Beta-Lactam Antibiotics Can Be Measured in the Exhaled Breath Condensate in Mechanically Ventilated Patients: A Pilot Study.

Different techniques have been proposed to measure antibiotic levels within the lung parenchyma; however, their use is limited because they are invasive and associated with adverse effects. We explore whether beta-lactam antibiotics could be measured in exhaled breath condensate collected from heat and moisture exchange filters (HMEFs) and correlated with the concentration of antibiotics measured from bronchoalveolar lavage (BAL). We designed an observational study in patients undergoing mechanical ventilation, which required a BAL to confirm or discard the diagnosis of pneumonia. We measured and correlated the concentration of beta-lactam antibiotics in plasma, epithelial lining fluid (ELF), and exhaled breath condensate collected from HMEFs. We studied 12 patients, and we detected the presence of antibiotics in plasma, ELF, and HMEFs from every patient studied. The concentrations of antibiotics were very heterogeneous over the population studied. The mean antibiotic concentration was 293.5 (715) ng/mL in plasma, 12.3 (31) ng/mL in ELF, and 0.5 (0.9) ng/mL in HMEF. We found no significant correlation between the concentration of antibiotics in plasma and ELF (R2 = 0.02, p = 0.64), between plasma and HMEF (R2 = 0.02, p = 0.63), or between ELF and HMEF (R2 = 0.02, p = 0.66). We conclude that beta-lactam antibiotics can be detected and measured from the exhaled breath condensate accumulated in the HMEF from mechanically ventilated patients. However, no correlations were observed between the antibiotic concentrations in HMEF with either plasma or ELF.

Efectividad de la hipnoterapia en escolares con trastornos de ansiedad fóbica / Effectiveness of hypnotherapy in school children with disorders of phobic anxiety: en

Introducción: La fobia es un trastorno de ansiedad caracterizado por temor o miedo intenso e irracional hacia algo. Presenta una tasa de incidencia anual de 8 % y la hipnosis es uno de los tratamientos más empleados en quienes la padecen. Objetivo: Evaluar la efectividad del modelo hipnoterapéutico aplicado a pacientes en edad escolar con trastornos de ansiedad fóbica. Métodos: Se realizó una intervención hipnoterapéutica cuasiexperimental en los 30 pacientes con fobia escolar que acudieron a la consulta multidisciplinaria de hipnosis en la Clínica de Hipnosis Terapéutica de Santiago de Cuba, desde octubre de 2016 hasta igual mes de 2018. A tal efecto, la intervención constó de 3 etapas y se aplicó la prueba de Mc-Nemar para dos muestras relacionadas, así como el estadígrafo de la Χ2. Resultados: En la serie predominaron los pacientes del sexo masculino (53,3 %), principalmente entre 8 y 9 años de edad (37,5 %), así como las fobias específicas. Luego de aplicada la hipnosis, se obtuvo una respuesta psicológica favorable en todos los pacientes. Conclusiones: El modelo hipnoterapéutico aplicado resultó ser efectivo, pues se logró una evolución clínica favorable y una buena respuesta al tratamiento.

Introduction: Phobia is an anxiety disorder characterized by fear or intense and irrational fear toward something. It presents an annual rate of incidence of 8 % and hypnosis is one of the most used treatments in those who suffer from this disorder. Objective: To evaluate the effectiveness of the hypnotherapeutic pattern applied to patients in school age with phobic anxiety disorders. Methods: A quasi-experiment hypnotherapeutic intervention was carried out in the 30 patients with school phobia that attended the hypnosis multidisciplinary service at the Therapeutic Hypnosis Clinic in Santiago de Cuba, from October, 2016 to the same month in 2018. To such an effect, the intervention consisted of 3 stages and the Mc-Nemar test was applied for 2 related samples, as well as the chi-square test. Results: In the series there was a prevalence of the male sex patients (53.3 %), mainly between 8 and 9 years (37.5 %), as well as the specific phobias. After having applied the hypnosis, a favorable psychological response was obtained in all the patients. Conclusions: The hypnotherapeutic pattern applied was effective, because a favorable clinical course and a good treatment response were achieved.

Lipase-Catalyzed Synthesis and Biological Evaluation of N-Picolineamides as Trypanosoma cruzi Antiproliferative Agents.

In our search for new safe antiparasitic agents, an enzymatic pathway was applied to synthesize a series of N-pyridinylmethyl amides derived from structurally different carboxylic acids. Thirty derivatives, including 11 new compounds, were prepared through lipase-catalyzed acylation in excellent yields. In order to optimize the synthetic methodology, the impact of different reaction parameters was analyzed. Some compounds were evaluated as antiproliferative agents against Trypanosoma cruzi, the parasite responsible for American trypanosomiasis (Chagas' disease). Some of them showed significant activity as parasite proliferation inhibitors. Amides derived from 2-aminopicoline and stearic and elaidic acids were as potent as nifurtimox against the amastigote form of T. cruzi, the clinically relevant form of the parasite. Even more, a powerful synergism between nifurtimox and N-(pyridin-2-ylmethyl)stereamide was observed, almost completely inhibiting the proliferation of the parasite. Besides, the obtained compounds showed no toxicity in Vero cells, making them excellent potential candidates as lead drugs.

Carcinoma metatípico de piel en colgajo cérvico-facial previo. A propósito de un caso / Metatypical carcinoma of the skin in a previous cervicofacial flap. A case report

El carcinoma baso escamoso (CBE) o metatípico, es considerado un subtipo de carcinoma basocelular (CBC). Con frecuencia es infradiagnosticado ya que no posee características clínicas ni histológicas definidas, por lo que se suele diagnosticar erróneamente como un carcinoma basocelular o espinocelular (CEC). En este artículo se presenta el caso de un paciente masculino de 86 años con un CBE que se expresó en un colgajo cérvico-facial previo. Se ha descrito un alto riesgo de recurrencia y metástasis, lo que supone un pronóstico desfavorable para los pacientes. No existen protocolos terapéuticos estandarizados para esta entidad, sin embargo, el manejo es fundamentalmente quirúrgico. No se encontraron en la literatura reportes previos de carcinoma metatípico en injertos autólogos de piel(AU)

Metatypical or basosquamous carcinoma (BSC) is considered a subtype of basal cell carcinoma (BCC). It is often underdiagnosed due to the lack of defined clinical and histological characteristics, leading to misdiagnosis as either BCC or squamous cell carcinoma (SCC). This article presents a case of an 86-year-old male patient with metatypical carcinoma that manifested in a previous cervicofacial flap. There is a high risk of recurrence and metastasis associated with this condition, leading to an unfavorable prognosis for patients. Although there are no standardized therapeutic protocols for this entity, surgical management is the primary approach. No previous reports of metatypical carcinoma in autologous skin grafts were found in the literature(AU)

Unraveling the Physiological Mechanisms Underlying the Intracultivar Variability of Water Use Efficiency in Vitis vinifera "Grenache".

Selecting genotypes with a better capacity to respond and adapt to soil water deficits is essential to achieve the sustainability of grapevine cultivation in the context of increasing water scarcity. However, cultivar changes are very poorly accepted, and therefore it is particularly interesting to explore the intracultivar genetic diversity in water use efficiency (WUE). In previous studies, the cultivar "Grenache" has shown up to 30% variability in WUE. This research aimed to confirm the intracultivar variability and to elucidate the traits underlying this variability in the response to a water deficit by analyzing the growth rates, water relations, osmotic potential, leaf morphology, leaf gas exchange and carbon isotope discrimination in nine "Grenache" genotypes grown in pots during two seasons. The results showed lower differences in WUE and carbon isotope ratio than in previous field studies, but fairly good consistency in genotype ranking. Leaf mass area and osmotic potential did not underlie differences in stem water potential and in stomatal conductance. Overall, stomatal regulation and photosynthetic capacity seem to underlie differences in WUE among genotypes with an important environmental influence. These results confirm the ability to select clones with higher WUE and present an opportunity for the genetic improvement of WUE in grapevines.

Design and manufacture of a scaled railway track with mechanically variable geometry.

The objective of this article is to present the design and manufacture of a scaled railroad track to be used as a laboratory track for the study of different railway applications. It could be a guideline for future laboratory railroad tracks. The ideal concept was based on possible future studies and, according to them, design requirements have been specified. The main characteristic of the track is that its geometry can be mechanically modified and irregularities can be introduced under controlled conditions in any kind of track sections: straight, curved and transition ones. Finally, the current installed track is shown and the performed quality controls are described.

Climate change and their impacts in the Balearic Islands: a guide for policy design in Mediterranean regions.

Understanding the local effects of global warming-derived impacts is important to island systems due to their fragile environmental conditions. This is especially true when it comes to Mediterranean insular regions as they are climate change (CC) hotspots where adaptation and mitigation policy design is an urgent matter. Looking at 2030 as a time horizon for climate action and focusing on the Balearic Islands, this paper reviews the physical changes projected for the coming decades as a result of CC and analyses their impacts on regional environmental, economic and social variables. Mitigation and adaptation measures are also proposed based on the identified priority impacts. The fact the Balearics are a top world holiday destination allows the analysis to serve as a guide to other Mediterranean islands with tourism-based economies facing similar CC scenarios. Results show the projected rise of temperature and sea level; the reduction of the average precipitation and increase in evapotranspiration, the droughts and the increase in ocean acidification and deoxygenation are the main threats faced by the Balearics, this putting their economy at risk due to the high tourism's vulnerability to CC. Mitigation and adaptation action on terrestrial and marine ecosystems, water resources, energy, infrastructure and urban planning, human health, economy, law and education is recommended. Sustainable mobility and waste managing are also viewed as important fields for mitigation action. Conclusions show that diversifying the current socioeconomic model is needed to increase the community and territory resilience. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10113-021-01810-1.

Intracultivar genetic diversity in grapevine: Water use efficiency variability within cv. Grenache.

The selection of genotypes best adapted to environmental conditions has traditionally focused on agronomic and grape composition parameters. However, to classify the genotypes most adapted to climate change conditions, the aim must be to focus on the ecophysiological responses that will ultimately determine their performance. The variability in water use efficiency of 13 Grenache genotypes over three-seasons was assessed under field conditions at leaf, grape and plant level. Results showed a significant effect of genotype at all three levels, and despite the large interannual variability there was a remarkable consistency among levels. Furthermore, using genotype-specific regressions it was possible to identify significant differences in the intrinsic water use efficiency response of each genotype as a function of the vine water status. The relationship between net photosynthesis and stomatal conductance, as well as carbon isotope discrimination in grapes, were also confirmed as reliable physiological indicators for selecting grapevine genotypes to future environmental conditions. Therefore, the proposed multi-level methodology was useful to quantify the intracultivar variability and the identification of more and less efficient genotypes within Grenache.

Efectividad de la hipnoterapia en pacientes deprimidos / Effectiveness of hypnotherapy in depressed patients

RESUMEN Introducción: la depresión es uno de los problemas de salud que más afecta a los seres humanos a nivel mundial. En Cuba, un elevado número de personas padece este flagelo, sin distinción de razas, sexos u otras categorías. Objetivo: evaluar la efectividad de la hipnosis como modalidad terapéutica en pacientes deprimidos. Materiales y métodos: se realizó un estudio explicativo de tipo experimental de comparación de grupo pre-post prueba en 30 pacientes con trastornos depresivos; 15 de ellos se atendieron con hipnoterapia (grupo estudio) y otros 15 mediante terapia racional emotiva conductual (grupo control). Por la importancia para enriquecer la investigación, se definió como variable independiente el tratamiento empleado según el grupo, y como variables dependientes la respuesta psicológica antidepresiva y ansiolítica. Los datos se procesaron cuantitativa y cualitativamente. Se empleó la prueba de las probabilidades exactas de Fisher y la t de Student para validar la significación del cambio. Resultados: en términos de evolución clínica, la hipnoterapia fue efectiva, ya que el 93,3 % de los pacientes mejoraron significativamente en comparación con los resultados obtenidos con la terapia conductual racional emotiva, dados en un 73,33 %. Conclusión: la hipnoterapia es tan efectiva como la terapia racional emotiva conductual, y si bien no hubo diferencias significativas por los resultados del estadígrafo matemático empleado, sí las hubo desde el punto de vista práctico y clínico, pues evolucionaron más rápido los pacientes del grupo estudio que los del grupo control (AU).

ABSTRACT Introduction: depression is one of the health problems more affecting the human being around the world. A high number of persons suffers this scourge, without distinction of race, sex or any other category. Objective: to assess hypnosis effectiveness as a therapeutic modality in depressed patients. Materials and methods: an experimental-kind explanatory study was carried out comparing a group of 30 patients with depressive disorders before and after test; 15 of them were treated with hypnotherapy (study group) and 15 with rational emotive behavioral therapy (control group). For the importance of enriching the research the treatment used according to each group was defined as independent variable and the anxiolytic and anti-depressive psychological answer. Data were quantitative and qualitatively processed. Fisher's exact test and T student test were used to validate the change significance. Results: in terms of clinical evolution, hypnotherapy was effective, since 93.3% of patients significantly improved in comparison to the results achieved with the rational emotive behavioral therapy, reaching 73.33%. Conclusions: hypnotherapy is as effective as rational emotive behavioral therapy, and although there were not significant differences due to the results of the used mathematical statistic, there they were from the practical and clinical point of view, because the patients from the study group improved faster than the ones in the control group AU).

Reversible phosphorylation of a protein from Trypanosoma equiperdum that exhibits homology with the regulatory subunits of mammalian cAMP-dependent protein kinases.

Homologous proteins of the cAMP-dependent protein kinase (PKA) regulatory and catalytic subunits have been identified in Trypanosoma equiperdum (TeqR-like and TeqC-like, respectively). Partially purified TeqR-like from parasites isolated in the presence of glucose migrated as an apparent 55 kDa/57 kDa polypeptide doublet when separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. However, a single polypeptide of 57 kDa was obtained when parasites were deprived of glucose, a condition that has been shown to activate a TeqC-like enzyme. As revealed by immunoblots using anti-phospothreonine antibodies, the 57 kDa band corresponded to a form of TeqR-like that was phosphorylated in threonine residues. TeqR-like phosphorylation was reversible since the level of phospho-TeqR-like decreased once glucose was readded to glucose starved-parasites. Dephospho- and phospho-TeqR-like proteins are monomers with native molecular masses of 54.93-57.41 kDa, Stokes radii of 3.42-3.37 nm, and slightly asymmetric shapes (frictional ratio f/fo = 1.36-1.32). A protein kinase of ∼40 kDa was also partially purified from glucose deprived-trypanosomes, which corresponded to the TeqC-like enzyme by its ability to phosphorylate kemptide, its inhibition by PKA-specific inhibitors, and its immunorecognition by anti-PKA catalytic subunit antibodies. TeqR-like and TeqC-like did not coelute following anion-exchange chromatography, revealing that these proteins are not associated forming a complex in T. equiperdum. Yet, when TeqR-like was incubated in vitro with TeqC-like in the presence of Mg2+ and ATP, the 55 kDa dephospho form of the 55kDa/57 kDa polypeptide doublet of TeqR-like was converted into the 57 kDa phospho form, demonstrating that TeqR-like is a substrate for TeqC-like.

A Track Geometry Measuring System Based on Multibody Kinematics, Inertial Sensors and Computer Vision.

This paper describes the kinematics used for the calculation of track geometric irregularities of a new Track Geometry Measuring System (TGMS) to be installed in railway vehicles. The TGMS includes a computer for data acquisition and process, a set of sensors including an inertial measuring unit (IMU, 3D gyroscope and 3D accelerometer), two video cameras and an encoder. The kinematic description, that is borrowed from the multibody dynamics analysis of railway vehicles used in computer simulation codes, is used to calculate the relative motion between the vehicle and the track, and also for the computer vision system and its calibration. The multibody framework is thus used to find the formulas that are needed to calculate the track irregularities (gauge, cross-level, alignment and vertical profile) as a function of sensor data. The TGMS has been experimentally tested in a 1:10 scaled vehicle and track specifically designed for this investigation. The geometric irregularities of a 90 m-scale track have been measured with an alternative and accurate method and the results are compared with the results of the TGMS. Results show a good agreement between both methods of calculation of the geometric irregularities.

Application and Experimental Validation of a Multibody Model with Weakly Coupled Lateral and Vertical Dynamics to a Scaled Railway Vehicle.

In this paper, a multibody dynamic model of a railway vehicle that assumes that vertical and lateral dynamics are weakly coupled, has been experimentally validated using an instrumented scaled vehicle running on a 5-inch-wide experimental track. The proposed linearised model treats the vertical and lateral dynamics of the multibody system almost independently, being coupled exclusively by the suspension forces. Several experiments have been carried out at the scaled railroad facilities at the University of Seville in order to test and validate the simulation model under different working conditions. The scaled vehicle used in the experiments is a bogie instrumented with various sensors that register the accelerations and angular velocities of the vehicle, its forward velocity, its position along the track, and the wheel-rail contact forces in the front wheelset. The obtained results demonstrate how the proposed computational model correctly reproduces the dynamics of the real mechanical system in an efficient computational manner.

Plant water status and genotype affect fruit respiration in grapevines.

An understanding of fruit gas exchange is necessary to determine the carbon balance in grapevines, but little attention has been paid to the relationships among fruit respiration, plant water status and genetic variability. The effect of plant water status and genotype on cluster respiration was studied over two seasons (2013 and 2014) under field conditions using a whole cluster respiration chamber. Whole cluster CO2 fluxes were measured in growing grapevines at hard-green, veraison and ripening stages under irrigated and non-irrigated conditions, and under light and dark conditions in two grapevine varieties, Tempranillo and Grenache. A direct relationship between cluster CO2 efflux and plant water status was found at hard-green stage. Genotype influenced the fruit CO2 efflux that resulted in higher carbon losses in Tempranillo than in Grenache. Fruit respiration rates decreased from the first berry developmental stages to ripening stage. The integration of fruit respiration rates under light and dark conditions showed the magnitude of fruit carbon losses and gains as well as interesting variety and environmental conditions effects on those processes.

Nano and Micro Unmanned Aerial Vehicles (UAVs): A New Grand Challenge for Precision Agriculture?

By collecting data at spatial and temporal scales that are inaccessible to satellite and field observation, unmanned aerial vehicles (UAVs) are revolutionizing a number of scientific and management disciplines. UAVs may be particularly valuable for precision agricultural applications, offering strong potential to improve the efficiency of water, nutrient, and disease management. However, some authors have suggested that the UAV industry has overhyped the potential value of this technology for agriculture, given that it is difficult for non-specialists to operate UAVs as well as to process and interpret the resulting data. Here, we analyze the barriers to applying UAVs for precision agriculture, which range from regulatory issues to technical requirements. We then evaluate how new developments in the nano- and micro-UAV (NAV and MAV, respectively) markets may help to overcome these barriers. Among the possible breakthroughs that we identify is the ability of NAV/MAV platforms to directly quantify plant traits using methods (e.g., object-oriented classification) that require less image calibration and interpretation than spectral index-based approaches. We suggest that this potential, when combined with steady improvements in sensor miniaturization, flight precision, and autonomy as well as cloud-based image processing, will make UAVs a tool with much broader adoption by agricultural managers in the near future. If this wider uptake is realized, then UAVs have real potential to improve agriculture's resource-use efficiency. © 2020 by John Wiley & Sons, Inc.

Leaf growth rate and nitrogen content determine respiratory costs during leaf expansion in grapevines.

Respiration processes are well recognized as fundamental for the plant carbon balance, but little attention has been paid to the relationships among respiration rates, environment and genetic variability. This can be of particular interest to understand the differences in net carbon balances in crops as grapevines. Night respiration (Rn ) and its associated growth (Rg ) and maintenance (Rm ) components were evaluated during leaf expansion in two grapevine cultivars (Tempranillo cv. and Garnacha cv.) that differ in their plant growth pattern and carbon balance. Simultaneously, leaf traits as leaf mass area, nitrogen (N) and carbon (C) content were evaluated in order to relate to the respiratory processes and the leaf growth. The results showed the differences in respiration rates associated with the leaf expansion pattern. Tempranillo developed leaves with higher leaf area and lower dry weight per leaf unit than Garnacha. Although differences between cultivars were observed in terms of growth costs in expanding leaves, the maintenance costs were similar for both cultivars. Also, a significant linear regression was found between respiration rates and N content in expanding and mature leaves. The results indicate that differences in structure and nitrogen content of expanding leaves may lead to respiratory differences between cultivars. These results also demonstrate the importance of respiratory cost components in carbon balance calculations in grapevines.

Whole-Plant Water Use in Field Grown Grapevine: Seasonal and Environmental Effects on Water and Carbon Balance.

Water scarcity is a main challenge in vineyards sustainability in most of the grapevine areas now and even more in near future due to climatic change perspectives. In consequence, water use efficiency (WUE) measurements are of the highest interest to improve the sustainability of this crop. The vast majority of WUE measurements relays on measurements of leaf carbon and water fluxes at leaf-level. However, less data are available at the whole-plant level, and for the moment those data are not totally coincident with conclusions reached at leaf scale. In this study, we used whole-plant chambers able to enclose an entire plant of 12 years old to measure at the same time water and carbon fluxes under realistic field grown conditions. The main objectives were to identify the technical issues interfering the whole-plant measurements and track the environmental and other abiotic factors that can affect water and carbon balance, i.e., WUE at the whole-plant scale. To achieve those objectives, we measured whole-plant water and carbon fluxes in grapevine exposed to two different water regimes at three phenological stages [pea size (July), ripening (August), and harvest (September)]. In September, measurements were repeated under high CO2 to also check its effect at the whole-plant scale. The results indicate that water and carbon fluxes are well coordinated under both water availability treatments. Under drought conditions, both fluxes were drastically reduced, but surprisingly the estimated WUE resulted not improved but decreased, contrarily to what is shown at the leaf scale. The phenology (September) also strongly decreased both water and carbon fluxes when compared to measurements in July. We hypostatized that harvest load respiration rates could have an important weight on the whole-plant net carbon exchange (NCE). Finally, high CO2 measurements, after correction for leaks, indicated an increase of whole-plant NCE as well as increased whole-plant WUE, as expected. Several technical issues were identified, like 1/instability of [CO2] during the night period that prevent robust estimation of whole-plant respiration and 2/condensation during last night and sun-rise hours which may affect the estimation of daily plant transpiration.

Extracellular Application of CRMP2 Increases Cytoplasmic Calcium through NMDA Receptors.

Collapsin Response Mediator Protein 2 (CRMP2) is an intracellular protein involved in axon and dendrite growth and specification. In this study, CRMP2 was identified in a conditioned media derived from degenerated sciatic nerves (CM). On cultured rat hippocampal neurons, acute extracellular application of CM or partially purified recombinant CRMP2 produced an increase in cytoplasmic calcium. The increase in cytoplasmic calcium was mostly mediated through NMDA receptors, with a minor contribution of N-type VDCC, and it was maintained as long as CM was present. By using live-labeling of CRMP2, Ca2+ channel binding domain 3 (CBD3) peptide derived from CRMP2, and recombinant CRMP2, we demonstrated that that this effect was mediated by an action on the extracellular side of the NMDA receptor. This is the first report of an extracellular action of CRMP2. Prolonged exposure to extracellular CRMP2, may contribute to neuronal calcium dysregulation and neuronal damage.

The inositol-1,2-cyclic phosphate moiety of the cross-reacting determinant, carbohydrate chains, and proteinaceous components are all responsible for the cross-reactivity of trypanosome variant surface glycoproteins.

Salivarian trypanosomes evade the host immune system by continually swapping their protective variant surface glycoprotein (VSG) coat. Given that VSGs from various trypanosome stocks exhibited cross-reactivity (Camargo et al., Vet. Parasitol. 207, 17-33, 2015), we analyzed here which components are the antigenic determinants for this cross-reaction. Soluble forms of VSGs were purified from four Venezuelan animal trypanosome isolates: TeAp-N/D1, TeAp-ElFrio01, TeAp-Mantecal01, and TeGu-Terecay323. By using the VSG soluble form from TeAp-N/D1, we found that neither the inositol-1,2-cyclic phosphate moiety of the cross-reacting determinant nor the carbohydrate chains were exclusively responsible for its cross-reactivity. Then, all four purified glycoproteins were digested with papain and the resulting peptides were separated by high-performance liquid chromatography. Dot blot evaluation of the fractions using sera from trypanosome-infected animals yielded peptides that possessed cross-reaction activity, demonstrating for the first time that proteinaceous epitopes are also responsible for the cross-reactivity of trypanosome VSGs.

The gene product of a Trypanosoma equiperdum ortholog of the cAMP-dependent protein kinase regulatory subunit is a monomeric protein that is not capable of binding cyclic nucleotides.

The full gene sequence encoding for the Trypanosoma equiperdum ortholog of the cAMP-dependent protein kinase (PKA) regulatory (R) subunits was cloned. A poly-His tagged construct was generated [TeqR-like(His)8], and the protein was expressed in bacteria and purified to homogeneity. The size of the purified TeqR-like(His)8 was determined to be ∼57,000 Da by molecular exclusion chromatography indicating that the parasite protein is a monomer. Limited proteolysis with various proteases showed that the T. equiperdum R-like protein possesses a hinge region very susceptible to proteolysis. The recombinant TeqR-like(His)8 did not bind either [3H] cAMP or [3H] cGMP up to concentrations of 0.40 and 0.65 µM, respectively, and neither the parasite protein nor its proteolytically generated carboxy-terminal large fragments were capable of binding to a cAMP-Sepharose affinity column. Bioinformatics analyses predicted that the carboxy-terminal region of the trypanosomal R-like protein appears to fold similarly to the analogous region of all known PKA R subunits. However, the protein amino-terminal portion seems to be unrelated and shows homology with proteins that contained Leu-rich repeats, a folding motif that is particularly appropriate for protein-protein interactions. In addition, the three-dimensional structure of the T. equiperdum protein was modeled using the crystal structure of the bovine PKA RIα subunit as template. Molecular docking experiments predicted critical changes in the environment of the two putative nucleotide binding clefts of the parasite protein, and the resulting binding energy differences support the lack of cyclic nucleotide binding in the trypanosomal R-like protein.