Biodiversity of Trichoderma species of healthy and Fusarium wilt-infected banana rhizosphere soils in Tenerife (Canary Islands, Spain).

Banana (Musa acuminata) is the most important crop in the Canary Islands (38.9% of the total cultivated area). The main pathogen affecting this crop is the soil fungal Fusarium oxysporum f. sp. cubense subtropical race 4 (Foc-STR4), for which there is no effective control method under field conditions. Therefore, the use of native biological control agents may be an effective and sustainable alternative. This study aims to: (i) investigate the diversity and distribution of Trichoderma species in the rhizosphere of different banana agroecosystems affected by Foc-STR4 in Tenerife (the island with the greatest bioclimatic diversity and cultivated area), (ii) develop and preserve a culture collection of native Trichoderma species, and (iii) evaluate the influence of soil chemical properties on the Trichoderma community. A total of 131 Trichoderma isolates were obtained from 84 soil samples collected from 14 farms located in different agroecosystems on the northern (cooler and wetter) and southern (warmer and drier) slopes of Tenerife. Ten Trichoderma species, including T. afroharzianum, T. asperellum, T. atrobrunneum, T. gamsii, T. guizhouense, T. hamatum, T. harzianum, T. hirsutum, T. longibrachiatum, and T. virens, and two putative novel species, named T. aff. harzianum and T. aff. hortense, were identified based on the tef1-α sequences. Trichoderma virens (35.89% relative abundance) and T. aff. harzianum (27.48%) were the most abundant and dominant species on both slopes, while other species were observed only on one slope (north or south). Biodiversity indices (Margalef, Shannon, Simpson, and Pielou) showed that species diversity and evenness were highest in the healthy soils of the northern slope. The Spearman analysis showed significant correlations between Trichoderma species and soil chemistry parameters (mainly with phosphorus and soil pH). To the best of our knowledge, six species are reported for the first time in the Canary Islands (T. afroharzianum, T. asperellum, T. atrobrunneum, T. guizhouense, T. hamatum, T. hirsutum) and in the rhizosphere of banana soils (T. afroharzianum, T. atrobrunneum, T. gamsii, T. guizhouense, T. hirsutum, T. virens). This study provides essential information on the diversity/distribution of native Trichoderma species for the benefit of future applications in the control of Foc-STR4.

Enhancing implementation of the I-PASS Handoff Tool Using a Provider Handoff Task Force at a Comprehensive Cancer Center.

BACKGROUND: Communication failures are among the most common causes of harmful medical errors. At one Comprehensive Cancer Center, patient handoffs varied among services. The authors describe the implementation and results of an Organization-wide project to improve handoffs and implement an evidence-based handoff tool across all inpatient services. METHODS: The research team created a task force composed of members from 22 hospital services-advanced practice providers (APPs), trainees, some faculty members, electronic health record (EHR) staff, education and training specialists, and nocturnal providers. Over two years, the task force expanded to include consulting services and Anesthesiology. Factors contributing to ineffective handoffs were identified and organized into categories. The EHR I-PASS tool was used to standardize handoff documentation. Training was provided to staff on its use, and compliance was monitored using a customized dashboard. I-PASS champions in each service were responsible for the rollout of I-PASS in their respective services. The data were reported quarterly to the Quality Assessment and Performance Improvement (QAPI) governing committee. Provider handoff perception was assessed through the biennial Institution-wide safety culture survey. RESULTS: All fellows, residents, APPs, and physician assistants were trained in the use of I-PASS, either online or in person. Adherence to the I-PASS written tool improved from 41.6% in 2019 to 70.5% in 2022 (p < 0.05), with improvements seen in most services. The frequency of updating I-PASS elements and the action list in the handoff tool also increased over time. The handoff favorability score on the safety culture survey improved from 38% in 2018 to 59% in 2022. CONCLUSION: The implementation approach developed by the Provider Handoff Task Force led to increased use of the I-PASS EHR tool and improved safety culture survey handoff favorability.

Treatment patterns and outcomes of high-grade immune checkpoint inhibitor-related pneumonitis in an oncology hospitalist service.

PURPOSE: Immune checkpoint inhibitors (ICI) have become standard of care for some types of lung cancer. Along with expanding usage comes the emergence of immune-related adverse events (irAEs), including ICI-related pneumonitis (ICI-P). Treatment guidelines for managing irAEs have been developed; however, how clinicians manage irAEs in the real-world setting is less well known. We aimed to describe the outcomes and care patterns of grade ≥ 3 ICI-P in an onco-hospitalist service. PATIENTS AND METHODS: We included patients with lung cancer treated with ICI who were admitted to an oncology hospitalist service with a suspicion of ICI-P. We described the hospitalization characteristics, treatment patterns, discharge practices, and clinical outcomes of patients with confirmed ICI-P. The primary outcome was time to start treatment for ICI-P. RESULTS: Among 49 patients admitted with a suspicion of ICI-P, 31 patients were confirmed to have ICI-P and subsequently received ICI-P directed treatment. Pulmonology was consulted in 97% of patients. Median time to start treatment for ICI-P was 1 day (IQR 0-3.5 days). All 31 patients received corticosteroids. Inpatient mortality was 32%. Majority of patients discharged with steroids were prescribed prophylaxis for gastritis and opportunistic infections. Thirty-eight percent of patients were seen by pulmonology and 86% were seen by the oncology team post-discharge. CONCLUSION: Our study confirms prior findings of high mortality among patients with high-grade ICI-P. Early diagnosis and treatment are key to improving clinical outcomes. Understanding the care patterns and adherence to treatment guidelines of clinicians caring for this patient population may help identify ways to further standardize management practices and improve patient outcomes.

Practice Changes in Checkpoint Inhibitor-Induced Immune-Related Adverse Event Management at a Tertiary Care Center.

Understanding of immune-related adverse events (irAEs) has evolved rapidly, and management guidelines are continually updated. We explored temporal changes in checkpoint inhibitor-induced irAE management at a tertiary cancer care center to identify areas for improvement. We conducted a single-center retrospective study of patients who developed a gastrointestinal, pulmonary, renal, or cardiac irAE between July and 1 October in 2019 or 2021. We collected patient demographic and clinical information up to 1 year after toxicity. Endoscopic evaluation and specialty follow-up after discharge for patients with gastrointestinal irAEs declined between the 2019 and 2021 periods. Symptom duration and steroid taper attempts also declined. For pulmonary irAEs, rates of specialty consultation, hospital admission and readmission, and mortality improved in 2021 compared with 2019. Follow-up rates after hospital discharge were consistently low (<50%) in both periods. For cardiac irAEs, consultation with a cardiologist was frequent and prompt in both periods. Outpatient treatment and earlier specialty consultation improved outcomes with gastrointestinal irAEs. Our study exploring irAE practice changes over time identified areas to improve management; specifically, timely specialty consultation was associated with better outcomes for gastrointestinal irAEs. These findings can help improve the quality of management algorithms at our institution and may inform policies in other institutions.

Humoral and T Cell Response to SARS-CoV-2 Vaccination in Patients With Rheumatoid Arthritis.

OBJECTIVE: The objective of this study was to assess the SARS-CoV-2-specific humoral and T cell response after a two-dose regimen of SARS-CoV-2 vaccine in patients with rheumatoid arthritis (RA). METHODS: In this observational study, patients with RA who are ≥18 years of age and vaccinated for SARS-CoV-2 according to the Argentine National Health Ministry's vaccination strategy were included. Anti-SARS-CoV-2 immunoglobulin G (IgG) antibodies (ELISA-COVIDAR test), neutralizing activity (cytotoxicity in VERO cells), and specific T cell response (IFN-γ ELISpot Assay) were assessed after the first and second dose. RESULTS: A total of 120 patients with RA were included. Mostly, homologous regimens were used, including Gam-COVID-Vac (27.5%), ChAdOx1 (24.2%), and BBIBP-CorV (22.5%). The most frequent combination was Gam-COVID-Vac/mRNA-1273 (21.7%). After the second dose, 81.7% presented with anti-SARS-CoV-2 antibodies, 70.0% presented with neutralizing activity, and 65.3% presented with specific T cell response. The use of BBIBP-CorV and treatment with abatacept (ABA) and rituximab (RTX) were associated with undetectable antibodies and no neutralizing activity after two doses. BBIBP-CorV was also associated with the absence of T cell response. The total incidence of adverse events was 357.1 events per 1,000 doses, significantly lower with BBIBP-CorV (166.7 events per 1,000 doses, P < 0.02). CONCLUSION: In this RA cohort vaccinated with homologous and heterologous regimens against COVID-19, 2 out of 10 patients did not develop anti-SARS-CoV-2 IgG, 70% presented with neutralizing activity, and 65% presented with specific T cell response. The use of BBIBP-CorV was associated with deficient humoral and cellular response, whereas treatment with ABA and RTX resulted in an impaired anti-SARS-CoV-2 IgG formation and neutralizing activity.

Amino acids and cancer: potential for therapies?

PURPOSE OF REVIEW: Cancer patients may have a variety of disorders associated with systemic inflammation caused by disease progression. Consequently, we have protein hypercatabolism. In view of this, protein and amino acid adequacy should be considered in relation to nutritional behavior. Therefore, this review aims to evaluate the influence of protein and amino acids in the nutritional therapy of cancer. RECENT FINDINGS: Diets with adequate protein levels appear to be beneficial in the treatment of cancer; guidelines suggest consumption of greater than 1.0-1.5 g/kg body weight/day. In patients diagnosed with malnutrition, sarcopenia, or cachexia, it is recommended to use the maximum amount of protein (1.5 g/kg of weight/day) to adapt the diet. In addition, based on the evidence found, there is no consensus on the dose and effects in cancer patients of amino acids such as branched-chain amino acids, glutamine, arginine, and creatine. SUMMARY: When evaluating the components of the diet of cancer patients, the protein recommendation should be greater than 1.0-1.5 g/kg of weight/day, with a distribution between animal and vegetable proteins. We found little evidence demonstrating clinical benefits regarding individual or combined amino acid supplementation. Still, it is unclear how the use, dose, and specificity for different types of cancer should be prescribed or at what stage of treatment amino acids should be prescribed.

Distinct patterns of auto-reactive antibodies associated with organ-specific immune-related adverse events.

The roles of preexisting auto-reactive antibodies in immune-related adverse events (irAEs) associated with immune checkpoint inhibitor therapy are not well defined. Here, we analyzed plasma samples longitudinally collected at predefined time points and at the time of irAEs from 58 patients with immunotherapy naïve metastatic non-small cell lung cancer treated on clinical protocol with ipilimumab and nivolumab. We used a proteomic microarray system capable of assaying antibody reactivity for IgG and IgM fractions against 120 antigens for systemically evaluating the correlations between auto-reactive antibodies and certain organ-specific irAEs. We found that distinct patterns of auto-reactive antibodies at baseline were associated with the subsequent development of organ-specific irAEs. Notably, ACHRG IgM was associated with pneumonitis, anti-cytokeratin 19 IgM with dermatitis, and anti-thyroglobulin IgG with hepatitis. These antibodies merit further investigation as potential biomarkers for identifying high-risk populations for irAEs and/or monitoring irAEs during immunotherapy treatment. Trial registration: ClinicalTrials.gov identifier: NCT03391869.

Improving handoff with the implementation of I-PASS at a tertiary oncology hospital.

BACKGROUND: Lack of consistent and standardised handoffs is a leading cause of patient harm. With increased census in our hospital medicine (HM) service, failure to handoff using a standardised method has the potential to cause significant patient harm. We used a quality improvement methodology to standardise an existing and validated handoff tool within our HM team to improve handoff communication among providers and improve patient safety. METHODS: A quality improvement team was charged with studying handoff communication among HM teams and between day and night shift providers at a tertiary oncology hospital. Multiple plan-do-study-act cycles were conducted, and process flow maps, root cause analysis and an affinity diagram were developed based on feedback from the HM team. The quality improvement team developed a plan to implement I-PASS (Illness severity, Patient summary, Action list, Situation awareness and contingency plan, and Synthesis by receiver) as the standardised handoff tool to be used among the providers in HM at the end of shift and for handoff to the nocturnal covering service. Rates of I-PASS use were collected before and after several educational interventions to encourage use of I-PASS and were displayed in a control chart. After the I-PASS interventions, HM providers were surveyed twice to evaluate the secondary outcomes: the tool's impact on workflow, perceptions of patient safety, ease of use and satisfaction with I-PASS. Survey results were compared using Fisher exact tests. RESULTS: The HM team's rate of use of I-PASS handoffs increased from 23% to 72%, an improvement of 68%. By the end of the quality improvement project, I-PASS use had increased to 90%. No significant differences were detected in the reported duration of handoffs after I-PASS implementation (on average <5 min per patient, p=0.205). Provider perceptions of handoff quality, efficiency, communication errors and the I-PASS tool's effectiveness were satisfactory. CONCLUSION: We used a quality improvement methodology to encourage the HM team's adoption of a validated handoff tool. Adherence to the standardised handoff tool significantly improved workflows and facilitated communication between the day and night shift teams.

Argentine Guidelines for the Prevention and Treatment of Glucocorticoid-Induced Osteoporosis in Postmenopausal Women and Men Aged 50 Years and Older.

OBJECTIVE: The aim of this study was to provide an evidence-based framework to guide health care professionals treating patients under glucocorticoid (GC) therapy and develop guidelines for the prevention and treatment of glucocorticoid-induced osteoporosis (GIO) in postmenopausal women and men aged ≥50 years. METHODS: An expert panel on bone diseases designed a series of clinically meaningful questions following the PICO (Population, Intervention, Comparator, and Outcome) structure. Using GRADE (Grading of Recommendations Assessment, Development, and Evaluation) methodology, we made a systematic literature review, extracted and summarized the effect estimates, and graded the quality of the evidence. The expert panel voted each PICO question and made recommendations after reaching an agreement of at least 70%. RESULTS: Seventeen recommendations (9 strong and 8 conditional) and 8 general principles were developed for postmenopausal women and men aged ≥50 years under GC treatment. Bone mineral density (BMD), occurrence of fragility fractures, probability of fracture at 10 years by Fracture Risk Assessment Tool, and other screening factors for low BMD are recommended for patient evaluation and stratification according to fragility fracture risk. The treatment of patients under GC therapy should include counseling on lifestyle habits and strict control of comorbidities. The goal of GIO treatment is the nonoccurrence of new fragility fractures as well as to increase or maintain BMD in certain clinical situations. This was considered for the therapeutic approach in different clinical scenarios. CONCLUSIONS: This GIO guideline provides evidence-based guidance for health care providers treating patients.

Multicenter lupus register from Argentina, the RELESSAR database: Influence of ethnicity on disease phenotype.

OBJECTIVE: The objective is to describe the main characteristics of patients with systemic lupus erythematosus (SLE) in Argentina and to examine the influence of ethnicity on the expression of the disease. PATIENTS AND METHODS: RELESSAR is a multicentre register carried out by 106 researchers from 67 rheumatologic Argentine centres. It is a cross-sectional study of SLE (1982/1997 ACR) patients. RELESSAR electronic database includes demographic, cumulative SLE manifestations, SELENA-SLEDAI, SLICC-SDI, Katz's severity and Charlson's comorbidity indexes and treatment patterns. RESULTS: We included 1,610 patients, 91.7% were female with a median age at diagnosis of 28.1 ± 12.8; 96.2% met ≥4 ACR 1982/97 criteria. Frequent manifestations were arthritis (83.5%), malar rash (79.5%), photosensitivity (75.3%), haematological (63.8%) and renal disease (47.4%), antinuclear antibodies (96%), anti-dsDNA (66.5%) and anti-Smith antibodies (29%). The mean Selena-SLEDAI score at last visit was 3.18 (SD 4.3) and mean SDI was 1 (SD 1.3). The accumulated treatments most frequently used were antimalarials (90.4%), corticosteroids (90%), azathioprine (31.8%), intravenous cyclophosphamide (30.2%), mycophenolate mofetil or mycophenolic acid (24.5%), methotrexate (19.3%), belimumab 5.3% and rituximab 5.1%. Refractory lupus was diagnosed in 9.3% of the cases. The main causes of death were lupus activity (25.0%), activity and concomitant infections (25.0%), infections (18.2%), vascular disease (13.6%) and cancer (4.5%). Mortality was associated with higher SLEDAI, Katz, damage indexes and comorbidities. Of the 1610 patients included, 44.6% were Caucasian, 44.5% Mestizo, 8.1% Amerindian and 1.2% Afro-Latin American. Mestizo patients had higher male representation, low socioeconomic status, more inadequate medical coverage, fewer formal years of education and shorter disease duration. Polyadenopathies and Raynaud's phenomenon were more frequent in Caucasians. In the logistic regression analysis higher damage index (OR 1.28, CI 95% 1.02-1.61, p = 0.03) remained associated to mestizo ethnicity. CONCLUSIONS: This study represents the largest number of adult patients with SLE studied in Argentina. Caucasian patients were differentiated by having Raynaud's phenomenon and polyadenopathy more frequently, while patients of Mestizo origin had higher damage indexes.

Low vitamin D levels and increased neutrophil in patients admitted at ICU with COVID-19.

BACKGROUND & AIMS: Systemic inflammation has been reported as a new predictor for COVID-19 outcomes. Thus, we hypothesized that ICU patients infected by COVID-19 had lower blood vitamin D levels and increased systemic inflammation. Therefore, this is the first Brazilian study to evaluate the vitamin D concentrations and NLR as a systemic inflammation in patients infected by COVID-19 admitted in ICU. METHODS: This cross-sectional study selected twenty-six patients from COVID-19 Data Sharing/FAPESP, Brazil. Twenty-five patients were enrolled from a single hospital and those with blood vitamin D and neutrophil and lymphocyte data were included and had all available data analyzed. Patients were divided in two groups: low vitamin D concentration when ≤20 ng/mL (low Vit D group, n = 8, 5M/3F, 62.7 ± 8.4 years old), and normal vitamin D when > 20 ng/mL (normal Vit D group, n = 17, 9M/8F, 74 ± 8.2 years old). Serum 25-hydroxy-vitamin D, C reactive protein (CRP), and count of neutrophils and lymphocytes concentrations were collected from COVID-19 Data Sharing/FAPESP. Statistical analyses were performed using the Prism version 5.0 and Student T test was applied to verify any difference between the groups. RESULTS: Low vitamin D group had 15.5 ± 3.3 ng/mL of 25OH Vit D concentrations and normal vitamin D group had 35.9 ± 8.8 ng/mL. Although no difference between groups for CRP concentrations (low Vit D: 4.5 ± 3.3 vs. normal Vit D: 4.2 ± 4.0 mg/dL, p = 0.45), we found higher neutrophil count and NLR values in the low Vit D group when compared to normal Vit D group (low Vit D: 6049.8 ± 3719.7 vs. normal Vit D: 3741.8 ± 1704.1 ng/mL, p = 0.02) and (low Vit D: 9.0 ± 8.6 vs. normal Vit D: 4.2 ± 4.0 ng/mL, p = 0.03), respectively. CONCLUSION: This data sharing-derived cases of COVID-19 in patients admitted at ICU showed that patients infected by COVID-19 had lower serum 25-hydroxy vitamin D and enhanced systemic inflammation when assessed by NLR values.

Treatment Satisfaction, Patient Preferences, and the Impact of Suboptimal Disease Control in a Large International Rheumatoid Arthritis Cohort: SENSE Study.

BACKGROUND: Patients' needs and perspectives are important determinants of treatment success in rheumatoid arthritis (RA). Assessing patients' perspectives can help identify unmet needs and enhance the understanding of treatment benefits. OBJECTIVE: The SENSE study assessed the impact of inadequate response to disease-modifying antirheumatic drugs (DMARDs) on treatment satisfaction, disease outcomes, and patient perspectives related to RA disease management. METHODS: SENSE was a noninterventional, cross-sectional study conducted in 18 countries across Europe, Asia, and South America. Adult patients with poorly controlled RA of moderate/high disease activity were eligible. Patient satisfaction was assessed by the Treatment Satisfaction Questionnaire for Medication (TSQM v1.4). Treatment adherence, healthcare resource utilization (HRU), quality of life (QoL), work ability, digital health literacy (DHL), patient preference information, and treatment strategy were also assessed. RESULTS: A total of 1624 patients were included in the study: most were female (84.2%) and middle-aged, and mean disease duration was 10.5 years. Mean TSQM global satisfaction subscore was 60.9, with only 13.5% of patients reporting good treatment satisfaction (TSQM global ≥80). The strongest predictor of good treatment satisfaction was treatment with advanced therapies. Most patients (87.4%) reported good treatment adherence. In general, patients had impaired QoL and work ability, high HRU, and 67.4% had poor DHL. Leading treatment expectations were "general improvement of arthritis" and "less joint pain". Most patients preferred oral RA medications (60.7%) and rapid (≤1 week) onset of action (71.1%). "Increased risk for malignancies" and "increased risk for cardiovascular disease" were the least acceptable side effects. Despite suboptimal control, advanced therapies were only used in a minority of patients, and DMARD switches were planned for only half of the patients. CONCLUSION: Suboptimal disease control negatively impacts treatment satisfaction, work ability, QoL, and HRU. Data collected on patient perspectives may inform shared decision-making and optimize treat-to-target strategies for improving patient outcomes in RA.

High neutrophil to lymphocyte ratio as a prognostic marker in COVID-19 patients.

Systemic inflammation has been reported as a new predictor for COVID-19 outcomes. Thus, we highlight in this viewpoint the importance of the neutrophil to lymphocyte ratio in COVID-19 pandemic-infected patients.

Antitrypanosomal, antileishmanial and cytotoxic activities of Brazilian red propolis and plant resin of Dalbergia ecastaphyllum (L) Taub.

The treatment for leishmaniasis and Chagas disease can be hard and painful, such that many patients give up on the treatment. In order to find an alternative path for the treatment of these diseases, researchers are using natural products to fight these parasites. The aim of this study was to evaluate the antiprotozoan and cytotoxic activities of red propolis samples collected from different Brazilian states and seasons whilst searching for possible activity differences. We also compared the red propolis results with the ones obtained for the plant resin extract collected from Dalbergia ecastaphyllum trees. The hydroethanolic red propolis extracts from Pernambuco and Alagoas, and the D. ecastaphyllum resin were evaluated regarding their antileishmanial, antitrypanosomal and cytotoxic activity. All extracts showed antiprotozoan and cytotoxic activity. RP-PER showed to be more cytotoxic against protozoan parasites and fibroblast cells. All propolis extracts showed a higher cytotoxic activity when compared to resin extracts. The propolis sample collected in Pernambuco during the rainy season killed the parasites with lower concentrations than the sample collected in the dry season. The IC50 observed against the parasites could be used without high fibroblast cell damage.

Bond-based bilinear indices for computational discovery of novel trypanosomicidal drug-like compounds through virtual screening.

Two-dimensional bond-based bilinear indices and linear discriminant analysis are used in this report to perform a quantitative structure-activity relationship study to identify new trypanosomicidal compounds. A data set of 440 organic chemicals, 143 with antitrypanosomal activity and 297 having other clinical uses, is used to develop the theoretical models. Two discriminant models, computed using bond-based bilinear indices, are developed and both show accuracies higher than 86% for training and test sets. The stochastic model correctly indentifies nine out of eleven compounds of a set of organic chemicals obtained from our synthetic collaborators. The in vitro antitrypanosomal activity of this set against epimastigote forms of Trypanosoma cruzi is assayed. Both models show a good agreement between theoretical predictions and experimental results. Three compounds showed IC50 values for epimastigote elimination (AE) lower than 50 µM, while for the benznidazole the IC50 = 54.7 µM which was used as reference compound. The value of IC50 for cytotoxicity of these compounds is at least 5 times greater than their value of IC50 for AE. Finally, we can say that, the present algorithm constitutes a step forward in the search for efficient ways of discovering new antitrypanosomal compounds.

A case of Creutzfeldt-Jakob disease following cataract surgery: sporadic versus iatrogenic cause.

Creutzfeldt-Jakob Disease (CJD) is a fatal neurologic disorder caused by an infectious agent called a human prion protein. CJD can be classified as sporadic CJD, familial CJD, variant CJD, and iatrogenic CJD. We report a 64-year-old man diagnosed with CJD three months after cataract surgery. Although sporadic CJD is the most common type, the patient's cataract surgery elicited the possibility of an iatrogenic transmission. It is important to consider whether visual symptoms are a manifestation of sporadic CJD, rather than cataract surgery resulting in iatrogenic CJD. Preceding cataract surgeries have been reported with CJD, but there is no proven causality. This case highlights consideration of sporadic versus iatrogenic cause when seen in association with cataract surgery.

Identification in silico and in vitro of novel trypanosomicidal drug-like compounds.

Atom-based bilinear indices and linear discriminant analysis are used to discover novel trypanosomicidal compounds. The obtained linear discriminant analysis-based quantitative structure-activity relationship models, using non-stochastic and stochastic indices, provide accuracies of 89.02% (85.11%) and 89.60% (88.30%) of the chemicals in the training (test) sets, respectively. Later, both models were applied to the virtual screening of 18 in-house synthesized compounds to find new pro-lead antitrypanosomal agents. The in vitro antitrypanosomal activity of this set against epimastigote forms of Trypanosoma cruzi is assayed. Predictions agree with experimental results to a great extent (16/18) of the chemicals. Sixteen compounds show more than 70% of epimastigote inhibition at a concentration 100 µg/mL. In addition, three compounds (CRIS 112, CRIS 140 and CRIS 147) present more than 70% of epimastigote inhibition at a concentration of 10 µg/mL (79.95%, 73.97% and 78.13%, respectively) with low values of cytotoxicity (19.7%, 7.44% and 20.63%, correspondingly).Taking into account all these results, we could say that these three compounds could be optimized in forthcoming works. Even though none of them resulted more active than nifurtimox, the current results constitute a step forward in the search for efficient ways to discover new lead antitrypanosomals.

Computational discovery of novel trypanosomicidal drug-like chemicals by using bond-based non-stochastic and stochastic quadratic maps and linear discriminant analysis.

Herein we present results of a quantitative structure-activity relationship (QSAR) studies to classify and design, in a rational way, new antitrypanosomal compounds by using non-stochastic and stochastic bond-based quadratic indices. A data set of 440 organic chemicals, 143 with antitrypanosomal activity and 297 having other clinical uses, is used to develop QSAR models based on linear discriminant analysis (LDA). Non-stochastic model correctly classifies more than 93% and 95% of chemicals in both training and external prediction groups, respectively. On the other hand, the stochastic model shows an accuracy of about the 87% for both series. As an experiment of virtual lead generation, the present approach is finally satisfactorily applied to the virtual evaluation of 9 already synthesized in house compounds. The in vitro antitrypanosomal activity of this series against epimastigote forms of Trypanosoma cruzi is assayed. The model is able to predict correctly the behaviour for the majority of these compounds. Four compounds (FER16, FER32, FER33 and FER 132) showed more than 70% of epimastigote inhibition at a concentration of 100 microg/mL (86.74%, 78.12%, 88.85% and 72.10%, respectively) and two of these chemicals, FER16 (78.22% of AE) and FER33 (81.31% of AE), also showed good activity at a concentration of 10 microg/mL. At the same concentration, compound FER16 showed lower value of cytotoxicity (15.44%), and compound FER33 showed very low value of 1.37%. Taking into account all these results, we can say that these three compounds can be optimized in forthcoming works, but we consider that compound FER33 is the best candidate. Even though none of them resulted more active than Nifurtimox, the current results constitute a step forward in the search for efficient ways to discover new lead antitrypanosomals.