Entamoeba histolytica: In Silico and In Vitro Oligomerization of EhHSTF5 Enhances Its Binding to the HSE of the EhPgp5 Gene Promoter.

Throughout its lifecycle, Entamoeba histolytica encounters a variety of stressful conditions. This parasite possesses Heat Shock Response Elements (HSEs) which are crucial for regulating the expression of various genes, aiding in its adaptation and survival. These HSEs are regulated by Heat Shock Transcription Factors (EhHSTFs). Our research has identified seven such factors in the parasite, designated as EhHSTF1 through to EhHSTF7. Significantly, under heat shock conditions and in the presence of the antiamoebic compound emetine, EhHSTF5, EhHSTF6, and EhHSTF7 show overexpression, highlighting their essential role in gene response to these stressors. Currently, only EhHSTF7 has been confirmed to recognize the HSE as a promoter of the EhPgp5 gene (HSE_EhPgp5), leaving the binding potential of the other EhHSTFs to HSEs yet to be explored. Consequently, our study aimed to examine, both in vitro and in silico, the oligomerization, and binding capabilities of the recombinant EhHSTF5 protein (rEhHSTF5) to HSE_EhPgp5. The in vitro results indicate that the oligomerization of rEhHSTF5 is concentration-dependent, with its dimeric conformation showing a higher affinity for HSE_EhPgp5 than its monomeric state. In silico analysis suggests that the alpha 3 α-helix (α3-helix) of the DNA-binding domain (DBD5) of EhHSTF5 is crucial in binding to the major groove of HSE, primarily through hydrogen bonding and salt-bridge interactions. In summary, our results highlight the importance of oligomerization in enhancing the affinity of rEhHSTF5 for HSE_EhPgp5 and demonstrate its ability to specifically recognize structural motifs within HSE_EhPgp5. These insights significantly contribute to our understanding of one of the potential molecular mechanisms employed by this parasite to efficiently respond to various stressors, thereby enabling successful adaptation and survival within its host environment.

Recent Advances in Serum Biomarkers for Risk Stratification and Patient Management in Cardio-Oncology.

PURPOSE OF REVIEW: Following significant advancements in cancer therapeutics and survival, the risk of cancer therapy-related cardiotoxicity (CTRC) is increasingly recognized. With ongoing efforts to reduce cardiovascular morbidity and mortality in cancer patients and survivors, cardiac biomarkers have been studied for both risk stratification and monitoring during and after therapy to detect subclinical disease. This article will review the utility for biomarker use throughout the cancer care continuum. RECENT FINDINGS: A recent meta-analysis shows utility for troponin in monitoring patients at risk for CTRC during cancer therapy. The role for natriuretic peptides is less clear but may be useful in patients receiving proteasome inhibitors. Early studies explore use of myeloperoxidase, growth differentiation factor 15, galectin 3, micro-RNA, and others as novel biomarkers in CTRC. Biomarkers have potential to identify subclinical CTRC and may reveal opportunities for early intervention. Further research is needed to elucidate optimal biomarkers and surveillance strategies.

NAFLD in Cardiovascular Diseases: A Contributor or Comorbidity?

Nonalcoholic fatty liver disease (NAFLD) and cardiovascular diseases are both highly prevalent conditions around the world, and emerging data have shown an association between them. This review found several longitudinal and cross-sectional studies showing that NAFLD was associated with coronary artery disease, cardiac remodeling, aortic valve remodeling, mitral annulus valve calcifications, diabetic cardiomyopathy, diastolic cardiac dysfunction, arrhythmias, and stroke. Although the specific underlying mechanisms are not clear, many hypotheses have been suggested, including that metabolic syndrome might act as an upstream metabolic defect, leading to end-organ manifestations in both the heart and liver. Management of NAFLD includes weight loss through lifestyle interventions or bariatric surgery, and pharmacological interventions, often targeting comorbidities. Although there are no Food and Drug Administration-approved nonalcoholic steatohepatitis-specific therapies, several drug candidates have demonstrated effect in the improvement in fibrosis or nonalcoholic steatohepatitis resolution. Further studies are needed to assess the effect of those interventions on cardiovascular outcomes, the major cause of mortality in patients with NAFLD. In conclusion, a more comprehensive, multidisciplinary approach to diagnosis and management of patients with NAFLD and cardiovascular diseases is needed to optimize clinical outcomes.

Protein arginine methyltransferases in protozoan parasites.

Arginine methylation is a post-translational modification involved in gene transcription, signalling pathways, DNA repair, RNA metabolism and splicing, among others, mechanisms that in protozoa parasites may be involved in pathogenicity-related events. This modification is performed by protein arginine methyltransferases (PRMTs), which according to their products are divided into three main types: type I yields monomethylarginine (MMA) and asymmetric dimethylarginine; type II produces MMA and symmetric dimethylarginine; whereas type III catalyses MMA only. Nine PRMTs (PRMT1 to PRMT9) have been characterized in humans, whereas in protozoa parasites, except for Giardia intestinalis, three to eight PRMTs have been identified, where in each group there are at least two enzymes belonging to type I, the majority with higher similarity to human PRMT1, and one of type II, related to human PRMT5. However, the information on the role of most of these enzymes in the parasites biology is limited so far. Here, current knowledge of PRMTs in protozoan parasites is reviewed; these enzymes participate in the cell growth, stress response, stage transitions and virulence of these microorganisms. Thus, PRMTs are attractive targets for developing new therapeutic strategies against these pathogens.

Towards a unified curriculum system based on a public health holistic approach. Renovation of the academic programs at the School of Public Health of Mexico.

Public health training cannot be practiced in isolation, but rather within the framework of substantive conceptual visions, the organizational structure and teaching culture in a broad sense. The School of Public Health of Mexico (ESPM), in the mist of its 100th anniversary, is implementing an educational restructure with the guidance of conceptual and ethical principles. The restructure of the academic pro-grams will follow a constructivist pedagogical model, based on renewed institutional practices that integrates research, teaching and community outreach, making for truly transfor-mative learning. The new design of the whole structure of its academic programs has the objetive of making them flexible, less technical-based but more practical, and a within an uni-fied curricular system that articulates and allows continuity between master's degrees and doctorates programs. In the new structure, the curriculum will have a common core for all the academic programs, emerging from the study of the essential bases of public health, human rights, including gender and social perspectives, principles of global health, ethics of public health practice, environmental and animal health inferences and community outreach in the form of social retribution. The Institute's research groups will be the functional units for investigation and teaching, thus students will be integrated into these at an early stage, under the guidance of a tutor. In this context, the requirements for a comprehensive, unifying and at the same time flexible cur-riculum will support training of Public Health with a holistic approach. The current programs were analyzed including the review of their courses, regarding the pertinence of their contents and proposed competencies. We present herein a description of these observations, and propose a new com-mon core (conceptual-operative) with compulsory courses as the base for all programs. The participation of all academic bodies in reviewing the proposed new common core, as well as the syllabus and courses, identified those that are essential in each program's study concentration area, is indicated.

Correcting On-the-Go Field Measurement-Coordinate Mismatch by Minimizing Nearest Neighbor Difference.

Many current precision agriculture applications involve on-the-go field measurements of soil and plant properties that require accurate georeferencing. Specific equipment configuration characteristics or data transmission, reception, or logging delays may cause a mismatch between the logged data and the GPS coordinates because of time and position lags that occur during data acquisition. We propose a simple coordinate translation along the measurement tracks to correct for such positional inaccuracies, based on the local travel speed and time lag, which is estimated by minimizing the average ln-transformed absolute difference with the nearest neighbors. The correction method is evaluated using electromagnetic induction soil-sensor data for different spatial measurement layouts and densities and by comparing variograms for raw and modified coordinates. Time lags of 1 s are shown to propagate into the spatial correlation structure up to lag distances of 10 m. The correction method performs best when repeated measurements in opposite driving directions are used and worst when measurements along parallel driving tracks are only repeated at the headland turns. In the latter case, the performance of the method is further improved by limiting the search neighborhood to adjacent measurement tracks. The proposed coordinate correction method is useful for improving the positional accuracy in a wide range of soil- and plant-sensing applications, without the need to grid the data first.

Synthesis, Optical Characterization in Solution and Solid-State, and DFT Calculations of 3-Acetyl and 3-(1'-(2'-Phenylhydrazono)ethyl)-coumarin-(7)-substituted Derivatives.

Intramolecular charge transfer (ICT) effects are responsible for the photoluminescent properties of coumarins. Hence, optical properties with different applications can be obtained by ICT modulation. Herein, four 3-acetyl-2H-chromen-2-ones (1a-d) and their corresponding fluorescent hybrids 3- (phenylhydrazone)-chromen-2-ones (2a-d) were synthesized in 74-65% yields. The UV-Vis data were in the 295-428 nm range. The emission depends on the substituent in position C-7 bearing electron-donating groups. Compounds 1b-d showed good optical properties due to the D-π-A structural arrangement. In compounds 2a-d, there is a quenching effect of fluorescence in solution. However, in the solid, an increase is shown due to an aggregation-induced emission (AIE) effect given by the rotational restraints and stacking in the crystal. Computational calculations of the HOMO-LUMO orbitals indicate high absorbance and emission values of the molecules, and gap values represent the bathochromic effect and the electronic efficiency of the compounds. Compounds 1a-d and 2a-d are good candidates for optical applications, such as OLEDs, organic solar cells, or fluorescence markers.

[Dolosigranulum pigrum in corneal abscess]. / Dolosigranulum pigrum en absceso corneal.

Dolosigranulum pigrum is a gram-positive, facultatively anaerobic coccus, which is part of the oral and upper respiratory tract microbiota. Although reports of infections by this microorganism are scarce, it has been associated with a wide spectrum of infectious diseases. The case of an elderly man with a lower corneal abscess, in which Dolosigranulum pigrum was isolated, is described. The microorganism was identified by mass spectrometry (MALDI-TOF MS) and by the sequencing of the 16S rRNA gene. Furthermore, the presumptive identification of the causative agent was achieved by using key phenotypic tests such as the cluster arrangement in Gram stain, the negative catalase test, the production of pyrrolidonyl arylamidase and leucine aminopeptidase activity, the growth in 6.5% NaCl and esculin hydrolysis. The data from the literature (and the present case) support the association of the microorganism with ocular infections, which often take a destructive course, mainly in elderly patients.

Residual Malaria: Limitations of Current Vector Control Strategies to Eliminate Transmission in Residual Foci.

The transmission of Plasmodium parasites in residual foci is currently a major roadblock for malaria elimination. Human activities and behavior, along with outdoor biting mosquitoes with opportunistic feeding preferences are the main causes of the inefficacy of the main vector control interventions, long lasting insecticide-impregnated nets and insecticide residual spraying. Several strategies to abate or repel outdoor biting mosquito vectors are currently being researched, but the impact of insecticide resistance on the efficacy of these and current indoor-applied insecticides requires further assessment. Understanding the human, ecological and vector factors, determining transmission in residual foci is necessary for the design and implementation of novel control strategies. Vector control alone is insufficient without adequate epidemiological surveillance and prompt treatment of malaria cases, the participation of endemic communities in prevention and control is required. In addition, malaria control programs should optimize their structure and organization, and their coordination with other government sectors.

Development of the indirect flight muscles of Aedes aegypti, a main arbovirus vector.

BACKGROUND: Flying is an essential function for mosquitoes, required for mating and, in the case of females, to get a blood meal and consequently function as a vector. Flight depends on the action of the indirect flight muscles (IFMs), which power the wings beat. No description of the development of IFMs in mosquitoes, including Aedes aegypti, is available. METHODS: A. aegypti thoraces of larvae 3 and larvae 4 (L3 and L4) instars were analyzed using histochemistry and bright field microscopy. IFM primordia from L3 and L4 and IFMs from pupal and adult stages were dissected and processed to detect F-actin labelling with phalloidin-rhodamine or TRITC, or to immunodetection of myosin and tubulin using specific antibodies, these samples were analyzed by confocal microscopy. Other samples were studied using transmission electron microscopy. RESULTS: At L3-L4, IFM primordia for dorsal-longitudinal muscles (DLM) and dorsal-ventral muscles (DVM) were identified in the expected locations in the thoracic region: three primordia per hemithorax corresponding to DLM with anterior to posterior orientation were present. Other three primordia per hemithorax, corresponding to DVM, had lateral position and dorsal to ventral orientation. During L3 to L4 myoblast fusion led to syncytial myotubes formation, followed by myotendon junctions (MTJ) creation, myofibrils assembly and sarcomere maturation. The formation of Z-discs and M-line during sarcomere maturation was observed in pupal stage and, the structure reached in teneral insects a classical myosin thick, and actin thin filaments arranged in a hexagonal lattice structure. CONCLUSIONS: A general description of A. aegypti IFM development is presented, from the myoblast fusion at L3 to form myotubes, to sarcomere maturation at adult stage. Several differences during IFM development were observed between A. aegypti (Nematoceran) and Drosophila melanogaster (Brachyceran) and, similitudes with Chironomus sp. were observed as this insect is a Nematoceran, which is taxonomically closer to A. aegypti and share the same number of larval stages.

Antibody response in patients admitted to the hospital with suspected SARS-CoV-2 infection: results from a multicenter study across Spain.

AIM: To evaluate the serological response against SARS-CoV-2 in a multicenter study representative of the Spanish COVID pandemic. METHODS: IgG and IgM + IgA responses were measured on 1466 samples from 1236 Spanish COVID-19 patients admitted to the hospital, two commercial ELISA kits (Vircell SL, Spain) based on the detection of antibodies against the viral spike protein and nucleoprotein, were used. RESULTS: Approximately half of the patients presented antibodies (56.8% were IgM + IgA positive and 43.0% were IgG positive) as soon as 2 days after the first positive PCR result. Serological test positivity increased with time from the PCR test, and 10 days after the first PCR result, 91.5% and 88.0% of the patients presented IgM + IgA and IgG antibodies, respectively. CONCLUSION: The high values of sensitivity attained in the present study from a relatively early period of time after hospitalization support the use of the evaluated serological assays as supplementary diagnostic tests for the clinical management of COVID-19.

The atypical protein arginine methyltrasferase of Entamoeba histolytica (EhPRMTA) is involved in cell proliferation, heat shock response and in vitro virulence.

Protein arginine methylation regulates several cellular events, including epigenetics, splicing, translation, and stress response, among others. This posttranslational modification is catalyzed by protein arginine methyltransferases (PRMTs), which according to their products are classified from type I to type IV. The type I produces monomethyl arginine and asymmetric dimethyl arginine; in mammalian there are six families of this PRMT type (PRMT1, 2, 3, 4, 6, and 8). The protozoa parasite Entamoeba histolytica has four PRMTs related to type I; three of them are similar to PRMT1, but the other one does not show significant homology to be grouped in any known PRMT family, thus we called it as atypical PRMT (EhPRMTA). Here, we showed that EhPRMTA does not contain several of the canonical amino acid residues of type I PRMTs, confirming that it is an atypical PRMT. A specific antibody against EhPRMTA localized this protein in cytoplasm. The recombinant EhPRMTA displayed catalytic activity on commercial histones and the native enzyme modified its expression level during heat shock and erythrophagocytosis. Besides, the knockdown of EhPRMTA produced an increment in cell growth, and phagocytosis, but decreases cell migration and the survival of trophozoites submitted to heat shock, suggesting that this protein is involved in regulate negatively or positively these events, respectively. Thus, results suggest that this methyltransferase regulates some cellular functions related to virulence and cell surviving.

Measures of resting state EEG rhythms for clinical trials in Alzheimer's disease: Recommendations of an expert panel.

The Electrophysiology Professional Interest Area (EPIA) and Global Brain Consortium endorsed recommendations on candidate electroencephalography (EEG) measures for Alzheimer's disease (AD) clinical trials. The Panel reviewed the field literature. As most consistent findings, AD patients with mild cognitive impairment and dementia showed abnormalities in peak frequency, power, and "interrelatedness" at posterior alpha (8-12 Hz) and widespread delta (< 4 Hz) and theta (4-8 Hz) rhythms in relation to disease progression and interventions. The following consensus statements were subscribed: (1) Standardization of instructions to patients, resting state EEG (rsEEG) recording methods, and selection of artifact-free rsEEG periods are needed; (2) power density and "interrelatedness" rsEEG measures (e.g., directed transfer function, phase lag index, linear lagged connectivity, etc.) at delta, theta, and alpha frequency bands may be use for stratification of AD patients and monitoring of disease progression and intervention; and (3) international multisectoral initiatives are mandatory for regulatory purposes.

Heuristic estimation of the α/ß ratio for a cohort of Mexican patients with prostate cancer treated with external radiotherapy techniques.

BACKGROUND: The aim of the study was to Estimate and compare the radiobiological ratio α/ß with the heuristic method for a cohort of Mexican patients with prostate cancer (PCa) who were treated with external radiotherapy (RT) techniques at three Hospital Institutions in Mexico City. With the Kaplan-Meier technique and the Cox proportional hazards model, the biochemical relapse-free survival (bRFS) is determined and characterized for cohorts of Mexican patients with PCa who received treatment with external RT. Using these clinical outcomes, the radiobiological parameter α/ß is determined using the heuristic methodology of Pedicini et. al. MATERIALS AND METHODS: The α/ß is calculated from the survival curves for different treatment schemes implemented at three distinct hospitals. The Pedicini's techniques allow to determine the parameters α/ß, k and N 0 when treatments are not radiobiologically equivalent, therefore, are built up of a set of curved pairs for the biologically effective dose (BED) versus the ratio α/ß, where the ratio is given by the intersection for each pair of curves. RESULTS: Six different values of α/ß were found: the first α/ß = 2.46 Gy, the second α/ß = 3.30 Gy, the third for α/ß = 3.25 Gy, the fourth α/ß = 3.24 Gy, the fifth α/ß = 3.38 Gy and the last α/ß = 4.08 Gy. These values can be explained as follows: a) The bRFS of the schemes presents a statistical variation; b) The absorbed doses given to the patient present uncertainties on the physical dosimetry that are not on the modeling; c) Finally, in the model for the bRFS of Eq. (3), there are parameters that have to be considered, such as: the number of clonogenic tumor cells N 0 , the overall treatment time (OTT), the kick-off time for tumor repopulation T k and the repopulation doubling time. Therefore, the mean value to α/ß for all schemes has an average value of 3.29 (± 0.52) Gy. CONCLUSIONS: The value of α / ß ¯ = 3.29 ( ± 0.52 ) Gy is determined from cohorts of Mexican patients with PC a treated with external radiotherapy using the time-dependent LQ model, which is a higher value with respect to the "dogma" value of α/ß 1.5 Gy obtained with the LQ model without temporal dependence. Therefore, there is a possibility of optimizing treatments radiobiologically and improving the results of bRFS in Mexican patients with PCa treated with external radiotherapy.

New prognosis score including absolute lymphocyte/monocyte ratio, red blood cell distribution width and beta-2 microglobulin in patients with diffuse large B-cell lymphoma treated with R-CHOP: Spanish Lymphoma Group Experience (GELTAMO).

The International Prognostic Index (IPI) is the most widely used score for non-Hodgkin lymphoma but lacks the ability to identify a high-risk population in diffuse large B-cell lymphoma (DLBCL). Low absolute lymphocyte count and high monocytes have proved to be unfavourable factors. Red-cell distribution width (RDW) has been associated with inflammation and beta-2 microglobulin (B2M) with tumour load. The retrospective study included 992 patients with DLBCL treated with R-CHOP. In the multivariate analysis, age, Eastern Cooperative Oncology Group performance status (ECOG-PS), stage, bulky mass, B2M, RDW, and lymphocyte/monocyte ratio (LMR) were independently related to progression-free survival (PFS). A new prognosis score was generated with these variables including age categorized into three groups (0, 1, 2 points); ECOG ≥ 3-4 with two; stage III/IV, bulky mass, high B2M, LMR < 2·25 and RDW > 0·96 with one each; for a maximum of 9. This score could improve the discrimination of a very high-risk subgroup with five-year PFS and overall survival (OS) of 19% and 24% versus 45% and 59% of R (revised)-IPI respectively. This score also showed greater predictive ability than IPI. A new score is presented including complete blood cell count variables and B2M, which are readily available in real-life practice without additional tests. Compared to R-IPI, it shows a more precise high-risk assessment and risk discrimination for both PFS and OS.

EhRabB mobilises the EhCPADH complex through the actin cytoskeleton during phagocytosis of Entamoeba histolytica.

Movement and phagocytosis are clue events in colonisation and invasion of tissues by Entamoeba histolytica, the protozoan causative of human amoebiasis. During phagocytosis, EhRab proteins interact with other functional molecules, conducting them to the precise cellular site. The gene encoding EhrabB is located in the complementary chain of the DNA fragment containing Ehcp112 and Ehadh genes, which encode for the proteins of the EhCPADH complex, involved in phagocytosis. This particular genetic organisation suggests that the three corresponding proteins may be functionally related. Here, we studied the relationship of EhRabB with EhCPADH and actin during phagocytosis. First, we obtained the EhRabB 3D structure to carry out docking analysis to predict the interaction sites involved in the EhRabB protein and the EhCPADH complex contact. By confocal microscopy, transmission electron microscopy, and immunoprecipitation assays, we revealed the interaction among these proteins when they move through different vesicles formed during phagocytosis. The role of the actin cytoskeleton in this event was also confirmed using Latrunculin A to interfere with actin polymerisation. This affected the movement of EhRabB and EhCPADH, as well as the rate of phagocytosis. Mutant trophozoites, silenced in EhrabB gene, evidenced the interaction of this molecule with EhCPADH and strengthened the role of actin during erythrophagocytosis.

Clinical course and risk factors for mortality from COVID-19 in patients with haematological malignancies.

BACKGROUND: The impact of coronavirus disease 2019 (COVID-19) in haematological patients (HP) has not been comprehensively reported. METHODS: We analysed 39 patients with SARS-CoV-2 infection and haematological malignancies. Clinical characteristics and outcomes were compared to a matched control group of 53 non-cancer patients with COVID-19. Univariate and multivariate analyses were carried out to assess the risk factors associated with poor outcome. RESULTS: The most frequent haematological diseases were lymphoma (30%) and multiple myeloma (30%). Eighty-seven % HP developed moderate or severe disease. Patients with haematological malignancies had a significantly higher mortality rate compared to non-cancer patients (35.9% vs 13.2%; P = .003 (odds ratio 6.652). The worst outcome was observed in chronic lymphocytic leukaemia patients. Only age >70 years and C reactive protein >10 mg/dl at admission were associated with higher risk of death (odds ratio 34.86, P = .003 and 13.56,P = .03). Persistent viral sheddind was detected in 5 HP. Active chemotherapy, viral load at diagnosis and COVID-19 therapy were not predictors of outcome. CONCLUSION: Mortality of COVID-19 is significantly higher in patients with haematological malignancies compared to non-cancer patients. The impact of persistent viral shedding must be considered in order to re-start therapies and maintain infectious control measures.

Evaluation of the MD Anderson tumor score for diffuse large B-cell lymphoma in the rituximab era.

OBJECTIVES: Diffuse large B-cell lymphoma (DLBCL) is an aggressive heterogeneous lymphoma with standard treatment. However, 30%-40% of patients still fail, so we should know which patients are candidates for alternative therapies. IPI is the main prognostic score but, in the rituximab era, it cannot identify a very high-risk (HR) subset. The MD Anderson Cancer Center reported a score in the prerituximab era exclusively considering tumor-related variables: Tumor Score (TS). We aim to validate TS in the rituximab era and to analyze its current potential role. METHODS: From GELTAMO DLBCL registry, we selected those patients homogeneously treated with R-CHOP (n = 1327). RESULTS: Five-years PFS and OS were 62% and 74%. All variables retained an independent prognostic role in the revised TS (R-TS), identifying four different risk groups, with 5-years PFS of 86%, 71%, 50%, and very HR (28%). With a further categorization of three variables of the original TS (Ann Arbor Stage, LDH and B2M), we generated a new index that allowed an improvement in HR assessment. CONCLUSIONS: (a) All variables of the original TS retain an independent prognostic role, and R-TS remains predictive in the rituximab era; (b) R-TS and additional categorization of LDH, B2M, and AA stage (enhanced TS) increased the ability to identify HR subsets.

Analytical strategies to study the formation and drug delivery capabilities of ferritin-encapsulated cisplatin in sensitive and resistant cell models.

One of the limitations in the use of cisplatin is its low penetration into cells. In addition, some cells develop the so called resistance, a multifactorial event that decreases significantly the intracellular cisplatin concentration. To circumvent these limitations, recent studies are focused on the use of nanocarriers that permit, among others, to achieve higher drug uptake. In this work, ferritin is evaluated as a nanostructured cisplatin-delivery system in cell models of ovarian cancer. One of the key aspects is the characterization of the encapsulated product, and for this aim, a battery of analytical techniques, including size exclusion chromatography (SEC) coupled to UV detection and to inductively coupled plasma mass spectrometry (ICP-MS) together with transmission electron microscopy (TEM), is conducted. Higher level of incorporation occurs when using initial concentrations of the Fe-containing form of the protein at 10 mg/mL and 1 mg/mL cisplatin solution. The incorporation of the free and encapsulated cisplatin is addressed in A2780 and A2780CIS, sensitive and cisplatin-resistant cell lines, respectively, showing a significantly higher uptake of the encapsulated form. These values ranged from 5- to 9-fold in the sensitive line and 2-4 in the resistant model, being always more pronounced at the lower doses. Functionality of the drug after encapsulation is addressed by monitoring the presence of Pt in DNA and normalizing DNA concentration through simultaneous P and Pt measurements by ICP-MS. Time elapsed between exposure and Pt detection in DNA proved to be critical in the encapsulated model, showing the slower drug release mechanism from the ferritin nanocage that could be advantageously used for a controlled therapy. Graphical abstract.

Molecular variation of Plasmodium vivax dehydrofolate reductase in Mexico and Nicaragua contrasts with that occurring in South America.

OBJECTIVE: To research mutations associated to pyrimethamine resistance in dihydrofolate reductase (pvdhfr) of Plasmodium vivax from Mexico and Nicaragua and compare it to that reported in the rest of America. MATERIALS AND METHODS: Genomic DNA was obtained from P. vivax-infected blood samples. A pvdhfr gene fragment was amplified and sequenced. The identified gene variations were compared to those observed in other affected sites of America. RESULTS: No mutations in pvdhfr were detected in P. vivax from Mexico and Nicaragua. One synonymous change and variation in the repeat domain was detected in Nicaraguan parasites. In South America, a high frequency of variant residues 58R and 117N associated to pyrimethamine resistance was reported. CONCLUSIONS: The lack of polymorphisms associated with pyrimethamine resistance suggests that drug-resistant P. vivax has not penetrated Mesoamerica, nor have local parasites been under selective pressure. These data contribute to establish the basis for the epidemiological surveillance of drug resistance.

OBJETIVO: Determinar mutaciones en la dihydrofolato reductasa de P. vivax (Pvdhfr) en parásitos de México y Nicaragua, y comparar con lo reportado en América. MATERIAL Y MÉTODOS: Del ADN de sangres infectadas con P. vivax de pacientes, el gen pvdhfr se amplifico y secuenció, y se contrastócon lo observado en América. RESULTADOS: No se detectaron mutaciones asociadas con la resistencia debida a pirimetamina. Los parásitos de Nicaragua tuvieron una mutación sinónima y variación en la región repetida. Se reportaron frecuentes mutaciones asociadas con la resistencia a la pirimetamina en Sudamérica. CONCLUSIONES: La ausencia de polimorfismos en Pvdhfr sugiere que no se han seleccionado ni introducido parásitos resistentes en la zona de estudio, lo que resulta muy útil para la vigilancia epidemiológica.