An in silico study on the influence of extracellular matrix mechanics on vasculogenesis.

BACKGROUND AND OBJECTIVES: Blood vessels form a network of capillaries throughout the body that perform essential functions for life. Vasculogenesis, i.e. the formation of new blood vessels, is regulated by many factors, biochemical ones being among the most important. However, others such as the biomechanical influence on shape, organization and structure of vessel networks require further investigation. In this paper, we develop a 3D agent-based mechanobiological model of vasculogenesis with the aim of analyzing how the mechanics of the extracellular matrix (ECM) affects vasculogenesis. METHODS: For this purpose, we consider a growing domain composed of different cells: tip cells, which are the driving cells located at the end of the vessels and stalk cells, which are found in the interior of the vascular network. ECM is considered as particles (agents) that surround the growth of the vascular network. Depending on the cell type, different sets of forces are considered, such as chemotactic, mechanical, random and viscoelastic forces among others. RESULTS: The growth of the network is iteratively analyzed and updated at each time step based on a mechanically-driven proliferation rule. The influence of different biomechanical factors, such as ECM stiffness or viscoelasticity are explored through in silico simulations. A number of indicators are defined along the algorithm, like number of cells, branches, tortuosity and anisotropy, in order to compare topological differences of the vascular network during vasculogenesis under different ECM conditions. The obtained results are qualitatively compared with other related works in the literature. CONCLUSIONS: The present study sheds some light and partially explain, from an in silico perspective, the role of ECM mechanics on vasculogenesis. The main conclusions of this work are: (i) increased stiffness increases proliferation, (ii) the network tends to migrate towards stiffer areas, and (iii) increased viscoelasticity decreases proliferation.

New evidence in severe pneumonia: imipenem/ cilastatin/relebactam.

Imipenem combined with beta-lactamase inhibitor relebactam (IMI/REL) has an extensive bactericidal activity against Gram-negative pathogens producing class A or class C beta-lactamases, not active against class B and class D. The phase 3 clinical trial (RESTORE-IMI-2), double-blind, randomized, evaluated IMI/REL vs. piperacillin-tazobactam (PIP/TAZ) for treatment of hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), demonstrated non-inferiority at all-cause mortality at 28 days (15.9% vs 21.3%), favorable clinical response at 7-14 days end of treatment (61% vs 59.8%) and with minor serious adverse effects (26.7% vs 32%). IMI/REL is a therapeutic option in HAP and VAP at approved dosage imipenem 500 mg, cilastatin 500 mg and relebactam 250 mg once every 6h, by an IV infusion over 30 min.

DYNLT1 gene expression is downregulated in whole blood of patients at different Huntington's disease stages.

Huntington's disease (HD) is a neurodegenerative disorder caused by a CAG nucleotide expansion, which encodes the amino acid glutamine, in the huntingtin gene. HD is characterized by motor, cognitive, and psychiatric dysfunctions. In a previous study, we showed by qPCR that some genes altered in an HD mouse model were also altered in blood of HD patients. These alterations were mainly with respect to the dynein family. Therefore, this study aimed to investigate whether dynein light chain Tctex type 1 (DYNLT1) is altered in HD patients and if there is a correlation between DYNLT1 gene expression changes and disease progression. We assessed the DYNLT1 gene expression in the blood of 19 HD patients and 20 healthy age-matched controls. Also, in 6 of these patients, we analyzed the DYNLT1 expression at two time points, 3 years apart. The DYNLT1 gene expression in the whole blood of HD patients was significantly downregulated and this difference was widened in later stages. These data suggest that DYNLT1 could emerge as a peripheral prognostic indicator in HD and, also, might be a target for potential intervention in the future.

Usefulness of a national hip fracture registry to evaluate the profile of patients in whom antiosteoporotic treatment is prescribed following hospital discharge.

This study was carried out to describe the profile of prescription of antiosteoporotic treatment at discharge after a hip fracture in the Spanish National Hip Fracture Registry. Prescription rates among hospitals ranged from 0 to 94% of patients discharged. The prescription rate was higher among patients with better cognitive and functional baseline status. PURPOSE: National hip fracture registries are useful for assessing current care processes. The goals of this study were as follows: first, to know the rate of antiosteoporotic prescription at discharge among hip fracture patients in hospitals participating in the Spanish National Hip Fracture Registry (RNFC); second, to compare the differences between treated and non-treated patients; third, to analyze patients' characteristics associated with antiosteoporotic prescription at discharge; and fourth, to evaluate whether there were differences in the profile of patients discharged from hospitals with high and low prescription rates. METHOD: Patients discharged after a fragility hip fracture in 2017 and participating in the RNFC were included. Demographic variables, cognitive and functional status, prefracture osteoporosis treatment, fracture type, anesthetic risk, hospital volume, and antiosteoporotic prescription at discharge were analyzed. Given that patients were clustered within hospitals, intraclass correlation was calculated and generalized estimating equations were fitted. RESULTS: A total of 6701 patients from 54 hospitals were included. Antiosteoporotic prescription at discharge was prescribed to 36.5% (CI95% 35.8-37.2%), with a wide inter-hospital variability (range 0-94%). The intraclass correlation due of clustering of patients within hospitals was 47.9%. Antiosteoporotic prescription was more likely in patients who were younger, lived at home, previously treated for osteoporosis, had better baseline functional and cognitive status, lower anesthetic risk, and were discharged from high-volume hospitals, all with p < 0.001. The general profile of patients discharged from hospitals with high and low rate of prescription was similar. CONCLUSIONS: There is a wide variability between hospitals regarding antiosteoporotic prescription after hip fracture. This is more likely to be initiated in patients with better clinical, functional, and mental status and in those discharged from hospitals with larger volumes of patients. These results offer insights regarding the selection of patients receiving secondary prevention and raises questions on who and how many should be treated.

The cannabinoid agonist WIN-2 affects acquisition but not consolidation of a spatial information in training and retraining processes: Relation with transcriptional regulation of the endocannabinoid system?

The endocannabinoid system is capable of modulating multiple physiological brain functions including learning and memory. Moreover, there is evidence that the processes of acquisition and consolidation have distinct biological basis. We used the cannabinoid agonist WIN 55,212-2 (WIN-2) to investigate whether chronic CB1 activation affects acquisition and consolidation differently by evaluating gene expression in the hippocampus (HIP) and prefrontal cortex (PFC). Swiss mice were treated with WIN-2 (2 mg/kg) and submitted to the Morris water maze to evaluate different aspects of memory. We observed short-term memory impairment in acquisition of the spatial task while consolidation remained unchanged. In the PFC, animals that received WIN-2 prior to the task exhibited increased expression of the 2-AG synthesis enzyme diacylglycerol lipase and decreased levels of the degradation enzyme monoacylglycerol lipase, while mice that were treated after the task for the evaluation of consolidation exhibited the opposite profile. With respect to genes related to AEA metabolism, no correlation between the molecular and behavioral data could be established. In this sense, the cognitive impairment in the acquisition promoted by WIN-2 treatment may be related to a possible increase in the concentration of 2-AG in the PFC. Overall, this study confirms the relevance of the endocannabinoid system in the modulation of cognitive processes. A better understanding of the mechanisms underlying endocannabinoids roles in cognition could provide guidance for the development of treatments to reduce the cognitive deficits caused by drug abuse.

Baseline and 1-year follow-up differences between hip-fracture patients admitted from nursing homes and the community. A cohort study on 509 consecutive patients (FONDA Cohort) / Diferencias iniciales y a 1 año de seguimiento entre los pacientes con fractura de cadera de residencia de ancianos y de comunidad. Estudio de una cohorte de 509 pacientes (Cohorte FONDA)

Objective: To determine the clinical and functional differences at hospital admission and at 1 year after a hip fracture (HF) in nursing homes (NH) and community-dwelling (CD) patients. Methods: All patients with HF admitted to the orthogeriatric unit at a university hospital between January 2013 and February 2014 were prospectively included. Clinical and functional variables, and mortality were recorded during the hospital admission. The patients were contacted by telephone at 1 year to determine their vital condition and functional status. Results: A total of 509 patients were included, 116 (22.8%) of whom came from NH. Compared with the CD patients, the NH patients had higher surgical risk (ASA ≥3: 83.6% vs. 66.4%, P<.001), poorer theoretical vital prognosis (Nottingham Profile ≥5: 98.3% vs. 56.6%, P<.001), higher rate of previous functional status (median Barthel index: 55 [IQR, 36-80] vs. 90 [IQR, 75-100], P<.001), poorer mental status (Pfeiffer's SPMSQ>2: 74.1% vs. 40.2%, P<.001), and a higher rate of sarcopenia (24.3% vs. 15.2%, P<.05). There were no differences in in-hospital or at 1-year mortality. At 1 year, NH patients recovered their previous walking capacity at a lower rate (38.5% vs. 56.2%, P<.001). Conclusions: Among the patients with HF treated in an orthogeriatric unit, NH patients had higher, surgical risk, functional and mental impairment, and a higher rate of sarcopenia than CD patients. At 1 year of follow-up, NH patients did not have higher mortality, but they recovered their previous capacity for walking less frequently

Objetivo: Determinar las diferencias clínicas y funcionales, basales y al año de la fractura, en los pacientes hospitalizados por fractura de cadera (FC) que provienen de residencia de ancianos (RA) y de la comunidad. Métodos: Se incluyeron de forma prospectiva todos los pacientes ingresados con el diagnóstico de FC en la unidad de ortogeriatría de un hospital universitario entre enero de 2013 y febrero de 2014. Se recogieron variables clínicas, funcionales, cognitivas y la evolución durante la hospitalización. Se contactó telefónicamente al año para conocer su estado vital y funcional. Resultados: Se incluyeron 509 pacientes, de los que 116 (22,8%) provenían de RA. Comparados con las personas que provenían de comunidad, éstos tenían un mayor riesgo quirúrgico (ASA≥3: 83,6% vs. 66,4%, p<0,001), peor pronóstico vital teórico (Perfil de Nottingham≥5: 98,3% vs. 56,6%, p<0,001), peor estado funcional basal (Índice Barthel medio: 55 [RIC, 36-80] vs. 90 [RIC, 75-100], p<0,001), peor estado mental (Test de Pfeiffer>2: 74,1% vs. 40,2%, p<0,001) y tasas más altas de sarcopenia (24,3% vs. 15,2%, p<0,05). No hubo diferencias en la mortalidad durante la hospitalización ni al año. Al año los pacientes de RA recuperaron su capacidad de ambulación previa con menos frecuencia (38,5% vs. 56,2%, p<0,001). Conclusiones: Los pacientes ingresados por FC provenientes de RA presentan mayor riesgo quirúrgico, mayor deterioro funcional y mental y mayor tasa de sarcopenia que los pacientes de la comunidad. No presentan mayor mortalidad durante el ingreso ni al año de la FC, pero recuperan su capacidad de deambulación previa con menos frecuencia

Spanish National Hip Fracture Registry (RNFC): analysis of its first annual report and international comparison with other established registries.

Hip fracture registries have helped improve quality of care and reduce variability, and several audits exist worldwide. The results of the Spanish National Hip Fracture Registry are presented and compared with 13 other national registries, highlighting similarities and differences to define areas of improvement, particularly surgical delay and early mobilization. INTRODUCTION: Hip fracture audits have been useful for monitoring current practice and defining areas in need of improvement. Most established registries are from Northern Europe. We present the results from the first annual report of the Spanish Hip Fracture Registry (RNFC) and compare them with other publically available audit reports. METHOD: Comparison of the results from Spain with the most recent reports from another ten established hip fracture registries highlights the differences in audit characteristics, casemix, management, and outcomes. RESULTS: Of the patients treated in 54 hospitals, 7.208 were included in the registry between January and October 2017. Compared with other registries, the RNFC included patients ≥ 75 years old; in general, they were older, more likely to be female, had a worse prefracture ambulation status, and were more likely to have extracapsular fractures. A larger proportion was treated with intramedullary nails than in other countries, and spinal anesthesia was most commonly used. With a mean of 75.7 h, Spain had by far the longest surgical delay, and the lowest proportion of patients mobilized on the first postoperative day (58.5%). Consequently, development of pressure ulcers was high, but length of stay, mortality, and discharge to home remained in the range of other audits. CONCLUSIONS: National hip fracture registries have proved effective in changing clinical practice and our understanding of patients with this condition. Such registries tend to be based on an internationally recognized common dataset which would make comparisons between national registries possible, but variations such as age inclusion criteria and follow-up are becoming evident across the world. This variation should be avoided if we are to maximize the comparability of registry results and help different countries learn from each other's practice. The results reported in the Spanish RNFC, compared with those of other countries, highlight the differences between countries and detect areas of improvement, particularly surgical delay and early mobilization.

Baseline and 1-year follow-up differences between hip-fracture patients admitted from nursing homes and the community. A cohort study on 509 consecutive patients (FONDA Cohort).

OBJECTIVE: To determine the clinical and functional differences at hospital admission and at 1 year after a hip fracture (HF) in nursing homes (NH) and community-dwelling (CD) patients. METHODS: All patients with HF admitted to the orthogeriatric unit at a university hospital between January 2013 and February 2014 were prospectively included. Clinical and functional variables, and mortality were recorded during the hospital admission. The patients were contacted by telephone at 1 year to determine their vital condition and functional status. RESULTS: A total of 509 patients were included, 116 (22.8%) of whom came from NH. Compared with the CD patients, the NH patients had higher surgical risk (ASA ≥3: 83.6% vs. 66.4%, P<.001), poorer theoretical vital prognosis (Nottingham Profile ≥5: 98.3% vs. 56.6%, P<.001), higher rate of previous functional status (median Barthel index: 55 [IQR, 36-80] vs. 90 [IQR, 75-100], P<.001), poorer mental status (Pfeiffer's SPMSQ>2: 74.1% vs. 40.2%, P<.001), and a higher rate of sarcopenia (24.3% vs. 15.2%, P<.05). There were no differences in in-hospital or at 1-year mortality. At 1 year, NH patients recovered their previous walking capacity at a lower rate (38.5% vs. 56.2%, P<.001). CONCLUSIONS: Among the patients with HF treated in an orthogeriatric unit, NH patients had higher, surgical risk, functional and mental impairment, and a higher rate of sarcopenia than CD patients. At 1 year of follow-up, NH patients did not have higher mortality, but they recovered their previous capacity for walking less frequently.

Staphylococcus aureus meningitis in adults: A comparative cohort study of infections caused by meticillin-resistant and meticillin-susceptible strains.

BACKGROUND: Staphylococcus aureus meningitis is an uncommon nosocomial infection usually associated with neurosurgical procedures, but spontaneous infections may occasionally appear. AIMS: To compare the features of meningitis caused by meticillin-resistant (MRSA) and meticillin-susceptible (MSSA) S. aureus and examine the prognostic factors for mortality, including MRSA infection and combined antimicrobial therapy. METHODS: Retrospective cohort study of 350 adults with S. aureus meningitis admitted to 11 hospitals in Spain (1981-2015). Logistic regression and propensity score matching were used to analyse prognostic factors. RESULTS: There were 118 patients (34%) with MRSA and 232 (66%) with MSSA. Postoperative infection (91% vs 73%) and nosocomial acquisition (93% vs 74%) were significantly more frequent in MRSA than in MSSA meningitis (P < 0.001). Combined therapy was given to 118 (34%) patients. Overall 30-day mortality rate was 23%. On multivariate analysis, mortality was associated with severe sepsis or shock (odds ratio (OR) 9.9, 95% confidence interval (CI) 4.5-22.0, P < 0.001), spontaneous meningitis (OR 4.2, 95% CI 1.9-9.1, P < 0.001), McCabe-Jackson score rapidly or ultimately fatal (OR 2.8, 95% CI 1.4-5.4, P = 0.002), MRSA infection (OR 2.6, 95% CI 1.3-5.3, P = 0.006), and coma (OR 2.6, 95% CI 1.1-6.1, P < 0.029). In postoperative cases, mortality was related to retention of cerebrospinal devices (OR 7.9, 95% CI 3.1-20.3, P < 0.001). CONCLUSIONS: Clinical and epidemiological differences between MRSA and MSSA meningitis may be explained by the different pathogenesis of postoperative and spontaneous infection. In addition to the severity of meningitis and underlying diseases, MRSA infection was associated with increased mortality. Combined antimicrobial therapy was not associated with increased survival.

Fractura de cadera por fragilidad en México: ¿En dónde estamos hoy? ¿Hacia dónde queremos ir? / Fragile hip fracture in Mexico: Where are we today? Where do we want to go?

Resumen: Introducción: La fractura de cadera (FC) se considera la consecuencia más grave de las caídas y la osteoporosis. Dieciocho por ciento de las mujeres sufrirán una FC y 25% muere en el primer año. Sólo 73% de los supervivientes caminará como lo hacía previamente. Conocemos poco de la asistencia y evolución de la FC en México. Objetivo: Revisar el estado actual de la literatura mexicana sobre FC, comparar estudios mexicanos entre sí y con los indicadores de calidad. Metodología: Se realizó una búsqueda de artículos mexicanos publicados entre 2000 y 2017 con las palabras clave: fractura de cadera, ancianos, México y hip fracture en las bases de datos PubMed, EBSCO y Bibliomed. Resultados: Se incluyeron 22 artículos. No se encontraron ensayos clínicos, informes de unidades multidisciplinarias, registros, ni metaanálisis. La media de edad fue de 76.9 años y 67.2% fueron mujeres. No se encontraron trabajos que reportaran indicadores de calidad. La comorbilidad se describe poco. Las complicaciones más frecuentes de la FC fueron delirium, neumonía y úlceras por presión. La mortalidad en la fase aguda fue de 0.97 a 12.5%. No se reportaron unidades ortogeriátricas. El costo de atención osciló entre 1,261 y 13,641 dólares estadounidenses (USD). Conclusiones: La información científica sobre FC en México es escasa, heterogénea y no permite obtener resultados concluyentes. Se requiere aumentar la cantidad y la calidad de la investigación en FC en México. Sería también conveniente difundir la utilidad de los equipos multidisciplinarios y registros de FC, lo que contribuiría a mejorar la atención.

Abstract: Introduction: Hip fracture is considered the most serious consequence of falls and osteoporosis. 18% of women will suffer one and 25% die in the first year. Only 73% of survivors will walk as they did previously. We know little about the assistance and evolution of it in Mexico. Our goal was to review the current state of Mexican literature on hip fracture, compare Mexican studies with each other and with quality indicators. Methods: We conducted a search of Mexican articles published between 2000-2017 with the key words: hip fracture, elderly, Mexico and hip fracture (in English) in the databases PubMed, EBSCO and Bibliomed. Results: Twenty-one articles were included. No clinical trials, multidisciplinary unit reports, records, or meta-analyses were found. The average age was 76.9 years and 67.2% were women. No papers were found to report quality indicators. Comorbidity is reported little. The most common complications of hip fractures were delirium, pneumonia and pressure ulcers. Mortality in the acute phase was 0.97 to 12.5%. Special units were not reported. The cost of care oscillated between 1,261 and 13,641 USD. Conclusions: The scientific information on hip fractures in Mexico is sparse, heterogeneous and does not allow for conclusive results. Increasing the amount and quality of research in hip fractures in Mexico is required. It would also be advisable to disseminate the usefulness of multidisciplinary teams and registry of hip fractures, which would help to improve attention.

Spanish National Hip Fracture Registry (SNHFR): a description of its objectives, methodology and implementation / Registro Nacional Español de Fracturas de Cadera (RNFC): descripción de sus objetivos, metodología e implementación

Objective: To ascertain the current situation and clinical variability of the provision of care for Hip Fracture (HF) in Spain and the factors related to it by using a National Registry (NHFR) with high patient numbers and territorial representation NHFR, and to compare results on a national and international level and propose standards and criteria to improve healthcare quality. Design: Continuous registry for at least three years of a representative sample of patients admitted to Spanish hospitals due to HF using the Minimum Common Dataset - international Fragility Fracture Network (FFN) MCD, adapted for Spanish. Study scope and subjects: all patients over the age of 74 years who are hospitalized with a diagnosis of a fragility HF at the participating hospitals distributed throughout the Spanish territory. Initially 48 hospitals are included, and we expect to incorporate the highest number of sites possible. Results: It is expected to ascertain the current situation of provision of care for HF in Spain. Each hospital will be offered information regarding their results and their situation compared to the rest. The results from national hospitals will be compared to others included in the registry and to hospitals abroad, which use the same database. Variability will be studied, care standards will be established, and objectives will be proposed for the continuous improvement of the care process of this condition

Objetivo: Conocer la situación actual y la variabilidad clínica del proceso asistencial a la Fractura de Cadera (FC) en España y los factores relacionados con la misma mediante la utilización de un Registro Nacional (RNFC) con elevada casuística y representación territorial RNFC, así como comparar resultados en el ámbito nacional e internacional y proponer estándares y criterios para mejorar la calidad asistencial. Diseño: Registro continuo durante al menos tres años de una muestra representativa de los pacientes ingresados por FC en los hospitales españoles mediante el Minimum Common Dataset - MCD internacional de la Fragility Fracture Network (FFN) adaptado al castellano. Ámbito y sujetos del estudio: se incluirán todos los pacientes mayores de 74 años hospitalizados con el diagnóstico de FC por fragilidad en los hospitales participantes repartidos por el territorio español. Inicialmente están incluidos 48 hospitales, a los que se espera que se vayan incorporando el mayor número posible de centros. Resultados: Se pretende conocer la situación actual de la atención a este proceso en España Se ofrecerá a cada hospital la información de sus resultados y su situación en relación al resto, se compararán los resultados de los hospitales nacionales entre sí y con los hospitales extranjeros incluidos en registros que usan la misma base de datos. Se estudiará la variabilidad, se establecerán estándares asistenciales y se plantearán objetivos para la mejora continua del proceso en la atención a esta patología

Spanish National Hip Fracture Registry (SNHFR): a description of its objectives, methodology and implementation.

OBJECTIVE: To ascertain the current situation and clinical variability of the provision of care for Hip Fracture (HF) in Spain and the factors related to it by using a National Registry (NHFR) with high patient numbers and territorial representation NHFR, and to compare results on a national and international level and propose standards and criteria to improve healthcare quality. DESIGN: Continuous registry for at least three years of a representative sample of patients admitted to Spanish hospitals due to HF using the Minimum Common Dataset - international Fragility Fracture Network (FFN) MCD, adapted for Spanish. STUDY SCOPE AND SUBJECTS: all patients over the age of 74 years who are hospitalized with a diagnosis of a fragility HF at the participating hospitals distributed throughout the Spanish territory. Initially 48 hospitals are included, and we expect to incorporate the highest number of sites possible. RESULTS: It is expected to ascertain the current situation of provision of care for HF in Spain. Each hospital will be offered information regarding their results and their situation compared to the rest. The results from national hospitals will be compared to others included in the registry and to hospitals abroad, which use the same database. Variability will be studied, care standards will be established, and objectives will be proposed for the continuous improvement of the care process of this condition.

Prevalence of malnutrition in a cohort of 509 patients with acute hip fracture: the importance of a comprehensive assessment.

Backgrounds/objectives:Malnutrition is very common in acute hip fracture (HF) patients. Studies differ widely in their findings, with reported prevalences between 31 and 88% mainly because of small sample sizes and the use of different criteria. The aim of this study was to learn the prevalence of malnutrition in a large cohort of HF patients in an comprehensive way that includes the frequency of protein-energy malnutrition, vitamin D deficiency and sarcopenia. SUBJECTS/METHODS: A 1-year consecutive sample of patients admitted with fragility HF in a 1300-bed public University Hospital, who were assessed within the first 72 h of admission. Clinical, functional, cognitive and laboratory variables were included. Energy malnutrition (body mass index (BMI) <22 kg/m2), protein malnutrition (serum total protein <6.5 g/dl or albumin <3.5 g/dl), vitamin D deficiency (serum 25-OH-vitamin D <30 ng/dl) and sarcopenia (low muscle mass plus low grip strength) were considered. RESULTS: Five hundred nine HF patients were included. The mean age was 85.6±6.9 years and 79.2% were women. Ninety-nine (20.1%) patients had a BMI <22 kg/m2. Four hundred nine patients (81.2%) had protein malnutrition. Eighty-seven (17.1%) patients had both energy and protein malnutrition. Serum vitamin D was <30 ng/ml in 466 (93%) patients. The prevalence of sarcopenia was 17.1%. CONCLUSIONS: Protein malnutrition and vitamin D deficiency are the rule in acute HF patients. Energy malnutrition and sarcopenia are also common. A nutritional assessment in these patients should include these aspects together.

[Fragile hip fracture in Mexico: Where are we today? Where do we want to go?] / Fractura de cadera por fragilidad en México: ¿En dónde estamos hoy? ¿Hacia dónde queremos ir?

INTRODUCTION: Hip fracture is considered the most serious consequence of falls and osteoporosis. 18% of women will suffer one and 25% die in the first year. Only 73% of survivors will walk as they did previously. We know little about the assistance and evolution of it in Mexico. Our goal was to review the current state of Mexican literature on hip fracture, compare Mexican studies with each other and with quality indicators. METHODS: We conducted a search of Mexican articles published between 2000-2017 with the key words: hip fracture, elderly, Mexico and hip fracture (in English) in the databases PubMed, EBSCO and Bibliomed. RESULTS: Twenty-one articles were included. No clinical trials, multidisciplinary unit reports, records, or meta-analyses were found. The average age was 76.9 years and 67.2% were women. No papers were found to report quality indicators. Comorbidity is reported little. The most common complications of hip fractures were delirium, pneumonia and pressure ulcers. Mortality in the acute phase was 0.97 to 12.5%. Special units were not reported. The cost of care oscillated between 1,261 and 13,641 USD. CONCLUSIONS: The scientific information on hip fractures in Mexico is sparse, heterogeneous and does not allow for conclusive results. Increasing the amount and quality of research in hip fractures in Mexico is required. It would also be advisable to disseminate the usefulness of multidisciplinary teams and registry of hip fractures, which would help to improve attention.

INTRODUCCIÓN: La fractura de cadera (FC) se considera la consecuencia más grave de las caídas y la osteoporosis. Dieciocho por ciento de las mujeres sufrirán una FC y 25% muere en el primer año. Sólo 73% de los supervivientes caminará como lo hacía previamente. Conocemos poco de la asistencia y evolución de la FC en México. OBJETIVO: Revisar el estado actual de la literatura mexicana sobre FC, comparar estudios mexicanos entre sí y con los indicadores de calidad. METODOLOGÍA: Se realizó una búsqueda de artículos mexicanos publicados entre 2000 y 2017 con las palabras clave: fractura de cadera, ancianos, México y hip fracture en las bases de datos PubMed, EBSCO y Bibliomed. RESULTADOS: Se incluyeron 22 artículos. No se encontraron ensayos clínicos, informes de unidades multidisciplinarias, registros, ni metaanálisis. La media de edad fue de 76.9 años y 67.2% fueron mujeres. No se encontraron trabajos que reportaran indicadores de calidad. La comorbilidad se describe poco. Las complicaciones más frecuentes de la FC fueron delirium, neumonía y úlceras por presión. La mortalidad en la fase aguda fue de 0.97 a 12.5%. No se reportaron unidades ortogeriátricas. El costo de atención osciló entre 1,261 y 13,641 dólares estadounidenses (USD). CONCLUSIONES: La información científica sobre FC en México es escasa, heterogénea y no permite obtener resultados concluyentes. Se requiere aumentar la cantidad y la calidad de la investigación en FC en México. Sería también conveniente difundir la utilidad de los equipos multidisciplinarios y registros de FC, lo que contribuiría a mejorar la atención.

Front microrheology of the non-Newtonian behaviour of blood: scaling theory of erythrocyte aggregation by aging.

We introduce a new framework to study the non-Newtonian behaviour of fluids at the microscale based on the analysis of front advancement. We apply this methodology to study the non-linear rheology of blood in microchannels. We carry out experiments in which the non-linear viscosity of blood samples is quantified at different haematocrits and ages. Under these conditions, blood exhibits a power-law dependence on the shear rate. In order to analyse our experimental data, we put forward a scaling theory which allows us to define an adhesion scaling number. This theory yields a scaling behaviour of the viscosity expressed as a function of the adhesion capillary number. By applying this scaling theory to samples of different ages, we are able to quantify how the characteristic adhesion energy varies as time progresses. This connection between microscopic and mesoscopic properties allows us to estimate quantitatively the change in the cell-cell adhesion energies as the sample ages.

Capillary Filling at the Microscale: Control of Fluid Front Using Geometry.

We propose an experimental and theoretical framework for the study of capillary filling at the micro-scale. Our methodology enables us to control the fluid flow regime so that we can characterise properties of Newtonian fluids such as their viscosity. In particular, we study a viscous, non-inertial, non-Washburn regime in which the position of the fluid front increases linearly with time for the whole duration of the experiment. The operating shear-rate range of our apparatus extends over nearly two orders of magnitude. Further, we analyse the advancement of a fluid front within a microcapillary in a system of two immiscible Newtonian liquids. We observe a non-Washburn regime in which the front can accelerate or decelerate depending on the viscosity contrast between the two liquids. We then propose a theoretical model which enables us to study and explain both non-Washburn regimes. Furthermore, our theoretical model allows us to put forward ways to control the emergence of these regimes by means of geometrical parameters of the experimental set-up. Our methodology allows us to design and calibrate a micro-viscosimetre which works at constant pressure.

Phase-field modelling of the dynamics of Z-ring formation in liposomes: Onset of constriction and coarsening.

We propose a model for the dynamics of the formation of rings of FtsZ on tubular liposomes which produce constriction on the corresponding membrane. Our phase-field model is based on a simple bending energy that captures the dynamics of the interplay between the protein and the membrane. The short-time regime is analyzed by a linear dispersion relation, with which we are able to predict the number of rings per unit length on a tubular liposome. We study numerically the long-time dynamics of the system in the non-linear regime where we observe coarsening of Z-rings on tubular liposomes. In particular, our numerical results show that, during the coarsening process, the number of Z-rings decreases as the radius of tubular liposome increases. This is consistent with the experimental observation that the separation between rings is proportional to the radius of the liposome. Our model predicts that the mechanism for the increased rate of coarsening in liposomes of larger radius is a consequence of the increased interface energy.

Parathyroid hormone response to two levels of vitamin D deficiency is associated with high risk of medical problems during hospitalization in patients with hip fracture.

BACKGROUND: Vitamin D and the parathyroid hormone (PTH) response play an important role in hip fracture patients. This study was carried out to determine the factors associated with the PTH response to different levels of vitamin D deficiency during hospitalization. METHODS: This was a cross-sectional study of patients over 64 years of age admitted with an acute fragility hip fracture between March 1st 2009 and November 30th 2012. Demographic, clinical, functional, and cognitive function were evaluated at admission and during hospitalization. Levels of 25-hydroxyvitamin D (25-OHD) and PTH were analyzed. Two 25-OHD cut-off points were considered, <12 ng/ml and 12-20 ng/ml. Multivariate logistic regression analysis was used. RESULTS: Mean age of the 607 patients included was 84.7 years (SD 7.10), and 81.9 % were women. The mean 25-OHD level in the total sample was 13.2 (SD 11.1) ng/ml. Levels of 25-OHD <12 ng/ml were present in 347 patients (57.2 %), of whom 158 (45.5 %) had secondary hyperparathyroidism (SHPT) (PTH >65 pg/ml). 25-OHD levels of 12-20 ng/ml were present in 168 (27.7 %) patients, of whom 47 (28 %) had SHPT. Following logistic regression, SHPT was associated in both groups (25-OHD <12 and 12-20 ng/ml) with a greater number of medical problems during hospitalization. In the 25-OHD group <12 ng/ml, SHPT was also associated with poorer glomerular filtration rates. CONCLUSION: The PTH response to vitamin D deficiency in hip fracture patients may be a marker for patients with higher risk of developing multiple medical problems, both when considering severe (<12 ng/ml) and moderate (12-20 ng/ml) vitamin D deficiency.