Silver Nanoparticles Produced by Laser Ablation and Re-Irradiation Are Effective Preventing Peri-Implantitis Multispecies Biofilm Formation.

Implant-associated infection due to biofilm formation is a growing problem. Given that silver nanoparticles (Ag-NPs) have shown antibacterial effects, our goal is to study their effect against multispecies biofilm involved in the development of peri-implantitis. To this purpose, Ag-NPs were synthesized by laser ablation in de-ionized water using two different lasers, leading to the production of colloidal suspensions. Subsequently, part of each suspension was subjected to irradiation one and three times with the same laser source with which it was obtained. Ag-NPs were immobilized on the surface of titanium discs and the resultant materials were compared with unmodified titanium coupons. Nanoparticles were physico-chemically analysed to determine their shape, crystallinity, chemical composition, and mean diameter. The materials were incubated for 90 min or 48 h, to evaluate bacterial adhesion or biofilm formation respectively with Staphylococcus aureus or oral mixed bacterial flora composed of Streptococcus oralis, Actinomyces naeslundii, Veionella dispar, and Porphyromonas gingivalis. Ag-NPs help prevent the formation of biofilms both by S. aureus and by mixed oral bacterial flora. Nanoparticles re-irradiated three times showed the biggest antimicrobial effects. Modifying dental implants in this way could prevent the development of peri-implantitis.

Partial wing transparency works better when disrupting wing edges: Evidence from a field experiment.

Lepidoptera-a group of insects in which wing transparency has arisen multiple times-exhibits much variation in the size and position of transparent wing zones. However, little is known as to how this variability affects detectability. Here, we test how the size and position of transparent elements affect the predation of artificial moths by wild birds in the field. Morphs with transparent elements touching wing borders showed a reduced predation risk, with the effect being the same regardless of the number of wing borders being touched. By contrast, transparent element size had little to no effect on predation risk. Overall, this experiment shows for the first time that transparency offers higher protection when it disrupts prey contour in terrestrial habitats.

How do predators generalize warning signals in simple and complex prey communities? Insights from a videogame.

The persistence of distinct warning signals within and between sympatric mimetic communities is a puzzling evolutionary question because selection favours convergence of colour patterns among toxic species. Such convergence is partly shaped by predators' reaction to similar but not identical stimulus (i.e. generalization behaviour), and generalization by predators is likely to be shaped by the diversity of local prey. However, studying generalization behaviour is generally limited to simple variations of prey colour patterns. Here, we used a computer game played by humans as surrogate predators to investigate generalization behaviours in simple (4 morphs) and complex (10 morphs) communities of unprofitable (associated with a penalty) and profitable butterflies. Colour patterns used in the game are observed in the natural populations of unprofitable butterfly species such as Heliconius numata. Analyses of 449 game participants' behaviours show that players avoided unprofitable prey more readily in simple than in complex communities. However, generalization was observed only in players that faced complex communities, enhancing the protection of profitable prey that looked similar to at least one unprofitable morph. Additionally, similarity among unprofitable prey also reduced attack rates only in complex communities. These results are consistent with previous studies using avian predators but artificial colour patterns and suggest that mimicry is more likely to evolve in complex communities where increases in similarity are more likely to be advantageous.

Transparency improves concealment in cryptically coloured moths.

Predation is a ubiquitous and strong selective pressure on living organisms. Transparency is a predation defence widespread in water but rare on land. Some Lepidoptera display transparent patches combined with already cryptic opaque patches. A recent study showed that transparency reduced detectability of aposematic prey with conspicuous patches. However, whether transparency has any effect at reducing detectability of already cryptic prey is still unknown. We conducted field predation experiments with free avian predators where we monitored and compared survival of a fully opaque grey artificial form (cryptic), a form including transparent windows and a wingless artificial butterfly body. Survival of the transparent forms was similar to that of wingless bodies and higher than that of fully opaque forms, suggesting a reduction of detectability conferred by transparency. This is the first evidence that transparency decreases detectability in cryptic terrestrial prey. Future studies should explore the organization of transparent and opaque patches in animals and their interplay on survival, as well as the costs and other potential benefits associated with transparency on land.

Warning signals are under positive frequency-dependent selection in nature.

Positive frequency-dependent selection (FDS) is a selection regime where the fitness of a phenotype increases with its frequency, and it is thought to underlie important adaptive strategies resting on signaling and communication. However, whether and how positive FDS truly operates in nature remains unknown, which hampers our understanding of signal diversity. Here, we test for positive FDS operating on the warning color patterns of chemically defended butterflies forming multiple coexisting mimicry assemblages in the Amazon. Using malleable prey models placed in localities showing differences in the relative frequencies of warningly colored prey, we demonstrate that the efficiency of a warning signal increases steadily with its local frequency in the natural community, up to a threshold where protection stabilizes. The shape of this relationship is consistent with the direct effect of the local abundance of each warning signal on the corresponding avoidance knowledge of the local predator community. This relationship, which differs from purifying selection acting on each mimetic pattern, indicates that predator knowledge, integrated over the entire community, is saturated only for the most common warning signals. In contrast, among the well-established warning signals present in local prey assemblages, most are incompletely known to local predators and enjoy incomplete protection. This incomplete predator knowledge should generate strong benefits to life history traits that enhance warning efficiency by increasing the effective frequency of prey visible to predators. Strategies such as gregariousness or niche convergence between comimics may therefore readily evolve through their effects on predator knowledge and warning efficiency.

Variation in cyanogenic compounds concentration within a Heliconius butterfly community: does mimicry explain everything?

BACKGROUND: Aposematic species advertise their unpalatability using warning signals such as striking coloration. Given that predators need to sample aposematic prey to learn that they are unprofitable, prey with similar warning signals share the cost of predator learning. This reduction in predation risk drives evolutionary convergence of warning signals among chemically defended prey (Müllerian mimicry). Whether such warning signal convergence is associated to similar defence levels among co-mimics is still an open question that has rarely been tested in wild populations. We quantified variation in cyanide-based (CN) chemical protection in wild caught individuals of eight aposematic Heliconius butterfly species belonging to four sympatric mimicry rings. We then tested for correlations between chemical protection and ecological species-specific traits. RESULTS: We report significant differences in CN concentrations both within and between sympatric species, even when accounting for the phylogeny, and within and between mimicry rings, even after considering inter-specific variation. We found significant correlations between CN concentration and both hostplant specialization and gregarious behaviour in adults and larvae. However, differences in CN concentrations were not significantly linked to mimicry ring abundance, although the two most toxic species did belong to the rarest mimicry ring. CONCLUSIONS: Our results suggest that mimicry can explain the variation in the levels of chemical defence to a certain extent, although other ecological factors are also relevant to the evolution of such variability.

Crossing fitness valleys: empirical estimation of a fitness landscape associated with polymorphic mimicry.

Characterizing fitness landscapes associated with polymorphic adaptive traits enables investigation of mechanisms allowing transitions between fitness peaks. Here, we explore how natural selection can promote genetic mechanisms preventing heterozygous phenotypes from falling into non-adaptive valleys. Polymorphic mimicry is an ideal system to investigate such fitness landscapes, because the direction of selection acting on complex mimetic colour patterns can be predicted by the local mimetic community composition. Using more than 5000 artificial butterflies displaying colour patterns exhibited by the polymorphic Müllerian mimic Heliconius numata, we directly tested the role of wild predators in shaping fitness landscapes. We compared predation rates on mimetic phenotypes (homozygotes at the supergene controlling colour pattern), intermediate phenotypes (heterozygotes), exotic morphs (absent from the local community) and palatable cryptic phenotypes. Exotic morphs were significantly more attacked than local morphs, highlighting predators' discriminatory capacities. Overall, intermediates were attacked twice as much as local homozygotes, suggesting the existence of deep fitness valleys promoting strict dominance and reduced recombination between supergene alleles. By including information on predators' colour perception, we also showed that protection on intermediates strongly depends on their phenotypic similarity to homozygous phenotypes and that ridges exist between similar phenotypes, which may facilitate divergence in colour patterns.

Extramedullary Imaging Manifestations of Leukemia/Lymphoblastic Lymphoma in Pediatrics: A Case Series.

Leukemia is the most common childhood malignancy and often presents with nonspecific symptoms. Occasionally, it presents with extramedullary manifestations, which have been more frequent in cases of myeloid lineage or T cells. However, precursor B-cell leukemia/lymphoblastic lymphoma can also have extramedullary manifestations in some patients. Describing certain clinical features along with diagnostic imaging can establish a presentation pattern and suggest a diagnosis in the pediatric population. Herein, we present a series of four patients with extramedullary manifestations of B-cell lymphoblastic leukemia, describing their clinical imaging and histopathological characteristics.

Megacystis-Microcolon-Intestinal Hypoperistalsis Syndrome: A Case Report of an Uncommon Condition.

The megacystis-microcolon-intestinal hypoperistalsis syndrome (MMIHS), also known as Berdon syndrome, is a rare congenital condition that falls within the spectrum of visceral myopathies. It is characterized by the presence of megacystis, microcolon, and hypoperistalsis, which are secondary to gastrointestinal and urinary system dysmotility. It is frequently associated with other alterations in the gastrointestinal and genitourinary tracts. Although it is possible to make the diagnosis in the prenatal period, most cases are diagnosed after birth through genetic and imaging studies. Advances in treatment have led to a progressive increase in survival rates. We present the case of a newborn with congenital alterations described prenatally and with imaging findings characteristic of the syndrome.

Imaging Diagnosis of Desmoplastic Small Round Cell Tumor: A Report of Two Cases.

Desmoplastic small round cell tumor (DSRCT) is a rare multifocal peritoneal sarcoma, typically found in adolescent and young adult males. Symptoms are nonspecific and vary depending on tumor involvement. Diagnosis is primarily histopathological, although imaging results can assist in the diagnostic process. Although not pathognomonic, certain radiologic findings can help narrow down potential diagnoses and sometimes suggest the condition, as seen in our cases. Treatment options are not well-established or effective, and despite employing various therapeutic approaches, the prognosis remains poor. We present two cases of boys aged 11 and 10 with a final diagnosis of DSRCT, emphasizing the imaging findings.

Deadly and venomous Lonomia caterpillars are more than the two usual suspects.

Caterpillars of the Neotropical genus Lonomia (Lepidoptera: Saturniidae) are responsible for some fatal envenomation of humans in South America inducing hemostatic disturbances in patients upon skin contact with the caterpillars' spines. Currently, only two species have been reported to cause hemorrhagic syndromes in humans: Lonomia achelous and Lonomia obliqua. However, species identifications have remained largely unchallenged despite improved knowledge of venom diversity and growing evidence that the taxonomy used over past decades misrepresents and underestimates species diversity. Here, we revisit the taxonomic diversity and distribution of Lonomia species using the most extensive dataset assembled to date, combining DNA barcodes, morphological comparisons, and geographical information. Considering new evidence for seven undescribed species as well as three newly proposed nomenclatural changes, our integrative approach leads to the recognition of 60 species, of which seven are known or strongly suspected to cause severe envenomation in humans. From a newly compiled synthesis of epidemiological data, we also examine the consequences of our results for understanding Lonomia envenomation risks and call for further investigations of other species' venom activities. This is required and necessary to improve alertness in areas at risk, and to define adequate treatment strategies for envenomed patients, including performing species identification and assessing the efficacy of anti-Lonomia serums against a broader diversity of species.

Association mapping of colour variation in a butterfly provides evidence that a supergene locks together a cluster of adaptive loci.

Supergenes are genetic architectures associated with discrete and concerted variation in multiple traits. It has long been suggested that supergenes control these complex polymorphisms by suppressing recombination between sets of coadapted genes. However, because recombination suppression hinders the dissociation of the individual effects of genes within supergenes, there is still little evidence that supergenes evolve by tightening linkage between coadapted genes. Here, combining a landmark-free phenotyping algorithm with multivariate genome-wide association studies, we dissected the genetic basis of wing pattern variation in the butterfly Heliconius numata. We show that the supergene controlling the striking wing pattern polymorphism displayed by this species contains several independent loci associated with different features of wing patterns. The three chromosomal inversions of this supergene suppress recombination between these loci, supporting the hypothesis that they may have evolved because they captured beneficial combinations of alleles. Some of these loci are, however, associated with colour variations only in a subset of morphs where the phenotype is controlled by derived inversion forms, indicating that they were recruited after the formation of the inversions. Our study shows that supergenes and clusters of adaptive loci in general may form via the evolution of chromosomal rearrangements suppressing recombination between co-adapted loci but also via the subsequent recruitment of linked adaptive mutations. This article is part of the theme issue 'Genomic architecture of supergenes: causes and evolutionary consequences'.

Ovarian Epithelioid Hemangioendothelioma in a Pediatric Patient: A Case Report.

We present a case of an eight-month-old girl who was brought to the emergency department with bloody stools. An initial ultrasound reported a mass in the left iliac fossa that was further characterized by magnetic resonance imaging (MRI) as a hypervascular ovarian tumor. Prior to surgical resection of the tumor, abdominal arteriography with selective embolization and vessel occlusion was performed. Pathology reported epithelioid hemangioendothelioma of the left ovary. This condition has not been previously reported in girls. In this case report, we describe the ultrasound, MRI, and arteriographic findings with a histopathologic correlation of an adnexal tumor that is unknown in the pediatric female population until now.

Palladium Nanoparticles Synthesized by Laser Ablation in Liquids for Antimicrobial Applications.

Antibiotic resistance is a leading cause of death worldwide. In this paper, we explore new alternatives in the treatment of infections. Noble metal nanoparticles could help to mitigate this problem. In this work, palladium nanoparticles were synthesized by laser ablation in order to explore their antimicrobial capacity. To obtain palladium nanoparticles, a palladium plate immersed in water, or methanol, was ablated, using two pulsed lasers that emit radiation with wavelengths of 532 nm and 1064 nm, respectively. Pure Pd-NPs with crystalline microstructure and rounded shape were obtained. The nanoparticles' size is more homogeneous if the laser wavelength is 532 nm, and it decreases when methanol is used as solvent, reaching mean diameters smaller than 6 nm. With the objective of studying antimicrobial activity against Staphylococcus aureus, the Pd-NPs were immobilized on the surface of titanium discs. The release of palladium ions was recorded during the first seven days, and the cytotoxicity of the immobilized NPs was also tested with L929 mouse fibroblast cell line. Palladium nanoparticles synthesized by means of the infrared laser in methanol showed a strong inhibitory effect on S. aureus and good cytocompatibility, with no toxic effect on fibroblast cells.

Laser-Deposited Beta Type Ti-42Nb Alloy with Anisotropic Mechanical Properties for Pioneering Biomedical Implants with a Very Low Elastic Modulus.

Present commercial titanium alloy implants have an elastic modulus higher than 100 GPa, whereas that of the cortical bone is much smaller (17−28 GPa). This elastic modulus mismatch produces a stress shielding effect and the resorption of the bone surrounding the implant. In the present work, a <100> fiber texture is developed in ß type Ti-42Nb (wt%) alloy ingots generated by laser-directed energy deposition (LDED) in order to achieve anisotropic mechanical properties. In addition, we demonstrate that laser-deposited ß type Ti-42Nb alloy ingots with an intense <100> fiber texture exhibit a very low elastic modulus in the building direction (Ez < 50 GPa) and high yield (σ0.2z > 700 MPa) and tensile (UTSz > 700 MPa) strengths. Laser-deposited Ti-42Nb alloy enhances the osteoinductive effect, promoting the adhesion, proliferation, and spreading of human osteoblast-like cells. Hence, we propose that laser-deposited ß type Ti-42Nb alloy is a potentially promising candidate for the manufacturing of pioneering biomedical implants with a very low elastic modulus that can suppress stress shielding.

Improvement of Fucosylated Oligosaccharides Synthesis by α-L-Fucosidase from Thermotoga maritima in Water-Organic Cosolvent Reaction System.

The effects of water activity (aw), pH, and temperature on transglycosylation activity of α-L-fucosidase from Thermotoga maritima in the synthesis of fucosylated oligosaccharides were evaluated using different water-organic cosolvent reaction systems. The optimum conditions of transglycosylation reaction were the pH range between 7 and 10 and temperature 90-95 °C. The addition of organic cosolvent decreased α-L-fucosidase transglycosylation activity in the following order: acetone > dimethyl sulfoxide (DMSO) > acetonitrile (0.51 > 0.42 > 0.18 mM/h). However, the presence of DMSO and acetone enhanced enzyme-catalyzed transglycosylation over hydrolysis as demonstrated by the obtained transglycosylation/hydrolysis rate (rT/H) values of 1.21 and 1.43, respectively. The lowest rT/H was calculated for acetonitrile (0.59), though all cosolvents tested improved the transglycosylation rate in comparison to a control assay (0.39). Overall, the study allowed the production of fucosylated oligosaccharides in water-organic cosolvent reaction media using α-L-fucosidase from T. maritima as biocatalyst.

Effects of postural threat on walking features of Parkinson's disease patients.

This study investigated whether or not gait kinematics among healthy older individuals and Parkinson's disease (PD) patients are influenced by postural threat. Eight healthy older individuals and eight PD patients were examined while walking at self-selected velocities, under three conditions of postural threat: unconstrained floor; constrained floor (19cm wide); constrained and elevated floor (19cm wide by 10cm high). Independent of the surface conditions, due to motor disturbances caused by the PD these patients walked slower, with shorter strides, and spent more time in the double support phase and less time in the swing phase than did their matched controls. Increases in postural threat resulted in altered gait kinematics for all subjects. Specifically, stride length, stride velocity, cadence, and heel contact velocity decreased, and stride duration and double support duration increased relative to increases in postural threat. All gait alterations were the result of participants' attempts to facilitate locomotion control and maintain stability. The results of this study reveal that width and height constraints effectively perturbed the balance of all of the walking older individuals. The PD patients were able to modulate gait parameters when faced by a postural threat task.

Wilms or non-Wílms tumors? Imaging features of renal tumors in pediatrics / ¿Tumores de Wilms o no Wilms? Características por imagen de los tumores renales en pediatría

Abstract Introduction: Identifying the imaging features of renal tumors in pediatric population allows reaching more accurate diagnoses and implementing more appropriate treatments. Objective: To describe the imaging findings of renal tumors in children and to assess the association between imaging findings and histological diagnosis of Wilms tumors versus Non-Wilms tumors, and between imaging features and intraoperative rupture of Wilms tumors, as well as the level of agreement between radiological and histological diagnosis (Wilms vs. Non-Wilms tumor). Materials and methods: Cross-sectional study conducted in 47 children with a pathological diagnosis of kidney tumor and treated between 2012 and 2018 in a pediatric hospital in Bogotá D.C., Colombia. The patients' medical records, as well as their ultrasound, tomography and magnetic resonance studies were reviewed. Two univariate logistic regression analyses were performed to assess the association between imaging findings and histopathological diagnosis and between imaging features and intraoperative rupture of Wilms tumors, calculating the respective Odds Ratio (OR) with a 95% confidence interval. In addition, the level of agreement between radiological and histological diagnosis was determined using the Cohen's kappa coefficient. Results: A significant association was found between histological diagnosis of Wilms tumor and the presence of necrosis, tumor enhancement, pseudocapsule, rupture signs, tumor volume and tumor size (OR: 21.6, 15.17, 14.57, 8.21, 7.93, and 4.37, respectively; p<0.05). An association between having Wilms tumors and a lower frequency of metastases was also found (OR: 0.19; p<0.05). The kappa coefficient between radiological diagnosis of Wilms/non- Wilms tumors and histological diagnosis was 0.78 (CI95%: 0.59-0.96; p<0.05). Additionally, Wilms tumors volumen was significantly associated with the occurrence of rupture (OR: 3.08; p<0.05). Conclusions: There are imaging findings such as necrosis, tumor enhancement and tumor volume that can help predict the histological diagnosis of Wilms tumors, as well as perioperative rupture. In addition, a moderate to very good concordance between radiological diagnosis of Wilms/non-Wilms tumors and histological findings was found.

Resumen Introducción. Identificar las características por imagen de los tumores renales en la población pediátrica permite realizar diagnósticos más precisos e implementar tratamientos más apropiados. Objetivo. Describir los hallazgos de imagen de tumores renales en niños y evaluar la asociación entre hallazgos imagenológicos y el diagnóstico histopatológico de tumores de Wilms versus tumores no Wilms, y entre las características de imagen y ruptura quirúrgica de tumores Wilms, así como el grado de concordancia entre el diagnóstico radiológico e histológico. Materiales y métodos. Estudio transversal realizado en 47 niños con diagnóstico patológico de tumor renal atendidos entre 2012 y 2018 en un hospital pediátrico de Bogotá D.C., Colombia. Se revisaron las historias clínicas de los pacientes, así como sus estudios de ultrasonografía, tomografía y resonancia magnética. Se realizaron dos análisis de regresión logística univariados para evaluar la asociación entre hallazgos imagenológicos y diagnóstico histopatológico y entre las características imagenológicas de los tumores de Wilms y ruptura quirúrgica, calculando los respectivos odds ratio (OR) con un intervalo de confianza del 95%. Además, se determinó el grado concordancia entre el diagnóstico radiológico e histopatológico mediante el coeficiente de kappa de Cohen. Resultados. Se encontró una asociación significativa entre el diagnóstico histológico de tumor de Wilms y la presencia de necrosis, realce tumoral, pseudocápsula, signos de ruptura, volumen y tamaño del tumor (OR: 21.6, 15.17, 14.57, 8.21, 7.93 y 4.37, respectivamente; p<0.05). También se observó una asociación entre tener tumores de Wilms y menor frecuencia de metástasis (OR:0.19; p<0.05). El coeficiente de Kappa entre el diagnóstico radiológico de los tumores (Wilms/no-Wilms) y el diagnóstico histológico fue 0.78 (IC95%: 0.59-0.96; p<0.05). Además, el volumen de los tumores de Wilms se asoció significativamente con la ocurrencia de ruptura (OR: 3.08; p<0.05). Conclusiones. Hay hallazgos imagenológicos como la necrosis, el realce tumoral y el volumen tumoral que ayudan a predecir el diagnóstico histológico de tumores de Wilms, así como la ruptura perioperatoria. Además, se observó una muy buena concordancia entre el diagnóstico radiológico de tumores Wilms/no Wilms y los hallazgos histológicos.

Transcriptomic and macroevolutionary evidence for phenotypic uncoupling between frog life history phases.

Anuran amphibians undergo major morphological transitions during development, but the contribution of their markedly different life-history phases to macroevolution has rarely been analysed. Here we generate testable predictions for coupling versus uncoupling of phenotypic evolution of tadpole and adult life-history phases, and for the underlying expression of genes related to morphological feature formation. We test these predictions by combining evidence from gene expression in two distantly related frogs, Xenopus laevis and Mantidactylus betsileanus, with patterns of morphological evolution in the entire radiation of Madagascan mantellid frogs. Genes linked to morphological structure formation are expressed in a highly phase-specific pattern, suggesting uncoupling of phenotypic evolution across life-history phases. This gene expression pattern agrees with uncoupled rates of trait evolution among life-history phases in the mantellids, which we show to have undergone an adaptive radiation. Our results validate a prevalence of uncoupling in the evolution of tadpole and adult phenotypes of frogs.

Descripción del posicionamiento de una copa monobloque no cementada en el posoperatorio inmediato / Description of uncemented monobloc cup positioning in the immediate postoperative period

Introducción El posicionamiento adecuado de la copa acetabular en el reemplazo total de cadera (RTC) puede mejorar la función, reducir el desgaste, el pinzamiento y la luxación. La posición de la copa se describe como la relación espacial entre el centro de rotación de la cadera y la pelvis. El objetivo de este estudio es describir el posicionamiento de una copa monobloque no cementada en el posoperatorio inmediato de los pacientes a quienes se les realizo un RTC primario. Materiales y Métodos Estudio observacional descriptivo, los pacientes fueron operados por 4 cirujanos especialistas en cirugía de reemplazo articular de cadera en 8 clínicas, los procedimientos se realizaron entre octubre de 2015 a agosto de 2018, las medidas radiológicas fueron la inclinación, anteversión, lateralización, porcentaje de descubrimiento y espacio detrás de la copa acetabular. Resultados Los mayores porcentajes son para las copas acetabulares con inclinación de 36 a 48 grados, anteversión de 5 a 15 grados, lateralización de -2 a +2mm, porcentaje de descubrimiento del 0% y espacio detrás de la copa de 0 a 3mm. Discusión Diferentes autores han identificado zonas seguras de implantación las cuales concuerdan con los resultados de nuestro estudio. El posicionamiento adecuado de la copa acetabular monobloque no cementada se pudo lograr con una correcta indicación del implante, un abordaje quirúrgico que permitió una ubicación tridimensional idónea y un acetábulo sin alteraciones anatómicas a nivel periférico.

Background Appropriate positioning of the acetabular cup in total hip arthroplasty (THA) can improve hip function, reduce wear, impingement and dislocation. The position of the cup is described as the spatial relationship between the centre of rotation of the hip and the pelvis. The aim of this study is to describe the positioning of the uncemented monoblock cup in the immediate postoperative period in patients who underwent a primary THA. Methods Descriptive observational study. The patients were operated by 4 joints arthroplasty surgeons in 8 different hospitals, from October 2015 to August 2018. The radiological measurements were taken from the AP Pelvis Xrays of the immediate postoperative. The inclination, anteversion, lateralization, percentage of cup uncovered and the space behind the acetabular cup. Results 82.05% of the cups were in the range of inclination from 36 to 48 degrees; 85.71% had an anteversion between 5 to 15 degrees, 76.56% presented a lateralization of -2 to +2mm, 94.51% of the patients didnt have a uncover cup, and 92.67% of the cups had a space behind the cup from 0 to 3mm. Discussion In our study the highest percentage of cups were implanted with parameters agree to the safety areas reported by various authors. Adequate positioning of the uncemented monoblock acetabular cup can be achieved with a proper indication, a surgical approach that allows an ideal three-dimensional location and an acetabulum with a good peripheral rim that provides the required press-fit.