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1.
Math Biosci ; 366: 109088, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37863283

RESUMO

Early Afterdepolarizations (EADs) are abnormal behaviors that can lead to cardiac failure and even cardiac death. In this paper we investigate the occurrence and development of these phenomena in a reduced Luo-Rudy cardiac model. Through a comprehensive dynamical analysis, we map out the distinct patterns observed in the parametric plane, differentiating between normal beats without EADs and pathological beats with EADs. By examining the bifurcation structure of the model, we elucidate the dynamical elements associated with these patterns and their transitions. Using a fast-slow analysis, we explore the emergence and evolution of EADs in the model. Notably, our approach combines the two commonly used fast-slow approaches (1-slow-2-fast and 2-slow-1-fast), and we show how both approaches together provide a more complete understanding of this phenomenon.


Assuntos
Miócitos Cardíacos , Potenciais de Ação
2.
Sci Rep ; 12(1): 12372, 2022 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-35859100

RESUMO

Many COVID-19 vaccines are proving to be highly effective to prevent severe disease and to diminish infections. Their uneven geographical distribution favors the appearance of new variants of concern, as the highly transmissible Delta variant, affecting particularly non-vaccinated people. It is important to device reliable models to analyze the spread of the different variants. A key factor is to consider the effects of vaccination as well as other measures used to contain the pandemic like social behaviour. The stochastic geographical model presented here, fulfills these requirements. It is based on an extended compartmental model that includes various strains and vaccination strategies, allowing to study the emergence and dynamics of the new COVID-19 variants. The model conveniently separates the parameters related to the disease from the ones related to social behavior and mobility restrictions. We applied the model to the United Kingdom by using available data to fit the recurrence of the currently prevalent variants. Our computer simulations allow to describe the appearance of periodic waves and the features that determine the prevalence of certain variants. They also provide useful predictions to help planning future vaccination boosters. We stress that the model could be applied to any other country of interest.


Assuntos
COVID-19 , SARS-CoV-2 , COVID-19/epidemiologia , Vacinas contra COVID-19 , Humanos , SARS-CoV-2/genética , Vacinação
3.
Sci Rep ; 12(1): 1603, 2022 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-35102216

RESUMO

In a world being hit by waves of COVID-19, vaccination is a light on the horizon. However, the roll-out of vaccination strategies and their influence on the pandemic are still open questions. In order to compare the effect of various strategies proposed by the World Health Organization and other authorities, a previously developed SEIRS stochastic model of geographical spreading of the virus is extended by adding a compartment for vaccinated people. The parameters of the model were fitted to describe the pandemic evolution in Argentina, Mexico and Spain to analyze the effect of the proposed vaccination strategies. The mobility parameters allow to simulate different social behaviors (e.g. lock-down interventions). Schemes in which vaccines are applied homogeneously in all the country, or limited to the most densely-populated areas, are simulated and compared. The second strategy is found to be more effective. Moreover, under the current global shortage of vaccines, it should be remarked that immunization is enhanced when mobility is reduced. Additionally, repetition of vaccination campaigns should be timed considering the immunity lapse of the vaccinated (and recovered) people. Finally, the model is extended to include the effect of isolation of detected positive cases, shown to be important to reduce infections.


Assuntos
Vacinas contra COVID-19/uso terapêutico , COVID-19/prevenção & controle , Acessibilidade aos Serviços de Saúde , Programas de Imunização/métodos , Modelos Estatísticos , Pandemias/prevenção & controle , SARS-CoV-2/imunologia , Vacinação/métodos , Argentina/epidemiologia , COVID-19/epidemiologia , COVID-19/transmissão , COVID-19/virologia , Humanos , México , Comportamento Social , Espanha , Processos Estocásticos , Viagem
4.
Anal Chim Acta ; 1191: 339309, 2022 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-35033252

RESUMO

The synthesis of polymers with tailored properties for the recognition of macromolecules such as proteins is challenging. In this work, the synthesis of a new polymer format, a linear polymer (LP), as the selective recognition element for the globular protein lactoferrin (LF) is proposed as a proof-of-concept study. For the synthesis, a solid-phase strategy using the reversible deactivation radical polymerisation (RDRP) mechanism is proposed. This approach, which is usually used in molecular imprinting, involves the immobilisation of LF on the surface of a solid support, but, unlike classical imprinting, a cross-linker in the polymerisation mixture is not required. Consequently, the copolymer is soluble and flexible, thus overcoming the drawbacks associated with traditional synthetic polymers for macromolecule imprinting. This new polymer format has great potential for replacing natural antibodies in bioassays such as enzyme-linked immunosorbent assays (ELISA), dot blot, western blot, or pull-down. In our case, the linear polymer was used as a recognition element to replace natural antibodies in a LF-selective ELISA. The responses of the linear polymer between LF concentrations of 0.1 nM and 0.25 µM were studied, and a significant difference was observed between the non-specific signals and the signals measured in the presence of the polymeric material. Further, the response versus log concentration curves were fitted to a logistic equation, allowing estimation of the EC50 value: 11.8 ± 1.4 nM. We also confirmed the selective detection of LF using the competitive inhibition of the selective LF-biotin conjugate (LF-Bi) binding to the plastic receptor (LP) for closely related proteins (e.g. those having similar molecular weights or isoelectric points) such as human lysozyme, trypsin, and albumin, which are present in human body fluids. The system presents a cross-reactivity value or selectivity of 1.95% for lysozyme, 0.028% for trypsin, and 0.016% for albumin. The applicability of this method for the determination of urine LF levels in inflammatory and infectious diseases of the human urinary tract is also demonstrated.


Assuntos
Impressão Molecular , Polímeros , Anticorpos , Ensaio de Imunoadsorção Enzimática , Humanos , Lactoferrina
5.
Sci Rep ; 11(1): 10024, 2021 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-33976342

RESUMO

We have studied the dynamic evolution of the Covid-19 pandemic in Argentina. The marked heterogeneity in population density and the very extensive geography of the country becomes a challenge itself. Standard compartment models fail when they are implemented in the Argentina case. We extended a previous successful model to describe the geographical spread of the AH1N1 influenza epidemic of 2009 in two essential ways: we added a stochastic local mobility mechanism, and we introduced a new compartment in order to take into account the isolation of infected asymptomatic detected people. Two fundamental parameters drive the dynamics: the time elapsed between contagious and isolation of infected individuals ([Formula: see text]) and the ratio of people isolated over the total infected ones (p). The evolution is more sensitive to the [Formula: see text]parameter. The model not only reproduces the real data but also predicts the second wave before the former vanishes. This effect is intrinsic of extensive countries with heterogeneous population density and interconnection.The model presented has proven to be a reliable predictor of the effects of public policies as, for instance, the unavoidable vaccination campaigns starting at present in the world an particularly in Argentina.


Assuntos
Doenças Assintomáticas/epidemiologia , COVID-19/epidemiologia , Modelos Teóricos , Argentina/epidemiologia , COVID-19/virologia , Humanos , Pandemias , SARS-CoV-2/isolamento & purificação
6.
Phys Biol ; 18(2): 026003, 2021 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-33296887

RESUMO

The improved in vitro regulation of human embryonic stem cell (hESC) pluripotency and differentiation trajectories is required for their promising clinical applications. The temporal and spatial quantification of the molecular interactions controlling pluripotency is also necessary for the development of successful mathematical and computational models. Here we use time-lapse experimental data of OCT4-mCherry fluorescence intensity to quantify the temporal and spatial dynamics of the pluripotency transcription factor OCT4 in a growing hESC colony in the presence and absence of BMP4. We characterise the internal self-regulation of OCT4 using the Hurst exponent and autocorrelation analysis, quantify the intra-cellular fluctuations and consider the diffusive nature of OCT4 evolution for individual cells and pairs of their descendants. We find that OCT4 abundance in the daughter cells fluctuates sub-diffusively, showing anti-persistent self-regulation. We obtain the stationary probability distributions governing hESC transitions amongst the different cell states and establish the times at which pro-fate cells (which later give rise to pluripotent or differentiated cells) cluster in the colony. By quantifying the similarities between the OCT4 expression amongst neighbouring cells, we show that hESCs express similar OCT4 to cells within their local neighbourhood within the first two days of the experiment and before BMP4 treatment. Our framework allows us to quantify the relevant properties of proliferating hESC colonies and the procedure is widely applicable to other transcription factors and cell populations.


Assuntos
Expressão Gênica , Células-Tronco Embrionárias Humanas/metabolismo , Fator 3 de Transcrição de Octâmero/genética , Diferenciação Celular/genética , Humanos , Fator 3 de Transcrição de Octâmero/metabolismo
7.
PLoS One ; 15(1): e0227562, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31935248

RESUMO

We study the time evolution of the shape of a vesicle membrane under time-dependent spontaneous curvature by means of phase-field model. We introduce the variation in time of the spontaneous curvature via a second field which represents the concentration of a substance that anchors with the lipid bilayer thus changing the local curvature and producing constriction. This constriction is mediated by the action on the membrane of an structure resembling the role of a Z ring. Our phase-field model is able to reproduce a number of different shapes that have been experimentally observed. Different shapes are associated with different constraints imposed upon the model regarding conservation of membrane area. In particular, we show that if area is conserved our model reproduces the so-called L-form shape. By contrast, if the area of the membrane is allowed to grow, our model reproduces the formation of a septum in the vicinity of the constriction. Furthermore, we propose a new term in the free energy which allows the membrane to evolve towards eventual pinching.


Assuntos
Lipossomos/química , Modelos Biológicos , Bicamadas Lipídicas/química , Tensão Superficial , Termodinâmica
8.
Sci Rep ; 9(1): 19000, 2019 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-31831864

RESUMO

We propose a model to generate electrocardiogram signals based on a discretized reaction-diffusion system to produce a set of three nonlinear oscillators that simulate the main pacemakers in the heart. The model reproduces electrocardiograms from healthy hearts and from patients suffering various well-known rhythm disorders. In particular, it is shown that under ventricular fibrillation, the electrocardiogram signal is chaotic and the transition from sinus rhythm to chaos is consistent with the Ruelle-Takens-Newhouse route to chaos, as experimental studies indicate. The proposed model constitutes a useful tool for research, medical education, and clinical testing purposes. An electronic device based on the model was built for these purposes.


Assuntos
Eletrocardiografia , Modelos Cardiovasculares , Processamento de Sinais Assistido por Computador , Arritmias Cardíacas/diagnóstico por imagem , Simulação por Computador , Difusão , Dinâmica não Linear , Análise Numérica Assistida por Computador , Fatores de Tempo , Fibrilação Ventricular/diagnóstico por imagem
9.
Food Funct ; 10(4): 2148-2160, 2019 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-30938723

RESUMO

Non-alcoholic fatty liver disease (NAFLD) is defined as the accumulation of fat in liver cells, which causes serious health consequences. Animal and human studies suggest that the gut microbiota plays a role in the pathogenesis of NAFLD. Here, we investigated whether spinach consumption could ameliorate high-fat-diet-induced disturbances in certain intestinal bacterial groups and products derived from their metabolism, such as short-chain fatty acids (SCFAs) and microbial phenolic catabolites. Attention is also paid to blood lipids and glucose. In the study, a rat model of high-fat-diet-induced NAFLD was used. There were six experimental groups: NC (normal diet), NB (normal diet + 2.5% spinach), NA (normal diet + 5% spinach), HC (high-fat diet), HB (high-fat diet + 2.5% spinach) and HA (high-fat diet + 5% spinach). The rats consumed these diets for five weeks, and after that, they were sacrificed and plasma, urine, intestinal content, faeces and liver samples were taken. Biochemical parameters were analyzed in plasma, phenolic catabolites were quantified in the faeces, urine, plasma and liver by UPLC-ESI-MS/MS, and the analysis of the microbiota and SCFAs in the intestinal content was performed by qPCR and GLC. Consumption of a high-fat diet caused NAFLD and dislipaemia and altered the gut microbiota and the pattern of SCFAs and phenolic gut microbial catabolites. Supplementation with spinach partially ameliorated some alterations induced by the high-fat diet, in particular by increasing the Lactobacillus counts, reducing the fasting glucose and total and LDL-cholesterol and preventing excess liver cholesterol accumulation, thereby improving the values of the steatosis biomarkers.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Microbioma Gastrointestinal , Metabolismo dos Lipídeos , Hepatopatia Gordurosa não Alcoólica/dietoterapia , Spinacia oleracea/metabolismo , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/metabolismo , LDL-Colesterol/metabolismo , Ácidos Graxos Voláteis/metabolismo , Humanos , Fígado/metabolismo , Masculino , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/microbiologia , Ratos , Ratos Sprague-Dawley
10.
J Pharm Biomed Anal ; 169: 82-89, 2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-30844626

RESUMO

Pediatric chronic kidney disease (CKD) is currently assessed using glomerular filtration rate (GFR), which is calculated from different equations based on serum creatinine concentration. However, serum creatinine is affected by several factors and is not reliable enough for the diagnosis of CKD, especially at early stages. Recent targeted and untargeted metabolomics studies found 7 new potential biomarkers that could be useful for early pediatric chronic kidney disease diagnosis. Thus, a new LC-QQQ-MS analytical method has been developed and validated aimed at routine analysis of these 7 potential biomarkers: NG,NG'-dimethyl-l-arginine di(p-hydroxyazobenzene-p'-sulfonate) (SDMA), S-adenosyl-l-methionine (SAM), n-butyryl-l-carnitine (nC4), iso-butyryl-l-carnitine (iC4), citrulline (CIT), creatinine (CNN) and d-erytro-sphingosine-1-phosphate (S1P), in addition to creatinine, the classical biomarker for CKD diagnosis. Then, this analytical method has been used for the quantification of plasma samples from a heterogeneous group of CKD pediatric patients and a control pediatric population. Data analysis of these results showed that it is possible to differentiate between CKD and control populations based on the metabolite concentration in plasma.


Assuntos
Biomarcadores/sangue , Biomarcadores/química , Plasma/química , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/diagnóstico , Arginina/análogos & derivados , Arginina/sangue , Arginina/química , Criança , Pré-Escolar , Cromatografia Líquida/métodos , Citrulina/química , Creatinina/sangue , Diagnóstico Precoce , Feminino , Taxa de Filtração Glomerular/fisiologia , Humanos , Masculino , Metabolômica/métodos , S-Adenosilmetionina/sangue , S-Adenosilmetionina/química , Espectrometria de Massas em Tandem/métodos
11.
Analyst ; 143(18): 4448-4458, 2018 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-30151522

RESUMO

Pediatric chronic kidney disease (CKD) is a clinical syndrome characterized by renal hypofunction occurring due to gradual and irreversible kidney damage that can further progress over time. New biomarkers may help early diagnosis of pediatric patients suffering from CKD and improve the outcome. Untargeted metabolomics based on LC-QTOF-MS has been used to find new biomarkers for the early diagnosis of CKD in plasma from pediatric patients. In order to avoid any bias in the determination of statistically significant entities as a consequence of the data analysis method followed, two different chemometric approaches have been used, Mass Profiler Professional (MPP) software and Matlab R2015a software. Metabolic fingerprints of control and CKD pediatric patients were compared and five metabolites which showed a significant change common to both data analysis procedures were identified. Sphingosine-1-phosphate, n-butyrylcarnitine, cis-4-decenoylcarnitine and an unidentified feature with 126.0930 m/z were found to be increased in plasma from pediatric patients with CKD, whereas bilirubin was significantly decreased. A partial least squares discriminant analysis model built with these 5 entities classified correctly 96% of the samples. In addition, when considering only early CKD patients against controls, a performance of 97% was obtained. Thus, these promising metabolites could be suitable biomarkers for the early diagnosis of pediatric CKD in a clinical setting.


Assuntos
Biomarcadores/sangue , Metabolômica/métodos , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/diagnóstico , Adolescente , Criança , Pré-Escolar , Cromatografia Líquida , Feminino , Humanos , Masculino , Espectrometria de Massas em Tandem
12.
J Pharm Biomed Anal ; 149: 46-56, 2018 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-29100030

RESUMO

Chronic kidney disease (CKD) is a progressive pathological condition in which renal function deteriorates in time. The first diagnosis of CKD is often carried out in general care attention by general practitioners by means of serum creatinine (CNN) levels. However, it lacks sensitivity and thus, there is a need for new robust biomarkers to allow the detection of kidney damage particularly in early stages. Multivariate data analysis of plasma concentrations obtained from LC-QTOF targeted metabolomics method may reveal metabolites suspicious of being either up-regulated or down-regulated from urea cycle, arginine methylation and arginine-creatine metabolic pathways in CKD pediatrics and controls. The results show that citrulline (CIT), symmetric dimethylarginine (SDMA) and S-adenosylmethionine (SAM) are interesting biomarkers to support diagnosis by CNN: early CKD samples and controls were classified with an increase in classification accuracy of 18% when using these 4 metabolites compared to CNN alone. These metabolites together allow classification of the samples into a definite stage of the disease with an accuracy of 74%, being the 90% of the misclassifications one level above or below the CKD stage set by the nephrologists. Finally, sex-related, age-related and treatment-related effects were studied, to evaluate whether changes in metabolite concentration could be attributable to these factors, and to correct them in case a new equation is developed with these potential biomarkers for the diagnosis and monitoring of pediatric CKD.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Metabolômica/métodos , Insuficiência Renal Crônica/diagnóstico , Espectrometria de Massas em Tandem/métodos , Adolescente , Fatores Etários , Arginina/análogos & derivados , Arginina/sangue , Arginina/metabolismo , Biomarcadores/sangue , Criança , Pré-Escolar , Cromatografia Líquida de Alta Pressão/instrumentação , Citrulina/sangue , Citrulina/metabolismo , Creatinina/sangue , Creatinina/metabolismo , Diagnóstico Precoce , Feminino , Taxa de Filtração Glomerular , Humanos , Masculino , Redes e Vias Metabólicas , Metabolômica/instrumentação , Análise Multivariada , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/metabolismo , S-Adenosilmetionina/sangue , S-Adenosilmetionina/metabolismo , Fatores Sexuais , Espectrometria de Massas em Tandem/instrumentação
13.
Food Funct ; 8(10): 3542-3552, 2017 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-28876011

RESUMO

Gut microbiota may play a role in the pathogenesis of NAFLD. We investigated whether tomato juice consumption for 5 weeks could ameliorate high-fat diet-induced alterations in certain intestinal bacterial groups and products arising from their metabolism (short-chain fatty acids and microbial phenolic catabolites). For this, we used a rat model with NAFLD induced by a high-fat diet, involving four experimental groups: NA (standard diet and water), NL (standard diet and tomato juice), HA (high-fat diet and water) and HL (high-fat diet and tomato juice). The onset of NAFLD impacted the gut microbiota profile, reducing the abundance of Bifidobacterium and Lactobacillus and increasing that of Enterobacteriaceae. Also, reduced concentrations of propionate, butyrate and phenolic catabolites and an increased acetate to propionate (Ac : Pr) ratio were observed. Tomato juice intake partially ameliorated high-fat diet-induced disturbances, particularly by increasing Lactobacillus abundance and diminishing the Ac : Pr ratio, suggesting a potential improvement of the metabolic pattern of NAFLD.


Assuntos
Bactérias/metabolismo , Sucos de Frutas e Vegetais/análise , Microbioma Gastrointestinal , Hepatopatia Gordurosa não Alcoólica/dietoterapia , Hepatopatia Gordurosa não Alcoólica/microbiologia , Prebióticos/análise , Solanum lycopersicum/metabolismo , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Ácidos Graxos Voláteis/metabolismo , Trato Gastrointestinal/metabolismo , Trato Gastrointestinal/microbiologia , Humanos , Masculino , Hepatopatia Gordurosa não Alcoólica/metabolismo , Ratos , Ratos Sprague-Dawley
14.
J Plant Physiol ; 188: 64-71, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-26433462

RESUMO

Studies of metabolic and physiological bases of plant tolerance and hardening against drought are essential to improve genetic breeding programs, especially in productive species such as Pinus radiata. The exposure to different drought cycles is a highly effective tool that improves plant conditioning, but limited information is available about the mechanisms that modulate this process. To clarify this issue, six P. radiata breeds with well-known differences in drought tolerance were analyzed after two consecutive drought cycles. Survival rate, concentration of several metabolites such as free soluble amino acids and polyamines, and main plant hormones varied between them after drought hardening, while relative growth ratio and water potential at both predawn and dawn did not. Hardening induced a strong increase in total soluble amino acids in all breeds, accumulating mainly those implicated in the glutamate metabolism (GM), especially L-proline, in the most tolerant breeds. Other amino acids from GM such as γ-aminobutyric acid (GABA) and L-arginine (Arg) were also strongly increased. GABA pathway could improve the response against drought, whereas Arg acts as precursor for the synthesis of spermidine. This polyamine showed a positive relationship with the survival capacity, probably due to its role as antioxidant under stress conditions. Finally, drought hardening also induced changes in phytohormone content, showing each breed a different profile. Although all of them accumulated indole-3-acetic acid and jasmonic acid and reduced zeatin content in needles, significant differences were observed regarding abscisic acid, salicylic acid and mainly zeatin riboside. These results confirm that hardening is not only species-dependent but also an intraspecific processes controlled through metabolite changes.


Assuntos
Secas , Pinus/fisiologia , Reguladores de Crescimento de Plantas/metabolismo , Prolina/metabolismo , Ácido gama-Aminobutírico/metabolismo , Pinus/genética , Melhoramento Vegetal , Especificidade da Espécie
15.
Rev. Esp. Cir. Ortop. Traumatol. (Ed. Impr.) ; 59(5): 333-342, sept.-oct. 2015. tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-140874

RESUMO

Objetivo. Describir las características de los pacientes y las fracturas femorales periprotésicas sobre hemiartroplastias, y realizar un análisis del tratamiento a partir de sus resultados. Material y método. Estudio observacional, longitudinal y retrospectivo de una serie de 17 pacientes con fracturas femorales periprotésicas sobre hemiartroplastias de cadera. Catorce se trataron quirúrgicamente. Se analizaron las características de los pacientes y de las fracturas y los resultados del tratamiento en términos de complicaciones, mortalidad y funcionalidad. Resultados. El 82% de los pacientes fueron mujeres, la edad media fue de 86 años y el índice ASA de 15 de ellos fue 3 o 4. Diez fracturas fueron de tipo B. Se registraron 8 complicaciones generales, una infección profunda, una movilización de la hemiartroplastia no recambiada y 2 seudoartrosis. Consolidaron el 85% de las fracturas y solo 5 pacientes recuperaron la función previa al traumatismo. Al final del estudio habían fallecido 9 pacientes (53%). Discusión. El tratamiento de las fracturas periprotésicas sobre hemiartroplastias, cuya frecuencia aumentará en los próximos años, es difícil. Conclusiones. Las fracturas femorales periprotésicas sobre hemiartroplastias son más frecuentes en mujeres próximas a los 90 años y suelen ocurrir en pacientes con importante morbilidad. La indicación de su tratamiento no debe basarse solo en la clasificación de Vancouver que, aunque fiable, simple y reproducible, no deja de ser una guía para decidir el mejor tratamiento en un paciente a menudo frágil. Cuando aquel sea quirúrgico, la planificación preoperatoria es fundamental (AU)


Purpose. To describe the characteristics of patients with periprosthetic femoral fractures after hemiarthroplasty and analyze their treatment. Material and method. An observational, longitudinal, retrospective study was conducted on a series of 17 patients with periprosthetic femoral fractures after hip hemiarthroplasty. Fourteen fractures were treated surgically. The characteristics of patients, fractures and treatment outcomes in terms of complications, mortality and functionality were analyzed. Results. The large majority (82%) of patients were women, the mean age was 86 years and with an ASA index of 3 or 4 in 15 patients. Ten fractures were type B. There were 8 general complications, one deep infection, one mobilization of a non-exchanged hemiarthroplasty, and 2 non-unions. There were 85% consolidated fractures, and only 5 patients recovered the same function prior to the injury. At the time of the study 9 patients had died (53%). Discussion. Periprosthetic femoral fractures after hemiarthroplasty will increase in the coming years and their treatment is difficult. Conclusion. Periprosthetic femoral fractures after hemiarthroplasty are more common in women around 90 years-old, and usually occur in patients with significant morbidity. Although the Vancouver classification is reliable, simple and reproducible, it is only a guide to decide on the best treatment in a patient often fragile. The preoperative planning is essential when deciding a surgical treatment (AU)


Assuntos
Feminino , Humanos , Masculino , Fraturas Periprotéticas/complicações , Fraturas Periprotéticas/diagnóstico , Fraturas do Fêmur/complicações , Fraturas do Fêmur , Hemiartroplastia/métodos , Hemiartroplastia/tendências , Fraturas Periprotéticas/fisiopatologia , Fraturas Periprotéticas , Estudos Longitudinais , Estudos Retrospectivos
16.
Eur Phys J E Soft Matter ; 38(6): 61, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26105960

RESUMO

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.


Assuntos
Lipossomos/química , Modelos Teóricos , Proteínas de Bactérias/química , Proteínas do Citoesqueleto/química
17.
Anal Chim Acta ; 858: 32-41, 2015 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-25597799

RESUMO

The current study presents a method for comprehensive untargeted metabolomic fingerprinting of the non-volatile profile of the Graciano Vitis vinifera wine variety, using liquid chromatography/electrospray ionization time of flight mass spectrometry (LC-ESI-QTOF). Pre-treatment of samples, chromatographic columns, mobile phases, elution gradients and ionization sources, were evaluated for the extraction of the maximum number of metabolites in red wine. Putative compounds were extracted from the raw data using the extraction algorithm, molecular feature extractor (MFE). For the metabolite identification the WinMet database was designed based on electronic databases and literature research and includes only the putative metabolites reported to be present in oenological matrices. The results from WinMet were compared with those in the METLIN database to evaluate how much the databases overlap for performing identifications. The reproducibility of the analysis was assessed using manual processing following replicate injections of Vitis vinifera cv. Graciano wine spiked with external standards. In the present work, 411 different metabolites in Graciano Vitis vinifera red wine were identified, including primary wine metabolites such as sugars (4%), amino acids (23%), biogenic amines (4%), fatty acids (2%), and organic acids (32%) and secondary metabolites such as phenols (27%) and esters (8%). Significant differences between varieties Tempranillo and Graciano were related to the presence of fifteen specific compounds.


Assuntos
Metabolômica/métodos , Vitis/química , Vinho/análise , Cromatografia Líquida , Bases de Dados de Compostos Químicos , Fermentação , Espanha , Espectrometria de Massas por Ionização por Electrospray , Vitis/crescimento & desenvolvimento
18.
Rev Esp Cir Ortop Traumatol ; 59(5): 333-42, 2015.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-25532696

RESUMO

PURPOSE: To describe the characteristics of patients with periprosthetic femoral fractures after hemiarthroplasty and analyze their treatment. MATERIAL AND METHOD: An observational, longitudinal, retrospective study was conducted on a series of 17 patients with periprosthetic femoral fractures after hip hemiarthroplasty. Fourteen fractures were treated surgically. The characteristics of patients, fractures and treatment outcomes in terms of complications, mortality and functionality were analyzed. RESULTS: The large majority (82%) of patients were women, the mean age was 86 years and with an ASA index of 3 or 4 in 15 patients. Ten fractures were type B. There were 8 general complications, one deep infection, one mobilization of a non-exchanged hemiarthroplasty, and 2 non-unions. There were 85% consolidated fractures, and only 5 patients recovered the same function prior to the injury. At the time of the study 9 patients had died (53%). DISCUSSION: Periprosthetic femoral fractures after hemiarthroplasty will increase in the coming years and their treatment is difficult. CONCLUSION: Periprosthetic femoral fractures after hemiarthroplasty are more common in women around 90 years-old, and usually occur in patients with significant morbidity. Although the Vancouver classification is reliable, simple and reproducible, it is only a guide to decide on the best treatment in a patient often fragile. The preoperative planning is essential when deciding a surgical treatment.


Assuntos
Artroplastia de Quadril , Fraturas do Fêmur , Hemiartroplastia , Fraturas Periprotéticas , Complicações Pós-Operatórias , Idoso , Idoso de 80 Anos ou mais , Feminino , Fraturas do Fêmur/diagnóstico , Fraturas do Fêmur/etiologia , Fraturas do Fêmur/cirurgia , Seguimentos , Fixação Interna de Fraturas , Humanos , Masculino , Fraturas Periprotéticas/diagnóstico , Fraturas Periprotéticas/etiologia , Fraturas Periprotéticas/cirurgia , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/cirurgia , Reoperação , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
19.
An. pediatr. (2003, Ed. impr.) ; 81(6): 389-392, dic. 2014. tab
Artigo em Espanhol | IBECS | ID: ibc-130821

RESUMO

OBJETIVO: Analizar el control metabólico y grado de satisfacción en un grupo de pacientes con DM1 tras cambiar de Unidad (Pediátrica [UDP], Adultos [UDA]). PACIENTES Y MÉTODOS: Estudio retrospectivo: 49 pacientes, 43% mujeres. Analizamos: edad al diagnóstico y paso a adultos, tiempo evolución, control metabólico (HbA1c), complicaciones diabéticas y características del seguimiento. Estudio estadístico: programa SPSS-versión-17.0. RESULTADOS: Edad media ± desviación estándar al diagnóstico 8,3 ± 4,6 y en transferencia 19,2 ± 1,8 años. Tiempo seguimiento en UDP, UDA y global: 10,8 ± 5,0, 4,1 ± 2,6 y 15,0 ± 5,7 años; el 6% perdió el seguimiento médico. En UDA: el 6% desconocía última HbA1c y el 29%las complicaciones crónicas. El control metabólico empeoró en 52% pacientes (aumento HbA1c +0,79 ± 0,70%). No encontramos correlación entre el tiempo evolución y la HbA1c. El 96% de los pacientes refirieron grado satisfacción bueno/muy bueno respecto a UDP y el 74% respecto a UDA. CONCLUSIÓN: Parece necesaria una mejor planificación de la transición de pacientes con DM1 alas UDA para evitar el empeoramiento del control clínico y/o la pérdida de seguimiento


INTRODUCTION: The transition between pediatric and adult care for young people with type 1 diabetes (T1D) is often poorly managed, with adverse consequences for health, as well as a decrease in the follow-up OBJECTIVE: To analyze the metabolic control and the degree of satisfaction in a group of patients with T1D after being transferred from the Pediatric Diabetes Unit (PDU) to Adult Diabetes Unit (ADU). PATIENTS AND METHODS: Retrospective study in a cohort of 49 patients (43% female) with T1D. The age at diagnosis and transfer to ADU, time of onset of the disease, metabolic control (HbA1c), presence of diabetic complications and characteristics of medical follow-up wereanalysed using the statistics program: SPSS, version 17.0. RESULTS: Mean age at diagnosis 8.3±4.6 years and transfer to ADU 19.2±1.8 years. Mean time since onset of T1D in pediatrics, adults and overall: 10.8±5.0, 4.1±2.6 and 15.0±5.7 years, respectively. The 6% of adult patients were not being medically tracked. Among adults, 25% did not provide data about chronic complications, and 6% did not know their last HbA1c. The metabolic control after their transfer to the ADU worsened in 52% of the patients (HbA1c +0.79±0.70%). No correlation was found between the time since onset and the HbA1c value. Degree of satisfaction was either good or very good in 96% of patients in the PDU and 74% in ADU. CONCLUSION: Better planning for the transfer of pediatric patients with T1D to ADU is highly recommended, in order to avoid deterioration of control and/or loss of follow-up


Assuntos
Humanos , Masculino , Feminino , Criança , Adolescente , Transferência de Pacientes/estatística & dados numéricos , Diabetes Mellitus Tipo 1/epidemiologia , Hiperglicemia/prevenção & controle , Estudos Retrospectivos , Fatores Etários , Qualidade da Assistência à Saúde/tendências
20.
Acta pediatr. esp ; 72(10): e349-e355, nov. 2014. ilus
Artigo em Espanhol | IBECS | ID: ibc-130805

RESUMO

La presencia de timo ectópico cervical es el resultado de la alteración en su migración durante la embriogénesis. Su degeneración maligna es muy infrecuente, pero es necesario establecer el diagnóstico mediante un estudio histológico. La hemiagenesia tiroidea es una alteración en el desarrollo de la glándula tiroides, un hallazgo accidental en la mayoría de los casos. Afecta más frecuentemente a las mujeres y su localización más habitual es el lóbulo tiroideo izquierdo. La mayoría de los pacientes presenta una función tiroidea normal. La asociación de hemiagenesia tiroidea y timo ectópico cervical no se ha descrito hasta el momento en la población pediátrica. Existe un solo caso descrito en adultos. Se presenta un caso clínico de hemiagenesia del lóbulo tiroideo derecho asociado a timo ectópico cervical localizado en la región tiroidea (AU)


Ectopical cervical thymus is the result of a disturbance in migration during embryogenesis. Although malignant transformations are scarce, the differential diagnosis needs to be established by pathology study. Thyroid hemiagenesis is a rare developmental anomaly which is usually detected incidentally. It affects more commonly females and the left lobe. Clinically, these patients are euthyroid in most of the cases. Ectopic cervical thymic tissue associated with thyroid hemiagenesis has never been described before in children and only one case has been described in adults. We report one case of hemiagenesis of the right thyroid lobe and ectopic cervical thymic tissue located in thyroid area (AU)


Assuntos
Humanos , Feminino , Pré-Escolar , Timo/anormalidades , Disgenesia da Tireoide/complicações , Diagnóstico Diferencial
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