Prevalence of electrocardiographic alterations in athletes associated with cardiovascular risk parameters / Prevalencia de alteraciones electrocardiográficas en deportistas asociadas a parametros de riesgo cardiovascular

Sport induces cardiac adaptations that are manifested with specific electrocardiographic alterations. This study was carried out in view of the need to identify the relationship between these electrocardiographic alterations with cardiovascular and demographic variables and physical exercise performed. Methodology: a descriptive cross-sectional study in 370 individuals, 211 men and 159 women (36 ± 13 years) that were distributed in three groups: male athletes, female athletes, and non-athlete men and women. Results: 51.08% of the studied subjects presented electrographic alterations, more frequent in athletes. Demographic and cardiovascular variables and the time of physical exercise performed were significantly associated with certain electrocardiographic alterations; the risk of presenting any of the alterations in athletes could be estimated based on the variables set out. Conclusion: There are associations between specific electrocardiographic alterations and cardiovascular, demographic and type of exercise variables that could classify athletes according to cardiovascular risk profiles (AU)

El deporte induce adaptaciones cardiacasque se manifiestan con alteraciones electrocardiográficas.Este estudio se realizóante la necesidad de identificar la relación existente entre estas alteraciones electrocardiográficas con variablescardiovasculares, demográficas y tiempo de ejerciciofísico. Metodología: estudio descriptivotrasversal en 370 individuos, 211 hombres y 159 mujeres (36 ±13 años)que se distribuyeron en tres grupos, hombres deportistas, mujeresdeportistas, yhombres y mujeres no deportistas.Resultados:El 51,08% de los sujetos estudiados presentaron alteraciones electrográficas, siendo más frecuentes en deportistas.Determinadas alteraciones electrocardiográficasen deportistas; se asociaron significativamente a las variables planteadaspudiendo estimar el riesgo de presentar alguna de las alteraciones electrocardiográficas en función de estas variables. Conclusión:Existen asociaciones entrealteraciones electrocardiográficas y variables cardiovasculares, demográficas y tiempo de ejercicio realizado que podrían clasificar a los deportistas según perfiles de riesgo cardiovascular (AU)

Effectiveness and safety of oral anticoagulant therapy in a real-world cohort with atrial fibrillation: The SIESTA-A study protocol.

INTRODUCTION: Oral anticoagulants (OACs) are first-line drugs for stroke prevention in patients with atrial fibrillation (AF). The introduction of new lines of therapy with direct oral anticoagulants (DOACs) has led to a decreased use of vitamin K antagonists (VKAs). Comparative analyses of DOACs in clinical trials are scarce and the comparator has mostly been warfarin. Their impact on health outcomes in observational studies has not always been consistent. The aim of this study is to evaluate the effectiveness and safety of DOACs and VKAs in patients with AF using Real-World Data (RWD). METHODS AND ANALYSIS: Population-based retrospective cohort study using RWD from actual practice. Period: January 2012-December 2020. Inclusion criteria: patients with AF who had not taken OACs in the previous 12 months. Exclusion criteria: <40 years, with severe mitral stenosis, or valvular heart disease or aortic and/or mitral valve procedures. Data source: The Andalusian Population Health Database, Spain. Outcome measures: a) Effectiveness: ischaemic stroke, transient ischaemic attack, systemic and pulmonary embolism, and death; b) Safety: gastrointestinal and intracranial haemorrhaging; Independent variables: age, sex, comorbidities, medication and health resource use, CHA2DS2-VASC, HAS-BLED, and analytical tests. Statistical analysis: crude incidence analysis, survival models, Kaplan-Meier, Cox regression analysis adjusted for possible confounding and paired analysis by propensity score matching.

Psychosis after buprenorphine, heroin, methadone, morphine, oxycodone, and tramadol withdrawal: a systematic review.

OBJECTIVE: This study's main objective is to carry out a systematic review of the onset of psychotic symptoms after opioid withdrawal. The opiate dependence correlated to psychiatric symptoms has been well described. MATERIALS AND METHODS: Following the PRISMA methodology. The consecutive search strategy was applied: (morphine OR buprenorphine OR oxycodone OR tramadol OR fentanyl OR remifentanil OR opioids OR heroin OR methadone) AND (Psychosis OR psychotic symptoms OR schizophrenia). RESULTS: 12 case reports, 3 series of cases, 2 clinical studies, and 2 reviews were found. It seems that the time association is present in all of them; symptoms appear days after the interruption of the opioid. Most of the articles reported are case reports that describe symptoms that appear after the suspension of the opioid substance; in most cases, the reintroduction of the opioid had therapeutic effects and provoked a remission of these symptoms. These preliminary findings indicate that opiates could have an antipsychotic effect; however, the literature is scarce. It is critical to consider, if needed, in opioid-dependent patients who start with psychosis after the opioid withdrawal the possible replacement or reintroduction of opioids to prevent further deterioration in the patient's mental status. CONCLUSIONS: This study encompasses a comprehensive description of the literature concerning the possible not well-studied outcome of opioid withdrawal. There are some reports of temporal association between withdrawal and psychotic symptoms that improved after the reintroduction of the opioid; it could be taken into consideration in the clinical practice.

Onychoscopy in a Colombian population with a diagnosis of toenail onychomycosis: an evaluation study for this diagnostic test.

BACKGROUND: Onychoscopy is a technique that uses a dermatoscope for the evaluation of specific features of different skin conditions that are not visible to the naked eye. There are few studies establishing parameters for the diagnosis of onychomycosis based on onychoscopy. Determining the sensitivity and specificity of a potentially new diagnostic test for onychomycosis requires an evaluation study of this new diagnostic test, as there are limited studies reporting onychoscopy results. AIM: To determine the sensitivity, specificity, positive predictive value and negative predictive value of onychoscopy findings in a Colombian population with onychomycosis. METHODS: We assessed outpatients with a diagnosis of toenail onychomycosis confirmed by potassium hydroxide preparation or fungal culture. Onychoscopy was performed using a dermatoscope, and digital images collected using a smartphone. RESULTS: The onychoscopy findings were: longitudinal striae, distal spiked pattern, distal irregular termination, linear edge and ruins aspect, while some patients were confirmed as having traumatic onycholysis. A statistically significant association was found between the clinical symptoms of onychomycosis and both the clinical feature of dyschromia and the onychoscopy feature of longitudinal striae. CONCLUSION: We suggest that this technique is an alternative method that should be used in patients with onychopathies because it has the potential to differentiate onychomycosis from traumatic onycholysis and another nail involvement.

Hidradenocarcinoma en miembro inferior: reporte de caso y revision de literatura / Hydradenocarcinoma in lower member: case report and review of literature

RESUMEN Objetivo : Presentación de un caso, consistente en una lesión tumoral, compatible con hidradenocarcinoma, desarrollado en un paciente joven, y revisión de la literatura referida a la entidad mencionada. Métodos : Se valora en el servicio de dermatología un paciente de 17 años con una lesión de crecimiento progresivo, localizada en tercio medio de la pierna derecha, la cual a la inspección muestra secreción hialina y sangrado, manifestando prurito como síntoma ocasional, al inicio de la lesión. Se decide tomar biopsia de la lesión para confirmar diagnóstico. Resultados : Se hace diagnóstico clínico e histopatológico de hidradenocarcinoma siendo este un tumor raro maligno, originado en glándulas sudoríparas que se localiza cualquier parte del cuerpo, el cual en la mayoría de los casos se ha descrito como de origen ecrino. Conclusiones : Aunque no es una patología frecuente tiene altas tasas de recurrencia y riesgo de metástasis. Por lo tanto, es importante considerarla siempre como uno de los diagnósticos diferenciales, y de esa manera ofrecer un oportuno tratamiento quirúrgico, con márgenes amplios de resección.

SUMMARY Objective : Presentation of a case report, consisting of a tumor lesion, compatible with hydradenocarcinoma, developed in a young patient, and review of the literature referring to the mentioned entity. Methods : A 17-year-old patient with a progressive growth lesion, located in the middle third of the right leg, was evaluated in the dermatology service, which upon inspection showed hyaline secretion and bleeding, manifesting pruritus as an occasional symptom. A skin biopsy was performed to confirm the diagnosis. Results : A clinical and histopathological diagnosis of hydradenocarcinoma is made, this being a rare and malignant tumor originating in sweat glands that is located anywhere in the body, which in most cases has been described as of eccrine origin. Conclusions : Although it is not a frequent pathology, it has high recurrence rates and risk of metastasis. Therefore, it is important to always consider it as one of the differential diagnoses, and thus offer timely surgical treatment, with wide resection margins.

PREvention of recurrent arrhythmias with Mediterranean diet (PREDIMAR) study in patients with atrial fibrillation: Rationale, design and methods.

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia. Catheter ablation aims to restore sinus rhythm. However, relapses occur in up to 30% of patients. A Mediterranean diet (MedDiet) enriched with extra-virgin olive oil (EVOO) substantially reduced the incidence of AF in the PREDIMED trial. The PREDIMAR will test a similar intervention in secondary prevention. Methods: PREDIMAR is a multicenter, randomized, single-blind trial testing the effect of a MedDiet enriched with EVOO to reduce tachyarrhythmia relapses after AF ablation. The primary outcome is the recurrence of any sustained atrial tachyarrhythmia after ablation (excluding those occurring only during the first 3 months after ablation). The target final sample size is 720 patients (360 per group) recruited from 4 Spanish hospitals. A remote intervention, maintained for 2 years, is delivered to the active intervention group including periodic phone calls by a dietitian and free provision of EVOO. The control group will receive delayed intervention after trial completion. Routine electrocardiogram (ECG) and Holter ECG are performed, and a portable cardiac rhythm monitoring device is provided to be worn by participants during 15 months. Results: Recruitment started in March 2017. Up to July 2019, 609 patients were randomized (average inclusion rate: 5.3 patients/wk). Retention rates after 18 months are >94%. Conclusions: If our hypothesis is confirmed, the utility of the MedDiet enriched with EVOO in slowing the progression of AF will be proven, preventing recurrences and potentially reducing complications.

Olive oil intake and risk of atrial fibrillation in the SUN cohort.

BACKGROUND AND AIMS: A Mediterranean-type diet enriched with extra virgin olive oil has been associated with a reduction in the incidence of atrial fibrillation (AF) in a population at high cardiovascular risk. However, no study has replicated these findings. In our study, we analyzed the association between olive oil consumption and AF in the SUN project, a cohort with young Spanish adults at low cardiovascular risk. METHODS AND RESULTS: We included all participants without prevalent AF at baseline (18,118 participants). Incident AF cases were confirmed by a cardiologist following a prespecified protocol. We used multivariable repeated-measurement Cox models adjusted for possible confounders (sex, age, BMI, and several classic cardiovascular risk factors). After a mean follow-up of 10.1 years, 94 AF incident cases were confirmed. Comparing to the lowest category of consumption (<7.9 g/d), the multivariable models showed hazard ratios (IC 95%) of 1.52 (0.93-2.48) for low-to-moderate, 1.44 (0.83-2.47) for moderate-to-high and 1.27 (0.56-2.86) for high olive oil intake. In a subgroup analysis stratified by overweight, an inverse although non-significant association was found only among overweight participants when we compared the highest vs the lowest category of consumption (p for interaction = 0.043). CONCLUSION: No association between olive oil and AF was found in this low-risk cohort, although the effect of extra-virgin olive oil on AF prevention especially among people with overweight deserves further investigation.

Silver-loaded nanoparticles affect ex-vivo mechanical behavior and mineralization of dentin.

BACKGROUND: The aim was to evaluate the effect of silver loaded nanoparticles (NPs) application on the triboscopic, crystallographic and viscoelastic properties of demineralized dentin. Polymethylmetacrylate-based NPs and Ag loaded NPs were applied on demineralized dentin. MATERIAL AND METHODS: Treated and untreated surfaces were probed by a nanoindenter to test viscoelasticity, and by atomic force microscopy to test nanoroughness and collagen fibril diameter. X-ray diffraction and transmission electron microscopy through selected area diffraction and bright-field imaging were also used. RESULTS: Dentin treated with Ag-NPs attained the lowest complex modulus, and the highest tan delta values after 7 days of storage. Dentin treated with undoped-NPs achieved the lowest nanoroughness and the greatest collagen bandwidths among groups. Crystals were identified as hydroxyapatite with the highest crystallographic maturity and crystallite size in dentin treated with undoped-NPs. Texture increased in all samples from 24 h to 7 d, except in dentin surfaces treated with Ag-NPs at 310 plane. Polyhedral, block-like, hexagonal or plate-like shaped apatite crystals constituted the bulk of minerals in dentin treated with Ag-NPs, after 7 d. Polyhedral or rounded/drop-like, and polymorphic in strata crystal apatite characterized the minerals when undoped-NPs were used, with more crystalline characteristics after 7 d than that found when Ag-NPs were applied. Ag-NPs application did not improve the mechanical performance of dentin and did not produce dentin remineralization. However, energy was dissipated through the dentin without showing stress concentration; contrary was occurring at dentin treated with undoped-NPs, that provoked bridge-like mineral deposits at the dentin surface. CONCLUSIONS: Ag-NPs application did not enhance the mechanical properties of cervical dentin, though the energy dissipation did not damage the dentin structure. Remineralization at dentin was not produced after Ag-NPs application, though improved crystallinity may lead to increase stability of the apatite that was generated at the dentin surface.

Intradialytic Exercise: One Size Doesn't Fit All.

Purpose: Hemodialysis patients commonly have impaired physical performance and mental health. We studied the effects of an intradialytic exercise program on these variables. Methods: 27 patients (33% women; 68 ± 13 years) were enrolled in a 14-week intradialytic endurance-resistance training program ('exercise' group, 40 programmed sessions per patient); 40 hemodialysis patients (28% women; 68 ± 11 years) performing no exercise during the same time length were used as controls. Endpoints included physical performance (6-min walk test [6MWT], 10-repetition sit to stand [STS-10] and handgrip strength), emotional status (Beck's depression inventory and State-Trait Anxiety Inventory), and mental and physical component scores of the short-from (SF)-12 Health Survey. Results: There were no differences (p> 0.05) between groups at baseline for sex distribution, or mean age, body mass index and time spent on dialysis. Exercise benefits were observed for 6MWT (11 and -3% for the exercise and control groups, respectively; p < 0.001), STS-10 performance time (-22 and 6%; p < 0.001) and handgrip strength (4 and -4%; p < 0.02). No significant benefits (p> 0.05) were observed for emotional status endpoints or SF-12 component scores. Despite significant benefits on physical performance, the proportion of clinically meaningful responders was low (<50%). Responsiveness was dependent on baseline physical performance (p < 0.05) but not on age or sex (p > 0.05). Conclusion: A 14-week intradialytic training program induced significant improvements on physical performance. However, the rate of clinically meaningful responders observed in the present study was low, being the level of responsiveness dependent on baseline physical status. Efforts to individualize exercise prescription are needed in clinical practice.

Study of Ras/MAPK pathway gene variants in Chilean patients with Cryptorchidism.

Cryptorchidism is one of the most common congenital disorders in boys, and several genetic, hormonal, and environmental factors have been proposed as possible causes for this genitourinary defect. Genetic factors have been intensively searched, but relatively few pathogenic variants have been described. Cryptorchidism is a frequent finding in patients with RASopathies, a group of syndrome caused by mutations in genes of the Ras/MAPK pathway. Our aim was to determine whether patients with isolated cryptorchidism (IC) exhibit Ras/MAPK pathway gene variants associated with RASopathies. Two hundred thirty-nine patients with IC were recruited after orchidopexy. Determination of Ras/MAPK pathway gene variants was performed by high-resolution melting (HRM) analysis followed by sequencing. Restriction or allele-specific amplification assay was applied to (i) variant confirmation; (ii) search in healthy controls; and (iii) segregation analysis. Controls correspond to 100 healthy Chilean adults without a history of cryptorchidism. Molecular analysis showed one synonymous substitution (BRAF_p.Q456Q) in two patients and four missense substitutions (SOS1_ p.R497Q, BRAF_ p.F595L, NRAS_ p.T50I, and MAP2K2_ p.Y134C) in five patients. Our results suggest that some patients with isolated cryptorchidism, but with no evidence of dysmorphic features suggestive of RASopathies, may harbor Ras/MAPK pathway gene alterations.

Ion-modified nanoparticles induce different apatite formation in cervical dentine.

AIM: To investigate if crystallinity and ultrastructure are modified when cervical dentine is treated with four different nanogels-based solutions for remineralizing purposes. METHODOLOGY: Experimental nanogels based on polymeric nanoparticles (NPs) and zinc, calcium or doxycycline-loaded NPs were applied to citric acid etched dentine to facilitate the occlusion of tubules and the mineralization of the dentine surface. Dentine surfaces were studied by X-ray diffraction and transmission electron microscopy through selected area diffraction and bright-field imaging. RESULTS: Crystals at the dentine surface were identified as hydroxyapatite with the highest crystallographic maturity and crystallite size in dentine treated with Zn-NPs-based gel. Texture increased in all samples from 24 h to 7 days, except in dentine surfaces treated with Zn-NPs gel. Polyhedral, plate-like and drop-like shaped apatite crystals constituted the bulk of minerals in dentine treated with Zn-NPs gel, after 7 days. Polymorphic, cubic and needle-like shaped crystals distinguished minerals, with more amorphous characteristics in dentine treated with Ca-NPs gel after 7 days than that found when Zn-NPs were applied. Doxycycline-NPs produced the smallest crystallites with poor crystallinity, maturity and chemical stability. CONCLUSIONS: Crystalline and amorphous phases of newly formed hydroxyapatite were described in both types of dentine treated with Zn-NPs as well as Ca-NPs gels with multiple shapes of crystallites. Crystal shapes ranged from rounded/drop-like or plate-like crystals to needle-like or polyhedral and cubic apatite appearance.

Eventos adversos en pacientes hospitalizados reportados por enfermería: un estudio multicéntrico en México / Nursing reported hospitalized patients adverse events: A multi-centric study in Mexico / Eventos adversos em pacientes hospitalizados relatados por enfermagem: um estudo multicéntrico no México

Introducción: Los eventos adversos (EA) son un daño no intencionado derivado de la atención sanitaria que se relacionan con los recursos humanos, los factores del sistema o las condiciones clínicas del paciente. Objetivo: Analizar factores relacionados con la calidad y la seguridad del paciente a través de los reportes de EA. Metodología: Diseño transversal, multicéntrico, realizado en 5 institutos nacionales de salud y en un hospital de alta especialidad, se estudiaron los EA ocurridos durante 18 meses, para lo cual se utilizó el instrumento SYREC 2007; análisis descriptivo y evaluación de asociación entre grado de evitabilidad y factores intrínsecos, extrínsecos y del sistema; se observaron los aspectos éticos vigentes. Resultados: Se analizaron un total de 540 EA, ocurrieron 55.5% en hombres, 58.7% estaban en estado de alerta, el 92.6% de los EA ocurrió en el servicio asignado, el 55.9% no se reportó a la familia, se consideró sin duda como evitable en el 70.5%, los factores del sistema estuvieron presentes en 80.6%, hubo asociación significativa entre estos y la evitabilidad del suceso. Discusión: Los principales resultados encontrados son coincidentes con otras investigaciones internacionales tales como: To err is human 1999, el estudio ENEAS de España 2006 y con el de prevalencia IBEAS 2010; en todos ellos se hizo evidente la necesidad de reforzar la cultura de la notificación de los EA y el clima para la seguridad del paciente, además de promover una reflexión interpersonal acerca de la calidad de los servicios asistenciales. Conclusiones: Los factores relacionados con el sistema tienen un mayor peso en la aparición de EA. Es de vital importancia su identificación a fin de poder evitarlos.

Introduction: Adverse events (AE) are unintended harms derived from human health attention, system factors, or clinical conditions in the patients. Objective: To analyze factors influencing the quality of patient healthcare and safety through the review of diverse records on AEs. Methodology: This transversal and multi-centric design study was carried out in five National Institutes of Health and a high specialty hospital. AEs in an 18 month period were studied using the SYREC 2007 instrument. Descriptive analysis, as well as assessments on the association between the preventability degree and the intrinsic, extrinsic, and system factors were all performed. Current ethical issues were observed. Results: A total of 540 AEs were analyzed; 55.5% occurred in men; 58.7% occurred during state of alertness; 92.6% occurred at the assigned service; 55.9% were not reported to the families; 70.5% were considered preventable; and system factors were present in 80.6% of them. A significant association between the AEs and the possibility to prevent them was found. Discussion: The main findings were consistent with those of other international studies including: ''To err is human'', 1999, the ENEAS study in Spain, 2006, and the IBEAS prevalence study, 2010. All of these studies emphasize the need to strengthen the culture of AE-notifying and to improve the patient safety climate, as well as to promote inter-personal reflections on to the quality of care services. Conclusions: System-related factors have the strongest influence on the occurrence of AEs, and thus, their identification becomes critical in order to enhance the quality of healthcare services.

Introdução: Os Eventos Adversos (EA) são um dano não intencionado derivado da atenção sanitária que se relaciona com os recursos humanos, os fatores do sistema ou as condições clínicas do paciente. Objetivo: Analisar fatores relacionados com a qualidade e a segurança do paciente a través dos relatórios de EA. Metodologia: Desenho transversal, multicéntrico, realizado em cinco Institutos Nacionais de Saúde e um hospital de alta especialidade, estudaram-se os EA ocorridos durante 18 meses, para o qual se utilizou o instrumento SYREC 2007; análise descritiva e avaliação de associação entre grau de evitabilidade e fatores intrínsecos, extrínsecos e do sistema; observaram-se os aspectos éticos vigentes. Resultados: Analisaram-se um total de 540 EA, ocorreram 55.5% em homens, 58.7% estavam em estado de alerta, o 92.6% o EA aconteceu no serviço assignado, o 55.9% não se informou à família, considerou-se sem dúvida como evitável no 70.5%, os fatores do sistema estiveram presentes em 80.6%, houve associação significativa entre estes e a evitabilidade do evento. Discussão: Os principais resultados encontrados são coincidentes com outras pesquisas internacionais tais como: ''To err is human'' 1999, o estudo ENEAS da Espanha 2006 e com o de prevalência IBEAS 2010; em todos eles se fez evidente a necessidade de reforçar a cultura da notificação dos EA e o clima para a segurança do paciente, além de promover una reflexão interpessoal acerca da qualidade dos serviços assistenciais. Conclusões: Os fatores relacionados com o sistema têm um maior peso na aparição de EA. É de vital importância sua identificação a fim de poder evitá-los.

Copy number variants of Ras/MAPK pathway genes in patients with isolated cryptorchidism.

Cryptorchidism is the most common congenital disorder in boys, but the cause for most cases remains unknown. Patients with Noonan Syndrome are characterized by a typical face, growth retardation, congenital heart defects, learning disabilities and cryptorchidism. Copy number variations of Ras/MAPK pathway genes are unusual in patients with several clinical features of Noonan Syndrome; however, they have not been studied in patients with only one feature of this condition, such as cryptorchidism. Our aim was to determine whether patients with isolated cryptorchidism exhibit Ras/MAPK pathway gene copy number variations (CNVs). Fifty-nine patients with isolated cryptorchidism and negative for mutations in genes associated with Noonan Syndrome were recruited. Determination of Ras/MAPK pathway gene CNVs was performed by Comparative Genome Hybridization array. A CNV was identified in two individuals, a ~175 kb microduplication at 3p25.2, partially including RAF1. A similar RAF1 microduplication has been observed in a patient with testicular aplasia. This suggests that some patients with isolated cryptorchidism may harbor Ras/MAPK pathway gene CNVs.

Shear elasticity of isotropic magnetic gels.

The paper deals with a theoretical study of the effective shear modulus of a magnetic gel, consisting of magnetizable particles randomly and isotropically distributed in an elastic matrix. The effect of an external magnetic field on the composite modulus is the focus of our consideration. We take into account that magnetic interaction between the particles can induce their spatial rearrangement and lead to internal anisotropy of the system. Our results show that, if this magnetically induced anisotropy is insignificant, the applied field reduces the total shear modulus of the composite. Strong anisotropy can qualitatively change the magnetomechanic effect and induce an increase of this modulus with the field.

Effect of particle concentration on the microstructural and macromechanical properties of biocompatible magnetic hydrogels.

We analyze the effect of nanoparticle concentration on the physical properties of magnetic hydrogels consisting of polymer networks of the human fibrin biopolymer with embedded magnetic particles, swollen by a water-based solution. We prepared these magnetic hydrogels by polymerization of mixtures consisting mainly of human plasma and magnetic nanoparticles with OH- functionalization. Microscopic observations revealed that magnetic hydrogels presented some cluster-like knots that were connected by several fibrin threads. By contrast, nonmagnetic hydrogels presented a homogeneous net-like structure with only individual connections between pairs of fibers. The rheological analysis demonstrated that the rigidity modulus, as well as the viscoelastic moduli, increased quadratically with nanoparticle content following a square-like function. Furthermore, we found that time for gel point was shorter in the presence of magnetic nanoparticles. Thus, we can conclude that nanoparticles favor the cross-linking process, serving as nucleation sites for the attachment of the fibrin polymer. Attraction between the positive groups of the fibrinogen, from which the fibrin is polymerized, and the negative OH- groups of the magnetic particle surface qualitatively justifies the positive role of the nanoparticles in the enhancement of the mechanical properties of the magnetic hydrogels. Indeed, we developed a theoretical model that semiquantitatively explains the experimental results by assuming the indirect attraction of the fibrinogen through the attached nanoparticles. Due to this attraction the monomers condense into nuclei of the dense phase and by the end of the polymerization process the nuclei (knots) of the dense phase cross-link the fibrin threads, which enhances their mechanical properties.

Kinetics of doublet formation in bicomponent magnetic suspensions: The role of the magnetic permeability anisotropy.

Micron-sized particles (microbeads) dispersed in a suspension of magnetic nanoparticles, i.e., ferrofluids, can be assembled into different types of structures upon application of an external magnetic field. This paper is devoted to theoretical modeling of a relative motion of a pair of microbeads (either soft ferromagnetic or diamagnetic) in the ferrofluid under the action of applied uniform magnetic field which induces magnetic moments in the microbeads making them attracting to each other. The model is based on a point-dipole approximation for the magnetic interactions between microbeads mediated by the ferrofluid; however, the ferrofluid is considered to possess an anisotropic magnetic permeability thanks to field-induced structuring of its nanoparticles. The model is tested against experimental results and shows generally better agreement with experiments than the model considering isotropic magnetic permeability of ferrofluids. The results could be useful for understanding kinetics of aggregation of microbeads suspended in a ferrofluid. From a broader perspective, the present study is believed to contribute to a general understanding of particle behaviors in anisotropic media.

Induction Immunosuppressive Therapy Use in Deceased Donor Kidney Transplantation: 11-Year Experience in Veracruz, Mexico.

BACKGROUND: Induction therapy reduces the frequency of acute rejection and delayed graft function in renal transplantation. Basiliximab and Thymoglobulin are most commonly used agents for induction. METHODS: A retrospective study of two transplant centers in Veracruz, Mexico compared induction therapy in deceased donor renal transplantation from 2003 to 2014. Efficacy and safety outcomes evaluated were primary graft nonfunction, delayed graft function, acute rejection episodes and hospitalizations during first year, and patient and graft survival. P < .05 was considered statistically significant. RESULTS: Seventy deceased kidney donors (40 male) were studied. Mean donor age was 32.9 ± 14.3 years, mean donor BMI 25.6 ± 4.3 kg/m(2), and mean donor creatinine 1.13 ± 0.58 mg/dL. Main cause of death was trauma (62.9%). In total, 125 kidney transplantations were performed, with female predominance (53.6%) and mean age 33.8 ± 11.8 years. Of these, 66.4% used basiliximab and 33.6% Thymoglobulin. Thymoglobulin patients were significantly older, with lower weight and BMI, and were on dialysis longer than basiliximab patients. DGF was present in 19.3% of basiliximab patients vs 16.7% in Thymoglobulin patients, acute rejection occurred in 16.9% of basiliximab patients vs 19% Thymoglobulin patients. A total of 33.7% basiliximab patients were hospitalized during the first year vs 47.6% Thymoglobulin-induced patients (P > .05). Mean graft survival was 84.2 ± 5.3 months (73.8-94.7) basiliximab vs 32.4 ± 28.7 months (28.7-36.1) Thymoglobulin, Kaplan-Meier survival did not show statistically significant differences between groups (P = .276; CI 95%). CONCLUSION: Similar transplant outcomes were obtained using basiliximab or Thymoglobulin induction in our population.

Parametric techniques for characterizing myocardial tissue by magnetic resonance imaging (part 1): T1 mapping. / Técnicas paramétricas de caracterización tisular del miocardio mediante resonancia magnética (parte 1): mapas de T1.

The development of myocardial fibrosis is a common process in the appearance of ventricular dysfunction in many heart diseases. Magnetic resonance imaging makes it possible to accurately evaluate the structure and function of the heart, and its role in the macroscopic characterization of myocardial fibrosis by late enhancement techniques has been widely validated clinically. Recent studies have demonstrated that T1-mapping techniques can quantify diffuse myocardial fibrosis and the expansion of the myocardial extracellular space in absolute terms. However, further studies are necessary to validate the usefulness of this technique in the early detection of tissue remodeling at a time when implementing early treatment would improve a patient's prognosis. This article reviews the state of the art for T1 mapping of the myocardium, its clinical applications, and its limitations.

Parametric methods for characterizing myocardial tissue by magnetic resonance imaging (part 2): T2 mapping.

Cardiac magnetic resonance imaging is considered the reference technique for characterizing myocardial tissue; for example, T2-weighted sequences make it possible to evaluate areas of edema or myocardial inflammation. However, traditional sequences have many limitations and provide only qualitative information. Moreover, traditional sequences depend on the reference to remote myocardium or skeletal muscle, which limits their ability to detect and quantify diffuse myocardial damage. Recently developed magnetic resonance myocardial mapping techniques enable quantitative assessment of parameters indicative of edema. These techniques have proven better than traditional sequences both in acute cardiomyopathy and in acute ischemic heart disease. This article synthesizes current developments in T2 mapping as well as their clinical applications and limitations.