Methodology for Preoperative Planning of Bone Deformities Using Three-dimensional Modeling Software.

Rapid prototyping technology, known as three-dimensional (3D) printing, and its use in the medical field are advancing. Studies on severe bone deformity treatment with 3D printing showed benefits in postoperative outcomes thanks to this technology. Even so, preoperative planning guidance for surgeons is lacking. This technical note describes a practical step-by-step guide to help surgeons use this technology to optimize the therapeutic plan with free license software and an intuitive interface. This study aims to organize the 3D modeling process using a preoperative computed tomography (CT) scan. This technology allows a deeper understanding of the case and its particularities, such as the direction, planes, and dimensions of the deformity. Planning considering these topics may reduce the surgical time and result in better functional outcomes by understanding the deformity and how to correct it. Associating planning via software with 3D printing can further enhance this therapeutic method.

Unveiling the Role of Sorghum RPAP3 in the Function of R2TP Complex: Insights into Protein Assembly in Plants.

The chaperone R2TP has multiple subunits that assist in the proper folding, assembly, and stabilization of various protein complexes in cells and its study can offer valuable insights into the regulation and maintenance of protein assemblies in plant systems. The 'T' component of R2TP is Tah1 in yeast, consisting of 111 residues, while its counterpart in humans is RPAP3, with 665 residues. RPAP3 acts as a co-chaperone of Hsp90 and facilitates interactions between RUVBL proteins and other complex components, enhancing the recruitment of client proteins by the R2TP complex. These facts further underscore the relevance of studying this complex in different organisms. The putative gene corresponding to the RPAP3 in Sorghum bicolor, a monocotyledon plant, was cloned, and the protein (396 residues) purified for biochemical characterization. SbRPAP3 exists as a folded monomer and has a RPAP3 domain, which is present in human RPAP3 but absent in yeast Tah1. SbRPAP3 retains its functional capabilities, including binding with RUVBLs, Hsp90, and Hsp70. By elucidating the role of RPAP3 in plant R2TP complex, we can further comprehend the molecular mechanisms underlying plant-specific protein assembly and contribute to advancements in plant biology and biotechnological applications.

Effectiveness in Sterilization of Objects Produced by 3D Printing with Polylactic Acid Material: Comparison Between Autoclave and Ethylene Oxide Methods.

Objective Due to the popularity of 3D technology, surgeons can create specific surgical guides and sterilize them in their institutions. The aim of the present study is to compare the efficacy of the autoclave and ethylene oxide (EO) sterilization methods for objects produced by 3D printing with polylactic acid (PLA) material. Methods Forty cubic-shaped objects were printed with PLA material. Twenty were solid and 20 were hollow (printed with little internal filling). Twenty objects (10 solid and 10 hollow) were sterilized in autoclave, forming Group 1. The others (10 solid and 10 hollow) were sterilized in EO, composing Group 2. After sterilization, they were stored and referred to culture. Hollow objects of both groups were broken during sowing, communicating the dead space with the culture medium. The results obtained were statistically analyzed (Fisher exact test and residue analysis). Results In group 1 (autoclave), there was bacterial growth in 50% of solid objects and in 30% of hollow objects. In group 2 (EO), growth occurred in 20% of hollow objects, with no bacterial growth in solid objects (100% of negative samples). The bacteria isolated in the positive cases was non-coagulase-producing Staphylococcus Gram positive. Conclusions Sterilization by both autoclave and EO was not effective for hollow printed objects. Solid objects sterilized by autoclave did not demonstrate 100% of negative samples and were not safe in the present assay. Complete absence of contamination occurred only with solid objects sterilized by EO, which is the combination recommended by the authors.

Clinical Profile and Risk Factors for Severe COVID-19 in Hospitalized Patients from Rio de Janeiro, Brazil: Comparison between the First and Second Pandemic Waves.

Since COVID-19 was declared a pandemic, Brazil has become one of the countries most affected by this disease. A year into the pandemic, a second wave of COVID-19 emerged, with a rapid spread of a new SARS-CoV-2 lineage of concern. Several vaccines have been granted emergency-use authorization, leading to a decrease in mortality and severe cases in many countries. However, the emergence of SARS-CoV-2 variants raises the alert for potential new waves of transmission and an increase in pathogenicity. We compared the demographic and clinical data of critically ill patients infected with COVID-19 hospitalized in Rio de Janeiro during the first and second waves between July 2020 and October 2021. In total, 106 participants were included in this study; among them, 88% had at least one comorbidity, and 37% developed severe disease. Disease severity was associated with older age, pre-existing neurological comorbidities, higher viral load, and dyspnea. Laboratory biomarkers related to white blood cells, coagulation, cellular injury, inflammation, renal, and liver injuries were significantly associated with severe COVID-19. During the second wave of the pandemic, the necessity of invasive respiratory support was higher, and more individuals with COVID-19 developed acute hepatitis, suggesting that the progression of the second wave resulted in an increase in severe cases. These results can contribute to understanding the behavior of the COVID-19 pandemic in Brazil and may be helpful in predicting disease severity, which is a pivotal for guiding clinical care, improving patient outcomes, and defining public policies.

Effectiveness in Sterilization of Objects Produced by 3D Printing with Polylactic Acid Material: Comparison Between Autoclave and Ethylene Oxide Methods / Eficácia na esterilização de objetos produzidos pela impressão 3D com material ácido polilático: Comparação entre os métodos autoclave e óxido de etileno

Abstract Objective Due to the popularity of 3D technology, surgeons can create specific surgical guides and sterilize them in their institutions. The aim of the present study is to compare the efficacy of the autoclave and ethylene oxide (EO) sterilization methods for objects produced by 3D printing with polylactic acid (PLA) material. Methods Forty cubic-shaped objects were printed with PLA material. Twenty were solid and 20 were hollow (printed with little internal filling). Twenty objects (10 solid and 10 hollow) were sterilized in autoclave, forming Group 1. The others (10 solid and 10 hollow) were sterilized in EO, composing Group 2. After sterilization, they were stored and referred to culture. Hollow objects of both groups were broken during sowing, communicating the dead space with the culture medium. The results obtained were statistically analyzed (Fisher exact test and residue analysis). Results In group 1 (autoclave), there was bacterial growth in 50% of solid objects and in 30% of hollow objects. In group 2 (EO), growth occurred in 20% of hollow objects, with no bacterial growth in solid objects (100% of negative samples). The bacteria isolated in the positive cases was non-coagulase-producing Staphylococcus Gram positive. Conclusions Sterilization by both autoclave and EO was not effective for hollow printed objects. Solid objects sterilized by autoclave did not demonstrate 100% of negative samples and were not safe in the present assay. Complete absence of contamination occurred only with solid objects sterilized by EO, which is the combination recommended by the authors.

Resumo Objetivo Devido à popularidade da tecnologia 3D, cirurgiões podem criar guias cirúrgicos específicos e esterilizá-los nas suas instituições. O objetivo do presente estudo é comparar a eficácia dos métodos de esterilização por autoclave e óxido de etileno (OE) de objetos produzidos pela impressão 3D com material ácido polilático (PLA, na sigla em inglês). Métodos Quarenta objetos em formato cúbico foram impressos com material de PLA. Vinte eram sólidos e 20 eram ocos (impressos com pouco enchimento interno). Vinte objetos (10 sólidos e 10 ocos) foram esterilizados em autoclave, formando o Grupo 1. Os demais (10 sólidos e 10 ocos) foram esterilizados em OE, compondo o Grupo 2. Após a esterilização, os objetos foram armazenados e encaminhados para cultura. Objetos ocos de ambos os grupos foram quebrados durante a semeadura, comunicando o espaço morto com o meio de cultura. Os resultados obtidos foram analisados estatisticamente (teste exato de Fisher e análise de resíduo). Resultados No grupo 1 (autoclave) houve crescimento bacteriano em 50% dos objetos sólidos e em 30% dos objetos ocos. No grupo 2 (OE) o crescimento ocorreu em 20% dos objetos ocos, com ausência de crescimento bacteriano nos objetos sólidos (100% de amostras negativas). A bactéria isolada nos casos positivos foi Staphylococcus Gram positivo não produtor de coagulase. Conclusões A esterilização tanto em autoclave quanto pelo OE não foi eficaz para objetos impressos no formato oco. Objetos sólidos esterilizados em autoclave não demonstraram 100% de amostras negativas, não sendo seguro no presente ensaio. Ausência completa de contaminação ocorreu apenas com objetos sólidos esterilizados pelo OE, sendo a combinação recomendada pelos autores.

Herpesvirus and neurological manifestations in patients with severe coronavirus disease.

BACKGROUND: Certain clinical manifestations of coronavirus disease (COVID-19) mimic those associated with human herpesvirus (HHV) infection. In this study, we estimated the prevalence of herpesvirus in patients with COVID-19 and determined if coinfection is associated with poorer outcomes and neurological symptoms. METHODS: We analyzed samples of 53 patients diagnosed with COVID-19. The samples were evaluated for the presence of alphaherpesviruses, betaherpesviruses, and gammaherpesviruses, and the viral loads were quantified using quantitative polymerase chain reaction (qPCR) method. RESULTS: Among the patients, in 79.2% had detection at least one type of herpesvirus. HHV-6 (47.2%), cytomegalovirus (43.3%), and HHV-7 (39.6%) showed the highest detection rates. Patients with a high severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) load were more likely to show herpes simplex virus 1 detection (p = 0.037). Among patients coinfected with SARS-CoV-2 and HHVs, 26.4% showed central nervous system-associated neurological symptoms and herpetic manifestations. A statistically significant association was observed between neurological changes and HHV-6 detection (p = 0.034). CONCLUSIONS: The findings showed a high prevalence of herpesvirus in patients with COVID-19. Furthermore, even though SARS-CoV-2 and HHV coinfection was not associated with poorer outcomes, the findings demonstrated the association between neurological symptoms and HHV-6 detection.

Structural, thermodynamic and functional studies of human 71 kDa heat shock cognate protein (HSPA8/hHsc70).

Human 71 kDa heat shock cognate protein (HSPA8, also known as Hsc70, Hsp70-8, Hsc71, Hsp71 or Hsp73) is a constitutively expressed chaperone that is critical for cell proteostasis. In the cytosol, HSPA8 plays a pivotal role in folding and refolding, facilitates protein trafficking across membranes and targets proteins for degradation, among other functions. Here, we report an in solution study of recombinant HSPA8 (rHSPA8) using a variety of biophysical and biochemical approaches. rHSPA8 shares several structural and functional similarities with others human Hsp70s. It has two domains with different stabilities and interacts with adenosine nucleotides with dissociation constants in the low micromolar range, which were higher in the presence of Mg2+. rHSPA8 showed lower ATPase activity than its homolog HSPA5/hGrp78/hBiP, but it was 4-fold greater than that of recombinant HSPA1A/hHsp70-1A, with which it is 86% identical. Small angle X-ray scattering indicated that rHSPA8 behaved as an elongated monomeric protein in solution with dimensions similar to those observed for HSPA1A. In addition, rHSPA8 showed structural flexibility between its compacted and extended conformations. The data also indicated that HSPA8 has capacity in preventing the aggregation of model client proteins. The present study expands the understanding of the structure and activity of this chaperone and aligns with the idea that human homologous Hsp70s have divergent functions.

Resuscitation fluid practices in Brazilian intensive care units: a secondary analysis of Fluid-TRIPS. / Práticas de ressuscitação volêmica em unidades de terapia intensiva brasileiras: uma análise secundária do estudo Fluid-TRIPS.

OBJECTIVE: To describe fluid resuscitation practices in Brazilian intensive care units and to compare them with those of other countries participating in the Fluid-TRIPS. METHODS: This was a prospective, international, cross-sectional, observational study in a convenience sample of intensive care units in 27 countries (including Brazil) using the Fluid-TRIPS database compiled in 2014. We described the patterns of fluid resuscitation use in Brazil compared with those in other countries and identified the factors associated with fluid choice. RESULTS: On the study day, 3,214 patients in Brazil and 3,493 patients in other countries were included, of whom 16.1% and 26.8% (p < 0.001) received fluids, respectively. The main indication for fluid resuscitation was impaired perfusion and/or low cardiac output (Brazil: 71.7% versus other countries: 56.4%, p < 0.001). In Brazil, the percentage of patients receiving crystalloid solutions was higher (97.7% versus 76.8%, p < 0.001), and 0.9% sodium chloride was the most commonly used crystalloid (62.5% versus 27.1%, p < 0.001). The multivariable analysis suggested that the albumin levels were associated with the use of both crystalloids and colloids, whereas the type of fluid prescriber was associated with crystalloid use only. CONCLUSION: Our results suggest that crystalloids are more frequently used than colloids for fluid resuscitation in Brazil, and this discrepancy in frequencies is higher than that in other countries. Sodium chloride (0.9%) was the crystalloid most commonly prescribed. Serum albumin levels and the type of fluid prescriber were the factors associated with the choice of crystalloids or colloids for fluid resuscitation.

OBJETIVO: Descrever as práticas de ressuscitação volêmica em unidades de terapia intensiva brasileiras e compará-las com as de outros países participantes do estudo Fluid-TRIPS. MÉTODOS: Este foi um estudo observacional transversal, prospectivo e internacional, de uma amostra de conveniência de unidades de terapia intensiva de 27 países (inclusive o Brasil), com utilização da base de dados Fluid-TRIPS compilada em 2014. Descrevemos os padrões de ressuscitação volêmica utilizados no Brasil em comparação com os de outros países e identificamos os fatores associados com a escolha dos fluidos. RESULTADOS: No dia do estudo, foram incluídos 3.214 pacientes do Brasil e 3.493 pacientes de outros países, dos quais, respectivamente, 16,1% e 26,8% (p < 0,001) receberam fluidos. A principal indicação para ressuscitação volêmica foi comprometimento da perfusão e/ou baixo débito cardíaco (Brasil 71,7% versus outros países 56,4%; p < 0,001). No Brasil, a percentagem de pacientes que receberam soluções cristaloides foi mais elevada (97,7% versus 76,8%; p < 0,001), e solução de cloreto de sódio a 0,9% foi o cristaloide mais comumente utilizado (62,5% versus 27,1%; p < 0,001). A análise multivariada sugeriu que os níveis de albumina se associaram com o uso tanto de cristaloides quanto de coloides, enquanto o tipo de prescritor dos fluidos se associou apenas com o uso de cristaloides. CONCLUSÃO: Nossos resultados sugerem que cristaloides são usados mais frequentemente do que coloides para ressuscitação no Brasil, e essa discrepância, em termos de frequências, é mais elevada do que em outros países. A solução de cloreto de sódio 0,9% foi o cristaloide mais frequentemente prescrito. Os níveis de albumina sérica e o tipo de prescritor de fluidos foram os fatores associados com a escolha de cristaloides ou coloides para a prescrição de fluidos.

New insights on human Hsp70-escort protein 1: Chaperone activity, interaction with liposomes, cellular localizations and HSPA's self-assemblies remodeling.

The 70 kDa heat shock proteins (Hsp70) are prone to self-assembly under thermal stress conditions, forming supramolecular assemblies (SMA), what may have detrimental consequences for cellular viability. In mitochondria, the cochaperone Hsp70-escort protein 1 (Hep1) maintains mitochondrial Hsp70 (mtHsp70) in a soluble and functional state, contributing to preserving proteostasis. Here we investigated the interaction between human Hep1 (hHep1) and HSPA9 (human mtHsp70) or HSPA1A (Hsp70-1A) in monomeric and thermic SMA states to unveil further information about the involved mechanisms. hHep1 was capable of blocking the formation of HSPA SMAs under a thermic treatment and stimulated HSPA ATPase activity in both monomeric and preformed SMA. The interaction of hHep1 with both monomeric and SMA HSPAs displayed a stoichiometric ratio close to 1, suggesting that hHep1 has access to most protomers within the SMA. Interestingly, hHep1 remodeled HSPA9 and HSPA1A SMAs into smaller forms. Furthermore, hHep1 was detected in the mitochondria and nucleus of cells transfected with the respective coding DNA and interacted with liposomes resembling mitochondrial membranes. Altogether, these new features reinforce that hHep1 act as a "chaperone for a chaperone", which may play a critical role in cellular proteostasis.

Crystal structure of a novel xylose isomerase from Streptomyces sp. F-1 revealed the presence of unique features that differ from conventional classes.

BACKGROUND: Enzymatic isomerization is a promising strategy to solve the problem of xylose fermentation and, consequently, to leverage the production of advanced biofuels and biochemicals. In a previous work, our research group discovered a new strain of Streptomyces with great biotechnological potential due to its ability to produce a broad arsenal of enzymes related to lignocellulose degradation. METHODS: We applied a multidisciplinary approach involving enzyme kinetics, biophysical methods, small angle X-ray scattering and X-ray crystallography to investigate two novel xylose isomerases, XylA1F1 and XylA2F1, from this strain. RESULTS: We showed that while XylA1F1 prefers to act at lower temperatures and relatively lower pH, XylA2F1 is extremely stable at higher temperatures and presents a higher turnover number. Structural analysis revealed that XylA1F1 exhibits unique properties in the active site not observed in classical XylAs from classes I and II nor in its ortholog XylA2F1. It encompasses the natural substitutions, M86A and T93K, that create an extra room for substrate accommodation and narrow the active-site entrance, respectively. Such modifications may contribute to the functional differentiation of these enzymes. CONCLUSIONS: We have characterized two novel xylose isomerases that display distinct functional behavior and harbor unprecedented amino-acid substitutions in the catalytic interface. GENERAL SIGNIFICANCE: Our findings contribute to a better understanding of the functional and structural aspects of xylose isomerases, which might be instrumental for the valorization of the hemicellulosic fraction of vegetal biomass.

Thermodynamic analysis of interactions of the Hsp90 with adenosine nucleotides: A comparative perspective.

Hsp90s are key proteins in cellular homeostasis since they interact with many client proteins. Several studies indicated that Hsp90s are potential targets for treating diseases, such as cancer or malaria. It has been shown that Hsp90s from different organisms have peculiarities despite their high sequence identity. Therefore, a detailed comparative analysis of several Hsp90 proteins is relevant to the overall understanding of their activity. Accordingly, the goal of this work was to evaluate the interaction of either ADP or ATP with recombinant Hsp90s from different organisms (human α and ß isoforms, Plasmodium falciparum, Leishmania braziliensis, yeast and sugarcane) by isothermal titration calorimetry. The measured thermodynamic signatures of those interactions indicated that despite the high identity among all Hsp90s, they have specific thermodynamic characteristics. Specifically, the interactions with ADP are driven by enthalpy but are opposed by entropy, whereas the interaction with ATP is driven by both enthalpy and entropy. Complimentary structural and molecular dynamics studies suggested that specific interactions with ADP that differ from those with ATP may contribute to the observed enthalpies and entropies. Altogether, the data suggest that selective inhibition may be more easily achieved using analogues of the Hsp90-ADP bound state than those of Hsp90-ATP bound state.

MEASURING THE DISTANCE BETWEEN STERNOCLAVICULAR JOINT AND HILAR STRUCTURES WITH TOMOGRAPHY.

OBJECTIVES: To evaluate the tomographic distance between the sternoclavicular joints and the nearest hilar structures. METHODS: Computed tomography images (axial and sagittal slices) in 120 healthy individuals (60 men and 60 women) between 18 and 60 years old were prospectively analyzed. The distances from both sternoclavicular joints to the respective brachiocephalic veins, trachea, esophagus, and lung apexes were measured and related to age, sex, and body mass index. RESULTS: Statistically significant differences were found in the distance from the right and left sternoclavicular joint distances and the corresponding brachiocephalic vein, esophagus, and lung apexes. In women, both sides were closer to the noble structures. In patients with body mass index <25, the distances were significantly less than in heavier patients. CONCLUSION: The left sternoclavicular joint is closer to the hilar structures than the contralateral side. In women, both sternoclavicular joints are closer to the brachiocephalic veins, esophagus, and lung apexes than in men. Patients with body mass index <25 have shorter distances between these joints and the brachiocephalic veins and esophagus. Level of Evidence II; Prognostic studies - Investigating the effect of a patient characteristic on the outcome of disease.

OBJETIVOS: avaliar a distância tomográfica entre as articulações esternoclaviculares até as estruturas hilares mais próximas. MÉTODOS: foram analisados prospectivamente cortes tomográficos axiais e sagitais em 120 indivíduos hígidos (60 homens e 60 mulheres), entre 18 e 60 anos, sendo mensuradas as distâncias de ambas as articulações esternoclaviculares até as respectivas veias braquiocefálicas, traqueia, esôfago e ápices pulmonares, relacionando-as com idade, gênero e índice de massa corporal. RESULTADOS: houve diferença estatisticamente significativa entre as distâncias da articulação esternoclavicular direita e esquerda até a veia braquiocefálica correspondente, esôfago e ápices pulmonares. Nas mulheres, ambos os lados estavam mais próximos das estruturas nobres. Pacientes com índice de massa corporal <25 as distâncias foram significativamente menores quando comparados a índices superiores. CONCLUSÃO: articulação esternoclavicular esquerda está mais próxima às estruturas hilares do que o lado direito. Nas mulheres, as articulações esternoclaviculares bilaterias encontram-se mais próximas das veias braquiocefálicas, esôfago e ápices pulmonares, comparadas aos homens. Pacientes com índice de massa corporal <25 apresentam distâncias menores da articulação até as veias braquiocefálicas e esôfago. Nível de Evidência II. Estudos prognósticos ­ Investigação do efeito de característica de um paciente sobre o desfecho da doença.

Measuring the distance between sternoclavicular joint and hilar structures with tomography / Medida da distância da articulação esternoclavicular as estruturas hilares por tomografia

ABSTRACT Objectives To evaluate the tomographic distance between the sternoclavicular joints and the nearest hilar structures. Methods Computed tomography images (axial and sagittal slices) in 120 healthy individuals (60 men and 60 women) between 18 and 60 years old were prospectively analyzed. The distances from both sternoclavicular joints to the respective brachiocephalic veins, trachea, esophagus, and lung apexes were measured and related to age, sex, and body mass index. Results Statistically significant differences were found in the distance from the right and left sternoclavicular joint distances and the corresponding brachiocephalic vein, esophagus, and lung apexes. In women, both sides were closer to the noble structures. In patients with body mass index <25, the distances were significantly less than in heavier patients. Conclusion The left sternoclavicular joint is closer to the hilar structures than the contralateral side. In women, both sternoclavicular joints are closer to the brachiocephalic veins, esophagus, and lung apexes than in men. Patients with body mass index <25 have shorter distances between these joints and the brachiocephalic veins and esophagus. Level of Evidence II; Prognostic studies - Investigating the effect of a patient characteristic on the outcome of disease.

RESUMO Objetivos avaliar a distância tomográfica entre as articulações esternoclaviculares até as estruturas hilares mais próximas. Métodos foram analisados prospectivamente cortes tomográficos axiais e sagitais em 120 indivíduos hígidos (60 homens e 60 mulheres), entre 18 e 60 anos, sendo mensuradas as distâncias de ambas as articulações esternoclaviculares até as respectivas veias braquiocefálicas, traqueia, esôfago e ápices pulmonares, relacionando-as com idade, gênero e índice de massa corporal. Resultados houve diferença estatisticamente significativa entre as distâncias da articulação esternoclavicular direita e esquerda até a veia braquiocefálica correspondente, esôfago e ápices pulmonares. Nas mulheres, ambos os lados estavam mais próximos das estruturas nobres. Pacientes com índice de massa corporal <25 as distâncias foram significativamente menores quando comparados a índices superiores. Conclusão articulação esternoclavicular esquerda está mais próxima às estruturas hilares do que o lado direito. Nas mulheres, as articulações esternoclaviculares bilaterias encontram-se mais próximas das veias braquiocefálicas, esôfago e ápices pulmonares, comparadas aos homens. Pacientes com índice de massa corporal <25 apresentam distâncias menores da articulação até as veias braquiocefálicas e esôfago. Nível de Evidência II. Estudos prognósticos - Investigação do efeito de característica de um paciente sobre o desfecho da doença.

Biomechanical evaluation of the long head of the biceps brachii tendon fixed by three techniques: a sheep model.

OBJECTIVE: To evaluate the biomechanical properties of the fixation of the long head of the biceps brachii into the humeral bone with suture anchors, interference screw, and soft tissue suture, comparing strength, highest traction load, and types of fixation failure. METHODS: Thirty fresh-frozen sheep shoulders were used, separated into three groups of ten for each technique. After fixation, the tendons were subjected to longitudinal continuous loading, obtaining load-to-failure (N) and displacement (mm). RESULTS: The mean load-to-failure for suture anchors was 95 ± 35.3 N, 152.7 ± 52.7 N for interference screw, and 104.7 ± 23.54 N for soft tissue technique. There was a statistically significant difference (p < 0.05), with interference screw demonstrating higher load-to-failure than suture anchor fixation (p = 0.00307) and soft tissue (p = 0.00473). The strength of interference screw was also superior when compared with the other two methods (p = 0.0000127 and p = 0.00000295, respectively). There were no differences between suture anchors and soft tissue technique regarding load-to-failure (p = 0.9420) and strength (p = 0.141). CONCLUSION: Tenodesis of the long head of the biceps brachii with interference screw was stronger than the suture anchors and soft tissue techniques. The other two techniques did not differ between themselves.

OBJETIVO: Avaliar biomecanicamente a fixação da cabeça longa do bíceps braquial no úmero com âncoras ósseas, parafuso de interferência e sutura em partes moles e comparar resistência, força máxima de tração e tipos de falha na fixação. MÉTODOS: Foram usados 30 ombros de ovinos frescos, divididos em três grupos de dez para cada técnica. Após fixação, os tendões foram submetidos a tração longitudinal contínua até falha do sistema e obtiveram-se força máxima de tração (N) e deslocamento (mm). RESULTADOS: A força máxima de tração foi em média 95 ± 35,3 N para âncoras ósseas, 152,7 ± 52,7 N para parafuso de interferência e 104,7 ± 23,54 N para partes moles. Houve diferença estatisticamente significativa (p < 0,05): o parafuso de interferência demonstrou força máxima de tração superior às fixações com âncoras ósseas (p = 0,00307) e partes moles (p = 0,00473). A resistência com parafuso de interferência também foi superior à dos outros dois métodos (p = 0,0000127 e p = 0,0000029,5 respectivamente). Âncoras ósseas e partes moles não apresentaram diferenças, tanto para força máxima de tração (p = 0,9420) quanto para resistência (p = 0,141). CONCLUSÃO: A tenodese da cabeça longa do bíceps braquial com parafuso de interferência demonstra maior resistência quando comparada com as técnicas com âncoras ósseas e partes moles. As duas últimas técnicas não diferem.

Biomechanical evaluation of the long head of the biceps brachii tendon fixed by three techniques: a sheep model / Avaliação biomecânica da fixação do tendão da cabeça longa do bíceps braquial por três técnicas: modelo em ovinos

ABSTRACT OBJECTIVE: To evaluate the biomechanical properties of the fixation of the long head of the biceps brachii into the humeral bone with suture anchors, interference screw, and soft tissue suture, comparing strength, highest traction load, and types of fixation failure. METHODS: Thirty fresh-frozen sheep shoulders were used, separated into three groups of ten for each technique. After fixation, the tendons were subjected to longitudinal continuous loading, obtaining load-to-failure (N) and displacement (mm). RESULTS: The mean load-to-failure for suture anchors was 95 ± 35.3 N, 152.7 ± 52.7 N for interference screw, and 104.7 ± 23.54 N for soft tissue technique. There was a statistically significant difference (p < 0.05), with interference screw demonstrating higher load-to-failure than suture anchor fixation (p = 0.00307) and soft tissue (p = 0.00473). The strength of interference screw was also superior when compared with the other two methods (p = 0.0000127 and p = 0.00000295, respectively). There were no differences between suture anchors and soft tissue technique regarding load-to-failure (p = 0.9420) and strength (p = 0.141). CONCLUSION: Tenodesis of the long head of the biceps brachii with interference screw was stronger than the suture anchors and soft tissue techniques. The other two techniques did not differ between themselves.

RESUMO OBJETIVO: Avaliar biomecanicamente a fixação da cabeça longa do bíceps braquial no úmero com âncoras ósseas, parafuso de interferência e sutura em partes moles e comparar resistência, força máxima de tração e tipos de falha na fixação. MÉTODOS: Foram usados 30 ombros de ovinos frescos, divididos em três grupos de dez para cada técnica. Após fixação, os tendões foram submetidos a tração longitudinal contínua até falha do sistema e obtiveram-se força máxima de tração (N) e deslocamento (mm). RESULTADOS: A força máxima de tração foi em média 95 ± 35,3 N para âncoras ósseas, 152,7 ± 52,7 N para parafuso de interferência e 104,7 ± 23,54 N para partes moles. Houve diferença estatisticamente significativa (p < 0,05): o parafuso de interferência demonstrou força máxima de tração superior às fixações com âncoras ósseas (p = 0,00307) e partes moles (p = 0,00473). A resistência com parafuso de interferência também foi superior à dos outros dois métodos (p = 0,0000127 e p = 0,0000029,5 respectivamente). Âncoras ósseas e partes moles não apresentaram diferenças, tanto para força máxima de tração (p = 0,9420) quanto para resistência (p = 0,141). CONCLUSÃO: A tenodese da cabeça longa do bíceps braquial com parafuso de interferência demonstra maior resistência quando comparada com as técnicas com âncoras ósseas e partes moles. As duas últimas técnicas não diferem.

Oblique popliteal ligament - an anatomical study / Estudo anatomico do ligamento popliteo obliquo

OBJECTIVE: To study the anatomy of the oblique popliteal ligament, as regards its dimensions, expansion and anatomical relationships. METHODS: Eleven cadaver knees were dissected in order to study the anatomy and take mea-surements of anatomical structures and relationships of the oblique popliteal ligament. The dissection was for posterior access to the proper exposure of the oblique popliteal ligament, the semimembranosus muscle and its expansions. For measurement of dimensions, 40 × 12 needles were used for marking the specific points and a caliper. The angles were calculated using the software ImagePro Plus(r) . RESULTS: The distance from the origin of the oblique popliteal ligament to the tibial plateau was 7.4 mm, the thickness at its origin was 7.3 mm, length was 33.6 mm and the tibial plateau angle 34.8°. The length of the expansion of the proximal oblique popliteal ligament was 39.2 mm, thickness 7.8 mm and angle of the oblique popliteal ligament with its expansion 32.2°. CONCLUSION: The oblique popliteal ligament is thick, rises in the semimembranosus and protrudes proximally forming an acute angle with the joint interline, crossing the popliteal fossa. In some cases it has a proximal expansion. .

OBJETIVO: Estudar a anatomia do ligamento poplíteo oblíquo no que se refere às suas dimensões, expansões e relações anatômicas. MÉTODOS: Onze joelhos de cadáveres foram dissecados com o intuito de se estudar a anatomia e fazer medições das estruturas e das relações anatômicas do ligamento poplíteo oblíquo. A dissecção foi por acesso posterior até a exposição adequada do ligamento poplíteo oblíquo, do músculo semimembranoso e de suas expansões. Para aferição das medidas, foram usados agulhas 40x12 na marcação dos pontos específicos e um paquímetro. Os ângulos foram calculados com o auxílio do software ImagePro Plus(r). RESULTADOS: A distância da origem do ligamento poplíteo oblíquo ao platô tibial foi de 7,4 mm, a espessura na sua origem foi de 7,3 mm, o comprimento foi de 33,6 mm e o ângulo com o platô tibial foi de 34,8°. O comprimento da expansão proximal do ligamento poplíteo oblíquo foi de 39,2 mm, a espessura foi de 7,8 mm e o ângulo do ligamento poplíteo oblíquo com sua expansão foi de 32,2°. CONCLUSÃO: O ligamento poplíteo oblíquo é espesso, nasce no músculo semimembranoso, projeta-se proximalmente, forma um ângulo agudo com a interlinha articular e cruza a fossa poplítea. Em alguns casos apresenta uma expansão proximal. .

Biochemical characterization of uracil phosphoribosyltransferase from Mycobacterium tuberculosis.

Uracil phosphoribosyltransferase (UPRT) catalyzes the conversion of uracil and 5-phosphoribosyl-α-1-pyrophosphate (PRPP) to uridine 5'-monophosphate (UMP) and pyrophosphate (PP(i)). UPRT plays an important role in the pyrimidine salvage pathway since UMP is a common precursor of all pyrimidine nucleotides. Here we describe cloning, expression and purification to homogeneity of upp-encoded UPRT from Mycobacterium tuberculosis (MtUPRT). Mass spectrometry and N-terminal amino acid sequencing unambiguously identified the homogeneous protein as MtUPRT. Analytical ultracentrifugation showed that native MtUPRT follows a monomer-tetramer association model. MtUPRT is specific for uracil. GTP is not a modulator of MtUPRT ativity. MtUPRT was not significantly activated or inhibited by ATP, UTP, and CTP. Initial velocity and isothermal titration calorimetry studies suggest that catalysis follows a sequential ordered mechanism, in which PRPP binding is followed by uracil, and PP(i) product is released first followed by UMP. The pH-rate profiles indicated that groups with pK values of 5.7 and 8.1 are important for catalysis, and a group with a pK value of 9.5 is involved in PRPP binding. The results here described provide a solid foundation on which to base upp gene knockout aiming at the development of strategies to prevent tuberculosis.

Oblique popliteal ligament - an anatomical study.

OBJECTIVE: To study the anatomy of the oblique popliteal ligament, as regards its dimensions, expansion and anatomical relationships. METHODS: Eleven cadaver knees were dissected in order to study the anatomy and take measurements of anatomical structures and relationships of the oblique popliteal ligament. The dissection was for posterior access to the proper exposure of the oblique popliteal ligament, the semimembranosus muscle and its expansions. For measurement of dimensions, 40 × 12 needles were used for marking the specific points and a caliper. The angles were calculated using the software ImagePro Plus®. RESULTS: The distance from the origin of the oblique popliteal ligament to the tibial plateau was 7.4 mm, the thickness at its origin was 7.3 mm, length was 33.6 mm and the tibial plateau angle 34.8°. The length of the expansion of the proximal oblique popliteal ligament was 39.2 mm, thickness 7.8 mm and angle of the oblique popliteal ligament with its expansion 32.2°. CONCLUSION: The oblique popliteal ligament is thick, rises in the semimembranosus and protrudes proximally forming an acute angle with the joint interline, crossing the popliteal fossa. In some cases it has a proximal expansion.

OBJETIVO: Estudar a anatomia do ligamento poplíteo oblíquo no que se refere às suas dimensões, expansões e relações anatômicas. MÉTODOS: Onze joelhos de cadáveres foram dissecados com o intuito de se estudar a anatomia e fazer medições das estruturas e das relações anatômicas do ligamento poplíteo oblíquo. A dissecção foi por acesso posterior até a exposição adequada do ligamento poplíteo oblíquo, do músculo semimembranoso e de suas expansões. Para aferição das medidas, foram usados agulhas 40 × 12 na marcação dos pontos específicos e um paquímetro. Os ângulos foram calculados com o auxílio do software ImagePro Plus®. RESULTADOS: A distância da origem do ligamento poplíteo oblíquo ao platô tibial foi de 7,4 mm, a espessura na sua origem foi de 7,3 mm, o comprimento foi de 33,6 mm e o ângulo com o platô tibial foi de 34,8°. O comprimento da expansão proximal do ligamento poplíteo oblíquo foi de 39,2 mm, a espessura foi de 7,8 mm e o ângulo do ligamento poplíteo oblíquo com sua expansão foi de 32,2°. CONCLUSÃO: O ligamento poplíteo oblíquo é espesso, nasce no músculo semimembranoso, projeta-se proximalmente, forma um ângulo agudo com a interlinha articular e cruza a fossa poplítea. Em alguns casos apresenta uma expansão proximal.

Resultados do tratamento artroscópico das rupturas do manguito rotador / Outcomes of arthroscopic treatment for rotator cuff tears

OBJETIVO: Analisar os resultados do reparo artroscópico das rupturas do manguito rotador. MÉTODOS: Realizado estudo retrospectivo com avaliação dos resultados da técnica em 42 pacientes operados entre 2002 e 2006. O seguimento médio foi de 31 meses e a média de idade foi de 57 anos, sendo o lado dominante operado em 73,8 por cento dos casos. Para avaliação foram usadas escalas de UCLA e Escala Visual Analógica da dor no pós-operatório. RESULTADOS: Os resultados foram satisfatórios em 85,7 por cento (59,5 por cento excelentes e 26,2 por cento bons respectivamente) e insatisfatórios em 14,3 por cento dos pacientes. Nos casos com lesões associadas, a mais frequente foi no tendão da porção longa do bíceps (57,1 por cento). Associação com outras lesões não comprometeu o resultado. O mesmo aconteceu com relação a idade e tempo de acompanhamento pós-cirurgia. Quanto ao tamanho da lesão, diferença significativa ocorreu nos casos de lesões grandes e maciças demonstrando resultados inferiores em relação às pequenas e médias. A função foi inferior principalmente nos casos de lesão maciça. CONCLUSÃO: A reparação artroscópica das lesões do manguito rotador (MR) proporciona baixa morbidade cirúrgica e possibilita diagnóstico de lesões articulares associadas. O benefício do procedimento foi confirmado principalmente pela melhora significativa da dor, mesmo nos casos de lesões maiores.

OBJECTIVE: To evaluate the results of arthroscopic treatment for rotator cuff tears. METHODS: A retrospective study was carried out demonstrating the results of this technique in 42 patients operated between 2002 and 2006. The mean follow-up was 31 months and average age was 57 years. The dominant limb was operated in 73.8 percent of cases. Function and pain were evaluated using criteria of UCLA Score System and Visual Analogic Scale respectively. RESULTS: The results were satisfactory in 85.7 percent (59.5 percent excellent and 26.2 percent good), with 14.3 percent unsatisfactory. The most frequent associated lesion was the long head of the biceps tendon (57.1 percent). Nevertheless, the presence of other lesions did not alter the end results. The same occurred in relation to age and follow-up period. When comparing large and massive tears with small and mid-sized ones, the first group had significantly inferior functional results. The function was worse in cases of massive tear. CONCLUSION: Arthroscopic rotator cuff repair provides lower surgical morbidity and intrarticular diagnosis of associated lesions in comparison to open surgery. The benefit of the procedure was confirmed mainly by pain relief, even in cases of more extensive lesions.

Insights on the structure of amyloid fibrils from site-directed mutagenesis.

To test the hypothesis that the ability to form ordered beta-rich amyloid fibers with identical structures is a generic property of proteins we present a study on the overall structures of fibers formed by apomyoglobin mutants that either stabilize or destabilize the native state or the intermediate. Our results indicate that, at least at the macroscopic level, ordered beta-rich amyloid fibers have similar structures.