Environmentally Relevant Concentrations of the Insecticide Fipronil Modulated Molecular Response in Chironomus riparius.

Pesticides employed worldwide for crop protection easily reach aquatic systems, which act as the main reservoirs, and become a risk factor for aquatic fauna. Fipronil is a broad-spectrum insecticide acting on the insect nervous system; however, other effects and systems unrelated to this mechanism could be affected in non-target organisms. Thus, the present study aimed to assess the impact of fipronil on the suborganismal response (gene expression and enzymatic activity) of Chironomus riparius larvae as a model organism in ecotoxicology. To this end, short-term toxicity tests were carried out with fourth-instar larvae exposed to 0.001, 0.01, and 0.1 µg L-1 of fipronil for 24 and 96 h. Messenger RNA levels of 42 genes related to diverse metabolic pathways were analyzed by real-time polymerase chain reaction, complemented with catalase (CAT), glutathione S-transferase (GST), and acetylcholinesterase (AChE) activities. Few effects were observed at 24 h; however, after longer exposure (96 h), genes involved in the endocrine, detoxification, stress, and immune response pathways were altered. Moreover, fipronil at 96 h increased CAT and GST activity at 0.01 µg L-1 and AChE at the highest concentrations. The results demonstrate that even low environmentally relevant fipronil concentrations can modulate the molecular response of several cellular pathways in C. riparius after short-term exposure. These results bring new information about the underlying response of fipronil and its mode of action on a key aquatic invertebrate. Despite no effects on mortality, strong modulation at the suborganismal level emphasizes the advantage of biomarkers as early damage responses and the harmful impact of this pesticide on freshwater organisms. Environ Toxicol Chem 2024;43:405-417. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.

Real-world Imatinib Mesylate Treatment in Patients with Chronic Myeloid Leukemia: The Importance of Molecular Monitoring and the Early Molecular Response.

INTRODUCTION: Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder characterized by the Philadelphia (Ph) chromosome. After the introduction of imatinib mesylate (IM) in 2000, the natural history of the disease changed. Data on the treatment of CML with IM are from randomized clinical trials. Establishing whether these results can be reproduced or if caution is needed when extrapolating data to the general population with CML is essential. OBJECTIVES: To evaluate the molecular response (MR) in patients with chronic-phase CML (CML-CP) not included in clinical studies and correlate them with the responses obtained in clinical trials. METHODS: Between January 2007 and January 2017, 227 patients newly diagnosed with CML-CP treated with IM as first-line treatment were included. This study is an observational, retrospective, and single-center study. RESULTS: At a median follow-up time of 7.3 years, 60.3% of the 227 patients who started IM were still on IM. Early molecular response (EMR) at 3 and 6 months was achieved by 74.2% and 65%, respectively. The median time to a MMR was nine months. The MR4.0 and MR4.5 were 67.2% and 51.1%, respectively. The overall survival (OS), progression-free survival (PFS), and event-free survival (EFS) of the patients who exclusively used IM were 91%, 91%, and 85.1%, respectively. CONCLUSION: The results presented are similar to those described in prospective and randomized trials, demonstrating that the outcomes are reproducible in the real world. EMR at 3 and 6 months reflects better long-term responses, including higher rates of deeper molecular responses. Considering treatment costs, the absence of literature evidence of an impact on overall survival demonstrated by first-line second-generation tyrosine kinase inhibitors (TKIs), and the global OS of 85.8%, imatinib mesylate (IM) is still an excellent therapeutic option.

Pro-adherence complementary audiovisual educational intervention model for chronic myeloid leukemia patients treated with imatinib mesylate.

BACKGROUND: Imatinib mesylate (IM) treatment adherence is a challenge, especially in an economic-social population neglected from developing countries. OBJECTIVE: To create a new complementary audiovisual educational intervention model to improve IM treatment adherence of CML patients. METHODS: Two adherence verification methods were applied before and after intervention: modified Morisky-Green test and molecular responses (BCR-ABL transcripts quantification). Adherence estimates were calculated using univariate and multivariate component analysis (MCA) for the socio-demographic and clinical characteristics of patients. RESULTS: Modified Morisky-Green test results demonstrated a substantial increase of CML patient adherence from 23% (pre-film) to 65% (post-film). Greater improvement was obtained for patients presenting major molecular response (MMR) from 38% (pre-film) to 60% (post-film). Although slight gain for complete molecular response (CMR) from 23% (pre-film) to 26% (post-film) was achieved, it represents a total tumour regression. MCA identified that females <50 years-old, using less than two medications (no disease associated) and CMR condition were the most benefited with intervention. CONCLUSION: Audiovisual educational intervention was an effective complementary pro-adherence model, activating patient memory and improving IM treatment adherence. Although this intervention shows effective, not all patients responded as expected, being necessary a combination of educational and clinical interventions to improve IM adherence.

Molecular and structural characterization of expansins modulated by fungal endophytes in the Antarctic Colobanthus quitensis (Kunth) Bartl. Exposed to drought stress.

Expansins are proteins involved in cell wall metabolism that play an important role in plant growth, development, fruit ripening and abiotic stress tolerance. In the present study, we analyzed putative expansins that respond to drought stress. Five expansin genes were identified in cDNA libraries isolated from Colobanthus quitensis gown either with or without endophytic fungi under hydric stress. A differential transcript abundance was observed by qPCR analysis upon drought stress. To compare these expansin genes, and to suggest a possible mechanism of action at the molecular level, the structural model of the deduced proteins was obtained by comparative modeling methodology. The structures showed two domains and an open groove on the surface of the proteins was observed in the five structural models. The proteins were evaluated in terms of their protein-ligand interactions using four different ligands. The results suggested differences in their mode of protein-ligand interaction, in particular concerning the residues involved in the protein-ligand interaction. The presented evidence supports the participation of some members of the expansin multiprotein family in the response to drought stress in C. quitensis and suggest that the response is modulated by endophytic fungi.

COVID-19 in chronic myeloid leukemia patients in Latin America.

This observational, multicenter study aimed to report the clinical evolution of COVID-19 in patients with chronic myeloid leukemia in Latin America. A total of 92 patients presented with COVID-19 between March and December 2020, 26% of whom were severe or critical. The median age at COVID-19 diagnosis was 48 years (22-79 years), 32% were 60 years or older, and 61% were male. Thirty-nine patients presented with at least one comorbidity (42.3%). Eighty-one patients recovered (88%), and 11 (11.9%) died from COVID-19. There was one case of reinfection. Patients with a major molecular response presented superior overall survival compared to patients with no major molecular response (91 vs. 61%, respectively; p = 0.004). Patients in treatment-free remission and receiving tyrosine kinase inhibitors showed higher survival rates than patients who underwent hematopoietic stem cell transplantation and those who did not receive tyrosine kinase inhibitors (100, 89, 50, and 33%, respectively; p < 0.001).

Situación actual de la leucemia mieloide crónica en Costa Rica / (Current situation of chronic myeloid leukemia in Costa Rica)

Resumen Justificación y objetivo: la leucemia mieloide crónica constituye un paradigma de reversión de neoplasia con un tratamiento específico basado en los inhibidores de tirosina quinasa. Aunque la situación epidemiológica ha sido estudiada en países primermundistas, los estudios en Latinoamérica son escasos. Con el fin de actualizar la situación real de la LMC en la región centroamericana, el estudio pretende describir la epidemiología de la leucemia mieloide crónica en Costa Rica. Métodos: se evaluaron 133 pacientes con la enfermedad, mediante monitoreo hematológico y molecular. Se analizó la respuesta de estos casos a tratamiento conforme a las siguientes variables: respuesta hematológica, respuesta molecular y supervivencia global, libre de evento, progresión, así como la prevalencia de mutaciones que confieren resistencia al tratamiento. Resultados: la respuesta hematológica completa fue del 97,7%, y la molecular mayor, a los 12 meses, fue del 43,4%. El seguimiento recomendado por la guía European LeukemiaNet se alcanzó solo en un 68,4% de los pacientes en el primer año, bajando al 57,7%, posteriormente. Un total de 92 pacientes alcanzó respuesta molecular mayor en algún momento; de ellos, el 87,0% conservó respuesta. La supervivencia libre de evento a 3 años fue del 65,7%, libre de progresión del 92,2% y global del 89,2%. La mutación más frecuente encontrada en el gen ABL fue la T315I. Conclusión: el tratamiento de la leucemia mieloide crónica en Costa Rica presenta una eficacia comparable a lo reportado en otros países, con una respuesta molecular mayor inferior a lo esperado, debido a dificultades de acceso al medicamento y monitoreo de la enfermedad.

Abstract Background and aim: Chronic myeloid leukemia is a paradigm of reversion of neoplasia with a specific treatment based on tyrosine kinase inhibitors. Although the epidemiological situation has been studied in first world countries, studies in Latin American countries are scarce. In order to update the real situation of the chronic myeloid leukemia in our Central American region, this study aims to describe the epidemiology of chronic myeloid leukemia in Costa Rica. Methods: 133 patients with the disease were evaluated through hematological and molecular monitoring. The response of these cases to treatment was analyzed by the following variables: haematological response, molecular response and overall survival, event-free, progression, as well as the prevalence of mutations that confer resistance to treatment. Results: The complete haematological response was 97.7% and the molecular response greater than 12 months was 43.4%. The follow-up recommended by the European LeukemiaNet guideline was reached in only 68.4% of the patients in the first year, decreasing to 57.7% later on. A total of 92 patients achieved a higher molecular response at some point, of which 87.0% retained a response. The 3-year event-free survival was 65.7%, progression free of 92.2% and overall of 89.2%. The most frequent mutation found in the ABL gene was T315I. Conclusion: The treatment of chronic myeloid leukemia in Costa Rica presents an efficacy comparable to that reported in other countries, with a lower molecular response than expected due to difficulties in accessing medication and monitoring the disease.

Molecular response to imatinib mesylate of Brazilian patients with chronic myeloid leukemia

Abstract Background Imatinib mesylate has revolutionized the treatment of chronic myeloid leukemia leading to significant reductions of BCR-ABL1 transcript levels in peripheral blood. Objective To evaluate the response to imatinib mesylate treatment (400 mg/day) in Brazilian patients in the chronic phase of chronic myeloid leukemia monitored by quantitative real time polymerase chain reaction. Methods Between October 2002 and October 2010, 3169 peripheral blood samples were collected from 1403 patients from 3 to 5 months, 6 to 11 months, 12 to 17 months, 18 to 23 months and ≥24 months after beginning imatinib treatment. Eighty-two patients had samples available and analyzed for all time intervals. BCR-ABL1 quantification was performed by quantitative real time polymerase chain reaction using the ABL1 gene as the control. Results of the BCR-ABL1 ratio as a percentage were reported by the international scale (IS) using the laboratory conversion factor (0.51). Results In the first interval, 80.8% of patients achieved the optimal response (BCR-ABL1 IS ≤ 10%). In the second period, 69.1% achieved optimal response (BCR-ABL1 IS ≤ 1%) and, between 12 and 17 months, 47.3% achieved major molecular response (BCR-ABL1 IS ≤ 0.1%). Conclusions The results of this retrospective study show that the response to imatinib treatment (400 mg/day) of Brazilian patients in the chronic phase of chronic myeloid leukemia is within the expected profile when compared to patients reported in international prospective randomized studies.

Molecular response to imatinib mesylate of Brazilian patients with chronic myeloid leukemia.

BACKGROUND: Imatinib mesylate has revolutionized the treatment of chronic myeloid leukemia leading to significant reductions of BCR-ABL1 transcript levels in peripheral blood. OBJECTIVE: To evaluate the response to imatinib mesylate treatment (400mg/day) in Brazilian patients in the chronic phase of chronic myeloid leukemia monitored by quantitative real time polymerase chain reaction. METHODS: Between October 2002 and October 2010, 3169 peripheral blood samples were collected from 1403 patients from 3 to 5 months, 6 to 11 months, 12 to 17 months, 18 to 23 months and ≥24 months after beginning imatinib treatment. Eighty-two patients had samples available and analyzed for all time intervals. BCR-ABL1 quantification was performed by quantitative real time polymerase chain reaction using the ABL1 gene as the control. Results of the BCR-ABL1 ratio as a percentage were reported by the international scale (IS) using the laboratory conversion factor (0.51). RESULTS: In the first interval, 80.8% of patients achieved the optimal response (BCR-ABL1IS≤10%). In the second period, 69.1% achieved optimal response (BCR-ABL1IS≤1%) and, between 12 and 17 months, 47.3% achieved major molecular response (BCR-ABL1IS≤0.1%). CONCLUSIONS: The results of this retrospective study show that the response to imatinib treatment (400mg/day) of Brazilian patients in the chronic phase of chronic myeloid leukemia is within the expected profile when compared to patients reported in international prospective randomized studies.

Concomitant essential thrombocythemia with JAK2 V617F mutation in a patient with chronic myeloid leukemia with major molecular response with imatinib and long-term follow-up.

The association of chronic myeloid leukemia (CML) with other myeloproliferative neoplasms (MPNs), in particular with the V617F mutation in the Janus kinase 2 (JAK2) gene, is very uncommon, and there are only a few cases reported in the literature. In the present study, the case of a 73-year-old man with CML and persistent thrombocytosis, is reported. The patient achieved a complete cytogenetic response and major molecular response (MR) with imatinib. The patient presented JAK2 V617F mutation, and bone marrow morphology was consistent with essential thrombocythemia. The patient was treated with imatinib and hydroxyurea to control the platelet count, and maintains complete MR with imatinib upon 10 years of follow-up. Although rare, the association of breakpoint cluster region-Abelson rearrangement and JAK2 V617F mutation should be investigated in patients with MPN, since both genetic anomalies may be present at diagnosis or may emerge during treatment, and require different therapeutic approaches.

Molecular responses at 3 and 6 months after switching to a second-generation tyrosine kinase inhibitor are complementary and predictive of long-term outcomes in patients with chronic myeloid leukemia who fail imatinib.

Early molecular response (MR) defined by BCR-ABL(IS) levels has prognostic impact in chronic myeloid leukemia (CML). MR was evaluated at 3 and 6 months after switching to nilotinib or dasatinib in 115 patients with resistance to imatinib. Three groups were delineated at 3 months (< 1%, 1-10% or > 10% BCR-ABL(IS) levels) with different outcomes at 3 years regarding major molecular response (MMR, 91%, 47%, 22%, p < 0.001), failure-free survival (FFS), progression-free survival (PFS, 96%, 89% and 78%, p = 0.05) and overall survival (OS). After 6 months, patients with MR < 1% had higher 3-year MMR (83% vs. 16%, p < 0.001), FFS, PFS (94% vs. 84%, p = 0.05) and OS. Four patients had 3-month and 6-month MR > 10% and < 1%, respectively (3-year FFS 50%). Thirteen had 3-month and 6-month MR < 10% and ≥ 1%, respectively (3-year FFS 38%). These findings confirm the strong predictive value of 3-month and 6-month BCR-ABL(IS) levels in imatinib-resistant patients.

In silico analysis of ESTs from roots of Rangpur lime (Citrus limonia Osbeck) under water stress

CitEST project resulted in the construction of cDNA libraries from different Citrus sp. tissues under various physiological conditions. Among them, plantlets of Rangpur lime were exposed to hydroponic conditions with and without water stress using PEG6000. RNA from roots was obtained and generated a total of 4,130 valid cDNA reads, with 2,020 from the non-stressed condition and 2,110 from the stressed set. Bioinformatic analyses measured the frequency of each read in the libraries and yielded an in silico transcriptional profile for each condition. A total of 40 contigs were differentially expressed and allowed to detect up-regulated homologue sequences to well known genes involved in stress response, such as aquaporins, dehydrin, sucrose synthase, and proline-related synthase. Some sequences could not be classified by using FunCat and remained with an unknown function. A large number of sequences presented high similarities to annotated genes involved with cell energy, protein synthesis and cellular transport, suggesting that Rangpur lime may sustain active cell growth under stressed condition. The presence of membrane transporters and cell signaling components could be an indication of a coordinated morphological adaptation and biochemical response during drought, helping to explain the higher tolerance of this rootstock to water stress.