Differential activation of basal and IL-7-induced PI3K/Akt/mTOR and JAK/STAT5 signaling distinguishes pediatric from adult acute lymphoblastic leukemia.

Not available.

The genetic landscape of mitochondrial diseases in the next-generation sequencing era: a Portuguese cohort study.

Introduction: Rare disorders that are genetically and clinically heterogeneous, such as mitochondrial diseases (MDs), have a challenging diagnosis. Nuclear genes codify most proteins involved in mitochondrial biogenesis, despite all mitochondria having their own DNA. The development of next-generation sequencing (NGS) technologies has revolutionized the understanding of many genes involved in the pathogenesis of MDs. In this new genetic era, using the NGS approach, we aimed to identify the genetic etiology for a suspected MD in a cohort of 450 Portuguese patients. Methods: We examined 450 patients using a combined NGS strategy, starting with the analysis of a targeted mitochondrial panel of 213 nuclear genes, and then proceeding to analyze the whole mitochondrial DNA. Results and Discussion: In this study, we identified disease-related variants in 134 (30%) analyzed patients, 88 with nuclear DNA (nDNA) and 46 with mitochondrial DNA (mtDNA) variants, most of them being pediatric patients (66%), of which 77% were identified in nDNA and 23% in mtDNA. The molecular analysis of this cohort revealed 72 already described pathogenic and 20 novel, probably pathogenic, variants, as well as 62 variants of unknown significance. For this cohort of patients with suspected MDs, the use of a customized gene panel provided a molecular diagnosis in a timely and cost-effective manner. Patients who cannot be diagnosed after this initial approach will be further selected for whole-exome sequencing. Conclusion: As a national laboratory for the study and research of MDs, we demonstrated the power of NGS to achieve a molecular etiology, expanding the mutational spectrum and proposing accurate genetic counseling in this group of heterogeneous diseases without therapeutic options.

Gene expression analysis reveals diabetes-related gene signatures.

BACKGROUND: Diabetes is a spectrum of metabolic diseases affecting millions of people worldwide. The loss of pancreatic ß-cell mass by either autoimmune destruction or apoptosis, in type 1-diabetes (T1D) and type 2-diabetes (T2D), respectively, represents a pathophysiological process leading to insulin deficiency. Therefore, therapeutic strategies focusing on restoring ß-cell mass and ß-cell insulin secretory capacity may impact disease management. This study took advantage of powerful integrative bioinformatic tools to scrutinize publicly available diabetes-associated gene expression data to unveil novel potential molecular targets associated with ß-cell dysfunction. METHODS: A comprehensive literature search for human studies on gene expression alterations in the pancreas associated with T1D and T2D was performed. A total of 6 studies were selected for data extraction and for bioinformatic analysis. Pathway enrichment analyses of differentially expressed genes (DEGs) were conducted, together with protein-protein interaction networks and the identification of potential transcription factors (TFs). For noncoding differentially expressed RNAs, microRNAs (miRNAs) and long noncoding RNAs (lncRNAs), which exert regulatory activities associated with diabetes, identifying target genes and pathways regulated by these RNAs is fundamental for establishing a robust regulatory network. RESULTS: Comparisons of DEGs among the 6 studies showed 59 genes in common among 4 or more studies. Besides alterations in mRNA, it was possible to identify differentially expressed miRNA and lncRNA. Among the top transcription factors (TFs), HIPK2, KLF5, STAT1 and STAT3 emerged as potential regulators of the altered gene expression. Integrated analysis of protein-coding genes, miRNAs, and lncRNAs pointed out several pathways involved in metabolism, cell signaling, the immune system, cell adhesion, and interactions. Interestingly, the GABAergic synapse pathway emerged as the only common pathway to all datasets. CONCLUSIONS: This study demonstrated the power of bioinformatics tools in scrutinizing publicly available gene expression data, thereby revealing potential therapeutic targets like the GABAergic synapse pathway, which holds promise in modulating α-cells transdifferentiation into ß-cells.

Association of early cleavage, morula compaction and blastocysts ploidy of IVF embryos cultured in a time-lapse system and biopsied for genetic test for aneuploidy.

IVF embryos have historically been evaluated by morphological characteristics. The time-lapse system (TLS) has become a promising tool, providing an uninterrupted evaluation of morphological and dynamic parameters of embryo development. Furthermore, TLS sheds light on unknown phenomena such as direct cleavage and incomplete morula compaction. We retrospectively analyzed the morphology (Gardner Score) and morphokinetics (KIDScore) of 835 blastocysts grown in a TLS incubator (Embryoscope+), which were biopsied for preimplantation genetic testing for aneuploidy (PGT-A). Only the embryos that reached the blastocyst stage were included in this study and time-lapse videos were retrospectively reanalysed. According to the pattern of initial cleavages and morula compaction, the embryos were classified as: normal (NC) or abnormal (AC) cleavage, and fully (FCM) or partially compacted (PCM) morulae. No difference was found in early cleavage types or morula compaction patterns between female age groups (< 38, 38-40 and > 40 yo). Most of NC embryos resulted in FCM (≅ 60%), while no embryos with AC resulted in FCM. Aneuploidy rate of AC-PCM group did not differ from that of NC-FCM group in women < 38 yo, but aneuploidy was significantly higher in AC-PCM compared to NC-FCM of women > 40 yo. However, the quality of embryos was lower in AC-PCM blastocysts in women of all age ranges. Morphological and morphokinetic scores declined with increasing age, in the NC-PCM and AC-PCM groups, compared to the NC-FCM. Similar aneuploidy rates among NC-FCM and AC-PCM groups support the hypothesis that PCM in anomalous-cleaved embryos can represent a potential correction mechanism, even though lower morphological/morphokinetic scores are seen on AC-PCM. Therefore, both morphological and morphokinetic assessment should consider these embryonic development phenomena.

Dysphagia and pulmonary complications in acute cerebrovascular disease: A retrospective observational study.

INTRODUCTION: Dysphagia is a common post-stroke complication, which may result in serious pulmonary sequelae. Early detection of dysphagia and aspiration risk can reduce morbidity, mortality and length of hospitalization. OBJECTIVES: This study aims to identify association between dysphagia and acute cerebrovascular disease, and evaluate the prevalence and impact of pulmonary complications on readmissions and mortality. MATERIAL AND METHODS: Retrospective observational study based on 250 clinical records of patients with acute cerebrovascular disease: clinical history, neurological examination, imaging and Gugging Swallowing Screen in the first 48h. Patients were followed for 3 months via medical records to estimate 3-month mortality and readmissions. RESULTS: Out of 250 clinical records analyzed, 102 (40.8%) were evaluated for dysphagia. The prevalence of dysphagia was 32.4%. The risk was higher in older patients (p<0.001), in severe stroke (p<0.001) and in the hemorrhagic subtype (p=0.008). An association was found with dysarthria and aphasia (p=0.003; p=0.017). Respiratory tract infections occurred in 14.4% of all patients (GUSS group 11.8% versus no GUSS group 16.2%), and in 75% of those with severe dysphagia (p<0.001). Mortality at 3 months was 24.2% in dysphagic patients, especially high in the severe dysphagia group (75%, p<0.001). CONCLUSIONS: The type of cerebrovascular disease, NIHSS and GCS scores, age, dysarthria, and aphasia were significant associated factors to dysphagia. The prevalence of respiratory tract infections was higher in patients with no GUSS record, and no statistical significance was observed in related readmissions. Mortality at 3 months was superior in the severe dysphagia group.

Niraparib plus abiraterone acetate with prednisone in patients with metastatic castration-resistant prostate cancer and homologous recombination repair gene alterations: second interim analysis of the randomized phase III MAGNITUDE trial.

BACKGROUND: Patients with metastatic castration-resistant prostate cancer (mCRPC) and BRCA alterations have poor outcomes. MAGNITUDE found patients with homologous recombination repair gene alterations (HRR+), particularly BRCA1/2, benefit from first-line therapy with niraparib plus abiraterone acetate and prednisone (AAP). Here we report longer follow-up from the second prespecified interim analysis (IA2). PATIENTS AND METHODS: Patients with mCRPC were prospectively identified as HRR+ with/without BRCA1/2 alterations and randomized 1 : 1 to niraparib (200 mg orally) plus AAP (1000 mg/10 mg orally) or placebo plus AAP. At IA2, secondary endpoints [time to symptomatic progression, time to initiation of cytotoxic chemotherapy, overall survival (OS)] were assessed. RESULTS: Overall, 212 HRR+ patients received niraparib plus AAP (BRCA1/2 subgroup, n = 113). At IA2 with 24.8 months of median follow-up in the BRCA1/2 subgroup, niraparib plus AAP significantly prolonged radiographic progression-free survival {rPFS; blinded independent central review; median rPFS 19.5 versus 10.9 months; hazard ratio (HR) = 0.55 [95% confidence interval (CI) 0.39-0.78]; nominal P = 0.0007} consistent with the first prespecified interim analysis. rPFS was also prolonged in the total HRR+ population [HR = 0.76 (95% CI 0.60-0.97); nominal P = 0.0280; median follow-up 26.8 months]. Improvements in time to symptomatic progression and time to initiation of cytotoxic chemotherapy were observed with niraparib plus AAP. In the BRCA1/2 subgroup, the analysis of OS with niraparib plus AAP demonstrated an HR of 0.88 (95% CI 0.58-1.34; nominal P = 0.5505); the prespecified inverse probability censoring weighting analysis of OS, accounting for imbalances in subsequent use of poly adenosine diphosphate-ribose polymerase inhibitors and other life-prolonging therapies, demonstrated an HR of 0.54 (95% CI 0.33-0.90; nominal P = 0.0181). No new safety signals were observed. CONCLUSIONS: MAGNITUDE, enrolling the largest BRCA1/2 cohort in first-line mCRPC to date, demonstrated improved rPFS and other clinically relevant outcomes with niraparib plus AAP in patients with BRCA1/2-altered mCRPC, emphasizing the importance of identifying this molecular subset of patients.

Impacto del COVID-19 en una enfermedad rara (melanoma uveal) en una unidad de referencia nacional de tumores intraoculares en España / Impact of COVID-19 on a rare disease (uveal melanoma) in a national reference unit of intraocular tumors in Spain

Objetivo Analizar el impacto de la pandemia por COVID-19 en el diagnóstico y manejo del melanoma uveal (tumor incluido en el catálogo de enfermedades raras por Orphanet), en una unidad de referencia nacional española de tumores intraoculares, durante el primer año de pandemia. Materiales y métodos Se realizó un estudio retrospectivo observacional de pacientes con melanoma uveal en la Unidad de Referencia Nacional de Tumores Intraoculares del Adulto del Hospital Clínico Universitario de Valladolid (España), analizando los periodos pre- y pos-COVID-19: del 15 de marzo de 2019 al 15 de marzo de 2020 y del 16 marzo de 2020 al 16 de marzo de 2021. Se recogieron datos demográficos, demora diagnóstica, tamaño del tumor, extensión extraocular, tratamiento y evolución. Se utilizó un modelo de regresión logística multivariable para identificar los factores que se asociaron a la variable: enucleación. Resultados Se incluyeron 82 pacientes con melanoma uveal, de los cuales 42(51,21%) pertenecían al periodo pre-COVID-19 y 40(40,78%) al periodo pos-COVID-19. Se observó un aumento del tamaño tumoral al diagnóstico y del número de enucleaciones durante el periodo pos-COVID-19 (p<0,05). La regresión logística multivariable demostró que tanto el tamaño tumoral mediano-grande como los pacientes diagnosticados en el periodo pos-COVID-19 estaban relacionados de forma independiente con un riesgo mayor de enucleación (OR 250, IC95%, 27,69-2256,37; p<0,01 y OR 10; IC95%,1,10-90,25; p=0,04, respectivamente). Conclusiones El incremento del tamaño tumoral observado en los melanomas uveales diagnosticados durante el primer año de pandemia por COVID-19 pudo favorecer el aumento de las enucleaciones realizadas en dicho periodo (AU)

Objective To analyze the impact of the COVID-19 pandemic on the diagnosis and management of uveal melanoma (a tumor included in the Orphanet catalog of rare diseases) in a Spanish national reference unit for intraocular tumors during the first year of the pandemic. Material and methods An observational retrospective study of patients with uveal melanoma in the National Reference Unit for Adult Intraocular Tumors of the Hospital Clínico Universitario de Valladolid (Spain) was performed, analyzing the pre- and post-COVID-19 periods: from March 15, 2019 to March 15, 2020 and from March 16, 2020 to March 16, 2021. Demographic data, diagnostic delay, tumor size, extraocular extension, treatment and evolution were collected. A multivariable logistic regression model was used to identify factors that were associated with the variable: enucleation. Results Eighty-two patients with uveal melanoma were included, of which 42(51.21%) belonged to the pre-COVID-19 period and 40(40.78%) to the post-COVID-19 period. An increase in tumor size at diagnosis and in the number of enucleations was observed during the post-COVID-19 period (p<0.05). Multivariable logistic regression demonstrated that both medium-large tumor size and patients diagnosed in the post-COVID-19 period were independently related to an increased risk of enucleation (OR 250, 95%CI, 27.69-2256.37; p<0.01 and OR 10; 95% CI,1.10-90.25; p=0.04, respectively). Conclusions The increase in tumor size observed in uveal melanomas diagnosed during the first year of the COVID-19 pandemic may have favored the increase in the number of enucleations performed during that period (AU)

Deep, rapid, and durable prostate-specific antigen decline with apalutamide plus androgen deprivation therapy is associated with longer survival and improved clinical outcomes in TITAN patients with metastatic castration-sensitive prostate cancer.

BACKGROUND: The first interim analysis of the phase III, randomized, double-blind, placebo-controlled, multinational TITAN study demonstrated improved overall survival (OS) and radiographic progression-free survival (rPFS) with apalutamide added to ongoing androgen deprivation therapy (ADT) in patients with metastatic castration-sensitive prostate cancer. The final analysis confirmed improvement in OS and other long-term outcomes. We evaluated prostate-specific antigen (PSA) kinetics and the association between PSA decline and outcomes in patients with metastatic castration-sensitive prostate cancer from TITAN. PATIENTS AND METHODS: Patients received apalutamide (240 mg/day) or placebo plus ADT (1 : 1). This post hoc exploratory analysis evaluated PSA kinetics and decline in relation to rPFS (22.7 months' follow-up) and OS, time to PSA progression, and time to castration resistance (44.0 months' follow-up) in patients with or without confirmed PSA decline using a landmark analysis, the Kaplan-Meier method, and Cox proportional hazards model. RESULTS: One thousand and fifty-two patients (apalutamide, 525; placebo, 527) were enrolled. Best confirmed PSA declines (≥50% or ≥90% from baseline or to ≤0.2 ng/ml) were achieved at any time during the study in 90%, 73%, and 68% of apalutamide-treated versus 55%, 29%, and 32% of placebo-treated patients, respectively. By 3 months of apalutamide treatment, best deep PSA decline of ≥90% or to ≤0.2 ng/ml occurred in 59% and 51% of apalutamide- and in 13% and 18% of placebo-treated patients, respectively. Achievement of deep PSA decline at landmark 3 months of apalutamide treatment was associated with longer OS [hazard ratio (HR) 0.35; 95% confidence interval (CI) 0.25-0.48), rPFS (HR 0.44; 95% CI 0.30-0.65), time to PSA progression (HR 0.31; 95% CI 0.22-0.44), and time to castration resistance (HR 0.38; 95% CI 0.27-0.52) compared with no decline (P < 0.0001 for all). Similar results were observed at landmark 6 and 12 months of apalutamide treatment. CONCLUSIONS: Apalutamide plus ADT demonstrated a robust (rapid, deep, and durable) PSA decline that was associated with improved clinical outcomes, including long-term survival.

Selection of indicator contaminants of emerging concern when reusing reclaimed water for irrigation - A proposed methodology.

Organic and microbial contaminants of emerging concern (CECs), even though not yet regulated, are of great concern in reclaimed water reuse projects. Due to the large number of CECs and their different characteristics, it is useful to include only a limited number of them in monitoring programs. The selection of the most representative CECs is still a current and open question. This study presents a new methodology for this scope, in particular for the evaluation of the performance of a polishing treatment and the assessment of the risk for the environment and the irrigated crops. As to organic CECs, the methodology is based on four criteria (occurrence, persistence, bioaccumulation and toxicity) expressed in terms of surrogates (respectively, concentrations in the secondary effluent, removal achieved in conventional activated sludge systems, Log Kow and predicted-no-effect concentration). It consists of: (i) development of a dataset including the CECs found in the secondary effluent, together with the corresponding values of surrogates found in the literature or by in-field investigations; (ii) normalization step with the assignment of a score between 1 (low environmental impact) and 5 (high environmental impact) to the different criteria based on threshold values set according to the literature and experts' judgement; (iii) CEC ranking according to their final score obtained as the sum of the specific scores; and (iv) selection of the representative CECs for the different needs. Regarding microbial CECs, the selection is based on their occurrence and their highest detection frequency in the secondary effluent and in the receiving water, the antibiotic consumption patterns, and recommendations by national and international organisations. The methodology was applied within the ongoing reuse project SERPIC resulting in a list of 30 indicator CECs, including amoxicillin, bisphenol A, ciprofloxacin, diclofenac, erythromycin, ibuprofen, iopromide, perfluorooctane sulfonate (PFOS), sulfamethoxazole, tetracycline, Escherichia coli, faecal coliform, 16S rRNA, sul1, and sul2.

The cytomegalovirus gB/MF59 vaccine candidate induces antibodies against an antigenic domain controlling cell-to-cell spread.

Vaccination against human cytomegalovirus (CMV) infection remains high priority. A recombinant form of a protein essential for CMV entry, glycoprotein B (gB), demonstrated partial protection in a clinical trial (NCT00299260) when delivered with the MF59 adjuvant. Although the antibody titre against gB correlated with protection poor neutralising responses against the 5 known antigenic domains (AD) of gB were evident. Here, we show that vaccination of CMV seronegative patients induces an antibody response against a region of gB we term AD-6. Responses to the polypeptide AD-6 are detected in >70% of vaccine recipients yet in <5% of naturally infected people. An AD-6 antibody binds to gB and to infected cells but not the virion directly. Consistent with this, the AD-6 antibody is non-neutralising but, instead, prevents cell-cell spread of CMV in vitro. The discovery of AD-6 responses has the potential to explain part of the protection mediated by gB vaccines against CMV following transplantation.

The influence of simultaneous pancreas-kidney transplantation on the evolution of diabetic foot lesions and peripheral arterial disease.

PURPOSE: Simultaneous pancreas-kidney transplantation (SPKT) remains the best treatment option in patients with type 1 diabetes and chronic kidney failure. There are only a few studies addressing the potential ischemic deterioration of peripheral arterial disease (PAD) due to blood diverting from the iliac artery to the kidney graft. We aimed to evaluate diabetic foot lesions and PAD evolution in SPKT recipients and investigate if they are more frequent in ipsilateral lower limb of kidney graft. METHODS: We developed a retrospective cohort, including patients submitted to SPKT in our tertiary center, between 2000 and 2017. Diabetic foot lesions and PAD frequencies were compared in the period before and after transplantation. RESULTS: Two hundred and eleven patients were included, 50.2% (n = 106) female, with a median age at transplantation of 35 years (IQR 9). After a median follow-up period of 10 years (IQR 7), patient, kidney, and pancreatic graft survival were 90.5% (n = 191), 83.4% (n = 176), and 74.9% (n = 158), respectively. Before transplant, 2.8% (n = 6) had PAD and 5.3% (n = 11) had history of foot lesions. In post-transplant period, 17.1% (n = 36) patients presented PAD and 25.6% (n = 54) developed diabetic foot ulcers, 47.6% (n = 35) of which in the ipsilateral and 53.3% (n = 40) in the contralateral lower limb of the kidney graft (p = 0.48). Nine patients (4.3%) underwent major lower limb amputation, 3 (30%) ipsilateral and 7 (70%) contralateral to the kidney graft (p = 0.29). CONCLUSIONS: Diabetic foot lesions were not more frequent in the ipsilateral lower limb of the kidney graft, therefore downgrading the 'steal syndrome' role in these patients.

The implementation of portable air-cleaning technologies in healthcare settings - a scoping review.

The COVID-19 pandemic revealed opportunities to improve prevention practices in healthcare settings, mainly related to the spread of airborne microbes (also known as bioaerosols). This scoping review aimed to map methodologies used to assess the implementation of portable air cleaners in healthcare settings, identify gaps, and propose recommendations for future research. The protocol was registered in the Open Science Framework and reported following the checklist provided by the Preferred Reporting Items for Systematic Reviews and Meta-Analysis - an extension for Scoping Reviews (PRISMA-ScR) statement. The search strategy was performed in five databases and one grey literature source. At the last selection phase, 24 articles that fulfilled our inclusion criteria were summarized and disseminated. Of these, 17 studies were conducted between 2020 and 2022; one of them was a protocol of a multicentre randomized controlled trial. The outcomes measured among the studies include airborne microbe counts, airborne particle concentrations, and rate of infections/interventions. The leading healthcare settings assessed were dental clinics (28%), patient's wards (16%), operating rooms (16%), and intensive care units (12%). Most of the devices demonstrated a significant potential to mitigate the impact of bioaerosols. Although some indoor air quality parameters can influence the mechanics of aerosols, only a few studies controlled these parameters in their analyses. Future clinical research should assess the rate of infections through randomized controlled trials with long-term follow-up and large sample sizes to determine the clinical importance of the findings.

Toxicity and larvicidal activity on Aedes aegypti of citronella essential oil submitted to enzymatic esterification / Toxicidade e atividade larvicida sobre Aedes aegypti de óleo essencial de citronella submetido à esterificação enzimática

Abstract The essential oil of citronella (Cymbopogon winterianus) has several biological activities, among them the insect repellent action. Some studies showed that cinnamic acid esters can be applied as natural pesticides, insecticides and fungicides. In this context, the objective of the present work was to evaluate the production of esters from citronella essential oil with cinnamic acid via enzymatic esterification. Besides, the essential oil toxicity before and after esterification against Artemia salina and larvicidal action on Aedes aegypti was investigated. Esters were produced using cinnamic acid as the acylating agent and citronella essential oil (3:1) in heptane and 15 wt% NS 88011 enzyme as biocatalysts, at 70 °C and 150 rpm. Conversion rates of citronellyl and geranyl cinnamates were 58.7 and 69.0% for NS 88011, respectively. For the toxicity to Artemia salina LC50 results of 5.29 μg mL-1 were obtained for the essential oil and 4.36 μg mL-1 for the esterified oils obtained with NS 88011. In the insecticidal activity against Aedes aegypti larvae, was obtained LC50 of 111.84 μg mL-1 for the essential oil of citronella and 86.30 μg mL-1 for the esterified oils obtained with the enzyme NS 88011, indicating high toxicity of the esters. The results demonstrated that the evaluated samples present potential of application as bioinsecticide.

Resumo O óleo essencial de citronela (Cymbopogon winterianus) possui diversas atividades biológicas, entre elas a ação repelente a insetos. Alguns estudos mostraram que os ésteres do ácido cinâmico podem ser aplicados como pesticidas naturais, inseticidas e fungicidas. Nesse contexto, o objetivo do presente trabalho foi avaliar a produção de ésteres a partir do óleo essencial de citronela com ácido cinâmico via esterificação enzimática. Além disso, foi investigada a toxicidade do óleo essencial antes e após a esterificação contra Artemia salina e a ação larvicida sobre Aedes aegypti. Os ésteres foram produzidos utilizando ácido cinâmico como agente acilante e óleo essencial de citronela (3: 1) em heptano e 15% em peso da enzima NS 88011 como biocatalisadores, a 70 ° C e 150 rpm. As taxas de conversão de cinamatos de citronelil e geranil foram 58,7 e 69,0% para NS 88011, respectivamente. Para a toxicidade sobre Artemia salina foram obtidos CL50 de 5,29 μg mL-1 para o óleo essencial e 4,36 μg mL-1 para os óleos esterificados com NS 88011. Na atividade inseticida contra larvas de Aedes aegypti, obteve-se CL50 de 111,84 μg mL-1 para o óleo essencial de citronela e 86,30 μg mL-1 para os óleos esterificados com a enzima NS 88011, indicando alta toxicidade dos ésteres. Os resultados demonstraram que as amostras avaliadas apresentam potencial de aplicação como bioinseticida.

Toxicity and larvicidal activity on Aedes aegypti of citronella essential oil submitted to enzymatic esterification / Toxicidade e atividade larvicida sobre Aedes aegypti de óleo essencial de citronella submetido à esterificação enzimática

The essential oil of citronella (Cymbopogon winterianus) has several biological activities, among them the insect repellent action. Some studies showed that cinnamic acid esters can be applied as natural pesticides, insecticides and fungicides. In this context, the objective of the present work was to evaluate the production of esters from citronella essential oil with cinnamic acid via enzymatic esterification. Besides, the essential oil toxicity before and after esterification against Artemia salina and larvicidal action on Aedes aegypti was investigated. Esters were produced using cinnamic acid as the acylating agent and citronella essential oil (3:1) in heptane and 15 wt% NS 88011 enzyme as biocatalysts, at 70 °C and 150 rpm. Conversion rates of citronellyl and geranyl cinnamates were 58.7 and 69.0% for NS 88011, respectively. For the toxicity to Artemia salina LC50 results of 5.29 μg mL-¹ were obtained for the essential oil and 4.36 μg mL-¹ for the esterified oils obtained with NS 88011. In the insecticidal activity against Aedes aegypti larvae, was obtained LC50 of 111.84 μg mL-¹ for the essential oil of citronella and 86.30 μg mL-¹ for the esterified oils obtained with the enzyme NS 88011, indicating high toxicity of the esters. The results demonstrated that the evaluated samples present potential of application as bioinsecticide.

O óleo essencial de citronela (Cymbopogon winterianus) possui diversas atividades biológicas, entre elas a ação repelente a insetos. Alguns estudos mostraram que os ésteres do ácido cinâmico podem ser aplicados como pesticidas naturais, inseticidas e fungicidas. Nesse contexto, o objetivo do presente trabalho foi avaliar a produção de ésteres a partir do óleo essencial de citronela com ácido cinâmico via esterificação enzimática. Além disso, foi investigada a toxicidade do óleo essencial antes e após a esterificação contra Artemia salina e a ação larvicida sobre Aedes aegypti. Os ésteres foram produzidos utilizando ácido cinâmico como agente acilante e óleo essencial de citronela (3: 1) em heptano e 15% em peso da enzima NS 88011 como biocatalisadores, a 70 ° C e 150 rpm. As taxas de conversão de cinamatos de citronelil e geranil foram 58,7 e 69,0% para NS 88011, respectivamente. Para a toxicidade sobre Artemia salina foram obtidos CL50 de 5,29 μg mL-¹ para o óleo essencial e 4,36 μg mL-¹ para os óleos esterificados com NS 88011. Na atividade inseticida contra larvas de Aedes aegypti, obteve-se CL50 de 111,84 μg mL-¹ para o óleo essencial de citronela e 86,30 μg mL-¹ para os óleos esterificados com a enzima NS 88011, indicando alta toxicidade dos ésteres. Os resultados demonstraram que as amostras avaliadas apresentam potencial de aplicação como bioinseticida.

Toxicity and larvicidal activity on Aedes aegypti of citronella essential oil submitted to enzymatic esterification

Abstract The essential oil of citronella (Cymbopogon winterianus) has several biological activities, among them the insect repellent action. Some studies showed that cinnamic acid esters can be applied as natural pesticides, insecticides and fungicides. In this context, the objective of the present work was to evaluate the production of esters from citronella essential oil with cinnamic acid via enzymatic esterification. Besides, the essential oil toxicity before and after esterification against Artemia salina and larvicidal action on Aedes aegypti was investigated. Esters were produced using cinnamic acid as the acylating agent and citronella essential oil (3:1) in heptane and 15 wt% NS 88011 enzyme as biocatalysts, at 70 °C and 150 rpm. Conversion rates of citronellyl and geranyl cinnamates were 58.7 and 69.0% for NS 88011, respectively. For the toxicity to Artemia salina LC50 results of 5.29 g mL-1 were obtained for the essential oil and 4.36 g mL-1 for the esterified oils obtained with NS 88011. In the insecticidal activity against Aedes aegypti larvae, was obtained LC50 of 111.84 g mL-1 for the essential oil of citronella and 86.30 g mL-1 for the esterified oils obtained with the enzyme NS 88011, indicating high toxicity of the esters. The results demonstrated that the evaluated samples present potential of application as bioinsecticide.

Resumo O óleo essencial de citronela (Cymbopogon winterianus) possui diversas atividades biológicas, entre elas a ação repelente a insetos. Alguns estudos mostraram que os ésteres do ácido cinâmico podem ser aplicados como pesticidas naturais, inseticidas e fungicidas. Nesse contexto, o objetivo do presente trabalho foi avaliar a produção de ésteres a partir do óleo essencial de citronela com ácido cinâmico via esterificação enzimática. Além disso, foi investigada a toxicidade do óleo essencial antes e após a esterificação contra Artemia salina e a ação larvicida sobre Aedes aegypti. Os ésteres foram produzidos utilizando ácido cinâmico como agente acilante e óleo essencial de citronela (3: 1) em heptano e 15% em peso da enzima NS 88011 como biocatalisadores, a 70 ° C e 150 rpm. As taxas de conversão de cinamatos de citronelil e geranil foram 58,7 e 69,0% para NS 88011, respectivamente. Para a toxicidade sobre Artemia salina foram obtidos CL50 de 5,29 g mL-1 para o óleo essencial e 4,36 g mL-1 para os óleos esterificados com NS 88011. Na atividade inseticida contra larvas de Aedes aegypti, obteve-se CL50 de 111,84 g mL-1 para o óleo essencial de citronela e 86,30 g mL-1 para os óleos esterificados com a enzima NS 88011, indicando alta toxicidade dos ésteres. Os resultados demonstraram que as amostras avaliadas apresentam potencial de aplicação como bioinseticida.

A transcriptional switch controls sex determination in Plasmodium falciparum.

Sexual reproduction and meiotic sex are deeply rooted in the eukaryotic tree of life, but mechanisms determining sex or mating types are extremely varied and are only well characterized in a few model organisms1. In malaria parasites, sexual reproduction coincides with transmission to the vector host. Sex determination is non-genetic, with each haploid parasite capable of producing either a male or a female gametocyte in the human host2. The hierarchy of events and molecular mechanisms that trigger sex determination and maintenance of sexual identity are yet to be elucidated. Here we show that the male development 1 (md1) gene is both necessary and sufficient for male fate determination in the human malaria parasite Plasmodium falciparum. We show that Md1 has a dual function stemming from two separate domains: in sex determination through its N terminus and in male development from its conserved C-terminal LOTUS/OST-HTH domain. We further identify a bistable switch at the md1 locus, which is coupled with sex determination and ensures that the male-determining gene is not expressed in the female lineage. We describe one of only a few known non-genetic mechanisms of sex determination in a eukaryote and highlight Md1 as a potential target for interventions that block malaria transmission.