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.

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.

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.

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.

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.

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.

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.

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.

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.

Hereditary coproporhyria

Abstract Hereditary coproporphyria (HCP) is a congenital, autosomal dominant disorder which occurs in approximately two to five people per million inhabitants, worldwide. It is a diagnostic challenge in patients with acute abdominal pain. We present the case of a 17-year-old adolescent who debuted with atypical abdominal pain with no clear etiology. Elevated urinary porphobilinogen was found, which was treated with hematin. A genetic study concluded that the adolescent was a heterozygous carrier of the c.717T>A; p.Cys239 pathogenic nonsense mutation in the CPOX gene, leading to a diagnosis of hereditary copropophyria. The available national literature has presented cases diagnosed with acute intermittent porphyria in patients with abdominal pain of unknown origin, without covering the existing classifications of hepatic porphyrias and without detailing the genetic diagnosis; thus, this case is a contribution to the national case studies. (Acta Med Colomb 2021; 46. DOI:https://doi.org/10.36104/amc.2021.1950).

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.

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.

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.

Clinical and microbiological characteristics of dogs in sepsis in an academic veterinary hospital in the north of Paraná / Características clínicas e microbiológicas de cães em sepse de um hospital veterinário escola do norte do Paraná

Sepsis is a life-threatening organ dysfunction caused by a patient's unregulated response to an infectious process. In veterinary medicine, the exact incidence of sepsis is unknown. Early recognition of sepsis in critically ill patients is essential for rapid and effective therapeutic intervention. The present study aimed to apply the criteria of an adapted sepsis assessment protocol based on the Second International Consensus Definition for Sepsis and Septic Shock or Sepsis-2 of human medicine, in canine patients with suspected systemic inflammatory response syndrome (SIRS) and/or organ dysfunction, and to identify infectious agents as well as their antimicrobial resistance profile in the focus of infection, in the bloodstream and colonizing the rectal mucosa. Patients were evaluated for survival and severity of sepsis. Of the 37/42 dogs that met the sepsis criteria, six presented septic shock, 26 (70.2%) had at least two signs of SIRS, and sepsis with organ dysfunction was diagnosed in 27 (73%) dogs. The primary dysfunctions observed were decreased level of consciousness in 21/37 (56.8%), hyperlactatemia in 19/37 (51.4%), and hypoalbuminemia in 18/37 (48.6%). Two or more SIRS signs associated with hypotension and hypoalbuminemia were related to more than half of the deaths. The most frequent infectious focus was skin and soft tissue in 20/37 (54%), followed by organs and cavities in 8/37 (21.6%). The survival rate was 56.7%. Blood culture confirmed bacteremia in nine patients (24.3%), with a predominance of Gram-positive microorganisms (Staphylococcus intermedius, Streptococcus spp.) in 66.6% of dogs and one yeast (Candida glabrata). The most frequent bacteria in the focus of infection were gram-negative bacteria (46.2%), mainly Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa, in 19.5%, 14.6%, and 12.1%, respectively. We observed colonization by gram-negative bacteria such as E. coli-ESBL (31.5%), K. pneumoniae-ESBL (15.7%), and P. aeruginosa (15.7%), and the presence of ESBL bacteria was more associated with death when compared with other microorganisms. Vancomycin-resistant Enterococcus (VRE) were isolated from rectal mucosa in four dogs. Gram-negative microorganisms were the most frequent in both infections and colonization, and most of them were resistant to fluoroquinolones, sulfonamides, tetracyclines, and cephalosporins. Based on this information, it can be concluded that mortality due to sepsis in dogs was high. Due to the presence of multi-resistant bacteria, the use of antimicrobials should be judicious, suggesting the implementation of the same precautions used in human hospitals to prevent the spread of multi-resistant microorganisms.(AU)

A sepse é uma disfunção orgânica ameaçadora à vida, causada por uma resposta desregulada do hospedeiro à infecção e na medicina veterinária sua incidência exata é desconhecida. O reconhecimento precoce da sepse nos pacientes críticos é essencial para que a intervenção terapêutica seja rápida e eficaz. Assim, os objetivos do presente estudo foram aplicar os critérios de um protocolo de avaliação da sepse adaptado com base no Segundo Consenso Internacional para Sepse e Choque Séptico, ou Sepse-2, da medicina humana, em pacientes caninos com suspeita de infecção e/ou Síndrome da Resposta Inflamatória Sistêmica e/ou disfunção orgânica e identificar os agentes infecciosos bem como seu perfil de resistência a antimicrobianos no foco de infecção, na corrente sanguínea e colonizando a mucosa retal. Os pacientes foram avaliados quanto à sobrevivência e severidade da sepse. Dos 37/42 cães que se enquadraram nos critérios de sepse, seis estavam em choque séptico, 26 (70,2%) apresentaram pelo menos dois sinais de SIRS, e a sepse com disfunção orgânica foi diagnosticada em 27 (73%) cães. As principais disfunções verificadas foram diminuição do nível de consciência em 21/37 (56,8%), hiperlactatemia em 19/37 (51,4%) e hipoalbuminemia em 18/37 (48,6%). A presença de dois ou mais sinais de SIRS associados com hipotensão e hipoalbuminemia estiveram relacionadas com mais da metade dos óbitos. O foco infeccioso mais frequente foi pele e partes moles em 20/37 (54%) seguido por órgãos e cavidades em 8/37 (21,6%). A taxa de sobrevivência foi de 56,7%. Na hemocultura confirmou-se bacteremia em nove pacientes (24,3%), com predominância de microrganismos gram-positivos (Staphylococcus intermedius, Streptococcus spp.) em 66,6% dos cães e uma levedura (Candida glabrata). As bactérias mais frequentes no foco de infecção foram as gram-negativas (46,2%) principalmente Escherichia coli, Klebsiella pneumoniae e Pseudomonas aeruginosa, em 19,5%, 14,6% e 12,1% respectivamente. Foi constatada colonização por bactérias gram-negativas como E. coli-ESBL (31,5%), K. pneumoniae-ESBL (15,7%) e P. aeruginosa (15,7%), sendo que a colonização de cães por bactérias ESBL foi associada ao óbito quando comparada com outros microrganismos. Foram também isolados da mucosa retal Enterococcus resistentes à vancomicina (VRE) em quatro cães. Os microrganismos gram-negativos foram os mais frequentes, tanto nas infecções quanto nas colonizações e a maioria apresentava resistência à fluorquinolonas, sulfonamidas, tetraciclinas e cefalosporinas. Com base nestas informações, conclui-se que a mortalidade em decorrência da sepse em cães foi alta, e devido à presença de bactérias multirresistentes, o uso de antimicrobianos deve ser criterioso, sugerindo-se ainda a implantação das mesmas precauções utilizadas em hospitais humanos para evitar disseminação de microrganismos multirresistentes.(AU)

Fallo hepático agudo por gripe A: manifestación poco común de un problema frecuente / Acute liver failure by Influenza A: rare manifestation of a common problem

El fallo hepático agudo es un cuadro grave y poco frecuente en Pediatría. Precisa un manejo multidisplinar. Aunque en la mitad de los casos no se llega a un diagnóstico etiológico definitivo, conviene conocer sus causas según los grupos de edad, debido a su implicación pronóstica y terapéutica. Se reconocen principalmente causas infecciosas, tóxicas, metabólicas y autoinmunes. Dentro de las causas infecciosas, destacan los virus de la familia herpes y los virus hepatotropos; sin embargo, también se ha relacionado con virus respiratorios y en concreto con el virus de la gripe, en cuyo caso, el pronóstico es bueno. Presentamos el caso de una niña de cuatro años que debutó con cuadro de fallo hepático agudo secundario a infección por virus influenza A con una evolución muy favorable

Acute liver failure is a severe disease uncommon in children, that needs a multidisciplinar approach. In over a half of the patients the etiology is unknown. Nevertheless, remains very important for the management and prognosis to understand the main etiologies upon the group of ages. The causes may be divided in infec­tious, toxin/drug, metabolic, and autoinmune. Over the infectious etiologies the herpes virus and other hepatotropic viruses are the most frequent. However, respiratory viruses, and particularly Virus Influenza have been identified as potential cause of acute liver failure, in which the prognosis is significantly better. We report on a four-year-old girl who developed acute liver failure due to an influenza A infection with very good outcome

Development of a lumbosacral intervertebral cage prototype for dogs / Desenvolvimento de um protótipo de cage intervertebral lombossacro para cães

Several surgical procedures aim to decompress and/or stabilize the lumbosacral (LS) joint of dogs; however, the lumbar interbody fusion technique, by using a cage combined with a bone graft, is the most indicated and used in human medicine. No specific implant is available for application to the canine lumbosacral joint. Thus, this study measured lumbosacral discs in large dogs, determined whether a human cage model could fit the dogs' L7-S1 intervertebral space, and developed a LS cage prototype for dogs. Ten cadaveric lumbosacral spines from adult dog weighing 20-35kg were used. The dogs had died for reasons unrelated to this study. The vertebral body dimensions and the L7-S1 intervertebral space occupied by the intervertebral disc were measured by lateral and ventrodorsal radiographs and by computed tomography in the dorsal, sagittal, and transverse views. Measurements were also taken of the anatomical specimens in the sagittal and transverse planes. After measuring the intervertebral discs, the following mean measures were obtained for L7-S1 discs: height 12.23mm, dorsal thickness 3.3mm, central thickness 4mm, ventral thickness 5.5mm, and width 24.74mm. The human lumbar cage models from brands LDR, Baumer Orthopedics, Stryker, Synthes, and Vertebral Technologies, Inc. and cervical stabilization cages from the brands B-Braun and Stryker were evaluated and were found to be unsuitable for large dogs. Cervical human cages had measurements similar to those found in this study; however, due to their quadrangular shape, the possibility of being introduced surgically through the surgical accesses available for the articulation between L7-S1 in dogs without injuring the cauda equina or the L7 root is small. A cage model was then developed using 3D modelling software. It was designed for insertion via dorsal laminectomy in the lateral portions of the intervertebral space. To avoid cauda equina lesion, the implant model was developed to be placed laterally to the midline. The cage surface is serrated to prevent using the locking screw to fix it, thus avoiding further injury to nerve structures. The serrated surfaces are also designed to avoid cage migration and promote stability. The prototype allows graft placement in the surrounding intervertebral space, which is fundamental for fusion through integration between the cage and the endplates as well as for bone growth between and around the cage. It was also considered studies on humans showing that the lateral regions of the endplates support a more considerable load. Biomechanical and in vivo studies on the developed model are necessary to evaluate the actual degree of distraction, mobility and the long-term rate of fusion between L7 and S1 and its possible impact on the adjacent motor units, combined or not with dorsal fixation techniques.(AU)

Vários procedimentos cirúrgicos visam descomprimir e/ou estabilizar a articulação lombossacra (LS) de cães; no entanto, a técnica de fusão lombar, usando um cage intersomático combinado com um enxerto ósseo, é a mais indicada e utilizada na medicina humana. Não há implante específico disponível para aplicação na articulação lombossacra canina. Assim, neste estudo foi realizada a mensuração do espaço do disco intervertebral lombossacro de cães de raças grandes, para verificar se algum modelo de cage usado na medicina humana poderia ser usado no espaço intervertebral L7-S1 de cães. O segundo objetivo foi desenvolver um protótipo de cage lombossacro para cães. Foram utilizadas dez colunas lombossacras provenientes de cadáveres de cães adultos com peso entre 20 e 35kg. Os cães vieram a óbito por razões não relacionadas a este estudo. As dimensões do corpo vertebral e o espaço intervertebral L7-S1 ocupado pelo disco intervertebral foram medidos por radiografias laterais e ventrodorsais e por tomografia computadorizada nos cortes dorsal, sagital e transversal. Também foram realizadas mensurações das peças anatômicas nos planos sagital e transversal. Após a mensuração dos discos intervertebrais, foram obtidas as seguintes medidas médias dos discos L7-S1: altura 12,23mm, espessura dorsal 3,3mm, espessura central 4mm, espessura ventral 5,5mm e largura 24,74mm. Os modelos de cage lombar humano das marcas LDR, Baumer Orthopaedics, Stryker, Synthes e Vertebral Technologies, Inc. não possuíam dimensões adequadas para os cães. Cages de estabilização cervical das marcas B-Braun e Stryker também foram avaliados e apresentaram medidas semelhantes às encontradas neste estudo; no entanto, devido à sua forma quadrangular, a possibilidade de serem introduzidos cirurgicamente através das abordagens disponíveis para a articulação entre L7-S1 em cães sem lesionar a cauda equina ou a raiz L7 é pequena. Um modelo de cage foi então desenvolvido usando-se o software de modelagem 3D. Foi projetado para inserção via laminectomia dorsal nas porções laterais do espaço intervertebral. Para evitar a lesão da cauda equina, o modelo de implante foi desenvolvido para ser colocado lateralmente à linha média. A superfície do cage é serrilhada para evitar o uso do parafuso de travamento, evitando-se lesões adicionais às estruturas nervosas. As superfícies serrilhadas também foram projetadas para evitar a migração do cage e promover estabilidade. O protótipo permite a colocação do enxerto no espaço intervertebral circundante, fundamental para a fusão através da integração entre o cage e as placas vertebrais terminais, bem como para o crescimento ósseo entre e ao redor do implante. Também foram considerados estudos em seres humanos que mostraram que as regiões laterais das placas vertebrais terminais suportam uma carga maior. São necessários estudos biomecânicos e in vivo do modelo desenvolvido para avaliar o grau real de distração, mobilidade e a taxa de fusão a longo prazo entre L7 e S1 e seu possível impacto nas unidades motoras adjacentes, quando combinado ou não com técnicas de fixação dorsal.(AU)

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.

Post mortem evaluation of spinal cord and protruded intervertebral discs in dogs without neurological abnormalities / Avaliação post mortem da medula espinhal e de discos intervertebrais protrusos em cães sem alterações neurológicas

The aim of this study was to verify the presence of protrusion of the intervertebral disc (IVD) causing compression of the spinal cord and/or roots of cauda equina in 30 dogs above seven years of age with no evidence of previous neurological abnormalities. After the occurrence of death or euthanasia, a laminectomy was performed from C2 to the sacral vertebra to verify the presence of IVD protrusions. The protruded IVD were macroscopically graded according to the Thompson scale, and the corresponding spinal cord segment was histologically analyzed for nervous tissue compression. Of the 30 dogs, twelve (40%) presented disc protrusion, and of these 12 dogs, seven (58%) presented more than one protruded disc. Disc protrusion was observed in 3.2% (25/780) of all IVD evaluated. Of the six chondrodystrophic dogs, five (83%) presented disc protrusion. Of the 24 nonchondrodystrophic dogs, seven (29%) presented IVD protrusion. The site that showed the highest frequency of protrusion was L4-L5 (6/25) followed by the L6-L7 region (3/25) and C6-C7 (3/25). Only two of the medullary segments evaluated showed histological changes, with presence of focal lymphocytic infiltration and multifocal mild hemorrhage in the gray matter. Under the conditions of this study, 40% of dogs older than seven years old showed IVD protrusions without showing neurological signs, with no abnormality of the nervous tissue in 92% of the evaluated segments. Thus, the protrusion of the IVD in some dogs, can only be a finding of no clinical relevance.(AU)

O objetivo do presente estudo foi verificar a presença de protrusão do disco intervertebral (DIV) causando compressão da medula espinhal e/ou raízes da cauda equina em cadáveres de cães, sem histórico de alterações neurológicas. Para isso, após a ocorrência de óbito ou realização de eutanásia em 30 cães com mais de sete anos de idade, sem histórico de alterações neurológicas, foi realizada a laminectomia entre C2 até a vértebra sacral para verificar a presença de protrusões do DIV. Os DIV protrusos foram graduados macroscopicamente quanto à degeneração segundo a escala de Thompson, e o segmentos medular correspondente à localização da compressão foi analisado microscopicamente em busca de lesões compressivas ao tecido nervoso. Quarenta por cento dos cães (12/30) apresentaram protrusão do DIV, e destes, 58% (7/12) apresentavam mais de um DIV protruso. A protrusão estava presente em 3,2% (25/780) de todos os DIV avaliados. Cães de raças condrodistróficas apresentaram protrusões em 83% dos casos (5/6) e raças não condrodistróficas em 29% (7/24). O local que apresentou maior frequência de protrusão foi L4-L5 (6/25), seguido da região L6-L7 (3/25) e C6-C7 (3/25). Apenas dois segmentos medulares avaliados na histopatologia apresentaram alterações, com presença de infiltrado linfoplasmocitário focal e hemorragia discreta multifocal na substância cinzenta. Nas condições do presente estudo, 40% dos cães com mais de sete anos de idade apresentaram protrusões do DIV sem que houvesse sinais neurológicos, com normalidade do tecido nervoso em 92% dos segmentos avaliados. Assim, a protrusão do DIV, em alguns cães, pode ser apenas um achado sem relevância clínica.(AU)