Trochanteric fractures: Tip-Apex distance, Calcar Tip-Apex distance, and Chang criteria-a multiple variable analysis.

Failure of osteosynthesis is a common complication of the nailing of trochanteric fractures which typically occurs through form of cut-out. Tip-Apex distance (TAD), Calcar Tip-Apex distance (CalTAD), and Chang criteria are validated variables to predict failure of cephalomedullary nailing. This is a retrospective study which analyzes treatment of trochanteric fractures from 2018 to 2020 (n = 296) evaluating postoperative radiographs and factors of mechanical failure. Our objective was to assess correlation among these variables and their influence on mechanical failure, either individually or creating a new score. Our results support the CalTAD and Chang's criteria as valid predictors of mechanical failure. Furthermore, they empathize the importance of fracture reduction and proper placement of cervical screw. To our knowledge, this is the first study performing multivariate analysis including these 3 variables.

A modular framework for the development of targeted Covid-19 blood transcript profiling panels.

BACKGROUND: Covid-19 morbidity and mortality are associated with a dysregulated immune response. Tools are needed to enhance existing immune profiling capabilities in affected patients. Here we aimed to develop an approach to support the design of targeted blood transcriptome panels for profiling the immune response to SARS-CoV-2 infection. METHODS: We designed a pool of candidates based on a pre-existing and well-characterized repertoire of blood transcriptional modules. Available Covid-19 blood transcriptome data was also used to guide this process. Further selection steps relied on expert curation. Additionally, we developed several custom web applications to support the evaluation of candidates. RESULTS: As a proof of principle, we designed three targeted blood transcript panels, each with a different translational connotation: immunological relevance, therapeutic development relevance and SARS biology relevance. CONCLUSION: Altogether the work presented here may contribute to the future expansion of immune profiling capabilities via targeted profiling of blood transcript abundance in Covid-19 patients.

Multi-Compartment Profiling of Bacterial and Host Metabolites Identifies Intestinal Dysbiosis and Its Functional Consequences in the Critically Ill Child.

OBJECTIVES: Adverse physiology and antibiotic exposure devastate the intestinal microbiome in critical illness. Time and cost implications limit the immediate clinical potential of microbial sequencing to identify or treat intestinal dysbiosis. Here, we examined whether metabolic profiling is a feasible method of monitoring intestinal dysbiosis in critically ill children. DESIGN: Prospective multicenter cohort study. SETTING: Three U.K.-based PICUs. PATIENTS: Mechanically ventilated critically ill (n = 60) and age-matched healthy children (n = 55). INTERVENTIONS: Collection of urine and fecal samples in children admitted to the PICU. A single fecal and urine sample was collected in healthy controls. MEASUREMENTS AND MAIN RESULTS: Untargeted and targeted metabolic profiling using 1H-nuclear magnetic resonance spectroscopy and liquid chromatography-mass spectrometry or urine and fecal samples. This was integrated with analysis of fecal bacterial 16S ribosomal RNA profiles and clinical disease severity indicators. We observed separation of global urinary and fecal metabolic profiles in critically ill compared with healthy children. Urinary excretion of mammalian-microbial co-metabolites hippurate, 4-cresol sulphate, and formate were reduced in critical illness compared with healthy children. Reduced fecal excretion of short-chain fatty acids (including butyrate, propionate, and acetate) were observed in the patient cohort, demonstrating that these metabolites also distinguished between critical illness and health. Dysregulation of intestinal bile metabolism was evidenced by increased primary and reduced secondary fecal bile acid excretion. Fecal butyrate correlated with days free of intensive care at 30 days (r = 0.38; p = 0.03), while urinary formate correlated inversely with vasopressor requirement (r = -0.2; p = 0.037). CONCLUSIONS: Disruption to the functional activity of the intestinal microbiome may result in worsening organ failure in the critically ill child. Profiling of bacterial metabolites in fecal and urine samples may support identification and treatment of intestinal dysbiosis in critical illness.

Pilot Mechanistic Study of Insulin Modulation of Somatotrophic Hormones, Inflammation, and Lipid Metabolism During Critical Illness in Children.

OBJECTIVES: To evaluate the mechanism of insulin modulation on somatotrophic response, inflammation, and lipid metabolism in critically ill children. DESIGN: Open-label randomized mechanistic study. SETTING: Two-center, tertiary PICU study. PATIENTS: Thirty critically ill children between 1 month and 14 years old, requiring mechanical ventilation and with evidence of two or more organ system failures. INTERVENTIONS: Randomized physiologic design of hyperinsulinemic-euglycemic clamp using continuous insulin infusion at 0.1 U/kg/hr versus conventional management. MEASUREMENTS AND MAIN RESULTS: Thirteen children underwent hyperinsulinemic-euglycemic clamp. Blood samples for somatotrophic, inflammatory, and metabolic evaluation were obtained before randomization, and 24 and 72 hours later. A growth hormone oscillation profile was obtained during the first night. There was no difference between groups at baseline. Growth hormone resistance, increased proinflammatory cytokines, and increased lipolysis with low lipoprotein levels were present in all patients. Hyperinsulinemic-euglycemic clamp did not affect growth hormone, insulin-like growth factor-1 or insulin-like growth factor binding protein-3 levels. By day 2, insulin reduced insulin-like growth factor binding protein-1 levels. Tumor necrosis factor-α and interleukin-1ß were similar in both groups, whereas interleukin-6 levels reduced over time only in children receiving hyperinsulinemic-euglycemic clamp. Hyperinsulinemic-euglycemic clamp also decreased free fatty acid levels, which was accompanied by increased low-density lipoprotein cholesterol and relative increase in high-density lipoprotein levels. Total cholesterol and triglycerides were unchanged. CONCLUSIONS: Insulin does not reverse most of the somatotrophic changes induced by the stress of critical illness. Rather, it may improve lipid metabolism and down-regulate some markers of the inflammatory response.

Mesenteric near-infrared spectroscopy and risk of gastrointestinal complications in infants undergoing surgery for congenital heart disease.

We hypothesised that lower mesenteric near-infrared spectroscopy values would be associated with a greater incidence of gastrointestinal complications in children weighing <10 kg who were recovering from cardiac surgery. We evaluated mesenteric near-infrared spectroscopy, central venous oxygen saturation, and arterial blood gases for 48 hours post-operatively. Enteral feeding intake, gastrointestinal complications, and markers of organ dysfunction were monitored for 7 days. A total of 50 children, with median age of 16.7 (3.2-31.6) weeks, were studied. On admission, the average mesenteric near-infrared spectroscopy value was 71±18%, and the systemic oxygen saturation was 93±7.5%. Lower admission mesenteric near-infrared spectroscopy correlated with longer time to establish enteral feeds (r=-0.58, p<0.01) and shorter duration of feeds at 7 days (r=0.48, p<0.01). Children with gastrointestinal complications had significantly lower admission mesenteric near-infrared spectroscopy (58±18% versus 73±17%, p=0.01) and higher mesenteric arteriovenous difference of oxygen at admission [39 (23-47) % versus 19 (4-27) %, p=0.02]. Based on multiple logistic regression, admission mesenteric near-infrared spectroscopy was independently associated with gastrointestinal complications (Odds ratio, 0.95; 95% confidence interval, 0.93-0.97; p=0.03). Admission mesenteric near-infrared spectroscopy showed an area under the receiver operating characteristic curve of 0.76 to identify children who developed gastrointestinal complications, with a suggested cut-off value of 72% (78% sensitivity, 68% specificity). In this pilot study, we conclude that admission mesenteric near-infrared spectroscopy is associated with gastrointestinal complications and enteral feeding tolerance in children after cardiac surgery.

A tailor-made "tag-receptor" affinity pair for the purification of fusion proteins.

A novel affinity "tag-receptor" pair was developed as a generic platform for the purification of fusion proteins. The hexapeptide RKRKRK was selected as the affinity tag and fused to green fluorescent protein (GFP). The DNA fragments were designed, cloned in Pet-21c expression vector and expressed in E. coli host as soluble protein. A solid-phase combinatorial library based on the Ugi reaction was synthesized: 64 affinity ligands displaying complementary functionalities towards the designed tag. The library was screened by affinity chromatography in a 96-well format for binding to the RKRKRK-tagged GFP protein. Lead ligand A7C1 was selected for the purification of RKRKRK fusion proteins. The affinity pair RKRKRK-tagged GFP with A7C1 emerged as a promising solution (Ka of 2.45×10(5) M(-1) ). The specificity of the ligand towards the tag was observed experimentally and theoretically through automated docking and molecular dynamics simulations.

Structural evaluation of an alternative Protein A biomimetic ligand for antibody purification.

Affinity chromatography is one of the most common techniques employed at the industrial-scale for antibody purification. In particular, the purification of human immunoglobulin G (hIgG) has gained relevance with the immobilization of its natural binding counterpart-Staphylococcus aureus Protein A (SpA) or with the recent development of biomimetic affinity ligands, namely triazine-based ligands. These ligands have been developed in order to overcome economic and leaching issues associated to SpA. The most recent triazine-based ligand-TPN-BM, came up as an analogue of 2-(3-amino-phenol)-6-(4-amino-1-naphthol)-4-chloro-sym-triazine ligand also known as ligand 22/8 with improved physico-chemical properties and a greener synthetic route. This work intends to evaluate the potential of TPN-BM as an alternative affinity ligand towards antibody recognition and binding, namely IgG, at an atomic level, since it has already been tested, after immobilization onto chitosan-based monoliths and demonstrated interesting affinity behaviour for this purpose. Herein, combining automated molecular docking and molecular dynamics simulations it was predicted that TPN-BM has high propensity to bind IgG through the same binding site found in the crystallographic structure of SpA_IgG complex, as well as theoretically predicted for ligand 22/8_IgG complex. Furthermore, it was found that TPN-BM established preferential interactions with aromatic residues at the Fab domain (Trp 50, Tyr 53, Tyr 98 and Trp 100), while in the Fc domain the main interactions are based on hydrogen bonds with pH sensitive residues at operational regime for binding and elution like histidines (His 460, His 464, His 466). Moreover, the pH dependence of TPN-BM_IgG complex formation was more evident for the Fc domain, where at pH 3 the protonation state and consequently the charge alteration of histidine residues located at the IgG binding site induced ligand detachment which explains the optimal elution condition at this pH observed experimentally.

Early postoperative outcomes following surgical repair of complete atrioventricular septal defects: is down syndrome a risk factor?

OBJECTIVE: To evaluate the impact of Down syndrome on the early postoperative outcomes of children undergoing complete atrioventricular septal defect repair. DESIGN: Retrospective cohort study. SETTING: Single tertiary pediatric cardiac center. PATIENTS: All children admitted to PICU following biventricular surgical repair of complete atrioventricular septal defect from January 2004 to December 2009. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A total of 107 children, 67 with Down syndrome, were included. Children with Down syndrome were operated earlier: 4 months (interquartile range, 3.5-6.6) versus 5.7 months (3-8.4) for Down syndrome and non-Down syndrome groups, respectively (p < 0.01). There was no early postoperative mortality. There was no significant difference in the prevalence of dysplastic atrioventricular valve between the two groups. Two children (2.9%) from Down syndrome and three children (7.5%) from non-Down syndrome group required early reoperation (p = 0.3). Junctional ectopic tachycardia was the most common arrhythmia, and the prevalence of junctional ectopic tachycardia was similar between the two groups (9% and 10% in Down syndrome and non-Down syndrome, respectively, p = 1). One patient from each group required insertion of permanent pacemaker for complete heart block. Children with Down syndrome had significantly higher prevalence of noncardiac complications, that is, pneumothorax, pleural effusions, and infections (p < 0.01), than children without Down syndrome. There was a trend for longer duration of mechanical ventilation in children with Down syndrome (41 hr [20-61 hr] vs 27.5 hr [15-62 hr], p = 0.2). However, there was no difference in duration of PICU stay between the two groups (2 d [1.3-3 d] vs 2 d [1-3 d], p = 0.9, respectively). CONCLUSIONS: In our study, we found no difference in the prevalence of atrioventricular valve dysplasia between children with and without Down syndrome undergoing complete atrioventricular septal defect repair. This finding contrasts with previously published data, and further confirmatory studies are required. Although clinical outcomes were similar, children with Down syndrome had a significantly higher prevalence of noncardiac complications in the early postoperative period than children without Down syndrome.

Prevalence of burnout in pediatric intensivists: an observational comparison with general pediatricians.

OBJECTIVE: To study the prevalence of burnout in general pediatricians and pediatric intensivists and to evaluate factors that may be associated with this syndrome. DESIGN: Observational cohort study. SETTING: Pediatric departments of two hospitals in south Brazil. PATIENTS: Pediatric intensivists working in two regional PICUs and general pediatricians working in the outpatient departments in the same hospitals. INTERVENTION: Two researchers, blinded to the workplace of the physicians, undertook the assessment of burnout using the Maslach Burnout Inventory scale. Burnout was defined as high score in the domains for "emotional exhaustion" or "depersonalization" or a low score in the "professional accomplishment" domain. MEASUREMENTS AND MAIN RESULTS: The PICU and general pediatrician groups were similar demographically, and each had 35 recruits. Burnout was present in 50% of the study recruits and was more frequent among pediatric intensivists than general pediatricians (71% vs 29%, respectively, p < 0.01). In regard to the individual Maslach Burnout Inventory domains, the average score was higher for emotional exhaustion and depersonalization and lower for professional accomplishment in the PICU group (p < 0.01). A cluster analysis showed that pediatric intensivists were more likely to develop the burnout syndrome involving all Maslach Burnout Inventory domains. The multivariate analysis found that the odds ratio for burnout in pediatric intensivists was 5.7 (95% CI, 1.9-16.7; p < 0.01). CONCLUSIONS: Burnout is frequent among pediatric intensivists and characterized by cumulative involvement of emotional exhaustion, depersonalization, and professional accomplishment. Earlier recognition of emotional exhaustion may be important in preventing the development of a complete burnout syndrome. Improvement in workplace characteristics and measures to improve physician resilience are entirely warranted.

Exploring the Potential of Recycled Polymers for 3D Printing Applications: A Review.

The integration of recycled polymers into additive manufacturing (AM) processes offers a promising opportunity for advancing sustainability within the manufacturing industry. This review paper summarizes existing research and developments related to the use of recycled materials in AM, focusing on distinct polymers, such as polylactic acid (PLA), polyethylene terephthalate (PET), and acrylonitrile butadiene styrene (ABS), among others. Key topics explored include the availability of recycled filaments on the market, challenges associated with material variability and traceability, and efforts toward establishing ethical product standards and sustainability characterization methodologies. Regulatory considerations and standards development by organizations such as ASTM and ISO are discussed, along with recommendations for future advancements in improving the sustainability of filament recycling and achieving net-zero emissions in AM processes. The collective efforts outlined in this paper underscore the potential of recycled polymers in AM to foster a more sustainable and environmentally friendly manufacturing industry.

Effect of Thermal Shock Conditions on the Low-Cycle Fatigue Performance of 3D-Printed Materials: Acrylonitrile Butadiene Styrene, Acrylonitrile-Styrene-Acrylate, High-Impact Polystyrene, and Poly(lactic acid).

3D printing technology is becoming a widely adopted alternative to traditional polymer manufacturing methods. The most important advantage of 3D printing over traditional manufacturing methods, such as injection molding or extrusion, is the short time from the creation of a new design to the finished product. Nevertheless, 3D-printed parts generally have lower strength and lower durability compared to the same parts manufactured using traditional methods. Resistance to the environmental conditions in which a 3D-printed part operates is important to its durability. One of the most important factors that reduces durability and degrades the mechanical properties of 3D-printed parts is temperature, especially rapid temperature changes. In the case of inhomogeneous internal geometry and heterogeneous material properties, rapid temperature changes can have a significant impact on the degradation of 3D-printed parts. This degradation is more severe in high-humidity environments. Under these complex service conditions, information on the strength and fatigue behavior of 3D-printed polymers is limited. In this study, we evaluated the effects of high humidity and temperature changes on the durability and strength properties of 3D-printed parts. Samples made of commonly available materials such as ABS (Acrylonitrile Butadiene Styrene), ASA (Acrylonitrile-Styrene-Acrylate), HIPS (High-Impact Polystyrene), and PLA (Poly(lactic acid)) were subjected to temperature cycling, from an ambient temperature to -20 °C, and then were heated to 70 °C. After thermal treatment, the samples were subjected to cyclic loading to determine changes in their fatigue life relative to non-thermally treated reference samples. The results of cyclic testing showed a decrease in durability for samples made of ASA and HIPS. The ABS material proved to be resistant to the environmental effects of shocks, while the PLA material exhibited an increase in durability. Changes in the internal structure and porosity of the specimens under temperature changes were also evaluated using microcomputed tomography (microCT). Temperature changes also affected the porosity of the samples, which varied depending on the material used.

Comparative Analysis of Impact Strength among Various Polymeric Materials for Orthotic Production.

Orthotic devices play an important role in medical treatment, addressing various pathologies and promoting patient recovery. Customization of orthoses to fit individual patient morphologies and needs is essential for optimal functionality and patient comfort. The advent of additive manufacturing has revolutionized the biomedical field, offering advantages such as cost reduction, increased personalization, and enhanced dimensional adaptability for orthotics manufacturing. This research focuses on the impact strength of nine polymeric materials printed by additive manufacturing, including an evaluation of the materials' performance under varying conditions comprising different printing directions (vertical and horizontal) and exposure to artificial sweat for different durations (0 days, 24 days, and 189 days). The results showed that Nylon 12 is good for short-term (24 days) immersion, with absorbed energies of 78 J and 64 J for the vertical and horizontal directions, whereas Polycarbonate (PC) is good for long-term immersion (189 days), with absorbed energies of 66 J and 78 J for the vertical and horizontal directions. Overall, the findings contribute to a better understanding of the suitability of these materials for biomedical applications, considering both short-term and long-term exposure to physiological and environmental conditions.

Mechanical Properties of Additively Manufactured Polymeric Materials-PLA and PETG-For Biomechanical Applications.

The study presented herein concerns the mechanical properties of two common polymers for potential biomedical applications, PLA and PETG, processed through fused filament fabrication (FFF)-Material Extrusion (ME). For the uniaxial tension tests carried out, two printing orientations-XY (Horizontal, H) and YZ (Vertical, V)-were considered according to the general principles for part positioning, coordinates, and orientation typically used in additive manufacturing (AM). In addition, six specimens were tested for each printing orientation and material, providing insights into mechanical properties such as Tensile Strength, Young's Modulus, and Ultimate Strain, suggesting the materials' potential for biomedical applications. The experimental results were then compared with correspondent mechanical properties obtained from the literature for other polymers like ASA, PC, PP, ULTEM 9085, Copolyester, and Nylon. Thereafter, fatigue resistance curves (S-N curves) for PLA and PETG, printed along 45°, were determined at room temperature for a load ratio, R, of 0.2. Scanning electron microscope observations revealed fibre arrangements, compression/adhesion between layers, and fracture zones, shedding light on the failure mechanisms involved in the fatigue crack propagation of such materials and giving design reference values for future applications. In addition, fractographic analyses of the fatigue fracture surfaces were carried out, as well as X-ray Computed Tomography (XCT) and Thermogravimetric (TGA)/Differential Scanning Calorimetric (DSC) tests.

Comparison of Surgical Procedures in the Treatment of Hip Periprosthetic Infection.

Objective The present study aimed to compare the cure rate recovery time and Merle d'Aubigné-Postel functional (MAPF) score after single-stage surgery (C1T) or two-stage surgery (C2T) to treat prosthetic infections of the hip considering sociodemographic and clinical features of the patients. Materials and Methods The present retrospective study occurred in a single center from 2011 to 2014 with 37 studied cases including 26 treated with C1T and 11 with C2T. We compared the cure rate recovery time and MAPF score in the two groups as well as the sociodemographic and clinical features of the patients. We also considered surgical complications and the most common infectious agents. Results The C1T group had a faster functional recovery than the C2T group but there were no significant differences in the cure rate surgical complications or MAPF score. However C1T group patients were significantly younger which may have influenced the outcomes. Staphylococcus spp. was the most common infectious agent (62%). Conclusion Although C2T appears superior regarding infection cure C1T may be preferable for faster functional recovery. However it is critical to consider individual patient characteristics when choosing treatment. Further research with a larger sample size is required to confirm these results.

Reduction in Errors in Roughness Evaluation with an Accurate Definition of the S-L Surface.

Characterization of surface topography, roughly divided into measurement and data analysis, can be valuable in the process of validation of the tribological performance of machined parts. Surface topography, especially the roughness, can respond straightly to the machining process and, in some cases, is defined as a fingerprint of the manufacturing. When considering the high precision of surface topography studies, the definition of both S-surface and L-surface can drive many errors that influence the analysis of the accuracy of the manufacturing process. Even if precise measuring equipment (device and method) is provided but received data are processed erroneously, the precision is still lost. From that matter, the precise definition of the S-L surface can be valuable in the roughness evaluation allowing a reduction in the rejection of properly made parts. In this paper, it was proposed how to select an appropriate procedure for the removal of the L- and S- components from the raw measured data. Various types of surface topographies were considered, e.g., plateau-honed (some with burnished oil pockets), turned, milled, ground, laser-textured, ceramic, composite, and, generally, isotropic. They were measured with different (stylus and optical) methods, respectively, and parameters from the ISO 25178 standard were also taken into consideration. It was found that commonly used and available commercial software methods can be valuable and especially helpful in the precise definition of the S-L surface; respectively, its usage requires an appropriate response (knowledge) from the users.

Recurrent Anterior Shoulder Dislocation After Trauma with Coracoid Apophysis Fracture - A Rare Association.

Anterior dislocations represent about 96% of total shoulder dislocations, with recurrence/instability being more common in young patients. Injury of other shoulder structures is frequent, namely bony Bankart lesion. However, the association with coracoid apophysis fracture is very rare. The present article describes the clinical case of a 67-year-old man who presented to the emergency department with complaints of persistent omalgia, with acute episodes, beginning after a fall from his own height. The patient also presented history of shoulder trauma 3 months earlier, which was evaluated at another hospital. Shoulder anterior dislocation was observed radiographically, and the computed tomography (CT) confirmed bone erosion of the anteroinferior part of the glenoid (bone loss of about 50% of the anteroposterior diameter in the lower region of the glenoid), with almost complete resorption of the bony Bankart lesion (apparent in later analysis of the radiography of the initial traumatic episode). Connectedly, a transverse fracture of the coracoid apophysis (type II in the Ogawa classification) was diagnosed. The patient was submitted to surgical treatment, with anterior bone stop confection using the remnant of the fractured fragment of the coracoid supplemented by tricortical autologous iliac graft, fixed with cannulated screws (according to the Bristow-Latarjet and Eden-Hybinett techniques). In the postoperative follow-up, a good functional result was observed, with no new episodes of dislocation and no significant pain complaints. A rare association of shoulder lesions is described, and the challenge of their treatment is highlighted, given the late diagnosis, as in the case presented.