[Prognostic factors associated with failure of modular knee arthroplasty in oncologic patients]. / Factores pronósticos asociados al fracaso de la artroplastía modular de rodilla en pacientes oncológicos.

INTRODUCTION: reconstruction of large bone defects using modular knee arthroplasty (MKA) presents a significant challenge in terms of functionality. The objective of the present work was to identify the different prognostic factors associated with failure of MKA in cancer patients. MATERIAL AND METHODS: a retrospective cohort study was conducted, including patients with a diagnosis of musculoskeletal tumor in the distal femur or proximal tibia, who underwent MKA between January 1, 2010, and December 31, 2021. RESULTS: 49 patients were included, of which 25 (51.02%) were women and 24 (48.98%) men, with a mean age of 29.57 years. Of these, 14 (28.57%) patients experienced some type of MKA failure. The most frequent complication that led to failure was periprosthetic infection, observed in seven (14.29%) patients. Variables associated with MKA failure included biopsies performed outside our hospital (HR 3.2, 95% CI 1.4-6.4, p = 0.02), the length of the long axis of the tumor (HR 2.1, 95% CI 1.2-4.6, p = 0.01) and a prolonged surgical time (HR 3.37, 95% CI 1.1-8.6, p = 0.04). CONCLUSION: the most significant prognostic factors associated with MKA failure in our cohort were tumor size, prolonged surgical time, and performance of the diagnostic biopsy in a center not specialized in the management of this type of patient. These findings highlight the importance of considering these variables to improve outcomes in patients undergoing MKA.

INTRODUCCIÓN: la reconstrucción de grandes defectos óseos mediante artroplastía modular de rodilla (AMR) representa un desafío significativo en términos de funcionalidad. El objetivo del presente trabajo fue identificar los diferentes factores pronósticos asociados al fracaso de la AMR en pacientes oncológicos. MATERIAL Y MÉTODOS: se realizó un estudio de cohorte retrospectiva, incluyendo pacientes con diagnóstico de tumor musculoesquelético en el fémur distal o la tibia proximal, que fueron sometidos a AMR entre el 1 de Enero de 2010 y el 31 de Diciembre de 2021. RESULTADOS: se incluyeron 49 pacientes, de los cuales 25 (51.02%) eran mujeres y 24 (48.98%) hombres, con una edad media de 29.57 años. De éstos, 14 (28.57%) pacientes experimentaron algún tipo de fracaso de la AMR. La complicación más frecuente que condicionó el fracaso fue la infección periprotésica, observada en siete (14.29%) pacientes. Las variables asociadas con el fracaso de las AMR incluyeron biopsias realizadas fuera de nuestro hospital (HR 3.2, IC95% 1.4-6.4, p = 0.02), longitud del eje mayor del tumor (HR 2.1, IC95% 1.2-4.6, p = 0.01) y tiempo quirúrgico prolongado (HR 3.37, IC95% 1.1-8.6, p = 0.04). CONCLUSIÓN: los factores pronósticos asociados al fracaso de las AMR en nuestra cohorte fueron el tamaño del tumor, un tiempo quirúrgico prolongado y la realización de la biopsia diagnóstica en un centro no especializado en el manejo de este tipo de pacientes. Estos hallazgos resaltan la importancia de considerar estas variables en pacientes sometidos a AMR.

Arcsine Laws of Light.

We demonstrate that the time-integrated light intensity transmitted by a coherently driven resonator obeys Lévy's arcsine laws-a cornerstone of extreme value statistics. We show that convergence to the arcsine distribution is algebraic, universal, and independent of nonequilibrium behavior due to nonconservative forces or nonadiabatic driving. We furthermore verify, numerically, that the arcsine laws hold in the presence of frequency noise and in Kerr-nonlinear resonators supporting non-Gaussian states. The arcsine laws imply a weak ergodicity breaking which can be leveraged to enhance the precision of resonant optical sensors with zero energy cost, as shown in our companion manuscript [V. G. Ramesh et al., companion paper, Phys. Rev. Res. (2024).PPRHAI2643-1564]. Finally, we discuss perspectives for probing the possible breakdown of the arcsine laws in systems with memory.

Barriers and facilitators to implementing a multilevel, multicomponent intervention promoting colorectal cancer screening in health centers: a qualitative study of key informant perspectives.

BACKGROUND: Colorectal cancer (CRC) continues to be a major cause of death in the U.S. despite the availability of effective screening tools. U.S. Latinos have lower rates of CRC screening and higher rates of death due to colorectal disease compared to non-Hispanic whites. Federally Qualified Health Centers (FQHCs) serve medically underserved populations, including many Latino patients. Given the low CRC screening rates, identifying culturally sensitive and cost-effective methods of promoting screening is a priority for many FQHCs. METHODS: We interviewed FQHC leaders and providers using the Consolidated Framework for Implementation Research (CFIR) to identify barriers and facilitators to implementation of a multilevel, multicomponent (ML-MC) CRC screening intervention (i.e., promotor navigation and group-based education) in FQHCs. A rapid qualitative analysis approach was used to identify themes organized according to the following CFIR constructs: intervention characteristics, outer and inner settings, and characteristics of the individual. RESULTS: We completed interviews with 13 healthcare professionals in leadership positions at six FQHCs. The participating FQHCs perceived the ML-MC screening CRC program as feasible and expressed interest in implementing the program at their sites. Facilitators included financial incentives for increasing screening rates, the need for patient education programming, and involving promotores to support the work of clinical teams. Barriers included concerns about available resources to implement new programs, lack of federal reimbursement for health education, competing priorities of other health concerns, and the need for more resources for confirmatory screening and treatment following a positive screen. CONCLUSIONS: FQHCs provide essential primary care to millions of underserved patients in the U.S. and have the ability and motivation to provide screenings for colorectal cancer. Partnering with an academic institution to deliver a group-based, promotor-led CRC screening intervention for patients not up to date with screening could help increase screening rates. By identifying the specific barriers and facilitators to implementing CRC intervention, findings suggest that group-based, promotor-led interventions are a promising approach.

Structural analysis of whey representation between rural and urban populations in western Mexico.

Whey is a by-product derived from cheese making. Despite being rich in nutrients, it is little used, it even represents a problem form the environment in Mexico. In this sense, it is important to know the meanings that are associated with this term, especially when it is intended to develop new products from this by-product. The objective of this work was to analyze the representation of the term whey in rural and urban populations through the Central core Theory. Additionally, the relationship between gender-place of residence with the evoked word is explored. Therefore, three hundred and sixty people (from rural and urban areas) were interviewed face to face in two areas in the western region of Mexico. Word association test was carried out, using "whey" as stimulus; the associated words were ordered according to their importance; the polarity index of each associated word was evaluated. The most frequently mentioned words were analyzed based on their frequency of mention and average importance to identify the conceptual structure of the concept representation. The results show and influence of the place of residence on the conceptual structure. Rural participants tend to generate more words with negative connotations, while the central elements of urban consumers are mainly related to dairy products. When comparing consumers by gender, rural and urban women associate "whey" with aspects of both the production process and dairy products. In the case of men, those from the urban zone, relate to aspects related to nutrition, dairy products and nutrients. In contrast, men from the rural area relate whey mainly to negative aspects such as pollution. The study confirms that there is a link between the place of residence and the conformation of the conceptual structure, where the gender-region relationship influences the definition of the term "whey".

An explainable machine learning approach for hospital emergency department visits forecasting using continuous training and multi-model regression.

BACKGROUND AND OBJECTIVE: In the last years, the Emergency Department (ED) has become an important source of admissions for hospitals. Since late 90s, the number of ED visits has been steadily increasing, and since Covid19 pandemic this trend has been much stronger. Accurate prediction of ED visits, even for moderate forecasting time-horizons, can definitively improve operational efficiency, quality of care, and patient outcomes in hospitals. METHODS: In this paper we propose two different interpretable approaches, based on Machine Learning algorithms, to accurately forecast hospital emergency visits. The proposed approaches involve a first step of data segmentation based on two different criteria, depending on the approach considered: first, a threshold-based strategy is adopted, where data is divided depending on the value of specific predictor variables. In a second approach, a cluster-based ensemble learning is proposed, in such a way that a clustering algorithm is applied to the training dataset, and ML models are then trained for each cluster. RESULTS: The two proposed methodologies have been evaluated in real data from two hospital ED visits datasets in Spain. We have shown that the proposed approaches are able to obtain accurate ED visits forecasting, in short-term and also long-term prediction time-horizons up to one week, improving the efficiency of alternative prediction methods for this problem. CONCLUSIONS: The proposed forecasting approaches have a strong emphasis on providing explainability to the problem. An analysis on which variables govern the problem and are pivotal for obtaining accurate predictions is finally carried out and included in the discussion of the paper.

Efficient catalytic activity of NiO and CeO2 films in benzoic acid removal using ozone.

This research focuses on the synthesis of NiO and CeO2 thin films using spray pyrolysis for the removal of benzoic acid using ozone as an oxidant. The results indicate that the addition of CeO2 films significantly enhances the mineralization of benzoic acid, achieving a rate of over 80% as the CeO2 films react with ozone to produce strong oxidant species, such as hydroxyl radicals, superoxide radicals, and singlet oxygen as demonstrated by the presence of quenchers in the reaction system. The difference in catalytic activity between NiO and CeO2 films was analyzed via XPS technique; specifically, hydroxyl oxygen groups in the CeO2 film were greater in number than those in the NiO film, thus benefitting catalytic oxidation as these species are considered active oxidation sites. The effects of nozzle-substrate distances and deposition time during the synthesis of the films on benzoic acid removal efficiency were also explored. Based on XRD characterization, it was established that the NiO and CeO2 films were polycrystalline with a cubic structure. NiO spherical nanoparticles were well-distributed on the substrate surface, while some pin holes and overgrown clusters were observed in the CeO2 films according to the SEM results. The stability of the CeO2 films after five consecutive cycles confirms their reusability. The retrieval of films is easy because it does not require additional separation methods, unlike the catalyst in powder form. The obtained results indicate that the CeO2 films have potential application in pollutant removal from water through catalytic ozonation.

Lesión medular asociada a hematoma epidural espinal espontáneo / Spinal cord injury associated with spontaneous spinal epidural hematoma

Introducción: El hematoma epidural espinal espontáneo (HEEE) es una entidad de baja incidencia, de elevada morbimortalidad y que causa una importante limitación funcional en la vida de los pacientes. Material y métodos: Con el objetivo de determinar la incidencia del HEEE y el tipo de lesión medular provocada y su repercusión funcional en este centro hospitalario, se realizó un estudio descriptivo retrospectivo analizando variables demográficas, de la lesión (ISCNSCI) y de la funcionalidad (SCIMIII). Resultados: Se revisaron los casos de HEEE atendidos en este centro. El 75% eran varones, con una mediana de edad de 55años. Todas las lesiones fueron incompletas. La localización más frecuente de las lesiones fue a nivel cervical bajo y dorsal alto. La mitad de los sangrados se produjeron en la región medular anterior. Se objetivó mejoría funcional tras el programa específico de rehabilitación. Conclusión: El HEEE podría considerarse de buen pronóstico funcional, relacionado con lesiones medulares habitualmente posteriores e incompletas sensitivo-motoras que se beneficiarían de un tratamiento rehabilitador específico precoz.(AU)

Introduction: Spontaneous spinal epidural hematoma (SSEH) is a disease with low incidence and high morbidity/mortality. It can cause severe loss of function. Material and methods: In order to determine the incidence, type of spinal injury and functional impact, a descriptive and retrospective study was developed, analysing demographic data, functional scores (SCIMIII) and neurological scores (ISCNSCI). Results: Cases of SSEH were reviewed. Seventy-five percent were male, median age was 55years old. All of the spinal injuries were incomplete and were frequently in the lower cervical and thoracic regions. Fifty percent of bleedings occurred in the anterior spinal cord. Most showed with a progress after an intensive rehabilitation program. Conclusion: SSEH could be considered to have a good functional prognosis, related to usually posterior and incomplete sensory-motor spinal cord injuries that would benefit from early specific rehabilitative treatment.(AU)

Attitudes scale toward cancer-related cognitive changes - an initial Colombian validation.

OBJECTIVE: The aim of this study was to develop an initial valid tool to measure attitudes toward cancer-related cognitive changes. SUBJECTS AND METHODS: After revising the literature, three main dimensions were hypothesized. Eight judges were contacted to obtain content validity evidence. A robust Exploratory Factor Analysis (EFA) was performed via a parallel analysis with an Unweighted Least Squares (ULS) estimator and polychoric correlations. The results were crossed with sociodemographic variables to find possible statistical differences and estimate the size effect. Analysis was performed in the software Factor and the statistical package R. RESULTS: A sample of 374 participants was obtained, involving oncology patients, their caregivers, and people from the general community. A statistical fit was found in two dimensions: Awareness and Judgments [root mean squared error of approximation (RMSEA) = 0.042, standardized root mean square residual (SRMR) = 0.02, comparative fit index (CFI) = 0.99, Tucker-Lewis index (TLI) = 0.98] with a moderate correlation between them (r = 0.612). Optimal reliability indices were obtained for the total scale and its dimensions. No real statistical difference was found between sociodemographic variables; the interpretation norms were established via the quartiles. CONCLUSIONS: The first attempt to measure the construct of interest was developed with two primary validity evidence based on the content and its internal structure. This instrument could help strengthen the prevention of cancer-related cognitive changes. More research is needed to adhere more valid evidence to the scale.

New perspectives on morphological and genetic variability of Corynosoma bullosum [Linstow, 1892] parasitizing southern elephant seals from the Antarctic Peninsula.

Previous descriptions of Corynosoma bullosum (Linstow, 1892) show that specimens vary greatly in the proportions of different body structures, measurements of females and males, number of rows of hooks, and egg measurements, among other features. We redescribe this species from specimens found in southern elephant seal faeces from King George Island. We also provide a molecular characterization, in addition to 5.8S and internal transcribed spacer (ITS) existing sequences. We examined 41 elephant seals, and 30 adult acanthocephalans were found in 15 of them. The specimens were identified as belonging to the genus Corynosoma due to each having a tubular body with an inflated anterior part forming a thorny disk and the posterior part bearing somatic spines on the ventral surface, and genital spines surrounding the genital pore. Individual morphology corresponded to C. bullosum: large size, marked sexual dimorphism, and proboscis with 16-18 rows of spines with 11-15 spines per row. The molecular profile of three specimens of C. bullosum was analysed using 18S rDNA. We inferred phylogenetic relationships of the family Polymorphidae using maximum likelihood and Bayesian inference. We provide an updated morphological redescription for C. bullosum including electron microscopy photographs and molecular data. The 18S gene sequences showed low genetic variation and supported that C. bullosum is a sister to Corynosoma australe.

Evaluation of the susceptibility of Tritrichomonas foetus to extracts of Lantana camara (Verbenaceae) by flow cytometry.

Bovine Trichomonosis (BT), a sexually transmitted disease endemic in countries with extensive cattle farming and natural service, is one of the most common causes of reproductive failure. 5-nitroimidazoles and their derivatives are used for its treatment, mainly metronidazole. The emergence of drug resistance mechanisms and treatment failures raise the need to investigate the effectiveness of new active compounds that contribute to parasite control. In this regard, extracts of Lantana camara (Verbenacea) have shown high biocidal potential against isolates of Trypanosoma cruzi and Leishmania braziliensis in vitro assays, although their effect on Tritrichomonas foetus has not been demonstrated yet. The available information on in vitro susceptibility of trichomonicidal drugs comes from the use of a diversity of methodologies and criteria, especially the observation of parasite motility under the optical microscope to assess their viability. Recently, in our laboratory, the use of flow cytometry has been described for the first time as a rapid and efficient method to evaluate the viability of T. foetus against metronidazole. The present study aimed to evaluate the cytostatic effect of L. camara extracts against T. foetus isolates by flow cytometry. Under aerobic conditions, IC50 values of 22.60 µg/mL were obtained on average. Under anaerobic conditions, the IC50 oscilated around 29.04 µg/mL. The results obtained allowed describing the susceptibility exhibited by these protozoa, being a valuable information for the development of potential BT treatments.

Influence of genetic and interannual factors on the fatty acids profile of virgin olive oil.

Among olive oil nutritional benefits, it is worth mentioning its fatty acids composition with predominance of monounsaturated fatty acids (MUFAs). We have evaluated the influence of the cultivar and interannual factors on the fatty acids profile of virgin olive oil samples obtained from 45 and 71 cultivars along three and two consecutive crop seasons, respectively. The cultivars were classified in two groups according to the fatty acids composition: (1) high content in MUFAs and moderate content in saturated and polyunsaturated fatty acids (SFAs and PUFAs, respectively) and (2) moderate content in MUFAs and high content in SFAs/PUFAs. We also observed variations in the fatty acids content with the climate conditions, which can significantly alter the saturated and unsaturated profiles. Thus, a significant decrease in MUFAs and an increase in SFAs/PUFAs concentrations was found when the precipitation accumulated within the June-October period was reduced.

Neuromuscular electrical stimulation in garments optimized for compliance.

PURPOSE: Physical inactivity is associated with muscle atrophy and venous thromboembolism, which may be prevented by neuromuscular electrical stimulation (NMES). This study aimed to investigate the effect on discomfort, current amplitude and energy consumption when varying the frequency and phase duration of low-intensity NMES (LI-NMES) via a sock with knitting-integrated transverse textile electrodes (TTE). METHODS: On eleven healthy participants (four females), calf-NMES via a TTE sock was applied with increasing intensity (mA) until ankle-plantar flexion at which point outcomes were compared when testing frequencies 1, 3, 10 and 36 Hz and phase durations 75, 150, 200, 300 and 400 µs. Discomfort was assessed with a numerical rating scale (NRS, 0-10) and energy consumption was calculated and expressed in milli-Joule (mJ). Significance set to p ≤ 0.05. RESULTS: 1 Hz yielded a median (inter-quartile range) NRS of 2.4 (1.0-3.4), significantly lower than both 3 Hz with NRS 2.8 (1.8-4.2), and 10 Hz with NRS 3.4 (1.4-5.4) (both p ≤ .014). Each increase in tested frequency resulted in significantly higher energy consumption, e.g. 0.6 mJ (0.5-0.8) for 1 Hz vs 14.9 mJ (12.3-21.2) for 36 Hz (p = .003). Longer phase durations had no significant effect on discomfort despite generally requiring significantly lower current amplitudes. Phase durations 150, 200 and 400 µs required significantly lower energy consumption compared to 75 µs (all p ≤ .037). CONCLUSION: LI-NMES applied via a TTE sock produces a relevant plantar flexion of the ankle with the best comfort and lowest energy consumption using 1 Hz and phase durations 150, 200 or 400 µs.

Política de medicamentos de alto costo en un hospital público pediátrico: Análisis de utilización y costos / High-cost medication policy at a public pediatric hospital: utilization and cost analysis

Objetivos. Analizar el circuito de utilización de los medicamentos de alto costo (MAC) y los resultados clínicos obtenidos en un hospital de pediatría público de alta complejidad de Argentina y presentar una estrategia de selección replicable para otras instituciones de similares características de la región. Métodos: Estudio prospectivo, descriptivo, aleatorizado, conducido en el Hospital de Pediatría Juan P. Garrahan de la Ciudad Autónoma de Buenos Aires en el período entre el 1 de setiembre de 2018 y el 31 de marzo de 2019. Se evaluaron dos unidades de estudio, la unidad paciente y la unidad MAC. Resultados: Los MAC consumen 7.921.200 dólares estadounidenses (USD) anuales y representan el 41% del costo de los medicamentos del hospital de alta complejidad. El 50% del costo de los MAC estuvo representado por la gammaglobulina (medicamento utilizado en diferentes enfermedades). Los pacientes proceden de toda la Argentina y otros países y un 44% tiene cobertura de salud. Los diagnósticos para los que se prescribieron MAC con mayor frecuencia fueron los relacionados con patología oncológica (leucemia linfoide aguda, leucemia mieloblástica aguda). El 54% de los pacientes presentó mejoría atribuible directamente a la administración de los MAC, 39% no presentó cambios y el 7% empeoró. Conclusiones: La efectividad en los resultados clínicos y el análisis de los circuitos de aprobación indican que, además de la aprobación por las entidades nacional e internacionales, la evaluación responsable por parte de las instituciones efectoras, mediante la discusión interdisciplinaria basada en la mejor evidencia, contribuye a optimizar la utilización de los MAC y la seguridad de los pacientes (AU)

Objectives. To analyze the utilization circuit of high-cost medications (HCM) and the clinical results obtained in a tertiarycare public pediatric hospital in Argentina and to present a selection strategy that may be disseminated to other institutions of similar characteristics in the region. Methods: A prospective, descriptive, randomized study was conducted at Hospital de Pediatría Juan P. Garrahan in Buenos Aires between September 1, 2018 and March 31, 2019. Two study units were evaluated, the patient and the HCM. Results: HCMs account for 7,921,200 US dollars (USD) per year and represent 41% of the cost of drugs in this tertiary-care hospital. Gamma globulin (a drug used for different diseases) accounted for 50% of the cost of HCMs. Patients came from Argentina and other countries and 44% had a health insurance. Cancer (acute lymphoid leukemia, acute myeloblastic leukemia) was the diagnosis for which HCMs were most frequently prescribed. Fifty-four percent of patients showed improvement directly attributable to the administration of HCMs, 39% showed no change, and 7% worsened. Conclusions: The effectiveness in clinical outcomes and the analysis of approval circuits show that, in addition to approval by national and international entities, responsible evaluation by the effector institutions through interdisciplinary discussion based on the best evidence contributes to optimizing the use of HCMs and patient safety (AU)

[Spinal cord injury associated with spontaneous spinal epidural hematoma]. / Lesión medular asociada a hematoma epidural espinal espontáneo.

INTRODUCTION: Spontaneous spinal epidural hematoma (SSEH) is a disease with low incidence and high morbidity/mortality. It can cause severe loss of function. MATERIAL AND METHODS: In order to determine the incidence, type of spinal injury and functional impact, a descriptive and retrospective study was developed, analysing demographic data, functional scores (SCIMIII) and neurological scores (ISCNSCI). RESULTS: Cases of SSEH were reviewed. Seventy-five percent were male, median age was 55years old. All of the spinal injuries were incomplete and were frequently in the lower cervical and thoracic regions. Fifty percent of bleedings occurred in the anterior spinal cord. Most showed with a progress after an intensive rehabilitation program. CONCLUSION: SSEH could be considered to have a good functional prognosis, related to usually posterior and incomplete sensory-motor spinal cord injuries that would benefit from early specific rehabilitative treatment.

Ixodicidal effect of extracts from Cordia boissieri, Artemisia ludoviciana and Litchi chinensis on Rhipicephalus (Boophilus) microplus (Acari: Ixodidae).

The ixodicidal activity of the methanolic extracts of Artemisia ludoviciana (Astereceae), Cordia boissieri (Boraginaceae) and Litchi chinensis (Sapindaceae) against two field populations of Rhipicephalus (Boophilus) microplus from the state of Nuevo Leon (NL) and Veracruz (VER) was evaluated. The extract of L. chinensis in the concentration of 150 mg/ml showed efficacies of 100% and 99% against engorged females and mortalities of 98% and 99% against larvae. C. boissieri in the same concentration showed efficacies of 71% and 37% against engorged adults and mortalities of 33.04% and 10.33% against larvae and A. ludoviciana had efficacies of 94% and 83% in adults and mortalities of 89.39% and 89.21% against larvae in both populations respectively. The enzymatic activity of Acetylcholinesterase (AChE), Carboxylesterase (CaE), Glutathione-S-Transferase (GST) and Alkaline Phosphatase (ALP) was measured in both populations of ticks. As a result, a significant difference between both populations was shown, being the VER population the one that exhibited a higher enzymatic activity (p ≤ 0.05). It can be concluded that the methanolic extract of the seed of L. chinensis shows potential ixodicidal activity and can be used as an alternative source of tick control, however, prior characterization, toxicity and formulation studies are necessary.

[Surgical margins as prognostic factor in pelvis chondrosarcoma. Cohort study in a sarcoma unit]. / Márgenes quirúrgicos como factor pronóstico del condrosarcoma de pelvis. Estudio de cohorte en una unidad de sarcomas.

INTRODUCTION: chondrosarcoma is the second most common primary malignant tumor, constitutes approximately one quarter of all primary bone sarcomas. Surgical margins in pelvic chondrosarcoma have a direct impact as a prognostic factor, both on overall survival and on recurrence-free survival of this disease. OBJECTIVES: to analyze the impact of surgical margins as a prognostic factor in pelvic chondrosarcoma. MATERIAL AND METHODS: a retrospective database cohort with prospective follow-up of sarcomas in patients diagnosed with primary pelvic chondrosarcoma who underwent surgical treatment. Clinical-demographic variables were obtained, a descriptive analysis of each variable was performed, and these were contrasted with the outcome variables. RESULTS: seventeen patients were included, of which nine were female. The median age was 41 years, ranging from 23 to 65 years. The average tumor size was 20.9 cm (range 5 to 46 cm). The average surgical margin was 5.3 mm, ranging from 1 to 30 mm, with 58% positive margins. The average overall survival was 64 months (range 7 to 108 months). The distribution of pelvic involvement was as follows: zone I in nine patients (52.9%), zone II in two (11.8%), a combination of zones I-III in two (11.8%), I+II in one (5.9%), II+III in one (5.9%), I-III plus sacrum in one (5.9%) and I plus sacrum in one (5.9%). Tumor grades were classified as low in seven patients (41.2%), intermediate in sven (41.2%), high in two (11.8%), and dedifferentiated in one (5.9%). Regarding the type of resection, 12 patients (70.6%) underwent internal hemipelvectomy and five (29.4%) external hemipelvectomy. Recurrence was recorded in five cases (29.4%), metastasis in three (17.6%), and mortality in four (23.5%). CONCLUSIONS: this series represents the largest cohort reported in Latin America of primary pelvic chondrosarcomas. A more favorable prognosis was observed in patients with surgical margins greater than 1 mm. The presence of chondrosarcoma in multiple pelvic zones was associated with a worse oncological prognosis. Additionally, a higher incidence of positive surgical margins and local recurrence rates were identified in pelvic chondrosarcomas compared to those located in the extremities.

INTRODUCCIÓN: el condrosarcoma (CS), el segundo tumor maligno óseo primario más común, constituye aproximadamente una cuarta parte de todos los sarcomas óseos primarios. Los márgenes quirúrgicos en el condrosarcoma pélvico tienen un impacto directo como factor pronóstico, tanto en la supervivencia global como en la supervivencia libre de recurrencia de esta enfermedad. OBJETIVOS: analizar el impacto de los márgenes quirúrgicos como factor pronóstico en el condrosarcoma de la pelvis. MATERIAL Y MÉTODOS: cohorte de base de datos retrospectiva con seguimiento prospectivo de sarcomas de pacientes con diagnóstico de condrosarcoma primario de la pelvis que fueron sometidos a tratamiento quirúrgico. Se obtuvieron variables clínico-demográficas, se realizó un análisis descriptivo de cada variable y se contrastaron con las variables desenlace. RESULTADOS: se incluyeron 17 pacientes, de los cuales nueve eran mujeres. La mediana de edad fue de 41 años (rango de 23 a 65 años). El tamaño promedio del tumor fue de 20.9 cm (rango de 5 a 46 cm). El margen quirúrgico promedio fue de 5.3 mm, variando entre 1 y 30 mm, con 58% de márgenes positivos. La supervivencia global promedio fue de 64 meses (rango de 7 a 108 meses). La distribución de la afectación pélvica fue: zona I en nueve pacientes (52.9%), zona II en dos (11.8%), combinación de zonas I-III en dos (11.8%), I+II en uno (5.9%), II+III en uno (5.9%), I-III más sacro en uno (5.9%) y I más sacro en uno (5.9%). Los grados tumorales se clasificaron en bajo en siete pacientes (41.2%), intermedio en siete (41.2%), alto en dos (11.8%) y desdiferenciado en uno (5.9%). Respecto al tipo de resección, 12 pacientes (70.6%) se sometieron a hemipelvectomía interna y cinco (29.4%) a hemipelvectomía externa. Se registró recurrencia en cinco casos (29.4%), metástasis en tres (17.6%) y mortalidad en cuatro (23.5%). CONCLUSIONES: esta serie representa la cohorte más extensa reportada en Latinoamérica de condrosarcomas primarios de la pelvis. Se observó un pronóstico más favorable en pacientes con márgenes quirúrgicos superiores a 1 mm. La presencia de condrosarcoma en múltiples zonas pélvicas se asoció con un peor pronóstico oncológico. Además, se identificó una mayor incidencia de márgenes quirúrgicos positivos y tasas de recurrencia local en condrosarcomas de la pelvis en comparación con aquellos ubicados en las extremidades.

Gadolinium-enhanced brain lesions in multiple sclerosis relapse.

OBJECTIVE: To study the clinico-radiological paradox in multiple sclerosis (MS) relapse by analyzing the number and location of gadolinium-enhanced (Gd+) lesions on brain MRI before methylprednisolone (MP) treatment. METHODS: We analyzed brain MRI from 90 relapsed MS patients in two Phase IV multicenter double-blind randomized clinical trials that showed the noninferiority of different routes and doses of MP administration. A 1.5- or 3-T brain MRI was performed at baseline before MP treatment and within 15 days of symptom onset. The number and location of Gd+ lesions were analyzed. Associations were studied using univariate analysis. RESULTS: Sixty-two percent of patients had at least 1 Gd+ brain lesion; the median number was 1 (interquartile range 0-4), and 41% of patients had 2 or more lesions. The most frequent location of Gd+ lesions was subcortical (41.4%). Gd+ brain lesions were found in 71.4% of patients with brainstem-cerebellum symptoms, 57.1% with spinal cord symptoms and 55.5% with optic neuritis (ON). Thirty percent of patients with brain symptoms did not have Gd+ lesions, and only 43.6% of patients had symptomatic Gd+ lesions. The univariate analysis showed a negative correlation between age and the number of Gd+ lesions (p=0.002). CONCLUSION: Most patients with relapse showed several Gd+ lesions on brain MRI, even when the clinical manifestation was outside of the brain. Our findings illustrate the clinico-radiological paradox in MS relapse and support the value of brain MRI in this scenario.

Hepatitis C Virus positivity prediction from serum samples using NIRS and L1-penalized classification.

AIMS: The hepatitis C virus (HCV) has developed a strategy to coexist with its host resulting in varying degrees of tissue and cell damage, which generate different pathological phenotypes, such as varying degrees of fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). However, there is no integrated information that can predict the evolutionary course of the infection. We propose to combine Near-infrared spectroscopy (NIRS) and machine learning techniques to provide a predictive model. In this work, we propose to discriminate HCV positivity in biobank patient serum samples. METHODS: 126 serum samples from 38 HCV patients in different stages of the disease were obtained from the Biobank of Hospital Universitario Fundación Alcorcon. NIRS spectrum was captured by a FT-NIRS Spectrum 100 (Perkin Elmer) device in reflectance mode. For each patient, the HCV positivity was identified (PCR) and labeled as detectable =1 and undetectable =0. We propose an L1-penalized logistic regression model to classify each spectrum as positive (1) or negative (0) for HCV presence (x). The regularization parameter is selected using 5- fold cross-validation. The penalized model will induce sparsity in the solution so that only a few relevant wavelengths will be different from zero. RESULTS: L1-penalized logistic regression model provided 167 wavelengths different from zero. The accuracy on an independent test set was 0.78. CONCLUSIONS: We present a straightforward promising approach to detect HCV positivity from patient serum samples combining NIRS and machine learning techniques. This result is encouraging to predict HCV progression, among other applications. Clinical relevance- We presented a simple while promising approach to use machine learning and NIRS to analyze viral presence on sample serums.