Global omics study of Tetraselmis chuii reveals time-related metabolic adaptations upon oxidative stress.

Microalgae species encounter oxidative stress in their natural environments, prompting the development of species-specific adaptation mechanisms. Understanding these mechanisms can offer valuable insights for biotechnological applications in microalgal metabolic manipulation. In this study, we investigated the response of Tetraselmis chuii, an industrially important microalga, to H2O2-induced oxidative stress. Exposure to 0.5-mM H2O2 resulted in reduced cell viability, and higher concentrations led to a drastic decline. After 1 h of exposure to H2O2, photosynthetic capacity (Qy) was negatively impacted, and this reduction intensified after 6 h of continuous stress. Global multi-omics analysis revealed that T. chuii rapidly responded to H2O2-induced oxidative stress within the first hour, causing significant changes in both transcriptomic and metabolomic profiles. Among the cellular functions negatively affected were carbon and energy flow, with photosynthesis-related PSBQ having a 2.4-fold downregulation, pyruvate kinase decreased by 1.5-fold, and urea content reduced by threefold. Prolonged exposure to H2O2 incurred a high energy cost, leading to unsuccessful attempts to enhance carbon metabolism, as depicted, for example, by the upregulation of photosystems-related PETC and PETJ by more than twofold. These findings indicate that T. chuii quickly responds to oxidative stress, but extended exposure can have detrimental effects on its cellular functions. KEY POINTS: • 0.5-mM H2O2-induced oxidative stress strongly affects T. chuii • Distinct short- and long-term adaptation mechanisms are induced • Major metabolic adaptations occur within the first hour of exposure.

Development of a Machine-Learning Model for Anterior Knee Pain After Total Knee Arthroplasty With Patellar Preservation Using Radiological Variables.

BACKGROUND: Anterior knee pain (AKP) following total knee arthroplasty (TKA) with patellar preservation is a common complication that significantly affects patients' quality of life. This study aimed to develop a machine-learning model to predict the likelihood of developing AKP after TKA using radiological variables. METHODS: A cohort of 131 anterior stabilized TKA cases (105 patients) without patellar resurfacing was included. Patients underwent a follow-up evaluation with a minimum 1-year follow-up. The primary outcome was AKP, and radiological measurements were used as predictor variables. There were 2 observers who made the radiological measurement, which included lower limb dysmetria, joint space, and coronal, sagittal, and axial alignment. Machine-learning models were applied to predict AKP. The best-performing model was selected based on accuracy, precision, sensitivity, specificity, and Kappa statistics. Python 3.11 with Pandas and PyCaret libraries were used for analysis. RESULTS: A total of 35 TKA had AKP (26.7%). Patient-reported outcomes were significantly better in the patients who did not have AKP. The Gradient Boosting Classifier performed best for both observers, achieving an area under the curve of 0.9261 and 0.9164, respectively. The mechanical tibial slope was the most important variable for predicting AKP. The Shapley test indicated that high/low mechanical tibial slope, a shorter operated leg, a valgus coronal alignment, and excessive patellar tilt increased AKP risk. CONCLUSIONS: The results suggest that global alignment, including sagittal, coronal, and axial alignment, is relevant in predicting AKP after TKA. These findings provide valuable insights for optimizing TKA outcomes and reducing the incidence of AKP.

Empirical adsorption kinetics: comparing linear and nonlinear regression analysis emphasizing the need for high throughput analysis.

This paper evaluates linear and nonlinear regression analysis to describe the empirical adsorption kinetics using pseudo-first-order (PFO) and pseudo-second-order (PSO) models. These models have been used to characterize the performance of adsorbents for environmental remediation and environmental modeling. Data were simulated using the PFO and PSO models with 1, 2, and 5% noise levels and fitted by nonlinear and linearized PFO and PSO equations. Nonlinear regression analysis provided rate constants and adsorption capacities with better accuracy than linearization. Besides the correlation coefficient, Chi-square and residual plot analysis helped choose the proper model to describe the adsorbent efficiency and validate the results. Both models and the NLR fitting were employed to reevaluate data obtained in our research group, including the adsorption of Hg(II) on thiol-modified vermiculite, glyphosate on soils rich in aluminum and iron oxides, phosphate on Fe(III) polyhydroxy cations modified montmorillonite, and paraquat on soil and vermiculite. While fitting the simulated data indicates an unequivocal and correct kinetic model, fitting the experimental data is not straightforward, suggesting mixed models rule the adsorption and that a large number of data points, especially at the initial steps of adsorption, provided by high throughput analysis, help to improve the kinetic modeling.

Pigeon foot feathering reveals conserved limb identity networks.

The tetrapod limb is a stunning example of evolutionary diversity, with dramatic variation not only among distantly related species, but also between the serially homologous forelimbs (FLs) and hindlimbs (HLs) within species. Despite this variation, highly conserved genetic and developmental programs underlie limb development and identity in all tetrapods, raising the question of how limb diversification is generated from a conserved toolkit. In some breeds of domestic pigeon, shifts in the expression of two conserved limb identity transcription factors, PITX1 and TBX5, are associated with the formation of feathered HLs with partial FL identity. To determine how modulation of PITX1 and TBX5 expression affects downstream gene expression, we compared the transcriptomes of embryonic limb buds from pigeons with scaled and feathered HLs. We identified a set of differentially expressed genes enriched for genes encoding transcription factors, extracellular matrix proteins, and components of developmental signaling pathways with important roles in limb development. A subset of the genes that distinguish scaled and feathered HLs are also differentially expressed between FL and scaled HL buds in pigeons, pinpointing a set of gene expression changes downstream of PITX1 and TBX5 in the partial transformation from HL to FL identity. We extended our analyses by comparing pigeon limb bud transcriptomes to chicken, anole lizard, and mammalian datasets to identify deeply conserved PITX1- and TBX5-responsive components of the limb identity program. Our analyses reveal a suite of predominantly low-level gene expression changes that are conserved across amniotes to regulate the identity of morphologically distinct limbs.

Isl1 mediates mesenchymal expansion in the developing external genitalia via regulation of Bmp4, Fgf10 and Wnt5a.

Genital malformations are among the most common human birth defects, and both genetic and environmental factors can contribute to these malformations. Development of the external genitalia in mammals relies on complex signaling networks, and disruption of these signaling pathways can lead to genital defects. Islet-1 (ISL1), a member of the LIM/Homeobox family of transcription factors, has been identified as a major susceptibility gene for classic bladder exstrophy in humans, a common form of the bladder exstrophy-epispadias complex (BEEC), and is implicated in a role in urinary tract development. We report that deletion of Isl1 from the genital mesenchyme in mice led to hypoplasia of the genital tubercle and prepuce, with an ectopic urethral opening and epispadias-like phenotype. These mice also developed hydroureter and hydronephrosis. Identification of ISL1 transcriptional targets via ChIP-Seq and expression analyses revealed that Isl1 regulates several important signaling pathways during embryonic genital development, including the BMP, WNT, and FGF cascades. An essential function of Isl1 during development of the external genitalia is to induce Bmp4-mediated apoptosis in the genital mesenchyme. Together, these studies demonstrate that Isl1 plays a critical role during development of the external genitalia and forms the basis for a greater understanding of the molecular mechanisms underlying the pathogenesis of BEEC and urinary tract defects in humans.

Determination of glyphosate, AMPA and glufosinate by high performance liquid chromatography with fluorescence detection in waters of the Santarém Plateau, Brazilian Amazon.

Herbicide use, mainly glyphosate, has been intense in worldwide agriculture, including in the Brazilian Amazon region. This study aimed to validate a method for determining glyphosate and its degradation product, AMPA, and glufosinate by HPLC-FL in 58 water samples collected at the Santarém plateau region (Planalto Santareno), in the western of Pará state, Brazil. The method involves filtration and direct injection in the HPLC-FL for AMPA analysis, or previous concentration (10×) by lyophilization for glufosinate and glyphosate analysis. Analytes were oxidized and complexed with o-phthalaldehyde and 2-mercaptoethanol in a post-column reaction before fluorescence detection. LOQs for AMPA, glyphosate and glufosinate were established at 0.5, 0.2 and 0.3 µg L-1, respectively. A total of 58 samples were collected. Glyphosate and glufosinate were not detected in any of the 30 surface water samples collected in 2015 (

PITX1 promotes chondrogenesis and myogenesis in mouse hindlimbs through conserved regulatory targets.

The PITX1 transcription factor is expressed during hindlimb development, where it plays a critical role in directing hindlimb growth and the specification of hindlimb morphology. While it is known that PITX1 regulates hindlimb formation, in part, through activation of the Tbx4 gene, other transcriptional targets remain to be elucidated. We have used a combination of ChIP-seq and RNA-seq to investigate enhancer regions and target genes that are directly regulated by PITX1 in embryonic mouse hindlimbs. In addition, we have analyzed PITX1 binding sites in hindlimbs of Anolis lizards to identify ancient PITX1 regulatory targets. We find that PITX1-bound regions in both mouse and Anolis hindlimbs are strongly associated with genes implicated in limb and skeletal system development. Gene expression analyses reveal a large number of misexpressed genes in the hindlimbs of Pitx1-/- mouse embryos. By intersecting misexpressed genes with genes that have neighboring mouse PITX1 binding sites, we identified 440 candidate targets of PITX1. Of these candidates, 68 exhibit ultra-conserved PITX1 binding events that are shared between mouse and Anolis hindlimbs. Among the ancient targets of PITX1 are important regulators of cartilage and skeletal muscle development, including Sox9 and Six1. Our data suggest that PITX1 promotes chondrogenesis and myogenesis in the hindlimb by direct regulation of several key members of the cartilage and muscle transcriptional networks.

Appendages and gene regulatory networks: Lessons from the limbless.

Among squamate reptiles, dozens of lineages have independently evolved complete or partial limb reduction. This remarkable convergence of limbless and limb-reduced phenotypes provides multiple natural replicates of different ages to explore the evolution and development of the vertebrate limb and the gene regulatory network that controls its formation. The most successful and best known of the limb-reduced squamates are snakes, which evolved a limb-reduced body form more than 100 million years ago. Recent studies have revealed the unexpected finding that many ancient limb enhancers are conserved in the genomes of snakes. Analyses in limbed animals show that many of these limb enhancers are also active during development of the phallus, suggesting that these enhancers may have been retained in snakes due their importance in regulating transcription in the external genitalia. This hypothesis is substantiated by functional tests of snake enhancers, which demonstrate that snake enhancer elements have lost limb function while retaining genital enhancer function. The large degree of overlap in the gene regulatory networks deployed during limb and phallus development may act to constrain the divergence of shared gene network components and the evolution of appendage morphology. Future studies will reveal whether limb regulatory elements have undergone similar functional changes in other lineages of limb-reduced squamates.

Antioxidant capacity and immunomodulatory effects of a chrysolaminarin-enriched extract in Senegalese sole.

The microalgae are an important source of bioactive molecules including ß-glucans that can be used as immunostimulants in aquaculture. In the present study, the antioxidant capacity, cytotoxicity and immunomodulatory activity of a chrysolaminarin-enriched extract obtained from the diatom Phaeodactylum tricornutum was evaluated. The extract showed a higher total antioxidant activity as determined by ORAC and FRAP assays and a lower DPPH scavenging activity than particulate yeast-ß-glucan. The cytotoxicity test indicated that extract concentrations higher than 0.01% w/v could impair cell viability of human dermal fibroblasts. To evaluate the immunomodulatory activity, juvenile soles were intraperitoneally injected with the chrysolaminarin-enriched extract suspended in coconut oil (1 mg/fish) followed by a reinjection at 7 days. A sham group injected with the carrier solution was maintained as a negative control. Cumulated mortality of fish injected with the chrysolaminarin-enriched extract was 29.4% after six days and no mortality was recorded after extract reinjection. Expression analyses of fifteen genes related to the innate immune system in kidney, spleen and intestine showed temporal and organ-specific responses. A rapid (2 days post-injection; dpi) and strong induction of the pro-inflammatory il1b and the antimicrobial peptide hamp1 in the three immunological organs, the hsp90aa in kidney and spleen, irf3 in intestine and c3 in spleen was observed indicating a potent inflammatory response. The recovery of steady-state levels for all activated genes at 5 dpi, and the down-regulation of c-lectin receptor as well as some interferon-related genes (ifn1, irf1, irf3, irf8, irf9 and mx) in kidney and cxc10 in spleen indicated that the soles were able to activate a homeostatic response against the ß-glucan insult. The reinjection of the chrysolaminarin-enriched extract did not activate a new inflammatory response but reduced the mRNA levels of hsp90aa and irf3 indicating that soles developed some resistance to ß-glucans. Overall, these results reveal this enriched extract as a novel and potent source of ß-glucans with antioxidant and immunomodulatory capacity suitable for immunostimulation in aquaculture.

Molecular characterization and transcriptional regulation of the renin-angiotensin system genes in Senegalese sole (Solea senegalensis Kaup, 1858): differential gene regulation by salinity.

In this work, the complete cDNA sequence encoding angiotensinogen (agt) in the euryhaline flatfish Senegalese sole was obtained. Additionally, putative coding sequences belonging to other renin-angiotensin system (RAS) genes including renin (ren), angiotensin-converting enzyme (ace), angiotensin-converting enzyme 2 (ace2), as well as angiotensin II receptor type I (agtr1) and type II (agtr2), were also identified. In juvenile tissues, agt transcripts were mainly detected in liver, ren in kidney, ace and ace2 in intestine, agtr1 in kidney and brain, and agtr2 in liver and kidney. Expression analysis of the six RAS genes after a salinity shift revealed a clear increase of agt mRNA abundance in liver just after transferring soles to high salinity water (60 ppt) with a peak at 48 h. Moreover, gene expression analysis in gills showed transcriptional regulation of ace and agtr1 at 48 h and agtr2 at 96 h after transferring soles to 60 ppt. Incubation of larvae before mouth opening (until 3 days post hatch; dph) at low salinity (10 ppt) resulted in a coordinated transcriptional up-regulation of RAS genes. Nevertheless, no differences in mRNA abundance between salinities were observed when larvae were cultivated to low salinity after mouth opening. Whole-mount in situ hybridization (WISH) signal for agt and ace in 3 dph larvae incubated at 10 ppt and 35 ppt confirmed that the former gene was mainly expressed in liver whereas the later gene was mainly located in pharynx and posterior gut, without pronounced differences in intensity between salinities. Possible physiological significance of all these results is discussed.

Pitx1 broadly associates with limb enhancers and is enriched on hindlimb cis-regulatory elements.

Extensive functional analyses have demonstrated that the pituitary homeodomain transcription factor Pitx1 plays a critical role in specifying hindlimb morphology in vertebrates. However, much less is known regarding the target genes and cis-regulatory elements through which Pitx1 acts. Earlier studies suggested that the hindlimb transcription factors Tbx4, HoxC10, and HoxC11 might be transcriptional targets of Pitx1, but definitive evidence for direct regulatory interactions has been lacking. Using ChIP-Seq on embryonic mouse hindlimbs, we have pinpointed the genome-wide location of Pitx1 binding sites during mouse hindlimb development and identified potential gene targets for Pitx1. We determined that Pitx1 binding is significantly enriched near genes involved in limb morphogenesis, including Tbx4, HoxC10, and HoxC11. Notably, Pitx1 is bound to the previously identified HLEA and HLEB hindlimb enhancers of the Tbx4 gene and to a newly identified Tbx2 hindlimb enhancer. Moreover, Pitx1 binding is significantly enriched on hindlimb relative to forelimb-specific cis-regulatory features that are differentially marked by H3K27ac. However, our analysis revealed that Pitx1 also strongly associates with many functionally verified limb enhancers that exhibit similar levels of activity in the embryonic mesenchyme of forelimbs and hindlimbs. We speculate that Pitx1 influences hindlimb morphology both through the activation of hindlimb-specific enhancers as well as through the hindlimb-specific modulation of enhancers that are active in both sets of limbs.

De novo assembly, characterization and functional annotation of Senegalese sole (Solea senegalensis) and common sole (Solea solea) transcriptomes: integration in a database and design of a microarray.

BACKGROUND: Senegalese sole (Solea senegalensis) and common sole (S. solea) are two economically and evolutionary important flatfish species both in fisheries and aquaculture. Although some genomic resources and tools were recently described in these species, further sequencing efforts are required to establish a complete transcriptome, and to identify new molecular markers. Moreover, the comparative analysis of transcriptomes will be useful to understand flatfish evolution. RESULTS: A comprehensive characterization of the transcriptome for each species was carried out using a large set of Illumina data (more than 1,800 millions reads for each sole species) and 454 reads (more than 5 millions reads only in S. senegalensis), providing coverages ranging from 1,384x to 2,543x. After a de novo assembly, 45,063 and 38,402 different transcripts were obtained, comprising 18,738 and 22,683 full-length cDNAs in S. senegalensis and S. solea, respectively. A reference transcriptome with the longest unique transcripts and putative non-redundant new transcripts was established for each species. A subset of 11,953 reference transcripts was qualified as highly reliable orthologs (>97% identity) between both species. A small subset of putative species-specific, lineage-specific and flatfish-specific transcripts were also identified. Furthermore, transcriptome data permitted the identification of single nucleotide polymorphisms and simple-sequence repeats confirmed by FISH to be used in further genetic and expression studies. Moreover, evidences on the retention of crystallins crybb1, crybb1-like and crybb3 in the two species of soles are also presented. Transcriptome information was applied to the design of a microarray tool in S. senegalensis that was successfully tested and validated by qPCR. Finally, transcriptomic data were hosted and structured at SoleaDB. CONCLUSIONS: Transcriptomes and molecular markers identified in this study represent a valuable source for future genomic studies in these economically important species. Orthology analysis provided new clues regarding sole genome evolution indicating a divergent evolution of crystallins in flatfish. The design of a microarray and establishment of a reference transcriptome will be useful for large-scale gene expression studies. Moreover, the integration of transcriptomic data in the SoleaDB will facilitate the management of genomic information in these important species.

Conserved regulation of hoxc11 by pitx1 in Anolis lizards.

Anolis lizards are an emerging model system for the study of limb development and evolution, but very little is known concerning the regulatory interactions that control limb patterning differences among Anolis species or what regulatory interactions are deeply conserved between Anolis and other tetrapod groups. Here we report the establishment of an embryonic limb micromass culture system that enables functional studies of forelimb and hindlimb gene regulatory networks in Anolis. Characterization of this culture system demonstrated that embryonic forelimb and hindlimb micromasses from different Anolis species are easy to sustain in culture for weeks, and the expression of forelimb and hindlimb-specific gene expression patterns are maintained for at least 8 days in culture. We tested the ability of this system to explore regulatory linkages between transcription factors and their putative target genes through the ectopic expression of a hindlimb-specific transcription factor, pitx1, in forelimb micromasses. We found that pitx1 expression in forelimb cells is sufficient to strongly induce the expression of hoxc11, a gene that normally exhibits hindlimb-restricted expression.

Somitogenesis in the anole lizard and alligator reveals evolutionary convergence and divergence in the amniote segmentation clock.

The axial skeleton is a defining feature of vertebrates and is patterned during somitogenesis. Cyclically expressed members of the notch and other signaling pathways, described as the 'segmentation clock', regulate the formation of somite boundaries. Comparisons among vertebrate model systems have revealed fundamental shifts in the regulation of expression among critical genes in the notch pathway. However, insights into the evolution of these expression differences have been limited by the lack of information from non-avian reptiles. We analyzed the segmentation clock of the first Lepidosaurian reptile sequenced, the green anole lizard, Anolis carolinensis, for comparison with avian and mammalian models. Using genomic sequence, RNA-Seq transcriptomic data, and in situ hybridization analysis of somite-stage embryos, we carried out comparative analyses of key genes and found that the anole segmentation clock displays features common to both amniote and anamniote vertebrates. Shared features with anamniotes, represented by Xenopus laevis and Danio rerio, include an absence of lunatic fringe (lfng) expression within the presomitic mesoderm (PSM), a hes6a gradient in the PSM not observed in the chicken or mouse, and EGF repeat structure of the divergent notch ligand, dll3. The anole and mouse share cycling expression of dll1 ligand in the PSM. To gain insight from an Archosaurian reptile, we analysed LFNG and DLL1 expressions in the American alligator. LFNG expression was absent in the alligator PSM, like the anole but unlike the chicken. In contrast, DLL1 expression does not cycle in the PSM of the alligator, similar to the chicken but unlike the anole. Thus, our analysis yields novel insights into features of the segmentation clock that are evolutionarily basal to amniotes versus those that are specific to mammals, Lepidosaurian reptiles, or Archosaurian reptiles.

Developmental origins of a novel gut morphology in frogs.

Phenotypic variation is a prerequisite for evolution by natural selection, yet the processes that give rise to the novel morphologies upon which selection acts are poorly understood. We employed a chemical genetic screen to identify developmental changes capable of generating ecologically relevant morphological variation as observed among extant species. Specifically, we assayed for exogenously applied small molecules capable of transforming the ancestral larval foregut of the herbivorous Xenopus laevis to resemble the derived larval foregut of the carnivorous Lepidobatrachus laevis. Appropriately, the small molecules that demonstrate this capacity modulate conserved morphogenetic pathways involved in gut development, including downregulation of retinoic acid (RA) signaling. Identical manipulation of RA signaling in a species that is more closely related to Lepidobatrachus, Ceratophrys cranwelli, yielded even more similar transformations, corroborating the relevance of RA signaling variation in interspecific morphological change. Finally, we were able to recover the ancestral gut phenotype in Lepidobatrachus by performing a reverse chemical manipulation to upregulate RA signaling, providing strong evidence that modifications to this specific pathway promoted the emergence of a lineage-specific phenotypic novelty. Interestingly, our screen also revealed pathways that have not yet been implicated in early gut morphogenesis, such as thyroid hormone signaling. In general, the chemical genetic screen may be a valuable tool for identifying developmental mechanisms that underlie ecologically and evolutionarily relevant phenotypic variation.

Total substitution of fish oil by vegetable oils in Senegalese sole (Solea senegalensis) diets: effects on fish performance, biochemical composition, and expression of some glucocorticoid receptor-related genes.

To study the substitution of fish oil by vegetable oils in fish diets, juveniles Senegalese sole (Solea senegalensis) were fed diets (56 % crude protein, 12 % crude lipid) containing either linseed (100LO) or soybean (100SO) oils in comparison with a 100 % fish oil-based diet (100FO) for 90 days. Samples of muscle, liver, and intestine were collected for biochemical analysis and for glucocorticoid receptor-related genes, including GR1 and GR2, and the associated heat shock proteins HSP70, HSP90AA, and HSP90AB. Besides, basal levels of plasma cortisol were also determined. After the feeding period, a stress test, consisting on 5 min of net chasing, was applied to a selected population of each dietary group. Total replacement of fish oil by vegetable oils did not induced changes in fish growth and performance, but affected fatty acid profile of muscle, liver, and intestine, reflecting those tissues the characteristic fatty acids of each type of dietary oil. A tendency to conserve the ARA/EPA ratio could be observed in the different tissues, despite of the level of these fatty acids in diet. Chasing stress induced an increase of muscle GR1 and a reduction in intestinal GR2 relative expressions at any of the experimental diets assayed. In liver, chasing stress induced an increase in both GR1 and GR2 gene expression in fish fed fish oil diets. Similarly, chasing stress induced an increase of muscle HSP70 and decrease of HSP90AB in liver at any of the experimental diet assayed. Besides, vegetable oils decreased the expression of HSP70 in intestine, being the relative expression of liver HSP90AA increased by the inclusion of linseed oil in the diet, at any of the experimental conditions assayed.

Access to knee arthroplasty among National Health Fund beneficiaries in Chile between 2004 and 2021. / Radiografía al acceso en artroplastia de rodilla entre los beneficiarios del Fondo Nacional de Salud entre 2004 y 2021.

Introduction: Knee osteoarthritis affects the quality of life, with knee arthroplasty being a cost-effective treatment for the severe stage of this disease. Access to knee arthroplasty is a health indicator of the Organisation for Economic Co-operation and Development. The objectives of this study are to determine the incidence of knee arthroplasty between 2004 and 2021 in beneficiaries of the National Health Fund in Chile, the proportion of patients who underwent surgery in the private system, and to estimate the patient's out-of-pocket expenditure for surgery. Methods: Cross-sectional study. We used the Department of Statistics and Health Information database. Patients discharged from a Chilean health center who underwent knee arthroplasty surgery between 2004 and 2021 were investigated. We analyzed the proportion of patients by their National Health Fund category and whether their surgery was performed in public or private network facilities. Results: Of the 31 526 knee arthroplasty procedures, 21 248 (67.38%) were performed on National Health Fund patients and 16 238 in public institutions (51.49%). Patients from the National Health Fund showed a systematic increase in knee arthroplasty volume until 2019 but decreased in 2020 and 2021 by 68% and 51%. Of the total number of patients in the public system operated on for knee arthroplasty, 856 (9%) belonged to group A1, 12 806 (60%) to group B, 2044 (10%) to group C, and 4421 (21%) to group D. The expenditure incurred by these patients was estimated to vary between 24.4% and 27.2%. The historical proportions of access to this surgery in private institutions are 7% in group A, 13% in group B, 24% in group C, and 52% in group D. Conclusion: Fifty percent of knee arthroplasty surgeries are performed in public institutions, and two-thirds are performed on patients of the National Health Fund. Forty-six percent of the C and D groups were operated in the private system. The pandemic has increased the access gap, leading to a substantial increase in the proportion of patients from the National Health Fund of the B, C, and D groups who have migrated to the private system to access this surgery.

Introducción: La artrosis de rodilla es una patología que afecta la calidad de vida, siendo la artroplastía de rodilla un tratamiento costo-efectivo para la etapa severa de esta enfermedad. El acceso a artroplastia de rodilla es un indicador de salud de la Organización de Cooperación y Desarrollo Económico. Los objetivos de este estudio son determinar la incidencia de artroplastia de rodilla entre 2004 y 2021 en los beneficiarios del Fondo Nacional de Salud en Chile, la proporción que se operaron en el sistema privado y estimar el gasto del bolsillo del paciente para operarse. Método: Estudio transversal. Se utilizó la base de datos del Departamento de Estadística e Información de Salud. Se pesquisaron pacientes que egresaron de un centro de salud chileno que fueron intervenidos por artroplastia rodilla entre 2004 y 2021. Se analizó la proporción de pacientes por tramo del Fondo Nacional de Salud y si se realizó su cirugía en establecimiento de la red pública o privada. Resultados: De las 31 526 intervenciones de artroplastia de rodilla, 21 248 (67,38%) fueron realizadas en pacientes del Fondo Nacional de Salud y 16 238 en instituciones públicas (51,49%). Los pacientes de dicho fondo presentan un alza sistemática en el volumen de artroplastías de rodilla hasta 2019, pero disminuyeron en 2020 y 2021 un 68% y un 51%. Del total de pacientes del sistema público operados de artroplastia de rodilla, 856 (9%) pertenecían al tramo A1, al tramo B 12 806 (60%), al tramo C 2044 (10%) y al tramo D 4421 (21%). Se estimó que el gasto incurrido por estos pacientes varía entre el 24,4 y 27,2%. Las proporciones históricas de acceso en instituciones privadas a esta cirugía son en el tramo A 7%, tramo B 13%, tramo C 24% y tramo D 52%. Conclusión: El 50% de las cirugías de artroplastía de rodilla se realizan en instituciones públicas y dos tercios se realizan en pacientes del Fondo Nacional de Salud. El 46% de los tramos C y D se operaron en el sistema privado. La pandemia ha aumentado la brecha de acceso, lo que ha provocado un alza significativa en la proporción de pacientes del Fondo Nacional de Salud de los tramos B, C y D que han migrado al sistema privado para acceder a esta cirugía.

Estimación de la eficiencia del uso de pabellones electivos en el sistema de salud público chileno entre 2018 y 2021. / Efficiency estimation on the use of elective surgical theaters in the Chilean public health system from 2018 to 2021.

Objective: The efficient use of wards intended for elective surgeries is essential to resolve cases on the surgical waiting list. This study aims to estimate the efficiency of ward use in the Chilean public health system between 2018 and 2021. Methods: The design was an ecological study. Section A.21 of the database constructed by the monthly statistical summaries that each public health network facility reported to the Ministry of Health between 2018 and 2021 was analyzed. Data from subsections A, E and F were extracted: ward staffing, total elective surgeries by specialty, number and causes of suspension of elective surgeries. Then, the surgical performance during working hours and the percentage of hourly occupancy for a working day was estimated. Additionally, an analysis was made by region with data from 2021. Results: The percentage of elective wards in use ranged from 81.1% to 94.1%, while those enabled for those staffing ranged from 70.5% to 90.4% during 2018 and 2021. The total number of surgeries was highest in 2019 (n = 416 339), but for 2018, 2020, and 2021 it ranged from 259 000 to 297 000. Suspensions varied between 10.8% (2019) and 6.9% (2021), with the leading cause being patient-related. When analyzing the number of cases canceled monthly by facility, we saw that the leading cause was trade union-related. The maximum throughput of a ward intended for elective surgery was reached in 2019 and was 2.5 surgeries; in 2018, 2020 and 2021, the throughput borders on two surgeries per ward enabled for elective surgery. The percentage of ward time occupied during working hours by contract day varies between 80.7% (2018) and 56.8% (2020). Conclusions: All the parameters found and estimated in this study show that there is an inefficient utilization of operating rooms in Chilean public healthcare facilities.

Objetivo: El uso eficiente de pabellones destinados a cirugías electivas es fundamental para resolver patologías en lista de espera quirúrgica. El objetivo general de este estudio es estimar la eficiencia del uso de pabellones en el sistema de salud público de Chile entre los años 2018 y 2021. Métodos: El diseño fue un estudio ecológico. Se analizó la Sección A.21 de la base de datos construida por los resúmenes estadísticos mensuales que cada establecimiento de la red de salud pública reportó al Ministerio de Salud de Chile entre 2018 y 2021. Se extrajeron los datos de la subsección A, E y F: dotación de pabellones, total de cirugías electivas por especialidad, número y causas de suspensión de cirugías electivas. Luego se estimó el rendimiento quirúrgico en horario hábil y el porcentaje de ocupación horaria respecto de una jornada laboral. Adicionalmente, se hizo un análisis por región con datos de 2021. Resultados: El porcentaje de pabellones electivos respecto de los en dotación varió entre 81,1 y 94,1%; mientras que los habilitados respecto de los en dotación varió entre 70,5 y 90,4% durante 2018 y 2021. El número total de cirugías fue más alto en 2019 (n = 416 339), pero en 2018, 2020 y 2021 variaron entre 259 y 297 mil cirugías. Las suspensiones varían entre 10,8 (2019) y 6,9%w(2021), siendo la principal causa de suspensión atribuida al "paciente". Al analizar la cantidad de pacientes suspendidos mensualmente por institución, se observa que la principal causa es "gremial". El rendimiento máximo de un pabellón destinado a cirugía electiva se alcanzó en 2019 y fue de 2,5 cirugías; mientras que en 2018, 2020 y 2021 el rendimiento bordea las dos cirugías por pabellón habilitado para cirugía electiva. El porcentaje de tiempo de pabellón ocupado en horario hábil respecto a una jornada de contrato varía entre 80,7 (2018) y 56,8% (2020). Conclusiones: Todos los parámetros encontrados y estimados en este estudio muestran que el uso de pabellones en el sistema público de Chile es ineficiente.

Anterior knee pain and sit-up tests predicts patients' satisfaction and improvement in quality of life after anterior stabilized total knee replacement without patellar resurfacing.

PURPOSE: The purpose of this study was to assess patient satisfaction and identify risk factors for dissatisfaction after anterior stabilised conventional total knee arthroplasty (TKA) without patellar resurfacing, using the Goodman score. METHODS: We conducted a cross-sectional study using data from our institutional database from 1 January 2018 to 1 March 2021. Patients who underwent TKA with the Vanguard® Cruciate Retaining Anterior Stabilized Knee System (Zimmer Biomet, Warsaw, Indiana, USA) without patellar replacement were included. Patients with other bearing surfaces (posterior stabilised or medial congruent) or diagnosed with infection or instability were excluded. Patients' reported outcomes, body mass index (BMI), passive range of motion, the timed up-and-go test, sit-up test, and algometry were assessed. Patients were also asked if they had anterior knee pain. Satisfaction was assessed using the Goodman scale, and logistic multivariate regression was used to identify variables associated with dissatisfaction and perceived improvement in quality of life. RESULTS: A total of 131 TKA patients were included in the study. The median satisfaction score was 100 (interquartile range [IQR], 87.5 to 100), with the 75-point threshold at the 90th percentile according to Section A of Goodman. Section B of Goodman showed that 113 TKA patients (86.26%) reported "great improvement" or "more than I ever dreamed." Multivariate logistic regression revealed that anterior knee pain (OR 5.16, 95% CI 1.24 to 21.39), the sit-up test (OR 0.63, 95% CI 0.49 to 0.81), and BMI (OR 0.84, 95% CI 0.70 to 0.99) were significantly associated with patient dissatisfaction and a worse perceived improvement in quality of life. The receiver operating characteristics curve for the models had areas under the curve of 0.83 (95% CI 0.69 to 0.97) and 0.82 (95% CI 0.70 to 0.94), respectively. CONCLUSION: Anterior stabilised TKA without patellar resurfacing can achieve 90% satisfaction and 86% improvement in quality of life. To improve these results, it is essential to prevent and treat anterior knee pain and enhance quadriceps strength. LEVEL OF EVIDENCE: Level III (retrospective cohort study).

Similar Patient Satisfaction and Quality of Life Improvement Achieved with TKA and THA According to the Goodman Scale: A Comparative Study.

Background: Total knee arthroplasty (TKA) and total hip arthroplasty (THA) are effective treatments for severe knee and hip osteoarthritis. Historically, TKA has been associated with lower satisfaction than THA, but recent advances in knee surgery have led to lower dissatisfaction rates. This study aimed to compare the satisfaction and self-reported improvement in the quality of life of two cohorts of patients who underwent TKA and THA, respectively. Methods: This observational study compared two previously published cohorts of patients who underwent THA and TKA in a single university center. The Goodman scale was used to assess satisfaction and self-perception of improved quality of life after TKA and THA at a minimum one-year follow-up. Propensity score matching was used to balance age, gender, and follow-up between groups. Significance was set at 0.05. Results: The study included a total of 105 THAs and 131 TKAs. Both groups had high levels of satisfaction with pain relief, ability to do house/yard work, and overall satisfaction, with above 90% satisfaction rates. Regarding improvement in quality of life, both groups had 86% of patients reporting improvement as "much better." After propensity score matching, no significant difference was found between THA and TKA for any of the comparisons made using the Goodman scale. Conclusions: The study showed that both TKA and THA resulted in high levels of satisfaction and improvement in quality of life. There was no significant difference in satisfaction rates between TKA and THA, contrary to the historical trend of lower satisfaction rates for TKA.