Regional disparity of HIV incidence and prevalence among men who have sex with men.

BACKGROUND: HIV incidence can be estimated with cross-sectional studies using clinical, serological, and molecular data. Worldwide, HIV incidence data in only men who have sex with men (MSM) are scarce and principally focus on those with healthcare or under treatment. However, better estimates can be obtained through studies with national representativeness. The objective was to estimate the prevalence, incidence, and factors associated with acquiring HIV in a national sample of MSM who attend meeting places, considering geographical regions. METHODS: A nationally representative survey of MSM attending meeting places was performed in Mexico. Participants answered a questionnaire, and a dried blood spot (DBS) was collected. Samples were classified as recent infections using an algorithm with HIV status, antiretroviral therapy, and the result of BED-EIA assay. Parameters were analysed considering regions and demographic and sexual behaviour characteristics. RESULTS: The national HIV prevalence was 17.4% with regional differences; the highest prevalence (20.7%) was found in Mexico City, and the lowest prevalence was found in the West region (11.5%). The incidence was 9.4 per 100 p/y, with regional values from 6.2 to 13.2 for the Northeast and the Centre regions, respectively. Age, age at sexual debut, low wealth index, and rewarded sex were associated with HIV prevalence. Centre region, use of private clinics as health services, and having sex exclusively with men were associated with recent HIV infections. CONCLUSIONS: The incidence and prevalence showed regional differences, suggesting a difference in the dynamics of HIV transmission; some regions have a greater case accumulation, and others have a greater rate of new infections. Understanding this dynamic will allow developing health programs focused on HIV prevention or treating people already living with HIV.

Challenges and recommendations for magnetic hyperthermia characterization measurements.

PURPOSE: The localized heating of magnetic nanoparticles (MNPs) via the application of time-varying magnetic fields - a process known as magnetic field hyperthermia (MFH) - can greatly enhance existing options for cancer treatment; but for broad clinical uptake its optimization, reproducibility and safety must be comprehensively proven. As part of this effort, the quantification of MNP heating - characterized by the specific loss power (SLP), measured in W/g, or by the intrinsic loss power (ILP), in Hm2/kg - is frequently reported. However, in SLP/ILP measurements to date, the apparatus, the analysis techniques and the field conditions used by different researchers have varied greatly, leading to questions as to the reproducibility of the measurements. MATERIALS AND METHODS: An interlaboratory study (across N = 21 European sites) of calorimetry measurements that constitutes a snapshot of the current state-of-the-art within the MFH community has been undertaken. Identical samples of two stable nanoparticle systems were distributed to all participating laboratories. Raw measurement data as well as the results of in-house analysis techniques were collected along with details of the measurement apparatus used. Raw measurement data was further reanalyzed by universal application of the corrected-slope method to examine relative influences of apparatus and results processing. RESULTS: The data show that although there is very good intralaboratory repeatability, the overall interlaboratory measurement accuracy is poor, with the consolidated ILP data having standard deviations on the mean of ca. ± 30% to ± 40%. There is a strong systematic component to the uncertainties, and a clear rank correlation between the measuring laboratory and the ILP. Both of these are indications of a current lack of normalization in this field. A number of possible sources of systematic uncertainties are identified, and means determined to alleviate or minimize them. However, no single dominant factor was identified, and significant work remains to ascertain and remove the remaining uncertainty sources. CONCLUSION: We conclude that the study reveals a current lack of harmonization in MFH characterization of MNPs, and highlights the growing need for standardized, quantitative characterization techniques for this emerging medical technology.

Pre-exposure prophylaxis and its implications in Mexico: notions of men who have sex with men.

Background The aim of this study was to analyse ideas regarding pre-exposure prophylaxis (PrEP) for the prevention of HIV among groups of men who have sex with men in Mexico for future implementation in health services. METHODS: During 2015, 54 people participated in four focus groups in three Mexican cities. Issues related to challenges for uses and limitations of PrEP were explored. RESULTS: In contrast with other qualitative studies, which emphasised problems with relationships with other people for PrEP use or access to key populations, Mexican participants focused their concerns around the public health services organisation: PrEP is too expensive and the health services have no resources, which will affect services and result in discrimination. Participants identified possible stigmatisation related to prejudices of medical providers who do not approve the decreased use of condoms. As a potential solution, participants suggested that the Mexican Government could negotiate a lower cost for PrEP and public health services could provide the medication, with periodical review of the arrangements by civil organisations. CONCLUSION: In the current context of the new Mexican government, it is necessary to propose public politics focused on negotiating with pharmaceutical companies on the costs of the PrEP, coordinating public services with groups within civil society and strengthening policies and actions to reduce stigma and discrimination.

Referral Criteria for Asthma: Consensus Document.

Asthma is one of the most prevalent chronic diseases in Spain. Current treatments ensure that the disease is controlled in most cases. However, disease is often uncontrolled in daily clinical practice, mainly owing to underdiagnosis, loss to follow-up, and poor adherence to therapy. In order to improve this situation, we must coordinate all those health professionals who intervene in patient care. Therefore, the Spanish Society of Allergology and Clinical Immunology (SEAIC), the Spanish Society of Primary Care Physicians (SEMERGEN), the Spanish Society of Family and Community Medicine (semFYC), the Spanish Society of General and Family Physicians (SEMG), and the Spanish Society of Pneumology and Thoracic Surgery (SEPAR) have drawn up a consensus document in which they establish criteria for referral and guidelines for the diagnosis, control, and follow-up of patients with asthma. The document aims to facilitate continuing and improved care in this area.

[Prevalence and risk factors for methicillin-resistant Staphylococcus aureus infection in children]. / Prevalencia y factores de riesgo de infección por Staphylococcus aureus resistente a meticilina en niños.

OBJECTIVE: The objectives of this work were to know the prevalence of methicillin-resistant S. aureus (MRSA) infections in the paediatric population of our health department, to describe the risk factors for infection by MRSA compared to those produced by methicillin-susceptible S. aureus (MSSA) and to know the antibiotic sensitivity profile of MRSA and MSSA isolates. METHODS: A retrospective, descriptive and analytical study of infections produced by MRSA versus those produced by MSSA was carried out during the years 2014 to 2018. Risk factors for MRSA infection were studied using a binary logistic regression model. RESULTS: 162 patients with S. aureus infections were identified. Of these, 25 (15.4%) were MRSA. The highest percentages of MRSA infection occurred among children who required hospital admission (23.4%). In the univariate analysis the need of hospital admission, antibiotic treatment in the last 3 months, the kind of infection and past MRSA infection or colonisation reached statistical significance. However, only the need of hospital admission and antibiotic treatment in the last 3 months maintained statistical significance in the binary logistic regression model. Correct antibiotic treatment was only prescribed in 26.7% of the MRSA infection cases admitted to the hospital. CONCLUSIONS: Our results suggest the need to review empirical local treatment regimen using drugs active against MRSA in infections of probable staphylococcal origin admitted to the hospital, especially if they have received antibiotic treatment in the last 3 months.

Neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio on postoperative day three as a biochemical predictor of clinically significant pancreatic fistula in patients undergoing distal pancreatectomy.

INTRODUCTION AND AIMS: Distal pancreatectomy is a frequent procedure and postoperative fistula, its most common complication, has an incidence of 30 to 60%. The aim of the present work was to study the role of the neutrophil-to-lymphocyte ratio and the platelet-to-lymphocyte ratio, as indicators of inflammatory response in the setting of pancreatic fistula. METHODS: A retrospective observational study was conducted on patients that underwent distal pancreatectomy. The diagnosis of postoperative pancreatic fistula was made according to the definition proposed by the International Study Group on Pancreatic Fistula. The relation of postoperative pancreatic fistula to the neutrophil-to-lymphocyte ratio and the platelet-to-lymphocyte ratio was determined in the postoperative evaluation. SPSS v.21 software was utilized for the statistical analysis and a P<.05 was considered statistically significant. RESULTS: A total of 12 patients (27.2%) developed grade B or grade C postoperative pancreatic fistula. ROC curves were constructed and a threshold of 8.3 (PPV 0.40, NPV 0.86) was established for the neutrophil-to-lymphocyte ratio, with an area under the curve of 0.71, sensitivity of 0.81, and specificity of 0.62, whereas a threshold of 33.2 (PPV 0.50, NPV 0.84) was established for the platelet-to-lymphocyte ratio, with an area under the curve of 0.72, sensitivity of 0.72, and specificity of 0.71. CONCLUSION: The neutrophil-to-lymphocyte ratio and the platelet-to-lymphocyte ratio are serologic markers that can aid in identifying patients that will present with grade B or grade C postoperative pancreatic fistula, thus helping to provide an opportune focus on care and resources.

[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.

[Delayed diagnosis of osteosarcoma in adults: a prognostic factor to be considered]. / Retraso en el diagnóstico de osteosarcoma en adultos: un factor pronóstico que debemos considerar.

INTRODUCTION: different variables have been associated with a worse prognosis of patients with osteosarcoma (OS), highlighting tumor size, location in the axial skeleton and the presence of metastases. The objective of this study is to analyze the prognostic impact of diagnostic delay in osteosarcoma in adults in the Mexican population in a center specialized in sarcomas. MATERIAL AND METHODS: retrospective cohort study from January 1, 2005, to December 31, 2016, 96 patients over 21 years of age with a diagnosis of osteosarcoma were analyzed. RESULTS: the median time to diagnosis from the onset of symptoms was six months (range: 2-36). This variable was dichotomized by applying the operator-dependent curve (ROC) analysis and we determined a cut-off value greater than five months, with an area under the curve (AUC) = 0.93 [95% CI 0.86-0.97], sensitivity 93.2% and specificity 94.6%. CONCLUSION: time until diagnosis is a critical factor in the survival of adult patients with osteosarcoma, highlighting its influence on disease progression and the appearance of metastasis. The correlation between diagnostic delay and an unfavorable prognosis reinforces the need for rapid and efficient evaluation in suspected cases of osteosarcoma.

INTRODUCCIÓN: diferentes variables se han asociado con un peor pronóstico de los pacientes con osteosarcoma, destacando el tamaño tumoral, la localización en esqueleto axial y la presencia de metástasis. El objetivo de este estudio fue analizar el impacto pronóstico del retraso diagnóstico en osteosarcoma en adultos en población mexicana en un centro especializado en sarcomas. MATERIAL Y MÉTODOS: estudio de tipo cohorte retrospectiva del 1 de Enero del 2005 al 31 de Diciembre de 2016, se analizaron 96 pacientes mayores de 21 años con diagnóstico de osteosarcoma. RESULTADOS: la mediana de tiempo al diagnóstico desde el inicio de síntomas fue de seis meses (rango: 2-36). Esta variable se dicotomizó aplicando el análisis de curva dependiente de operador (ROC) y determinamos un valor de corte mayor a cinco meses con un área bajo la curva (AUC) = 0.93 [IC95% 0.86-0.97], sensibilidad 93.2% y especificidad 94.6%. CONCLUSIÓN: el tiempo hasta el diagnóstico es un factor crítico en la supervivencia de los pacientes adultos con osteosarcoma, destacando su influencia en la progresión de la enfermedad y la aparición de metástasis. La correlación entre el retraso diagnóstico y un pronóstico desfavorable refuerza la necesidad de una evaluación rápida y eficiente en casos sospechosos de osteosarcoma.

Positive impact of Distintivo Soludable on implementation of sun protection policies and practices in schools of Andalusia, Spain.

The incidence of skin cancer is increasing worldwide even though its main risk factor is preventable. This study evaluated the impact of the Distintivo Soludable pilot intervention on implementation of photoprotection policies and practices in preschool and primary schools in Andalusia, Spain. We completed two rounds of a Sun Protection Policies and Practices Survey (SPPPS) nine months apart. At baseline, 67 Andalusian schools earned a median score of 3/12 points (range 0-8; IQR: 2). Ten schools involved in Distintivo Soludable intervention group significantly increased their scores from 4 to 7.5/12 points (p = 0.014). We also detected a modest positive effect in 57 control group schools, an increase from 2 to 3 points (p = 0.002). This pilot study demonstrated that the main achievement of the Distintivo Soludable intervention was implementation of organizational policies regarding sun protection, an essential starting point for establishing positive attitudes toward sun protection in school communities.

Thermal relaxation and collective dynamics of interacting aerosol-generated hexagonal NiFe2O4 nanoparticles.

This article reports on the magnetic properties of interacting uncoated nickel ferrite (NiFe2O4) nanoparticles synthesized through an aerosol levitation-jet technique. A comprehensive set of samples with different compositions of background gas and metal precursors, as well as applied electric field intensities, has been studied. Nanoparticles prepared under a field of 210 kV m(-1) show moderately high-field irreversibility and shifted hysteresis loops after field-cooling, also exhibiting a joint temperature decrease of the exchange field and coercivity. The appearance of memory effects has been checked using the genuine ZFC protocol and the observed behavior cannot be fully explained in terms of thermal relaxation. Although dipolar interactions prevail, exchange interactions occur to a certain extent within a narrow range of applied fields. The origin of the slow dynamics in the system is found to be given by the interplay of the distribution of energy barriers due to size dispersion and the cooperative dynamics associated with frustrated interactions.

Bleeding control in endoscopic sinus surgery: a systematic review of the literature.

In the literature various methods are described to reduce bleeding in endoscopic sinus surgery. Scientific evidence and results were gathered and analysed to determine the effectiveness of the various methods used. A total of 20 articles fulfilled the inclusion criteria. Two retrospective articles studied the differences between local and general anaesthesia. Three articles analysed the use of local methods to control bleeding. The majority of the articles analysed the use of different systemic drugs to control intraoperative bleeding. Certain procedures, such as the reverse Trendelenburg position, the use of high doses of epinephrine, the infiltration of phenylephrine and lidocaine into the pterygopalatine fossa, the preoperative use of prednisone, and the control of the heart rate (with dexmedetomidine or remifentanil), appear to reduce the intraoperative blood loss and/or improve the visualisation of the surgical field. However, the evidence supporting these conclusions is poor. The benefits of other procedures, such as the preoperative use of ß-blockers, antihypertensive agents, and surgical pledgets with oxymetazoline, phenylephrine, or cocaine, for bleeding control are not evidenced in the literature. In addition, the literature does not present any evidence on the benefits of local anaesthesia compared with general anaesthesia or the use of propofol compared to inhaled analgesics in terms of intraoperative bleeding or complication rates.

A new class of protein sensor links spirochete pleomorphism, persistence, and chemotaxis.

IMPORTANCE: A new class of bacterial protein sensors monitors intracellular levels of S-adenosylmethionine to modulate cell morphology, chemotaxis, and biofilm formation. Simultaneous regulation of these behaviors enables bacterial pathogens to survive within their niche. This sensor, exemplified by Treponema denticola CheWS, is anchored to the chemotaxis array and its sensor domain is located below the chemotaxis rings. This position may allow the sensor to directly interact with the chemotaxis histidine kinase CheA. Collectively, these data establish a critical role of CheWS in pathogenesis and further illustrate the impact of studying non-canonical chemotaxis proteins.

[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.

[Methicillin-resistant Staphylococcus epidermidis infectious keratitis: Clinical and microbiological profile].

OBJECTIVE: Staphylococcus epidermidis (SE) is a common cause of bacterial keratitis in certain geographic areas. A high percentage of resistance to methicillin is shown, which gives it cross resistance to beta-lactams and sometimes resistance to other antibacterial groups. We analyzed clinical and microbiological variables in patients with infectious keratitis due to SE. METHODS: Medical records of 43 patients with suspected infectious keratitis and microbiological confirmation for SE, between October 2017 and October 2020, were retrospectively studied. Clinical characteristics (risk factors, size of lesions, treatment, evolution) and microbiological (susceptibility to antibiotics) were analyzed, and groups of patients with methicillin-resistant (MRSE) and methicillin-susceptible (MSSE) infection were compared. RESULTS: MRSE was present in 37.2% of infectious keratitis. All isolates were sensitive to vancomycin and linezolid. Rates of resistance to tetracyclines and ciprofloxacin were 50% and 56% in the MRSE group, and 11% and 7% in the MSSE group. The clinical characteristics, including size of lesion, visual axis involvement, inflammation of anterior chamber, presence of risk factors and follow-up time, did not show statistically significant differences between groups. CONCLUSIONS: MRSE is a common cause of infectious keratitis caused by SE and shows a high rate of multidrug resistance. Clinically, it does not differ from MSSE keratitis. Additional work is needed to confirm these findings.

SELNET clinical practice guidelines for bone sarcoma.

Bone sarcoma are infrequent diseases, representing < 0.2% of all adult neoplasms. A multidisciplinary management within reference centers for sarcoma, with discussion of the diagnostic and therapeutic strategies within an expert multidisciplinary tumour board, is essential for these patients, given its heterogeneity and low frequency. This approach leads to an improvement in patient's outcome, as demonstrated in several studies. The Sarcoma European Latin-American Network (SELNET), aims to improve clinical outcome in sarcoma care, with a special focus in Latin-American countries. These Clinical Practice Guidelines (CPG) have been developed and agreed by a multidisciplinary expert group (including medical and radiation oncologist, surgical oncologist, orthopaedic surgeons, radiologist, pathologist, molecular biologist and representatives of patients advocacy groups) of the SELNET consortium, and are conceived to provide the standard approach to diagnosis, treatment and follow-up of bone sarcoma patients in the Latin-American context.

Comparison of four recombinant hepatitis B vaccines applied on an accelerated schedule in healthy adults.

A post-marketing, double blind, randomised, controlled clinical trial to assess the immunogenicity and safety profiles of four commercially available recombinant hepatitis B vaccines was performed. The vaccines included in this study were Heberbiovac-HB (®) (Heber Biotec S.A., Havana, Cuba), Euvax-B (®) (LG Chemical Ltd., Seoul, Korea), Hepavax-Gene (®)   (Greencross Vaccine Corp., Seoul, Korea), and Engerix-B (®) (GlaxoSmithKline Biologicals, Rixensart, Belgium). Vaccines were administered intramuscularly to healthy adults in three 20mg doses at monthly intervals (0 - 1 -  2 months). Four hundred volunteers aged 18 to 45 years (average age, 35 years) non-reactive for serological markers of hepatitis B virus infection were vaccinated. Volunteers were randomly assigned (ratio 1:1:1:1) to one of the four treatment groups. The antibody response (anti-HBs) was assessed at days 60, 90 and 365 post-vaccination using a commercial kit. The four vaccines showed to be safe and highly immunogenic. Similar seroprotection rates (anti-HBs ≥10 IU/L) about one month after application of the second and third dose were obtained for Engerix-B (®) , Hepavax-Gene (®) , Euvax-B (®) , and Heberbiovac-HB (®) vaccines 96.7%, 96.6%, 100%, 100% and 98.8%, 89.5%, 100%, 100%, respectively.. Heberbiovac-HB (®) vaccine achieved significantly higher geometric mean antibody titers (GMT) and rate of good and  hyper-responders at all time-points post-vaccination. The GMT on day 365 after full vaccination was significantly reduced in all groups compared to day 90, although Heberbiovac-HB (®) showed the highest anti-HBs GMT and good-responders rate. The four vaccines were well tolerated and poorly reactogenic. No serious adverse events were observed. This study confirms an overall good immune response and rapid priming for the  four vaccines in the course of an accelerated schedule, with higher anti-HBs geometric mean concentrations and better responses for Heberbiovac-HB (®) . [WHO primary Registry Number: RPCEC00000075].

Introduction to Nanomaterials Applied to Life Sciences.

A. Espinosa, F. J. Teran and D. Ortega introduce the Nanoscale Advances themed collection on Nanomaterials Applied to Life Sciences.

[Strategy for planning and execution of a large-scale SARS-CoV-2 seroprevalence study on teaching hospital workers during a pandemic situation]. / Estrategia de planificación y ejecución de un estudio a gran escala de seroprevalencia de SARS-CoV-2 en trabajadores de un hospital universitario durante una situación de pandemia.

OBJECTIVE: To describe the planning and execution process of a massive seroprevalence study for SARS-CoV-2 in professionals of the Hospital Universitario Fundación Alcorcón (HUFA) (Spain). METHODS: A description is presented of the plan designed and developed at the HUFA for the execution of the extraction of the samples for serology from all the professionals who worked in the hospital between 14 and 29 April 2020. A descriptive analysis of the participation of the professionals in the study is carried out. Extraction areas, health personnel, and execution times were planned. A total of 2326 extractions were assigned to health personnel, the remaining extractions were assigned to workers from external companies. RESULTS: A total of 2641 workers (90.5%) out of 2918 candidates participated in the study. The professional category most analysed was nursing with 28.3% (n = 590). The percentage of compliance with schedule planning was 28.6%. Up to a maximum of 298 daily extractions were planned. The busiest day was the 4th day of the study with 399 extractions. CONCLUSIONS: The organising of such a large study, with a 100% coverage of those who worked in the hospital, and with such a great response from the workers involved, has led to obtaining results of high reliability in the seroprevalence study carried out. Although the percentage of participation was very high, the level of compliance with the planning was low.

[Current status of chondrosarcoma in a reference center]. / Estado actual del condrosarcoma en un centro de referencia.

INTRODUCTION: Chondrosarcoma is the second most frequent primary malignant bone tumor, is characterized by the formation of a chondroid matrix, is more frequent in advanced ages and its prognosis is directly related to the histological subtype and tumor grade. The objective of this article is to present the demographic and treatment profile in a reference center. MATERIAL AND METHODS: A retrospective, descriptive, observational, analytical cohort-type study was conducted in a reference center between January 1, 2005 and December 31, 2019, the demographic variables were analyzed and contrasted with the outcome variables that were overall survival and disease-free period. RESULTS: 85 patients were included, the mean age of presentation was 43.3 years, the clinical stage at the time of presentation was mostly IIa and IIb covering 54.1%. 35 patients had metastases with clinical stage IV. The main site of metastasis was the lung in 32 patients (37.6%). Thirty-six patients (42.3%) had specific mortality. 35 patients (41.2%) died as a result of metastatic disease to lung or other organs, one patient died from direct extension of the tumor in the cervical spine. CONCLUSION: The important prognostic factors found in our series that influence global survival are: the presence of metastases and axial localization.

INTRODUCCIÓN: El condrosarcoma es el segundo tumor óseo maligno primario más frecuente, se caracteriza por la formación de matriz condroide, es más común en edades avanzadas y su pronóstico guarda relación directa con el subtipo histológico y el grado tumoral. El objetivo de este artículo es presentar el perfil demográfico y de tratamiento en un centro de referencia. MATERIAL Y MÉTODOS: Se realizó un estudio retrospectivo, descriptivo, observacional, analítico de tipo cohorte en un centro de referencia entre el 01 de Enero de 2005 y el 31 de Diciembre de 2019, se analizaron las variables demográficas y se contrastaron con las variables de desenlace que fueron supervivencia global y período libre de enfermedad. RESULTADOS: Se incluyeron 85 pacientes, la media edad de presentación fue 43.3 años, la etapa clínica al momento de la presentación fue mayormente IIa y IIb abarcando 54.1%, 35 pacientes tuvieron metástasis con etapa clínica IV. El principal sitio de metástasis fue el pulmón en 32 pacientes (37.6%). De los pacientes, 36 (42.3%) presentaron mortalidad cáncer específica, 35 (41.2%) fallecieron como consecuencia de la enfermedad metastásica a pulmón u otros órganos y un paciente falleció por extensión directa del tumor en columna cervical. CONCLUSIÓN: Los factores pronósticos importantes hallados en nuestra serie que influyen en la supervivencia global son: la presencia de metástasis y la localización axial.