytic processing, protein structure and receptor interactions in Vip3Aa's toxicity. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Successful Sirolimus Treatment for Recurrent Pericardial Effusion in a Large Cervicomediastinal Provisionally Unclassified Vascular Anomaly: A Case Report.

Provisionally unclassified vascular anomalies (PUVA) are a group of diseases with unique characteristics that make them unclassifiable within vascular tumors or malformations. We describe a PUVA as the cause of recurrent pericardial effusion and its response to sirolimus. A 6-year-old girl was referred with a cervicothoracic vascular anomaly, a violaceous, and irregular lesion in the neck and upper chest, diagnosed as "hemangioma". She had pericardial effusion at the neonatal age that required pericardiocentesis, propranolol, and corticosteroids. She remained stable for 5 years, when she presented with a severe pericardial effusion. A magnetic resonance visualized a diffuse vascular image in the cervical and thoracic region with mediastinal extension. The pathological study showed a vascular proliferation in the dermis and hypodermis with positive staining for Wilms' Tumor 1 Protein (WT1) and negative for Glut-1. Genetic testing found a variant in GNA14 , for which the diagnosis of PUVA was established. When a pericardial drain was placed without response, treatment with sirolimus was started with resolution of the effusion. Sixteen months later, the malformation is stable and there has been no recurrence of pericardial effusion. In a significant group of patients, definitive diagnosis is not possible despite pathological and genetic analysis. Mammalian target of rapamycin inhibitors may become a therapeutic option if symptoms are severe enough, with a low rate of reported side effects.

Structural and functional role of Domain I for the insecticidal activity of the Vip3Aa protein from Bacillus thuringiensis.

Vip3 proteins are produced by Bacillus thuringiensis and are toxic against lepidopterans, reason why the vip3Aa gene has been introduced into cotton and corn to control agricultural pests. Recently, the structure of Vip3 proteins has been determined and consists of a tetramer where each monomer is composed of five structural domains. The transition from protoxin to the trypsin-activated form involves a major conformational change of the N-terminal Domain I, which is remodelled into a tetrameric coiled-coil structure that is thought to insert into the apical membrane of the midgut cells. To better understand the relevance of this major change in Domain I for the insecticidal activity, we have generated several mutants aimed to alter the activity and remodelling capacity of this central region to understand its function. These mutants have been characterized by proteolytic processing, negative staining electron microscopy, and toxicity bioassays against Spodoptera exigua. The results show the crucial role of helix α1 for the insecticidal activity and in restraining the Domain I in the protoxin conformation, the importance of the remodelling of helices α2 and α3, the proteolytic processing that takes place between Domains I and II, and the role of the C-t Domains IV and V to sustain the conformational change necessary for toxicity.

Effect of physical therapy on bone remodelling in preterm infants: a multicenter randomized controlled clinical trial.

BACKGROUND: Preterm infants have a low level of bone mineralization compared to those born at term, since 80% of calcium incorporation occurs at the end of pregnancy. The purpose of the present study was to investigate the effect of reflex locomotion therapy on bone modeling and growth in preterm infants and to compare its effect with those of other Physiotherapy modalities. METHODS: A multicentre randomized controlled clinical trial was conducted (02/2016 - 07/2020). 106 preterm infants born at the Virgen de la Arrixaca University Clinical Hospital, the General University Hospital of Elche and the Torrecárdenas University Hospital of Almería, between 26 and 34 weeks with hemodynamic stability, complete enteral nutrition and without any metabolic, congenital, genetic, neurological or respiratory disorders were evaluated for inclusion. Infants were randomly assigned to three groups: one group received reflex locomotion therapy (EGrlt); another group received passive mobilizations with gentle joint compression (EGpmc); and the control group received massage (CG). All treatments were carried out in the neonatal units lasting one month. The main outcome measure was bone formation and resorption measured with bone biomarkers. A mixed ANOVA was used to compare the results of bone biomarkers, and anthropometric measurements. RESULTS: Infants were randomized to EGrlt (n = 38), EGpmc (n = 32), and CG (n = 36). All groups were similar in terms of gender (p = 0.891 female 47.2%), gestational age (M = 30.753, SD = 1.878, p = 0.39) and birth weight (M = 1413.45, SD = 347.36, p = 0.157). At the end of the study, significant differences were found between the groups in their interaction in bone formation, measured with osteocalcin [F (2,35) = 4.92, p = 0.013, ηp2 = 0.043], in benefit of the EGrlt. CONCLUSIONS: Reflex locomotion therapy has been effective in improving bone formation, more so than other Physiotherapy modalities. Therefore, reflex locomotion therapy could be considered one of the most effective physiotherapeutic modalities for the prevention and treatment of osteopenia of prematurity. TRIAL REGISTRSTION: Trial retrospectively registered at ClinicalTrials.gov. First posted on 22/04/2020. REGISTRATION NUMBER: NCT04356807 .

In vivo competition assays between Vip3 proteins confirm the occurrence of shared binding sites in Spodoptera littoralis.

Due to their different specificity, the use of Vip3 proteins from Bacillus thuringiensis in combination with the conventionally used Cry proteins in crop protection is being essential to counteract the appearance of insect resistance. Therefore, understanding the mode of action of Vip3 proteins is crucial for their better application, with special interest on the binding to membrane receptors as the main step for specificity. Derived from in vitro heterologous competition binding assays using 125I-Vip3A and other Vip3 proteins as competitors, it has been shown that Vip3 proteins share receptors in Spodoptera frugiperda and Spodoptera exigua brush border membrane vesicles (BBMV). In this study, using 125I-Vip3Aa, we have first extended the in vitro competition binding site model of Vip3 proteins to Spodoptera littoralis. With the aim to understand the relevance (in terms of toxicity) of the binding to the midgut sites observed in vitro on the insecticidal activity of these proteins, we have performed in vivo competition assays with S. littoralis larvae, using disabled mutant (non-toxic) Vip3 proteins as competitors for blocking the toxicity of Vip3Aa and Vip3Af. The results of the in vivo competition assays confirm the occurrence of shared binding sites among Vip3 proteins and help understand the functional role of the shared binding sites as revealed in vitro.

Critical Domains in the Specific Binding of Radiolabeled Vip3Af Insecticidal Protein to Brush Border Membrane Vesicles from Spodoptera spp. and Cultured Insect Cells.

Vegetative insecticidal proteins (Vip3) from Bacillus thuringiensis have been used, in combination with Cry proteins, to better control insect pests and as a strategy to delay the evolution of resistance to Cry proteins in Bt crops (crops protected from insect attack by the expression of proteins from B. thuringiensis). In this study, we have set up the conditions to analyze the specific binding of 125I-Vip3Af to Spodoptera frugiperda and Spodoptera exigua brush border membrane vesicles (BBMV). Heterologous competition binding experiments revealed that Vip3Aa shares the same binding sites with Vip3Af, but Vip3Ca does not recognize all of them. As expected, Cry1Ac and Cry1F did not compete for Vip3Af binding sites. By trypsin treatment of selected alanine mutants, we were able to generate truncated versions of Vip3Af. Their use as competitors with 125I-Vip3Af indicated that only those molecules containing domains I to III (DI-III and DI-IV) were able to compete with the trypsin-activated Vip3Af protein for binding and that molecules only containing either domain IV or domains IV and V (DIV and DIV-V) were unable to compete with Vip3Af. These results were further confirmed with competition binding experiments using 125I-DI-III. In addition, the truncated protein 125I-DI-III also bound specifically to Sf21 cells. Cell viability assays showed that the truncated proteins DI-III and DI-IV were as toxic to Sf21 cells as the activated Vip3Af, suggesting that domains IV and V are not necessary for the toxicity to Sf21 cells, in contrast to their requirement in vivo.IMPORTANCE This study shows that Vip3Af binding sites are fully shared with Vip3Aa, only partially shared with Vip3Ca, and not shared with Cry1Ac and Cry1F in two Spodoptera spp. Truncated versions of Vip3Af revealed that only domains I to III were necessary for the specific binding, most likely because they can form the functional tetrameric oligomer and because domain III is supposed to contain the binding epitopes. In contrast to results obtained in vivo (bioassays against larvae), domains IV and V are not necessary for ex vivo toxicity to Sf21 cells.

Evaluation of the Toxicity of Supernatant Cultures and Spore-Crystal Mixtures of Bacillus thuringiensis Strains Isolated from Algeria.

Bacillus thuringiensis (Bt) is the most used technology for biological control of insect pathogens worldwide. In order to select new Bt candidates challenging the emergence of insect's resistance, a mass bioassay and molecular screening was performed on an autochthonous collection. Toxicity assays against neonate larvae of three lepidopteran species (Mamestra brassicae, Grapholita molesta, and Spodoptera exigua) were conducted using spore-crystal mixtures and supernatant cultures of 49 Bt isolates harboring at least one gene coding for a lepidopteran-specific insecticidal protein. A threshold of 30% of "functional mortality" was used to discriminate between "nontoxic" and "toxic" isolates. The toxicity of many Bt isolates competed with that of Btk-HD1. However, only three of them (Bl4NA, Bl5NA, and Bl9NA) showed high toxicity in both spore-crystal mixtures and supernatant cultures against the three lepidopteran species. The Bt isolates Bl4NA and Bl9NA express a protein of 130 kDa whereas the Bt isolate Bl5NA expresses a protein of 65-70 kDa. The LC-MS/MS results indicate that the major peptides in the 130 kDa band of Bl9NA were Cry1Da, Cry1Ca, Cry1Ab, and Cry1Aa, and those in the 70 kDa band of Bl5NA were Cry1Aa and Cry1Ca. The evaluation of the protein content of the supernatants by comparison to Btk-HD1 indicates the overproduction of Vip3 proteins in these strains (most likely Vip3Aa in Bl4NA and Bl9NA and Vip3Ca in Bl5NA). In addition, these three Bt strains do not produce ß-exotoxins. Based on our results, the three selected strains could be considered promising candidates to be used in insect pest control.

Desarrollo y aplicación de un panel de indicadores de calidad para evaluar servicios de cuidados paliativos / Development and application of a quality indicator panel to evaluate palliative care services

INTRODUCCIÓN: Existe una necesidad creciente de cuidados paliativos a nivel mundial en parte debido a la mayor prevalencia de enfermedades no transmisibles y al envejecimiento poblacional. La OMS instó a las naciones a trabajar en el desarrollo, fortalecimiento y monitorización de los cuidados paliativos aún insuficientes. En Argentina, en 2014 se desarrolló un panel de 23 indicadores de calidad (10 de Estructura, 12 de Proceso, 1 de Resultado) para evaluar recursos (etapa 1). El objetivo actual fue la aplicación de dicho panel (etapa 2) en las 5 regiones del país, probando su factibilidad para identificar áreas de mejora. MÉTODO: Estudio exploratorio, prospectivo, observacional, de identificación y auditoría, transversal en 6 fases (julio 2016-julio 2018) utilizando el panel desarrollado con estándares preestablecidos. Se realizó el análisis descriptivo por indicador y recurso. RESULTADOS: Fase 1, Censo de 128 recursos; Fase 2, Cartografía y categorización de los recursos en niveles de organización (38 % de respuestas); Fase 3, Capacitación del grupo investigador; Fase 4, Auditoría en terreno. Participaron 22 recursos. Se auditaron 30 historias clínicas de pacientes oncológicos fallecidos y actividades programadas, gestión, docencia, investigación; Fase 5, Análisis: los equipos de nivel 3 alcanzaron y superaron el estándar deseable para 3 indicadores de proceso (identificación del cuidador principal, plan farmacoterapéutico y emergencias); Fase 6, Interpretación y comunicación de las áreas de mejora. CONCLUSIONES: La aplicación del panel de indicadores fue factible y se lograron identificar áreas de mejora. Un sistema de monitorización de la calidad promovería estándares asistenciales y facilitaría la planificación de acciones de capacitación y fortalecimiento institucional en Argentina

INTRODUCTION: There is a growing need for palliative care worldwide, due to a higher prevalence of non-communicable diseases and the aging of the population. The WHO urged nations to work on palliative care development, strengthening, and monitoring, which remain inadequate as of today. In 2014 a 23-quality indicator panel (10 for structure, 12 for process, 1 for outcome) was developed in Argentina to evaluate resources (stage 1). Our objective was to use this panel (stage 2) in 5 country regions to test its viability and to identify areas for improvement. METHOD: An exploratory, prospective, cross-sectional, observational study for identification and audit purposes along 6 phases (July 2016-July 2018) using the developed panel with preset standards. A descriptive analysis by indicator and resource was carried out. RESULTS: Phase 1: Census of 128 palliative care resources; Phase 2: Mapping and categorization of resources in levels of organization (38 % of answers); Phase 3: Group training; Phase 4: On-site audit. 22 resources participated. The medical records of 30 deceased patients, as well as scheduled management, teaching, and research activities were audited; Phase 5: Analysis: level-3 teams reached and even surpassed the desired standards for 3 process indicators (pharmacological plan, main caregiver identification, emergency instructions); Phase 6: Interpretation and communication of areas for improvement. CONCLUSIONS: The implementation of the indicator panel was found to be feasible and areas for improvement were identified. A quality monitoring system would boost up healthcare standards and ease planning for training and institutional strengthening actions in Argentina

Physicochemical characterization of pomegranate wines fermented with three different Saccharomyces cerevisiae yeast strains.

Three commercial Saccharomyces cerevisiae yeast strains: Viniferm Revelación, Viniferm SV and Viniferm PDM were evaluated for the production of pomegranate wine from a juice coupage of the two well-known varieties Mollar and Wonderfull. Further malolactic fermentation was carried out spontaneously. The same fermentation patterns were observed for pH, titratable acidity, density, sugar consumption, and ethanol and glycerol production. Glucose was exhausted while fructose residues remained at the end of alcoholic fermentation. A high ethanol concentration (10.91 ± 0.27% v/v) in combination with 1.49 g/L glycerol was achieved. Citric acid concentration increased rapidly a 31.7%, malic acid disappeared as result of malolactic fermentation and the lactic acid levels reached values between 0.40 and 0.96 g/L. The analysis of CIEa parameter and total anthocyanin content highlights a lower degradation of monomeric anthocyanins during winemaking with Viniferm PDM yeast. The resulting wine retains a 34.5% of total anthocyanin content of pomegranate juice blend.